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Sample records for cell antigen cd123

  1. Redirecting Specificity of T cells Using the Sleeping Beauty System to Express Chimeric Antigen Receptors by Mix-and-Matching of VL and VH Domains Targeting CD123+ Tumors.

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    Thokala, Radhika; Olivares, Simon; Mi, Tiejuan; Maiti, Sourindra; Deniger, Drew; Huls, Helen; Torikai, Hiroki; Singh, Harjeet; Champlin, Richard E; Laskowski, Tamara; McNamara, George; Cooper, Laurence J N

    2016-01-01

    Adoptive immunotherapy infusing T cells with engineered specificity for CD19 expressed on B- cell malignancies is generating enthusiasm to extend this approach to other hematological malignancies, such as acute myelogenous leukemia (AML). CD123, or interleukin 3 receptor alpha, is overexpressed on most AML and some lymphoid malignancies, such as acute lymphocytic leukemia (ALL), and has been an effective target for T cells expressing chimeric antigen receptors (CARs). The prototypical CAR encodes a VH and VL from one monoclonal antibody (mAb), coupled to a transmembrane domain and one or more cytoplasmic signaling domains. Previous studies showed that treatment of an experimental AML model with CD123-specific CAR T cells was therapeutic, but at the cost of impaired myelopoiesis, highlighting the need for systems to define the antigen threshold for CAR recognition. Here, we show that CARs can be engineered using VH and VL chains derived from different CD123-specific mAbs to generate a panel of CAR+ T cells. While all CARs exhibited specificity to CD123, one VH and VL combination had reduced lysis of normal hematopoietic stem cells. This CAR's in vivo anti-tumor activity was similar whether signaling occurred via chimeric CD28 or CD137, prolonging survival in both AML and ALL models. Co-expression of inducible caspase 9 eliminated CAR+ T cells. These data help support the use of CD123-specific CARs for treatment of CD123+ hematologic malignancies.

  2. Redirecting Specificity of T cells Using the Sleeping Beauty System to Express Chimeric Antigen Receptors by Mix-and-Matching of VL and VH Domains Targeting CD123+ Tumors

    Science.gov (United States)

    Olivares, Simon; Mi, Tiejuan; Maiti, Sourindra; Deniger, Drew; Huls, Helen; Torikai, Hiroki; Singh, Harjeet; Champlin, Richard E.; Laskowski, Tamara; McNamara, George; Cooper, Laurence J. N.

    2016-01-01

    Adoptive immunotherapy infusing T cells with engineered specificity for CD19 expressed on B- cell malignancies is generating enthusiasm to extend this approach to other hematological malignancies, such as acute myelogenous leukemia (AML). CD123, or interleukin 3 receptor alpha, is overexpressed on most AML and some lymphoid malignancies, such as acute lymphocytic leukemia (ALL), and has been an effective target for T cells expressing chimeric antigen receptors (CARs). The prototypical CAR encodes a VH and VL from one monoclonal antibody (mAb), coupled to a transmembrane domain and one or more cytoplasmic signaling domains. Previous studies showed that treatment of an experimental AML model with CD123-specific CAR T cells was therapeutic, but at the cost of impaired myelopoiesis, highlighting the need for systems to define the antigen threshold for CAR recognition. Here, we show that CARs can be engineered using VH and VL chains derived from different CD123-specific mAbs to generate a panel of CAR+ T cells. While all CARs exhibited specificity to CD123, one VH and VL combination had reduced lysis of normal hematopoietic stem cells. This CAR’s in vivo anti-tumor activity was similar whether signaling occurred via chimeric CD28 or CD137, prolonging survival in both AML and ALL models. Co-expression of inducible caspase 9 eliminated CAR+ T cells. These data help support the use of CD123-specific CARs for treatment of CD123+ hematologic malignancies. PMID:27548616

  3. Cysteine protease antigens cleave CD123, the α subunit of murine IL-3 receptor, on basophils and suppress IL-3-mediated basophil expansion

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    Nishikado, Hideto [Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo (Japan); Fujimura, Tsutomu; Taka, Hikari; Mineki, Reiko [Laboratory of Proteomics and Biomolecular Science, BioMedical Research Center, Juntendo University Graduate School of Medicine, Tokyo (Japan); Ogawa, Hideoki; Okumura, Ko [Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo (Japan); Takai, Toshiro, E-mail: t-takai@juntendo.ac.jp [Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, Tokyo (Japan)

    2015-05-01

    Th2 type immune responses are essential for protective immunity against parasites and play crucial roles in allergic disorders. Helminth parasites secrete a variety of proteases for their infectious cycles including for host entry, tissue migration, and suppression of host immune effector cell function. Furthermore, a number of pathogen-derived antigens, as well as allergens such as papain, belong to the family of cysteine proteases. Although the link between protease activity and Th2 type immunity is well documented, the mechanisms by which proteases regulate host immune responses are largely unknown. Here, we demonstrate that the cysteine proteases papain and bromelain selectively cleave the α subunit of the IL-3 receptor (IL-3Rα/CD123) on the surface of murine basophils. The decrease in CD123 expression on the cell surface, and the degradation of the extracellular domain of recombinant CD123 were dependent on the protease activity of papain and bromelain. Pre-treatment of murine basophils with papain resulted in inhibition of IL-3-IL-3R signaling and suppressed IL-3- but not thymic stromal lymphopoietin-induced expansion of basophils in vitro. Our unexpected findings illuminate a novel mechanism for the regulation of basophil functions by protease antigens. Because IL-3 plays pivotal roles in the activation and proliferation of basophils and in protective immunity against helminth parasites, pathogen-derived proteases might contribute to the pathogenesis of infections by regulating IL-3-mediated functions in basophils. - Highlights: • We identified the murine IL3R as a novel target of papain-family cysteine proteases. • Papain-family cysteine proteases cleaved IL3Rα/CD123 on murine basophils. • Papain suppressed IL3- but not TSLP-induced expansion of murine basophils. • The inactivation of IL3R might be a strategy for pathogens to suppress host immunity.

  4. Langerhans cells (CD1a and CD207), dermal dendrocytes (FXIIIa) and plasmacytoid dendritic cells (CD123) in skin lesions of leprosy patients.

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    Hirai, Kelly Emi; Aarão, Tinara Leila de Sousa; Silva, Luciana Mota; de Sousa, Jorge Rodrigues; de Souza, Juarez; Dias, Leonidas Braga; Carneiro, Francisca Regina Oliveira; Fuzii, Hellen Thais; Quaresma, Juarez Antonio Simões

    2016-02-01

    The clinical course of infection with Mycobacterium leprae varies widely and depends on the pattern of the host immune response. Dendritic cells play an important role in the activation of the innate and adaptive immune system and seem to be essential for the development of the disease. To analyze the presence of epidermal dendritic cells (CD1a and CD207), plasmacytoid dendritic cells (CD123) and dermal dendrocytes (factor XIIIa) in lesion fragments of leprosy patients, skin samples from 30 patients were studied. These samples were submitted to immunohistochemistry against CD1a, CD207, FXIIIa, and CD123. The results showed a larger number of Langerhans cells, detected with the CD1a or CD207 marker, dermal dendrocytes and plasmacytoid dendritic cells in patients with the tuberculoid form. A positive correlation was observed between the Langerhans cell markers CD1a and CD207 in both the tuberculoid and lepromatous forms, and between Langerhans cells and dermal dendrocytes in samples with the tuberculoid form. The present results indicate the existence of a larger number of dendritic cells in patients at the resistant pole of the disease (tuberculoid) and suggest that the different dendritic cells studied play a role, favoring an efficient immune response against infection with M. leprae.

  5. Expression of the T cell receptor αβ on a CD123+ BDCA2+ HLA-DR+ subpopulation in head and neck squamous cell carcinoma.

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    Annette Thiel

    Full Text Available Human Plasmacytoid Dendritic Cells (PDCs infiltrating solid tumor tissues and draining lymph nodes of Head and Neck Squamous Cell Carcinoma (HNSCC show an impaired immune response. In addition to an attenuated secretion of IFN-α little is known about other HNSCC-induced functional alterations in PDCs. Particular objectives in this project were to gain new insights regarding tumor-induced phenotypical and functional alterations in the PDC population. We showed by FACS analysis and RT-PCR that HNSCC orchestrates an as yet unknown subpopulation exhibiting functional autonomy in-vitro and in-vivo besides bearing phenotypical resemblance to PDCs and T cells. A subset, positive for the PDC markers CD123, BDCA-2, HLA-DR and the T cell receptor αβ (TCR-αβ was significantly induced subsequent to stimulation with HNSCC in-vitro (p = 0.009 and also present in metastatic lymph nodes in-vivo. This subgroup could be functionally distinguished due to an enhanced production of IL-2 (p = 0.02, IL-6 (p = 0.0007 and TGF-β (not significant. Furthermore, after exposure to HNSCC cells, mRNA levels revealed a D-J-beta rearrangement of the TCR-beta chain besides a strong enhancement of the CD3ε chain in the PDC population. Our data indicate an interface between the PDC and T cell lineage. These findings will improve our understanding of phenotypical and functional intricacies concerning the very heterogeneous PDC population in-vivo.

  6. Toll样受体9和CD123在寻常型银屑病患者皮损中的表达%Expression of Toll-like Receptors 9 and CD123 Plasmacytoid Dendritic Cells in Lesions of Patients with Psoriasis Vulgaris

    Institute of Scientific and Technical Information of China (English)

    王洪燕

    2015-01-01

    Objective To investigate the expression of toll-like receptors 9( TLR9) and CD123 plasma-cytoid dendritic cells in skin lesions of patients with psoriasis vulgaris and its significance .Methods A total of 26 patients with psoriasis vulgaris admitted in People′s hospital of Yanzhou City from Jun.2012 to Apr. 2013 were selected as the experimental group,another 23 healthy people underwent physical examination were selected as the control group.Skin lesion samples from the bodies of all the cases were collected by the method of general skin surgeries and received biopsies,and the expression of CD123 and TLR9 in the samples were detected by S-P immunohistochemical method and reverse transcription-polymerase chain reaction ( RT-PCR) ,and the relationship between the overexpression of the two factors and the pathogenesis of psoria-sis vulgaris was analyzed.Results The positive expression rate of CD123 and TLR9 in the experiment group detected by S-P immunohistochemical method were both 100%,the expression mean values of CD123 and TLR9 were respectively (10.1 ±2.3) figures/mm3,(14.4 ±2.0)figures/mm3,while in control group,the expression mean values of CD123 and TLR9 were respectively (1.5 ±0.6) figures/mm3,(2.2 ±1.0) fig-ures/mm3 ,both without positive expression;the expression levels of TLR mRNA in experiment group and con-trol group detected by RT-PCR method were (1.32 ±0.08) figures/mm3 and (0.87 ±0.04) figures/mm3, respectively,the difference was statistically significant(P<0.01).Conclusion Plasmacytoid dendritic cells may be involved in stimulating the activation and proliferation of autoimmune T cell ,which is an important mechanism of the incidence of psoriasis vulgaris.%目的:探讨 Toll 样受体9( TLR9)和 CD123在寻常型银屑病患者皮损中的表达及意义。方法选择2012年6月至2013年4月兖州市人民医院收治的26例寻常型银屑病患者为试验组,另选23例健康体检者为对照组,分别按照

  7. A Human Lin(-) CD123(+) CD127(low) Population Endowed with ILC Features and Migratory Capabilities Contributes to Immunopathological Hallmarks of Psoriasis.

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    Mora-Velandia, Luz María; Castro-Escamilla, Octavio; Méndez, Andrés González; Aguilar-Flores, Cristina; Velázquez-Avila, Martha; Tussié-Luna, María Isabel; Téllez-Sosa, Juan; Maldonado-García, César; Jurado-Santacruz, Fermín; Ferat-Osorio, Eduardo; Martínez-Barnetche, Jesus; Pelayo, Rosana; Bonifaz, Laura C

    2017-01-01

    expresses skin-homing receptors (cutaneous lymphocyte antigen and CXCR4) and transmigrates through endothelial cells in response to SDF-1. An equivalent Lin(-) CD123(low) population was identified in control skin, which shows a broader phenotypic diversity and cytokine production, including IL-22 and IL-17. Remarkably, the CD123(low) population in the lesion and non-lesion skin of psoriasis patients expresses IL-17 and IL-22. Our findings suggest the identification of an alternative Lin(-) CD123(+) CD127(low) population with ILC features endowed with migratory capabilities that might contribute to immunopathological hallmarks of psoriasis.

  8. A Human Lin− CD123+ CD127low Population Endowed with ILC Features and Migratory Capabilities Contributes to Immunopathological Hallmarks of Psoriasis

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    Mora-Velandia, Luz María; Castro-Escamilla, Octavio; Méndez, Andrés González; Aguilar-Flores, Cristina; Velázquez-Avila, Martha; Tussié-Luna, María Isabel; Téllez-Sosa, Juan; Maldonado-García, César; Jurado-Santacruz, Fermín; Ferat-Osorio, Eduardo; Martínez-Barnetche, Jesus; Pelayo, Rosana; Bonifaz, Laura C.

    2017-01-01

    -homing receptors (cutaneous lymphocyte antigen and CXCR4) and transmigrates through endothelial cells in response to SDF-1. An equivalent Lin− CD123low population was identified in control skin, which shows a broader phenotypic diversity and cytokine production, including IL-22 and IL-17. Remarkably, the CD123low population in the lesion and non-lesion skin of psoriasis patients expresses IL-17 and IL-22. Our findings suggest the identification of an alternative Lin− CD123+ CD127low population with ILC features endowed with migratory capabilities that might contribute to immunopathological hallmarks of psoriasis. PMID:28303135

  9. CD123在儿童急性B淋巴细胞白血病中的表达及其在微小残留病检测中的应用%Expressions of CD123 in childhood B-lineage acute lymphoblastic leukemia and the application of CD123 in minimal residual disease detection

    Institute of Scientific and Technical Information of China (English)

    计雪强; 季正华; 邵惠江; 王红英; 何亚香; 朱宏; 邵雪君

    2012-01-01

    Objective: Detecting the expression of CD123 in childhood B-lineage acute lymphoblastic leukemia ( B-ALL ) and discussing the application and significance of CD123 in minimal residual disease ( MRD ) detection. Methods: With the normal children bone marrow lymphocytes as control, multiparame-ter flow cytometry was used to study the bone marrow lymphocytes immunophenotype and the expression of CD123 in 91 cases of children with B-ALL, 78 cases of which were underwent bone marrow cells chromosome cultivation and cytogenetic analysis. 65 cases of B-ALL children with CD123 positive expression were screened and monitored by CD10/CD123/CD34/CD19 in MRD detection. Results: The expression of CD 123 in normal children bone marrow lymphocytes was negative, while 65 cases of 91 in B-ALL children was positive( positive rate 71.43% ), and the expression level of CD123 was negatively correlated with the leukemic cells maturity. When children had a high expression of CD34, the expression of CD123 was also in a high level. The results of cytogenetic analysis showed that hyperdiploid B-ALL children had a higher level of CD123 expression, when comparing with the non-hyperdiploid cases. Forty-seven cases of B-ALL children ( 51. 65% ) had a high level of CD 123 expression, and CD 123 could be used as an effective marker for MRD monitoring. Conclusion: Most of B-ALL children had an expression of CD123 , which was negatively correlated with the leukemic cells maturity. CD123 can be used as a maker for MRD monitoring in childhood B-ALL.%目的:检测细胞表面抗原CD123在儿童急性B淋巴细胞白血病(B-lineage acute lymphoblastic leukemia,B-ALL)中的表达,并探讨其在儿童B-ALL微小残留病(minimal residual disease,MRD)检测中的应用及意义.方法:以健康儿童骨髓淋巴细胞为对照,应用多参数流式细胞术检测91例儿童B-ALL患者骨髓淋巴细胞免疫表型及CD123的表达,其中78例B-ALL患者进行了骨髓细胞染色体培养及

  10. HLA-DR+ Immature Cells Exhibit Reduced Antigen-Presenting Cell Function But Respond to CD40 Stimulation

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    Alberto Pinzon-Charry

    2005-12-01

    Full Text Available Dendritic cells (DC have been implicated in the defective function of the immune system during cancer progression. We have demonstrated that patients with cancer have fewer myeloid (CD11c+ and plasmacytoid (CD123hi DC and a concurrent accumulation of CD11c−CD123− immature cells expressing HLA-DR (DR+IC. Notably, DR+IC from cancer patients have a reduced capacity to stimulate allogeneic T-cells. DR+IC are also present in healthy donors, albeit in smaller numbers. In this study, we assessed whether DR+IC could have an impact on the immune response by comparing their function with DC counterparts. For this purpose, DR+IC and DC were purified and tested in the presentation of antigens through major histocompatibility complex (MHC II and MHC-I molecules. DR+IC were less efficient than DC at presenting antigens to T-cells. DR`IC induced a limited activation of T-cells, eliciting poor T-helper (Th 1 and preferentially inducing Th2-biased responses. Importantly, despite DR+IC's poor responsiveness to inflammatory factors, in samples from healthy volunteers and breast cancer patients, CD40 ligation induced phenotypic maturation and interleukin 12 secretion, in turn generating more efficient T-cell responses. These data underscore the importance of inefficient antigen presentation as a mechanism for tumor evasion and suggest an approach to improve the efficacy of DC-based immunotherapy for cancer.

  11. CD 123 - Wheat bread for white flour in cool regions of Brazil

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    Volmir Sergio Marchioro

    2014-11-01

    Full Text Available Cultivar CD 123 is recommendable for the wheat-growing regions 1, 2 and 3 of the States of Rio Grande do Sul, Santa Catarina and Paraná. It is a white flour wheat destined for production in cooler regions. The mean potential yield is 3514 kg ha-1, exceeding that of the control cultivars by 5%.

  12. Case Report: A case of hypertrophic lupus erythematosus with negative CD123 staining and absence of transepidermal elimination of elastin [v2; ref status: indexed, http://f1000r.es/3n7

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    Matthew Hughes

    2014-06-01

    Full Text Available We report the case of a 49-year-old male with clinical and histological findings consistent with hypertrophic lupus erythematosus (HLE. HLE must be clinically and histologically differentiated from keratoacanthoma, hypertrophic lichen planus, squamous cell carcinoma and plaque type psoriasis. CD123 positivity and transepidermal elimination of elastin have recently been reported as tools to distinguish HLE. Interestingly, in this case, biopsies of two separate lesions failed to reveal these two features. The etiology of this discrepancy is unknown and further studies are needed to clarify the utility of CD123 positivity and transepidermal elimination of elastin in the diagnosis of hypertrophic lupus erythematosus.

  13. Antigen-specific memory B cell development.

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    McHeyzer-Williams, Louise J; McHeyzer-Williams, Michael G

    2005-01-01

    Helper T (Th) cell-regulated B cell immunity progresses in an ordered cascade of cellular development that culminates in the production of antigen-specific memory B cells. The recognition of peptide MHC class II complexes on activated antigen-presenting cells is critical for effective Th cell selection, clonal expansion, and effector Th cell function development (Phase I). Cognate effector Th cell-B cell interactions then promote the development of either short-lived plasma cells (PCs) or germinal centers (GCs) (Phase II). These GCs expand, diversify, and select high-affinity variants of antigen-specific B cells for entry into the long-lived memory B cell compartment (Phase III). Upon antigen rechallenge, memory B cells rapidly expand and differentiate into PCs under the cognate control of memory Th cells (Phase IV). We review the cellular and molecular regulators of this dynamic process with emphasis on the multiple memory B cell fates that develop in vivo.

  14. Presentation of antigen by B cells subsets. Pt. 2. The role of CD5 B cells in the presentation of antigen to antigen-specific T cells

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    Zimecki, Michal [Polish Academy of Sciences, Wroclaw (Poland). Institute of Immunology and Experimental Therapy; Kapp, Judith A. [Emory Univ., Atlanta, GA (United States). School of Medicine

    1994-12-31

    We demonstrate that peritoneal B cells have a much higher ability to present antigen to antigen-specific T cell lines splenic B cells. Presentation of antigen by B cells is abrogated or drastically reduced after removal of Lyb-5{sup +} cells from the population of splenic or peritoneal B cells. Peritoneal B cells, precultured for 7 days prior to the antigen presentation assay, retain their antigen presenting cell (APC) function. Enrichment for CD5{sup +} cells in the peritoneal B cell population results in a more effective antigen presentation. Lastly, stimulation of B cells via CD5 antigen, by treatment of cells with anti-CD5 antibodies or cross-linking of CD5 receptors, enhances APC function of these cells. The results indicate, both indirectly and directly, that CD5{sup +} B cells play a predominant role in the presentation of conventional antigens to antigen-specific T cells. (author). 30 refs, 6 tabs.

  15. Antigen Export Reduces Antigen Presentation and Limits T Cell Control of M. tuberculosis.

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    Srivastava, Smita; Grace, Patricia S; Ernst, Joel D

    2016-01-13

    Persistence of Mycobacterium tuberculosis results from bacterial strategies that manipulate host adaptive immune responses. Infected dendritic cells (DCs) transport M. tuberculosis to local lymph nodes but activate CD4 T cells poorly, suggesting bacterial manipulation of antigen presentation. However, M. tuberculosis antigens are also exported from infected DCs and taken up and presented by uninfected DCs, possibly overcoming this blockade of antigen presentation by infected cells. Here we show that the first stage of this antigen transfer, antigen export, benefits M. tuberculosis by diverting bacterial proteins from the antigen presentation pathway. Kinesin-2 is required for antigen export and depletion of this microtubule-based motor increases activation of antigen-specific CD4 T cells by infected cells and improves control of intracellular infection. Thus, although antigen transfer enables presentation by bystander cells, it does not compensate for reduced antigen presentation by infected cells and represents a bacterial strategy for CD4 T cell evasion.

  16. Antigen presentation by MHC-dressed cells

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    Masafumi eNakayama

    2015-01-01

    Full Text Available Professional antigen presenting cells (APCs such as conventional dendritic cells (DCs process protein antigens to MHC-bound peptides and then present the peptide-MHC complexes to T cells. In addition to this canonical antigen presentation pathway, recent studies have revealed that DCs and non-APCs can acquire MHC class I (MHCI and/or MHC class II (MHCII from neighboring cells through a process of cell-cell contact-dependent membrane transfer called trogocytosis. These MHC-dressed cells subsequently activate or regulate T cells via the preformed antigen peptide-MHC complexes without requiring any further processing. In addition to trogocytosis, intercellular transfer of MHCI and MHCII can be mediated by secretion of membrane vesicles such as exosomes from APCs, generating MHC-dressed cells. This review focuses on the physiological role of antigen presentation by MHCI- or MHCII-dressed cells, and also discusses differences and similarities between trogocytosis and exosome-mediated transfer of MHC.

  17. Harnessing Dendritic Cells for Tumor Antigen Presentation

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    Nierkens, Stefan [Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Geert Grooteplein 28, Nijmegen 6525 GA (Netherlands); Janssen, Edith M., E-mail: edith.janssen@cchmc.org [Division of Molecular Immunology, Cincinnati Children' s Hospital Research Foundation, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229 (United States)

    2011-04-26

    Dendritic cells (DC) are professional antigen presenting cells that are crucial for the induction of anti-tumor T cell responses. As a consequence, research has focused on the harnessing of DCs for therapeutic interventions. Although current strategies employing ex vivo-generated and tumor-antigen loaded DCs have been proven feasible, there are still many obstacles to overcome in order to improve clinical trial successes and offset the cost and complexity of customized cell therapy. This review focuses on one of these obstacles and a pivotal step for the priming of tumor-specific CD8{sup +} and CD4{sup +} T cells; the in vitro loading of DCs with tumor antigens.

  18. Hematopoietic stem cells express multiple myeloid markers: implications for the origin and targeted therapy of acute myeloid leukemia

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    Taussig, David C.; Pearce, Daniel J; Simpson, Catherine; Rohatiner, Ama Z; Lister, T. Andrew; Kelly, Gavin; Luongo, Jennifer L.; Danet-Desnoyers, Gwenn-aël H.; Bonnet, Dominique

    2005-01-01

    Human hematopoietic stem cells (HSCs) are generally regarded as being devoid of the markers expressed by differentiated blood cells, the lineage-specific antigens. However, recent work suggests that genes associated with the myeloid lineage are transcribed in mouse HSCs. Here, we explore whether myeloid genes are actually translated in human HSCs. We show that CD33, CD13, and CD123, well-established myeloid markers, are expressed on human long-term repopulating cells from cord blood and bone ...

  19. The Antigen Presenting Cells Instruct Plasma Cell Differentiation

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    Wei eXu

    2014-01-01

    Full Text Available The professional antigen presenting cells (APCs, including many subsets of dendritic cells and macrophages, not only mediate prompt but nonspecific response against microbes, but also bridge the antigen-specific adaptive immune response through antigen presentation. In the latter, typically activated B cells acquire cognate signals from T helper cells in the germinal center of lymphoid follicles to differentiate into plasma cells, which generate protective antibodies. Recent advances have revealed that many APC subsets provide not only signal 1 (the antigen, but also signal 2 to directly instruct the differentiation process of plasma cells in a T cell-independent manner. Herein, the different signals provided by these APC subsets to direct B cell proliferation, survival, class switching and terminal differentiation are discussed. We furthermore propose that the next generation of vaccines for boosting antibody response could be designed by targeting APCs.

  20. The expression of CD123 can decrease with basophil activation: implications for the gating strategy of the basophil activation test

    OpenAIRE

    Santos, Alexandra F.; Bécares, Natalia; Stephens, Alick; Turcanu, Victor; Lack, Gideon

    2016-01-01

    Background Basophil activation test (BAT) reproduces IgE-mediated allergic reactions in vitro and has been used as a diagnostic test. Different markers can be used to identify basophils in whole blood and have implications for the outcome of the test. We aimed to assess changes in the expression of CD123 and HLA-DR following basophil activation and to select the best gating strategy for BAT using these markers. Methods BAT was performed in whole blood from 116 children. Peanut extract, anti-I...

  1. Antigen presentation for priming T cells in central system.

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    Dasgupta, Shaoni; Dasgupta, Subhajit

    2017-01-01

    Generation of myelin antigen-specific T cells is a major event in neuroimmune responses that causes demyelination. The antigen-priming of T cells and its location is important in chronic and acute inflammation. In autoimmune multiple sclerosis, the effector T cells are considered to generate in periphery. However, the reasons for chronic relapsing-remitting events are obscure. Considering mechanisms, a feasible aim of research is to investigate the role of antigen-primed T cells in lupus cerebritis. Last thirty years of investigations emphasize the relevance of microglia and infiltrated dendritic cells/macrophages as antigen presenting cells in the central nervous system. The recent approach towards circulating B-lymphocytes is an important area in the context. Here, we analyze the existing findings on antigen presentation in the central nervous system. The aim is to visualize signaling events of myelin antigen presentation to T cells and lead to the strategy of future goals on immunotherapy research.

  2. Expression of leukemic stem cell associated membrane antigens in acute leukemia cells%白血病干细胞相关抗原在急性白血病细胞中的表达

    Institute of Scientific and Technical Information of China (English)

    肖平; 曾耀英; 林蔚

    2011-01-01

    目的 探讨白血病干细胞(leukemia stem cell,LSC)相关抗原在不同亚型急性白血病细胞中的表达规律.方法 采用流式细胞术检测LSC相关抗原CD96,CD90,CD123,CD71等在50例不同亚型急性白血病细胞中的表达,包括急性粒细胞白血病未分化型(M1)、急性粒细胞白血病部分分化型(M2)、急性早幼粒细胞白血病(Ms)、急性粒-单核细胞白血病(M4)和急性B淋巴细胞白血病.结果 CD96在M.的表达率(90.00%)明显高于M2(18.18%)和急性B淋巴细胞白血病(20.00%)(P<0.05);各亚型急性白血病均表达CD123,但差异无统计学意义(P>0.05) ;CD71在急性髓细胞白血病各亚型中(M1、M2、M3和M4)阳性表达率分别为80.00%、72.73%、90.00%和100.00%,明显高于急性B淋巴细胞白血病(P<0.05);CD90在急性B淋巴细胞白血病中阳性表达率为13.33%,高于急性髓细胞白血病(P>0.05).结论 CD71与CD96的表达有亚型特异性,CD96可能具有指示系列分化和细胞分化程度的作用,CD71可用于区分急性淋巴细胞白血病和急性髓细胞白血病.%Objective To study the expression of leukemic stem cell associated membrane antigens in acute leukemia cells with different subtypes. Methods Leukemic stem cell associated membrane antigens CD96, CD90, CD123 and CD71 were detected with flow cytometry in 50 acute leukemia patients with different subtypes including acute myeloblast leukemia without cell maturation (M1), acute myeloblast leukemia with cell maturation (M2), acute promyelocytic leukemia (M3), acute myelomonocytic leukemia (AMML) and B-acute lymphoblastic leukemia (B-ALL). Results The positive rate of CD96 expression in M3(90. 00%) was significantly higher than that in M2(18. 18%) and B-ALL (20. 00%)(P 0. 05). The positive rate of CD71 expression in four subtypes of acute myeloid leukemia (M1 , M2, M3 and M4) was 80. 00%, 72. 73%, 90. 00% and 100. 00% respectively, all of which were significantly higher than

  3. Immunotherapy of acute leukemia by chimeric antigen receptor-modified lymphocytes using an improved Sleeping Beauty transposon platform.

    Science.gov (United States)

    Magnani, Chiara F; Turazzi, Nice; Benedicenti, Fabrizio; Calabria, Andrea; Tenderini, Erika; Tettamanti, Sarah; Giordano Attianese, Greta M P; Cooper, Laurence J N; Aiuti, Alessandro; Montini, Eugenio; Biondi, Andrea; Biagi, Ettore

    2016-08-09

    Chimeric antigen receptor (CAR)-modified T-cell adoptive immunotherapy is a remarkable therapeutic option proven effective in the treatment of hematological malignancies. In order to optimize cell manufacturing, we sought to develop a novel clinical-grade protocol to obtain CAR-modified cytokine-induced killer cells (CIKs) using the Sleeping Beauty (SB) transposon system. Administration of irradiated PBMCs overcame cell death of stimulating cells induced by non-viral transfection, enabling robust gene transfer together with efficient T-cell expansion. Upon single stimulation, we reached an average of 60% expression of CD123- and CD19- specific 3rd generation CARs (CD28/OX40/TCRzeta). Furthermore, modified cells displayed persistence of cell subsets with memory phenotype, specific and effective lytic activity against leukemic cell lines and primary blasts, cytokine secretion, and proliferation. Adoptive transfer of CD123.CAR or CD19.CAR lymphocytes led to a significant anti-tumor response against acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) disseminated diseases in NSG mice. Notably, we found no evidence of integration enrichment near cancer genes and transposase expression at the end of the differentiation. Taken all together, our findings describe a novel donor-derived non-viral CAR approach that may widen the repertoire of available methods for T cell-based immunotherapy.

  4. Antigen specificity of invariant natural killer T-cells

    Directory of Open Access Journals (Sweden)

    Alysia M. Birkholz

    2015-12-01

    Full Text Available Natural killer T-cells, with an invariant T-cell antigen receptor α-chain (iNKT cells, are unique and conserved subset of lymphocytes capable of altering the immune system through their rapid and potent cytokine responses. They are reactive to lipid antigens presented by the CD1d molecule, an antigen-presenting molecule that is not highly polymorphic. iNKT cell responses frequently involve mixtures of cytokines that work against each other, and therefore attempts are underway to develop synthetic antigens that elicit only strong interferon-gamma (IFNγ or only strong interleukin-4 responses but not both. Strong IFNγ responses may correlate with tighter binding to CD1d and prolonged stimulation of iNKT cells, and this may be useful for vaccine adjuvants and for stimulating anti-tumor responses. iNKT cells are self-reactive although the structure of the endogenous antigen is controversial. By contrast, bacterial and fungal lipids that engage the T-cell receptor and activate IFNγ from iNKT cells have been identified from both pathogenic and commensal organisms and the responses are in some cases highly protective from pathogens in mice. It is possible that the expanding knowledge of iNKT cell antigens and iNKT cell activation will provide the basis for therapies for patients suffering from infectious and immune diseases and cancer.

  5. Antigen specificity of invariant natural killer T-cells.

    Science.gov (United States)

    Birkholz, Alysia M; Kronenberg, Mitchell

    2015-12-01

    Natural killer T-cells, with an invariant T-cell antigen receptor α-chain (iNKT cells), are unique and conserved subset of lymphocytes capable of altering the immune system through their rapid and potent cytokine responses. They are reactive to lipid antigens presented by the CD1d molecule, an antigen-presenting molecule that is not highly polymorphic. iNKT cell responses frequently involve mixtures of cytokines that work against each other, and therefore attempts are underway to develop synthetic antigens that elicit only strong interferon-gamma (IFNγ) or only strong interleukin-4 responses but not both. Strong IFNγ responses may correlate with tighter binding to CD1d and prolonged stimulation of iNKT cells, and this may be useful for vaccine adjuvants and for stimulating anti-tumor responses. iNKT cells are self-reactive although the structure of the endogenous antigen is controversial. By contrast, bacterial and fungal lipids that engage the T-cell receptor and activate IFNγ from iNKT cells have been identified from both pathogenic and commensal organisms and the responses are in some cases highly protective from pathogens in mice. It is possible that the expanding knowledge of iNKT cell antigens and iNKT cell activation will provide the basis for therapies for patients suffering from infectious and immune diseases and cancer.

  6. Fibroblasts as Efficient Antigen-Presenting Cells in Lymphoid Organs

    Science.gov (United States)

    Kundig, Thomas M.; Bachmann, Martin F.; Dipaolo, Claudio; Simard, John J. L.; Battegay, Manuel; Lother, Heinz; Gessner, Andre; Kuhlcke, Klaus; Ohashi, Pamela S.; Hengartner, Hans; Zinkernagel, Rolf M.

    1995-06-01

    Only so-called "professional" antigen-presenting cells (APCs) of hematopoietic origin are believed capable of inducing T lymphocyte responses. However, fibroblasts transfected with viral proteins directly induced antiviral cytotoxic T lymphocyte responses in vivo, without involvement of host APCs. Fibroblasts induced T cells only in the milieu of lymphoid organs. Thus, antigen localization affects self-nonself discrimination and cell-based vaccine strategies.

  7. Responses of synovial fluid and peripheral blood mononuclear cells to bacterial antigens and autologous antigen presenting cells.

    Science.gov (United States)

    Klasen, I S; Melief, M J; Swaak, T J; Severijnen, A J; Hazenberg, M P

    1993-01-01

    The specificity of T cells in the inflamed joints of patients with rheumatoid arthritis (RA) has been the subject of much study. Bacterial antigens are suspect in the aetiology of rheumatic diseases. The responsiveness of the mononuclear cell fraction of peripheral blood and synovial fluid of patients with RA and of patients with rheumatic diseases other than RA to bacterial antigens such as cell wall fragments of the anaerobic intestinal flora, cell wall fragments of Streptococcus pyogenes, intestinal flora derived peptidoglycan polysaccharide complexes, the 65 kilodalton protein of Mycobacterium tuberculosis, and muramyldipeptide was investigated. No significant difference in response was found to all these bacterial antigens in the synovial fluid of patients with RA compared with the responses in patients with other rheumatic diseases. The highest responsiveness in the synovial fluid of the patients with RA was to the streptococcal cell wall fragments and to the 65 kilodalton protein. Higher responses to several bacterial antigens in the synovial fluid of patients with RA were found compared with peripheral blood from the same patient group. The antigen presenting cell population of the synovial fluid in patients with RA and the patients with other rheumatic diseases was found to be stimulatory for autologous peripheral blood T cells even in the absence of antigen. This suggests an important role for the synovial antigen presenting cell in the aetiology of inflammatory joint diseases. PMID:8447692

  8. Antigen loading on dendritic cells affects the lell function in stimulating T cells.

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective: To study the effect of antigen loading on dendritic cells (DC). Methods: DCs collected from peripheral blood monocytes were loaded with a tumor antigen from XG-7 cell line. These DCs were then co-cultured with allogeneic T cells and were compared with those DCs without antigen exposure.

  9. Facts on the fragmentation of antigens in presenting cells, on the association of antigen fragments with MHC molecules in cell-free systems, and speculation on the cell biology of antigen processing

    DEFF Research Database (Denmark)

    Werdelin, O; Mouritsen, S; Petersen, B L;

    1988-01-01

    The processing of a protein antigen is a multi-step event taking place in antigen-presenting cells. Processing is a prerequisite for the recognition of most antigens by T lymphocytes. The antigen is ingested by endocytosis, transported to an acid cellular compartment and subjected to proteolytic ...

  10. Photoaffinity antigens for human γδ T cells1

    Science.gov (United States)

    Sarikonda, Ghanashyam; Wang, Hong; Puan, Kia-Joo; Liu, Xiao-hui; Lee, Hoi K.; Song, Yongcheng; Distefano, Mark D.; Oldfield, Eric; Prestwich, Glenn D.; Morita, Craig T.

    2009-01-01

    Vγ2Vδ2 T cells comprise the major subset of peripheral blood γ δ T cells in humans and expand during infections by recognizing small, nonpeptide prenyl pyrophosphates. These molecules include (E)-4-hydroxy-3-methyl-but-2-enyl-pyrophosphate (HMBPP), a microbial isoprenoid intermediate, and isopentenyl pyrophosphate (IPP), an endogenous isoprenoid intermediate. Recognition of these nonpeptide antigens is mediated by the Vγ2Vδ2 T cell antigen receptor (TCR). Several findings suggest that prenyl pyrophosphates are presented by an antigen presenting molecule: contact between T cells and APCs is required; the antigens do not bind the Vγ2Vδ2 TCR directly; and antigen recognition is abrogated by TCR mutations in CDRs distant from the putative antigen recognition site. Identification of the putative antigen presenting molecule, however, has been hindered by the inability to achieve stable association of nonpeptide prenyl pyrophosphate antigens with the presenting molecule. In this study, we show that photoaffinity analogs of HMBPP, meta/para-benzophenone-(methylene)-prenyl pyrophosphates (m/p-BZ-(C)-C5-OPP), can cross-link to the surface of tumor cell lines and be presented as antigens to γ δ T cells. Mutant tumor cell lines lacking MHC class I, MHC class II, β2-microglobulin, and CD1, as well as tumor cell lines from a variety of tissues and individuals, will all crosslink to and present m-BZ-C5-OPP. Finally, pulsing of BZ-(C)-C5-OPP is inhibited by IPP and an inactive analog, suggesting that they bind to the same molecule. Taken together, these results suggest that nonpeptide antigens are presented by a novel antigen presenting molecule that is widely distributed, non-polymorphic, but not classical MHC class I, MHC class II, or CD1. This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript

  11. Antigen-presenting cells in human cutaneous leishmaniasis due to Leishmania major

    DEFF Research Database (Denmark)

    ElHassan, A M; Gaafar, A; Theander, T G

    1995-01-01

    , identified morphologically and by their expression of specific cell markers, included Langerhans cells, macrophages, follicular dendritic cells, and interdigitating reticulum cells of the paracortex of lymph nodes. These cells expressed MHC class II antigens and contained Leishmania antigen. Since some...

  12. Analysis of cell surface antigens by Surface Plasmon Resonance imaging

    NARCIS (Netherlands)

    Stojanovic, I.; Schasfoort, R.B.M.; Terstappen, L.W.M.M.

    2013-01-01

    Surface Plasmon Resonance (SPR) is most commonly used to measure bio-molecular interactions. SPR is used significantly less frequent for measuring whole cell interactions. Here we introduce a method to measure whole cells label free using the specific binding of cell surface antigens expressed on th

  13. Recognition of antigen-specific B-cell receptors from chronic lymphocytic leukemia patients by synthetic antigen surrogates.

    Science.gov (United States)

    Sarkar, Mohosin; Liu, Yun; Morimoto, Jumpei; Peng, Haiyong; Aquino, Claudio; Rader, Christoph; Chiorazzi, Nicholas; Kodadek, Thomas

    2014-12-18

    In patients with chronic lymphocytic leukemia (CLL), a single neoplastic antigen-specific B cell accumulates and overgrows other B cells, leading to immune deficiency. CLL is often treated with drugs that ablate all B cells, leading to further weakening of humoral immunity, and a more focused therapeutic strategy capable of targeting only the pathogenic B cells would represent a significant advance. One approach to this would be to develop synthetic surrogates of the CLL antigens allowing differentiation of the CLL cells and healthy B cells in a patient. Here, we describe nonpeptidic molecules capable of targeting antigen-specific B cell receptors with good affinity and selectivity using a combinatorial library screen. We demonstrate that our hit compounds act as synthetic antigen surrogates and recognize CLL cells and not healthy B cells. Additionally, we argue that the technology we developed can be used to identify other classes of antigen surrogates.

  14. Regulator T cells: specific for antigen and/or antigen receptors?

    Science.gov (United States)

    Rubin, B; de Durana, Y Diaz; Li, N; Sercarz, E E

    2003-05-01

    Adaptive immune responses are regulated by many different molecular and cellular effectors. Regulator T cells are coming to their rights again, and these T cells seem to have ordinary alpha/beta T-cell receptors (TCRs) and to develop in the thymus. Autoimmune responses are tightly regulated by such regulatory T cells, a phenomenon which is beneficial to the host in autoimmune situations. However, the regulation of autoimmune responses to tumour cells is harmful to the host, as this regulation delays the defence against the outgrowth of neoplastic cells. In the present review, we discuss whether regulatory T cells are specific for antigen and/or for antigen receptors. Our interest in these phenomena comes from the findings that T cells produce many more TCR-alpha and TCR-beta chains than are necessary for surface membrane expression of TCR-alphabeta heterodimers with CD3 complexes. Excess TCR chains are degraded by the proteasomes, and TCR peptides thus become available to the assembly pathway of major histocompatibility complex class I molecules. Consequently, do T cells express two different identification markers on the cell membrane, the TCR-alphabeta clonotype for recognition by B-cell receptors and clonotypic TCR-alphabeta peptides for recognition by T cells?

  15. T Cells as Antigen Carriers for Anti-tumor Vaccination.

    Science.gov (United States)

    Traversari, Catia; Russo, Vincenzo

    2016-01-01

    The exploitation of the physiologic processing and presenting machinery of dendritic cells (DCs) by in vivo loading of tumor-associated antigens may improve the immunogenic potential and clinical efficacy of DC-based cancer vaccines. The approach developed by our group was based on the clinical observation that some patients treated with the infusion of donor lymphocytes transduced to express the HSV-TK suicide gene for relapse of hematologic malignancies, after allogeneic hematopoietic stem cell transplantation, developed a T cell-mediated immune response specifically directed against the HSV-TK gene product.We demonstrated that lymphocytes genetically modified to express HSV-TK as well as self/tumor antigens, acting as antigen carriers, efficiently target DCs in vivo in tumor-bearing mice. The infusion of TRP-2-transduced lymphocytes induced the establishment of protective immunity and long-term memory in tumor-bearing mice by cross-presentation of the antigen mediated by the CD11c(+)CD8a(+) DCs subset. A similar approach was applied in a clinical setting. Ten patients affected by MAGE-3(+) metastatic melanoma were treated with autologous lymphocytes retrovirally transduced to express the MAGE-3 tumor antigen. In three patients, the treatment led to the increase of MAGE-3 specific CD8+ and CD4+ effectors and the development of long-term memory, which ultimately correlated with a favorable clinical outcome. Transduced lymphocytes represent an efficient way for in vivo loading of tumor-associated antigens of DCs.

  16. Antigen-induced and non-antigen-induced histamine release from rat mast cells sensitized with mouse antiserum.

    Directory of Open Access Journals (Sweden)

    Kurose,Masao

    1981-10-01

    Full Text Available Marked IgE-mediated histamine release from rat mast cells sensitized in vitro with mouse antiserum occurs in the presence of added Ca++ and phosphatidylserine (PS, although a considerable degree of antigen-induced histamine release which may utilize intracellular or cell-bound calcium is also observed. The decay in the responsiveness to Ca++ of the sensitized cells stimulated by antigen in Ca++-free medium in the presence of PS is relatively slow, and maximum release is produced by Ca++ added 1 min after antigen. Histamine release also occurs when Ca++ is added after PS in the absence of antigen to the sensitized cells suspended in Ca++-free medium. Unlike the antigen-induced release, the intensity of this non-antigen-induced release varies depending on both mast-cell and antiserum pools. A heat-labile factor(s, which is different from antigen-specific IgE antibody and is also contained in normal mouse serum, is involved in this reaction. In the antigen-nondependent (PS + Ca++-induced release, no decay in the responsiveness to Ca++ is observed after PS addition. Both the antigen-induced and non-antigen-induced release are completed fairly rapidly and are dependent of temperature, pH and energy.

  17. Self-antigen presentation by dendritic cells in autoimmunity

    Directory of Open Access Journals (Sweden)

    Ann-Katrin eHopp

    2014-02-01

    Full Text Available The operation of both central and peripheral tolerance ensures the prevention of autoimmune diseases. The maintenance of peripheral tolerance requires self-antigen presentation by professional antigen presenting cells (APCs. Dendritic cells (DCs are considered as major APCs involved in this process. The current review discusses the role of DCs in autoimmune diseases, the various factors involved in the induction and maintenance of tolerogenic DC phenotype and pinpoints their therapeutic capacity as well as potential novel targets for future clinical studies.

  18. In Vitro Generation of Antigen-Specific T Cells from Induced Pluripotent Stem Cells of Antigen-Specific T Cell Origin.

    Science.gov (United States)

    Kaneko, Shin

    2016-01-01

    Induced pluripotent stem (iPS) cells derived from T lymphocyte (T-iPS cells) preserve the T cell receptor (TCR) α and β gene rearrangements identical to the original T cell clone. Re-differentiated CD8 single positive αβ T cells from the T-iPS cells exhibited antigen-specific cytotoxicity, improved proliferative response, and elongation of telomere indicating rejuvenation of antigen specific T cell immunity in vitro. To regenerate antigen specific cytotoxic T lymphocytes (CTL), first, we have optimized a method for reprogramming-resistant CD8 T cell clones into T-iPS cells by using sendaiviral vectors. Second, we have optimized stepwise differentiation methods for inducing hematopoietic progenitor cells, T cell progenitors, and functionally matured CD8 single positive CTL. These protocols provide useful in vitro tools and models both for research of antigen-specific T cell immunotherapy and for research of normal and pathological thymopoiesis.

  19. Regulatory T Cells Are Dispensable for Tolerance to RBC Antigens.

    Science.gov (United States)

    Richards, Amanda L; Kapp, Linda M; Wang, Xiaohong; Howie, Heather L; Hudson, Krystalyn E

    2016-01-01

    Autoimmune hemolytic anemia (AIHA) occurs when pathogenic autoantibodies against red blood cell (RBC) antigens are generated. While the basic disease pathology of AIHA is well studied, the underlying mechanism(s) behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs) in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved.

  20. Regulatory T cells are Dispensable for Tolerance to RBC Antigens

    Directory of Open Access Journals (Sweden)

    Amanda L Richards

    2016-09-01

    Full Text Available Autoimmune hemolytic anemia (AIHA occurs when pathogenic autoantibodies against red blood cell (RBC antigens are generated. Whilst the basic disease pathology of AIHA is well studied, the underlying mechanism(s behind the failure in tolerance to RBC autoantigens are poorly understood. Thus, to investigate the tolerance mechanisms required for the establishment and maintenance of tolerance to RBC antigens, we developed a novel murine model. With this model, we evaluated the role of regulatory T cells (Tregs in tolerance to RBC-specific antigens. Herein, we show that neither sustained depletion of Tregs nor immunization with RBC-specific proteins in conjunction with Treg depletion led to RBC-specific autoantibody generation. Thus, these studies demonstrate that Tregs are not required to prevent autoantibodies to RBCs and suggest that other tolerance mechanisms are likely involved.

  1. Stem cell antigen 2 expression in adult and developing mice.

    Science.gov (United States)

    Antica, M; Wu, L; Scollay, R

    1997-01-01

    Stem cell antigen 2 (Sca-2) expression can distinguish the most immature T-lymphocyte precursors in the thymus from the hemopoietic stem cells. Sequence analysis of the Sca-2 protein showed that Sca-2 is a glycosylphosphatidylinositol (GPI) anchored molecule that shares some characteristics with the members of the Ly-6 multigene family, and that it is the same as the thymic shared antigen-1 (TSA-1). Here we extend these studies and critically reassess the expression of the Sca-2/TSA-1 antigen in hematopoietic tissues of adult and developing mice. With more sensitive methods we show that the distribution of Sca-2/TSA-1 differs from existing reports. We find especially high expression of Sca-2/TSA1 at day 14 of fetal development.

  2. Dissection of T-cell antigen specificity in human melanoma

    DEFF Research Database (Denmark)

    Andersen, Rikke Sick; Albæk Thrue, Charlotte; Junker, Niels

    2012-01-01

    Tumor-infiltrating lymphocytes (TIL) isolated from melanoma patients and expanded in vitro by interleukin (IL)-2 treatment can elicit therapeutic response after adoptive transfer, but the antigen specificities of the T cells transferred have not been determined. By compiling all known melanoma......-associated antigens and applying a novel technology for high-throughput analysis of T-cell responses, we dissected the composition of melanoma-restricted T-cell responses in 63 TIL cultures. T-cell reactivity screens against 175 melanoma-associated epitopes detected 90 responses against 18 different epitopes...... from different fragments of resected melanoma lesions. In summary, our findings provide an initial definition of T-cell populations contributing to tumor recognition in TILs although the specificity of many tumor-reactive TILs remains undefined....

  3. Targeting LSCs through membrane antigens selectively or preferentially expressed on these cells.

    Science.gov (United States)

    Pelosi, Elvira; Castelli, Germana; Testa, Ugo

    2015-12-01

    Studies of xenotransplantation of bone marrow and blood cells of AML patients have supported the existence of rare leukemic stem cells, able to initiate and maintain the leukemic process and bearing the typical leukemic abnormalities. LSCs possess self-renewal capacity and are responsible for the growth of the more differentiated leukemic progeny in the bone marrow and in the blood. These cells are more resistant than bulk leukemic cells to anti-leukemic drugs, thus survive to treatment and are, at a large extent, responsible for leukemia relapse. During the last two decades, considerable progresses have been made in the understanding of the peculiar cellular and molecular properties of LSCs. In this context, particularly relevant was the discovery of several membrane markers, selectively or preferentially expressed on LSCs. These membrane markers offer now unique opportunities to identify LSCs and to distinguish them from normal HSCs, to monitor the response of the various anti-leukemic treatments at the level of the LSC compartment, to identify relevant therapeutic targets. Concerning this last point, the most promising therapeutic targets are CD33 and CD123.

  4. Molecular structure and biological function of proliferating cell nuclear antigen

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Proliferating cell nuclear antigen (PCNA) is the core component of replication complex in eukaryote.As a processive factor of DNA polymerase delta, PCNA coordinates the replication process by interacting with various replication proteins. PCNA appears to play an essential role in many cell events, such as DNA damage repair, cell cycle regulation, and apoptosis, through the coordination or organization of different partners. PCNA is an essential factor in cell proliferation, and has clinical significance in tumor research. In this article we review the functional structure of PCNA, which acts as a function switch in different cell events.

  5. Uptake of antigen-antibody complexes by human dendritic cells.

    Science.gov (United States)

    Fanger, N A; Guyre, P M; Graziano, R F

    2001-01-01

    Fc receptors specific for IgG (FcγR) potentiate the immune response by facilitating the interaction between myeloid cells and antibody-coated targets (1-3). Monocyte and neutrophil FcyR engagement can lead to the induction of lytic-type mechanisms associated with innate responses. FcyR triggering can also play a key role in adaptive immune responses. For example, FcyR-directed capture and uptake of antigens (Ag) by dendritic cells (DC) results in processing and presentation to naive Ag-specific T cells, leading to their expansion and maturation into effector T-cell populations. This chapter describes methodology currently in use to explore and manipulate antigen-antibody (Ag-Ab) uptake by FcyR expressed on DC.

  6. MHC class II antigen presentation by B cells in health and disease

    NARCIS (Netherlands)

    Souwer, Yuri

    2009-01-01

    MHC class II antigen presentation by B cells is important to activate CD4+ T cells that stimulate the B cell to produce antibodies. Besides this, disruption of MHC class II antigen presentation could play a role in immune escape by tumor cells. This thesis describes MHC class II antigen presentation

  7. Trafficking of B cell antigen in lymph nodes

    DEFF Research Database (Denmark)

    Gonzalez, Santiago F.; Degn, Søren Egedal; Pitcher, Lisa A.

    2011-01-01

    The clonal selection theory first proposed by Macfarlane Burnet is a cornerstone of immunology ( 1 ). At the time, it revolutionized the thinking of immunologists because it provided a simple explanation for lymphocyte specificity, immunological memory, and elimination of self-reactive clones ( 2......, 5 ) have provided new insights into the trafficking of B cells and their antigen. In this review, we summarize these advances in the context of our current view of B cell circulation and activation....

  8. Adsorption of multimeric T cell antigens on carbon nanotubes

    DEFF Research Database (Denmark)

    Fadel, Tarek R; Li, Nan; Shah, Smith;

    2013-01-01

    Antigen-specific activation of cytotoxic T cells can be enhanced up to three-fold more than soluble controls when using functionalized bundled carbon nanotube substrates ((b) CNTs). To overcome the denaturing effects of direct adsorption on (b) CNTs, a simple but robust method is demonstrated...... to stabilize the T cell stimulus on carbon nanotube substrates through non-covalent attachment of the linker neutravidin....

  9. Existence of a squamous cell carcinoma antigen-immunoglobulin complex causes a deviation between squamous cell carcinoma antigen concentrations determined using two different immunoassays: first report of squamous cell carcinoma antigen coupling with immunoglobulin A.

    Science.gov (United States)

    Mori, Eriko; Kurano, Makoto; Tobita, Akiko; Shimosaka, Hironori; Yatomi, Yutaka

    2017-01-01

    Background Squamous cell carcinoma antigen is used as a tumour marker and is routinely measured in clinical laboratories. We validated two different immunoassays and found three cases in which the squamous cell carcinoma antigen concentrations deviated greatly between the two immunoassays. Here, we aimed to elucidate the mechanisms responsible for these deviations. Methods The squamous cell carcinoma antigen concentrations were determined using the ARCHITECT SCC (CLIA method) and the ST AIA-PACK SCC (FEIA method). We performed polyethylene glycol precipitation and size exclusion chromatography to assess the molecular weight and spike recovery and absorption tests to examine the presence of an autoantibody. Results Both methods exhibited good performances for the measurement of squamous cell carcinoma antigen, although a correlation test showed large differences in the squamous cell carcinoma antigen concentrations measured using the two methods in three cases. The results of polyethylene glycol treatment and size exclusion chromatography indicated the existence of a large molecular weight squamous cell carcinoma antigen in these three cases. The spike recovery tests suggested the possible presence of an autoantibody against squamous cell carcinoma antigen. Moreover, the absorption test revealed that large squamous cell carcinoma antigen complexes were formed by the association of squamous cell carcinoma antigen with IgG in two cases and with both IgG and IgA in one case. Conclusions This study describes the existence of large molecular weight squamous cell carcinoma antigen that has complexed with immunoglobulin in the serum samples. The reason for the deviations between the two immunoassays might be due to differences of their reactivities against the squamous cell carcinoma antigen immune complexes with their autoantibody. To our knowledge, this is the first report to describe the coupling of squamous cell carcinoma antigen with IgA.

  10. Toxicities of chimeric antigen receptor T cells: recognition and management.

    Science.gov (United States)

    Brudno, Jennifer N; Kochenderfer, James N

    2016-06-30

    Chimeric antigen receptor (CAR) T cells can produce durable remissions in hematologic malignancies that are not responsive to standard therapies. Yet the use of CAR T cells is limited by potentially severe toxicities. Early case reports of unexpected organ damage and deaths following CAR T-cell therapy first highlighted the possible dangers of this new treatment. CAR T cells can potentially damage normal tissues by specifically targeting a tumor-associated antigen that is also expressed on those tissues. Cytokine release syndrome (CRS), a systemic inflammatory response caused by cytokines released by infused CAR T cells can lead to widespread reversible organ dysfunction. CRS is the most common type of toxicity caused by CAR T cells. Neurologic toxicity due to CAR T cells might in some cases have a different pathophysiology than CRS and requires different management. Aggressive supportive care is necessary for all patients experiencing CAR T-cell toxicities, with early intervention for hypotension and treatment of concurrent infections being essential. Interleukin-6 receptor blockade with tocilizumab remains the mainstay pharmacologic therapy for CRS, though indications for administration vary among centers. Corticosteroids should be reserved for neurologic toxicities and CRS not responsive to tocilizumab. Pharmacologic management is complicated by the risk of immunosuppressive therapy abrogating the antimalignancy activity of the CAR T cells. This review describes the toxicities caused by CAR T cells and reviews the published approaches used to manage toxicities. We present guidelines for treating patients experiencing CRS and other adverse events following CAR T-cell therapy.

  11. Genomic Typing of Red Cell Antigens

    Science.gov (United States)

    2011-09-01

    Antigen‐Matched  Red  Cells  for  Sickle  Cell  Anemia   Patients  Using  Molecular Typing to Augment Testing: Meghan Delaney, Prashant Gaur, Askale...Storry JR &  Delaney, M. CASE  REPORT OF TESTING AND MANAGEMENT OF BOMBAY  (OH)  PREGNANCY . XXXIst  International  Congress of the ISBT, Berlin, Germany...JK null Phenotype (Manuscript in preparation).  5. Delaney M et al: A Genetic Impossibility? Case report of Bombay (Oh)  pregnancy  with Group AB

  12. Bystander T cells in human immune responses to dengue antigens

    Directory of Open Access Journals (Sweden)

    Suwannasaen Duangchan

    2010-09-01

    Full Text Available Abstract Background Previous studies of T cell activation in dengue infection have focused on restriction of specific T cell receptors (TCRs and classical MHC molecules. However, bystander T cell activation, which is TCR independent, occurs via cytokines in other viral infections, both in vitro and in vivo, and enables T cells to bypass certain control checkpoints. Moreover, clinical and pathological evidence has pointed to cytokines as the mediators of dengue disease severity. Therefore, we investigated bystander T cell induction by dengue viral antigen. Results Whole blood samples from 55 Thai schoolchildren aged 13-14 years were assayed for in vitro interferon-gamma (IFN-γ induction in response to inactivated dengue serotype 2 antigen (Den2. The contribution of TCR-dependent and independent pathways was tested by treatment with cyclosporin A (CsA, which inhibits TCR-dependent activation of T cells. ELISA results revealed that approximately 72% of IFN-γ production occurred via the TCR-dependent pathway. The major IFN-γ sources were natural killer (NK (mean ± SE = 55.2 ± 3.3, CD4+T (24.5 ± 3.3 and CD8+T cells (17.9 ± 1.5, respectively, as demonstrated by four-color flow cytometry. Interestingly, in addition to these cells, we found CsA-resistant IFN-γ producing T cells (CD4+T = 26.9 ± 3.6% and CD8+T = 20.3 ± 2.1% implying the existence of activated bystander T cells in response to dengue antigen in vitro. These bystander CD4+ and CD8+T cells had similar kinetics to NK cells, appeared after 12 h and were inhibited by anti-IL-12 neutralization indicating cytokine involvement. Conclusions This study described immune cell profiles and highlighted bystander T cell activation in response to dengue viral antigens of healthy people in an endemic area. Further studies on bystander T cell activation in dengue viral infection may reveal the immune mechanisms that protect or enhance pathogenesis of secondary dengue infection.

  13. Chimeric Antigen Receptor T Cell Therapy in Hematology.

    Science.gov (United States)

    Ataca, Pınar; Arslan, Önder

    2015-12-01

    It is well demonstrated that the immune system can control and eliminate cancer cells. Immune-mediated elimination of tumor cells has been discovered and is the basis of both cancer vaccines and cellular therapies including hematopoietic stem cell transplantation. Adoptive T cell transfer has been improved to be more specific and potent and to cause less off-target toxicity. Currently, there are two forms of engineered T cells being tested in clinical trials: T cell receptor (TCR) and chimeric antigen receptor (CAR) modified T cells. On 1 July 2014, the United States Food and Drug Administration granted 'breakthrough therapy' designation to anti-CD19 CAR T cell therapy. Many studies were conducted to evaluate the benefits of this exciting and potent new treatment modality. This review summarizes the history of adoptive immunotherapy, adoptive immunotherapy using CARs, the CAR manufacturing process, preclinical and clinical studies, and the effectiveness and drawbacks of this strategy.

  14. Red-blood-cell alloimmunisation in relation to antigens' exposure and their immunogenicity: a cohort study.

    NARCIS (Netherlands)

    Evers, D.; Middelburg, R.A.; Haas, M. de; Zalpuri, S.; Vooght, K.M. De; Kerkhof, D. van de; Visser, O; Pequeriaux, N.C.V.; Hudig, F.; Schonewille, H.; Zwaginga, J.J.; Bom, J.G. Van Der

    2016-01-01

    BACKGROUND: Matching donor red blood cells based on recipient antigens prevents alloimmunisation. Knowledge about the immunogenicity of red-blood-cell antigens can help optimise risk-adapted matching strategies. We set out to assess the immunogenicity of red-blood-cell antigens. METHODS: In an incid

  15. Microfluidic squeezing for intracellular antigen loading in polyclonal B-cells as cellular vaccines

    Science.gov (United States)

    Lee Szeto, Gregory; van Egeren, Debra; Worku, Hermoon; Sharei, Armon; Alejandro, Brian; Park, Clara; Frew, Kirubel; Brefo, Mavis; Mao, Shirley; Heimann, Megan; Langer, Robert; Jensen, Klavs; Irvine, Darrell J.

    2015-05-01

    B-cells are promising candidate autologous antigen-presenting cells (APCs) to prime antigen-specific T-cells both in vitro and in vivo. However to date, a significant barrier to utilizing B-cells as APCs is their low capacity for non-specific antigen uptake compared to “professional” APCs such as dendritic cells. Here we utilize a microfluidic device that employs many parallel channels to pass single cells through narrow constrictions in high throughput. This microscale “cell squeezing” process creates transient pores in the plasma membrane, enabling intracellular delivery of whole proteins from the surrounding medium into B-cells via mechano-poration. We demonstrate that both resting and activated B-cells process and present antigens delivered via mechano-poration exclusively to antigen-specific CD8+T-cells, and not CD4+T-cells. Squeezed B-cells primed and expanded large numbers of effector CD8+T-cells in vitro that produced effector cytokines critical to cytolytic function, including granzyme B and interferon-γ. Finally, antigen-loaded B-cells were also able to prime antigen-specific CD8+T-cells in vivo when adoptively transferred into mice. Altogether, these data demonstrate crucial proof-of-concept for mechano-poration as an enabling technology for B-cell antigen loading, priming of antigen-specific CD8+T-cells, and decoupling of antigen uptake from B-cell activation.

  16. Correlation of urine cytology with ABO(H) antigenicity in transitional cell carcinoma of the bladder.

    OpenAIRE

    1988-01-01

    Cell surface ABO(H) antigenicity of superficial bladder tumours was assessed by the indirect immunoperoxidase test in 49 patients. Good correlation was obtained between surface antigenicity of tumours and the results of urine cytology. Malignant cells were detected cytologically in 22(56%) of cases with ABO(H) antigen negative tumours which are known to behave more aggressively than ABO(H) antigen positive ones. In contrast, malignant cells were found in the urine cytology of only one (10%) o...

  17. Cell wall anchoring of the Campylobacter antigens to Lactococcus lactis

    Directory of Open Access Journals (Sweden)

    Patrycja Anna Kobierecka

    2016-02-01

    Full Text Available Campylobacter jejuni is the most frequent cause of human food-borne gastroenteritis and chicken meat is the main source of infection. Recent studies showed that broiler chicken immunization against Campylobacter should be the most efficient way to lower the number of human infections by this pathogen. Induction of the mucosal immune system after oral antigen administration should provide protective immunity to chickens. In this work we tested the usefulness of Lactococcus lactis, the most extensively studied lactic acid bacterium, as a delivery vector for Campylobacter antigens. First we constructed hybrid protein – CjaA antigen presenting CjaD peptide epitopes on its surface. We showed that specific rabbit anti-rCjaAD serum reacted strongly with both CjaA and CjaD produced by a wild type Campylobacter jejuni strain. Next, rCjaAD and CjaA were fused to the C-terminus of the L. lactis YndF containing the LPTXG motif. The genes expressing these proteins were transcribed under control of the L. lactis Usp45 promoter and their products contain the Usp45 signal sequences. This strategy ensures a cell surface location of both analysed proteins, which was confirmed by immunofluorescence assay. In order to evaluate the impact of antigen location on vaccine prototype efficacy, a L. lactis strain producing cytoplasm-located rCjaAD was also generated. Animal experiments showed a decrease of Campylobacter cecal load in vaccinated birds as compared with the control group and showed that the L. lactis harboring the surface-exposed rCjaAD antigen afforded greater protection than the L. lactis producing cytoplasm-located rCjaAD. To the best of our knowledge, this is the first attempt to employ LAB (Lactic Acid Bacteria strains as a mucosal delivery vehicle for chicken immunization. Although the observed reduction of chicken colonization by Campylobacter resulting from vaccination was rather moderate, the experiments showed that LAB strains can be considered

  18. Comparison of antigen-specific T-cell responses of tuberculosis patients using complex or single antigens of Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Mustafa, A S; Amoudy, H A; Wiker, H G;

    1998-01-01

    GroES, rPstS, rGroEL and rDnaK) antigens of Mycobacterium tuberculosis. The responses of PBMC to these defined antigens were compared with the corresponding results obtained with complex antigens, such as whole-cell M. tuberculosis, M. tuberculosis culture filtrate (MT-CF) and cell wall antigens, as well...... as the vaccine strain, Mycobacterium bovis bacillus Calmette-Guerin (BCG). In addition, M. tuberculosis and MT-CF-induced T-cell lines were tested in the same assays against the panel of purified and complex antigens. The compiled data from PBMC and T-cell lines tested for antigen-induced proliferation and IFN......We have screened peripheral blood mononuclear cells (PBMC) from tuberculosis (TB) patients for proliferative reactivity and interferon-gamma (IFN-gamma) secretion against a panel of purified recombinant (r) and natural (n) culture filtrate (rESAT-6, nMPT59, nMPT64 and nMPB70) and somatic-derived (r...

  19. Original encounter with antigen determines antigen-presenting cell imprinting of the quality of the immune response in mice.

    Directory of Open Access Journals (Sweden)

    Valérie Abadie

    Full Text Available BACKGROUND: Obtaining a certain multi-functionality of cellular immunity for the control of infectious diseases is a burning question in immunology and in vaccine design. Early events, including antigen shuttling to secondary lymphoid organs and recruitment of innate immune cells for adaptive immune response, determine host responsiveness to antigens. However, the sequence of these events and their impact on the quality of the immune response remain to be elucidated. Here, we chose to study Modified Vaccinia virus Ankara (MVA which is now replacing live Smallpox vaccines and is proposed as an attenuated vector for vaccination strategies against infectious diseases. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed in vivo mechanisms triggered following intradermal (i.d. and intramuscular (i.m. Modified Vaccinia virus Ankara (MVA administration. We demonstrated significant differences in the antigen shuttling to lymphoid organs by macrophages (MPhis, myeloid dendritic cells (DCs, and neutrophils (PMNs. MVA i.d. administration resulted in better antigen distribution and more sustained antigen-presenting cells (APCs recruitment into draining lymph nodes than with i.m. administration. These APCs, which comprise both DCs and MPhis, were differentially involved in T cell priming and shaped remarkably the quality of cytokine-producing virus-specific T cells according to the entry route of MVA. CONCLUSIONS/SIGNIFICANCE: This study improves our understanding of the mechanisms of antigen delivery and their consequences on the quality of immune responses and provides new insights for vaccine development.

  20. Comparison of antigen-specific T-cell responses of tuberculosis patients using complex or single antigens of Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Mustafa, A S; Amoudy, H A; Wiker, H G

    1998-01-01

    We have screened peripheral blood mononuclear cells (PBMC) from tuberculosis (TB) patients for proliferative reactivity and interferon-gamma (IFN-gamma) secretion against a panel of purified recombinant (r) and natural (n) culture filtrate (rESAT-6, nMPT59, nMPT64 and nMPB70) and somatic-derived (r......GroES, rPstS, rGroEL and rDnaK) antigens of Mycobacterium tuberculosis. The responses of PBMC to these defined antigens were compared with the corresponding results obtained with complex antigens, such as whole-cell M. tuberculosis, M. tuberculosis culture filtrate (MT-CF) and cell wall antigens, as well...... as the vaccine strain, Mycobacterium bovis bacillus Calmette-Guerin (BCG). In addition, M. tuberculosis and MT-CF-induced T-cell lines were tested in the same assays against the panel of purified and complex antigens. The compiled data from PBMC and T-cell lines tested for antigen-induced proliferation and IFN...

  1. Circadian control of antigen-specific T cell responses

    Directory of Open Access Journals (Sweden)

    Nobis CC

    2016-09-01

    Full Text Available Chloé C Nobis,1–3 Nathalie Labrecque,2–4 Nicolas Cermakian1,5–8 1Douglas Mental Health University Institute, 2Maisonneuve-Rosemont Hospital Research Centre, 3Department of Microbiology, Infectious Diseases and Immunology, 4Department of Medicine, University of Montreal, 5Department of Psychiatry, 6Department of Microbiology and Immunology, 7Department of Neurology and Neurosurgery, 8Department of Physiology, McGill University, Montreal, QC, Canada Abstract: The immune system is composed of two arms, the innate and the adaptive immunity. While the innate response constitutes the first line of defense and is not specific for a particular pathogen, the adaptive response is highly specific and allows for long-term memory of the pathogen encounter. T lymphocytes (or T cells are central players in the adaptive immune response. Various aspects of T cell functions vary according to the time of day. Circadian clocks located in most tissues and cell types generate 24-hour rhythms of various physiological processes. These clocks are based on a set of clock genes, and this timing mechanism controls rhythmically the expression of numerous other genes. Clock genes are expressed in cells of the immune system, including T cells. In this review, we provide an overview of the circadian control of the adaptive immune response, with emphasis on T cells, including their development, trafficking, response to antigen, and effector functions. Keywords: circadian clock, adaptive immune response, T lymphocyte, antigen, cytokine, proliferation

  2. Physical and functional association between thymic shared antigen-1/stem cell antigen-2 and the T cell receptor complex.

    Science.gov (United States)

    Kosugi, A; Saitoh, S; Noda, S; Miyake, K; Yamashita, Y; Kimoto, M; Ogata, M; Hamaoka, T

    1998-05-15

    Thymic shared antigen-1 (TSA-1)/stem cell Ag-2 (Sca-2) is a glycosylphosphatidylinositol (GPI)-anchored antigen expressed on lymphocytes. We have previously demonstrated that a signal via TSA-1/Sca-2 inhibits T cell receptor (TCR)-mediated T cell activation and apoptosis. To elucidate a molecular mechanism for TSA-1-mediated modulation of the TCR-signaling pathway, we examined whether TSA-1 is physically coupled to the TCR in the present study. TSA-1 was clearly associated with CD3zeta chains in T cell hybridomas, activated T cells, and COS-7 cells transfected with TSA-1 and CD3zeta cDNA. The physical association was confirmed on the surface of T cells in immunoprecipitation and confocal microscopy. The analysis using stable and transient transfectants expressing a transmembrane form of TSA-1 revealed that the association of CD3zeta did not require the GPI anchor of TSA-1. Finally, tyrosine phosphorylation of CD3zeta chains was induced after stimulation with anti-TSA-1, suggesting that a functional association between these two molecules also exists. These results imply that the physical association to CD3zeta underlies a regulatory role of TSA-1/Sca-2 in the TCR-signaling pathway.

  3. Autoantibodies in autoimmune thyroid disease promote immune complex formation with self antigens and increase B cell and CD4+ T cell proliferation in response to self antigens

    DEFF Research Database (Denmark)

    Nielsen, Claus Henrik; Hegedüs, Laszlo; Leslie, Robert Graham Quinton

    2004-01-01

    B cells are centrally involved as antigen-presenting cells in certain autoimmune diseases. To establish whether autoantibodies form immune complexes (IC) with self-antigens in autoimmune thyroid disease (AITD) and promote B cell uptake of self-antigen, sera from patients with Hashimoto......'s thyroiditis (HT), Graves' disease (GD) and healthy controls were incubated with human thyroglobulin (Tg) before adding normal peripheral blood mononuclear cells. The deposition of immunoglobulins and C3 fragments on B cells was then assessed. Inclusion of Tg in serum from HT patients promoted B cell capture...

