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Sample records for antigen-presenting cells

  1. [Mucose associated lymphoid tissue. Antigen presenting cells].

    Science.gov (United States)

    Luzardo-Baptista, Mario J; Luzardo, José Rafael

    2013-12-01

    We studied samples of normal and abnormal human mucosae, including oral tissue and uterine cervix, using electron microscopy. Special attention was given to the functions and mechanisms of defense carried out by the epithelial (EC) and dendritic cells (DC). Activated epithelial cells posses the capacity to uptake and process antigens, in order to present them, subsequently, to the dendritic cells. The structures and elements of the cells intervening on this function are: micropinocytic vesicles, multivesicular bodies, lysosomes, phagosomes, clathrin-covered vesicles, dense granules covered by a unit membrane, granules with onion likes leaves, microbodies, and dense granules with acid phosphatase activity. When they first arrive within the epithelial layers, the DC are clear with long cytoplasmic projections, which later become short, and the density of their cytoplasm increases. They possess mycropinocytic vesicles, some clathrine-covered vesicles, lysososmes and Birbeck granules. At this moment, they are known as Langerhans cells. EC and DC present many surface folds rich in micropynocytic vesicles. Between EC and DC there are many contacts (close junctions or tight junctions), through which antigens, phagocitized and processed by the EC, are given to the DC. These cells join them to major histocompatibility complex molecules or to other molecules with similar functions (CD1). Then the Langerhans cells travel to the lymphatic node to activate T cells and continue the immunologic task. So, in this way, both the EC and the DC are a link between the natural and the acquired immunological mechanisms. PMID:24502183

  2. 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.

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

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    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.

  4. 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.

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

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    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.

  6. 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.

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

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    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.

  8. 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

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

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    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

  10. 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

    In this study biopsies from skin lesions and draining lymph nodes of patients suffering from cutaneous leishmaniasis caused by Leishmania major were examined by immunohistochemistry, and by light and electron microscopy to identify the types of antigen-presenting cells (APC) and their location. APC...

  11. 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

  12. Vaccine delivery by penetratin: mechanism of antigen presentation by dendritic cells.

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    Pouniotis, Dodie; Tang, Choon-Kit; Apostolopoulos, Vasso; Pietersz, Geoffrey

    2016-08-01

    Cell-penetrating peptides (CPP) or membrane-translocating peptides such as penetratin from Antennapedia homeodomain or TAT from human immunodeficiency virus are useful vectors for the delivery of protein antigens or their cytotoxic (Tc) or helper (Th) T cell epitopes to antigen-presenting cells. Mice immunized with CPP containing immunogens elicit antigen-specific Tc and/or Th responses and could be protected from tumor challenges. In the present paper, we investigate the mechanism of class I and class II antigen presentation of ovalbumin covalently linked to penetratin (AntpOVA) by bone marrow-derived dendritic cells with the use of biochemical inhibitors of various pathways of antigen processing and presentation. Results from our study suggested that uptake of AntpOVA is via a combination of energy-independent (membrane fusion) and energy-dependent pathways (endocytosis). Once internalized by either mechanism, multiple tap-dependent or independent antigen presentation pathways are accessed while not completely dependent on proteasomal processing but involving proteolytic trimming in the ER and Golgi compartments. Our study provides an understanding on the mechanism of antigen presentation mediated by CPP and leads to greater insights into future development of vaccine formulations. PMID:27138940

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

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    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.

  14. Circulating human basophils lack the features of professional antigen presenting cells

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    Sharma, Meenu; Hegde, Pushpa; Aimanianda, Vishukumar; Beau, Remi; Sénéchal, Helene; Poncet, Pascal; Latgé, Jean-Paul; Kaveri, Srini V; Bayry, Jagadeesh

    2013-01-01

    Recent reports in mice demonstrate that basophils function as antigen presenting cells (APC). They express MHC class II and co-stimulatory molecules CD80 and CD86, capture and present soluble antigens or IgE-antigen complexes and polarize Th2 responses. Therefore, we explored whether human circulating basophils possess the features of professional APC. We found that unlike dendritic cells (DC) and monocytes, steady-state circulating human basophils did not express HLA-DR and co-stimulatory mo...

  15. 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.

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

    International Nuclear Information System (INIS)

    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

  17. 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.

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

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    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.

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

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    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.

  20. Pollen-induced antigen presentation by mesenchymal stem cells and T cells from allergic rhinitis.

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    Desai, Mauli B; Gavrilova, Tatyana; Liu, Jianjun; Patel, Shyam A; Kartan, Saritha; Greco, Steven J; Capitle, Eugenio; Rameshwar, Pranela

    2013-10-01

    Mesenchymal stem cells (MSCs) are promising cellular suppressor of inflammation. This function of MSCs is partly due to their licensing by inflammatory mediators. In cases with reduced inflammation, MSCs could become immune-enhancer cells. MSCs can suppress the inflammatory response of antigen-challenged lymphocytes from allergic asthma. Although allergic rhinitis (AR) is also an inflammatory response, it is unclear if MSCs can exert similar suppression. This study investigated the immune effects (suppressor vs enhancer) of MSCs on allergen-stimulated lymphocytes from AR subjects (grass or weed allergy). In contrast to subjects with allergic asthma, MSCs caused a significant (Pcells (antigen-presenting cells (APCs)). This correlated with increased production of inflammatory cytokines from T cells, and increased expressions of major histocompatibility complex (MHC)-II and CD86 on MSCs. The specificity of APC function was demonstrated in APC assay using MSCs that were knocked down for the master regulator of MHC-II transcription, CIITA. The difference in the effects of MSCs on allergic asthma and AR could not be explained by the sensitivity to the allergen, based on skin tests. Thus, we deduced that the contrasting immune effects of MSCs for antigen-challenged lymphocytes on AR and allergic asthma could be disease specific. It is possible that the enhanced inflammation from asthma might be required to license the MSCs to become suppressor cells. This study underscores the need for robust preclinical studies to effectively translate MSCs for any inflammatory disorder. PMID:25505949

  1. 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....

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

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    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

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

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    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

  4. Antigen presentation by murine epidermal langerhans cells and its alteration by ultraviolet B light

    International Nuclear Information System (INIS)

    Mice that are chronically exposed in vivo to ultraviolet B light (UV-B) display altered immunologic reactivity to various antigenic stimuli. A possible mode of UV-B action is that it exerts adverse effects on antigen-presenting cell function. Because the epidermis is the only tissue that is naturally subject to UV exposure we investigated if murine epidermal cells (EC) could perform an antigen presentation function and, if so, could this function be altered by UV-B irradiation. For this purpose, T cells immune to purified protein derivative of tuberculin (PPD) and dinitrophenylated ovalbumin (DNP6-OVA) from either BALB/c or C3H/He mice were incubated with syngeneic, semisyngeneic, or allogeneic EC or, for control purposes, with peritoneal exudate cells (PEC) that had been pulse-exposed to either the immunizing antigens or, as controls, left unpulsed, or pulsed to human serum albumin (HSA). After 4 days of culture, T cell proliferation was assessed by 3H-thymidine incorporation. PPD- and DNP/6-OVA pulsed, but not HSA-pulsed EC and PEC, induced vigorous proliferation of syngeneic and semisyngeneic, but not allogeneic, immune T cells. Pretreatment of stimulator cells with specific anti-Ia serum and complement virtually abolished this response, which indicated that among EC, Ia-bearing Langerhans cells are the critical stimulators. Exposure of EC either before or after pulsing to UV-B resulted in a dose-dependent impairment of antigen-specific T cell proliferation; the T proliferative response was abolished after administration of 20 mJ/cm2 UV-B. UV-B in the dose range employed did not produce immediate lethal cell damage, premature death of cultured EC, or toxic factors inhibitory for T cell proliferation

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

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    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

  6. 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

  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. Modulation of innate antigen-presenting cell function by pre-patent schistosome infection.

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    Christine E Ferragine

    Full Text Available Schistosomes are intravascular helminths that infect over 200 million people worldwide. Deposition of eggs by adult schistosomes stimulates Th2 responses to egg antigens and induces granulomatous pathology that is a hallmark of schistosome infection. Paradoxically, schistosomes require host immune function for their development and reproduction and for egress of parasite eggs from the host. To identify potential mechanisms by which immune cells might influence parasite development prior to the onset of egg production, we assessed immune function in mice infected with developing schistosomes. We found that pre-patent schistosome infection is associated with a loss of T cell responsiveness to other antigens and is due to a diminution in the ability of innate antigen-presenting cells to stimulate T cells. Diminution of stimulatory capacity by schistosome worms specifically affected CD11b(+ cells and did not require concomitant adaptive responses. We could not find evidence for production of a diffusible inhibitor of T cells by innate cells from infected mice. Rather, inhibition of T cell responsiveness by accessory cells required cell contact and only occurred when cells from infected mice outnumbered competent APCs by more than 3∶1. Finally, we show that loss of T cell stimulatory capacity may in part be due to suppression of IL-12 expression during pre-patent schistosome infection. Modulation of CD4(+ T cell and APC function may be an aspect of host immune exploitation by schistosomes, as both cell types influence parasite development during pre-patent schistosome infection.

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

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    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.

  10. 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...... (DC) and macrophages infiltrate the CNS during experimental autoimmune encephalomyelitis (EAE). Microglia are not considered to be as effective APC as DC or macrophages. METHODS: In this work we compared the antigen presenting capacity of CD11c+ and CD11c- microglia subsets with infiltrating CD11c...... for cytokine expression. They were co-cultured with primed T cells to measure induction of T cell proliferation and cytokine response. RESULTS: The number of CD11c+ microglia cells increased dramatically in EAE. They expressed equivalent levels of major histocompatibility complex and co-stimulatory ligands CD...

  11. HAM56 and CD68 antigen presenting cells surrounding a sarcoidal granulomatous tattoo

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    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.

  12. Antigen presenting cell abnormalities in the Cln3(-/-) mouse model of juvenile neuronal ceroid lipofuscinosis.

    Science.gov (United States)

    Hersrud, Samantha L; Kovács, Attila D; Pearce, David A

    2016-07-01

    Mutations of the CLN3 gene lead to juvenile neuronal ceroid lipofuscinosis (JNCL), an autosomal recessive lysosomal storage disorder that causes progressive neurodegeneration in children and adolescents. There is evidence of immune system involvement in pathology that has been only minimally investigated. We characterized bone marrow stem cell-derived antigen presenting cells (APCs), peritoneal macrophages, and leukocytes from spleen and blood, harvested from the Cln3(-/-) mouse model of JNCL. We detected dramatically elevated CD11c surface levels and increased total CD11c protein in Cln3(-/-) cell samples compared to wild type. This phenotype was specific to APCs and also to a loss of CLN3, as surface levels did not differ from wild type in other leukocyte subtypes nor in cells from two other NCL mouse models. Subcellularly, CD11c was localized to lipid rafts, indicating that perturbation of surface levels is attributable to derangement of raft dynamics, which has previously been shown in Cln3 mutant cells. Interrogation of APC function revealed that Cln3(-/-) cells have increased adhesiveness to CD11c ligands as well as an abnormal secretory pattern that closely mimics what has been previously reported for Cln3 mutant microglia. Our results show that CLN3 deficiency alters APCs, which can be a major contributor to the autoimmune response in JNCL. PMID:27101989

  13. Selective susceptibility of human skin antigen presenting cells to productive dengue virus infection.

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    Daniela Cerny

    2014-12-01

    Full Text Available Dengue is a growing global concern with 390 million people infected each year. Dengue virus (DENV is transmitted by mosquitoes, thus host cells in the skin are the first point of contact with the virus. Human skin contains several populations of antigen-presenting cells which could drive the immune response to DENV in vivo: epidermal Langerhans cells (LCs, three populations of dermal dendritic cells (DCs, and macrophages. Using samples of normal human skin we detected productive infection of CD14(+ and CD1c(+ DCs, LCs and dermal macrophages, which was independent of DC-SIGN expression. LCs produced the highest viral titers and were less sensitive to IFN-β. Nanostring gene expression data showed significant up-regulation of IFN-β, STAT-1 and CCL5 upon viral exposure in susceptible DC populations. In mice infected intra-dermally with DENV we detected parallel populations of infected DCs originating from the dermis and migrating to the skin-draining lymph nodes. Therefore dermal DCs may simultaneously facilitate systemic spread of DENV and initiate the adaptive anti-viral immune response.

  14. Carbohydrate-functionalized nanovaccines preserve HIV-1 antigen stability and activate antigen presenting cells.

    Science.gov (United States)

    Vela Ramirez, J E; Roychoudhury, R; Habte, H H; Cho, M W; Pohl, N L B; Narasimhan, B

    2014-01-01

    The functionalization of polymeric nanoparticles with ligands that target specific receptors on immune cells offers the opportunity to tailor adjuvant properties by conferring pathogen mimicking attributes to the particles. Polyanhydride nanoparticles are promising vaccine adjuvants with desirable characteristics such as immunomodulation, sustained antigen release, activation of antigen presenting cells (APCs), and stabilization of protein antigens. These capabilities can be exploited to design nanovaccines against viral pathogens, such as HIV-1, due to the important role of dendritic cells (DCs) and macrophages in viral spread. In this work, an optimized process was developed for carbohydrate functionalization of HIV-1 antigen-loaded polyanhydride nanoparticles. The carbohydrate-functionalized nanoparticles preserved antigenic properties upon release and also enabled sustained antigen release kinetics. Particle internalization was observed to be chemistry-dependent with positively charged nanoparticles being taken up more efficiently by DCs. Up-regulation of the activation makers CD40 and CD206 was demonstrated with carboxymethyl-α-d-mannopyranosyl-(1,2)-d-mannopyranoside functionalized nanoparticles. The secretion of the cytokines IL-6 and TNF-α was shown to be chemistry-dependent upon stimulation with carbohydrate-functionalized nanoparticles. These results offer important new insights upon the interactions between carbohydrate-functionalized nanoparticles and APCs and provide foundational information for the rational design of targeted nanovaccines against HIV-1. PMID:25068589

  15. "Danger" conditions increase sulfamethoxazole-protein adduct formation in human antigen-presenting cells.

    Science.gov (United States)

    Lavergne, S N; Wang, H; Callan, H E; Park, B K; Naisbitt, D J

    2009-11-01

    Antigen-presenting cells (APC) are thought to play an important role in the pathogenesis of drug-induced immune reactions. Various pathological factors can activate APC and therefore influence the immune equilibrium. It is interesting that several diseases have been associated with an increased rate of drug allergy. The aim of this project was to evaluate the impact of such "danger signals" on sulfamethoxazole (SMX) metabolism in human APC (peripheral blood mononuclear cells, Epstein-Barr virus-modified B lymphocytes, monocyte-derived dendritic cells, and two cell lines). APC were incubated with SMX (100 microM-2 mM; 5 min-24 h), in the presence of pathological factors: bacterial endotoxins (lipopolysaccharide and staphylococcal enterotoxin B), flu viral proteins, cytokines [interleukin (IL)-1beta, IL-6, IL-10; tumor necrosis factor-alpha; interferon-gamma; and transforming growth factor-beta], inflammatory molecules (prostaglandin E2, human serum complement, and activated protein C), oxidants (buthionine sulfoximine and H(2)O(2)), and hyperthermia (37.5-39.5 degrees C). Adduct formation was evaluated by enzyme-linked immunosorbent assay and confocal microscopy. SMX-protein adduct formation was time- and concentration-dependent for each cell type tested, in both physiological and danger conditions. A danger environment significantly increased the formation of SMX-protein adducts and significantly shortened the delay for their detection. An additive effect was observed with a combination of danger signals. Dimedone (chemical selectively binding cysteine sulfenic acid) and antioxidants decreased both baseline and danger-enhanced SMX-adduct formation. Various enzyme inhibitors were associated with a significant decrease in SMX-adduct levels, with a pattern varying depending on the cell type and the culture conditions. These results illustrate that danger signals enhance the formation of intracellular SMX-protein adducts in human APC. These findings might be relevant

  16. Antigen presenting cell-selective drug delivery by glycan-decorated nanocarriers.

    Science.gov (United States)

    Frenz, Theresa; Grabski, Elena; Durán, Verónica; Hozsa, Constantin; Stępczyńska, Anna; Furch, Marcus; Gieseler, Robert K; Kalinke, Ulrich

    2015-09-01

    Targeted drug delivery systems hold promise for selective provision of active compounds to distinct tissues or cell subsets. Thus, locally enhanced drug concentrations are obtained that would confer improved efficacy. As a consequence adverse effects should be diminished, as innocent bystander cells are less affected. Currently, several controlled drug delivery systems based on diverse materials are being developed. Some systems exhibit material-associated toxic effects and/or show low drug loading capacity. In contrast, liposomal nanocarriers are particularly favorable because they are well tolerated, poorly immunogenic, can be produced in defined sizes, and offer a reasonable payload capacity. Compared with other immune cells, professional antigen-presenting cells (APCs) demonstrate enhanced liposome uptake mediated by macropinocytosis, phagocytosis and presumably also by clathrin- and caveolae-mediated endocytosis. In order to further enhance the targeting efficacy toward APCs, receptor-mediated uptake appears advisable. Since APC subsets generally do not express single linage-specific receptors, members of the C-type lectin receptor (CLR) family are compelling targets. Examples of CLR expressed by APCs include DEC-205 (CD205) expressed by myeloid dendritic cells (DC) and monocytes, the mannose receptor C type 1 (MR, CD206) expressed by DC, monocytes and macrophages, DC-SIGN (CD209) expressed by DC, and several others. These receptors bind glycans, which are typically displayed by pathogens and thus support pathogen uptake and endocytosis. Further research will elucidate whether glycan-decorated liposomes will not only enhance APCs targeting but also enable preferential delivery of their payload to discrete subcellular compartments. PMID:25701806

  17. A novel laser vaccine adjuvant increases the motility of antigen presenting cells.

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    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.

  18. Seoul virus suppresses NF-κB-mediated inflammatory responses of antigen presenting cells from Norway rats

    OpenAIRE

    Au, Rebecca Y.; Jedlicka, Anne E.; Li, Wei; Pekosz, Andrew; Klein, Sabra L.

    2010-01-01

    Hantavirus infection reduces antiviral defenses, increases regulatory responses, and causes persistent infection in rodent hosts. To address whether hantaviruses alter the maturation and functional activity of antigen presenting cells (APCs), rat bone marrow-derived dendritic cells (BMDCs) and macrophages (BMDMs) were generated and infected with Seoul virus (SEOV) or stimulated with TLR ligands. SEOV infected both DCs and macrophages, but copies of viral RNA, viral antigen, and infectious vir...

  19. CD8+ T cell priming by dendritic cell vaccines requires antigen transfer to endogenous antigen presenting cells.

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    Alice W Yewdall

    Full Text Available Immunotherapeutic strategies to stimulate anti-tumor immunity are promising approaches for cancer treatment. A major barrier to their success is the immunosuppressive microenvironment of tumors, which inhibits the functions of endogenous dendritic cells (DCs that are necessary for the generation of anti-tumor CD8+ T cells. To overcome this problem, autologous DCs are generated ex vivo, loaded with tumor antigens, and activated in this non-suppressive environment before administration to patients. However, DC-based vaccines rarely induce tumor regression.We examined the fate and function of these DCs following their injection using murine models, in order to better understand their interaction with the host immune system. Contrary to previous assumptions, we show that DC vaccines have an insignificant role in directly priming CD8+ T cells, but instead function primarily as vehicles for transferring antigens to endogenous antigen presenting cells, which are responsible for the subsequent activation of T cells.This reliance on endogenous immune cells may explain the limited success of current DC vaccines to treat cancer and offers new insight into how these therapies can be improved. Future approaches should focus on creating DC vaccines that are more effective at directly priming T cells, or abrogating the tumor induced suppression of endogenous DCs.

  20. Tubulin and actin interplay at the T cell and Antigen-presenting cell interface

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    Noa B Martín-Cófreces

    2011-07-01

    Full Text Available T cells reorganize their actin and tubulin-based cytoskeletons to provide a physical basis to the immune synapse. However, growing evidence shows that their roles on T cell activation are more dynamic than merely serving as tracks or scaffold for different molecules. The cross-talk between both skeletons may be important for the formation and movement of the lamella at the IS by increasing the adhesion of the T cell to the APC, thus favoring the transport of components towards the plasma membrane and in turn regulating the T-APC intercellular communication. Microtubules and F-actin appear to be essential for the transport of the different signaling microclusters along the membrane, therefore facilitating the propagation of the signal. Finally, they can also be important for regulating the endocytosis, recycling and degradation of the TCR signaling machinery, thus helping both to sustain the activated state and to switch it off.

  1. 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.

  2. Corruption of dendritic cell antigen presentation during acute GVHD leads to regulatory T-cell failure and chronic GVHD.

    Science.gov (United States)

    Leveque-El Mouttie, Lucie; Koyama, Motoko; Le Texier, Laetitia; Markey, Kate A; Cheong, Melody; Kuns, Rachel D; Lineburg, Katie E; Teal, Bianca E; Alexander, Kylie A; Clouston, Andrew D; Blazar, Bruce R; Hill, Geoffrey R; MacDonald, Kelli P A

    2016-08-11

    Chronic graft-versus-host disease (cGVHD) is a major cause of late mortality following allogeneic bone marrow transplantation (BMT) and is characterized by tissue fibrosis manifesting as scleroderma and bronchiolitis obliterans. The development of acute GVHD (aGVHD) is a powerful clinical predictor of subsequent cGVHD, suggesting that aGVHD may invoke the immunologic pathways responsible for cGVHD. In preclinical models in which sclerodermatous cGVHD develops after a preceding period of mild aGVHD, we show that antigen presentation within major histocompatibility complex (MHC) class II of donor dendritic cells (DCs) is markedly impaired early after BMT. This is associated with a failure of regulatory T-cell (Treg) homeostasis and cGVHD. Donor DC-restricted deletion of MHC class II phenocopied this Treg deficiency and cGVHD. Moreover, specific depletion of donor Tregs after BMT also induced cGVHD, whereas adoptive transfer of Tregs ameliorated it. These data demonstrate that the defect in Treg homeostasis seen in cGVHD is a causative lesion and is downstream of defective antigen presentation within MHC class II that is induced by aGVHD. PMID:27338097

  3. Corruption of dendritic cell antigen presentation during acute GVHD leads to regulatory T-cell failure and chronic GVHD.

    Science.gov (United States)

    Leveque-El Mouttie, Lucie; Koyama, Motoko; Le Texier, Laetitia; Markey, Kate A; Cheong, Melody; Kuns, Rachel D; Lineburg, Katie E; Teal, Bianca E; Alexander, Kylie A; Clouston, Andrew D; Blazar, Bruce R; Hill, Geoffrey R; MacDonald, Kelli P A

    2016-08-11

    Chronic graft-versus-host disease (cGVHD) is a major cause of late mortality following allogeneic bone marrow transplantation (BMT) and is characterized by tissue fibrosis manifesting as scleroderma and bronchiolitis obliterans. The development of acute GVHD (aGVHD) is a powerful clinical predictor of subsequent cGVHD, suggesting that aGVHD may invoke the immunologic pathways responsible for cGVHD. In preclinical models in which sclerodermatous cGVHD develops after a preceding period of mild aGVHD, we show that antigen presentation within major histocompatibility complex (MHC) class II of donor dendritic cells (DCs) is markedly impaired early after BMT. This is associated with a failure of regulatory T-cell (Treg) homeostasis and cGVHD. Donor DC-restricted deletion of MHC class II phenocopied this Treg deficiency and cGVHD. Moreover, specific depletion of donor Tregs after BMT also induced cGVHD, whereas adoptive transfer of Tregs ameliorated it. These data demonstrate that the defect in Treg homeostasis seen in cGVHD is a causative lesion and is downstream of defective antigen presentation within MHC class II that is induced by aGVHD.

  4. Malassezia yeasts activate the NLRP3 inflammasome in antigen-presenting cells via Syk-kinase signalling.

    Science.gov (United States)

    Kistowska, Magdalena; Fenini, Gabriele; Jankovic, Dragana; Feldmeyer, Laurence; Kerl, Katrin; Bosshard, Philipp; Contassot, Emmanuel; French, Lars E

    2014-12-01

    Although being a normal part of the skin flora, yeasts of the genus Malassezia are associated with several common dermatologic conditions including pityriasis versicolour, seborrhoeic dermatitis (SD), folliculitis, atopic eczema/dermatitis (AE/AD) and dandruff. While Malassezia spp. are aetiological agents of pityriasis versicolour, a causal role of Malassezia spp. in AE/AD and SD remains to be established. Previous reports have shown that fungi such as Candida albicans and Aspergillus fumigatus are able to efficiently activate the NLRP3 inflammasome leading to robust secretion of the pro-inflammatory cytokine IL-1β. To date, innate immune responses to Malassezia spp. are not well characterized. Here, we show that different Malassezia species could induce NLRP3 inflammasome activation and subsequent IL-1β secretion in human antigen-presenting cells. In contrast, keratinocytes were not able to secrete IL-1β when exposed to Malassezia spp. Moreover, we demonstrate that IL-1β secretion in antigen-presenting cells was dependent on Syk-kinase signalling. Our results identify Malassezia spp. as potential strong inducers of pro-inflammatory responses when taken up by antigen-presenting cells and identify C-type lectin receptors and the NLRP3 inflammasome as crucial actors in this process. PMID:25267545

  5. CD8(+ T cells restrict Yersinia pseudotuberculosis infection: bypass of anti-phagocytosis by targeting antigen-presenting cells.

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    Molly A Bergman

    2009-09-01

    Full Text Available All Yersinia species target and bind to phagocytic cells, but uptake and destruction of bacteria are prevented by injection of anti-phagocytic Yop proteins into the host cell. Here we provide evidence that CD8(+ T cells, which canonically eliminate intracellular pathogens, are important for restricting Yersinia, even though bacteria are primarily found in an extracellular locale during the course of disease. In a model of infection with attenuated Y. pseudotuberculosis, mice deficient for CD8(+ T cells were more susceptible to infection than immunocompetent mice. Although exposure to attenuated Y. pseudotuberculosis generated T(H1-type antibody responses and conferred protection against challenge with fully virulent bacteria, depletion of CD8(+ T cells during challenge severely compromised protective immunity. Strikingly, mice lacking the T cell effector molecule perforin also succumbed to Y. pseudotuberculosis infection. Given that the function of perforin is to kill antigen-presenting cells, we reasoned that cell death marks bacteria-associated host cells for internalization by neighboring phagocytes, thus allowing ingestion and clearance of the attached bacteria. Supportive of this model, cytolytic T cell killing of Y. pseudotuberculosis-associated host cells results in engulfment by neighboring phagocytes of both bacteria and target cells, bypassing anti-phagocytosis. Our findings are consistent with a novel function for cell-mediated immune responses protecting against extracellular pathogens like Yersinia: perforin and CD8(+ T cells are critical for hosts to overcome the anti-phagocytic action of Yops.

  6. A Francisella tularensis live vaccine strain that improves stimulation of antigen-presenting cells does not enhance vaccine efficacy.

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    Deanna M Schmitt

    Full Text Available Vaccination is a proven strategy to mitigate morbidity and mortality of infectious diseases. The methodology of identifying and testing new vaccine candidates could be improved with rational design and in vitro testing prior to animal experimentation. The tularemia vaccine, Francisella tularensis live vaccine strain (LVS, does not elicit complete protection against lethal challenge with a virulent type A Francisella strain. One factor that may contribute to this poor performance is limited stimulation of antigen-presenting cells. In this study, we examined whether the interaction of genetically modified LVS strains with human antigen-presenting cells correlated with effectiveness as tularemia vaccine candidates. Human dendritic cells infected with wild-type LVS secrete low levels of proinflammatory cytokines, fail to upregulate costimulatory molecules, and activate human T cells poorly in vitro. One LVS mutant, strain 13B47, stimulated higher levels of proinflammatory cytokines from dendritic cells and macrophages and increased costimulatory molecule expression on dendritic cells compared to wild type. Additionally, 13B47-infected dendritic cells activated T cells more efficiently than LVS-infected cells. A deletion allele of the same gene in LVS displayed similar in vitro characteristics, but vaccination with this strain did not improve survival after challenge with a virulent Francisella strain. In vivo, this mutant was attenuated for growth and did not stimulate T cell responses in the lung comparable to wild type. Therefore, stimulation of antigen-presenting cells in vitro was improved by genetic modification of LVS, but did not correlate with efficacy against challenge in vivo within this model system.

  7. Probiotic metabolites from Bacillus coagulans GanedenBC30TM support maturation of antigen-presenting cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Kathleen F Benson; Kimberlee A Redman; Steve G Carter; David Keller; Sean Farmer; John R Endres; Gitte S Jensen

    2012-01-01

    AIM:To study the effects of probiotic metabolites on maturation stage of antigen-presenting immune cells.METHODS:Ganeden Bacillus coagulans 30 (GBC30)bacterial cultures in log phase were used to isolate the secreted metabolite (MET) fraction.A second fraction was made to generate a crude cell-wall-enriched fraction,by centrifugation and lysis,followed by washing.A preparation of MET was subjected to size exclusion centrifugation,generating three fractions:< 3 kDa,3-30 kDa,and 30-200 kDa and activities were tested in comparison to crude MET and cell wall in primary cultures of human peripheral blood mononuclear cell (PBMC) as a source of antigen-presenting mononuclear phagocytes.The maturation status of mononudear phagocytes was evaluated by staining with monoclonal antibodies towards CD14,CD16,CD80 and CD86 and analyzed by flow cytometry.RESULTS:Treatment of PBMC with MET supported maturation of mononuclear phagocytes toward both macrophage and dendritic cell phenotypes.The biological activity unique to the metabolites included a reduction of CD14+ CD16+ pro-inflammatory ceils,and this property was associated with the high molecular weight metabolite fraction.Changes were also seen for the dendritic cell maturation markers CD80 and CD86.On CD14dim cells,an increase in both CD80 and CD86 expression was seen,in contrast to a selective increase in CD86 expression on CD14bright cells.The co-expression of CD80 and CD86 indicates effective antigen presentation to T cells and support of T helper cell differentiation.The selective expression of CD86 in the absence of CD80 points to a role in generating T regulatory cells.CONCLUSION:The data show that a primary mechanism of action of GBC30 metabolites involves support of more mature phenotypes of antigen-presenting cells,important for immunological decision-making.

  8. Loss of proliferation and antigen presentation activity following internalization of polydispersed carbon nanotubes by primary lung epithelial cells.

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    Mandavi Kumari

    Full Text Available Interactions between poly-dispersed acid functionalized single walled carbon nanotubes (AF-SWCNTs and primary lung epithelial (PLE cells were studied. Peritoneal macrophages (PMs, known phagocytic cells were used as positive controls in this study. Recovery of live cells from cultures of PLE cells and PMs was significantly reduced in the presence of AF-SWCNTs, in a time and dose dependent manner. Both PLE cells as well as PMs could take up fluorescence tagged AF-SWCNTs in a time dependent manner and this uptake was significantly blocked by cytochalasin D, an agent that blocks the activity of acto-myosin fibers and therefore the phagocytic activity of cells. Confocal microscopic studies confirmed that AF-SWCNTs were internalized by both PLE cells and PMs. Intra-trachially instilled AF-SWCNTs could also be taken up by lung epithelial cells as well as alveolar macrophages. Freshly isolated PLE cells had significant cell division activity and cell cycling studies indicated that treatment with AF-SWCNTs resulted in a marked reduction in S-phase of the cell cycle. In a previously standardized system to study BCG antigen presentation by PLE cells and PMs to sensitized T helper cells, AF-SWCNTs could significantly lower the antigen presentation ability of both cell types. These results show that mouse primary lung epithelial cells can efficiently internalize AF-SWCNTs and the uptake of nanotubes interfered with biological functions of PLE cells including their ability to present BCG antigens to sensitized T helper cells.

  9. Luciferase mRNA Transfection of Antigen Presenting Cells Permits Sensitive Nonradioactive Measurement of Cellular and Humoral Cytotoxicity

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    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.

  10. Distribution of primed T cells and antigen-loaded antigen presenting cells following intranasal immunization in mice.

    Directory of Open Access Journals (Sweden)

    Annalisa Ciabattini

    Full Text Available Priming of T cells is a key event in vaccination, since it bears a decisive influence on the type and magnitude of the immune response. T-cell priming after mucosal immunization via the nasal route was studied by investigating the distribution of antigen-loaded antigen presenting cells (APCs and primed antigen-specific T cells. Nasal immunization studies were conducted using the model protein antigen ovalbumin (OVA plus CpG oligodeoxynucleotide adjuvant. Trafficking of antigen-specific primed T cells was analyzed in vivo after adoptive transfer of OVA-specific transgenic T cells in the presence or absence of fingolimod, a drug that causes lymphocytes sequestration within lymph nodes. Antigen-loaded APCs were observed in mediastinal lymph nodes, draining the respiratory tract, but not in distal lymph nodes. Antigen-specific proliferating T cells were first observed within draining lymph nodes, and later in distal iliac and mesenteric lymph nodes and in the spleen. The presence at distal sites was due to migration of locally primed T cells as shown by fingolimod treatment that caused a drastic reduction of proliferated T cells in non-draining lymph nodes and an accumulation of extensively divided T cells within draining lymph nodes. Homing of nasally primed T cells in distal iliac lymph nodes was CD62L-dependent, while entry into mesenteric lymph nodes depended on both CD62L and α4β7, as shown by in vivo antibody-mediated inhibition of T-cell trafficking. These data, elucidating the trafficking of antigen-specific primed T cells to non-draining peripheral and mucosa-associated lymph nodes following nasal immunization, provide relevant insights for the design of vaccination strategies based on mucosal priming.

  11. Increased generation of Foxp3(+) regulatory T cells by manipulating antigen presentation in the thymus.

    Science.gov (United States)

    Lin, Jiqiang; Yang, Lu; Silva, Hernandez Moura; Trzeciak, Alissa; Choi, Yongwon; Schwab, Susan R; Dustin, Michael L; Lafaille, Juan J

    2016-01-01

    Regulatory T-cell (Treg) selection in the thymus is essential to prevent autoimmune diseases. Although important rules for Treg selection have been established, there is controversy regarding the degree of self-reactivity displayed by T-cell receptors expressed by Treg cells. In this study we have developed a model of autoimmune skin inflammation, to determine key parameters in the generation of skin-reactive Treg cells in the thymus (tTreg). tTreg development is predominantly AIRE dependent, with an AIRE-independent component. Without the knowledge of antigen recognized by skin-reactive Treg cells, we are able to enhance skin-specific tTreg cell generation using three approaches. First, we increase medullary thymic epithelial cells by using mice lacking osteoprotegerin or by adding TRANCE (RANKL, Tnfsf11). Second, we inject intrathymically peripheral dendritic cells from skin-draining sites. Finally, we inject skin tissue lysates intrathymically. These findings have implications for enhancing the generation of organ-specific Treg cells in autoimmune diseases. PMID:26923114

  12. Hepatitis B virus-like particles access major histocompatibility class I and II antigen presentation pathways in primary dendritic cells.

    Science.gov (United States)

    Moffat, Jessica M; Cheong, Wan-Shoo; Villadangos, José A; Mintern, Justine D; Netter, Hans J

    2013-04-26

    Virus-like particles (VLPs) represent high density displays of viral proteins that efficiently trigger immunity. VLPs composed of the small hepatitis B virus envelope protein (HBsAgS) are useful vaccine platforms that induce humoral and cellular immune responses. Notably, however, some studies suggest HBsAgS VLPs impair dendritic cell (DC) function. Here we investigated HBsAgS VLP interaction with DC subsets and antigen access to major histocompatibility complex (MHC) class I and II antigen presentation pathways in primary DCs. HBsAgS VLPs impaired plasmacytoid DC (pDC) interferon alpha (IFNα) production in response to CpG in vitro, but did not alter conventional DC (cDC) or pDC phenotype when administered in vivo. To assess cellular immune responses, HBsAgS VLPs were generated containing the ovalbumin (OVA) model epitopes OVA(257-264) and OVA(323-339) to access MHCI and MHCII antigen presentation pathways, respectively; both in vitro and following immunisation in vivo. HBsAgS VLP-OVA(257-264) elicited CTL responses in vivo that were not enhanced by inclusion of an additional MHCII helper epitope. HBsAgS VLP-OVA(257-264) administered in vivo was cross-presented by CD8(+) DCs, but not CD8(-) DCs. Therefore, HBsAgS VLPs can deliver antigen to both MHCI and MHCII antigen presentation pathways in primary DCs and promote cytotoxic and helper T cell priming despite their suppressive effect on pDCs. PMID:23473776

  13. The Plasticity of γδT Cells: Innate Immunity, Antigen Presentation and New Immunotherapy

    Institute of Scientific and Technical Information of China (English)

    Rita Casetti; Angelo Martino

    2008-01-01

    Several signals influence dendritic cell (DC) functions and consequent the immune responses to infectious pathogens. Our recent findings provide a new model of intervention on DCs implicating human γδ T cell stimuli. Vγ9Vδ2 T cells represent the major subset of circulating human γδ T cells and can be activated by non-peptidic molecules derived from different microorganisms or abnormal metabolic routes. With activated-Vγ9Vδ2 T cell co-culture, immature DCs acquire features of mature DCs, such as increasing the migratory activity, up-regulating the chemokine receptors, and triggering the Thl immune response. Similar to the NK-derived signals, DC activation is mediated by soluble factors as well as cell-to-cell contact. Many non-peptidic molecules including nitrogen- containing bisphosphonates and pyrophosphomonoester drugs, can stimulate the activity of Vγ9Vδ2 T cells in vitro and in vivo. The relatively low in vivo toxicity of many of these drugs makes possible novel vaccine and immune-based strategies against infectious diseases. Cellular & Molecular Immunology. 2008;5(3):161-170.

  14. 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

  15. Defects in Antigen-Presenting Cells in the BB-DP Rat Model of Diabetes

    NARCIS (Netherlands)

    V. Sommandas (Vinod)

    2008-01-01

    textabstractType-1 diabetes is the result of a T cell mediated immune response against the insulin-producing β cells in the islet of Langerhans. In humans, until now, the disease is only clearly detectable at the onset of the disease. Therefore studies to identify initial factors involved in

  16. Sinks, suppressors and antigen presenters: how lymphodepletion enhances T cell-mediated tumor immunotherapy

    OpenAIRE

    Klebanoff, Christopher A.; Khong, Hung T.; Antony, Paul A.; Douglas C Palmer; Restifo, Nicholas P

    2005-01-01

    Lymphodepletion followed by adoptive cell transfer (ACT) of autologous, tumor-reactive T cells boosts antitumor immunotherapeutic activity in mouse and in humans. In the most recent clinical trials, lymphodepletion together with ACT has an objective response rate of 50% in patients with solid metastatic tumors. The mechanisms underlying this recent advance in cancer immunotherapy are beginning to be elucidated and include: the elimination of cellular cytokine ‘sinks’ for homeostatic γC-cytoki...

  17. Cytokine profiles and phenotype regulation of antigen presenting cells by genotype-I porcine reproductive and respiratory syndrome virus isolates

    Directory of Open Access Journals (Sweden)

    Gimeno Mariona

    2011-01-01

    Full Text Available Abstract The present study examined the immunological response of antigen presenting cells (APC to genotype-I isolates of porcine reproductive and respiratory syndrome virus (PRRSV infection by analysing the cytokine profile induced and evaluating the changes taking place upon infection on immunologically relevant cell markers (MHCI, MHCII, CD80/86, CD14, CD16, CD163, CD172a, SWC9. Several types of APC were infected with 39 PRRSV isolates. The results show that different isolates were able to induce different patterns of IL-10 and TNF-α. The four possible phenotypes based on the ability to induce IL-10 and/or TNF-α were observed, although different cell types seemed to have different capabilities. In addition, isolates inducing different cytokine-release profiles on APC could induce different expression of cell markers.

  18. Immune tolerance maintained by cooperative interactions between T cells and antigen presenting cells shapes a diverse TCR repertoire

    Directory of Open Access Journals (Sweden)

    Katharine eBest

    2015-08-01

    Full Text Available The T cell population in an individual needs to avoid harmful activation by self-peptides while maintaining the ability to respond to an unknown set of foreign peptides. This property is acquired by a combination of thymic and extra-thymic mechanisms. We extend current models for the development of self/non-self discrimination to consider the acquisition of self-tolerance as an emergent system level property of the overall T cell receptor repertoire. We propose that tolerance is established at the level of the antigen presenting cell/T cell cluster, which facilitates and integrates co-operative interactions between T cells of different specificity. The threshold for self-reactivity is therefore imposed at a population level, and not at the level of the individual T cell/antigen encounter. Mathematically, the model can be formulated as a linear programming optimisation problem, which can be implemented as a multiplicative update algorithm which shows a rapid convergence to a stable state. The model constrains self-reactivity within a predefined threshold, but maintains the diversity and cross reactivity which are key characteristics of human T cell immunity. We show further that the size of individual clones in the model repertoire remains heterogeneous, and that new clones can establish themselves even when the repertoire is stable. Our study combines the salient features of the danger model of self/non-self discrimination with the concepts of quorum sensing, and extends repertoire generation models to encompass the establishment of tolerance. Furthermore, the dynamic and continuous repertoire reshaping which underlies tolerance in this model suggests opportunities for therapeutic intervention to achieve long-term tolerance following transplantation.

  19. A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

    International Nuclear Information System (INIS)

    Highlights: → Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. → An ideal artificial APCs system was successfully prepared in vivo. → Controlled release of IL-2 leads to much more T-cell expansion. → This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparation of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.

  20. A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Han, Hui [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Peng, Ji-Run, E-mail: pengjr@medmail.com.cn [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Chen, Peng-Cheng; Gong, Lei [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Qiao, Shi-Shi [Department of Hepatobiliary Surgery, The First Affiliated Hospital, Zhengzhou University, Zhengzhou 450052 (China); Wang, Wen-Zhen; Cui, Zhu-Qingqing; Yu, Xin; Wei, Yu-Hua [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China); Leng, Xi-Sheng, E-mail: lengxs2003@yahoo.com.cn [Department of Hepatobiliary Surgery, Peking University People' s Hospital, Beijing 100044 (China)

    2011-08-05

    Highlights: {yields} Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. {yields} An ideal artificial APCs system was successfully prepared in vivo. {yields} Controlled release of IL-2 leads to much more T-cell expansion. {yields} This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparation of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.

  1. Minimum information about tolerogenic antigen-presenting cells (MITAP): a first step towards reproducibility and standardisation of cellular therapies.

    Science.gov (United States)

    Lord, Phillip; Spiering, Rachel; Aguillon, Juan C; Anderson, Amy E; Appel, Silke; Benitez-Ribas, Daniel; Ten Brinke, Anja; Broere, Femke; Cools, Nathalie; Cuturi, Maria Cristina; Diboll, Julie; Geissler, Edward K; Giannoukakis, Nick; Gregori, Silvia; van Ham, S Marieke; Lattimer, Staci; Marshall, Lindsay; Harry, Rachel A; Hutchinson, James A; Isaacs, John D; Joosten, Irma; van Kooten, Cees; Lopez Diaz de Cerio, Ascension; Nikolic, Tatjana; Oral, Haluk Barbaros; Sofronic-Milosavljevic, Ljiljana; Ritter, Thomas; Riquelme, Paloma; Thomson, Angus W; Trucco, Massimo; Vives-Pi, Marta; Martinez-Caceres, Eva M; Hilkens, Catharien M U

    2016-01-01

    Cellular therapies with tolerogenic antigen-presenting cells (tolAPC) show great promise for the treatment of autoimmune diseases and for the prevention of destructive immune responses after transplantation. The methodologies for generating tolAPC vary greatly between different laboratories, making it difficult to compare data from different studies; thus constituting a major hurdle for the development of standardised tolAPC therapeutic products. Here we describe an initiative by members of the tolAPC field to generate a minimum information model for tolAPC (MITAP), providing a reporting framework that will make differences and similarities between tolAPC products transparent. In this way, MITAP constitutes a first but important step towards the production of standardised and reproducible tolAPC for clinical application. PMID:27635311

  2. Minimum information about tolerogenic antigen-presenting cells (MITAP): a first step towards reproducibility and standardisation of cellular therapies

    Science.gov (United States)

    Spiering, Rachel; Aguillon, Juan C.; Anderson, Amy E.; Appel, Silke; Benitez-Ribas, Daniel; ten Brinke, Anja; Broere, Femke; Cools, Nathalie; Cuturi, Maria Cristina; Diboll, Julie; Geissler, Edward K.; Giannoukakis, Nick; Gregori, Silvia; van Ham, S. Marieke; Lattimer, Staci; Marshall, Lindsay; Harry, Rachel A.; Hutchinson, James A.; Isaacs, John D.; Joosten, Irma; van Kooten, Cees; Lopez Diaz de Cerio, Ascension; Nikolic, Tatjana; Oral, Haluk Barbaros; Sofronic-Milosavljevic, Ljiljana; Ritter, Thomas; Riquelme, Paloma; Thomson, Angus W.; Trucco, Massimo; Vives-Pi, Marta; Martinez-Caceres, Eva M.

    2016-01-01

    Cellular therapies with tolerogenic antigen-presenting cells (tolAPC) show great promise for the treatment of autoimmune diseases and for the prevention of destructive immune responses after transplantation. The methodologies for generating tolAPC vary greatly between different laboratories, making it difficult to compare data from different studies; thus constituting a major hurdle for the development of standardised tolAPC therapeutic products. Here we describe an initiative by members of the tolAPC field to generate a minimum information model for tolAPC (MITAP), providing a reporting framework that will make differences and similarities between tolAPC products transparent. In this way, MITAP constitutes a first but important step towards the production of standardised and reproducible tolAPC for clinical application. PMID:27635311

  3. 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

  4. CD80 and CD86 Differentially Regulate Mechanical Interactions of T-Cells with Antigen-Presenting Dendritic Cells and B-Cells

    OpenAIRE

    Tong Seng Lim; James Kang Hao Goh; Alessandra Mortellaro; Chwee Teck Lim; Hämmerling, Günter J.; Paola Ricciardi-Castagnoli

    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 ...

  5. Antigen presentation by small intestinal epithelial cells uniquely enhances IFN-γ secretion from CD4+ intestinal intraepithelial lymphocytes

    International Nuclear Information System (INIS)

    Highlights: •Small intestinal epithelial cells (sIECs). •sIECs are able to induce antigen specific proliferation of CD4+ IELs. •sIECs induce markedly enhanced IFN-γ secretion by CD4+ IELs. •Induction of enhanced IFN-γ secretion by sIECs is uniquely observed in CD4+ 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+ 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+ LPLs and primed splenic CD4+ T cells was observed when stimulated with sIECs. Taken together, these results suggest that sIECs uniquely activate CD4+ IELs and induce remarkable IFN-γ secretion upon antigenic stimulation in vivo

  6. Self-Antigen Presentation by Keratinocytes in the Inflamed Adult Skin Modulates T-Cell Auto-Reactivity.

    Science.gov (United States)

    Meister, Michael; Tounsi, Amel; Gaffal, Evelyn; Bald, Tobias; Papatriantafyllou, Maria; Ludwig, Julia; Pougialis, Georg; Bestvater, Felix; Klotz, Luisa; Moldenhauer, Gerhard; Tüting, Thomas; Hämmerling, Günter J; Arnold, Bernd; Oelert, Thilo

    2015-08-01

    Keratinocytes have a pivotal role in the regulation of immune responses, but the impact of antigen presentation by these cells is still poorly understood, particularly in a situation where the antigen will be presented only in adult life. Here, we generated a transgenic mouse model in which keratinocytes exclusively present a myelin basic protein (MBP) peptide covalently linked to the major histocompatibility complex class II β-chain, solely under inflammatory conditions. In these mice, inflammation caused by epicutaneous contact sensitizer treatment resulted in keratinocyte-mediated expansion of MBP-specific CD4(+) T cells in the skin. Moreover, repeated contact sensitizer application preceding a systemic MBP immunization reduced the reactivity of the respective CD4(+) T cells and lowered the symptoms of the resulting experimental autoimmune encephalomyelitis. This downregulation was CD4(+) T-cell-mediated and dependent on the presence of the immune modulator Dickkopf-3. Thus, presentation of a neo self-antigen by keratinocytes in the inflamed, adult skin can modulate CD4(+) T-cell auto-aggression at a distal organ. PMID:25835957

  7. 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.

  8. 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.

  9. Neonatal colonisation expands a specific intestinal antigen-presenting cell subset prior to CD4 T-cell expansion, without altering T-cell repertoire.

    Directory of Open Access Journals (Sweden)

    Charlotte F Inman

    Full Text Available Interactions between the early-life colonising intestinal microbiota and the developing immune system are critical in determining the nature of immune responses in later life. Studies in neonatal animals in which this interaction can be examined are central to understanding the mechanisms by which the microbiota impacts on immune development and to developing therapies based on manipulation of the microbiome. The inbred piglet model represents a system that is comparable to human neonates and allows for control of the impact of maternal factors. Here we show that colonisation with a defined microbiota produces expansion of mucosal plasma cells and of T-lymphocytes without altering the repertoire of alpha beta T-cells in the intestine. Importantly, this is preceded by microbially-induced expansion of a signal regulatory protein α-positive (SIRPα(+ antigen-presenting cell subset, whilst SIRPα(-CD11R1(+ antigen-presenting cells (APCs are unaffected by colonisation. The central role of intestinal APCs in the induction and maintenance of mucosal immunity implicates SIRPα(+ antigen-presenting cells as orchestrators of early-life mucosal immune development.

  10. Peptide-beta2-microglobulin-major histocompatibility complex expressing cells are potent antigen-presenting cells that can generate specific T cells.

    Science.gov (United States)

    Obermann, Sonja; Petrykowska, Susanne; Manns, Michael P; Korangy, Firouzeh; Greten, Tim F

    2007-09-01

    Adoptive T-cell therapy represents a promising therapeutic approach for the treatment of cancer. Successful adoptive immunotherapy depends on the ex vivo priming and expansion of antigen-specific T cells. However, the in vitro generation of adequate numbers of functional antigen-specific T cell remains a major obstacle. It is important to develop efficient and reproducible methods to generate high numbers of antigen-specific T cells for adoptive T-cell transfer. We have developed a new artificial antigen-presenting cell (aAPC) by transfection of major histocompatibility (MHC) class I negative Daudi cells with a peptide-beta2-microglobulin-MHC fusion construct (single-chain aAPC) ensuring presentation of the peptide-MHC complex of interest. Using this artificial antigen-presenting cell, we could generate up to 9.2 x 10(8) antigen-specific cytotoxic CD8(+) T cells from 10 ml blood. In vitro generated T cells lysed endogenously presented antigens. Direct comparison of the single-chain aAPC with autologous monocyte-derived dendritic cells demonstrated that these cells were equally efficient in stimulation of T cells. Finally, we were able to generate antigen-specific T cell lines from perpheral blood mononuclear cells of patients receiving cytotoxic chemotherapy. The use of single-chain aAPC represent a promising option for the generation of antigen-specific CD8(+) T cells, which could be used for adoptive T-cell therapy.

  11. Peptide-β2-microglobulin-major histocompatibility complex expressing cells are potent antigen-presenting cells that can generate specific T cells

    Science.gov (United States)

    Obermann, Sonja; Petrykowska, Susanne; Manns, Michael P; Korangy, Firouzeh; Greten, Tim F

    2007-01-01

    Adoptive T-cell therapy represents a promising therapeutic approach for the treatment of cancer. Successful adoptive immunotherapy depends on the ex vivo priming and expansion of antigen-specific T cells. However, the in vitro generation of adequate numbers of functional antigen-specific T cell remains a major obstacle. It is important to develop efficient and reproducible methods to generate high numbers of antigen-specific T cells for adoptive T-cell transfer. We have developed a new artificial antigen-presenting cell (aAPC) by transfection of major histocompatibility (MHC) class I negative Daudi cells with a peptide-β2-microglobulin–MHC fusion construct (single-chain aAPC) ensuring presentation of the peptide–MHC complex of interest. Using this artificial antigen-presenting cell, we could generate up to 9·2 × 108 antigen-specific cytotoxic CD8+ T cells from 10 ml blood. In vitro generated T cells lysed endogenously presented antigens. Direct comparison of the single-chain aAPC with autologous monocyte-derived dendritic cells demonstrated that these cells were equally efficient in stimulation of T cells. Finally, we were able to generate antigen-specific T cell lines from perpheral blood mononuclear cells of patients receiving cytotoxic chemotherapy. The use of single-chain aAPC represent a promising option for the generation of antigen-specific CD8+ T cells, which could be used for adoptive T-cell therapy. PMID:17472719

  12. Gene Related to Anergy in Lymphocytes (GRAIL) Expression in CD4+ T Cells Impairs Actin Cytoskeletal Organization during T Cell/Antigen-presenting Cell Interactions*

    OpenAIRE

    Schartner, Jill M.; Simonson, William T; Wernimont, Sarah A.; Nettenstrom, Lauren M.; Huttenlocher, Anna; Seroogy, Christine M.

    2009-01-01

    GRAIL (gene related to anergy in lymphocytes), is an E3 ubiquitin ligase with increased expression in anergic CD4+ T cells. The expression of GRAIL has been shown to be both necessary and sufficient for the induction of T cell (T) anergy. To date, several subsets of anergic T cells have demonstrated altered interactions with antigen-presenting cells (APC) and perturbed TCR-mediated signaling. The role of GRAIL in mediating these aspects of T cell anergy remains unclear. We used flow cytometry...

  13. Establishment and Characterization of a Cell Based Artificial Antigen-Presenting Cell for Expansion and Activation of CD8+ T Cells Ex Vivo

    Institute of Scientific and Technical Information of China (English)

    Weijuan Gong; Mingchun Ji; Zhengfeng Cao; Liheng Wang; Yayun Qian; Maozhi Hu; Li Qian; Xingyuan Pan

    2008-01-01

    Atificial antigen-presenting cells are expected to stimulate the expansion and acquisition of optimal therapeutic features of T cells before infusion. Here CD32 that binds to a crystallizable fragment of IgG monoclonal antibody was genetically expressed on human K562 leukemia cells to provide a ligand for T-cell receptor. CD86 and 4-1BBL, which are ligands of CO. stimulating receptors of CD28 and 4-1BB. respectively, were also expressed on K562 cells. Then we accomplished the artificial antigen-presenting cells by coupling K32, CD86/4-IBBL cell with OKT3 monoclonal antibody against CD3.named K32/CD86/4-lBBL/OKT3 cells. These artificial modified cells had the abilities of inducing CD8+ T cell activation. promoting CD8+ T cell proliferation, division, and long-term growth, inhibiting CD8+ T cell apoptosis, and enhancing CD8+ T cell secretion of IFN-Y and perforin. Furthermore, antigen. secific cytotoxic T lymphocytes could be retained in the culture stimulated with K32/CD86/4-1BBL/OKT3 cells at least within 28 day This approach was robust, simple, reproducible and economical for expansion and activation of CD8+ T cells and may have important therapeutic implications for adoptive immunotherapy. Cellular & Molecular Immunology.2007;5(1):47-53.

  14. Rationally designed inhibitor targeting antigen-trimming aminopeptidases enhances antigen presentation and cytotoxic T-cell responses.

    Science.gov (United States)

    Zervoudi, Efthalia; Saridakis, Emmanuel; Birtley, James R; Seregin, Sergey S; Reeves, Emma; Kokkala, Paraskevi; Aldhamen, Yasser A; Amalfitano, Andrea; Mavridis, Irene M; James, Edward; Georgiadis, Dimitris; Stratikos, Efstratios

    2013-12-01

    Intracellular aminopeptidases endoplasmic reticulum aminopeptidases 1 and 2 (ERAP1 and ERAP2), and as well as insulin-regulated aminopeptidase (IRAP) process antigenic epitope precursors for loading onto MHC class I molecules and regulate the adaptive immune response. Their activity greatly affects the antigenic peptide repertoire presented to cytotoxic T lymphocytes and as a result can regulate cytotoxic cellular responses contributing to autoimmunity or immune evasion by viruses and cancer cells. Therefore, pharmacological regulation of their activity is a promising avenue for modulating the adaptive immune response with possible applications in controlling autoimmunity, in boosting immune responses to pathogens, and in cancer immunotherapy. In this study we exploited recent structural and biochemical analysis of ERAP1 and ERAP2 to design and develop phosphinic pseudopeptide transition state analogs that can inhibit this family of enzymes with nM affinity. X-ray crystallographic analysis of one such inhibitor in complex with ERAP2 validated our design, revealing a canonical mode of binding in the active site of the enzyme, and highlighted the importance of the S2' pocket for achieving inhibitor potency. Antigen processing and presentation assays in HeLa and murine colon carcinoma (CT26) cells showed that these inhibitors induce increased cell-surface antigen presentation of transfected and endogenous antigens and enhance cytotoxic T-cell responses, indicating that these enzymes primarily destroy epitopes in those systems. This class of inhibitors constitutes a promising tool for controlling the cellular adaptive immune response in humans by modulating the antigen processing and presentation pathway. PMID:24248368

  15. 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

  16. Aedes aegypti saliva alters leukocyte recruitment and cytokine signaling by antigen-presenting cells during West Nile virus infection.