  4. Do FY antigens act as minor histocompatibility antigens in the graft-versus-host disease paradigm after human leukocyte antigen-identical sibling hematopoietic stem cell transplantation?

    Science.gov (United States)

    Sellami, Mohamed Hichem; Chaabane, Manel; Kaabi, Houda; Torjemane, Lamia; Ladeb, Saloua; Ben Othmane, Tarek; Hmida, Slama

    2012-03-01

    FY antigens are candidate minor histocompatibility antigens relevant to renal allograft rejection, but no data have been reported about their role in graft-versus-host disease (GVHD) incidence after human leukocyte antigen (HLA)-identical siblings hematopoietic stem cell transplantation (HSCT). The aim of this study was to examine the effect of donor/recipient disparity at FY antigens on the incidence of GVHD in Tunisian patients receiving an HLA-identical HSCT. This work enrolled 105 Tunisian pairs of recipients and their HLA-identical sibling donors of HSCs. FY genotyping was performed with the polymerase chain reaction-sequence-specific primer method and donor/recipient disparity for these antigens was analyzed at two levels: incompatibility and nonidentity. The case-control analyses showed no significant correlation between FY disparity and the incidence of either acute or chronic GVHD. Sample size calculation showed that 572 cases and 1716 controls would be necessary to be able to detect a significant association with 80% power and two-sided type I error level of 5% (α=0.05). The lack of association in the studied cohort may be explained by the low immunogenicity of FY antigens in HSCT context, compared with other antigens such as HA-1 and CD31.

  5. T cells expressing an anti-B-cell maturation antigen chimeric antigen receptor cause remissions of multiple myeloma.

    Science.gov (United States)

    Ali, Syed Abbas; Shi, Victoria; Maric, Irina; Wang, Michael; Stroncek, David F; Rose, Jeremy J; Brudno, Jennifer N; Stetler-Stevenson, Maryalice; Feldman, Steven A; Hansen, Brenna G; Fellowes, Vicki S; Hakim, Frances T; Gress, Ronald E; Kochenderfer, James N

    2016-09-29

    Therapies with novel mechanisms of action are needed for multiple myeloma (MM). B-cell maturation antigen (BCMA) is expressed in most cases of MM. We conducted the first-in-humans clinical trial of chimeric antigen receptor (CAR) T cells targeting BCMA. T cells expressing the CAR used in this work (CAR-BCMA) specifically recognized BCMA-expressing cells. Twelve patients received CAR-BCMA T cells in this dose-escalation trial. Among the 6 patients treated on the lowest 2 dose levels, limited antimyeloma activity and mild toxicity occurred. On the third dose level, 1 patient obtained a very good partial remission. Two patients were treated on the fourth dose level of 9 × 10(6) CAR(+) T cells/kg body weight. Before treatment, the first patient on the fourth dose level had chemotherapy-resistant MM, making up 90% of bone marrow cells. After treatment, bone marrow plasma cells became undetectable by flow cytometry, and the patient's MM entered a stringent complete remission that lasted for 17 weeks before relapse. The second patient on the fourth dose level had chemotherapy-resistant MM making up 80% of bone marrow cells before treatment. Twenty-eight weeks after this patient received CAR-BCMA T cells, bone marrow plasma cells were undetectable by flow cytometry, and the serum monoclonal protein had decreased by >95%. This patient is in an ongoing very good partial remission. Both patients treated on the fourth dose level had toxicity consistent with cytokine-release syndrome including fever, hypotension, and dyspnea. Both patients had prolonged cytopenias. Our findings demonstrate antimyeloma activity of CAR-BCMA T cells. This trial was registered to www.clinicaltrials.gov as #NCT02215967.

  6. Stable isotope labeling of oligosaccharide cell surface antigens

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Silks, L.A. III; Martinez, R.A. [and others

    1998-12-31

    The overall goal of this Laboratory Directed Research and Development (LDRD) project was to develop new methods for synthesis of {sup 13}C-labeled oligosaccharides that are required for nuclear magnetic resonance (NMR) studies of their solution conformation. Oligosaccharides are components of the cell`s outer surface and are involved in important processes such as cell-cell recognition and adhesion. Recently, Danishefsky and coworkers at Slone-Kettering Cancer Center developed a method for the solid-phase chemical synthesis of oligosaccharides. The specific goal of this LDRD project was to prepare uniform {sup 13}C-labeled aldohexose precursors required for the solid-phase synthesis of the Lewis blood-group antigenic determinants. We report the synthesis of {sup 13}C-labeled D-glucal, D-galactal and Fucosyl precursors. We have been collaborating with the Danishefsky group on the synthesis of the Lewis oligosaccharides and the NMR analysis of their solution conformation.

  7. Pattern of distribution of blood group antigens on human epidermal cells during maturation

    DEFF Research Database (Denmark)

    Dabelsteen, Erik; Buschard, Karsten; Hakomori, Sen-Itiroh

    1984-01-01

    The distribution in human epidermis of A, B, and H blood group antigens and of a precursor carbohydrate chain, N-acetyl-lactosamine, was examined using immunofluorescence staining techniques. The material included tissue from 10 blood group A, 4 blood group B, and 9 blood group O persons. Murine...... on the lower spinous cells whereas H antigen was seen predominantly on upper spinous cells or on the granular cells. Epithelia from blood group A or B persons demonstrated A or B antigens, respectively, but only if the tissue sections were trypsinized before staining. In such cases A or B antigens were found...... monoclonal antibodies were used to identify H antigen (type 2 chain) and N-acetyl-lactosamine. Human antisera were used to identify A and B antigens. In all groups N-acetyl-lactosamine and H antigen were found on the cell membranes of the spinous cell layer. N-acetyl-lactosamine was present mainly...

  8. Antigen Processing by Autoreactive B Cells Promotes Determinant Spreading

    Institute of Scientific and Technical Information of China (English)

    Yang D.Dai; George Carayanniotis; Eli Sercarz

    2005-01-01

    Acute primary immune responses tend to focus on few immunodominant determinants using a very limited number of T cell clones for expansion, whereas chronic inflammatory responses generally recruit a large number of different T cell clones to attack a broader range of determinants of the invading pathogens or the inflamed tissues.In T cell-mediated organ-specific autoimmune disease, a transition from the acute to the chronic phase contributes to pathogenesis, and the broadening process is called determinant spreading. The cellular components catalyzing the spreading reaction are not identified. It has been suggested that autoreactive B cells may play a central role in diversifying autoreactive T cell responses, possibly through affecting antigen processing and presentation. The clonal identity and diversity of the B cells and antibodies seem critical in regulating T cell activity and subsequent tissue damage or repair. Here, we use two autoimmune animal models, experimental autoimmune thyroiditis (EAT)and type 1 diabetes (T1D), to discuss how autoreactive B cells or antibodies alter the processing and presentation of autoantigens to regulate specific T cell response.

  9. Chemokine programming dendritic cell antigen response: part I - select chemokine programming of antigen uptake even after maturation.

    Science.gov (United States)

    Park, Jaehyung; Wu, Cindy T; Bryers, James D

    2013-05-01

    Here, we report on the successful programming of dendritic cells (DCs) using selectively applied mixtures of chemokines as a novel protocol for engineering vaccine efficiency. Antigen internalization by DCs is a pivotal step in antigen uptake/presentation for bridging innate and adaptive immunity and in exogenous gene delivery used in vaccine strategies. Contrary to most approaches to improve vaccine efficiency, active enhancement of antigen internalization by DCs as a vaccine strategy has been less studied because DCs naturally down-regulate antigen internalization upon maturation. Whereas chemokines are mainly known as signal proteins that induce leucocyte chemotaxis, very little research has been carried out to identify any additional effects of chemokines on DCs following maturation. Here, immature DCs are pre-treated with select chemokines before intentional maturation using lipopolysaccharide (LPS). When pre-treated with a mixture of CCL3 and CCL19 in a 7 : 3 ratio, then matured with LPS, chemokine pre-treated DCs exhibited 36% higher antigen uptake capacity than immature DCs and 27% higher antigen-processing capacity than immature DCs treated only with LPS. Further, CCL3 : CCL19 (7 : 3) pre-treatment of DCs modulated MHC molecule expression and secretion of various cytokines of DCs. Collectively, DC programming was feasible using a specific chemokine combination and these results provide a novel strategy for enhancing DC-based vaccine efficiency. In Part II, we report on the phenotype changes and antigen presentation capacity of chemokine pre-treated murine bone marrow-derived DCs examined in long-term co-culture with antigen-specific CD4(+) T cells.

  10. Liposome-coupled antigens are internalized by antigen-presenting cells via pinocytosis and cross-presented to CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Yuriko Tanaka

    Full Text Available We have previously demonstrated that antigens chemically coupled to the surface of liposomes consisting of unsaturated fatty acids were cross-presented by antigen-presenting cells (APCs to CD8+ T cells, and that this process resulted in the induction of antigen-specific cytotoxic T lymphocytes. In the present study, the mechanism by which the liposome-coupled antigens were cross-presented to CD8+ T cells by APCs was investigated. Confocal laser scanning microscopic analysis demonstrated that antigens coupled to the surface of unsaturated-fatty-acid-based liposomes received processing at both MHC class I and class II compartments, while most of the antigens coupled to the surface of saturated-fatty-acid-based liposomes received processing at the class II compartment. In addition, flow cytometric analysis demonstrated that antigens coupled to the surface of unsaturated-fatty-acid-liposomes were taken up by APCs even in a 4°C environment; this was not true of saturated-fatty-acid-liposomes. When two kinds of inhibitors, dimethylamiloride (DMA and cytochalasin B, which inhibit pinocytosis and phagocytosis by APCs, respectively, were added to the culture of APCs prior to the antigen pulse, DMA but not cytochalasin B significantly reduced uptake of liposome-coupled antigens. Further analysis of intracellular trafficking of liposomal antigens using confocal laser scanning microscopy revealed that a portion of liposome-coupled antigens taken up by APCs were delivered to the lysosome compartment. In agreement with the reduction of antigen uptake by APCs, antigen presentation by APCs was significantly inhibited by DMA, and resulted in the reduction of IFN-γ production by antigen-specific CD8+ T cells. These results suggest that antigens coupled to the surface of liposomes consisting of unsaturated fatty acids might be pinocytosed by APCs, loaded onto the class I MHC processing pathway, and presented to CD8+ T cells. Thus, these liposome-coupled antigens

  11. An Immunohistochemical Study of Langerhans Cells,T-Cells and the HLA Antigen in Human Cornea

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    The distribution of Langerhans cells (LC),T-cell subsets andHLA antigen in 12 normal and 7 morbid corneas,including 4 of suppurativecorneal ulcer and 3 of uveogenic endophthalmitis,was investigated withmonoclonal antibodies.The results revealed that a small amount of LC andT-cell subsets were present in the limbal region of normal corneas,whilelarge numbers of LC and OKT_4~+ were observed in the corneas of suppurativeulcer.HLA-A,B,C antigens were expressed on the epithelial cells andkeratocytes of the n...

  12. An Overview of B-1 Cells as Antigen-Presenting Cells

    Science.gov (United States)

    Popi, Ana F.; Longo-Maugéri, Ieda M.; Mariano, Mario

    2016-01-01

    The role of B cells as antigen-presenting cells (APCs) has been extensively studied, mainly in relation to the activation of memory T cells. Considering the B cell subtypes, the role of B-1 cells as APCs is beginning to be explored. Initially, it was described that B-1 cells are activated preferentially by T-independent antigens. However, some reports demonstrated that these cells are also involved in a T-dependent response. The aim of this review is to summarize information about the ability of B-1 cells to play a role as APCs and to briefly discuss the role of the BCR and toll-like receptor signals in this process. Furthermore, some characteristics of B-1 cells, such as natural IgM production and phagocytic ability, could interfere in the participation of these cells in the onset of an adaptive response. PMID:27148259

  13. Dietary antigens limit mucosal immunity by inducing regulatory T cells in the small intestine.

    Science.gov (United States)

    Kim, Kwang Soon; Hong, Sung-Wook; Han, Daehee; Yi, Jaeu; Jung, Jisun; Yang, Bo-Gie; Lee, Jun Young; Lee, Minji; Surh, Charles D

    2016-02-19

    Dietary antigens are normally rendered nonimmunogenic through a poorly understood "oral tolerance" mechanism that involves immunosuppressive regulatory T (Treg) cells, especially Treg cells induced from conventional T cells in the periphery (pTreg cells). Although orally introducing nominal protein antigens is known to induce such pTreg cells, whether a typical diet induces a population of pTreg cells under normal conditions thus far has been unknown. By using germ-free mice raised and bred on an elemental diet devoid of dietary antigens, we demonstrated that under normal conditions, the vast majority of the small intestinal pTreg cells are induced by dietary antigens from solid foods. Moreover, these pTreg cells have a limited life span, are distinguishable from microbiota-induced pTreg cells, and repress underlying strong immunity to ingested protein antigens.

  14. Modes of Antigen Presentation by Lymph Node Stromal Cells and Their Immunological Implications.

    Science.gov (United States)

    Hirosue, Sachiko; Dubrot, Juan

    2015-01-01

    Antigen presentation is no longer the exclusive domain of cells of hematopoietic origin. Recent works have demonstrated that lymph node stromal cell (LNSC) populations, such as fibroblastic reticular cells, lymphatic and blood endothelial cells, not only provide a scaffold for lymphocyte interactions but also exhibit active immunomodulatory roles that are critical to mounting and resolving effective immune responses. Importantly, LNSCs possess the ability to present antigens and establish antigen-specific interactions with T cells. One example is the expression of peripheral tissue antigens, which are presented on major histocompatibility complex (MHC)-I molecules with tolerogenic consequences on T cells. Additionally, exogenous antigens, including self and tumor antigens, can be processed and presented on MHC-I complexes, which result in dysfunctional activation of antigen-specific CD8(+) T cells. While MHC-I is widely expressed on cells of both hematopoietic and non-hematopoietic origins, antigen presentation via MHC-II is more precisely regulated. Nevertheless, LNSCs are capable of endogenously expressing, or alternatively, acquiring MHC-II molecules. Transfer of antigen between LNSC and dendritic cells in both directions has been recently suggested to promote tolerogenic roles of LNSCs on the CD4(+) T cell compartment. Thus, antigen presentation by LNSCs is thought to be a mechanism that promotes the maintenance of peripheral tolerance as well as generates a pool of diverse antigen-experienced T cells for protective immunity. This review aims to integrate the current and emerging literature to highlight the importance of LNSCs in immune responses, and emphasize their role in antigen trafficking, retention, and presentation.

  15. A Population of HLA-DR+ Immature Cells Accumulates in the Blood Dendritic Cell Compartment of Patients with Different Types of Cancer

    Directory of Open Access Journals (Sweden)

    Alberto Pinzon-Charry

    2005-12-01

    Full Text Available Dendritic cell (DC defects are an important component of immunosuppression in cancer. Here, we assessed whether cancer could affect circulating DC populations and its correlation with tumor progression. The blood DC compartment was evaluated in 136 patients with breast cancer, prostate cancer, and malignant glioma. Phenotypic, quantitative, and functional analyses were performed at various stages of disease. Patients had significantly fewer circulating myeloid (CD11c+ and plasmacytoid (CD123+ DC, and a concurrent accumulation of CD11c−CD123− immature cells that expressed high levels of HLA-DR+ immature cells (DR+IC. Although DR+IC exhibited a limited expression of markers ascribed to mature hematopoietic lineages, expression of HLA-DR, CD40, and CD86 suggested a role as antigenpresenting cells. Nevertheless, DR+IC had reduced capacity to capture antigens and elicited poor proliferation and interferon-γ secretion by T-lymphocytes. Importantly, increased numbers of DR+IC correlated with disease status. Patients with metastatic breast cancer showed a larger number of DR+IC in the circulation than patients with local/nodal disease. Similarly, in patients with fully resected glioma, the proportion of DR+IC in the blood increased when evaluation indicated tumor recurrence. Reduction of blood DC correlating with accumulation of a population of immature cells with poor immunologic function may be associated with increased immunodeficiency observed in cancer.

  16. Signal transduction by HLA class II antigens expressed on activated T cells

    DEFF Research Database (Denmark)

    Ødum, Niels; Martin, P J; Schieven, G L;

    1991-01-01

    Human T cells express HLA class II antigens upon activation. Although activated, class II+ T cells can present alloantigens under certain circumstances, the functional role of class II antigens on activated T cells remains largely unknown. Here, we report that cross-linking of HLA-DR molecules ex...

  17. Expression of maturation-specific nuclear antigens in differentiating human myeloid leukemia cells

    Energy Technology Data Exchange (ETDEWEB)

    Murao, S.; Epstein, A.L.; Clevenger, C.V.; Huberman, E.

    1985-02-01

    The expression of three myeloid-specific nuclear antigens was studied by indirect immunofluorescence with murine monoclonal antibodies in human myeloid (HL-60, ML-2, KG-1, and B-II) leukemia cells treated with chemical inducers of cell differentiation. Treatment of the promyelocytic HL-60 cells with dimethyl sulfoxide or 1,25-dihydroxyvitamin DT induced the cells to acquire a phenotype that resembled that of granulocytes and monocytesmacrophages, respectively. These phenotypes were characterized by changes in cell growth, cell morphology, expression of specific cell surface antigens, and activities of lysozyme and nonspecific esterase enzymes. Induction of these differentiation markers in the HL-60 cells was associated with induction of the myeloid-specific nuclear antigens. The ML-2 cells, which are arrested at the myeloblast-promyelocyte stage, were also susceptible to the induction of cell differentiation and to changes in the expression of the nuclear antigens, but the degree of susceptibility was less than in the HL-60 cells. The less-differentiated KG-1 and B-II myeloid cells were either not responsive or responded only in a limited degree to the induction of cell differentiation or to changes in the expression of the nuclear antigens. The authors suggest that the reactivity of cells with monoclonal antibodies to specific nuclear antigens can be used as a maturational marker in cell differentiation studies. Furthermore, nuclear antigens expressed early in cellular differentiation may provide information about changes in regulatory elements in normal and malignant cells. 40 references, 2 figures, 1 table.

  18. Chemotactic migration of T cells towards dendritic cells promotes the detection of rare antigens.

    Directory of Open Access Journals (Sweden)

    Renske M A Vroomans

    Full Text Available In many immunological processes chemoattraction is thought to play a role in guiding cells to their sites of action. However, based on in vivo two-photon microscopy experiments in the absence of cognate antigen, T cell migration in lymph nodes (LNs has been roughly described as a random walk. Although it has been shown that dendritic cells (DCs carrying cognate antigen in some circumstances attract T cells chemotactically, it is currently still unclear whether chemoattraction of T cells towards DCs helps or hampers scanning. Chemoattraction towards DCs could on the one hand help T cells to rapidly find DCs. On the other hand, it could be deleterious if DCs become shielded by a multitude of attracted yet non-specific T cells. Results from a recent simulation study suggested that the deleterious effect dominates. We re-addressed the question whether T cell chemoattraction towards DCs is expected to promote or hamper the detection of rare antigens using the Cellular Potts Model, a formalism that allows for dynamic, flexible cellular shapes and cell migration. Our simulations show that chemoattraction of T cells enhances the DC scanning efficiency, leading to an increased probability that rare antigen-specific T cells find DCs carrying cognate antigen. Desensitization of T cells after contact with a DC further improves the scanning efficiency, yielding an almost threefold enhancement compared to random migration. Moreover, the chemotaxis-driven migration still roughly appears as a random walk, hence fine-tuned analysis of cell tracks will be required to detect chemotaxis within microscopy data.

  19. Chemotactic migration of T cells towards dendritic cells promotes the detection of rare antigens.

    Science.gov (United States)

    Vroomans, Renske M A; Marée, Athanasius F M; de Boer, Rob J; Beltman, Joost B

    2012-01-01

    In many immunological processes chemoattraction is thought to play a role in guiding cells to their sites of action. However, based on in vivo two-photon microscopy experiments in the absence of cognate antigen, T cell migration in lymph nodes (LNs) has been roughly described as a random walk. Although it has been shown that dendritic cells (DCs) carrying cognate antigen in some circumstances attract T cells chemotactically, it is currently still unclear whether chemoattraction of T cells towards DCs helps or hampers scanning. Chemoattraction towards DCs could on the one hand help T cells to rapidly find DCs. On the other hand, it could be deleterious if DCs become shielded by a multitude of attracted yet non-specific T cells. Results from a recent simulation study suggested that the deleterious effect dominates. We re-addressed the question whether T cell chemoattraction towards DCs is expected to promote or hamper the detection of rare antigens using the Cellular Potts Model, a formalism that allows for dynamic, flexible cellular shapes and cell migration. Our simulations show that chemoattraction of T cells enhances the DC scanning efficiency, leading to an increased probability that rare antigen-specific T cells find DCs carrying cognate antigen. Desensitization of T cells after contact with a DC further improves the scanning efficiency, yielding an almost threefold enhancement compared to random migration. Moreover, the chemotaxis-driven migration still roughly appears as a random walk, hence fine-tuned analysis of cell tracks will be required to detect chemotaxis within microscopy data.

  20. Antigen-activated dendritic cells ameliorate influenza A infections

    Science.gov (United States)

    Boonnak, Kobporn; Vogel, Leatrice; Orandle, Marlene; Zimmerman, Daniel; Talor, Eyal; Subbarao, Kanta

    2013-01-01

    Influenza A viruses cause significant morbidity and mortality worldwide. There is a need for alternative or adjunct therapies, as resistance to currently used antiviral drugs is emerging rapidly. We tested ligand epitope antigen presentation system (LEAPS) technology as a new immune-based treatment for influenza virus infection in a mouse model. Influenza-J-LEAPS peptides were synthesized by conjugating the binding ligand derived from the β2-microglobulin chain of the human MHC class I molecule (J-LEAPS) with 15 to 30 amino acid–long peptides derived from influenza virus NP, M, or HA proteins. DCs were stimulated with influenza-J-LEAPS peptides (influenza-J-LEAPS) and injected intravenously into infected mice. Antigen-specific LEAPS-stimulated DCs were effective in reducing influenza virus replication in the lungs and enhancing survival of infected animals. Additionally, they augmented influenza-specific T cell responses in the lungs and reduced the severity of disease by limiting excessive cytokine responses, which are known to contribute to morbidity and mortality following influenza virus infection. Our data demonstrate that influenza-J-LEAPS–pulsed DCs reduce virus replication in the lungs, enhance survival, and modulate the protective immune responses that eliminate the virus while preventing excessive cytokines that could injure the host. This approach shows promise as an adjunct to antiviral treatment of influenza virus infections. PMID:23934125

  1. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity

    NARCIS (Netherlands)

    Kreutz, M.; Giquel, B.; Hu, Q.; Abuknesha, R.; Uematsu, S.; Akira, S.; Nestle, F.O.; Diebold, S.S.

    2012-01-01

    Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC) by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is par

  2. Regulation of NK-cell function by mucins via antigen-presenting cells.

    Science.gov (United States)

    Laskarin, G; Redzovic, A; Medancic, S Srsen; Rukavina, D

    2010-12-01

    Decidual antigen-presenting cells including dendritic cells (DCs) and CD14(+) macrophages, as mediators of the first encounter with fetal antigens, appear to be critically involved in the initiation of primary immune response by regulating innate- and adaptive immunity. Interleukin-15, produced by them, permits the proliferation and differentiation of CD3(-)CD16(-)CD94(+)NKG2A(+)CD56(+bright) decidual NK cells that identify trophoblast cells. These cells are able to kill them after Th1 cytokine overstimulation and by increasing the release of preformed cytotoxic mediators. Thus, the local microenvironment is a potent modulator of antigen-presenting cell functions. Tumor associated glycoprotein-72 (TAG-72) and mucine 1 (MUC-1) are glycoproteins secreted by uterine epithelial cells. Our hypothesis is that TAG-72 and MUC-1 are the natural ligands for carbohydrate recognition domains (CRDs) of endocytic mannose receptor (MR or CD206) and DC-specific ICAM non-integrin (DC-SIGN or CD209) expressed on decidual CD14(+) macrophages and CD1a(+) DCs. They might be able to condition antigen-presenting cells to produce distinct profiles of cyto/chemokines with consequential reduction in NK-cell numbers and cytotoxic potential leading to insufficient control over trophoblast growth. This hypothesis could explain the disappearance of MUC-1 beneath the attached embryo during the process of successful implantation when tight regulation of trophoblast invasion is needed. As IL-15 is the earliest and the most important factor in NK-cell proliferation, differentiation, and maturation, we expected primarily an increase of IL-15 expression in antigen-presenting cells concomitant with the disappearance of mucins and the enhancement in NK cells numbers and of cytotoxic potential after their close contact with early pregnancy decidual antigen-presenting cells. If our hypothesis is correct, it would contribute to the understanding of the role of mucins in the redirection of immune response

  3. Activation of Type II Cells into Regenerative Stem Cell Antigen-1+ Cells during Alveolar Repair

    Science.gov (United States)

    Kumar, Varsha Suresh; Zhang, Wei; Rehman, Jalees; Malik, Asrar B.

    2015-01-01

    The alveolar epithelium is composed of two cell types: type I cells comprise 95% of the gas exchange surface area, whereas type II cells secrete surfactant, while retaining the ability to convert into type I cells to induce alveolar repair. Using lineage-tracing analyses in the mouse model of Pseudomonas aeruginosa–induced lung injury, we identified a population of stem cell antigen (Sca)-1–expressing type II cells with progenitor cell properties that mediate alveolar repair. These cells were shown to be distinct from previously reported Sca-1–expressing bronchioalveolar stem cells. Microarray and Wnt reporter studies showed that surfactant protein (Sp)-C+Sca-1+ cells expressed Wnt signaling pathway genes, and inhibiting Wnt/β-catenin signaling prevented the regenerative function of Sp-C+Sca-1+ cells in vitro. Thus, P. aeruginosa–mediated lung injury induces the generation of a Sca-1+ subset of type II cells. The progenitor phenotype of the Sp-C+Sca-1+ cells that mediates alveolar epithelial repair might involve Wnt signaling. PMID:25474582

  4. Expression of basement membrane antigens in spindle cell melanoma.

    Science.gov (United States)

    Prieto, V G; Woodruff, J M

    1998-07-01

    Spindle cell melanoma (SCM) is an uncommon form of melanoma that may be confused histologically with other tumors, including malignant peripheral nerve sheath tumors (MPNST). Tumors with neural differentiation and melanocytic nevi may both show basement membrane immunohistochemically and at the ultrastructural level. However, most ultrastructural studies of melanoma have failed to demonstrate well formed basement membrane around tumor cells. The presence of basement membrane has been used by some authors as evidence favoring MPNST, as opposed to SCM. To evaluate this distinction immunohistochemically, 22 primary and metastatic cutaneous melanomas having a spindle cell component (SCM) were studied using monoclonal antibodies against laminin and Type IV collagen. S100 protein and HMB45 antigen expression were also studied. All but one of the SCM were reactive for S100 protein in at least 25% of the cells. Thirteen of 20 tumors (65%) were focally reactive with HMB45. Laminin was expressed in 42% of the tumors (only membranous pattern in 3; cytoplasmic and membranous in 5). Seventeen tumors (77%) expressed type IV collagen (only membranous pattern in 7; cytoplasmic and membranous pattern in 10). Laminin and type IV collagen, known components of basement membrane, are often found in SCM. Therefore, their detection cannot be used to distinguish SCM from MPNST.

  5. Antigenic modulation of metastatic breast and ovary carcinoma cells by intracavitary injection of IFN-alpha.

    Science.gov (United States)

    Giacomini, P.; Mottolese, M.; Fraioli, R.; Benevolo, M.; Venturo, I.; Natali, P. G.

    1992-01-01

    Antigenic modulation of major histocompatibility and tumour associated antigens was observed in neoplastic cells obtained from patients with pleural and abdominal effusions of breast and ovary carcinomas following a single intracavitary dose of 18 x 10(6) U recombinant IFN-alpha. This regimen resulted in antigenic modulation in seven out of 11 tested cases, suggesting a potential, although limited, responsiveness of at least a fraction of breast and ovary carcinoma cells to in situ biomodification with IFN-alpha. PMID:1503908

  6. The effects of Fasciola hepatica tegumental antigens on mast cell function.

    Science.gov (United States)

    Vukman, Krisztina V; Adams, Paul N; Dowling, David; Metz, Martin; Maurer, Marcus; O'Neill, Sandra M

    2013-06-01

    Fasciola hepatica infection is associated with T helper 2/T regulatory immune responses and increased mast cell numbers. The aim of this study was to examine the interaction between F. hepatica tegumental coat antigen and mast cells in vivo and in vitro. Firstly, BALB/C, C57BL/6 or STAT6(-/-) mice were infected with F. hepatica metacercarie or mice were treated with F. hepatica tegumental coat antigen and then mast cells numbers in the peritoneal cavity and/or the liver were quantified. Also, the proliferation, chemotaxis, degranulation and cytokine secretion of mast cells from bone marrow or from peritoneal exudate cells stimulated with F. hepatica tegumental coat antigen were measured. Finally, we tested whether F. hepatica tegumental coat antigen inhibits degranulation of mast cells in vivo in a passive cutaneous and systemic anaphylaxis mouse model. Mast cell numbers increased in the peritoneal cavity and liver of F. hepatica infected mice, and this was mimicked by injection of F. hepatica tegumental coat antigen in a STAT6(-/-) independent manner. The increase in mast cell number was not the result of F. hepatica tegumental coat antigen-induced proliferation; rather F. hepatica tegumental coat antigen indirectly induces mast cell migration by dendritic cell-derived chemokines. Fasciola hepatica tegumental coat antigen interactions with mast cells do not drive T helper 2 or T regulatory immune responses. These studies on mast cell and F. hepatica tegumental coat antigen interaction may help us to understand the function of mast cells in immunity against F. hepatica and the immunomodulatory effect of F. hepatica tegumental coat antigen on these cells.

  7. Analysis of the antibody repertoire of patients with mantle cell lymphoma directed against mantle cell lymphoma-associated antigens

    OpenAIRE

    Zwick, Carsten; Preuss, Klaus-Dieter; Kubuschok, Boris; Held, Gerhard; Ahlgrimm, Manfred; Bittenbring, Joerg; Schubert, Joerg; Neumann, Frank; Pfreundschuh, Michael

    2009-01-01

    Abstract Treatment results of mantle cell lymphomas (MCL) are not satisfactory and novel therapeutic approaches are warranted. Because ?shared? tumor antigens like the group of cancer testis antigens are only rarely expressed in MCL, we applied serological analysis of antigens using recombinant expression cloning (SEREX) to a complementary DNA library derived from five cases of MCL using the sera of eight patients with MCL in order to define MCL-associated antigens that are immunog...

  8. Red blood cells as innovative antigen carrier to induce specific immune tolerance.

    Science.gov (United States)

    Cremel, Magali; Guérin, Nathalie; Horand, Françoise; Banz, Alice; Godfrin, Yann

    2013-02-25

    The route of administration, the dose of antigen as well as the type of antigen-presenting cells (APCs) targeted are important factors to induce immune tolerance. Despite encouraging results obtained in animal models, intravenous injection of soluble antigen is unsuccessful in human clinical trials on autoimmune disease due to inefficient antigen delivery. To improve antigen delivery, we used mouse red blood cells (RBCs) as antigen vehicles to specifically target APCs which are responsible for removal of senescent RBCs after phagocytosis. In this study, we demonstrated that antigen-delivery by RBCs induced a strong decrease in the humoral response compared with the ovalbumin (OVA) free form in mice. In addition, OVA-loaded RBC treated with [bis(sulphosuccinimidyl)] suberate (BS3), a chemical compound known to enhance RBC phagocytosis, induced an inhibition of antigen-specific T cell responses and an increase in the percentage of regulatory T cells. The state of tolerance induced is long lasting, antigen-specific and sufficiently robust to withstand immunization with antigen mixed with cholera toxin adjuvant. This RBC strategy, which does not abolish the immune system, constitutes an attractive approach for induction of tolerance compared to systemic immunosuppressant therapies already in use.

  9. Chloroquine inhibits accessory cell presentation of soluble natural and synthetic protein antigens

    DEFF Research Database (Denmark)

    Buus, S; Werdelin, O

    1984-01-01

    was time- and dose-dependent. A brief treatment solely of the accessory cells with the drug compromised their ability to stimulate primed T cells in a subsequent culture provided the accessory cells were treated with chloroquine before their exposure to the antigen. These results suggest that chloroquine......We have studied the in vitro effect of the lysosomotrophic agent, chloroquine, on the presentation of soluble protein antigens by guinea pig accessory cells. Chloroquine inhibited the capacity of antigen-pulsed accessory cells to stimulate proliferation in appropriately primed T cells. The effect...

  10. Regulation of protein synthesis and autophagy in activated dendritic cells: implications for antigen processing and presentation.

    Science.gov (United States)

    Argüello, Rafael J; Reverendo, Marisa; Gatti, Evelina; Pierre, Philippe

    2016-07-01

    Antigenic peptides presented in the context of major histocompatibility complex (MHC) molecules originate from the degradation of both self and non-self proteins. T cells can therefore recognize at the surface of surveyed cells, the self-peptidome produced by the cell itself (mostly inducing tolerance) or immunogenic peptides derived from exogenous origins. The initiation of adaptive immune responses by dendritic cells (DCs), through the antigenic priming of naïve T cells, is associated to microbial pattern recognition receptors engagement. Activation of DCs by microbial product or inflammatory cytokines initiates multiple processes that maximize DC capacity to present exogenous antigens and stimulate T cells by affecting major metabolic and membrane traffic pathways. These include the modulation of protein synthesis, the regulation of MHC and co-stimulatory molecules transport, as well as the regulation of autophagy, that, all together promote exogenous antigen presentation while limiting the display of self-antigens by MHC molecules.

  11. Detection of Avian Antigen-Specific T Cells Induced by Viral Vaccines

    DEFF Research Database (Denmark)

    Dalgaard, Tina Sørensen; Norup, Liselotte Rothmann; Juul-Madsen, Helle Risdahl

    2016-01-01

    Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen. There is ......Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen....... There is a particular interest in developing robust high-throughput assays as chicken vaccine trials usually comprise many individuals. In many respects, the avian immune system differs from the mammalian, and T cell assessment protocols must be adjusted accordingly to account for, e.g., differences in leukocyte...... responding to the stimulation. This method has been successfully applied to studies of chicken antigen-specific T cells....

  12. Identification of a highly antigenic linear B cell epitope within Plasmodium vivax apical membrane antigen 1 (AMA-1.

    Directory of Open Access Journals (Sweden)

    Lilian Lacerda Bueno

    Full Text Available Apical membrane antigen 1 (AMA-1 is considered to be a major candidate antigen for a malaria vaccine. Previous immunoepidemiological studies of naturally acquired immunity to Plasmodium vivax AMA-1 (PvAMA-1 have shown a higher prevalence of specific antibodies to domain II (DII of AMA-1. In the present study, we confirmed that specific antibody responses from naturally infected individuals were highly reactive to both full-length AMA-1 and DII. Also, we demonstrated a strong association between AMA-1 and DII IgG and IgG subclass responses. We analyzed the primary sequence of PvAMA-1 for B cell linear epitopes co-occurring with intrinsically unstructured/disordered regions (IURs. The B cell epitope comprising the amino acid sequence 290-307 of PvAMA-1 (SASDQPTQYEEEMTDYQK, with the highest prediction scores, was identified in domain II and further selected for chemical synthesis and immunological testing. The antigenicity of the synthetic peptide was identified by serological analysis using sera from P. vivax-infected individuals who were knowingly reactive to the PvAMA-1 ectodomain only, domain II only, or reactive to both antigens. Although the synthetic peptide was recognized by all serum samples specific to domain II, serum with reactivity only to the full-length protein presented 58.3% positivity. Moreover, IgG reactivity against PvAMA-1 and domain II after depletion of specific synthetic peptide antibodies was reduced by 18% and 33% (P = 0.0001 for both, respectively. These results suggest that the linear epitope SASDQPTQYEEEMTDYQK is highly antigenic during natural human infections and is an important antigenic region of the domain II of PvAMA-1, suggesting its possible future use in pre-clinical studies.

  13. Detection of 2 immunoreactive antigens in the cell wall of Sporothrix brasiliensis and Sporothrix globosa.

    Science.gov (United States)

    Ruiz-Baca, Estela; Hernández-Mendoza, Gustavo; Cuéllar-Cruz, Mayra; Toriello, Conchita; López-Romero, Everardo; Gutiérrez-Sánchez, Gerardo

    2014-07-01

    The cell wall of members of the Sporothrix schenckii complex contains highly antigenic molecules which are potentially useful for the diagnosis and treatment of sporotrichosis. In this study, 2 immunoreactive antigens of 60 (Gp60) and 70 kDa (Gp70) were detected in the cell wall of the yeast morphotypes of Sporothrix brasiliensis and Sporothrix globosa.

  14. Human antigen-specific regulatory T cells generated by T cell receptor gene transfer.

    Directory of Open Access Journals (Sweden)

    Todd M Brusko

    Full Text Available BACKGROUND: Therapies directed at augmenting regulatory T cell (Treg activities in vivo as a systemic treatment for autoimmune disorders and transplantation may be associated with significant off-target effects, including a generalized immunosuppression that may compromise beneficial immune responses to infections and cancer cells. Adoptive cellular therapies using purified expanded Tregs represents an attractive alternative to systemic treatments, with results from animal studies noting increased therapeutic potency of antigen-specific Tregs over polyclonal populations. However, current methodologies are limited in terms of the capacity to isolate and expand a sufficient quantity of endogenous antigen-specific Tregs for therapeutic intervention. Moreover, FOXP3+ Tregs fall largely within the CD4+ T cell subset and are thus routinely MHC class II-specific, whereas class I-specific Tregs may function optimally in vivo by facilitating direct tissue recognition. METHODOLOGY/PRINCIPAL FINDINGS: To overcome these limitations, we have developed a novel means for generating large numbers of antigen-specific Tregs involving lentiviral T cell receptor (TCR gene transfer into in vitro expanded polyclonal natural Treg populations. Tregs redirected with a high-avidity class I-specific TCR were capable of recognizing the melanoma antigen tyrosinase in the context of HLA-A*0201 and could be further enriched during the expansion process by antigen-specific reactivation with peptide loaded artificial antigen presenting cells. These in vitro expanded Tregs continued to express FOXP3 and functional TCRs, and maintained the capacity to suppress conventional T cell responses directed against tyrosinase, as well as bystander T cell responses. Using this methodology in a model tumor system, murine Tregs designed to express the tyrosinase TCR effectively blocked antigen-specific effector T cell (Teff activity as determined by tumor cell growth and luciferase reporter

  15. A Lipid Based Antigen Delivery System Efficiently Facilitates MHC Class-I Antigen Presentation in Dendritic Cells to Stimulate CD8(+) T Cells.

    Science.gov (United States)

    Maji, Mithun; Mazumder, Saumyabrata; Bhattacharya, Souparno; Choudhury, Somsubhra Thakur; Sabur, Abdus; Shadab, Md; Bhattacharya, Pradyot; Ali, Nahid

    2016-06-02

    The most effective strategy for protection against intracellular infections such as Leishmania is vaccination with live parasites. Use of recombinant proteins avoids the risks associated with live vaccines. However, due to low immunogenicity, they fail to trigger T cell responses particularly of CD8(+) cells requisite for persistent immunity. Previously we showed the importance of protein entrapment in cationic liposomes and MPL as adjuvant for elicitation of CD4(+) and CD8(+) T cell responses for long-term protection. In this study we investigated the role of cationic liposomes on maturation and antigen presentation capacity of dendritic cells (DCs). We observed that cationic liposomes were taken up very efficiently by DCs and transported to different cellular sites. DCs activated with liposomal rgp63 led to efficient presentation of antigen to specific CD4(+) and CD8(+) T cells. Furthermore, lymphoid CD8(+) T cells from liposomal rgp63 immunized mice demonstrated better proliferative ability when co-cultured ex vivo with stimulated DCs. Addition of MPL to vaccine enhanced the antigen presentation by DCs and induced more efficient antigen specific CD8(+) T cell responses when compared to free and liposomal antigen. These liposomal formulations presented to CD8(+) T cells through TAP-dependent MHC-I pathway offer new possibilities for a safe subunit vaccine.

  16. A Lipid Based Antigen Delivery System Efficiently Facilitates MHC Class-I Antigen Presentation in Dendritic Cells to Stimulate CD8+ T Cells

    Science.gov (United States)

    Maji, Mithun; Mazumder, Saumyabrata; Bhattacharya, Souparno; Choudhury, Somsubhra Thakur; Sabur, Abdus; Shadab, Md.; Bhattacharya, Pradyot; Ali, Nahid

    2016-06-01

    The most effective strategy for protection against intracellular infections such as Leishmania is vaccination with live parasites. Use of recombinant proteins avoids the risks associated with live vaccines. However, due to low immunogenicity, they fail to trigger T cell responses particularly of CD8+ cells requisite for persistent immunity. Previously we showed the importance of protein entrapment in cationic liposomes and MPL as adjuvant for elicitation of CD4+ and CD8+ T cell responses for long-term protection. In this study we investigated the role of cationic liposomes on maturation and antigen presentation capacity of dendritic cells (DCs). We observed that cationic liposomes were taken up very efficiently by DCs and transported to different cellular sites. DCs activated with liposomal rgp63 led to efficient presentation of antigen to specific CD4+ and CD8+ T cells. Furthermore, lymphoid CD8+ T cells from liposomal rgp63 immunized mice demonstrated better proliferative ability when co-cultured ex vivo with stimulated DCs. Addition of MPL to vaccine enhanced the antigen presentation by DCs and induced more efficient antigen specific CD8+ T cell responses when compared to free and liposomal antigen. These liposomal formulations presented to CD8+ T cells through TAP-dependent MHC-I pathway offer new possibilities for a safe subunit vaccine.

  17. The uptake of soluble and particulate antigens by epithelial cells in the mouse small intestine.

    Science.gov (United States)

    Howe, Savannah E; Lickteig, Duane J; Plunkett, Kyle N; Ryerse, Jan S; Konjufca, Vjollca

    2014-01-01

    Intestinal epithelial cells (IECs) overlying the villi play a prominent role in absorption of digested nutrients and establish a barrier that separates the internal milieu from potentially harmful microbial antigens. Several mechanisms by which antigens of dietary and microbial origin enter the body have been identified; however whether IECs play a role in antigen uptake is not known. Using in vivo imaging of the mouse small intestine, we investigated whether epithelial cells (enterocytes) play an active role in the uptake (sampling) of lumen antigens. We found that small molecular weight antigens such as chicken ovalbumin, dextran, and bacterial LPS enter the lamina propria, the loose connective tissue which lies beneath the epithelium via goblet cell associated passageways. However, epithelial cells overlying the villi can internalize particulate antigens such as bacterial cell debris and inert nanoparticles (NPs), which are then found co-localizing with the CD11c+ dendritic cells in the lamina propria. The extent of NP uptake by IECs depends on their size: 20-40 nm NPs are taken up readily, while NPs larger than 100 nm are taken up mainly by the epithelial cells overlying Peyer's patches. Blocking NPs with small proteins or conjugating them with ovalbumin does not inhibit their uptake. However, the uptake of 40 nm NPs can be inhibited when they are administered with an endocytosis inhibitor (chlorpromazine). Delineating the mechanisms of antigen uptake in the gut is essential for understanding how tolerance and immunity to lumen antigens are generated, and for the development of mucosal vaccines and therapies.

  18. T cells expressing VHH-directed oligoclonal chimeric HER2 antigen receptors

    DEFF Research Database (Denmark)

    Jamnani, Fatemeh Rahimi; Rahbarizadeh, Fatemeh; Shokrgozar, Mohammad Ali;

    2014-01-01

    Adoptive cell therapy with engineered T cells expressing chimeric antigen receptors (CARs) originated from antibodies is a promising strategy in cancer immunotherapy. Several unsuccessful trials, however, highlight the need for alternative conventional binding domains and the better combination...

  19. SPONGIOTIC DERMATITIS WITH A MIXED INFLAMMATORY INFILTRATE OF LYMPHOCYTES, ANTIGEN PRESENTING CELLS, IMMUNOGLOBULINS AND COMPLEMENT

    Directory of Open Access Journals (Sweden)

    Abreu Velez Ana Maria

    2011-04-01

    Full Text Available Background: The clinical and histological presentation of spongiotic dermatitis and its inflammatory infiltrates warrant further investigation. In this case documentation of a patient with cutaneous spongiotic reactivity, we aim to characterize antigen presenting cells, as well as the skin-specific cutaneous lymphocyte antigen population by multiple techniques. Case report: A 30 year old Caucasian female presented with a two week history of blistering and erosions around the vaginal, rectal and axillary areas. Material and Methods: We utilized hematoxylin and eosin histology, direct immunofluorescence, immunohistochemistry and confocal microscopy methods to evaluate the immune reaction patterns of the cutaneous inflammatory cells. Results: In the primary histologic areas of spongiotic dermatitis, a mixed population of B and T lymphocytes was seen. Ki-67 antigen proliferative index staining was accentuated in these areas, correlating with the presence of large numbers of epidermal and dermal antigen presenting cells. Among the antigen presenting cell population, we detected strong positivities with CD1a, Factor XIIIa, myeloid/hystoid antigen, S100, HAM-56, and CD68. Interestingly, immunoglobulins G, D and M and Complement factors C1q and C3 were also strongly expressed in antigen presenting cell areas, including positivity within the spongiotic epidermis and around dermal vessels. Conclusions: We document a heterogeneous population of B and T lymphocytes and the presence of multiple classes of antigen presenting cells, immunoglobulins and complement in and surrounding histologically spongiotic areas; these findings further correlated with increased levels of expression of Ki-67.

  20. Unique interplay between sugar and lipid in determining the antigenic potency of bacterial antigens for NKT cells.

    Directory of Open Access Journals (Sweden)

    Enrico Girardi

    2011-11-01

    Full Text Available Invariant natural killer T (iNKT cells are an evolutionary conserved T cell population characterized by features of both the innate and adaptive immune response. Studies have shown that iNKT cells are required for protective responses to Gram-positive pathogens such as Streptococcus pneumoniae, and that these cells recognize bacterial diacylglycerol antigens presented by CD1d, a non-classical antigen-presenting molecule. The combination of a lipid backbone containing an unusual fatty acid, vaccenic acid, as well as a glucose sugar that is weaker or not stimulatory when linked to other lipids, is required for iNKT cell stimulation by these antigens. Here we have carried out structural and biophysical studies that illuminate the reasons for the stringent requirement for this unique combination. The data indicate that vaccenic acid bound to the CD1d groove orients the protruding glucose sugar for TCR recognition, and it allows for an additional hydrogen bond of the glucose with CD1d when in complex with the TCR. Furthermore, TCR binding causes an induced fit in both the sugar and CD1d, and we have identified the CD1d amino acids important for iNKT TCR recognition and the stability of the ternary complex. The studies show also how hydrogen bonds formed by the glucose sugar can account for the distinct binding kinetics of the TCR for this CD1d-glycolipid complex. Therefore, our studies illuminate the mechanism of glycolipid recognition for antigens from important pathogens.

  1. Effective Delivery of Antigen-Encapsulin Nanoparticle Fusions to Dendritic Cells Leads to Antigen-Specific Cytotoxic T Cell Activation and Tumor Rejection.

    Science.gov (United States)

    Choi, Bongseo; Moon, Hyojin; Hong, Sung Joon; Shin, Changsik; Do, Yoonkyung; Ryu, Seongho; Kang, Sebyung

    2016-08-23

    In cancer immunotherapy, robust and efficient activation of cytotoxic CD8(+) T cell immune responses is a promising, but challenging task. Dendritic cells (DCs) are well-known professional antigen presenting cells that initiate and regulate antigen-specific cytotoxic CD8(+) T cells that kill their target cells directly as well as secrete IFN-γ, a cytokine critical in tumor rejection. Here, we employed recently established protein cage nanoparticles, encapsulin (Encap), as antigenic peptide nanocarriers by genetically incorporating the OT-1 peptide of ovalbumin (OVA) protein to the three different positions of the Encap subunit. With them, we evaluated their efficacy in activating DC-mediated antigen-specific T cell cytotoxicity and consequent melanoma tumor rejection in vivo. DCs efficiently engulfed Encap and its variants (OT-1-Encaps), which carry antigenic peptides at different positions, and properly processed them within phagosomes. Delivered OT-1 peptides were effectively presented by DCs to naïve CD8(+) T cells successfully, resulting in the proliferation of antigen-specific cytotoxic CD8(+) T cells. OT-1-Encap vaccinations in B16-OVA melanoma tumor bearing mice effectively activated OT-1 peptide specific cytotoxic CD8(+) T cells before or even after tumor generation, resulting in significant suppression of tumor growth in prophylactic as well as therapeutic treatments. A large number of cytotoxic CD8(+) T cells that actively produce both intracellular and secretory IFN-γ were observed in tumor-infiltrating lymphocytes collected from B16-OVA tumor masses originally vaccinated with OT-1-Encap-C upon tumor challenges. The approaches we describe herein may provide opportunities to develop epitope-dependent vaccination systems that stimulate and/or modulate efficient and epitope-specific cytotoxic T cell immune responses in nonpathogenic diseases.

  2. Blockade of LFA-1 augments in vitro differentiation of antigen-induced Foxp3+ Treg cells

    Science.gov (United States)

    Verhagen, Johan; Wraith, David C.

    2014-01-01

    Adoptive transfer of antigen-specific, in vitro-induced Foxp3+ Treg (iTreg) cells protects against autoimmune disease. To generate antigen-specific iTreg cells at high purity, however, remains a challenge. Whereas polyclonal T cell stimulation with anti-CD3 and anti-CD28 antibody yields Foxp3+ iTreg cells at a purity of 90–95%, antigen-induced iTreg cells typically do not exceed a purity of 65–75%, even in a TCR-transgenic model. In a similar vein to thymic Treg cell selection, iTreg cell differentiation is influenced not only by antigen recognition and the availability of TGF-β but also by co-factors including costimulation and adhesion molecules. In this study, we demonstrate that blockade of the T cell integrin Leukocyte Function-associated Antigen-1 (LFA-1) during antigen-mediated iTreg cell differentiation augments Foxp3 induction, leading to approximately 90% purity of Foxp3+ iTreg cells. This increased efficacy not only boosts the yield of Foxp3+ iTreg cells, it also reduces contamination with activated effector T cells, thus improving the safety of adoptive transfer immunotherapy. PMID:25108241

  3. Diminished Memory T-Cell Expansion Due to Delayed Kinetics of Antigen Expression by Lentivectors.

    Directory of Open Access Journals (Sweden)

    Karina Furmanov

    Full Text Available Memory CD8(+ T lymphocytes play a central role in protective immunity. In attempt to increase the frequencies of memory CD8(+ T cells, repeated immunizations with viral vectors are regularly explored. Lentivectors have emerged as a powerful vaccine modality with relatively low pre-existing and anti-vector immunity, thus, thought to be ideal for boosting memory T cells. Nevertheless, we found that lentivectors elicited diminished secondary T-cell responses that did not exceed those obtained by priming. This was not due to the presence of anti-vector immunity, as limited secondary responses were also observed following heterologous prime-boost immunizations. By dissecting the mechanisms involved in this process, we demonstrate that lentivectors trigger exceptionally slow kinetics of antigen expression, while optimal activation of lentivector-induced T cells relays on durable expression of the antigen. These qualities hamper secondary responses, since lentivector-encoded antigen is rapidly cleared by primary cytotoxic T cells that limit its presentation by dendritic cells. Indeed, blocking antigen clearance by cytotoxic T cells via FTY720 treatment, fully restored antigen presentation. Taken together, while low antigen expression is expected during secondary immunization with any vaccine vector, our results reveal that the intrinsic delayed expression kinetics of lentiviral-encoded antigen, further dampens secondary CD8(+ T-cell expansion.

  4. Potent antigen-specific immune response induced by infusion of spleen cells coupled with succinimidyl-4-(N-maleimidomethyl cyclohexane)-1-carboxylate (SMCC) conjugated antigens.

    Science.gov (United States)

    Guo, Yixian; Werbel, Tyler; Wan, Suigui; Wu, Haitao; Li, Yaohua; Clare-Salzler, Michael; Xia, Chang-Qing

    2016-02-01

    In the present study, we report our recently developed new approach to inducing antigen-specific immune response. We use two nucleophilic substitution "click" chemistry processes to successfully couple protein antigens or peptides to mouse spleen cells or T cells by a heterobifunctional crosslinker, succinimidyl-4-(N-maleimidomethyl cyclohexane)-1-carboxylate (SMCC) or sulfo-SMCC. SMCC and its water-soluble analog sulfo-SMCC contain N-hydroxysuccinimide (NHS) ester and maleimide groups, which allow stable covalent conjugation of amine- and sulfhydryl-containing molecules in trans. Protein coupling to cells relies on the free sulfhydryls (thiols) on cell surfaces and the free amines on protein antigens. Although the amount of protein coupled to cells is limited due to the limited number of cell surface thiols, the injection of spleen cells coupled with antigenic proteins, such as keyhole limpet hemocyanin (KLH) or ovalbumin (OVA), induces a potent antigen-specific immune response in vivo, which is even stronger than that induced by the injection of a large dose of protein plus adjuvants. In addition, short peptides coupled to purified splenic T cells also potently elicit peptide-specific T cell proliferation in vivo after injection. Further studies show that antigen-coupled spleen cell treatment leads to augmented IFN-γ-producing T cells. Our study provides a unique antigen delivery method that efficiently distributes antigen to the entire immune system, subsequently eliciting a potent antigen-specific immune response with enhanced IFN-γ production. The findings in the present study suggest that this antigen-cell coupling strategy could be employed in immunotherapy for cancers, infectious diseases as well as immune-mediated disorders.

  5. Segmented filamentous bacteria antigens presented by intestinal dendritic cells drive mucosal Th17 cell differentiation.

    Science.gov (United States)

    Goto, Yoshiyuki; Panea, Casandra; Nakato, Gaku; Cebula, Anna; Lee, Carolyn; Diez, Marta Galan; Laufer, Terri M; Ignatowicz, Leszek; Ivanov, Ivaylo I

    2014-04-17

    How commensal microbiota contributes to immune cell homeostasis at barrier surfaces is poorly understood. Lamina propria (LP) T helper 17 (Th17) cells participate in mucosal protection and are induced by commensal segmented filamentous bacteria (SFB). Here we show that MHCII-dependent antigen presentation of SFB antigens by intestinal dendritic cells (DCs) is crucial for Th17 cell induction. Expression of MHCII on CD11c(+) cells was necessary and sufficient for SFB-induced Th17 cell differentiation. Most SFB-induced Th17 cells recognized SFB in an MHCII-dependent manner. SFB primed and induced Th17 cells locally in the LP and Th17 cell induction occurred normally in mice lacking secondary lymphoid organs. The importance of other innate cells was unveiled by the finding that MHCII deficiency in group 3 innate lymphoid cells (ILCs) resulted in an increase in SFB-independent Th17 cell differentiation. Our results outline the complex role of DCs and ILCs in the regulation of intestinal Th17 cell homeostasis.

  6. Detecting Antigen-Specific T Cell Responses: From Bulk Populations to Single Cells

    Directory of Open Access Journals (Sweden)

    Chansavath Phetsouphanh

    2015-08-01

    Full Text Available A new generation of sensitive T cell-based assays facilitates the direct quantitation and characterization of antigen-specific T cell responses. Single-cell analyses have focused on measuring the quality and breadth of a response. Accumulating data from these studies demonstrate that there is considerable, previously-unrecognized, heterogeneity. Standard assays, such as the ICS, are often insufficient for characterization of rare subsets of cells. Enhanced flow cytometry with imaging capabilities enables the determination of cell morphology, as well as the spatial localization of the protein molecules within a single cell. Advances in both microfluidics and digital PCR have improved the efficiency of single-cell sorting and allowed multiplexed gene detection at the single-cell level. Delving further into the transcriptome of single-cells using RNA-seq is likely to reveal the fine-specificity of cellular events such as alternative splicing (i.e., splice variants and allele-specific expression, and will also define the roles of new genes. Finally, detailed analysis of clonally related antigen-specific T cells using single-cell TCR RNA-seq will provide information on pathways of differentiation of memory T cells. With these state of the art technologies the transcriptomics and genomics of Ag-specific T cells can be more definitively elucidated.

  7. Presentation of antigen by B cells subsets. Pt. 1. Lyb-5{sup +} and Lyb-5{sup -} B cells differ in ability to stimulate specific T cells

    Energy Technology Data Exchange (ETDEWEB)

    Zimecki, M. [Polska Akademia Nauk, Wroclaw (Poland). Inst. Immunologii i Terapii Doswiadczalnej; Whiteley, P.J. [Merck and Co., Inc., Rahway, NJ (United States); Pierce, C.W.; Kapp, J.A. [Harrington Cancer Center, Amarillo (United States). Dept. of Cellular and Molecular Immunology

    1994-12-31

    We have examined the antigen presenting cell (APC) function of different B cells. Resident, peritoneal B cells from normal mice were more efficient than splenic B cells in presenting antigen to CD4{sup +} T cell lines. Peritoneal B cells from X-linked immunodeficient (Xid) mice, by contrast, stimulated no detectable responses. Xid splenic B cells were much less efficient APC than normal splenic B cells. B cells from neonatal mice also were very poor APC until the mice were 3 to 4 weeks old. Xid B cells presented antigen to T cell hybridomas as well as normal B cells showing that they process antigen normally. Thus, the defect is most likely in providing secondary signals. The ability of B cells to present antigen efficiency correlates with the percentage of B cells reported to express the Lyb-5 antigen. Anti-Lyb-5 serum and complement abrogated the APC activity of B cells suggesting that Lyb-5{sup +}, but not Lyb-5{sup -} cells are efficient APC. We also found that activated and resting normal splenic B cells, separated by buoyant density, presented antigen equally. Both populations also contained Lyb-5{sup +} B cells although they were a larger fraction of the activated cells. Lyb-5 is now thought to be an activation antigen rather than a differentiation antigen. If this idea is correct, then our data indicate that anti-Lyb-5 more cleanly separates activated and resting B cells than buoyant density techniques. (author). 38 refs, 7 figs, 1 tab.

  8. Antibody-antigen-adjuvant conjugates enable co-delivery of antigen and adjuvant to dendritic cells in cis but only have partial targeting specificity.

    Directory of Open Access Journals (Sweden)

    Martin Kreutz

    Full Text Available Antibody-antigen conjugates, which promote antigen-presentation by dendritic cells (DC by means of targeted delivery of antigen to particular DC subsets, represent a powerful vaccination approach. To ensure immunity rather than tolerance induction the co-administration of a suitable adjuvant is paramount. However, co-administration of unlinked adjuvant cannot ensure that all cells targeted by the antibody conjugates are appropriately activated. Furthermore, antigen-presenting cells (APC that do not present the desired antigen are equally strongly activated and could prime undesired responses against self-antigens. We, therefore, were interested in exploring targeted co-delivery of antigen and adjuvant in cis in form of antibody-antigen-adjuvant conjugates for the induction of anti-tumour immunity. In this study, we report on the assembly and characterization of conjugates consisting of DEC205-specific antibody, the model antigen ovalbumin (OVA and CpG oligodeoxynucleotides (ODN. We show that such conjugates are more potent at inducing cytotoxic T lymphocyte (CTL responses than control conjugates mixed with soluble CpG. However, our study also reveals that the nucleic acid moiety of such antibody-antigen-adjuvant conjugates alters their binding and uptake and allows delivery of the antigen and the adjuvant to cells partially independently of DEC205. Nevertheless, antibody-antigen-adjuvant conjugates are superior to antibody-free antigen-adjuvant conjugates in priming CTL responses and efficiently induce anti-tumour immunity in the murine B16 pseudo-metastasis model. A better understanding of the role of the antibody moiety is required to inform future conjugate vaccination strategies for efficient induction of anti-tumour responses.

  9. Epstein-Barr virus nuclear antigen 2 specifically induces expression of the B-cell activation antigen CD23

    Energy Technology Data Exchange (ETDEWEB)

    Wang, F.; Gregory, C.D.; Rowe, M.; Rickinson, A.B.; Wang, D.; Birkenbach, M.; Kikutani, H.; Kishimoto, T.; Kieff, E.

    1987-05-01

    Epstein-Barr virus (EBV) infection of EBV-negative Burkitt lymphoma (BL) cells includes some changes similar to those seen in normal B lymphocytes that have been growth transformed by EBV. The role of individual EBV genes in this process was evaluated by introducing each of the viral genes that are normally expressed in EBV growth-transformed and latently infected lymphoblasts into an EBV-negative BL cell line, using recombinant retrovirus-mediated transfer. Clones of cells were derived that stably express the EBV nuclear antigen 1 (EBNA-1), EBNA-2, EBNA-3, EBNA-leader protein, or EBV latent membrane protein (LMP). These were compared with control clones infected with the retrovirus vector. All 10 clones converted to EBNA-2 expression differed from control clones or clones expressing other EBV proteins by growth in tight clumps and by markedly increased expression of one particular surface marker of B-cell activation, CD23. Other activation antigens were unaffected by EBNA-2 expression, as were markers already expressed on the parent BL cell line. The results indicate that EBNA-2 is a specific direct or indirect trans-activator of CD23. This establishes a link between an EBV gene and cell gene expression. Since CD23 has been implicated in the transduction of B-cell growth signals, its specific induction by EBNA-2 could be important in EBV induction of B-lymphocyte transformation.

  10. Dynamic imaging of experimental Leishmania donovani-induced hepatic granulomas detects Kupffer cell-restricted antigen presentation to antigen-specific CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Lynette Beattie

    2010-03-01

    Full Text Available Kupffer cells (KCs represent the major phagocytic population within the liver and provide an intracellular niche for the survival of a number of important human pathogens. Although KCs have been extensively studied in vitro, little is known of their in vivo response to infection and their capacity to directly interact with antigen-specific CD8(+ T cells. Here, using a combination of approaches including whole mount and thin section confocal microscopy, adoptive cell transfer and intra-vital 2-photon microscopy, we demonstrate that KCs represent the only detectable population of mononuclear phagocytes within granulomas induced by Leishmania donovani infection that are capable of presenting parasite-derived peptide to effector CD8(+ T cells. This restriction of antigen presentation to KCs within the Leishmania granuloma has important implications for the identification of new candidate vaccine antigens and for the design of novel immuno-therapeutic interventions.

  11. Recruitment of dendritic cells to the cerebrospinal fluid in bacterial neuroinfections.

    Science.gov (United States)

    Pashenkov, Mikhail; Teleshova, Natalia; Kouwenhoven, Mathilde; Smirnova, Tatiana; Jin, Ya Ping; Kostulas, Vasilios; Huang, Yu Min; Pinegin, Boris; Boiko, Alexey; Link, Hans

    2002-01-01

    Dendritic cells (DC) accumulate in the CNS during inflammation and may contribute to local immune responses. Two DC subsets present in human cerebrospinal fluid (CSF) are probably recruited from myeloid (CD11c(+)CD123(dim)) and plasmacytoid (CD11c(-)CD123(high)) blood DC. In bacterial meningitis and especially in Lyme meningoencephalitis, numbers of myeloid and plasmacytoid DC in CSF were increased, compared to non-inflammatory neurological diseases, and correlated with chemotactic activity of CSF for immature monocyte-derived DC (moDC). Multiple DC chemoattractants, including macrophage inflammatory protein (MIP)-1beta, monocyte chemotactic protein (MCP)-1, MCP-3, RANTES and stromal cell-derived factor (SDF)-1alpha were elevated in CSF in these two neuroinfections. Chemotaxis of immature moDC induced by these CSFs could be partially inhibited by mAbs against CXCR4, the receptor for SDF-1alpha, and CD88, the receptor for C5a. SDF-1alpha present in CSF also chemoattracted mature moDC, which in vivo could correspond to a diminished migration of antigen-bearing DC from the CSF to secondary lymphoid organs. Regulation of DC trafficking to and from the CSF may represent a mechanism of controlling the CNS inflammation.

  12. Towards efficient cancer immunotherapy: advances in developing artificial antigen-presenting cells

    NARCIS (Netherlands)

    Eggermont, L.J.; Paulis, L.E.M.; Tel, J.; Figdor, C.G.

    2014-01-01

    Active anti-cancer immune responses depend on efficient presentation of tumor antigens and co-stimulatory signals by antigen-presenting cells (APCs). Therapy with autologous natural APCs is costly and time-consuming and results in variable outcomes in clinical trials. Therefore, development of artif

  13. Axotomy induces MHC class I antigen expression on rat nerve cells

    DEFF Research Database (Denmark)

    Maehlen, J; Schröder, H D; Klareskog, L;

    1988-01-01

    Immunomorphological staining demonstrates that class I major histocompatibility complex (MHC)-coded antigen expression can be selectively induced on otherwise class I-negative rat nerve cells by peripheral axotomy. Induction of class I as well as class II antigen expression was simultaneously see...

  14. Interplay between carbohydrate and lipid in recognition of glycolipid antigens by natural killer T cells.

    Science.gov (United States)

    Pei, Bo; Vela, Jose Luis; Zajonc, Dirk; Kronenberg, Mitchell

    2012-04-01

    Natural killer T (NKT) cells are a T cell subpopulation that were named originally based on coexpression of receptors found on natural killer (NK) cells, cells of the innate immune system, and by T lymphocytes. The maturation and activation of NKT cells requires presentation of glycolipid antigens by CD1d, a cell surface protein distantly related to the major histocompatibility complex (MHC)-encoded antigen presenting molecules. This specificity distinguishes NKT cells from most CD4(+) and CD8(+) T cells that recognize peptides presented by MHC class I and class II molecules. The rapid secretion of a large amount of both Th1 and Th2 cytokines by activated NKT cells endows them with the ability to play a vital role in the host immune defense against various microbial infections. In this review, we summarize progress on identifying the sources of microbe-derived glycolipid antigens recognized by NKT cells and the biochemical basis for their recognition.

  15. How T-cells use large deviations to recognize foreign antigens

    CERN Document Server

    Zint, Natali; Hollander, Frank den

    2008-01-01

    A stochastic model for the activation of T-cells is analysed. T-cells are part of the immune system and recognize foreign antigens against a background of the body's own molecules. The model under consideration is a slight generalization of a model introduced by Van den Berg, Rand and Burroughs in 2001, and is capable of explaining how this recognition works on the basis of rare stochastic events. With the help of a refined large deviation theorem and numerical evaluation it is shown that, for a wide range of parameters, T-cells can distinguish reliably between foreign antigens and self-antigens.

  16. A fibroblast-associated antigen: Characterization in fibroblasts and immunoreactivity in smooth muscle differentiated stromal cells

    DEFF Research Database (Denmark)

    Rønnov-Jessen, Lone; Celis, Julio E.; van Deurs, Bo

    1992-01-01

    Fibroblasts with smooth muscle differentiation are frequently derived from human breast tissue. Immunofluorescence cytochemistry of a fibroblast-associated antigen recognized by a monoclonal antibody (MAb), 1B10, was analyzed with a view to discriminating smooth muscle differentiated fibroblasts...... from vascular smooth muscle cells. The antigen was detected on the cell surface and in cathepsin D-positive and acridine orange-accumulating vesicular compartments of fibroblasts. Ultrastructurally, the antigen was revealed in coated pits and in endosomal and lysosomal structures. 1B10 recognized three...... immunoreactivity was specific to fibroblasts and smooth muscle differentiated fibroblasts within the context of vascular smooth muscle cells....

  17. Red Blood Cell Antigen Genotyping for Sickle Cell Disease, Thalassemia, and Other Transfusion Complications.

    Science.gov (United States)

    Fasano, Ross M; Chou, Stella T

    2016-10-01

    Since the discovery of the ABO blood group in the early 20th century, more than 300 blood group antigens have been categorized among 35 blood group systems. The molecular basis for most blood group antigens has been determined and demonstrates tremendous genetic diversity, particularly in the ABO and Rh systems. Several blood group genotyping assays have been developed, and 1 platform has been approved by the Food and Drug Administration as a "test of record," such that no phenotype confirmation with antisera is required. DNA-based red blood cell (RBC) phenotyping can overcome certain limitations of hemagglutination assays and is beneficial in many transfusion settings. Genotyping can be used to determine RBC antigen phenotypes in patients recently transfused or with interfering allo- or autoantibodies, to resolve discrepant serologic typing, and/or when typing antisera are not readily available. Molecular RBC antigen typing can facilitate complex antibody evaluations and guide RBC selection for patients with sickle cell disease (SCD), thalassemia, and autoimmune hemolytic anemia. High-resolution RH genotyping can identify variant RHD and RHCE in patients with SCD, which have been associated with alloimmunization. In the future, broader access to cost-efficient, high-resolution RBC genotyping technology for both patient and donor populations may be transformative for the field of transfusion medicine.

  18. Selective culling of high avidity antigen-specific CD4+ T cells after virulent Salmonella infection.

    Science.gov (United States)

    Ertelt, James M; Johanns, Tanner M; Mysz, Margaret A; Nanton, Minelva R; Rowe, Jared H; Aguilera, Marijo N; Way, Sing Sing

    2011-12-01

    Typhoid fever is a persistent infection caused by host-adapted Salmonella strains adept at circumventing immune-mediated host defences. Given the importance of T cells in protection, the culling of activated CD4+ T cells after primary infection has been proposed as a potential immune evasion strategy used by this pathogen. We demonstrate that the purging of activated antigen-specific CD4+ T cells after virulent Salmonella infection requires SPI-2 encoded virulence determinants, and is not restricted only to cells with specificity to Salmonella-expressed antigens, but extends to CD4+ T cells primed to expand by co-infection with recombinant Listeria monocytogenes. Unexpectedly, however, the loss of activated CD4+ T cells during Salmonella infection demonstrated using a monoclonal population of adoptively transferred CD4+ T cells was not reproduced among the endogenous repertoire of antigen-specific CD4+ T cells identified with MHC class II tetramer. Analysis of T-cell receptor variable segment usage revealed the selective loss and reciprocal enrichment of defined CD4+ T-cell subsets after Salmonella co-infection that is associated with the purging of antigen-specific cells with the highest intensity of tetramer staining. Hence, virulent Salmonella triggers the selective culling of high avidity activated CD4+ T-cell subsets, which re-shapes the repertoire of antigen-specific T cells that persist later after infection.

  19. Viral sequestration of antigen subverts cross presentation to CD8(+ T cells.

    Directory of Open Access Journals (Sweden)

    Eric F Tewalt

    2009-05-01

    Full Text Available Virus-specific CD8(+ T cells (T(CD8+ are initially triggered by peptide-MHC Class I complexes on the surface of professional antigen presenting cells (pAPC. Peptide-MHC complexes are produced by two spatially distinct pathways during virus infection. Endogenous antigens synthesized within virus-infected pAPC are presented via the direct-presentation pathway. Many viruses have developed strategies to subvert direct presentation. When direct presentation is blocked, the cross-presentation pathway, in which antigen is transferred from virus-infected cells to uninfected pAPC, is thought to compensate and allow the generation of effector T(CD8+. Direct presentation of vaccinia virus (VACV antigens driven by late promoters does not occur, as an abortive infection of pAPC prevents production of these late antigens. This lack of direct presentation results in a greatly diminished or ablated T(CD8+ response to late antigens. We demonstrate that late poxvirus antigens do not enter the cross-presentation pathway, even when identical antigens driven by early promoters access this pathway efficiently. The mechanism mediating this novel means of viral modulation of antigen presentation involves the sequestration of late antigens within virus factories. Early antigens and cellular antigens are cross-presented from virus-infected cells, as are late antigens that are targeted to compartments outside of the virus factories. This virus-mediated blockade specifically targets the cross-presentation pathway, since late antigen that is not cross-presented efficiently enters the MHC Class II presentation pathway. These data are the first to describe an evasion mechanism employed by pathogens to prevent entry into the cross-presentation pathway. In the absence of direct presentation, this evasion mechanism leads to a complete ablation of the T(CD8+ response and a potential replicative advantage for the virus. Such mechanisms of viral modulation of antigen presentation

  20. A human T cell clone that mediates the monocyte procoagulant response to specific sensitizing antigen.

    Science.gov (United States)

    Schwartz, B S; Reitnauer, P J; Hank, J A; Sondel, P M

    1985-09-01

    A panel of human purified protein derivative of the tubercle bacillus (PPD)-reactive T cell clones was derived by cloning out of soft agar followed by cultivation on inactivated feeder cells in the presence of interleukin-2. 1 of 4 clones tested was able to mediate an increase in monocyte procoagulant activity (PCA) in response to PPD. All four clones had identical surface marker phenotypes (T4+, T8-) and proliferated in response to antigen. The reactive T cell clone possessed no PCA of its own, but upon being presented with PPD was able to instruct monocytes to increase their expression of PCA. Antigen presentation could be performed only by autologous monocytes; allogeneic monocytes from donors unrelated to the donor of the reactive clone could not present antigen to cells of the clone in a way that would initiate the procoagulant response. Cells of the reactive clone did not mediate increased monocyte PCA in response to Candida, even though peripheral blood mononuclear cells from the donor demonstrated increased PCA to both Candida and PPD. Thus, the PCA response to specific antigen can be mediated by a single clone of cells that shows specificity in the recognition of both antigen and antigen presenting cell.

  1. Immune Responses of Dendritic Cells Loaded with Antigens from Apoptotic Cholangiocarcinoma Cells Caused by γ-Irradation

    Institute of Scientific and Technical Information of China (English)

    WUGang; HANBenli; PEIXuetao

    2002-01-01

    Objective:To investigate the induction cytotoxic T cells(CTLs) with antitumor activity and therapeutic efficacy after dendritic cells(DCs) acquired antigen from apoptotic cholangiocarcinoma cells caused by γ-irradiation. Methods:DCs from peripheral blood mononuclear cells (PBMC) that maintain the antigen capturing and processing capacity charateristic of immature cells have been established in vitro, using granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4). Then, in cholangiocarcinoma cells apoptosis was induced by γ-irradiation. The experimental groups were as follows:(1)coculture of DCs and apoptotic cancer cells and T cells;(2)coculture of DCs and necrotic cancer cells and T cells;(3)coculture of DCs, cultured cancer cell and T cells. They are cocultured for 7 days.DCs and T cells were riched, isolated and their antitumor response was tested. Results:The cells had typical dendritic morphology, expressed high levels of CDla and B7, acquired antigen from apoptotic cells caused by γ-irradiation and induced an increased T cell stimulatory capacity in mixed lymphocyte reactions (MLR). Conclusion:DCs obtained from PBMCs using GM-CSF and IL-4 can efficiently present antigen derived from apoptotic cells caused by γ-irradiation and efficiently induce T cells.This strategy, therefore, may present an effective approach to transduce DCs with antigen.

  2. Chimeric Antigen Receptor T Cell (Car T Cell Therapy In Hematology

    Directory of Open Access Journals (Sweden)

    Pinar Ataca

    2015-12-01

    Full Text Available It is well demonstrated that immune system can control and eliminate cancer cells. Immune-mediated elimination of tumor cells has been discovered and is the basis of both cancer vaccines and cellular therapies including hematopoietic stem cell transplantation (HSCT. Adoptive T cell transfer has been improved to be more specific and potent and cause less off-target toxicities. Currently, there are two forms of engineered T cells being tested in clinical trials: T cell receptor (TCR and chimeric antigen receptor (CAR modified T cells. On July 1, 2014, the United States Food and Drug Administration granted ‘breakthrough therapy’ designation to anti-CD19 CAR T cell therapy. Many studies were conducted to evaluate the beneficiaries of this exciting and potent new treatment modality. This review summarizes the history of adoptive immunotherapy, adoptive immunotherapy using CARs, the CAR manufacturing process, preclinical-clinical studies, effectiveness and drawbacks of this strategy.

  3. Docking of B-cell epitope antigen to specific hepatitis B antibody

    Indian Academy of Sciences (India)

    R Rajkannan; E J Padma Malar

    2007-09-01

    The interaction of pres1 region of hepatitis B virus B-cell epitope antigen with specific hepatitis B neutralizing monoclonal antibody was examined by docking study. We modelled the 3D complex structure of B-cell epitope antigen residues CTTPAQGNSMFPSCCCTKPTDGNCY by homology modelling and docked it with the crystal structure of monoclonal antibody specific for the pres1 region of the hepatitis B virus. At the optimized docked conformation, the interactions between the amino acids of antigen and antibody were examined. It is found that the docked complex is stabilized by 59.3 kcal/mol. The stability of the docked antigen-antibody complex is due to hydrogen bonding and van der Waals interactions. The amino acids of the antigen and antibody responsible for the interaction were identified.

  4. In vivo requirement for Atg5 in antigen presentation by dendritic cells.

    Science.gov (United States)

    Lee, Heung Kyu; Mattei, Lisa M; Steinberg, Benjamin E; Alberts, Philipp; Lee, Yun Hee; Chervonsky, Alexander; Mizushima, Noboru; Grinstein, Sergio; Iwasaki, Akiko

    2010-02-26

    Autophagy is known to be important in presentation of cytosolic antigens on MHC class II (MHC II). However, the role of autophagic process in antigen presentation in vivo is unclear. Mice with dendritic cell (DC)-conditional deletion in Atg5, a key autophagy gene, showed impaired CD4(+) T cell priming after herpes simplex virus infection and succumbed to rapid disease. The most pronounced defect of Atg5(-/-) DCs was the processing and presentation of phagocytosed antigens containing Toll-like receptor stimuli for MHC class II. In contrast, cross-presentation of peptides on MHC I was intact in the absence of Atg5. Although induction of metabolic autophagy did not enhance MHC II presentation, autophagic machinery was required for optimal phagosome-to-lysosome fusion and subsequent processing of antigen for MHC II loading. Thus, our study revealed that DCs utilize autophagic machinery to optimally process and present extracellular microbial antigens for MHC II presentation.

  5. Focused specificity of intestinal TH17 cells towards commensal bacterial antigens.

    Science.gov (United States)

    Yang, Yi; Torchinsky, Miriam B; Gobert, Michael; Xiong, Huizhong; Xu, Mo; Linehan, Jonathan L; Alonzo, Francis; Ng, Charles; Chen, Alessandra; Lin, Xiyao; Sczesnak, Andrew; Liao, Jia-Jun; Torres, Victor J; Jenkins, Marc K; Lafaille, Juan J; Littman, Dan R

    2014-06-05

    T-helper-17 (TH17) cells have critical roles in mucosal defence and in autoimmune disease pathogenesis. They are most abundant in the small intestine lamina propria, where their presence requires colonization of mice with microbiota. Segmented filamentous bacteria (SFB) are sufficient to induce TH17 cells and to promote TH17-dependent autoimmune disease in animal models. However, the specificity of TH17 cells, the mechanism of their induction by distinct bacteria, and the means by which they foster tissue-specific inflammation remain unknown. Here we show that the T-cell antigen receptor (TCR) repertoire of intestinal TH17 cells in SFB-colonized mice has minimal overlap with that of other intestinal CD4(+) T cells and that most TH17 cells, but not other T cells, recognize antigens encoded by SFB. T cells with antigen receptors specific for SFB-encoded peptides differentiated into RORγt-expressing TH17 cells, even if SFB-colonized mice also harboured a strong TH1 cell inducer, Listeria monocytogenes, in their intestine. The match of T-cell effector function with antigen specificity is thus determined by the type of bacteria that produce the antigen. These findings have significant implications for understanding how commensal microbiota contribute to organ-specific autoimmunity and for developing novel mucosal vaccines.

  6. Detection of Rare Antigen Presenting Cells through T cell-intrinsic meandering motility, mediated by Myo1g

    OpenAIRE

    Gérard, Audrey; Patino-Lopez, Genaro; Beemiller, Peter; Nambiar, Rajalakshmi; Ben-Aissa, Khadija; Liu, Yin; Totah, Fadi J.; Tyska, Matthew J.; Shaw, Stephen; Krummel, Matthew F.

    2014-01-01

    To mount an immune response, T lymphocytes must successfully search for foreign material bound to the surface of antigen-presenting cells. How T cells optimize their chances of encountering and responding to these antigens is unknown. T cell motility in tissues resembles a random or Levy walk and is regulated in part by external factors including chemokines and lymph node topology, but motility parameters such as speed and propensity to turn may also be cell-intrinsic. Here we found that the ...

  7. Cancer Patient T Cells Genetically Targeted to Prostate-Specific Membrane Antigen Specifically Lyse Prostate Cancer Cells and Release Cytokines in Response to Prostate-Specific Membrane Antigen

    Directory of Open Access Journals (Sweden)

    Michael C. Gong

    1999-06-01

    Full Text Available The expression of immunoglobulin-based artificial receptors in normal T lymphocytes provides a means to target lymphocytes to cell surface antigens independently of major histocompatibility complex restriction. Such artificial receptors have been previously shown to confer antigen-specific tumoricidal properties in murine T cells. We constructed a novel ζ chain fusion receptor specific for prostate-specific membrane antigen (PSMA termed Pz-1. PSMA is a cell-surface glycoprotein expressed on prostate cancer cells and the neovascular endothelium of multiple carcinomas. We show that primary T cells harvested from five of five patients with different stages of prostate cancer and transduced with the Pz-1 receptor readily lyse prostate cancer cells. Having established a culture system using fibroblasts that express PSMA, we next show that T cells expressing the Pz-1 receptor release cytokines in response to cell-bound PSMA. Furthermore, we show that the cytokine release is greatly augmented by B7.1-mediated costimulation. Thus, our findings support the feasibility of adoptive cell therapy by using genetically engineered T cells in prostate cancer patients and suggest that both CD4+ and CD8+ T lymphocyte functions can be synergistically targeted against tumor cells.

  8. Strategy for eliciting antigen-specific CD8+ T cell-mediated immune response against a cryptic CTL epitope of merkel cell polyomavirus large T antigen

    Directory of Open Access Journals (Sweden)

    Gomez Bianca P

    2012-10-01

    Full Text Available Abstract Background Merkel cell carcinoma (MCC is a relatively new addition to the expanding category of oncovirus-induced cancers. Although still comparably rare, the number of cases has risen dramatically in recent years. Further complicating this trend is that MCC is an extremely aggressive neoplasm with poor patient prognosis and limited treatment options for advanced disease. The causative agent of MCC has been identified as the merkel cell polyomavirus (MCPyV. The MCPyV-encoded large T (LT antigen is an oncoprotein that is theorized to be essential for virus-mediated tumorigenesis and is therefore, an excellent MCC antigen for the generation of antitumor immune responses. As a foreign antigen, the LT oncoprotein avoids the obstacle of immune tolerance, which normally impedes the development of antitumor immunity. Ergo, it is an excellent target for anti-MCC immunotherapy. Since tumor-specific CD8+ T cells lead to better prognosis for MCC and numerous other cancers, we have generated a DNA vaccine that is capable of eliciting LT-specific CD8+ T cells. The DNA vaccine (pcDNA3-CRT/LT encodes the LT antigen linked to a damage-associated molecular pattern, calreticulin (CRT, as it has been demonstrated that the linkage of CRT to antigens promotes the induction of antigen-specific CD8+ T cells. Results The present study shows that DNA vaccine-induced generation of LT-specific CD8+ T cells is augmented by linking CRT to the LT antigen. This is relevant since the therapeutic effects of the pcDNA3-CRT/LT DNA vaccine is mediated by LT-specific CD8+ T cells. Mice vaccinated with the DNA vaccine produced demonstrably more LT-specific CD8+ T cells. The DNA vaccine was also able to confer LT-specific CD8+ T cell-mediated protective and therapeutic effects to prolong the survival of mice with LT-expressing tumors. In the interest of determining the LT epitope which most MCC-specific CD8+ T cells recognize, we identified the amino acid sequence of the

  9. Proliferating cell nuclear antigen and Ki-67 immunohistochemistry of oligodendrogliomas with special reference to prognosis

    DEFF Research Database (Denmark)

    HEEGAARD, S.; Sommer, Helle Mølgaard; BROHOLM, H.;

    1995-01-01

    Background. The biologic behavior of oligodendrogliomas is somewhat unpredictable. A supplementary prognostic factor is, therefore, desirable. Methods. Thirty-two pure supratentorial oligodendrogliomas were investigated using proliferating cell nuclear antigen (PCNA) and Ki-67 immunohistochemical...

  10. Antigen selection in B-cell lymphomas--tracing the evidence.

    Science.gov (United States)

    Sutton, Lesley-Ann; Agathangelidis, Andreas; Belessi, Chrysoula; Darzentas, Nikos; Davi, Frederic; Ghia, Paolo; Rosenquist, Richard; Stamatopoulos, Kostas

    2013-12-01

    While signaling through the B cell receptor (BcR) facilitates B cell development and maintenance, it also carries intertwined risks for the development of lymphomas since malignant B cells can exploit these pathways in order to trigger and fuel clonal expansion. This corruption of the normal B cell response to antigens, leading to sustained BcR signaling, has given great impulse to investigate in detail the role of antigen in lymphomas. Suffice it to conclude from such studies, largely immunogenetics based, that the evidence implicating antigens (exogenous or self) in lymphoma development is substantial and that lymphomagenesis is functionally driven and dynamic, rather than a simple stochastic process. As the paradigm of antigen-driven lymphoma evolves, further investigation will be paramount to the identification of the inciting agent(s) that may be responsible for immunoproliferative neoplasms and also for the development of therapeutic agents targeting effectors of the BcR signaling pathway.

  11. Tandem CAR T cells targeting HER2 and IL13Rα2 mitigate tumor antigen escape.

    Science.gov (United States)

    Hegde, Meenakshi; Mukherjee, Malini; Grada, Zakaria; Pignata, Antonella; Landi, Daniel; Navai, Shoba A; Wakefield, Amanda; Fousek, Kristen; Bielamowicz, Kevin; Chow, Kevin K H; Brawley, Vita S; Byrd, Tiara T; Krebs, Simone; Gottschalk, Stephen; Wels, Winfried S; Baker, Matthew L; Dotti, Gianpietro; Mamonkin, Maksim; Brenner, Malcolm K; Orange, Jordan S; Ahmed, Nabil

    2016-08-01

    In preclinical models of glioblastoma, antigen escape variants can lead to tumor recurrence after treatment with CAR T cells that are redirected to single tumor antigens. Given the heterogeneous expression of antigens on glioblastomas, we hypothesized that a bispecific CAR molecule would mitigate antigen escape and improve the antitumor activity of T cells. Here, we created a CAR that joins a HER2-binding scFv and an IL13Rα2-binding IL-13 mutein to make a tandem CAR exodomain (TanCAR) and a CD28.ζ endodomain. We determined that patient TanCAR T cells showed distinct binding to HER2 or IL13Rα2 and had the capability to lyse autologous glioblastoma. TanCAR T cells exhibited activation dynamics that were comparable to those of single CAR T cells upon encounter of HER2 or IL13Rα2. We observed that TanCARs engaged HER2 and IL13Rα2 simultaneously by inducing HER2-IL13Rα2 heterodimers, which promoted superadditive T cell activation when both antigens were encountered concurrently. TanCAR T cell activity was more sustained but not more exhaustible than that of T cells that coexpressed a HER2 CAR and an IL13Rα2 CAR, T cells with a unispecific CAR, or a pooled product. In a murine glioblastoma model, TanCAR T cells mitigated antigen escape, displayed enhanced antitumor efficacy, and improved animal survival. Thus, TanCAR T cells show therapeutic potential to improve glioblastoma control by coengaging HER2 and IL13Rα2 in an augmented, bivalent immune synapse that enhances T cell functionality and reduces antigen escape.

  12. Engineering antigen-specific T cells from genetically modified human hematopoietic stem cells in immunodeficient mice.

    Directory of Open Access Journals (Sweden)

    Scott G Kitchen

    Full Text Available There is a desperate need for effective therapies to fight chronic viral infections. The immune response is normally fastidious at controlling the majority of viral infections and a therapeutic strategy aimed at reestablishing immune control represents a potentially powerful approach towards treating persistent viral infections. We examined the potential of genetically programming human hematopoietic stem cells to generate mature CD8+ cytotoxic T lymphocytes that express a molecularly cloned, "transgenic" human anti-HIV T cell receptor (TCR. Anti-HIV TCR transduction of human hematopoietic stem cells directed the maturation of a large population of polyfunctional, HIV-specific CD8+ cells capable of recognizing and killing viral antigen-presenting cells. Thus, through this proof-of-concept we propose that genetic engineering of human hematopoietic stem cells will allow the tailoring of effector T cell responses to fight HIV infection or other diseases that are characterized by the loss of immune control.

  13. Effect of BSA Antigen Sensitization during the Acute Phase of Influenza A Viral Infection on CD11c+ Pulmonary Antigen Presenting Cells

    Directory of Open Access Journals (Sweden)

    Fumitaka Sato

    2009-01-01

    Conclusions: BSA antigen sensitization during the acute phase of influenza A viral infection enhanced IL-10 production from naive CD4+ T cell interaction with CD11c+ pulmonary APCs. The IL-10 secretion evoked Th2 responses in the lungs with downregulation of Th1 responses and was important for the eosinophil recruitment into the lungs after BSA antigen challenge.

  14. T cell re-targeting to EBV antigens following TCR gene transfer: CD28-containing receptors mediate enhanced antigen-specific IFNgamma production

    NARCIS (Netherlands)

    N. van der Schaft (Niels); B. Lankiewicz (Birgit); H.A. Drexhage (Hemmo); C.A. Berrevoets (Cor); D.J. Moss (Denis); V. Levitsky (Victor); M. Bonneville (Marc); S.P. Lee (Steven); A.J. McMichael (Andrew); J.W. Gratama (Jan-Willem); R.L.H. Bolhuis (Reinder); R.A. Willemsen (Ralph); J.E.M.A. Debets (Reno)

    2006-01-01

    textabstractAbstract EBV is associated with a broad range of malignancies. Adoptive immunotherapy of these tumors with EBV-specific CTL proved useful. We generated a panel of primary human T cells specific to various EBV antigens (i.e. Epstein-Barr nuclear antigen 3A, 3B and BamHI-M leftward reading

  15. Antigen-Specific lgA B Memory Cell Responses to Shigella Antigens Elicited in Volunteers Immunized with Live Attenuated Shigella flexneri 2a Oral Vaccine Candidates

    Science.gov (United States)

    2011-01-01

    cell responses to Shigella antigens elicited in volunteers immunized with live attenuated Shigella flexneri 2a oral vaccine candidates J.K. Simona,b... Shigella ;. B cell memory; Immunoglobulin lgA; Mucosal immunity Abstract We studied the induction of antigen-specific lgA memory B cells (BM) in...volunteers who received live attenuated Shigella flexneri 2a vaccines. Subjects ingested a single oral dose of 107 , 108 or 109 CFU of S. flexneri 2a with

  16. Combinational targeting offsets antigen escape and enhances effector functions of adoptively transferred T cells in glioblastoma.

    Science.gov (United States)

    Hegde, Meenakshi; Corder, Amanda; Chow, Kevin K H; Mukherjee, Malini; Ashoori, Aidin; Kew, Yvonne; Zhang, Yi Jonathan; Baskin, David S; Merchant, Fatima A; Brawley, Vita S; Byrd, Tiara T; Krebs, Simone; Wu, Meng Fen; Liu, Hao; Heslop, Helen E; Gottschalk, Stephen; Gottachalk, Stephen; Yvon, Eric; Ahmed, Nabil

    2013-11-01

    Preclinical and early clinical studies have demonstrated that chimeric antigen receptor (CAR)-redirected T cells are highly promising in cancer therapy. We observed that targeting HER2 in a glioblastoma (GBM) cell line results in the emergence of HER2-null tumor cells that maintain the expression of nontargeted tumor-associated antigens. Combinational targeting of these tumor-associated antigens could therefore offset this escape mechanism. We studied the single-cell coexpression patterns of HER2, IL-13Rα2, and EphA2 in primary GBM samples using multicolor flow cytometry and immunofluorescence, and applied a binomial routine to the permutations of antigen expression and the related odds of complete tumor elimination. This mathematical model demonstrated that cotargeting HER2 and IL-13Rα2 could maximally expand the therapeutic reach of the T cell product in all primary tumors studied. Targeting a third antigen did not predict an added advantage in the tumor cohort studied. We therefore generated bispecific T cell products from healthy donors and from GBM patients by pooling T cells individually expressing HER2 and IL-13Rα2-specific CARs and by making individual T cells to coexpress both molecules. Both HER2/IL-13Rα2-bispecific T cell products offset antigen escape, producing enhanced effector activity in vitro immunoassays (against autologous glioma cells in the case of GBM patient products) and in an orthotopic xenogeneic murine model. Further, T cells coexpressing HER2 and IL-13Rα2-CARs exhibited accentuated yet antigen-dependent downstream signaling and a particularly enhanced antitumor activity.

  17. Protection from anti-TCR/CD3-induced apoptosis in immature thymocytes by a signal through thymic shared antigen-1/stem cell antigen-2

    OpenAIRE

    1996-01-01

    During T cell development in the thymus, the expression of thymic shared antigen-1 (TSA-1)/stem cell antigen-2 (Sca-2), a glycosylphosphatidylinositol (GPI)-anchored differentiation antigen, is developmentally regulated. The expression level of TSA-1 is the highest in most immature CD4- CD8- thymocytes, high in CD4+ CD8+ thymocytes, but barely detectable in mature CD4+ CD8- or CD4- CD8- thymocytes and peripheral T cells. We have previously shown that surface TSA-1 expression in peripheral T c...

  18. The uptake of soluble and particulate antigens by epithelial cells in the mouse small intestine.

    Directory of Open Access Journals (Sweden)

    Savannah E Howe

    Full Text Available Intestinal epithelial cells (IECs overlying the villi play a prominent role in absorption of digested nutrients and establish a barrier that separates the internal milieu from potentially harmful microbial antigens. Several mechanisms by which antigens of dietary and microbial origin enter the body have been identified; however whether IECs play a role in antigen uptake is not known. Using in vivo imaging of the mouse small intestine, we investigated whether epithelial cells (enterocytes play an active role in the uptake (sampling of lumen antigens. We found that small molecular weight antigens such as chicken ovalbumin, dextran, and bacterial LPS enter the lamina propria, the loose connective tissue which lies beneath the epithelium via goblet cell associated passageways. However, epithelial cells overlying the villi can internalize particulate antigens such as bacterial cell debris and inert nanoparticles (NPs, which are then found co-localizing with the CD11c+ dendritic cells in the lamina propria. The extent of NP uptake by IECs depends on their size: 20-40 nm NPs are taken up readily, while NPs larger than 100 nm are taken up mainly by the epithelial cells overlying Peyer's patches. Blocking NPs with small proteins or conjugating them with ovalbumin does not inhibit their uptake. However, the uptake of 40 nm NPs can be inhibited when they are administered with an endocytosis inhibitor (chlorpromazine. Delineating the mechanisms of antigen uptake in the gut is essential for understanding how tolerance and immunity to lumen antigens are generated, and for the development of mucosal vaccines and therapies.

  19. Modulation of TCR-mediated signaling pathway by thymic shared antigen-1 (TSA-1)/stem cell antigen-2 (Sca-2).

    Science.gov (United States)

    Saitoh, S; Kosugi, A; Noda, S; Yamamoto, N; Ogata, M; Minami, Y; Miyake, K; Hamaoka, T

    1995-12-15

    Thymic shared antigen-1 (TSA-1) is a glycosyl-phosphatidylinositol (GPI)-anchored differentiation Ag expressed on murine lymphocytes, and is identical to stem cell Ag-2 (Sca-2). Using newly established mAb against TSA-1/Sca-2, we have previously shown that surface TSA-1 expression is induced upon activation in T cells, and that anti-TSA-1 inhibits IL-2 production induced by anti-CD3 stimulation in T cell hybridomas. In the present study, we have analyzed the functional role of TSA-1 during T cell activation using normal T cells, T cell hybridomas, and transfected Jurkat cell lines that expressed either GPI-anchored or transmembrane form of TSA-1. Anti-TSA-1 inhibited IL-2 production from normal T cells stimulated with soluble anti-CD3 plus accessory cells. Anti-TSA-1 exhibited the inhibitory effect on T cells, but not on accessory cells, because anti-TSA-1 inhibited IL-2 production in Jurkat cells transfected with TSA-1 cDNA, but not in control transfectant. A transmembrane form of TSA-1 was expressed in Jurkat cells by fusing the extracellular portion of TSA-1 to the transmembrane and cytoplasmic regions of the class 1 Db. The analysis using this transfectant revealed that anti-TSA-1-mediated inhibition of IL-2 production did not require the GPI anchor of TSA-1. Finally, in addition to the inhibition of IL-2 production, tyrosine phosphorylation of CD3 zeta-chains observed following TCR stimulation, one of the important early activation events, was markedly reduced by anti-TSA-1. These results imply that TSA-1/Sca-2 plays an important regulatory role in the TCR signaling pathway of activated T cells in addition to its role in T cell differentiation.

  20. Cytotoxicity of tumor antigen specific human T cells is unimpaired by arginine depletion.

    Directory of Open Access Journals (Sweden)

    Markus Munder

    Full Text Available Tumor-growth is often associated with the expansion of myeloid derived suppressor cells that lead to local or systemic arginine depletion via the enzyme arginase. It is generally assumed that this arginine deficiency induces a global shut-down of T cell activation with ensuing tumor immune escape. While the impact of arginine depletion on polyclonal T cell proliferation and cytokine secretion is well documented, its influence on chemotaxis, cytotoxicity and antigen specific activation of human T cells has not been demonstrated so far. We show here that chemotaxis and early calcium signaling of human T cells are unimpaired in the absence of arginine. We then analyzed CD8(+ T cell activation in a tumor peptide as well as a viral peptide antigen specific system: (i CD8(+ T cells with specificity against the MART-1aa26-35*A27L tumor antigen expanded with in vitro generated dendritic cells, and (ii clonal CMV pp65aa495-503 specific T cells and T cells retrovirally transduced with a CMV pp65aa495-503 specific T cell receptor were analyzed. Our data demonstrate that human CD8(+ T cell antigen specific cytotoxicity and perforin secretion are completely preserved in the absence of arginine, while antigen specific proliferation as well as IFN-γ and granzyme B secretion are severely compromised. These novel results highlight the complexity of antigen specific T cell activation and demonstrate that human T cells can preserve important activation-induced effector functions in the context of arginine deficiency.

  1. Successive Administration of Streptococcus Type 5 Group A Antigens and S. typhimurium Antigenic Complex Corrects Elevation of Serum Cytokine Concentration and Number of Bone Marrow Stromal Pluripotent Cells in CBA Mice Induced by Each Antigen Separately.

    Science.gov (United States)

    Gorskaya, Yu F; Danilova, T A; Grabko, V I; Nesterenko, V G

    2015-12-01

    Administration of bacterial antigens to CBA mice induced an increase in serum concentration of virtually all cytokines with a peak in 4 h after administration of S. typhimurium antigens and in 7 h after administration of streptococcus antigens. In 20 h, cytokine concentrations returned to the control level or were slightly below it. In 4 h after administration of S. typhimurium antigens preceded 3 h before by administration of streptococcus antigens, we observed a significant decrease in serum concentrations of IFN-γ, IL-10, GM-CSF, IL-12, and TNF-α, in comparison with injection S. typhimurium antigens alone and IL-5, IL-10, GM-CSF, and TNF-α in comparison with injection of streptococcus antigens alone; the concentrations of IL-2 and IFN-γ, in contrast, increased by 1.5 times in this case. In 20 h after administration of S. typhimurium antigens, the number of multipotential stromal cells (MSC) in the bone marrow and their cloning efficiency (ECF-MSC) increased by 4.8 and 4.4 times, respectively, in comparison with the control, while after administration of streptococcus antigens by 2.6 and 2.4 times, respectively. In 20 h after administration of S. typhimurium antigens preceded 3 h before by administration of streptococcus antigens, these parameters increased by 3.2 and 2.9 times, respectively, in comparison with the control, i.e. the observed increase in the level of MSC count and ECF-MSC is more consistent with the response of the stromal tissue to streptococcus antigens. Thus, successive administration of two bacterial antigens corrected both serum cytokine profiles and MSC response to administration of each antigen separately, which indicates changeability of the stromal tissue in response to changes in the immune response.

  2. Antigen-induced regulatory T cells in HBV chronically infected patients.

    Science.gov (United States)

    Barboza, Luisa; Salmen, Siham; Goncalves, Loredana; Colmenares, Melisa; Peterson, Darrell; Montes, Henry; Cartagirone, Raimondo; Gutiérrez, Maria del Carmen; Berrueta, Lisbeth

    2007-11-10

    T cell response against HBV is vigorous in patients with acute hepatitis who clear the virus, whereas it is weak and narrowly focused in patients with chronic disease. We report that following incubation with HBcAg, a population of CD4+FoxP3+ cells expressing phenotypic markers of both natural and induced Tregs, can be antigen-induced from peripheral mononuclear cells. Conversely, naive and naturally immune subjects did not increase CD4+FoxP3+ Tregs following stimulation with HBcAg, supporting the idea that natural Tregs are able to respond specifically to HBV antigen. Furthermore, increased frequencies of antigen-induced CD4+FoxP3+IL-10+ Tregs correlated with viral load, suggesting that antigen-induced Tregs could contribute to an inadequate response against the virus, leading to chronic infection and support the view that specific natural Tregs may be implicated in host immune tolerance during HBV infection.

  3. Neural Crest Cells Isolated from the Bone Marrow of Transgenic Mice Express JCV T-Antigen.

    Directory of Open Access Journals (Sweden)

    Jennifer Gordon

    Full Text Available JC virus (JCV, a common human polyomavirus, is the etiological agent of the demyelinating disease, progressive multifocal leukoencephalopathy (PML. In addition to its role in PML, studies have demonstrated the transforming ability of the JCV early protein, T-antigen, and its association with some human cancers. JCV infection occurs in childhood and latent virus is thought to be maintained within the bone marrow, which harbors cells of hematopoietic and non-hematopoietic lineages. Here we show that non-hematopoietic mesenchymal stem cells (MSCs isolated from the bone marrow of JCV T-antigen transgenic mice give rise to JCV T-antigen positive cells when cultured under neural conditions. JCV T-antigen positive cells exhibited neural crest characteristics and demonstrated p75, SOX-10 and nestin positivity. When cultured in conditions typical for mesenchymal cells, a population of T-antigen negative cells, which did not express neural crest markers arose from the MSCs. JCV T-antigen positive cells could be cultured long-term while maintaining their neural crest characteristics. When these cells were induced to differentiate into neural crest derivatives, JCV T-antigen was downregulated in cells differentiating into bone and maintained in glial cells expressing GFAP and S100. We conclude that JCV T-antigen can be stably expressed within a fraction of bone marrow cells differentiating along the neural crest/glial lineage when cultured in vitro. These findings identify a cell population within the bone marrow permissible for JCV early gene expression suggesting the possibility that these cells could support persistent viral infection and thus provide clues toward understanding the role of the bone marrow in JCV latency and reactivation. Further, our data provides an excellent experimental model system for studying the cell-type specificity of JCV T-antigen expression, the role of bone marrow-derived stem cells in the pathogenesis of JCV-related diseases

  4. Interaction between antigen presenting cells and autoreactive T cells derived from BXSB mice with murine lupus

    Institute of Scientific and Technical Information of China (English)

    Peng Yang; Bo Li; Ping Lv; Yan Zhang; XiaoMing Gao

    2007-01-01

    Systemic lupus erythematosus (SLE) is a typical autoimmune disease involving multiple systems and organs. Ample evidence suggests that autoreactive T cells play a pivotal role in the development of this autoimmune disorder. This study was undertaken to investigate the mechanisms of interaction between antigen presenting cells (APCs) and an autoreactive T cell (ATL1) clone obtained from lupus-prone BXSB mice. ATL1 cells, either before or after γ-ray irradiation, were able to activate naive B cells, as determined by B cell proliferation assays. Macrophages from BXSB mice were able to stimulate the proliferation of resting ATL1 cells at a responder/stimulator (R/S) ratio of 1/2.5. Dendritic cells (DCs) were much more powerful stimulators for ATL1 cells on a per cell basis. The T cell stimulating ability of macrophages and B cells, but not DCs, was sensitive toγ-ray irradiation. Monoclonal antibodies against mouse MHC-Ⅱand CD4 were able to block DC-mediated stimulation of ATL1 proliferation, indicating cognate recognition between ATL1 and APCs. Our data suggest that positive feedback loops involving macrophages, B cells and autoreactive T cells may play a pivotal role in keeping the momentum of autoimmune responses leading to autoimmune diseases.

  5. Expression of tumor antigens on primary ovarian cancer cells compared to established ovarian cancer cell lines

    Science.gov (United States)

    Kloudová, Kamila; Hromádková, Hana; Partlová, Simona; Brtnický, Tomáš; Rob, Lukáš; Bartůňková, Jiřina; Hensler, Michal; Halaška, Michael J.; Špíšek, Radek; Fialová, Anna

    2016-01-01

    In order to select a suitable combination of cancer cell lines as an appropriate source of antigens for dendritic cell-based immunotherapy of ovarian cancer, we analyzed the expression level of 21 tumor associated antigens (BIRC5, CA125, CEA, DDX43, EPCAM, FOLR1, Her-2/neu, MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-A6, MAGE-A10, MAGE-A12, MUC-1, NY-ESO-1, PRAME, p53, TPBG, TRT, WT1) in 4 established ovarian cancer cell lines and in primary tumor cells isolated from the high-grade serous epithelial ovarian cancer tissue. More than 90% of tumor samples expressed very high levels of CA125, FOLR1, EPCAM and MUC-1 and elevated levels of Her-2/neu, similarly to OVCAR-3 cell line. The combination of OV-90 and OVCAR-3 cell lines showed the highest overlap with patients' samples in the TAA expression profile. PMID:27323861

  6. In vitro expansion of antigen-specific CD8(+) T cells distorts the T-cell repertoire.

    Science.gov (United States)

    Koning, Dan; Costa, Ana I; Hasrat, Raiza; Grady, Bart P X; Spijkers, Sanne; Nanlohy, Nening; Keşmir, Can; van Baarle, Debbie

    2014-03-01

    Short-term in vitro expansion of antigen-specific T cells is an appreciated assay for the analysis of small memory T-cell populations. However, how well short-term expanded T cells represent the direct ex vivo situation remains to be elucidated. In this study we compared the clonality of Epstein-Barr virus (EBV) and cytomegalovirus (CMV)-specific CD8(+) T cells directly ex vivo and after in vitro stimulation with antigen. Our data show that the antigen-specific T cell repertoire significantly alters after in vitro culture. Clear shifts in clonotype hierarchy were observed, with the most dominant ex vivo clonotype decreasing after stimulation at the expense of several previously subdominant clonotypes. Notably, these alterations were more pronounced in polyclonal T-cell populations compared to mono- or oligoclonal repertoires. Furthermore, TCR diversity significantly increased after culture with antigen. These results suggest that the T-cell repertoire is highly subjective to variation after in vitro stimulation with antigen. Hence, although short-term expansion of T cells provides a simple and efficient tool to examine antigen-specific immune responses, caution is required if T-cell populations are expanded prior to detailed, clonotypic analyses or other repertoire-based investigations.

  7. The T-cell anergy induced by Leishmania amazonensis antigens is related with defective antigen presentation and apoptosis

    Directory of Open Access Journals (Sweden)

    Roberta O. Pinheiro

    2004-09-01

    Full Text Available Leishmania amazonensis is the main agent of diffuse cutaneous leishmaniasis, a disease associated with anergic immune responses. In this study we show that the crude antigen of Leishmania amazonensis (LaAg but not L. braziliensis promastigotes (LbAg contains substances that suppress mitogenic and spontaneous proliferative responses of T cells. The suppressive substances in LaAg are thermoresistant (100ºC/1h and partially dependent on protease activity. T cell anergy was not due to a decreased production of growth factors as it was not reverted by addition of exogenous IL-2, IL-4, IFN-gamma or IL-12. LaAg did not inhibit anti-CD3-induced T cell activation, suggesting that anergy was due to a defect in antigen presentation. It was also not due to cell necrosis, but was accompanied by expressive DNA fragmentation in lymph node cells, indicative of apoptosis. Although pre-incubation of macrophages with LaAg prevented their capacity to present antigens, this effect was not due to apoptosis of the former. These results suggest that the T cell anergy found in diffuse leishmaniasis may be the result of parasite antigen-driven apoptosis of those cells following defective antigen presentation.A Leishmania amazonensis é o principal agente etiológico da leishmaniose cutânea difusa, uma doença associada a respostas imunes anérgicas. Neste estudo nós mostramos que o extrato bruto de promastigotas de Leishmania amazonensis (LaAg, mas não de L. braziliensis (LbAg, contém substâncias que suprimem respostas proliferativas, espontâneas e mitogênicas, de células T. As substâncias supressoras no LaAg são termo-resistentes (100°C/1h e parcialmente dependentes da atividade de proteases. A anergia de células T não foi devida à diminuição na produção de fatores de crescimento, uma vez que não foi revertida pela adição de: IL-2, IL-4, IFN-gama ou IL-12. O LaAg não inibiu a ativação de células T induzida por anti-CD3, sugerindo que a anergia

  8. Presentation of antigen by B cell subsets. Pt. 4. Defective T-B cell signalling causes inability to present antigen by B cells from immunodeficient mice

    Energy Technology Data Exchange (ETDEWEB)

    Zimecki, Michal [Polish Academy of Sciences, Wroclaw (Poland). Institute of Immunology and Experimental Therapy; Kapp, Judith A. [Emory Univ., Atlanta, GA (United States). School of Medicine

    1994-12-31

    The purpose of this study was to investigate differences in T-B cell signalling between B cells from normal and immunodeficient mice. B cell blasts from normal and immunodeficient mice expressed comparable levels of membrane-associated IL-1. B cells from normal, but not immunodeficient mice, prefixed with glutar-aldehyde and cultured with thymocytes or a T cell line BK33, induce in T cells production of a factor which causes release of IL-1 by macrophages. This factor, preincubated with B cells from immunodeficient mice significantly enhances their APC function. Furthermore, this cytokine induces expression of Lyb-5 alloantigen on B cells from immunodeficient mice. This effect could be blocked by neutralizing antibodies to IL-6 but not to IL-2, IL-4 or GM-CSF. We conclude that immature B cells from immunodeficient (CBA/N x BALB/c)F{sub 1} mice are unable to stimulate interacting T cells to produce IL-6 and therefore are inefficient antigen presenting cells. (author). 30 refs, 2 figs, 3 tabs.

  9. A new Kupffer cell receptor mediating plasma clearance of carcinoembryonic antigen by the rat.

    Science.gov (United States)

    Toth, C A; Thomas, P; Broitman, S A; Zamcheck, N

    1982-05-15

    Native human carcinoembryonic antigen is rapidly removed from the circulation by the rat liver Kupffer cell after intravenous injection. The molecule is subsequently transferred to the hepatocyte in an immunologically identifiable form. Carcinoembryonic antigen has a circulatory half-life of 3.7 (+/- 0.8) min, and cellular entry is by receptor-mediated endocytosis. Non-specific fluid pinocytosis and phagocytosis can be excluded as possible mechanisms by the kinetics of clearance and failure of colloidal carbon to inhibit uptake. Substances with known affinity for the hepatic receptors for mannose, N-acetylglucosamine, fucose and galactose all fail to inhibit carcinoembryonic antigen clearance. After two cycles of the Smith degradation, carcinoembryonic antigen is still able to inhibit clearance of the native molecule. Receptor specificity is apparently not dependent on those non-reducing terminal sugars of the native molecule. Performic acid-oxidized carcinoembryonic antigen also inhibits clearance of carcinoembryonic antigen in vivo. Receptor binding is not dependent on tertiary protein conformation. Non-specific cross-reacting antigen, a glycoprotein structurally similar to carcinoembryonic antigen, is cleared by the same mechanism.

  10. Vitamin D controls T cell antigen receptor signaling and activation of human T cells

    DEFF Research Database (Denmark)

    von Essen, Marina Rode; Kongsbak-Wismann, Martin; Schjerling, Peter

    2010-01-01

    Phospholipase C (PLC) isozymes are key signaling proteins downstream of many extracellular stimuli. Here we show that naive human T cells had very low expression of PLC-gamma1 and that this correlated with low T cell antigen receptor (TCR) responsiveness in naive T cells. However, TCR triggering...... led to an upregulation of approximately 75-fold in PLC-gamma1 expression, which correlated with greater TCR responsiveness. Induction of PLC-gamma1 was dependent on vitamin D and expression of the vitamin D receptor (VDR). Naive T cells did not express VDR, but VDR expression was induced by TCR...... signaling via the alternative mitogen-activated protein kinase p38 pathway. Thus, initial TCR signaling via p38 leads to successive induction of VDR and PLC-gamma1, which are required for subsequent classical TCR signaling and T cell activation....

  11. Hepatitis C virus and ethanol alter antigen presentation in liver cells

    Institute of Scientific and Technical Information of China (English)

    Natalia A Osna

    2009-01-01

    Alcoholic patients have a high incidence of hepatitis Cvirus (HCV) infection. Alcohol consumption enhances the severity of the HCV disease course and worsens the outcome of chronic hepatitis C. The accumulation of virally infected cells in the liver is related to the HCVinduced inability of the immune system to recognizeinfected cells and to develop the immune responses. This review covers the effects of HCV proteins and ethanol on major histocompatibility complex (MHC) classⅠ- and class Ⅱ-restricted antigen presentation. Here, we discuss the liver which functions as an immune privilege organ; factors, which affect cleavage and loading of antigenic peptides onto MHC classⅠand class Ⅱ in hepatocytes and dendritic cells, and the modulating effects of ethanol and HCV on antigen presentation by liver cells. Altered antigen presentation in the liver limits the ability of the immune system to clear HCV and infected cells and contributes to disease progression. HCV by itself affects dendritic cell function, switching their cytokine profile to the suppressive phenotype of interleukin-10 (IL-10) and transforming growth factor beta (TGFβ) predominance,preventing cell maturation and allostimulation capacity.The synergistic action of ethanol with HCV results in the suppression of MHC class Ⅱ-restricted antigen presentation. In addition, ethanol metabolism and HCV proteins reduce proteasome function and interferon signaling, thereby suppressing the generation of peptides for MHC classⅠ-restricted antigen presentation.Collectively, ethanol exposure further impairs antigen presentation in HCV-infected liver cells, which may provide a partial explanation for exacerbations and the poor outcome of HCV infection in alcoholics.

  12. Diverse endogenous antigens for mouse NKT cells: self-antigens that are not glycosphingolipids.

    Science.gov (United States)

    Pei, Bo; Speak, Anneliese O; Shepherd, Dawn; Butters, Terry; Cerundolo, Vincenzo; Platt, Frances M; Kronenberg, Mitchell

    2011-02-01

    NKT cells with an invariant Ag receptor (iNKT cells) represent a highly conserved and unique subset of T lymphocytes having properties of innate and adaptive immune cells. They have been reported to regulate a variety of immune responses, including the response to cancers and the development of autoimmunity. The development and activation of iNKT cells is dependent on self-Ags presented by the CD1d Ag-presenting molecule. It is widely believed that these self-Ags are glycosphingolipids (GSLs), molecules that contain ceramide as the lipid backbone. In this study, we used a variety of methods to show that mammalian Ags for mouse iNKT cells need not be GSLs, including the use of cell lines deficient in GSL biosynthesis and an inhibitor of GSL biosynthesis. Presentation of these Ags required the expression of CD1d molecules that could traffic to late endosomes, the site where self-Ag is acquired. Extracts of APCs contain a self-Ag that could stimulate iNKT cells when added to plates coated with soluble, rCD1d molecules. The Ag(s) in these extracts are resistant to sphingolipid-specific hydrolase digestion, consistent with the results using live APCs. Lyosphosphatidylcholine, a potential self-Ag that activated human iNKT cell lines, did not activate mouse iNKT cell hybridomas. Our data indicate that there may be more than one type of self-Ag for iNKT cells, that the self-Ags comparing mouse and human may not be conserved, and that the search to identify these molecules should not be confined to GSLs.

  13. Switching CAR T cells on and off: a novel modular platform for retargeting of T cells to AML blasts

    Science.gov (United States)

    Cartellieri, M; Feldmann, A; Koristka, S; Arndt, C; Loff, S; Ehninger, A; von Bonin, M; Bejestani, E P; Ehninger, G; Bachmann, M P

    2016-01-01

    The adoptive transfer of CD19-specific chimeric antigen receptor engineered T cells (CAR T cells) resulted in encouraging clinical trials in indolent B-cell malignancies. However, they also show the limitations of this fascinating technology: CAR T cells can lead to even life-threatening off-tumor, on-target side effects if CAR T cells crossreact with healthy tissues. Here, we describe a novel modular universal CAR platform technology termed UniCAR that reduces the risk of on-target side effects by a rapid and reversible control of CAR T-cell reactivity. The UniCAR system consists of two components: (1) a CAR for an inert manipulation of T cells and (2) specific targeting modules (TMs) for redirecting UniCAR T cells in an individualized time- and target-dependent manner. UniCAR T cells can be armed against different tumor targets simply by replacement of the respective TM for (1) targeting more than one antigen simultaneously or subsequently to enhance efficacy and (2) reducing the risk for development of antigen-loss tumor variants under treatment. Here we provide ‘proof of concept' for retargeting of UniCAR T cells to CD33- and/or CD123-positive acute myeloid leukemia blasts in vitro and in vivo. PMID:27518241

  14. Rheumatoid arthritis and its association with HLA-DR antigens. I. Cell mediated immune response against connective tissue antigens.

    Science.gov (United States)

    Vullo, C M; Pesoa, S A; Onetti, C M; Riera, C M

    1987-04-01

    HLA-DR antigens and cellular sensitivity to native bovine type I and type II collagen and proteoglycans were examined in patients with classic rheumatoid arthritis (RA) and normal individuals. Fifty eight percent of patients with RA (n = 88) and 28% of normals (n = 52) were DR4+ (pc less than 0.01). DR4 phenotype was significantly increased in patients with severe disease stages (III-IV), as defined by the ARA criteria, in contrast to those showing mild disease stages (I-II) (p less than 0.05). Furthermore, peripheral blood mononuclear cells from 55 patients and 30 controls were evaluated for the in vitro production of leukocyte inhibitory factor in response to native type I and type II collagen and proteoglycans. By using this assay, cells from the arthritic group exhibited a statistically significant response when stimulated with native type I collagen and proteoglycans. The cellular immune response was not associated with any particular HLA-DR antigens, or to the disease stage or severity.

  15. Antigen-presenting cells in parotid glands contain cystatin D originating from acinar cells.

    Science.gov (United States)

    Nashida, Tomoko; Sato, Ritsuko; Haga-Tsujimura, Maiko; Yoshie, Sumio; Yoshimura, Ken; Imai, Akane; Shimomura, Hiromi

    2013-02-01

    Cystatin D encoded by Cst5 is a salivary classified type II cystatin. We investigated the dynamism of cystatin D by examining the distribution of cystatin D protein and mRNA in rats, to identify novel functions. The simultaneous expression of Cst5 and cystatin D was observed in parotid glands, however in situ hybridization showed that only acinar cells produced cystatin D. Synthesized cystatin D was localized in small vesicles and secreted from the apical side to the saliva, and from the basolateral side to the extracellular region, a second secretory pathway for cystatin D. We also identified antigen-presenting cells in the parotid glands that contained cystatin D without the expression of Cst5, indicating the uptake of cystatin D from the extracellular region. Cystatin D was detected in blood serum and renal tubular cells with megalin, indicating the circulation of cystatin D through the body and uptake by renal tubular cells. Thus, the novel dynamism of cystatin D was shown and a function for cystatin D in the regulation of antigen-presenting cell activity was proposed.

  16. Pooled protein immunization for identification of cell surface antigens in Streptococcus sanguinis.

    Directory of Open Access Journals (Sweden)

    Xiuchun Ge

    Full Text Available BACKGROUND: Available bacterial genomes provide opportunities for screening vaccines by reverse vaccinology. Efficient identification of surface antigens is required to reduce time and animal cost in this technology. We developed an approach to identify surface antigens rapidly in Streptococcus sanguinis, a common infective endocarditis causative species. METHODS AND FINDINGS: We applied bioinformatics for antigen prediction and pooled antigens for immunization. Forty-seven surface-exposed proteins including 28 lipoproteins and 19 cell wall-anchored proteins were chosen based on computer algorithms and comparative genomic analyses. Eight proteins among these candidates and 2 other proteins were pooled together to immunize rabbits. The antiserum reacted strongly with each protein and with S. sanguinis whole cells. Affinity chromatography was used to purify the antibodies to 9 of the antigen pool components. Competitive ELISA and FACS results indicated that these 9 proteins were exposed on S. sanguinis cell surfaces. The purified antibodies had demonstrable opsonic activity. CONCLUSIONS: The results indicate that immunization with pooled proteins, in combination with affinity purification, and comprehensive immunological assays may facilitate cell surface antigen identification to combat infectious diseases.

  17. Low antigenicity of hematopoietic progenitor cells derived from human ES cells

    Directory of Open Access Journals (Sweden)

    Eun-Mi Kim

    2010-02-01

    Full Text Available Eun-Mi Kim1, Nicholas Zavazava1,21Department of Internal Medicine, University of Iowa and Veterans Affairs Medical Center, Iowa City, Iowa, USA; 2Immunology Graduate Program, University of Iowa, Iowa City, Iowa, USAAbstract: Human embryonic stem (hES cells are essential for improved understanding of diseases and our ability to probe new therapies for use in humans. Currently, bone marrow cells and cord blood cells are used for transplantation into patients with hematopoietic malignancies, immunodeficiencies and in some cases for the treatment of autoimmune diseases. However, due to the high immunogenicity of these hematopoietic cells, toxic regimens of drugs are required for preconditioning and prevention of rejection. Here, we investigated the efficiency of deriving hematopoietic progenitor cells (HPCs from the hES cell line H13, after co-culturing with the murine stromal cell line OP9. We show that HPCs derived from the H13 ES cells poorly express major histocompatibility complex (MHC class I and no detectable class II antigens (HLA-DR. These characteristics make hES cell-derived hematopoietic cells (HPCs ideal candidates for transplantation across MHC barriers under minimal immunosuppression.Keywords: human embryonic stem cells, H13, hematopoiesis, OP9 stromal cells, immunogenicity

  18. Flow Cytometric Analysis of T, B, and NK Cells Antigens in Patients with Mycosis Fungoides

    Science.gov (United States)

    Yazıcı, Serkan; Bülbül Başkan, Emel; Budak, Ferah; Oral, Barbaros; Adim, Şaduman Balaban; Ceylan Kalin, Zübeyde; Özkaya, Güven; Aydoğan, Kenan; Saricaoğlu, Hayriye; Tunali, Şükran

    2015-01-01

    We retrospectively analyzed the clinicopathological correlation and prognostic value of cell surface antigens expressed by peripheral blood mononuclear cells in patients with mycosis fungoides (MF). 121 consecutive MF patients were included in this study. All patients had peripheral blood flow cytometry as part of their first visit. TNMB and histopathological staging of the cases were retrospectively performed in accordance with International Society for Cutaneous Lymphomas/European Organization of Research and Treatment of Cancer (ISCL/EORTC) criteria at the time of flow cytometry sampling. To determine prognostic value of cell surface antigens, cases were divided into two groups as stable and progressive disease. 17 flow cytometric analyses of 17 parapsoriasis (PP) and 11 analyses of 11 benign erythrodermic patients were included as control groups. Fluorescent labeled monoclonal antibodies were used to detect cell surface antigens: T cells (CD3+, CD4+, CD8+, TCRαβ+, TCRγδ+, CD7+, CD4+CD7+, CD4+CD7−, and CD71+), B cells (HLA-DR+, CD19+, and HLA-DR+CD19+), NKT cells (CD3+CD16+CD56+), and NK cells (CD3−CD16+CD56+). The mean value of all cell surface antigens was not statistically significant between parapsoriasis and MF groups. Along with an increase in cases of MF stage statistically significant difference was found between the mean values of cell surface antigens. Flow cytometric analysis of peripheral blood cell surface antigens in patients with mycosis fungoides may contribute to predicting disease stage and progression. PMID:26788525

  19. Flow Cytometric Analysis of T, B, and NK Cells Antigens in Patients with Mycosis Fungoides

    Directory of Open Access Journals (Sweden)

    Serkan Yazıcı

    2015-01-01

    Full Text Available We retrospectively analyzed the clinicopathological correlation and prognostic value of cell surface antigens expressed by peripheral blood mononuclear cells in patients with mycosis fungoides (MF. 121 consecutive MF patients were included in this study. All patients had peripheral blood flow cytometry as part of their first visit. TNMB and histopathological staging of the cases were retrospectively performed in accordance with International Society for Cutaneous Lymphomas/European Organization of Research and Treatment of Cancer (ISCL/EORTC criteria at the time of flow cytometry sampling. To determine prognostic value of cell surface antigens, cases were divided into two groups as stable and progressive disease. 17 flow cytometric analyses of 17 parapsoriasis (PP and 11 analyses of 11 benign erythrodermic patients were included as control groups. Fluorescent labeled monoclonal antibodies were used to detect cell surface antigens: T cells (CD3+, CD4+, CD8+, TCRαβ+, TCRγδ+, CD7+, CD4+CD7+, CD4+CD7−, and CD71+, B cells (HLA-DR+, CD19+, and HLA-DR+CD19+, NKT cells (CD3+CD16+CD56+, and NK cells (CD3−CD16+CD56+. The mean value of all cell surface antigens was not statistically significant between parapsoriasis and MF groups. Along with an increase in cases of MF stage statistically significant difference was found between the mean values of cell surface antigens. Flow cytometric analysis of peripheral blood cell surface antigens in patients with mycosis fungoides may contribute to predicting disease stage and progression.

  20. Production of Exocytic Vesicular Antigens by Primary Liver Cell Cultures

    Science.gov (United States)

    1990-05-08

    microbial symbionts which occur naturally in the gut and on mucous membranes. Another method invclves the use of synthetic peptides which mimic...Streptococcus pneumoniae, hepatitis B virus, Plasmodium spp. and dengue virus, which are creating tremendous burdens worldwide [32]. Most of the...place in the immune system when an antibody’s unique antigen-binding peptide sequence (the idiotype) stimulates production of another antibody directed

  1. Antigen-activated dendritic cells ameliorate influenza A infections

    OpenAIRE

    2013-01-01

    Influenza A viruses cause significant morbidity and mortality worldwide. There is a need for alternative or adjunct therapies, as resistance to currently used antiviral drugs is emerging rapidly. We tested ligand epitope antigen presentation system (LEAPS) technology as a new immune-based treatment for influenza virus infection in a mouse model. Influenza-J-LEAPS peptides were synthesized by conjugating the binding ligand derived from the β2-microglobulin chain of the human MHC class I molecu...

  2. Antigen-bound C3b and C4b enhance antigen-presenting cell function in activation of human T-cell clones.

    Science.gov (United States)

    Arvieux, J; Yssel, H; Colomb, M G

    1988-10-01

    The effect of complement fragments C3b and C4b, on the triggering of antigen-specific human T-cell clones by Epstein-Barr virus-transformed human lymphoblastoid B cells (LCL) when these fragments are covalently coupled to the antigen tetanus toxin (TT) is described. TT was chemically cross-linked to purified C3b [(TT-C3b)n], C4b [(TT-C4b)n] or bovine serum albumin [(TT-BSA)n] as a control. T-cell activation was quantified by tritiated thymidine incorporation and 51Cr release. (TT-C3b)n and (TT-C4b)n induced proliferative responses comparable to (TT-BSA)n but at 18-25 and 4-6 lower concentrations, respectively. This enhancing effect required the covalent cross-linking of the complement fragments to the antigen and involved intracellular processing of the latter by LCL. Antigen presentation was similarly enhanced when measuring the cytotoxic activity of a helper T-cell clone against LCL previously pulsed with (TT-C3b)n or (TT-C4b)n compared with (TT-BSA)n. Binding studies, carried out on LCL using TT radiolabelled with 125I before cross-linking, indicated that (TT-C3b)n and (TT-C4b)n gave three- to four-fold more binding than (TT-BSA)n. Addition of antibodies against CR1 and CR2 or proteolytic removal of these complement receptors with trypsin inhibited by about 60% the enhancing effect of TT-bound C3b and C4b in both binding and functional assays. These results indicate that binding of C3b or C4b to antigen enhances antigen-specific proliferative and cytotoxic responses of T cells by targeting opsonized antigen onto complement receptors CR1 and CR2 of LCL. The putative significance of these findings in terms of regulation of immune responses by complement is discussed.

  3. Macrophages transfer antigens to dendritic cells by releasing exosomes containing dead-cell-associated antigens partially through a ceramide-dependent pathway to enhance CD4(+) T-cell responses.

    Science.gov (United States)

    Xu, Yingping; Liu, Yi; Yang, Chunqing; Kang, Li; Wang, Meixiang; Hu, Jingxia; He, Hao; Song, Wengang; Tang, Hua

    2016-10-01

    Defects in rapid clearance of apoptotic cells lead to an accumulation of dead cells (late apoptotic or secondary necrotic cells), which results in an aberrant immune response. However, little is known about whether and how macrophages (Mφs) cooperate with dendritic cells (DCs) in the presentation of dead-cell-associated antigens in this process. By transferring high numbers of dead cells to mimic a failure of apoptotic cell clearance in vivo, we found that Mφs and neutrophils were the predominant phagocytes in the uptake of dead cells in the spleen. Moreover, both Mφs and DCs were required for an optimal CD4(+) T-cell response triggered by dead-cell-associated antigens. Importantly, although Mφs alone had a poor capacity for antigen presentation, they could transfer phagocytosed antigens to DCs for potent antigen presentation to enhance T-cell responses. Finally, we found that exosomes released from Mφs acted as a transmitter to convey antigens to DCs partially in a ceramide-dependent manner, since treatment with the neutral sphingomyelinase inhibitor GW4869 and spiroepoxide resulted in a significant reduction of T-cell proliferation in vitro and in vivo. These findings point to a novel pathway of cross-talk between Mφs and DCs, which will be helpful to explain possible mechanisms for autoimmune diseases characterized by increased rates of apoptosis.

  4. Isolation of the phagocytosis-inducing IgG-binding antigen on senescent somatic cells

    Science.gov (United States)

    Kay, Marguerite M. B.

    1981-02-01

    To remove senescent red blood cells (RBCs) from the circulation, macrophages must distinguish them from mature RBCs. That is achieved by a specific recognition system1,2. An antigen that develops on the surface of a senescing RBC is recognized and bound by the Fab region1 of an IgG autoantibody in the serum2. Subsequently the Fc region of the autoantibody is recognized and bound by a macrophage3, which proceeds to phagocytose the RBC. The antigenic molecule can be extracted from senescent but not young RBCs with Triton X-100 (ref. 4), although 10-30% as much antigen can be extracted from middle-aged as from senescent RBCs4. I have now used IgG autoantibodies eluted from senescent RBCs to isolate and purify the IgG-binding antigen on senescent RBCs, andto detect the antigen on other somatic cells. The antigen is a ~=62,000-Mr protein which is present on stored platelets, lymphocytes and neutrophils, and on cultured human adult liver and embryonic kidney cells, as well as senescent RBCs.

  5. Development of an algorithm for production of inactivated arbovirus antigens in cell culture.

    Science.gov (United States)

    Goodman, C H; Russell, B J; Velez, J O; Laven, J J; Nicholson, W L; Bagarozzi, D A; Moon, J L; Bedi, K; Johnson, B W

    2014-11-01

    Arboviruses are medically important pathogens that cause human disease ranging from a mild fever to encephalitis. Laboratory diagnosis is essential to differentiate arbovirus infections from other pathogens with similar clinical manifestations. The Arboviral Diseases Branch (ADB) reference laboratory at the CDC Division of Vector-Borne Diseases (DVBD) produces reference antigens used in serological assays such as the virus-specific immunoglobulin M antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA). Antigen production in cell culture has largely replaced the use of suckling mice; however, the methods are not directly transferable. The development of a cell culture antigen production algorithm for nine arboviruses from the three main arbovirus families, Flaviviridae, Togaviridae, and Bunyaviridae, is described here. Virus cell culture growth and harvest conditions were optimized, inactivation methods were evaluated, and concentration procedures were compared for each virus. Antigen performance was evaluated by the MAC-ELISA at each step of the procedure. The antigen production algorithm is a framework for standardization of methodology and quality control; however, a single antigen production protocol was not applicable to all arboviruses and needed to be optimized for each virus.

  6. A sharp T-cell antigen receptor signaling threshold for T-cell proliferation

    Science.gov (United States)

    Au-Yeung, Byron B.; Zikherman, Julie; Mueller, James L.; Ashouri, Judith F.; Matloubian, Mehrdad; Cheng, Debra A.; Chen, Yiling; Shokat, Kevan M.; Weiss, Arthur

    2014-01-01

    T-cell antigen receptor (TCR) signaling is essential for activation, proliferation, and effector function of T cells. Modulation of both intensity and duration of TCR signaling can regulate these events. However, it remains unclear how individual T cells integrate such signals over time to make critical cell-fate decisions. We have previously developed an engineered mutant allele of the critical T-cell kinase zeta-chain-associated protein kinase 70 kDa (Zap70) that is catalytically inhibited by a small molecule inhibitor, thereby blocking TCR signaling specifically and efficiently. We have also characterized a fluorescent reporter Nur77–eGFP transgenic mouse line in which T cells up-regulate GFP uniquely in response to TCR stimulation. The combination of these technologies unmasked a sharp TCR signaling threshold for commitment to cell division both in vitro and in vivo. Further, we demonstrate that this threshold is independent of both the magnitude of the TCR stimulus and Interleukin 2. Similarly, we identify a temporal threshold of TCR signaling that is required for commitment to proliferation, after which T cells are able to proliferate in a Zap70 kinase-independent manner. Taken together, our studies reveal a sharp threshold for the magnitude and duration of TCR signaling required for commitment of T cells to proliferation. These results have important implications for understanding T-cell responses to infection and optimizing strategies for immunomodulatory drug delivery. PMID:25136127

  7. Purification and characterization of fetal hematopoietic cells that express the common acute lymphoblastic leukemia antigen (CALLA)

    DEFF Research Database (Denmark)

    Hokland, P; Rosenthal, P; Griffin, J D

    1983-01-01

    Fetal hematopoietic cells that express the common acute lymphoblastic leukemia antigen (CALLA) were purified from both fetal liver and fetal bone marrow by immune rosetting with sheep erythrocytes coated with rabbit anti-mouse immunoglobulin and by fluorescence-activated cell sorting. Dual...... antigen. Furthermore, using methanol-fixed cells, it could be shown that approximately 20% contained intracytoplasmic mu chains (cyto-mu) and that approximately 15% were positive for the terminal transferase enzyme (TdT) marker. The CALLA+ fetal cells thus closely resemble the childhood acute...... that these cells are relatively immature lymphoid cells, CALLA+ cells do not appear to contain either myeloid precursor cells (CFU-G/M) or the earliest lymphoid stem cells. Udgivelsesdato: 1983-Jan-1...

  8. Comparison of microglia and infiltrating CD11c+ cells as antigen presenting cells for T cell proliferation and cytokine response

    DEFF Research Database (Denmark)

    Wlodarczyk, Agnieszka; Løbner, Morten; Cédile, Oriane

    2014-01-01

    BACKGROUND: Tissue-resident antigen-presenting cells (APC) exert a major influence on the local immune environment. Microglia are resident myeloid cells in the central nervous system (CNS), deriving from early post-embryonic precursors, distinct from adult hematopoietic lineages. Dendritic cells...... but detectable levels of all these cytokines. Transforming growth factor beta expression was similar in all three populations. Although CNS-resident and blood-derived CD11c+ cells showed equivalent ability to induce proliferation of myelin oligodendrocyte glycoprotein-immunised CD4+ T cells, CD11c+ microglia...

  9. Cationic liposomes promote antigen cross-presentation in dendritic cells by alkalizing the lysosomal pH and limiting the degradation of antigens.

    Science.gov (United States)

    Gao, Jie; Ochyl, Lukasz J; Yang, Ellen; Moon, James J

    2017-01-01

    Cationic liposomes (CLs) have been widely examined as vaccine delivery nanoparticles since they can form complexes with biomacromolecules, promote delivery of antigens and adjuvant molecules to antigen-presenting cells (APCs), and mediate cellular uptake of vaccine components. CLs are also known to trigger antigen cross-presentation - the process by which APCs internalize extracellular protein antigens, degrade them into minimal CD8(+) T-cell epitopes, and present them in the context of major histocompatibility complex-I (MHC-I). However, the precise mechanisms behind CL-mediated induction of cross-presentation and cross-priming of CD8(+) T-cells remain to be elucidated. In this study, we have developed two distinct CL systems and examined their impact on the lysosomal pH in dendritic cells (DCs), antigen degradation, and presentation of peptide:MHC-I complexes to antigen-specific CD8(+) T-cells. To achieve this, we have used 3β-[N-(N',N'-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as the prototypical components of CLs with tertiary amine groups and compared the effect of CLs and anionic liposomes on lysosomal pH, antigen degradation, and cross-presentation by DCs. Our results showed that CLs, but not anionic liposomes, elevated the lysosomal pH in DCs and reduced antigen degradation, thereby promoting cross-presentation and cross-priming of CD8(+) T-cell responses. These studies shed new light on CL-mediated cross-presentation and suggest that intracellular fate of vaccine components and subsequent immunological responses can be controlled by rational design of nanomaterials.

  10. Cationic liposomes promote antigen cross-presentation in dendritic cells by alkalizing the lysosomal pH and limiting the degradation of antigens

    Science.gov (United States)

    Gao, Jie; Ochyl, Lukasz J; Yang, Ellen; Moon, James J

    2017-01-01

    Cationic liposomes (CLs) have been widely examined as vaccine delivery nanoparticles since they can form complexes with biomacromolecules, promote delivery of antigens and adjuvant molecules to antigen-presenting cells (APCs), and mediate cellular uptake of vaccine components. CLs are also known to trigger antigen cross-presentation – the process by which APCs internalize extracellular protein antigens, degrade them into minimal CD8+ T-cell epitopes, and present them in the context of major histocompatibility complex-I (MHC-I). However, the precise mechanisms behind CL-mediated induction of cross-presentation and cross-priming of CD8+ T-cells remain to be elucidated. In this study, we have developed two distinct CL systems and examined their impact on the lysosomal pH in dendritic cells (DCs), antigen degradation, and presentation of peptide:MHC-I complexes to antigen-specific CD8+ T-cells. To achieve this, we have used 3β-[N-(N′,N′-dimethylaminoethane)-carbamoyl] cholesterol (DC-Chol) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as the prototypical components of CLs with tertiary amine groups and compared the effect of CLs and anionic liposomes on lysosomal pH, antigen degradation, and cross-presentation by DCs. Our results showed that CLs, but not anionic liposomes, elevated the lysosomal pH in DCs and reduced antigen degradation, thereby promoting cross-presentation and cross-priming of CD8+ T-cell responses. These studies shed new light on CL-mediated cross-presentation and suggest that intracellular fate of vaccine components and subsequent immunological responses can be controlled by rational design of nanomaterials. PMID:28243087

  11. Detection of Avian Antigen-Specific T Cells Induced by Viral Vaccines.

    Science.gov (United States)

    Dalgaard, Tina Sørensen; Norup, Liselotte Rothmann; Juul-Madsen, Helle Risdahl

    2016-01-01

    Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen. There is a particular interest in developing robust high-throughput assays as chicken vaccine trials usually comprise many individuals. In many respects, the avian immune system differs from the mammalian, and T cell assessment protocols must be adjusted accordingly to account for, e.g., differences in leukocyte subsets.The carboxyfluorescein succinimidyl ester (CFSE) method described in this chapter has been adapted to chicken cells. In this test, cells of interest are stained with CFSE. The succinimidyl ester group covalently binds to cellular amines forming fluorescent conjugates that are retained in the cells even throughout division. This leads to daughter cells containing half the fluorescence of their parents. When lymphocytes are loaded with CFSE prior to ex vivo stimulation with specific antigen, the measurement of serial halving of its fluorescence by flow cytometry identifies the cells responding to the stimulation. This method has been successfully applied to studies of chicken antigen-specific T cells.

  12. Pros and Cons of Antigen-Presenting Cell Targeted Tumor Vaccines

    Directory of Open Access Journals (Sweden)

    Cleo Goyvaerts

    2015-01-01

    Full Text Available In therapeutic antitumor vaccination, dendritic cells play the leading role since they decide if, how, when, and where a potent antitumor immune response will take place. Since the disentanglement of the complexity and merit of different antigen-presenting cell subtypes, antitumor immunotherapeutic research started to investigate the potential benefit of targeting these subtypes in situ. This review will discuss which antigen-presenting cell subtypes are at play and how they have been targeted and finally question the true meaning of targeting antitumor-based vaccines.

  13. In vivo targeting of antigens to maturing dendritic cells via the DEC-205 receptor improves T cell vaccination.

    Science.gov (United States)

    Bonifaz, Laura C; Bonnyay, David P; Charalambous, Anna; Darguste, Dara I; Fujii, Shin-Ichiro; Soares, Helena; Brimnes, Marie K; Moltedo, Bruno; Moran, Thomas M; Steinman, Ralph M

    2004-03-15

    The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic alpha-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the alphaDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell-mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models.

  14. A Single Subset of Dendritic Cells Controls the Cytokine Bias of Natural Killer T Cell Responses to Diverse Glycolipid Antigens

    Science.gov (United States)

    Arora, Pooja; Baena, Andres; Yu, Karl O.A.; Saini, Neeraj K.; Kharkwal, Shalu S.; Goldberg, Michael F.; Kunnath-Velayudhan, Shajo; Carreño, Leandro J.; Venkataswamy, Manjunatha M.; Kim, John; Lazar-Molnar, Eszter; Lauvau, Gregoire; Chang, Young-tae; Liu, Zheng; Bittman, Robert; Al-Shamkhani, Aymen; Cox, Liam R.; Jervis, Peter J.; Veerapen, Natacha; Besra, Gurdyal S.; Porcelli, Steven A.

    2014-01-01

    Summary Many hematopoietic cell types express CD1d and are capable of presenting glycolipid antigens to invariant natural killer T cells (iNKT cells). However, the question of which cells are the principal presenters of glycolipid antigens in vivo remains controversial, and it has been suggested that this might vary depending on the structure of a particular glycolipid antigen. Here we have shown that a single type of cell, the CD8α+ DEC-205+ dendritic cell, was mainly responsible for capturing and presenting a variety of different glycolipid antigens, including multiple forms of α-galactosylceramide that stimulate widely divergent cytokine responses. After glycolipid presentation, these dendritic cells rapidly altered their expression of various costimulatory and coinhibitory molecules in a manner that was dependent on the structure of the antigen. These findings show flexibility in the outcome of two-way communication between CD8α+ dendritic cells and iNKT cells, providing a mechanism for biasing toward either proinflammatory or anti-inflammatory responses. PMID:24412610

  15. A single subset of dendritic cells controls the cytokine bias of natural killer T cell responses to diverse glycolipid antigens.

    Science.gov (United States)

    Arora, Pooja; Baena, Andres; Yu, Karl O A; Saini, Neeraj K; Kharkwal, Shalu S; Goldberg, Michael F; Kunnath-Velayudhan, Shajo; Carreño, Leandro J; Venkataswamy, Manjunatha M; Kim, John; Lazar-Molnar, Eszter; Lauvau, Gregoire; Chang, Young-tae; Liu, Zheng; Bittman, Robert; Al-Shamkhani, Aymen; Cox, Liam R; Jervis, Peter J; Veerapen, Natacha; Besra, Gurdyal S; Porcelli, Steven A

    2014-01-16

    Many hematopoietic cell types express CD1d and are capable of presenting glycolipid antigens to invariant natural killer T cells (iNKT cells). However, the question of which cells are the principal presenters of glycolipid antigens in vivo remains controversial, and it has been suggested that this might vary depending on the structure of a particular glycolipid antigen. Here we have shown that a single type of cell, the CD8α(+) DEC-205(+) dendritic cell, was mainly responsible for capturing and presenting a variety of different glycolipid antigens, including multiple forms of α-galactosylceramide that stimulate widely divergent cytokine responses. After glycolipid presentation, these dendritic cells rapidly altered their expression of various costimulatory and coinhibitory molecules in a manner that was dependent on the structure of the antigen. These findings show flexibility in the outcome of two-way communication between CD8α(+) dendritic cells and iNKT cells, providing a mechanism for biasing toward either proinflammatory or anti-inflammatory responses.

  16. Targeting proliferating cell nuclear antigen and its protein interactions induces apoptosis in multiple myeloma cells.