    Directory of Open Access Journals (Sweden)

    Bradley S Schneider

    Full Text Available West Nile virus (WNV is transmitted during mosquito bloodfeeding. Consequently, the first vertebrate cells to contact WNV are cells in the skin, followed by those in the draining lymph node. Macrophages and dendritic cells are critical early responders in host defense against WNV infection, not just because of their role in orchestrating the immune response, but also because of their importance as sites of early peripheral viral replication. Antigen-presenting cell (APC signals have a profound effect on host antiviral responses and disease severity. During transmission, WNV is intimately associated with mosquito saliva. Due to the ability of mosquito saliva to affect inflammation and immune responses, and the importance of understanding early events in WNV infection, we investigated whether mosquito saliva alters APC signaling during arbovirus infection, and if alterations in cell recruitment occur when WNV infection is initiated with mosquito saliva. Accordingly, experiments were performed with cultured dendritic cells and macrophages, flow cytometry was used to characterize infiltrating cell types in the skin and lymph nodes during early infection, and real-time RT-PCR was employed to evaluate virus and cytokine levels. Our in vitro results suggest that mosquito saliva significantly decreases the expression of interferon-beta and inducible nitric oxide synthase in macrophages (by as much as 50 and 70%, respectively, whilst transiently enhancing interleukin-10 (IL-10 expression. In vivo results indicate that the predominate effect of mosquito feeding is to significantly reduce the recruitment of T cells, leading the inoculation site of mice exposed to WNV alone to have up to 2.8 fold more t cells as mice infected in the presence of mosquito saliva. These shifts in cell population are associated with significantly elevated IL-10 and WNV (up to 4.0 and 10 fold, respectively in the skin and draining lymph nodes. These results suggest that mosquito

  17. Human parvovirus B19 induced apoptotic bodies contain altered self-antigens that are phagocytosed by antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Kanoktip Thammasri

    Full Text Available Human parvovirus B19 (B19V from the erythrovirus genus is known to be a pathogenic virus in humans. Prevalence of B19V infection has been reported worldwide in all seasons, with a high incidence in the spring. B19V is responsible for erythema infectiosum (fifth disease commonly seen in children. Its other clinical presentations include arthralgia, arthritis, transient aplastic crisis, chronic anemia, congenital anemia, and hydrops fetalis. In addition, B19V infection has been reported to trigger autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. However, the mechanisms of B19V participation in autoimmunity are not fully understood. B19V induced chronic disease and persistent infection suggests B19V can serve as a model for viral host interactions and the role of viruses in the pathogenesis of autoimmune diseases. Here we investigate the involvement of B19V in the breakdown of immune tolerance. Previously, we demonstrated that the non-structural protein 1 (NS 1 of B19V induces apoptosis in non-permissive cells lines and that this protein can cleave host DNA as well as form NS1-DNA adducts. Here we provide evidence that through programmed cell death, apoptotic bodies (ApoBods are generated by B19V NS1 expression in a non-permissive cell line. Characterization of purified ApoBods identified potential self-antigens within them. In particular, signature self-antigens such as Smith, ApoH, DNA, histone H4 and phosphatidylserine associated with autoimmunity were present in these ApoBods. In addition, when purified ApoBods were introduced to differentiated macrophages, recognition, engulfment and uptake occurred. This suggests that B19V can produce a source of self-antigens for immune cell processing. The results support our hypothesis that B19V NS1-DNA adducts, and nucleosomal and lysosomal antigens present in ApoBods created in non-permissive cell lines, are a source of self-antigens.

  18. Epigenetic regulations in the IFNγ signalling pathway: IFNγ-mediated MHC class I upregulation on tumour cells is associated with DNA demethylation of antigen-presenting machinery genes.

    Science.gov (United States)

    Vlková, Veronika; Štěpánek, Ivan; Hrušková, Veronika; Šenigl, Filip; Mayerová, Veronika; Šrámek, Martin; Šímová, Jana; Bieblová, Jana; Indrová, Marie; Hejhal, Tomáš; Dérian, Nicolas; Klatzmann, David; Six, Adrien; Reiniš, Milan

    2014-08-30

    Downregulation of MHC class I expression on tumour cells, a common mechanism by which tumour cells can escape from specific immune responses, can be associated with coordinated silencing of antigen-presenting machinery genes. The expression of these genes can be restored by IFNγ. In this study we documented association of DNA demethylation of selected antigen-presenting machinery genes located in the MHC genomic locus (TAP-1, TAP-2, LMP-2, LMP-7) upon IFNγ treatment with MHC class I upregulation on tumour cells in several MHC class I-deficient murine tumour cell lines (TC-1/A9, TRAMP-C2, MK16 and MC15). Our data also documented higher methylation levels in these genes in TC-1/A9 cells, as compared to their parental MHC class I-positive TC-1 cells. IFNγ-mediated DNA demethylation was relatively fast in comparison with demethylation induced by DNA methyltransferase inhibitor 5-azacytidine, and associated with increased histone H3 acetylation in the promoter regions of APM genes. Comparative transcriptome analysis in distinct MHC class I-deficient cell lines upon their treatment with either IFNγ or epigenetic agents revealed that a set of genes, significantly enriched for the antigen presentation pathway, was regulated in the same manner. Our data demonstrate that IFNγ acts as an epigenetic modifier when upregulating the expression of antigen-presenting machinery genes.

  19. Artificial antigen-presenting cells plus IL-15 and IL-21 efficiently induce melanoma-specific cytotoxic CD8+CD28+ T lymphocyte responses

    Institute of Scientific and Technical Information of China (English)

    Xia Yu; Yuan Fang; Xi Li; Nuo Zhou; Yong-Xiang Zhao; Xiao-Ling Lu; Jian He; Sodaly Mongkhoune; Yi Peng; Yuan Xie; Jing Su; Su-Fang Zhou; Xiao-Xun Xie; Guo-Rong Luo

    2013-01-01

    To develop a novel artificial antigen-presenting system for efficiently inducing melanoma-specific CD8+CD28+ cytotoxic T lymphocyte (CTL) responses. Methods: Cell-sized Dynabeads® M-450 Epoxy beads coated with H-2Kb:Ig-TRP2180-188 and anti-CD28 antibody were used as artificial antigen-presenting cells (aAPCs) to induce melanoma-specific CD8+CD28+CTL responses with the help of IL-21 and IL-15. Dimer staining, proliferation, ELISPOT, and cytotoxicity experiments were conducted to evaluate the frequency and activity of induced CTLs. Results: Dimer staining demonstrated that the new artificial antigen-presenting system efficiently induced melanoma TRP2-specific CD8+CD28+ CTLs. Proliferation and ELISPOT assays indicated that the induced CTLs rapidly proliferate and produce increased IFN-γ under the stimulation of H-2Kb:Ig-TRP2-aAPCs, IL-15, and IL-21. In addition, cytotoxicity experiments showed that induced CTLs have specific killing activity of target cells. Conclusions: The new artificial antigen-presenting system including aAPCs plus IL-21 and IL-15 can induce a large number of antigen-specific CD8+CD28+ CTLs against the melanoma. Our study provides evidence for a novel adoptive immunotherapy against tumors.

  20. Analysis of detergent-free lipid rafts isolated from CD4+ T cell line: interaction with antigen presenting cells promotes coalescing of lipid rafts

    Directory of Open Access Journals (Sweden)

    Kennedy Colleen

    2011-12-01

    Full Text Available Abstract Background Lipid rafts present on the plasma membrane play an important role in spatiotemporal regulation of cell signaling. Physical and chemical characterization of lipid raft size and assessment of their composition before, and after cell stimulation will aid in developing a clear understanding of their regulatory role in cell signaling. We have used visual and biochemical methods and approaches for examining individual and lipid raft sub-populations isolated from a mouse CD4+ T cell line in the absence of detergents. Results Detergent-free rafts were analyzed before and after their interaction with antigen presenting cells. We provide evidence that the average diameter of lipid rafts isolated from un-stimulated T cells, in the absence of detergents, is less than 100 nm. Lipid rafts on CD4+ T cell membranes coalesce to form larger structures, after interacting with antigen presenting cells even in the absence of a foreign antigen. Conclusions Findings presented here indicate that lipid raft coalescence occurs during cellular interactions prior to sensing a foreign antigen.

  1. 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.

  2. Transfection of B7-1 cDNA empowers antigen presentation of blood malignant cells for activation of anti-tumor T cells

    Institute of Scientific and Technical Information of China (English)

    克晓燕; 贾丽萍; 王晶; 王德炳

    2003-01-01

    Objective To define roles of B7-1 co-stimulation factor expressed in human malignant cell lines in mediating anti-tumor T cell immune responses. Methods Examining human leucocyte antigen (HLA) and B7 expressions on 8 human blood malignancies cell lines by flow cytometry. Transfecting B7-1 gene to B7-1 negative (B7*!-) Raji and B7*!- Jurkat cell lines by liposome, and comparing the potencies of blood malignant cell lines in the induction of T cell activation by examination of T cell cytokine mRNAs before and after transfection using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). Results High level of HLA Ⅰ and Ⅱ molecules were expressed in most human blood malignant cell lines examined, and the co-stimulatory factor B7-2 was also highly expressed. In contrast, another member of B7 family: B7-1 was either not expressed or very limitedly expressed in most of these hematopoietic malignant cell lines. Most importantly, transfection of B7-1 gene to B7*!-. Raji and B7*!-. Jurkat cell lines made these cell lines better antigen presenting cells for stimulation of anti-tumor T cell activation, which was demonstrated by up regulation of expression of T cell cytokines IL-2, IL-4 and INF-γ mRNAs after incubation of these tumor cells with T cells for 24 h. Conclusions B7 co-stimulation plays an important role in anti-tumor immunity. Transfection of B7-1 gene to the human hematopoietic malignant cell lines that are deficient in the B7-1 expression empowers their antigen presentation potency for activation of anti-tumor T cells. Our results suggested that repairing the deficiency of B7-1 co-stimulatory pathway in tumor cells might be a novel immunotherapeutic approach for human hematopoietic malignancies.

  3. Antigen presenting B cells facilitate CD4 T cell cooperation resulting in enhanced generation of effector and memory CD4 T cells.

    Directory of Open Access Journals (Sweden)

    David R Kroeger

    Full Text Available We show that the in vivo generation of cytokine-producing CD4 T cells specific for a given major histocompatibility class-II (MHCII-binding peptide of hen egg lysozyme (HEL is facilitated when mice are immunized with splenic antigen presenting cells (APC pulsed with this HEL peptide and another peptide that binds a different MHCII molecule. This enhanced generation of peptide-specific effector CD4 T cells requires that the same splenic APC be pulsed with both peptides. Pulsed B cells, but not pulsed dendritic cells (DCs, can mediate CD4 T cell cooperation, which can be blocked by disrupting OX40-OX40L (CD134-CD252 interactions. In addition, the generation of HEL peptide-specific CD4 T cell memory is greater when mice are primed with B cells pulsed with the two peptides than with B cells pulsed with the HEL- peptide alone. Based on our findings, we suggest CD4 T cell cooperation is important for vaccine design, underlies the phenomenon of "epitope-spreading" seen in autoimmunity, and that the efficacy of B cell-depletion in the treatment of human cell-mediated autoimmune disease is due to the abrogation of the interactions between autoimmune CD4 T cells that facilitates their activation.

  4. CD80 and CD86 differentially regulate mechanical interactions of T-cells with antigen-presenting dendritic cells and B-cells.

    Directory of Open Access Journals (Sweden)

    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.

  5. 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.

  6. 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. PMID:23024807

  7. Human antigen-presenting cells respond differently to gut-derived probiotic bacteria but mediate similar strain-dependent NK and T cell activation

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen; Zeuthen, Louise Hjerrild; Ferlazzo, Guido;

    2007-01-01

    (APC) was compared; blood myeloid dendritic cells (DC), monocyte-derived DC and monocytes, and the effector response of natural killer cells and naïve T cells was characterized. Maturation induced by gut-derived bacteria differed between APC, with blood DC and monocytes responding with the production...... of IL-6 and tumour necrosis factor-alpha to bacteria, which elicited mainly IL-10 in monocyte-derived DC. In contrast, comparable IFN-gamma production patterns were found in both natural killer cells and T cells induced by all bacteria-matured APC. An inhibitory effect of certain strains on this IFN......, in vitro assessment of the immunomodulatory effects of distinct strains may depend strongly on the cell type used as a model. To select the most appropriate model for screening of beneficial bacteria in human cells, the response to strains of intestinal bacteria of three types of antigen-presenting cells...

  8. Autophagy and ATP-induced anti-apoptosis in antigen presenting cells (APC) follows the cytokine storm in patients after major trauma

    OpenAIRE

    Schneider, E Marion; Flacke, Sarah; Liu, Fengguang; Lorenz, Myriam R.; Schilling, Patricia; Nass, Max E.; Foehr, Karl J.; Huber-Lang, Markus; Weiss, Manfred E.

    2011-01-01

    Severe trauma and the systemic inflammatory response syndrome (SIRS) occur as a result of a cytokine storm which is in part due to ATP released from damaged tissue. This pathology also leads to increased numbers of immature antigen presenting cells (APC) sharing properties of dendritic cells (DC) or macrophages (MΦ). The occurrence of immature APC appears to coincide with the reactivation of herpes virus infections such as Epstein Barr virus (EBV). The aim of this study was the comparative an...

  9. Availability of 25-hydroxyvitamin D3 to antigen presenting cells controls the balance between regulatory and inflammatory T cell responses

    OpenAIRE

    Jeffery, Louisa E.; Wood, Alice M; Qureshi, Omar S.; Hou, Tie Zheng; Gardner, David; Briggs, Zoe; Kaur, Satdip; Raza, Karim; Sansom, David M

    2012-01-01

    1,25-dihydroxyvitamin D3 (1,25(OH)2D3), the active form of vitamin D, exerts potent effects on several tissues including cells of the immune system, where it affects T cell activation, differentiation and migration. The circulating, inactive form of vitamin D, 25(OH)D3, is generally used as an indication of “vitamin D status”. However, utilization of this precursor depends on its uptake by cells and subsequent conversion by the enzyme 25(OH)D3-1α-hydroxylase (CYP27B1) into active 1,25(OH)2D3....

  10. Ubiquitination by March-I prevents MHC class II recycling and promotes MHC class II turnover in antigen-presenting cells.

    Science.gov (United States)

    Cho, Kyung-Jin; Walseng, Even; Ishido, Satoshi; Roche, Paul A

    2015-08-18

    MHC class II (MHC-II)-dependent antigen presentation by antigen-presenting cells (APCs) is carefully controlled to achieve specificity of immune responses; the regulated assembly and degradation of antigenic peptide-MHC-II complexes (pMHC-II) is one aspect of such control. In this study, we have examined the role of ubiquitination in regulating pMHC-II biosynthesis, endocytosis, recycling, and turnover in APCs. By using APCs obtained from MHC-II ubiquitination mutant mice, we find that whereas ubiquitination does not affect pMHC-II formation in dendritic cells (DCs), it does promote the subsequent degradation of newly synthesized pMHC-II. Acute activation of DCs or B cells terminates expression of the MHC-II E3 ubiquitin ligase March-I and prevents pMHC-II ubiquitination. Most importantly, this change results in very efficient pMHC-II recycling from the surface of DCs and B cells, thereby preventing targeting of internalized pMHC-II to lysosomes for degradation. Biochemical and functional assays confirmed that pMHC-II turnover is suppressed in MHC-II ubiquitin mutant DCs or by acute activation of wild-type DCs. These studies demonstrate that acute APC activation blocks the ubiquitin-dependent turnover of pMHC-II by promoting efficient pMHC-II recycling and preventing lysosomal targeting of internalized pMHC-II, thereby enhancing pMHC-II stability for efficient antigen presentation to CD4 T cells.

  11. 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.

  12. Intracellular transport of MHC class II and associated invariant chain in antigen presenting cells from AP-3-deficient mocha mice.

    Science.gov (United States)

    Sevilla, L M; Richter, S S; Miller, J

    2001-06-15

    MHC class II-restricted antigen presentation requires trafficking of newly synthesized class II-invariant chain complexes from the trans-Golgi network to endosomal, peptide-loading compartments. This transport is mediated by dileucine-like motifs within the cytosolic tail of the invariant chain. Although these signals have been well characterized, the cytosolic proteins that interact with these dileucine signals and mediate Golgi sorting and endosomal transport have not been identified. Recently, an adaptor complex, AP-3, has been identified that interacts with dileucine motifs and mediates endosomal/lysosomal transport in yeast, Drosophila, and mammals. In this report, we have assessed class II-invariant chain trafficking in a strain of mice (mocha) which lacks expression of AP-3. Our studies demonstrate that the lack of AP-3 does not affect the kinetics of invariant chain degradation, the route of class II-invariant chain transport, or the rate and extent of class II-peptide binding as assessed by the generation of SDS-stable dimers. The possible role of other known or unknown adaptor complexes in class II-invariant chain transport is discussed. PMID:11520080

  13. Distinct Gut-Derived Bacteria Differentially Affect Three Types of Antigen-Presenting Cells and Impact on NK- and T-Cell Responses

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen; Hansen, Anne Marie Valentin; Frøkiær, Hanne

    Objectives Gut bacteria are assumed essential for development and maintenance of a balanced immune system. Specifically, stimulation of antigen-presenting cells (APCs) by gut bacteria is important for polarisation of the immune response. This experiment was designed to reveal similarities...... from monocytes. Monocyte-derived dendritic cells constitute a commonly used model of dendritic cell function. The APCs were cultured for 18 h with four different gut bacteria: Lactobacillus acidophilus X37, Lactobacillus reuteri DSM 12246, E. coli Nissle 1917 or Bifidobacterium longum Q46. Results...... & Discussion To examine the polarising effect of gut bacteria on APCs, surface markers and cytokines were measured. The co-stimulatory molecules CD40 and CD86 were induced to a different extent together with CD83. Interleukin-12 (a Th1 cytokine) was only induced by Lactobacillus acidophilus. Interleukin-10...

  14. Effects of low dose X-ray irradiation on antigen presentation and IL-12 secretion in human dendritic cells in vitro

    International Nuclear Information System (INIS)

    Objective: To explore the effects of low dose X-ray irradiation on the ability of antigen presentation and IL-12 secretion in human dendritic cells that had been cultured for different time in vitro. Methods: The human peripheral blood mononuclear cells (PBMC) were collected and differentiated to dendritic cells (DCs) by rhGM-CSF and rhIL-4 treatment in vitro. The DCs were divided into 3 groups, group A: DCs were cultured for 2 d and then irradiated with 0.05, 0.1, 0.2 and 0.5 Gy X-rays; group B: DCs were cultured for 6 d and then irradiated as above; group C:DCs were cultured without irradiation.At 8 d of cell culture, the DCs were applied to activate T cells and CCK-8 was used to detect MLR (mixed lymphocyte reaction), and the antigen presentation ability of DCs was evaluated. MTT assay was also used to test the cell-killing effect of the activated T-cells on A549 cells. IL-12 in the culture medium of DCs was detected by ELISA. Results: After irradiation with 0.2 and 0.5 Gy X-rays, the antigen presentation ability of DCs was decreased in group A (t=2.79 and 3.71, P<0.05), but significantly increased in group B (t=3.60 and 3.11, P<0.05). The ability of the T cell activation was detected and the proliferation of A549 cells was slightly inhibited by the DCs in group A (t=2.89 and 2.91, P<0.05), but was obviously inhibited by the DCs in group B (t=2.91 and 2.82, P<0.05). Meanwhile,the level of IL-12 was dramatically decreased in group A (t=4.44 and 6.93, P<0.05), but was increased in group B (t=3.51 and 4.12, P<0.05). Conclusions: The abilities of antigen presentation and proliferation inhibition of DCs could be down-regulated by low dose (<0.5 Gy) of X-ray irradiation at the early stage of DCs, but was up-regulated at the late stage of DCs culture. (authors)

  15. Human antigen-presenting cells respond differently to gut-derived probiotic bacteria but mediate similar strain-dependent NK and T cell activation.

    Science.gov (United States)

    Fink, Lisbeth N; Zeuthen, Louise H; Ferlazzo, Guido; Frøkiaer, Hanne

    2007-12-01

    The intestinal microbiota is essential for homeostasis of the local and systemic immune system, and particularly strains of lactic acid bacteria and Escherichia coli have been shown to have balancing effects on inflammatory conditions such as allergy and inflammatory bowel disease. However, in vitro assessment of the immunomodulatory effects of distinct strains may depend strongly on the cell type used as a model. To select the most appropriate model for screening of beneficial bacteria in human cells, the response to strains of intestinal bacteria of three types of antigen-presenting cells (APC) was compared; blood myeloid dendritic cells (DC), monocyte-derived DC and monocytes, and the effector response of natural killer cells and naïve T cells was characterized. Maturation induced by gut-derived bacteria differed between APC, with blood DC and monocytes responding with the production of IL-6 and tumour necrosis factor-alpha to bacteria, which elicited mainly IL-10 in monocyte-derived DC. In contrast, comparable IFN-gamma production patterns were found in both natural killer cells and T cells induced by all bacteria-matured APC. An inhibitory effect of certain strains on this IFN-gamma production was also mediated by all types of APC. The most potent responses were induced by monocyte-derived DC, which thus constitute a sensitive screening model. PMID:17903206

  16. 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.

  17. Tunable chemokine production by antigen presenting dendritic cells in response to changes in regulatory T cell frequency in mouse reactive lymph nodes.

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    Valentina Dal Secco

    Full Text Available BACKGROUND: Although evidence exists that regulatory T cells (Tregs can suppress the effector phase of immune responses, it is clear that their major role is in suppressing T cell priming in secondary lymphoid organs. Recent experiments using two photon laser microscopy indicate that dendritic cells (DCs are central to Treg cell function and that the in vivo mechanisms of T cell regulation are more complex than those described in vitro. PRINCIPAL FINDINGS: Here we have sought to determine whether and how modulation of Treg numbers modifies the lymph node (LN microenvironment. We found that pro-inflammatory chemokines -- CCL2 (MCP-1 and CCL3 (MIP-la -- are secreted in the LN early (24 h after T cell activation, that this secretion is dependent on antigen-specific DC-T cell interactions, and that it was inversely related to the frequency of Tregs specific for the same antigen. Furthermore, we demonstrate that Tregs modify the chemoattractant properties of antigen-presenting DCs, which, as the frequency of Tregs increases, fail to produce CCL2 and CCL3 and to attract antigen-specific T cells. CONCLUSIONS: These results substantiate a major role of Tregs in LN patterning during antigen-specific immune responses.

  18. Antigen-presenting cells represent targets for R5 HIV-1 infection in the first trimester pregnancy uterine mucosa.

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    Romain Marlin

    Full Text Available BACKGROUND: During the first trimester of pregnancy, HIV-1 mother-to-child transmission is relatively rare despite the permissivity of placental cells to cell-to-cell HIV-1 infection. The placenta interacts directly with maternal uterine cells (decidual cells but the physiological role of the decidua in the control of HIV-1 transmission and whether decidua could be a source of infected cells is unknown. METHODOLOGY/PRINCIPAL FINDINGS: To answer to this question, decidual mononuclear cells were exposed to HIV-1 in vitro. Decidual cells were shown to be more susceptible to infection by an R5 HIV-1, as compared to an X4 HIV-1. Infected cells were identified by flow cytometry analysis. The results showed that CD14(+ cells were the main targets of HIV-1 infection in the decidua. These infected CD14(+ cells expressed DC-SIGN, CD11b, CD11c, the Fc gamma receptor CD16, CD32 and CD64, classical MHC class-I and class-II and maturation and activation molecules CD83, CD80 and CD86. The permissivity of decidual tissue was also evaluated by histoculture. Decidual tissue was not infected by X4 HIV-1 but was permissive to R5 HIV-1. Different profiles of infection were observed depending on tissue localization. CONCLUSIONS/SIGNIFICANCE: The presence of HIV-1 target cells in the decidua in vitro and the low rate of in utero mother-to-child transmission during the first trimester of pregnancy suggest that a natural control occurs in vivo limiting cell-to-cell infection of the placenta and consequently infection of the fetus.

  19. Rainbow trout CK9, a CCL25-like ancient chemokine that attracts and regulates B cells and macrophages, the main antigen presenting cells in fish

    Science.gov (United States)

    Aquilino, Carolina; Granja, Aitor G.; Castro, Rosario; Wang, Tiehui; Abos, Beatriz; Parra, David; Secombes, Christopher J.; Tafalla, Carolina

    2016-01-01

    CK9 is a rainbow trout (Oncorhynchus mykiss) CC chemokine phylogenetically related to mammalian CCL25. Although CK9 is known to be transcriptionally regulated in response to inflammation particularly in mucosal tissues, its functionality has never been revealed. In the current work, we have demonstrated that CK9 is chemoattractant for antigen presenting cells (APCs) expressing major histocompatibility complex class II (MHC II) on the cell surface. Among these APCs, CK9 has a strong chemotactic capacity for both B cells (IgM+ and IgT+) and macrophages. Along with its chemotactic capacities, CK9 modulated the MHC II turnover of B lymphocytes and up-regulated the phagocytic capacity of both IgM+ cells and macrophages. Although CK9 had no lymphoproliferative effects, it increased the survival of IgT+ lymphocytes. Furthermore, we have established that the chemoattractant capacity of CK9 is strongly increased after pre-incubation of leukocytes with a T-independent antigen, whereas B cell receptor (BCR) cross-linking strongly abrogated their capacity to migrate to CK9, indicating that CK9 preferentially attracts B cells at the steady state or under BCR-independent stimulation. These results point to CK9 being a key regulator of B lymphocyte trafficking in rainbow trout, able to modulate innate functions of teleost B lymphocytes and macrophages. PMID:27003360

  20. Airway eosinophils accumulate in the mediastinal lymph nodes but lack antigen-presenting potential for naive T cells

    NARCIS (Netherlands)

    L.S. van Rijt (Leonie); N. Vos (Nanda); D. Hijdra; V.C. de Vries (Victor); H.C. Hoogsteden (Henk); B.N.M. Lambrecht (Bart)

    2003-01-01

    textabstractAsthma is characterized by infiltration of the airway wall with eosinophils. Although eosinophils are considered to be effector cells, recent studies have reported their ability to activate primed Th2 cells. In this study, we investigated whether eosinophils are capable

  1. Novel CD47: SIRPα dependent mechanism for the activation of STAT3 in antigen-presenting cell.

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    Natan Toledano

    Full Text Available Cell surface CD47 interacts with its receptor, signal-regulatory-protein α (SIRPα that is expressed predominantly on macrophages, to inhibit phagocytosis of normal, healthy cells. This "don't eat me" signal is mediated through tyrosine phosphorylation of SIRPα at the cytoplasmic ITIM motifs and the recruitment of the phosphatase, SHP-1. We previously revealed a novel mechanism for the activation of the STAT3 pathway and the regulation of human APC maturation and function that is based on cell:cell interaction. In this study, we present evidence supporting the notion that CD47:SIRPα serves as a cell surface receptor: ligand pair involved in this contact-dependent STAT3 activation and regulation of APC maturation. We show that upon co-culturing APC with various primary and tumor cell lines STAT3 phosphorylation and IL-10 expression are induced, and such regulation could be suppressed by specific CD47 siRNAs and shRNAs. Significantly, >50% reduction in CD47 expression abolished the contact-dependent inhibition of T cell activation. Furthermore, co-immunoprecipitation experiments revealed a physical association between SIRPα and STAT3. Thus, we suggest that in addition to signaling through the ITIM-SHP-1 complex that transmit an anti-phagocytotic, CD47:SIRPα also triggers STAT3 signaling that is linked to an immature APC phenotype and peripheral tolerance under steady state and pathological conditions.

  2. Suppressive effects of Bifidobacterium longum on the production of Th2-attracting chemokines induced with T cell-antigen-presenting cell interactions.

    Science.gov (United States)

    Iwabuchi, Noriyuki; Takahashi, Noritoshi; Xiao, Jin-Zhong; Yonezawa, Sumiko; Yaeshima, Tomoko; Iwatsuki, Keiji; Hachimura, Satoshi

    2009-04-01

    In human trials, Bifidobacterium longum BB536 alleviates subjective symptoms of Japanese cedar pollinosis, an IgE-mediated type I allergy caused by exposure to Japanese cedar, and significantly suppresses the increase of plasma thymus- and activation-regulated chemokine (TARC) associated with pollen dispersion. In the present study, we investigated the suppressive effects of BB536 on the production of T helper type 2 (Th2)-attracting chemokines, such as TARC and macrophage-derived chemokine (MDC), together with the mechanisms of their production. Murine splenocytes were cultured with heat-killed BB536, and the levels of Th2-attracting chemokines in the supernatants were measured. TARC and MDC were produced in cultures without stimulation, and the production was significantly suppressed by BB536. These chemokines were produced by antigen-presenting cells (APCs) of splenocytes stimulated with an anti-CD40 antibody. Furthermore, TARC production was induced with granulocyte macrophage colony-stimulating factor that was produced by T cells and dendritic cells. BB536 suppressed MDC production induced with the anti-CD40 antibody by APCs from the spleen, mesenteric lymph nodes (MLNs) and Peyer's patches, and it suppressed TARC production by APCs from the spleen and MLNs. These results indicate that BB536 suppresses the production of Th2-attracting chemokines induced by the T cell-APC interaction, suggesting a novel mechanism for alleviating symptoms of allergic disorders by probiotics.

  3. ESAT-6 Targeting to DEC205+ Antigen Presenting Cells Induces Specific-T Cell Responses against ESAT-6 and Reduces Pulmonary Infection with Virulent Mycobacterium tuberculosis.

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    Aarón Silva-Sánchez

    Full Text Available Airways infection with Mycobacterium tuberculosis (Mtb is contained mostly by T cell responses, however, Mtb has developed evasion mechanisms which affect antigen presenting cell (APC maturation/recruitment delaying the onset of Ag-specific T cell responses. Hypothetically, bypassing the natural infection routes by delivering antigens directly to APCs may overcome the pathogen's naturally evolved evasion mechanisms, thus facilitating the induction of protective immune responses. We generated a murine monoclonal fusion antibody (α-DEC-ESAT to deliver Early Secretory Antigen Target (ESAT-6 directly to DEC205+ APCs and to assess its in vivo effects on protection associated responses (IFN-γ production, in vivo CTL killing, and pulmonary mycobacterial load. Treatment with α-DEC-ESAT alone induced ESAT-6-specific IFN-γ producing CD4+ T cells and prime-boost immunization prior to Mtb infection resulted in early influx (d14 post-infection and increased IFN-γ+ production by specific T cells in the lungs, compared to scarce IFN-γ production in control mice. In vivo CTL killing was quantified in relevant tissues upon transferring target cells loaded with mycobacterial antigens. During infection, α-DEC-ESAT-treated mice showed increased target cell killing in the lungs, where histology revealed cellular infiltrate and considerably reduced bacterial burden. Targeting the mycobacterial antigen ESAT-6 to DEC205+ APCs before infection expands specific T cell clones responsible for early T cell responses (IFN-γ production and CTL activity and substantially reduces lung bacterial burden. Delivering mycobacterial antigens directly to APCs provides a unique approach to study in vivo the role of APCs and specific T cell responses to assess their potential anti-mycobacterial functions.

  4. Cathepsin B in antigen-presenting cells controls mediators of the Th1 immune response during Leishmania major infection.

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    Iris J Gonzalez-Leal

    2014-09-01

    Full Text Available Resistance and susceptibility to Leishmania major infection in the murine model is determined by the capacity of the host to mount either a protective Th1 response or a Th2 response associated with disease progression. Previous reports involving the use of cysteine cathepsin inhibitors indicated that cathepsins B (Ctsb and L (Ctsl play important roles in Th1/Th2 polarization during L. major infection in both susceptible and resistant mouse strains. Although it was hypothesized that these effects are a consequence of differential patterns of antigen processing, the mechanisms underlying these differences were not further investigated. Given the pivotal roles that dendritic cells and macrophages play during Leishmania infection, we generated bone-marrow derived dendritic cells (BMDC and macrophages (BMM from Ctsb-/- and Ctsl-/- mice, and studied the effects of Ctsb and Ctsl deficiency on the survival of L. major in infected cells. Furthermore, the signals used by dendritic cells to instruct Th cell polarization were addressed: the expression of MHC class II and co-stimulatory molecules, and cytokine production. We found that Ctsb-/- BMDC express higher levels of MHC class II molecules than wild-type (WT and Ctsl-/- BMDC, while there were no significant differences in the expression of co-stimulatory molecules between cathepsin-deficient and WT cells. Moreover, both BMDC and BMM from Ctsb-/- mice significantly up-regulated the levels of interleukin 12 (IL-12 expression, a key Th1-inducing cytokine. These findings indicate that Ctsb-/- BMDC display more pro-Th1 properties than their WT and Ctsl-/- counterparts, and therefore suggest that Ctsb down-regulates the Th1 response to L. major. Moreover, they propose a novel role for Ctsb as a regulator of cytokine expression.

  5. Constitutive expression of a costimulatory ligand on antigen-presenting cells in the nervous system drives demyelinating disease

    DEFF Research Database (Denmark)

    Zehntner, Simone P; Brisebois, Marcel; Tran, Elise;

    2003-01-01

    that transgenic mice constitutively expressing the costimulatory ligand B7.2/CD86 on microglia in the central nervous system (CNS) and on related cells in the proximal peripheral nervous tissue spontaneously develop autoimmune demyelinating disease. Disease-affected nervous tissue in transgenic mice showed...

  6. Pharmacologic IKK/NF-κB inhibition causes antigen presenting cells to undergo TNFα dependent ROS-mediated programmed cell death

    Science.gov (United States)

    Tilstra, Jeremy S.; Gaddy, Daniel F.; Zhao, Jing; Davé, Shaival H.; Niedernhofer, Laura J.; Plevy, Scott E.; Robbins, Paul D.

    2014-01-01

    Monocyte-derived antigen presenting cells (APC) are central mediators of the innate and adaptive immune response in inflammatory diseases. As such, APC are appropriate targets for therapeutic intervention to ameliorate certain diseases. APC differentiation, activation and functions are regulated by the NF-κB family of transcription factors. Herein, we examined the effect of NF-κB inhibition, via suppression of the IκB Kinase (IKK) complex, on APC function. Murine bone marrow-derived macrophages and dendritic cells (DC), as well as macrophage and DC lines, underwent rapid programmed cell death (PCD) after treatment with several IKK/NF-κB inhibitors through a TNFα-dependent mechanism. PCD was induced proximally by reactive oxygen species (ROS) formation, which causes a loss of mitochondrial membrane potential and activation of a caspase signaling cascade. NF-κB-inhibition-induced PCD of APC may be a key mechanism through which therapeutic targeting of NF-κB reduces inflammatory pathologies.

  7. Identification of the major T-cell antigens present in the Brucella melitensis B115 protein preparation, Brucellergene OCB.

    Science.gov (United States)

    Denoel, P A; Vo, T K; Weynants, V E; Tibor, A; Gilson, D; Zygmunt, M S; Limet, J N; Letesson, J J

    1997-09-01

    Brucellergene is a commercial allergen prepared from Brucella melitensis strain B115 and containing at least 20 cytoplasmic proteins. These proteins were separated by SDS-PAGE. The unstained gel was divided into 18 fractions and proteins were eluted from the gel fractions. The capacity of the separated proteins to elicit delayed-type hypersensitivity (DTH) in infected guinea-pigs or to induce the production of interferon-gamma (IFN-gamma) by blood cells from infected cattle was evaluated. The biological activity of the corresponding protein fractions blotted on to nitrocellulose was measured in a lymphocyte blastogenesis assay. Among the 18 fractions tested, two-spanning the mol. wt ranges 17-22 (fraction 8) and 35-42-kDa (fraction 17)-showed the maximum biological activity in the three tests. These fractions contain two antigens, the Brucella bacterioferritin (BFR) and P39 proteins. Both proteins are good candidates for the detection of cellular immunity to Brucella. PMID:9291893

  8. Rapid detection of dendritic cell and monocyte disorders using CD4 as a lineage marker of the human peripheral blood antigen presenting cell compartment

    Directory of Open Access Journals (Sweden)

    Laura eJardine

    2013-12-01

    Full Text Available Dendritic cells (DCs and monocytes are critical regulators and effectors of innate and adaptive immune responses. Monocyte expansion has been described in many pathological states while monocyte and DC deficiency syndromes are relatively recent additions to the catalogue of human primary immunodeficiency disorders. Clinically applicable screening tests to diagnose and monitor these conditions are lacking. Conventional strategies for identifying human DCs and monocytes have been based on the use of a lineage gate to exclude lymphocytes, thus preventing simultaneous detection of DCs, monocytes and lymphocyte subsets. Here we demonstrate that CD4 is a reliable lineage marker for the human peripheral blood antigen presenting cell compartment that can be used to identify DCs and monocytes in parallel with lymphocytes. Based on this principle, simple modification of a standard lymphocyte phenotyping assay permits simultaneous enumeration of four lymphocyte and five DC/monocyte populations from a single sample. This approach is applicable to clinical samples and facilitates the diagnosis of DC and monocyte disorders in a wide range of clinical settings, including genetic deficiency, neoplasia and inflammation.

  9. Tumor Destruction and In Situ Delivery of Antigen Presenting Cells Promote Anti-Neoplastic Immune Responses: Implications for the Immunotherapy of Pancreatic Cancer

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    Manfredi AA

    2004-07-01

    Full Text Available Antigen presenting cells (APCs activate helper and cytotoxic T cells specific for antigens expressed by tissue cells, including neoplastic cells. This event occurs after the antigen transfer from tissue cells to APC, and is referred to as "cross-presentation". The number and the state of activation of APC in the tumor control the outcome of cross-presentation, including the establishment of protective immune responses. Cell death favors cross-presentation. Cancer cells normally die, either spontaneously or as a consequence of targeted therapies. The transfer of tumor antigens from dying tumor cells to APCs in vivo, exploiting the cross-presentation pathway, has the potential of yielding novel immunotherapeutic strategies. Their success will depend on at least two factors: the induction of synchronized cell death in the tumor, and the recruitment of activated dendritic cells in the tumor. Under normal conditions, pancreatic cancer represents a privileged environment; its profound chemoresistance reflects limited apoptosis after chemotherapy. Moreover, it usually contains only a few cells endowed with APC function. Endoscopic ultrasonography offers attractive possibilities of circumventing this privilege, including the delivery of ultrasound, radiofrequency or radiation in order to destroy the tumor and the delivery in situ of autologous APC or appropriate chemotactic signals. In general, loco-regional approaches offer the possibility of using the tumor of each patient as a complex antigen source, thus limiting the risk of tumor escape and reducing the need for extensive ex vivo handling of the neoplasm and of the patient APCs.

  10. Mitomycin C-treated antigen-presenting cells as a tool for control of allograft rejection and autoimmunity: from bench to bedside.

    Science.gov (United States)

    Terness, Peter; Kleist, Christian; Simon, Helmut; Sandra-Petrescu, Flavius; Ehser, Sandra; Chuang, Jing-Jing; Mohr, Elisabeth; Jiga, Lucian; Greil, Johann; Opelz, Gerhard

    2009-07-01

    Cells have been previously used in experimental models for tolerance induction in organ transplantation and autoimmune diseases. One problem with the therapeutic use of cells is standardization of their preparation. We discuss an immunosuppressive strategy relying on cells irreversibly transformed by a chemotherapeutic drug. Dendritic cells (DCs) of transplant donors pretreated with mitomycin C (MMC) strongly prolonged rat heart allograft survival when injected into recipients before transplantation. Likewise, MMC-DCs loaded with myelin basic protein suppressed autoreactive T cells of MS patients in vitro and prevented experimental autoimmune encephalitis in mice. Comprehensive gene microarray analysis identified genes that possibly make up the suppressive phenotype, comprising glucocorticoid leucine zipper, immunoglobulin-like transcript 3, CD80, CD83, CD86, and apoptotic genes. Based on these findings, a hypothetical model of tolerance induction by MMC-treated DCs is delineated. Finally, we describe the first clinical application of MMC-treated monocyte-enriched donor cells in an attempt to control the rejection of a haploidentical stem cell transplant in a sensitized recipient and discuss the pros and cons of using MMC-treated antigen-presenting cells for tolerance induction. Although many questions remain, MMC-treated cells are a promising clinical tool for controlling allograft rejection and deleterious immune responses in autoimmune diseases. PMID:19393276

  11. Artificial antigen-presenting cells transduced with telomerase efficiently expand epitope-specific, human leukocyte antigen-restricted cytotoxic T cells.

    Science.gov (United States)

    Dupont, Jakob; Latouche, Jean-Baptiste; Ma, Chia; Sadelain, Michel

    2005-06-15

    Human telomerase reverse transcriptase (hTERT) is overexpressed in most human tumors, making it a potential target for cancer immunotherapy. hTERT-derived CTL epitopes have been identified previously, including p865 (RLVDDFLLV) and p540 (ILAKFLHWL), which are restricted by the human leukocyte antigen (HLA) class I A*0201 allele. However, it remains a major challenge to efficiently and consistently expand hTERT-specific CTLs from donor peripheral blood T lymphocytes. To bypass the need for generating conventional antigen-presenting cells (APC) on an autologous basis, we investigated the potential ability of fibroblast-derived artificial APCs (AAPC) to activate and expand HLA-A*0201-restricted CTLs. We show here that AAPCs stably expressing HLA-A*0201, human beta(2)-microglobulin, B7.1, intercellular adhesion molecule-1, and LFA-3, together with either p540 and p865 minigenes or the full-length hTERT, effectively stimulate tumoricidal, hTERT-specific CTLs. hTERT-expressing AAPCs stimulated both p540 and p865 CTLs as shown by peptide-specific cytolysis and tetramer staining, indicating that hTERT is processed by the AAPCs and that the two peptides are presented as codominant epitopes. The level of cytotoxic activity against a panel of tumors comprising hematologic and epithelial malignancies varied, correlating overall with the level of HLA-A2 and hTERT expression by the target cell. Starting from 100 mL blood, approximately 100 million hTERT-specific CTLs could be generated over the course of five sequential stimulations, representing an expansion of approximately 1 x 10(5). Our data show that AAPCs process hTERT antigen and efficiently stimulate hTERT-specific CTLs from human peripheral blood T lymphocytes and suggest that sufficient expansion could be achieved to be clinically useful for adoptive cell therapy.

  12. Candida soluble cell wall β-glucan facilitates ovalbumin-induced allergic airway inflammation in mice: Possible role of antigen-presenting cells

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    Tamura Hiroshi

    2009-07-01

    Full Text Available Abstract Background Although fungi have been implicated as initiating/deteriorating factors for allergic asthma, their contributing components have not been fully elucidated. We previously isolated soluble β-glucan from Candida albicans (CSBG (Ohno et al., 2007. In the present study, the effects of CSBG exposure on airway immunopathology in the presence or absence of other immunogenic allergen was investigated in vivo, and their cellular mechanisms were analyzed both in vivo and in vitro. Methods In vivo, ICR mice were divided into 4 experimental groups: vehicle, CSBG (25 μg/animal, ovalbumin (OVA: 2 μg/animal, and CSBG + OVA were repeatedly administered intratracheally. The bronchoalveolar lavage cellular profile, lung histology, levels of cytokines and chemokines in the lung homogenates, the expression pattern of antigen-presenting cell (APC-related molecules in the lung digests, and serum immunoglobulin values were studied. In vitro, the impacts of CSBG (0–12.5 μg/ml on the phenotype and function of immune cells such as splenocytes and bone marrow-derived dendritic cells (BMDCs were evaluated in terms of cell proliferation, the surface expression of APC-related molecules, and OVA-mediated T-cell proliferating activity. Results In vivo, repeated pulmonary exposure to CSBG induced neutrophilic airway inflammation in the absence of OVA, and markedly exacerbated OVA-related eosinophilic airway inflammation with mucus metaplasia in mice, which was concomitant with the amplified lung expression of Th2 cytokines and IL-17A and chemokines related to allergic response. Exposure to CSBG plus OVA increased the number of cells bearing MHC class II with or without CD80 in the lung compared to that of others. In vitro, CSBG significantly augmented splenocyte proliferation in the presence or absence of OVA. Further, CSBG increased the expression of APC-related molecules such as CD80, CD86, and DEC205 on BMDCs and amplified OVA-mediated T-cell

  13. Characterization of Yellow Fever Virus Infection of Human and Non-human Primate Antigen Presenting Cells and Their Interaction with CD4+ T Cells.

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    Yu Cong

    2016-05-01

    Full Text Available Humans infected with yellow fever virus (YFV, a mosquito-borne flavivirus, can develop illness ranging from a mild febrile disease to hemorrhagic fever and death. The 17D vaccine strain of YFV was developed in the 1930s, has been used continuously since development and has proven very effective. Genetic differences between vaccine and wild-type viruses are few, yet viral or host mechanisms associated with protection or disease are not fully understood. Over the past 20 years, a number of cases of vaccine-associated disease have been identified following vaccination with 17D; these cases have been correlated with reduced immune status at the time of vaccination. Recently, several studies have evaluated T cell responses to vaccination in both humans and non-human primates, but none have evaluated the response to wild-type virus infection. In the studies described here, monocyte-derived macrophages (MDM and dendritic cells (MoDC from both humans and rhesus macaques were evaluated for their ability to support infection with either wild-type Asibi virus or the 17D vaccine strain and the host cytokine and chemokine response characterized. Human MoDC and MDM were also evaluated for their ability to stimulate CD4+ T cells. It was found that MoDC and MDM supported viral replication and that there were differential cytokine responses to infection with either wild-type or vaccine viruses. Additionally, MoDCs infected with live 17D virus were able to stimulate IFN-γ and IL-2 production in CD4+ T cells, while cells infected with Asibi virus were not. These data demonstrate that wild-type and vaccine YFV stimulate different responses in target antigen presenting cells and that wild-type YFV can inhibit MoDC activation of CD4+ T cells, a critical component in development of protective immunity. These data provide initial, but critical insight into regulatory capabilities of wild-type YFV in development of disease.

  14. Particle-based transcutaneous administration of HIV-1 p24 protein to human skin explants and targeting of epidermal antigen presenting cells.

    Science.gov (United States)

    Rancan, Fiorenza; Amselgruber, Sarah; Hadam, Sabrina; Munier, Sevérine; Pavot, Vincent; Verrier, Bernard; Hackbarth, Steffen; Combadiere, Behazine; Blume-Peytavi, Ulrike; Vogt, Annika

    2014-02-28

    Transcutaneous immunization is a promising vaccination strategy for the treatment of infectious diseases and cancer. In this study, we investigate the combination of cyanoacrylate skin surface stripping (CSSS) and particle-based antigen delivery to target the HIV-1 p24 protein to skin antigen presenting cells (APC). The CSSS treatment pre-activates skin APC and opens hair follicles, where protein-loaded particles accumulate and allow for sustained delivery of the loaded antigen to perifollicular APC. We found that poly-lactic acid (PLA) and polystyrene (PS) particles targeted the adsorbed HIV-1 p24 protein to the hair follicles. Small amounts of PS and PLA particles were found to translocate to the epidermis and be internalized by skin cells, whereas most of the particles aggregated in the hair follicle canal, where they released the loaded antigen. The p24 protein diffused to the epidermis and dermis and was detected in skin cells, especially in Langerhans cells and dermal dendritic cells. Furthermore, the combination of CSSS and particle-based delivery resulted in activation and maturation of Langerhans cells (HLA-DR, CD80 and CD83). We conclude that particle-based antigen delivery across partially disrupted skin barrier is a feasible and effective approach to needle-free transcutaneous vaccination.

  15. Particle-based transcutaneous administration of HIV-1 p24 protein to human skin explants and targeting of epidermal antigen presenting cells.

    Science.gov (United States)

    Rancan, Fiorenza; Amselgruber, Sarah; Hadam, Sabrina; Munier, Sevérine; Pavot, Vincent; Verrier, Bernard; Hackbarth, Steffen; Combadiere, Behazine; Blume-Peytavi, Ulrike; Vogt, Annika

    2014-02-28

    Transcutaneous immunization is a promising vaccination strategy for the treatment of infectious diseases and cancer. In this study, we investigate the combination of cyanoacrylate skin surface stripping (CSSS) and particle-based antigen delivery to target the HIV-1 p24 protein to skin antigen presenting cells (APC). The CSSS treatment pre-activates skin APC and opens hair follicles, where protein-loaded particles accumulate and allow for sustained delivery of the loaded antigen to perifollicular APC. We found that poly-lactic acid (PLA) and polystyrene (PS) particles targeted the adsorbed HIV-1 p24 protein to the hair follicles. Small amounts of PS and PLA particles were found to translocate to the epidermis and be internalized by skin cells, whereas most of the particles aggregated in the hair follicle canal, where they released the loaded antigen. The p24 protein diffused to the epidermis and dermis and was detected in skin cells, especially in Langerhans cells and dermal dendritic cells. Furthermore, the combination of CSSS and particle-based delivery resulted in activation and maturation of Langerhans cells (HLA-DR, CD80 and CD83). We conclude that particle-based antigen delivery across partially disrupted skin barrier is a feasible and effective approach to needle-free transcutaneous vaccination. PMID:24384300

  16. Runx1 Regulates Myeloid Precursor Differentiation Into Osteoclasts Without Affecting Differentiation Into Antigen Presenting or Phagocytic Cells in Both Males and Females.

    Science.gov (United States)

    Paglia, David N; Yang, Xiaochuan; Kalinowski, Judith; Jastrzebski, Sandra; Drissi, Hicham; Lorenzo, Joseph

    2016-08-01

    Runt-related transcription factor 1 (Runx1), a master regulator of hematopoiesis, is expressed in preosteoclasts. Previously we evaluated the bone phenotype of CD11b-Cre Runx1(fl/fl) mice and demonstrated enhanced osteoclasts and decreased bone mass in males. However, an assessment of the effects of Runx1 deletion in female osteoclast precursors was impossible with this model. Moreover, the role of Runx1 in myeloid cell differentiation into other lineages is unknown. Therefore, we generated LysM-Cre Runx1(fl/fl) mice, which delete Runx1 equally (∼80% deletion) in myeloid precursor cells from both sexes and examined the capacity of these cells to differentiate into osteoclasts and phagocytic and antigen-presenting cells. Both female and male LysM-Cre Runx1(fl/fl) mice had decreased trabecular bone mass (72% decrease in bone volume fraction) and increased osteoclast number (2-3 times) (P nuclear factor-κB ligand to stimulate osteoclast formation and fusion in female and male mice without affecting other myeloid cell fates. In turn, increased osteoclast activity in LysM-Cre Runx1(fl/fl) mice likely contributed to a decrease in bone mass. These dramatic effects were not due to increased osteoclast precursors in the deleted mutants and argue that inhibition of Runx1 in multipotential myeloid precursor cells is important for osteoclast formation and function. PMID:27267711

  17. 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. PMID:2973431

  18. 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.

  19. Antigen presentation by non-immune B-cell hybridoma clones: presentation of synthetic antigenic sites reveals clones that exhibit no specificity and clones that present only one epitope

    Science.gov (United States)

    Cohly, H. H.; Morrison, D. R.; Atassi, M. Z.

    1989-01-01

    Recently, we reported the preparation and antigen-presenting properties of hybridoma B-cell clones obtained after fusing non-secreting, non-antigen presenting Balb/c 653-myeloma cells with non-immune SJL spleen cells. It was found that antigen presentation at the clonal level can be specific or non-specific, depending on the particular B-cell clone. In the present work, one specific and one general presenter B-cell clones were tested for their epitope presentation ability to SJL T-cells that were specific to lysozyme or myoglobin. B-cell clone A1G12, a general presenter which presented both lysozyme and myoglobin to their respective T-cell lines, was found to present all five myoglobin epitopes while clone A1L16, a lysozyme specific presenter presented only one of the three epitopes of lysozyme. The latter reveals a hitherto unknown submolecular specificity (to a given epitope within a protein) for antigen presenting cells at the clonal level. Therefore, the specificity of T-cell recognition does not only derive from the T-cell but may also be dependent on the epitope specificity of the antigen-presenting B-cell.

  20. Differential Impact of PD-1 and/or Interleukin-10 Blockade on HIV-1-Specific CD4 T Cell and Antigen-Presenting Cell Functions

    Science.gov (United States)

    Porichis, Filippos; Hart, Meghan G.; Zupkosky, Jennifer; Barblu, Lucie; Kwon, Douglas S.; McMullen, Ashley; Brennan, Thomas; Ahmed, Rafi; Freeman, Gordon J.; Kavanagh, Daniel G.

    2014-01-01

    that a population of white blood cells called CD4 T cells that targets the virus fails to work properly. At least part of this impairment is under the control of inhibitory mechanisms that can be blocked to improve the function of these CD4 T cells. In this report, we show that blocking one or two of the molecules involved, called PD-1 and IL-10, has different effects on the individual functions of these cells and that one is strongly improved. We investigate how these effects are caused by interactions between CD4 T cells and antigen-presenting cells. These observations can have implications for new therapeutic approaches in HIV infection. PMID:24352453

  1. Induction of antigen-presenting capacity in tumor cells upon infection with non-replicating recombinant vaccinia virus encoding murine MHC class II and costimulatory molecules.

    Science.gov (United States)

    Marti, W R; Oertli, D; Meko, J B; Norton, J A; Tsung, K

    1997-01-15

    The possibility of inducing antigen-presenting capacity in cells normally lacking such capacity, currently represents a major goal in vaccine research. To address this issue we attempted to generate 'artificial' APC able to stimulate CD4+ T cell responses when tumor cells were infected with a single, recombinant, vaccinia virus (rVV) containing the two genes encoding murine MHC class II I-Ak and a third gene encoding the murine B7-1 (mB7-1) costimulatory molecule. To minimize the cytopathic effect and to improve safety, in view of possible in vivo applications, we made this rVV replication incompetent by Psoralen and long wave UV treatment. Tumor cells infected with rVV encoding I-Ak alone, pulsed with hen egg white lysozyme peptide (HEL46-61), induced IL-2 secretion by an antigen-specific T hybridoma. Tumor cells infected with the rVV encoding mB7-1 provided costimulation for activating resting CD4+ T cells in the presence of ConA. Tumor cells infected with the rVV encoding I-Ak and mB7-1, and pulsed with chicken ovotransferrin peptide (conalbumin133-145), induced a significantly higher response in a specific Th2 cell clone (D10.G4.1) as compared to cells infected with rVV encoding I-Ak molecules only. Thus, this replication incompetent rVV represents a safe, multiple gene, vector system able to confer in one single infection step effective APC capacity to non-professional APCs.

  2. Nanoparticle-based targeting of vaccine compounds to skin antigen-presenting cells by hair follicles and their transport in mice.

    Science.gov (United States)

    Mahe, Brice; Vogt, Annika; Liard, Christelle; Duffy, Darragh; Abadie, Valérie; Bonduelle, Olivia; Boissonnas, Alexandre; Sterry, Wolfram; Verrier, Bernard; Blume-Peytavi, Ulrike; Combadiere, Behazine

    2009-05-01

    Particle-based drug delivery systems target active compounds to the hair follicle and may result in a better penetration and higher efficiency of compound uptake by skin resident cells. As previously proposed, such delivery systems could be important tools for vaccine delivery. In this study, we investigated the penetration of solid fluorescent 40 or 200 nm polystyrene nanoparticles (NPs) as well as virus particles in murine skin to further investigate the efficacy of transcutaneously (TC) applied particulate vaccine delivery route. We demonstrated that 40 and 200 nm NPs and modified vaccinia Ankara (MVA) expressing the green-fluorescent protein penetrated deeply into hair follicles and were internalized by perifollicular antigen-presenting cells (APCs). Fibered-based confocal microscopy analyses allowed visualizing in vivo particle penetration along the follicular duct, diffusion into the surrounding tissue, uptake by APCs and transport to the draining lymph nodes. The application of small particles, such as ovalbumin coding DNA or MVA, induced both humoral and cellular immune responses. Furthermore, TC applied MVA induced protection against vaccinia virus challenge. Our results strengthen the concept of TC targeting of cutaneous APCs by hair follicles and will contribute to the development of advanced vaccination protocols using NPs or viral vectors.

  3. Nanoparticle-based targeting of vaccine compounds to skin antigen-presenting cells by hair follicles and their transport in mice.