    Directory of Open Access Journals (Sweden)

    Rebekka Müller

    Full Text Available Multiple myeloma is a hematological cancer that is considered incurable despite advances in treatment strategy during the last decade. Therapies targeting single pathways are unlikely to succeed due to the heterogeneous nature of the malignancy. Proliferating cell nuclear antigen (PCNA is a multifunctional protein essential for DNA replication and repair that is often overexpressed in cancer cells. Many proteins involved in the cellular stress response interact with PCNA through the five amino acid sequence AlkB homologue 2 PCNA-interacting motif (APIM. Thus inhibiting PCNA's protein interactions may be a good strategy to target multiple pathways simultaneously. We initially found that overexpression of peptides containing the APIM sequence increases the sensitivity of cancer cells to contemporary therapeutics. Here we have designed a cell-penetrating APIM-containing peptide, ATX-101, that targets PCNA and show that it has anti-myeloma activity. We found that ATX-101 induced apoptosis in multiple myeloma cell lines and primary cancer cells, while bone marrow stromal cells and primary healthy lymphocytes were much less sensitive. ATX-101-induced apoptosis was caspase-dependent and cell cycle phase-independent. ATX-101 also increased multiple myeloma cells' sensitivity against melphalan, a DNA damaging agent commonly used for treatment of multiple myeloma. In a xenograft mouse model, ATX-101 was well tolerated and increased the anti-tumor activity of melphalan. Therefore, targeting PCNA by ATX-101 may be a novel strategy in multiple myeloma treatment.

  17. HIV-1 Trans Infection of CD4+ T Cells by Professional Antigen Presenting Cells

    Directory of Open Access Journals (Sweden)

    Charles R. Rinaldo

    2013-01-01

    Full Text Available Since the 1990s we have known of the fascinating ability of a complex set of professional antigen presenting cells (APCs; dendritic cells, monocytes/macrophages, and B lymphocytes to mediate HIV-1 trans infection of CD4+ T cells. This results in a burst of virus replication in the T cells that is much greater than that resulting from direct, cis infection of either APC or T cells, or trans infection between T cells. Such APC-to-T cell trans infection first involves a complex set of virus subtype, attachment, entry, and replication patterns that have many similarities among APC, as well as distinct differences related to virus receptors, intracellular trafficking, and productive and nonproductive replication pathways. The end result is that HIV-1 can sequester within the APC for several days and be transmitted via membrane extensions intracellularly and extracellularly to T cells across the virologic synapse. Virus replication requires activated T cells that can develop concurrently with the events of virus transmission. Further research is essential to fill the many gaps in our understanding of these trans infection processes and their role in natural HIV-1 infection.

  18. The clinical value of squamous cell carcinoma antigen in cancer of the uterine cervix

    NARCIS (Netherlands)

    de Bruijn, HWA; Duk, JM; van der Zee, AGJ; Pras, E; Willemse, PHB; Hollema, H; Mourits, MJE; de Vries, EGE; Aalders, JG; Boonstra, J.

    1998-01-01

    A review is given of the clinical use and interpretation of serum tumor marker levels during the treatment of patients with cancer of the uterine cervix, Pretreatment serum squamous cell carcinoma (SCC) antigen provides a new prognostic factor in early stage squamous cell carcinoma of the uterine ce

  19. Robust and Accurate Discrimination of Self/Non-Self Antigen Presentations by Regulatory T Cell Suppression

    Science.gov (United States)

    Furusawa, Chikara; Yamaguchi, Tomoyuki

    2016-01-01

    The immune response by T cells usually discriminates self and non-self antigens, even though the negative selection of self-reactive T cells is imperfect and a certain fraction of T cells can respond to self-antigens. In this study, we construct a simple mathematical model of T cell populations to analyze how such self/non-self discrimination is possible. The results demonstrate that the control of the immune response by regulatory T cells enables a robust and accurate discrimination of self and non-self antigens, even when there is a significant overlap between the affinity distribution of T cells to self and non-self antigens. Here, the number of regulatory T cells in the system acts as a global variable controlling the T cell population dynamics. The present study provides a basis for the development of a quantitative theory for self and non-self discrimination in the immune system and a possible strategy for its experimental verification. PMID:27668873

  20. Diversification of the antigen-specific T cell receptor repertoire after varicella zoster vaccination.

    Science.gov (United States)

    Qi, Qian; Cavanagh, Mary M; Le Saux, Sabine; NamKoong, Hong; Kim, Chulwoo; Turgano, Emerson; Liu, Yi; Wang, Chen; Mackey, Sally; Swan, Gary E; Dekker, Cornelia L; Olshen, Richard A; Boyd, Scott D; Weyand, Cornelia M; Tian, Lu; Goronzy, Jörg J

    2016-03-30

    Diversity and size of the antigen-specific T cell receptor (TCR) repertoire are two critical determinants for successful control of chronic infection. Varicella zoster virus (VZV) that establishes latency during childhood can escape control mechanisms, in particular with increasing age. We examined the TCR diversity of VZV-reactive CD4 T cells in individuals older than 50 years by studying three identical twin pairs and three unrelated individuals before and after vaccination with live attenuated VZV. Although all individuals had a small number of dominant T cell clones, the breadth of the VZV-specific repertoire differed markedly. A genetic influence was seen for the sharing of individual TCR sequences from antigen-reactive cells but not for repertoire richness or the selection of dominant clones. VZV vaccination favored the expansion of infrequent VZV antigen-reactive TCRs, including those from naïve T cells with lesser boosting of dominant T cell clones. Thus, vaccination does not reinforce the in vivo selection that occurred during chronic infection but leads to a diversification of the VZV-reactive T cell repertoire. However, a single-booster immunization seems insufficient to establish new clonal dominance. Our results suggest that repertoire analysis of antigen-specific TCRs can be an important readout to assess whether a vaccination was able to generate memory cells in clonal sizes that are necessary for immune protection.

  1. T Cell Receptors that Recognize the Tyrosinase Tumor Antigen | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Cancer Institute, Surgery Branch, Tumor Immunology Section, is seeking statements of capability or interest from parties interested in collaborative research to further develop, evaluate, or commercialize T Cells Attacking Cancer: T Cell Receptors that Recognize the Tyrosinase Tumor Antigen

  2. Squamous cell carcinoma antigen isoforms in serum from cervical cancer patients

    NARCIS (Netherlands)

    Roijer, E; de Bruijn, HWA; Dahlen, U; ten Hoor, K; Lundin, M; Nilsson, K; Soderstrom, K; Nilsson, O

    2006-01-01

    Squamous cell carcinoma antigen (SCCA) is a serological marker of squamous cell carcinomas (SCC). To study whether any of the SCCA isoforms would provide additional and more specific/sensitive clinical information than total SCCA, immunoassays specific for the different forms of SCCA (free SCCA2, to

  3. Discovering naturally processed antigenic determinants that confer protective T cell immunity

    DEFF Research Database (Denmark)

    Gilchuk, Pavlo; Spencer, Charles T; Conant, Stephanie B;

    2013-01-01

    CD8+ T cells (TCD8) confer protective immunity against many infectious diseases, suggesting that microbial TCD8 determinants are promising vaccine targets. Nevertheless, current T cell antigen identification approaches do not discern which epitopes drive protective immunity during active infectio...

  4. The B cell antigen receptor and overexpression of MYC can cooperate in the genesis of B cell lymphomas.

    Directory of Open Access Journals (Sweden)

    Yosef Refaeli

    2008-06-01

    Full Text Available A variety of circumstantial evidence from humans has implicated the B cell antigen receptor (BCR in the genesis of B cell lymphomas. We generated mouse models designed to test this possibility directly, and we found that both the constitutive and antigen-stimulated state of a clonal BCR affected the rate and outcome of lymphomagenesis initiated by the proto-oncogene MYC. The tumors that arose in the presence of constitutive BCR differed from those initiated by MYC alone and resembled chronic B cell lymphocytic leukemia/lymphoma (B-CLL, whereas those that arose in response to antigen stimulation resembled large B-cell lymphomas, particularly Burkitt lymphoma (BL. We linked the genesis of the BL-like tumors to antigen stimulus in three ways. First, in reconstruction experiments, stimulation of B cells by an autoantigen in the presence of overexpressed MYC gave rise to BL-like tumors that were, in turn, dependent on both MYC and the antigen for survival and proliferation. Second, genetic disruption of the pathway that mediates signaling from the BCR promptly killed cells of the BL-like tumors as well as the tumors resembling B-CLL. And third, growth of the murine BL could be inhibited by any of three distinctive immunosuppressants, in accord with the dependence of the tumors on antigen-induced signaling. Together, our results provide direct evidence that antigenic stimulation can participate in lymphomagenesis, point to a potential role for the constitutive BCR as well, and sustain the view that the constitutive BCR gives rise to signals different from those elicited by antigen. The mouse models described here should be useful in exploring further the pathogenesis of lymphomas, and in preclinical testing of new therapeutics.

  5. Antigen-Experienced T cells Limit the Priming of Naïve T cells During Infection with Leishmania major1

    Science.gov (United States)

    Gray, Peter M.; Reiner, Steven L.; Smith, Deborah F.; Kaye, Paul M.; Scott, Phillip

    2009-01-01

    One mechanism to control immune responses following infection is to rapidly down regulate antigen presentation, which has been observed in acute viral and bacterial infections. Here we describe experiments designed to address whether antigen presentation is decreased after an initial response to Leishmania major. Naïve α-β-Leishmania-specific (ABLE) T cell receptor transgenic T cells were adoptively transferred into mice at various times after L. major infection to determine the duration of presentation of parasite-derived antigens. ABLE T cells responded vigorously at the initiation of infection, but the ability to prime these cells quickly diminished, independent of IL-10, regulatory T cells or antigen load. However, antigen-experienced clonal and polyclonal T cell populations could respond, indicating that the diminution in naïve ABLE cell responses was not due to lack of antigen presentation. Since naïve T cell priming could be restored by removal of the endogenous T cell population, or adoptive transfer of antigen pulsed dendritic cells, it appears that T cells that have previously encountered antigen during infection compete with naïve antigen-specific T cells. These results suggest that during L. major infection antigen-experienced T cells, rather than naïve T cells, may be primarily responsible for sustaining the immune response. PMID:16818747

  6. In Vivo Targeting of Antigens to Maturing Dendritic Cells via the DEC-205 Receptor Improves T Cell Vaccination

    Science.gov (United States)

    Bonifaz, Laura C.; Bonnyay, David P.; Charalambous, Anna; Darguste, Dara I.; Fujii, Shin-Ichiro; Soares, Helena; Brimnes, Marie K.; Moltedo, Bruno; Moran, Thomas M.; Steinman, Ralph M.

    2004-01-01

    The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic α-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4+ and CD8+ T cell repertoire. Unexpectedly, the αDEC-205 antigen conjugates, given s.c., targeted to dendritic cells systemically and for long periods, and ovalbumin peptide was presented on MHC class I for 2 weeks. This was associated with stronger CD8+ T cell–mediated immunity relative to other forms of antigen delivery, even when the latter was given at a thousand times higher doses. In parallel, the mice showed enhanced resistance to an established rapidly growing tumor and to viral infection at a mucosal site. By better harnessing the immunizing functions of maturing dendritic cells, antibody-mediated antigen targeting via the DEC-205 receptor increases the efficiency of vaccination for T cell immunity, including systemic and mucosal resistance in disease models. PMID:15024047

  7. Isolation and characterization of antigen-Ia complexes involved in T cell recognition

    DEFF Research Database (Denmark)

    Buus, S; Sette, A; Colon, S M

    1986-01-01

    Using equilibrium dialysis, it has been previously demonstrated that immunogenic peptides bind specifically to the Ia molecules serving as restriction elements in the immune response to these antigens. Using gel filtration to study the formation of ovalbumin (OVA) peptide-I-Ad complexes, it is he......Using equilibrium dialysis, it has been previously demonstrated that immunogenic peptides bind specifically to the Ia molecules serving as restriction elements in the immune response to these antigens. Using gel filtration to study the formation of ovalbumin (OVA) peptide-I-Ad complexes...... with glutaraldehyde revealed that the ovalbumin peptide was cross-linked solely to the alpha chain of I-Ad. Planar membranes containing I-Ad-OVA complexes stimulated a T cell response with 2 X 10(4) less antigen than required when uncomplexed antigen was used, thus demonstrating the biologic importance...

  8. Long-term in vivo provision of antigen-specific T cell immunity by programming hematopoietic stem cells

    Science.gov (United States)

    Yang, Lili; Baltimore, David

    2005-03-01

    A method to genetically program mouse hematopoietic stem cells to develop into functional CD8 or CD4 T cells of defined specificity in vivo is described. For this purpose, a bicistronic retroviral vector was engineered that efficiently delivers genes for both and chains of T cell receptor (TCR) to hematopoietic stem cells. When modified cell populations were used to reconstruct the hematopoietic lineages of recipient mice, significant percentages of antigen-specific CD8 or CD4 T cells were observed. These cells expressed normal surface markers and responded to peptide antigen stimulation by proliferation and cytokine production. Moreover, they could mature into memory cells after peptide stimulation. Using TCRs specific for a model tumor antigen, we found that the recipient mice were able to partially resist a challenge with tumor cells carrying the antigen. By combining cells modified with CD8- and CD4-specific TCRs, and boosting with dendritic cells pulsed with cognate peptides, complete suppression of tumor could be achieved and even tumors that had become established would regress and be eliminated after dendritic cell/peptide immunization. This methodology of "instructive immunotherapy" could be developed for controlling the growth of human tumors and attacking established pathogens.

  9. Antigen-engaged B cells undergo chemotaxis toward the T zone and form motile conjugates with helper T cells.

    Directory of Open Access Journals (Sweden)

    Takaharu Okada

    2005-06-01

    Full Text Available Interactions between B and T cells are essential for most antibody responses, but the dynamics of these interactions are poorly understood. By two-photon microscopy of intact lymph nodes, we show that upon exposure to antigen, B cells migrate with directional preference toward the B-zone-T-zone boundary in a CCR7-dependent manner, through a region that exhibits a CCR7-ligand gradient. Initially the B cells show reduced motility, but after 1 d, motility is increased to approximately 9 microm/min. Antigen-engaged B cells pair with antigen-specific helper T cells for 10 to more than 60 min, whereas non-antigen-specific interactions last less than 10 min. B cell-T cell conjugates are highly dynamic and migrate extensively, being led by B cells. B cells occasionally contact more than one T cell, whereas T cells are strictly monogamous in their interactions. These findings provide evidence of lymphocyte chemotaxis in vivo, and they begin to define the spatiotemporal cellular dynamics associated with T cell-dependent antibody responses.

  10. Expression of I-A and I-E,C region-coded Ia antigens on functional B cell subpopulations.

    Science.gov (United States)

    Frelinger, J A; Hibbler, F J; Hill, S W

    1978-12-01

    Ia antigens from specific subregions have been examined on functional B cell populations. Expression of both I-A and I-E,C region antigens was demonstrated on cells required for both lipopolysaccharide mitogenesis and polyclonal activation. Similar I-A and I-E,C subregion expression was found on cells required for response to the T-independent antigen, polyvinylpyrrolidone. TNP-specific IgM and hen egg lysozyme-specific IgG plaque-forming cells also express I-A and I-E,C region antigens. No evidence was found for an Ia- population responsive in the systems tested. Further, no evidence of preferential expression of I-A or I-E,C region antigens was observed in any system examined. Therefore, it appears that B cells express both I-A and I-E,C region-coded Ia antigens.

  11. Manufacture of clinical-grade CD19-specific T cells stably expressing chimeric antigen receptor using Sleeping Beauty system and artificial antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Harjeet Singh

    Full Text Available Adoptive transfer of T cells expressing a CD19-specific chimeric antigen receptor (CAR is being evaluated in multiple clinical trials. Our current approach to adoptive immunotherapy is based on a second generation CAR (designated CD19RCD28 that signals through a CD28 and CD3-ζ endodomain. T cells are electroporated with DNA plasmids from the Sleeping Beauty (SB transposon/transposase system to express this CAR. Stable integrants of genetically modified T cells can then be retrieved when co-cultured with designer artificial antigen presenting cells (aAPC in the presence of interleukin (IL-2 and 21. Here, we reveal how the platform technologies of SB-mediated transposition and CAR-dependent propagation on aAPC were adapted for human application. Indeed, we have initiated clinical trials in patients with high-risk B-lineage malignancies undergoing autologous and allogeneic hematopoietic stem-cell transplantation (HSCT. We describe the process to manufacture clinical grade CD19-specific T cells derived from healthy donors. Three validation runs were completed in compliance with current good manufacturing practice for Phase I/II trials demonstrating that by 28 days of co-culture on γ-irradiated aAPC ∼10(10 T cells were produced of which >95% expressed CAR. These genetically modified and propagated T cells met all quality control testing and release criteria in support of infusion.

  12. The impact of T cell intrinsic antigen adaptation on peripheral immune tolerance.

    Directory of Open Access Journals (Sweden)

    Nevil J Singh

    2006-10-01

    Full Text Available Overlapping roles have been ascribed for T cell anergy, clonal deletion, and regulation in the maintenance of peripheral immunological tolerance. A measurement of the individual and additive impacts of each of these processes on systemic tolerance is often lacking. In this report we have used adoptive transfer strategies to tease out the unique contribution of T cell intrinsic receptor calibration (adaptation in the maintenance of tolerance to a systemic self-antigen. Adoptively transferred naïve T cells stably calibrated their responsiveness to a persistent self-antigen in both lymphopenic and T cell-replete hosts. In the former, this state was not accompanied by deletion or suppression, allowing us to examine the unique contribution of adaptation to systemic tolerance. Surprisingly, adapting T cells could chronically help antigen-expressing B cells, leading to polyclonal hypergammaglobulinemia and pathology, in the form of mild arthritis. The helper activity mediated by CD40L and cytokines was evident even if the B cells were introduced after extended adaptation of the T cells. In contrast, in the T cell-replete host, neither arthritis nor autoantibodies were induced. The containment of systemic pathology required host T cell-mediated extrinsic regulatory mechanisms to synergize with the cell intrinsic adaptation process. These extrinsic mechanisms prevented the effector differentiation of the autoreactive T cells and reduced their precursor frequency, in vivo.

  13. SIV antigen immunization induces transient antigen-specific T cell responses and selectively activates viral replication in draining lymph nodes in retroviral suppressed rhesus macaques

    Directory of Open Access Journals (Sweden)

    Barry Peter A

    2011-07-01

    Full Text Available Abstract Background HIV infection causes a qualitative and quantitative loss of CD4+ T cell immunity. The institution of anti-retroviral therapy (ART restores CD4+ T cell responses to many pathogens, but HIV-specific responses remain deficient. Similarly, therapeutic immunization with HIV antigens of chronically infected, ART treated subjects results in poor induction of HIV-specific CD4 responses. In this study, we used a macaque model of ART treatment during chronic infection to study the virologic consequences of SIV antigen stimulation in lymph nodes early after immunization. Rhesus CMV (RhCMV seropositive, Mamu A*01 positive rhesus macaques were chronically infected with SIVmac251 and treated with ART. The immune and viral responses to SIV gag and RhCMV pp65 antigen immunization in draining lymph nodes and peripheral blood were analyzed. Animals were immunized on contralateral sides with SIV gag and RhCMV pp65 encoding plasmids, which allowed lymph nodes draining each antigen to be obtained at the same time from the same animal for direct comparison. Results We observed that both SIV and RhCMV immunizations stimulated transient antigen-specific T cell responses in draining lymph nodes. The RhCMV-specific responses were potent and sustained (50 days post-immunization in the periphery, while the SIV-specific responses were transient and extinguished quickly. The SIV antigen stimulation selectively induced transient SIV replication in draining lymph nodes. Conclusions The data are consistent with a model whereby viral replication in response to SIV antigen stimulation limits the generation of SIV antigen-specific responses and suggests a potential mechanism for the early loss and poor HIV-specific CD4+ T cell response observed in HIV-infected individuals.

  14. HCA520, A NOVEL TUMOR ASSOCIATED ANTIGEN, INVOLVED IN CELL PROLIFERATION AND APOPTOSIS

    Institute of Scientific and Technical Information of China (English)

    杨美香; 曲迅; 刘福利; 郑广娟

    2003-01-01

    Objective: Tumor associated antigen encoding gene HCA520 (AF146019) was identified by screening a human hepatocellular carcinoma expressing cDNA library using SEREX technique. In this experiment we studied the effect of HCA520 on cell proliferation and apoptosis. Methods: Gene HCA520 was gained by PCR and transfected into 293 cells. The stable expression cells were obtained by G418 selection. The cell proliferation was measured by [3H]-TdR uptake and apoptosis assay was measured by FACS. Results: Eukaryotic expression plasmid pcDNA3-HCA520 was constructed and its stable transfectants were obtained. Overexpression of HCA520 inhibited the cell proliferation and enhanced cell apoptosis after serum deprivation. Conclusion: HCA520 is a novel tumor associated antigen that can affect cell proliferation and apoptosis.

  15. The perivascular phagocyte of the mouse pineal gland: An antigen-presenting cell

    DEFF Research Database (Denmark)

    Møller, Morten; Rath, Martin F; Klein, David C

    2006-01-01

    The perivascular space of the rat pineal gland is known to contain phagocytic cells that are immunoreactive for leukocyte antigens, and thus they appear to belong to the macrophage/microglial cell line. These cells also contain MHC class II proteins. We investigated this cell type in the pineal...... gland of mice. Actively phagocytosing cells with a prominent lysosomal system were found in the pericapillary spaces of the mouse pineal gland following intravenous injection of horseradish peroxidase. The cells also exhibited strong acid phosphatase activity. Perivascular cells were immunopositive...... for MHC class II protein and for CD68, a marker of monocytes/phagocytes. This study verifies that perivascular phagocytes with antigen-presenting properties are present in the mouse pineal gland....

  16. Viral Escape Mutant Epitope Maintains TCR Affinity for Antigen yet Curtails CD8 T Cell Responses.

    Directory of Open Access Journals (Sweden)

    Shayla K Shorter

    Full Text Available T cells have the remarkable ability to recognize antigen with great specificity and in turn mount an appropriate and robust immune response. Critical to this process is the initial T cell antigen recognition and subsequent signal transduction events. This antigen recognition can be modulated at the site of TCR interaction with peptide:major histocompatibility (pMHC or peptide interaction with the MHC molecule. Both events could have a range of effects on T cell fate. Though responses to antigens that bind sub-optimally to TCR, known as altered peptide ligands (APL, have been studied extensively, the impact of disrupting antigen binding to MHC has been highlighted to a lesser extent and is usually considered to result in complete loss of epitope recognition. Here we present a model of viral evasion from CD8 T cell immuno-surveillance by a lymphocytic choriomeningitis virus (LCMV escape mutant with an epitope for which TCR affinity for pMHC remains high but where the antigenic peptide binds sub optimally to MHC. Despite high TCR affinity for variant epitope, levels of interferon regulatory factor-4 (IRF4 are not sustained in response to the variant indicating differences in perceived TCR signal strength. The CD8+ T cell response to the variant epitope is characterized by early proliferation and up-regulation of activation markers. Interestingly, this response is not maintained and is characterized by a lack in IL-2 and IFNγ production, increased apoptosis and an abrogated glycolytic response. We show that disrupting the stability of peptide in MHC can effectively disrupt TCR signal strength despite unchanged affinity for TCR and can significantly impact the CD8+ T cell response to a viral escape mutant.

  17. Myeloid dendritic cells frequencies are increased in children with autism spectrum disorder and associated with amygdala volume and repetitive behaviors.

    Science.gov (United States)

    Breece, Elizabeth; Paciotti, Brian; Nordahl, Christine Wu; Ozonoff, Sally; Van de Water, Judy A; Rogers, Sally J; Amaral, David; Ashwood, Paul

    2013-07-01

    The pathophysiology of autism spectrum disorder (ASD) is not yet known; however, studies suggest that dysfunction of the immune system affects many children with ASD. Increasing evidence points to dysfunction of the innate immune system including activation of microglia and perivascular macrophages, increases in inflammatory cytokines/chemokines in brain tissue and CSF, and abnormal peripheral monocyte cell function. Dendritic cells are major players in innate immunity and have important functions in the phagocytosis of pathogens or debris, antigen presentation, activation of naïve T cells, induction of tolerance and cytokine/chemokine production. In this study, we assessed circulating frequencies of myeloid dendritic cells (defined as Lin-1(-)BDCA1(+)CD11c(+) and Lin-1(-)BDCA3(+)CD123(-)) and plasmacytoid dendritic cells (Lin-1(-)BDCA2(+)CD123(+) or Lin-1(-)BDCA4(+) CD11c(-)) in 57 children with ASD, and 29 typically developing controls of the same age, all of who were enrolled as part of the Autism Phenome Project (APP). The frequencies of dendritic cells and associations with behavioral assessment and MRI measurements of amygdala volume were compared in the same participants. The frequencies of myeloid dendritic cells were significantly increased in children with ASD compared to typically developing controls (pfrequencies of myeloid dendritic cells were positively associated with abnormal right and left amygdala enlargement, severity of gastrointestinal symptoms and increased repetitive behaviors. The frequencies of plasmacytoid dendritic cells were also associated with amygdala volumes as well as developmental regression in children with ASD. Dendritic cells play key roles in modulating immune responses and differences in frequencies or functions of these cells may result in immune dysfunction in children with ASD. These data further implicate innate immune cells in the complex pathophysiology of ASD.

  18. Whole tumor antigen vaccination using dendritic cells: Comparison of RNA electroporation and pulsing with UV-irradiated tumor cells

    Directory of Open Access Journals (Sweden)

    Benencia Fabian

    2008-04-01

    Full Text Available Abstract Because of the lack of full characterization of tumor associated antigens for solid tumors, whole antigen use is a convenient approach to tumor vaccination. Tumor RNA and apoptotic tumor cells have been used as a source of whole tumor antigen to prepare dendritic cell (DC based tumor vaccines, but their efficacy has not been directly compared. Here we compare directly RNA electroporation and pulsing of DCs with whole tumor cells killed by ultraviolet (UV B radiation using a convenient tumor model expressing human papilloma virus (HPV E6 and E7 oncogenes. Although both approaches led to DCs presenting tumor antigen, electroporation with tumor cell total RNA induced a significantly higher frequency of tumor-reactive IFN-gamma secreting T cells, and E7-specific CD8+ lymphocytes compared to pulsing with UV-irradiated tumor cells. DCs electroporated with tumor cell RNA induced a larger tumor infiltration by T cells and produced a significantly stronger delay in tumor growth compared to DCs pulsed with UV-irradiated tumor cells. We conclude that electroporation with whole tumor cell RNA and pulsing with UV-irradiated tumor cells are both effective in eliciting antitumor immune response, but RNA electroporation results in more potent tumor vaccination under the examined experimental conditions.

  19. Limited transplantation of antigen-expressing hematopoietic stem cells induces long-lasting cytotoxic T cell responses.

    Directory of Open Access Journals (Sweden)

    Warren L Denning

    Full Text Available Harnessing the ability of cytotoxic T lymphocytes (CTLs to recognize and eradicate tumor or pathogen-infected cells is a critical goal of modern immune-based therapies. Although multiple immunization strategies efficiently induce high levels of antigen-specific CTLs, the initial increase is typically followed by a rapid contraction phase resulting in a sharp decline in the frequency of functional CTLs. We describe a novel approach to immunotherapy based on a transplantation of low numbers of antigen-expressing hematopoietic stem cells (HSCs following nonmyeloablative or partially myeloablative conditioning. Continuous antigen presentation by a limited number of differentiated transgenic hematopoietic cells results in an induction and prolonged maintenance of fully functional effector T cell responses in a mouse model. Recipient animals display high levels of antigen-specific CTLs four months following transplantation in contrast to dendritic cell-immunized animals in which the response typically declines at 4-6 weeks post-immunization. Majority of HSC-induced antigen-specific CD8+ T cells display central memory phenotype, efficiently kill target cells in vivo, and protect recipients against tumor growth in a preventive setting. Furthermore, we confirm previously published observation that high level engraftment of antigen-expressing HSCs following myeloablative conditioning results in tolerance and an absence of specific cytotoxic activity in vivo. In conclusion, the data presented here supports potential application of immunization by limited transplantation of antigen-expressing HSCs for the prevention and treatment of cancer and therapeutic immunization of chronic infectious diseases such as HIV-1/AIDS.

  20. Molecular characterization of antigen-peptide pulsed dendritic cells: immature dendritic cells develop a distinct molecular profile when pulsed with antigen peptide.

    Directory of Open Access Journals (Sweden)

    Amy X Yang

    Full Text Available As dendritic cells (DCs are the most potent professional antigen-presenting cells, they are being tested as cancer vaccines for immunotherapy of established cancers. Although numerous studies have characterized DCs by their phenotype and function, few have identified potential molecular markers of antigen presentation prior to vaccination of host. In this study we generated pre-immature DC (piDC, immature DC (iDC, and mature DC (mDC from human peripheral blood monocytes (PBMC obtained from HLA-A2 healthy donors, and pulsed them with human papillomavirus E7 peptide (p11-20, a class I HLA-A2 binding antigen. We then characterized DCs for cell surface phenotype and gene expression profile by microarray technology. We identified a set of 59 genes that distinguished three differentiation stages of DCs (piDC, iDC and mDC. When piDC, iDC and mDC were pulsed with E7 peptide for 2 hrs, the surface phenotype did not change, however, iDCs rather than mDCs showed transcriptional response by up-regulation of a set of genes. A total of 52 genes were modulated in iDC upon antigen pulsing. Elongation of pulse time for iDCs to 10 and 24 hrs did not significantly bring further changes in gene expression. The E7 peptide up-modulated immune response (KPNA7, IGSF6, NCR3, TREM2, TUBAL3, IL8, NFKBIA, pro-apoptosis (BTG1, SEMA6A, IGFBP3 and SRGN, anti-apoptosis (NFKBIA, DNA repair (MRPS11, RAD21, TXNRD1, and cell adhesion and cell migration genes (EPHA1, PGF, IL8 and CYR61 in iDCs. We confirmed our results by Q-PCR analysis. The E7 peptide but not control peptide (PADRE induced up-regulation of NFKB1A gene only in HLA-A2 positive iDCs and not in HLA-A2 negative iDCs. These results suggest that E7 up-regulation of genes is specific and HLA restricted and that these genes may represent markers of antigen presentation and help rapidly assess the quality of dendritic cells prior to administration to the host.

  1. Cord Blood Derived CD4+CD25high T Cells Become Functional Regulatory T Cells upon Antigen Encounter

    Science.gov (United States)

    Mayer, Elisabeth; Bannert, Christina; Gruber, Saskia; Klunker, Sven; Spittler, Andreas; Akdis, Cezmi A.

    2012-01-01

    Background: Upon antigen exposure, cord blood derived T cells respond to ubiquitous environmental antigens by high proliferation. To date it remains unclear whether these “excessive” responses relate to different regulatory properties of the putative T regulatory cell (Treg) compartment or even expansion of the Treg compartment itself. Methods: Cord blood (>37 week of gestation) and peripheral blood (healthy controls) were obtained and different Treg cell subsets were isolated. The suppressive potential of Treg populations after antigen exposure was evaluated via functional inhibition assays ([3H]thymidine incorporation assay and CFSE staining) with or without allergen stimulation. The frequency and markers of CD4+CD25highFoxP3+ T cells were characterized by mRNA analysis and flow cytometry. Results: Cord blood derived CD4+CD25high cells did not show substantial suppressor capacity upon TCR activation, in contrast to CD4+CD25high cells freshly purified from adult blood. This could not be explained by a lower frequency of FoxP3+CD4+CD25highcells or FOXP3 mRNA expression. However, after antigen-specific stimulation in vitro, these cells showed strong proliferation and expansion and gained potent suppressive properties. The efficiency of their suppressive capacity can be enhanced in the presence of endotoxins. If T-cells were sorted according to their CD127 expression, a tiny subset of Treg cells (CD4+CD25+CD127low) is highly suppressive even without prior antigen exposure. Conclusion: Cord blood harbors a very small subset of CD4+CD25high Treg cells that requires antigen-stimulation to show expansion and become functional suppressive Tregs. PMID:22272233

  2. The peripheral blood fibrocyte is a potent antigen-presenting cell capable of priming naive T cells in situ.

    Science.gov (United States)

    Chesney, J; Bacher, M; Bender, A; Bucala, R

    1997-06-10

    Recent studies have identified a novel population of blood-borne cells, termed fibrocytes, that have a distinct cell surface phenotype (collagen+/CD13(+)/CD34(+)/CD45(+)), rapidly enter sites of tissue injury, and synthesize connective tissue matrix molecules. We found by flow cytometry that purified human fibrocytes express each of the known surface components that are required for antigen presentation, including class II major histocompatability complex molecules (HLA-DP, -DQ, and -DR), the costimulatory molecules CD80 and CD86, and the adhesion molecules CD11a, CD54, and CD58. Human fibrocytes induced antigen-presenting cell-dependent T cell proliferation when cultured with specific antigen and this proliferative activity was significantly higher than that induced by monocytes and nearly as high as that induced by purified dendritic cells. Mouse fibrocytes also were found to express the surface components required for antigen presentation and to function as potent APCs in vitro. Mouse fibrocytes pulsed in vitro with the HIV-proteins p24 or gp120 and delivered to a site of cutaneous injury were found to migrate to proximal lymph nodes and to specifically prime naive T cells. These data suggest that fibrocytes play an early and important role in the initiation of antigen-specific immunity.

  3. Antibodies to new beta cell antigen ICA12 in Latvian diabetes patients.

    Science.gov (United States)

    Shtauvere-Brameus, A; Hagopian, W; Rumba, I; Sanjeevi, C B

    2002-04-01

    In Latvia diabetes mellitus is diagnosed using the WHO's clinical criteria, and assays for the detection of autoantibodies are not available. In consequence, slowly progressive autoimmune diabetes or LADA is likely to be missed. Antibodies to GAD65 and IA-2 are the major immunological markers in autoimmune diabetes. Recently, a new beta cell antigen, called ICA12, has been identified, which has a homology to the SOX family of transcription factors. The aim of the study was to analyze the prevalence of ICA12 antibodies in diabetes mellitus patients and controls from Latvia and to see whether this antigen is important in revealing autoimmunity when antibodies against major antigens are not present. We studied 88 IDDM patients and 100 NIDDM patients as well as controls for the prevalence of GAD65, IA-2, and ICA12 antibodies by radioligand binding assay (RIA) using (35)S-labeled islet antigens. We found ICA12Abs in 26 of 88 IDDM patients (30%) vs. 4% in healthy controls (4/100) and in 9 of 100 NIDDM patients (9%) vs. 2% controls (2/100). ICA12Abs alone are present in only 3% (3/88) of the patients with IDDM and 1% (1/100) of the NIDDM patients. We conclude that ICA12 represents the minor antigens in autoimmune diabetes and that, as a minor antigen, ICA12 alone does not contribute significantly in revealing new cases of autoimmunity.

  4. Expression of the Gastrin-Releasing Peptide Receptor, the Prostate Stem Cell Antigen and the Prostate-Specific Membrane Antigen in Lymph Node and Bone Metastases of Prostate Cancer

    NARCIS (Netherlands)

    Ananias, Hildo J. K.; van den Heuvel, Marius C.; Helfrich, Wijnand; de Jong, Igle J.

    2009-01-01

    OBJECTIVE. Cell membrane antigens like the gastrin-releasing peptide receptor (GRPR), the prostate stem cell antigen (PSCA), and the prostate-specific membrane antigen (PSMA), expressed in prostate cancer, are attractive targets for new therapeutic and diagnostic applications. Therefore, we investig

  5. Evaluation of germ-cell kinetics in infertile patients with proliferating cell nuclear antigen proliferating index

    Institute of Scientific and Technical Information of China (English)

    Li ZENG; Xiang-Tian KONG; Jin-Wei SU; Tong-Li XIA; Yan-Qun NA; Ying-Lu GUO

    2001-01-01

    To explore the usefulness of proliferating cell nuclear antigen proliferating index (PCNA PI) in the pathological diagnosis and treatment of male infertility. Methods: Testicular biopsy specimen obtained from 48 cases of male infertility and 2 normal controls were fixed and embedded. The sections were stained with anti-PCNA monoclonal antibodies or haematoxylin/eosin. Proliferating index (PI), expressed as the percentage of germ-cell nuclei positively stained with PCNA antibody, was assessed from more than 20 seminiferous tubules or 600 germ-cells. Results: The infertile patients were divided into 4 groups: Group 1, normal spermatogenesis ( 14 cases); Group 2, hypospermatogenesis (16 cases); Group 3, germinal arrest (10 cases); Group 4, Sertoli cell only syndrome (8 cases). The PCNA PI of normal control testis was 86.5% (mean value). Group 3 had a significantly lower PCNA PI (29.8%) than normal testis; Group 1 and 2 had similar Pis (82.3% and 82.3%, respectively) as the control testis. PI of the negative control (Group 4) was 0 as no germ-cells were found. Conclusion: PCNA PI is useful for assessing germ-cell kinetics, especially for pathological diagnosis of germinal arrest which is difficult to differentiate by routine HE staining technique. In germinal arrest, there is a significantly lowered PCNA PI, which is an indication of DNA synthesis deterioration, suggesting the use of therapies be different from those for hypospermatogenesis.

  6. Longitudinal microarray analysis of cell surface antigens on peripheral blood mononuclear cells from HIV+ individuals on highly active antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Wang Bin

    2008-03-01

    Full Text Available Abstract Background The efficacy of highly active antiretroviral therapy (HAART determined by simultaneous monitoring over 100 cell-surface antigens overtime has not been attempted. We used an antibody microarray to analyze changes in the expression of 135 different cell-surface antigens overtime on PBMC from HIV+ patients on HAART. Two groups were chosen, one (n = 6 achieved sustainable response by maintaining below detectable plasma viremia and the other (n = 6 responded intermittently. Blood samples were collected over an average of 3 years and 5–8 time points were selected for microarray assay and statistical analysis. Results Significant trends over time were observed for the expression of 7 cell surface antigens (CD2, CD3epsilon, CD5, CD95, CD36, CD27 and CD28 for combined patient groups. Between groups, expression levels of 10 cell surface antigens (CD11a, CD29, CD38, CD45RO, CD52, CD56, CD57, CD62E, CD64 and CD33 were found to be differential. Expression levels of CD9, CD11a, CD27, CD28 and CD52, CD44, CD49d, CD49e, CD11c strongly correlated with CD4+ and CD8+ T cell counts, respectively. Conclusion Our findings not only detected markers that may have potential prognostic/diagnostic values in evaluating HAART efficacy, but also showed how density of cell surface antigens could be efficiently exploited in an array-like manner in relation to HAART and HIV-infection. The antigens identified in this study should be further investigated by other methods such as flow cytometry for confirmation as biological analysis of these antigens may help further clarify their role during HAART and HIV infection.

  7. Structural characteristics of an antigen required for its interaction with Ia and recognition by T cells

    DEFF Research Database (Denmark)

    Sette, A; Buus, S; Colon, S;

    1987-01-01

    A detailed analysis of the residues within an immunogenic peptide that endow it with the capacity to interact with Ia and to be recognized by T cells is presented. Ia interacts with only a few of the peptide residues and overall exhibits a very broad specificity. Some residues appear to interact...... both with Ia and with T cells, leading to a model in which a peptide antigen is 'sandwiched' between Ia and the T-cell receptor....

  8. Nanoscale Patterning of Antigen on Silicon Substrate to Examine Mast Cell Activation

    Science.gov (United States)

    2002-04-01

    Examine Mast Cell Activation DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report: TITLE...Materials Research Society N4.3 Nanoscale Patterning of Antigen on Silicon Substrate to Examine Mast Cell Activation Reid N. Orth", Min Wu2 , Theodore G...nanometer scale to spatially control the stimulation of specific immunoreceptors on RBL mast cells . This work was motivated by previous research to

  9. Antigen-presenting cells transfected with Hsp65 messenger RNA fail to treat experimental tuberculosis

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, C.D.; Trombone, A.P.F.; Lorenzi, J.C.C.; Almeida, L.P.; Gembre, A.F.; Padilha, E. [Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Ramos, S.G. [Departamento de Patologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Silva, C.L.; Coelho-Castelo, A.A.M. [Departamento de Bioquímica e Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP (Brazil)

    2012-09-21

    In the last several years, the use of dendritic cells has been studied as a therapeutic strategy against tumors. Dendritic cells can be pulsed with peptides or full-length protein, or they can be transfected with DNA or RNA. However, comparative studies suggest that transfecting dendritic cells with messenger RNA (mRNA) is superior to other antigen-loading techniques in generating immunocompetent dendritic cells. In the present study, we evaluated a new therapeutic strategy to fight tuberculosis using dendritic cells and macrophages transfected with Hsp65 mRNA. First, we demonstrated that antigen-presenting cells transfected with Hsp65 mRNA exhibit a higher level of expression of co-stimulatory molecules, suggesting that Hsp65 mRNA has immunostimulatory properties. We also demonstrated that spleen cells obtained from animals immunized with mock and Hsp65 mRNA-transfected dendritic cells were able to generate a mixed Th1/Th2 response with production not only of IFN-γ but also of IL-5 and IL-10. In contrast, cells recovered from mice immunized with Hsp65 mRNA-transfected macrophages were able to produce only IL-5. When mice were infected with Mycobacterium tuberculosis and treated with antigen-presenting cells transfected with Hsp65 mRNA (therapeutic immunization), we did not detect any decrease in the lung bacterial load or any preservation of the lung parenchyma, indicating the inability of transfected cells to confer curative effects against tuberculosis. In spite of the lack of therapeutic efficacy, this study reports for the first time the use of antigen-presenting cells transfected with mRNA in experimental tuberculosis.

  10. Mapping of B-Cell Epitopes in a Trypanosoma cruzi Immunodominant Antigen Expressed in Natural Infections

    Science.gov (United States)

    Lesénéchal, Mylène; Becquart, Laurence; Lacoux, Xavier; Ladavière, Laurent; Baida, Renata C. P.; Paranhos-Baccalà, Glaucia; da Silveira, José Franco

    2005-01-01

    Tc40 is an immunodominant antigen present in natural Trypanosoma cruzi infections. This immunogen was thoroughly mapped by using overlapping amino acid sequences identified by gene cloning and chemical peptide synthesis. To map continuous epitopes of the Tc40 antigen, an epitope expression library was constructed and screened with sera from human chagasic patients. A major, linear B-cell epitope spanning residues 403 to 426 (PAKAAAPPAA) was identified in the central domain of Tc40. A synthetic peptide spanning this region reacted strongly with 89.8% of the serum samples from T. cruzi-infected individuals. This indicates that the main antigenic site is defined by the linear sequence of the peptide rather than a conformation-dependent structure. The major B-cell epitope of Tc40 shares a high degree of sequence identity with T. cruzi ribosomal and RNA binding proteins, suggesting the existence of cross-reactivity among these molecules. PMID:15699429

  11. The dendritic cell-specific C-type lectin DC-SIGN is a receptor for Schistosoma mansoni egg antigens and recognizes the glycan antigen Lewis x.

    NARCIS (Netherlands)

    Die, van I.M.; Vliet, van SJ; Nyame, AK; Cummings, RD; Bank, CM; Appelmelk, B.J.; Geijtenbeek, T.B.H.; Kooijk, van Y.

    2003-01-01

    Schistosoma mansoni soluble egg antigens (SEAs) are crucially involved in modulating the host immune response to infection by S. mansoni. We report that human dendritic cells bind SEAs through the C-type lectin dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN). Monoclonal antibodies agai

  12. Dichotomy of the human T cell response to Leishmania antigens. I. Th1-like response to Leishmania major promastigote antigens in individuals recovered from cutaneous leishmaniasis

    DEFF Research Database (Denmark)

    Kemp, M; Hey, A S; Kurtzhals, J A

    1994-01-01

    The T cell response to antigens from Leishmania major promastigotes was investigated in peripheral blood mononuclear cells from Sudanese individuals with a history of cutaneous leishmaniasis (CL), Sudanese individuals with positive DTH reaction in the leishmanin skin test but with no history...

  13. Large, but not small, antigens require time- and temperature-dependent processing in accessory cells before they can be recognized by T cells

    DEFF Research Database (Denmark)

    Buus, S; Werdelin, O

    1986-01-01

    of antigen presentation we used the proliferative response of appropriately primed T cells during a co-culture with the paraformaldehyde-fixed and antigen-exposed presenting cells. We demonstrate that the large synthetic polypeptide antigen, dinitrophenyl-poly-L-lysine, requires processing. After an initial...... time-lag of 30 min this antigen is fully processed within 2 to 4 of culture at 37 degrees C. In contrast, the immunogenic heptapeptide, angiotensin III, can be presented by pre-fixed accessory cells, viz. without any prior processing. Antigen processing was found to be temperature...

  14. Phenotype of Antigen Unexperienced TH Cells in the Inflamed Central Nervous System in Experimental Autoimmune Encephalomyelitis.

    Science.gov (United States)

    Franck, Sophia; Paterka, Magdalena; Birkenstock, Jerome; Zipp, Frauke; Siffrin, Volker; Witsch, Esther

    2016-11-10

    Multiple sclerosis is a chronic, disseminated inflammation of the central nervous system which is thought to be driven by autoimmune T cells. Genetic association studies in multiple sclerosis and a large number of studies in the animal model of the disease support a role for effector/memory T helper cells. However, the mechanisms underlying relapses, remission and chronic progression in multiple sclerosis or the animal model experimental autoimmune encephalomyelitis, are not clear. In particular, there is only scarce information on the role of central nervous system-invading naive T helper cells in these processes. By applying two-photon laser scanning microscopy we could show in vivo that antigen unexperienced T helper cells migrated into the deep parenchyma of the inflamed central nervous system in experimental autoimmune encephalomyelitis, independent of their antigen specificity. Using flow cytometric analyses of central nervous system-derived lymphocytes we found that only antigen-specific, formerly naive T helper cells became activated during inflammation of the central nervous system encountering their corresponding antigen.

  15. CD8α− Dendritic Cells Induce Antigen-Specific T Follicular Helper Cells Generating Efficient Humoral Immune Responses

    Directory of Open Access Journals (Sweden)

    Changsik Shin

    2015-06-01

    Full Text Available Recent studies on T follicular helper (Tfh cells have significantly advanced our understanding of T cell-dependent B cell responses. However, little is known about the early stage of Tfh cell commitment by dendritic cells (DCs, particularly by the conventional CD8α+ and CD8α− DC subsets. We show that CD8α− DCs localized at the interfollicular zone play a pivotal role in the induction of antigen-specific Tfh cells by upregulating the expression of Icosl and Ox40l through the non-canonical NF-κB signaling pathway. Tfh cells induced by CD8α− DCs function as true B cell helpers, resulting in significantly increased humoral immune responses against various human pathogenic antigens, including Yersinia pestis LcrV, HIV Gag, and hepatitis B surface antigen. Our findings uncover a mechanistic role of CD8α− DCs in the initiation of Tfh cell differentiation and thereby provide a rationale for investigating CD8α− DCs in enhancing antigen-specific humoral immune responses for improving vaccines and therapeutics.

  16. Chimeric antigen receptor T cells: a novel therapy for solid tumors.

    Science.gov (United States)

    Yu, Shengnan; Li, Anping; Liu, Qian; Li, Tengfei; Yuan, Xun; Han, Xinwei; Wu, Kongming

    2017-03-29

    The chimeric antigen receptor T (CAR-T) cell therapy is a newly developed adoptive antitumor treatment. Theoretically, CAR-T cells can specifically localize and eliminate tumor cells by interacting with the tumor-associated antigens (TAAs) expressing on tumor cell surface. Current studies demonstrated that various TAAs could act as target antigens for CAR-T cells, for instance, the type III variant epidermal growth factor receptor (EGFRvIII) was considered as an ideal target for its aberrant expression on the cell surface of several tumor types. CAR-T cell therapy has achieved gratifying breakthrough in hematological malignancies and promising outcome in solid tumor as showed in various clinical trials. The third generation of CAR-T demonstrates increased antitumor cytotoxicity and persistence through modification of CAR structure. In this review, we summarized the preclinical and clinical progress of CAR-T cells targeting EGFR, human epidermal growth factor receptor 2 (HER2), and mesothelin (MSLN), as well as the challenges for CAR-T cell therapy.

  17. [The surface glycolipid antigen specific for the internal cell mass of the mouse blastocyst and of the stem cells of murine teratocarcinoma F9].

    Science.gov (United States)

    Anfimova, M L; Bannikov, G A; Troianovskiĭ, S M

    1989-01-01

    A new monoclonal antibody that recognizes a new antigen on the surface of mouse teratocarcinoma F9 stem cells has been described. This antigen is a glycolipid as demonstrated by inhibition of immunofluorescence by different monosaccharides, glycoproteins and glycolipid fraction of F9 cells as well as by chemical analysis. Immunofluorescent staining of in vitro cultivated preimplantation mouse embryos has demonstrated that this antigen is specific only of internal cell mass cells of late blastocyst.

  18. Antigen-induced recruitment of eosinophils: importance of CD4+ T cells, IL5, and mast cells.

    Science.gov (United States)

    Hom, J T; Estridge, T

    1994-12-01

    Eosinophils of sensitized mice readily recruit to the site of antigen challenge. In the present study, experiments were performed to determine the involvement of different cell types in the antigen-induced recruitment of eosinophils. We demonstrated that a single treatment with anti-L3T4 monoclonal antibody (mAb) on the day of allergen challenge significantly decreased antigen-induced recruitment of eosinophils. Treatments with anti-L3T4 mAb during the sensitization period also caused a substantial reduction in the migration of eosinophils into the site of challenge with antigen. Thus, it appears that both stages of eosinophil recruitment, sensitization and antigen-challenge, are dependent upon the presence of L3T4+ T cells. Moreover, while treatments with anti-IL5 mAb blocked eosinophil migration, anti-IL2 mAb failed to alter the antigen-induced recruitment of eosinophils. In addition, significant numbers of eosinophils from the mast-cell-deficient mice were found to migrate into the peritoneal cavities upon allergen challenge. Eosinophil migration was also observed in several mouse strains of different H-2 haplotypes. The present findings suggest that CD4+ T cells and IL5 but not IL2 may play important roles in modulating the recruitment of eosinophils. Moreover, the involvement of mast cells does not appear to be essential for eosinophil migration. Finally, the development of antigen-induced recruitment of eosinophils is probably not under the immunogenetic regulation by genes within the H-2 complex.

  19. Modulation of Immune Responses by Exosomes Derived from Antigen-Presenting Cells

    Science.gov (United States)

    Shenoda, Botros B.; Ajit, Seena K.

    2016-01-01

    Exosome-mediated signaling is important in mediating the inflammatory response. To exert their biological or pathophysiological functions in the recipient cells, exosomes deliver a diverse array of biomacromolecules including long and short coding and non-coding RNAs, proteins, and lipids. Exosomes secreted by antigen-presenting cells can confer therapeutic benefits by attenuating or stimulating the immune response. Exosomes play a crucial role in carrying and presenting functional major histocompatibility peptide complexes to modulate antigen-specific T cell responses. Exosomes from Dendritic Cells (DCs) can activate T and B cells and have been explored for their immunostimulatory properties in cancer therapy. The immunosuppressive properties of exosomes derived from macrophages and DCs can reduce inflammation in animal models for several inflammatory disorders. This review focuses on the protective role of exosomes in attenuating inflammation or augmenting immune response, emphasizing studies on exosomes derived from DCs and macrophages. PMID:27660518

  20. Efficient induction of CD25- iTreg by co-immunization requires strongly antigenic epitopes for T cells

    Directory of Open Access Journals (Sweden)

    Li Jinyao

    2011-05-01

    Full Text Available Abstract Background We previously showed that co-immunization with a protein antigen and a DNA vaccine coding for the same antigen induces CD40low IL-10high tolerogenic DCs, which in turn stimulates the expansion of antigen-specific CD4+CD25-Foxp3+ regulatory T cells (CD25- iTreg. However, it was unclear how to choose the antigen sequence to maximize tolerogenic antigen presentation and, consequently, CD25- iTreg induction. Results In the present study, we demonstrated the requirement of highly antigenic epitopes for CD25- iTreg induction. Firstly, we showed that the induction of CD25- iTreg by tolerogenic DC can be blocked by anti-MHC-II antibody. Next, both the number and the suppressive activity of CD25- iTreg correlated positively with the overt antigenicity of an epitope to activate T cells. Finally, in a mouse model of dermatitis, highly antigenic epitopes derived from a flea allergen not only induced more CD25- iTreg, but also more effectively prevented allergenic reaction to the allergen than did weakly antigenic epitopes. Conclusions Our data thus indicate that efficient induction of CD25- iTreg requires highly antigenic peptide epitopes. This finding suggests that highly antigenic epitopes should be used for efficient induction of CD25- iTreg for clinical applications such as flea allergic dermatitis.

  1. Antigen-sensitized CD4+CD62Llow memory/effector T helper 2 cells can induce airway hyperresponsiveness in an antigen free setting

    Directory of Open Access Journals (Sweden)

    Nagatani Katsuya

    2005-05-01

    Full Text Available Abstract Background Airway hyperresponsiveness (AHR is one of the most prominent features of asthma, however, precise mechanisms for its induction have not been fully elucidated. We previously reported that systemic antigen sensitization alone directly induces AHR before development of eosinophilic airway inflammation in a mouse model of allergic airway inflammation, which suggests a critical role of antigen-specific systemic immune response itself in the induction of AHR. In the present study, we examined this possibility by cell transfer experiment, and then analyzed which cell source was essential for this process. Methods BALB/c mice were immunized with ovalbumin (OVA twice. Spleen cells were obtained from the mice and were transferred in naive mice. Four days later, AHR was assessed. We carried out bronchoalveolar lavage (BAL to analyze inflammation and cytokine production in the lung. Fluorescence and immunohistochemical studies were performed to identify T cells recruiting and proliferating in the lung or in the gut of the recipient. To determine the essential phenotype, spleen cells were column purified by antibody-coated microbeads with negative or positive selection, and transferred. Then, AHR was assessed. Results Transfer of spleen cells obtained from OVA-sensitized mice induced a moderate, but significant, AHR without airway antigen challenge in naive mice without airway eosinophilia. Immunization with T helper (Th 1 elicited antigen (OVA with complete Freund's adjuvant did not induce the AHR. Transferred cells distributed among organs, and the cells proliferated in an antigen free setting for at least three days in the lung. This transfer-induced AHR persisted for one week. Interleukin-4 and 5 in the BAL fluid increased in the transferred mice. Immunoglobulin E was not involved in this transfer-induced AHR. Transfer of in vitro polarized CD4+ Th2 cells, but not Th1 cells, induced AHR. We finally clarified that CD4+CD62Llow memory

  2. Antigen-Specific Th17 Cells Are Primed by Distinct and Complementary Dendritic Cell Subsets in Oropharyngeal Candidiasis.

    Directory of Open Access Journals (Sweden)

    Kerstin Trautwein-Weidner

    2015-10-01

    Full Text Available Candida spp. can cause severe and chronic mucocutaneous and systemic infections in immunocompromised individuals. Protection from mucocutaneous candidiasis depends on T helper cells, in particular those secreting IL-17. The events regulating T cell activation and differentiation toward effector fates in response to fungal invasion in different tissues are poorly understood. Here we generated a Candida-specific TCR transgenic mouse reactive to a novel endogenous antigen that is conserved in multiple distant species of Candida, including the clinically highly relevant C. albicans and C. glabrata. Using TCR transgenic T cells in combination with an experimental model of oropharyngeal candidiasis (OPC we investigated antigen presentation and Th17 priming by different subsets of dendritic cells (DCs present in the infected oral mucosa. Candida-derived endogenous antigen accesses the draining lymph nodes and is directly presented by migratory DCs. Tissue-resident Flt3L-dependent DCs and CCR2-dependent monocyte-derived DCs collaborate in antigen presentation and T cell priming during OPC. In contrast, Langerhans cells, which are also present in the oral mucosa and have been shown to prime Th17 cells in the skin, are not required for induction of the Candida-specific T cell response upon oral challenge. This highlights the functional compartmentalization of specific DC subsets in different tissues. These data provide important new insights to our understanding of tissue-specific antifungal immunity.

  3. Three-day dendritic cells for vaccine development: Antigen uptake, processing and presentation

    Directory of Open Access Journals (Sweden)

    Schendel Dolores J

    2010-09-01

    Full Text Available Abstract Background Antigen-loaded dendritic cells (DC are capable of priming naïve T cells and therefore represent an attractive adjuvant for vaccine development in anti-tumor immunotherapy. Numerous protocols have been described to date using different maturation cocktails and time periods for the induction of mature DC (mDC in vitro. For clinical application, the use of mDC that can be generated in only three days saves on the costs of cytokines needed for large scale vaccine cell production and provides a method to produce cells within a standard work-week schedule in a GMP facility. Methods In this study, we addressed the properties of antigen uptake, processing and presentation by monocyte-derived DC prepared in three days (3d mDC compared with conventional DC prepared in seven days (7d mDC, which represent the most common form of DC used for vaccines to date. Results Although they showed a reduced capacity for spontaneous antigen uptake, 3d mDC displayed higher capacity for stimulation of T cells after loading with an extended synthetic peptide that requires processing for MHC binding, indicating they were more efficient at antigen processing than 7d DC. We found, however, that 3d DC were less efficient at expressing protein after introduction of in vitro transcribed (ivtRNA by electroporation, based on published procedures. This deficit was overcome by altering electroporation parameters, which led to improved protein expression and capacity for T cell stimulation using low amounts of ivtRNA. Conclusions This new procedure allows 3d mDC to replace 7d mDC for use in DC-based vaccines that utilize long peptides, proteins or ivtRNA as sources of specific antigen.

  4. Nematode-Derived Proteins Suppress Proliferation and Cytokine Production of Antigen-Specific T Cells via Induction of Cell Death

    Science.gov (United States)

    Hartmann, Wiebke; Brenz, Yannick; Kingsley, Manchang Tanyi; Ajonina-Ekoti, Irene; Brattig, Norbert W.; Liebau, Eva; Breloer, Minka

    2013-01-01

    In order to establish long-lasting infections in their mammalian host, filarial nematodes have developed sophisticated strategies to dampen their host’s immune response. Proteins that are actively secreted by the parasites have been shown to induce the expansion of regulatory T cells and to directly interfere with effector T cell function. Here, we analyze the suppressive capacity of Onchocercavolvulus-derived excreted/secreted proteins. Addition of two recombinant O. volvulus proteins, abundant larval transcript-2 (OvALT-2) and novel larval transcript-1 (OvNLT-1) to cell cultures of T cell receptor transgenic CD4+ and CD8+ T cells suppressed antigen-specific stimulation in vitro. Ovalbumin-specific CD4+ DO11.10 and OT-II T cells that had been stimulated with their cognate antigen in the presence of OvALT-2 or OvNLT-1 displayed reduced DNA synthesis quantified by 3H-thymidine incorporation and reduced cell division quantified by CFSE dilution. Furthermore, the IL-2 and IFN-γ response of ovalbumin-specific CD8+ OT-I T cells was suppressed by OvALT-2 and OvNLT-1. In contrast, another recombinant O. volvulus protein, microfilariae surface-associated antigen (Ov103), did not modulate T cell activation, thus serving as internal control for non-ESP-mediated artifacts. Suppressive capacity of the identified ESP was associated with induction of apoptosis in T cells demonstrated by increased exposure of phosphatidylserine on the plasma membrane. Of note, the digestion of recombinant proteins with proteinase K did not abolish the suppression of antigen-specific proliferation although the suppressive capacity of the identified excreted/secreted products was not mediated by low molecular weight contaminants in the undigested preparations. In summary, we identified two suppressive excreted/secreted products from O. volvulus, which interfere with the function of antigen-specific T cells in vitro. PMID:23861729

  5. Nematode-derived proteins suppress proliferation and cytokine production of antigen-specific T cells via induction of cell death.

    Directory of Open Access Journals (Sweden)

    Wiebke Hartmann

    Full Text Available In order to establish long-lasting infections in their mammalian host, filarial nematodes have developed sophisticated strategies to dampen their host's immune response. Proteins that are actively secreted by the parasites have been shown to induce the expansion of regulatory T cells and to directly interfere with effector T cell function. Here, we analyze the suppressive capacity of Onchocercavolvulus-derived excreted/secreted proteins. Addition of two recombinant O. volvulus proteins, abundant larval transcript-2 (OvALT-2 and novel larval transcript-1 (OvNLT-1 to cell cultures of T cell receptor transgenic CD4(+ and CD8(+ T cells suppressed antigen-specific stimulation in vitro. Ovalbumin-specific CD4(+ DO11.10 and OT-II T cells that had been stimulated with their cognate antigen in the presence of OvALT-2 or OvNLT-1 displayed reduced DNA synthesis quantified by (3H-thymidine incorporation and reduced cell division quantified by CFSE dilution. Furthermore, the IL-2 and IFN-γ response of ovalbumin-specific CD8(+ OT-I T cells was suppressed by OvALT-2 and OvNLT-1. In contrast, another recombinant O. volvulus protein, microfilariae surface-associated antigen (Ov103, did not modulate T cell activation, thus serving as internal control for non-ESP-mediated artifacts. Suppressive capacity of the identified ESP was associated with induction of apoptosis in T cells demonstrated by increased exposure of phosphatidylserine on the plasma membrane. Of note, the digestion of recombinant proteins with proteinase K did not abolish the suppression of antigen-specific proliferation although the suppressive capacity of the identified excreted/secreted products was not mediated by low molecular weight contaminants in the undigested preparations. In summary, we identified two suppressive excreted/secreted products from O. volvulus, which interfere with the function of antigen-specific T cells in vitro.

  6. Activated human nasal epithelial cells modulate specific antibody response against bacterial or viral antigens.

    Directory of Open Access Journals (Sweden)

    Chiou-Yueh Yeh

    Full Text Available Nasal mucosa is an immune responsive organ evidenced by eliciting both specific local secretory IgA and systemic IgG antibody responses with intra-nasal administration of antigens. Nevertheless, the role of nasal epithelial cells in modulating such responses is unclear. Human nasal epithelial cells (hNECs obtained from sinus mucosa of patients with chronic rhinosinusitis were cultured in vitro and firstly were stimulated by Lactococcus lactis bacterium-like particles (BLPs in order to examine their role on antibody production. Secondly, both antigens of immunodominant protein IDG60 from oral Streptococcus mutans and hemagglutinin (HA from influenza virus were tested to evaluate the specific antibody response. Stimulated hNECs by BLPs exhibited a significant increase in the production of interleukin-6 (IL-6, and thymic stromal lymphopoietin (TSLP. Conditioned medium of stimulated hNECs has effects on enhancing the proliferation of CD4+ T cells together with interferon-γ and IL-5 production, increasing the costimulatory molecules on dendritic cells and augmenting the production of IDG60 specific IgA, HA specific IgG, IgA by human peripheral blood lymphocytes. Such production of antigen specific IgG and IgA is significantly counteracted in the presence of IL-6 and TSLP neutralizing antibodies. In conclusion, properly stimulated hNECs may impart immuno-modulatory effects on the antigen-specific antibody response at least through the production of IL-6 and TSLP.

  7. Identification of Theileria lestoquardi Antigens Recognized by CD8+ T Cells

    Science.gov (United States)

    Ngugi, Daniel; Lizundia, Regina; Hostettler, Isabel; Woods, Kerry; Ballingall, Keith; MacHugh, Niall D.; Morrison, W. Ivan; Weir, Willie; Shiels, Brian; Werling, Dirk

    2016-01-01

    As part of an international effort to develop vaccines for Theileria lestoquardi, we undertook a limited screen to test T. lestoquardi orthologues of antigens recognised by CD8+ T lymphocyte responses against T. annulata and T. parva in cattle. Five MHC defined sheep were immunized by live T. lestoquardi infection and their CD8+ T lymphocyte responses determined. Thirteen T. lestoquardi orthologues of T. parva and T. annulata genes, previously shown to be targets of CD8+ T lymphocyte responses of immune cattle, were expressed in autologous fibroblasts and screened for T cell recognition using an IFNγ assay. Genes encoding T. lestoquardi antigens Tl8 (putative cysteine proteinase, 349 aa) or Tl9 (hypothetical secreted protein, 293 aa) were recognise by T cells from one animal that displayed a unique MHC class I genotype. Antigenic 9-mer peptide epitopes of Tl8 and Tl9 were identified through peptide scans using CD8+ T cells from the responding animal. These experiments identify the first T. lestoquardi antigens recognised by CD8+ T cell responses linked to specific MHC class I alleles. PMID:27611868

  8. MHC-based detection of antigen-specific CD8(+) T cell responses

    DEFF Research Database (Denmark)

    Hadrup, Sine Reker; Schumacher, Nana Maria Pii

    2010-01-01

    The hallmark of adaptive immunity is its ability to recognise a wide range of antigens and technologies that capture this diversity are therefore of substantial interest. New methods have recently been developed that allow the parallel analysis of T cell reactivity against vast numbers of differe...

  9. Aspergillus galactomannan antigen levels in allogeneic haematopoietic stem cell transplant recipients given total parenteral nutrition.

    NARCIS (Netherlands)

    Blijlevens, N.M.A.; Donnelly, J.P.; Meis, J.F.G.M.; Verweij, P.E.; Pauw, B.E. de

    2002-01-01

    False-positive tests for Aspergillus galactomannan have been reported in neutropenic patients. We failed to detect any circulating antigen during the 2 weeks following allogeneic haematopoietic stem cell transplantation of 12 patients who had severe mucositis but were unable to eat.

  10. Defining the HLA class I-associated viral antigen repertoire from HIV-1-infected human cells

    DEFF Research Database (Denmark)

    Ternette, Nicola; Yang, Hongbing; Partridge, Thomas

    2016-01-01

    % of the identified sequences originated from viral protein regions for which T-cell responses have previously been reported but for which the precise HLA class I-binding sequences have not yet been defined. These results validate and expand the current knowledge of virus-specific antigenic peptide presentation...

  11. Tolerization of an established αb-crystallin-reactive T-cell response by intravenous antigen

    NARCIS (Netherlands)

    Verbeek, R.; Mark, K. van der; Wawrousek, E.F.; Plomp, A.C.; Noort, J.M. van

    2007-01-01

    Tolerance induction to prevent activation of a naïve T-cell repertoire has been well documented in rodents and can be readily achieved by intravenous, oral or intranasal administration of antigen in the absence of adjuvants. In autoimmune diseases such as multiple sclerosis (MS) the presence of an e

  12. CLIC1 regulates dendritic cell antigen processing and presentation by modulating phagosome acidification and proteolysis

    Directory of Open Access Journals (Sweden)

    Kanin Salao

    2016-05-01

    Full Text Available Intracellular chloride channel protein 1 (CLIC1 participates in inflammatory processes by regulating macrophage phagosomal functions such as pH and proteolysis. Here, we sought to determine if CLIC1 can regulate adaptive immunity by actions on dendritic cells (DCs, the key professional antigen presenting cells. To do this, we first generated bone marrow-derived DCs (BMDCs from germline CLIC1 gene-deleted (CLIC1−/− and wild-type (CLIC1+/+ mice, then studied them in vitro and in vivo. We found phagocytosis triggered cytoplasmic CLIC1 translocation to the phagosomal membrane where it regulated phagosomal pH and proteolysis. Phagosomes from CLIC1−/− BMDCs displayed impaired acidification and proteolysis, which could be reproduced if CLIC1+/+, but not CLIC1−/− cells, were treated with IAA94, a CLIC family ion channel blocker. CLIC1−/− BMDC displayed reduced in vitro antigen processing and presentation of full-length myelin oligodendrocyte glycoprotein (MOG and reduced MOG-induced experimental autoimmune encephalomyelitis. These data suggest that CLIC1 regulates DC phagosomal pH to ensure optimal processing of antigen for presentation to antigen-specific T-cells. Further, they indicate that CLIC1 is a novel therapeutic target to help reduce the adaptive immune response in autoimmune diseases.

  13. Impaired cell surface expression of HLA-B antigens on mesenchymal stem cells and muscle cell progenitors

    DEFF Research Database (Denmark)

    Isa, Adiba; Nehlin, Jan; Sabir, Hardee Jawad;

    2010-01-01

    HLA class-I expression is weak in embryonic stem cells but increases rapidly during lineage progression. It is unknown whether all three classical HLA class-I antigens follow the same developmental program. In the present study, we investigated allele-specific expression of HLA-A, -B, and -C...... at the mRNA and protein levels on human mesenchymal stem cells from bone marrow and adipose tissue as well as striated muscle satellite cells and lymphocytes. Using multicolour flow cytometry, we found high cell surface expression of HLA-A on all stem cells and PBMC examined. Surprisingly, HLA-B was either...... undetectable or very weakly expressed on all stem cells protecting them from complement-dependent cytotoxicity (CDC) using relevant human anti-B and anti-Cw sera. IFNgamma stimulation for 48-72 h was required to induce full HLA-B protein expression. Quantitative real-time RT-PCR showed that IFNgamma induced...

  14. Expression Patterns of Cancer-Testis Antigens in Human Embryonic Stem Cells and Their Cell Derivatives Indicate Lineage Tracks

    OpenAIRE

    Nadya Lifantseva; Anna Koltsova; Tatyana Krylova; Tatyana Yakovleva; Galina Poljanskaya; Olga Gordeeva

    2011-01-01

    Pluripotent stem cells can differentiate into various lineages but undergo genetic and epigenetic changes during long-term cultivation and, therefore, require regular monitoring. The expression patterns of cancer-testis antigens (CTAs) MAGE-A2, -A3, -A4, -A6, -A8, -B2, and GAGE were examined in undifferentiated human embryonic stem (hES) cells, their differentiated derivatives, teratocarcinoma (hEC) cells, and cancer cell lines of neuroectodermal and mesodermal origin. Undifferentiated hES ce...

  15. Affinity for self antigen selects Treg cells with distinct functional properties.

    Science.gov (United States)

    Wyss, Lena; Stadinski, Brian D; King, Carolyn G; Schallenberg, Sonja; McCarthy, Nicholas I; Lee, Jun Young; Kretschmer, Karsten; Terracciano, Luigi M; Anderson, Graham; Surh, Charles D; Huseby, Eric S; Palmer, Ed

    2016-09-01

    The manner in which regulatory T cells (Treg cells) control lymphocyte homeostasis is not fully understood. We identified two Treg cell populations with differing degrees of self-reactivity and distinct regulatory functions. We found that GITR(hi)PD-1(hi)CD25(hi) (Triple(hi)) Treg cells were highly self-reactive and controlled lympho-proliferation in peripheral lymph nodes. GITR(lo)PD-1(lo)CD25(lo) (Triple(lo)) Treg cells were less self-reactive and limited the development of colitis by promoting the conversion of CD4(+) Tconv cells into induced Treg cells (iTreg cells). Although Foxp3-deficient (Scurfy) mice lacked Treg cells, they contained Triple(hi)-like and Triple(lo)-like CD4(+) T cells zsuper> T cells infiltrated the skin, whereas Scurfy Triple(lo)CD4(+) T cells induced colitis and wasting disease. These findings indicate that the affinity of the T cell antigen receptor for self antigen drives the differentiation of Treg cells into distinct subsets with non-overlapping regulatory activities.

  16. Inflammatory environment and oxidized LDL convert circulating human proangiogenic cells into functional antigen-presenting cells.

    Science.gov (United States)

    Vinci, Maria Cristina; Piacentini, Luca; Chiesa, Mattia; Saporiti, Federica; Colombo, Gualtiero I; Pesce, Maurizio

    2015-09-01

    The function of human circulating PACs has been described extensively. However, little focus has been placed on understanding how these cells differ in their functions in the presence of microenvironments mimicking vascular inflammation. We hypothesized that exposure to proinflammatory cytokines or the oxLDL, an autoantigen abundant in advanced atherosclerotic plaques, converts PACs into immune-modulating/proinflammatory cells. Hence, we examined the effect of oxLDL and inflammatory stimuli on their phenotype by use of a functional genomics model based on secretome and whole genome transcriptome profiling. PACs obtained from culturing a PBMC fraction in angiogenic medium were primed with DC differentiation cytokines and then exposed to proinflammatory cytokines or oxLDL. Under these conditions, PACs converted into APCs, expressed maturation markers CD80 and CD83, and showed an increased up-regulation of CD86. APCcy and APCox induced a robust T cell BrdU incorporation. Despite a similar ability to induce lymphocyte proliferation, APCcy and APCox differed for the secretory pathway and mRNA expression. Analysis of the differentially expressed genes identified 4 gene "clusters," showing reciprocal modulation in APCcy vs. APCox, justifying, according to functional genomics analyses, a different putative function of the cells in antigen processing. Together, these data show that treatment with inflammatory cytokines or oxLDL converts human PAC phenotypes and functions into that of APCs with similar lymphocyte-activating ability but distinct maturation degree and paracrine functions.

  17. Inhibitory activities of microalgal extracts against Epstein-Barr Virus (EBV antigen expression in lymphoblastoid cells

    Directory of Open Access Journals (Sweden)

    Koh Yih Yih

    2014-01-01

    Full Text Available The inhibitory activities of microalgal extracts against the expression of three EBV antigens, latent membrane protein (LMP1, Epstein-Barr nuclear antigen (EBNA1 and Z Epstein-Barr reactivation activator (ZEBRA were assessed by immunocytochemistry. The observation that the methanol extracts and their fractions from Ankistrodesmus convolutus, Synechococcus elongatus and Spirulina platensis exhibited inhibitory activity against EBV proteins in three Burkitt’s lymphoma cell lines at concentrations as low as 20 μg/ml suggests that microalgae could be a potential source of antiviral compounds against EBV.

  18. Effective expansion of forkhead box P3⁺ regulatory T cells via early secreted antigenic target 6 and antigen 85 complex B from Mycobacterium tuberculosis.

    Science.gov (United States)

    Wu, Ying-E; Du, Zhong-Ren; Cai, Ying-Mu; Peng, Wen-Guang; Zheng, Gao-Zhe; Zheng, Geng-Long; Wu, Li-Biao; Li, Ke

    2015-04-01

    The expansion of CD4+ CD25+ forkhead box (FOX)P3+ regulatory T (Treg) cells has been observed in patients with Mycobacterium (M.) tuberculosis; however, the mechanism of expansion remains to be elucidated. The aim of the present study was to examine the role of the early secreted antigenic target 6(ESAT‑6) and antigen 85 complex B (Ag85B) from M. tuberculosis on Treg cell expansion. To investigate the sensitivity of peripheral blood cultures to the M. tuberculosis ESAT‑6 and Ag85B antigens, the proportion of circulating CD4+ CD25+ FOXP3+ Treg cells was determined using flow cytometry and the levels of FOXP3 mRNA were determined using reverse transcription quantitative polymerase chain reaction. The mRNA levels of FOXP3 and the proportion of circulating CD4+ CD25+ FOXP3+ Treg cells were increased in multiplicitous drug‑resistant tuberculosis patients compared with those in healthy controls and patients with latent tuberculosis (TB) infection (LTBI) (Ptuberculosis antigens ESAT‑6 and Ag85B induced CD4+ CD25+ FOXP3+ Treg‑cell expansion, particularly in patients with LTBI. These findings indicated that CD4+ CD25+ FOXP3+ Treg cells may have a primary role in the failure of the host immune system to eradicate M. tuberculosis.

  19. Detection of cells captured with antigens on shear horizontal surface-acoustic-wave sensors.

    Science.gov (United States)

    Hao, Hsu-Chao; Chang, Hwan-You; Wang, Tsung-Pao; Yao, Da-Jeng

    2013-02-01

    Techniques to separate cells are widely applied in immunology. The technique to separate a specific antigen on a microfluidic platform involves the use of a shear horizontal surface-acoustic-wave (SH-SAW) sensor. With specific antibodies conjugated onto the surface of the SH-SAW sensors, this technique can serve to identify specific cells in bodily fluids. Jurkat cells, used as a target in this work, provide a model of cells in small abundance (1:1000) for isolation and purification with the ultimate goal of targeting even more dilute cells. T cells were separated from a mixed-cell medium on a chip (Jurkat cells/K562 cells, 1/1000). A novel microchamber was developed to capture cells during the purification, which required a large biosample. Cell detection was demonstrated through the performance of genetic identification on the chip.

  20. Inhibition of effector antigen-specific T cells by intradermal administration of heme oxygenase-1 inducers.

    Science.gov (United States)

    Simon, Thomas; Pogu, Julien; Rémy, Séverine; Brau, Frédéric; Pogu, Sylvie; Maquigneau, Maud; Fonteneau, Jean-François; Poirier, Nicolas; Vanhove, Bernard; Blancho, Gilles; Piaggio, Eliane; Anegon, Ignacio; Blancou, Philippe

    2017-03-22

    Developing protocols aimed at inhibiting effector T cells would be key for the treatment of T cell-dependent autoimmune diseases including type 1 autoimmune diabetes (T1D) and multiple sclerosis (MS). While heme oxygenase-1 (HO-1) inducers are clinically approved drugs for non-immune-related diseases, they do have immunosuppressive properties when administered systemically in rodents. Here we show that HO-1 inducers inhibit antigen-specific effector T cells when injected intradermally together with the T cell cognate antigens in mice. This phenomenon was observed in both a CD8(+) T cell-mediated model of T1D and in a CD4(+) T cell-dependent MS model. Intradermal injection of HO-1 inducers induced the recruitment of HO-1(+) monocyte-derived dendritic cell (MoDCs) exclusively to the lymph nodes (LN) draining the site of intradermal injection. After encountering HO-1(+)MoDCs, effector T-cells exhibited a lower velocity and a reduced ability to migrate towards chemokine gradients resulting in impaired accumulation to the inflamed organ. Intradermal co-injection of a clinically approved HO-1 inducer and a specific antigen to non-human primates also induced HO-1(+) MoDCs to accumulate in dermal draining LN and to suppress delayed-type hypersensitivity. Therefore, in both mice and non-human primates, HO-1 inducers delivered locally inhibited effector T-cells in an antigen-specific manner, paving the way for repositioning these drugs for the treatment of immune-mediated diseases.

  1. T cell responses to hepatitis B surface antigen are detectable in non-vaccinated individuals

    Institute of Scientific and Technical Information of China (English)

    Martin R Weihrauch; Michael von Bergwelt-Baildon; Milos Kandic; Martin Weskott; Winfried Klamp; Joachim R(o)sier; Joachim L Schultze

    2008-01-01

    AIM: To evaluate, whether humoral hepatitis-B-vaccine non-responders also fail to mount a T cell response and to compare these results to normal vaccinees.METHODS: Fourty-seven health care employees were enrolled in this study including all available nonresponders (n = 13) with an anti-HBsAg titer 1000 kU/L as controls.PBMC from all subjects were analyzed by IFN-γ and IL-4 ELISPOT assays for the presence of hepatitis B surface antigen (HBsAg) reactive T cells.RESULTS: Non-responders and low-responders had no or only very limited T cell responses, respectively.Individuals responding to vaccination with the induction of a high anti-HBsAg titer showed a strong T cell response after the third vaccination.Surprisingly, these individuals showed response even before the first vaccination.T cell response to control antigens and mitogens was similar in all groups.CONCLUSION: Our data suggest that there is no general immune deficiency in non-/low-responders.Thus,we hypothesize that the induction of anti-HBsAg responses by vaccination is significantly dependent on the pre-existing T cell repertoire against the specific antigen rather than the presence of a general T cell defect.

  2. Going viral: chimeric antigen receptor T-cell therapy for hematological malignancies.

    Science.gov (United States)

    Gill, Saar; June, Carl H

    2015-01-01

    On July 1, 2014, the United States Food and Drug Administration granted 'breakthrough therapy' designation to CTL019, the anti-CD19 chimeric antigen receptor T-cell therapy developed at the University of Pennsylvania. This is the first personalized cellular therapy for cancer to be so designated and occurred 25 years after the first publication describing genetic redirection of T cells to a surface antigen of choice. The peer-reviewed literature currently contains the outcomes of more than 100 patients treated on clinical trials of anti-CD19 redirected T cells, and preliminary results on many more patients have been presented. At last count almost 30 clinical trials targeting CD19 were actively recruiting patients in North America, Europe, and Asia. Patients with high-risk B-cell malignancies therefore represent the first beneficiaries of an exciting and potent new treatment modality that harnesses the power of the immune system as never before. A handful of trials are targeting non-CD19 hematological and solid malignancies and represent the vanguard of enormous preclinical efforts to develop CAR T-cell therapy beyond B-cell malignancies. In this review, we explain the concept of chimeric antigen receptor gene-modified T cells, describe the extant results in hematologic malignancies, and share our outlook on where this modality is likely to head in the near future.

  3. Effect of Exogenous Ghrelin on Cell Differentiation Antigen 40 Expression in Endothelial Cells

    Institute of Scientific and Technical Information of China (English)

    Min ZHANG; Fang YUAN; Hui CHEN; Xingbiao QIU; Weiyi FANG

    2007-01-01

    Ghrelin is a brain-gut peptide that serves as a natural ligand for growth hormone secretagogue receptor (GHSR). It also exists abundantly in the cardiovascular system. In order to evaluate the possible role of ghrelin in the development of atherosclerosis, the effect of ghrelin on the expression of cell differentiation antigen 40 (CD40) were studied. Human umbilical vein endothelial cell (HUVEC) line-ECV 304 was pretreated with different concentrations of ghrelin, des-acyl ghrelin or [d-Lys]-GHRP-6 (a ghrelin receptor antagonist), and then induced with tumor necrosis factor-α (TNF-α) and interferon γ (IFN-γ). The mRNA levels of CD40 were analyzed by reverse transcription-polymerase chain reaction, and the expressions of CD40 protein in the cells were measured by flow cytometry (FCM) and Western blotting. The results showed that exogenous ghrelin could significantly inhibit TNF-α/IFN-γinduced CD40 expression in HUVEC cells in a concentration-dependent manner. When treated with 1000 ng/ml of ghrelin, the mRNA level of CD40 in the cells was decreased by approximately 77%, but when treated with both 1000 ng/ml of ghrelin and 1000 ng/ml of [d-Lys]-GHRP-6, the mRNA level of CD40 in the cells was decreased by only 42%,suggesting that [d-Lys]-GHRP-6 could counteract the inhibitory effect of ghrelin in these cells. However,CD40 expression was not inhibited by des-acyl ghrelin at 1000 ng/ml. The results in protein expression analysis detected by FCM and Western blotting further confirmed these results. Our results suggested that in the cardiovascular system, ghrelin not only has an anti-inflammatory effect, but also has a significant immunoregulatory effect that may be mediated through the GHSR-1 a receptor.

  4. Ethanol Metabolism Alters Major Histocompatibility Complex Class I-Restricted Antigen Presentation In Liver Cells

    Science.gov (United States)

    Osna, Natalia A.; White, Ronda L.; Thiele, Geoffrey M.; Donohue, Terrence M.

    2009-01-01

    The proteasome is a major enzyme that cleaves proteins for antigen presentation. Cleaved peptides traffic to the cell surface, where they are presented in the context of MHC class I. Recognition of these complexes by cytotoxic T lymphocytes is crucial for elimination of cells bearing “non-self” proteins. Our previous studies revealed that ethanol suppresses proteasome function in ethanol-metabolizing liver cells. We hypothesized that proteasome suppression reduces the hydrolysis of antigenic peptides, thereby decreasing the presentation of the peptide-MHC class I-complexes on the cell surface. To test this, we used the mouse hepatocyte cell line (CYP2E1/ADH-transfected HepB5 cells) or primary mouse hepatocytes, both derived from livers of C57Bl/6 mice, which present the ovalbumin peptide, SIINFEKL, complexed with H2Kb. To induce H2Kb expression, HepB5 cells were treated with interferon gamma (IFNγ) and then exposed to ethanol. In these cells, ethanol metabolism decreased not only proteasome activity, but also hydrolysis of the C-extended peptide, SIINFEKL-TE and the presentation of SIINFEKL-H2Kb complexes measured after the delivery of SIINFEKL-TE to cytoplasm. The suppressive effects of ethanol were, in part, attributed to ethanol-elicited impairment of IFNγ signaling. However, in primary hepatocytes, even in the absence of IFNγ, we observed a similar decline in proteasome activity and antigen presentation after ethanol exposure. We conclude that proteasome function is directly suppressed by ethanol metabolism and indirectly, by preventing the activating effects of IFNγ. Ethanol-elicited reduction in proteasome activity contributes to the suppression of SIINFEKL-H2Kb presentation on the surface of liver cells. Immune response to viral antigens plays a crucial role in the pathogenesis of hepatitis C or B viral infections (HCV and HBV, respectively). Professional antigen-presenting cells (dendritic cells and macrophages) are responsible for priming the

  5. Studies of the antigenicity and immunogenicity of bromelain-pretreated red blood cells.

    Science.gov (United States)

    Cox, K O; Baddams, H; Evans, A

    1977-02-01

    The effects of the proteolytic enzyme bromelain (Br) on the antigenicity and immunogenicity of sheep and mouse red blood cells (RBC) have been investigated. The results presented support the previous claim that there are antigens present on Br RBC that are not present in an exposed form on untreated RBC and that Br RBC have lost some of the antigens present on the surface of normal RBC. The susceptibility of Br RBC to osmotic lysis was very similar to that of normal RBC, implying that the modified RBC were not more fragile than normal RBC. Injection of mice with Br mouse-RBC did not increase the unusually high "background" number of cells producing IgM antibodies against Br mouse-RBC and mice did not mount delayed-type hypersensitivity reactions against Br mouse-RBC, either before or after sensitizing injections of Br mouse-RBC. However, mouse-RBC and Br mouse-RBC elicited similar antibody responses in rabbits and guinea pigs. Although mice appeared unresponsive to Br mouse-RBC injections, delayed-type hypersensitivity responses and antibody production in primary and secondary responses were of similar levels irrespective of whether sheep-RBC or Br sheep-RBC were used as immunogens. From these studies it appears that mice have B-cells producing antibodies against the "new" antigens on Br mouse-RBC, but there are no T-cells that respond to these antigens by way of "helper" activity in antibody production or by way of cell-mediated immune reactions.

  6. Dendritic cells engineered to express defined allo-HLA peptide complexes induce antigen-specific cytotoxic T cells efficiently killing tumour cells

    DEFF Research Database (Denmark)

    Stronen, E; Abrahamsen, I W; Gaudernack, G;

    2009-01-01

    presented by a non-self human leucocyte antigen (HLA) molecule and transferred to cancer patients expressing that HLA molecule. Obtaining allo-restricted CTL of high-avidity and low cross-reactivity has, however, proven difficult. Here, we show that dendritic cells transfected with mRNA encoding HLA-A*0201...... and efficiently killed HLA-A*0201(+) melanoma cells, whilst sparing HLA-A*0201(+) B-cells. Allo-restricted CTL specific for peptides from the leukaemia-associated antigens CD33 and CD19 were obtained with comparable efficiency. Collectively, the results show that dendritic cells engineered to express defined allo......Most tumour-associated antigens (TAA) are non-mutated self-antigens. The peripheral T cell repertoire is devoid of high-avidity TAA-specific cytotoxic T lymphocytes (CTL) due to self-tolerance. As tolerance is major histocompatibility complex-restricted, T cells may be immunized against TAA...

  7. Application of an enzyme-labeled antigen method for visualizing plasma cells producing antibodies against Strep A, a carbohydrate antigen of Streptococcus pyogenes, in recurrent tonsillitis.

    Science.gov (United States)

    Onouchi, Takanori; Mizutani, Yasuyoshi; Shiogama, Kazuya; Inada, Ken-ichi; Okada, Tatsuyoshi; Naito, Kensei; Tsutsumi, Yutaka

    2015-01-01

    Streptococcus pyogenes is the main causative pathogen of recurrent tonsillitis. Histologically, lesions of recurrent tonsillitis contain numerous plasma cells. Strep A is an antigenic carbohydrate molecule on the cell wall of S. pyogenes. As expected, plasma cells in subjects with recurrent tonsillitis secrete antibodies against Strep A. The enzyme-labeled antigen method is a novel histochemical technique that visualizes specific antibody-producing cells in tissue sections by employing a biotin-labeled antigen as a probe. The purpose of the present study was to visualize plasma cells producing antibodies reactive with Strep A in recurrent tonsillitis. Firstly, the lymph nodes of rats immunized with boiled S. pyogenes were paraformaldehyde-fixed and specific plasma cells localized in frozen sections with biotinylated Strep A. Secondly, an enzyme-labeled antigen method was used on human tonsil surgically removed from 12 patients with recurrent tonsillitis. S. pyogenes genomes were PCR-detected in all 12 specimens. The emm genotypes belonged to emm12 in nine specimens and emm1 in three. Plasma cells producing anti-Strep A antibodies were demonstrated in prefixed frozen sections of rat lymph nodes, 8/12 human specimens from patients with recurrent tonsillitis but not in two control tonsils. In human tonsils, Strep A-reactive plasma cells were observed within the reticular squamous mucosa and just below the mucosa, and the specific antibodies belonged to either IgA or IgG classes. Our technique is effective in visualizing immunocytes producing specific antibodies against the bacterial carbohydrate antigen, and is thus a novel histochemical tool for analyzing immune reactions in infectious disorders.

  8. Human tumour antigens defined by cytotoxicity and proliferative responses of cultured lymphoid cells

    Science.gov (United States)

    Vose, Brent M.; Bonnard, Guy D.

    1982-03-01

    The long-term goal of many laboratories has been to develop cellular reagents having specific reactivity against human tumour cells. Such immune cells should prove useful for defining the antigenicity of human malignancies and may have important therapeutic potential, as has been clearly shown in some animal models1. Here we describe methods of initiating continued lymphocyte cultures (CLC) having specific anti-tumour reactivity using conditioned media containing interleukin-2 (IL-2).

  9. Preclinical targeting of human T-cell malignancies using CD4-specific chimeric antigen receptor (CAR)-engineered T cells.

    Science.gov (United States)

    Pinz, K; Liu, H; Golightly, M; Jares, A; Lan, F; Zieve, G W; Hagag, N; Schuster, M; Firor, A E; Jiang, X; Ma, Y

    2016-03-01

    Peripheral T-cell lymphomas (PTCLs) are aggressive lymphomas with no effective upfront standard treatment and ineffective options in relapsed disease, resulting in poorer clinical outcomes as compared with B-cell lymphomas. The adoptive transfer of T cells engineered to express chimeric antigen receptors (CARs) is a promising new approach for treatment of hematological malignancies. However, preclinical reports of targeting T-cell lymphoma with CARs are almost non-existent. Here we have designed a CAR, CD4CAR, which redirects the antigen specificity of CD8+ cytotoxic T cells to CD4-expressing cells. CD4CAR T cells derived from human peripheral blood mononuclear cells and cord blood effectively redirected T-cell specificity against CD4+ cells in vitro. CD4CAR T cells efficiently eliminated a CD4+ leukemic cell line and primary CD4+ PTCL patient samples in co-culture assays. Notably, CD4CAR T cells maintained a central memory stem cell-like phenotype (CD8+CD45RO+CD62L+) under standard culture conditions. Furthermore, in aggressive orthotropic T-cell lymphoma models, CD4CAR T cells efficiently suppressed the growth of lymphoma cells while also significantly prolonging mouse survival. Combined, these studies demonstrate that CD4CAR-expressing CD8+ T cells are efficacious in ablating malignant CD4+ populations, with potential use as a bridge to transplant or stand-alone therapy for the treatment of PTCLs.

  10. IL-4Rα-Associated Antigen Processing by B Cells Promotes Immunity in Nippostrongylus brasiliensis Infection

    Science.gov (United States)

    Hoving, Jennifer C.; Nieuwenhuizen, Natalie; McSorley, Henry J.; Ndlovu, Hlumani; Bobat, Saeeda; Kimberg, Matti; Kirstein, Frank; Cutler, Anthony J.; DeWals, Benjamin; Cunningham, Adam F.; Brombacher, Frank

    2013-01-01

    In this study, B cell function in protective TH2 immunity against N. brasiliensis infection was investigated. Protection against secondary infection depended on IL-4Rα and IL-13; but not IL-4. Protection did not associate with parasite specific antibody responses. Re-infection of B cell-specific IL-4Rα−/− mice resulted in increased worm burdens compared to control mice, despite their equivalent capacity to control primary infection. Impaired protection correlated with reduced lymphocyte IL-13 production and B cell MHC class II and CD86 surface expression. Adoptive transfer of in vivo N. brasiliensis primed IL-4Rα expressing B cells into naïve BALB/c mice, but not IL-4Rα or IL-13 deficient B cells, conferred protection against primary N. brasiliensis infection. This protection required MHC class II compatibility on B cells suggesting cognate interactions by B cells with CD4+ T cells were important to co-ordinate immunity. Furthermore, the rapid nature of these protective effects by B cells suggested non-BCR mediated mechanisms, such as via Toll Like Receptors, was involved, and this was supported by transfer experiments using antigen pulsed Myd88−/− B cells. These data suggest TLR dependent antigen processing by IL-4Rα-responsive B cells producing IL-13 contribute significantly to CD4+ T cell-mediated protective immunity against N. brasiliensis infection. PMID:24204255

  11. Enhanced Dendritic Cell-Mediated Antigen-Specific CD4+ T Cell Responses: IFN-Gamma Aids TLR Stimulation

    Directory of Open Access Journals (Sweden)

    Kuo-Ching Sheng

    2013-01-01

    Full Text Available Phenotypic maturation and T cell stimulation are two functional attributes of DCs critical for immune induction. The combination of antigens, including those from cancer, with Toll-like receptor (TLR ligands induces far superior cellular immune responses compared to antigen alone. In this study, IFN-gamma treatment of bone marrow-derived DC, followed by incubation with the TLR2, TLR4, or TLR9 agonists, enhanced DC activation compared to TLR ligation alone. Most notably, the upregulation of CD40 with LPS stimulation and CD86 with CpG stimulation was observed in in vitro cultures. Similarly, IFN-gamma coinjected with TLR ligands was able to promote DC activation in vivo, with DCs migrating from the site of immunization to the popliteal lymph nodes demonstrating increased expression of CD80 and CD86. The heightened DC activation translated to a drastic increase in T cell stimulatory capacity in both antigen independent and antigen dependent fashions. This is the first time that IFN-gamma has been shown to have a combined effect with TLR ligation to enhance DC activation and function. The results demonstrate the novel use of IFN-gamma together with TLR agonists to enhance antigen-specific T cell responses, for applications in the development of enhanced vaccines and drug targets against diseases including cancer.

  12. Human leukocyte antigen E contributes to protect tumor cells from lysis by natural killer cells.

    Science.gov (United States)

    Lo Monaco, Elisa; Tremante, Elisa; Cerboni, Cristina; Melucci, Elisa; Sibilio, Leonardo; Zingoni, Alessandra; Nicotra, Maria Rita; Natali, Pier Giorgio; Giacomini, Patrizio

    2011-09-01

    The nonclassic class I human leukocyte antigen E (HLA-E) molecule engages the inhibitory NKG2A receptor on several cytotoxic effectors, including natural killer (NK) cells. Its tissue distribution was claimed to be wider in normal than in neoplastic tissues, and surface HLA-E was undetectable in most tumor cell lines. Herein, these issues were reinvestigated taking advantage of HLA-E-specific antibodies, immunohistochemistry, and biochemical methods detecting intracellular and surface HLA-E regardless of conformation. Contrary to published evidence, HLA-E was detected in a few normal epithelia and in a large fraction (approximately 1/3) of solid tumors, including those derived from HLA-E-negative/low-normal counterparts. Remarkably, HLA-E was detected in 30 of 30 tumor cell lines representative of major lymphoid and nonlymphoid lineages, and in 11 of 11, it was surface-expressed, although in a conformation poorly reactive with commonly used antibodies. Coexpression of HLA-E and HLA class I ligand donors was not required for surface expression but was associated with NKG2A-mediated protection from lysis by the cytotoxic cell line NKL and polyclonal NK cells from healthy donors, as demonstrated by antibody-mediated relief of protection in 10% to 20% of the tested target-effector combinations. NKG2A-mediated protection of additional targets became evident on NK effector blocking with antibodies to activating receptors (DNAM-1, natural cytotoxicity receptors, and NKG2D). Thus, initial evidence that the long-elusive HLA-E molecule is enhanced by malignant transformation and is functional in tumor cells is presented here, although its importance and precise functional role remain to be addressed in the context of a general understanding of the NK ligand-receptor network.

  13. Human Leukocyte Antigen E Contributes to Protect Tumor Cells from Lysis by Natural Killer Cells

    Directory of Open Access Journals (Sweden)

    Elisa Lo Monaco

    2011-09-01

    Full Text Available The nonclassic class I human leukocyte antigen E (HLA-E molecule engages the inhibitory NKG2A receptor on several cytotoxic effectors, including natural killer (NK cells. Its tissue distribution was claimed to be wider in normal than in neoplastic tissues, and surface HLA-E was undetectable in most tumor cell lines. Herein, these issues were reinvestigated taking advantage of HLA-E-specific antibodies, immunohistochemistry, and biochemical methods detecting intracellular and surface HLA-E regardless of conformation. Contrary to published evidence, HLA-E was detected in a few normal epithelia and in a large fraction (approximately 1/3 of solid tumors, including those derived from HLA-E-negative/low-normal counterparts. Remarkably, HLA-E was detected in 30 of 30 tumor cell lines representative of major lymphoid and nonlymphoid lineages, and in 11 of 11, it was surface-expressed, although in a conformation poorly reactive with commonly used antibodies. Coexpression of HLA-E and HLA class I ligand donors was not required for surface expression but was associated with NKG2A-mediated protection from lysis by the cytotoxic cell line NKL and polyclonal NK cells from healthy donors, as demonstrated by antibody-mediated relief of protection in 10% to 20% of the tested target-effector combinations. NKG2A-mediated protection of additional targets became evident on NK effector blocking with antibodies to activating receptors (DNAM-1, natural cytotoxicity receptors, and NKG2D. Thus, initial evidence that the long-elusive HLA-E molecule is enhanced by malignant transformation and is functional in tumor cells is presented here, although its importance and precise functional role remain to be addressed in the context of a general understanding of the NK ligand-receptor network.

  14. Human Leukocyte Antigen E Contributes to Protect Tumor Cells from Lysis by Natural Killer Cells12

    Science.gov (United States)

    Monaco, Elisa Lo; Tremante, Elisa; Cerboni, Cristina; Melucci, Elisa; Sibilio, Leonardo; Zingoni, Alessandra; Nicotra, Maria Rita; Natali, Pier Giorgio; Giacomini, Patrizio

    2011-01-01

    The nonclassic class I human leukocyte antigen E (HLA-E) molecule engages the inhibitory NKG2A receptor on several cytotoxic effectors, including natural killer (NK) cells. Its tissue distribution was claimed to be wider in normal than in neoplastic tissues, and surface HLA-E was undetectable in most tumor cell lines. Herein, these issues were reinvestigated taking advantage of HLA-E-specific antibodies, immunohistochemistry, and biochemical methods detecting intracellular and surface HLA-E regardless of conformation. Contrary to published evidence, HLA-E was detected in a few normal epithelia and in a large fraction (approximately 1/3) of solid tumors, including those derived from HLA-E-negative/low-normal counterparts. Remarkably, HLA-E was detected in 30 of 30 tumor cell lines representative of major lymphoid and nonlymphoid lineages, and in 11 of 11, it was surface-expressed, although in a conformation poorly reactive with commonly used antibodies. Coexpression of HLA-E and HLA class I ligand donors was not required for surface expression but was associated with NKG2A-mediated protection from lysis by the cytotoxic cell line NKL and polyclonal NK cells from healthy donors, as demonstrated by antibody-mediated relief of protection in 10% to 20% of the tested target-effector combinations. NKG2A-mediated protection of additional targets became evident on NK effector blocking with antibodies to activating receptors (DNAM-1, natural cytotoxicity receptors, and NKG2D). Thus, initial evidence that the long-elusive HLA-E molecule is enhanced by malignant transformation and is functional in tumor cells is presented here, although its importance and precise functional role remain to be addressed in the context of a general understanding of the NK ligand-receptor network. PMID:21969815

  15. Detection and manipulation of live antigen-expressing cells using conditionally stable nanobodies

    Science.gov (United States)

    Tang, Jonathan CY; Drokhlyansky, Eugene; Etemad, Behzad; Rudolph, Stephanie; Guo, Binggege; Wang, Sui; Ellis, Emily G; Li, Jonathan Z; Cepko, Constance L

    2016-01-01

    The ability to detect and/or manipulate specific cell populations based upon the presence of intracellular protein epitopes would enable many types of studies and applications. Protein binders such as nanobodies (Nbs) can target untagged proteins (antigens) in the intracellular environment. However, genetically expressed protein binders are stable regardless of antigen expression, complicating their use for applications that require cell-specificity. Here, we created a conditional system in which the stability of an Nb depends upon an antigen of interest. We identified Nb framework mutations that can be used to rapidly create destabilized Nbs. Fusion of destabilized Nbs to various proteins enabled applications in living cells, such as optogenetic control of neural activity in specific cell types in the mouse brain, and detection of HIV-infected human cells by flow cytometry. These approaches are generalizable to other protein binders, and enable the rapid generation of single-polypeptide sensors and effectors active in cells expressing specific intracellular epitopes. DOI: http://dx.doi.org/10.7554/eLife.15312.001 PMID:27205882

  16. Prolonged antigen presentation is required for optimal CD8+ T cell responses against malaria liver stage parasites.

    Directory of Open Access Journals (Sweden)

    Ian A Cockburn

    2010-05-01

    Full Text Available Immunization with irradiated sporozoites is currently the most effective vaccination strategy against liver stages of malaria parasites, yet the mechanisms underpinning the success of this approach are unknown. Here we show that the complete development of protective CD8+ T cell responses requires prolonged antigen presentation. Using TCR transgenic cells specific for the malaria circumsporozoite protein, a leading vaccine candidate, we found that sporozoite antigen persists for over 8 weeks after immunization--a remarkable finding since irradiated sporozoites are incapable of replication and do not differentiate beyond early liver stages. Persisting antigen was detected in lymphoid organs and depends on the presence of CD11c+ cells. Prolonged antigen presentation enhanced the magnitude of the CD8+ T cell response in a number of ways. Firstly, reducing the time primed CD8+ T cells were exposed to antigen in vivo severely reduced the final size of the developing memory population. Secondly, fully developed memory cells expanded in previously immunized mice but not when transferred to naïve animals. Finally, persisting antigen was able to prime naïve cells, including recent thymic emigrants, to become functional effector cells capable of eliminating parasites in the liver. Together these data show that the optimal development of protective CD8+ T cell immunity against malaria liver stages is dependent upon the prolonged presentation of sporozoite-derived antigen.

  17. Antigen-specific cytotoxicity by invariant NKT cells in vivo is CD95/CD178 dependent and is correlated with antigenic potency

    Science.gov (United States)

    Wingender, Gerhard; Krebs, Philippe; Beutler, Bruce; Kronenberg, Mitchell

    2010-01-01

    Invariant NKT (iNKT) cells are a unique subset of T lymphocytes that rapidly carry out effector functions following activation with glycolipid Ags, such as the model Ag α-galactosylceramide (αGalCer). Numerous studies have investigated the mechanisms leading to Th1- and Th2 cytokine production by iNKT cells, and the effects of the copious amounts of cytokines these cells produce. Less is known, however, about the mechanisms of iNKT cell cytotoxicity. Here we investigated the effect of antigen availability and strength, as well as the molecules involved in iNKT cytotoxicity. We demonstrate that the iNKT cell cytotoxicity in vivo correlates directly with the amount of CD1d expressed by the targets as well as the TCR affinity for the target glycolipid Ag. iNKT cells from spleen, liver and thymus were comparable in their cytotoxicity in vitro. Surprisingly, we show that the antigen-specific cytotoxicity of iNKT cells in vivo depended almost exclusively on the interaction of CD95 (Fas) with CD178 (FasL), and that this mechanism can be efficiently utilized for tumor protection. Therefore unlike NK cells, which rely mostly on perforin/granzyme mediated mechanisms, the antigen-specific cytotoxicity of iNKT cells in vivo is largely restricted to the CD95/CD178 pathway. PMID:20660713

  18. Tumor antigen-specific CD4+ T cells in cancer immunity: from antigen identification to tumor prognosis and development of therapeutic strategies.

    Science.gov (United States)

    Protti, M P; De Monte, L; Monte, L D; Di Lullo, G; Lullo, G D

    2014-04-01

    CD4(+) T cells comprise a large fraction of tumor infiltrating lymphocytes and it is now established that they may exert an important role in tumor immune-surveillance. Several CD4(+) T cell subsets [i.e. T helper (Th)1, Th2, T regulatory (Treg), Th17, Th22 and follicular T helper (Tfh)] have been described and differentiation of each subset depends on both the antigen presenting cells responsible for its activation and the cytokine environment present at the site of priming. Tumor antigen-specific CD4(+) T cells with different functional activity have been found in the blood of cancer patients and different CD4(+) T cell subsets have been identified at the tumor site by the expression of specific transcription factors and the profile of secreted cytokines. Importantly, depending on the subset, CD4(+) T cells may exert antitumor versus pro-tumor functions. Here we review the studies that first identified the presence of tumor-specific CD4(+) T cells in cancer patients, the techniques used to identify the tumor antigens recognized, the role of the different CD4(+) T cell subsets in tumor immunity and in cancer prognosis and the development of therapeutic strategies aimed at activating efficient antitumor CD4(+) T cell effectors.

  19. Chimeric Antigen Receptor Therapy for B-cell Malignancies

    Directory of Open Access Journals (Sweden)

    David L Porter, Michael Kalos, Zhaohui Zheng, Bruce Levine, Carl June

    2011-01-01

    Full Text Available We presented data showing that the CART-19 cells expressing the 4-1BB signaling domain can have unprecedented and massive in-vivo expansion, traffic to tumor sites, persist long term in vivo, and induce rapid and potent anti-tumor activity in chemotherapy refractory CLL patients.

  20. Complement-dependent transport of antigen into B cell follicles

    DEFF Research Database (Denmark)

    Gonzalez, Santiago F.; Lukacs-Kornek, Veronika; Kuligowski, Michael P.

    2010-01-01

    an additional novel pathway in which complement C3 and its receptors enhance humoral immunity through delivery of Ag to the B cell compartment. In this review, we discuss this pathway and highlight several novel exceptions recently found with a model influenza vaccine, such as mannose-binding lectin...

  1. Association of Autophagy in the Cell Death Mediated by Dihydrotestosterone in Autoreactive T Cells Independent of Antigenic Stimulation.

    Science.gov (United States)

    Jia, Ting; Anandhan, Annandurai; Massilamany, Chandirasegaran; Rajasekaran, Rajkumar A; Franco, Rodrigo; Reddy, Jay

    2015-12-01

    Gender disparity is well documented in the mouse model of experimental autoimmune encephalomyelitis (EAE) induced with proteolipid protein (PLP) 139-151, in which female, but not male, SJL mice show a chronic relapsing-remitting paralysis. Furthermore, dihydrotestosterone (DHT) has been shown to ameliorate the severity of EAE, but the underlying mechanisms of its protective effects are unclear. Using major histocompatibility complex (MHC) class II dextramers for PLP 139-151, we tested the hypothesis that DHT selectively modulates the expansion and functionalities of antigen-specific T cells. Unexpectedly, we noted that DHT induced cell death in antigen-specific, autoreactive T cells, but the effects were not selective, because both proliferating and non-proliferating cells were equally affected independent of antigenic stimulation. Furthermore, DHT-exposed PLP 139-151-specific T cells did not show any shift in cytokine production; rather, frequencies of cytokine-producing PLP-specific T cells were significantly reduced, irrespective of T helper (Th) 1, Th2, and Th17 subsets of cytokines. By evaluating cell death and autophagy pathways, we provide evidence for the induction of autophagy to be associated with cell death caused by DHT. Taken together, the data provide new insights into the role of DHT and indicate that cell death and autophagy contribute to the therapeutic effects of androgens in autoreactive T cells.

  2. Induction of the Epstein-Barr Virus Latent Membrane Protein 2 Antigen-specific Cytotoxic T Lymphocytes Using Human Leukocyte Antigen Tetramer-based Artificial Antigen-presenting Cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-Ling LU; Zhi-Hui LIANG; Cai-E ZHANG; Sheng-Jun LU; Xiu-Fang WENG; Xiong-Wen WU

    2006-01-01

    Cytotoxic T lymphocytes (CTLs) specific for the Epstein-Barr virus (EBV) latent membrane protein 2 (LMP2) antigen are important reagents for the treatment of some EBV-associated malignancies,such as EBV-positive Hodgkin's disease and nasopharyngeal carcinoma. However, the therapeutic amount of CTLs is often hampered by the limited supply of antigen-presenting cells. To address this issue, an artificial antigen-presenting cell (aAPC) was made by coating a human leukocyte antigen (HLA)-pLMP2 tetrameric complex, anti-CD28 antibody and CD54 molecule to a cell-sized latex bead, which provided the dual signals required for T cell activation. By co-culture of the HLA-A2-LMP2 bearing aAPC and peripheral blood mononuclear cells from HLA-A2 positive healthy donors, LMP2 antigen-specific CTLs were induced and expanded in vitro. The specificity of the aAPC-induced CTLs was demonstrated by both HLA-A2-LMP2tetramer staining and cytotoxicity against HLA-A2-LMP2 bearing T2 cell, the cytotoxicity was inhibited by the anti-HLA class I antibody (W6/32). These results showed that LMP2 antigen-specific CTLs could be induced and expanded in vitro by the HLA-A2-LMP2-bearing aAPC. Thus, aAPCs coated with an HLApLMP2 complex, anti-CD28 and CD54 might be promising tools for the enrichment of LMP2-specific CTLs for adoptive immunotherapy.

  3. Dendritic cells take up and present antigens from viable and apoptotic polymorphonuclear leukocytes.

    Directory of Open Access Journals (Sweden)

    Carlos Alfaro

    Full Text Available Dendritic cells (DC are endowed with the ability to cross-present antigens from other cell types to cognate T cells. DC are poised to meet polymorphonuclear leukocytes (PMNs as a result of being co-attracted by interleukin-8 (IL-8, for instance as produced by tumor cells or infected tissue. Human monocyte-derived and mouse bone marrow-derived DC can readily internalize viable or UV-irradiated PMNs. Such internalization was abrogated at 4°C and partly inhibited by anti-CD18 mAb. In mice, DC which had internalized PMNs containing electroporated ovalbumin (OVA protein, were able to cross-present the antigen to CD8 (OT-1 and CD4 (OT-2 TCR-transgenic T cells. Moreover, in humans, tumor cell debris is internalized by PMNs and the tumor-cell material can be subsequently taken up from the immunomagnetically re-isolated PMNs by DC. Importantly, if human neutrophils had endocytosed bacteria, they were able to trigger the maturation program of the DC. Moreover, when mouse PMNs with E. coli in their interior are co-injected in the foot pad with DC, many DC loaded with fluorescent material from the PMNs reach draining lymph nodes. Using CT26 (H-2(d mouse tumor cells, it was observed that if tumor cells are intracellularly loaded with OVA protein and UV-irradiated, they become phagocytic prey of H-2(d PMNs. If such PMNs, that cannot present antigens to OT-1 T cells, are immunomagnetically re-isolated and phagocytosed by H-2(b DC, such DC productively cross-present OVA antigen determinants to OT-1 T cells. Cross-presentation to adoptively transferred OT-1 lymphocytes at draining lymph nodes also take place when OVA-loaded PMNs (H-2(d are coinjected in the footpad of mice with autologous DC (H-2(b. In summary, our results indicate that antigens phagocytosed by short-lived PMNs can be in turn internalized and productively cross-presented by DC.

  4. Different serotypes of dengue viruses differently regulate the expression of the host cell antigen processing machinery.

    Science.gov (United States)

    Gan, Chye Sheng; Yusof, Rohana; Othman, Shatrah

    2015-09-01

    Dengue virus (DV) infection demonstrates an intriguing virus-induced intracellular membrane alteration that results in the augmentation of major histocompatibility complex (MHC) class I-restricted antigen presentation. As oppose to its biological function in attracting CD8(+) T-cells, this phenomenon appears to facilitate the immune evasion. However, the molecular events that attribute to the dysregulation of the antigen presenting mechanism (APM) by DV remain obscure. In this study, we aimed to characterize the host cell APM upon infection with all serotypes of whole DV. Cellular RNA were isolated from infected cells and the gene expressions of LMP2, LMP7, TAP1, TAP2, TAPBP, CALR, CANX, PDIA3, HLA-A and HLA-B were analyzed via quantitative PCR. The profiles of the gene expression were further validated. We showed that all four DV serotypes modulate host APM at the proteasomal level with DV2 showing the most prominent expression profile.

  5. Proliferating cell nuclear antigen immunostaining in breast carcinoma and its relationship to clinical and pathological variables.

    Science.gov (United States)

    Agarwal, S; Jain, R; Rusia, U; Gupta, R L

    1997-01-01

    Tumour proliferative activity of 74 breast lesions was assessed by determining mitotic index and immunostaining for proliferative cell nuclear antigen using Peroxidase antiperoxidase method. The indices were correlated with histomorphology and clinical stage of the disease. Positively stained nuclei and mitotic figures were counted per 1000 cells to calculate Proliferating Cell Nuclear Antigen (PCNA) and mitotic index respectively. Sixty four cases stained positive for PCNA. The index ranged between 0 to 98. PCNA index was significantly low in benign lesions as compared to malignant lesions (p < 0.0002). There was a linear correlation between the mitotic index and PCNA index. PCNA index also showed significant correlation with tumour size and histologic grade; however, it had no correlation with axillary lymph node status.

  6. Spotlight on chimeric antigen receptor engineered T cell research and clinical trials in China.

    Science.gov (United States)

    Luo, Can; Wei, Jianshu; Han, Weidong

    2016-04-01

    T cell mediated adoptive immune response has been characterized as the key to anti-tumor immunity. Scientists around the world including in China, have been trying to harness the power of T cells against tumors for decades. Recently, the biosynthetic chimeric antigen receptor engineered T cell (CAR-T) strategy was developed and exhibited encouraging clinical efficacy, especially in hematological malignancies. Chimeric antigen receptor research reports began in 2009 in China according to our PubMed search results. Clinical trials have been ongoing in China since 2013 according to the trial registrations on clinicaltrials. gov.. After years of assiduous efforts, research and clinical scientists in China have made their own achievements in the CAR-T therapy field. In this review, we aim to highlight CAR-T research and clinical trials in China, to provide an informative reference for colleagues in the field.

  7. Criculating fibrocytes: a potent cell population in antigen-presenting and wound healing

    Institute of Scientific and Technical Information of China (English)

    FAN Xia; LIANG Hua-ping

    2010-01-01

    Fibrocytes are bone marrow-derived mesenchymal progenitors that co-express hematopoietic cell antigens and markers ofmonocytic lineage as well as fibro-blast products.During wound healing, fibrocytes have been found to possess the ability of antigen-presentation to naive T cells in the inflammatory phase.Moreover, they can pro-mote the endothelial cell proliferation, migration and angio-genesis by secreting several proteins.Fibrocytes can fur-ther differentiate into mature mesenchymocyte lineage, suchas fibroblasts, myofibroblasts and adipocytes, and they may represent the systemic source of myofibroblasts that exert a contractile force required to close tissue wounds.A deep understanding of the mechanism involved in fibrocyte mi-gration and differentiation may lead to the development of a novel theory of normal physiology and pathology.

  8. Osteopontin promotes dendritic cell maturation and function in response to HBV antigens

    Directory of Open Access Journals (Sweden)

    Cui GY

    2015-06-01

    Full Text Available Guangying Cui,1,2 Jianing Chen,1,2 Jianqin He,1,2 Chong Lu,1,2 Yingfeng Wei,1,2 Lin Wang,1,2 Xuejun Xu,3 Lanjuan Li,1,2 Toshimitsu Uede,4 Hongyan Diao1,2 1State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, the First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, 2Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, 3Department of Oral Orthodontics, Affiliated Stomatology Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, People’s Republic of China; 4Molecular Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan Purpose: Dendritic cells (DCs play critical roles in promoting innate and adaptive immunity in microbial infection. Functional impairment of DCs may mediate the suppression of viral-specific T-cell immune response in chronic hepatitis B (CHB patients. Osteopontin (OPN is involved in several liver diseases and infectious diseases. However, whether OPN affects DC function in hepatitis B virus (HBV infection is unknown.Methods: Twenty CHB patients and 20 healthy volunteers were recruited. OPN secreted by DCs was compared. Peripheral blood mononuclear cells cultured with OPN antibody were examined to study the costimulatory molecular expression and interleukin (IL-12 production of DCs after HBV antigenic stimulation. OPN-deficient mice were used to investigate the influence of OPN on DC maturation and function after HBV antigenic stimulation in vitro and in vivo. Exogenous OPN was administrated to further verify the functioning of DCs from CHB patients upon HBV antigenic stimulation.Results: We found that OPN production of DCs from CHB patients was significantly lower than those from healthy volunteers. The absence of OPN impaired IL-12 production and costimulatory molecular expression of DCs upon stimulation with HBV antigens. Defective DC function led to reduced activation of Th1 response to

  9. Screening of human tumor antigens for CD4 T cell epitopes by combination of HLA-transgenic mice, recombinant adenovirus and antigen peptide libraries.

    Directory of Open Access Journals (Sweden)

    Wolfram Osen

    Full Text Available BACKGROUND: As tumor antigen-specific CD4+ T cells can mediate strong therapeutic anti-tumor responses in melanoma patients we set out to establish a comprehensive screening strategy for the identification of tumor-specific CD4+ T cell epitopes suitable for detection, isolation and expansion of tumor-reactive T cells from patients. METHODS AND FINDINGS: To scan the human melanoma differentiation antigens TRP-1 and TRP-2 for HLA-DRB1*0301-restricted CD4+ T cell epitopes we applied the following methodology: Splenocytes of HLA-DRB1*0301-transgenic mice immunized with recombinant adenovirus encoding TRP-1 (Ad5.TRP-1 or TRP-2 (Ad5.TRP-2 were tested for their T cell reactivity against combinatorial TRP-1- and TRP-2-specific peptide libraries. CD4+ T cell epitopes thus identified were validated in the human system by stimulation of peripheral blood mononuclear cells (PBMC from healthy donors and melanoma patients. Using this strategy we observed that recombinant Ad5 induced strong CD4+ T cell responses against the heterologous tumor antigens. In Ad5.TRP-2-immunized mice CD4+ T cell reactivity was detected against the known HLA-DRB1*0301-restricted TRP-2(60-74 epitope and against the new epitope TRP-2(149-163. Importantly, human T cells specifically recognizing target cells loaded with the TRP-2(149-163-containing library peptide or infected with Ad5.TRP-2 were obtained from healthy individuals, and short term in vitro stimulation of PBMC revealed the presence of epitope-reactive CD4+ T cells in melanoma patients. Similarly, immunization of mice with Ad5.TRP-1 induced CD4+ T cell responses against TRP-1-derived peptides that turned out to be recognized also by human T cells, resulting in the identification of TRP-1(284-298 as a new HLA-DRB1*0301-restricted CD4+ T cell epitope. CONCLUSIONS: Our screening approach identified new HLA-DRB1*0301-restricted CD4+ T cell epitopes derived from melanoma antigens. This strategy is generally applicable to target

  10. Immunological and clinical significance of HLA class I antigen processing machinery component defects in malignant cells

    Science.gov (United States)

    Concha-Benavente, Fernando; Srivastava, Raghvendra; Ferrone, Soldano; Ferris, Robert L.

    2017-01-01

    Experimental as well as clinical studies demonstrate that the immune system plays a major role in controlling generation and progression of tumors. The cancer immunoediting theory supports the notion that tumor cell immunogenicity is dynamically shaped by the immune system, as it eliminates immunogenic tumor cells in the early stage of the disease and then edits their antigenicity. The end result is the generation of a tumor cell population able to escape from immune recognition and elimination by tumor infiltrating lymphocytes. Two major mechanisms, which affect the target cells and the effector phase of the immune response, play a crucial role in the editing process. One is represented by the downregulation of tumor antigen (TA) processing and presentation because of abnormalities in the HLA class I antigen processing machinery (APM). The other one is represented by the anergy of effector immune infiltrates in the tumor microenvironment caused by aberrant inhibitory signals triggered by immune checkpoint receptor (ICR) ligands, such as programmed death ligand-1 (PD-L1). In this review, we will focus on tumor immune escape mechanisms caused by defects in HLA class I APM component expression and/or function in different types of cancer, with emphasis on head and neck cancer (HNC). We will also discuss the immunological implications and clinical relevance of these HLA class I APM abnormalities. Finally, we will describe strategies to counteract defective TA presentation with the expectation that they will enhance tumor recognition and elimination by tumor infiltrating effector T cells. PMID:27264839

  11. Autologous Dendritic Cells Prolong Allograft Survival Through Tmem176b-Dependent Antigen Cross-Presentation

    Science.gov (United States)

    Charnet, P.; Savina, A.; Tilly, G.; Gautreau, L.; Carretero-Iglesia, L.; Beriou, G.; Cebrian, I.; Cens, T.; Hepburn, L.; Chiffoleau, E.; Floto, R. A.; Anegon, I.; Amigorena, S.; Hill, M.; Cuturi, M. C.

    2015-01-01

    The administration of autologous (recipient-derived) tolerogenic dendritic cells (ATDCs) is under clinical evaluation. However, the molecular mechanisms by which these cells prolong graft survival in a donor-specific manner is unknown. Here, we tested mouse ATDCs for their therapeutic potential in a skin transplantation model. ATDC injection in combination with anti-CD3 treatment induced the accumulation of CD8+CD11c+ T cells and significantly prolonged allograft survival. TMEM176B is an intracellular protein expressed in ATDCs and initially identified in allograft tolerance. We show that Tmem176b−/− ATDCs completely failed to trigger both phenomena but recovered their effect when loaded with donor peptides before injection. These results strongly suggested that ATDCs require TMEM176B to cross-present antigens in a tolerogenic fashion. In agreement with this, Tmem176b−/− ATDCs specifically failed to cross-present male antigens or ovalbumin to CD8+ T cells. Finally, we observed that a Tmem176b-dependent cation current controls phagosomal pH, a critical parameter in cross-presentation. Thus, ATDCs require TMEM176B to cross-present donor antigens to induce donor-specific CD8+CD11c+ T cells with regulatory properties and prolong graft survival. PMID:24731243

  12. Antigen presenting cells in the skin of a patient with hair loss and systemic lupus erythematosus

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu Velez

    2009-01-01

    Full Text Available Context: Hair loss is one of the most striking clinical features of active systemic lupus erythematosus (SLE, however, very few studies have investigated the immunological features of this process. Case report: We describe a 33 years old female who presented with scalp hair loss and arthralgias. Physical examination revealed erythematous plaques on the nose and scalp, with bitemporal hair loss. Scalp biopsies revealed epidermal hyperkeratosis, with a mild interface infiltrate of lymphocytes and histiocytes and a superficial and deep, perivascular and periadnexal infiltrate of mostly CD4 positive cells. Antibodies to HAM 56, CD68, CD1a, S-100, mast cell tryptase and c-kit/CD117 were strongly positive around the hair follicles, and in the adjacent sebaceous glands. Conclusion : We present the first report showing a significant presence of several antigen presenting cells around the hair follicular units in a patient with alopecia in active SLE. Today, antigen presenting cells and dendritic cells (DC are modeled as the master regulators of human immunity. One aspect that has become clearly appreciated is the great diversity of DC subtypes, each with considerable functional differences. Thus, we suggest that APC and DCs are equipped with Pattern Recognition Receptors (PRRs to some hair follicular unit antigens; that these innate sensors recognize conserved molecular patterns on self- tissue, and play a significant role in the pathophysiology of alopecia in SLE patients

  13. Extra-thymically induced T regulatory cell subsets: the optimal target for antigen-specific immunotherapy

    Science.gov (United States)

    Verhagen, Johan; Wegner, Anja; Wraith, David C

    2015-01-01

    Antigen-specific immunotherapy aims to selectively restore tolerance to innocuous antigens in cases of autoimmune or allergic disease, without the need for general immune suppression. Although the principle of antigen-specific immunotherapy was discovered more than a century ago, its clinical application to date is limited, particularly in the control of autoimmunity. This has resulted mainly from a lack of in-depth understanding of the underlying mechanism. More recently, the differentiation of extra-thymically induced T regulatory (Treg) cell subsets has been shown to be instrumental in peripheral tolerance induction. Two main types of inducible Treg cells, interleukin-10-secreting or Foxp3+, have now been described, each with distinct characteristics and methods of therapeutic induction. It is crucial, therefore, to identify the suitability of either subset in the control of specific immune disorders. This review explores their natural function, the known mechanisms of therapeutic differentiation of either subset as well as their in vivo functionality and discusses new developments that may aid their use in antigen-specific immunotherapy, with a focus on autoimmune disease. PMID:25716063

  14. HYBRIDOMA PRODUCTION USING IMMUNE LYMPHOCYTES AGAINST BRUGIA MALAYI ANTIGEN WITH MYELOMA CELLS

    Directory of Open Access Journals (Sweden)

    Soeyoko Soeyoko

    2012-09-01

    Full Text Available Wuchereria bancrofti, Brugia malayi, and Brugia timori are the causative agents of lymphatic hiariasis in Indonesia, but in some endemic areas, Brugia malayi is the most commonly found,Diagnosis of hiariasis is normally based on clinical and parasitological examinations, but both have limitations. Therefore now the immunological examination plays an important role in the diagnosis of filariasis. The discovery of monoclonal antibodies recently may probably give a firm scientific basis in immunology and add a new dimension to the efforts of developing a specific and sensitive immunological test for various stages of filarial infection. In this study, the production of hybridoma cells to develop monoclonal antibodies against B. malayi integrated a number of techniques: preparations of B. malayi surface antigen, immune lymphocyte cells, NSI myeloma cells and macrophage feeder layers, and a fusion of immune lymphocytes with myeloma cells. The results of this study can be concluded in three points: Protein analysis of the surface antigen was examined by Biureet and SDS-PAGE. A total of fourteen examinations were conducted by using 4000 L3 for each experiment. Three were not detected by Biureet method, but showed five protein fractions by SDS-PAGE. The protein concentration of the surface L3 was varied from 85.0/µg/ml to 769.23/µg/ml, with an average of 297.04/µg/ml.The immunoreactivifies of Balb/c mice antibodies to B. malayi L3 surface antigen were tested by ELISA and showed a gradual increase after four times immunizations at two weeks interval. The optical density (OD after four times immunizations was varied from 0.363 to 0.878 each mouse, where as the positive control sera OD was 0.570.Hybridization using immune lymphocytes against B. malayi L3 surface antigen with myeloma cells yielded 60.41% hybrid cells and none of them produced monoclonal antibodies tested of ELISA.

  15. Prostate specific antigen gene expression in androgen insensitive prostate carcinoma subculture cell line.

    Science.gov (United States)

    Tsui, Ke-Hung; Feng, Tsui-Hsia; Chung, Li-Chuan; Chao, Chun-Hsiang; Chang, Phei-Lang; Juang, Horng-Heng

    2008-01-01

    A novel prostate cancer cell line (PC-J) was isolated from an androgen independent non-prostate specific antigen (non-PSA) producing carcinoma cell line. The homologous correlation between PC-J and PC-3 was determined by short tandem repeat analysis. The PSA promoter activity was detected by transient expression assay in the PC-J and LNCaP cells but not in androgen insensitive PC-3 cells. When the PC-J cells were cotransfected with androgen receptor, androgen receptor coactivators and PSA reporter vector cells, the reporter assays indicated that nuclear receptor coactivator 4 (NCOA4) but not androgen receptor activator 24 (ARA24) increased the sensitivity and maximum stimulation of dihydrotestosterone (DHT)-inducing PSA promoter activity. The RT-PCR assays revealed that the expression of several tumor markers, including interleukin-6, prostate stem cell antigen (PSCA), prostate epithelium-specific Ets transcription factor (PDEF) and matriptase, was lower in the PC-J cells than in the PC-3 cells. This cell model elucidated the regulation of PSA expression and enabled comparison of the gene profile at different stages of metastasis in prostatic carcinoma.

  16. Cell-mediated immune response of synovial fluid lymphocytes to ureaplasma antigen in Reiter's syndrome

    Directory of Open Access Journals (Sweden)

    Pavlica Ljiljana

    2003-01-01

    Full Text Available INTRODUCTION Reiter's syndrome (RS is an seronegative arthritis that occurs after urogenital or enteric infection which in addition with occular and/or mucocutaneous manifestations presents complete form of disease. According to previous understanding arthritis in the RS is the reactive one, which means that it is impossible to isolate its causative agent. However, there are the more and more authors suggesting that arthritis in the urogenital form of disease is caused by the infective agent in the affected joint. This suggestion is based on numerous studies on the presence of Chlmaydia trachomatis and Ureaplasma urealyticum in the inflamed joint by using new diagnostic methods in molecular biology published in the recent literature [1-3]. Besides, numerous studies of the humoral and cell-mediated immune response to "triggering" bacteria in the affected joint have supported previous suggestions [4-7]. Aim of the study was to determine whether synovial fluid T-cells specifically recognize the "triggering" bacteria presumably responsible for the Reiter's syndrome. METHOD The 3H-thymidine uptake procedure for measuring lymphocyte responses was applied to lymphocytes derived concurrently from synovial fluid (SF and from peripheral blood (PB [8]. Ureaplasma antigen and mitogen PHA stimulated lymphocytes in 24 RS patients (24 PB samples, 9 SF samples and the results were compared with those found in 10 patients with rheumatoid arthritis (RA (10 PB samples, 5 SF samples. Preparation of ureaplasma antigen. Ureaplasma was cultured on cell-free liquid medium [9]. Sample of 8 ml was heat-inactivated for 15 minutes at 601C and permanently stirred with magnetic mixer. The sample was centrifuged at 2000 x g for 40 minutes and than deposits carefully carried to other sterile glass tubes (Corex and recentrifuged at 9000 x g for 30 minutes. The deposit was washed 3 times in sterile 0.9% NaCl, and final sediment was resuspended in 1.2 ml sterile 0.9% Na

  17. Involvement of proliferating cell nuclear antigen (Cyclin) in DNA replication in living cells

    Energy Technology Data Exchange (ETDEWEB)

    Zuber, M.; Tan, E.M.; Ryoji, M.

    1989-01-01

    Proliferating cell nuclear antigen (PCNA) (also called cyclin) is known to stimulate the activity of DNA polymerase /delta/ but not the other DNA polymerases in vitro. The authors injected a human autoimmune antibody against PCNA into unfertilized eggs of Xenopus laevis and examined the effects of this antibody on the replication of injected plasmid DNA as well as egg chromosomes. The anti-PCNA antibody inhibited plasmid replication by up to 67%, demonstrating that PCNA is involved in plasmid replication in living cells. This result further implies that DNA polymerase /delta/ is necessary for plasmid replication in vivo, Anti-PCNA antibody alone did not block plasmid replication completely, but the residual replication was abolished by coinjection of a monoclonal antibody against DNA polymerase /alpha/. Anti-DNA polymerase /alpha/ alone inhibited plasmid replication by 63%. Thus, DNA ploymerase /alpha/ is also required for plasmid replication in this system. In similar studies on the replication of egg chromosomes, the inhibition by anti-PCNA antibody was only 30%, while anti-DNA polymerase /alpha/ antibody blocked 73% of replication. They concluded that the replication machineries of chromosomes and plasmid differ in their relative content of DNA polymerase /delta/. In addition, they obtained evidence through the use of phenylbutyl deoxyguanosine, an inhibitor of DNA polymearse /alpha/, that the structure of DNA polymerase /alpha/ holoenzyme for chromosome replication is significantly different from that for plasmid replication.

  18. Is Stage-Specific Embryonic Antigen 4 a Marker for Human Ductal Stem/Progenitor Cells?

    Science.gov (United States)

    Kayali, Ayse; Lopez, Ana; Hayek, Alberto

    2012-01-01

    Abstract The presence of pancreatic stem cells (PnSCs) has not been firmly demonstrated in the human or animal pancreas. Previous reports have suggested that ductal and acinar structures in the exocrine pancreas can be a potential source of progenitor cells. More recently, immature insulin precursors in the periphery of human islets have been found to self-replicate and differentiate to endocrine cells in vitro. Transplantation of these cells under the kidney capsule improves the diabetic state in mice. The controversy surrounding where PnSCs reside could be resolved if a specific marker were to be found that allowed their identification, purification, and directed differentiation to endocrine cells. We have identified in human pancreas cells positive for the stage-specific embryonic antigen 4 (SSEA4), a stem cell marker. These cells also express ductal, pancreatic progenitor, and stem cell protein markers. Interestingly, some of the SSEA4+ cells scattered in the ducts do not show a ductal cell phenotype. SSEA4+-sorted cells formed aggregate-like spheres in culture and robustly differentiated to pancreatic hormone-expressing cells in conditions of high glucose concentration and B27 supplementation. We hypothesize that SSEA4+ cells or a subpopulation of those cells residing in the pancreatic ducts may be the elusive PnSCs, and in this case, SSEA4 may represent a potential surface antigen marker for human PnSCs. The discovery of specific markers for the identification and purification of human PnSCs would greatly facilitate studies aimed at the expansion of these cells and the development of targeting tools for their potential induction to insulin-producing cells. PMID:23515456

  19. Is stage-specific embryonic antigen 4 a marker for human ductal stem/progenitor cells?

    Science.gov (United States)

    Afrikanova, Ivka; Kayali, Ayse; Lopez, Ana; Hayek, Alberto

    2012-08-01

    The presence of pancreatic stem cells (PnSCs) has not been firmly demonstrated in the human or animal pancreas. Previous reports have suggested that ductal and acinar structures in the exocrine pancreas can be a potential source of progenitor cells. More recently, immature insulin precursors in the periphery of human islets have been found to self-replicate and differentiate to endocrine cells in vitro. Transplantation of these cells under the kidney capsule improves the diabetic state in mice. The controversy surrounding where PnSCs reside could be resolved if a specific marker were to be found that allowed their identification, purification, and directed differentiation to endocrine cells. We have identified in human pancreas cells positive for the stage-specific embryonic antigen 4 (SSEA4), a stem cell marker. These cells also express ductal, pancreatic progenitor, and stem cell protein markers. Interestingly, some of the SSEA4(+) cells scattered in the ducts do not show a ductal cell phenotype. SSEA4(+)-sorted cells formed aggregate-like spheres in culture and robustly differentiated to pancreatic hormone-expressing cells in conditions of high glucose concentration and B27 supplementation. We hypothesize that SSEA4(+) cells or a subpopulation of those cells residing in the pancreatic ducts may be the elusive PnSCs, and in this case, SSEA4 may represent a potential surface antigen marker for human PnSCs. The discovery of specific markers for the identification and purification of human PnSCs would greatly facilitate studies aimed at the expansion of these cells and the development of targeting tools for their potential induction to insulin-producing cells.

  20. Antigens expressed by myelinating glia cells induce peripheral cross-tolerance of endogenous CD8+ T cells.

    Science.gov (United States)

    Schildknecht, Anita; Probst, Hans Christian; McCoy, Kathy D; Miescher, Iris; Brenner, Corinne; Leone, Dino P; Suter, Ueli; Ohashi, Pamela S; van den Broek, Maries

    2009-06-01

    Auto-reactivity of T cells is largely prevented by central and peripheral tolerance. Nevertheless, immunization with certain self-antigens emulsified in CFA induces autoimmunity in rodents, suggesting that tolerance to some self-antigens is not robust. To investigate the fate of nervous system-specific CD8(+) T cells, which only recently came up as being important contributors for MS pathogenesis, we developed a mouse model that allows inducible expression of lymphocytic choriomeningitis virus-derived CD8(+) T-cell epitopes specifically in oligodendrocytes and Schwann cells, the myelinating glia of the nervous system. These transgenic CD8(+) T-cell epitopes induced robust tolerance of endogenous auto-reactive T cells, which proved thymus-independent and was mediated by cross-presenting bone-marrow-derived cells. Immunohistological staining of secondary lymphoid organs demonstrated the presence of glia-derived antigens in DC, suggesting that peripheral tolerance of CD8(+) T cells results from uptake and presentation by steady state DC.

  1. Antigen experience shapes phenotype and function of memory Th1 cells.

    Directory of Open Access Journals (Sweden)

    Aaruni Khanolkar

    Full Text Available Primary and secondary (boosted memory CD8 T cells exhibit differences in gene expression, phenotype and function. The impact of repeated antigen stimulations on memory CD4 T cells is largely unknown. To address this issue, we utilized LCMV and Listeria monocytogenes infection of mice to characterize primary and secondary antigen (Ag-specific Th1 CD4 T cell responses. Ag-specific primary memory CD4 T cells display a CD62L(loCCR7(hi CD27(hi CD127(hi phenotype and are polyfunctional (most produce IFNγ, TNFα and IL-2. Following homologous prime-boost immunization we observed pathogen-specific differences in the rate of CD62L and CCR7 upregulation on memory CD4 T cells as well as in IL-2+IFNγco-production by secondary effectors. Phenotypic and functional plasticity of memory Th1 cells was observed following heterologous prime-boost immunization, wherein secondary memory CD4 T cells acquired phenotypic and functional characteristics dictated by the boosting agent rather than the primary immunizing agent. Our data also demonstrate that secondary memory Th1 cells accelerated neutralizing Ab formation in response to LCMV infection, suggesting enhanced capacity of this population to provide quality help for antibody production. Collectively these data have important implications for prime-boost vaccination strategies that seek to enhance protective immune responses mediated by Th1 CD4 T cell responses.

  2. Detection of DR antigen on leukemic cells from a patient suffering from adult T-cell leukemia and progressive systemic sclerosis.

    Directory of Open Access Journals (Sweden)

    Mizushima,Keiichi

    1983-10-01

    Full Text Available This report concerns an unusual case of adult T cell leukemia (ATL complicated with progressive systemic sclerosis (PSS. The surface markers of peripheral blood mononuclear cells (PBM and lymph node cells, both of which mainly consisted of leukemic cells, were examined. The effect of these cells on the pokeweed mitogen (PWM-induced IgG synthesis by normal PBM also was studied. The leukemic cells formed rosettes with sheep red blood cells (SRBC; E and expressed T cell antigen, Leu-1, and DR antigen. The detection of cell surface antigens was carried out by employing monoclonal antibodies against these antigens. We diagnosed this case as DR positive ATL. In terms of the immunoregulatory function of these leukemic cells, the co-culture experiments showed that these cells had some suppressive effect on the PWM-induced IgG production by allogeneic normal PBM.

  3. Immature CD4+ dendritic cells conditioned with donor kidney antigen prolong renal allograft survival in rats

    Institute of Scientific and Technical Information of China (English)

    WANG Tao; XU Lin; LI Heng; HUANG Zheng-yu; ZHANG Sheng-ping; MIAO Bin; NA Ning

    2012-01-01

    Background AIIogeneic transplant rejection is currently a major problem encountered during organ transplantation.The dendritic cell (DC) is the most effective powerful known professional antigen-presenting cell,and recent studies have found that DCs can also induce immune tolerance,and avoid or reduce the degree of transplant rejection.The aim of this study was to evaluate the effect of transfused immature CD4+ DCs on renal allografts in the rat model.Methods In this study,we induced CD4+ immature DCs from rat bone marrow cells by a cytokine cocktail.The immature CD4+ DCs were identified by morphological analysis and then the suppressive activity of these cells conditioned with donor kidney antigen was evaluated in vitro and in vivo.Results Immature CD4+ DCs conditioned with donor kidney antigen possessed immunosuppressive activity in vitro and they were able to prolong renal transplant survival in an allograft rat model in vivo.Conclusions Our study provides new information on efficacious renal transplantation,which might be useful for understanding the function of immature CD4+ DCs in modulating renal transplant rejection and improving clinical outcome in future studies.

  4. Kinetics of T cell-activation molecules in response to Mycobacterium tuberculosis antigens

    Directory of Open Access Journals (Sweden)

    Antas Paulo RZ

    2002-01-01

    Full Text Available The phenotypic features acquired subsequent to antigen-specific stimulation in vitro were evaluated by means of the kinetic expressions of CD69 and CD25 activation molecules on T lymphocytes and assayed by flow cytometry in response to PPD, Ag85B, and ferritin in PPD-positive healthy control individuals. In response to PHA, CD69 staining on both CD4+ and CD8+ T cells became initially marked after 4 h, peaked at 24 h, and quickly decreased after 120 h. For CD25, a latter expression was detected around 8 h, having increased after 96 h. As expected, the response rate to the mycobacterial antigens was much lower than that to the mitogen. Positive staining was high after 96 h for CD25 and after 24 h for CD69. CD69 expression was significantly enhanced (p < 0.05 on CD8+ as compared to CD4+ T cells. High levels were also found between 96-120 h. Regarding Ag85B, CD25+ cells were mostly CD4+ instead of CD8+ T cells. Moreover, in response to ferritin, a lower CD25 expression was noted. The present data will allow further characterization of the immune response to new mycobacterial-specific antigens and their evaluation for possible inclusion in developing new diagnostic techniques for tuberculosis as well in a new vaccine to prevent the disease.

  5. Dendritic Cell Targeting of Bacillus anthracis Protective Antigen Expressed by Lactobacillus acidophilus Protects Mice from Lethal Challenge

    Science.gov (United States)

    2008-10-28

    Dendritic cell targeting of Bacillus anthracis protective antigen expressed by Lactobacillus acidophilus protects mice from lethal challenge M...lethal chal- lenge. A vaccine strategy was established by using Lactobacillus acidophilus to deliver Bacillus anthracis protective antigen (PA) via...include species of Lactobacillus , Lactococcus, Leuconostoc, Pedio- coccus, and Streptococcus. It is widely accepted that Lactobacillus species play a

  6. Abnormal expressions of proliferating cell nuclear antigen and P27 protein in brain glioma

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND: Both proliferating cell nuclear antigen and P27 protein are important factors to regulate cell cycle. While, the combination of them can provide exactly objective markers to evaluate prognosis of patients with brain glioma needs to be further studied based on pathological level.OBJECTIVE: To observe the expressions of proliferating cell nuclear antigen and P27 protein in both injured and normal brain glioma tissues and analyze the effect of them on onset and development of brain glioma.DESIGN: Case contrast observation.SETTING: Department of Neurosurgery, the Second Affiliated Hospital of Xi'an Jiaotong University.PARTICIPANTS: A total of 63 patients with brain glioma were selected from Department of Neurosurgery,the Second Affiliated Hospital of Xi'an Jiaotong University from July 1996 to June 2000. There were 38 males and 25 females and their ages ranged from 23 to 71 years. Based on pathological classification and grading standards of brain glioma, patients were divided into grade Ⅰ - tⅡ (n =30) and grade Ⅲ - Ⅳ (n =33). All cases received one operation but no radiotherapy and chemiotherapy before operation. Sample tissues were collected from tumor parenchyma. Non-neoplastic brain tissues were collected from another 12 non-tumor subjects who received craniocerebral trauma infra-decompression and regarded as the control group. There were 10 males and 2 females and their ages ranged from 16 to 54 years. The experiment had got confirmed consent from local ethic committee and the collection was provided confirmed consent from patients and their relatives. All samples were restained with HE staining so as to diagnose as the brain glioma.While, all patients with brain glioma received radiotherapy after operation and their survival periods were followed up.METHODS: Primary lesion wax of brain glioma was cut into serial sections and stained with S-P immunohistochemical staining. Brown substance which was observed in tumor nucleus was regarded as the

  7. Survival and signaling changes in antigen presenting cell subsets after radiation

    Science.gov (United States)

    Parker, Jennifer Janell

    Radiation therapy is a widely used cancer treatment that has the potential to influence anti-tumor immune responses. Both myeloablative and non-myeloablative radiation are often used as part of preparatory regimens for hematopoetic stem cell transplantation, in combination with other chemotherapy or immuno-modulatory (e.g. Anti-thymocyte globulin (ATG)) therapies for both cytotoxic and immune modulatory purposes. However, the mechanisms responsible for the effect of radiation on antigen presenting cell (APC) responsiveness and radioresistance are poorly understood. The first studies described in this thesis were designed to identify and characterize early radiation-induced signaling changes in antigen presenting cells and to determine the effects of these signaling changes on APC receptor expression and function. The NFkappaB pathway in antigen presenting cells was chosen for study because it is activated by radiation in a wide range of other cell types and plays a vital role in the maintenance and regulation of the immune system. The effects of therapeutically relevant doses radiation (2 and 20 Gy) were compared at various timepoints in the human monocytic cell line (U937) using phospho-flow cytometry staining methods and cytometric analysis. These studies demonstrated that radiation-induced changes in the phosphorylation state of NFkappaB family members that were p53 independent. However, these changes were dependent upon activation of ATM in response to single or double-stranded breaks in DNA, as shown in experiments using an inhibitor of ATM and ATM siRNA knockdown U937 cells. In addition, studies examining the effect of radiation on co-stimulatory receptors with and without inhibition of the NFkappaB pathway via phospho-flow cytometry revealed that radiation-induced phosphorylation of NEMO promoted the activation and functional maturation of U937 cells. Furthermore, functional studies using both phospho-flow cytometry and/or mixed lymphocyte reactions to

  8. Enhanced cytotoxicity of natural killer cells following the acquisition of chimeric antigen receptors through trogocytosis.