    Science.gov (United States)

    Mahe, Brice; Vogt, Annika; Liard, Christelle; Duffy, Darragh; Abadie, Valérie; Bonduelle, Olivia; Boissonnas, Alexandre; Sterry, Wolfram; Verrier, Bernard; Blume-Peytavi, Ulrike; Combadiere, Behazine

    2009-05-01

    Particle-based drug delivery systems target active compounds to the hair follicle and may result in a better penetration and higher efficiency of compound uptake by skin resident cells. As previously proposed, such delivery systems could be important tools for vaccine delivery. In this study, we investigated the penetration of solid fluorescent 40 or 200 nm polystyrene nanoparticles (NPs) as well as virus particles in murine skin to further investigate the efficacy of transcutaneously (TC) applied particulate vaccine delivery route. We demonstrated that 40 and 200 nm NPs and modified vaccinia Ankara (MVA) expressing the green-fluorescent protein penetrated deeply into hair follicles and were internalized by perifollicular antigen-presenting cells (APCs). Fibered-based confocal microscopy analyses allowed visualizing in vivo particle penetration along the follicular duct, diffusion into the surrounding tissue, uptake by APCs and transport to the draining lymph nodes. The application of small particles, such as ovalbumin coding DNA or MVA, induced both humoral and cellular immune responses. Furthermore, TC applied MVA induced protection against vaccinia virus challenge. Our results strengthen the concept of TC targeting of cutaneous APCs by hair follicles and will contribute to the development of advanced vaccination protocols using NPs or viral vectors. PMID:19052565

  4. Properties of glycolipid-enriched membrane rafts in antigen presentation.

    Science.gov (United States)

    Rodgers, William; Smith, Kenneth

    2005-01-01

    Presentation of antigen to T cells represents one of the central events in the engagement of the immune system toward the defense of the host against pathogens. Accordingly, understanding the mechanisms by which antigen presentation occurs is critical toward our understanding the properties of host defense against foreign antigen, as well as insight into other features of the immune system, such as autoimmune disease. The entire antigen-presentation event is complex, and many features of it remain poorly understood. However, recent studies have provided evidence showing that glycolipid-enriched membrane rafts are important for efficient antigen presentation; the studies suggest that one such function of rafts is trafficking of antigen-MHC II complexes to the presentation site on the surface of the antigen-presenting cell. Here, we present a critical discussion of rafts and their proposed functions in antigen presentation. Emerging topics of rafts and antigen presentation that warrant further investigation are also highlighted.

  5. Meningitis Caused by Toscana Virus Is Associated with Strong Antiviral Response in the CNS and Altered Frequency of Blood Antigen-Presenting Cells

    Directory of Open Access Journals (Sweden)

    Stefania Varani

    2015-11-01

    Full Text Available Toscana virus (TOSV is a Phlebotomus-transmitted RNA virus and a frequent cause of human meningitis and meningoencephalitis in Southern Europe during the summer season. While evidence for TOSV-related central nervous system (CNS cases is increasing, little is known about the host defenses against TOSV. We evaluated innate immune response to TOSV by analyzing frequency and activation of blood antigen-presenting cells (APCs and cytokine levels in plasma and cerebrospinal fluid (CSF from patients with TOSV neuroinvasive infection and controls. An altered frequency of different blood APC subsets was observed in TOSV-infected patients, with signs of monocytic deactivation. Nevertheless, a proper or even increased responsiveness of toll-like receptor 3 and 7/8 was observed in blood APCs of these patients as compared to healthy controls. Systemic levels of cytokines remained low in TOSV-infected patients, while levels of anti-inflammatory and antiviral mediators were significantly higher in CSF from TOSV-infected patients as compared to patients with other infectious and noninfectious neurological diseases. Thus, the early host response to TOSV appears effective for viral clearance, by proper response to TLR3 and TLR7/8 agonists in peripheral blood and by a strong and selective antiviral and anti-inflammatory response in the CNS.

  6. Granulocyte-Macrophage Colony-Stimulating Factor Expressed by Recombinant Respiratory Syncytial Virus Attenuates Viral Replication and Increases the Level of Pulmonary Antigen-Presenting Cells

    Science.gov (United States)

    Bukreyev, Alexander; Belyakov, Igor M.; Berzofsky, Jay A.; Murphy, Brian R.; Collins, Peter L.

    2001-01-01

    An obstacle to developing a vaccine against human respiratory syncytial virus (RSV) is that natural infection typically does not confer solid immunity to reinfection. To investigate methods to augment the immune response, recombinant RSV (rRSV) was constructed that expresses murine granulocyte-macrophage colony-stimulating factor (mGM-CSF) from a transcription cassette inserted into the G-F intergenic region. Replication of rRSV/mGM-CSF in the upper and lower respiratory tracts of BALB/c mice was reduced 23- to 74- and 5- to 588-fold, respectively, compared to that of the parental rRSV. Despite this strong attenuation of replication, the level of RSV-specific serum antibodies induced by rRSV/mGM-CSF was comparable to, or marginally higher than, that of the parental rRSV. The induction of RSV-specific CD8+ cytotoxic T cells was moderately reduced during the initial infection, which might be a consequence of reduced antigen expression. Mice infected with rRSV/mGM-CSF had elevated levels of pulmonary mRNA for gamma interferon (IFN-γ) and interleukin 12 (IL-12) p40 compared to animals infected by wild-type rRSV. Elevated synthesis of IFN-γ could account for the restriction of RSV replication, as was observed previously with an IFN-γ-expressing rRSV. The accumulation of total pulmonary mononuclear cells and total CD4+ T lymphocytes was accelerated in animals infected with rRSV/mGM-CSF compared to that in animals infected with the control virus, and the level of IFN-γ-positive or IL-4-positive pulmonary CD4+ cells was elevated approximately twofold. The number of pulmonary lymphoid and myeloid dendritic cells and macrophages was increased up to fourfold in mice infected with rRSV/mGM-CSF compared to those infected with the parental rRSV, and the mean expression of major histocompatibility complex class II molecules, a marker of activation, was significantly increased in the two subsets of dendritic cells. Enhanced antigen presentation likely accounts for the

  7. CD80 and CD86 Costimulatory Molecules Differentially Regulate OT-II CD4+ T Lymphocyte Proliferation and Cytokine Response in Cocultures with Antigen-Presenting Cells Derived from Pregnant and Pseudopregnant Mice

    Science.gov (United States)

    Maj, Tomasz; Slawek, Anna

    2014-01-01

    Immune phenomena during the preimplantation period of pregnancy are poorly understood. The aim of our study was to assess the capacity for antigen presentation of splenic antigen-presenting cells (APCs) derived from pregnant and pseudopregnant mice in in vitro conditions. Therefore, sorted CD11c+ dendritic cells and macrophages F4/80+ and CD11b+ presenting ovalbumin (OVA) were cocultured with CD4+ T cells derived from OT-II mice's (C57BL6/J-Tg(TcraTcrb)1100Mjb/J) spleen. After 132 hours of cell culture, proliferation of lymphocytes (ELISA-BrdU), activation of these cells (flow cytometry), cytokine profile (ELISA), and influence of costimulatory molecules blocking on these parameters were measured. We did not detect any differences in regulation of Th1/Th2 cytokine balance. CD86 seems to be the main costimulatory molecule involved in the proliferation response but CD80 is the main costimulatory molecule influencing cytokine secretion in pregnant mice. In conclusion, this study showed that CD80 and CD86 costimulatory molecules regulate OT-II CD4+ T lymphocyte proliferation and cytokine response in cocultures with antigen-presenting cells derived from pregnant and pseudopregnant mice. The implications of these changes still remain unclear. PMID:24771983

  8. CD80 and CD86 Costimulatory Molecules Differentially Regulate OT-II CD4+ T Lymphocyte Proliferation and Cytokine Response in Cocultures with Antigen-Presenting Cells Derived from Pregnant and Pseudopregnant Mice

    Directory of Open Access Journals (Sweden)

    Tomasz Maj

    2014-01-01

    Full Text Available Immune phenomena during the preimplantation period of pregnancy are poorly understood. The aim of our study was to assess the capacity for antigen presentation of splenic antigen-presenting cells (APCs derived from pregnant and pseudopregnant mice in in vitro conditions. Therefore, sorted CD11c+ dendritic cells and macrophages F4/80+ and CD11b+ presenting ovalbumin (OVA were cocultured with CD4+ T cells derived from OT-II mice’s (C57BL6/J-Tg(TcraTcrb1100Mjb/J spleen. After 132 hours of cell culture, proliferation of lymphocytes (ELISA-BrdU, activation of these cells (flow cytometry, cytokine profile (ELISA, and influence of costimulatory molecules blocking on these parameters were measured. We did not detect any differences in regulation of Th1/Th2 cytokine balance. CD86 seems to be the main costimulatory molecule involved in the proliferation response but CD80 is the main costimulatory molecule influencing cytokine secretion in pregnant mice. In conclusion, this study showed that CD80 and CD86 costimulatory molecules regulate OT-II CD4+ T lymphocyte proliferation and cytokine response in cocultures with antigen-presenting cells derived from pregnant and pseudopregnant mice. The implications of these changes still remain unclear.

  9. Skewed Helper T-Cell Responses to IL-12 Family Cytokines Produced by Antigen-Presenting Cells and the Genetic Background in Behcet’s Disease

    Directory of Open Access Journals (Sweden)

    Jun Shimizu

    2013-01-01

    Full Text Available Behcet’s disease (BD is a multisystemic inflammatory disease and is characterized by recurrent attacks on eyes, brain, skin, and gut. There is evidence that skewed T-cell responses contributed to its pathophysiology in patients with BD. Recently, we found that Th17 cells, a new helper T (Th cell subset, were increased in patients with BD, and both Th type 1 (Th1 and Th17 cell differentiation signaling pathways were overactivated. Several researches revealed that genetic polymorphisms in Th1/Th17 cell differentiation signaling pathways were associated with the onset of BD. Here, we summarize current findings on the Th cell subsets, their contribution to the pathogenesis of BD and the genetic backgrounds, especially in view of IL-12 family cytokine production and pattern recognition receptors of macrophages/monocytes.

  10. Production of CXC and CC chemokines by human antigen-presenting cells in response to Lassa virus or closely related immunogenic viruses, and in cynomolgus monkeys with lassa fever.

    OpenAIRE

    Delphine Pannetier; Stéphanie Reynard; Marion Russier; Xavier Carnec; Sylvain Baize

    2014-01-01

    International audience The pathogenesis of Lassa fever (LF), a hemorrhagic fever endemic to West Africa, remains unclear. We previously compared Lassa virus (LASV) with its genetically close, but nonpathogenic homolog Mopeia virus (MOPV) and demonstrated that the strong activation of antigen-presenting cells (APC), including type I IFN production, observed in response to MOPV probably plays a crucial role in controlling infection. We show here that human macrophages (MP) produce large amou...

  11. Turnover of Ia-peptide complexes is facilitated in viable antigen-presenting cells: biosynthetic turnover of Ia vs. peptide exchange.

    OpenAIRE

    Harding, C V; Roof, R W; Unanue, E R

    1989-01-01

    Macrophages and B cells process antigens to produce antigenic peptides that associate with class II major histocompatibility complex molecules (e.g., Ia molecules); these Ia-peptide complexes are recognized by CD4+ T lymphocytes. Processing of the antigen hen egg white lysozyme was inhibited by cycloheximide in peritoneal exudate cells (PECs, largely macrophages), but not in TA3 B-lymphoma cells. The uptake and metabolism of hen egg white lysozyme was largely intact in cycloheximide-treated P...

  12. CD40-induced aggregation of MHC class II and CD80 on the cell surface leads to an early enhancement in antigen presentation.

    Science.gov (United States)

    Clatza, Abigail; Bonifaz, Laura C; Vignali, Dario A A; Moreno, José

    2003-12-15

    Ligation of CD40 on B cells increases their ability to present Ag and to activate MHC class II (MHC-II)-restricted T cells. How this occurs is not entirely clear. In this study we demonstrate that CD40 ligation on Ag-presenting B cells (APC) for a short period between 30 min and 3 h has a rapid, augmenting effect on the ability of a B cell line and normal B cells to activate T cells. This is not due to alterations in Ag processing or to an increase in surface expression of CD80, CD86, ICAM-1, or MHC-II. This effect is particularly evident with naive, resting T lymphocytes and appears to be more pronounced under limiting Ag concentrations. Shortly after CD40 ligation on a B cell line, MHC-II and CD80 progressively accumulated in cholesterol-enriched microdomains on the cell surface, which correlated with an initial enhancement in their Ag presentation ability. Moreover, CD40 ligation induced a second, late, more sustained enhancement of Ag presentation, which correlates with a significant increase in CD80 expression by APC. Thus, CD40 signaling enhances the efficiency with which APC activate T cells by at least two related, but distinct, mechanisms: an early stage characterized by aggregation of MHC-II and CD80 clusters, and a late stage in which a significant increase in CD80 expression is observed. These results raise the possibility that one important role of CD40 is to contribute to the formation of the immunological synapse on the APC side.

  13. Interleukin-19: a constituent of the regulome that controls antigen presenting cells in the lungs and airway responses to microbial products.

    Directory of Open Access Journals (Sweden)

    Carol Hoffman

    Full Text Available BACKGROUND: Interleukin (IL-19 has been reported to enhance chronic inflammatory diseases such as asthma but the in vivo mechanism is incompletely understood. Because IL-19 is produced by and regulates cells of the monocyte lineage, our studies focused on in vivo responses of CD11c positive (CD11c+ alveolar macrophages and lung dendritic cells. METHODOLOGY/PRINCIPAL FINDINGS: IL-19-deficient (IL-19-/- mice were studied at baseline (naïve and following intranasal challenge with microbial products, or recombinant cytokines. Naïve IL-19-/- mixed background mice had a decreased percentage of CD11c+ cells in the bronchoalveolar-lavage (BAL due to the deficiency in IL-19 and a trait inherited from the 129-mouse strain. BAL CD11c+ cells from fully backcrossed IL-19-/- BALB/c or C57BL/6 mice expressed significantly less Major Histocompatibility Complex class II (MHCII in response to intranasal administration of lipopolysaccharide, Aspergillus antigen, or IL-13, a pro-allergic cytokine. Neurogenic-locus-notch-homolog-protein-2 (Notch2 expression by lung monocytes, the precursors of BAL CD11c+ cells, was dysregulated: extracellular Notch2 was significantly decreased, transmembrane/intracellular Notch2 was significantly increased in IL-19-/- mice relative to wild type. Instillation of recombinant IL-19 increased extracellular Notch2 expression and dendritic cells cultured from bone marrow cells in the presence of IL-19 showed upregulated extracellular Notch2. The CD205 positive subset among the CD11c+ cells was 3-5-fold decreased in the airways and lungs of naïve IL-19-/- mice relative to wild type. Airway inflammation and histological changes in the lungs were ameliorated in IL-19-/- mice challenged with Aspergillus antigen that induces T lymphocyte-dependent allergic inflammation but not in IL-19-/- mice challenged with lipopolysaccharide or IL-13. CONCLUSIONS/SIGNIFICANCE: Because MHCII is the molecular platform that displays peptides to T

  14. Hepatitis B virus induces IL-23 production in antigen presenting cells and causes liver damage via the IL-23/IL-17 axis.

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    Qinghong Wang

    Full Text Available IL-23 regulates myriad processes in the innate and adaptive immune systems, and is a critical mediator of the proinflammatory effects exerted by Th17 cells in many diseases. In this study, we investigated whether and how hepatitis B virus (HBV causes liver damage directly through the IL-23 signaling pathway. In biopsied liver tissues from HBV-infected patients, expression of both IL-23 and IL-23R was remarkably elevated. In vivo observations also indicated that the main sources of IL-23 were myeloid dendritic cells (mDCs and macrophages. Analysis of in vitro differentiated immature DCs and macrophages isolated from healthy donors revealed that the HBV surface antigen (HBsAg efficiently induces IL-23 secretion in a mannose receptor (MR-dependent manner. Culture with an endosomal acidification inhibitor and the dynamin inhibitor showed that, upon binding to the MR, the HBsAg is taken up by mDCs and macrophages through an endocytosis mechanism. In contrast, although the HBV core antigen (HBcAg can also stimulate IL-23 secretion from mDCs, the process was MR- and endocytosis-independent. In addition, IL-23 was shown to be indispensible for HBsAg-stimulated differentiation of naïve CD4(+ T cells into Th17 cells, which were determined to be the primary source of IL-17 in HBV-infected livers. The cognate receptor, IL-17R, was found to exist on the hepatic stellate cells and mDCs, both of which might represent the potential target cells of IL-17 in hepatitis B disease. These data provide novel insights into a yet unrecognized mechanism of HBV-induced hepatitis, by which increases in IL-23 expression, through an MR/endocytosis-dependent or -independent manner, produce liver damage through the IL-23/IL-17 axis.

  15. Activation of human antigen-presenting cells by the mycobacterial cord factor and its glycolipid adjuvant analogue trehalose-6,6’-dibehenate

    OpenAIRE

    Ostrop, Jenny

    2015-01-01

    The mycobacterial cord factor trehalose-6,6’-dimycolate (TDM) is an abundant cell wall glycolipid of Mycobacterium tuberculosis and other mycobacteria. It causes inflammation and adjuvanticity, but it is also a major virulence factor of M. tuberculosis. Its synthetic analogue trehalose-6,6’-dibehenate (TDB) has robust adjuvant activity and induces a Th1/Th17 T cell response in animal models. The TDB-containing liposomal adjuvant formulation Caf01 has entered phase I clinical studies in humans...

  16. Frequent lack of translation of antigen presentation-associated molecules MHC class I, CD1a and Beta(2)-microglobulin in Reed-Sternberg cells

    NARCIS (Netherlands)

    van den Berg, A.; Visser, L; Eberwine, J; Dadvand, L; Poppema, S

    2000-01-01

    Epstein-Barr virus (EBV) is present in Reed-Sternberg (RS) cells of a substantial proportion of Hodgkin's lymphoma cases. Most EBV-positive cases are also MHC class I-positive, whereas the majority of EBV-negative cases lack detectable levels of MHC class I expression. Application of the SAGE techni

  17. A Neoglycoconjugate Containing the Human Milk Sugar LNFPIII Drives Anti-Inflammatory Activation of Antigen Presenting Cells in a CD14 Dependent Pathway.

    Science.gov (United States)

    Tundup, Smanla; Srivastava, Leena; Norberg, Thomas; Watford, Wendy; Harn, Donald

    2015-01-01

    The milk pentasaccharide LNFPIII has therapeutic action for metabolic and autoimmune diseases and prolongs transplant survival in mice when presented as a neoglycoconjugate. Within LNFPIII is the Lewisx trisaccharide, expressed by many helminth parasites. In humans, LNFPIII is found in human milk and also known as stage-specific embryonic antigen-1. LNFPIII-NGC drives alternative activation of macrophages and dendritic cells via NFκB activation in a TLR4 dependent mechanism. However, the connection between LNFPIII-NGC activation of APCs, TLR4 signaling and subsequent MAP kinase signaling leading to anti-inflammatory activation of APCs remains unknown. In this study we determined that the innate receptor CD14 was essential for LNFPIII-NGC induction of both ERK and NFkB activation in APCs. Induction of ERK activation by LNFPIII-NGC was completely dependent on CD14/TLR4-Ras-Raf1/TPL2-MEK axis in bone marrow derived dendritic cells (BMDCs). In addition, LNFPIII-NGC preferentially induced the production of Th2 "favoring" chemokines CCL22 and matrix metalloprotease protein-9 in a CD14 dependent manner in BMDCs. In contrast, LNFPIII-NGC induces significantly lower levels of Th1 "favoring" chemokines, MIP1α, MIP1β and MIP-2 compared to levels in LPS stimulated cells. Interestingly, NGC of the identical human milk sugar LNnT, minus the alpha 1-3 linked fucose, failed to activate APCs via TLR4/MD2/CD14 receptor complex, suggesting that the alpha 1-3 linked fucose in LNFPIII and not on LNnT, is required for this process. Using specific chemical inhibitors of the MAPK pathway, we found that LNFPIII-NGC induction of CCL22, MMP9 and IL-10 production was dependent on ERK activation. Over all, this study suggests that LNFPIII-NGC utilizes CD14/TLR4-MAPK (ERK) axis in modulating APC activation to produce anti-inflammatory chemokines and cytokines in a manner distinct from that seen for the pro-inflammatory PAMP LPS. These pathways may explain the in vivo therapeutic effect of

  18. A Neoglycoconjugate Containing the Human Milk Sugar LNFPIII Drives Anti-Inflammatory Activation of Antigen Presenting Cells in a CD14 Dependent Pathway.

    Directory of Open Access Journals (Sweden)

    Smanla Tundup

    Full Text Available The milk pentasaccharide LNFPIII has therapeutic action for metabolic and autoimmune diseases and prolongs transplant survival in mice when presented as a neoglycoconjugate. Within LNFPIII is the Lewisx trisaccharide, expressed by many helminth parasites. In humans, LNFPIII is found in human milk and also known as stage-specific embryonic antigen-1. LNFPIII-NGC drives alternative activation of macrophages and dendritic cells via NFκB activation in a TLR4 dependent mechanism. However, the connection between LNFPIII-NGC activation of APCs, TLR4 signaling and subsequent MAP kinase signaling leading to anti-inflammatory activation of APCs remains unknown. In this study we determined that the innate receptor CD14 was essential for LNFPIII-NGC induction of both ERK and NFkB activation in APCs. Induction of ERK activation by LNFPIII-NGC was completely dependent on CD14/TLR4-Ras-Raf1/TPL2-MEK axis in bone marrow derived dendritic cells (BMDCs. In addition, LNFPIII-NGC preferentially induced the production of Th2 "favoring" chemokines CCL22 and matrix metalloprotease protein-9 in a CD14 dependent manner in BMDCs. In contrast, LNFPIII-NGC induces significantly lower levels of Th1 "favoring" chemokines, MIP1α, MIP1β and MIP-2 compared to levels in LPS stimulated cells. Interestingly, NGC of the identical human milk sugar LNnT, minus the alpha 1-3 linked fucose, failed to activate APCs via TLR4/MD2/CD14 receptor complex, suggesting that the alpha 1-3 linked fucose in LNFPIII and not on LNnT, is required for this process. Using specific chemical inhibitors of the MAPK pathway, we found that LNFPIII-NGC induction of CCL22, MMP9 and IL-10 production was dependent on ERK activation. Over all, this study suggests that LNFPIII-NGC utilizes CD14/TLR4-MAPK (ERK axis in modulating APC activation to produce anti-inflammatory chemokines and cytokines in a manner distinct from that seen for the pro-inflammatory PAMP LPS. These pathways may explain the in vivo

  19. ONCOLYTIC VIRUS-MEDIATED REVERSAL OF IMPAIRED TUMOR ANTIGEN PRESENTATION

    Directory of Open Access Journals (Sweden)

    Shashi Ashok Gujar

    2014-04-01

    Full Text Available Anti-tumor immunity can eliminate existing cancer cells and also maintain a constant surveillance against possible relapse. Such an antigen-specific adaptive response begins when tumor-specific T cells become activated. T cell activation requires two signals on antigen presenting cells (APCs: antigen presentation through MHC molecules and co-stimulation. In the absence of one or both of these signals, T cells remain inactivated or can even become tolerized. Cancer cells and their associated microenvironment strategically hinder the processing and presentation of tumor antigens and consequently prevent the development of anti-tumor immunity. Many studies, however, demonstrate that interventions that overturn tumor-associated immune evasion mechanisms can establish anti-tumor immune responses of therapeutic potential. One such intervention is oncolytic virus (OV-based anti-cancer therapy. Here we discuss how OV-induced immunological events override tumor-associated antigen presentation impairment and promote appropriate T cell:APC interaction. Detailed understanding of this phenomenon is pivotal for devising the strategies that will enhance the efficacy of OV-based anti-cancer therapy by complementing its inherent oncolytic

  20. Modulation of Th1/Th2 Immune Responses by Killed Propionibacterium acnes and Its Soluble Polysaccharide Fraction in a Type I Hypersensitivity Murine Model: Induction of Different Activation Status of Antigen-Presenting Cells

    Science.gov (United States)

    Mussalem, Juliana Sekeres; Ishimura, Mayari Eika; Longo-Maugéri, Ieda Maria

    2015-01-01

    Propionibacterium acnes (P. acnes) is a gram-positive anaerobic bacillus present in normal human skin microbiota, which exerts important immunomodulatory effects, when used as heat- or phenol-killed suspensions. We previously demonstrated that heat-killed P. acnes or its soluble polysaccharide (PS), extracted from the bacterium cell wall, suppressed or potentiated the Th2 response to ovalbumin (OVA) in an immediate hypersensitivity model, depending on the treatment protocol. Herein, we investigated the mechanisms responsible for these effects, using the same model and focusing on the activation status of antigen-presenting cells (APCs). We verified that higher numbers of APCs expressing costimulatory molecules and higher expression levels of these molecules are probably related to potentiation of the Th2 response to OVA induced by P. acnes or PS, while higher expression of toll-like receptors (TLRs) seems to be related to Th2 suppression. In vitro cytokines production in cocultures of dendritic cells and T lymphocytes indicated that P. acnes and PS seem to perform their effects by acting directly on APCs. Our data suggest that P. acnes and PS directly act on APCs, modulating the expression of costimulatory molecules and TLRs, and these differently activated APCs drive distinct T helper patterns to OVA in our model. PMID:25973430

  1. Production of CXC and CC chemokines by human antigen-presenting cells in response to Lassa virus or closely related immunogenic viruses, and in cynomolgus monkeys with lassa fever.

    Directory of Open Access Journals (Sweden)

    Delphine Pannetier

    Full Text Available The pathogenesis of Lassa fever (LF, a hemorrhagic fever endemic to West Africa, remains unclear. We previously compared Lassa virus (LASV with its genetically close, but nonpathogenic homolog Mopeia virus (MOPV and demonstrated that the strong activation of antigen-presenting cells (APC, including type I IFN production, observed in response to MOPV probably plays a crucial role in controlling infection. We show here that human macrophages (MP produce large amounts of CC and CXC chemokines in response to MOPV infection, whereas dendritic cells (DC release only moderate amounts of CXC chemokines. However, in the presence of autologous T cells, DCs produced CC and CXC chemokines. Chemokines were produced in response to type I IFN synthesis, as the levels of both mediators were strongly correlated and the neutralization of type I IFN resulted in an inhibition of chemokine production. By contrast, LASV induced only low levels of CXCL-10 and CXCL-11 production. These differences in chemokine production may profoundly affect the generation of virus-specific T-cell responses and may therefore contribute to the difference of pathogenicity between these two viruses. In addition, a recombinant LASV (rLASV harboring the NP-D389A/G392A mutations, which abolish the inhibition of type I IFN response by nucleoprotein (NP, induced the massive synthesis of CC and CXC chemokines in both DC and MP, confirming the crucial role of arenavirus NP in immunosuppression and pathogenicity. Finally, we confirmed, using PBMC samples and lymph nodes obtained from LASV-infected cynomolgus monkeys, that LF was associated with high levels of CXC chemokine mRNA synthesis, suggesting that the very early synthesis of these mediators may be correlated with a favourable outcome.

  2. Production of CXC and CC chemokines by human antigen-presenting cells in response to Lassa virus or closely related immunogenic viruses, and in cynomolgus monkeys with lassa fever.

    Science.gov (United States)

    Pannetier, Delphine; Reynard, Stéphanie; Russier, Marion; Carnec, Xavier; Baize, Sylvain

    2014-01-01

    The pathogenesis of Lassa fever (LF), a hemorrhagic fever endemic to West Africa, remains unclear. We previously compared Lassa virus (LASV) with its genetically close, but nonpathogenic homolog Mopeia virus (MOPV) and demonstrated that the strong activation of antigen-presenting cells (APC), including type I IFN production, observed in response to MOPV probably plays a crucial role in controlling infection. We show here that human macrophages (MP) produce large amounts of CC and CXC chemokines in response to MOPV infection, whereas dendritic cells (DC) release only moderate amounts of CXC chemokines. However, in the presence of autologous T cells, DCs produced CC and CXC chemokines. Chemokines were produced in response to type I IFN synthesis, as the levels of both mediators were strongly correlated and the neutralization of type I IFN resulted in an inhibition of chemokine production. By contrast, LASV induced only low levels of CXCL-10 and CXCL-11 production. These differences in chemokine production may profoundly affect the generation of virus-specific T-cell responses and may therefore contribute to the difference of pathogenicity between these two viruses. In addition, a recombinant LASV (rLASV) harboring the NP-D389A/G392A mutations, which abolish the inhibition of type I IFN response by nucleoprotein (NP), induced the massive synthesis of CC and CXC chemokines in both DC and MP, confirming the crucial role of arenavirus NP in immunosuppression and pathogenicity. Finally, we confirmed, using PBMC samples and lymph nodes obtained from LASV-infected cynomolgus monkeys, that LF was associated with high levels of CXC chemokine mRNA synthesis, suggesting that the very early synthesis of these mediators may be correlated with a favourable outcome. PMID:24421914

  3. Production of CXC and CC Chemokines by Human Antigen-Presenting Cells in Response to Lassa Virus or Closely Related Immunogenic Viruses, and in Cynomolgus Monkeys with Lassa Fever

    Science.gov (United States)

    Russier, Marion; Carnec, Xavier; Baize, Sylvain

    2014-01-01

    The pathogenesis of Lassa fever (LF), a hemorrhagic fever endemic to West Africa, remains unclear. We previously compared Lassa virus (LASV) with its genetically close, but nonpathogenic homolog Mopeia virus (MOPV) and demonstrated that the strong activation of antigen-presenting cells (APC), including type I IFN production, observed in response to MOPV probably plays a crucial role in controlling infection. We show here that human macrophages (MP) produce large amounts of CC and CXC chemokines in response to MOPV infection, whereas dendritic cells (DC) release only moderate amounts of CXC chemokines. However, in the presence of autologous T cells, DCs produced CC and CXC chemokines. Chemokines were produced in response to type I IFN synthesis, as the levels of both mediators were strongly correlated and the neutralization of type I IFN resulted in an inhibition of chemokine production. By contrast, LASV induced only low levels of CXCL-10 and CXCL-11 production. These differences in chemokine production may profoundly affect the generation of virus-specific T-cell responses and may therefore contribute to the difference of pathogenicity between these two viruses. In addition, a recombinant LASV (rLASV) harboring the NP-D389A/G392A mutations, which abolish the inhibition of type I IFN response by nucleoprotein (NP), induced the massive synthesis of CC and CXC chemokines in both DC and MP, confirming the crucial role of arenavirus NP in immunosuppression and pathogenicity. Finally, we confirmed, using PBMC samples and lymph nodes obtained from LASV-infected cynomolgus monkeys, that LF was associated with high levels of CXC chemokine mRNA synthesis, suggesting that the very early synthesis of these mediators may be correlated with a favourable outcome. PMID:24421914

  4. MHC Class Ⅰ Antigen Presentation- Recently Trimmed and Well Presented

    Institute of Scientific and Technical Information of China (English)

    Barry Flutter; Bin Gao

    2004-01-01

    Presentation of antigenic peptide to T cells by major histocompatibility complex (MHC) class Ⅰ molecules is the key to the cellular immune response. Non-self intracellular proteins are processed into short peptides and transported into endoplasmic reticulum (ER) where they are assembled with class Ⅰ molecules assisted by several chaperone proteins to form trimeric complex. MHC class Ⅰ complex loaded with optimised peptides travels to the cell surface of antigen presentation cells to be recognised by T cells. The cells presenting non-self peptides are cleared by CD8 positive T cells. In order to ensure that T cells detect an infection or mutation within the target cells the process of peptide loading and class Ⅰ expression must be carefully regulated. Many of the cellular components involved in antigen processing and class Ⅰ presentation are known and their various functions are now becoming clearer. Cellular & Molecular Immunology. 2004;1(1):22-30.

  5. MHC Class I Antigen Presentation- Recently Trimmed and Well Presented

    Institute of Scientific and Technical Information of China (English)

    BarryFlutter; BinGao

    2004-01-01

    Presentation of antigenic peptide to T cells by major histocompatibility complex (MHC) class I molecules is the key to the cellular immune response. Non-self intracellular proteins are processed into short peptides and transported into endoplasmic reticulum (ER) where they are assembled with class I molecules assisted by several chaperone proteins to form trimeric complex. MHC class I complex loaded with optimised peptides travels to the cell surface of antigen presentation cells to be recognised by T cells. The cells presenting non-self peptides are cleared by CD8 positive T cells. In order to ensure that T cells detect an infection or mutation within the target cells the process of peptide loading and class I expression must be carefully regulated. Many of the cellular components involved in antigen processing and class I presentation are known and their various functions are now becoming clearer. Cellular & Molecular Immunology. 2004;1(1):22-30.

  6. The role of FcRn in antigen presentation

    Directory of Open Access Journals (Sweden)

    Kristi eBaker

    2014-08-01

    Full Text Available Immunoglobulins are unique molecules capable of simultaneously recognizing a diverse array of antigens and themselves being recognized by a broad array of receptors. The abundance specifically of the IgG subclass and the variety of signaling receptors to which it binds render this an important immunomodulatory molecule. In addition to the classical Fcγ receptors (FcγR which bind IgG at the cell surface, the neonatal Fc receptor (FcRn is a lifelong resident of the endolysosomal system of most hematopoietic cells where it determines the intracellular fate of both IgG and IgG-containing immune complexes (IgG IC. Crosslinking of FcRn by multivalent IgG IC within antigen presenting cells such as dendritic cells (DC initiates specific mechanisms which result in trafficking of the antigen-bearing IgG IC into compartments from which the antigen can successfully be processed into peptide epitopes compatible with loading onto both MHC class I and II molecules. In turn, this enables the synchronous activation of both CD4+ and CD8+ T cell responses against the cognate antigen, thereby bridging the gap between the humoral and cellular branches of the adaptive immune response. Critically, FcRn-driven T cell priming is efficient at very low doses of antigen due to the exquisite sensitivity of the IgG-mediated antigen delivery system through which it operates. FcRn-mediated antigen presentation has important consequences in tissue compartments replete with IgG and serves not only to determine homeostatic immune activation at a variety of sites but also to induce inflammatory responses upon exposure to antigens perceived as foreign. Therapeutically targeting the pathway by which FcRn enables T cell activation in response to IgG IC is thus a highly attractive prospect not only for the treatment of diseases that are driven by immune complexes but also for manipulating local immune responses against defined antigens such as those present during infections and

  7. Efficient targeting of protein antigen to the dendritic cell receptor DEC-205 in the steady state leads to antigen presentation on major histocompatibility complex class I products and peripheral CD8+ T cell tolerance.

    Science.gov (United States)

    Bonifaz, Laura; Bonnyay, David; Mahnke, Karsten; Rivera, Miguel; Nussenzweig, Michel C; Steinman, Ralph M

    2002-12-16

    To identify endocytic receptors that allow dendritic cells (DCs) to capture and present antigens on major histocompatibility complex (MHC) class I products in vivo, we evaluated DEC-205, which is abundant on DCs in lymphoid tissues. Ovalbumin (OVA) protein, when chemically coupled to monoclonal alphaDEC-205 antibody, was presented by CD11c+ lymph node DCs, but not by CD11c- cells, to OVA-specific, CD4+ and CD8+ T cells. Receptor-mediated presentation was at least 400 times more efficient than unconjugated OVA and, for MHC class I, the DCs had to express transporter of antigenic peptides (TAP) transporters. When alphaDEC-205:OVA was injected subcutaneously, OVA protein was identified over a 4-48 h period in DCs, primarily in the lymph nodes draining the injection site. In vivo, the OVA protein was selectively presented by DCs to TCR transgenic CD8+ cells, again at least 400 times more effectively than soluble OVA and in a TAP-dependent fashion. Targeting of alphaDEC-205:OVA to DCs in the steady state initially induced 4-7 cycles of T cell division, but the T cells were then deleted and the mice became specifically unresponsive to rechallenge with OVA in complete Freund's adjuvant. In contrast, simultaneous delivery of a DC maturation stimulus via CD40, together with alphaDEC-205:OVA, induced strong immunity. The CD8+ T cells responding in the presence of agonistic alphaCD40 antibody produced large amounts of interleukin 2 and interferon gamma, acquired cytolytic function in vivo, emigrated in large numbers to the lung, and responded vigorously to OVA rechallenge. Therefore, DEC-205 provides an efficient receptor-based mechanism for DCs to process proteins for MHC class I presentation in vivo, leading to tolerance in the steady state and immunity after DC maturation.

  8. Efficient Targeting of Protein Antigen to the Dendritic Cell Receptor DEC-205 in the Steady State Leads to Antigen Presentation on Major Histocompatibility Complex Class I Products and Peripheral CD8+ T Cell Tolerance

    Science.gov (United States)

    Bonifaz, Laura; Bonnyay, David; Mahnke, Karsten; Rivera, Miguel; Nussenzweig, Michel C.; Steinman, Ralph M.

    2002-01-01

    To identify endocytic receptors that allow dendritic cells (DCs) to capture and present antigens on major histocompatibility complex (MHC) class I products in vivo, we evaluated DEC-205, which is abundant on DCs in lymphoid tissues. Ovalbumin (OVA) protein, when chemically coupled to monoclonal αDEC-205 antibody, was presented by CD11c+ lymph node DCs, but not by CD11c− cells, to OVA-specific, CD4+ and CD8+ T cells. Receptor-mediated presentation was at least 400 times more efficient than unconjugated OVA and, for MHC class I, the DCs had to express transporter of antigenic peptides (TAP) transporters. When αDEC-205:OVA was injected subcutaneously, OVA protein was identified over a 4–48 h period in DCs, primarily in the lymph nodes draining the injection site. In vivo, the OVA protein was selectively presented by DCs to TCR transgenic CD8+ cells, again at least 400 times more effectively than soluble OVA and in a TAP-dependent fashion. Targeting of αDEC-205:OVA to DCs in the steady state initially induced 4–7 cycles of T cell division, but the T cells were then deleted and the mice became specifically unresponsive to rechallenge with OVA in complete Freund's adjuvant. In contrast, simultaneous delivery of a DC maturation stimulus via CD40, together with αDEC-205:OVA, induced strong immunity. The CD8+ T cells responding in the presence of agonistic αCD40 antibody produced large amounts of interleukin 2 and interferon γ, acquired cytolytic function in vivo, emigrated in large numbers to the lung, and responded vigorously to OVA rechallenge. Therefore, DEC-205 provides an efficient receptor-based mechanism for DCs to process proteins for MHC class I presentation in vivo, leading to tolerance in the steady state and immunity after DC maturation. PMID:12486105

  9. Current status of multiple antigen-presenting peptide vaccine systems: Application of organic and inorganic nanoparticles

    Directory of Open Access Journals (Sweden)

    Taguchi Hiroaki

    2011-08-01

    Full Text Available Abstract Many studies are currently investigating the development of safe and effective vaccines to prevent various infectious diseases. Multiple antigen-presenting peptide vaccine systems have been developed to avoid the adverse effects associated with conventional vaccines (i.e., live-attenuated, killed or inactivated pathogens, carrier proteins and cytotoxic adjuvants. Recently, two main approaches have been used to develop multiple antigen-presenting peptide vaccine systems: (1 the addition of functional components, e.g., T-cell epitopes, cell-penetrating peptides, and lipophilic moieties; and (2 synthetic approaches using size-defined nanomaterials, e.g., self-assembling peptides, non-peptidic dendrimers, and gold nanoparticles, as antigen-displaying platforms. This review summarizes the recent experimental studies directed to the development of multiple antigen-presenting peptide vaccine systems.

  10. Antigen presentation by liposomes bearing class II MHC and membrane IL-1.

    OpenAIRE

    Bakouche, O; LACHMAN, L.B.

    1990-01-01

    Liposomes containing membrane IL-1, Iak, and the antigen conalbumin were evaluated as "synthetic antigen presenting cells." The role of these three molecules in macrophage-T cell interaction was studied by testing their ability to induce the proliferation of a T-cell clone specific to conalbumin (the D10 cell line) or immune spleen cells sensitized three times in vivo with conalbumin. In the latter case, splenic macrophages were eliminated by adherence and a lysomotropic agent. The antigen co...

  11. Calcipotriol inhibits the proliferation of hyperproliferative CD29 positive keratinocytes in psoriatic epidermis in the absence of an effect on the function and number of antigen-presenting cells

    DEFF Research Database (Denmark)

    Jensen, A.M.; Llado, Minna Fyhn Lykke; Skov, L.;

    1998-01-01

    for infiltrating leucocytes (CD45+) and Langerhans cells (CD1a+). Flow cytometric analysis showed that calcipotriol did not alter the number of CD45+ cells or Langerhans cells in psoriatic skin. These results indicate that calcipotriol does not alter either the number of the function of epidermal antigen......The aim of this study was to elucidate some of the possible mechanisms of action of the vitamin D analogue calcipotriol in vivo. Calcipotriol is finding increasing use in the treatment of psoriasis, but the primary target cell in vivo has not yet been identified. We treated psoriatic patients...... and healthy volunteers with calcipotriol and placebo ointment for 4 and 7 days, and obtained epidermal cell suspensions from treated areas. Epidermal cells were cocultured with autologous T cells, isolated from peripheral blood, in the absence or the presence of a classical antigen or a superantigen. In both...

  12. Normal adult ramified microglia separated from other central nervous system macrophages by flow cytometric sorting: Phenotypic differences defined and direct ex vivo antigen presentation to myelin basic protein-reactive CD4{sup +} T cells compared

    Energy Technology Data Exchange (ETDEWEB)

    Ford, A.L.; Goodsall, A.L.; Sedgwick, J.D. [Centenary Institute of Cancer Medicine and Cell Biology, Sydney (Australia)] [and others

    1995-05-01

    Ramified microglia in the adult central nervous system (CNS) are the principal glial element up-regulating MHC class I and II expression in response to inflammatory events or neuronal damage. A proportion of these cells also express MHC class II constitutively in the normal CNS. The role of microglia as APCs for CD4{sup +} cells extravasating into the CNS remains undefined. In this study, using irradiation bone marrow chimeras in CD45-congenic rats, the phenotype CD45{sup low}CD11b/c{sup +} is shown to identify microglial cells specifically within the CNS. Highly purified populations of microglia and nonmicroglial but CNS-associated macrophages (CD45{sup high}CD11b/c{sup +}) have been obtained directly from the adult CNS, by using flow cytometric sorting. Morphologically, freshly isolated microglia vs other CNS macrophages are quite distinct. Of the two populations recovered from the normal CNS, it is the minority CD45{sup high}CD11 b/c{sup +} transitional macrophage population, and not microglia, that is the effective APC for experimental autoimmune encephalomyelitis-inducing CD4{sup +} myelin basic protein (MBP)-reactive T cells. CD45{sup high}CD11b/c{sup +} CNS macrophages also stimulate MBP-reactive T cells without addition of MBP to culture suggesting presentation of endogenous Ag. This is the first study in which microglia vs other CNS macrophages have been analyzed for APC ability directly from the CNS, with substantial cross-contamination between the two populations eliminated. The heterogeneity of these populations in terms of APC function is clearly demonstrated. Evidence is still lacking that adult CNS microglia have the capacity to interact with and stimulate CD4{sup +} T cells to proliferate or secrete IL-2. 60 refs., 6 figs., 1 tab.

  13. Suppression of autophagy and antigen presentation by Mycobacterium tuberculosis PE_PGRS47.

    Science.gov (United States)

    Saini, Neeraj K; Baena, Andres; Ng, Tony W; Venkataswamy, Manjunatha M; Kennedy, Steven C; Kunnath-Velayudhan, Shajo; Carreño, Leandro J; Xu, Jiayong; Chan, John; Larsen, Michelle H; Jacobs, William R; Porcelli, Steven A

    2016-01-01

    Suppression of major histocompatibility complex (MHC) class II antigen presentation is believed to be among the major mechanisms used by Mycobacterium tuberculosis to escape protective host immune responses. Through a genome-wide screen for the genetic loci of M. tuberculosis that inhibit MHC class II-restricted antigen presentation by mycobacteria-infected dendritic cells, we identified the PE_PGRS47 protein as one of the responsible factors. Targeted disruption of the PE_PGRS47 (Rv2741) gene led to attenuated growth of M. tuberculosis in vitro and in vivo, and a PE_PGRS47 mutant showed enhanced MHC class II-restricted antigen presentation during in vivo infection of mice. Analysis of the effects of deletion or over-expression of PE_PGRS47 implicated this protein in the inhibition of autophagy in infected host phagocytes. Our findings identify PE_PGRS47 as a functionally relevant, non-redundant bacterial factor in the modulation of innate and adaptive immunity by M. tuberculosis, suggesting strategies for improving antigen presentation and the generation of protective immunity during vaccination or infection. PMID:27562263

  14. Suppression of autophagy and antigen presentation by Mycobacterium tuberculosis PE_PGRS47.

    Science.gov (United States)

    Saini, Neeraj K; Baena, Andres; Ng, Tony W; Venkataswamy, Manjunatha M; Kennedy, Steven C; Kunnath-Velayudhan, Shajo; Carreño, Leandro J; Xu, Jiayong; Chan, John; Larsen, Michelle H; Jacobs, William R; Porcelli, Steven A

    2016-08-15

    Suppression of major histocompatibility complex (MHC) class II antigen presentation is believed to be among the major mechanisms used by Mycobacterium tuberculosis to escape protective host immune responses. Through a genome-wide screen for the genetic loci of M. tuberculosis that inhibit MHC class II-restricted antigen presentation by mycobacteria-infected dendritic cells, we identified the PE_PGRS47 protein as one of the responsible factors. Targeted disruption of the PE_PGRS47 (Rv2741) gene led to attenuated growth of M. tuberculosis in vitro and in vivo, and a PE_PGRS47 mutant showed enhanced MHC class II-restricted antigen presentation during in vivo infection of mice. Analysis of the effects of deletion or over-expression of PE_PGRS47 implicated this protein in the inhibition of autophagy in infected host phagocytes. Our findings identify PE_PGRS47 as a functionally relevant, non-redundant bacterial factor in the modulation of innate and adaptive immunity by M. tuberculosis, suggesting strategies for improving antigen presentation and the generation of protective immunity during vaccination or infection.

  15. Effects of antigen presentation of eosinophils on lung Th1/Th2 imbalance

    Institute of Scientific and Technical Information of China (English)

    XIE Zheng-fu; SHI Huan-zhong; QIN Xue-jun; KANG Lan-fu; HUANG Chun-ping; CHEN Yi-qiang

    2005-01-01

    Background Antigen-loaded eosinophils (EOSs) instilled intratracheally into mice were capable of inducing Th2-type cytokine production in the draining lymph nodes. The aim of the present study was to evaluate whether EOSs within the tracheobronchial lumen can stimulate Th2 cell expansion in the lung tissues.Methods Airway EOSs were recovered from ovalbumin-sensitized and -challenged BALB/c mice, these EOSs were then cocultured with CD4+ cells isolated from sensitized mice in the absence or presence of anti-CD80 or/and -CD86 monoclonal antibodies. Airway EOSs were instilled into the trachea of sensitized mice. At the day 3 thereafter, the lung tissues were removed and prepared into cell suspensions for culture. Cell-free culture supernatants were collected for detection of cytokines.Results Airway EOSs functioned as CD80- and CD86-dependent antigen-presenting cells to stimulate lung CD4+ lymphocytes to produce interleukin-4, interleukin-5 and interleukin-13, but not interferon-γ in in vitro assay. When instilled intratracheally in sensitized recipient mice, airway EOSs primed lung Th2 cells in vivo for interleukin-4, interleukin-5 and interleukin-13, but not interferon-γ, production during the in vitro culture that was also CD80- and CD86-dependent. Conclusion EOSs within the lumina of airways could process inhaled antigen and function in vitro and in vivo as antigen-presenting cells to promote expansion of Th2 cells in the lungs.

  16. 小剂量X射线照射对人树突状细胞抗原递呈及白介素-12分泌的影响%Effects of low dose X-ray irradiation on antigen presentation and IL-12 secretion in human dendritic cells in vitro

    Institute of Scientific and Technical Information of China (English)

    闫鹏; 江其生; 李峰生; 何蕊; 王翠兰; 李晓

    2012-01-01

    Objective To explore the effects of low dose X-ray irradiation on the ability of antigen presentation and IL-12 secretion in human dendritic cells that had been cultured for different time in vitro.Methods The human peripheral blood mononuclear cells ( PBMC ) were collected and differentiated to dendritic cells (DCs) by rhGM-CSF and rhIL-4 treatment in vitro.The DCs were divided into 3 groups,group A:DCs were cultured for 2 d and then irradiated with 0.05,0.1,0.2 and 0.5 Gy X-rays; group B:DCs were cultured for 6 d and then irradiated as above; group C:DCs were cultured without irradiation.At 8 d of cell culture,the DCs were applied to activate T cells and CCK-8 was used to detect MLR ( mixed lymphocyte reaction),and the antigen presentation ability of DCs was evaluated.MTT assay was also used to test the cell-killing effect of the activated T-cells on A549 cells.IL-12 in the culture medium of DCs was detected by ELISA.Results After irradiation with 0.2 and 0.5 Gy X-rays,the antigen presentation ability of DCs was decreased in group A (t =2.79 and 3.71,P < 0.05 ),but significantly increased in group B (t =3.60 and 3.11,P < 0.05).The ability of the T cell activation was detected and the proliferation of A549 cells was slightly inhibited by the DCs in group A (t =2.89 and 2.91,P < 0.05),but was obviously inhibited by the DCs in group B (t =2.91 and 2.82,P <0.05).Meanwhile,the level of IL-12 was dramatically decreased in group A (t =4.44 and 6.93,P < 0.05),but was increased in group B (t =3.51 and 4.12,P <0.05).Conclusions The abilities of antigen presentation and proliferation inhibition of DCs could be down-regulated by low dose( < 0.5 Gy) of X-ray irradiation at the early stage of DCs,but was up-regulated at the late stage of DCs culture.%目的 探讨小剂量x射线照射对体外不同培养时间的人外周血树突状细胞( dendritic cell,DC)抗原递呈及白介素-12(IL-12)分泌的影响.方法 分离人外周血单个核细胞(PBMC),以人

  17. Antigen Presentation Ability of Salmonella Carrying DNA Vaccine Model and MCP-3 gene

    Directory of Open Access Journals (Sweden)

    Endang Winiati Bachtiar

    2015-11-01

    Full Text Available The objective of this study is to determine the antigen presentation ability of a DNA vaccine model that is co-delivered with that of recombinant Salmonella enterica serovar Typhimurium (STM1 expressing chemokine macrophage chemotactic protein-3 (MCP-3. The DNA vaccine, pVROVA, was constructed by amplification of the ovalbumin coding region from sOVA-C1. Dendritic cells (DCs were obtained from IL-4 and GMCSF stimulated mouse bone marrow stem cell. Cultured DCs were incubated with STM1 carrying a model ovalbumin gene (pVROVA. Furthermore, MHC class I antigen presentation of a dominant OVA peptide was assayed in vitro. The experiments were designed to determine the effect of co-delivering MCP-3 with that of ovalbumin in STM1. Our results show that a plasmid pROVA-carrying ovalbumin gene was succesfully constructed and sequence analysis of the ovalbumin-coding revealed an identity match of 100% with that of the chicken ovalbumin DNA sequences from the GenBank database. We also found that the presence of the MCP-3 encoding plasmid in STM1 or E. coli DH1 could increase the recovery of both STM1 and E. coli DH1 over those that carry the empty plasmids. Antigen presentation assay also indicates that MCP-3 can positively influence the presentation of ovalbumin. Conclusion: the infection of DCs by STM1-carrying DNA vaccine and MCP-3 results in an increase of processing and presentation of ovalbumin in vitro.Keywords : DNA vaccine, MCP-3, APC, Salmonella, Dendritic cells

  18. Effect of multiple genetic polymorphisms on antigen presentation and susceptibility to Mycobacterium tuberculosis infection.

    Science.gov (United States)

    Chang, Stewart T; Linderman, Jennifer J; Kirschner, Denise E

    2008-07-01

    Several molecules related to antigen presentation, including gamma interferon (IFN-gamma) and the major histocompatibility complex (MHC), are encoded by polymorphic genes. Some polymorphisms were found to affect susceptibility to tuberculosis (TB) when they were considered singly in epidemiological studies, but how multiple polymorphisms interact to determine susceptibility to TB in an individual remains an open question. We hypothesized that polymorphisms in some genes may counteract or intensify the effects of polymorphisms in other genes. For example, an increase in IFN-gamma expression may counteract the weak binding that a particular MHC variant displays for a peptide from Mycobacterium tuberculosis to establish the same T-cell response as another, more strongly binding MHC variant. To test this hypothesis, we developed a mathematical model of antigen presentation based on experimental data for the known effects of genetic polymorphisms and simulated time courses when multiple polymorphisms were present. We found that polymorphisms in different genes could affect antigen presentation to the same extent and therefore compensate for each other. Furthermore, we defined the conditions under which such relationships could exist. For example, increased IFN-gamma expression compensated for decreased peptide-MHC affinity in the model only above a certain threshold of expression. Below this threshold, changes in IFN-gamma expression were ineffectual compared to changes in peptide-MHC affinity. The finding that polymorphisms exhibit such relationships could explain discrepancies in the epidemiological literature, where some polymorphisms have been inconsistently associated with susceptibility to TB. Furthermore, the model allows polymorphisms to be ranked by effect, providing a new tool for designing association studies.

  19. Cross-dressing: an alternative mechanism for antigen presentation.

    Science.gov (United States)

    Campana, Stefania; De Pasquale, Claudia; Carrega, Paolo; Ferlazzo, Guido; Bonaccorsi, Irene

    2015-12-01

    Cross-dressing involves the transfer of preformed functional peptide-MHC complexes from the surface of donor cells to recipient cells, such as dendritic cells (DCs). These cross-dressed cells might eventually present the intact, unprocessed peptide-MHC complexes to T lymphocytes. In this review we will discuss some recent findings concerning the intercellular transfer of preformed MHC complexes and the possible mechanisms by which the transfer may occur. We will report evidences showing that both MHC class I and MHC class II functional complexes might be transferred, highlighting the physiological relevance of these cross-dressed cells for the presentation of exogenous antigens to both cytotoxic and helper T lymphocytes.

  20. Regulation of antigen presentation by acidic pH

    OpenAIRE

    1990-01-01

    The effect of pH on functional association of peptide antigens with APC membranes was investigated by using aldehyde-fixed B cells and class II- restricted T cell hybridomas to assess antigen/MHC complex formation. The results indicated that the rate and extent of functional peptide binding was markedly increased at pH 5.0 as compared with pH 7.3. The pH dependence of binding was preserved after pretreatment of fixed APC with pH 5.0 buffer, suggesting that pH had a direct effect on the intera...

  1. NLRC5, AT THE HEART OF ANTIGEN PRESENTATION

    Directory of Open Access Journals (Sweden)

    Andreas eNeerincx

    2013-11-01

    Full Text Available Nucleotide-binding domain and leucine-rich repeat containing receptors (NLRs are intracellular proteins mainly involved in pathogen recognition, inflammatory responses, and cell death. Until recently, the function of the family member NLR caspase recruitment domain (CARD containing 5 (NLRC5 has been a matter of debate. It is now clear that NLRC5 acts as a transcriptional regulator of the major-histocompatibility complex (MHC class I. In this review we detail the development of our understanding of NLRC5 function, discussing both the accepted and the controversial aspects of NLRC5 activity. We give insight into the molecular mechanisms, and the potential implications, of NLRC5 function in health and disease.

  2. A role for NADPH oxidase in antigen presentation

    Directory of Open Access Journals (Sweden)

    Gail J Gardiner

    2013-09-01

    Full Text Available The nicotinamide adenine dinucleotide phosphate (NADPH oxidase expressed in phagocytes is a multi-subunit enzyme complex that generates superoxide (O2.-. This radical is an important precursor of hydrogen peroxide (H2O2 and other reactive oxygen species (ROS needed for microbicidal activity during innate immune responses. Inherited defects in NADPH oxidase give rise to chronic granulomatous disease (CGD, a primary immunodeficiency characterized by recurrent infections and granulomatous inflammation. Interestingly, CGD, CGD carrier status, and oxidase gene polymorphisms have all been associated with autoinflammatory and autoimmune disorders, suggesting a potential role for NADPH oxidase in regulating adaptive immune responses. Here, NADPH oxidase function in antigen processing and presentation is reviewed. NADPH oxidase influences dendritic cell (DC crosspresentation by major histocompatibility complex class I molecules (MHC-I through regulation of the phagosomal microenvironment, while in B lymphocytes, NADPH oxidase alters epitope selection by major histocompatibility complex class II molecules (MHC-II.

  3. MHC-restricted antigen presentation and recognition: constraints on gene, recombinant and peptide vaccines in humans

    Directory of Open Access Journals (Sweden)

    Cunha-Neto E.

    1999-01-01

    Full Text Available The target of any immunization is to activate and expand lymphocyte clones with the desired recognition specificity and the necessary effector functions. In gene, recombinant and peptide vaccines, the immunogen is a single protein or a small assembly of epitopes from antigenic proteins. Since most immune responses against protein and peptide antigens are T-cell dependent, the molecular target of such vaccines is to generate at least 50-100 complexes between MHC molecule and the antigenic peptide per antigen-presenting cell, sensitizing a T cell population of appropriate clonal size and effector characteristics. Thus, the immunobiology of antigen recognition by T cells must be taken into account when designing new generation peptide- or gene-based vaccines. Since T cell recognition is MHC-restricted, and given the wide polymorphism of the different MHC molecules, distinct epitopes may be recognized by different individuals in the population. Therefore, the issue of whether immunization will be effective in inducing a protective immune response, covering the entire target population, becomes an important question. Many pathogens have evolved molecular mechanisms to escape recognition by the immune system by variation of antigenic protein sequences. In this short review, we will discuss the several concepts related to selection of amino acid sequences to be included in DNA and peptide vaccines.

  4. No major role for insulin-degrading enzyme in antigen presentation by MHC molecules.

    Directory of Open Access Journals (Sweden)

    Slobodan Culina

    Full Text Available Antigen presentation by MHC class I molecules requires degradation of epitope source proteins in the cytosol. Although the preeminent role of the proteasome is clearly established, evidence suggesting a significant role for proteasome-independent generation of class I ligands has been reported repeatedly. However, an enzyme responsible for such a role has not been identified. Recently insulin-degrading enzyme (IDE was shown to produce an antigenic peptide derived from the tumor antigen MAGE-A3 in an entirely proteasome-independent manner, raising the question of the global impact of IDE in MHC class I antigen processing. Here we report that IDE knockdown in human cell lines, or knockout in two different mouse strains, has no effect on cell surface expression of various MHC class I molecules, including allomorphs such as HLA-A3 and HLA-B27 suggested to be loaded in an at least a partly proteasome-independent manner. Moreover, reduced or absent IDE expression does not affect presentation of five epitopes including epitopes derived from beta amyloid and proinsulin, two preferred IDE substrates. Thus, IDE does not play a major role in MHC class I antigen processing, confirming the dominant and almost exclusive role of the proteasome in cytosolic production of MHC class I ligands.

  5. No major role for insulin-degrading enzyme in antigen presentation by MHC molecules.

    Science.gov (United States)

    Culina, Slobodan; Mauvais, François-Xavier; Hsu, Hsiang-Ting; Burgevin, Anne; Guénette, Suzanne; Moser, Anna; van Endert, Peter

    2014-01-01

    Antigen presentation by MHC class I molecules requires degradation of epitope source proteins in the cytosol. Although the preeminent role of the proteasome is clearly established, evidence suggesting a significant role for proteasome-independent generation of class I ligands has been reported repeatedly. However, an enzyme responsible for such a role has not been identified. Recently insulin-degrading enzyme (IDE) was shown to produce an antigenic peptide derived from the tumor antigen MAGE-A3 in an entirely proteasome-independent manner, raising the question of the global impact of IDE in MHC class I antigen processing. Here we report that IDE knockdown in human cell lines, or knockout in two different mouse strains, has no effect on cell surface expression of various MHC class I molecules, including allomorphs such as HLA-A3 and HLA-B27 suggested to be loaded in an at least a partly proteasome-independent manner. Moreover, reduced or absent IDE expression does not affect presentation of five epitopes including epitopes derived from beta amyloid and proinsulin, two preferred IDE substrates. Thus, IDE does not play a major role in MHC class I antigen processing, confirming the dominant and almost exclusive role of the proteasome in cytosolic production of MHC class I ligands.

  6. Salt bridge residues between I-Ak dimer of dimers alpha-chains modulate antigen presentation.

    Science.gov (United States)

    Yadati, S; Nydam, T; Demian, D; Wade, T K; Gabriel, J L; Barisas, B G; Wade, W F

    1999-03-15

    Class II dimers of dimers are predicted to have functional significance in antigen presentation. The putative contact amino acids of the I-Ak class II dimer of dimers have been identified by molecular modeling based on the DR1 crystal structure (Nydam et al., Int. Immunol. 10, 1237,1998). We have previously reported the role in antigen presentation of dimer of dimers contact amino acids located in the C-terminal domains of the alpha- and beta-chains of class II. Our calculations show that residues Ealpha89 and Ralpha145 in the alpha2-domain form an inter alpha-chain salt bridge between pairs of alphabeta-heterodimers. Other residues, Qalpha92 and Nalpha115, may be involved in close association in that part of the alpha-chain. We investigated the role of these amino acids on class II expression and antigen presentation. Class II composed of an Ealpha89K substituted alpha-chain paired with a wt beta-chain exhibited inhibited antigen presentation and expression of alpha-chain serologic epitopes. In contrast, mutation of Ralpha145E had less affect on antigen presentation and did not affect I-Ak serologic epitopes. Interchanging charges of the salt bridge residues by expressing both Ralpha145E and Ealpha89K on the same chain obviated the large negative effect of the Ealpha89K mutation on antigen presentation but not on the serologic epitopes. Our results are similar for those reported for mutation of DR3's inter-chain salt bridge with the exception that double mutants did not moderate the DR3 defect. Interestingly, the amino acids differences between I-A and DR change the location of the inter-chain salt bridges. In DR1 these residues are located at positions Ealpha88 and Kalpha111; in I-Ak these residues are located at position Ealpha89 and Ralpha145. Inter alpha-chain salt bridges are thus maintained in various class II molecules by amino acids located in different parts of the alpha2-domain. This conservation of structure suggests that considerable functional

  7. Parasite Manipulation of the Invariant Chain and the Peptide Editor H2-DM Affects Major Histocompatibility Complex Class II Antigen Presentation during Toxoplasma gondii Infection.

    Science.gov (United States)

    Leroux, Louis-Philippe; Nishi, Manami; El-Hage, Sandy; Fox, Barbara A; Bzik, David J; Dzierszinski, Florence S

    2015-10-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4(+) T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms inhibiting MHC-II function are currently unknown. Here, we show that, in addition to transcriptional regulation of MHC-II, the parasite modulates the expression of key components of the MHC-II antigen presentation pathway, namely, the MHC-II-associated invariant chain (Ii or CD74) and the peptide editor H2-DM, in professional antigen-presenting cells (pAPCs). Genetic deletion of CD74 restored the ability of infected dendritic cells to present a parasite antigen in the context of MHC-II in vitro. CD74 mRNA and protein levels were, surprisingly, elevated in infected cells, whereas MHC-II and H2-DM expression was inhibited. CD74 accumulated mainly in the endoplasmic reticulum (ER), and this phenotype required live parasites, but not active replication. Finally, we compared the impacts of genetic deletion of CD74 and H2-DM genes on parasite dissemination toward lymphoid organs in mice, as well as activation of CD4(+) T cells and interferon gamma (IFN-γ) levels during acute infection. Cyst burdens and survival during the chronic phase of infection were also evaluated in wild-type and knockout mice. These results highlight the fact that the infection is influenced by multiple levels of parasite manipulation of the MHC-II antigen presentation pathway. PMID:26195549

  8. Parasite Manipulation of the Invariant Chain and the Peptide Editor H2-DM Affects Major Histocompatibility Complex Class II Antigen Presentation during Toxoplasma gondii Infection

    OpenAIRE

    Leroux, Louis-Philippe; Nishi, Manami; El-Hage, Sandy; Fox, Barbara A.; Bzik, David J.; Dzierszinski, Florence S.

    2015-01-01

    Toxoplasma gondii is an obligate intracellular protozoan parasite. This apicomplexan is the causative agent of toxoplasmosis, a leading cause of central nervous system disease in AIDS. It has long been known that T. gondii interferes with major histocompatibility complex class II (MHC-II) antigen presentation to attenuate CD4+ T cell responses and establish persisting infections. Transcriptional downregulation of MHC-II genes by T. gondii was previously established, but the precise mechanisms...

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

    NARCIS (Netherlands)

    Faraco, J.; Lin, L.; Kornum, B.R.; Kenny, E.E.; Trynka, G.; Einen, M.; Rico, T.J.; Lichtner, P.; Dauvilliers, Y.; Arnulf, I.; Lecendreux, M.; Javidi, S.; Geisler, P.; Mayer, G.; Pizza, F.; Poli, F.; Plazzi, G.; Overeem, S.; Lammers, G.J.; Kemlink, D.; Sonka, K.; Nevsimalova, S.; Rouleau, G.; Desautels, A.; Montplaisir, J.; Frauscher, B.; Ehrmann, L.; Hogl, B.; Jennum, P.; Bourgin, P.; Peraita-Adrados, R.; Iranzo, A.; Bassetti, C.; Chen, W.M.; Concannon, P.; Thompson, S.D.; Damotte, V.; Fontaine, B.; Breban, M.; Gieger, C.; Klopp, N.; Deloukas, P.; Wijmenga, C.; Hallmayer, J.; Onengut-Gumuscu, S.; Rich, S.S.; Winkelmann, J.; Mignot, E.

    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

  10. 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 w...

  11. Balancing selection maintains a form of ERAP2 that undergoes nonsense-mediated decay and affects antigen presentation.

    Directory of Open Access Journals (Sweden)

    Aida M Andrés

    2010-10-01

    Full Text Available A remarkable characteristic of the human major histocompatibility complex (MHC is its extreme genetic diversity, which is maintained by balancing selection. In fact, the MHC complex remains one of the best-known examples of natural selection in humans, with well-established genetic signatures and biological mechanisms for the action of selection. Here, we present genetic and functional evidence that another gene with a fundamental role in MHC class I presentation, endoplasmic reticulum aminopeptidase 2 (ERAP2, has also evolved under balancing selection and contains a variant that affects antigen presentation. Specifically, genetic analyses of six human populations revealed strong and consistent signatures of balancing selection affecting ERAP2. This selection maintains two highly differentiated haplotypes (Haplotype A and Haplotype B, with frequencies 0.44 and 0.56, respectively. We found that ERAP2 expressed from Haplotype B undergoes differential splicing and encodes a truncated protein, leading to nonsense-mediated decay of the mRNA. To investigate the consequences of ERAP2 deficiency on MHC presentation, we correlated surface MHC class I expression with ERAP2 genotypes in primary lymphocytes. Haplotype B homozygotes had lower levels of MHC class I expressed on the surface of B cells, suggesting that naturally occurring ERAP2 deficiency affects MHC presentation and immune response. Interestingly, an ERAP2 paralog, endoplasmic reticulum aminopeptidase 1 (ERAP1, also shows genetic signatures of balancing selection. Together, our findings link the genetic signatures of selection with an effect on splicing and a cellular phenotype. Although the precise selective pressure that maintains polymorphism is unknown, the demonstrated differences between the ERAP2 splice forms provide important insights into the potential mechanism for the action of selection.

  12. Shedding light on anti-estrogen resistance and antigen presentation through biophysical techniques

    NARCIS (Netherlands)

    Zwart, Willem Teunis

    2009-01-01

    This thesis is composed of two parts part one: The study on anti-estrogen resistance and defining criteria a cell has to meet in order to become resistant to anti-estrogenic compounds. part two: the study of antigen-loading, vesicle positioning and costimulation.

  13. Emerging roles for antigen presentation in establishing host-microbiome symbiosis.

    Science.gov (United States)

    Bessman, Nicholas J; Sonnenberg, Gregory F

    2016-07-01

    Trillions of beneficial bacteria inhabit the intestinal tract of healthy mammals from birth. Accordingly, mammalian hosts have evolved a series of complementary and redundant pathways to limit pathologic immune responses against these bacteria, while simultaneously protecting against enteric pathogen invasion. These pathways can be generically responsive to the presence of any commensal bacteria and innate in nature, as for IL-22-related pathways. Alternatively, specific bacterial antigens can drive a distinct set of adaptive immune cell responses, including IgA affinity maturation and secretion, and a recently described pathway of intestinal selection whereby MHCII(+) ILC3 deletes commensal bacteria-reactive CD4 T cells. These pathways can either promote or inhibit colonization by specific subsets of commensal bacteria, and cooperatively maintain intestinal homeostasis. In this review, we will highlight recent developments in understanding how these diverse pathways complement each other to cooperatively shape the symbiotic relationship between commensal bacteria and mammalian hosts. PMID:27319348

  14. Adjuvant effects of liposomes containing lipid A: enhancement of liposomal antigen presentation and recruitment of macrophages.

    OpenAIRE

    Verma, J N; Rao, M.; Amselem, S; Krzych, U; Alving, C R; Green, S J; Wassef, N M

    1992-01-01

    Liposomes containing lipid A induced potent humoral immune responses in mice against an encapsulated malaria antigen (R32NS1) containing NANP epitopes. The immune response was not enhanced by lipid A alone or by empty liposomes containing lipid A. Experiments to investigate the adjuvant mechanisms of liposomes and lipid A revealed that liposome-encapsulated R32NS1 was actively presented by bone marrow-derived macrophages to NANP-specific cloned T cells. The degree of presentation was related ...

  15. Large adipocytes function as antigen-presenting cells to activate CD4+ T cells via upregulating MHCII in obesity

    OpenAIRE

    Xiao, L; Yang, X.; Lin, Y.; Li, S.; Jiang, J; Qian, S.(State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China); Tang, Q; He, R; Li, X.

    2015-01-01

    Background/Objectives: Although obesity is associated with low-grade inflammation and metabolic disorders, clinical studies suggested some obese people were metabolically healthy with smaller adipocyte size compared with metabolically abnormal obese (MAO). This indicated adipocyte size may be an important predictor underlay the distinction between MAO and metabolically healthy obese. As recent study has shown that adipocytes expressed class II major histocompatibility complex (MHCII), which f...

  16. White button mushroom enhances maturation of bone marrow derived dendritic cells and their antigen presenting function in mice

    Science.gov (United States)

    Mushrooms have been shown to enhance immune response, which contributes to their anti-tumor property. White button mushrooms (Agaricus bisporus) (WBM) constitute 90 percent of the total mushrooms consumed in the United States; however, the health benefit of this strain in general is not well studied...

  17. An alternative and effective HIV vaccination approach based on inhibition of antigen presentation attenuators in dendritic cells.

    OpenAIRE

    Xiao-Tong Song; Kevin Evel-Kabler; Lisa Rollins; Melissa Aldrich; Feng Gao; Xue F Huang; Si-Yi Chen

    2006-01-01

    BACKGROUND: Current efforts to develop HIV vaccines that seek to stimulate immune responses have been disappointing, underscoring the inability of natural immune responses to control HIV-1 infection. Here we tested an alternative strategy to induce anti-HIV immune responses by inhibiting a host's natural immune inhibitor. METHODS AND FINDINGS: We used small interfering RNA (siRNA) to inhibit suppressor of cytokine signaling (SOCS) 1, a key negative regulator of the JAK/STAT pathway, and inves...

  18. CNS myelin induces regulatory functions of DC-SIGN-expressing, antigen-presenting cells via cognate interaction with MOG

    NARCIS (Netherlands)

    J.J. Garcia-Vallejo; J.M. Ilarregui; H. Kalay; S. Chamorro; N. Koning; W.W. Unger; M. Ambrosini; V. Montserrat; R.J. Fernandes; S.C.M. Bruijns; J.R.T. van Weering; N.J. Paauw; T. O'Toole; J. van Horssen; P. van der Valk; K. Nazmi; J.G.M. Bolscher; J. Bajramovic; C.D. Dijkstra; B.A. 't Hart; Y. van Kooyk

    2014-01-01

    Myelin oligodendrocyte glycoprotein (MOG), a constituent of central nervous system myelin, is an important autoantigen in the neuroinflammatory disease multiple sclerosis (MS). However, its function remains unknown. Here, we show that, in healthy human myelin, MOG is decorated with fucosylated N-gly

  19. A Francisella tularensis Live Vaccine Strain That Improves Stimulation of Antigen-Presenting Cells Does Not Enhance Vaccine Efficacy

    OpenAIRE

    Schmitt, Deanna M; Dawn M O'Dee; Joseph Horzempa; Paul E Carlson; Russo, Brian C.; Bales, Jacqueline M.; Brown, Matthew J.; Nau, Gerard J.

    2012-01-01

    Vaccination is a proven strategy to mitigate morbidity and mortality of infectious diseases. The methodology of identifying and testing new vaccine candidates could be improved with rational design and in vitro testing prior to animal experimentation. The tularemia vaccine, Francisella tularensis live vaccine strain (LVS), does not elicit complete protection against lethal challenge with a virulent type A Francisella strain. One factor that may contribute to this poor performance is limited s...

  20. Fatal Attraction: Interactions between antigen-presenting cells and islets of Langerhans in the pathogenesis of autoimmune diabetes

    NARCIS (Netherlands)

    J.G.M. Rosmalen (Judith)

    2000-01-01

    textabstractThe onset of diabetes mellitus is characterized by various symptoms, all the result of a disturbed glucose metabolism. The main symptoms are thirst and an excessive production of urine. The disturbed glucose metabolism underlying these symptoms is due to an absolute deficiency of insulin

  1. From Antigen Presenting Cells to Antigen Presenting Vesicles:philosophic thinking on cancer immunotherapy%从抗原提呈细胞到抗原提呈小体

    Institute of Scientific and Technical Information of China (English)

    张红梅; 张利旺; 刘文超

    2006-01-01

    树突状细胞是体内专职抗原提呈细胞,在抗肿瘤免疫治疗中发挥重要作用.而exosome是树突状细胞分泌的一种膜性微囊小体,富含树突状细胞的MHC-Ⅰ/Ⅱ类分子、协同刺激分子等多种生物活性分子,亦在抗肿瘤免疫应答中发挥重要作用.从树突状细胞到exosome,是细胞性瘤苗向非细胞性瘤苗的飞跃,对免疫治疗研究产生极为深远的影响.

  2. The ESAT-6 Protein of Mycobacterium tuberculosis Interacts with Beta-2-Microglobulin (β2M) Affecting Antigen Presentation Function of Macrophage

    Science.gov (United States)

    Parveen, Nazia; Jha, Vishwanath; Valluri, Vijaya Lakshmi; Ghosh, Sudip; Mukhopadhyay, Sangita

    2014-01-01

    ESAT-6, an abundantly secreted protein of Mycobacterium tuberculosis (M. tuberculosis) is an important virulence factor, inactivation of which leads to reduced virulence of M. tuberculosis. ESAT-6 alone, or in complex with its chaperone CFP-10 (ESAT-6:CFP-10), is known to modulate host immune responses; however, the detailed mechanisms are not well understood. The structure of ESAT-6 or ESAT-6:CFP-10 complex does not suggest presence of enzymatic or DNA-binding activities. Therefore, we hypothesized that the crucial role played by ESAT-6 in the virulence of mycobacteria could be due to its interaction with some host cellular factors. Using a yeast two-hybrid screening, we identified that ESAT-6 interacts with the host protein beta-2-microglobulin (β2M), which was further confirmed by other assays, like GST pull down, co-immunoprecipitation and surface plasmon resonance. The C-terminal six amino acid residues (90–95) of ESAT-6 were found to be essential for this interaction. ESAT-6, in complex with CFP-10, also interacts with β2M. We found that ESAT-6/ESAT-6:CFP-10 can enter into the endoplasmic reticulum where it sequesters β2M to inhibit cell surface expression of MHC-I-β2M complexes, resulting in downregulation of class I-mediated antigen presentation. Interestingly, the ESAT-6:β2M complex could be detected in pleural biopsies of individuals suffering from pleural tuberculosis. Our data highlight a novel mechanism by which M. tuberculosis may undermine the host adaptive immune responses to establish a successful infection. Identification of such novel interactions may help us in designing small molecule inhibitors as well as effective vaccine design against tuberculosis. PMID:25356553

  3. The ESAT-6 protein of Mycobacterium tuberculosis interacts with beta-2-microglobulin (β2M affecting antigen presentation function of macrophage.

    Directory of Open Access Journals (Sweden)

    Gopalkrishna Sreejit

    2014-10-01

    Full Text Available ESAT-6, an abundantly secreted protein of Mycobacterium tuberculosis (M. tuberculosis is an important virulence factor, inactivation of which leads to reduced virulence of M. tuberculosis. ESAT-6 alone, or in complex with its chaperone CFP-10 (ESAT-6:CFP-10, is known to modulate host immune responses; however, the detailed mechanisms are not well understood. The structure of ESAT-6 or ESAT-6:CFP-10 complex does not suggest presence of enzymatic or DNA-binding activities. Therefore, we hypothesized that the crucial role played by ESAT-6 in the virulence of mycobacteria could be due to its interaction with some host cellular factors. Using a yeast two-hybrid screening, we identified that ESAT-6 interacts with the host protein beta-2-microglobulin (β2M, which was further confirmed by other assays, like GST pull down, co-immunoprecipitation and surface plasmon resonance. The C-terminal six amino acid residues (90-95 of ESAT-6 were found to be essential for this interaction. ESAT-6, in complex with CFP-10, also interacts with β2M. We found that ESAT-6/ESAT-6:CFP-10 can enter into the endoplasmic reticulum where it sequesters β2M to inhibit cell surface expression of MHC-I-β2M complexes, resulting in downregulation of class I-mediated antigen presentation. Interestingly, the ESAT-6:β2M complex could be detected in pleural biopsies of individuals suffering from pleural tuberculosis. Our data highlight a novel mechanism by which M. tuberculosis may undermine the host adaptive immune responses to establish a successful infection. Identification of such novel interactions may help us in designing small molecule inhibitors as well as effective vaccine design against tuberculosis.

  4. Human Leukocyte Antigen-Presented Macrophage Migration Inhibitory Factor Is a Surface Biomarker and Potential Therapeutic Target for Ovarian Cancer.

    Science.gov (United States)

    Patterson, Andrea M; Kaabinejadian, Saghar; McMurtrey, Curtis P; Bardet, Wilfried; Jackson, Ken W; Zuna, Rosemary E; Husain, Sanam; Adams, Gregory P; MacDonald, Glen; Dillon, Rachelle L; Ames, Harold; Buchli, Rico; Hawkins, Oriana E; Weidanz, Jon A; Hildebrand, William H

    2016-02-01

    T cells recognize cancer cells via HLA/peptide complexes, and when disease overtakes these immune mechanisms, immunotherapy can exogenously target these same HLA/peptide surface markers. We previously identified an HLA-A2-presented peptide derived from macrophage migration inhibitory factor (MIF) and generated antibody RL21A against this HLA-A2/MIF complex. The objective of the current study was to assess the potential for targeting the HLA-A2/MIF complex in ovarian cancer. First, MIF peptide FLSELTQQL was eluted from the HLA-A2 of the human cancerous ovarian cell lines SKOV3, A2780, OV90, and FHIOSE118hi and detected by mass spectrometry. By flow cytometry, RL21A was shown to specifically stain these four cell lines in the context of HLA-A2. Next, partially matched HLA-A*02:01+ ovarian cancer (n = 27) and normal fallopian tube (n = 24) tissues were stained with RL21A by immunohistochemistry to assess differential HLA-A2/MIF complex expression. Ovarian tumor tissues revealed significantly increased RL21A staining compared with normal fallopian tube epithelium (P < 0.0001), with minimal staining of normal stroma and blood vessels (P < 0.0001 and P < 0.001 compared with tumor cells) suggesting a therapeutic window. We then demonstrated the anticancer activity of toxin-bound RL21A via the dose-dependent killing of ovarian cancer cells. In summary, MIF-derived peptide FLSELTQQL is HLA-A2-presented and recognized by RL21A on ovarian cancer cell lines and patient tumor tissues, and targeting of this HLA-A2/MIF complex with toxin-bound RL21A can induce ovarian cancer cell death. These results suggest that the HLA-A2/MIF complex should be further explored as a cell-surface target for ovarian cancer immunotherapy.

  5. Differential Impact of PD-1 and/or Interleukin-10 Blockade on HIV-1-Specific CD4 T Cell and Antigen-Presenting Cell Functions

    OpenAIRE

    Porichis, Filippos; Hart, Meghan G.; Zupkosky, Jennifer; Barblu, Lucie; Kwon, Douglas S; McMullen, Ashley; Brennan, Thomas; Ahmed, Rafi; Freeman, Gordon J.; Kavanagh, Daniel G.; Kaufmann, Daniel E.

    2014-01-01

    Antigen persistence in chronic infections and cancer upregulates inhibitory networks, such as the PD-1 and interleukin-10 (IL-10) pathways, that impair immunity and lead to disease progression. These pathways are attractive targets for immunotherapy, as demonstrated by recent clinical trials of PD-1/PD-L1 blockade in cancer patients. However, in HIV-1 infection not all subjects respond to inhibition of either pathway and the mechanistic interactions between these two networks remain to be bet...

  6. Antigen-presenting cells exposed to Lactobacillus acidophilus NCFM, Bifidobacterium bifidum BI-98, and BI-504 reduce regulatory T cell activity

    DEFF Research Database (Denmark)

    Schmidt, Esben Gjerløff Wedebye; Claesson, Mogens Helweg; Jensen, Simon Skjøde;

    2010-01-01

    BACKGROUND:: The effect in vitro of six different probiotic strains including Lactobacillus acidophilus NCFM, Lactobacillus salivarius Ls-33, Lactobacillus paracasei subsp. paracasei YS8866441, Lactobacillus plantarum Lp-115, Bifidobacterium bifidum BI-504 and BI-98 was studied on splenic...

  7. Migration of antigen-presenting B cells from peripheral to mucosal lymphoid tissues may induce intestinal antigen-specific IgA following parenteral immunization

    NARCIS (Netherlands)

    Coffin, SE; Clark, SL; Bos, NA; Brubaker, JO; Offit, PA

    1999-01-01

    Parenterally administered immunizations have long been used to induce protection from mucosal pathogens such as Bordetella pertussis and influenza virus. We previously found that i.m. inoculation of mice with the intestinal pathogen, rotavirus, induced virus-specific Ab production by intestinal lymp

  8. 三肽基肽酶Ⅱ(TPPⅡ)对抗原的提呈作用机制研究进展%Progress on mechanism of tripeptidyl-peptidase Ⅱ in the antigenic presentation

    Institute of Scientific and Technical Information of China (English)

    吴玢; 吕凤林; 孔祥军; 任勇刚

    2012-01-01

    Ripetidyl peptidase Ⅱ is a multi-purpose macromolecule serine protease existing in the cytoplasm, which can assists proteasome and other extracellular enzyme participating in the protein metabolism cycle. Recent figures showed that TPP Ⅱ plays a vital contradictory role both in the generation and destroy of MHC- Ⅰ antigen ligands. However, the mechanism involved in these processes remains unclear. In this paper, we first explore the cell biology characteristics of TPP Ⅱ , and then focus on the role of TPPⅡ in the process of MHC - Ⅰ antigen presentation. Finally, we presume that TPP Ⅱ has the important meaning in the new vaccine design.%三肽基肽酶Ⅱ (Ripetidyl PeptidaseⅡ,TPPⅡ)是存在于细胞质中的一种多功能丝氨酸蛋白酶,主要协助蛋白酶体和其他的胞外酶并且参与蛋白周期代谢,最近的数据显示,TPPⅡ对MHC-Ⅰ类分子抗原表位的产生与破坏均有重要作用,但是TPPⅡ在MHC- Ⅰ类抗原递呈中的具体作用机制尚有待进一步研究.本文综述TPPⅡ的细胞生物学特征,着重探究TPPⅡ在MHC- Ⅰ类抗原递呈中作用,并且指出TPPⅡ在新型疫苗设计上具有重要的指导意义.

  9. Antigenic presentation of heterologous epitopes engineered into the outer surface-exposed helix 4 loop region of human papillomavirus L1 capsomeres

    Directory of Open Access Journals (Sweden)

    Murata Yoshihiko

    2009-06-01

    Full Text Available Abstract Background Human papillomavirus (HPV L1 capsid proteins can self-assemble into pentamers (capsomeres that are immunogenic and can elicit neutralizing antibodies. Structural modelling of L1 inter-pentameric interactions predicts that helix 4 (h4 of each of the five L1 monomers project laterally and outwards from the pentamer. We sought to utilize HPV L1 capsomeres as a vaccine platform by engineering heterologous epitopes within L1 derivatives deleted for h4 domain. Results We used baculovirus – infected Trichoplusia ni cells and ultracentrifugation to synthesize and purify three 16L1 derivatives: one bearing a short deletion (amino acids 404–436 encompassing the h4 domain, and two others, each bearing a conserved neutralizing epitope of the human respiratory syncytial virus (RSV fusion (F protein (residues 255–278 and 423–436 that was substituted for the deleted L1 h4 domain residues. Each of the three capsomere derivatives was recognized by anti-L1 antibodies, while two bearing the RSV F-derived moieties were recognized by anti-RSV F antibodies. All three L1 derivatives formed ring-like structures that were similar in morphology and size to those described for native 16L1 capsomeres. When injected into mice, each of the capsomere derivatives was immunogenic with respect to L1 protein, and immunization with chimeric L1-RSV F pentamers resulted in RSV non-neutralizing antisera that recognized purified RSV F protein in immunoblots. Conclusion HPV L1 monomers bearing heterologous epitopes within the L1 h4 region can self-assemble into capsomeres that elicit antibody response against such non-HPV encoded epitopes. Thus, the L1 h4 region can function as a novel antigen display site within the L1 pentamer, which in turn may serve as a potential vaccine template.

  10. B cells exposed to enterobacterial components suppress development of experimental colitis

    DEFF Research Database (Denmark)

    Schmidt, Esben Gjerløff Wedebye; Larsen, Hjalte List; Kristensen, Nanna Ny;

    2012-01-01

    BACKGROUND: B cells positively contribute to immunity by antigen presentation to CD4(+) T cells, cytokine production, and differentiation into antibody secreting plasma cells. Accumulating evidence implies that B cells also possess immunoregulatory functions closely linked to their capability of ...

  11. Polymorphisms of transporter associated with antigen presentation, tumor necrosis factor-α and interleukin-10 and their implications for protection and susceptibility to severe forms of dengue fever in patients in Sri Lanka

    Directory of Open Access Journals (Sweden)

    Anira N Fernando

    2015-01-01

    Full Text Available Context: To date, a clear understanding of dengue disease pathogenesis remains elusive. Some infected individuals display no symptoms while others develop severe life-threatening forms of the disease. It is widely believed that host genetic factors influence dengue severity. Aims: This study evaluates the relationship between certain polymorphisms and dengue severity in Sri Lankan patients. Settings and Design: Polymorphism studies are carried out on genes for; transporter associated with antigen presentation (TAP, promoter of tumor necrosis factor-α (TNF-α, and promoter of interleukin-10 (IL-10. In other populations, TAP1 (333, TAP2 (379, TNF-α (−308, and IL-10 (−1082, −819, −592 have been associated with dengue and a number of different diseases. Data have not been collected previously for these polymorphisms for dengue patients in Sri Lanka. Materials and Methods: The polymorphisms were typed by amplification refractory mutation system polymerase chain reaction in 107 dengue hemorrhagic fever (DHF patients together with 62 healthy controls. Statistical Analysis Used: Pearson′s Chi-square contingency table analysis with Yates′ correction. Results: Neither the TAP nor the IL-10 polymorphisms considered individually can define dengue disease outcome with regard to severity. However, the genotype combination, IL-10 (−592/−819/−1082 CCA/ATA was significantly associated with development of severe dengue in these patients, suggesting a risk factor to developing DHF. Also, identified is the genotype combination IL-10 (−592/−819/−1082 ATA/ATG which suggested a possibility for protection from DHF. The TNF-α (−308 GG genotype was also significantly associated with severe dengue, suggesting a significant risk factor. Conclusions: The results reported here are specific to the Sri Lankan population. Comparisons with previous reports imply that data may vary from population to population.

  12. 抗原提呈细胞在银屑病发病机制中的作用%The role of antigen presenting cell in the pathogenesis of psoriasis

    Institute of Scientific and Technical Information of China (English)

    邹炳辉; 王蓉蓉; 张虎祥; 陈霖; 李秉煦; 朱启建

    2010-01-01

    目的:观察银屑病皮损组织内郎格罕氏细胞(LC)、真皮树突细胞(DDC)、巨噬细胞的变化及角阮细胞HPV感染情况,探讨LC、DDC、巨噬细胞及HPV与银屑病发病的关系.方法:选用我院病理科2003-2008年期间确诊为银屑病的病理切片,采用免疫组织化学方法观察银屑病皮损组织表皮CD1a、真皮CD1a、真皮CD68+的表达.用Image-Pro Plus 6.0图像处理软件测定每个高倍视野表皮中CD1 α+的LC的数目,真皮内CD1 α+的DDC的数目、CD68+的巨噬细胞的数目.采用原住杂交方法,检测银屑病表皮组织内HPV13、HPV16、HPV32 DNA.结果:银屑病组皮损组织郎格罕氏细胞数目明显增多,急性进行期为(15.82±1.48)个,慢性静止期为(14.96±1.74)个,正常对照组为(4.23±1.42)个,与正常组比较,差异均有显著性(P<0.05).银屑病DDC、巨噬细胞数目明显增多,分别为(9.08±2.48)个、(27.19±4.3)个,正常对照组分别为(2.45±1.04)个、(6.7±1.43)个,两组比较差异有显著性(P<0.05).银屑病表皮组织内未检测HPV13、HPV16、HPV32 DNA.结论:LC、DDC、巨噬细胞与银屑病的发病密切相关,而与HPV的感染可能无关.

  13. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...

  14. Human plasmacytoid dendritic cells: from molecules to intercellular communication network

    OpenAIRE

    Till Sebastian Manuel Mathan; Carl Gustav Figdor; Sonja Ingrid Buschow

    2013-01-01

    Plasmacytoid Dendritic Cells (pDCs) are a specific subset of naturally occurring dendritic cells, that secrete large amounts of Type I interferon and play an important role in the immune response against viral infection. Several studies have highlighted that they are also effective antigen presenting cells (APCs), making them an interesting target for immunotherapy against cancer. However, the modes of action of pDCs are not restricted to antigen presentation and IFN secretion alone. In this ...

  15. Human Plasmacytoid Dendritic Cells: From Molecules to Intercellular Communication Network

    OpenAIRE

    Mathan, Till S. M.; Figdor, Carl G.; Buschow, Sonja I.

    2013-01-01

    Plasmacytoid dendritic cells (pDCs) are a specific subset of naturally occurring dendritic cells, that secrete large amounts of Type I interferon and play an important role in the immune response against viral infection. Several studies have highlighted that they are also effective antigen presenting cells, making them an interesting target for immunotherapy against cancer. However, the modes of action of pDCs are not restricted to antigen presentation and IFN secretion alone. In this review ...

  16. Exosomes Derived from M. Bovis BCG Infected Macrophages Activate Antigen-Specific CD4+ and CD8+ T Cells In Vitro and In Vivo

    OpenAIRE

    Giri, Pramod K.; Schorey, Jeffrey S.

    2008-01-01

    Activation of both CD4(+) and CD8(+) T cells is required for an effective immune response to an M. tuberculosis infection. However, infected macrophages are poor antigen presenting cells and may be spatially separated from recruited T cells, thus limiting antigen presentation within a granuloma. Our previous studies showed that infected macrophages release from cells small membrane-bound vesicles called exosomes which contain mycobacterial lipid components and showed that these exosomes could...

  17. Dendritic cell-tumor cell hybrids and immunotherapy

    DEFF Research Database (Denmark)

    Cathelin, Dominique; Nicolas, Alexandra; Bouchot, André;

    2011-01-01

    Dendritic cells (DC) are professional antigen-presenting cells currently being used as a cellular adjuvant in cancer immunotherapy strategies. Unfortunately, DC-based vaccines have not demonstrated spectacular clinical results. DC loading with tumor antigens and DC differentiation and activation...

  18. Targeting vaccines to dendritic cells

    DEFF Research Database (Denmark)

    Foged, Camilla; Sundblad, Anne; Hovgaard, Lars

    2002-01-01

    Dendritic cells (DC) are specialized antigen presenting cells (APC) with a remarkable ability to take up antigens and stimulate major histocompatibility complex (MHC)-restricted specific immune responses. Recent discoveries have shown that their role in initiating primary immune responses seems t...

  19. Dendritic cells modified by vitamin D

    DEFF Research Database (Denmark)

    Pedersen, Ayako Wakatsuki; Claesson, Mogens Helweg; Zocca, Mai-Britt

    2011-01-01

    Dendritic cells (DCs), the most potent antigen-presenting cells of the immune system, express nuclear receptors for 1,25-dihydroxyvitamin D(3) (VD3) and they are one of its main targets. In the presence of VD3, DCs differentiate into a phenotype that resembles semimature DCs, with reduced T cell...

  20. Skin Dendritic Cells in Burn Patients

    OpenAIRE

    D’Arpa, N.; D’Amelio, L.; Accardo-Palumbo, A.; Pileri, D.; Mogavero, R.; Amato, G.; Napoli, B.; Alessandro, G.; Lombardo, C.; F. Conte

    2009-01-01

    The body's immunological response to burn injury has been a subject of great inquiry in recent years. Burn injury disturbs the immune system, resulting in a progressive suppression of the immune response that is thought to contribute to the development of sepsis. Dendritic cells (DCs) are potent antigen-presenting cells that possess the ability to stimulate naïve T cells.

  1. Regulatory T-cell compartmentalization and trafficking

    OpenAIRE

    Wei, Shuang; Kryczek, Ilona; Zou, Weiping

    2006-01-01

    CD4+CD25+FOXP3+ regulatory T cells (CD4+ Treg cells) are thought to differentiate in the thymus and immigrate from the thymus to the periphery. Treg cells can regulate both acquired and innate immunity through multiple modes of suppression. The cross-talk between Treg cells and targeted cells, such as antigen-presenting cells (APCs) and T cells, is crucial for ensuring suppression by Treg cells in the appropriate microenvironment. Emerging evidence suggests that Treg compartmentalization and ...

  2. Autoinflammation and HLA-B27: Beyond Antigen Presentation.

    Science.gov (United States)

    Sibley, Cailin H

    2016-08-01

    HLA-B27 associated disorders comprise a group of inflammatory conditions which have in common an association with the HLA class I molecule, HLA-B27. Given this association, these diseases are classically considered disorders of adaptive immunity. However, mounting data are challenging this assumption and confirming that innate immunity plays a more prominent role in pathogenesis than previously suspected. In this review, the concept of autoinflammation is discussed and evidence is presented from human and animal models to support a key role for innate immunity in HLA-B27 associated disorders. PMID:27229619

  3. Cell to Cell Signalling via Exosomes Through esRNA

    OpenAIRE

    Lotvall, Jan; Valadi, Hadi

    2007-01-01

    Exosomes are small vesicles of endosomal origin that can be released by many different cells to the microenvironment. Exosomes have been shown to participate in the immune system, by mediating antigen presentation. We have recently shown the presence of both mRNA and microRNA in exosomes, specifically in exosomes derived from mast cells. This RNA can be transferred between one mast cell to another, most likely through fusion of the exosome to the recipient cell membrane. The delivered RNA is ...

  4. Human Vδ2+ γδ T cells differentially induce maturation, cytokine production and alloreactive T cell stimulation by dendritic cells and B cells

    OpenAIRE

    Andreea ePetrasca; Doherty, Derek G.

    2014-01-01

    Human γδ T cells expressing the Vγ9Vδ2 T cell receptor can induce maturation of dendritic (DC) into antigen-presenting cells (APC) and B cells into antibody-secreting plasma cells. Since B cells are capable of presenting antigens to T cells, we investigated if Vγ9Vδ2 T cells can influence antigen presentation by these cells. We report that Vδ2 T cells induced expression of CD86, HLA-DR and CD40 by B cells and stimulated the release of IL-4, IL-6, TNF-α, and IgG, IgA and IgM. Vγ9Vδ2 T cells al...

  5. Auto-presentation of Staphylococcal enterotoxin A by mouse CD4+ T cells

    Science.gov (United States)

    The currently accepted model for superantigen (SAg )induced T cell activation suggests that SAg, without being processed, cross links both MHC class II, from Antigen Presenting Cells (APC), and V-beta, from T-cell receptor (TCR), initiating nonspecific T-cell activation. This T-cell proliferation in...

  6. Immunomodulation by mesenchymal stem cells: Interplay between mesenchymal stem cells and regulatory lymphocytes

    Science.gov (United States)

    Ma, Oscar Ka-Fai; Chan, Koon Ho

    2016-01-01

    Mesenchymal stem cells (MSCs) possess immunomodulatory properties, which confer enormous potential for clinical application. Considerable evidence revealed their efficacy on various animal models of autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus and uveitis. MSCs elicit their immunomodulatory effects by inhibiting lymphocyte activation and proliferation, forbidding the secretion of proinflammatory cytokines, limiting the function of antigen presenting cells, and inducing regulatory T (Treg) and B (Breg) cells. The induction of Treg and Breg cells is of particular interest since Treg and Breg cells have significant roles in maintaining immune tolerance. Several mechanisms have been proposed regarding to the MSCs-mediated induction of Treg and Breg cells. Accordingly, MSCs induce regulatory lymphocytes through secretion of multiple pleiotropic cytokines, cell-to-cell contact with target cells and modulation of antigen-presenting cells. Here, we summarized how MSCs induce Treg and Breg cells to provoke immunosuppression.

  7. Immunomodulation by mesenchymal stem cells: Interplay between mesenchymal stem cells and regulatory lymphocytes.

    Science.gov (United States)

    Ma, Oscar Ka-Fai; Chan, Koon Ho

    2016-09-26

    Mesenchymal stem cells (MSCs) possess immunomodulatory properties, which confer enormous potential for clinical application. Considerable evidence revealed their efficacy on various animal models of autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus and uveitis. MSCs elicit their immunomodulatory effects by inhibiting lymphocyte activation and proliferation, forbidding the secretion of proinflammatory cytokines, limiting the function of antigen presenting cells, and inducing regulatory T (Treg) and B (Breg) cells. The induction of Treg and Breg cells is of particular interest since Treg and Breg cells have significant roles in maintaining immune tolerance. Several mechanisms have been proposed regarding to the MSCs-mediated induction of Treg and Breg cells. Accordingly, MSCs induce regulatory lymphocytes through secretion of multiple pleiotropic cytokines, cell-to-cell contact with target cells and modulation of antigen-presenting cells. Here, we summarized how MSCs induce Treg and Breg cells to provoke immunosuppression. PMID:27679683

  8. Pancreatic islet-specific T-cell clones from nonobese diabetic mice.

    OpenAIRE

    Haskins, K; Portas, M; Bergman, B.; Lafferty, K; Bradley, B

    1989-01-01

    We have produced a panel of islet-specific T-cell clones from nonobese diabetic (NOD) mice. These clones proliferate and make interleukin 2 in an antigen-specific manner in response to NOD antigen-presenting cells and islet cells. Most of the clones respond to islet-cell antigen from different mouse strains but only in the presence of antigen-presenting cells bearing the class II major histocompatibility complex of the NOD mouse. In vivo, the clones mediate the destruction of islet, but not p...

  9. Dendritic Cells and Liver Fibrosis

    OpenAIRE

    Rahman, Adeeb H.; Aloman, Costica

    2013-01-01

    Dendritic cells are a relative rare population of specialized antigen presenting cells that are distributed through most lymphoid and non-lymphoid tissues and play a critical role in linking the innate and adaptive arms of the immune system. The liver contains a heterogeneous population of dendritic cells that may contribute to liver inflammation and fibrosis through a number of mechanisms. This review summarizes current knowledge on the development and characterization of liver dendritic cel...

  10. Selective transport of internalized antigens to the cytosol for MHC class I presentation in dendritic cells

    NARCIS (Netherlands)

    Rodriguez, A; Regnault, A; Kleijmeer, M; Ricciardi-Castagnoli, P; Amigorena, S

    1999-01-01

    In order for cytotoxic T cells to initiate immune responses, peptides derived from internalized antigens must be presented to the cytotoxic T cells on major histocompatibility complex (MHC) class I molecules. Here we show that dendritic cells, the only antigen-presenting cells that initiate immune r

  11. Multivalent glycopeptide dendrimers for the targeted delivery of antigens to dendritic cells

    NARCIS (Netherlands)

    J.J. García-Vallejo; M. Ambrosini; A. Overbeek; W.E. van Riel; K. Bloem; W.W.J. Unger; F. Chiodo; J.G. Bolscher; K. Nazmi; H. Kalay; Y. van Kooyk

    2013-01-01

    Dendritic cells are the most powerful type of antigen presenting cells. Current immunotherapies targeting dendritic cells have shown a relative degree of success but still require further improvement. One of the most important issues to solve is the efficiency of antigen delivery to dendritic cells

  12. Mast Cell-Derived Exosomes Promote Th2 Cell Differentiation via OX40L-OX40 Ligation

    OpenAIRE

    Fei Li; Yuping Wang; Lihui Lin; Juan Wang; Hui Xiao; Jia Li; Xia Peng; Huirong Dai; Li Li

    2016-01-01

    Exosomes are nanovesicles released by different cell types, such as dendritic cells (DCs), mast cells (MCs), and tumor cells. Exosomes of different origin play a role in antigen presentation and modulation of immune response to infectious disease. In this study, we demonstrate that mast cells and CD4+ T cells colocated in peritoneal lymph nodes from BALB/c mouse. Further, bone marrow-derived mast cells (BMMCs) constitutively release exosomes, which express CD63 and OX40L. BMMC-exosomes partia...

  13. Staining of Langerhans cells with monoclonal antibodies to macrophages and lymphoid cells.

    OpenAIRE

    Haines, K A; Flotte, T. J.; Springer, T A; Gigli, I; Thorbecke, G. J.

    1983-01-01

    Langerhans cells are Ia-bearing antigen-presenting cells in the epidermis that share many functions with macrophages. We have used monoclonal antibodies to the macrophage antigens, Mac-2 and-3, Ia antigen, Fc fragment receptor and the common leukocyte antigen CLA to compare the cell surface antigens of these cells with those of interdigitating and follicular dendritic cells and of macrophages in lymphoid tissues. Immunoperoxidase staining was carried out with epidermal sheets from BALB/c mice...

  14. "Flagellated" cancer cells propel anti-tumor immunity.

    Science.gov (United States)

    Garaude, Johan; Blander, J Magarian

    2012-09-01

    The use of innate immune receptor agonists in cancer therapies has suffered from many drawbacks. Our recent observations suggest that some of these hurdles can be overcome by introducing flagellin into tumor cells to promote tumor antigen presentation by dendritic cells (DCs) and simultaneously trigger two types of pattern recognition receptors (PRRs).

  15. B Cells Promote Th1- Skewed NKT Cell Response by CD1d-TCR Interaction

    OpenAIRE

    Shin, Jung Hoon; Park, Se-Ho

    2013-01-01

    CD1d expressing dendritic cells (DCs) are good glyco-lipid antigen presenting cells for NKT cells. However, resting B cells are very weak stimulators for NKT cells. Although α-galactosylceramide (α-GalCer) loaded B cells can activate NKT cells, it is not well defined whether B cells interfere NKT cell stimulating activity of DCs. Unexpectedly, we found in this study that B cells can promote Th1-skewed NKT cell response, which means a increased level of IFN-γ by NKT cells, concomitant with a d...

  16. Dendritic cells in rheumatoid arthritis: Which subset should be used as a tool to induce tolerance?

    NARCIS (Netherlands)

    M.C. Lebre; P.P. Tak

    2009-01-01

    Dendritic cells (DC) comprise a complex network of heterogeneous antigen-presenting cells (APC) that are critical not only to the initiation and regulation of adaptive immunity (Th1/Th2/Th17 responses), but also to the maintenance of both central and peripheral tolerance (regulatory T cells, periphe

  17. Canine Distemper Virus Infection Leads to an Inhibitory Phenotype of Monocyte-Derived Dendritic Cells In Vitro with Reduced Expression of Co-Stimulatory Molecules and Increased Interleukin-10 Transcription

    OpenAIRE

    Visar Qeska; Yvonne Barthel; Vanessa Herder; Stein, Veronika M.; Andrea Tipold; Carola Urhausen; Anne-Rose Günzel-Apel; Karl Rohn; Wolfgang Baumgärtner; Andreas Beineke

    2014-01-01

    Canine distemper virus (CDV) exhibits a profound lymphotropism that causes immunosuppression and increased susceptibility of affected dogs to opportunistic infections. Similar to human measles virus, CDV is supposed to inhibit terminal differentiation of dendritic cells (DCs), responsible for disturbed repopulation of lymphoid tissues and diminished antigen presenting function in dogs. In order to testify the hypothesis that CDV-infection leads to an impairment of professional antigen present...

  18. Enteroantigen-presenting B cells efficiently stimulate CD4(+) T cells in vitro

    DEFF Research Database (Denmark)

    Schmidt, Esben Gjerløff Wedebye; Kristensen, Nanna Ny; Claesson, Mogens Helweg;

    2011-01-01

    Presentation of enterobacterial antigens by antigen-presenting cells and activation of enteroantigen-specific CD4(+) T cells are considered crucial steps in inflammatory bowel disease (IBD) pathology. The detrimental effects of such CD4(+) T cells have been thoroughly demonstrated in models...... of colitis. Also, we have previously established an in vitro assay where murine enteroantigen-specific colitogenic CD4(+) CD25(-) T cells are activated by splenocytes pulsed with an enterobacterial extract....

  19. Langerhans Cell Histiocytosis Presenting as Uncontrolled Asthma

    OpenAIRE

    Rawlins, Frederic A.; Hull, James E.; Morgan, Julia A.; Morris, Michael J.

    2013-01-01

    Langerhans cell histiocytosis (LCH) is an uncommon disorder affecting primarily young adult smokers. It is characterized by abnormal proliferation of Langerhans cells, specialized monocyte-macrophage lineage antigen-presenting cells. LCH can affect the lungs in isolation or as part of a systemic disease. Most commonly, the disease presents in the third or fourth decade without gender predominance. Symptoms typically include dyspnea and cough. Commonly, physical examination is unremarkable but...

  20. Immunologic glycosphingolipidomics and NKT cell development in mouse thymus

    DEFF Research Database (Denmark)

    Li, Yunsen; Thapa, Prakash; Hawke, David;

    2009-01-01

    Invariant NKT cells are a hybrid cell type of Natural Killer cells and T cells, whose development is dependent on thymic positive selection mediated by double positive thymocytes through their recognition of natural ligands presented by CD1d, a nonpolymorphic, non-MHC, MHC-like antigen presenting...... for identifying additional ligands for NKT cells. Our results also provide early insights into cellular lipidomics studies, with a specific focus on the important immunological functions of glycosphingolipids....

  1. Langerhans cells and their role in oral mucosal diseases.

    Science.gov (United States)

    Upadhyay, Juhi; Upadhyay, Ram B; Agrawal, Pankaj; Jaitley, Shweta; Shekhar, Rhitu

    2013-09-01

    Dendritic cells are arguably the most potent antigen-presenting cells and may be the only cells capable of initiating the adaptive immune response. The epithelial residents of dendritic cells are Langerhans cells, which serve as the "sentinels" of the mucosa, altering the immune system not only to pathogen entry but also of tolerance to self antigen and commensal microbes. Oral mucosal Langerhans cells are capable of engaging and internalizing a wide variety of pathogens and have been found responsive to nickel in patients with nickel allergies, oral Candida species, oral lichen planus, lichenoid drug eruptions, graft versus host diseases, periodontal diseases median rhomboid glossitis, human immunodeficiency virus infection, hairy leukoplakia of the tongue, and oral squamous cell carcinoma. Review focuses on the role of antigen-presenting cells in particular Langerhans cells to better understand the mechanisms underlying immune responses. In this review, comprehensive detail about mucosal diseases has been compiled using the PubMed database and through textbooks. PMID:24251267

  2. Intravenous delivery of HIV-based lentiviral vectors preferentially transduces F4/80+ and Ly-6C+ cells in spleen, important target cells in autoimmune arthritis

    NARCIS (Netherlands)

    Brand, B.T. van den; Vermeij, E.A.; Waterborg, C.E.; Arntz, O.J.; Kracht, M.; Bennink, M.B.; Berg, W.B. van den; Loo, F.A. van de

    2013-01-01

    Antigen presenting cells (APCs) play an important role in arthritis and APC specific gene therapeutic targeting will enable intracellular modulation of cell activity. Viral mediated overexpression is a potent approach to achieve adequate transgene expression levels and lentivirus (LV) is useful for

  3. Proteomic analysis of exosomes secreted by human mesothelioma cells

    NARCIS (Netherlands)

    J.P.J.J. Hegmans (Joost); A. Hemmes (Annabrita); T.M. Luider (Theo); M.J. Kleijmeer (Monique); J-B. Prins (Jan-Bas); L. Zitvogel; S.A. Burgers (Sjaak); H.C. Hoogsteden (Henk); B.N.M. Lambrecht (Bart); M.P.L. Bard (Martin)

    2004-01-01

    textabstractExosomes are small membrane vesicles secreted into the extracellular compartment by exocytosis. Tumor exosomes may be involved in the sampling of antigens to antigen presenting cells or as decoys allowing the tumor to escape immune-directed destruction. The proteins pre

  4. Geometry sensing by dendritic cells dictates spatial organization and PGE(2)-induced dissolution of podosomes.

    NARCIS (Netherlands)

    Dries, K. van den; Helden, S.F.G. van; Riet, J.T. te; Diez-Ahedo, R.; Manzo, C.; Oud, M.M.; Leeuwen, F.N. van; Brock, R.E.; Garcia-Parajo, M.F.; Cambi, A.; Figdor, C.G.

    2012-01-01

    Assembly and disassembly of adhesion structures such as focal adhesions (FAs) and podosomes regulate cell adhesion and differentiation. On antigen-presenting dendritic cells (DCs), acquisition of a migratory and immunostimulatory phenotype depends on podosome dissolution by prostaglandin E(2) (PGE(2

  5. Aging and the Dendritic Cell System: Implications for Cancer

    OpenAIRE

    Shurin, Michael R.; Shurin, Galina V.; Chatta, Gurkamal S.

    2007-01-01

    The immune system shows a decline in responsiveness to antigens both with aging, as well as in the presence of tumors. The malfunction of the immune system with age can be attributed to developmental and functional alterations in several cell populations. Previous studies have shown defects in humoral responses and abnormalities in T cell function in aged individuals, but have not distinguished between abnormalities in antigen presentation and intrinsic T cell or B cell defects in aged indivi...

  6. Langerhans Cell Histiocytosis of Thyroid—A Diagnostic Dilemma

    OpenAIRE

    Pandyaraj, R. A.; Sathik Mohamed Masoodu, K.; Maniselvi, S.; S Savitha; Divya Devi, H.

    2014-01-01

    Langerhans cell histiocytosis (LCH) is a rare disease of antigen presenting cells and involvement of thyroid is really uncommon. The thyroid if involved is usually seen in multisystem disease but isolated thyroid involvement is very rare. The diagnosis of Langerhans cell histiocytosis of the thyroid is very challenging due to its rarity and is usually misdiagnosed as benign goiters, undifferentiated carcinoma, lymphoma, etc. Management of Langerhans cell histiocytosis of the thyroid also rema...

  7. Production of lentiviral vectors with enhanced efficiency to target dendritic cells by attenuating mannosidase activity of mammalian cells

    OpenAIRE

    Wang Pin; Joo Kye-Il; Froelich Steven; Tai April

    2011-01-01

    Abstract Background Dendritic cells (DCs) are antigen-presenting immune cells that interact with T cells and have been widely studied for vaccine applications. To achieve this, DCs can be manipulated by lentiviral vectors (LVs) to express antigens to stimulate the desired antigen-specific T cell response, which gives this approach great potential to fight diseases such as cancers, HIV, and autoimmune diseases. Previously we showed that LVs enveloped with an engineered Sindbis virus glycoprote...

  8. Immunomodulatory properties of probiotic bacteria:Effects on dendritic cells and their interactions with NK cells and T cells

    OpenAIRE

    Fink, Lisbeth Nielsen; Christensen, Hanne Risager; Frøkiær, Hanne

    2007-01-01

    Certain lactic acid bacteria (LAB) are part of the commensal intestinal flora and considered beneficial for health, as they compete with pathogens for adhesion sites in the intestine and ferment otherwise indigestible compounds. Another important property of these so-called probiotic bacteria is the ability to modulate the immune response. This thesis describes the immunomodulatory properties of gut-derived bacterial strains on different antigen-presenting cells, and the effector cell respons...

  9. Activated Human T Cells Secrete Exosomes That Participate in IL-2 Mediated Immune Response Signaling

    OpenAIRE

    Wahlgren, Jessica; Tanya De L Karlson; Glader, Pernilla; Telemo, Esbjörn; Valadi, Hadi

    2012-01-01

    It has previously been shown that nano-meter sized vesicles (30–100 nm), exosomes, secreted by antigen presenting cells can induce T cell responses thus showing the potential of exosomes to be used as immunological tools. Additionally, activated CD3+ T cells can secrete exosomes that have the ability to modulate different immunological responses. Here, we investigated what effects exosomes originating from activated CD3+ T cells have on resting CD3+ T cells by studying T cell proliferation, c...