    Directory of Open Access Journals (Sweden)

    Fu-Nan Cho

    Full Text Available Natural killer (NK cells have the capacity to target tumors and are ideal candidates for immunotherapy. Viral vectors have been used to genetically modify in vitro expanded NK cells to express chimeric antigen receptors (CARs, which confer cytotoxicity against tumors. However, use of viral transduction methods raises the safety concern of viral integration into the NK cell genome. In this study, we used trogocytosis as a non-viral method to modify NK cells for immunotherapy. A K562 cell line expressing high levels of anti-CD19 CARs was generated as a donor cell to transfer the anti-CD19 CARs onto NK cells via trogocytosis. Anti-CD19 CAR expression was observed in expanded NK cells after these cells were co-cultured for one hour with freeze/thaw-treated donor cells expressing anti-CD19 CARs. Immunofluorescence analysis confirmed the localization of the anti-CD19 CARs on the NK cell surface. Acquisition of anti-CD19 CARs via trogocytosis enhanced NK cell-mediated cytotoxicity against the B-cell acute lymphoblastic leukemia (B-ALL cell lines and primary B-ALL cells derived from patients. To our knowledge, this is the first report that describes the increased cytotoxicity of NK cells following the acquisition of CARs via trogocytosis. This novel strategy could be a potential valuable therapeutic approach for the treatment of B-cell tumors.

  9. Affinity isolation of antigen-specific circulating B cells for generation of phage display-derived human monoclonal antibodies

    DEFF Research Database (Denmark)

    Ditzel, Henrik

    2009-01-01

    A method is described for affinity isolation of antigen-specific circulating B cells of interest for subsequent generation of immune antibody phage display libraries. This approach should overcome the problem of low yields of monoclonal antibodies of interest in the libraries generated from...... peripheral blood lymphocytes caused by the low abundance of antigen-specific B cells in the circulation. The preselection of B cells is based on the specificity of the surface Ig receptor and is accomplished using the antigen of interest conjugated to magnetic beads. This method should significantly increase...

  10. A human T cell clone that mediates the monocyte procoagulant response to specific sensitizing antigen.

    OpenAIRE

    Schwartz, B S; Reitnauer, P J; Hank, J A; Sondel, P M

    1985-01-01

    A panel of human purified protein derivative of the tubercle bacillus (PPD)-reactive T cell clones was derived by cloning out of soft agar followed by cultivation on inactivated feeder cells in the presence of interleukin-2. 1 of 4 clones tested was able to mediate an increase in monocyte procoagulant activity (PCA) in response to PPD. All four clones had identical surface marker phenotypes (T4+, T8-) and proliferated in response to antigen. The reactive T cell clone possessed no PCA of its o...

  11. Transcriptional and posttranscriptional regulation of the proliferating cell nuclear antigen gene.

    OpenAIRE

    1990-01-01

    The steady-state mRNA levels of the proliferating cell nuclear antigen (PCNA) gene are growth regulated. In a previous paper (L. Ottavio, C.-D. Chang, M. G. Rizzo, S. Travali, C. Casadevall, and R. Baserga, Mol. Cell. Biol. 10:303-309, 1990), we reported that introns (especially intron 4) participate in growth regulation of the PCNA gene. We have now investigated the role of the 5'-flanking sequence of the human PCNA gene stably transfected into BALB/c 3T3 cells. Promoters of different length...

  12. ImmunoChip Study Implicates Antigen Presentation to T Cells in Narcolepsy

    DEFF Research Database (Denmark)

    Faraco, Juliette; Lin, Ling; Kornum, Birgitte Rahbek;

    2013-01-01

    Recent advances in the identification of susceptibility genes and environmental exposures provide broad support for a post-infectious autoimmune basis for narcolepsy/hypocretin (orexin) deficiency. We genotyped loci associated with other autoimmune and inflammatory diseases in 1,886 individuals...... with hypocretin-deficient narcolepsy and 10,421 controls, all of European ancestry, using a custom genotyping array (ImmunoChip). Three loci located outside the Human Leukocyte Antigen (HLA) region on chromosome 6 were significantly associated with disease risk. In addition to a strong signal in the T cell...... receptor alpha (TRA@), variants in two additional narcolepsy loci, Cathepsin H (CTSH) and Tumor necrosis factor (ligand) superfamily member 4 (TNFSF4, also called OX40L), attained genome-wide significance. These findings underline the importance of antigen presentation by HLA Class II to T cells...

  13. ImmunoChip study implicates antigen presentation to T cells in narcolepsy.

    Directory of Open Access Journals (Sweden)

    Juliette Faraco

    Full Text Available Recent advances in the identification of susceptibility genes and environmental exposures provide broad support for a post-infectious autoimmune basis for narcolepsy/hypocretin (orexin deficiency. We genotyped loci associated with other autoimmune and inflammatory diseases in 1,886 individuals with hypocretin-deficient narcolepsy and 10,421 controls, all of European ancestry, using a custom genotyping array (ImmunoChip. Three loci located outside the Human Leukocyte Antigen (HLA region on chromosome 6 were significantly associated with disease risk. In addition to a strong signal in the T cell receptor alpha (TRA@, variants in two additional narcolepsy loci, Cathepsin H (CTSH and Tumor necrosis factor (ligand superfamily member 4 (TNFSF4, also called OX40L, attained genome-wide significance. These findings underline the importance of antigen presentation by HLA Class II to T cells in the pathophysiology of this autoimmune disease.

  14. Receptor-mediated endocytosis of carcinoembryonic antigen by rat liver Kupffer cells.

    Science.gov (United States)

    Toth, C A; Thomas, P; Broitman, S A; Zamcheck, N

    1985-01-01

    In vivo, carcinoembryonic antigen (CEA) is removed from the circulation by the liver Kupffer cells. Immunologically identifiable CEA is transferred from these macrophages to the hepatocytes, where degradation is completed. Circulatory clearance of CEA is specific, rapid [t1/2 = 3.7 +/- 0.9 (S.D.) min], and saturable. In vitro, Kupffer cells take up CEA by a saturable process which is time/temperature dependent and colchicine sensitive. Isolated Kupffer cells endocytose CEA with an apparent Km of 6 X 10(-8) M. There are approximately 16,000 CEA binding sites per cell. Nonspecific cross-reacting antigen (NCA), a glycoprotein structurally similar to CEA, is recognized with lower affinity by the same receptor. Endocytosis is independent of the nonreducing terminal sugars on the molecule: CEA modified by Smith degradation inhibits Kupffer cell recognition of native CEA. Since performic acid oxidized CEA also inhibits endocytosis, receptor binding is similarly independent of intact protein conformation. Isolated Kupffer cells have mannose and/or N-acetyl glucosamine receptor activity but do not internalize CEA by that mechanism. Galactose-terminated glycoproteins impede CEA and NCA clearance in vivo but not Kupffer cell endocytosis in vitro. Radiolabeled CEA released from isolated Kupffer cells following endocytosis shows no apparent molecular weight change. However, the released CEA contains species with higher isoelectric points, suggesting that perhaps the removal of sialic acid and the resulting exposure of galactose residues mediate the subsequent transfer to the hepatocyte.

  15. Antigen presenting cells costimulatory signaling during pre-implantation pregnancy 

    Directory of Open Access Journals (Sweden)

    Anna Sławek

    2012-09-01

    Full Text Available  Success of pregnancy depends on many factors. Three phenomena inducing immune tolerance against semi-allogeneic conceptus may play a crucial role in the pre-implantation period of pregnancy: influence of sex hormones in sex cycle, presence of oocyte or embryo and the presence of semen in the female reproductive tract. On the other hand dendritic cells are the most effective antigen-presenting cells in regulation of immune phenomena and also are considered as potent participants in inducing immune tolerance in the pregnancy. They communicate with T cells in cell contact-dependent manner or via cytokines. During cell-cell contacts, costimulatory molecules play a key role and their expression is often dependent on cytokines milieu. Both costimulatory molecules and cytokines influence generation of T regulatory cells. Interactions of these molecules are closely related. In this paper we would like to pay attention to the importance of antigen presenting cells costimulatory potency in immune regulation during a pre-implantation period of pregnancy.

  16. Kinetics of antibody-induced modulation of respiratory syncytial virus antigens in a human epithelial cell line

    Directory of Open Access Journals (Sweden)

    Gómez-Garcia Beatriz

    2007-07-01

    Full Text Available Abstract Background The binding of viral-specific antibodies to cell-surface antigens usually results in down modulation of the antigen through redistribution of antigens into patches that subsequently may be internalized by endocytosis or may form caps that can be expelled to the extracellular space. Here, by use of confocal-laser-scanning microscopy we investigated the kinetics of the modulation of respiratory syncytial virus (RSV antigen by RSV-specific IgG. RSV-infected human epithelial cells (HEp-2 were incubated with anti-RSV polyclonal IgG and, at various incubation times, the RSV-cell-surface-antigen-antibody complexes (RSV Ag-Abs and intracellular viral proteins were detected by indirect immunoflourescence. Results Interaction of anti-RSV polyclonal IgG with RSV HEp-2 infected cells induced relocalization and aggregation of viral glycoproteins in the plasma membrane formed patches that subsequently produced caps or were internalized through clathrin-mediated endocytosis participation. Moreover, the concentration of cell surface RSV Ag-Abs and intracellular viral proteins showed a time dependent cyclic variation and that anti-RSV IgG protected HEp-2 cells from viral-induced death. Conclusion The results from this study indicate that interaction between RSV cell surface proteins and specific viral antibodies alter the expression of viral antigens expressed on the cells surface and intracellular viral proteins; furthermore, interfere with viral induced destruction of the cell.

  17. Mycobacterial cell-wall skeleton as a universal vaccine vehicle for antigen conjugation.

    Science.gov (United States)

    Paik, Tae-Hyun; Lee, Ji-Sook; Kim, Ki-Hye; Yang, Chul-Su; Jo, Eun-Kyeong; Song, Chang-Hwa

    2010-11-23

    Mycobacterial cell-wall skeleton (CWS) is an immunoactive and biodegradable particulate adjuvant and has been used for immunotherapy in patients with cancer. The CWS of Mycobacterium bovis bacillus Calmette-Guérin (BCG-CWS) was studied as a universal vaccine vehicle for antigen conjugation, to develop potentially effective and safe vaccines. Here, we describe experiments in which protein antigens, such as keyhole limpet haemocyanin (KLH), ovalbumin (OVA) and bovine serum albumin (BSA) were highly efficiently coupled to 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS)-activated carboxyl groups of BCG-CWS, and tested the immunogenicity of OVA-conjugated BCG-CWS vaccine. We found that a strong immune response was induced in mice immunised with OVA-conjugated BCG-CWS, which was similar to the enhancement of the immune responses in mice immunised with OVA and complete Freund's adjuvant. Covalent conjugation of OVA to BCG-CWS was essential for Th1-skewed immune responses, with prominent expression of IFN-γ. Furthermore, antigen-conjugated BCG-CWS vaccine is simple to manufacture, safe, and easy to use. Our results suggest that mycobacterial CWS as a universal vaccine vehicle for conjugation of a wide variety of antigens constitutes a breakthrough for development of the most promising vaccines for infections, allergic diseases, and cancer.

  18. Functional role of T-cell receptor nanoclusters in signal initiation and antigen discrimination.

    Science.gov (United States)

    Pageon, Sophie V; Tabarin, Thibault; Yamamoto, Yui; Ma, Yuanqing; Bridgeman, John S; Cohnen, André; Benzing, Carola; Gao, Yijun; Crowther, Michael D; Tungatt, Katie; Dolton, Garry; Sewell, Andrew K; Price, David A; Acuto, Oreste; Parton, Robert G; Gooding, J Justin; Rossy, Jérémie; Rossjohn, Jamie; Gaus, Katharina

    2016-09-13

    Antigen recognition by the T-cell receptor (TCR) is a hallmark of the adaptive immune system. When the TCR engages a peptide bound to the restricting major histocompatibility complex molecule (pMHC), it transmits a signal via the associated CD3 complex. How the extracellular antigen recognition event leads to intracellular phosphorylation remains unclear. Here, we used single-molecule localization microscopy to quantify the organization of TCR-CD3 complexes into nanoscale clusters and to distinguish between triggered and nontriggered TCR-CD3 complexes. We found that only TCR-CD3 complexes in dense clusters were phosphorylated and associated with downstream signaling proteins, demonstrating that the molecular density within clusters dictates signal initiation. Moreover, both pMHC dose and TCR-pMHC affinity determined the density of TCR-CD3 clusters, which scaled with overall phosphorylation levels. Thus, TCR-CD3 clustering translates antigen recognition by the TCR into signal initiation by the CD3 complex, and the formation of dense signaling-competent clusters is a process of antigen discrimination.

  19. Induction of CD8+ T-cell responses against subunit antigens by the novel cationic liposomal CAF09 adjuvant

    DEFF Research Database (Denmark)

    Korsholm, Karen Smith; Hansen, Jon; Karlsen, Kasper

    2014-01-01

    Vaccines inducing cytotoxic T-cell responses are required to achieve protection against cancers and intracellular infections such as HIV and Hepatitis C virus. Induction of CD8+ T cell responses in animal models can be achieved by the use of viral vectors or DNA vaccines but so far without much...... clinical success. Here we describe the novel CD8+ T-cell inducing adjuvant, cationic adjuvant formulation (CAF) 09, consisting of dimethyldioctadecylammonium (DDA)-liposomes stabilized with monomycoloyl glycerol (MMG)-1 and combined with the TLR3 ligand, Poly(I:C). Different antigens from tuberculosis (TB......10.3, H56), HIV (Gag p24), HPV (E7) and the model antigen ovalbumin were formulated with CAF09 and administering these vaccines to mice resulted in a high frequency of antigen-specific CD8+ T cells. CAF09 was superior in its ability to induce antigen-specific CD8+ T cells as compared to other...

  20. Changes in tumor-antigen expression proifle as human small-cell lung cancers progress

    Institute of Scientific and Technical Information of China (English)

    Li-Sheng Ge; Neil T Hoa; Nils Lambrecht; Maria Dacosta-Iyer; Yi Ouyang; Amir Abolhoda; Martin R Jadus

    2015-01-01

    AbstrAct Objective:Our group has previously observed that in patients with small-cell lung cancers (SCLCs), the expression of a tumor antigen, glioma big potassium (gBK) ion channel, is higher at the time of death than when the cancer is ifrst treated by surgical resection. This study aimed to determine whether this dichotomy was common in other potential lung tumor antigens by examining the same patient samples using our more extensive proifle analysis of tumor-antigen precursor protein (TAPP). We then tested the hypothesis that therapeutic intervention may inadvertently cause this increased gBK production. Methods:SCLC samples (eight surgical resections and three autopsy samples) and three control lungs were examined by quantitative real-time polymerase chain reaction for 42 potential TAPPs that represent potential T-cell-mediated immunological targets. Results:Twenty-two TAPP mRNAs displayed the same profile as gBK, i.e., more mRNAs were expressed at autopsy than in their surgical counterparts. B-cyclin and mouse double minute 2, human homolog of P53-binding protein were elevated in both autopsy and surgical specimens above the normal-lung controls. When HTB119 cells were incubated with doxorubicin, gBK was strongly induced, as conifrmed by intracellular lfow cytometry with a gBK-speciifc antibody. Conclusion:Our findings suggested that more immunological targets became available as the tumor responded to chemotherapy and proceeded toward its terminal stages.

  1. Rapid and sustained CD4(+) T-cell-independent immunity from adenovirus-encoded vaccine antigens

    DEFF Research Database (Denmark)

    Holst, Peter J; Bartholdy, Christina; Buus, Anette Stryhn

    2007-01-01

    Many novel vaccine strategies rely on recombinant viral vectors for antigen delivery, and adenovirus vectors have emerged among the most potent of these. In this report, we have compared the immune response induced through priming with adenovirus vector-encoded full-length viral protein to that e......Many novel vaccine strategies rely on recombinant viral vectors for antigen delivery, and adenovirus vectors have emerged among the most potent of these. In this report, we have compared the immune response induced through priming with adenovirus vector-encoded full-length viral protein...... to that elicited with an adenovirus-encoded minimal epitope covalently linked to beta(2)-microglobulin. We demonstrate that the beta(2)-microglobulin-linked epitope induced an accelerated and augmented CD8(+) T-cell response. Furthermore, the immunity conferred by vaccination with beta(2)-microglobulin...... in the absence of CD4(+) T-cell help were sustained in the long term and able to expand and control a secondary challenge with LCMV. Our results demonstrate that modifications to the antigen used in adenovirus vaccines may be used to improve the induced T-cell response. Such a strategy for CD4(+) T...

  2. Improved Activation toward Primary Colorectal Cancer Cells by Antigen-Specific Targeting Autologous Cytokine-Induced Killer Cells

    Directory of Open Access Journals (Sweden)

    Claudia Schlimper

    2012-01-01

    Full Text Available Adoptive therapy of malignant diseases with cytokine-induced killer (CIK cells showed promise in a number of trials; the activation of CIK cells from cancer patients towards their autologous cancer cells still needs to be improved. Here, we generated CIK cells ex vivo from blood lymphocytes of colorectal cancer patients and engineered those cells with a chimeric antigen receptor (CAR with an antibody-defined specificity for carcinoembryonic antigen (CEA. CIK cells thereby gained a new specificity as defined by the CAR and showed increase in activation towards CEA+ colon carcinoma cells, but less in presence of CEA− cells, indicated by increased secretion of proinflammatory cytokines. Redirected CIK activation was superior by CAR-mediated CD28-CD3ζ than CD3ζ signaling only. CAR-engineered CIK cells from colon carcinoma patients showed improved activation against their autologous, primary carcinoma cells from biopsies resulting in more efficient tumour cell lysis. We assume that adoptive therapy with CAR-modified CIK cells shows improved selectivity in targeting autologous tumour lesions.

  3. Differentiation induced by physiological and pharmacological stimuli leads to increased antigenicity of human neuroblastoma cells

    Institute of Scientific and Technical Information of China (English)

    Lena-Maria Carlson; Sven P(a)hlman; Anna De Geer; Per Kogner; Jelena Levitskaya

    2008-01-01

    Sympathetic neuronal differentiation is associated with favorable prognosis of neuroblastoma (NB), the most common extra-cranial solid tumor of early childhood. Differentiation agents have proved useful in clinical protocols of NB treatment, but using them as a sole treatment is not sufficient to induce tumor elimination in patients. Therefore, complementary approaches, such as immunotherapy, are warranted. Here we demonstrate that differentiation of NB cell lines and ex vivo isolated tumor cells in response to physiological or pharmacological stimuli is associated with acquisition of increased antigenicity. This manifests as increased expression of surface major histocompatibility class I complexes and ICAM-1 molecules and translates into increased sensitivity of NB cells to lysis by cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. The latter is paralleled by enhanced ability of differentiated cells to form immune conjugates and bind increased amounts of granzyme B to the cell surface. We demonstrate, for the first time, that, regardless of the stimulus applied, the differentiation state in NBs is associated with increased tumor antigenicity that enables more efficient elimination of tumor cells by cytotoxic lymphocytes and paves the way for combined application of differentiation-inducing agents and immunotherapy as an auxiliary approach in NB patients.

  4. Beyond the antigen receptor: editing the genome of T-cells for cancer adoptive cellular therapies

    Directory of Open Access Journals (Sweden)

    Angharad eLloyd

    2013-08-01

    Full Text Available Recent early-stage clinical trials evaluating the adoptive transfer of patient CD8+ T-cells re-directed with antigen receptors recognising tumours have shown very encouraging results. These reports provide strong support for further development of the therapeutic concept as a curative cancer treatment. In this respect combining the adoptive transfer of tumour-specific T-cells with therapies that increase their anti-tumour capacity is viewed as a promising strategy to improve treatment outcome. The ex-vivo genetic engineering step that underlies T-cell re-direction offers a unique angle to combine antigen receptor delivery with the targeting of cell intrinsic pathways that restrict T-cell effector functions. Recent progress in genome editing technologies such as protein- and RNA-guided endonucleases raise the possibility of disrupting gene expression in T-cells in order to enhance effector functions or to bypass tumour immune suppression. This approach would avoid the systemic administration of compounds that disrupt immune homeostasis, potentially avoiding autoimmune adverse effects, and could improve the efficacy of T-cell based adoptive therapies.

  5. Current status and regulatory perspective of chimeric antigen receptor-modified T cell therapeutics.

    Science.gov (United States)

    Kim, Mi-Gyeong; Kim, Dongyoon; Suh, Soo-Kyung; Park, Zewon; Choi, Min Joung; Oh, Yu-Kyoung

    2016-04-01

    Chimeric antigen receptor-modified T cells (CAR-T) have emerged as a new modality for cancer immunotherapy due to their potent efficacy against terminal cancers. CAR-Ts are reported to exert higher efficacy than monoclonal antibodies and antibody-drug conjugates, and act via mechanisms distinct from T cell receptor-engineered T cells. These cells are constructed by transducing genes encoding fusion proteins of cancer antigen-recognizing single-chain Fv linked to intracellular signaling domains of T cell receptors. CAR-Ts are classified as first-, second- and third-generation, depending on the intracellular signaling domain number of T cell receptors. This review covers the current status of CAR-T research, including basic proof-of-concept investigations at the cell and animal levels. Currently ongoing clinical trials of CAR-T worldwide are additionally discussed. Owing to the lack of existing approved products, several unresolved concerns remain with regard to safety, efficacy and manufacturing of CAR-T, as well as quality control issues. In particular, the cytokine release syndrome is the major side-effect impeding the successful development of CAR-T in clinical trials. Here, we have addressed the challenges and regulatory perspectives of CAR-T therapy.

  6. Interleukin 10 (IL-10)-mediated Immunosuppression: MARCH-I INDUCTION REGULATES ANTIGEN PRESENTATION BY MACROPHAGES BUT NOT DENDRITIC CELLS.

    Science.gov (United States)

    Mittal, Sharad K; Cho, Kyung-Jin; Ishido, Satoshi; Roche, Paul A

    2015-11-06

    Efficient immune responses require regulated antigen presentation to CD4 T cells. IL-10 inhibits the ability of dendritic cells (DCs) and macrophages to stimulate antigen-specific CD4 T cells; however, the mechanisms by which IL-10 suppresses antigen presentation remain poorly understood. We now report that IL-10 stimulates expression of the E3 ubiquitin ligase March-I in activated macrophages, thereby down-regulating MHC-II, CD86, and antigen presentation to CD4 T cells. By contrast, IL-10 does not stimulate March-I expression in DCs, does not suppress MHC-II or CD86 expression on either resting or activated DCs, and does not affect antigen presentation by activated DCs. IL-10 does, however, inhibit the process of DC activation itself, thereby reducing the efficiency of antigen presentation in a March-I-independent manner. Thus, IL-10 suppression of antigen presenting cell function in macrophages is March-I-dependent, whereas in DCs, suppression is March- I-independent.

  7. Cinnamon extract suppresses experimental colitis through modulation of antigen-presenting cells

    Institute of Scientific and Technical Information of China (English)

    Ho-Keun Kwon; Zee Yong Park; Sin-Hyeog Im; Ji-Sun Hwang; Choong-Gu Lee; Jae-Seon So; Anupama Sahoo; Chang-Rok Im; Won Kyung Jeon; Byoung Seob Ko; Sung Haeng Lee

    2011-01-01

    AIM:To investigate the anti-inflammatory effects of cinnamon extract and elucidate its mechanisms for targeting the function of antigen presenting cells. METHODS:Cinnamon extract was used to treat murine macrophage cell line (Raw 264.7),mouse primary antigen-presenting cells (APCs,MHCII+) and CD11c+ dendritic cells to analyze the effects of cinnamon extract on APC function.The mechanisms of action of cinnamon extract on APCs were investigated by analyzing cytokine production,and expression of MHC antigens and co-stimulatory molecules by quantitative real-time PCR and flow cytometry.In addition,the effect of cinnamon extract on antigen presentation capacity and APC-dependent T-cell differentiation were analyzed by [H3]-thymidine incorporation and cytokine analysis,respectively. To confirm the anti-inflammatory effects of cinnamon extract in vivo ,cinnamon or PBS was orally administered to mice for 20 d followed by induction of experimental colitis with 2,4,6 trinitrobenzenesulfonic acid.The protective effects of cinnamon extract against experimental colitis were measured by checking clinical symptoms,histological analysis and cytokine expression profiles in inflamed tissue. RESULTS:Treatment with cinnamon extract inhibited maturation of MHCII+ APCs or CD11c+ dendritic cells (DCs) by suppressing expression of co-stimulatory molecules (B7.1,B7.2,ICOS-L),MHCII and cyclooxygenase (COX)-2.Cinnamon extract induced regulatory DCs (rDCs) that produce low levels of pro-inflammatory cytokines [interleukin (IL)-1β,IL-6,IL-12,interferon (IFN)-γ and tumor necrosis factor (TNF)-α] while expressing high levels of immunoregulatory cytokines (IL-10 and transforming growth factor-β).In addition, rDCs generated by cinnamon extract inhibited APC-dependent T-cell proliferation,and converted CD4+ T cells into IL-10high CD4+ T cells.Furthermore,oral administration of cinnamon extract inhibited development and progression of intestinal colitis by inhibiting expression of COX-2 and pro

  8. Automated manufacturing of chimeric antigen receptor T cells for adoptive immunotherapy using CliniMACS prodigy.

    Science.gov (United States)

    Mock, Ulrike; Nickolay, Lauren; Philip, Brian; Cheung, Gordon Weng-Kit; Zhan, Hong; Johnston, Ian C D; Kaiser, Andrew D; Peggs, Karl; Pule, Martin; Thrasher, Adrian J; Qasim, Waseem

    2016-08-01

    Novel cell therapies derived from human T lymphocytes are exhibiting enormous potential in early-phase clinical trials in patients with hematologic malignancies. Ex vivo modification of T cells is currently limited to a small number of centers with the required infrastructure and expertise. The process requires isolation, activation, transduction, expansion and cryopreservation steps. To simplify procedures and widen applicability for clinical therapies, automation of these procedures is being developed. The CliniMACS Prodigy (Miltenyi Biotec) has recently been adapted for lentiviral transduction of T cells and here we analyse the feasibility of a clinically compliant T-cell engineering process for the manufacture of T cells encoding chimeric antigen receptors (CAR) for CD19 (CAR19), a widely targeted antigen in B-cell malignancies. Using a closed, single-use tubing set we processed mononuclear cells from fresh or frozen leukapheresis harvests collected from healthy volunteer donors. Cells were phenotyped and subjected to automated processing and activation using TransAct, a polymeric nanomatrix activation reagent incorporating CD3/CD28-specific antibodies. Cells were then transduced and expanded in the CentriCult-Unit of the tubing set, under stabilized culture conditions with automated feeding and media exchange. The process was continuously monitored to determine kinetics of expansion, transduction efficiency and phenotype of the engineered cells in comparison with small-scale transductions run in parallel. We found that transduction efficiencies, phenotype and function of CAR19 T cells were comparable with existing procedures and overall T-cell yields sufficient for anticipated therapeutic dosing. The automation of closed-system T-cell engineering should improve dissemination of emerging immunotherapies and greatly widen applicability.

  9. CD4+ T cell-mediated presentation of non-infectious HIV-1virion antigens to HIV-specific CD8+ T cells

    Institute of Scientific and Technical Information of China (English)

    XU Jian-qing; Franco Lori; Julianna Lisziewicz

    2006-01-01

    Background The mechanism of chronic immune activation and impairment of HIV-specific immune responses during chronic infection is not fully understood. However, it is known that high immune activation leads to more rapid progression to AIDS. We hypothesize that CD4+ T cell-mediated viral antigen presentation contributes to this pathologic immune activation in HIV-infected individuals.Methods HIV-specific T cells, responding to noninfectious HIV-1 virions as antigen, were measured by flow cytometric assays. These experimental conditions reflect the in vivo condition where noninfectious HIV-1 represents more than 99% of the antigens.Results CD4+ T cells purified from HIV-infected individuals were capable of cross presenting exogenous noninfectious HIV-1 virions to HIV-1-specific CD8+ T cells. Cross presentation required the entry of HIV-1 to CD4+ T cells and antigen translocation from endoplasmic reticulum to the Golgi complex. Blocking CD4+mediated activation of HIV-specific CD8+ T cells and redirecting the viral antigens to antigen presenting cells improved HIV-specific T cell responses.Conclusions One possible cause of chronic immune activation and impairment of HIV-1 specific T cell responses is represented by HIV-1 harboring CD4+ T cells cross presenting HIV-1 antigen to activate CD8+ T cells. This new mechanism provides the first evidence that cross presentation of noninfectious HIV-1. Virions play a role in the immunopathogenesis of HIV-1 infection.

  10. Stage-specific embryonic antigen: determining expression in canine glioblastoma, melanoma, and mammary cancer cells

    Science.gov (United States)

    Ito, Daisuke

    2017-01-01

    The expression of stage-specific embryonic antigens (SSEAs) was determined in several types of canine cancer cells. Flow cytometry showed SSEA-1 expression in glioblastoma, melanoma, and mammary cancer cells, although none expressed SSEA-3 or SSEA-4. Expression of SSEA-1 was not detected in lymphoma, osteosarcoma, or hemangiosarcoma cell lines. Relatively stable SSEA-1 expression was observed between 24 and 72 h of culture. After 8 days in culture, sorted SSEA-1− and SSEA-1+ cells re-established SSEA-1 expression to levels comparable to those observed in unsorted cells. Our results document, for the first time, the expression of SSEA-1 in several canine cancer cell lines. PMID:27456773

  11. Protection from anti-TCR/CD3-induced apoptosis in immature thymocytes by a signal through thymic shared antigen-1/stem cell antigen-2.

    Science.gov (United States)

    Noda, S; Kosugi, A; Saitoh, S; Narumiya, S; Hamaoka, T

    1996-05-01

    During T cell development in the thymus, the expression of thymic shared antigen-1 (TSA-1)/stem cell antigen-2 (Sca-2), a glycosylphosphatidylinositol (GPI)-anchored differentiation antigen, is developmentally regulated. The expression level of TSA-1 is the highest in most immature CD4- CD8- thymocytes, high in CD4+ CD8+ thymocytes, but barely detectable in mature CD4+ CD8- or CD4- CD8- thymocytes and peripheral T cells. We have previously shown that surface TSA-1 expression in peripheral T cells is induced upon activation and that anti-TSA-1 mAb inhibits the T cell receptor (TCR) signaling pathway in activated T cells. In the present study, we have analyzed a role of TSA-1 in thymic selection events, especially in TCR-mediated apoptosis. In in vitro experiments, anti-TSA-1 blocked anti-CD3-induced cell death of T cell hybridomas. When anti-TSA-1 was injected into newborn mice in vivo together with anti-CD3 epsilon or anti-TCR-beta, TCR/CD3-mediated apoptosis of thymocytes was almost completely blocked. The blockade of apoptosis was defined by the inhibition of, first, the decrease in total number of thymocytes; second, the decrease in percentages of CD4+ CD8+ thymocytes; and third, the induction of DNA fragmentation. However, anti-TSA-1 did not block either steroid- or radiation-induced apoptosis, indicating that a signal via TSA-1 does not inhibit a common pathway of thymocyte apoptosis. Since TCR-mediated apoptosis is pivotal in thymic ontogeny, these results suggest that TSA-1/Sca-2 is an important cell surface molecule regulating the fate of a developing T cell.

  12. Targeting self- and foreign antigens to dendritic cells via DC-ASGPR generates IL-10-producing suppressive CD4+ T cells.

    Science.gov (United States)

    Li, Dapeng; Romain, Gabrielle; Flamar, Anne-Laure; Duluc, Dorothée; Dullaers, Melissa; Li, Xiao-Hua; Zurawski, Sandra; Bosquet, Nathalie; Palucka, Anna Karolina; Le Grand, Roger; O'Garra, Anne; Zurawski, Gerard; Banchereau, Jacques; Oh, Sangkon

    2012-01-16

    Dendritic cells (DCs) can initiate and shape host immune responses toward either immunity or tolerance by their effects on antigen-specific CD4(+) T cells. DC-asialoglycoprotein receptor (DC-ASGPR), a lectinlike receptor, is a known scavenger receptor. Here, we report that targeting antigens to human DCs via DC-ASGPR, but not lectin-like oxidized-LDL receptor, Dectin-1, or DC-specific ICAM-3-grabbing nonintegrin favors the generation of antigen-specific suppressive CD4(+) T cells that produce interleukin 10 (IL-10). These findings apply to both self- and foreign antigens, as well as memory and naive CD4(+) T cells. The generation of such IL-10-producing CD4(+) T cells requires p38/extracellular signal-regulated kinase phosphorylation and IL-10 induction in DCs. We further demonstrate that immunization of nonhuman primates with antigens fused to anti-DC-ASGPR monoclonal antibody generates antigen-specific CD4(+) T cells that produce IL-10 in vivo. This study provides a new strategy for the establishment of antigen-specific IL-10-producing suppressive T cells in vivo by targeting whole protein antigens to DCs via DC-ASGPR.

  13. Effect of Bacterial Infection on Proliferating Cell Nuclear Antigen Expression after Partial Splenectomy of Rabbits Using Microwave Coagulator

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The purpose of this study was to investigate the proliferating cell nuclear antigen (PCNA) expression of preserved spleen in rabbits when pneumonia diplococcus suspension was administered after partial splenectomy using microwaver coagulator.

  14. Alphavirus replicon particles acting as adjuvants promote CD8+ T cell responses to co-delivered antigen.

    Science.gov (United States)

    Thompson, Joseph M; Whitmore, Alan C; Staats, Herman F; Johnston, Robert E

    2008-08-05

    Alphavirus replicon particles induce strong antibody and CD8+ T cell responses to expressed antigens in numerous experimental systems. We have recently demonstrated that Venezuelan equine encephalitis virus replicon particles (VRP) possess adjuvant activity for systemic and mucosal antibody responses. In this report, we demonstrate that VRP induced an increased and balanced serum IgG subtype response to co-delivered antigen, with simultaneous induction of antigen-specific IgG1 and IgG2a antibodies, and increased both systemic and mucosal antigen-specific CD8+ T cell responses, as measured by an IFN-gamma ELISPOT assay. Additionally, VRP further increased antigen-specific T cell immunity in an additive fashion following co-delivery with the TLR ligand, CpG DNA. VRP infection led to recruitment of CD8+ T cells into the mucosal compartment, possibly utilizing the mucosal homing receptor, as this integrin was upregulated on CD8+ T cells in the draining lymph node of VRP-infected animals, where VRP-infected dendritic cells reside. This newly recognized ability of VRP to mediate increased T cell response towards co-delivered antigen provides the potential to both define the molecular basis of alphavirus-induced immunity, and improve alphavirus-based vaccines.

  15. Systemic activation of antigen-presenting cells via RNA-loaded nanoparticles

    Science.gov (United States)

    Sayour, Elias J.; Pham, Christina; Grippin, Adam; Kemeny, Hanna; Chua, Joshua; Sampson, John H.; Sanchez-Perez, Luis; Flores, Catherine; Mitchell, Duane A.

    2017-01-01

    ABSTRACT While RNA-pulsed dendritic cell (DC) vaccines have shown promise, the advancement of cellular therapeutics is fraught with developmental challenges. To circumvent the challenges of cellular immunotherapeutics, we developed clinically translatable nanoliposomes that can be combined with tumor-derived RNA to generate personalized tumor RNA-nanoparticles (NPs) with considerable scale-up capacity. RNA-NPs bypass MHC restriction, are amenable to central distribution, and can provide near immediate immune induction. We screened commercially available nanoliposomal preparations and identified the cationic lipid 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) as an efficient mRNA courier to antigen-presenting cells (APCs). When administered intravenously, RNA-NPs mediate systemic activation of APCs in reticuloendothelial organs such as the spleen, liver, and bone marrow. RNA-NPs increase percent expression of MHC class I/II, B7 co-stimulatory molecules, and maturation markers on APCs (all vital for T-cell activation). RNA-NPs also increase activation markers on tumor APCs and elicit potent expansion of antigen-specific T-cells superior to peptide vaccines formulated in complete Freund's adjuvant. We demonstrate that both model antigen-encoding and physiologically-relevant tumor-derived RNA-NPs expand potent antitumor T-cell immunity. RNA-NPs were shown to induce antitumor efficacy in a vaccine model and functioned as a suitable alternative to DCs in a stringent cellular immunotherapy model for a radiation/temozolomide resistant invasive murine high-grade glioma. Although cancer vaccines have suffered from weak immunogenicity, we have advanced a RNA-NP formulation that systemically activates host APCs precipitating activated T-cell frequencies necessary to engender antitumor efficacy. RNA-NPs can thus be harnessed as a more feasible and effective immunotherapy to re-program host-immunity. PMID:28197373

  16. Interview: glycolipid antigen presentation by CD1d and the therapeutic potential of NKT cell activation.

    Science.gov (United States)

    Kronenberg, Mitchell

    2007-01-01

    Natural Killer T cells (NKT) are critical determinants of the immune response to cancer, regulation of autioimmune disease, clearance of infectious agents, and the development of artheriosclerotic plaques. In this interview, Mitch Kronenberg discusses his laboratory's efforts to understand the mechanism through which NKT cells are activated by glycolipid antigens. Central to these studies is CD1d--the antigen presenting molecule that presents glycolipids to NKT cells. The advent of CD1d tetramer technology, a technique developed by the Kronenberg lab, is critical for the sorting and identification of subsets of specific glycolipid-reactive T cells. Mitch explains how glycolipid agonists are being used as therapeutic agents to activate NKT cells in cancer patients and how CD1d tetramers can be used to assess the state of the NKT cell population in vivo following glycolipid agonist therapy. Current status of ongoing clinical trials using these agonists are discussed as well as Mitch's prediction for areas in the field of immunology that will have emerging importance in the near future.

  17. Epitope distance to the target cell membrane and antigen size determine the potency of T cell-mediated lysis by BiTE antibodies specific for a large melanoma surface antigen.

    Science.gov (United States)

    Bluemel, Claudia; Hausmann, Susanne; Fluhr, Petra; Sriskandarajah, Mirnalini; Stallcup, William B; Baeuerle, Patrick A; Kufer, Peter

    2010-08-01

    Melanoma chondroitin sulfate proteoglycan (MCSP; also called CSPG4, NG2, HMW-MAA, MSK16, MCSPG, MEL-CSPG, or gp240) is a surface antigen frequently expressed on human melanoma cells, which is involved in cell adhesion, invasion and spreading, angiogenesis, complement inhibition, and signaling. MCSP has therefore been frequently selected as target antigen for development of antibody- and vaccine-based therapeutic approaches. We have here used a large panel of monoclonal antibodies against human MCSP for generation of single-chain MCSP/CD3-bispecific antibodies of the BiTE (for bispecific T cell engager) class. Despite similar binding affinity to MCSP, respective BiTE antibodies greatly differed in their potency of redirected lysis of CHO cells stably transfected with full-length human MCSP, or with various MCSP deletion mutants and fusion proteins. BiTE antibodies binding to the membrane proximal domain D3 of MCSP were more potent than those binding to more distal domains. This epitope distance effect was corroborated with EpCAM/CD3-bispecific BiTE antibody MT110 by testing various fusion proteins between MCSP and EpCAM as surface antigens. CHO cells expressing small surface target antigens were generally better lysed than those expressing larger target antigens, indicating that antigen size was also an important determinant for the potency of BiTE antibody. The present study for the first time relates the positioning of binding domains and size of surface antigens to the potency of target cell lysis by BiTE-redirected cytotoxic T cells. In case of the MCSP antigen, this provides the basis for selection of a maximally potent BiTE antibody candidate for development of a novel melanoma therapy.

  18. TAP-deficient human iPS cell-derived myeloid cell lines as unlimited cell source for dendritic cell-like antigen-presenting cells.

    Science.gov (United States)

    Haruta, M; Tomita, Y; Yuno, A; Matsumura, K; Ikeda, T; Takamatsu, K; Haga, E; Koba, C; Nishimura, Y; Senju, S

    2013-05-01

    We previously reported a method to generate dendritic cell (DC)-like antigen-presenting cells (APC) from human induced pluripotent stem (iPS) cells. However, the method is relatively complicated and laborious. In the current study, we attempted to establish a method through which we could obtain a large number of functional APC with a simple procedure. We transduced iPS cell-derived CD11b(+) myeloid cells with genes associated with proliferative or anti-senescence effects, enabling the cells to propagate for more than 4 months in a macrophage colony-stimulating factor (M-CSF)-dependent manner while retaining their capacity to differentiate into functional APC. We named these iPS cell-derived proliferating myeloid cells 'iPS-ML', and the iPS-ML-derived APC 'ML-DC'. In addition, we generated TAP2-deficient iPS cell clones by zinc finger nuclease-aided targeted gene disruption. TAP2-deficient iPS cells and iPS-ML avoided recognition by pre-activated allo-reactive CD8(+) T cells. TAP2-deficient ML-DC expressing exogenously introduced HLA-A2 genes stimulated HLA-A2-restricted MART-1-specific CD8(+) T cells obtained from HLA-A2-positive allogeneic donors, resulting in generation of MART-1-specific cytotoxic T lymphocyte (CTL) lines. TAP-deficient iPS-ML introduced with various HLA class I genes may serve as an unlimited source of APC for vaccination therapy. If administered into allogeneic patients, ML-DC with appropriate genetic modifications may survive long enough to stimulate antigen-specific CTL and, after that, be completely eliminated. Based on the present study, we propose an APC-producing system that is simple, safe and applicable to all patients irrespective of their HLA types.

  19. Enhanced expression of beta2-microglobulin and HLA antigens on human lymphoid cells by interferon

    DEFF Research Database (Denmark)

    Heron, I; Hokland, M; Berg, K

    1979-01-01

    Mononuclear cells from the blood of healthy normal humans were kept in cultures under nonstimulating conditions for 16 hr in the presence or absence of human interferon. The relative quantities of HLA antigens and beta(2)-microglobulin on the cultured cells were determined by quantitative...... was observed on B- and T-enriched lymphocyte populations and was found to be dose dependent with the optimum with "physiological" concentrations of interferon. Pretreatment of lymphocytes with interferon for 2 hr was found to be as effective as having interferon present during the total culture period...

  20. Safety and therapeutic efficacy of adoptive p53-specific T cell antigen receptor (TCR) gene transfer

    OpenAIRE

    2014-01-01

    Immunotherapy with T cells genetically modified by retroviral transfer of tumor-associated antigen (TAA)-specific T cell receptors (TCR) is a promising approach in targeting cancer. Therefore, using a universal TAA to target different tumor entities by only one therapeutic approach was the main criteria for our TAA-specific TCR. Here, an optimized (opt) αβ-chain p53(264-272)-specific and an opt single chain (sc) p53(264-272)-specific TCR were designed, to reduce mispairing reactions of endoge...

  1. In vitro cell-mediated cytotoxicity to the male specific (H-Y) antigen in man.

    Science.gov (United States)

    Singal, D P; Wadia, Y J; Naipaul, N

    1981-02-01

    We have studied the role of HLA antigens in restricting specificity of the cytotoxic lymphocytes (CTL). CTL's developed between female responder/male stimulator combinations, were tested for H-Y antigen killing in cell-mediated lympholysis. Two CTL's demonstrated HLA-restricted H-Y cytotoxicity. In both instances, the responders are married parous females and both are positive for HLA-A2. These CTL's lysed target cells from donors who are either positive for the sensitizing HLA antigen or who are HLA-A2-positive males. On the other hand, one CTL where the HLA-A2-positive responder is not a parous female did not show HLA-restricted H-Y cytotoxicity. Also, CTL's where responders do not carry HLA-A2 showed no H-Y cytotoxicity. The data suggest that pregnancy(ies) is sufficient in itself to induce HLA-restricted H-Y cytotoxicity and that it can be recalled by in vitro stimulation with lymphocytes from an unrelated male donor. Also, in these studies HLA-restricted H-Y cytotoxicity was obtained only with targets that shared HLA-A2 with the effectors.

  2. Mast cell density and the context of clinicopathological parameters and expression of p185,estrogen receptor,and proliferating cell nuclear antigen in gastric carcinoma

    Institute of Scientific and Technical Information of China (English)

    Ying-AnJiang; You-YuanZhang; He-ShengLuo; Shou-FuXing

    2002-01-01

    AIM:To investigate the relationship between the mast cell density(MCD)and the context of clinicopathological parameters and expression of p185,estrogen receptor(ER),and proliferating cell nuclear antigen(PCNA)in gastric carcinoma.

  3. The T cell antigen receptor: the Swiss army knife of the immune system.

    Science.gov (United States)

    Attaf, M; Legut, M; Cole, D K; Sewell, A K

    2015-07-01

    The mammalian T cell receptor (TCR) orchestrates immunity by responding to many billions of different ligands that it has never encountered before and cannot adapt to at the protein sequence level. This remarkable receptor exists in two main heterodimeric isoforms: αβ TCR and γδ TCR. The αβ TCR is expressed on the majority of peripheral T cells. Most αβ T cells recognize peptides, derived from degraded proteins, presented at the cell surface in molecular cradles called major histocompatibility complex (MHC) molecules. Recent reports have described other αβ T cell subsets. These 'unconventional' T cells bear TCRs that are capable of recognizing lipid ligands presented in the context of the MHC-like CD1 protein family or bacterial metabolites bound to the MHC-related protein 1 (MR1). γδ T cells constitute a minority of the T cell pool in human blood, but can represent up to half of total T cells in tissues such as the gut and skin. The identity of the preferred ligands for γδ T cells remains obscure, but it is now known that this receptor can also functionally engage CD1-lipid, or immunoglobulin (Ig) superfamily proteins called butyrophilins in the presence of pyrophosphate intermediates of bacterial lipid biosynthesis. Interactions between TCRs and these ligands allow the host to discriminate between self and non-self and co-ordinate an attack on the latter. Here, we describe how cells of the T lymphocyte lineage and their antigen receptors are generated and discuss the various modes of antigen recognition by these extraordinarily versatile receptors.

  4. Selective Conditions Are Required for the Induction of Invariant NKT Cell Hyporesponsiveness by Antigenic Stimulation.

    Science.gov (United States)

    Wingender, Gerhard; Birkholz, Alysia M; Sag, Duygu; Farber, Elisa; Chitale, Sampada; Howell, Amy R; Kronenberg, Mitchell

    2015-10-15

    Activation of invariant (i)NKT cells with the model Ag α-galactosylceramide induces rapid production of multiple cytokines, impacting a wide variety of different immune reactions. In contrast, following secondary activation with α-galactosylceramide, the behavior of iNKT cells is altered for months, with the production of most cytokines being strongly reduced. The requirements for the induction of this hyporesponsive state, however, remain poorly defined. In this study, we show that Th1-biasing iNKT cell Ags could induce iNKT cell hyporesponsiveness, as long as a minimum antigenic affinity was reached. In contrast, the Th2-biasing Ag OCH did not induce a hyporesponsive state, nor did cytokine-driven iNKT cell activation by LPS or infections. Furthermore, although dendritic cells and B cells have been reported to be essential for iNKT cell stimulation, neither dendritic cells nor B cells were required to induce iNKT cell hyporesponsiveness. Therefore, our data indicate that whereas some bone marrow-derived cells could induce iNKT cell hyporesponsiveness, selective conditions, dependent on the structure and potency of the Ag, were required to induce hyporesponsiveness.

  5. Red cell antigen prevalence predicted by molecular testing in ethnic groups of South Texas blood donors.

    Science.gov (United States)

    Aranda, Lorena I; Smith, Linda A; Jones, Scott; Beddard, Rachel

    2015-01-01

    Alloimmunization to red blood cell antigens is seen in patients receiving chronic blood transfusion. Knowing the prevalence of blood group antigens of the different ethnicities of South Texas donors can provide better management of rare blood inventory for patients in this geographical area. A total of 4369 blood donors were tested and analyzed for various antigens in the following blood group systems: ABO, Rh, Kell, Duffy, Kidd, MNS, Lutheran, Dombrock, Landsteiner-Wiener, Diego, Colton, and Scianna. Donors tested to be group 0 or A were serologically tested for the Rh (C, E, c, e) antigens. Those that tested as presumably R1R1, R2R2, or Ror were then genotyped. Donors constituted three major ethnicities: black (18.3%), Hispanic (36.3%), and Caucasian (41.1%); ethnicities comprised of Asian, American Indian, multiracial, and other accounted for the remaining donors (4.3%). The most likely common Rh phenotype for each ethnicity is as follows: black -Ror (44.4%), Hispanic -R1R1 (59.0%), and Caucasian -R1R1 (38.9%). The prevalence of Kell, Duffy, and Kidd blood group system antigens in black and Caucasian donors is comparable with published reports for the entire U.S. The black South Texas donor population had an 8.8 percent increase in prevalence of the Fy(a+b-) phenotype as compared with these published reports; the Hispanic South Texas donor population had a prevalence of 36.1 percent of the Fy(a+b-) phenotype. Regarding the Diego blood group system, the Hispanic donor population in South Texas had a prevalence of 93.5 percent for the Di(a-b+) phenotype as compared with published reports for the entire U.S. (>99.9%). The Hispanic population had a prevalence of 7.9 percent of donors testing as M-N+S-s+ as compared with 20.2 percent and 15.6 percent for black and Caucasian donors, respectively. This study helped us determine the prevalence of each of the blood group antigens in the South Texas donor population to establish and maintain adequate rare inventory of

  6. Interleukin mRNA changes in mast cells stimulated by TSL-1 antigens

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    Arizmendi N.

    2001-06-01

    Full Text Available In this work we analyzed by RT-PCR, the mRNA changes for IL-4, IL-10, TNF and IFN ( induced by TSL-1 antigens in a rat mast cell line (HRMC with mucosal characteristics. The data obtained showed an increase of 65 and 52 % in mRNA expression for IL-4 and TNF respectively and a decrease of 59 and 55 % in mRNAs for IFNγ and IL-10. Our results suggest that TSL-1 antigens induce the release from MC of regulatory molecules, such as IL-4 by an IgE independent mechanism. Our data also provides important information related to the ability of MC to participate not only in the effector phase against the infectious agents, but also in the orchestration of the immune response by the host against parasites.

  7. Further Exploration of the Dendritic Cell Algorithm: Antigen Multiplier and Time Windows

    CERN Document Server

    Gu, Feng; Aickelin, Uwe

    2010-01-01

    As an immune-inspired algorithm, the Dendritic Cell Algorithm (DCA), produces promising performances in the field of anomaly detection. This paper presents the application of the DCA to a standard data set, the KDD 99 data set. The results of different implementation versions of the DXA, including the antigen multiplier and moving time windows are reported. The real-valued Negative Selection Algorithm (NSA) using constant-sized detectors and the C4.5 decision tree algorithm are used, to conduct a baseline comparison. The results suggest that the DCA is applicable to KDD 99 data set, and the antigen multiplier and moving time windows have the same effect on the DCA for this particular data set. The real-valued NSA with constant-sized detectors is not applicable to the data set, and the C4.5 decision tree algorithm provides a benchmark of the classification performance for this data set.

  8. Role of very late antigen-1 in T-cell-mediated immunity to systemic viral infection

    DEFF Research Database (Denmark)

    Ørding Kauffmann, Susanne; Thomsen, Allan Randrup; Christensen, Jan Pravsgaard

    2006-01-01

    The T-cell response to lymphocytic choriomeningitis virus was studied in mice lacking very late antigen-1 (VLA-1). The generation of virus-specific effector T cells was unimpaired in VLA-1(-/-) mice. In the memory phase, VLA-1 deficiency did not influence the number of memory CD8(+) T cells or th......, the current findings indicate that the expression of VLA-1 is not pivotal for T-cell-mediated antiviral immunity to a systemic infection.......-cell-mediated inflammation, no significant influence of VLA-1 was found either in the primary response or in the memory phase. However, alpha-VLA-4 antibody reduced the DTH-like reaction in VLA-1(-/-) mice to a higher degree than in wt mice, suggesting a synergistic effect of blocking both integrins. Taken together...

  9. Epigenetic modulation of cancer-germline antigen gene expression in tumorigenic human mesenchymal stem cells: implications for cancer therapy

    DEFF Research Database (Denmark)

    Gjerstorff, Morten; Burns, Jorge S; Nielsen, Ole;

    2009-01-01

    Cancer-germline antigens are promising targets for cancer immunotherapy, but whether such therapies will also eliminate the primary tumor stem cell population remains undetermined. We previously showed that long-term cultures of telomerized adult human bone marrow mesenchymal stem cells can...... spontaneously evolve into tumor-initiating, mesenchymal stem cells (hMSC-TERT20), which have characteristics of clinical sarcoma cells. In this study, we used the hMSC-TERT20 tumor stem cell model to investigate the potential of cancer-germline antigens to serve as tumor stem cell targets. We found...... that tumorigenic transformation of hMSC-TERT20 cells induced the expression of members of several cancer-germline antigen gene families (ie, GAGE, MAGE-A, and XAGE-1), with promoter hypomethylation and histone acetylation of the corresponding genes. Both in vitro cultures and tumor xenografts derived from...

  10. Identification of Makorin 1 as a novel SEREX antigen of esophageal squamous cell carcinoma

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    Nomura Fumio

    2009-07-01

    Full Text Available Abstract Background Esophageal squamous cell carcinoma (SCC represents one of the most malignant tumors. To improve the poor prognosis, it is necessary to diagnose esophageal SCC at early stages using new tumor markers. SEREX (serological identification of antigens by recombinant cDNA expression cloning is suitable for large-scale screening of tumor antigens and has been applied for various types of human tumors. Methods Tumor markers of esophageal squamous cell carcinoma (SCC were screened by SEREX method. The presence of serum anti-makorin 1 (MKRN1 antibodies (s-MKRN1-Abs was examined by Western blotting using bacterially expressed MKRN1 protein. The expression levels of MKRN1 mRNA in tissues were examined by RT-PCR. The biological activity of MKRN1 was examined by transfection of ras-NIH3T3 mouse fibroblasts with MKRN1 cDNA. Major ubiquitinated proteins in MKRN1-transfected cells were identified by immunoprecipitation with anti-ubiquitin antibody followed by mass spectrometry. Results MKRN1 was identified as a novel SEREX antigen of esophageal SCC. Although a total of 18 (25% of 73 patients with esophageal SCC had s-MKRN1-Abs, none of the 43 healthy donors had a detectable level of s-MKRN1-Abs. There was no correlation between the presence of s-MKRN1-Abs and clinicopathological variables other than histological grading. Well-differentiated tumors were associated significantly with the presence of s-MKRN1-Abs in the patients. The mRNA levels of MKRN1 were frequently higher in esophageal SCC tissues than in the peripheral normal esophageal mucosa. Stable transfection of ras-NIH3T3 cells with MKRN1 cDNA induced prominent morphological changes such as enlargement of the cell body and spreading. Ubiquitination of 80- and 82-kDa proteins were clearly observed in MKRN1-transfected cells but not in the parental cells, which were identified as L-FILIP (filamin A interacting protein 1. Conclusion MKRN1 is a novel SEREX antigen of esophageal SCC, and s

  11. Salmonella enterica serovar Typhi impairs CD4 T cell responses by reducing antigen availability.

    Science.gov (United States)

    Atif, Shaikh M; Winter, Sebastian E; Winter, Maria G; McSorley, Stephen J; Bäumler, Andreas J

    2014-06-01

    Salmonella enterica serovar Typhi is associated with a disseminated febrile illness in humans, termed typhoid fever, while Salmonella enterica serovar Typhimurium causes localized gastroenteritis in immunocompetent individuals. One of the genetic differences between both pathogens is the presence in S. Typhi of TviA, a regulatory protein that shuts down flagellin (FliC) expression when bacteria transit from the intestinal lumen into the intestinal mucosa. Here we investigated the consequences of TviA-mediated flagellum gene regulation on flagellin-specific CD4 T cell responses in a mouse model of S. Typhimurium infection. Introduction of the S. Typhi tviA gene into S. Typhimurium suppressed antigen presentation of dendritic cells to flagellin-specific CD4 T cells in vitro. Furthermore, TviA-mediated repression of flagellin expression impaired the activation and proliferation of naive flagellin-specific CD4 T cells in Peyer's patches and mesenteric lymph nodes, which was accompanied by increased bacterial dissemination to the spleen. We conclude that TviA-mediated repression of flagellin expression reduces antigen availability, thereby weakening flagellin-specific CD4 T cell responses.

  12. Antigen Gene Transfer to Human Plasmacytoid Dendritic Cells Using Recombinant Adenovirus and Vaccinia Virus Vectors

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    Hetty J. Bontkes

    2005-01-01

    Full Text Available Recombinant adenoviruses (RAd and recombinant vaccinia viruses (RVV expressing tumour-associated antigens (TAA are used as anti-tumour vaccines. It is important that these vaccines deliver the TAA to dendritic cells (DC for the induction of a strong immune response. Infection of myeloid DC (MDC with RAd alone is relatively inefficient but CD40 retargeting significantly increases transduction efficiency and DC maturation. Infection with RVV is efficient without DC maturation. Plasmacytoid dendritic cells (PDC play a role in the innate immune response to viral infections through the secretion of IFNα but may also play a role in specific T-cell induction. The aim of our study was to investigate whether PDC are better targets for RAd and RVV based vaccines. RAd alone hardly infected PDC (2% while CD40 retargeting did not improve transduction efficiency, but it did increase PDC maturation (25% CD83 positive cells. Accordingly, specific CTL activation by RAd infected PDC was limited (the number of IFNγ producing CTL was reduced by 75% compared to stimulation with peptide loaded PDC. RVV infected PDC specifically stimulated CTL but PDC were not activated. These Results indicate that PDC are not ideal targets for RAd and RVV based vaccines. However, PDC induced specific CTL activation after pulsing with recombinant protein, indicating that PDC can also cross-present antigens released from surrounding infected cells.

  13. Adhesion molecule expression stimulated by Bacteroides thetaiotaomicron cell-surface antigens.

    Science.gov (United States)

    Rokosz, A; Meisel-Mikołajczyk, F; Malchar, C; Nowaczyk, M; Górski, A

    1999-01-01

    Bacteroides thetaiotaomicron, a Gram-negative anaerobic rod belonging to the Bacteroides fragilis group (BFG), is involved in many systemic and local, most frequently suppurative infections in man. The cell envelope of these rods is composed of two carbohydrate-containing antigens: lipopolysaccharide (LPS) and capsular polysaccharide (CPS). Adhesion molecules ICAM-1, VCAM-1 and E-selectin (ELAM-1) are induced on the endothelial cells by mediators of inflammation. The aim of this study was to assay the ability of B. thetaiotaomicron surface antigens to induce adhesion molecule expression on the endothelial cells. The influence of LPS and CPS on the expression of adhesion molecules on HMEC-1 cell line was examined in an ELISA test. ELISA was performed with monoclonal mouse anti-human: ICAM-1, VCAM-1 and E-selectin antibodies of the IgG class. B. thetaiotaomicron lipopolysaccharides revealed the ability to induce ICAM-1, VCAM-1 and E-selectin expression on the endothelial cells. Their activities were similar, but lower than the activity of Eschericha coli LPS. ICAM-1 was the most stimulated adhesion molecule. The strongest activation by LPS was achieved at the concentrations of 10.0 and 1.0 micrograms/ml. The ability of capsular polysaccharide to induce the expression of adhesion molecules was considerably weaker.

  14. Expression, purification and serological analysis of hepatocellular carcinoma associated antigen HCA587 in insect cells

    Institute of Scientific and Technical Information of China (English)

    Bing Li; Hong-Yan Wu; Xiao-Ping Qian; Yan Li; Wei-Feng Chen

    2003-01-01

    AIM: In order to assess hepatocellular carcinoma associated antigen HCA587 as a potential target for immunotherapy,the Bac-to-Bac expression system was used to express recombinant protein HCA587 in insect cells.METHODS: The cDNA encoding HCA587 gene was cloned into donor vector pFasBacHtb and recombinant pFasBac Htb587 was transformed into competent cells DH10Bac.Recombinant Bacmid-587 was transfected into Sf9 insect cells using CELLFECTIN, Recombinant HCA587 protein was produced in Sf9 insect cells after infection with recombinant baculovirus, and was purified using Ni-NTA resin. Sera from HCC patients were also screened using recombinant protein HCA587.RESULTS: The molecular weight of the recombinant protein HCA587 expressed in insect cells was approximately 43kd.Western blot results proved the recombinant protein HCA587had the similar antigenicity with its native counterpart.Serological analysis told that the rate of seroreactivity to HCA587 was not high in HCC patients.CONCLUSION: The recombinant protein HCA587 was successfully expressed and purified using Bac-to-Bac expression system. It paved the way for generation of specific antibody and investigation of immunohistochemical analysis and immune responses of HCC in the future.

  15. Prolonged antigen presentation by immune complex-binding dendritic cells programs the proliferative capacity of memory CD8 T cells.

    Science.gov (United States)

    León, Beatriz; Ballesteros-Tato, André; Randall, Troy D; Lund, Frances E

    2014-07-28

    The commitment of naive CD8 T cells to effector or memory cell fates can occur after a single day of antigenic stimulation even though virus-derived antigens (Ags) are still presented by DCs long after acute infection is resolved. However, the effects of extended Ag presentation on CD8 T cells are undefined and the mechanisms that regulate prolonged Ag presentation are unknown. We showed that the sustained presentation of two different epitopes from influenza virus by DCs prevented the premature contraction of the primary virus-specific CD8 T cell response. Although prolonged Ag presentation did not alter the number of memory CD8 T cells that developed, it was essential for programming the capacity of these cells to proliferate, produce cytokines, and protect the host after secondary challenge. Importantly, prolonged Ag presentation by DCs was dependent on virus-specific, isotype-switched antibodies (Abs) that facilitated the capture and cross-presentation of viral Ags by FcγR-expressing DCs. Collectively, our results demonstrate that B cells and Abs can regulate the quality and functionality of a subset of antiviral CD8 T cell memory responses and do so by promoting sustained Ag presentation by DCs during the contraction phase of the primary T cell response.

  16. Targeted antigen delivery to dendritic cells elicits robust antiviral T cell-mediated immunity in the liver

    Science.gov (United States)

    Volckmar, Julia; Gereke, Marcus; Ebensen, Thomas; Riese, Peggy; Philipsen, Lars; Lienenklaus, Stefan; Wohlleber, Dirk; Klopfleisch, Robert; Stegemann-Koniszewski, Sabine; Müller, Andreas J.; Gruber, Achim D.; Knolle, Percy; Guzman, Carlos A.; Bruder, Dunja

    2017-01-01

    Hepatotropic viruses such as hepatitis C virus cause life-threatening chronic liver infections in millions of people worldwide. Targeted in vivo antigen-delivery to cross-presenting dendritic cells (DCs) has proven to be extraordinarily efficient in stimulating antigen-specific T cell responses. To determine whether this approach would as well be suitable to induce local antiviral effector T cells in the liver we compared different vaccine formulations based on either the targeting of DEC-205 or TLR2/6 on cross-presenting DCs or formulations not involving in vivo DC targeting. As read-outs we used in vivo hepatotropic adenovirus challenge, histology and automated multidimensional fluorescence microscopy (MELC). We show that targeted in vivo antigen delivery to cross-presenting DCs is highly effective in inducing antiviral CTLs capable of eliminating virus-infected hepatocytes, while control vaccine formulation not involving DC targeting failed to induce immunity against hepatotropic virus. Moreover, we observed distinct patterns of CD8+ T cell interaction with virus-infected and apoptotic hepatocytes in the two DC-targeting groups suggesting that the different vaccine formulations may stimulate distinct types of effector functions. Our findings represent an important step toward the future development of vaccines against hepatotropic viruses and the treatment of patients with hepatic virus infection after liver transplantation to avoid reinfection. PMID:28266658

  17. Antigen-Specific Inhibition of High-Avidity T Cell Target Lysis by Low-Avidity T Cells via Trogocytosis

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    Brile Chung

    2014-08-01

    Full Text Available Current vaccine conditions predominantly elicit low-avidity cytotoxic T lymphocytes (CTLs, which are non-tumor-cytolytic but indistinguishable by tetramer staining or enzyme-linked immunospot from high-avidity CTLs. Using CTL clones of high or low avidity for melanoma antigens, we show that low-avidity CTLs can inhibit tumor lysis by high-avidity CTLs in an antigen-specific manner. This phenomenon operates in vivo: high-avidity CTLs control tumor growth in animals but not in combination with low-avidity CTLs specific for the same antigen. The mechanism involves stripping of specific peptide-major histocompatibility complexes (pMHCs via trogocytosis by low-avidity melanoma-specific CTLs without degranulation, leading to insufficient levels of specific pMHC on target cell surface to trigger lysis by high-avidity CTLs. As such, peptide repertoire on the cell surface is dynamic and continually shaped by interactions with T cells. These results describe immune regulation by low-avidity T cells and have implications for vaccine design.

  18. Induction of anti-tumor CD8 T cell responses by experimental ECP-induced human dendritic antigen presenting cells.

    Science.gov (United States)

    Kibbi, N; Sobolev, O; Girardi, M; Edelson, R L

    2016-08-01

    Extracorporeal photochemotherapy (ECP), or photopheresis, is distinguished by the specificity of the clinically potent immunologic reactions it initiates or regulates. The selectivity of ECP-induced immunoprotection for the malignant clone in cutaneous T cell lymphoma (CTCL), and for the pathogenic clones in allograft rejection and graft-versus-host disease (GVHD), has suggested a central mechanistic role for dendritic antigen presenting cells (DC). Discovery of ECP's induction of monocyte-derived DC, via monocyte signaling by ECP-plate activated platelets, and the absolute dependency of experimental ECP on such induced DC, supports that premise. Herein, we show that ECP-induced DC are capable of stimulating CD8 T cell responses to tumor antigens with which they are loaded. They internalize an antigen-specific melanoma-associated protein then present it onto a class I major histocompatibility, which then stimulates expansion of anti-tumor CD8 T cell populations. We conclude that ECP-induced DC prominently contribute to its initiation of anti-tumor immunity and raise the possibility that the therapy may be applicable to the immunotherapeutic management of a broader spectrum of cancers.

  19. An Essential Role of the Avidity of T-Cell Receptor in Differentiation of Self-Antigen-reactive CD8+ T Cells.

    Science.gov (United States)

    Kondo, Kenta; Fujiki, Fumihiro; Nakajima, Hiroko; Yatsukawa, Erika; Morimoto, Soyoko; Tatsumi, Naoya; Nishida, Sumiyuki; Nakata, Jun; Oka, Yoshihiro; Tsuboi, Akihiro; Hosen, Naoki; Oji, Yusuke; Sugiyama, Haruo

    2016-04-01

    Many studies demonstrated crucial roles of avidity of T-cell receptor (TCR) in T-cell fate. However, majority of these findings resulted from analysis of non-self-antigen-specific CD8 T cells, and little is known about roles of TCR avidity in the fate of self-antigen-specific CD8 T cells. Wilms tumor gene 1 (WT1) protein is a self-antigen most suitable for addressing this issue because WT1 protein is a highly immunogenic, typical self-antigen. Here, we isolated 2 distinct and functional TCRs, TCR1 and TCR2, from murine WT1 peptide (RMFPNAPYL)-specific cytotoxic T lymphocytes (WT1-CTLs) and generated TCR1-retrogenic (Rg) and TCR2-Rg mice under T and B-cell-deficient and -reconstituted conditions. TCR1-transduced CD8 T (TCR1-T) cells had approximately 2-fold higher avidity to WT1 peptide than TCR2-transduced CD8 T (TCR2-T) cells. Cytokine production profiles and cell surface phenotypes showed that TCR1-T cells were more differentiated than TCR2-T cells under both conditions. Therefore, TCR1-T cells with TCR avidity higher than that of TCR2-T cells are more differentiated compared with TCR2-T cells. Furthermore, TCR1-T cells that developed under T and B-cell-reconstituted conditions displayed cytotoxicity against endogenously WT1-expressing tumor cells, whereas TCR2 T cells that developed under the same conditions did not. Thus, it was demonstrated, for the first time, that TCR avidity played an essential role in differentiation of self-antigen-reactive T cells, through the success of establishment of two distinct WT1-CTLs with a difference in only TCR avidity under the identical genetic background. Present results should provide us with an insight for elucidation of the differentiation mechanisms of self-antigen-reactive T cells, including tumor antigen-reactive T cells.

  20. Monoclonal Antibodies as Probes for Unique Antigens in Secretory Cells of Mixed Exocrine Organs

    Science.gov (United States)

    Basbaum, C. B.; Mann, J. K.; Chow, A. W.; Finkbeiner, W. E.

    1984-07-01

    In the past, it has been difficult to identify the secretory product and control mechanisms associated with individual cell types making up mixed exocrine organs. This report establishes the feasibility of using immunological methods to characterize both the biochemical constituents and regulatory mechanisms associated with secretory cells in the trachea. Monoclonal antibodies directed against components of tracheal mucus were produced by immunizing mice with dialyzed, desiccated secretions harvested from tracheal organ culture. An immunofluorescence assay revealed that of the total 337 hybridomas screened, 100 produced antibodies recognizing goblet cell granules; 64, gland cell granules; and 3, antigen confined to the ciliated apical surface of the epithelium. The tracheal goblet cell antibody described in this report was strongly cross-reactive with intestinal goblet cells, as well as with a subpopulation of submandibular gland cells, but not with cells of Brunner's glands or the ciliated cell apical membrane. The serous cell antibody was not cross-reactive with goblet, Brunner's gland, or submandibular cells, or the ciliated cell apical membrane. The antibody directed against the apical membrane of ciliated cells did not cross-react with gland or goblet cells or the apical membrane of epithelial cells in the duodenum. Monoclonal antibodies, therefore, represent probes by which products unique to specific cells or parts of cells in the trachea can be distinguished. The antibodies, when used in enzyme immunoassays, can be used to quantitatively monitor secretion by individual cell types under a variety of physiological and pathological conditions. They also provide the means for purification and characterization of cell-specific products by immunoaffinity chromatography.

  1. Mutual helper effect in copulsing of dendritic cells with 2 antigens: a novel approach for improvement of dendritic-based vaccine efficacy against tumors and infectious diseases simultaneously.

    Science.gov (United States)

    Shojaeian, Jaleh; Jeddi-Tehrani, Mahmood; Dokouhaki, Pouneh; Mahmoudi, Ahmad Reza; Ghods, Roya; Bozorgmehr, Mahmood; Nikoo, Shohreh; Bayat, Ali Ahmad; Akhondi, Mohammad Mehdi; Ostadkarampour, Mahyar; Rezania, Simin; Zarnani, Amir Hassan

    2009-05-01

    To develop an efficient dendritic cell (DC)-based immunotherapy protocol, we examined whether simultaneous pulsing of DCs with a given antigen and a third-party antigen could enhance their antigen presentation capacity. Purified splenic DCs of Balb/c mice were pulsed separately with immunoglobulin G, ovalbumin, conalbumin, P15 peptide of Mycobacterium tuberculosis, and prostate-specific antigen or double combinations of the aforementioned antigens. In some settings, DCs pulsed with 1 antigen were mixed equally with those pulsed with another antigen. Antigen-pulsed DCs were injected into the footpad of syngeneic mice and proliferation of whole, CD4 and CD8 depleted lymph node cells was measured after restimulation with cognate antigen. Antigen-specific production of interferon-gamma (IFNgamma) was tested in culture supernatants. Frequency of responding lymph node cells was determined by IFNgamma enzyme-linked immunosorbent spot assay. Our results showed that copulsing of DCs with 2 unrelated antigens increased the capacity of DCs to induce antigen-specific T-cell proliferation against both antigens up to 16-fold. Injection of 2 populations of DCs each pulsed with a different antigen, increased proliferation of primed T cells significantly as well. Both CD4 and CD8 depleted populations showed vigorous proliferative response in copulsing system. In addition, copulsing of DCs with 2 antigens resulted in higher frequency of antigen-specific responding cells and significantly more IFNgamma production. Our results clearly showed that unrelated peptides and proteins could be used to enhance efficacy of DC-based vaccines and in this system, each antigen served to help the other one, a condition that we termed as "mutual helper effect."

  2. Cholera Toxin Inhibits the T-Cell Antigen Receptor-Mediated Increases in Inositol Trisphosphate and Cytoplasmic Free Calcium

    Science.gov (United States)

    Imboden, John B.; Shoback, Dolores M.; Pattison, Gregory; Stobo, John D.

    1986-08-01

    The addition of monoclonal antibodies to the antigen receptor complex on the malignant human T-cell line Jurkat generates increases in inositol trisphosphate and in the concentration of cytoplasmic free calcium. Exposure of Jurkat cells to cholera toxin for 3 hr inhibited these receptor-mediated events and led to a selective, partial loss of the antigen receptor complex from the cellular surface. None of the effects of cholera toxin on the antigen receptor complex were mimicked by the B subunit of cholera toxin or by increasing intracellular cAMP levels with either forskolin or 8-bromo cAMP. These results suggest that a cholera toxin substrate can regulate signal transduction by the T-cell antigen receptor.

  3. Specific mutation of a gammaherpesvirus-expressed antigen in response to CD8 T cell selection in vivo.

    Science.gov (United States)

    Loh, Joy; Popkin, Daniel L; Droit, Lindsay; Braaten, Douglas C; Zhao, Guoyan; Zhang, Xin; Vachharajani, Punit; Myers, Nancy; Hansen, Ted H; Virgin, Herbert W

    2012-03-01

    Herpesviruses are thought to be highly genetically stable, and their use as vaccine vectors has been proposed. However, studies of the human gammaherpesvirus, Epstein-Barr virus, have found viral isolates containing mutations in HLA class I-restricted epitopes. Using murine gammaherpesvirus 68 expressing ovalbumin (OVA), we examined the stability of a gammaherpesvirus antigenic locus under strong CD8 T cell selection in vivo. OVA-specific CD8 T cells selected viral isolates containing mutations in the OVA locus but minimal alterations in other genomic regions. Thus, a CD8 T cell response to a gammaherpesvirus-expressed antigen that is not essential for replication or pathogenesis can result in selective mutation of that antigen in vivo. This finding may have relevance for the use of herpesvirus vectors for chronic antigen expression in vivo.

  4. Identification of Bacterial Surface Antigens by Screening Peptide Phage Libraries Using Whole Bacteria Cell-Purified Antisera

    Science.gov (United States)

    Hu, Yun-Fei; Zhao, Dun; Yu, Xing-Long; Hu, Yu-Li; Li, Run-Cheng; Ge, Meng; Xu, Tian-Qi; Liu, Xiao-Bo; Liao, Hua-Yuan

    2017-01-01

    Bacterial surface proteins can be good vaccine candidates. In the present study, we used polyclonal antibodies purified with intact Erysipelothrix rhusiopthiae to screen phage-displayed random dodecapeptide and loop-constrained heptapeptide libraries, which led to the identification of mimotopes. Homology search of the mimotope sequences against E. rhusiopthiae-encoded ORF sequences revealed 14 new antigens that may localize on the surface of E. rhusiopthiae. When these putative surface proteins were used to immunize mice, 9/11 antigens induced protective immunity. Thus, we have demonstrated that a combination of using the whole bacterial cells to purify antibodies and using the phage-displayed peptide libraries to determine the antigen specificities of the antibodies can lead to the discovery of novel bacterial surface antigens. This can be a general approach for identifying surface antigens for other bacterial species. PMID:28184219

  5. Functional Specialty of CD40 and Dendritic Cell Surface Lectins for Exogenous Antigen Presentation to CD8(+) and CD4(+) T Cells.

    Science.gov (United States)

    Yin, Wenjie; Gorvel, Laurent; Zurawski, Sandra; Li, Dapeng; Ni, Ling; Duluc, Dorothée; Upchurch, Katherine; Kim, JongRok; Gu, Chao; Ouedraogo, Richard; Wang, Zhiqing; Xue, Yaming; Joo, HyeMee; Gorvel, Jean-Pierre; Zurawski, Gerard; Oh, SangKon

    2016-03-01

    Dendritic cells (DCs) are major antigen-presenting cells that can efficiently prime and cross-prime antigen-specific T cells. Delivering antigen to DCs via surface receptors is thus an appealing strategy to evoke cellular immunity. Nonetheless, which DC surface receptor to target to yield the optimal CD8(+) and CD4(+) T cell responses remains elusive. Herein, we report the superiority of CD40 over 9 different lectins and scavenger receptors at evoking antigen-specific CD8(+) T cell responses. However, lectins (e.g., LOX-1 and Dectin-1) were more efficient than CD40 at eliciting CD4(+) T cell responses. Common and distinct patterns of subcellular and intracellular localization of receptor-bound αCD40, αLOX-1 and αDectin-1 further support their functional specialization at enhancing antigen presentation to either CD8(+) or CD4(+) T cells. Lastly, we demonstrate that antigen targeting to CD40 can evoke potent antigen-specific CD8(+) T cell responses in human CD40 transgenic mice. This study provides fundamental information for the rational design of vaccines against cancers and viral infections.

  6. Antigen-specific memory B-cell responses to enterotoxigenic Escherichia coli infection in Bangladeshi adults.

    Directory of Open Access Journals (Sweden)

    Mohammad Murshid Alam

    2014-04-01

    Full Text Available BACKGROUND: Multiple infections with diverse enterotoxigenic E. coli (ETEC strains lead to broad spectrum protection against ETEC diarrhea. However, the precise mechanism of protection against ETEC infection is still unknown. Therefore, memory B cell responses and affinity maturation of antibodies to the specific ETEC antigens might be important to understand the mechanism of protection. METHODOLOGY: In this study, we investigated the heat labile toxin B subunit (LTB and colonization factor antigens (CFA/I and CS6 specific IgA and IgG memory B cell responses in Bangladeshi adults (n = 52 who were infected with ETEC. We also investigated the avidity of IgA and IgG antibodies that developed after infection to these antigens. PRINCIPAL FINDINGS: Patients infected with ETEC expressing LT or LT+heat stable toxin (ST and CFA/I group or CS6 colonization factors developed LTB, CFA/I or CS6 specific memory B cell responses at day 30 after infection. Similarly, these patients developed high avidity IgA and IgG antibodies to LTB, CFA/I or CS6 at day 7 that remained significantly elevated at day 30 when compared to the avidity of these specific antibodies at the acute stage of infection (day 2. The memory B cell responses, antibody avidity and other immune responses to CFA/I not only developed in patients infected with ETEC expressing CFA/I but also in those infected with ETEC expressing CFA/I cross-reacting epitopes. We also detected a significant positive correlation of LTB, CFA/I and CS6 specific memory B cell responses with the corresponding increase in antibody avidity. CONCLUSION: This study demonstrates that natural infection with ETEC induces memory B cells and high avidity antibodies to LTB and colonization factor CFA/I and CS6 antigens that could mediate anamnestic responses on re-exposure to ETEC and may help in understanding the requirements to design an effective vaccination strategies.

  7. IFN-Gamma Inhibits JC Virus Replication in Glial Cells by Suppressing T-Antigen Expression.

    Directory of Open Access Journals (Sweden)

    Francesca Isabella De-Simone

    Full Text Available Patients undergoing immune modulatory therapies for the treatment of autoimmune diseases such as multiple sclerosis, and individuals with an impaired-immune system, most notably AIDS patients, are in the high risk group of developing progressive multifocal leukoencephalopathy (PML, an often lethal disease of the brain characterized by lytic infection of oligodendrocytes in the central nervous system (CNS with JC virus (JCV. The immune system plays an important regulatory role in controlling JCV reactivation from latent sites by limiting viral gene expression and replication. However, little is known regarding the molecular mechanisms responsible for this regulation.Here, we investigated the impact of soluble immune mediators secreted by activated PBMCs on viral replication and gene expression by cell culture models and molecular virology techniques. Our data revealed that viral gene expression and viral replication were suppressed by soluble immune mediators. Further studies demonstrated that soluble immune mediators secreted by activated PBMCs inhibit viral replication induced by T-antigen, the major viral regulatory protein, by suppressing its expression in glial cells. This unexpected suppression of T-antigen was mainly associated with the suppression of translational initiation. Cytokine/chemokine array studies using conditioned media from activated PBMCs revealed several candidate cytokines with possible roles in this regulation. Among them, only IFN-γ showed a robust inhibition of T-antigen expression. While potential roles for IFN-β, and to a lesser extent IFN-α have been described for JCV, IFN-γ has not been previously implicated. Further analysis of IFN-γ signaling pathway revealed a novel role of Jak1 signaling in control of viral T-antigen expression. Furthermore, IFN-γ suppressed JCV replication and viral propagation in primary human fetal glial cells, and showed a strong anti-JCV activity.Our results suggest a novel role for

  8. Regulation of T cell response to leishmania antigens by determinants of histocompatibility leukocyte class I and II molecules

    Directory of Open Access Journals (Sweden)

    Bacellar O.

    1998-01-01

    Full Text Available It has been shown that HLA class I molecules play a significant role in the regulation of the proliferation of T cells activated by mitogens and antigens. We evaluated the ability of mAb to a framework determinant of HLA class I molecules to regulate T cell proliferation and interferon gamma (IFN-g production against leishmania, PPD, C. albicans and tetanus toxoid antigens in patients with tegumentary leishmaniasis and healthy subjects. The anti-major histocompatibility complex (MHC mAb (W6/32 suppressed lymphocyte proliferation by 90% in cultures stimulated with aCD3, but the suppression was variable in cultures stimulated with leishmania antigen. This suppression ranged from 30-67% and was observed only in 5 of 11 patients. IFN-g production against leishmania antigen was also suppressed by anti-HLA class I mAb. In 3 patients IFN-g levels were suppressed by more than 60%, while in the other 2 cultures IFN-g levels were 36 and 10% lower than controls. The suppression by HLA class I mAb to the proliferative response in leishmaniasis patients and in healthy controls varied with the antigens and the patients or donors tested. To determine whether the suppression is directed at antigen presenting cells (APCs or at the responding T cells, experiments with antigen-primed non-adherent cells, separately incubated with W6/32, were performed. Suppression of proliferation was only observed when the W6/32 mAb was added in the presence of T cells. These data provide evidence that a mAb directed at HLA class I framework determinants can suppress proliferation and cytokine secretion in response to several antigens.

  9. Vaccinia virus infection attenuates innate immune responses and antigen presentation by epidermal dendritic cells.

    Science.gov (United States)

    Deng, Liang; Dai, Peihong; Ding, Wanhong; Granstein, Richard D; Shuman, Stewart

    2006-10-01

    Langerhans cells (LCs) are antigen-presenting cells in the skin that play sentinel roles in host immune defense by secreting proinflammatory molecules and activating T cells. Here we studied the interaction of vaccinia virus with XS52 cells, a murine epidermis-derived dendritic cell line that serves as a surrogate model for LCs. We found that vaccinia virus productively infects XS52 cells, yet this infection displays an atypical response to anti-poxvirus agents. Whereas adenosine N1-oxide blocked virus production and viral protein synthesis during a synchronous infection, cytosine arabinoside had no effect at concentrations sufficient to prevent virus replication in BSC40 monkey kidney cells. Vaccinia virus infection of XS52 cells not only failed to elicit the production of various cytokines, including tumor necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, IL-10, IL-12 p40, alpha interferon (IFN-alpha), and IFN-gamma, it actively inhibited the production of proinflammatory cytokines TNF-alpha and IL-6 by XS52 cells in response to exogenous lipopolysaccharide (LPS) or poly(I:C). Infection with a vaccinia virus mutant lacking the E3L gene resulted in TNF-alpha secretion in the absence of applied stimuli. Infection of XS52 cells or BSC40 cells with the DeltaE3L virus, but not wild-type vaccinia virus, triggered proteolytic decay of IkappaBalpha. These results suggest a novel role for the E3L protein as an antagonist of the NF-kappaB signaling pathway. DeltaE3L-infected XS52 cells secreted higher levels of TNF-alpha and IL-6 in response to LPS and poly(I:C) than did cells infected with the wild-type virus. XS52 cells were productively infected by a vaccinia virus mutant lacking the K1L gene. DeltaK1L-infected cells secreted higher levels of TNF-alpha and IL-6 in response to LPS than wild-type virus-infected cells. Vaccinia virus infection of primary LCs harvested from mouse epidermis was nonpermissive, although a viral reporter protein was

  10. Detection of nuclear and membrane antigens by liquid-based cytology following long-term storage of d1 cells, karpas cells, and peripheral blood mononuclear cells.

    Science.gov (United States)

    Zappacosta, Roberta; Aiello, Francesca B; D'Antuono, Tommaso; Procopio, Antonio D; Durum, Scott K; Conti, Pio; Rosini, Sandra

    2011-01-01

    Immunofluorescence is the most frequently utilized technique to analyze protein expression. Fixed immunofluorescent cell suspensions, however, can only be stored for a week. We investigated whether liquid-based cytology could be used to detect antigens in cultured cells after a long storage period. Murine and human cells were fixed in PreservCyt solution, stored for various periods, and then used to perform an automated immunocytochemical analysis. Phosphorylation of the nuclear transcription factor Stat-5 induced by IL-7 was detected up to 4 months after IL-7 stimulation. Simultaneous nuclear positivity for the proliferation index MIB-1 and membrane positivity for the CD30 antigen were evident three months after fixation. Liquid-based cytology thus ensures long-lasting nuclear and membrane antigen immunoreactivity and permits the storage of cells from laborious experiments at room temperature for future analyses.

  11. Expression of HSV-1 ICP0 Antigen Peptide in Prokaryotic Cells and Preparation of Specific Antibody

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As an immediate-early protein of herpes simplex virus, infected-cell polypeptide 0 (ICP0) exhibits complicated interactions with host cells, and its regulatory function on gene expression is of great importance. Since the ICP0 encoding sequence contains many rare codons which are absent in E.coli, and ICP0 is highly unstable in prokaryotic cells, expression of entire ICP0 in prokaryotic cells has never been reported. In order to further investigate the function of ICP0, a recombinant plasmid was constructed by subcloning a cDNA fragment encoding an amino-terminal of 105 residues of the ICP0 protein into pGEX-5x-1 vector. The resulting GST-105 fusion antigen peptide was expressed with high efficiency in E.coli. Antibodies prepared after the immunization of mice with purified fusion protein can recognize not only the denatured ICP0 protein, but also the native ICP0 protein with normal biological conformation.

  12. Tumor associated antigen specific T-cell populations identified in ex vivo expanded TIL cultures

    DEFF Research Database (Denmark)

    Junker, Niels; Kvistborg, Pia; Køllgaard, Tania;

    2012-01-01

    Ex vivo expanded tumor infiltrating lymphocytes (TILs) from malignant melanoma (MM) and head & neck squamous cell carcinoma (HNSCC) share a similar oligoclonal composition of T effector memory cells, with HLA class I restricted lysis of tumor cell lines. In this study we show that ex vivo expanded...... TILs from MM and HNSCC demonstrate a heterogeneous composition in frequency and magnitude of tumor associated antigen specific populations by Elispot IFN¿ quantitation. TILs from MM and HNSCC shared reactivity towards NY ESO-1, cyclin B1 and Bcl-x derived peptides. Additionally we show that dominating...... the heterogeneous tumors upon adoptive transfer; increasing the probability of tumor control by minimizing immune evasion by tumor cell escape variants....

  13. Antigenic protein synthesis of Campylobacter jejuni in contact with chicken cells

    DEFF Research Database (Denmark)

    Vegge, Christina Skovgaard; Bang, Dang D.; Li, Yiping

    to the environment of the avian gastrointestinal tract. Consequently, the most important reservoir for C. jejuni is the gut of chickens, which are colonized efficiently without causing disease in the birds. Upon co-cultivation with mammalian cells, C. jejuni secrete specific Cia proteins, which are required...... the synthesis of antigenic C. jejuni proteins upon cultivation with chicken cells. Two strains of C. jejuni (the human isolate NCTC11168 and the chicken isolate DVI-SC11) were incubated with primary intestinal chicken cells and subsequently used to raise antisera in rabbits. Negative controls were carried out...... in parallel. These antisera were tested by Western blotting against C. jejuni total protein as well as periplasmic-, surface- and extracellular protein fractions. A unique antibody reaction was discovered to a protein from samples, which had been cultivated with chicken cells. The identity of this protein...

  14. Regulatory T Cells Occupy an Isolated Niche in the Intestine that Is Antigen Independent

    Directory of Open Access Journals (Sweden)

    Lisa L. Korn

    2014-12-01

    Full Text Available Regulatory T cells (Tregs are CD4+ T cells that maintain immune homeostasis and prevent autoimmunity. Like all CD4+ T cells, Tregs require antigen-specific signals via T cell receptor-major histocompatibility complex class II (TCR-MHCII interactions for their development. However, the requirement for MHCII in Treg homeostasis in tissues such as intestinal lamina propria (LP is unknown. We examined LP Treg homeostasis in a transgenic mouse model that lacks peripheral TCR-MHCII interactions and generation of extrathymic Tregs (iTregs. Thymically generated Tregs entered the LP of weanlings and proliferated independently of MHCII to fill the compartment. The adult LP was a closed niche; new thymic Tregs were excluded, and Tregs in parabiotic pairs were LP resident. The isolated LP niche was interleukin-2 (IL-2 independent but dependent on commensal bacteria. Thus, an LP Treg niche can be filled, isolated, and maintained independently of antigen signals and iTregs. This niche may represent a tissue-specific mechanism for maintaining immune tolerance.

  15. Functional expression of a cattle MHC class II DR-like antigen on mouse L cells

    Energy Technology Data Exchange (ETDEWEB)

    Fraser, D.C.; Craigmile, S.; Campbell, J.D.M. [Roslin Inst., Midlothian (United Kingdom)] [and others

    1996-09-01

    Cattle DRA and DRB genes, cloned by reverse-transcription polymerase chain reaction, were transfected into mouse L cells. The cattle DR-expressing L-cell transfectant generated was analyzed serologically, biochemically, and functionally. Sequence analysis of the transfected DRB gene clearly showed showed that it was DRB3 allele DRB3*0101, which corresponds to the 1D-IEF-determined allele DRBF3. 1D-IEF analysis of the tranfectant confirmed that the expressed DR product was DRBF3. Functional integrity of the transfected gene products was demonstrated by the ability of the transfectant cell line to present two antigens (the foot-and-mouth disease virus-derived peptide FMDV15, and ovalbumin) to antigen-specific CD4{sup +} T cells from both the original animal used to obtain the genes, and also from an unrelated DRBF3{sup +} heterozygous animal. Such transfectants will be invaluable tools, allowing us to dissect the precise contributions each locus product makes to the overall immune response in heterozygous animals, information essential for rational vaccine design. 45 refs., 5 figs., 1 tab.

  16. Intravacuolar Membranes Regulate CD8 T Cell Recognition of Membrane-Bound Toxoplasma gondii Protective Antigen

    Directory of Open Access Journals (Sweden)

    Jodie Lopez

    2015-12-01

    Full Text Available Apicomplexa parasites such as Toxoplasma gondii target effectors to and across the boundary of their parasitophorous vacuole (PV, resulting in host cell subversion and potential presentation by MHC class I molecules for CD8 T cell recognition. The host-parasite interface comprises the PV limiting membrane and a highly curved, membranous intravacuolar network (IVN of uncertain function. Here, using a cell-free minimal system, we dissect how membrane tubules are shaped by the parasite effectors GRA2 and GRA6. We show that membrane association regulates access of the GRA6 protective antigen to the MHC I pathway in infected cells. Although insertion of GRA6 in the PV membrane is key for immunogenicity, association of GRA6 with the IVN limits presentation and curtails GRA6-specific CD8 responses in mice. Thus, membrane deformations of the PV regulate access of antigens to the MHC class I pathway, and the IVN may play a role in immune modulation.

  17. ANA detected by ELISA using nucleus of egg cell as antigen.

    Science.gov (United States)

    Hui, Liu; Shijun, Li; Yue, Ma

    2008-01-01

    Antinuclear antibodies, ANA, were usually detected with antigen of somatic cell nucleus. It has not been reported to detect ANA with egg cell nucleus as antigen. Enzyme linked immuosorbent assay, ELISA, coated with yolk was developed to detect ANA in our laboratory. A quality control test, cross absorption test, and cross antibody-induced test with yolk were performed. Results showed a good agreement between our method and IFA through measurement of the same samples from patients suspected of having rheumatic connective tissue diseases (Kappa=0.668, P=0.000). The results were not influenced by the RF and different sources of egg. CVs of inter-assay, were less than 10%. The cross absorption test was negative, as well; the ANA to somatic cell nucleus could be induced with egg cell nucleus. It is implied that there were both cross as well as overlapped Egg-ANA and Somatic-ANA. As egg nucleus, its volume was large, its purification was simple, so the better method might be established.

  18. Antigen-Specific Priming is Dispensable in Depletion of Apoptosis-Sensitive T Cells for GvHD Prophylaxis.

    Science.gov (United States)

    Yarkoni, Shai; Stein, Jerry; Yaniv, Isaac; Askenasy, Nadir

    2014-01-01

    Prophylactic approaches to graft versus host disease (GvHD) have employed both phenotypic reduction of T cells and selective elimination of host-primed donor T cells in vitro and in vivo. An additional approach to GvHD prophylaxis by functional depletion of apoptosis-sensitive donor T cells without host-specific sensitization ex vivo showed remarkable reduction in GHD incidence and severity. We address the role and significance of antigen-specific sensitization of donor T cells and discuss the mechanisms of functional T cell purging by apoptosis for GvHD prevention. Host-specific sensitization is dispensable because migration is antigen-independent and donor T cell sensitization is mediated by multiple and redundant mechanisms of presentation of major and minor histocompatibility complex and tissue antigens by donor and host antigen-presenting cells. Our data suggest that potential murine and human GvH effectors reside within subsets of preactivated T cells susceptible to negative regulation by apoptosis prior to encounter of and sensitization to specific antigens.

  19. Phenotypic studies of natural killer cell subsets in human transporter associated with antigen processing deficiency.

    Directory of Open Access Journals (Sweden)

    Jacques Zimmer

    Full Text Available Peripheral blood natural killer (NK cells from patients with transporter associated with antigen processing (TAP deficiency are hyporesponsive. The mechanism of this defect is unknown, but the phenotype of TAP-deficient NK cells is almost normal. However, we noticed a high percentage of CD56(bright cells among total NK cells from two patients. We further investigated TAP-deficient NK cells in these patients and compared them to NK cells from two other TAP-deficient patients with no clinical symptoms and to individuals with chronic inflammatory diseases other than TAP deficiency (chronic lung diseases or vasculitis. Peripheral blood mononuclear cells isolated from venous blood were stained with fluorochrome-conjugated antibodies and the phenotype of NK cells was analyzed by flow cytometry. In addition, (51Chromium release assays were performed to assess the cytotoxic activity of NK cells. In the symptomatic patients, CD56(bright NK cells represented 28% and 45%, respectively, of all NK cells (higher than in healthy donors. The patients also displayed a higher percentage of CD56(dimCD16(- NK cells than controls. Interestingly, this unusual NK cell subtype distribution was not found in the two asymptomatic TAP-deficient cases, but was instead present in several of the other patients. Over-expression of the inhibitory receptor CD94/NKG2A by TAP-deficient NK cells was confirmed and extended to the inhibitory receptor ILT2 (CD85j. These inhibitory receptors were not involved in regulating the cytotoxicity of TAP-deficient NK cells. We conclude that expansion of the CD56(bright NK cell subtype in peripheral blood is not a hallmark of TAP deficiency, but can be found in other diseases as well. This might reflect a reaction of the immune system to pathologic conditions. It could be interesting to investigate the relative distribution of NK cell subsets in various respiratory and autoimmune diseases.

  20. Role of sustained antigen release from nanoparticle vaccines in shaping the T cell memory phenotype.

    Science.gov (United States)

    Demento, Stacey L; Cui, Weiguo; Criscione, Jason M; Stern, Eric; Tulipan, Jacob; Kaech, Susan M; Fahmy, Tarek M

    2012-06-01

    Particulate vaccines are emerging promising technologies for the creation of tunable prophylactics against a wide variety of conditions. Vesicular and solid biodegradable polymer platforms, exemplified by liposomes and polyesters, respectively, are two of the most ubiquitous platforms in vaccine delivery studies. Here we directly compared the efficacy of each in a long-term immunization study and in protection against a model bacterial antigen. Immunization with poly(lactide-co-glycolide) (PLGA) nanoparticles elicited prolonged antibody titers compared to liposomes and alum. The magnitude of the cellular immune response was also highest in mice vaccinated with PLGA, which also showed a higher frequency of effector-like memory T cell phenotype, leading to an effective clearance of intracellular bacteria. The difference in performance of these two common particulate platforms is shown not to be due to material differences but appears to be connected to the kinetics of antigen delivery. Thus, this study highlights the importance of sustained antigen release mediated by particulate platforms and its role in the long-term appearance of effector memory cellular response.

  1. Rational design of T cell receptors with enhanced sensitivity for antigen.

    Directory of Open Access Journals (Sweden)

    Rajshekhar Alli

    Full Text Available Enhancing the affinity of therapeutic T cell receptors (TCR without altering their specificity is a significant challenge for adoptive immunotherapy. Current efforts have primarily relied on empirical approaches. Here, we used structural analyses to identify a glycine-serine variation in the TCR that modulates antigen sensitivity. A G at position 107 within the CDR3β stalk is encoded within a single mouse and human TCR, TRBV13-2 and TRBV12-5 respectively. Most TCR bear a S107. The S hydroxymethyl side chain intercalates into the core of the CDR3β loop, stabilizing it. G107 TRBV possess a gap in their CDR3β where this S hydroxymethyl moiety would fit. We predicted based on modeling and molecular dynamics simulations that a G107S substitution would increase CDR3β stability and thereby augment receptor sensitivity. Experimentally, a G107S replacement led to an ∼10-1000 fold enhanced antigen sensitivity in 3 of 4 TRBV13-2(+ TCR tested. Analysis of fine specificity indicated a preserved binding orientation. These results support the feasibility of developing high affinity antigen specific TCR for therapeutic purposes through the identification and manipulation of critical framework residues. They further indicate that amino acid variations within TRBV not directly involved in ligand contact can program TCR sensitivity, and suggest a role for CDR3 stability in this programming.

  2. Identification of chimeric antigen receptors that mediate constitutive or inducible proliferation of T cells.

    Science.gov (United States)

    Frigault, Matthew J; Lee, Jihyun; Basil, Maria Ciocca; Carpenito, Carmine; Motohashi, Shinichiro; Scholler, John; Kawalekar, Omkar U; Guedan, Sonia; McGettigan, Shannon E; Posey, Avery D; Ang, Sonny; Cooper, Laurence J N; Platt, Jesse M; Johnson, F Brad; Paulos, Chrystal M; Zhao, Yangbing; Kalos, Michael; Milone, Michael C; June, Carl H

    2015-04-01

    This study compared second-generation chimeric antigen receptors (CAR) encoding signaling domains composed of CD28, ICOS, and 4-1BB (TNFRSF9). Here, we report that certain CARs endow T cells with the ability to undergo long-term autonomous proliferation. Transduction of primary human T cells with lentiviral vectors encoding some of the CARs resulted in sustained proliferation for up to 3 months following a single stimulation through the T-cell receptor (TCR). Sustained numeric expansion was independent of cognate antigen and did not require the addition of exogenous cytokines or feeder cells after a single stimulation of the TCR and CD28. Results from gene array and functional assays linked sustained cytokine secretion and expression of T-bet (TBX21), EOMES, and GATA-3 to the effect. Sustained expression of the endogenous IL2 locus has not been reported in primary T cells. Sustained proliferation was dependent on CAR structure and high expression, the latter of which was necessary but not sufficient. The mechanism involves constitutive signaling through NF-κB, AKT, ERK, and NFAT. The propagated CAR T cells retained a diverse TCR repertoire, and cellular transformation was not observed. The CARs with a constitutive growth phenotype displayed inferior antitumor effects and engraftment in vivo. Therefore, the design of CARs that have a nonconstitutive growth phenotype may be a strategy to improve efficacy and engraftment of CAR T cells. The identification of CARs that confer constitutive or nonconstitutive growth patterns may explain observations that CAR T cells have differential survival patterns in clinical trials.

  3. The Novel Toll-Like Receptor 2 Agonist SUP3 Enhances Antigen Presentation and T Cell Activation by Dendritic Cells

    Science.gov (United States)

    Guo, Xueheng; Wu, Ning; Shang, Yingli; Liu, Xin; Wu, Tao; Zhou, Yifan; Liu, Xin; Huang, Jiaoyan; Liao, Xuebin; Wu, Li

    2017-01-01

    Dendritic cells (DCs) are highly specialized antigen-presenting cells that play crucial roles in innate and adaptive immunity. Previous studies suggested that Toll-like receptor (TLR) agonists could be used as potential adjuvants, as activation of TLRs can boost DC-induced immune responses. TLR2 agonists have been shown to enhance DC-mediated immune responses. However, classical TLR2 agonists such as Pam3CSK4 are not stable enough in vivo, which limits their clinical applications. In this study, a novel structurally stable TLR2 agonist named SUP3 was designed. Functional analysis showed that SUP3 induced much stronger antitumor response than Pam3CSK4 by promoting cytotoxic T lymphocytes activation in vivo. This effect was achieved through the following mechanisms: SUP3 strongly enhanced the ability of antigen cross-presentation by DCs and subsequent T cell activation. SUP3 upregulated the expression of costimulatory molecules on DCs and increased antigen deposition in draining lymph nodes. More interestingly, SUP3 induced less amount of pro-inflammatory cytokine production in vivo compared to other TLR agonists such as lipopolysaccharide. Taken together, SUP3 could serve as a novel promising immune adjuvant in vaccine development and immune modulations.

  4. Application of Adoptive T-Cell Therapy Using Tumor Antigen-Specific T-Cell Receptor Gene Transfer for the Treatment of Human Leukemia

    Directory of Open Access Journals (Sweden)

    Toshiki Ochi

    2010-01-01

    Full Text Available The last decade has seen great strides in the field of cancer immunotherapy, especially the treatment of melanoma. Beginning with the identification of cancer antigens, followed by the clinical application of anti-cancer peptide vaccination, it has now been proven that adoptive T-cell therapy (ACT using cancer antigen-specific T cells is the most effective option. Despite the apparent clinical efficacy of ACT, the timely preparation of a sufficient number of cancer antigen-specific T cells for each patient has been recognized as its biggest limitation. Currently, therefore, attention is being focused on ACT with engineered T cells produced using cancer antigen-specific T-cell receptor (TCR gene transfer. With regard to human leukemia, ACT using engineered T cells bearing the leukemia antigen-specific TCR gene still remains in its infancy. However, several reports have provided preclinical data on TCR gene transfer using Wilms' tumor gene product 1 (WT1, and also preclinical and clinical data on TCR gene transfer involving minor histocompatibility antigen, both of which have been suggested to provide additional clinical benefit. In this review, we examine the current status of anti-leukemia ACT with engineered T cells carrying the leukemia antigen-specific TCR gene, and discuss the existing barriers to progress in this area.

  5. High expression of carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 6 and 8 in primary myelofibrosis

    DEFF Research Database (Denmark)

    Hasselbalch, Hans Carl; Skov, Vibe; Larsen, Thomas Stauffer;

    2011-01-01

    for the egress of CD34+ cells from the bone marrow. Carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 6 has been implicated in cell adhesion, cellular invasiveness, angiogenesis, and inflammation, which are all key processes in the pathophysiology of PMF. Accordingly, CEACAMs may play an important...

  6. Chimeric antigen receptor T cell therapy in AML: How close are we?

    Science.gov (United States)

    Gill, Saar

    2016-12-01

    The majority of patients presenting with acute myeloid leukemia (AML) initially respond to chemotherapy but post-remission therapy is required to consolidate this response and achieve long-term disease-free survival. The most effective form of post-remission therapy relies on T cell immunotherapy in the form of allogeneic hematopoietic cell transplantation (HCT). However, patients with active disease cannot usually expect to be cured with HCT. This inherent dichotomy implies that traditional T cell-based immunotherapy in the form of allogeneic HCT stops being efficacious somewhere between the measurable residual disease (MRD) and the morphologically obvious range. This is in part because the full power of T cells must be restrained in order to avoid lethal graft-versus-host disease (GVHD) and partly because only a sub-population of donor T cells are expected to be able to recognize AML cells via their T cell receptor. Chimeric antigen receptor (CAR) T cell therapy, most advanced in the treatment of patients with B-cell malignancies, may circumvent some of these limitations. However, major challenges remain to be overcome before CAR T cell therapy can be safely applied to AML.

  7. Uptake of synthetic naked RNA by skin-resident dendritic cells via macropinocytosis allows antigen expression and induction of T-cell responses in mice.

    Science.gov (United States)

    Selmi, Abderraouf; Vascotto, Fulvia; Kautz-Neu, Kordula; Türeci, Özlem; Sahin, Ugur; von Stebut, Esther; Diken, Mustafa; Kreiter, Sebastian

    2016-09-01

    Intradermal administration of antigen-encoding RNA has entered clinical testing for cancer vaccination. However, insight into the underlying mechanism of RNA uptake, translation and antigen presentation is still limited. Utilizing pharmacologically optimized naked RNA, the dose-response kinetics revealed a rise in reporter signal with increasing RNA amounts and a prolonged RNA translation of reporter protein up to 30 days after intradermal injection. Dendritic cells (DCs) in the dermis were shown to engulf RNA, and the signal arising from the reporter RNA was significantly diminished after DC depletion. Macropinocytosis was relevant for intradermal RNA uptake and translation in vitro and in vivo. By combining intradermal RNA vaccination and inhibition of macropinocytosis, we show that effective priming of antigen-specific CD8(+) T-cells also relies on this uptake mechanism. This report demonstrates that direct antigen translation by dermal DCs after intradermal naked RNA vaccination is relevant for efficient priming of antigen-specific T-cells.

  8. Fluorescent imaging of antigen released by a skin-invading helminth reveals differential uptake and activation profiles by antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Ross A Paveley

    Full Text Available Infection of the mammalian host by the parasitic helminth Schistosoma mansoni is accompanied by the release of excretory/secretory molecules (ES from cercariae which aid penetration of the skin. These ES molecules are potent stimulants of innate immune cells leading to activation of acquired immunity. At present however, it is not known which cells take up parasite antigen, nor its intracellular fate. Here, we develop a technique to label live infectious cercariae which permits the imaging of released antigens into macrophages (MPhi and dendritic cells (DCs both in vitro and in vivo. The amine reactive tracer CFDA-SE was used to efficiently label the acetabular gland contents of cercariae which are released upon skin penetration. These ES products, termed '0-3hRP', were phagocytosed by MHC-II(+ cells in a Ca(+ and actin-dependent manner. Imaging of a labelled cercaria as it penetrates the host skin over 2 hours reveals the progressive release of ES material. Recovery of cells from the skin shows that CFDA-SE labelled ES was initially (3 hrs taken up by Gr1(+MHC-II(- neutrophils, followed (24 hrs by skin-derived F4/80(+MHC-II(lo MPhi and CD11c(+ MHC-II(hi DC. Subsequently (48 hrs, MPhi and DC positive for CFDA-SE were detected in the skin-draining lymph nodes reflecting the time taken for antigen-laden cells to reach sites of immune priming. Comparison of in vitro-derived MPhi and DC revealed that MPhi were slower to process 0-3hRP, released higher quantities of IL-10, and expressed a greater quantity of arginase-1 transcript. Combined, our observations on differential uptake of cercarial ES by MPhi and DC suggest the development of a dynamic but ultimately balanced response that can be potentially pushed towards immune priming (via DC or immune regulation (via MPhi.

  9. Cellular Immune Responses for Squamous Cell Carcinoma Antigen Recognized by T Cells 3 in Patients with Hepatocellular Carcinoma

    Science.gov (United States)

    Kaji, Kiichiro; Mizukoshi, Eishiro; Yamashita, Tatsuya; Arai, Kuniaki; Sunagozaka, Hajime; Fushimi, Kazumi; Nakagawa, Hidetoshi; Yamada, Kazutoshi; Terashima, Takeshi; Kitahara, Masaaki; Kaneko, Shuichi

    2017-01-01

    Background & Aims Squamous cell carcinoma antigen recognized by T cells 3 (SART3), a tumor-associated antigen expressed in many cancers, functions in tumor rejection. In this study, we investigated its usefulness as an immunotherapeutic target in hepatocellular carcinoma (HCC). Methods The expression of SART3 in hepatoma cell lines and HCC tissues was investigated by immunofluorescence and immunohistochemical analyses. Two peptides derived from SART3 (SART3109 and SART3315) were used for immunological analysis. T-cell responses were investigated by interferon-gamma (IFN-γ) enzyme-linked immunospot and cytotoxic T lymphocyte (CTL) assays using peripheral blood mononuclear cells (PBMCs) in 47 patients, and tumor-infiltrating lymphocytes in 8 of 47 patients with HCC. The safety of immunotherapy using a SART3-derived peptide was investigated by vaccinations of SART3109 in 12 patients with HCC (trial registration: UMIN000005677). Results The immunofluorescence and immunohistochemical analyses showed that SART3 was expressed in six HCC cell lines, and in HCC tissues including of alpha-fetoprotein-negative individuals. SART3-specific CTLs were generated by stimulating PBMCs with the peptides, and they showed cytotoxicity against HCC cells expressing the protein. Of the 47 HCC patients, 25.5% and 10.6% showed significant responses to SART3109 and SART3315, respectively. The infiltration of SART3109-specific IFN-γ-producing CTLs into the tumor site was confirmed. In the vaccination study, no severe adverse events were observed, and the peptide-specific CTLs were newly induced in four of five patients tested. Conclusions SART3 is an immunotherapeutic candidate, and peptides from this antigen may be applied in HCC immunotherapy. Trial Registration UMIN000005677 PMID:28114424

  10. Modulation of T cell responses after cross-talk between antigen presenting cells and T cells: a give-and-take relationship.

    Science.gov (United States)

    Wauben, Marca H M; 't Hoen, Esther N M; Taams, Leonie S

    2003-01-01

    T cells presenting antigens in the context of MHC class II can induce anergy. In rat CD4+ T cell clones we have shown that depending on the depth of anergy other T cell responses can be inhibited in the presence of professional antigen presenting cells (APCs). This inhibition is cell-contact dependent, and APCs recovered from co-cultures with suppressive anergic T cells are modulated in their capacity to activate T cells. No changes in cell surface expression of MHC molecules, B7-1/B7-2, and OX40L were detected. Remarkably cell clusters formed by anergic T cells appeared to be more tight than clusters of activated T cells, and after fluorescent cell surface labelling of T cells, transfer of label was more profound in co-cultures of anergic T cells and APCs compared to activated T cells and APCs. Previously, it has been shown that activated T cells can absorb molecules from APCs in a unidirectional process. We now have evidence that also APCs can absorb cell surface molecules from T cells during APC-T cell co-cultures. We speculate that the quantity and quality of molecule reshuffling during cross-talk between T cells and APCs play a role in the regulation of the T cell response.

  11. The cancer-germline antigen SSX2 causes cell cycle arrest and DNA damage in cancer cells

    DEFF Research Database (Denmark)

    Greve, Katrine Buch Vidén; Lindgreen, Jonas; Terp, Mikkel Green

    2011-01-01

    The SSX family of cancer and germline antigens is mainly expressed in the germ cells of healthy individuals as well as wide range of cancers and is therefore potential targets for immunotherapy. However, little is known about the role of SSX proteins in tumorigenesis and normal cell function. Here......, we show that SSX2 is involved in regulation of cancer cell growth. We found that ectopic expression of SSX2 in melanoma and colon cancer cells strongly reduced cell growth and induced apoptosis in vitro. Importantly, in a xenograft mouse model, the growth of tumors derived from SSX2 overexpressing...... an increase in the number of gamma-H2AX ‘DNA damage foci’, indicating replicative stress, which may lead to genomic instability. As the p53 tumor suppressor is an inducer of G1 arrest after DNA damage and often deregulated in cancer cells, we investigated if the growth reduction due to SSX2 expression was p53...

  12. Chimeric Antigen Receptor T Cells and Hematopoietic Cell Transplantation: How Not to Put the CART Before the Horse.

    Science.gov (United States)

    Kenderian, Saad S; Porter, David L; Gill, Saar

    2017-02-01

    Hematopoietic cell transplantation (HCT) remains an important and potentially curative option for most hematologic malignancies. As a form of immunotherapy, allogeneic HCT (allo-HCT) offers the potential for durable remissions but is limited by transplantation- related morbidity and mortality owing to organ toxicity, infection, and graft-versus-host disease. The recent positive outcomes of chimeric antigen receptor T (CART) cell therapy in B cell malignancies may herald a paradigm shift in the management of these disorders and perhaps other hematologic malignancies as well. Clinical trials are now needed to address the relative roles of CART cells and HCT in the context of transplantation-eligible patients. In this review, we summarize the state of the art of the development of CART cell therapy for leukemia, lymphoma, and myeloma and discuss our perspective of how CART cell therapy can be applied in the context of HCT.

  13. Identifying protective Streptococcus pyogenes vaccine antigens recognized by both B and T cells in human adults and children

    DEFF Research Database (Denmark)

    Mortensen, Rasmus; Nissen, Thomas Nørrelykke; Fredslund, Sine

    2016-01-01

    No commercial vaccine exists against Group A streptococci (GAS; Streptococcus pyogenes) and only little is known about anti-GAS protective immunity. In our effort to discover new protective vaccine candidates, we selected 21 antigens based on an in silico evaluation. These were all well......-conserved among different GAS strains, upregulated in host-pathogen interaction studies, and predicted to be extracellular or associated with the surface of the bacteria. The antigens were tested for both antibody recognition and T cell responses in human adults and children. The antigenicity of a selected group...

  14. Antigen and Memory CD8 T Cells: Were They Both Right?

    Directory of Open Access Journals (Sweden)

    Epelman Slava

    2007-06-01

    Full Text Available Picture yourself as a researcher in immunology. To begin your project, you ask a question: Do CD8 T cells require antigen to maintain a memory response? This question is of prime importance to numerous medical fields. In chronologic order, you digest the literature, but unfortunately, you hit a major stumbling block in the 1990s. The crux of the problem is that which so often happens in science: two well-recognized, capable groups emerge with diametrically opposed conclusions, leaving you pondering which set of wellcontrolled data to believe. Fortunately, years later, a surprising group of articles sheds light on this mystery and subtly reconciles these two positions.

  15. Prostate stem cell antigen interacts with nicotinic acetylcholine receptors and is affected in Alzheimer's disease

    DEFF Research Database (Denmark)

    Jensen, Majbrit Myrup; Mikkelsen, Jens D.; Arvaniti, Maria

    2015-01-01

    Alzheimer's disease (AD) is a neurodegenerative disorder involving impaired cholinergic neurotransmission and dysregulation of nicotinic acetylcholine receptors (nAChRs). Ly-6/neurotoxin (Lynx) proteins have been shown to modulate cognition and neural plasticity by binding to nAChR subtypes...... and modulating their function. Hence, changes in nAChR regulatory proteins such as Lynx proteins could underlie the dysregulation of nAChRs in AD. Using Western blotting, we detected bands corresponding to the Lynx proteins prostate stem cell antigen (PSCA) and Lypd6 in human cortex indicating that both proteins...

  16. IFN-induced modulation of histocompatibility antigens on human cells. Background, mechanisms and perspectives

    DEFF Research Database (Denmark)

    Hokland, M; Basse, P; Justesen, J

    1989-01-01

    (MHC) antigens. The latter effects have been characterized as immunomodulatory, whereas the well-known inhibition of growth of malignant cells has been termed anti-proliferative. This review summarizes the current knowledge of the enhancement of MHC products by IFNs. Whereas the basic methodologies...... to the classical anti-viral mechanism. This concept proposes that the MHC-enhancing effect of IFNs is a vital part of the immunological defense against virus infections and an integral part of the anti-viral effects of IFN proteins. Udgivelsesdato: 1988-Nov...

  17. Antigen 43-mediated autotransporter display, a versatile bacterial cell surface presentation system

    DEFF Research Database (Denmark)

    Kjærgaard, Kristian; Hasman, Henrik; Schembri, Mark;

    2002-01-01

    Antigen 43 (Ag43), a self-recognizing outer membrane protein of Escherichia coli, has been converted into an efficient and versatile tool for surface display of foreign protein segments. Ag43 is an autotransporter protein characterized by the feature that all information required for transport...... to the outer membrane and secretion through the cell envelope is contained within the protein itself. Ag43 consists of two subunits (alpha and beta), where the beta-subunit forms an integral outer membrane translocator to which the alpha-subunit is noncovalently attached. The simplicity of the Ag43 system...

  18. Crystallization and X-ray diffraction studies of crustacean proliferating cell nuclear antigen

    Science.gov (United States)

    Carrasco-Miranda, Jesus S.; Cardona-Felix, Cesar S.; Lopez-Zavala, Alonso A.; de-la-Re-Vega, Enrique; De la Mora, Eugenio; Rudiño-Piñera, Enrique; Sotelo-Mundo, Rogerio R.; Brieba, Luis G.

    2012-01-01

    Proliferating cell nuclear antigen (PCNA), a member of the sliding clamp family of proteins, interacts specifically with DNA replication and repair proteins through a small peptide motif called the PCNA-interacting protein or PIP box. PCNA is recognized as one of the key proteins involved in DNA metabolism. In the present study, the recombinant PCNA from Litopenaeus vannamei (LvPCNA) was heterologously overexpressed and purified using metal ion-affinity chromatography. Crystals suitable for diffraction grew overnight using the hanging-drop vapour-diffusion method. LvPCNA crystals belong to space group C2 with unit-cell parameters a = 144.6, b = 83.4, c = 74.3 Å, β = 117.6°. One data set was processed to 3 Å resolution, with an overall R meas of 0.09 and a completeness of 93.3%. Initial phases were obtained by molecular replacement using a homology model of LvPCNA as the search model. Refinement and structural analysis are underway. This report is the first successful crystallographic analysis of a marine crustacean decapod shrimp (L. vannamei) proliferating cell nuclear antigen. PMID:23143251

  19. T-cell response to p53 tumor-associated antigen in patients with colorectal carcinoma.

    Science.gov (United States)

    Bueter, Marco; Gasser, Martin; Schramm, Nicolai; Lebedeva, Tatiana; Tocco, Georges; Gerstlauer, Christiane; Grimm, Martin; Nichiporuk, Ekaterina; Thalheimer, Andreas; Thiede, Arnulf; Meyer, Detlef; Benichou, Gilles; Waaga-Gasser, Ana Maria

    2006-02-01

    Despite the radical surgical resection performed in patients with colorectal carcinoma, there is a high rate of tumor recurrence. Over an observation period of 3 years, 18% of the patients in our collective suffered a tumor relapse with local or distinct metastases after initial R0-resection. Some evidence suggests that this may be due to suppression of anti-tumor responses, a phenomenon that might be attributed to regulatory T cells. The aim of our study was to investigate the tumor-specific immune response depending on the UICC stage of patients with colorectal cancer. The cellular immune responses against defined antigens that are overexpressed in most of the patients with colorectal cancer were characterized. For this purpose, the tumor suppressor gene, p53, was chosen as the tumor-associated antigen that exhibits mutations and overexpression in up to 60% of colorectal carcinoma. We observed that p53 induced both IFN-gamma and IL-10 secretion. The predominance of IL-10 production indicated that regulatory T cells directly participate in modulating the anti-tumor immune response. IL-10 levels in the blood as well as the expression of regulatory T-cell specific genes at the tumor site correlate with the UICC stage of the disease. These results may provide an explanation for the poor prognosis and increased recurrence rate in patients with advanced carcinoma.

  20. Localization of human immunodeficiency virus antigens in infected cells by scanning/transmission-immunogold techniques

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, M.I.; Santa Maria, I.; de Andres, R.; Najera, R.

    1988-01-01

    An application of high resolution scanning/transmission electron microscopy (STEM) and gold-labelling techniques for the rapid detection of human immunodeficiency virus (HIV) in infected cells has been developed. Experimental in vitro studies for detecting two HIV structural proteins, gp41 and p17, were performed following an indirect labeling procedure that uses monoclonal anti-p17 and anti-gp41 antibodies as primary antibodies and 40 nm gold-linked goat antimouse IgG as secondary antibodies. The cells were then studied by STEM in the scanning mode. Unambiguous localization of the viral antigens was possible by combining the three-dimensional image provided by the secondary electron image and the atomic number-dependent backscattered electron image for the identification of the gold marker. This technique combines both the morphological information and the rapid procedures of scanning electron microscopy with the precise and sensitive antigen detection provided by the use of STEM and immunological methods. The preliminary results of its application to the study of peripheral blood mononuclear cells from four anti-HIV-seropositive patients showing the presence of specific labeling in all of them suggest that it might prove useful for early detection of HIV infection before seroconversion, as well as for quantitative studies.

  1. Size-dependent accumulation of particles in lysosomes modulates dendritic cell function through impaired antigen degradation

    Directory of Open Access Journals (Sweden)

    Seydoux E

    2014-08-01

    Full Text Available Emilie Seydoux,1,2 Barbara Rothen-Rutishauser,1,3 Izabela M Nita,1 Sandor Balog,3 Amiq Gazdhar,1 Philip A Stumbles,4,5 Alke Petri-Fink,3,6 Fabian Blank,1,* Christophe von Garnier1,*1Department of Respiratory Medicine, Inselspital, Bern University Hospital, Department of Clinical Research, University of Bern, 2Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland; 3Adolphe Merkle Institute, University of Fribourg, Fribourg, Switzerland; 4School of Veterinary and Life Sciences, Molecular and Biomedical Sciences, Murdoch University, Perth, WA, Australia; 5Telethon Kids Institute, Perth, WA, Australia; 6Department of Chemistry, University of Fribourg, Fribourg, Switzerland*These authors contributed equally to the manuscriptIntroduction: Nanosized particles may enable therapeutic modulation of immune responses by targeting dendritic cell (DC networks in accessible organs such as the lung. To date, however, the effects of nanoparticles on DC function and downstream immune responses remain poorly understood. Methods: Bone marrow–derived DCs (BMDCs were exposed in vitro to 20 or 1,000 nm polystyrene (PS particles. Particle uptake kinetics, cell surface marker expression, soluble protein antigen uptake and degradation, as well as in vitro CD4+ T-cell proliferation and cytokine production were analyzed by flow cytometry. In addition, co-localization of particles within the lysosomal compartment, lysosomal permeability, and endoplasmic reticulum stress were analyzed. Results: The frequency of PS particle–positive CD11c+/CD11b+ BMDCs reached an early plateau after 20 minutes and was significantly higher for 20 nm than for 1,000 nm PS particles at all time-points analyzed. PS particles did not alter cell viability or modify expression of the surface markers CD11b, CD11c, MHC class II, CD40, and CD86. Although particle exposure did not modulate antigen uptake, 20 nm PS particles decreased the capacity

  2. Identification of Anti-tumor Cells Carrying Natural Killer (NK Cell Antigens in Patients With Hematological Cancers

    Directory of Open Access Journals (Sweden)

    Ewelina Krzywinska

    2015-10-01

    Full Text Available Natural killer (NK cells, a cytotoxic lymphocyte lineage, are able to kill tumor cells in vitro and in mouse models. However, whether these cells display an anti-tumor activity in cancer patients has not been demonstrated. Here we have addressed this issue in patients with several hematological cancers. We found a population of highly activated CD56dimCD16+ NK cells that have recently degranulated, evidence of killing activity, and it is absent in healthy donors. A high percentage of these cells expressed natural killer cell p46-related protein (NKp46, natural-killer group 2, member D (NKG2D and killer inhibitory receptors (KIRs and a low percentage expressed NKG2A and CD94. They are also characterized by a high metabolic activity and active proliferation. Notably, we found that activated NK cells from hematological cancer patients have non-NK tumor cell antigens on their surface, evidence of trogocytosis during tumor cell killing. Finally, we found that these activated NK cells are distinguished by their CD45RA+RO+ phenotype, as opposed to non-activated cells in patients or in healthy donors displaying a CD45RA+RO− phenotype similar to naïve T cells. In summary, we show that CD45RA+RO+ cells, which resemble a unique NK population, have recognized tumor cells and degranulate in patients with hematological neoplasias.

  3. Plasmacytoid dendritic cell role in cutaneous malignancies.

    Science.gov (United States)

    Saadeh, Dana; Kurban, Mazen; Abbas, Ossama

    2016-07-01

    Plasmacytoid dendritic cells (pDCs) correspond to a specialized dendritic cell population that exhibit plasma cell morphology, express CD4, CD123, HLA-DR, blood-derived dendritic cell antigen-2 (BDCA-2), and Toll-like receptor (TLR)7 and TLR9 within endosomal compartments. Through their production of type I interferons (IFNs) and other pro-inflammatory cytokines, pDCs provide anti-viral resistance and link the innate and adaptive immunity by controlling the function of myeloid DCs, lymphocytes, and natural killer (NK) cells. While lacking from normal skin, pDCs are usually recruited to the skin in several cutaneous pathologies where they appear to be involved in the pathogenesis of several infectious, inflammatory/autoimmune, and neoplastic entities. Among the latter group, pDCs have the potential to induce anti-tumour immunity; however, the complex interaction of pDCs with tumor cells and their micro-environment appears to contribute to immunologic tolerance. In this review, we aim at highlighting the role played by pDCs in cutaneous malignancies with special emphasis on the underlying mechanisms.

  4. A human monoclonal antibody to high-frequency red cell antigen Jra.

    Science.gov (United States)

    Miyazaki, T; Kwon, K W; Yamamoto, K; Tone, Y; Ihara, H; Kato, T; Ikeda, H; Sekiguchi, S

    1994-01-01

    A human-mouse heterohybridoma (HMR0921) secreting human monoclonal IgG3, lambda antibody was produced from peripheral blood lymphocytes of a healthy blood donor with serum antibody to Jra, by EBV transformation and hybridization with mouse myeloma cell line P3X63Ag8.653. The reactivity of HMR0921 antibody was assessed by antiglobulin test with a panel of red cells including 14 different rare blood types. Only Jr(a-) red cells were negative. The strict specificity of this antibody to Jra antigen was further confirmed by absorption test with fluorescence flow cytometry. On screening of 28,744 blood donor samples by HMR0921 antibody, we detected 19 agglutination-negative samples, which were confirmed as Jr(a-) by conventional anti-Jra antisera. Therefore, our HMR0921 antibody is extremely useful for detecting rare Jr(a-) blood.

  5. Multiple chimeric antigen receptors successfully target chondroitin sulfate proteoglycan 4 in several different cancer histologies and cancer stem cells

    OpenAIRE

    Beard, Rachel E; Zheng, Zhili; Lagisetty, Kiran H.; Burns, William R.; Tran, Eric; Hewitt, Stephen M.; Abate-Daga, Daniel; Rosati, Shannon F.; Fine, Howard A.; Ferrone, Soldano; Rosenberg, Steven A.; Morgan, Richard A.

    2014-01-01

    Background The development of immunotherapy has led to significant progress in the treatment of metastatic cancer, including the development of genetic engineering technologies that redirect lymphocytes to recognize and target a wide variety of tumor antigens. Chimeric antigen receptors (CARs) are hybrid proteins combining antibody recognition domains linked to T cell signaling elements. Clinical trials of CAR-transduced peripheral blood lymphocytes (PBL) have induced remission of both solid ...

  6. Fcγ receptor antigen targeting potentiates cross-presentation by human blood and lymphoid tissue BDCA-3+ dendritic cells.

    Science.gov (United States)

    Flinsenberg, Thijs W H; Compeer, Ewoud B; Koning, Dan; Klein, Mark; Amelung, Femke J; van Baarle, Debbie; Boelens, Jaap Jan; Boes, Marianne

    2012-12-20

    The reactivation of human cytomegalovirus (HCMV) poses a serious health threat to immune compromised individuals. As a treatment strategy, dendritic cell (DC) vaccination trials are ongoing. Recent work suggests that BDCA-3(+) (CD141(+)) subset DCs may be particularly effective in DC vaccination trials. BDCA-3(+) DCs had however been mostly characterized for their ability to cross-present antigen from necrotic cells. We here describe our study of human BDCA-3(+) DCs in elicitation of HCMV-specific CD8(+) T-cell clones. We show that Fcgamma-receptor (FcγR) antigen targeting facilitates antigen cross-presentation in several DC subsets, including BDCA-3(+) DCs. FcγR antigen targeting stimulates antigen uptake by BDCA-1(+) rather than BDCA-3(+) DCs. Conversely, BDCA-3(+) DCs and not BDCA-1(+) DCs show improved cross-presentation by FcγR targeting, as measured by induced release of IFNγ and TNF by antigen-specific CD8(+) T cells. FcγR-facilitated cross-presentation requires antigen processing in both an acidic endosomal compartment and by the proteasome, and did not induce substantial DC maturation. FcγRII is the most abundantly expressed FcγR on both BDCA-1(+) and BDCA-3(+) DCs. Furthermore we show that BDCA-3(+) DCs express relatively more stimulatory FcγRIIa than inhibitory FcγRIIb in comparison with BDCA-1(+) DCs. These studies support the exploration of FcγR antigen targeting to BDCA-3(+) DCs for human vaccination purposes.

  7. T cell activation. II. Activation of human T lymphoma cells by cross-linking of their MHC class I antigens

    DEFF Research Database (Denmark)

    Dissing, S; Geisler, C; Rubin, B;

    1990-01-01

    The present work demonstrates that antibody-induced cross-linking of MHC class I antigens on Jurkat T lymphoma cells leads to a rise in intracellular calcium (Cai2+) and, in the presence of phorbol ester (PMA), to IL-2 production and IL-2 receptor expression. The rise in Cai2+ exhibited a profile...... very different from that obtained after anti-CD3 antibody-induced activation suggesting that activation signals are transduced differently after binding of anti-CD3 antibody and class I cross-linking, respectively. However, when Cai2+ was examined in individual Jurkat cells by means of a digital image...

  8. Antigen-affinity controls pre-germinal centser B cell selection by promoting Mcl-1 induction through BAFF receptor signaling

    Science.gov (United States)

    Wensveen, Felix M.; Slinger, Erik; van Attekum, Martijn HA; Brink, Robert; Eldering, Eric

    2016-01-01

    Upon antigen encounter, the responsive B cell pool undergoes stringent selection which eliminates cells with low B cell receptor (BCR) affinity. Already before formation of the germinal center, activated B cells of low-affinity are negatively selected in a process that is molecularly not well understood. In this study, we investigated the mechanism behind pre-GC affinity-mediated B cell selection. We applied affinity mutants of HEL antigen and found that rapidly after activation B cells become highly dependent on the cytokine BAFF. Moreover, expression of BAFF receptor CD268 is regulated in a BCR-affinity dependent fashion. High affinity responses via BAFF correlated with PI3K activation, which controlled expression of the pro-survival protein Mcl-1, and thereby increased survival. In the presence of excess BAFF, or in absence of the Mcl-1 antagonist Noxa, more low-affinity B cells survived the first two days after antigen encounter. This resulted in increased numbers of antigen-specific B cells of low affinity upon immunization and reduced the overall affinity of cells that contributed to the germinal center reaction. Our findings elucidate a crucial molecular pathway of B cell selection in the earliest phases of activation by identifying a novel link between BCR affinity and BAFF-R signaling towards Mcl-1. PMID:27762293

  9. Kinetics of antigen specific and non-specific polyclonal B-cell responses during lethal Plasmodium yoelii malaria

    Directory of Open Access Journals (Sweden)

    Laurence Rolland

    1992-06-01

    Full Text Available In order to study the kinetics and composition of the polyclonal B-cell activation associated to malaria infection, antigen-specific and non-specific B-cell responses were evaluated in the spleens of mice infected with Plasmodium yoelii 17 XL or injected with lysed erythrocytes or plasma from P. yoelii infected mice or with P. falciparum culture supernatants. Spleen/body weigth ratio, numbers of nucleated spleen cells and Immunoglobulin-containing and Immunoglobulin-secreting cells increased progressively during the course of infection,in parallel to the parasitemia. A different pattern of kinetics was observed when anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell plaque forming cells response were studied: maximum values were observed at early stages of infection, whereas the number of total Immunoglobulin-containing and Immunoglobulin-secreting cells were not yet altered. Conversely, at the end of infection, when these latter values reached their maximum, the anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell specific responses were normal or even infranormal. In mice injected with Plasmodium-derived material, a higher increase in antigen-specific PFC was observed, as compared to the increase of Immunoglobulin-containing and Immunoglobulin-secreting cell numbers. This suggested a "preferential" (antigen-plus mitogen-induced stimulation of antigen-specific cells rather than a generalized non-specific (mitogen-induced triggering of B-lymphocytes. On the basis of these and previous results, it is suggested that polyclonal B-cell activation that takes place during the course of infection appears as a result of successive waves of antigen-specific B-cell activation.

  10. Retinoic acid induction of CD38 antigen expression on normal and leukemic human myeloid cells: relationship with cell differentiation.

    Science.gov (United States)

    Prus, Eugenia; Fibach, Eitan

    2003-04-01

    Differentiation in the hematopoietic system involves, among other changes, altered expression of antigens, including the CD34 and CD38 surface antigens. In normal hematopoiesis, the most immature stem cells have the CD34 + CD34 - phenotype. In acute myeloid leukemia (AML), although blasts from most patients are CD38 +, some are CD38 - . AML blasts are blocked at early stages of differentiation; in some leukemic cells this block can be overcome by a variety of agents, including retinoids, that induce maturation into macrophages and granulocytes both in vitro and in vivo. Retinoids can also induce CD38 expression. In the present study, we investigated the relationship between induction of CD38 expression and induction of myeloid differentiation by retinoic acid (RA) in normal and leukemic human hematopoietic cells. In the promyelocytic (PML) CD34 - cell lines, HL60 and CB-1, as well as in normal CD34 + CD34 - hematopietic progenitor cells RA induced both CD38 expression as well as morphological and functional myeloid differentiation that resulted in loss of self-renewal. In contrast, in the myeloblastic CD34 + leukemic cell lines, ML-1 and KG-1a, as well as in primary cultures of cells derived from CD34 + -AML (M0 and M1) patients, RA caused an increase in CD38 + that was not associated with significant differentiation. Yet, long exposure of ML-1, but not KG-1, cells to RA resulted in loss of self-renewal. The results suggest that while in normal hematopoietic cells and in PML CD34 - cells induction of CD38 antigen expression by RA results in terminal differentiation along the myeloid lineage, in early myeloblastic leukemic CD34 + cells, induction of CD38 and differentiation are not functionally related. Since, several lines of evidence suggest that the CD38 - cells are the targets of leukemic transformation, transition of these cellsinto CD38 + phenotype by RA or other drugs may have therapeutic effect, either alone or in conjunction with cytotoxic drugs, regardless

  11. The Fas antigen (CD95) on human lymphoid cells: epitope analysis with ten antibodies.

    Science.gov (United States)

    Zola, H; Fusco, M; Ridings, J; Flego, L R; Weedon, H M; Nicholson, I; Organ, N; Roberton, D M; Macardle, P J

    1996-11-01

    The expression of CD95 antigen was examined on adult and cord blood lymphocytes using a highly sensitive immunofluorescence/flow cytometric procedure. CD95 was expressed by the majority of circulating blood T cells in adults, and by a smaller proportion of CD4+ and CD8+ T cells in cord blood. The majority of circulating B cells did not react with seven CD95 antibodies, but three antibodies did stain B cells. In tonsil sections, CD95 was expressed throughout the tissue but germinal centres showed generally stronger staining than the surrounding follicular mantle and interfollicular areas. This was confirmed by flow cytometry, which showed expression preferentially on B cells with a germinal centre phenotype. Because different antibodies stained different proportions of B cells, CD95 epitopes were examined by inhibition, additive binding and protease susceptibility studies using a panel of ten CD95 antibodies. B cells apparently reacting selectively with CD95 antibodies were sorted and CD95 mRNA was reverse transcribed to cDNA and analyzed, in order to confirm the presence of CD95 in cells which reacted selectively and to explore the possible existence of CD95 isoforms. The major cDNA band was identical in the two populations. Inhibition of N-glycosylation suggested that the epitopes detected differentially could not be accounted for by differential N-glycosylation.

  12. Chimeric Antigen Receptor-Modified T Cells for Solid Tumors: Challenges and Prospects

    Directory of Open Access Journals (Sweden)

    Yelei Guo

    2016-01-01

    Full Text Available Recent studies have highlighted the successes of chimeric antigen receptor-modified T- (CART- cell-based therapy for B-cell malignancies, and early phase clinical trials have been launched in recent years. The few published clinical studies of CART cells in solid tumors have addressed safety and feasibility, but the clinical outcome data are limited. Although antitumor effects were confirmed in vitro and in animal models, CART-cell-based therapy still faces several challenges when directed towards solid tumors, and it has been difficult to achieve the desired outcomes in clinical practice. Many studies have struggled to improve the clinical responses to and benefits of CART-cell treatment of solid tumors. In this review, the status quo of CART cells and their clinical applications for solid tumors will be summarized first. Importantly, we will suggest improvements that could increase the therapeutic effectiveness of CART cells for solid tumors and their future clinical applications. These interventions will make treatment with CART cells an effective and routine therapy for solid tumors.

  13. Functional expression of CD95/Fas Antigen and Bcl-2 on Cord blood Hematopoietic Progenitor Cells

    Institute of Scientific and Technical Information of China (English)

    马艳萍; 邹萍

    2002-01-01

    The cell-surface expression and functional status of the CD95/Fas antigen on primitive hematopoietic progenitors isolated from human cord blood (CB) were studied. The CD34+ cells freshly isolated from CB displayed low CD95 expression. The combinations of cytokines such as SCF+FL could up-regulate the expression of CD95 in vitro culture and tumor necrosis factor-e (TNF-α) and interon-γ (IFN-γ) further increased the CD95 expression induced by positive cytokines. The functional status of CD95-mediated apoptosis were analyzed by incubation of CD34+CB cells in the presence of anti-CD95 monoclonal antibodies (McAbs). The effects of anti-CD95 McAbs were measured by viable cell counting, flow cytometry, LTIC and CFU-C assays. A decrease of viable cells, CFUC and LTIC numbers were observed in the presence of anti-CD95 McAbs and TNF-α or IFN-γ.However, growth factor deprivation or the early-acting cytokine such as SCF and FL cross-linking to CD95 caused low apoptosis of CD34+ cells. The correlation of increased intracytoplasmic levels of bcl2 and the presence of CD95 on fresh CB CD34+ cells suggested that bcl-2 might be involved in protecting against CD95-mediated apoptosis of CB CD34+ cells.

  14. IDENTIFICATION OF ACROSOME AS THE MAIN ANTIGEN OF THE SPERM CELLS PROVOKING AUTOANTIBODIES IN VASECTOMIZED IRANIAN MEN

    Directory of Open Access Journals (Sweden)

    M R Nowroozi

    2008-12-01

    Full Text Available "nVasectomy is one of the extensively used methods of contraception in family planning programs. Antisperm antibodies (ASA develop after vasectomy which can result in auto-immune male infertility. The precise sperm antigens involved in the autoimmune response are still poorly defined, therefore we determined the circulating ASA and identified relevant sperm antigens based on localization of binding sites of ASA to sperm cell antigens, using a rapid, inexpensive and clinically relevant assay in vasectomized men. Results showed that 2.5% of men had ASA at the time of vasectomy, whereas 53.5% of the study population subsequently developed ASA. The numbers of men with circulating ASA increased significantly for the first three months after vasectomy. These antibodies were distinguishable into three groups based on their bindings to different sites of sperm cell antigens including against acrosome and tail in 67.56% and 10.8%, respectively; 21.6% of subjects had antibody to the other parts of the sperm cell antigens. The results of this study are discussed in terms of an autoimmune response against sperm antigens and development of ASA.

  15. CD19-Targeted chimeric antigen receptor-modified T-cell immunotherapy for B-cell malignancies.

    Science.gov (United States)

    Turtle, C J; Riddell, S R; Maloney, D G

    2016-09-01

    Chimeric antigen receptors (CARs) comprise a tumor-targeting moiety, often in the form of a single chain variable fragment derived from a monoclonal antibody, fused to one or more intracellular T-cell signaling sequences. Lymphodepletion chemotherapy followed by infusion of T cells that are genetically modified to express a CD19-specific CAR is a promising therapy for patients with refractory CD19(+) B-cell malignancies, producing rates of complete remission that are remarkably high in acute lymphoblastic leukemia and encouraging in non-Hodgkin lymphoma and chronic lymphocytic leukemia. Responses are often durable, although additional studies are needed to define the role of CAR-T cell immunotherapy in the context of other treatments. CAR-modified T-cell immunotherapy can be complicated by cytokine release syndrome and neurologic toxicity, which in most cases are manageable and reversible. Here we review recent clinical trial data and discuss issues for the field.

  16. Participation of CD45, NKR-P1A and ANK61 antigen in rat hepatic NK cell (pit cell)-mediated target cell cytotoxicity

    Institute of Scientific and Technical Information of China (English)

    Dian Zhong Luo; David Vermijlen; B lent Ahishali; Vasilis Triantis; Eddie Wisse; Karin Vanderkerken; Peter J.K. Kuppen

    2000-01-01

    AIM Several triggering receptors have been described to be involved in natural killer (NK) cellmediated target cytotoxicity. In these studies, NK cells derived from blood or spleen were used. Pit cells are liver-specific NK cells that possess a higher level of natural cytotoxicity and a different morphology when compared to blood NK cells. The aim of this study was to characterize the role of the NK-triggering molecules NKR-P1A, ANK61 antigen, and CD45 in pit cell-mediated killing of target cells. METHODS 51 Cr-release and DNA fragmentation were used to quantify target cell lysis and apoptosis, respectively. RESULTS Flow cytometric analysis showed that pit cells expressed CD45, NKR-P1A, and ANK61 antigen. Treatment of pit cells with monoclonal antibody ( mAb ) to CD45 ( ANK74 ) not only inhibited CC531s or YAC-1 target lysis but also apoptosis induced by pit cells. The mAbs to NKRP1A (3.2.3) and ANK61 antigen (ANK61) had no effect on pit cell-mediated CC531s or YAC-1 target cytolysis or apoptosis, while they did increase the Fcγ receptor positive (FcγR+) P815 cytolysis and apoptosis. This enhanced cytotoxicity could he inhibited by 3,4-dichloroisocoumarin, an inhibitor of granzymes. CONCLUSION These results indicate that CD45 participates in pit cell-mediated CC531s and YAC-1 target cytolysis and apoptosis. NKR-P1A and ANK61 antigen on pit cells function as activation structures against FcγR+ P815 cells, which was mediated by the perforin/granzyme pathway.

  17. A Fusion Protein between Streptavidin and the Endogenous TLR4 Ligand EDA Targets Biotinylated Antigens to Dendritic Cells and Induces T Cell Responses In Vivo

    Directory of Open Access Journals (Sweden)

    Laura Arribillaga

    2013-01-01

    Full Text Available The development of tools for efficient targeting of antigens to antigen presenting cells is of great importance for vaccine development. We have previously shown that fusion proteins containing antigens fused to the extra domain A from fibronectin (EDA, an endogenous TLR4 ligand, which targets antigens to TLR4-expressing dendritic cells (DC, are highly immunogenic. To facilitate the procedure of joining EDA to any antigen of choice, we have prepared the fusion protein EDAvidin by linking EDA to the N terminus of streptavidin, allowing its conjugation with biotinylated antigens. We found that EDAvidin, as streptavidin, forms tetramers and binds biotin or biotinylated proteins with a Kd ~ 2.6 × 10−14 mol/L. EDAvidin favours the uptake of biotinylated green fluorescent protein by DC. Moreover, EDAvidin retains the proinflammatory properties of EDA, inducing NF-κβ by TLR4-expressing cells, as well as the production of TNF-α by the human monocyte cell line THP1 and IL-12 by DC. More importantly, immunization of mice with EDAvidin conjugated with the biotinylated nonstructural NS3 protein from hepatitis C virus induces a strong anti-NS3 T cell immune response. These results open a new way to use the EDA-based delivery tool to target any antigen of choice to DC for vaccination against infectious diseases and cancer.

  18. Cis-acting pathways selectively enforce the non-immunogenicity of shed placental antigen for maternal CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Chin-Siean Tay

    Full Text Available Maternal immune tolerance towards the fetus and placenta is thought to be established in part by pathways that attenuate T cell priming to antigens released from the placenta into maternal blood. These pathways remain largely undefined and their existence, at face value, seems incompatible with a mother's need to maintain a functional immune system during pregnancy. A particular conundrum is evident if we consider that maternal antigen presenting cells, activated in order to prime T cells to pathogen-derived antigens, would also have the capacity to prime T cells to co-ingested placental antigens. Here, we address this paradox using a transgenic system in which placental membranes are tagged with a strong surrogate antigen (ovalbumin. We find that although a remarkably large quantity of acellular ovalbumin-containing placental material is released into maternal blood, splenic CD8 T cells in pregnant mice bearing unmanipulated T cell repertoires are not primed to ovalbumin even if the mice are intravenously injected with adjuvants. This failure was largely independent of regulatory T cells, and instead was linked to the intrinsic characteristics of the released material that rendered it selectively non-immunogenic, potentially by sequestering it from CD8α(+ dendritic cells. The release of ovalbumin-containing placental material into maternal blood thus had no discernable impact on CD8 T cell priming to soluble ovalbumin injected intravenously during pregnancy, nor did it induce long-term tolerance to ovalbumin. Together, these results outline a major pathway governing the maternal immune response to the placenta, and suggest how tolerance to placental antigens can be maintained systemically without being detrimental to host defense.