  10. Lung-resident tissue macrophages generate Foxp3+ regulatory T cells and promote airway tolerance

    OpenAIRE

    Soroosh, Pejman; Doherty, Taylor A.; Duan, Wei; Mehta, Amit Kumar; Choi, Heonsik; Adams, Yan Fei; Mikulski, Zbigniew; Khorram, Naseem; Rosenthal, Peter; Broide, David H.; Croft, Michael

    2013-01-01

    Airway tolerance is the usual outcome of inhalation of harmless antigens. Although T cell deletion and anergy are likely components of tolerogenic mechanisms in the lung, increasing evidence indicates that antigen-specific regulatory T cells (inducible Treg cells [iTreg cells]) that express Foxp3 are also critical. Several lung antigen-presenting cells have been suggested to contribute to tolerance, including alveolar macrophages (MØs), classical dendritic cells (DCs), and plasmacytoid DCs, b...

  11. Imaging and Analysis of OT1 T Cell Activation on Lipid Bilayers

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: Peter Beemiller, Jordan Jacobelli & Matthew Krummel ### Abstract Supported lipid bilayers are frequently used to study cell membrane protein dynamics during immune synapse formation by T cells. Here we describe methods for the imaging and analysis of OT1+ T cell activation and T-cell receptor (TCR) dynamics on lipid bilayers. ### Introduction T cells are activated at immune synapses when TCRs bind agonist ligands on antigen presenting cells (APCs). Glass cover...

  12. HIV and mature dendritic cells : Trojan exosomes riding the Trojan horse?

    OpenAIRE

    Nuria Izquierdo-Useros; Mar Naranjo-Gómez; Itziar Erkizia; Maria Carmen Puertas; Francesc E Borràs; Julià Blanco; Javier Martinez-Picado

    2010-01-01

    Exosomes are secreted cellular vesicles that can induce specific CD4(+) T cell responses in vivo when they interact with competent antigen-presenting cells like mature dendritic cells (mDCs). The Trojan exosome hypothesis proposes that retroviruses can take advantage of the cell-encoded intercellular vesicle traffic and exosome exchange pathway, moving between cells in the absence of fusion events in search of adequate target cells. Here, we discuss recent data supporting this hypothesis, whi...

  13. [Dendritic cells in cancer immunotherapy].

    Science.gov (United States)

    Gato, M; Liechtenstein, T; Blanco-Luquín, I; Zudaire, M I; Kochan, G; Escors, D

    2015-01-01

    Since the beginning of the 20th century, biomedical scientists have tried to take advantage of the natural anti-cancer activities of the immune system. However, all the scientific and medical efforts dedicated to this have not resulted in the expected success. In fact, classical antineoplastic treatments such as surgery, radio and chemotherapy are still first line treatments. Even so, there is a quantity of experimental evidence demonstrating that cancer cells are immunogenic. However, the effective activation of anti-cancer T cell responses closely depends on an efficient antigen presentation carried out by professional antigen presenting cells such as DC. Although there are a number of strategies to strengthen antigen presentation by DC, anti-cancer immunotherapy is not as effective as we would expect according to preclinical data accumulated in recent decades. We do not aim to make an exhaustive review of DC immunotherapy here, which is an extensive research subject already dealt with in many specialised reviews. Instead, we present the experimental approaches undertaken by our group over the last decade, by modifying DC to improve their anti-tumour capacities. PMID:26486534

  14. A yeast surface display system for the discovery of ligands that trigger cell activation.

    Science.gov (United States)

    Cho, B K; Kieke, M C; Boder, E T; Wittrup, K D; Kranz, D M

    1998-11-01

    Opposing cells often communicate signalling events using multivalent interactions between receptors present on their cell surface. For example, T cells are typically activated when the T cell receptor (TCR) and its associated costimulatory molecules are multivalently engaged by the appropriate ligands present on an antigen presenting cell. In this report, yeast expressing high cell-surface levels of a TCR ligand (a recombinant antibody to the TCR Vbeta domain) were shown to act as 'pseudo' antigen presenting cells and induce T cell activation as monitored by increased levels of CD25 and CD69 and by downregulation of cell surface TCR. Similar levels of T cell activation could occur even when a 30-fold excess of irrelevant yeast was present, suggesting that such a yeast display system, by virtue of its ability to present ligands multivalently, may be used in highly sensitive procedures to identify novel polypeptides that interact multivalently with cell surface receptors and thereby trigger specific cellular responses.

  15. PD-L1/PD-1 Co-Stimulation, a Brake for T cell Activation and a T cell Differentiation Signal.

    Science.gov (United States)

    Liechtenstein, Therese; Dufait, Ines; Bricogne, Christopher; Lanna, Alessio; Pen, Joeri; Breckpot, Karine; Escors, David

    2012-10-30

    For T cell activation, three signals have to be provided from the antigen presenting cell; Signal 1 (antigen recognition), signal 2 (co-stimulation) and signal 3 (cytokine priming). Blocking negative co-stimulation during antigen presentation to T cells is becoming a promising therapeutic strategy to enhance cancer immunotherapy. Here we will focus on interference with PD-1/PD-L1 negative co-stimulation during antigen presentation to T cells as a therapeutic approach. We will discuss the potential mechanisms and the therapeutic consequences by which interference/inhibition with this interaction results in anti-tumour immunity. Particularly, we will comment on whether blocking negative co-stimulation provides differentiation signals to T cells undergoing antigen presentation. A major dogma in immunology states that T cell differentiation signals are given by cytokines and chemokines (signal 3) rather than co-stimulation (signal 2). We will discuss whether this is the case when blocking PD-L1/PD-1 negative co-stimulation.

  16. Semiallogenic fusions of MSI+ tumor cells and activated B cells induce MSI-specific T cell responses

    Directory of Open Access Journals (Sweden)

    Klier Ulrike

    2011-09-01

    Full Text Available Abstract Background Various strategies have been developed to transfer tumor-specific antigens into antigen presenting cells in order to induce cytotoxic T cell responses against tumor cells. One approach uses cellular vaccines based on fusions of autologous antigen presenting cells and allogeneic tumor cells. The fusion cells combine antigenicity of the tumor cell with optimal immunostimulatory capacity of the antigen presenting cells. Microsatellite instability caused by mutational inactivation of DNA mismatch repair genes results in translational frameshifts when affecting coding regions. It has been shown by us and others that these mutant proteins lead to the presentation of immunogenic frameshift peptides that are - in principle - recognized by a multiplicity of effector T cells. Methods We chose microsatellite instability-induced frameshift antigens as ideal to test for induction of tumor specific T cell responses by semiallogenic fusions of microsatellite instable carcinoma cells with CD40-activated B cells. Two fusion clones of HCT116 with activated B cells were selected for stimulation of T cells autologous to the B cell fusion partner. Outgrowing T cells were phenotyped and tested in functional assays. Results The fusion clones expressed frameshift antigens as well as high amounts of MHC and costimulatory molecules. Autologous T cells stimulated with these fusions were predominantly CD4+, activated, and reacted specifically against the fusion clones and also against the tumor cell fusion partner. Interestingly, a response toward 6 frameshift-derived peptides (of 14 tested could be observed. Conclusion Cellular fusions of MSI+ carcinoma cells and activated B cells combine the antigen-presenting capacity of the B cell with the antigenic repertoire of the carcinoma cell. They present frameshift-derived peptides and can induce specific and fully functional T cells recognizing not only fusion cells but also the carcinoma cells. These

  17. Dendritic cells are less susceptible to human immunodeficiency virus type 2 (HIV-2) infection than to HIV-1 infection

    NARCIS (Netherlands)

    M.G. Duvall (Melody); K. Loré (Karin); H. Blaak (Hetty); D.A. Ambrozak (David); W.C. Adams (William); K. Santos (Kathlyn); C. Geldmacher (Christof); J.R. Mascola (John); A.J. McMichael (Andrew); A. Jaye (Assan); H. Whittle; S.L. Rowland-Jones (Sarah); R.A. Koup (Richard)

    2007-01-01

    textabstractHuman immunodeficiency virus type 1 (HIV-1) infection of dendritic cells (DCs) has been documented in vivo and may be an important contributor to HIV-1 transmission and pathogenesis. HIV-1-specific CD4+T cells respond to HIV antigens presented by HIV-1-infected DCs and in this process be

  18. Proteasomal targeting and minigene repetition improve cell-surface presentation of a transfected, modified melanoma tumour antigen

    DEFF Research Database (Denmark)

    Rasmussen, A B; Zocca, M-B; Bonefeld, C M;

    2004-01-01

    on the density of specific major histocompatibility complex-peptide complexes on the surface of the antigen-presenting cell. In this study, we explored the cell-surface presentation of a substituted MART-1 peptide encoded by transfected minigenes. We investigated the potential of proteasomal targeting compared...

  19. The role of the epithelial cell in asthma

    OpenAIRE

    Mota-Pinto, Anabela; Todo-Bom, Ana

    2009-01-01

    It is done a review of the intervention of the epithelial bronchial cell in the pathophysiology of asthma. The respiratory epithelium acts as a physical barrier that separates the external environment from the pulmonary internal environment. It controls the intercellular and trans -cellular permeability and this way the accessibility of the inhaled pathogens to the antigen presenting cells involved in the immuno -inflammatory response. Epithelial cells connected by tight junctions contribute ...

  20. Redefining the role of dendritic cells in periodontics

    OpenAIRE

    Gomathinayagam Venkatesan; Ashita Uppoor; Naik, Dilip G.

    2013-01-01

    A properly functioning adaptive immune system signifies the best features of life. It is diverse beyond compare, tolerant without fail, and capable of behaving appropriately with a myriad of infections and other challenges. Dendritic cells (DCs) are required to explain how this remarkable system is energized and directed. DCs consist of a family of antigen presenting cells, which are bone-marrow-derived cells that patrol all tissues of the body with the possible exceptions of the brain and te...

  1. Recognition Strategies of Group 3 Innate Lymphoid Cells

    OpenAIRE

    Killig, Monica; Glatzer, Timor; Romagnani, Chiara

    2014-01-01

    During the early phase of an inflammatory response, innate cells can use different strategies to sense environmental danger. These include the direct interaction of specific activating receptors with pathogen-encoded/danger molecules or the engagement of cytokine receptors by pro-inflammatory mediators produced by antigen presenting cells in the course of the infection. These general recognition strategies, which have been extensively described for innate myeloid cells, are shared by innate l...

  2. Bi-specific MHC Heterodimers for Characterization of Cross-reactive T Cells*

    OpenAIRE

    Shen, Zu T.; Brehm, Michael A; Daniels, Keith A.; Sigalov, Alexander B.; Selin, Liisa K.; Welsh, Raymond M.; Stern, Lawrence J.

    2010-01-01

    T cell cross-reactivity describes the phenomenon whereby a single T cell can recognize two or more different peptide antigens presented in complex with MHC proteins. Cross-reactive T cells have previously been characterized at the population level by cytokine secretion and MHC tetramer staining assays, but single-cell analysis is difficult or impossible using these methods. In this study, we describe development of a novel peptide-MHC heterodimer specific for cross-reactive T cells. MHC-pepti...

  3. 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 ...

  4. Exosomes derived from M. Bovis BCG infected macrophages activate antigen-specific CD4+ and CD8+ T cells in vitro and in vivo.

    Directory of Open Access Journals (Sweden)

    Pramod K Giri

    Full Text Available Activation of both CD4(+ and CD8(+ T cells is required for an effective immune response to an M. tuberculosis infection. However, infected macrophages are poor antigen presenting cells and may be spatially separated from recruited T cells, thus limiting antigen presentation within a granuloma. Our previous studies showed that infected macrophages release from cells small membrane-bound vesicles called exosomes which contain mycobacterial lipid components and showed that these exosomes could stimulate a pro-inflammatory response in naïve macrophages. In the present study we demonstrate that exosomes stimulate both CD4(+ and CD8(+ splenic T cells isolated from mycobacteria-sensitized mice. Although the exosomes contain MHC I and II as well as costimulatory molecules, maximum stimulation of T cells required prior incubation of exosomes with antigen presenting cells. Exosomes isolated from M. bovis and M. tuberculosis infected macrophages also stimulated activation and maturation of mouse bone marrow-derived dendritic cells. Interestingly, intranasal administration of mice with exosomes isolated from M. bovis BCG infected macrophages induce the generation of memory CD4(+ and CD8(+ T cells. The isolated T cells also produced IFN-gamma upon restimulation with BCG antigens. The release of exosomes from infected macrophages may overcome some of the defects in antigen presentation associated with mycobacterial infections and we suggest that exosomes may be a promising M. tuberculosis vaccine candidate.

  5. Tolerogenicity of resting and activated B cells

    OpenAIRE

    1994-01-01

    Antigen presentation by resting splenic B cells has been shown previously to induce T helper 1 cell (Th1) anergy. In contrast to expectations, it was found here that B cells treated with F(ab')2 goat anti-mouse immunoglobulin (IgM) for 24 or 48 h also presented antigen (Ag) to Th1 cells in a manner that induced dramatic Ag-specific proliferative inactivation. The tolerogenicity of the anti-Ig-treated B cells was consistent with the observation that these B cells were only slightly more effici...

  6. Mechanisms of mouse spleen dendritic cell function in the generation of influenza-specific, cytolytic T lymphocytes

    OpenAIRE

    1992-01-01

    We have evaluated the capacity of dendritic cells to function as antigen-presenting cells (APCs) for influenza and have examined their mechanism of action. Virus-pulsed dendritic cells were 100 times more efficient than bulk spleen cells in stimulating cytotoxic T lymphocyte (CTL) formation. The induction of CTLs required neither exogenous lymphokines nor APCs in the responding T cell population. Infectious virus entered dendritic cells through intracellular acidic vacuoles and directed the s...

  7. [Role of Langerhans cells in the physiopathology of atopic dermatitis].

    Science.gov (United States)

    Bieber, T

    1995-12-01

    The demonstration of IgE receptors on the surface of epidermal dendritic cells and on other antigen presenting cells is a crucial element in the understanding of the pathophysiological role of these cells in the genesis of atopic disease, and especially the atopic dermatitis (AD). The sensibilisation phase to an aeroallergen at the level of nasal or bronchial mucosa and even at the skin may be mediated by dendritic cells expressing Fc epsilon RI. Distinct forms of AD may then represent the equivalent of the ellicitation phase of the classical allergic contact dermatitis. Fc epsilon RI would lead, via specific IgE, to an efficient antigen capture, to the activation of the dendritic cells and finally to an antigen presentation. Thus, AD may represent the paradigma of an IgE-mediated type IV reaction. PMID:8786892

  8. [Role of Langerhans cells in the physiopathology of atopic dermatitis].

    Science.gov (United States)

    Bieber, T

    1995-12-01

    The demonstration of IgE receptors on the surface of epidermal dendritic cells and on other antigen presenting cells is a crucial element in the understanding of the pathophysiological role of these cells in the genesis of atopic disease, and especially the atopic dermatitis (AD). The sensibilisation phase to an aeroallergen at the level of nasal or bronchial mucosa and even at the skin may be mediated by dendritic cells expressing Fc epsilon RI. Distinct forms of AD may then represent the equivalent of the ellicitation phase of the classical allergic contact dermatitis. Fc epsilon RI would lead, via specific IgE, to an efficient antigen capture, to the activation of the dendritic cells and finally to an antigen presentation. Thus, AD may represent the paradigma of an IgE-mediated type IV reaction.

  9. Maternal low protein diet leads to dysregulation of placental iNKT cells and M1/M2 macrophage ratio, body weight loss in male, neonate Sprague-Dawley rats and increased UCP-1 mediated thermogenesis

    Science.gov (United States)

    Placental immune cells provide cytokines and growth factors that are necessary for placenta development and function. Invariant natural killer T (iNKT) cells are innate cells specific for glycolipid antigens presented by the CD1d molecule and secrete Th1 cytokines in the placenta, suggesting an imm...

  10. Fast generation of dendritic cells

    DEFF Research Database (Denmark)

    Kvistborg, P; Bøgh, Marie; Claesson, M H;

    2009-01-01

    Dendritic cells (DC) are potent antigen presenting cells capable of inducing immune responses. DC are widely used as vaccine adjuvant in experimental clinical settings. DC-based vaccines are normally generated using a standard 8day DC protocol (SDDC). In attempts to shorten the vaccine production...... SDDC to the IL-10 inducing stimulus of TLR ligands (R848 and LPS). Thus to determine the clinical relevance of fast DC protocols in cancer settings, small phase I trials should be conducted monitoring regulatory T cells carefully....

  11. Alterations in regulatory T-cells: rediscovered pathways in immunotoxicology

    OpenAIRE

    Corsini, E; Oukka, M; Pieters, R; Kerkvliet, N.I.; Ponce, R.; Germolec, D R

    2011-01-01

    In addition to the effector T-cells subsets, T-cells can also differentiate into cells that play a suppressive or regulatory role in adaptive immune responses. The cell types currently identified as regulatory T-cells (Tregs) include natural or thymic-derived Tregs, T-cells which express Foxp3+CD25+CD4+ and can suppress immune responses to autoreactive T-cells, as well as inducible Tregs, that are generated from naïve T-cells in the periphery after interaction with antigens presented by dendr...

  12. C-type lectin Langerin is a beta-glucan receptor on human Langerhans cells that recognizes opportunistic and pathogenic fungi

    NARCIS (Netherlands)

    M.A.W.P. de Jong; L.E.M. Vriend; B. Theelen; M.E. Taylor; D. Fluitsma; T. Boekhout; T.B.H. Geijtenbeek

    2010-01-01

    Langerhans cells (LCs) lining the stratified epithelia and mucosal tissues are the first antigen presenting cells to encounter invading pathogens, such as viruses, bacteria and fungi. Fungal infections form a health threat especially in immuno-compromised individuals. LCs express C-type lectin Lange

  13. Human Monocyte-derived Dendritic Cells Pulsed with Wild-field name="type" p53 Protein Efficiently Induce Cytotoxic T-lymphocytes against p53 overexpressing Human Cancer Cells

    OpenAIRE

    德永, 尚之

    2005-01-01

    PURPOSE: Dendritic cells are the most potent antigen-presenting cells for initiating cellular immune responses. Dendritic cells are attractive immunoregulatory cells for cancer immunotherapy, and their efficacy has been investigated in clinical trials. The tumor suppressor gene p53 is pivotal in the regulation of apoptosis, and p53-based immunization is an attractive approach to cancer immunotherapy because of the accumulation of p53 protein in malignant but not in normal cells. It has been s...

  14. OX40/OX40 Ligand Interactions in T-Cell Regulation and Asthma

    OpenAIRE

    Kaur, Davinder; Brightling, Christopher

    2012-01-01

    The OX40 receptor is preferentially expressed by T cells, and its cognate ligand OX40L is primarily expressed by antigen-presenting cells such as dendritic cells following activation by thymic stromal lymphopoietin (TSLP). TSLP is released by the bronchial epithelium, airway smooth muscle, and some inflammatory cells in response to numerous insults such as allergens, viruses, and physical damage. OX40L is a costimulatory molecule that plays a sentinel role in the adaptive immune response by p...

  15. The Role of γδ T Cells in Systemic Lupus Erythematosus

    OpenAIRE

    Meng Wu; Jinhua Yang; Xiaofeng Li; Junwei Chen

    2016-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease that is characterized by the overproduction of autoantibodies against an array of nuclear and cytoplasmic antigens and affects multiple organs, such as the skin, joints, kidneys, and neuronal tissues. T cells have been recognized as important players in the development of SLE due to their functions in cytokine secretion, antigen presentation, and supporting B cells for antibody production. γδ T cells are a minor population of T cells...

  16. Treatment of pulmonary metastatic tumors in mice using lentiviral vector-engineered stem cells

    OpenAIRE

    Zhang, X.; Zhao, P; Kennedy, C; Chen, K.; Wiegand, J; Washington, G; Marrero, L; Cui, Y.

    2007-01-01

    Active cancer immunotherapy relies on functional tumor-specific effector T lymphocytes for tumor elimination. Dendritic cells (DCs), as most potent antigen-presenting cells, have been popularly employed in clinical and experimental tumor treatments. We have previously demonstrated that lentiviral vector-mediated transgene delivery to DC progenitors, including bone marrow cells and hematopoietic stem cells, followed by transplantation supports systemic generation of great numbers of tumor anti...

  17. HIV-1 Infection of Placental Cord Blood Monocyte-Derived Dendritic Cells

    OpenAIRE

    FOLCIK, RENEE M.; Merrill, Jeffrey D.; Li, Yuan; GUO, CHANG-JIANG; Douglas, Steven D.; STARR, STUART E.; Ho, Wen-Zhe

    2001-01-01

    Dendritic cells (DC), the most potent antigen-presenting cells (APC), have been implicated as the initial targets of HIV infection in skin and mucosal surfaces. DC can be generated in vitro from blood-isolated CD14+ monocytes or CD34+ hematopoietic progenitor cells in the presence of various cytokines. In this study, we investigated whether monocytes obtained from placental cord blood are capable of differentiation into dendritic cells when cultured with a combination of cytokines—granulocyte...

  18. Apoptosis and systemic autoimmunity: the dendritic cell connection

    Directory of Open Access Journals (Sweden)

    AA Manfredi

    2009-12-01

    Full Text Available Much effort has been devoted in recent years to the events linking recognition and disposal of apoptotic cells to sustained immunity towards the antigens they contain. Programmed death via apoptosis indeed provides most of the raw material the immune system exploits to establish self tolerance, i.e. to learn how to distinguish between self constituents and foreign antigens, belonging to invading pathogens. In parallel, events occurring during cell death may enable a restricted array of molecules endowed with diverse structure, function and intracellular distribution to satisfy the requirement to evoke and maintain autoimmune responses. Dendritic cells (DCs, the most potent antigen presenting cells, appear to play a crucial role. Here we will discuss some of the constrains regulating the access of dying cells’ antigens to DCs, as well as censorship mechanisms that prevent their maturation and the full explication of their antigen presenting function.

  19. Thymic Selection of T-Cell Receptors as an Extreme Value Problem

    Science.gov (United States)

    Kosmrlj, Andrej; Chakraborty, Arup K.; Kardar, Mehran; Shakhnovich, Eugene I.

    2010-03-01

    T lymphocytes (T cells) orchestrate adaptive immune responses that clear pathogens from infected hosts. T cells recognize short peptides (p) derived from foreign proteins, which are bound to major histocompatibility complex (MHC) gene products (displayed on antigen- presenting cells). Recognition occurs when T cell receptor (TCR) proteins expressed on T cells bind sufficiently strongly to antigen- derived pMHC complexes on the surface of antigen-presenting cells. A diverse repertoire of self-tolerant TCR sequences is shaped during development of T cells in the thymus by processes called positive and negative selection. We map thymic selection processes to an extreme value problem and provide analytic expression for the amino acid composition of selected TCR sequences (which enable its recognition functions).

  20. Opposing roles for RhoH GTPase during T-cell migration and activation

    DEFF Research Database (Denmark)

    Baker, Christina M; Comrie, William A; Hyun, Young-Min;

    2012-01-01

    T cells spend the majority of their time perusing lymphoid organs in search of cognate antigen presented by antigen presenting cells (APCs) and then quickly recirculate through the bloodstream to another lymph node. Therefore, regulation of a T-cell response is dependent upon the ability of cells...... to arrive in the correct location following chemokine gradients ("go" signal) as well as to receive appropriate T-cell receptor (TCR) activation signals upon cognate antigen recognition ("stop" signal). However, the mechanisms by which T cells regulate these go and stop signals remain unclear. We found...... that overexpression of the hematopoietic-specific RhoH protein in the presence of chemokine signals resulted in decreased Rap1-GTP and LFA-1 adhesiveness to ICAM-1, thus impairing T-cell chemotaxis; while in the presence of TCR signals, there were enhanced and sustained Rap1-GTP and LFA-1 activation as well...

  1. NEW EMBO MEMBER’S REVIEW: Dendritic cell regulation of immune responses: a new role for interleukin 2 at the intersection of innate and adaptive immunity

    OpenAIRE

    Granucci, Francesca; Zanoni, Ivan; Feau, Sonia; Ricciardi-Castagnoli, Paola

    2003-01-01

    Dendritic cells are professional antigen-presenting cells able to initiate innate and adaptive immune responses against invading pathogens. In response to external stimuli dendritic cells undergo a complete genetic reprogramming that allows them to become, soon after activation, natural killer cell activators and subsequently T cell stimulators. The recent observation that dendritic cells produce interleukin 2 following microbial stimulation opens new possibilities for understanding the effic...

  2. Targeting epidermal Langerhans cells by epidermal powder immunization

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Immune reactions to foreign or self-antigens lead to protective immunity and, sometimes, immune disorders such as allergies and autoimmune diseases. Antigen presenting cells (APC) including epidermal Langerhans cells (LCs) play an important role in the course and outcome of the immune reactions. Epidermal powder immunization (EPI) is a technology that offers a tool to manipulate the LCs and the potential to harness the immune reactions towards prevention and treatment of infectious diseases and immune disorders.

  3. Rapid CD4+ T-cell responses to bacterial flagellin require dendritic cell expression of Syk and CARD9

    OpenAIRE

    Atif, Shaikh M.; Lee, Seung-Joo; Li, Lin-Xi; Uematsu, Satoshi; Akira, Shizuo; Gorjestani, Sara; Lin, Xin; Schweighoffer, Edina; Tybulewicz, Victor L.J.; McSorley, Stephen J.

    2014-01-01

    Toll-like receptors (TLRs) can recognize microbial patterns and utilize adaptor molecules, such as-MyD88 or (TRIF TIR-domain-containing adapter-inducing interferon-β), to initiate downstream signaling that ultimately affects the initiation of adaptive immunity. In addition to this inflammatory role, TLR5 expression on dendritic cells can favor antigen presentation of flagellin peptides and thus increase the sensitivity of flagellin-specific T-cell responses in vitro and in vivo. Here, we exam...

  4. CTLA-4 blockade during dendritic cell based booster vaccination influences dendritic cell survival and CTL expansion

    DEFF Research Database (Denmark)

    Pedersen, Anders E; Ronchese, Franca

    2007-01-01

    Dendritic cells (DCs) are potent antigen-presenting cells and critical for the priming of CD8+ T cells. Therefore the use of these cells as adjuvant cells has been tested in a large number of experimental and clinical vaccination studies, in particular cancer vaccine studies. A number of protocols....... We have previously reported that DCs loaded with specific antigens are eliminated by antigen specific CTLs in vivo and that this elimination affects the potential for in vivo CTL generation. We now show that CTLA-4 blockade increases the number of DC vaccine induced LCMV gp33 specific CTLs...

  5. Requirements for Peptide-induced T Cell Receptor Downregulation on Naive CD8+ T Cells

    OpenAIRE

    Cai, Zeling; Kishimoto, Hidehiro; Brunmark, Anders; Jackson, Michael R.; Peterson, Per A.; Sprent, Jonathan

    1997-01-01

    The requirements for inducing downregulation of α/β T cell receptor (TCR) molecules on naive major histocompatibility complex class I–restricted T cells was investigated with 2C TCR transgenic mice and defined peptides as antigen. Confirming previous results, activation of 2C T cells in response to specific peptides required CD8 expression on the responder cells and was heavily dependent upon costimulation provided by either B7-1 or ICAM-1 on antigen-presenting cells (APC). These stringent re...

  6. MHC class II-associated proteins in B-cell exosomes and potential functional implications for exosome biogenesis.

    NARCIS (Netherlands)

    Buschow, S.I.; Balkom, B.W.M. van; Aalberts, M.; Heck, A.J.R. van; Wauben, M.; Stoorvogel, W.

    2010-01-01

    Professional antigen-presenting cells secrete major histocompatibility complex class II (MHC II) carrying exosomes with unclear physiological function(s). Exosomes are first generated as the intraluminal vesicles (ILVs) of a specific type of multivesicular body, and are then secreted by fusion of th

  7. An improved protocol for generation of immuno-potent dendritic cells through direct electroporation of CD14+monocytes

    NARCIS (Netherlands)

    Milano, Francesca; van Baal, Jantine W. P. M.; Rygiel, Agnieszka M.; Bergman, Jacques J. G. H. M.; Van Deventer, Sander J. H.; Kapsenberg, Martien L.; Peppelenbosch, Maikel P.; Krishnadath, Kausilia K.

    2007-01-01

    In this study we demonstrate a novel protocol showing that electroporation of CD14+ monocytes directly isolated from blood with green fluorescent protein (GFP) RNA results in a 3-fold higher yield of antigen presenting dendritic cells (DCs) when compared to conventional methods employing immature DC

  8. Production of Listeria-specific rat T-cell clones and role of interleukin-2 receptors in regulation of Listeria-dependent T-cell clone growth in vitro.

    OpenAIRE

    Stolpmann, R M; Näher, H; Osawa, H.; Herrmann, T.; Hahn, H; Diamantstein, T

    1985-01-01

    Splenic T lymphocytes from rats immunized with the facultative intracellular bacterium Listeria monocytogenes were cloned by the limiting-dilution technique in the presence of accessory cells, heat-killed L. monocytogenes as antigen, and conditioned medium containing interleukin-2. The cloned rat T-cells were Listeria-specific cells, and their proliferation depended on class II-restricted antigen presentation by accessory cells. As demonstrated by their reactivity to the monoclonal antibody W...

  9. Interleukin-2 Production by Dendritic Cells and its Immuno-Regulatory Functions

    OpenAIRE

    Zelante, Teresa; Fric, Jan; Wong, Alicia Y. W.; Ricciardi-Castagnoli, Paola

    2012-01-01

    Dendritic cells (DCs) are uniquely potent antigen presenting cells that acquire microbial products and prime adaptive immune responses against pathogens. Furthermore, DCs also play a key role in induction and maintenance of tolerance. Although numerous studies have assessed the diverse functions of DCs, many unanswered questions remain regarding the molecular mechanisms that DCs use to achieve immunoregulation. While not widely regarded as a significant provider of T-cell growth factors, DCs ...

  10. Plasmacytoid dendritic cells sequester high prion titres at early stages of prion infection.

    OpenAIRE

    Rocio Castro-Seoane; Holger Hummerich; Trevor Sweeting; M Howard Tattum; Linehan, Jacqueline M.; Mar Fernandez de Marco; Sebastian Brandner; John Collinge; Peter-Christian Klöhn

    2012-01-01

    In most transmissible spongiform encephalopathies prions accumulate in the lymphoreticular system (LRS) long before they are detectable in the central nervous system. While a considerable body of evidence showed that B lymphocytes and follicular dendritic cells play a major role in prion colonization of lymphoid organs, the contribution of various other cell types, including antigen-presenting cells, to the accumulation and the spread of prions in the LRS are not well understood. A comprehens...

  11. Various Forms of Tissue Damage and Danger Signals Following Hematopoietic Stem-Cell Transplantation

    OpenAIRE

    Ramadan, Abdulraouf; Paczesny, Sophie

    2015-01-01

    Hematopoietic stem-cell transplantation (HSCT) is the most potent curative therapy for many malignant and non-malignant disorders. Unfortunately, a major complication of HSCT is graft-versus-host disease (GVHD), which is mediated by tissue damage resulting from the conditioning regimens before the transplantation and the alloreaction of dual immune components (activated donor T-cells and recipient’s antigen-presenting cells). This tissue damage leads to the release of alarmins and the trigger...

  12. Assessing T cell clonal size distribution: a non-parametric approach

    OpenAIRE

    Bolkhovskaya, Olesya V.; Daniil Yu Zorin; Ivanchenko, Mikhail V.

    2014-01-01

    Clonal structure of the human peripheral T-cell repertoire is shaped by a number of homeostatic mechanisms, including antigen presentation, cytokine and cell regulation. Its accurate tuning leads to a remarkable ability to combat pathogens in all their variety, while systemic failures may lead to severe consequences like autoimmune diseases. Here we develop and make use of a non-parametric statistical approach to assess T cell clonal size distributions from recent next generation sequencing d...

  13. Autocrine secretion of interferon gamma negatively regulates homing of immature B cells.

    Science.gov (United States)

    Flaishon, L; Hershkoviz, R; Lantner, F; Lider, O; Alon, R; Levo, Y; Flavell, R A; Shachar, I

    2000-11-01

    The mechanism by which immature B cells are sequestered from encountering foreign antigens present in lymph nodes or sites of inflammation, before their final maturation in the spleen, has not been elucidated. We show here that immature B cells fail to home to the lymph nodes. These cells can actively exclude themselves from antigen-enriched sites by downregulating their integrin-mediated adhesion to the extracellular matrix protein, fibronectin. This inhibition is mediated by interferon gamma secretion. Perturbation of interferon gamma activity in vivo leads to the homing of immature B cells to the lymph nodes. This is the first example of autocrine regulation of immune cell migration to sites of foreign antigen presentation. PMID:11067886

  14. Development, Expansion, and In vivo Monitoring of Human NK Cells from Human Embryonic Stem Cells (hESCs) and and Induced Pluripotent Stem Cells (iPSCs)

    OpenAIRE

    Bock, Allison M.; Knorr, David; Kaufman, Dan S.

    2013-01-01

    We present a method for deriving natural killer (NK) cells from undifferentiated hESCs and iPSCs using a feeder-free approach. This method gives rise to high levels of NK cells after 4 weeks culture and can undergo further 2-log expansion with artificial antigen presenting cells. hESC- and iPSC-derived NK cells developed in this system have a mature phenotype and function. The production of large numbers of genetically modifiable NK cells is applicable for both basic mechanistic as well as an...

  15. 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

  16. Human leukocyte antigen-DO regulates surface presentation of human leukocyte antigen class II-restricted antigens on B cell malignancies

    NARCIS (Netherlands)

    Kremer, A.N.; Meijden, E.D. van der; Honders, M.W.; Pont, M.J.; Goeman, J.J.; Falkenburg, J.H.F.; Griffioen, M.

    2014-01-01

    Hematological malignancies often express surface HLA class II, making them attractive targets for CD4+ T cell therapy. We previously demonstrated that HLA class II ligands can be divided into DM-resistant and DM-sensitive antigens. In contrast to presentation of DM-resistant antigens, presentation o

  17. Class II-associated invariant chain peptide down-modulation enhances the immunogenicity of myeloid leukemic blasts resulting in increased CD4(+) T-cell responses

    NARCIS (Netherlands)

    M.M. van Luijn; M.E.D. Chamuleau; J.A. Thompson; S. Ostrand-Rosenberg; T.M. Westers; Y. Souwer; G.J. Ossenkoppele; S.M. Ham; A.A. van de Loosdrecht

    2010-01-01

    Background Disease recurrence in patients with acute myeloid leukemia may be partially explained by the escape of leukemic blasts from CD4(+) T-cell recognition. The current study investigates the role of aberrant HLA class II antigen presentation on leukemic blasts by determining both the clinical

  18. Stepwise Protocol for Cytospin-enhanced Smearing for Scraped Corneal Epithelial Cells.

    Science.gov (United States)

    Jeyalatha, Mani V; Malathi, Jambulingam; Madhavan, Hajib N

    2016-01-01

    Proteins and antigens present on the cell surface are usually determined by immunofluorescence staining. Uniform distribution of cells is required to appreciate the presence of surface proteins. Improper smearing or crushing of the corneal epithelial cells can potentially destroy the cellular integrity. Thus a simplified, systemic method was designed to smear the cells scraped from the cornea. The procedure includes trypsinisation for dissociation of corneal epithelial cells and cytospinning for concentrating the cells in a smear. The standardized protocol was found to be efficient in maintaining the integrity of the corneal epithelial cells and also the distribution of the cells in the smear. PMID:26633702

  19. Dendritic Cells Coordinate the Development and Homeostasis of Organ-Specific Regulatory T Cells.

    Science.gov (United States)

    Leventhal, Daniel S; Gilmore, Dana C; Berger, Julian M; Nishi, Saki; Lee, Victoria; Malchow, Sven; Kline, Douglas E; Kline, Justin; Vander Griend, Donald J; Huang, Haochu; Socci, Nicholas D; Savage, Peter A

    2016-04-19

    Although antigen recognition mediated by the T cell receptor (TCR) influences many facets of Foxp3(+) regulatory T (Treg) cell biology, including development and function, the cell types that present antigen to Treg cells in vivo remain largely undefined. By tracking a clonal population of Aire-dependent, prostate-specific Treg cells in mice, we demonstrated an essential role for dendritic cells (DCs) in regulating organ-specific Treg cell biology. We have shown that the thymic development of prostate-specific Treg cells required antigen presentation by DCs. Moreover, Batf3-dependent CD8α(+) DCs were dispensable for the development of this clonotype and had negligible impact on the polyclonal Treg cell repertoire. In the periphery, CCR7-dependent migratory DCs coordinated the activation of organ-specific Treg cells in the prostate-draining lymph nodes. Our results demonstrate that the development and peripheral regulation of organ-specific Treg cells are dependent on antigen presentation by DCs, implicating DCs as key mediators of organ-specific immune tolerance.

  20. The influence of infectious factors on dendritic cell apoptosis

    OpenAIRE

    Kubicka-Sierszen, Agata; Grzegorczyk, Janina Ł.

    2015-01-01

    Pathogens can have a negative influence on dendritic cells (DCs), causing their apoptosis, which prevents active presentation of foreign antigens. It results in a state of immunosuppression which makes the body susceptible to secondary infections. Infected immature DCs have lower expression of co-stimulatory and adhesion molecules, reduced ability to secrete cytokines and an inhibited maturation process and are incapable of effective antigen presentation and activation of T-lymphocytes. In so...

  1. A major population of mucosal memory CD4+ T cells, coexpressing IL-18Rα and DR3, display innate lymphocyte functionality

    DEFF Research Database (Denmark)

    Holmkvist, P.; Roepstorff, K.; Uronen-Hansson, H.;

    2015-01-01

    Mucosal tissues contain large numbers of memory CD4+ T cells that, through T-cell receptor-dependent interactions with antigen-presenting cells, are believed to have a key role in barrier defense and maintenance of tissue integrity. Here we identify a major subset of memory CD4+ Tcells at barrier......, these results suggest that human memory IL-18Rα+DR3+CD4+ T cells may contribute to antigen-independent innate responses at barrier surfaces....

  2. Clinical implications of basic science discoveries: janus resurrected--two faces of B cell and plasma cell biology.

    Science.gov (United States)

    Woodle, E S; Rothstein, D M

    2015-01-01

    B cells play a complex role in the immune response. In addition to giving rise to plasma cells (PCs) and promoting T cell responses via antigen presentation, they perform immunoregulatory functions. This knowledge has created concerns regarding nonspecific B cell depletional therapy because of the potential to paradoxically augment immune responses. Recent studies now indicate that PCs have immune functions beyond immunoglobulin synthesis. Evidence for a new role for PCs as potent regulatory cells (via IL-10 and IL-35 production) is discussed including the implications for PC-targeted therapies currently being developed for clinical transplantation.

  3. Expansion of CD8+ T cells lacking Sema4D/CD100 during HIV-1 infection identifies a subset of T cells with decreased functional capacity

    OpenAIRE

    Eriksson, Emily M.; Milush, Jeffrey M.; Ho, Emily L.; Batista, Mariana D.; Holditch, Sara J.; Keh, Chris E.; Norris, Philip J.; Keating, Sheila M.; Deeks, Steven G; Hunt, Peter W.; Martin, Jeffrey N.; Rosenberg, Michael G.; Hecht, Frederick M.; Nixon, Douglas F.

    2012-01-01

    Sema4D, also known as CD100, is a constitutively expressed immune semaphorin on T cells and NK cells. CD100 has important immune regulatory functions that improve antigen-specific priming by antigen-presenting cells, and can also act as a costimulatory molecule on T cells. We investigated the consequence of HIV-1 infection on CD100 expression by T cells, and whether CD100 expression signifies functionally competent effector cells. CD100 expression on T cells from healthy individuals was compa...

  4. CD28 and T cell antigen receptor signal transduction coordinately regulate interleukin 2 gene expression in response to superantigen stimulation

    OpenAIRE

    1992-01-01

    Activation of an immune response requires intercellular contact between T lymphocytes and antigen-presenting cells (APC). Interaction of the T cell antigen receptor (TCR) with antigen in the context of major histocompatibility molecules mediates signal transduction, but T cell activation appears to require the induction of a second costimulatory signal transduction pathway. Recent studies suggest that interaction of CD28 with B7 on APC might deliver such a costimulatory signal. To investigate...

  5. Gene expression profiling in host-pathogen interactions and identification of the molecular mechanisms involved in dendrictic cells activation

    OpenAIRE

    Torri,, M.

    2009-01-01

    In this thesis we used a functional genomic approach to study host-pathogen interactions [1]. We analyzed the interaction from the host point of view and in particular from the dendritic cells point of view. Dendritic cells (DCs) constitute a heterogeneous group of antigen-presenting leukocytes important in activation of both innate and adaptive immunity [2]. In the first part of this thesis we explored the possibility to use dendritic cell transcriptomes to generate biomarkers of inflamma...

  6. A New Humanized HLA Transgenic Mouse Model of Multiple Sclerosis Expressing Class II on Mouse CD4 T Cells

    OpenAIRE

    Mangalam, Ashutosh; Rodriguez, Moses; David, Chella

    2007-01-01

    Among all the genetic factors associated with MS susceptibility, strongest association has been seen with expression of certain MHC class II molecules, although analysis of their exact function remains complicated. In general expression of class II is restricted to professional antigen presenting cells, however human but not mice CD4+ T cells express class II on their surface. Functional studies of classII+CD4+ T cells have been hampered due to lack of proper animal model. Here we describe de...

  7. T cell migration, search strategies and mechanisms.

    Science.gov (United States)

    Krummel, Matthew F; Bartumeus, Frederic; Gérard, Audrey

    2016-03-01

    T cell migration is essential for T cell responses; it allows for the detection of cognate antigen at the surface of antigen-presenting cells and for interactions with other cells involved in the immune response. Although appearing random, growing evidence suggests that T cell motility patterns are strategic and governed by mechanisms that are optimized for both the activation stage of the cell and for environment-specific cues. In this Opinion article, we discuss how the combined effects of T cell-intrinsic and -extrinsic forces influence T cell motility patterns in the context of highly complex tissues that are filled with other cells involved in parallel motility. In particular, we examine how insights from 'search theory' can be used to describe T cell movement across an 'exploitation-exploration trade-off' in the context of activation versus effector function and lymph nodes versus peripheral tissues. PMID:26852928

  8. In vitro antitumor immune response induced by fusion of dendritic cells and colon cancer cells

    Institute of Scientific and Technical Information of China (English)

    Feng Xu; Ying-Jiang Ye; Shan Wang

    2004-01-01

    AIM: The prevention of recurrence of colon cancer (CC)after operation is very important for improvement of the prognosis of CC patients, especially those with micrometastasis. The generation of fused cells between dendritic cells (DCs) and tumor cells maybe an effective approach for tumor antigen presentation in immunotherapy. In this study,we fused human colon caner SW480 cells and human peripheral blood - derived DCs to induce an antitumor activity against human CC.METHODS: CC SW480 cells and human peripheral blood derived DCs were fused with 500 mL/L polyethylene glycol (PEG).RESULTS: The specific T cell responses activated by fusion cells (FCs), were observed. About 100 mL/L to 160 mL/L of the PEG-treated non-adherent cells with fluorescences were considered to be dendritomas that highly expressed the key molecules for antigen presentation in our five cases. In vitro studies showed that fusions effectively activated CD8+ T lymphocytes to secrete interferon-γ. The early apoptotic ratio of the colon cancer SW480 cells was higher than that of controls, which was affected by cytotoxic T lymphocytes (CTLs) stimulated by dendritomas.CONCLUSION: The data indicate that fusion of tumor cells with DCs is an attractive strategy to induce tumor rejection.

  9. Induction of HLA-B27 heavy chain homodimer formation after activation in dendritic cells

    OpenAIRE

    Santos, Susana G.; Lynch, Sarah; Campbell, Elaine C.; Antoniou, Antony N.; Simon J Powis

    2008-01-01

    Introduction Ankylosing spondylitis (AS) is a severe, chronic inflammatory arthritis, with a strong association to the human major histocompatibilty complex (MHC) class I allele human leucocyte antigen (HLA) B27. Disulfide-linked HLA-B27 heavy-chain homodimers have been implicated as novel structures involved in the aetiology of AS. We have studied the formation of HLA-B27 heavy-chain homodimers in human dendritic cells, which are key antigen-presenting cells and regulators of mammalian immun...

  10. Regulation of dendritic cell differentiation and function by estrogen receptor ligands

    OpenAIRE

    Kovats, Susan; Carreras, Esther

    2008-01-01

    Estrogen receptor (ER) ligands can modulate innate and adaptive immunity and hematopoiesis, which may explain the clear sex differences in immune responses during autoimmunity, infection or trauma. Dendritic cells (DC) are antigen-presenting cells important for initiation of innate and adaptive immunity, as well as immune tolerance. DC progenitors and terminally differentiated DC express ER, indicating the ER ligands may regulate DC at multiple developmental and functional stages. Although th...

  11. Impact of cathepsins on the activation of proinsulin-reactive T cells in type 1 diabetes

    OpenAIRE

    Zou, Fang

    2012-01-01

    Autoantigenic peptides resulting from self-proteins such as proinsulin are important players in the development of type 1 diabetes mellitus (T1D). Self-proteins can be processed by cathepsins (Cats) within endocytic compartments and loaded to major histocompatibility complex (MHC) class II molecules for CD4+ T cell inspection. However, the processing and presentation of proinsulin by antigen-presenting cells (APC) in humans is only partially understood. Here we demonstrate that the processing...

  12. Rationale for a multimodality strategy to enhance the efficacy of dendritic cell-based cancer immunotherapy

    OpenAIRE

    Jashodeep eDatta; Erik eBerk; Jessica A Cintolo; Shuwen eXu; Roses, Robert E; Czerniecki, Brian J.

    2015-01-01

    Dendritic cells (DC), master antigen-presenting cells that orchestrate interactions between the adaptive and innate immune arms, are increasingly utilized in cancer immunotherapy. Despite remarkable progress in our understanding of DC immunobiology, as well as several encouraging clinical applications — such as DC-based sipuleucel-T for metastatic castration-resistant prostate cancer — clinically effective DC-based immunotherapy as monotherapy for a majority of tumors remains a distant goal. ...

  13. Rationale for a Multimodality Strategy to Enhance the Efficacy of Dendritic Cell-Based Cancer Immunotherapy

    OpenAIRE

    Datta, Jashodeep; Berk, Erik; Jessica A Cintolo; Xu, Shuwen; Roses, Robert E; Czerniecki, Brian J.

    2015-01-01

    Dendritic cells (DC), master antigen-presenting cells that orchestrate interactions between the adaptive and innate immune arms, are increasingly utilized in cancer immunotherapy. Despite remarkable progress in our understanding of DC immunobiology, as well as several encouraging clinical applications – such as DC-based sipuleucel-T for metastatic castration-resistant prostate cancer – clinically effective DC-based immunotherapy as monotherapy for a majority of tumors remains a distant goal. ...

  14. Calcium Signalling Triggered by NAADP in T Cells Determines Cell Shape and Motility During Immune Synapse Formation

    Science.gov (United States)

    Nebel, Merle; Zhang, Bo; Odoardi, Francesca; Flügel, Alexander; Potter, Barry V. L.; Guse, Andreas H.

    2016-01-01

    Nicotinic acid adenine dinucleotide phosphate (NAADP) has been implicated as an initial Ca2+ trigger in T cell Ca2+ signalling, but its role in formation of the immune synapse in CD4+ effector T cells has not been analysed. CD4+ T cells are activated by the interaction with peptide-MHCII complexes on the surface of antigen-presenting cells. Establishing a two-cell system including primary rat CD4+ T cells specific for myelin basic protein and rat astrocytes enabled us to mirror this activation process in vitro and to analyse Ca2+ signalling, cell shape changes and motility in T cells during formation and maintenance of the immune synapse. After immune synapse formation, T cells showed strong, antigen-dependent increases in free cytosolic calcium concentration ([Ca2+]i). Analysis of cell shape and motility revealed rounding and immobilization of T cells depending on the amplitude of the Ca2+ signal. NAADP-antagonist BZ194 effectively blocked Ca2+ signals in T cells evoked by the interaction with antigen-presenting astrocytes. BZ194 reduced the percentage of T cells showing high Ca2+ signals thereby supporting the proposed trigger function of NAADP for global Ca2+ signalling. Taken together, the NAADP signalling pathway is further confirmed as a promising target for specific pharmacological intervention to modulate T cell activation. PMID:27747143

  15. Staining of Langerhans Cells with Monoclonal Antibodies to Macrophages and Lymphoid Cells

    Science.gov (United States)

    Haines, Kathleen A.; Flotte, Thomas J.; Springer, Timothy A.; Gigli, Irma; Thorbecke, G. Jeanette

    1983-06-01

    Langerhans cells are Ia-bearing antigen-presenting cells in the epidermis that share many functions with macrophages. We have used monoclonal antibodies to the macrophage antigens, Mac-2 and -3, Ia antigen, Fc fragment receptor, and the common leukocyte antigen CLA to compare the cell surface antigens of these cells with those of interdigitating and follicular dendritic cells and of macrophages in lymphoid tissues. Immunoperoxidase staining was carried out with epidermal sheets from BALB/c mice and epidermal cell suspensions enriched for Langerhans cells by Fc rosetting. Langerhans cells stained for all of these antigens. Comparison with the staining properties of other dendritic cells and macrophages, in combination with previous observations, indicates a close relationship of Langerhans cells to the interdigitating cells of lymphoid tissues.

  16. Developing a novel hepatitis B core – based antigen presentation system

    OpenAIRE

    Peyret, Hadrien

    2014-01-01

    Plant-produced proteins of pharmaceutical interest are beginning to reach the market, and the advantages of transient plant expression systems are gaining increasing recognition. In parallel, the use of virus-like particles (VLPs) has become standard in vaccine design. The pEAQ-HT vector derived from the cowpea mosaic virus – based CPMV-HT expression system has been shown to allow the production of large amounts of recombinant proteins, including VLPs, in Nicotiana benthamiana. Moreover, prev...

  17. Manipulations of the ubiquitin proteasome system and their effects on antigen presentation

    NARCIS (Netherlands)

    Groothuis, Tom Alphonsus Maria

    2006-01-01

    Surgery is the most effective cancer therapy, followed by radiotherapy. These techniques usually target tumour specific tissue only, unlike most forms of chemotherapy as is best illustrated by the relatively moderate side effects of such treatments. When the immune system could find and destroy tumo

  18. N-3 polyunsaturated fatty acids modulate B cell activity in pre-clinical models: Implications for the immune response to infections.

    Science.gov (United States)

    Whelan, Jarrett; Gowdy, Kymberly M; Shaikh, Saame Raza

    2016-08-15

    B cell antigen presentation, cytokine production, and antibody production are targets of pharmacological intervention in inflammatory and infectious diseases. Here we review recent pre-clinical evidence demonstrating that pharmacologically relevant levels of n-3 polyunsaturated fatty acids (PUFA) derived from marine fish oils influence key aspects of B cell function through multiple mechanisms. N-3 PUFAs modestly diminish B cell mediated stimulation of classically defined naïve CD4(+) Th1 cells through the major histocompatibility complex (MHC) class II pathway. This is consistent with existing data showing that n-3 PUFAs suppress the activation of Th1/Th17 cells through direct effects on helper T cells and indirect effects on antigen presenting cells. Mechanistically, n-3 PUFAs lower antigen presentation and T cell signaling by disrupting the formation of lipid microdomains within the immunological synapse. We then review data to show that n-3 PUFAs boost B cell activation and antibody production in the absence and presence of antigen stimulation. This has potential benefits for several clinical populations such as the aged and obese that have poor humoral immunity. The mode of action by which n-3 PUFA boost B cell activation and antibody production remains unclear, but may involve Th2 cytokines, enhanced production of specialized proresolving lipid mediators, and targeting of protein lateral organization in lipid microdomains. Finally, we highlight evidence to show that different n-3 PUFAs are not biologically equivalent, which has implications for the development of future interventions to target B cell activity.

  19. Targeted delivery of lipid antigen to macrophages via the CD169/sialoadhesin endocytic pathway induces robust invariant natural killer T cell activation

    OpenAIRE

    Kawasaki, Norihito; Vela, Jose Luis; Nycholat, Corwin M.; Rademacher, Christoph; Khurana, Archana; van Rooijen, Nico; Crocker, Paul R.; Kronenberg, Mitchell; Paulson, James C.

    2013-01-01

    Invariant natural killer T (iNKT) cells induce a protective immune response triggered by foreign glycolipid antigens bound to CD1d on antigen-presenting cells (APCs). A limitation of using glycolipid antigens to stimulate immune responses in human patients has been the inability to target them to the most effective APCs. Recent studies have implicated phagocytic CD169+ macrophages as major APCs in lymph nodes for priming iNKT cells in mice immunized with glycolipid antigen in particulate form...

  20. An indirect immunofluorescence assay using a cell culture-derived antigen for detection of antibodies to the agent of human granulocytic ehrlichiosis.

    OpenAIRE

    Nicholson, W L; Comer, J A; Sumner, J W; Gingrich-Baker, C; Coughlin, R T; Magnarelli, L A; Olson, J G; Childs, J. E.

    1997-01-01

    An indirect immunofluorescence assay for the detection of human antibodies to the agent of human granulocytic ehrlichiosis (HGE) was developed and standardized. Antigen was prepared from a human promyelocytic leukemia cell line (HL-60) infected with a tick-derived isolate of the HGE agent (USG3). Suitable antigen presentation and preservation of cellular morphology were obtained when infected cells were applied and cultured on the slide, excess medium was removed, and cells were fixed with ac...

  1. Transgelin-2 in B-Cells Controls T-Cell Activation by Stabilizing T Cell - B Cell Conjugates

    Science.gov (United States)

    Chae, Myoung-Won; Kim, Hye-Ran; Kim, Chang-Hyun; Jun, Chang-Duk; Park, Zee-Yong

    2016-01-01

    The immunological synapse (IS), a dynamic and organized junction between T-cells and antigen presenting cells (APCs), is critical for initiating adaptive immunity. The actin cytoskeleton plays a major role in T-cell reorganization during IS formation, and we previously reported that transgelin-2, an actin-binding protein expressed in T-cells, stabilizes cortical F-actin, promoting T-cell activation in response to antigen stimulation. Transgelin-2 is also highly expressed in B-cells, although no specific function has been reported. In this study, we found that deficiency in transgelin-2 (TAGLN2-/-) in B-cells had little effect on B-cell development and activation, as measured by the expression of CD69, MHC class II molecules, and CD80/86. Nevertheless, in B-cells, transgelin-2 accumulated in the IS during the interaction with T-cells. These results led us to hypothesize that transgelin-2 may also be involved in IS stability in B-cells, thereby influencing T-cell function. Notably, we found that transgelin-2 deficiency in B-cells reduced T-cell activation, as determined by the release of IL-2 and interferon-γ and the expression of CD69. Furthermore, the reduced T-cell activation was correlated with reduced B-cell–T-cell conjugate formation. Collectively, these results suggest that actin stability in B-cells during IS formation is critical for the initiation of adaptive T-cell immunity. PMID:27232882

  2. Relay of herpes simplex virus between Langerhans cells and dermal dendritic cells in human skin.

    Directory of Open Access Journals (Sweden)

    Min Kim

    2015-04-01

    Full Text Available The mechanism by which immunity to Herpes Simplex Virus (HSV is initiated is not completely defined. HSV initially infects mucosal epidermis prior to entering nerve endings. In mice, epidermal Langerhans cells (LCs are the first dendritic cells (DCs to encounter HSV, but it is CD103(+ dermal DCs that carry viral antigen to lymph nodes for antigen presentation, suggesting DC cross-talk in skin. In this study, we compared topically HSV-1 infected human foreskin explants with biopsies of initial human genital herpes lesions to show LCs are initially infected then emigrate into the dermis. Here, LCs bearing markers of maturation and apoptosis formed large cell clusters with BDCA3(+ dermal DCs (thought to be equivalent to murine CD103(+ dermal DCs and DC-SIGN(+ DCs/macrophages. HSV-expressing LC fragments were observed inside the dermal DCs/macrophages and the BDCA3(+ dermal DCs had up-regulated a damaged cell uptake receptor CLEC9A. No other infected epidermal cells interacted with dermal DCs. Correspondingly, LCs isolated from human skin and infected with HSV-1 in vitro also underwent apoptosis and were taken up by similarly isolated BDCA3(+ dermal DCs and DC-SIGN(+ cells. Thus, we conclude a viral antigen relay takes place where HSV infected LCs undergo apoptosis and are taken up by dermal DCs for subsequent antigen presentation. This provides a rationale for targeting these cells with mucosal or perhaps intradermal HSV immunization.