  19. Rudimentary study on humanization of porcine red blood cells: Enzymatic removal of galactose-α1,3-galactose antigen from porcine red blood cell

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The serological and biochemical characterization of porcine red blood cells (pRBCs) are similar to human red blood cells. Porcine erythrocytes are considered as an alternative source for human blood transfusion. But there exist galactose-α1,3-galactose antigens (Galα1,3Galβ1, 4GalNAc-R, abbreviated αGal antigen) on pRBCs, which can induce anti-(Gal antibodies in human serum. The (Galepitopes are the major antigen responsible for hyperacute rejection in xenotransfusion. In this study, recombined soybean α-galactosidase (rSα-GalE) was usedto remove the (Gal antigens from pPRCs for humanization. The results showed that (Gal antigen was cleared by rSα-GalE and the structure and function of rSα-GalE treated pRBC were normal.

  20. Stable expression of sialyl-Tn antigen in T47-D cells induces a decrease of cell adhesion and an increase of cell migration.

    Science.gov (United States)

    Julien, Sylvain; Lagadec, Chann; Krzewinski-Recchi, Marie-Ange; Courtand, Gilles; Le Bourhis, Xuefen; Delannoy, Philippe

    2005-03-01

    Sialyl-Tn is a carbohydrate antigen overexpressed in several epithelial cancers including breast cancer, and usually associated with poor prognosis. Sialyl-Tn is synthesized by a CMP-Neu5Ac: GalNAc alpha2,6-sialyltransferase: ST6GalNAc I, which catalyzes the transfer of a sialic acid residue in alpha2,6-linkage to the GalNAcalpha1-O-Ser/Thr structure. The resulting disaccharide (Neu5Acalpha2-6GalNAcalpha1-O-Ser/Thr) cannot be further elongated and sialyl-Tn expression results therefore in a shortening of the O-glycan chains. However, usual breast cancer cell lines express neither ST6GalNAc I nor sialyl-Tn antigen. We have previously shown that stable transfection of MDA-MB-231 cells with the hST6GalNAc I cDNA induces the sialyl-Tn antigen expression at the cell surface and leads to a decreased cell growth and an increased cell migration. We describe herein the generation of new T47-D clones expressing sialyl-Tn antigen after hST6GalNAc I cDNA stable transfection. sialyl-Tn antigen is carried by several high molecular weight membrane bound O-glycoproteins, including MUC1. We show that sialyl-Tn expression induces a decrease of cell growth and adhesion, and an increase of cell migration in sialyl-Tn positive clones compared to mock transfected cells. These observations show that the alteration of the O-glycans pattern is sufficient to modify the biological features of cancer cells. These T47-D sialyl-Tn expressing clones might allow further in vivo investigation to determine precisely the impact of such O-glycosylation modifications on breast cancer development.

  1. Dendritic cells cross-present HIV antigens from live as well as apoptotic infected CD4+ T lymphocytes

    Science.gov (United States)

    Marañón, Concepción; Desoutter, Jean-François; Hoeffel, Guillaume; Cohen, William; Hanau, Daniel; Hosmalin, Anne

    2004-04-01

    A better understanding of the antigen presentation pathways that lead to CD8+ T cell recognition of HIV epitopes in vivo is needed to achieve better immune control of HIV replication. Here, we show that cross-presentation of very small amounts of HIV proteins from apoptotic infected CD4+ T lymphocytes by dendritic cells to CD8+ T cells is much more efficient than other known HIV presentation pathways, i.e., direct presentation of infectious virus or cross-presentation of defective virus. Unexpectedly, dendritic cells also take up actively antigens into endosomes from live infected CD4+ T lymphocytes and cross-present them as efficiently as antigens derived from apoptotic infected cells. Moreover, live infected CD4+ T cells costimulate cross-presenting dendritic cells in the process. Therefore, dendritic cells can present very small amounts of viral proteins from infected T cells either after apoptosis, which is frequent during HIV infection, or not. Thus, if HIV expression is transiently induced while costimulation is enhanced (for instance after IL-2 and IFN immune therapy), this HIV antigen presentation pathway could be exploited to eradicate latently infected reservoirs, which are poorly recognized by patients' immune systems.

  2. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells.

    Directory of Open Access Journals (Sweden)

    Yukiko Kiniwa

    Full Text Available Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8(+ T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4(+ T helper (Th cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4(+ T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1 as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4(+ Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4(+ T cell-mediated immunotherapy in melanoma.

  3. Antigen recognition and presentation in periapical tissues: a role for TLR expressing cells?

    Science.gov (United States)

    Desai, S V; Love, R M; Rich, A M; Seymour, G J

    2011-02-01

    Bacteria are the prime cause of periapical diseases and root canal microbiology is a well-researched area of endodontics. Antigen-presenting cells (APCs) are present in periapical lesions of endodontic origin and play a substantial role in recognizing, processing and presenting pathogenic antigens to the adaptive immune system such as an effective and long-lasting immune response is generated against the specific pathogens. Toll-like receptors (TLRs) are germ-line encoded pathogen recognition receptors (PRR) expressed by various APCs which induce their maturation, lead to gene transcription in the nucleus and the production of several pro- and anti-inflammatory cytokines. Thirteen TLRs have been discovered, 10 of which have been identified in humans so far. Preliminary studies of dental pulp tissue have demonstrated various cell types expressing different TLRs in response to commonly encountered microorganisms. However, there is little information available regarding the expression and function of the various TLRs in human periapical lesions. This review discusses the interactions of various APCs in periapical lesions and the possible roles of different TLRs and APCs in pulp/periapical pathogen recognition and presentation to the adaptive immune system in the initiation and sustaining of periapical diseases.

  4. Antigen presentation by small intestinal epithelial cells uniquely enhances IFN-γ secretion from CD4{sup +} intestinal intraepithelial lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Hatano, Ryo; Yamada, Kiyoshi; Iwamoto, Taku; Maeda, Nana; Emoto, Tetsuro; Shimizu, Makoto; Totsuka, Mamoru, E-mail: atotuka@mail.ecc.u-tokyo.ac.jp

    2013-06-14

    Highlights: •Small intestinal epithelial cells (sIECs). •sIECs are able to induce antigen specific proliferation of CD4{sup +} IELs. •sIECs induce markedly enhanced IFN-γ secretion by CD4{sup +} IELs. •Induction of enhanced IFN-γ secretion by sIECs is uniquely observed in CD4{sup +} IELs. -- Abstract: Small intestinal epithelial cells (sIECs) express major histocompatibility complex class II molecules even in a normal condition, and are known to function as antigen presenting cells (APCs) at least in vitro. These findings raised the possibility that sIECs play an important role in inducing immune responses against luminal antigens, especially those of intestinal intraepithelial lymphocytes (IELs) and lamina propria lymphocytes (LPLs). We herein showed that antigenic stimulation with sIECs induced markedly greater secretion of interferon-gamma (IFN-γ) by CD4{sup +} IELs, but not interleukin (IL)-4, IL-10 and IL-17 although the proliferative response was prominently lower than that with T cell-depleted splenic APCs. In contrast, no enhanced IFN-γ secretion by CD4{sup +} LPLs and primed splenic CD4{sup +} T cells was observed when stimulated with sIECs. Taken together, these results suggest that sIECs uniquely activate CD4{sup +} IELs and induce remarkable IFN-γ secretion upon antigenic stimulation in vivo.

  5. Quantifying cell binding kinetics mediated by surface-bound blood type B antigen to immobilized antibodies

    Institute of Scientific and Technical Information of China (English)

    LI BaoXia; CHEN Juan; LONG Mian

    2008-01-01

    Cell adhesion is crucial to many biological processes, such as inflammatory responses, tumor metastasis and thrombosis formation. Recently a commercial surface plasmon resonance (SPR)-based BIAcore biosensor has been extended to determine cell binding mediated by surface-bound biomolecular interactions. How such cell binding is quantitatively governed by kinetic rates and regulating factors, however, has been poorly understood. Here we developed a novel assay to determine the binding kinetics of surface-bound biomolecular interactions using a commercial BIAcore 3000 biosensor. Human red blood cells (RBCs) presenting blood group B antigen and CM5 chip bearing immobilized anti-B monoclonal antibody (mAb) were used to obtain the time courses of response unit, or sensorgrams, when flowing RBCs over the chip surface. A cellular kinetic model was proposed to correlate the sensorgrams with kinetic rates. Impacts of regulating factors, such as cell concentration,flow duration and rate, antibody-presenting level, as well as Ph value and osmotic pressure of suspending medium were tested systematically, which imparted the confidence that the approach can be applied to kinetic measurements of cell adhesion mediated by surface-bound biomolecular interactions.These results provided a new insight into quantifying cell binding using a commercial SPR-based BIAcore biosensor.

  6. The fenestrin antigen in submembrane skeleton of the ciliate Tetrahymena thermophila is proposed as a marker of cell polarity during cell division and in oral replacement.

    Science.gov (United States)

    Kaczanowska, Janina; Joachimiak, Ewa; Kiersnowska, Mauryla; Krzywicka, Anna; Golinska, Krystyna; Kaczanowski, Andrzej

    2003-07-01

    Tetrahymena thermophila cells have two types of polarized morphogenesis: divisional morphogenesis and oral reorganization (OR). The aim of this research is the analysis of cortical patterns of immunostaining during cell division and in OR using previously characterized antibodies against fenestrin and epiplasm B proteins. During cell division, the anarchic field of basal body proliferation of the new developing oral apparatus (AF) showed concomitant strong binding of the fenestrin antigen and withdrawal of a signal of the epiplasm B antigen. At a specific stage, the fenestrin antigen also appeared as a character of the anterior cortex pole, with a co-localized decrease in the detected epiplasm B antigen. The fenestrin antigen also showed a polarity of duplicating basal bodies in ciliary rows. Indirect immunofluorescence and immunogold labeling experiments were performed in the absence and presence of an inhibitor of activity of serine/threonine kinases, 6-dimethylaminopurine (6-DMAP) as an inducer of the oral replacement process. In the presence of 6-DMAP, one class of cells started OR, and some others were trapped and affected in cell division. Both types of cells showed an instability of oral structures and formed enlarged primordial oral fields. These anarchic fields (AFs) bind the fenestrin antigen, with disappearance of epiplasmic antigen staining. Only one protein (about 64 kDa) is detected in western blots by the anti-fenestrin antibody and it accumulated in 6-DMAP-treated cells that are involved in uncompleted morphogenetic activity. At a defined stage of oral development, both during cell division and in OR, the fenestrin antigen served as a marker of polarity of the cell of the anterior pole character.

  7. Quantitative detection of the tumor-associated antigen large external antigen in colorectal cancer tissues and cells using quantum dot probe

    Directory of Open Access Journals (Sweden)

    Wang S

    2016-01-01

    Full Text Available Shuo Wang, Wanming Li, Dezheng Yuan, Jindan Song, Jin Fang Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, People’s Republic of China Abstract: The large external antigen (LEA is a cell surface glycoprotein that has been proven to be highly expressed in colorectal cancer (CRC as a tumor-associated antigen. To evaluate and validate the relationship between LEA expression and clinical characteristics of CRC with high efficiency, LEA expression levels were detected in 85 tissue blocks from CRC patients by quantum dot-based immunohistochemistry (QD-IHC combined with imaging quantitative analysis using quantum dots with a 605 nm emission wavelength (QD605 conjugated to an ND-1 monoclonal antibody against LEA as a probe. Conventional IHC was performed in parallel for comparison. Both QD-IHC and conventional IHC showed that LEA was specifically expressed in CRC, but not in non-CRC tissues, and high LEA expression was significantly associated with a more advanced T-stage (P<0.05, indicating that LEA is likely to serve as a CRC prognostic marker. Compared with conventional IHC, receiver operating characteristic analysis revealed that QD-IHC possessed higher sensitivity, resulting in an increased positive detection rate of CRC, from 70.1% to 89.6%. In addition, a simpler operation, objective analysis of results, and excellent repeatability make QD-IHC an attractive alternative to conventional IHC in clinical practice. Furthermore, to explore whether the QD probes can be utilized to quantitatively detect living cells or single cells, quantum dot-based immunocytochemistry (QD-ICC combined with imaging quantitative analysis was developed to evaluate LEA expression in several CRC cell lines. It was demonstrated that QD-ICC could also predict the correlation between LEA expression and the T-stage characteristics of

  8. Antigen processing of glycoconjugate vaccines; the polysaccharide portion of the pneumococcal CRM(197) conjugate vaccine co-localizes with MHC II on the antigen processing cell surface.

    Science.gov (United States)

    Lai, Zengzu; Schreiber, John R

    2009-05-21

    Pneumococcal (Pn) polysaccharides (PS) are T-independent (TI) antigens and do not induce immunological memory or antibodies in infants. Conjugation of PnPS to the carrier protein CRM(197) induces PS-specific antibody in infants, and memory similar to T-dependent (Td) antigens. Conjugates have improved immunogenicity via antigen processing and presentation of carrier protein with MHC II and recruitment of T cell help, but the fate of the PS attached to the carrier is unknown. To determine the location of the PS component of PnPS-CRM(197) in the APC, we separately labeled PS and protein and tracked their location. The PS of types 14-CRM(197) and 19F-CRM(197) was specifically labeled by Alexa Fluor 594 hydrazide (red). The CRM(197) was separately labeled red in a reaction that did not label PS. Labeled antigens were incubated with APC which were fixed, permeabilized and incubated with anti-MHC II antibody labeled green by Alexa Fluor 488, followed by confocal microscopy. Labeled CRM(197) was presented on APC surface and co-localized with MHC II (yellow). Labeled unconjugated 14 or 19F PS did not go to the APC surface, but PS labeled 14-CRM(197) and 19F-CRM(197) was internalized and co-localized with MHC II. Monoclonal antibody to type 14 PS bound to intracellular type 14 PS and PS-CRM(197). Brefeldin A and chloroquine blocked both CRM(197) and PS labeled 14-CRM(197) and 19F-CRM(197) from co-localizing with MHC II. These data suggest that the PS component of the CRM(197) glycoconjugate enters the endosome, travels with CRM(197) peptides to the APC surface and co-localizes with MHC II.

  9. Antigen-specific B cells reactivate an effective cytotoxic T cell response against phagocytosed Salmonella through cross-presentation.

    Directory of Open Access Journals (Sweden)

    Jelle de Wit

    Full Text Available BACKGROUND: The eradication of facultative intracellular bacterial pathogens, like Salmonella typhi, requires the concerted action of both the humoral immune response and the cytotoxic CD8(+ T cell response. Dendritic cells (DCs are considered to orchestrate the cytotoxic CD8(+ T cell response via cross-presentation of bacterial antigens onto MHC class I molecules. Cross-presentation of Salmonella by DCs however, is accompanied by the induction of apoptosis in the DCs. Besides antibody production, B cells are required to clear Salmonella infection for other unknown reasons. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that Salmonella-specific B cells that phagocytose Salmonella upon BCR-ligation reactivate human memory CD8(+ T cells via cross-presentation yielding a Salmonella-specific cytotoxic T cell response. The reactivation of CD8(+ T cells is dependent on CD4(+ T cell help. Unlike the DCs, B cell-mediated cross-presentation of Salmonella does not coincide with apoptosis. CONCLUSIONS/SIGNIFICANCE: B cells form a new player in the activation of the cytotoxic effector arm of the immune response and the generation of effective adaptive immunity in Salmonella infection.

  10. Transforming growth factor-beta inhibits human antigen-specific CD4(+) T cell proliferation without modulating the cytokine response

    NARCIS (Netherlands)

    Tiemessen, MM; Kunzmann, S; Schmidt-Weber, CB; Garssen, J; Bruijnzeel-Koomen, CAFM; Knol, EF; Van Hoffen, E

    2003-01-01

    Transforming growth factor (TGF)-beta has been demonstrated to play a key role in the regulation of the immune response, mainly by its suppressive function towards cells of the immune system. In humans, the effect of TGF-beta on antigen-specific established memory T cells has not been investigated y

  11. The monoclonal antibody ER-BMDM1 recognizes a macrophage and dendritic cell differentiation antigen with aminopeptidase activity

    NARCIS (Netherlands)

    P.J. Leenen (Pieter); M.L. Melis (Marleen); G. Kraal (Georg); A.T. Hoogeveen (Andre); W. van Ewijk (Willem)

    1992-01-01

    markdownabstractAbstract Here we describe the reactivity of monoclonal antibody (mAb) ER-BMDM1, directed against a 160-kDa cell membrane-associated antigen (Ag) with aminopeptidase activity. The aminopeptidase recognized by ER-BMDM1 is present on various mouse macrophage (MΦ) and dendritic cell (D

  12. Naive CD8 T-Cells Initiate Spontaneous Autoimmunity to a Sequestered Model Antigen of the Central Nervous System

    Science.gov (United States)

    Na, Shin-Young; Cao, Yi; Toben, Catherine; Nitschke, Lars; Stadelmann, Christine; Gold, Ralf; Schimpl, Anneliese; Hunig, Thomas

    2008-01-01

    In multiple sclerosis, CD8 T-cells are thought play a key pathogenetic role, but mechanistic evidence from rodent models is limited. Here, we have tested the encephalitogenic potential of CD8 T-cells specific for the model antigen ovalbumin (OVA) sequestered in oligodendrocytes as a cytosolic molecule. We show that in these "ODC-OVA" mice, the…

  13. Targeting of non-dominant antigens as a vaccine strategy to broaden T-cell responses during chronic viral infection

    DEFF Research Database (Denmark)

    Holst, Peter Johannes; Jensen, Benjamin Anderschou Holbech; Ragonnaud, Emeline;

    2015-01-01

    challenge with live virus, the CD8+ T cells specific for vaccine-encoded epitopes, displayed a phenotype typically associated with prolonged/persistent antigenic stimulation marked by high levels of KLRG-1, as compared to T cells reacting to epitopes not included in the vaccine. Notably, this association...

  14. Reduced response to Epstein-Barr virus antigens by T-cells in systemic lupus erythematosus patients

    DEFF Research Database (Denmark)

    Draborg, Anette Holck; Jacobsen, Søren; Westergaard, Marie

    2014-01-01

    OBJECTIVE: Epstein-Barr virus (EBV) has for long been associated with systemic lupus erythematosus (SLE). In this study, we investigated the levels of latent and lytic antigen EBV-specific T-cells and antibodies in SLE patients. METHODS: T cells were analyzed by flow cytometry and antibodies were...

  15. Induction of complete and molecular remissions in acute myeloid leukemia by Wilms' tumor 1 antigen-targeted dendritic cell vaccination.

    NARCIS (Netherlands)

    Tendeloo, V.F. Van; Velde, A. van de; Driessche, A. Van; Cools, N.; Anguille, S.; Ladell, K.; Gostick, E.; Vermeulen, K.; Pieters, K.; Nijs, G.; Stein, B.; Smits, E.L.; Schroyens, W.A.; Gadisseur, A.P.; Vrelust, I.; Jorens, P.G.; Goossens, H.; Vries, I.J.M. de; Price, D.A.; Oji, Y.; Oka, Y.; Sugiyama, H.; Berneman, Z.N.

    2010-01-01

    Active immunization using tumor antigen-loaded dendritic cells holds promise for the adjuvant treatment of cancer to eradicate or control residual disease, but so far, most dendritic cell trials have been performed in end-stage cancer patients with high tumor loads. Here, in a phase I/II trial, we i

  16. Targeting Tumor Initiating Cells through Inhibition of Cancer Testis Antigens and Notch Signaling: A Hypothesis.

    Science.gov (United States)

    Colombo, Michela; Mirandola, Leonardo; Reidy, Adair; Suvorava, Natallia; Konala, Venu; Chiaramonte, Raffaella; Grizzi, Fabio; Rahman, Rakhshanda Layeequr; Jenkins, Marjorie R; Nugyen, Diane D; Dalhbeck, Scott; Cobos, Everardo; Figueroa, Jose A; Chiriva-Internati, Maurizio

    2015-03-01

    Tumor initiating cells (TICs) differ from normal stem cells (SCs) in their ability to initiate tumorigenesis, invasive growth, metastasis and the acquisition of chemo and/or radio-resistance. Over the past years, several studies have indicated the potential role of the Notch system as a key regulator of cellular stemness and tumor development. Furthermore, the expression of cancer testis antigens (CTA) in TICs, and their role in SC differentiation and biology, has become an important area of investigation. Here, we propose a model in which CTA expression and Notch signaling interacts to maintain the sustainability of self-replicating tumor populations, ultimately leading to the development of metastasis, drug resistance and cancer progression. We hypothesize that Notch-CTA interactions in TICs offer a novel opportunity for meaningful therapeutic interventions in cancer.

  17. Keratinocytes function as accessory cells for presentation of endogenous antigen expressed in the epidermis.

    Science.gov (United States)

    Kim, Brian S; Miyagawa, Fumi; Cho, Young-Hun; Bennett, Clare L; Clausen, Björn E; Katz, Stephen I

    2009-12-01

    The precise contribution(s) of skin dendritic cells (DCs) to immune responses in the skin has not been well delineated. We developed an intradermal (i.d.) injection model in which CD8+ T (OT-I) cells that express ovalbumin (OVA) peptide-specific TCRs (Valpha2/Vbeta5) are delivered directly to the dermis of transgenic (Tg) mice expressing OVA in the epidermis. After i.d. injection, these mice reliably develop skin graft-versus-host disease (GVHD) by day 7. To determine the relative contribution of Langerhans cells (LCs) to the ensuing GVHD-like reaction, we generated K14-OVA x Langerin-diphtheria-toxin-receptor (Langerin-DTR) Tg mice to allow conditional ablation of LCs in the epidermis. To delineate the role of dermal DCs (dDCs) in the reaction, we also generated K14-OVA Tg chimeras using beta(2)-microglobulin-deficient (beta(2)m) congenic donor bone marrow cells. Dermal DCs in these mice cannot present OVA to autoreactive T cells (OT-I cells), whereas the LCs are antigen presentation-competent. Unexpectedly, OT-I cell injection into diphtheria toxin (DT)-treated beta(2)m --> K14-OVA x Langerin-DTR Tg mice resulted in skin GVHD. Thus, in vivo, both LC and dDC appear to be dispensable for the induction of keratinocyte-directed, CD8-mediated effector immune responses. Furthermore and surprisingly, OVA-expressing epidermal cells depleted of LCs that could not initiate allogeneic epidermal lymphocyte reactions activated naive OT-I cells in vitro. These results indicate that keratinocytes may function as accessory cells competent to prime naive skin-reactive T cells.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://network.nature.com/group/jidclub.

  18. A novel laser vaccine adjuvant increases the motility of antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Xinyuan Chen

    Full Text Available BACKGROUND: Development of a potent vaccine adjuvant without introduction of any side effects remains an unmet challenge in the field of the vaccine research. METHODOLOGY/PRINCIPAL FINDINGS: We found that laser at a specific setting increased the motility of antigen presenting cells (APCs and immune responses, with few local or systemic side effects. This laser vaccine adjuvant (LVA effect was induced by brief illumination of a small area of the skin or muscle with a nondestructive, 532 nm green laser prior to intradermal (i.d. or intramuscular (i.m. administration of vaccines at the site of laser illumination. The pre-illumination accelerated the motility of APCs as shown by intravital confocal microscopy, leading to sufficient antigen (Ag-uptake at the site of vaccine injection and transportation of the Ag-captured APCs to the draining lymph nodes. As a result, the number of Ag(+ dendritic cells (DCs in draining lymph nodes was significantly higher in both the 1° and 2° draining lymph nodes in the presence than in the absence of LVA. Laser-mediated increases in the motility and lymphatic transportation of APCs augmented significantly humoral immune responses directed against a model vaccine ovalbumin (OVA or influenza vaccine i.d. injected in both primary and booster vaccinations as compared to the vaccine itself. Strikingly, when the laser was delivered by a hair-like diffusing optical fiber into muscle, laser illumination greatly boosted not only humoral but also cell-mediated immune responses provoked by i.m. immunization with OVA relative to OVA alone. CONCLUSION/SIGNIFICANCE: The results demonstrate the ability of this safe LVA to augment both humoral and cell-mediated immune responses. In comparison with all current vaccine adjuvants that are either chemical compounds or biological agents, LVA is novel in both its form and mechanism; it is risk-free and has distinct advantages over traditional vaccine adjuvants.

  19. Suboptimal B-cell antigen receptor signaling activity in vivo elicits germinal center counterselection mechanisms.

    Science.gov (United States)

    Königsberger, Sebastian; Weis, Vanessa; Prodöhl, Jan; Stehling, Martin; Hobeika, Elias; Reth, Michael; Kiefer, Friedemann

    2015-02-01

    Syk and Zap-70 constitute a closely related nonreceptor protein tyrosine kinase family, of which both members are functionally indispensable for conferring their respective antigen receptors with enzymatic activity. In this study, we analyze the impact of altering BCR signaling output on B-cell germinal center (GC) fate selection by constitutive, as well as inducible, monoallelic Syk kinase loss in the presence of a Zap-70 knock-in rescue allele. Cre-mediated Syk deletion in Syk(flox/Zap-70) B cells lowers pErk, but not pAkt-mediated signaling. Surprisingly, the use of a B-cell-specific constitutive mb1-cre deleter mouse model showed that a small cohort of peripheral Syk(flox/Zap-70);mb1-cre B cells efficiently circumvents deletion, which ultimately favors these Syk-sufficient cells to contribute to the GC reaction. Using a developmentally unbiased Syk(flox/Zap-70);mb1-creER(T2) approach in combination with an inducible tdRFP allele, we further demonstrate that this monoallelic deletion escape is not fully explained by leakiness of Cre expression, but is possibly the result of differential Syk locus accessibility in maturing B cells. Altogether, this underscores the importance of proper Syk kinase function not only during central and peripheral selection processes, but also during GC formation and maintenance.

  20. Transcription Activity of Ectogenic Human Carcinoembryonic Antigen Promoter in Lung Adenocarcinoma Cells A549

    Institute of Scientific and Technical Information of China (English)

    XIONG Weining; FANG Huijuan; XU Yongjian; XIONG Shendao; CAO Yong; SONG Qingfeng; ZENG Daxiong; ZHANG Huilan

    2006-01-01

    The transcription activity of ectogenic human carcinoembryonic antigen (CEA) promoter in lung adenocarcinoma cells A549 was investigated for the further gene-targeting therapy. The reporter gene green fluorescent protein (GFP) driven by CEA promoter and human cytomegalovirus (CMV) promoter were relatively constructed and named plasmid pCEA-EGFP and pCMV-GFP respectively. The intensity of fluorescence was detected by fluorescence microscope and flow cytometry analysis after the pCEA-GFP and pSNAV-GFP plasmids were transfected into A549 cells through liposome respectively. The results showed (4.08±0.63) % of the A549 cells transfected with pCEA-AFP plasmid expressed, significantly lower than that of the A549 cells transfected with pCMV-GFP [(43.27±3.54) %]. It was suggested that ectogenic human CEA promoter in lung adenocarcinoma cells A549 was weakly expressed. The distinct specificity of CEA promoter in CEA high expression cells was regarded as a tool in selective gene therapy, but the transcription activity of ectogenic human CEA promoter was needed to increase in the future.

  1. Regulation of Hemichannels and Gap Junction Channels by Cytokines in Antigen-Presenting Cells

    Directory of Open Access Journals (Sweden)

    Pablo J. Sáez

    2014-01-01

    Full Text Available Autocrine and paracrine signals coordinate responses of several cell types of the immune system that provide efficient protection against different challenges. Antigen-presenting cells (APCs coordinate activation of this system via homocellular and heterocellular interactions. Cytokines constitute chemical intercellular signals among immune cells and might promote pro- or anti-inflammatory effects. During the last two decades, two membrane pathways for intercellular communication have been demonstrated in cells of the immune system. They are called hemichannels (HCs and gap junction channels (GJCs and provide new insights into the mechanisms of the orchestrated response of immune cells. GJCs and HCs are permeable to ions and small molecules, including signaling molecules. The direct intercellular transfer between contacting cells can be mediated by GJCs, whereas the release to or uptake from the extracellular milieu can be mediated by HCs. GJCs and HCs can be constituted by two protein families: connexins (Cxs or pannexins (Panxs, which are present in almost all APCs, being Cx43 and Panx1 the most ubiquitous members of each protein family. In this review, we focus on the effects of different cytokines on the intercellular communication mediated by HCs and GJCs in APCs and their impact on purinergic signaling.

  2. Development of Auto Antigen-specific Regulatory T Cells for Diabetes Immunotherapy

    Science.gov (United States)

    2016-01-01

    CD4+ regulatory T cells (Tregs) are essential for normal immune surveillance, and their dysfunction can lead to the development of autoimmune diseases, such as type-1 diabetes (T1D). T1D is a T cell-mediated autoimmune disease characterized by islet β cell destruction, hypoinsulinemia, and severely altered glucose homeostasis. Tregs play a critical role in the development of T1D and participate in peripheral tolerance. Pluripotent stem cells (PSCs) can be utilized to obtain a renewable source of healthy Tregs to treat T1D as they have the ability to produce almost all cell types in the body, including Tregs. However, the right conditions for the development of antigen (Ag)-specific Tregs from PSCs (i.e., PSC-Tregs) remain undefined, especially molecular mechanisms that direct differentiation of such Tregs. Auto Ag-specific PSC-Tregs can be programmed to be tissue-associated and infiltrate to local inflamed tissue (e.g., islets) to suppress autoimmune responses after adoptive transfer, thereby avoiding potential overall immunosuppression from non-specific Tregs. Developing auto Ag-specific PSC-Tregs can reduce overall immunosuppression after adoptive transfer by accumulating inflamed islets, which drives forward the use of therapeutic PSC-Tregs for cell-based therapies in T1D.

  3. An inducible transgenic mouse model for immune mediated hepatitis showing clearance of antigen expressing hepatocytes by CD8+ T cells.

    Directory of Open Access Journals (Sweden)

    Marcin Cebula

    Full Text Available The liver has the ability to prime immune responses against neo antigens provided upon infections. However, T cell immunity in liver is uniquely modulated by the complex tolerogenic property of this organ that has to also cope with foreign agents such as endotoxins or food antigens. In this respect, the nature of intrahepatic T cell responses remains to be fully characterized. To gain deeper insight into the mechanisms that regulate the CD8+ T cell responses in the liver, we established a novel OVA_X_CreER(T2 mouse model. Upon tamoxifen administration OVA antigen expression is observed in a fraction of hepatocytes, resulting in a mosaic expression pattern. To elucidate the cross-talk of CD8+ T cells with antigen-expressing hepatocytes, we adoptively transferred K(b/OVA257-264-specific OT-I T cells to OVA_X_CreER(T2 mice or generated triple transgenic OVA_X CreER(T2_X_OT-I mice. OT-I T cells become activated in OVA_X_CreER(T2 mice and induce an acute and transient hepatitis accompanied by liver damage. In OVA_X_CreER(T2_X_OT-I mice, OVA induction triggers an OT-I T cell mediated, fulminant hepatitis resulting in 50% mortality. Surviving mice manifest a long lasting hepatitis, and recover after 9 weeks. In these experimental settings, recovery from hepatitis correlates with a complete loss of OVA expression indicating efficient clearance of the antigen-expressing hepatocytes. Moreover, a relapse of hepatitis can be induced upon re-induction of cured OVA_X_CreER(T2_X_OT-I mice indicating absence of tolerogenic mechanisms. This pathogen-free, conditional mouse model has the advantage of tamoxifen inducible tissue specific antigen expression that reflects the heterogeneity of viral antigen expression and enables the study of intrahepatic immune responses to both de novo and persistent antigen. It allows following the course of intrahepatic immune responses: initiation, the acute phase and antigen clearance.

  4. CD19-Chimeric Antigen Receptor T Cells for Treatment of Chronic Lymphocytic Leukaemia and Acute Lymphoblastic Leukaemia

    DEFF Research Database (Denmark)

    Lorentzen, C L; thor Straten, Per

    2015-01-01

    Adoptive cell therapy (ACT) for cancer represents a promising new treatment modality. ACT based on the administration of cytotoxic T cells genetically engineered to express a chimeric antigen receptor (CAR) recognizing CD19 expressed by B cell malignancies has been shown to induce complete lasting......-associated toxicities, which needs attention. Herein we review current data and discuss key aspects of this powerful approach to treat and potentially cure B cell malignancies....

  5. Epigenetic mechanisms regulate MHC and antigen processing molecules in human embryonic and induced pluripotent stem cells.

    Directory of Open Access Journals (Sweden)

    Beatriz Suárez-Alvarez

    Full Text Available BACKGROUND: Human embryonic stem cells (hESCs are an attractive resource for new therapeutic approaches that involve tissue regeneration. hESCs have exhibited low immunogenicity due to low levels of Mayor Histocompatibility Complex (MHC class-I and absence of MHC class-II expression. Nevertheless, the mechanisms regulating MHC expression in hESCs had not been explored. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the expression levels of classical and non-classical MHC class-I, MHC class-II molecules, antigen-processing machinery (APM components and NKG2D ligands (NKG2D-L in hESCs, induced pluripotent stem cells (iPSCs and NTera2 (NT2 teratocarcinoma cell line. Epigenetic mechanisms involved in the regulation of these genes were investigated by bisulfite sequencing and chromatin immunoprecipitation (ChIP assays. We showed that low levels of MHC class-I molecules were associated with absent or reduced expression of the transporter associated with antigen processing 1 (TAP-1 and tapasin (TPN components in hESCs and iPSCs, which are involved in the transport and load of peptides. Furthermore, lack of beta2-microglobulin (beta2m light chain in these cells limited the expression of MHC class I trimeric molecule on the cell surface. NKG2D ligands (MICA, MICB were observed in all pluripotent stem cells lines. Epigenetic analysis showed that H3K9me3 repressed the TPN gene in undifferentiated cells whilst HLA-B and beta2m acquired the H3K4me3 modification during the differentiation to embryoid bodies (EBs. Absence of HLA-DR and HLA-G expression was regulated by DNA methylation. CONCLUSIONS/SIGNIFICANCE: Our data provide fundamental evidence for the epigenetic control of MHC in hESCs and iPSCs. Reduced MHC class I and class II expression in hESCs and iPSCs can limit their recognition by the immune response against these cells. The knowledge of these mechanisms will further allow the development of strategies to induce tolerance and improve stem cell

  6. Cancer-testis antigen expression in digestive tract carcinomas: frequent expression in esophageal squamous cell carcinoma and its precursor lesions.

    Science.gov (United States)

    Chen, Yao-Tseng; Panarelli, Nicole C; Piotti, Kathryn C; Yantiss, Rhonda K

    2014-05-01

    Cancer-testis (CT) antigens are attractive tumor antigens for cancer immunotherapy. They comprise a group of proteins normally expressed in germ cells and aberrantly activated in a variety of human cancers. The protein expression of eight cancer-testis antigens [MAGEA, NY-ESO-1, GAGE, MAGEC1 (CT7), MAGEC2 (CT10), CT45, SAGE1, and NXF2] was evaluated by immunohistochemistry in 61 esophageal carcinomas (40 adenocarcinoma and 21 squamous cell carcinoma), 50 gastric carcinomas (34 diffuse and 16 intestinal type), and 141 colorectal carcinomas. The highest frequency of expression was found in esophageal squamous cell carcinomas: Positive staining for MAGEA, CT45, CT7, SAGE1, GAGE, NXF2, NY-ESO-1, and CT10 was observed in 57%, 38%, 33%, 33%, 29%, 29%, 19%, and 14% of squamous cell carcinomas, respectively. Similar staining patterns were observed in squamous dysplasias. Expression frequencies of cancer-testis antigens were seen in 2% to 24% of gastroesophageal adenocarcinomas and were not significantly different between adenocarcinomas of the stomach versus the esophagus, or between diffuse and intestinal types of gastric adenocarcinomas. Colorectal cancers did not express NY-ESO-1, CT7, CT10, or GAGE, and only infrequently expressed SAGE1 (0.7%) MAGEA (1.4%), CT45 (3.5%), and NXF2 (8.5%). We conclude that cancer-testis antigens are frequently expressed in esophageal squamous neoplasms. Although cancer-testis antigens are generally considered to be expressed later in tumor progression, they are found in squamous dysplasias, suggesting a potential diagnostic role for cancer-testis antigens in the evaluation of premalignant squamous lesions.

  7. Evaluation of the Cell Proliferation Process of Ovarian Follicles in Hypothyroid Rats by Proliferation Cell Nuclear Antigen Immunohistochemical Technique

    Directory of Open Access Journals (Sweden)

    M. Moghaddam Dorafshani

    2012-10-01

    Full Text Available Introduction & Objective: The normal females reproductive function , needs hypothalamus-hypophysis-ovarian extensive hormonal messages. Primary hypothyroidism is characterized by reduced production and secretion of thyroid hormones. During follicular growth PCNA (Proliferating Cell Nuclear Antigen and cycklin D complex play an important role in regulating cell proliferation .This study aimed to determine the cell proliferation index and how this process changes induced by thyroid hormone decreased in rat ovarian follicles.Materials & Methods: In this experimental study, 20 Wistar female rats were divided into experimental and control groups. Experimental group was chemically thyroidectomized by administering propylthiouracil (PTU (500 mg per liter of drinking water. The control group received normal drinking water. After three weeks rats were killed and their ovaries dissected and fixed for the histological preparation. Cell proliferation was determined by PCNA and stereological methods were used for counting cells.Results: Cell proliferation index showed a significant decrease in the frequency of follicular growth from prenatal to graafian follicles in hypothyroidism groups(P0.05 . PCNA expression determined that Primary follicle growth begins earlier. Positive PCNA cells were not observed in primordial follicles of the groups.Conclusion: According to the results of our study, this hypothesis is raised that granulosa cells in growing follicles may be increased by follicle adjacent cells in ovarian stroma . Hormonal changes following the reduction of thyroid hormones may greatly affect the cell proliferation index and lead to faster follicle degeneration.(Sci J Hamadan Univ Med Sci 2012; 19 (3:5-15

  8. Modification of T-cell antigenic properties of tetanus toxoid by SDS-PAGE separation. Implications for T-cell blotting

    DEFF Research Database (Denmark)

    Christensen, C B; Theander, T G

    1997-01-01

    Using Tetanus Toxoid (TT) as a model antigen the T-cell Blotting method was evaluated. Peripheral blood mononuclear cell (PBMC) cultures were stimulated by blotted nitrocellulose-bound TT or soluble TT. SDS-Poly-Acrylamide-Gel-Electrophoresis separated TT only induced proliferation in 20% of the ......Using Tetanus Toxoid (TT) as a model antigen the T-cell Blotting method was evaluated. Peripheral blood mononuclear cell (PBMC) cultures were stimulated by blotted nitrocellulose-bound TT or soluble TT. SDS-Poly-Acrylamide-Gel-Electrophoresis separated TT only induced proliferation in 20...... that SDS-PAGE alters the ability of TT to induce T-cell proliferation, possibly due to unpolymerized acrylamide binding to proteins during SDS-PAGE. The use of SDS-PAGE T-cell blotting in the screening for T-cell antigens must therefore be reconsidered. We suggest the use of SDS-Agarose Gel Electrophoresis...

  9. Myelin-reactive antibodies initiate T cell-mediated CNS autoimmune disease by opsonization of endogenous antigen.

    Science.gov (United States)

    Kinzel, Silke; Lehmann-Horn, Klaus; Torke, Sebastian; Häusler, Darius; Winkler, Anne; Stadelmann, Christine; Payne, Natalie; Feldmann, Linda; Saiz, Albert; Reindl, Markus; Lalive, Patrice H; Bernard, Claude C; Brück, Wolfgang; Weber, Martin S

    2016-07-01

    In the pathogenesis of central nervous system (CNS) demyelinating disorders, antigen-specific B cells are implicated to act as potent antigen-presenting cells (APC), eliciting waves of inflammatory CNS infiltration. Here, we provide the first evidence that CNS-reactive antibodies (Ab) are similarly capable of initiating an encephalitogenic immune response by targeting endogenous CNS antigen to otherwise inert myeloid APC. In a transgenic mouse model, constitutive production of Ab against myelin oligodendrocyte glycoprotein (MOG) was sufficient to promote spontaneous experimental autoimmune encephalomyelitis (EAE) in the absence of B cells, when mice endogenously contained MOG-recognizing T cells. Adoptive transfer studies corroborated that anti-MOG Ab triggered activation and expansion of peripheral MOG-specific T cells in an Fc-dependent manner, subsequently causing EAE. To evaluate the underlying mechanism, anti-MOG Ab were added to a co-culture of myeloid APC and MOG-specific T cells. At otherwise undetected concentrations, anti-MOG Ab enabled Fc-mediated APC recognition of intact MOG; internalized, processed and presented MOG activated naïve T cells to differentiate in an encephalitogenic manner. In a series of translational experiments, anti-MOG Ab from two patients with an acute flare of CNS inflammation likewise facilitated detection of human MOG. Jointly, these observations highlight Ab-mediated opsonization of endogenous CNS auto-antigen as a novel disease- and/or relapse-triggering mechanism in CNS demyelinating disorders.

  10. CD80 and CD86 differentially regulate mechanical interactions of T-cells with antigen-presenting dendritic cells and B-cells.

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    Tong Seng Lim

    Full Text Available Functional T-cell responses are initiated by physical interactions between T-cells and antigen-presenting cells (APCs, including dendritic cells (DCs and B-cells. T-cells are activated more effectively by DCs than by B-cells, but little is known about the key molecular mechanisms that underpin the particular potency of DC in triggering T-cell responses. To better understand the influence of physical intercellular interactions on APC efficacy in activating T-cells, we used single cell force spectroscopy to characterize and compare the mechanical forces of interactions between DC:T-cells and B:T-cells. Following antigen stimulation, intercellular interactions of DC:T-cell conjugates were stronger than B:T-cell interactions. DCs induced higher levels of T-cell calcium mobilization and production of IL-2 and IFNγ than were elicited by B-cells, thus suggesting that tight intercellular contacts are important in providing mechanically stable environment to initiate T-cell activation. Blocking antibodies targeting surface co-stimulatory molecules CD80 or CD86 weakened intercellular interactions and dampen T-cell activation, highlighting the amplificatory roles of CD80/86 in regulating APC:T-cell interactions and T-cell functional activation. The variable strength of mechanical forces between DC:T-cells and B:T-cell interactions were not solely dependent on differential APC expression of CD80/86, since DCs were superior to B-cells in promoting strong interactions with T-cells even when CD80 and CD86 were inhibited. These data provide mechanical insights into the effects of co-stimulatory molecules in regulating APC:T-cell interactions.

  11. CD80 and CD86 differentially regulate mechanical interactions of T-cells with antigen-presenting dendritic cells and B-cells.

    Science.gov (United States)

    Lim, Tong Seng; Goh, James Kang Hao; Mortellaro, Alessandra; Lim, Chwee Teck; Hämmerling, Günter J; Ricciardi-Castagnoli, Paola

    2012-01-01

    Functional T-cell responses are initiated by physical interactions between T-cells and antigen-presenting cells (APCs), including dendritic cells (DCs) and B-cells. T-cells are activated more effectively by DCs than by B-cells, but little is known about the key molecular mechanisms that underpin the particular potency of DC in triggering T-cell responses. To better understand the influence of physical intercellular interactions on APC efficacy in activating T-cells, we used single cell force spectroscopy to characterize and compare the mechanical forces of interactions between DC:T-cells and B:T-cells. Following antigen stimulation, intercellular interactions of DC:T-cell conjugates were stronger than B:T-cell interactions. DCs induced higher levels of T-cell calcium mobilization and production of IL-2 and IFNγ than were elicited by B-cells, thus suggesting that tight intercellular contacts are important in providing mechanically stable environment to initiate T-cell activation. Blocking antibodies targeting surface co-stimulatory molecules CD80 or CD86 weakened intercellular interactions and dampen T-cell activation, highlighting the amplificatory roles of CD80/86 in regulating APC:T-cell interactions and T-cell functional activation. The variable strength of mechanical forces between DC:T-cells and B:T-cell interactions were not solely dependent on differential APC expression of CD80/86, since DCs were superior to B-cells in promoting strong interactions with T-cells even when CD80 and CD86 were inhibited. These data provide mechanical insights into the effects of co-stimulatory molecules in regulating APC:T-cell interactions.

  12. Catalytic activity of the mouse guanine nucleotide exchanger mSOS is activated by Fyn tyrosine protein kinase and the T-cell antigen receptor in T cells.

    OpenAIRE

    1996-01-01

    mSOS, a guanine nucleotide exchange factor, is a positive regulator of Ras. Fyn tyrosine protein kinase is a potential mediator in T-cell antigen receptor signal transduction in subsets of T cells. We investigated the functional and physical interaction between mSOS and Fyn in T-cell hybridoma cells. Stimulation of the T-cell antigen receptor induced the activation of guanine nucleotide exchange activity in mSOS immunoprecipitates. Overexpression of Fyn mutants with an activated kinase mutati...

  13. Detection of T- and B-cell Target Antigens of Fowlpox Virus Isolated from Backyard Chickens in India.

    Science.gov (United States)

    Roy, Bithi; Joardar, Siddhartha N; Samanta, Indranil; Das, Pradip K; Alam, Sk Sahanawaz; Nandi, Sudip

    2015-06-01

    With the aim of assessing the antigenic characteristics of a circulating pool of fowlpox virus (FPV) that exists in the backyard poultry system in India, one of the field isolates generated was characterized by in vitro immunologic techniques. FPV was isolated from clinically positive fowlpox cases (n  =  10) from the Jhargram (West Midnapur district) and Kakdwip (South 24 Pargana district) areas of West Bengal State, India. Initially, FPV-specific PCR was performed for confirmation of the samples. Isolation of FPV was done using embryonated chicken eggs and the choreoallantoic membrane route. Subsequently, FPV antigen was prepared from chicken embryo fibroblast cell culture-adapted field isolate. Biologic transmission of FPV was performed in Rhode Island red chickens experimentally to assess humoral and cell-mediated immune (CMI) responses. High level of anti-FPV antibodies were observed in test birds as assessed by indirect ELISA. Seroreactive polypeptides (B-cell antigens) of FPV antigen with molecular weights of 44.5, 66.5, 75, 90.5, and 99 kDa were detected by western blot analysis. Significant increases in CMI responses were observed in inoculated chickens as assessed by lymphocyte proliferation assay, cytotoxicity assay, and T-cell immunoblotting. The predominant T-cell antigen of FPV detected had a molecular weight of 66.5 kDa. The present study revealed the antigenic characteristics of FPV that exists in backyard poultry system in West Bengal for the first time, thus exploring the rationality of designing future T- and B-cell vaccines against fowlpox.

  14. Targeting dendritic cells in lymph node with an antigen peptide-based nanovaccine for cancer immunotherapy.

    Science.gov (United States)

    Qian, Yuan; Jin, Honglin; Qiao, Sha; Dai, Yanfeng; Huang, Chuan; Lu, Lisen; Luo, Qingming; Zhang, Zhihong

    2016-08-01

    The design of peptide-based subunit vaccine formulations for the direct delivery of tumor antigen peptides (Aps) to dendritic cells (DCs) localized within draining lymph nodes (DLNs) is challenging. Mature DCs (mDCs) are abundantly distributed within DLNs but have dramatically reduced endocytic uptake and antigen-processing abilities, so their role as potential vaccine targets has been largely overlooked. Here we report an ultra-small biocompatible nanovaccine (α-Ap-FNP) functionalized by avidly targeting delivery of Ap via the scavenger receptor class B1 (SR-B1) pathway to mDCs. The self-assembly, small size (∼30 nm), SR-B1-targeting and optical properties of α-Ap-FNP resulted in its efficient Ap loading, substantial LN accumulation, targeting of mDCs and enhanced Ap presentation, and fluorescence trafficking, respectively. We also demonstrate that the α-Ap-FNP can be either used alone or encapsulated with CpG oligodeoxynucleotide as a prophylactic and therapeutic vaccine. Thus, the excellent properties of α-Ap-FNP provide it potential for clinical applications as a potent nanovaccine for cancer immunotherapy.

  15. Fluorescent BAPAD Dendrimeric Antigens Are Efficiently Internalized by Human Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Pablo Mesa-Antunez

    2016-03-01

    Full Text Available A new fluorescent dendrimeric antigen (DeAn based on a dendron with amoxicilloyl terminal groups was synthesized. The synthesis was carried out using a novel class of all-aliphatic polyamide dendrimer (BisAminoalkylPolyAmide Dendrimers, or BAPAD involving the direct condensation of 3,3′-diazidopivalic acid as a building block. Iterative azide reduction/amide formation increases the dendrimer generation. The BAPAD dendrimer was designed with a cystamine core. Reduction of the disulfide bond allows the incorporation of BAPAD dendrons into a 1,8-naphthalimide functionalized with a maleimide group. The fluorescence properties of DeAn were studied in PBS and compared with the properties of an equivalent dendron possessing amino-terminal groups. Both molecules shown high fluorescence quantum yields in PBS and could readily be visualized by fluorescence microscopy. DeAn was used as a synthetic antigen in a biomedical assay that tests their potential as an amoxicillin carrier in drug internalization by dendritic cells (DC from tolerant and allergic patients. Cytometry data suggest that the dendrons are non-toxic and easily internalized by DCs, while confocal microscopy images indicate that the compounds are preferentially accumulated in the cytoplasm. These results indicate that BAPAD dendrons are good candidates for synthetic scaffolds for biomedical applications.

  16. Antigen transfer from exosomes to dendritic cells as an explanation for the immune enhancement seen by IgE immune complexes.

    Directory of Open Access Journals (Sweden)

    Rebecca K Martin

    Full Text Available IgE antigen complexes induce increased specific T cell proliferation and increased specific IgG production. Immediately after immunization, CD23(+ B cells capture IgE antigen complexes, transport them to the spleen where, via unknown mechanisms, dendritic cells capture the antigen and present it to T cells. CD23, the low affinity IgE receptor, binds IgE antigen complexes and internalizes them. In this study, we show that these complexes are processed onto B-cell derived exosomes (bexosomes in a CD23 dependent manner. The bexosomes carry CD23, IgE and MHC II and stimulate antigen specific T-cell proliferation in vitro. When IgE antigen complex stimulated bexosomes are incubated with dendritic cells, dendritic cells induce specific T-cell proliferation in vivo, similar to IgE antigen complexes. This suggests that bexosomes can provide the essential transfer mechanism for IgE antigen complexes from B cells to dendritic cells.

  17. Antigen-specific regulatory T cells and low dose of IL-2 in treatment of type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Minh N. Pham

    2016-01-01

    Full Text Available Regulatory T cells (Tregs play an important role in preventing effector T-cell (Teff targeting of self-antigens that can lead to tissue destruction in autoimmune settings, including type 1 diabetes (T1D. Autoimmunity is caused in part by an imbalance between Teff and Tregs. Early attempts to treat with immunosuppressive agents have led to serious side effects, thus requiring a more targeted approach. Low-dose IL-2 (LD IL-2 can provide immuno-regulation with few side effects by preferentially acting on Tregs to drive tolerance. The concept of LD IL-2 as a therapeutic approach is supported by data in mouse models where autoimmunity is cured and further strengthened by success in human clinical studies in Hepatitis C Virus (HCV induced vasculitis, chronic graft vs host disease (GVHD and Alopecia areata (AA. Treatment will require identification of a safe therapeutic window, which is a difficult task given that patients are reported to have deficient or defective IL-2 production or signalling and have experienced mild activation of NK cells and eosinophils with LD IL-2 therapy. In T1D, a LD IL-2 clinical trial concluded that Tregs can be safely expanded in humans; however, the study was not designed to address efficacy. Antigen-specific therapies have also aimed at regulation of the autoimmune response, but have been filled with disappointment despite an extensive list of diverse islet antigens tested in humans. This approach could be enhanced through the addition of LD IL-2 to the antigenic treatment regimen to improve the frequency and function of antigen-specific Tregs, without global immunosuppression. Here we will discuss the use of LD IL-2 and islet antigen to enhance antigen-specific Tregs in T1D and focus on what is known about their immunological impact, their safety and potential efficacy, and need for better methods to identify therapeutic effectiveness.

  18. Luciferase mRNA Transfection of Antigen Presenting Cells Permits Sensitive Nonradioactive Measurement of Cellular and Humoral Cytotoxicity

    Directory of Open Access Journals (Sweden)

    Tana A. Omokoko

    2016-01-01

    Full Text Available Immunotherapy is rapidly evolving as an effective treatment option for many cancers. With the emerging fields of cancer vaccines and adoptive cell transfer therapies, there is an increasing demand for high-throughput in vitro cytotoxicity assays that efficiently analyze immune effector functions. The gold standard 51Cr-release assay is very accurate but has the major disadvantage of being radioactive. We reveal the development of a versatile and nonradioactive firefly luciferase in vitro transcribed (IVT RNA-based assay. Demonstrating high efficiency, consistency, and excellent target cell viability, our optimized luciferase IVT RNA is used to transfect dividing and nondividing primary antigen presenting cells. Together with the long-lasting expression and minimal background, the direct measurement of intracellular luciferase activity of living cells allows for the monitoring of killing kinetics and displays paramount sensitivity. The ability to cotransfect the IVT RNA of the luciferase reporter and the antigen of interest into the antigen presenting cells and its simple read-out procedure render the assay high-throughput in nature. Results generated were comparable to the 51Cr release and further confirmed the assay’s ability to measure antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity. The assay’s combined simplicity, practicality, and efficiency tailor it for the analysis of antigen-specific cellular and humoral effector functions during the development of novel immunotherapies.

  19. Breadth of T cell responses after immunization with adenovirus vectors encoding ancestral antigens or polyvalent papillomavirus antigens

    DEFF Research Database (Denmark)

    Ragonnaud, Emeline; Pedersen, Anders Gorm; Holst, Peter Johannes

    2017-01-01

    to the other PV proteins. The PV sequences were fused to a T cell adjuvant, the murine invariant chain and encoded in a recombinant adenoviral vector which was administered to naïve outbred mice. By measuring T cell responses induced by these different vaccines and towards peptide pools representing 3...

  20. Generation of antigen-specific T cell immunity through T cell receptor gene transfer

    NARCIS (Netherlands)

    Coccoris, Miriam

    2009-01-01

    Cancer cells often escape the attack of immune cells because they originate from self-tissue. Through T cell receptor gene transfer it is possible to equip peripheral T cells with a desired specificity, and this strategy may be useful to generate tumor-specific T cells for the treatment of cancer in

  1. Alloantigens of human lymphoid cell lines; `human Ia-like antigens'

    Science.gov (United States)

    Koyama, K.; Nakamuro, K.; Tanigaki, N.; Pressman, D.

    1977-01-01

    Membrane glycoproteins that appear to belong to a new alloantigen system were partially purified by gel filtration and lentil-lectin affinity chromatography from a non-ionic detergent (Renex 30) solubilized membrane fraction of each of two Burkitt lymphoma cell lines, B46M and Daudi. The preparations were radioiodinated and further purified by gel filtration, lentil—lectin affinity chromatography and anti-HLA antibody affinity chromatography. The labelled preparations thus obtained did not have binding activity with any of rabbit anti-HLA, rabbit anti-human β2-microglobulin and rabbit anti-human IgG-Fab antisera, but did have a high level of binding activity with rabbit anti-B-cell membrane antiserum. Moreover, the labelled preparations showed relatively high binding activity with some conventional HLA typing sera. Out of sixty-eight human tissue typing alloantisera tested, three (Berlin 373, Betz and TO-29-01) gave especially high binding with both of the labeled preparations. The antigens involved in reaction with these alloantisera and also with the rabbit anti-B-cell membrane antiserum contained two components, one 31,000 ∼ 32,000 daltons and another 24,000 ∼ 25,000 daltons, bound non-covalently. The alloantigens were specific to B cell type cell lines (B-lymphoid cell lines and Burkitt-lymphoma cell lines) in cultured cell lines and also to B lymphocytes in peripheral blood. In organs and tissues, however, they were found to be present widely distributed in lymphoid organs (thymus as well as spleen and lymph node) and in non-lymphoid organs (including liver, kidney, testis and heart). PMID:24587

  2. Sperm associated antigen 9 plays an important role in bladder transitional cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Deepika Kanojia

    Full Text Available BACKGROUND: Majority of bladder cancer deaths are caused due to transitional cell carcinoma (TCC which is the most prevalent and chemoresistant malignancy of urinary bladder. Therefore, we analyzed the role of Sperm associated antigen 9 (SPAG9 in bladder TCC. METHODOLOGY AND FINDINGS: We examined SPAG9 expression and humoral response in 125 bladder TCC patients. Four bladder cancer cell lines were assessed for SPAG9 expression. In addition, we investigated the effect of SPAG9 ablation on cellular proliferation, cell cycle, migration and invasion in UM-UC-3 bladder cancer cells by employing gene silencing approach. Our SPAG9 gene and protein expression analysis revealed SPAG9 expression in 81% of bladder TCC tissue specimens. High SPAG9 expression (>60% SPAG9 positive cells was found to be significantly associated with superficial non-muscle invasive stage (P = 0.042 and low grade tumors (P = 0.002 suggesting SPAG9 putative role in early spread and tumorigenesis. Humoral response against SPAG9 was observed in 95% of patients found positive for SPAG9 expression. All four bladder cancer cell lines revealed SPAG9 expression. In addition, SPAG9 gene silencing in UM-UC-3 cells resulted in induction of G0-G1 arrest characterized by up-regulation of p16 and p21 and consequent down-regulation of cyclin E, cyclin D and cyclin B, CDK4 and CDK1. Further, SPAG9 gene silencing also resulted in reduction in cellular growth, and migration and invasion ability of cancer cells in vitro. CONCLUSIONS: Collectively, our data in clinical specimens indicated that SPAG9 is potential biomarker and therapeutic target for bladder TCC.

  3. Human macrophages and dendritic cells can equally present MART-1 antigen to CD8(+ T cells after phagocytosis of gamma-irradiated melanoma cells.

    Directory of Open Access Journals (Sweden)

    María Marcela Barrio

    Full Text Available Dendritic cells (DC can achieve cross-presentation of naturally-occurring tumor-associated antigens after phagocytosis and processing of dying tumor cells. They have been used in different clinical settings to vaccinate cancer patients. We have previously used gamma-irradiated MART-1 expressing melanoma cells as a source of antigens to vaccinate melanoma patients by injecting irradiated cells with BCG and GM-CSF or to load immature DC and use them as a vaccine. Other clinical trials have used IFN-gamma activated macrophage killer cells (MAK to treat cancer patients. However, the clinical use of MAK has been based on their direct tumoricidal activity rather than on their ability to act as antigen-presenting cells to stimulate an adaptive antitumor response. Thus, in the present work, we compared the fate of MART-1 after phagocytosis of gamma-irradiated cells by clinical grade DC or MAK as well as the ability of these cells to cross present MART-1 to CD8(+ T cells. Using a high affinity antibody against MART-1, 2A9, which specifically stains melanoma tumors, melanoma cell lines and normal melanocytes, the expression level of MART-1 in melanoma cell lines could be related to their ability to stimulate IFN-gamma production by a MART-1 specific HLA-A*0201-restricted CD8(+ T cell clone. Confocal microscopy with Alexa Fluor®(647-labelled 2A9 also showed that MART-1 could be detected in tumor cells attached and/or fused to phagocytes and even inside these cells as early as 1 h and up to 24 h or 48 h after initiation of co-cultures between gamma-irradiated melanoma cells and MAK or DC, respectively. Interestingly, MART-1 was cross-presented to MART-1 specific T cells by both MAK and DC co-cultured with melanoma gamma-irradiated cells for different time-points. Thus, naturally occurring MART-1 melanoma antigen can be taken-up from dying melanoma cells into DC or MAK and both cell types can induce specific CD8(+ T cell cross-presentation thereafter.

  4. Analysis of antigenically important residues in human influenza A virus in terms of B-cell epitopes.

    Science.gov (United States)

    Lees, William D; Moss, David S; Shepherd, Adrian J

    2011-09-01

    In this paper we undertake an analysis of the antigenicity of influenza A virus hemagglutinin. We developed a novel computational approach to the identification of antigenically active regions and showed that the amino acid substitutions between successive predominant seasonal strains form clusters that are consistent, in terms of both their location and their size, with the properties of B-cell epitopes in general and with those epitopes that have been identified experimentally in influenza A virus hemagglutinin to date. Such an interpretation provides a biologically plausible framework for an understanding of the location of antigenically important substitutions that is more specific than the canonical "antigenic site" model and provides an effective basis for deriving models that predict antigenic escape in the H3N2 subtype. Our results support recent indications that antibodies binding to the "stalk" region of hemagglutinin are found in the human population and exert evolutionary pressure on the virus. Our computational approach provides a possible method for identifying antigenic escape through evolution in this region, which in some cases will not be identified by the hemagglutinin inhibition assay.

  5. Defective signaling through the B cell antigen receptor in Epstein-Barr virus-transformed ataxia-telangiectasia cells.

    Science.gov (United States)

    Khanna, K K; Yan, J; Watters, D; Hobson, K; Beamish, H; Spring, K; Shiloh, Y; Gatti, R A; Lavin, M F

    1997-04-04

    A characteristic series of immunological abnormalities are observed in the human genetic disorder ataxia-telangiectasia (A-T). The recent cloning of a gene mutated in this syndrome provides additional evidence for a defect in intracellular signaling in A-T. We have investigated the possibility that signaling through the B cell antigen receptor is one manifestation of the A-T defect. In response to cross-linking of the B cell receptor, several A-T cell lines were defective in their mitogenic response; in addition Ca2+ mobilization from internal stores was either absent or considerably reduced in these cell lines in response to cross-linking. The defect in signaling was not due to difference in expression of surface immunoglobulin. The defective response in A-T cells was also evident in several arms of the intracellular cascade activated by B cell cross-linking. Tyrosine phosphorylation of phospholipase Cgamma1, a key step in activation of the enzyme, was reduced or negligible in some A-T cell lines. This defect in signaling was also seen at the level of Lyn tyrosine kinase activation and its association with and activation of phosphatidylinositol 3-kinase. Our results provide evidence for a role for the ATM gene product in intracellular signaling which may account at least in part for the abnormalities in B cell function in A-T.

  6. Tissue-resident memory CD8+ T cells continuously patrol skin epithelia to quickly recognize local antigen.

    Science.gov (United States)

    Ariotti, Silvia; Beltman, Joost B; Chodaczek, Grzegorz; Hoekstra, Mirjam E; van Beek, Anna E; Gomez-Eerland, Raquel; Ritsma, Laila; van Rheenen, Jacco; Marée, Athanasius F M; Zal, Tomasz; de Boer, Rob J; Haanen, John B A G; Schumacher, Ton N

    2012-11-27

    Recent work has demonstrated that following the clearance of infection a stable population of memory T cells remains present in peripheral organs and contributes to the control of secondary infections. However, little is known about how tissue-resident memory T cells behave in situ and how they encounter newly infected target cells. Here we demonstrate that antigen-specific CD8(+) T cells that remain in skin following herpes simplex virus infection show a steady-state crawling behavior in between keratinocytes. Spatially explicit simulations of the migration of these tissue-resident memory T cells indicate that the migratory dendritic behavior of these cells allows the detection of antigen-expressing target cells in physiologically relevant time frames of minutes to hours. Furthermore, we provide direct evidence for the identification of rare antigen-expressing epithelial cells by skin-patrolling memory T cells in vivo. These data demonstrate the existence of skin patrol by memory T cells and reveal the value of this patrol in the rapid detection of renewed infections at a previously infected site.

  7. Reduced response to Epstein–Barr virus antigens by T-cells in systemic lupus erythematosus patients

    Science.gov (United States)

    Draborg, Anette Holck; Jacobsen, Søren; Westergaard, Marie; Mortensen, Shila; Larsen, Janni Lisander; Houen, Gunnar; Duus, Karen

    2014-01-01

    Objective Epstein–Barr virus (EBV) has for long been associated with systemic lupus erythematosus (SLE). In this study, we investigated the levels of latent and lytic antigen EBV-specific T-cells and antibodies in SLE patients. Methods T cells were analyzed by flow cytometry and antibodies were analyzed by enzyme-linked immunosorbent assay. Results SLE patients showed a significantly reduced number of activated (CD69) T-cells upon ex vivo stimulation with EBV nuclear antigen (EBNA) 1 or EBV early antigen diffuse (EBV-EA/D) in whole blood samples compared with healthy controls. Also, a reduced number of T-cells from SLE patients were found to produce interferon-γ upon stimulation with these antigens. Importantly, responses to a superantigen were normal in SLE patients. Compared with healthy controls, SLE patients had fewer EBV-specific T-cells but higher titres of antibodies against EBV. Furthermore, an inverse correlation was revealed between the number of lytic antigen EBV-specific T-cells and disease activity of the SLE patients, with high-activity SLE patients having fewer T-cells than low-activity SLE patients. Conclusions These results indicate a limited or a defective EBV-specific T-cell response in SLE patients, which may suggest poor control of EBV infection in SLE with an immune reaction shift towards a humoral response in an attempt to control viral reactivation. A role for decreased control of EBV as a contributing agent in the development or exacerbation of SLE is proposed. PMID:25396062

  8. A sharp T-cell antigen receptor signaling threshold for T-cell proliferation

    OpenAIRE

    Au-Yeung, Byron B.; Zikherman, Julie; James L. Mueller; Ashouri, Judith F.; Matloubian, Mehrdad; Cheng, Debra A.; Chen, Yiling; Shokat, Kevan M; Weiss, Arthur

    2014-01-01

    Biochemical signals triggered by the T-cell receptor (TCR) are required for stimulating T cells and can be initiated within seconds. However, a hallmark of T-cell activation, cell division, occurs hours after TCR signaling has begun, implying that T cells require a minimum duration and/or accumulate TCR signaling events to drive proliferation. To visualize the accumulated signaling experienced by T cells, we used a fluorescent reporter gene that is activated by TCR stimulation. This technique...

  9. 1,25-Dihydroxyvitamin D3 inhibits proliferation but not the suppressive function of regulatory T cells in the absence of antigen-presenting cells.

    NARCIS (Netherlands)

    Khoo, A.L.; Joosten, I.; Michels, M.; Woestenenk, R.M.; Preijers, F.W.M.B.; He, X.; Netea, M.G.; Ven, A.J.A.M. van der; Koenen, H.J.P.M.

    2011-01-01

    Vitamin D3 is known to induce regulatory T (Treg) cells by rendering antigen-presenting cells tolerogenic, its direct effect on human naturally occurring Treg cells is unclear. Here, we investigated if and how 1,25-dihydroxyvitamin D(3) [1,25(OH)2D3] can directly affect the proliferation and functio

  10. Processing and MHC class II presentation of exogenous soluble antigen involving a proteasome-dependent cytosolic pathway in CD40-activated B cells.

    Science.gov (United States)

    Becker, Hans Jiro; Kondo, Eisei; Shimabukuro-Vornhagen, Alexander; Theurich, Sebastian; von Bergwelt-Baildon, Michael S

    2016-08-01

    Activated B cells have the capacity to present antigen and induce immune responses as potent antigen-presenting cells (APCs). As in other APCs, antigen presentation by B cells involves antigen internalization, antigen processing, and peptide loading onto MHC molecules. However, while the mechanism of antigen processing has been studied extensively in other APCs, this pathway remains elusive in B cells. The aim of this study was to investigate the MHC class II processing pathway in CD40-activated B cells (CD40Bs), as a model for activated, antigen-presenting B cells. Using CMV pp65 as a model antigen, we evaluated processing and presentation of the CD4 + T-cell epitope 509-523 (K509) by human CD40Bs in ELISPOT assays. As expected, stimulation of specific CD4 + T-cell clones was attenuated after pretreatment of CD40Bs with inhibitors of classic class II pathway components. However, proteasome inhibitors such as epoxomicin limited antigen presentation as well. This suggests that the antigen is processed in a non-classical, cytosolic MHC class II pathway. Further experiments with truncated protein variants revealed involvement of the proteasome in processing of the N and C extensions of the epitope. Access to the cytosol was shown to be size dependent. Epoxomicin sensitivity exclusively in CD40B cells, but not in dendritic cells, suggests a novel processing mechanism unique to this APC. Our data suggest that B cells process antigen using a distinct, non-classical class II pathway.

  11. EXPRESSION OF P53 PROTEIN AND PROLIFERATING CELL NUCLEAR ANTIGEN IN HUMAN GESTATION TROPHOBLASTIC DISEASE

    Institute of Scientific and Technical Information of China (English)

    黄铁军; 王志忠; 方光光; 刘志恒

    2004-01-01

    Objective: To study the relationship between p53 protein, proliferating cell nuclear antigen (PCNA) expression and benign or malignant gestational trophoblastic disease (MGTD). Methods: The histotomic sections of 48 patients with gestational trophoblastic disease and 24 patients of normal chorionic villi were stained using immunohistochemistry. The monoclonal antibodies were used to determine p53 protein and PCNA. Results: The frequency of p53 and PCNA positive expression were significantly different among the chorionic villi of normal pregnancy, hydratidiform mole (HM) and MGTD. But neither p53 nor PCNA has any relation with the clinical staging or metastasis of MGTD. Conclusion: Both P53 and PCNA are valuable in diagnosis of human gestational trophoblastic disease.

  12. HAM56 and CD68 antigen presenting cells surrounding a sarcoidal granulomatous tattoo

    Directory of Open Access Journals (Sweden)

    Ana Maria Abreu Velez

    2011-01-01

    Full Text Available Context : Tattoos are produced by introducing colorants of various compositions into the skin, either accidentally or for cosmetic purposes. Case Report: A 62-year-old male presented with a cosmetic tattoo and requested a total excision of the lesion. Dermatopathologic analysis of the excised tissue with hematoxylin and eosin examination, as well as immunohistochemistry was performed. H&E staining demonstrated classic histologic features of a tattoo. Utilizing immunohistochemistry, dermal histiocytic antigen presenting cells stained with HAM56 and CD68 antibodies; the staining was present surrounding the tattoo pigment. Conclusions : We identified two macrophage markers (HAM56 and CD68 surrounding dermal tattoo pigment. A minimal dermal inflammatory immune was noted to the tattoo pigment. Moreover, the immune response and/or tolerance to tattoos is not well characterized. We suggest that tattoo materials and techniques could be utilized in therapeutic delivery for diseases such recessive dystrophic epidermolysis bullosa, potentially preventing immune rejection of gene therapy agents.

  13. In vitro and in vivo analyses of a genetically—restricted antigen specific factor from mixed cell cultures of macrophage,T and B lymphocytes

    Institute of Scientific and Technical Information of China (English)

    CHAURMW; LAUASK

    1990-01-01

    An immunostimulatory factor was identified to be secreted by antigen-pulsed macrophages.This factor was able to induce the generation of antigen specific T helper lymphocytes in vitro as well as in vivo.Further in vitro experiments testing for the genetic restriction of this factor indicated that it is a geneticallyrestricted antigen specific factor (ASF).The Cunningham plaque assay was used to quantify the generation of T helper lymphocytes by measuring the number of plaque forming cells after sequential incubations of antigen-qulsed macrophages with T lymphocytes,and then spleen cells,and finally the TNP-coated sheep red blood cells.

  14. An endogenous nanomineral chaperones luminal antigen and peptidoglycan to intestinal immune cells

    Science.gov (United States)

    Powell, Jonathan J.; Thomas-McKay, Emma; Thoree, Vinay; Robertson, Jack; Hewitt, Rachel E.; Skepper, Jeremy N.; Brown, Andy; Hernandez-Garrido, Juan Carlos; Midgley, Paul A.; Gomez-Morilla, Inmaculada; Grime, Geoffrey W.; Kirkby, Karen J.; Mabbott, Neil A.; Donaldson, David S.; Williams, Ifor R.; Rios, Daniel; Girardin, Stephen E.; Haas, Carolin T.; Bruggraber, Sylvaine F. A.; Laman, Jon D.; Tanriver, Yakup; Lombardi, Giovanna; Lechler, Robert; Thompson, Richard P. H.; Pele, Laetitia C.

    2015-05-01

    In humans and other mammals it is known that calcium and phosphate ions are secreted from the distal small intestine into the lumen. However, why this secretion occurs is unclear. Here, we show that the process leads to the formation of amorphous magnesium-substituted calcium phosphate nanoparticles that trap soluble macromolecules, such as bacterial peptidoglycan and orally fed protein antigens, in the lumen and transport them to immune cells of the intestinal tissue. The macromolecule-containing nanoparticles utilize epithelial M cells to enter Peyer's patches, small areas of the intestine concentrated with particle-scavenging immune cells. In wild-type mice, intestinal immune cells containing these naturally formed nanoparticles expressed the immune tolerance-associated molecule ‘programmed death-ligand 1’, whereas in NOD1/2 double knockout mice, which cannot recognize peptidoglycan, programmed death-ligand 1 was undetected. Our results explain a role for constitutively formed calcium phosphate nanoparticles in the gut lumen and show how this helps to shape intestinal immune homeostasis.

  15. An Endogenous Nanomineral Chaperones Luminal