  3. Enhancing DNA Vaccine Potency by Combining a Strategy to Prolong Dendritic Cell Life and Intracellular Targeting Strategies with a Strategy to Boost CD4+ T Cells

    OpenAIRE

    Kim, Daejin; Hoory, Talia; Wu, T.-C.; Hung, Chien-Fu

    2007-01-01

    Intradermal administration of DNA vaccines, using a gene gun, represents an effective means of delivering DNA directly into professional antigen-presenting cells (APCs) in the skin and thus allows the application of strategies to modify the properties of APCs to enhance DNA vaccine potency. In the current study, we hypothesized that the potency of human papillomavirus (HPV) type 16 E7 DNA vaccines employing intracellular targeting strategies combined with a strategy to prolong the life of den...

  4. Cross-presentation of cell-associated antigens by MHC class I in dendritic cell subsets

    Directory of Open Access Journals (Sweden)

    Enric eGutiérrez-Martínez

    2015-07-01

    Full Text Available Dendritic cells have the unique ability to pick up dead cells carrying antigens in tissue and migrate to the lymph nodes where they can cross-present cell-associated antigens by MHC class I to CD8+ T cells. There is strong in vivo evidence that the mouse XCR1+ dendritic cells subset acts as a key player in this process. The intracellular processes underlying cross-presentation remain controversial and several pathways have been proposed. Indeed, a wide number of studies have addressed the cellular process of cross-presentation in vitro using a variety of sources of antigen and antigen presenting cells. Here we review the in vivo and in vitro evidence supporting the current mechanistic models and disscuss their physiological relevance to the cross-presentation of cell-associated antigens by dendritic cells subsets

  5. The role of cytokine signaling in the pathogenesis of cutaneous T-cell lymphoma

    DEFF Research Database (Denmark)

    abraham, Robert; Zhang, Qiang; Ødum, Niels;

    2011-01-01

    Cutaneous T-cell lymphoma (CTCL) displays immunosuppressive properties and phenotypic plasticity. The malignant T cells in CTCL can possess features of immunomodulating regulatory T cells (Treg) and IL-17-producing helper T cells (Th17) depending on the stimuli they receive from antigen presenting...... cells and other sources. IL-2-type cytokines activate STAT5 to promote expression of Treg-related FoxP3, while various cytokines can activate STAT3 to induce synthesis of IL-10 and IL-17. When the Treg phenotype is activated in the early stages of CTCL, “immune evasion” can occur, allowing the clonal T...

  6. Thymic selection of T-cell receptors as an extreme value problem

    CERN Document Server

    Kosmrlj, Andrej; Kardar, Mehran; Shakhnovich, Eugene I

    2009-01-01

    T lymphocytes (T cells) orchestrate adaptive immune responses upon activation. T cell activation requires sufficiently strong binding of T cell receptors (TCRs) on their surface to short peptides (p) derived from foreign proteins, which are bound to major histocompatibility (MHC) gene products (displayed on antigen presenting cells). A diverse and self-tolerant T cell repertoire is selected in the thymus. We map thymic selection processes to an extreme value problem and provide an analytic expression for the amino acid compositions of selected TCRs (which enable its recognition functions).

  7. Clinical evaluation of serum tumour marker CA 242 in non-small cell lung cancer.

    OpenAIRE

    Pujol, J L; Cooper, E H; Lehmann, M.; Purves, D. A.; Dan-Aouta, M.; Midander, J.; Godard, P.; Michel, F B

    1993-01-01

    CA 242, a novel tumour carbohydrate antigen present in serum (upper limit of normal values: 20.0 U ml-1), has been measured in a group of 102 pathologically confirmed non-small cell lung cancer patients. The aim of the present prospective study was to identify any relationship between pre-treatment serum CA 242 level and different features of lung cancer including prognosis. Serum CA 242 was measured using the delayed europium lanthanide fluoroimmunometric assay. Sensitivity and specificity w...

  8. Antibodies to human fetal erythroid cells from a nonimmune phage antibody library

    OpenAIRE

    Huie, Michael A.; Cheung, Mei-Chi; Muench, Marcus O.; Becerril, Baltazar; Kan, Yuet W.; Marks, James D.

    2001-01-01

    The ability to isolate fetal nucleated red blood cells (NRBCs) from the maternal circulation makes possible prenatal genetic analysis without the need for diagnostic procedures that are invasive for the fetus. Such isolation requires antibodies specific to fetal NRBCs. To generate a panel of antibodies to antigens present on fetal NRBCs, a new type of nonimmune phage antibody library was generated in which multiple copies of antibody fragments are displayed on each pha...

  9. CD4+ T cells mediate mucosal and systemic immune responses to experimental hookworm infection

    OpenAIRE

    DONDJI, B.; Sun, T.; BUNGIRO, R. D.; VERMEIRE, J. J.; HARRISON, L. M.; BIFULCO, C.; Cappello, M

    2010-01-01

    Hookworm infection is associated with anaemia and malnutrition in many resource-limited countries. Ancylostoma hookworms have previously been shown to modulate host cellular immune responses through multiple mechanisms, including reduced mitogen-mediated lymphocyte proliferation, impaired antigen presentation/processing, and relative reductions in CD4+ T cells in the spleen and mesenteric lymph nodes. Syrian hamsters were depleted of CD4+ for up to 9 days following intraperitoneal injection (...

  10. Langerhans cells and their role in oral mucosal diseases

    Directory of Open Access Journals (Sweden)

    Juhi Upadhyay

    2013-01-01

    Full Text Available Dendritic cells are arguably the most potent antigen-presenting cells and may be the only cells capable of initiating the adaptive immune response. The epithelial residents of dendritic cells are Langerhans cells, which serve as the "sentinels" of the mucosa, altering the immune system not only to pathogen entry but also of tolerance to self antigen and commensal microbes. Oral mucosal Langerhans cells are capable of engaging and internalizing a wide variety of pathogens and have been found responsive to nickel in patients with nickel allergies, oral Candida species, oral lichen planus, lichenoid drug eruptions, graft versus host diseases, periodontal diseases median rhomboid glossitis, human immunodeficiency virus infection, hairy leukoplakia of the tongue, and oral squamous cell carcinoma. Review focuses on the role of antigen-presenting cells in particular Langerhans cells to better understand the mechanisms underlying immune responses. In this review, comprehensive detail about mucosal diseases has been compiled using the PubMed database and through textbooks.

  11. Production of LacZ inducible T cell hybridoma specific for human and mouse gp100₂₅₋₃₃ peptides.

    Directory of Open Access Journals (Sweden)

    Gal Cafri

    Full Text Available Identification and quantification of immunogenic peptides and tumor-derived epitopes presented on MHC-I molecules are essential for basic studies and vaccines generation. Although lymphocytes derived from transgenic mice can serve as sensitive detectors of processes of antigen presentation and recognition, they are not always available. The use of cell lines might be extremely useful. In this study, we generated a lacZ inducible CD8⁺ hybridoma (BUSA14 capable of recognizing both human and mouse gp100₂₅₋₃₃ melanoma antigens presented on dendritic and tumor cell lines. This hybridoma expresses a variety of membranal T cell markers and secretes IL-2 and TNFα. Thus, BUSA14 offers a quantifiable, cheap and straightforward tool for studying peptide presentation by MHC-I molecules on the cell surface.

  12. T-cell response to allergens.

    Science.gov (United States)

    Ozdemir, Cevdet; Akdis, Mübeccel; Akdis, Cezmi A

    2010-01-01

    Anaphylaxis is a life-threatening IgE-dependent type 1 hypersensitivity reaction in which multiple organ systems are involved. The existence of allergen exposure and specific IgE are the major contributors to this systemic reaction. The decision of the immune system to respond to allergens is highly dependent on factors including the type and load of allergen, behavior and type of antigen-presenting cells, innate immune response stimulating substances in the same micromilieu, the tissue of exposure, interactions between T and B lymphocytes, costimulators, and genetic propensity known as atopy. Antigen-presenting cells introduce processed allergens to T-helper lymphocytes, where a decision of developing different types of T-cell immunity is given under the influence of several cytokines, chemokines, costimulatory signals and regulatory T cells. Among Th2-type cytokines, interleukin (IL)-4 and IL-13 are responsible for class switching in B cells, which results in production of allergen-specific IgE antibodies that bind to specific receptors on mast cells and basophils. After re-exposure to the sensitized allergen, this phase is followed by activation of IgE Fc receptors on mast cells and basophils resulting in biogenic mediator releases responsible for the symptoms and signs of anaphylaxis. Since the discovery of regulatory T cells, the concepts of immune regulation have substantially changed during the last decade. Peripheral T-cell tolerance is a key immunologic mechanism in healthy immune response to self antigens and non-infectious non-self antigens. Both naturally occurring CD4+CD25+ regulatory T (Treg) cells and inducible populations of allergen-specific, IL-10-secreting Treg type 1 cells inhibit allergen-specific effector cells and have been shown to play a central role in the maintenance of peripheral homeostasis and the establishment of controlled immune responses. On the other hand, Th17 cells are characterized by their IL-17 (or IL-17A), IL-17F, IL-6

  13. Plasmacytoid dendritic cells sequester high prion titres at early stages of prion infection.

    Directory of Open Access Journals (Sweden)

    Rocio Castro-Seoane

    2012-02-01

    Full Text Available In most transmissible spongiform encephalopathies prions accumulate in the lymphoreticular system (LRS long before they are detectable in the central nervous system. While a considerable body of evidence showed that B lymphocytes and follicular dendritic cells play a major role in prion colonization of lymphoid organs, the contribution of various other cell types, including antigen-presenting cells, to the accumulation and the spread of prions in the LRS are not well understood. A comprehensive study to compare prion titers of candidate cell types has not been performed to date, mainly due to limitations in the scope of animal bioassays where prohibitively large numbers of mice would be required to obtain sufficiently accurate data. By taking advantage of quantitative in vitro prion determination and magnetic-activated cell sorting, we studied the kinetics of prion accumulation in various splenic cell types at early stages of prion infection. Robust estimates for infectious titers were obtained by statistical modelling using a generalized linear model. Whilst prions were detectable in B and T lymphocytes and in antigen-presenting cells like dendritic cells and macrophages, highest infectious titers were determined in two cell types that have previously not been associated with prion pathogenesis, plasmacytoid dendritic (pDC and natural killer (NK cells. At 30 days after infection, NK cells were more than twice, and pDCs about seven-fold, as infectious as lymphocytes respectively. This result was unexpected since, in accordance to previous reports prion protein, an obligate requirement for prion replication, was undetectable in pDCs. This underscores the importance of prion sequestration and dissemination by antigen-presenting cells which are among the first cells of the immune system to encounter pathogens. We furthermore report the first evidence for a release of prions from lymphocytes and DCs of scrapie-infected mice ex vivo, a process that

  14. Plasmacytoid dendritic cells sequester high prion titres at early stages of prion infection.

    Science.gov (United States)

    Castro-Seoane, Rocio; Hummerich, Holger; Sweeting, Trevor; Tattum, M Howard; Linehan, Jacqueline M; Fernandez de Marco, Mar; Brandner, Sebastian; Collinge, John; Klöhn, Peter-Christian

    2012-02-01

    In most transmissible spongiform encephalopathies prions accumulate in the lymphoreticular system (LRS) long before they are detectable in the central nervous system. While a considerable body of evidence showed that B lymphocytes and follicular dendritic cells play a major role in prion colonization of lymphoid organs, the contribution of various other cell types, including antigen-presenting cells, to the accumulation and the spread of prions in the LRS are not well understood. A comprehensive study to compare prion titers of candidate cell types has not been performed to date, mainly due to limitations in the scope of animal bioassays where prohibitively large numbers of mice would be required to obtain sufficiently accurate data. By taking advantage of quantitative in vitro prion determination and magnetic-activated cell sorting, we studied the kinetics of prion accumulation in various splenic cell types at early stages of prion infection. Robust estimates for infectious titers were obtained by statistical modelling using a generalized linear model. Whilst prions were detectable in B and T lymphocytes and in antigen-presenting cells like dendritic cells and macrophages, highest infectious titers were determined in two cell types that have previously not been associated with prion pathogenesis, plasmacytoid dendritic (pDC) and natural killer (NK) cells. At 30 days after infection, NK cells were more than twice, and pDCs about seven-fold, as infectious as lymphocytes respectively. This result was unexpected since, in accordance to previous reports prion protein, an obligate requirement for prion replication, was undetectable in pDCs. This underscores the importance of prion sequestration and dissemination by antigen-presenting cells which are among the first cells of the immune system to encounter pathogens. We furthermore report the first evidence for a release of prions from lymphocytes and DCs of scrapie-infected mice ex vivo, a process that is associated with

  15. 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.

  16. Regulatory T Cells in Tumor-Associated Tertiary Lymphoid Structures Suppress Anti-tumor T Cell Responses.

    Science.gov (United States)

    Joshi, Nikhil S; Akama-Garren, Elliot H; Lu, Yisi; Lee, Da-Yae; Chang, Gregory P; Li, Amy; DuPage, Michel; Tammela, Tuomas; Kerper, Natanya R; Farago, Anna F; Robbins, Rebecca; Crowley, Denise M; Bronson, Roderick T; Jacks, Tyler

    2015-09-15

    Infiltration of regulatory T (Treg) cells into many tumor types correlates with poor patient prognoses. However, mechanisms of intratumoral Treg cell function remain to be elucidated. We investigated Treg cell function in a genetically engineered mouse model of lung adenocarcinoma and found that Treg cells suppressed anti-tumor responses in tumor-associated tertiary lymphoid structures (TA-TLSs). TA-TLSs have been described in human lung cancers, but their function remains to be determined. TLSs in this model were spatially associated with >90% of tumors and facilitated interactions between T cells and tumor-antigen-presenting dendritic cells (DCs). Costimulatory ligand expression by DCs and T cell proliferation rates increased in TA-TLSs upon Treg cell depletion, leading to tumor destruction. Thus, we propose that Treg cells in TA-TLSs can inhibit endogenous immune responses against tumors, and targeting these cells might provide therapeutic benefit for cancer patients.

  17. 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.

  18. Hybrid human immunodeficiency virus Gag particles as an antigen carrier system: induction of cytotoxic T-cell and humoral responses by a Gag:V3 fusion.

    OpenAIRE

    Griffiths, J C; Harris, S. J.; Layton, G T; Berrie, E L; French, T J; Burns, N R; Adams, S E; Kingsman, A J

    1993-01-01

    In attempts to increase the immunogenicity of recombinant antigens, a number of particulate antigen presentation systems have been developed. In this study, we used human immunodeficiency virus Gag particles as carriers for the human immunodeficiency virus envelope V3 region. Gag:V3 fusion proteins were expressed from baculovirus expression vectors; they migrated to the insect cell membrane and budded from the cells as hybrid particles. An immunization study carried out with rats showed that ...

  19. The immune stimulatory effect of cyanacrylate skin surface stripping on the activation and migration of langerhans cells in human skin in vitro and in vivo

    OpenAIRE

    Deckert, Iliane

    2010-01-01

    Transcutanous immunization (TCI) is a promising alternative to conventional injections, because in contrast to muscle and fat tissue, the skin is especially rich in antigen-presenting cells, e.g. Langerhans cells (LC). Different techniques have been proposed to overcome the barrier function of the skin. Recently, a newly developed protocol based on cyanoacrylate skin surface stripping (CSSS), which facilitates penetration via hair follicles, has been shown to be safe and effective in inducing...

  20. Cellular Adjuvant Properties, Direct Cytotoxicity of Re-differentiated Vα24 Invariant NKT-like Cells from Human Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Shuichi Kitayama

    2016-02-01

    Full Text Available Vα24 invariant natural killer T (iNKT cells are a subset of T lymphocytes implicated in the regulation of broad immune responses. They recognize lipid antigens presented by CD1d on antigen-presenting cells and induce both innate and adaptive immune responses, which enhance effective immunity against cancer. Conversely, reduced iNKT cell numbers and function have been observed in many patients with cancer. To recover these numbers, we reprogrammed human iNKT cells to pluripotency and then re-differentiated them into regenerated iNKT cells in vitro through an IL-7/IL-15-based optimized cytokine combination. The re-differentiated iNKT cells showed proliferation and IFN-γ production in response to α-galactosylceramide, induced dendritic cell maturation and downstream activation of both cytotoxic T lymphocytes and NK cells, and exhibited NKG2D- and DNAM-1-mediated NK cell-like cytotoxicity against cancer cell lines. The immunological features of re-differentiated iNKT cells and their unlimited availability from induced pluripotent stem cells offer a potentially effective immunotherapy against cancer.

  1. 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.

  2. Potential use of [gammadelta] T cell-based vaccines in cancer immunotherapy

    Directory of Open Access Journals (Sweden)

    Mohd Wajid A. Khan

    2014-10-01

    Full Text Available Immunotherapy is a fast advancing methodology involving one of two approaches: 1 compounds targeting immune checkpoints, and 2 cellular immunomodulators. The latter approach is still largely experimental and features in vitro generated, live immune effector cells or antigen-presenting cells (APC. [gammadelta] T cells are known for their efficient in vitro tumor killing activities. Consequently, many laboratories worldwide are currently testing the tumor killing function of [gammadelta] T cells in clinical trials. Reported benefits are modest; however, these studies have demonstrated that large [gammadelta] T cell infusions were well tolerated. Here, we discuss the potential of using human [gammadelta] T cells not as effector cells but as a novel cellular vaccine for treatment of cancer patients. Antigen-presenting [gammadelta] T cells do not require to home to tumor tissues but, instead, need to interact with endogenous, tumor-specific [alphabeta] T cells in secondary lymphoid tissues. Newly mobilised effector [alphabeta] T cells are then thought to overcome the immune blockade by creating proinflammatory conditions fit for effector T cell homing to and killing of tumor cells. Immunotherapy may include tumor antigen-loaded [gammadelta] T cells alone or in combination with immune checkpoint inhibitors.

  3. Immune Monitoring Using mRNA-Transfected Dendritic Cells.

    Science.gov (United States)

    Borch, Troels Holz; Svane, Inge Marie; Met, Özcan

    2016-01-01

    Dendritic cells are known to be the most potent antigen presenting cell in the immune system and are used as cellular adjuvants in therapeutic anticancer vaccines using various tumor-associated antigens or their derivatives. One way of loading antigen into the dendritic cells is by mRNA electroporation, ensuring presentation of antigen through major histocompatibility complex I and potentially activating T cells, enabling them to kill the tumor cells. Despite extensive research in the field, only one dendritic cell-based vaccine has been approved. There is therefore a great need to elucidate and understand the immunological impact of dendritic cell vaccination in order to improve clinical benefit. In this chapter, we describe a method for performing immune monitoring using peripheral blood mononuclear cells and autologous dendritic cells transfected with tumor-associated antigen-encoding mRNA. PMID:27236804

  4. Characteristics and functions of Sendai virus-specific T-cell clones.

    OpenAIRE

    Ertl, H C; Finberg, R W

    1984-01-01

    Several murine Sendai virus-specific T-cell clones were characterized in vitro and in vivo. All T-cell clones were phenotypically Thy-1.2+, and most clones were Lyt-1+,2-; one T-cell clone was Lyt-1-,2-. Some of the clones proliferated in response to antigen presented on I region-compatible stimulator cells. Proliferation could be inhibited by monoclonal antibodies directed against class II antigens. Clones which proliferated in response to antigen secreted lymphokines which could be identifi...

  5. In-Vitro differentiation of mature dendritic cells from human blood monocytes

    OpenAIRE

    Robert Gieseler; Dirk Heise; Afsaneh Soruri; Peter Schwartz; J. Hinrich Peters

    1998-01-01

    Representing the most potent antigen-presenting cells, dendritic cells (DC) can now be generated from human blood monocytes. We recently presented a novel protocol employing GM-CSF, IL-4, and IFN-γ to differentiate monocyte-derived DC in vitro. Here, such cells are characterized in detail. Cells in culture exhibited both dendritic and veiled morphologies, the former being adherent and the latter suspended. Phenotypically, they were CD1a-/dim, CD11a+, CD11b++, CD11c+, CD14dim/-, CD16a-/dim, CD...

  6. The inability to process a self-peptide allows autoreactive T cells to escape tolerance

    OpenAIRE

    1993-01-01

    It is now clear that antigen presenting cells (APCs) do not present all the possible peptides of self-proteins to the immune system. When then, is the fate of T cells specific for those self-peptides that escape processing? In this study, the COOH-terminal peptide (residues 81-104) of self cytochrome c (cyt c) elicited strong autoimmune T cells, as well as autoantibodies specific for this immunogen. These T cells did not respond to stimulation with the whole self cyt c molecule, demonstrating...

  7. Evidence for lipopolysaccharide-induced differentiation of RAW264⋅ 7 murine macrophage cell line into dendritic like cells

    Indian Academy of Sciences (India)

    Rajiv K Saxena; Val Vallyathan; Daniel M Lewis

    2003-02-01

    Effect of lipopolysaccharide (LPS) on RAW264.7 macrophage cell line was studied. LPS-treated RAW264.7 cells increased in cell size and acquired distinct dendritic morphology. At the optimal dose of LPS (1 g/ml), almost 70% RAW264.7 cells acquired dendritic morphology. Flow cytometric studies indicate that the cell surface markers known to be expressed on dendritic cells and involved in antigen presentation and T cell activation (B7.1, B7.2, CD40, MHC class II antigens and CD1d) were also markedly upregulated on LPS-treated RAW264.7 cells. Our results suggest the possibility that LPS by itself could constitute a sufficient signal for differentiation of macrophages into DC-like cells.

  8. 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.

  9. Hybrid human immunodeficiency virus Gag particles as an antigen carrier system: induction of cytotoxic T-cell and humoral responses by a Gag:V3 fusion.

    Science.gov (United States)

    Griffiths, J C; Harris, S J; Layton, G T; Berrie, E L; French, T J; Burns, N R; Adams, S E; Kingsman, A J

    1993-06-01

    In attempts to increase the immunogenicity of recombinant antigens, a number of particulate antigen presentation systems have been developed. In this study, we used human immunodeficiency virus Gag particles as carriers for the human immunodeficiency virus envelope V3 region. Gag:V3 fusion proteins were expressed from baculovirus expression vectors; they migrated to the insect cell membrane and budded from the cells as hybrid particles. An immunization study carried out with rats showed that the particles elicited a strong anti-Gag antibody response and a weak antibody response to the V3 region. A strong anti-V3 cytolytic T-cell response was elicited in immunized mice. These data show that retroviral Gag particles can be used as antigen presentation vehicles. PMID:8497047

  10. Human intestinal dendritic cells as controllers of mucosal immunity

    Directory of Open Access Journals (Sweden)

    David Bernardo

    2013-06-01

    Full Text Available Dendritic cells are the most potent, professional antigen-presenting cells in the body; following antigen presentation they control the type (proinflammatory/regulatory of immune response that will take place, as well as its location. Given their high plasticity and maturation ability in response to local danger signals derived from innate immunity, dendritic cells are key actors in the connection between innate immunity and adaptive immunity responses. In the gut dendritic cells control immune tolerance mechanisms against food and/or commensal flora antigens, and are also capable of initiating an active immune response in the presence of invading pathogens. Dendritic cells are thus highly efficient in controlling the delicate balance between tolerance and immunity in an environment so rich in antigens as the gut, and any factor involving these cells may impact their function, ultimately leading to the development of bowel conditions such as celiac disease or inflammatory bowel disease. In this review we shall summarize our understanding of human intestinal dendritic cells, their ability to express and induce migration markers, the various environmental factors modulating their properties, their subsets in the gut, and the problems entailed by their study, including identification strategies, differences between humans and murine models, and phenotypical variations along the gastrointestinal tract.

  11. Human intestinal dendritic cells as controllers of mucosal immunity.

    Science.gov (United States)

    Bernardo, David

    2013-01-01

    Dendritic cells are the most potent, professional antigen-presenting cells in the body; following antigen presentation they control the type (proinflammatory/regulatory) of immune response that will take place, as well as its location. Given their high plasticity and maturation ability in response to local danger signals derived from innate immunity, dendritic cells are key actors in the connection between innate immunity and adaptive immunity responses. In the gut dendritic cells control immune tolerance mechanisms against food and/or commensal flora antigens, and are also capable of initiating an active immune response in the presence of invading pathogens. Dendritic cells are thus highly efficient in controlling the delicate balance between tolerance and immunity in an environment so rich in antigens as the gut, and any factor involving these cells may impact their function, ultimately leading to the development of bowel conditions such as celiac disease or inflammatory bowel disease. In this review we shall summarize our understanding of human intestinal dendritic cells, their ability to express and induce migration markers, the various environmental factors modulating their properties, their subsets in the gut, and the problems entailed by their study, including identification strategies, differences between humans and murine models, and phenotypical variations along the gastrointestinal tract.

  12. Clinical Significance of Langerhans Cells in Squamous Cell Carcinoma of the Larynx

    Directory of Open Access Journals (Sweden)

    Francisco Esteban

    2012-01-01

    Full Text Available Langerhans cells (LCs may be involved in the immunosurveillance against tumors as antigen-presenting cells. Our objective has been to determine the relevance of LC in progression of larynx squamous cell carcinomas and their relationship with different subpopulations of tumor-infiltrating cells. LCs were investigated by immunohistochemical methods using anti-CD1 antibody. LCs were detected in most of the primary tumors studied (44 out of 50 and also in metastases (6 out of 10 and recurrences (2 out of 3, but we did not find any statistical association between number of LCs and clinical-pathological parameters or survival. However, the number of LCs was increased in patients with evident infiltration of lymphocytes, mainly cytotoxic T cells. We can conclude that although LCs did not show clinical utility as prognostic marker, they may play a role in releasing an active immune response in larynx carcinomas, according to their ability to present antigens to sensitized T cells.

  13. Activated human CD4 T cells express transporters for both cysteine and cystine

    DEFF Research Database (Denmark)

    Levring, Trine Bøegh; Hansen, Ann Kathrine; Nielsen, Bodil Lisbeth;

    2012-01-01

    Because naïve T cells are unable to import cystine due to the absence of cystine transporters, it has been suggested that T cell activation is dependent on cysteine generated by antigen presenting cells. The aim of this study was to determine at which phases during T cell activation exogenous...... cystine/cysteine is required and how T cells meet this requirement. We found that early activation of T cells is independent of exogenous cystine/cysteine, whereas T cell proliferation is strictly dependent of uptake of exogenous cystine/cysteine. Naïve T cells express no or very low levels of both...... cystine and cysteine transporters. However, we found that these transporters become strongly up-regulated during T cell activation and provide activated T cells with the required amount of cystine/cysteine needed for T cell proliferation. Thus, T cells are equipped with mechanisms that allow T cell...

  14. Monoclonal immunoglobulin M antibody to Japanese encephalitis virus that can react with a nuclear antigen in mammalian cells.

    OpenAIRE

    Gould, E A; Chanas, A C; Buckley, A.; Clegg, C S

    1983-01-01

    An immunoglobulin M (IgM) class monoclonal antibody raised against Japanese encephalitis virus reacted with an epitope on the nonstructural virus protein P74 (NV4 in the old nomenclature) of several flaviviruses and also with an antigen present in the nuclei of a variety of mammalian cell types. This antigen had a characteristic granular distribution by immunofluorescence and may correspond to a polypeptide of molecular weight 56,000 seen in nitrocellulose transfers of sodium dodecyl sulfate-...

  15. Lactic Acid Bacteria Differentially Activate Natural Killer Cells

    DEFF Research Database (Denmark)

    Fink, Lisbeth Nielsen; Christensen, Hanne Risager; Frøkiær, Hanne

    proliferation of the NK cells and induced IFN-gamma production, both to levels comparable to PHA stimulation. The proliferative response was further enhanced when autologous monocytes were present, probably because cytokines secreted by monocytes having engulfed bacteria stimulated the growth of the NK cells...... antigen presenting cells and T-cells. Bacteria translocating across the gastrointestinal mucosa are presumed to gain access to NK cell compartments, as consumption of certain strains of lactic acid bacteria has been shown to increase in vivo NK cytotoxic activity. On-going research in our lab aims...... at describing strain-dependent effects of lactic acid bacteria on regulatory functions of NK-cells. Here, we have investigated how human gut flora-derived non-pathogenic lactic acid bacteria affect NK cells in vitro, by measuring proliferation and IFN-gamma production of human peripheral blood NK cells upon...

  16. The timing of T cell priming and cycling

    Directory of Open Access Journals (Sweden)

    Reinhard eObst

    2015-11-01

    Full Text Available The proliferation of specific lymphocytes is the central tenet of the clonal selection paradigm. Antigen recognition by T cells triggers a series of events that produces expanded clones of differentiated effector cells. TCR signaling events are detectable within seconds and minutes and are likely to continue for hours and days in vivo. Here, I review the work done on the importance of TCR signals in the later part of the expansion phase of the primary T cell response, primarily regarding the regulation of the cell cycle in CD4+ and CD8+ cells. The results suggest a degree of programming by early signals for effector differentiation, particularly in the CD8+ T cell compartment, with optimal expansion supported by persistent antigen presentation later on. Differences to CD4+ T cell expansion and new avenues towards a molecular understanding of cell cycle regulation in lymphocytes are discussed.

  17. Dendritic Cells for Anomaly Detection

    CERN Document Server

    Greensmith, Julie; Aickelin, Uwe

    2010-01-01

    Artificial immune systems, more specifically the negative selection algorithm, have previously been applied to intrusion detection. The aim of this research is to develop an intrusion detection system based on a novel concept in immunology, the Danger Theory. Dendritic Cells (DCs) are antigen presenting cells and key to the activation of the human signals from the host tissue and correlate these signals with proteins know as antigens. In algorithmic terms, individual DCs perform multi-sensor data fusion based on time-windows. The whole population of DCs asynchronously correlates the fused signals with a secondary data stream. The behaviour of human DCs is abstracted to form the DC Algorithm (DCA), which is implemented using an immune inspired framework, libtissue. This system is used to detect context switching for a basic machine learning dataset and to detect outgoing portscans in real-time. Experimental results show a significant difference between an outgoing portscan and normal traffic.

  18. Dendritic cell targeted vaccines: Recent progresses and challenges.

    Science.gov (United States)

    Chen, Pengfei; Liu, Xinsheng; Sun, Yuefeng; Zhou, Peng; Wang, Yonglu; Zhang, Yongguang

    2016-03-01

    Dendritic cells (DCs) are known to be a set of morphology, structure and function of heterogeneous professional antigen presenting cells (APCs), as well as the strongest functional antigen presenting cells, which can absorb, process and present antigens. As the key regulators of innate and adaptive immune responses, DCs are at the center of the immune system and capable of interacting with both B cells and T cells, thereby manipulating the humoral and cellular immune responses. DCs provide an essential link between the innate and adaptive immunity, and the strong immune activation function of DCs and their properties of natural adjuvants, make them a valuable target for antigen delivery. Targeting antigens to DC-specific endocytic receptors in combination with the relevant antibodies or ligands along with immunostimulatory adjuvants has been recently recognized as a promising strategy for designing an effective vaccine that elicits a strong and durable T cell response against intracellular pathogens and cancer. This opinion article provides a brief summary of the rationales, superiorities and challenges of existing DC-targeting approaches.

  19. Toll-Like Receptor 3/TRIF-Dependent IL-12p70 Secretion Mediated by Streptococcus pneumoniae RNA and Its Priming by Influenza A Virus Coinfection in Human Dendritic Cells

    OpenAIRE

    Spelmink, Laura; Sender, Vicky; Hentrich, Karina; Kuri, Thomas; Plant, Laura; Henriques-Normark, Birgitta

    2016-01-01

    ABSTRACT A functional immune response is crucial to prevent and limit infections with Streptococcus pneumoniae. Dendritic cells (DCs) play a central role in orchestrating the adaptive and innate immune responses by communicating with other cell types via antigen presentation and secretion of cytokines. In this study, we set out to understand how pneumococci activate human monocyte-derived DCs to produce interleukin-12 (IL-12) p70, an important cytokine during pneumococcal infections. We show ...

  20. Sensitivity of Dendritic Cells to Microenvironment Signals

    Science.gov (United States)

    Motta, Juliana Maria; Rumjanek, Vivian Mary

    2016-01-01

    Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies. PMID:27088097

  1. Sensitivity of Dendritic Cells to Microenvironment Signals

    Directory of Open Access Journals (Sweden)

    Juliana Maria Motta

    2016-01-01

    Full Text Available Dendritic cells are antigen-presenting cells capable of either activating the immune response or inducing and maintaining immune tolerance. They do this by integrating stimuli from the environment and changing their functional status as a result of plasticity. The modifications suffered by these cells have consequences in the way the organism may respond. In the present work two opposing situations known to affect dendritic cells are analyzed: tumor growth, leading to a microenvironment that favors the induction of a tolerogenic profile, and organ transplantation, which leads to a proinflammatory profile. Lessons learned from these situations may help to understand the mechanisms of modulation resulting not only from the above circumstances, but also from other pathologies.

  2. Transcriptional regulation of dendritic cell diversity.

    Science.gov (United States)

    Chopin, Michaël; Allan, Rhys S; Belz, Gabrielle T

    2012-01-01

    Dendritic cells (DCs) are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration, and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These findings open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle - identification of similar DC populations in mouse and man - now sets the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  3. Deciphering dendritic cell heterogenity in immunity

    Directory of Open Access Journals (Sweden)

    Michaël eChopin

    2012-02-01

    Full Text Available Dendritic cells (DCs are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These finding open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle – identification of similar DC populations in mouse and man – now set the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  4. TAP-independent self-peptides enhance T cell recognition of immune-escaped tumors.

    Science.gov (United States)

    Doorduijn, Elien M; Sluijter, Marjolein; Querido, Bianca J; Oliveira, Cláudia C; Achour, Adnane; Ossendorp, Ferry; van der Burg, Sjoerd H; van Hall, Thorbald

    2016-02-01

    Tumor cells frequently escape from CD8+ T cell recognition by abrogating MHC-I antigen presentation. Deficiency in processing components, like the transporter associated with antigen processing (TAP), results in strongly decreased surface display of peptide/MHC-I complexes. We previously identified a class of hidden self-antigens known as T cell epitopes associated with impaired peptide processing (TEIPP), which emerge on tumor cells with such processing defects. In the present study, we analyzed thymus selection and peripheral behavior of T cells with specificity for the prototypic TEIPP antigen, the "self" TRH4 peptide/Db complex. TEIPP T cells were efficiently selected in the thymus, egressed with a naive phenotype, and could be exploited for immunotherapy against immune-escaped, TAP-deficient tumor cells expressing low levels of MHC-I (MHC-Ilo). In contrast, overt thymus deletion and functionally impaired TEIPP T cells were observed in mice deficient for TAP1 due to TEIPP antigen presentation on all body cells in these mice. Our results strongly support the concept that TEIPPs derive from ubiquitous, nonmutated self-antigens and constitute a class of immunogenic neoantigens that are unmasked during tumor immune evasion. These data suggest that TEIPP-specific CD8+ T cells are promising candidates in the treatment of tumors that have escaped from conventional immunotherapies. PMID:26784543

  5. TAP-independent self-peptides enhance T cell recognition of immune-escaped tumors

    Science.gov (United States)

    Doorduijn, Elien M.; Sluijter, Marjolein; Querido, Bianca J.; Oliveira, Cláudia C.; Achour, Adnane; Ossendorp, Ferry; van der Burg, Sjoerd H.; van Hall, Thorbald

    2016-01-01

    Tumor cells frequently escape from CD8+ T cell recognition by abrogating MHC-I antigen presentation. Deficiency in processing components, like the transporter associated with antigen processing (TAP), results in strongly decreased surface display of peptide/MHC-I complexes. We previously identified a class of hidden self-antigens known as T cell epitopes associated with impaired peptide processing (TEIPP), which emerge on tumor cells with such processing defects. In the present study, we analyzed thymus selection and peripheral behavior of T cells with specificity for the prototypic TEIPP antigen, the “self” TRH4 peptide/Db complex. TEIPP T cells were efficiently selected in the thymus, egressed with a naive phenotype, and could be exploited for immunotherapy against immune-escaped, TAP-deficient tumor cells expressing low levels of MHC-I (MHC-Ilo). In contrast, overt thymus deletion and functionally impaired TEIPP T cells were observed in mice deficient for TAP1 due to TEIPP antigen presentation on all body cells in these mice. Our results strongly support the concept that TEIPPs derive from ubiquitous, nonmutated self-antigens and constitute a class of immunogenic neoantigens that are unmasked during tumor immune evasion. These data suggest that TEIPP-specific CD8+ T cells are promising candidates in the treatment of tumors that have escaped from conventional immunotherapies. PMID:26784543

  6. An IFN-gamma-IL-18 signaling loop accelerates memory CD8+ T cell proliferation.

    Directory of Open Access Journals (Sweden)

    Yoshiko Iwai

    Full Text Available Rapid proliferation is one of the important features of memory CD8(+ T cells, ensuring rapid clearance of reinfection. Although several cytokines such as IL-15 and IL-7 regulate relatively slow homeostatic proliferation of memory T cells during the maintenance phase, it is unknown how memory T cells can proliferate more quickly than naïve T cells upon antigen stimulation. To examine antigen-specific CD8(+ T cell proliferation in recall responses in vivo, we targeted a model antigen, ovalbumin(OVA, to DEC-205(+ dendritic cells (DCs with a CD40 maturation stimulus. This led to the induction of functional memory CD8(+ T cells, which showed rapid proliferation and multiple cytokine production (IFN-gamma, IL-2, TNF-alpha during the secondary challenge to DC-targeted antigen. Upon antigen-presentation, IL-18, an IFN-gamma-inducing factor, accumulated at the DC:T cell synapse. Surprisingly, IFN-gamma receptors were required to augment IL-18 production from DCs. Mice genetically deficient for IL-18 or IFN-gamma-receptor 1 also showed delayed expansion of memory CD8(+ T cells in vivo. These results indicate that a positive regulatory loop involving IFN-gamma and IL-18 signaling contributes to the accelerated memory CD8(+ T cell proliferation during a recall response to antigen presented by DCs.

  7. Sphingosine 1-phosphate as a novel immune regulator of dendritic cells

    Indian Academy of Sciences (India)

    Angelo Martino

    2007-09-01

    Although originally described as an intracellular second messenger, sphingosine 1-phosphate (S1P) has recently been shown to be involved in several physiological and pathological functions as an extracellular mediator. S1P receptors are widely expressed and thought to regulate important functions in cell signalling. Recently, the role of S1P on the immune system has evoked great interest. In particular, several aspects of the effects on antigen-presenting cells (APCs) as dendritic cells (DC) in mice and humans have been reported. In this review, we focus on the role played by S1P on the DC system and its effects in immune-related pathological states.

  8. The study of exosomes and microvesicles secreted from breast cancer cell lines

    OpenAIRE

    Zheng, Ying

    2012-01-01

    Exosomes are small secreted vesicles of endocytic origin with a size range of 50-150 nm. They are secreted by many cell types and display multiple biological functions including immune-activation, immune-suppression, antigen presentation, and the shuttling of mRNA and miRNA, as well as other cargo. We have characterised the exosomes secreted from two breast cancer cell lines, MDA-MB-231 and MCF7. Exosomes secreted from both cell lines display typical markers including ALIX, Tsg101, CD9 and CD...

  9. Programming tumor-reactive effector memory CD8+ T cells in vitro obviates the requirement for in vivo vaccination

    OpenAIRE

    Klebanoff, Christopher A.; Yu, Zhiya; Hwang, Leroy N.; Douglas C Palmer; Gattinoni, Luca; Restifo, Nicholas P

    2009-01-01

    Naive and memory CD8+ T cells can undergo programmed activation and expansion in response to a short T-cell receptor stimulus, but the extent to which in vitro programming can qualitatively substitute for an in vivo antigen stimulation remains unknown. We show that self-/tumor-reactive effector memory CD8+ T cells (TEM) programmed in vitro either with peptide-pulsed antigen-presenting cells or plate-bound anti-CD3/anti-CD28 embark on a highly stereotyped response of in vivo clonal expansion a...

  10. Anti-B-Cell Therapies in Autoimmune Neurological Diseases: Rationale and Efficacy Trials.

    Science.gov (United States)

    Alexopoulos, Harry; Biba, Angie; Dalakas, Marinos C

    2016-01-01

    B cells have an ever-increasing role in the etiopathology of a number of autoimmune neurological disorders, acting as antibody-producing cells and, most importantly, as sensors, coordinators, and regulators of the immune response. B cells, among other functions, regulate the T-cell activation process through their participation in antigen presentation and production of cytokines. The availability of monoclonal antibodies or fusion proteins against B-cell surface molecules or B-cell trophic factors bestows a rational approach for treating autoimmune neurological disorders, even when T cells are the main effector cells. This review summarizes basic aspects of B-cell biology, discusses the role(s) of B cells in neurological autoimmunity, and presents anti-B-cell drugs that are either currently on the market or are expected to be available in the near future for treating neurological autoimmune disorders.

  11. The Mertk Receptor Tyrosine Kinase Promotes T-B interaction Stimulated by IgD B-cell Receptor Cross-linking

    OpenAIRE

    Shao, Wen-Hai; Zhen, Yuxuan; Finkelman, Fred D.; Cohen, Philip L.

    2014-01-01

    The Mertk receptor tyrosine kinase facilitates macrophage and DC apoptotic-cell clearance and regulates immune tolerance. Mertk may also contribute to B-cell activation, because Mertk-KO mice fail to develop autoantibodies when allo-activated by T cells. We investigated this possibility with a well-characterized model in which injection of mice with goat anti-IgD antibody causes membrane IgD cross-linking that induces T-independent B cell activation and antigen presentation to T cells. Goat a...

  12. A strategy of tumor treatment in mice with doxorubicin-cyclophosphamide combination based on dendritic cell activation by human double-stranded DNA preparation

    OpenAIRE

    Alyamkina, Ekaterina A; Nikolin, Valeriy P; Popova, Nelly A.; Dolgova, Evgenia V; Proskurina, Anastasia S; Orishchenko, Konstantin E.; Efremov, Yaroslav R.; Chernykh, Elena R.; Ostanin, Alexandr A.; Sidorov, Sergey V; Ponomarenko, Dmitriy M.; Zagrebelniy, Stanislav N; Bogachev, Sergey S.; Shurdov, Mikhail A

    2010-01-01

    Background Immunization of mice with tumor homogenate after combined treatment with cyclophosphamide (CP) and double-stranded DNA (dsDNA) preparation is effective at inhibition of growth of tumor challenged after the treatment. It was assumed that this inhibition might be due to activation of the antigen-presenting cells. The purpose was to develop improved antitumor strategy using mice. We studied the combined action of cytostatics doxorubicin (Dox) plus CP with subsequent dsDNA preparation ...

  13. The Mertk receptor tyrosine kinase promotes T-B interaction stimulated by IgD B-cell receptor cross-linking.

    Science.gov (United States)

    Shao, Wen-Hai; Zhen, Yuxuan; Finkelman, Fred D; Cohen, Philip L

    2014-09-01

    The Mertk receptor tyrosine kinase facilitates macrophage and DC apoptotic-cell clearance and regulates immune tolerance. Mertk may also contribute to B-cell activation, because Mertk-KO mice fail to develop autoantibodies when allo-activated by T cells. We investigated this possibility with a well-characterized model in which injection of mice with goat anti-IgD antibody causes membrane IgD cross-linking that induces T-independent B cell activation and antigen presentation to T cells. Goat anti-mouse IgD antibody-injected C57BL/6 Mertk-KO mice had normal initial B cell activation and proliferation, but significantly lower T cell activation and proliferation, as well as lower IgE and IgG anti-goat IgG responses, as compared to C57BL/6 WT controls. B cell antigen processing, analyzed by evaluating B cell fluorescence following injection of monoclonal anti-IgD antibody labeled with biotin or FITC, was comparable between Mertk-KO mice and WT mice. IgD Ab primed B cells from Mertk-KO mice exhibited significantly lower ability in activating memory T cells isolated from WT mice injected with the same antigen 10 days before. These observations suggest that Mertk expression is required for optimal B-cell antigen presentation, which is, in turn, required in this model for optimal T cell activation and subsequent T cell-dependent B cell differentiation. PMID:24768065

  14. 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...... of IgG and C3 fragments. Furthermore, the binding of Tg to B cells in preparations of normal blood cells was higher in HT serum than in serum from controls and correlated positively with the serum anti-Tg activity, as did the B and CD4+ T cell proliferation. Disruption of the three-dimensional structure...

  15. Monoclonal antibodies against the human leukemia cell line K 562.

    Science.gov (United States)

    Böttger, V; Hering, S; Jantscheff, P; Micheel, B

    1985-01-01

    Three monoclonal antibodies raised against K 562, a cell line originally established from a patient with chronic myeloid leukemia (CML) in terminal blast crisis, were selected according to their distinct reaction pattern. Whereas two antibodies (ZIK-C1-A/C5 and ZIK-C1-A/H5 also designated C and H) recognized antigens, present on K 562 cells and other immature and mature hematopoietic cells (cell lines and normal blood and bone marrow cells), antibody ZIK-C1-A/D9 also designated Y showed an exclusive binding to K 562 cells. The results obtained (here and in the following paper) indicate, that antibody ZIK-C1-A/D9 defines an early differentiation antigen of hematopoiesis or a leukemia-associated antigen.

  16. TCR trafficking in resting and stimulated T cells

    DEFF Research Database (Denmark)

    Geisler, Carsten

    2004-01-01

    Dynamic regulation of TCR expression levels plays important roles in modulating T-cell responses during T-cell development and in mature T cells. TCR expression levels are determined by the rate constants for synthesis, endocytosis, recycling, and degradation. This review examines the rate...... constants, the molecular mechanisms, and the proposed physiological roles of TCR trafficking in resting and stimulated T cells. In resting T cells, the TCR slowly and constitutively cycles between the plasma membrane and the intracellular compartment. Constitutive TCR cycling is dependent on the di....../or might ensure an internal store of TCR that can be rerouted to the immunological synapse during the encounter with an antigen-presenting cell....

  17. Pulmonary Langerhans cell Histiocytosis.

    Science.gov (United States)

    Harari, S; Comel, A

    2001-10-01

    Pulmonary Langerhans cell Histiocytosis is a rare granulomatous disease affecting both sexes, with greater incidence in the second and third decades of life; smoking appears to be the most important risk factor. Its etiology is unknown, although there are data indicating an uncontrolled immune response as possible cause, sustained by the Langerhans cells, antigen presenting cells for T lymphocytes, and their accumulation in the distal bronchioles; these cells express on their surface the CD1a and CD1c antigens, and the B7 molecule, essential for activating quiescent T lymphocytes. In its evolution the granuloma is characterized by the progressive reduction in the LC number, with the increase of fibrosis, surrounding and destroying the bronchiolar lumen; the remaining of the lumen, or the traction exerted by fibrous tissue on the adjacent alveolar spaces leads to the cyst development. Vascular involvement occurs frequently, and may explain the onset of pulmonary hypertension in advanced cases of the disease. The disease may be asymptomatic, or it may present with aspecific respiratory signs and symptoms, and has characteristic radiological findings, being included in the group of cysticaerial parenchymal alterations. The diagnosis could be suggested by the finding of a number of LC in BAL greater than 5%. Different therapies have been proposed, but it seems that the most important measure is smoking cessation. PMID:11587096

  18. Establishing and maintaining the Langerhans cell network.

    Science.gov (United States)

    Chopin, Michaël; Nutt, Stephen L

    2015-05-01

    Langerhans cells (LCs) are the unique antigen-presenting cell of the epidermis. LCs have long been depicted in textbooks as the archetypical dendritic cell that alerts the immune system upon pathogen induced skin barrier breakage, however recent findings argue instead for a more tolerogenic function. While the LCs that populate the epidermis in steady-state arise from progenitors that seed the skin during embryogenesis, it is now apparent that a second pathway generating LCs from a bone marrow derived progenitor is active in inflammatory settings. This review emphasizes the determinants underpinning the establishment of the LC network in steady-state and under inflammatory conditions, as well as the transcriptional machinery governing their differentiation. The dual origin of LCs raises important questions about the functional differences between these subsets in balancing the epidermal immune response between immunity and tolerance.

  19. NKT cells in HIV-1 infection

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Natural killer T (NKT) cells are a unique T cell population that have important immunoregulatory functions and have been shown to be involved in host immunity against a range of microorganisms. It also emerges that they might play a role in HIV-1 infection, and therefore be selectively depleted during the early stages of infection. Recent studies are reviewed regarding the dynamics of NKT depletion during HIV-I infection and their recovery under highly active antiretrovirai treatment (HAART). Possible mechanisms for these changes are proposed based on the recent developments in HIV pathogenesis. Further discussions are focused on HIV's disruption of NKT activation by downregulating CDId expression on antigen presentation cells (APC). HIV-1 protein Nefis found to play the major role by interrupting the intraceilular trafficking of nascent and recycling CDId molecules.

  20. Rapid CD4+ T-cell responses to bacterial flagellin require dendritic cell expression of Syk and CARD9.

    Science.gov (United States)

    Atif, Shaikh M; Lee, Seung-Joo; Li, Lin-Xi; Uematsu, Satoshi; Akira, Shizuo; Gorjestani, Sara; Lin, Xin; Schweighoffer, Edina; Tybulewicz, Victor L J; McSorley, Stephen J

    2015-02-01

    Toll-like receptors (TLRs) can recognize microbial patterns and utilize adaptor molecules, such as-MyD88 or (TRIF TIR-domain-containing adapter-inducing interferon-β), to initiate downstream signaling that ultimately affects the initiation of adaptive immunity. In addition to this inflammatory role, TLR5 expression on dendritic cells can favor antigen presentation of flagellin peptides and thus increase the sensitivity of flagellin-specific T-cell responses in vitro and in vivo. Here, we examined the role of alternative signaling pathways that might regulate flagellin antigen presentation in addition to MyD88. These studies suggest a requirement for spleen tyrosine kinase, a noncanonical TLR-signaling adaptor molecule, and its downstream molecule CARD9 in regulating the sensitivity of flagellin-specific CD4(+) T-cell responses in vitro and in vivo. Thus, a previously unappreciated signaling pathway plays an important role in regulating the dominance of flagellin-specific T-cell responses. PMID:25430631

  1. The role of T cell subsets and cytokines in the regulation of intracellular bacterial infection

    Directory of Open Access Journals (Sweden)

    Oliveira S.C.

    1998-01-01

    Full Text Available Cellular immune responses are a critical part of the host's defense against intracellular bacterial infections. Immunity to Brucella abortus crucially depends on antigen-specific T cell-mediated activation of macrophages, which are the major effectors of cell-mediated killing of this organism. T lymphocytes that proliferate in response to B. abortus were characterized for phenotype and cytokine activity. Human, murine, and bovine T lymphocytes exhibited a type 1 cytokine profile, suggesting an analogous immune response in these different hosts. In vivo protection afforded by a particular cell type is dependent on the antigen presented and the mechanism of antigen presentation. Studies using MHC class I and class II knockout mice infected with B. abortus have demonstrated that protective immunity to brucellosis is especially dependent on CD8+ T cells. To target MHC class I presentation we transfected ex vivo a murine macrophage cell line with B. abortus genes and adoptively transferred them to BALB/c mice. These transgenic macrophage clones induced partial protection in mice against experimental brucellosis. Knowing the cells required for protection, vaccines can be designed to activate the protective T cell subset. Lastly, as a new strategy for priming a specific class I-restricted T cell response in vivo, we used genetic immunization by particle bombardment-mediated gene transfer

  2. Expression of Programmed Cell Death 1 Ligands (PD-L1 and PD-L2) in Histiocytic and Dendritic Cell Disorders.

    Science.gov (United States)

    Xu, Jie; Sun, Heather H; Fletcher, Christopher D M; Hornick, Jason L; Morgan, Elizabeth A; Freeman, Gordon J; Hodi, F Stephen; Pinkus, Geraldine S; Rodig, Scott J

    2016-04-01

    Programmed cell death 1 ligands 1 and 2 (PD-L1 and PD-L2) are cell surface proteins expressed by activated antigen-presenting cells and by select malignancies that bind PD-1 on T cells to inhibit immune responses. Antibodies targeting PD-1 or PD-L1 elicit antitumor immunity in a subset of patients, and clinical response correlates with PD-1 ligand expression by malignant or immune cells within the tumor microenvironment. We examined the expression of PD-1 ligands on subsets of antigen-presenting cells and 87 histiocytic and dendritic cell disorders including those that are benign, borderline, and malignant. Within reactive lymphoid tissue, strong PD-L1 is detected on most macrophages, subsets of interdigitating dendritic cells, and plasmacytoid dendritic cells, but not on follicular dendritic cells or Langerhans cells. Macrophage/dendritic cell subsets do not express discernible PD-L2. Seven of 7 cases of sarcoidosis (100%), 6 of 6 cases of histiocytic necrotizing lymphadenitis (Kikuchi-Fujimoto disease) (100%), 2 of 11 cases of Rosai-Dorfman disease (18%), and 3 of 15 cases of Langerhans cell histiocytosis (20%) exhibited positivity for PD-L1. All cases of sarcoidosis were also positive for PD-L2. Seven of 14 histiocytic sarcomas (50%), 2 of 5 interdigitating dendritic cell sarcomas (40%), 10 of 20 follicular dendritic cell sarcomas (50%), and none of 9 blastic plasmacytoid dendritic cell neoplasms were positive for PD-L1. Eleven of 20 (55%) follicular dendritic cell sarcomas were also positive for PD-L2. PD-L1 and PD-L2 are useful new markers for identifying select histiocyte and dendritic cell disorders and reveal novel patient populations as rational candidates for immunotherapy. PMID:26752545

  3. Tumor Evasion from T Cell Surveillance

    Directory of Open Access Journals (Sweden)

    Katrin Töpfer

    2011-01-01

    Full Text Available An intact immune system is essential to prevent the development and progression of neoplastic cells in a process termed immune surveillance. During this process the innate and the adaptive immune systems closely cooperate and especially T cells play an important role to detect and eliminate tumor cells. Due to the mechanism of central tolerance the frequency of T cells displaying appropriate arranged tumor-peptide-specific-T-cell receptors is very low and their activation by professional antigen-presenting cells, such as dendritic cells, is frequently hampered by insufficient costimulation resulting in peripheral tolerance. In addition, inhibitory immune circuits can impair an efficient antitumoral response of reactive T cells. It also has been demonstrated that large tumor burden can promote a state of immunosuppression that in turn can facilitate neoplastic progression. Moreover, tumor cells, which mostly are genetically instable, can gain rescue mechanisms which further impair immune surveillance by T cells. Herein, we summarize the data on how tumor cells evade T-cell immune surveillance with the focus on solid tumors and describe approaches to improve anticancer capacity of T cells.

  4. The Influence of T Cell Development on Pathogen Specificity and Autoreactivity

    Science.gov (United States)

    Košmrlj, Andrej; Kardar, Mehran; Chakraborty, Arup K.

    2012-10-01

    T cells orchestrate adaptive immune responses upon activation. T cell activation requires sufficiently strong binding of T cell receptors on their surface to short peptides derived from foreign proteins bound to protein products of the major histocompatibility (MHC) gene products, which are displayed on the surface of antigen presenting cells. T cells can also interact with peptide-MHC complexes, where the peptide is derived from host (self) proteins. A diverse repertoire of relatively self-tolerant T cell receptors is selected in the thymus. We study a model, computationally and analytically, to describe how thymic selection shapes the repertoire of T cell receptors, such that T cell receptor recognition of pathogenic peptides is both specific and degenerate. We also discuss the escape probability of autoimmune T cells from the thymus.

  5. The influence of T cell development on pathogen specificity and autoreactivity

    CERN Document Server

    Kosmrlj, Andrej; Chakraborty, Arup K

    2012-01-01

    T cells orchestrate adaptive immune responses upon activation. T cell activation requires sufficiently strong binding of T cell receptors on their surface to short peptides derived from foreign proteins bound to protein products of the major histocompatibility (MHC) gene products, which are displayed on the surface of antigen presenting cells. T cells can also interact with peptide-MHC complexes, where the peptide is derived from host (self) proteins. A diverse repertoire of relatively self-tolerant T cell receptors is selected in the thymus. We study a model, computationally and analytically, to describe how thymic selection shapes the repertoire of T cell receptors, such that T cell receptor recognition of pathogenic peptides is both specific and degenerate. We also discuss the escape probability of autoimmune T cells from the thymus.

  6. Phenotypic and Functional Alterations of Dendritic Cells Induced by Human Herpesvirus 6 Infection

    OpenAIRE

    Kakimoto, Miki; Hasegawa, Atsuhiko; Fujita, Shigeru; Yasukawa, Masaki

    2002-01-01

    Human herpesvirus 6 (HHV-6) has a tropism for T lymphocytes and monocytes/macrophages, suggesting that HHV-6 infection affects the immunosurveillance system. In the present study, we investigated the HHV-6-induced phenotypic and functional alterations of dendritic cells (DCs), which are professional antigen-presenting cells. HHV-6 infection of monocyte-derived immature DCs appeared to induce the up-regulation of CD80, CD83, CD86, and HLA class I and class II molecules, suggesting that HHV-6 i...

  7. Dendritic-cell-based technology landscape: Insights from patents and citation networks.

    Science.gov (United States)

    Kong, Xiangjun; Hu, Yuanjia; Cai, Zhifang; Yang, Fengqing; Zhang, Qianru

    2015-01-01

    As the most potent antigen-presenting cells, dendritic cells (DCs) are pivotal players in regulating immune responses. DC-based technologies have generated a series of typical and promising therapeutic options, especially after the first DC-based cancer vaccine was approved by US. Food and Drug Administration (US. FDA). In this context, this paper employs patents and citation networks to conduct a fundamental analysis in order to show overall landscape of DC-based technologies. The results in this research can be used as references for decision-making in developing efficacious DC therapeutic products. PMID:25714961

  8. Association of HMGB1 polymorphisms with outcome after allogeneic hematopoietic cell transplantation

    DEFF Research Database (Denmark)

    Kornblit, Brian Thomas; Masmas, Tania; Petersen, Søren;

    2010-01-01

    activation of antigen presenting cells (APCs) and propagation of inflammation. HMGB1 is implicated in the pathophysiology of a variety of inflammatory diseases, and we have recently found the variation in the HMGB1 gene to be associated with mortality in patients with systemic inflammatory response syndrome......Several studies have demonstrated that genetic variation in cytokine genes can modulate the immune reactions after allogeneic hematopoietic cell transplantation (HCT). High mobility group box 1 protein (HMBG1) is a pleiotropic cytokine that functions as a pro-inflammatory signal, important for the...

  9. Influenza A virus infection of human primary dendritic cells impairs their ability to cross-present antigen to CD8 T cells.

    Directory of Open Access Journals (Sweden)

    Anna Smed-Sörensen

    Full Text Available Influenza A virus (IAV infection is normally controlled by adaptive immune responses initiated by dendritic cells (DCs. We investigated the consequences of IAV infection of human primary DCs on their ability to function as antigen-presenting cells. IAV was internalized by both myeloid DCs (mDCs and plasmacytoid DCs but only mDCs supported viral replication. Although infected mDCs efficiently presented endogenous IAV antigens on MHC class II, this was not the case for presentation on MHC class I. Indeed, cross-presentation by uninfected cells of minute amounts of endocytosed, exogenous IAV was -300-fold more efficient than presentation of IAV antigens synthesized by infected cells and resulted in a statistically significant increase in expansion of IAV-specific CD8 T cells. Furthermore, IAV infection also impaired cross-presentation of other exogenous antigens, indicating that IAV infection broadly attenuates presentation on MHC class I molecules. Our results suggest that cross-presentation by uninfected mDCs is a preferred mechanism of antigen-presentation for the activation and expansion of CD8 T cells during IAV infection.

  10. Influenza A virus infection of human primary dendritic cells impairs their ability to cross-present antigen to CD8 T cells.

    Science.gov (United States)

    Smed-Sörensen, Anna; Chalouni, Cécile; Chatterjee, Bithi; Cohn, Lillian; Blattmann, Peter; Nakamura, Norihiro; Delamarre, Lélia; Mellman, Ira

    2012-01-01

    Influenza A virus (IAV) infection is normally controlled by adaptive immune responses initiated by dendritic cells (DCs). We investigated the consequences of IAV infection of human primary DCs on their ability to function as antigen-presenting cells. IAV was internalized by both myeloid DCs (mDCs) and plasmacytoid DCs but only mDCs supported viral replication. Although infected mDCs efficiently presented endogenous IAV antigens on MHC class II, this was not the case for presentation on MHC class I. Indeed, cross-presentation by uninfected cells of minute amounts of endocytosed, exogenous IAV was -300-fold more efficient than presentation of IAV antigens synthesized by infected cells and resulted in a statistically significant increase in expansion of IAV-specific CD8 T cells. Furthermore, IAV infection also impaired cross-presentation of other exogenous antigens, indicating that IAV infection broadly attenuates presentation on MHC class I molecules. Our results suggest that cross-presentation by uninfected mDCs is a preferred mechanism of antigen-presentation for the activation and expansion of CD8 T cells during IAV infection. PMID:22412374

  11. Virulent Salmonella enterica serovar typhimurium evades adaptive immunity by preventing dendritic cells from activating T cells.

    Science.gov (United States)

    Tobar, Jaime A; Carreño, Leandro J; Bueno, Susan M; González, Pablo A; Mora, Jorge E; Quezada, Sergio A; Kalergis, Alexis M

    2006-11-01

    Dendritic cells (DCs) constitute the link between innate and adaptive immunity by directly recognizing pathogen-associated molecular patterns (PAMPs) in bacteria and by presenting bacterial antigens to T cells. Recognition of PAMPs renders DCs as professional antigen-presenting cells able to prime naïve T cells and initiate adaptive immunity against bacteria. Therefore, interfering with DC function would promote bacterial survival and dissemination. Understanding the molecular mechanisms that have evolved in virulent bacteria to evade activation of adaptive immunity requires the characterization of virulence factors that interfere with DC function. Salmonella enterica serovar Typhimurium, the causative agent of typhoid-like disease in the mouse, can prevent antigen presentation to T cells by avoiding lysosomal degradation in DCs. Here, we show that this feature of virulent Salmonella applies in vivo to prevent activation of adaptive immunity. In addition, this attribute of virulent Salmonella requires functional expression of a type three secretion system (TTSS) and effector proteins encoded within the Salmonella pathogenicity island 2 (SPI-2). In contrast to wild-type virulent Salmonella, mutant strains carrying specific deletions of SPI-2 genes encoding TTSS components or effectors proteins are targeted to lysosomes and are no longer able to prevent DCs from activating T cells in vitro or in vivo. SPI-2 mutant strains are attenuated in vivo, showing reduced tissue colonization and enhanced T-cell activation, which confers protection against a challenge with wild-type virulent Salmonella. Our data suggest that impairment of DC function by the activity of SPI-2 gene products is crucial for Salmonella pathogenesis.

  12. RIG-I Signaling Is Critical for Efficient Polyfunctional T Cell Responses during Influenza Virus Infection.

    Directory of Open Access Journals (Sweden)

    Matheswaran Kandasamy

    2016-07-01

    Full Text Available Retinoic acid inducible gene-I (RIG-I is an innate RNA sensor that recognizes the influenza A virus (IAV RNA genome and activates antiviral host responses. Here, we demonstrate that RIG-I signaling plays a crucial role in restricting IAV tropism and regulating host immune responses. Mice deficient in the RIG-I-MAVS pathway show defects in migratory dendritic cell (DC activation, viral antigen presentation, and priming of CD8+ and CD4+ T cell responses during IAV infection. These defects result in decreased frequency of polyfunctional effector T cells and lowered protection against heterologous IAV challenge. In addition, our data show that RIG-I activation is essential for protecting epithelial cells and hematopoietic cells from IAV infection. These diverse effects of RIG-I signaling are likely imparted by the actions of type I interferon (IFN, as addition of exogenous type I IFN is sufficient to overcome the defects in antigen presentation by RIG-I deficient BMDC. Moreover, the in vivo T cell defects in RIG-I deficient mice can be overcome by the activation of MDA5 -MAVS via poly I:C treatment. Taken together, these findings demonstrate that RIG-I signaling through MAVS is critical for determining the quality of polyfunctional T cell responses against IAV and for providing protection against subsequent infection from heterologous or novel pandemic IAV strains.

  13. Polyelectrolyte coating of ferumoxytol nanoparticles for labeling of dendritic cells

    Science.gov (United States)

    Celikkin, Nehar; Jakubcová, Lucie; Zenke, Martin; Hoss, Mareike; Wong, John Erik; Hieronymus, Thomas

    2015-04-01

    Engineered magnetic nanoparticles (MNPs) are emerging to be used as cell tracers, drug delivery vehicles, and contrast agents for magnetic resonance imaging (MRI) for enhanced theragnostic applications in biomedicine. In vitro labeling of target cell populations with MNPs and their implantation into animal models and patients shows promising outcomes in monitoring successful cell engraftment, differentiation and migration by using MRI. Dendritic cells (DCs) are professional antigen-presenting cells that initiate adaptive immune responses. Thus, DCs have been the focus of cellular immunotherapy and are increasingly applied in clinical trials. Here, we addressed the coating of different polyelectrolytes (PE) around ferumoxytol particles using the layer-by-layer technique. The impact of PE-coated ferumoxytol particles for labeling of DCs and Flt3+ DC progenitors was then investigated. The results from our studies revealed that PE-coated ferumoxytol particles can be readily employed for labeling of DC and DC progenitors and thus are potentially suitable as contrast agents for MRI tracking.

  14. Dendritic Cell Apoptosis and the Pathogenesis of Dengue

    Directory of Open Access Journals (Sweden)

    Lysangela R. Alves

    2012-11-01

    Full Text Available Dengue viruses and other members of the Flaviviridae family are emerging human pathogens. Dengue is transmitted to humans by Aedes aegypti female mosquitoes. Following infection through the bite, cells of the hematopoietic lineage, like dendritic cells, are the first targets of dengue virus infection. Dendritic cells (DCs are key antigen presenting cells, sensing pathogens, processing and presenting the antigens to T lymphocytes, and triggering an adaptive immune response. Infection of DCs by dengue virus may induce apoptosis, impairing their ability to present antigens to T cells, and thereby contributing to dengue pathogenesis. This review focuses on general mechanisms by which dengue virus triggers apoptosis, and possible influence of DC-apoptosis on dengue disease severity.

  15. Polyelectrolyte coating of ferumoxytol nanoparticles for labeling of dendritic cells

    International Nuclear Information System (INIS)

    Engineered magnetic nanoparticles (MNPs) are emerging to be used as cell tracers, drug delivery vehicles, and contrast agents for magnetic resonance imaging (MRI) for enhanced theragnostic applications in biomedicine. In vitro labeling of target cell populations with MNPs and their implantation into animal models and patients shows promising outcomes in monitoring successful cell engraftment, differentiation and migration by using MRI. Dendritic cells (DCs) are professional antigen-presenting cells that initiate adaptive immune responses. Thus, DCs have been the focus of cellular immunotherapy and are increasingly applied in clinical trials. Here, we addressed the coating of different polyelectrolytes (PE) around ferumoxytol particles using the layer-by-layer technique. The impact of PE-coated ferumoxytol particles for labeling of DCs and Flt3+ DC progenitors was then investigated. The results from our studies revealed that PE-coated ferumoxytol particles can be readily employed for labeling of DC and DC progenitors and thus are potentially suitable as contrast agents for MRI tracking

  16. Human thymic epithelial cells express functional HLA-DP molecules

    DEFF Research Database (Denmark)

    Jørgensen, A; Röpke, C; Nielsen, M;

    1996-01-01

    T lymphocytes, we examined whether human thymic epithelial cells (TEC) expressed HLA-DP molecules. We present evidence that TEC obtained from short time culture express low but significant levels of HLA-DP molecules. The expression of HLA-DP molecules was comparable to or higher than the expression...... of HLA-DP allospecific primed lymphocyte typing (PLT) CD4 T cell lines. IFN-gamma treatment strongly upregulated the HLA-DP allospecific PLT responses whereas other PLT responses remained largely unchanged. In conclusion, these data indicate that human thymus epithelial cells express significant levels......HLA-DP molecules function as restriction elements in the presentation of foreign antigens to T cells by antigen presenting cells and certain HLA-DP molecules confer susceptibility to autoimmune disease. Because HLA molecules play an essential role in thymic selection and elimination of autoreactive...

  17. 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.

  18. Alternative spliced CD1d transcripts in human bronchial epithelial cells.

    Directory of Open Access Journals (Sweden)

    Kambez Hajipouran Benam

    Full Text Available CD1d is a MHC I like molecule which presents glycolipid to natural killer T (NKT cells, a group of cells with diverse but critical immune regulatory functions in the immune system. These cells are required for optimal defence against bacterial, viral, protozoan, and fungal infections, and control of immune-pathology and autoimmune diseases. CD1d is expressed on antigen presenting cells but also found on some non-haematopoietic cells. However, it has not been observed on bronchial epithelium, a site of active host defence in the lungs. Here, we identify for the first time, CD1D mRNA variants and CD1d protein expression on human bronchial epithelial cells, describe six alternatively spliced transcripts of this gene in these cells; and show that these variants are specific to epithelial cells. These findings provide the basis for investigations into a role for CD1d in lung mucosal immunity.

  19. Regulatory T cell effects in antitumor laser immunotherapy: a mathematical model and analysis

    Science.gov (United States)

    Dawkins, Bryan A.; Laverty, Sean M.

    2016-03-01

    Regulatory T cells (Tregs) have tremendous influence on treatment outcomes in patients receiving immunotherapy for cancerous tumors. We present a mathematical model incorporating the primary cellular and molecular components of antitumor laser immunotherapy. We explicitly model developmental classes of dendritic cells (DCs), cytotoxic T cells (CTLs), primary and metastatic tumor cells, and tumor antigen. Regulatory T cells have been shown to kill antigen presenting cells, to influence dendritic cell maturation and migration, to kill activated killer CTLs in the tumor microenvironment, and to influence CTL proliferation. Since Tregs affect explicitly modeled cells, but we do not explicitly model dynamics of Treg themselves, we use model parameters to analyze effects of Treg immunosuppressive activity. We will outline a systematic method for assigning clinical outcomes to model simulations and use this condition to associate simulated patient treatment outcome with Treg activity.

  20. Messenger RNA electroporation: an efficient tool in immunotherapy and stem cell research.

    Directory of Open Access Journals (Sweden)

    P Ponsaerts

    2005-12-01

    Full Text Available Over the last decades medicine has developed tremendously, but still many diseases are incurable. The last years, cellular (gene therapy has become a hot topic in biomedical research for the potential treatment of cancer, AIDS and diseases involving cell loss or degeneration. Here, we will focus on two major areas within cellular therapy, cellular immunotherapy and stem cell therapy, that could benefit from the introduction of neo-expressed genes through mRNA electroporation for basic research as well as for clinical applications. For cellular immunotherapy, we will provide a state-of-the-art on loading antigen-presenting cells with antigens in the mRNA format for manipulation of T cell immunity. In the area of stem cell research, we will highlight current gene transfer methods into adult and embryonic stem cells and discuss the use of mRNA electroporation for controlling guided differentiation of stem cells into specialized cell lineages.

  1. Infection of chicken bone marrow mononuclear cells with subgroup J avian leukosis virus inhibits dendritic cell differentiation and alters cytokine expression.

    Science.gov (United States)

    Liu, Di; Qiu, Qianqian; Zhang, Xu; Dai, Manman; Qin, Jianru; Hao, Jianjong; Liao, Ming; Cao, Weisheng

    2016-10-01

    Subgroup J avian leukosis virus (ALV-J) is an oncogenic retrovirus known to induce tumor formation and immunosuppression in infected chickens. One of the organs susceptible to ALV-J is the bone marrow, from which specialized antigen-presenting cells named dendritic cells (BM-DCs) are derived. Notably, these cells possess the unique ability to induce primary immune responses. In the present study, a method of cultivating and purifying DCs from chicken bone marrow in vitro was established to investigate the effects of ALV-J infection on BM-DC differentiation or generation. The results indicated that ALV-J not only infects the chicken bone marrow mononuclear cells but also appears to inhibit the differentiation and maturation of BM-DCs and to trigger apoptosis. Moreover, substantial reductions in the mRNA expression of TLR1, TLR2, TLR3, MHCI, and MHCII and in cytokine production were detected in the surviving BM-DCs following ALV-J infection. These findings indicate that ALV-J infection disrupts the process of bone marrow mononuclear cell differentiation into BM-DCs likely via altered antigen presentation, resulting in a downstream immune response in affected chickens.

  2. Generation of Immune Inhibitory Dendritic Cells and

    Directory of Open Access Journals (Sweden)

    Abediankenari Saeid

    2009-03-01

    Full Text Available Variety of positive as well as negative regulatory signals are provided by antigen presenting cell in particular by dendritic cells. In this research, we studied the capacity of dendritic cells to expand antigen-specific T regulatory cells.We also investigated the role of TGF-beta in induction inhibitory functions of dendritic cells in mixed leukocyte reactions.Dendritic cells were generated from blood CD14+ monocytes with granulocyte-Monocyte colony stimulating factor and interleukin-4 with or without TGF-beta (TGF-β-GM-DC or GM-DC. CD4+ T cell were isolated to assess lymphocyte proliferation by lymphocyte transformation test assay and the ratio of CD4+FOXp3+ CD25+ T cells were determined by fluorescene-activated cell sorter. T cell proliferation responses in GM-DC showed a significance antigen-specific proliferative response comparing with TGFβ-GM -DC. T Cell proliferation was inhibited in co-culture system containing DC-treated TGF-β. It can be suggested that the expsansion of T regulatory by TGF-β-GM-DC provides a means for antigen specific control of unwanted immune reactions.

  3. Intracellular Signals of T Cell Costimulation

    Institute of Scientific and Technical Information of China (English)

    Jianxun Song; Fengyang Tylan Lei; Xiaofang Xiong; Rizwanul Haque

    2008-01-01

    Ligation of T cell receptor (TCR) alone is insufficient to induce full activation of T lymphocytes. Additional ligand-receptor interactions (costimulation) on antigen presenting cells (APCs) and T cells are required. T cell costimulation has been shown to be essential for eliciting efficient T cell responses, involving all phases during T cell development. However, the mechanisms by which costimulation affects the function of T cells still need to be elucidated. In recent years, advances have been made in studies of costimulation as potential therapies in cancer, infectious disease as well as autoimmune disease. In this review, we discussed intracellular costimulation signals that regulate T cell proliferation, cell cycle progression, cytokine production, survival, and memory development. In general, the pathway of phosphoinositide-3 kinase (PBK)/protein kinase B (PKB, also known as Akt)/nuclear factor κB (NF-κB) might be central to many costimulatory effects. Through these pathways, costimulation controls T-cell expansion and proliferation by maintenance of survivin and aurora B expression, and sustains long-term T-cell survival and memory development by regulating the expression of bci-2 family members. Cellular & Molecular Immunology.2008;5(4):239-247.

  4. High Throughput Method to Quantify Anterior-Posterior Polarity of T-Cells and Epithelial Cells

    Directory of Open Access Journals (Sweden)

    Susan J. Marriott

    2011-11-01

    Full Text Available The virologic synapse (VS, which is formed between a virus-infected and uninfected cell, plays a central role in the transmission of certain viruses, such as HIV and HTLV-1. During VS formation, HTLV-1-infected T-cells polarize cellular and viral proteins toward the uninfected T-cell. This polarization resembles anterior-posterior cell polarity induced by immunological synapse (IS formation, which is more extensively characterized than VS formation and occurs when a T-cell interacts with an antigen-presenting cell. One measure of cell polarity induced by both IS or VS formation is the repositioning of the microtubule organizing center (MTOC relative to the contact point with the interacting cell. Here we describe an automated, high throughput system to score repositioning of the MTOC and thereby cell polarity establishment. The method rapidly and accurately calculates the angle between the MTOC and the IS for thousands of cells. We also show that the system can be adapted to score anterior-posterior polarity establishment of epithelial cells. This general approach represents a significant advancement over manual cell polarity scoring, which is subject to experimenter bias and requires more time and effort to evaluate large numbers of cells.

  5. Tumor-derived death receptor 6 modulates dendritic cell development.

    Science.gov (United States)

    DeRosa, David C; Ryan, Paul J; Okragly, Angela; Witcher, Derrick R; Benschop, Robert J

    2008-06-01

    Studies in murine models of cancer as well as in cancer patients have demonstrated that the immune response to cancer is often compromised. This paradigm is viewed as one of the major mechanisms of tumor escape. Many therapies focus on employing the professional antigen presenting dendritic cells (DC) as a strategy to overcome immune inhibition in cancer patients. Death receptor 6 (DR6) is an orphan member of the tumor necrosis factor receptor superfamily (TNFRSF21). It is overexpressed on many tumor cells and DR6(-/-) mice display altered immunity. We investigated whether DR6 plays a role in tumorigenesis by negatively affecting the generation of anti-tumor activity. We show that DR6 is uniquely cleaved from the cell surface of tumor cell lines by the membrane-associated matrix metalloproteinase (MMP)-14, which is often overexpressed on tumor cells and is associated with malignancy. We also demonstrate that >50% of monocytes differentiating into DC die when the extracellular domain of DR6 is present. In addition, DR6 affects the cell surface phenotype of the resulting immature DC and changes their cytokine production upon stimulation with LPS/IFN-gamma. The effects of DR6 are mostly amended when these immature DC are matured with IL-1beta/TNF-alpha, as measured by cell surface phenotype and their ability to present antigen. These results implicate MMP-14 and DR6 as a mechanism tumor cells can employ to actively escape detection by the immune system by affecting the generation of antigen presenting cells.

  6. Aetiology and pathogenesis of reactive arthritis: role of non-antigen-presenting effects of HLA-B27

    OpenAIRE

    Vähämiko, Sanna; Penttinen, Markus A.; Granfors, Kaisa

    2005-01-01

    Spondyloarthropathies are inflammatory diseases closely associated with human leukocyte antigen (HLA)-B27 by unknown mechanisms. One of these diseases is reactive arthritis (ReA), which is typically triggered by Gram-negative bacteria, which have lipopolysaccharide as an integral component of their outer membrane. Several findings in vivo and in vitro obtained from patients with ReA and from different model systems suggest that HLA-B27 modulates the interaction between ReA-triggering bacteria...

  7. Identification of putative cathepsin S in mangrove red snapper Lutjanus argentimaculatus and its role in antigen presentation.

    Science.gov (United States)

    Zhou, Jin; Li, Lei; Cai, Zhong-Hua

    2012-05-01

    Cathepsin S (CTSS) is a key enzyme employed in the histocompatibility complex (MHC) class II-restricted antigens, which are presented by processing class II-associated invariant chains and loaded antigen peptides into class II molecules. To date, little is known about the character and function of CTSS in fish. In the present study, we screened and identified a CTSS cDNA sequence from the mangrove red snapper head kidney cDNA library. The full-length CTSS cDNA contained 1339-bp nucleotide acids encoding 337 amino acids. The sequence shared high identity and similarity with other known cathepsins, especially CTSS (about 56-78% and 79-89%, respectively). Like other cathepsins, the deduced peptide consisted of regions with N-terminal signal peptides, propeptides, and mature peptides. A typical ERWNIN motif in L-like cathepsins and three conservative catalytic activity sites forming a catalytic triad active center were respectively identified in the pro-peptide and mature peptide regions of CTSS. Phylogenetic analysis revealed that mangrove red snapper CTSS was located in the CTSS clade belonging to the L-like cathepsin group, and evolved from the same ancestry. To further characterize the biological activity of the putative CTSS of mangrove snapper, CTSS was expressed in Escherichia coli M15 strains. Like other mammalian CTSS, the recombinant CTSS (rCTSS) had autocatalytic activation properties, can remove pro-peptides, and can release active mature peptides. Active CTSS had the ability to catalyze Z-Phe-Arg-AMC substrates in acidic conditions (pH 5.0) and weak alkaline environments (pH 7.5); this activity could be blocked by the cysteine protease inhibitor E-64. Active CTSS can process recombinant Ii chains (invariant chains) in a stepwise manner in vitro. The results indicate that mangrove red snapper CTSS is a lysosomal cysteine protease family member with a key role in antigen processing in fish.

  8. Balancing selection maintains a form of ERAP2 that undergoes nonsense-mediated decay and affects antigen presentation.

    OpenAIRE

    Andrés, Aida M.; Megan Y Dennis; Warren W Kretzschmar; Cannons, Jennifer L.; Shih-Queen Lee-Lin; Belen Hurle; Schwartzberg, Pamela L.; Williamson, Scott H.; Bustamante, Carlos D.; Rasmus Nielsen; Clark, Andrew G.; Green, Eric D.

    2010-01-01

    A remarkable characteristic of the human major histocompatibility complex (MHC) is its extreme genetic diversity, which is maintained by balancing selection. In fact, the MHC complex remains one of the best-known examples of natural selection in humans, with well-established genetic signatures and biological mechanisms for the action of selection. Here, we present genetic and functional evidence that another gene with a fundamental role in MHC class I presentation, endoplasmic reticulum amino...

  9. Balancing selection maintains a form of ERAP2 that undergoes nonsense-mediated decay and affects antigen presentation

    OpenAIRE

    de Andrés, A.; Dennis, M.; Kretzschmar, W; Cannons, J.; Lee-Lin, S.; Hurle, B.; Schwartzberg, P; Williamson, S.; Bustamante, C; Nielsen, R; Clark, A.; Green, E.

    2010-01-01

    A remarkable characteristic of the human major histocompatibility complex (MHC) is its extreme genetic diversity, which is maintained by balancing selection. In fact, the MHC complex remains one of the best-known examples of natural selection in humans, with well-established genetic signatures and biological mechanisms for the action of selection. Here, we present genetic and functional evidence that another gene with a fundamental role in MHC class I presentation, endoplasmic reticulum amino...

  10. Factors affecting T cell responses induced by fully synthetic glyco-gold-nanoparticles

    Science.gov (United States)

    Fallarini, Silvia; Paoletti, Tiziana; Battaglini, Carolina Orsi; Ronchi, Paolo; Lay, Luigi; Bonomi, Renato; Jha, Satadru; Mancin, Fabrizio; Scrimin, Paolo; Lombardi, Grazia

    2012-12-01

    We have synthesized and characterized nearly monodisperse and highly pure gold nanoparticles (2 and 5 nm) coated with non-immunoactive mono- and disaccharides, modelled after the capsular polysaccharide of serogroup A of the Neisseria meningitidis bacterium. We have used them to test their ability to induce immune cell responses as a consequence of their multivalency. The results indicate that they are indeed immunoactive and that immunoactivity is strongly dependent on size, and larger, 5 nm nanoparticles perform far better than smaller, 2 nm ones. Immune response (activation of macrophages) initiates with the whole nanoparticle recognition by the surface of antigen-presenting cells, independent of the saccharide oligomerization (or charge) on the nanoparticle surface. The induction of T cell proliferation and the increase of IL-2 levels, a consequence of the expression of MHC II involved in antigen presentation, require the presence of a disaccharide on the nanoparticle, not just a monosaccharide. A possible explanation is that, at this stage, the saccharides are detached from the gold surface. These results may provide leads for designing new saccharide-based, nanoparticle-conjugate vaccines.We have synthesized and characterized nearly monodisperse and highly pure gold nanoparticles (2 and 5 nm) coated with non-immunoactive mono- and disaccharides, modelled after the capsular polysaccharide of serogroup A of the Neisseria meningitidis bacterium. We have used them to test their ability to induce immune cell responses as a consequence of their multivalency. The results indicate that they are indeed immunoactive and that immunoactivity is strongly dependent on size, and larger, 5 nm nanoparticles perform far better than smaller, 2 nm ones. Immune response (activation of macrophages) initiates with the whole nanoparticle recognition by the surface of antigen-presenting cells, independent of the saccharide oligomerization (or charge) on the nanoparticle surface. The

  11. The influence of infectious factors on dendritic cell apoptosis.

    Science.gov (United States)

    Kubicka-Sierszen, Agata; Grzegorczyk, Janina Ł

    2015-10-12

    Pathogens can have a negative influence on dendritic cells (DCs), causing their apoptosis, which prevents active presentation of foreign antigens. It results in a state of immunosuppression which makes the body susceptible to secondary infections. Infected immature DCs have lower expression of co-stimulatory and adhesion molecules, reduced ability to secrete cytokines and an inhibited maturation process and are incapable of effective antigen presentation and activation of T-lymphocytes. In some cases, the ability of DCs to undergo rapid apoptosis is important for the body defense, which is probably because of DCs' ability to cross-present and cooperate with other cells. Apoptotic bodies released from the infected DCs are phagocytosed by other DCs, which then stimulate the effector cells and present antigens more efficiently than infected cells. The aim of this article is to review how the DCs respond to viral and bacterial factors and which biochemical mechanisms are responsible for their apoptosis. PMID:26528349

  12. Dendritic Cells, Viruses, and the Development of Atopic Disease

    Directory of Open Access Journals (Sweden)

    Jonathan S. Tam

    2012-01-01

    Full Text Available Dendritic cells are important residents of the lung environment. They have been associated with asthma and other inflammatory diseases of the airways. In addition to their antigen-presenting functions, dendritic cells have the ability to modulate the lung environment to promote atopic disease. While it has long been known that respiratory viral infections associate with the development and exacerbation of atopic diseases, the exact mechanisms have been unclear. Recent studies have begun to show the critical importance of the dendritic cell in this process. This paper focuses on these data demonstrating how different populations of dendritic cells are capable of bridging the adaptive and innate immune systems, ultimately leading to the translation of viral illness into atopic disease.

  13. Involvement of dendritic cells in autoimmune diseases in children

    Directory of Open Access Journals (Sweden)

    Reed Ann M

    2007-07-01

    Full Text Available Abstract Dendritic cells (DCs are professional antigen-presenting cells that are specialized in the uptake of antigens and their transport from peripheral tissues to the lymphoid organs. Over the last decades, the properties of DCs have been intensely studied and much knowledge has been gained about the role of DCs in various diseases and health conditions where the immune system is involved, particularly in cancer and autoimmune disorders. Emerging clues in autoimmune diseases, suggest that dendritic cell dysregulation might be involved in the development of various autoimmune disorders in both adults and children. However, studies investigating a possible contribution of DCs in autoimmune diseases in the pediatric population alone are scanty. The purpose of this review is to give a general overview of the current literature on the relevance of dendritic cells in the most common autoimmune conditions of childhood.

  14. The impact of dendritic cell-tumor fusion cells on cancer vaccines - past progress and future strategies.

    Science.gov (United States)

    Kajihara, Mikio; Takakura, Kazuki; Ohkusa, Toshifumi; Koido, Shigeo

    2015-01-01

    Dendritic cells (DCs) are potent antigen-presenting cells that can be used in cancer vaccines. Thus, various strategies have been developed to deliver tumor-associated antigens via DCs. One strategy includes administering DC-tumor fusion cells (DC-tumor FCs) to induce antitumor immune responses in cancer patients. However, clinical trials using this strategy have fallen short of expectations. Several factors might limit the efficacy of these anticancer vaccines. To induce efficient antitumor immune responses and enhance potential clinical benefits, DC-tumor FC-based cancer vaccines require manipulations that improve immunogenicity for both DCs and whole tumor cells. This review addresses recent progress in improving clinical outcomes using DC-tumor FC-based cancer vaccines. PMID:26507578

  15. B cells contribute to MS pathogenesis through antibody-dependent and antibody-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Wilson HL

    2012-05-01

    Full Text Available Heather L Wilson1,21Vaccine and Infectious Disease Organization-International Vaccine Center, 2Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, CanadaAbstract: For many years, central dogma defined multiple sclerosis (MS as a T cell-driven autoimmune disorder; however, over the past decade there has been a burgeoning recognition that B cells contribute to the pathogenesis of certain MS disease subtypes. B cells may contribute to MS pathogenesis through production of autoantibodies (or antibodies directed at foreign bodies, which unfortunately cross-react with self-antigens, through promotion of T cell activation via antigen presentation, or through production of cytokines. This review highlights evidence for antibody-dependent and antibody-independent B cell involvement in MS pathogenesis.Keywords: autoantibodies, antibody targets, clinically isolated MS, primary progressive MS, secondary progressive MS, relapsing and remitting MS, T cells, T regulatory cells

  16. B cells in the pathophysiology of autoimmune neurological disorders: a credible therapeutic target.

    Science.gov (United States)

    Dalakas, Marinos C

    2006-10-01

    There is evidence that B cells are involved in the pathophysiology of many neurological diseases, either in a causative or contributory role, via production of autoantibodies, cytokine secretion, or by acting as antigen-presenting cells leading to T cell activation. Clonal expansion of B cells either in situ or intrathecally and circulating autoantibodies are critical elements in multiple sclerosis (MS), Devic's disease, paraneoplastic central nervous system disorders, stiff-person syndrome, myasthenia gravis, autoimmune demyelinating neuropathies and dermatomyositis. The pathogenic role of B cells and autoantibodies in central and peripheral nervous system disorders, as reviewed here, provides a rationale for investigating whether depletion of B cells with new agents can improve clinical symptomatology and, potentially, restore immune function. Preliminary results from several clinical studies and case reports suggest that B cell depletion may become a viable alternative approach to the treatment of autoimmune neurological disorders.

  17. Disparate effects of depletion of CD1d-reactive T cells during early versus late stages of disease in a genetically susceptible model of lupus

    OpenAIRE

    Jacinto, J; Kim, PJ; Singh, RR

    2011-01-01

    Some T cells react with lipid antigens bound to antigen-presenting molecule CD1d. Numbers and functions of a subset of such lipid-reactive T cells are reduced in patients with systemic lupus erythematosus (SLE) and their relatives, as well as in genetically susceptible and chemically induced animal models of lupus-like disease. We have reported that the germline deletion of CD1d exacerbates lupus, suggesting a protective role of these cells in the development of lupus. The use of a knockout m...

  18. Regulation of IL-10 and IL-12 production and function in macrophages and dendritic cells [version 1; referees: 3 approved

    Directory of Open Access Journals (Sweden)

    Xiaojing Ma

    2015-12-01

    Full Text Available Interleukin-10 and Interleukin-12 are produced primarily by pathogen-activated antigen-presenting cells, particularly macrophages and dendritic cells. IL-10 and IL-12 play very important immunoregulatory roles in host defense and immune homeostasis. Being anti- and pro-inflammatory in nature, respectively, their functions are antagonistically opposing. A comprehensive and in-depth understanding of their immunological properties and signaling mechanisms will help develop better clinical intervention strategies in therapy for a wide range of human disorders. Here, we provide an update on some emerging concepts, controversies, unanswered questions, and opinions regarding the immune signaling of IL-10 and IL-12.

  19. Extracorporeal Photopheresis for the Prevention of Acute GVHD in Patients Undergoing Standard Myeloablative Conditioning and Allogeneic Hematopoietic Stem Cell Transplantation

    OpenAIRE

    Shaughnessy, Paul J; Bolwell, Brian J.; van Besien, Koen; Mistrik, Martin; Grigg, Andrew; Dodds, Anthony; Prince, H. Miles; Durrant, Simon; Ilhan, Osman; Parenti, Dennis; Rogers, Jon; Gallo, Jose; Foss, Francine; Apperley, Jane; Zhang, Mei-Jie

    2009-01-01

    Graft-versus-host disease (GVHD) is partly mediated by host antigen presenting cells (APCs) that activate donor T-cells. Extracorporeal photopheresis (ECP) can modulate APC function and benefit some patients with GVHD. We report the results of a study using ECP administered prior to a standard myeloablative preparative regimen intended to prevent GVHD. Grade II-IV aGVHD developed in 9 (30%) of 30 recipients of HLA-matched related transplants and 13 (42%) of 31 recipients of HLA-matched unrela...

  20. Mobilization of regulatory T cells in response to carotid injury does not influence subsequent neointima formation.

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    Amit Saxena

    Full Text Available AIM: T cells have been attributed an important role in modulating repair responses following vascular injury. The aim of this study was to investigate the role of different T cell subsets in this context. METHODS AND RESULTS: A non-obstructive collar was introduced to inflict carotid artery injury in mice and subsequent activation of immune cells in draining lymph nodes and spleen were studied by flow cytometry. Carotid artery injury of wild type mice was associated with mobilization of both Th1 type CD4(+IFNγ(+ and regulatory CD4(+CD25(+FoxP3(+ T cells in draining lymph nodes. Studies using FoxP3-green fluorescent protein (GFP transgenic C57/Bl6 mice demonstrated scattered presence of regulatory T cells in the adventitial tissue of injured arteries as well as a massive emigration of regulatory T cells from the spleen in response to carotid injury. However, deletion of antigen presentation to CD4+ T cells (H2(0 mice, as well as deletion of regulatory T cells (through treatment with blocking anti-CD25 antibodies, did not affect neointima formation. Also deletion of antigen presentation to CD8(+ T cells (Tap1(0 mice was without effect on carotid collar-induced neointima formation. CONCLUSION: The results demonstrate that carotid artery injury is associated with mobilization of regulatory T cells. Depletion of regulatory T cells does not, however, influence the subsequent repair processes leading to the formation of a neointima. The results also demonstrate that lack of CD8(+ T cells does not influence neointima formation in presence of functional CD4(+ T cells and B cells.

  1. Characterization of inflammatory cell infiltration in feline allergic skin disease.

    Science.gov (United States)

    Taglinger, K; Day, M J; Foster, A P

    2007-11-01

    Sixteen cats with allergic dermatitis and six control cats with no skin disease were examined. Lymphoid and histiocytic cells in skin sections were examined immunohistochemically and mast cells were identified by toluidine blue staining. The 16 allergic cats showed one or more of several features (alopecia, eosinophilic plaques or granulomas, papulocrusting lesions), and histopathological findings were diverse. In control cats there were no cells that expressed IgM or MAC387, a few that were immunolabelled for IgG, IgA or CD3, and moderate numbers of mast cells. In allergic cats, positively labelled inflammatory cells were generally more numerous in lesional than in non-lesional skin sections, and were particularly associated with the superficial dermis and perifollicular areas. There were low numbers of plasma cells expressing cytoplasmic immunoglobulin; moderate numbers of MHC II-, MAC387- and CD3-positive cells; and moderate to numerous mast cells. MHC class II expression was associated with inflammatory cells morphologically consistent with dermal dendritic cells and macrophages, and epidermal Langerhans cells. Dendritic cells expressing MHC class II were usually associated with an infiltrate of CD3 lymphocytes, suggesting that these cells participate in maintenance of the local immune response by presenting antigen to T lymphocytes. These findings confirm that feline allergic skin disease is characterized by infiltration of activated antigen-presenting cells and T lymphocytes in addition to increased numbers of dermal mast cells. This pattern mimics the dermal inflammation that occurs in the chronic phase of both canine and human atopic dermatitis.

  2. Myeloid cells - targets of medication in multiple sclerosis.

    Science.gov (United States)

    Mishra, Manoj K; Yong, V Wee

    2016-09-01

    Discussions of multiple sclerosis (MS) pathophysiology tend to focus on T cells and B cells of the adaptive immune response. The innate immune system is less commonly considered in this context, although dendritic cells, monocytes, macrophages and microglia - collectively referred to as myeloid cells - have prominent roles in MS pathogenesis. These populations of myeloid cells function as antigen-presenting cells and effector cells in neuroinflammation. Furthermore, a vicious cycle of interactions between T cells and myeloid cells exacerbates pathology. Several disease-modifying therapies are now available to treat MS, and insights into their mechanisms of action have largely focused on the adaptive immune system, but these therapies also have important effects on myeloid cells. In this Review, we discuss the evidence for the roles of myeloid cells in MS and the experimental autoimmune encephalomyelitis model of MS, and consider how interactions between myeloid cells and T cells and/or B cells promote MS pathology. Finally, we discuss the direct and indirect effects of existing MS medications on myeloid cells. PMID:27514287

  3. Canine distemper virus infection leads to an inhibitory phenotype of monocyte-derived dendritic cells in vitro with reduced expression of co-stimulatory molecules and increased interleukin-10 transcription.

    Directory of Open Access Journals (Sweden)

    Visar Qeska

    Full Text Available Canine distemper virus (CDV exhibits a profound lymphotropism that causes immunosuppression and increased susceptibility of affected dogs to opportunistic infections. Similar to human measles virus, CDV is supposed to inhibit terminal differentiation of dendritic cells (DCs, responsible for disturbed repopulation of lymphoid tissues and diminished antigen presenting function in dogs. In order to testify the hypothesis that CDV-infection leads to an impairment of professional antigen presenting cells, canine DCs have been generated from peripheral blood monocytes in vitro and infected with CDV. Virus infection was confirmed and quantified by transmission electron microscopy, CDV-specific immunofluorescence, and virus titration. Flow cytometric analyses revealed a significant down-regulation of the major histocompatibility complex class II and co-stimulatory molecules CD80 and CD86 in CDV-infected DCs, indicative of disturbed antigen presenting capacity. Molecular analyses revealed an increased expression of the immune inhibitory cytokine interleukin-10 in DCs following infection. Results of the present study demonstrate that CDV causes phenotypical changes and altered cytokine expression of DCs, which represent potential mechanisms to evade host immune responses and might contribute to immune dysfunction and virus persistence in canine distemper.

  4. Subdominant H60 antigen-specific CD8 T-cell response precedes dominant H4 antigen-specific response during the initial phase of allogenic skin graft rejection.

    Science.gov (United States)

    Yoo, Kang Il; Jeon, Ji Yeong; Ryu, Su Jeong; Nam, Giri; Youn, Hyewon; Choi, Eun Young

    2015-02-13

    In allogeneic transplantation, including the B6 anti-BALB.B settings, H60 and H4 are two representative dominant minor histocompatibility antigens that induce strong CD8 T-cell responses. With different distribution patterns, H60 expression is restricted to hematopoietic cells, whereas H4 is ubiquitously expressed. H60-specific CD8 T-cell response has been known to be dominant in most cases of B6 anti-BALB.B allo-responses, except in the case of skin transplantation. To understand the mechanism underlying the subdominance of H60 during allogeneic skin transplantation, we investigated the dynamics of the H60-specific CD8 T cells in B6 mice transplanted with allogeneic BALB.B tail skin. Unexpectedly, longitudinal bioluminescence imaging and flow cytometric analyses revealed that H60-specific CD8 T cells were not always subdominant to H4-specific cells but instead showed a brief dominance before the H4 response became predominant. H60-specific CD8 T cells could expand in the draining lymph node and migrate to the BALB.B allografts, indicating their active participation in the anti-BALB.B allo-response. Enhancing the frequencies of H60-reactive CD8 T cells prior to skin transplantation reversed the immune hierarchy between H60 and H4. Additionally, H60 became predominant when antigen presentation was limited to the direct pathway. However, when antigen presentation was restricted to the indirect pathway, the expansion of H60-specific CD8 T cells was limited, whereas H4-specific CD8 T cells expanded significantly, suggesting that the temporary immunodominance and eventual subdominance of H60 could be due to their reliance on the direct antigen presentation pathway. These results enhance our understanding of the immunodominance phenomenon following allogeneic tissue transplantation.

  5. The Role of γδ T Cells in Systemic Lupus Erythematosus.

    Science.gov (United States)

    Wu, Meng; Yang, Jinhua; Li, Xiaofeng; Chen, Junwei

    2016-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disease that is characterized by the overproduction of autoantibodies against an array of nuclear and cytoplasmic antigens and affects multiple organs, such as the skin, joints, kidneys, and neuronal tissues. T cells have been recognized as important players in the development of SLE due to their functions in cytokine secretion, antigen presentation, and supporting B cells for antibody production. γδ T cells are a minor population of T cells that play important roles in infection and tumor-associated disease. In recent years, the role of γδ T cells in autoimmune diseases has been investigated. In this review, we discussed the role of γδ T cells in the pathogenesis of SLE. PMID:26981547

  6. The Role of γδ T Cells in Systemic Lupus Erythematosus

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    Meng Wu

    2016-01-01

    Full Text Available Systemic lupus erythematosus (SLE is an autoimmune disease that is characterized by the overproduction of autoantibodies against an array of nuclear and cytoplasmic antigens and affects multiple organs, such as the skin, joints, kidneys, and neuronal tissues. T cells have been recognized as important players in the development of SLE due to their functions in cytokine secretion, antigen presentation, and supporting B cells for antibody production. γδ T cells are a minor population of T cells that play important roles in infection and tumor-associated disease. In recent years, the role of γδ T cells in autoimmune diseases has been investigated. In this review, we discussed the role of γδ T cells in the pathogenesis of SLE.

  7. Becoming self-aware: the thymic education of regulatory T cells.

    Science.gov (United States)

    Lio, Chan-Wang J; Hsieh, Chyi-Song

    2011-04-01

    The generation of Foxp3(+) regulatory T (Treg) cells in the thymus is essential for immune homeostasis. In the past several years, substantial progress has been made in understanding the mechanisms by which a minor portion of developing thymocytes are selected to become Treg cells. Although previously controversial, recent data support the importance of TCR specificity as a primary determinant for selecting self-reactive thymocytes to become Treg cells in a multi-step process involving cytokines, co-stimulatory molecules, and a variety of antigen-presenting cells. Importantly, the antigenic niche for Treg cell development appears to be typically quite small, implying the recognition of tissue-specific, rather than ubiquitous, self-antigens. Finally, it appears that an NF-κB transcription factor, c-Rel, may be the link between TCR recognition and the induction of Foxp3 expression, which is required for the function and stability of the natural Treg cell population.

  8. Cytotoxic activity of interferon alpha induced dendritic cells as a biomarker of glioblastoma

    Science.gov (United States)

    Mishinov, S. V.; Stupak, V. V.; Tyrinova, T. V.; Leplina, O. Yu.; Ostanin, A. A.; Chernykh, E. R.

    2016-08-01

    Dendritic cells (DCs) are the most potent antigen presenting cells that can play direct role in anti-tumor immune response as killer cells. DC tumoricidal activity can be stimulated greatly by type I IFN (IFNα and IFNβ). In the present study, we examined cytostatic and cytotoxic activity of monocyte-derived IFNα-induced DCs generated from patients with brain glioma and evaluated the potential use of these parameters in diagnostics of high-grade gliomas. Herein, we demonstrated that patient DCs do not possess the ability to inhibit the growth of tumor HEp-2 cell line but low-grade and high-grade glioma patients do not differ significantly in DC cytostatic activity. However, glioma patient DCs are characterized by reduced cytotoxic activity against HEp-2 cells. The impairment of DC cytotoxic function is observed mainly in glioblastoma patients. The cytotoxic activity of DCs against HEp-2 cells below 9% is an informative marker for glioblastomas.

  9. The role of dendritic cells in graft-versus-tumor effect

    Directory of Open Access Journals (Sweden)

    Pavan eReddy

    2014-02-01

    Full Text Available Dendritic cells (DCs are the most potent antigen presenting cells (APCs. DCs play a pivotal role in determining the character and magnitude of immune responses to tumors. Host and donor hematopoietic derived DCs play a critical role in the development of graft-versus host disease (GVHD following allogeneic hematopoietic cell transplantation (allo-HCT. GVHD is tightly linked with the graft-versus-tumor (GVT effect. Although both host and donor DCs are important regulators of GVHD, the role of DCs in GVT is poorly understood. GVT is caused by donor T cells that attack recipient tumor cells. The donor T cells recognize alloantigens and tumor specific antigens (TSAs are mediating GVHD. The process of presentation of these antigens, especially TSAs remains unknown. Recent data suggested that DC may be essential role for inducing GVT. The mechanisms that DCs possess may include direct presentation, cross-presentation, cross-dressing. . The role they play in GVT will be reviewed.

  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. Enteric glial cells and their role in gastrointestinal motor abnormalities: Introducing the neuro-gliopathies

    Institute of Scientific and Technical Information of China (English)

    Gabrio Bassotti; Vincenzo Villanacci; Simona Fisogni; Elisa Rossi; Paola Baronio; Carlo Clerici; Christoph A Maurer; Gieri Cathomas; Elisabetta Antonelli

    2007-01-01

    The role of enteric glial cells has somewhat changed from that of mere mechanical support elements, gluing together the various components of the enteric nervous system, to that of active participants in the complex interrelationships of the gut motor and inflammatory events. Due to their multiple functions, spanning from supporting elements in the myenteric plexuses to neurotransmitters, to neuronal homeostasis, to antigen presenting cells, this cell population has probably more intriguing abilities than previously thought. Recently,some evidence has been accumulating that shows how these cells may be involved in the pathophysiological aspects of some diseases. This review will deal with the properties of the enteric glial cells more strictly related to gastrointestinal motor function and the human pathological conditions in which these cells may play a role, suggesting the possibility of enteric neurogliopathies.

  12. Mesenchymal Stem Cells as Immunomodulators in a Vascularized Composite Allotransplantation

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    Yur-Ren Kuo

    2012-01-01

    Full Text Available Vascularized composite allotransplantations (VCAs are not routinely performed for tissue reconstruction because of the potentially harmful adverse effects associated with lifelong administration of immunosuppressive agents. Researchers have been eagerly seeking alternative methods that circumvent the long-term use of immunosuppressants. Mesenchymal stem cells (MSCs show promise as an immunomodulatory therapeutic agent and are currently being tested in preclinical and clinical settings as therapies for autoimmune disorders or transplant rejection. The mechanisms by which MSCs modulate the immune response are still under thorough investigation, but these most likely involve expression of local factors influencing T-cell regulation, modulation of cytokine expression (e.g., IL-10, TGF-β, TNF-, INF-γ, etc., and interactions with dendritic or antigen presenting cells. In this paper, we summarize the current understanding of immunomodulation achieved by MSC therapies and introduce a possible outline for future clinical applications in VCA.

  13. Anthrax Lethal Toxin and the Induction of CD4 T Cell Immunity

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    Daniel M. Altmann

    2012-10-01

    Full Text Available Bacillus anthracis secretes exotoxins which act through several mechanisms including those that can subvert adaptive immunity with respect both to antigen presenting cell and T cell function. The combination of Protective Antigen (PA and Lethal Factor (LF forming Lethal Toxin (LT, acts within host cells to down-regulate the mitogen activated protein kinase (MAPK signaling cascade. Until recently the MAPK kinases were the only known substrate for LT; over the past few years it has become evident that LT also cleaves Nlrp1, leading to inflammasome activation and macrophage death. The predicted downstream consequences of subverting these important cellular pathways are impaired antigen presentation and adaptive immunity. In contrast to this, recent work has indicated that robust memory T cell responses to B. anthracis antigens can be identified following natural anthrax infection. We discuss how LT affects the adaptive immune response and specifically the identification of B. anthracis epitopes that are both immunogenic and protective with the potential for inclusion in protein sub-unit based vaccines.

  14. Aflatoxins of type B and G affect porcine dendritic cell maturation in vitro.

    Science.gov (United States)

    Mehrzad, Jalil; Devriendt, Bert; Baert, Kim; Cox, Eric

    2015-01-01

    The toxic effects of highly carcinogenic mycotoxins, especially aflatoxins (AF), on key antigen-presenting cells, such as dendritic cells (DC), are largely unknown. To elucidate the effect of AF on DC function, porcine monocyte-derived DC (MoDC) were treated with a mixture of several AF (i.e., AFB1, AFB2, AFG1, and AFG2) and the phagocytic capacity, the membrane expression level of several DC activation markers, the T-cell proliferation-inducing capacity, and the cytokine secretion pattern were assessed. As compared to untreated MoDC, AF significantly up-regulated the expression of the co-stimulatory molecules CD25 and CD80/86. However, the phagocytic activity of MoDC was not affected by AF treatment. While the cytokine secretion pattern of AF-treated MoDC was similar to control MoDC, the T-cell proliferation-inducing capacity of MoDC was increased upon aflatoxin treatment. The results indicate that a mixture of naturally occurring AF enhances the antigen-presenting capacity of DC, which could explain the observed immunotoxicity of AF by breaking down tolerance and further emphasizes the need to reduce the admissible level of AF in agricultural commodities.

  15. HIV/SIV infection primes monocytes and dendritic cells for apoptosis.

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    Mireille Laforge

    2011-06-01

    Full Text Available Subversion or exacerbation of antigen-presenting cells (APC death modulates host/pathogen equilibrium. We demonstrated during in vitro differentiation of monocyte-derived macrophages and monocyte-derived dendritic cells (DCs that HIV sensitizes the cells to undergo apoptosis in response to TRAIL and FasL, respectively. In addition, we found that HIV-1 increased the levels of pro-apoptotic Bax and Bak molecules and decreased the levels of anti-apoptotic Mcl-1 and FLIP proteins. To assess the relevance of these observations in the context of an experimental model of HIV infection, we investigated the death of APC during pathogenic SIV-infection in rhesus macaques (RMs. We demonstrated increased apoptosis, during the acute phase, of both peripheral blood DCs and monocytes (CD14(+ from SIV(+RMs, associated with a dysregulation in the balance of pro- and anti-apoptotic molecules. Caspase-inhibitor and death receptors antagonists prevented apoptosis of APCs from SIV(+RMs. Furthermore, increased levels of FasL in the sera of pathogenic SIV(+RMs were detected, compared to non-pathogenic SIV infection of African green monkey. We suggest that inappropriate apoptosis of antigen-presenting cells may contribute to dysregulation of cellular immunity early in the process of HIV/SIV infection.

  16. Dendritic cells: The warriors upfront-turned defunct in chronic hepatitis C infection

    Institute of Scientific and Technical Information of China (English)

    Meenakshi; Sachdeva; Yogesh; K; Chawla; Sunil; K; Arora

    2015-01-01

    Hepatitis C virus(HCV) infection causes tremendousmorbidity and mortality with over 170 million people infected worldwide. HCV gives rise to a sustained, chronic disease in the majority of infected individuals owing to a failure of the host immune system to clear the virus. In general, an adequate immune response is elicited by an efficient antigen presentation by dendritic cells(DCs), the cells that connect innate and adaptive immune system to generate a specific immune response against a pathogen. However, HCV seems to dysregulate the activity of DCs, making them less proficient antigen presenting cells for the optimal stimulation of virusspecific T cells, hence interfering with an optimal antiviral immune response. There are discordant reports on the functional status of DCs in chronic HCV infection(CHC), from no phenotypic or functional defects to abnormal functions of DCs. Furthermore, the molecular mechanisms behind the impairment of DC function are even so not completely elucidated during CHC. Understanding the mechanisms of immune dysfunction would help in devising strategies for better management of the disease at the immunological level and help to predict the prognosis of the disease in the patients receiving antiviral therapy. In this review, we have discussed the outcomes of the interaction of DCs with HCV and the mechanisms of DC impairment during HCV infection with its adverse effects on the immune response in the infected host.

  17. Differential use of autophagy by primary dendritic cells specialized in cross-presentation.

    Science.gov (United States)

    Mintern, Justine D; Macri, Christophe; Chin, Wei Jin; Panozza, Scott E; Segura, Elodie; Patterson, Natalie L; Zeller, Peter; Bourges, Dorothee; Bedoui, Sammy; McMillan, Paul J; Idris, Adi; Nowell, Cameron J; Brown, Andrew; Radford, Kristen J; Johnston, Angus Pr; Villadangos, Jose A

    2015-01-01

    Antigen-presenting cells survey their environment and present captured antigens bound to major histocompatibility complex (MHC) molecules. Formation of MHC-antigen complexes occurs in specialized compartments where multiple protein trafficking routes, still incompletely understood, converge. Autophagy is a route that enables the presentation of cytosolic antigen by MHC class II molecules. Some reports also implicate autophagy in the presentation of extracellular, endocytosed antigen by MHC class I molecules, a pathway termed "cross-presentation." The role of autophagy in cross-presentation is controversial. This may be due to studies using different types of antigen presenting cells for which the use of autophagy is not well defined. Here we report that active use of autophagy is evident only in DC subtypes specialized in cross-presentation. However, the contribution of autophagy to cross-presentation varied depending on the form of antigen: it was negligible in the case of cell-associated antigen or antigen delivered via receptor-mediated endocytosis, but more prominent when the antigen was a soluble protein. These findings highlight the differential use of autophagy and its machinery by primary cells equipped with specific immune function, and prompt careful reassessment of the participation of this endocytic pathway in antigen cross-presentation.

  18. T cell avidity and tumor recognition: implications and therapeutic strategies

    Directory of Open Access Journals (Sweden)

    Roszkowski Jeffrey J

    2005-09-01

    Full Text Available Abstract In the last two decades, great advances have been made studying the immune response to human tumors. The identification of protein antigens from cancer cells and better techniques for eliciting antigen specific T cell responses in vitro and in vivo have led to improved understanding of tumor recognition by T cells. Yet, much remains to be learned about the intricate details of T cell – tumor cell interactions. Though the strength of interaction between T cell and target is thought to be a key factor influencing the T cell response, investigations of T cell avidity, T cell receptor (TCR affinity for peptide-MHC complex, and the recognition of peptide on antigen presenting targets or tumor cells reveal complex relationships. Coincident with these investigations, therapeutic strategies have been developed to enhance tumor recognition using antigens with altered peptide structures and T cells modified by the introduction of new antigen binding receptor molecules. The profound effects of these strategies on T cell – tumor interactions and the clinical implications of these effects are of interest to both scientists and clinicians. In recent years, the focus of much of our work has been the avidity and effector characteristics of tumor reactive T cells. Here we review concepts and current results in the field, and the implications of therapeutic strategies using altered antigens and altered effector T cells.

  19. Isolation of Human Skin Dendritic Cell Subsets.

    Science.gov (United States)

    Gunawan, Merry; Jardine, Laura; Haniffa, Muzlifah

    2016-01-01

    Dendritic cells (DCs) are specialized leukocytes with antigen-processing and antigen-presenting functions. DCs can be divided into distinct subsets by anatomical location, phenotype and function. In human, the two most accessible tissues to study leukocytes are peripheral blood and skin. DCs are rare in human peripheral blood (Nestle et al., J Immunol 151:6535-6545, 1993). These factors led to the extensive use of skin DCs as the "prototype" migratory DCs in human studies. In this chapter, we detail the protocols to isolate DCs and resident macrophages from human skin. We also provide a multiparameter flow cytometry gating strategy to identify human skin DCs and to distinguish them from macrophages. PMID:27142012

  20. Mast Cell-Derived Exosomes Promote Th2 Cell Differentiation via OX40L-OX40 Ligation.

    Science.gov (United States)

    Li, Fei; Wang, Yuping; Lin, Lihui; Wang, Juan; Xiao, Hui; Li, Jia; Peng, Xia; Dai, Huirong; Li, Li

    2016-01-01

    Exosomes are nanovesicles released by different cell types, such as dendritic cells (DCs), mast cells (MCs), and tumor cells. Exosomes of different origin play a role in antigen presentation and modulation of immune response to infectious disease. In this study, we demonstrate that mast cells and CD4(+) T cells colocated in peritoneal lymph nodes from BALB/c mouse. Further, bone marrow-derived mast cells (BMMCs) constitutively release exosomes, which express CD63 and OX40L. BMMC-exosomes partially promoted the proliferation of CD4(+) T cells. BMMC-exosomes significantly enhanced the differentiation of naive CD4(+) T cells to Th2 cells in a surface contact method, and this ability was partly inhibited by the addition of anti-OX40L Ab. In conclusion, BMMC-exosomes promoted the proliferation and differentiation of Th2 cells via ligation of OX40L and OX40 between exosomes and T cells. This method represents a novel mechanism, in addition to direct cell surface contacts, soluble mediators, and synapses, to regulate T cell actions by BMMC-exosomes. PMID:27066504

  1. Mast Cell-Derived Exosomes Promote Th2 Cell Differentiation via OX40L-OX40 Ligation

    Directory of Open Access Journals (Sweden)

    Fei Li

    2016-01-01

    Full Text Available Exosomes are nanovesicles released by different cell types, such as dendritic cells (DCs, mast cells (MCs, and tumor cells. Exosomes of different origin play a role in antigen presentation and modulation of immune response to infectious disease. In this study, we demonstrate that mast cells and CD4+ T cells colocated in peritoneal lymph nodes from BALB/c mouse. Further, bone marrow-derived mast cells (BMMCs constitutively release exosomes, which express CD63 and OX40L. BMMC-exosomes partially promoted the proliferation of CD4+ T cells. BMMC-exosomes significantly enhanced the differentiation of naive CD4+ T cells to Th2 cells in a surface contact method, and this ability was partly inhibited by the addition of anti-OX40L Ab. In conclusion, BMMC-exosomes promoted the proliferation and differentiation of Th2 cells via ligation of OX40L and OX40 between exosomes and T cells. This method represents a novel mechanism, in addition to direct cell surface contacts, soluble mediators, and synapses, to regulate T cell actions by BMMC-exosomes.

  2. Antibody-independent control of gamma-herpesvirus latency via B cell induction of anti-viral T cell responses.

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    Kelly B McClellan

    2006-06-01

    Full Text Available B cells can use antibody-dependent mechanisms to control latent viral infections. It is unknown whether this represents the sole function of B cells during chronic viral infection. We report here that hen egg lysozyme (HEL-specific B cells can contribute to the control of murine gamma-herpesvirus 68 (gammaHV68 latency without producing anti-viral antibody. HEL-specific B cells normalized defects in T cell numbers and proliferation observed in B cell-/- mice during the early phase of gammaHV68 latency. HEL-specific B cells also reversed defects in CD8 and CD4 T cell cytokine production observed in B cell-/- mice, generating CD8 and CD4 T cells necessary for control of latency. Furthermore, HEL-specific B cells were able to present virally encoded antigen to CD8 T cells. Therefore, B cells have antibody independent functions, including antigen presentation, that are important for control of gamma-herpesvirus latency. Exploitation of this property of B cells may allow enhanced vaccine responses to chronic virus infection.

  3. Close Encounters of Lymphoid Cells and Bacteria

    Science.gov (United States)

    Cruz-Adalia, Aranzazu; Veiga, Esteban

    2016-01-01

    During infections, the first reaction of the host against microbial pathogens is carried out by innate immune cells, which recognize conserved structures on pathogens, called pathogen-associated molecular patterns. Afterward, some of these innate cells can phagocytose and destroy the pathogens, secreting cytokines that would modulate the immune response to the challenge. This rapid response is normally followed by the adaptive immunity, more specific and essential for a complete pathogen clearance in many cases. Some innate immune cells, usually named antigen-presenting cells, such as macrophages or dendritic cells, are able to process internalized invaders and present their antigens to lymphocytes, triggering the adaptive immune response. Nevertheless, the traditional boundary of separated roles between innate and adaptive immunity has been blurred by several studies, showing that very specialized populations of lymphocytes (cells of the adaptive immunity) behave similarly to cells of the innate immunity. These “innate-like” lymphocytes include γδ T cells, invariant NKT cells, B-1 cells, mucosal-associated invariant T cells, marginal zone B cells, and innate response activator cells, and together with the newly described innate lymphoid cells are able to rapidly respond to bacterial infections. Strikingly, our recent data suggest that conventional CD4+ T cells, the paradigm of cells of the adaptive immunity, also present innate-like behavior, capturing bacteria in a process called transinfection. Transinfected CD4+ T cells digest internalized bacteria like professional phagocytes and secrete large amounts of proinflammatory cytokines, protecting for further bacterial challenges. In the present review, we will focus on the data showing such innate-like behavior of lymphocytes following bacteria encounter.

  4. Exosomes and nanotubes: Control of immune cell communication.

    Science.gov (United States)

    McCoy-Simandle, Kessler; Hanna, Samer J; Cox, Dianne

    2016-02-01

    Cell-cell communication is critical to coordinate the activity and behavior of a multicellular organism. The cells of the immune system not only must communicate with similar cells, but also with many other cell types in the body. Therefore, the cells of the immune system have evolved multiple ways to communicate. Exosomes and tunneling nanotubes (TNTs) are two means of communication used by immune cells that contribute to immune functions. Exosomes are small membrane vesicles secreted by most cell types that can mediate intercellular communication and in the immune system they are proposed to play a role in antigen presentation and modulation of gene expression. TNTs are membranous structures that mediate direct cell-cell contact over several cell diameters in length (and possibly longer) and facilitate the interaction and/or the transfer of signals, material and other cellular organelles between connected cells. Recent studies have revealed additional, but sometimes conflicting, structural and functional features of both exosomes and TNTs. Despite the new and exciting information in exosome and TNT composition, origin and in vitro function, biologically significant functions are still being investigated and determined. In this review, we discuss the current field regarding exosomes and TNTs in immune cells providing evaluation and perspectives of the current literature.

  5. Mechanisms of Innate Lymphoid Cell and Natural Killer T Cell Activation during Mucosal Inflammation

    Directory of Open Access Journals (Sweden)

    David Nau

    2014-01-01

    Full Text Available Mucosal surfaces in the airways and the gastrointestinal tract are critical for the interactions of the host with its environment. Due to their abundance at mucosal tissue sites and their powerful immunomodulatory capacities, the role of innate lymphoid cells (ILCs and natural killer T (NKT cells in the maintenance of mucosal tolerance has recently moved into the focus of attention. While NKT cells as well as ILCs utilize distinct transcription factors for their development and lineage diversification, both cell populations can be further divided into three polarized subpopulations reflecting the distinction into Th1, Th2, and Th17 cells in the adaptive immune system. While bystander activation through cytokines mediates the induction of ILC and NKT cell responses, NKT cells become activated also through the engagement of their canonical T cell receptors (TCRs by (glycolipid antigens (cognate recognition presented by the atypical MHC I like molecule CD1d on antigen presenting cells (APCs. As both innate lymphocyte populations influence inflammatory responses due to the explosive release of copious amounts of different cytokines, they might represent interesting targets for clinical intervention. Thus, we will provide an outlook on pathways that might be interesting to evaluate in this context.

  6. Reactivity of Monoclonal Antibodies Directed against Lung Cancer Antigens with Human Lung, Breast and Colon Cancer Cell Lines

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    Udo Schumacher

    1993-01-01

    Full Text Available A panel of monoclonal antibodies (n=72 including controls directed against lung cancer antigens was screened immunohistochemically against a panel of seven human lung cancer cell lines (including small cell carcinoma, squamous cell carcinoma, adenocarcinoma and mesothelioma, six human breast cancer cell lines and one human colon cancer cell line, The majority of the antibodies (n=42 reacted also with antigens present on breast and colon cancer cell lines, This cross reactivity especially between lung and breast cancer cell lines is not altogether unexpected since antigens common to breast and lung tissue including their neoplasms such as MUC1 antigen have been described, Our results indicate that epitopes shared by lung and breast cancers are probably more common than previously thought. The relevance for prognosis and therapy of these shared antigens, especially as disease markers in breast cancer, has to be investigated.

  7. A Rapid Culture Technique Produces Functional Dendritic-Like Cells from Human Acute Myeloid Leukemia Cell Lines

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    Jian Ning

    2011-01-01

    Full Text Available Most anti-cancer immunotherapeutic strategies involving dendritic cells (DC as vaccines rely upon the adoptive transfer of DC loaded with exogenous tumour-peptides. This study utilized human acute myeloid leukemia (AML cells as progenitors from which functional dendritic-like antigen presenting cells (DLC were generated, that constitutively express tumour antigens for recognition by CD8+ T cells. DLC were generated from AML cell lines KG-1 and MUTZ-3 using rapid culture techniques and appropriate cytokines. DLC were evaluated for their cell-surface phenotype, antigen uptake and ability to stimulate allogeneic responder cell proliferation, and production of IFN-γ; compared with DC derived from normal human PBMC donors. KG-1 and MUTZ-3 DLC increased expression of CD80, CD83, CD86, and HLA-DR, and MUTZ-3 DLC downregulated CD14 and expressed CD1a. Importantly, both KG-1 and MUTZ-3-derived DLC promoted proliferation of allogeneic responder cells more efficiently than unmodified cells; neither cells incorporated FITC-labeled dextran, but both stimulated IFN-γ production from responding allogeneic CD8+ T cells. Control DC produced from PBMC using the FastDC culture also expressed high levels of critical cell surface ligands and demonstrated good APC function. This paper indicates that functional DLC can be cultured from the AML cell lines KG-1 and MUTZ-3, and FastDC culture generates functional KG-1 DLC.

  8. Non-hematopoietic cells in lymph nodes drive memory CD8 T cell inflation during murine cytomegalovirus infection.

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    Nicole Torti

    2011-10-01

    Full Text Available During human and murine cytomegalovirus (MCMV infection an exceptionally large virus-specific CD8 T cell pool is maintained in the periphery lifelong. This anomalous response is only seen for specific subsets of MCMV-specific CD8 T cells which are referred to as 'inflationary T cells'. How memory CD8 T cell inflation is induced and maintained is unclear, though their activated phenotype strongly suggests an involvement of persistent antigen encounter during MCMV latency. To dissect the cellular and molecular requirements for memory CD8 T cell inflation, we have generated a transgenic mouse expressing an MHC class I-restricted T cell receptor specific for an immunodominant inflationary epitope of MCMV. Through a series of adoptive transfer experiments we found that memory inflation was completely dependent on antigen presentation by non-hematopoietic cells, which are also the predominant site of MCMV latency. In particular, non-hematopoietic cells selectively induced robust proliferation of inflationary CD8 T cells in lymph nodes, where a majority of the inflationary CD8 T cells exhibit a central-memory phenotype, but not in peripheral tissues, where terminally differentiated inflationary T cells accumulate. These results indicate that continuous restimulation of central memory CD8 T cells in the lymph nodes by infected non-hematopoietic cells ensures the maintenance of a functional effector CD8 T pool in the periphery, providing protection against viral reactivation events.

  9. Progress in dendritic cells immunotherapy%树突状细胞免疫治疗的新进展

    Institute of Scientific and Technical Information of China (English)

    刘博文; 张斌; 曹旭晨

    2011-01-01

    Cancer immunotherapy is a new approach to cancer treatment. Dendritic cells, the most potent antigen-presenting cells found in humans, have attracted a lot of researches. However, dendritic cells are insufficient to cross-present self-antigens in-vivo. To improve the dendritic cells' antigen-presenting capabilities and the anti-tumor effect, in vitro preparation of dendritic cell vaccine and combination with pro-apoptotic treatments such as chemotherapy are being used.%树突状细胞(DC)为目前发现的体内最强的专职抗原提呈细胞,但在体内并不能进行充分的交叉提呈.目前可通过在体外制备DC疫苗或者与化疗等促凋亡治疗联用的方法,增强DC的抗原提呈能力,提高机体免疫系统的抗肿瘤作用.

  10. The T-cell accessory molecule CD4 recognizes a monomorphic determinant on isolated Ia

    DEFF Research Database (Denmark)

    Gay, D; Buus, S; Pasternak, J;

    1988-01-01

    The membrane protein CD4 is commonly found on mature T cells specific for antigen in association with class II major histocompatibility complex (MHC; Ia) proteins. This correlation has led to the suggestion that CD4 binds to a monomorphic region of the Ia molecule on the antigen-presenting cell...... proteins into a planar membrane system, we show that different Ia molecules can greatly enhance the ability of a CD4+ but not a CD4- variant of this class I-restricted T hybrid to respond to isolated class I molecules. T-cell responses can be strongly augmented by the concurrent expression of CD4 on the T...... cell and any of four different Ia proteins on planar membranes, thus supporting the idea that CD4 binds to a monomorphic region of the Ia molecule and increases the avidity with which the T cell can interact with its target....

  11. Introducing Dendritic Cells as a Novel Immune-Inspired Algorithm for Anomoly Detection

    CERN Document Server

    Greensmith, Julie; Cayzer, Steve

    2010-01-01

    Dendritic cells are antigen presenting cells that provide a vital link between the innate and adaptive immune system. Research into this family of cells has revealed that they perform the role of coordinating T-cell based immune responses, both reactive and for generating tolerance. We have derived an algorithm based on the functionality of these cells, and have used the signals and differentiation pathways to build a control mechanism for an artificial immune system. We present our algorithmic details in addition to some preliminary results, where the algorithm was applied for the purpose of anomaly detection. We hope that this algorithm will eventually become the key component within a large, distributed immune system, based on sound immunological concepts.

  12. T cell inactivation by poxviral B22 family proteins increases viral virulence.

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    Dina Alzhanova

    2014-05-01

    Full Text Available Infections with monkeypox, cowpox and weaponized variola virus remain a threat to the increasingly unvaccinated human population, but little is known about their mechanisms of virulence and immune evasion. We now demonstrate that B22 proteins, encoded by the largest genes of these viruses, render human T cells unresponsive to stimulation of the T cell receptor by MHC-dependent antigen presentation or by MHC-independent stimulation. In contrast, stimuli that bypass TCR-signaling are not inhibited. In a non-human primate model of monkeypox, virus lacking the B22R homologue (MPXVΔ197 caused only mild disease with lower viremia and cutaneous pox lesions compared to wild type MPXV which caused high viremia, morbidity and mortality. Since MPXVΔ197-infected animals displayed accelerated T cell responses and less T cell dysregulation than MPXV US2003, we conclude that B22 family proteins cause viral virulence by suppressing T cell control of viral dissemination.

  13. Targeting vaccines to dendritic cells.

    Science.gov (United States)

    Foged, Camilla; Sundblad, Anne; Hovgaard, Lars

    2002-03-01

    Dendritic cells (DC) are specialized antigen presenting cells (APC) with a remarkable ability to take up antigens and stimulate major histocompatibility complex (MHC)-restricted specific immune responses. Recent discoveries have shown that their role in initiating primary immune responses seems to be far superior to that of B-cells and macrophages. DC are localized at strategic places in the body at sites used by pathogens to enter the organism, and are thereby in an optimal position to capture antigens. In general, vaccination strategies try to mimic the invasiveness of the pathogens. DC are considered to play a central role for the provocation of primary immune responses by vaccination. A rational way of improving the potency and safety of new and already existing vaccines could therefore be to direct vaccines specifically to DC. There is a need for developing multifunctional vaccine drug delivery systems (DDS) with adjuvant effect that target DC directly and induce optimal immune responses. This paper will review the current knowledge of DC physiology as well as the progress in the field of novel vaccination strategies that directly or indirectly aim at targeting DC.

  14. Cytomegalovirus-Infected Cells Resist T Cell Mediated Killing in an HLA-Recognition Independent Manner.

    Science.gov (United States)

    Proff, Julia; Walterskirchen, Christian; Brey, Charlotte; Geyeregger, Rene; Full, Florian; Ensser, Armin; Lehner, Manfred; Holter, Wolfgang

    2016-01-01

    In order to explore the potential of HLA-independent T cell therapy for human cytomegalovirus (HCMV) infections, we developed a chimeric antigen receptor (CAR) directed against the HCMV encoded glycoprotein B (gB), which is expressed at high levels on the surface of infected cells. T cells engineered with this anti-gB CAR recognized HCMV-infected cells and released cytokines and cytotoxic granules. Unexpectedly, and in contrast to analogous approaches for HIV, Hepatitis B or Hepatitis C virus, we found that HCMV-infected cells were resistant to killing by the CAR-modified T cells. In order to elucidate whether this phenomenon was restricted to the use of CARs, we extended our experiments to T cell receptor (TCR)-mediated recognition of infected cells. To this end we infected fibroblasts with HCMV-strains deficient in viral inhibitors of antigenic peptide presentation and targeted these HLA-class I expressing peptide-loaded infected cells with peptide-specific cytotoxic T cells (CTLs). Despite strong degranulation and cytokine production by the T cells, we again found significant inhibition of lysis of HCMV-infected cells. Impairment of cell lysis became detectable 1 day after HCMV infection and gradually increased during the following 3 days. We thus postulate that viral anti-apoptotic factors, known to inhibit suicide of infected host cells, have evolved additional functions to directly abrogate T cell cytotoxicity. In line with this hypothesis, CAR-T cell cytotoxicity was strongly inhibited in non-infected fibroblasts by expression of the HCMV-protein UL37x1, and even more so by additional expression of UL36. Our data extend the current knowledge on Betaherpesviral evasion from T cell immunity and show for the first time that, beyond impaired antigen presentation, infected cells are efficiently protected by direct blockade of cytotoxic effector functions through viral proteins.

  15. Estrogen influences the differentiation, maturation and function of dendritic cells in rats with experimental autoimmune encephalomyelitis

    Institute of Scientific and Technical Information of China (English)

    Qing-hong ZHANG; Yu-zhen HU; Jun CAO; Yan-qing ZHONG; Yu-feng ZHAO; Qi-bing MEI

    2004-01-01

    AIM: To examine if estrogen can affect the immune response at the dendritic cells (DCs) level in rats with experimental autoimmune encephalomyelitis (EAE). METHODS: Lewis rats were immunized with inoculum containing MBP68-86. DCs were derived from spleen monocytes of EAE rats with IL-4 and GM-CSF in presence of 17β-estradiol (E2). Nitric oxide (NO) was detected by Griess reagent. The surface markers and cytokines production of DCs were shown by flow cytometry. DCs were cocultured with MBP-specific T cells, [3H]-TdR incoportation was used to reveal the antigen presentability, the supematant of the coculture were collected to examine the cytokines secretion by ELISA. RESULTS: E2 activated DCs by accelerating the maturation process characterized by upregulation of MHC II and costimulating molecule B7-1, B7-2, drastic high expression of CD40. IFN-γ-producing DCs were also elevated without any alteration of IL-10. Estradiol-treated DCs (E2-DCs) secreted more NO in the culture supernatant. By contrast, E2-DCs showed decreased antigen presentation ability with reduced secretion of IFN-γ but no alteration of IL-10 in the coculture with T cells. CONCLUSION: Estrogen can affect the differentiation, maturation and function of DCs from EAE rats, which may be attributed to its protection against EAE and the remission of multiple sclerosis patients in pregnancy.

  16. Human immunodeficiencies related to APC/T cell interaction

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    Marinos eKallikourdis

    2015-08-01

    Full Text Available The primary event for initiating adaptive immune responses is the encounter between T lymphocytes and antigen presenting cells (APC in the T cell area of secondary lymphoid organs and the formation of highly organized inter-cellular junctions referred to as the immune synapses. In vivo live-cell imaging of APC-T cell interactions combined to functional studies unveiled that T cell fate is dictated, in large part, by the stability of the initial contact. Immune cell interaction is equally important during delivery of T cell help to B cells and for the killing of target cells by cytotoxic T cells and NK cells. The critical role of contact dynamics and synapse stability on the immune response is well illustrated by human immune deficiencies in which disease pathogenesis is linked to altered adhesion or defective cross-talk between the synaptic partners. Here we will discuss in details the mechanisms of defective APC-T cell communications in Wiskott-Aldrich syndrome (WAS and in warts, hypogammaglobulinemia, infections, myelokathexis syndrome (WHIM. In addition, we will summarize the evidences pointing to a compromised conjugate formation in WIP deficiency, DOCK8 deficiency and X-linked lymphoproliferative syndrome.

  17. Comparison of monocyte-derived dendritic cells from colorectal cancer patients, non-small-cell-lung-cancer patients and healthy donors

    DEFF Research Database (Denmark)

    Kvistborg, P; Bechmann, C M; Pedersen, A W;

    2009-01-01

    were analyzed by flow cytometry and the obtained data were used as a basis to set guideline values for our quality control of GMP produced DC vaccines. Each vaccine batch was analyzed for the expression of the surface maturation and differentiation molecules CD14, CD1a, CD83, CD86, MHC class II and CCR......Dendritic cells (DCs) are bone marrow-derived professional antigen presenting cells. Due to their role as potent inducers of immune responses, these cells are widely used as adjuvant in experimental clinical settings for cancer immune therapy. We have developed a DC-based vaccine using autologous...... blood monocytes loaded with allogeneic tumor cell lysate rich in cancer/testis antigens. This vaccine has at present been tested for activity in three phase II clinical trials including two cohorts of patients with advanced colorectal cancer (CRC) and one cohort of patients with advanced non...

  18. Dynamic Imaging of CD8(+) T cells and dendritic cells during infection with Toxoplasma gondii.

    Science.gov (United States)

    John, Beena; Harris, Tajie H; Tait, Elia D; Wilson, Emma H; Gregg, Beth; Ng, Lai Guan; Mrass, Paulus; Roos, David S; Dzierszinski, Florence; Weninger, Wolfgang; Hunter, Christopher A

    2009-07-01

    To better understand the initiation of CD8(+) T cell responses during infection, the primary response to the intracellular parasite Toxoplasma gondii was characterized using 2-photon microscopy combined with an experimental system that allowed visualization of dendritic cells (DCs) and parasite specific CD8(+) T cells. Infection with T. gondii induced localization of both these populations to the sub-capsular/interfollicular region of the draining lymph node and DCs were required for the expansion of the T cells. Consistent with current models, in the presence of cognate antigen, the average velocity of CD8(+) T cells decreased. Unexpectedly, infection also resulted in modulation of the behavior of non-parasite specific T cells. This TCR-independent process correlated with the re-modeling of the lymph node micro-architecture and changes in expression of CCL21 and CCL3. Infection also resulted in sustained interactions between the DCs and CD8(+) T cells that were visualized only in the presence of cognate antigen and were limited to an early phase in the response. Infected DCs were rare within the lymph node during this time frame; however, DCs presenting the cognate antigen were detected. Together, these data provide novel insights into the earliest interaction between DCs and CD8(+) T cells and suggest that cross presentation by bystander DCs rather than infected DCs is an important route of antigen presentation during toxoplasmosis.

  19. Dynamic Imaging of CD8(+ T cells and dendritic cells during infection with Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Beena John

    2009-07-01

    Full Text Available To better understand the initiation of CD8(+ T cell responses during infection, the primary response to the intracellular parasite Toxoplasma gondii was characterized using 2-photon microscopy combined with an experimental system that allowed visualization of dendritic cells (DCs and parasite specific CD8(+ T cells. Infection with T. gondii induced localization of both these populations to the sub-capsular/interfollicular region of the draining lymph node and DCs were required for the expansion of the T cells. Consistent with current models, in the presence of cognate antigen, the average velocity of CD8(+ T cells decreased. Unexpectedly, infection also resulted in modulation of the behavior of non-parasite specific T cells. This TCR-independent process correlated with the re-modeling of the lymph node micro-architecture and changes in expression of CCL21 and CCL3. Infection also resulted in sustained interactions between the DCs and CD8(+ T cells that were visualized only in the presence of cognate antigen and were limited to an early phase in the response. Infected DCs were rare within the lymph node during this time frame; however, DCs presenting the cognate antigen were detected. Together, these data provide novel insights into the earliest interaction between DCs and CD8(+ T cells and suggest that cross presentation by bystander DCs rather than infected DCs is an important route of antigen presentation during toxoplasmosis.

  20. CD8+ Tumor-Infiltrating T Cells Are Trapped in the Tumor-Dendritic Cell Network

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    Alexandre Boissonnas

    2013-01-01

    Full Text Available Chemotherapy enhances the antitumor adaptive immune T cell response, but the immunosuppressive tumor environment often dominates, resulting in cancer relapse. Antigen-presenting cells such as tumor-associated macrophages (TAMs and tumor dendritic cells (TuDCs are the main protagonists of tumor-infiltrating lymphocyte (TIL immuno-suppression. TAMs have been widely investigated and are associated with poor prognosis, but the immuno-suppressive activity of TuDCs is less well understood. We performed two-photon imaging of the tumor tissue to examine the spatiotemporal interactions between TILs and TuDCs after chemotherapy. In a strongly immuno-suppressive murine tumor model, cyclophosphamide-mediated chemotherapy transiently enhanced the antitumor activity of adoptively transferred ovalbumin-specific CD8+ T cell receptor transgenic T cells (OTI but barely affected TuDC compartment within the tumor. Time lapse imaging of living tumor tissue showed that TuDCs are organized as a mesh with dynamic interconnections. Once infiltrated into the tumor parenchyma, OTI T cells make antigen-specific and long-lasting contacts with TuDCs. Extensive analysis of TIL infiltration on histologic section revealed that after chemotherapy the majority of OTI T cells interact with TuDCs and that infiltration is restricted to TuDC-rich areas. We propose that the TuDC network exerts antigen-dependent unproductive retention that trap T cells and limit their antitumor effectiveness.

  1. Exploiting the role of endogenous lymphoid-resident dendritic cells in the priming of NKT cells and CD8+ T cells to dendritic cell-based vaccines.

    Directory of Open Access Journals (Sweden)

    Troels R Petersen

    Full Text Available Transfer of antigen between antigen-presenting cells (APCs is potentially a physiologically relevant mechanism to spread antigen to cells with specialized stimulatory functions. Here we show that specific CD8+ T cell responses induced in response to intravenous administration of antigen-loaded bone marrow-derived dendritic cells (BM-DCs, were ablated in mice selectively depleted of endogenous lymphoid-resident langerin+ CD8α+ dendritic cells (DCs, suggesting that the antigen is transferred from the injected cells to resident APCs. In contrast, antigen-specific CD4+ T cells were primed predominantly by the injected BM-DCs, with only very weak contribution of resident APCs. Crucially, resident langerin+ CD8α+ DCs only contributed to the priming of CD8+ T cells in the presence of maturation stimuli such as intravenous injection of TLR ligands, or by loading the BM-DCs with the glycolipid α-galactosylceramide (α-GalCer to recruit the adjuvant activity of activated invariant natural killer-like T (iNKT cells. In fact, injection of α-GalCer-loaded CD1d-/- BM-DCs resulted in potent iNKT cell activation, suggesting that this glycolipid antigen can also be transferred to resident CD1d+ APCs. While iNKT cell activation per se was independent of langerin+ CD8α+ DCs, some iNKT cell-mediated activities were reduced, notably release of IL-12p70 and transactivation of NK cells. We conclude that both protein and glycolipid antigens can be exchanged between distinct DC species. These data suggest that the efficacy of DC-based vaccination strategies may be improved by the incorporation of a systemic maturation signal aimed to engage resident APCs in CD8+ T cell priming, and α-GalCer may be particularly well suited to this purpose.

  2. Host Cell Autophagy in Immune Response to Zoonotic Infections

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    Panagiotis Skendros

    2012-01-01

    Full Text Available Autophagy is a fundamental homeostatic process in which cytoplasmic targets are sequestered within double-membraned autophagosomes and subsequently delivered to lysosomes for degradation. Accumulating evidence supports the pivotal role of autophagy in host defense against intracellular pathogens implicating both innate and adaptive immunity. Many of these pathogens cause common zoonotic infections worldwide. The induction of the autophagic machinery by innate immune receptors signaling, such as TLRs, NOD1/2, and p62/SQSTM1 in antigen-presenting cells results in inhibition of survival and elimination of invading pathogens. Furthermore, Th1 cytokines induce the autophagic process, whereas autophagy also contributes to antigen processing and MHC class II presentation, linking innate to adaptive immunity. However, several pathogens have developed strategies to avoid autophagy or exploit autophagic machinery to their advantage. This paper focuses on the role of host cell autophagy in the regulation of immune response against intracellular pathogens, emphasizing on selected bacterial and protozoan zoonoses.

  3. Non-CpG Oligonucleotides Exert Adjuvant Effects by Enhancing Cognate B Cell-T Cell Interactions, Leading to B Cell Activation, Differentiation, and Isotype Switching

    Directory of Open Access Journals (Sweden)

    Melinda Herbáth

    2015-01-01

    Full Text Available Natural and synthetic nucleic acids are known to exert immunomodulatory properties. Notably, nucleic acids are known to modulate immune function via several different pathways and various cell types, necessitating a complex interpretation of their effects. In this study we set out to compare the effects of a CpG motif containing oligodeoxynucleotide (ODN with those of a control and an inhibitory non-CpG ODN during cognate B cell-T cell interactions. We employed an antigen presentation system using splenocytes from TCR transgenic DO11.10 mice and the ovalbumin peptide recognized by the TCR as model antigen. We followed early activation events by measuring CD69 expression, late activation by MHC class II expression, cell division and antibody production of switched, and nonswitched isotypes. We found that both of the tested non-CpG ODN exerted significant immunomodulatory effects on early T cell and on late B cell activation events. Importantly, a synergism between non-CpG effects and T cell help acting on B cells was observed, resulting in enhanced IgG production following cognate T cell-B cell interactions. We propose that non-CpG ODN may perform as better adjuvants when a strong antigen-independent immune activation, elicited by CpG ODNs, is undesirable.

  4. Invited article: inhibition of B cell functions: implications for neurology.

    Science.gov (United States)

    Dalakas, Marinos C

    2008-06-01

    B cells are involved in the pathophysiology of many neurologic diseases, either in a causative or contributory role, via production of autoantibodies, cytokine secretion, or by acting as antigen-presenting cells leading to T cell activation. B cells are clonally expanded in various CNS disorders, such as multiple sclerosis (MS), paraneoplastic CNS disorders, or stiff-person syndrome, and are activated to produce pathogenic autoantibodies in demyelinating neuropathies and myasthenia. B cell activating factor (BAFF) and a proliferating inducing ligand (APRIL), key cytokines for B cell survival, are strongly unregulated in MS brain and in muscles of inflammatory myopathies. Modulation of B cell functions using a series of monoclonal antibodies against CD20+ B cells or the molecules that increase B cell survival, such as BAFF/APRIL and their receptors BAFF-R, TACI, and BCMA, provide a rational approach to the treatment of the aforementioned neurologic disorders. In controlled studies, rituximab, a B cell-depleting monoclonal antibody, has been encouraging in MS and paraproteinemic anti-MAG demyelinating neuropathy, exerting long-lasting remissions. In uncontrolled series, benefit has been reported in several disorders. B cell depletion is a well-tolerated therapeutic option currently explored in the treatment of several autoimmune neurologic disorders.

  5. B cells as a target of immune modulation

    Directory of Open Access Journals (Sweden)

    Hawker Kathleen

    2009-01-01

    Full Text Available B cells have recently been identified as an integral component of the immune system; they play a part in autoimmunity through antigen presentation, antibody secretion, and complement activation. Animal models of multiple sclerosis (MS suggest that myelin destruction is partly mediated through B cell activation (and plasmablasts. MS patients with evidence of B cell involvement, as compared to those without, tend to have a worse prognosis. Finally, the significant decrease in new gadolinium-enhancing lesions, new T2 lesions, and relapses in MS patients treated with rituximab (a monoclonal antibody against CD20 on B cells leads us to the conclusion that B cells play an important role in MS and that immune modulation of these cells may ameliorate the disease. This article will explore the role of B cells in MS and the rationale for the development of B cell-targeted therapeutics. MS is an immune-mediated disease that affects over 2 million people worldwide and is the number one cause of disability in young patients. Most therapeutic targets have focused on T cells; however, recently, the focus has shifted to the role of B cells in the pathogenesis of MS and the potential of B cells as a therapeutic target.

  6. Dendritic-tumor fusion cells in cancer immunotherapy.

    Science.gov (United States)

    Takakura, Kazuki; Kajihara, Mikio; Ito, Zensho; Ohkusa, Toshifumi; Gong, Jianlin; Koido, Shigeo

    2015-03-01

    A promising area of clinical investigation is the use of cancer immunotherapy to treat cancer patients. Dendritic cells (DCs) operate as professional antigen-presenting cells (APCs) and play a critical role in the induction of antitumor immune responses. Thus, DC-based cancer immunotherapy represents a powerful strategy. One DC-based cancer immunotherapy strategy that has been investigated is the administration of fusion cells generated with DCs and whole tumor cells (DC-tumor fusion cells). The DC-tumor fusion cells can process a broad array of tumor-associated antigens (TAAs), including unidentified molecules, and present them through major histocompatibility complex (MHC) class I and II pathways in the context of co-stimulatory signals. Improving the therapeutic efficacy of DC-tumor fusion cell-based cancer immunotherapy requires increased immunogenicity of DCs and whole tumor cells. We discuss the potential ability of DC-tumor fusion cells to activate antigen-specific T cells and strategies to improve the immunogenicity of DC-tumor fusion cells as anticancer vaccines.

  7. In vitro immunomodulation of a whole blood IFN-γ release assay enhances T cell responses in subjects with latent tuberculosis infection.

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    Rajiv L Gaur

    Full Text Available BACKGROUND: Activation of innate immunity via pathogen recognition receptors (PRR modulates adaptive immune responses. PRR ligands are being exploited as vaccine adjuvants and as therapeutics, but their utility in diagnostics has not been explored. Interferon-gamma (IFN-γ release assays (IGRAs are functional T cell assays used to diagnose latent tuberculosis infection (LTBI; however, novel approaches are needed to improve their sensitivity. METHODS: In vitro immunomodulation of a whole blood IGRA (QuantiFERON®-TB GOLD In-Tube with Toll-like receptor agonists poly(I:C, LPS, and imiquimod was performed on blood from subjects with LTBI and negative controls. RESULTS: In vitro immunomodulation significantly enhanced the response of T cells stimulated with M. tuberculosis antigens from subjects with LTBI but not from uninfected controls. Immunomodulation of IGRA revealed T cell responses in subjects with LTBI whose T cells otherwise do not respond to in vitro stimulation with antigens alone. Similar to their in vivo functions, addition of poly(I:C and LPS to whole blood induced secretion of inflammatory cytokines and IFN-α and enhanced the surface expression of antigen presenting and costimulatory molecules on antigen presenting cells. CONCLUSIONS: In vitro immunomodulation of whole blood IGRA may be an effective strategy for enhancing the sensitivity of T cells for diagnosis of LTBI.

  8. Immature, Semi-mature and Fully mature Dendritic Cells: Towards a DC-cancer cells interface that augments anticancer immunity

    Directory of Open Access Journals (Sweden)

    Aleksandra Maria Dudek

    2013-12-01

    Full Text Available Dendritic cells (DCs are the sentinel antigen-presenting cells of the immune system; such that their productive interface with the dying cancer cells is crucial for proper communication of the non-self status of cancer cells to the adaptive immune system. Efficiency and the ultimate success of such a communication hinges upon the maturation status of the DCs, attained following their interaction with cancer cells. Immature DCs facilitate tolerance towards cancer cells (observed for many apoptotic inducers while fully mature DCs can strongly promote anticancer immunity if they secrete the correct combinations of cytokines (observed when DCs interact with cancer cells undergoing immunogenic cell death (ICD. However, an intermediate population of DC maturation, called semi-mature DCs exists, which can potentiate either tolerogenicity or pro-tumourigenic responses (as happens in the case of certain chemotherapeutics and agents exerting ambivalent immune reactions. Specific combinations of DC phenotypic markers, DC-derived cytokines/chemokines, dying cancer cell-derived danger signals and other less characterized entities (e.g. exosomes can define the nature and evolution of the DC maturation state. In the present review, we discuss these different maturation states of DCs, how they might be attained and which anticancer agents or cell death modalities (e.g. tolerogenic cell death vs. ICD may regulate these states.

  9. Innate recognition of cell wall β-glucans drives invariant Natural Killer T (iNKT) cell responses against fungi

    Science.gov (United States)

    Cohen, Nadia R.; Tatituri, Raju V.V.; Rivera, Amariliz; Watts, Gerald F.M.; Kim, Edy Y.; Chiba, Asako; Fuchs, Beth B.; Mylonakis, Eleftherios; Besra, Gurdyal S.; Levitz, Stuart M.; Brigl, Manfred; Brenner, Michael B.

    2016-01-01

    SUMMARY iNKT cells are innate T lymphocytes recognizing endogenous and foreign lipid antigens presented in the MHC-like molecule CD1d. The semi-invariant iNKT cell TCR can detect certain bacterial and parasitic lipids, and drive iNKT cell responses. How iNKT cells respond to fungi, however, is unknown. We found that CD1d-deficient mice, which lack iNKT cells, poorly control infection with the fungal pathogen Aspergillus fumigatus. Furthermore, A. fumigatus rapidly activates iNKT cells in vivo and in vitro in the presence of APCs. Surprisingly, despite a requirement for CD1d recognition, the anti-fungal iNKT cell response does not require fungal lipids. Instead, Dectin-1 and MyD88-mediated responses to β-1,3 glucans, major fungal cell-wall polysaccharides, trigger IL-12 production by APCs that drives self-reactive iNKT cells to secrete IFN-γ. Innate recognition of β-1,3 glucans also drives iNKT cell responses against Candida, Histoplasma and Alternaria, suggesting that this mechanism may broadly define the basis for anti-fungal iNKT cell responses. PMID:22100160

  10. The complement inhibitor FUT-175 suppresses T cell autoreactivity in experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Li, Qing; Nacion, Kristine; Bu, Hong; Lin, Feng

    2009-08-01

    Several recent studies have shown that interacting antigen presenting cells and/or T cells produced complement activation products C5a and C3a, are integrally involved in T-cell activation, and promote the generation of myelin oligodendrocyte glycoprotein (MOG(35-55))-specific interferon-gamma and interleukin-17-producing T cells in experimental autoimmune encephalomyelitis, a rodent model of multiple sclerosis. In this study, we tested whether FUT-175, a clinical pharmaceutical that has been shown to inhibit the formation of C3/C5 convertases, can attenuate myelin-specific T-cell responses, as well as disease severity in experimental autoimmune encephalomyelitis. In vitro, FUT-175 inhibited local C5a/C3a production by antigen presenting cell-T-cell complexes and attenuated MOG(35-55)-specific Th1 and Th17 responses with little nonspecific cytotoxicity. In vivo administration of FUT-175 delayed experimental autoimmune encephalomyelitis disease onset, lowered clinical scores, decreased central nervous system inflammation, and reduced demyelination. The FUT-175-treated mice exhibited decreased numbers of MOG(35-55)-specific interferon-gamma- and interleukin-17-producing T cells. In addition, results from the FUT-175 treatment of naive recipients of adoptively transferred splenocytes from MOG(35-55)-immunized mice suggested that the effect of FUT-175 was on MOG-specific cellular responses and not on anti-MOG antibodies. These results argue that complement regulators, which inhibit C5a/C3a production, may have therapeutic efficacy in multiple sclerosis and in other clinical conditions in which T cells drive disease pathogenesis. PMID:19608865

  11. A full scale comparative study of methods for generation of functional Dendritic cells for use as cancer vaccines

    Directory of Open Access Journals (Sweden)

    Kvalheim Gunnar

    2007-07-01

    Full Text Available Background Dendritic cells (DCs are professional antigen-presenting cells with the ability to induce primary T-cell responses and are commonly produced by culturing monocytes in the presence of IL-4 and GM-CSF for 5–7 days (Standard DC. Recently, Dauer and co-workers presented a modified protocol for differentiation of human monocytes into mature DCs within 48 hours (Fast DC. Here we report a functional comparison of the two strategies for generation of DCs from human monocytes with adaptions for large-scale clinical use. Methods The Elutra Cell Selection System was used to isolate monocytes after collection of leukapheresis product. The enriched monocytes were cultured in gas permeable Teflon bags with IL-4 and GM-CSF for 24 hours (Fast DC or 5 days (Standard DC to obtain immature DCs. The cells were then transfected with mRNA from the leukemia cell line Jurkat E6 by electroporation and incubated for additional 24 h or 2 days in the presence of pro-inflammatory cytokines (TNFα, IL-1β, IL-6 and PGE2 to obtain mature DCs. Results Mature Fast DC and Standard DC displayed comparable levels of many markers expressed on DC, including HLA-DR, CD83, CD86, CD208 and CCR7. However, compared to Standard DC, mature Fast DC was CD14high CD209low. Fast DC and Standard DC transfected with Jurkat E6-cell mRNA were equally able to elicit T cell specifically recognizing transfected DCs in vitro. IFNγ-secreting T cells were observed in both the CD4+ and CD8+ subsets. Conclusion Our results indicate that mature Fast DC are functional antigen presenting cells (APCs capable of inducing primary T-cell responses, and suggest that these cells may be valuable for generation of anti-tumor vaccines.

  12. Phosphatidylinositol 4-phosphate 5-kinases in the regulation of T cell activation

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    Loretta eTuosto

    2016-05-01

    Full Text Available Phosphatidylinositol 4,5-biphosphate kinases (PIP5K are critical regulators of T cell activation being the main enzymes involved in the synthesis of phosphatidylinositol 4,5-biphosphate (PIP2. PIP2 is indeed a pivotal regulator of the actin cytoskeleton, thus controlling T cell polarization and migration, stable adhesion to antigen presenting cells (APC, spatial organization of the immunological synapse (IS, and costimulation. Moreover, PIP2 serves also as a precursor for the second messengers inositol triphosphate (IP3, diacylglycerol (DAG and phosphatidylinositol 3,4,5-triphosphate (PIP3, which are essential for the activation of signalling pathways regulating cytokine production, cell cycle progression, survival, metabolism and differentiation. Here, we discuss the impact of PIP5Ks on several T lymphocyte functions with a specific focus on the role of CD28 co-stimulation in PIP5K compartimentalization and activation.

  13. T and B cell cooperation: a dance of life and death.

    Science.gov (United States)

    Bernard, Alain; Coitot, Sylvie; Brémont, Aurore; Bernard, Ghislaine

    2005-02-15

    In order for the body to develop a good antibody response, B cells need to react intimately with antigen specific T cells. Experimental evidence using hapten-carriers revealed that T and B cells do not recognize the same epitope and this led to the view that the physical contact is mediated by the antigen. Although the modern concept of antigen presentation has changed our perception on how the antigen can bridge both cells, the basic virtues of earlier bridging models remain. Over the past few years, a number of surface ligand-receptor pathways have been described, most of them belonging either to the CD28/B7 Ig or to the TNF/TNFR-like families. These act in concert, whether they are agonist or antagonist, in a timely and spatially organized manner. They form cascades of successive induction and recruitment to ensure that T-B cooperation is closely controlled at all stages of antibody induction. PMID:15699753

  14. Microencapsulation technology by nature: Cell derived extracellular vesicles with therapeutic potential.

    Science.gov (United States)

    Kittel, A; Falus, A; Buzás, E

    2013-06-01

    Cell derived extracellular vesicles are submicron structures surrounded by phospholipid bilayer and released by both prokaryotic and eukaryotic cells. The sizes of these vesicles roughly fall into the size ranges of microbes, and they represent efficient delivery platforms targeting complex molecular information to professional antigen presenting cells. Critical roles of these naturally formulated units of information have been described in many physiological and pathological processes. Extracellular vesicles are not only potential biomarkers and possible pathogenic factors in numerous diseases, but they are also considered as emerging therapeutic targets and therapeutic vehicles. Strikingly, current drug delivery systems, designed to convey therapeutic proteins and peptides (such as liposomes), show many similarities to extracellular vesicles. Here we review some aspects of therapeutic implementation of natural, cell-derived extracellular vesicles in human diseases. Exploration of molecular and functional details of extracellular vesicle release and action may provide important lessons for the design of future drug delivery systems.

  15. Dendritic Cell as Therapeutic Vaccines against Tumors and Its Role in Therapy for Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    Kang Sun; Liang Wang; Yanyun Zhang

    2006-01-01

    Dendritic cells (DCs) are the most potent professional antigen-presenting cells, and capable of stimulating naive T cells and driving primary immune responses. DCs are poised to capture antigen, migrate to draining lymphoid organs, and after a process of maturation, select antigen-specific !ymphocytes to which they present the processed antigen, thereby inducing immune responses. The development of protocols for the ex vivo generation of DCs may provide a rationale for designing and developing DC-based vaccination for the treatment of tumors. There are now several strategies being applied to upload antigens to DCs and manipulate DC vaccines. DC vaccines are able to induce therapeutic and protective antitumor immunity. Numerous studies indicated that hepatocellular carcinoma (HCC) immunotherapies utilizing DC-presenting tumor-associated antigens could stimulate an antitumour T cell response leading to clinical benefit without any significant toxicity. DC-based tumor vaccines have become a novel immunoadjuvant therapy for HCC.

  16. Effects of ceftriaxone-induced intestinal dysbacteriosis on dendritic cells of small intestine in mice.

    Science.gov (United States)

    Li, Ming; Li, Weihua; Wen, Shu; Liu, Yinhui; Tang, Li

    2013-08-01

    Intestinal microflora plays a pivotal role in the development of the innate immune system and is essential in shaping adaptive immunity. Dysbacteriosis of intestinal microflora induces altered immune responses and results in disease susceptibility. Dendritic cells (DCs), the professional antigen-presenting cells, have gained increasing attention because they connect innate and adaptive immunity. They generate both immunity in response to stimulation by pathogenic bacteria and immune tolerance in the presence of commensal bacteria. However, few studies have examined the effects of intestinal dysbacteriosis on DCs. In this study, changes of DCs in the small intestine of mice under the condition of dysbacteriosis induced by ceftriaxone sodium were investigated. It was found that intragastric administration of ceftriaxone sodium caused severe dysteriosis in mice. Compared with controls, numbers of DCs in mice with dysbacteriosis increased significantly (P = 0.0001). However, the maturity and antigen-presenting ability of DCs were greatly reduced. In addition, there was a significant difference in secretion of IL-10 and IL-12 between DCs from mice with dysbacteriosis and controls. To conclude, ceftriaxone-induced intestinal dysbacteriosis strongly affected the numbers and functions of DCs. The present data suggest that intestinal microflora plays an important role in inducing and maintaining the functions of DCs and thus is essential for the connection between innate and adaptive immune responses.

  17. The significant role of mast cells in cancer.

    Science.gov (United States)

    Khazaie, Khashayarsha; Blatner, Nichole R; Khan, Mohammad Wasim; Gounari, Fotini; Gounaris, Elias; Dennis, Kristen; Bonertz, Andreas; Tsai, Fu-Nien; Strouch, Matthew J; Cheon, Eric; Phillips, Joseph D; Beckhove, Philipp; Bentrem, David J

    2011-03-01

    Mast cells (MC) are a bone marrow-derived, long-lived, heterogeneous cellular population that function both as positive and negative regulators of immune responses. They are arguably the most productive chemical factory in the body and influence other cells through both soluble mediators and cell-to-cell interaction. MC are commonly seen in various tumors and have been attributed alternatively with tumor rejection or tumor promotion. Tumor-infiltrating MC are derived both from sentinel and recruited progenitor cells. MC can directly influence tumor cell proliferation and invasion but also help tumors indirectly by organizing its microenvironment and modulating immune responses to tumor cells. Best known for orchestrating inflammation and angiogenesis, the role of MC in shaping adaptive immune responses has become a focus of recent investigations. MC mobilize T cells and antigen-presenting dendritic cells. They function as intermediaries in regulatory T cells (Treg)-induced tolerance but can also modify or reverse Treg-suppressive properties. The central role of MC in the control of innate and adaptive immunity endows them with the ability to tune the nature of host responses to cancer and ultimately influence the outcome of disease and fate of the cancer patient. PMID:21287360

  18. B cells mediate chronic allograft rejection independently of antibody production.

    Science.gov (United States)

    Zeng, Qiang; Ng, Yue-Harn; Singh, Tripti; Jiang, Ke; Sheriff, Khaleefathullah A; Ippolito, Renee; Zahalka, Salwa; Li, Qi; Randhawa, Parmjeet; Hoffman, Rosemary A; Ramaswami, Balathiripurasundari; Lund, Frances E; Chalasani, Geetha

    2014-03-01

    Chronic rejection is the primary cause of long-term failure of transplanted organs and is often viewed as an antibody-dependent process. Chronic rejection, however, is also observed in mice and humans with no detectable circulating alloantibodies, suggesting that antibody-independent pathways may also contribute to pathogenesis of transplant rejection. Here, we have provided direct evidence that chronic rejection of vascularized heart allografts occurs in the complete absence of antibodies, but requires the presence of B cells. Mice that were deficient for antibodies but not B cells experienced the same chronic allograft vasculopathy (CAV), which is a pathognomonic feature of chronic rejection, as WT mice; however, mice that were deficient for both B cells and antibodies were protected from CAV. B cells contributed to CAV by supporting splenic lymphoid architecture, T cell cytokine production, and infiltration of T cells into graft vessels. In chimeric mice, in which B cells were present but could not present antigen, both T cell responses and CAV were markedly reduced. These findings establish that chronic rejection can occur in the complete absence of antibodies and that B cells contribute to this process by supporting T cell responses through antigen presentation and maintenance of lymphoid architecture.

  19. B cells as therapeutic targets in autoimmune neurological disorders.

    Science.gov (United States)

    Dalakas, Marinos C

    2008-10-01

    B cells have a fundamental role in the pathogenesis of various autoimmune neurological disorders, not only as precursors of antibody-producing cells, but also as important regulators of the T-cell activation process through their participation in antigen presentation, cytokine production, and formation of ectopic germinal centers in the intermeningeal spaces. Two B-cell trophic factors-BAFF (B-cell-activating factor) and APRIL (a proliferation-inducing ligand)-and their receptors are strongly upregulated in many immunological disorders of the CNS and PNS, and these molecules contribute to clonal expansion of B cells in situ. The availability of monoclonal antibodies or fusion proteins against B-cell surface molecules and trophic factors provides a rational approach to the treatment of autoimmune neurological diseases. This article reviews the role of B cells in autoimmune neurological disorders and summarizes the experience to date with rituximab, a B-cell-depleting monoclonal antibody against CD20, for the treatment of relapsing-remitting multiple sclerosis, autoimmune neuropathies, neuromyelitis optica, paraneoplastic neurological disorders, myasthenia gravis, and inflammatory myopathies. It is expected that ongoing controlled trials will establish the efficacy and long-term safety profile of anti-B-cell agents in several autoimmune neurological disorders, as well as exploring the possibility of a safe and synergistic effect with other immunosuppressants or immunomodulators.

  20. Role of Kupffer cells in the pathogenesis of liver disease

    Institute of Scientific and Technical Information of China (English)

    George Kolios; Vassilis Valatas; Elias Kouroumalis

    2006-01-01

    Kupffer cells, the resident liver macrophages have long been considered as mostly scavenger cells responsible for removing particulate material from the portal circulation. However, evidence derived mostly from animal models, indicates that Kupffer cells may be implicated in the pathogenesis of various liver diseases including viral hepatitis, steatohepatitis, alcoholic liver disease, intrahepatic cholostasis, activation or rejection of the liver during liver transplantation and liver fibrosis. There is accumulating evidence, reviewed in this paper, suggesting that Kupffer cells may act both as effector cells in the destruction of hepatocytes by producing harmful soluble mediators as well as antigen presenting cells during viral infections of the liver. Moreover they may represent a significant source of chemoattractant molecules for cytotoxic CD8 and regulatory T cells. Their role in fibrosis is well established as they are one of the main sources of TGFβ1 production, which leads to the transformation of stellate cells into myofibroblasts. Whether all these variable functions in the liver are mediated by different Kupffer cell subpopulations remains to be evaluated. In this review we propose a model that demonstrates the role of Kupffer cells in the pathogenesis of liver disease.

  1. B cells mediate chronic allograft rejection independently of antibody production.

    Science.gov (United States)

    Zeng, Qiang; Ng, Yue-Harn; Singh, Tripti; Jiang, Ke; Sheriff, Khaleefathullah A; Ippolito, Renee; Zahalka, Salwa; Li, Qi; Randhawa, Parmjeet; Hoffman, Rosemary A; Ramaswami, Balathiripurasundari; Lund, Frances E; Chalasani, Geetha

    2014-03-01

    Chronic rejection is the primary cause of long-term failure of transplanted organs and is often viewed as an antibody-dependent process. Chronic rejection, however, is also observed in mice and humans with no detectable circulating alloantibodies, suggesting that antibody-independent pathways may also contribute to pathogenesis of transplant rejection. Here, we have provided direct evidence that chronic rejection of vascularized heart allografts occurs in the complete absence of antibodies, but requires the presence of B cells. Mice that were deficient for antibodies but not B cells experienced the same chronic allograft vasculopathy (CAV), which is a pathognomonic feature of chronic rejection, as WT mice; however, mice that were deficient for both B cells and antibodies were protected from CAV. B cells contributed to CAV by supporting splenic lymphoid architecture, T cell cytokine production, and infiltration of T cells into graft vessels. In chimeric mice, in which B cells were present but could not present antigen, both T cell responses and CAV were markedly reduced. These findings establish that chronic rejection can occur in the complete absence of antibodies and that B cells contribute to this process by supporting T cell responses through antigen presentation and maintenance of lymphoid architecture. PMID:24509079

  2. The intensity of T cell receptor engagement determines the cytokine pattern of human allergen-specific T helper cells.

    Science.gov (United States)

    Carballido, J M; Faith, A; Carballido-Perrig, N; Blaser, K

    1997-02-01

    Enhanced production of T helper (Th)2 cytokines by allergen-specific Th cells plays a major role in the induction and maintenance of IgE-mediated allergic disorders. The mechanism that triggers this type of response in atopic individuals is not fully understood. Allergen-specific human Th cell clones produce interleukin (IL)-4 and low or undetectable levels of interferon (IFN)-gamma after stimulation with low concentrations of antigen. However, these Th cell clones are capable of generating significant amounts of IFN-gamma after optimal activation through their T cell receptor (TcR). Allergen-specific Th cell clones isolated from allergic individuals required higher doses of antigen to reach the plateau of proliferation and to generate Th0 cytokine responses than their counterparts isolated from nonallergic subjects. On the other hand, if allergen was replaced by anti-CD3 monoclonal antibody (mAb), both allergic and nonallergic Th cell clones attained the highest level of proliferation and significant IFN-gamma production in response to equivalent concentrations of anti-CD3 mAb. These results indicate that the strength of T cell ligation, which can be modulated by the availability of the TcR ligand, controls the balance of Thl/Th2 cytokines produced by memory Th cells in vitro. In the particular case of bee venom phospholipase A2, it is shown that the expression of allergen-specific surface Ig on antigen-presenting B cells has little influence on antigen uptake and therefore in determining the levels of T cell activation and cytokine production. Alternatively, the affinity of particular major histocompatibility complex class II molecules on antigen-presenting cells for allergen-derived peptides might determine the amount of specific ligand presented to the Th cells and play a decisive role skewing the Th cell cytokine production towards Th1 or Th2 phenotypes. These findings, which are consistent with the changes in cytokine patterns observed following clinical

  3. Production of good manufacturing practice-grade cytotoxic T lymphocytes specific for Epstein-Barr virus, cytomegalovirus and adenovirus to prevent or treat viral infections post-allogeneic hematopoietic stem cell transplant.

    Science.gov (United States)

    Sili, Uluhan; Leen, Ann M; Vera, Juan F; Gee, Adrian P; Huls, Helen; Heslop, Helen E; Bollard, Catherine M; Rooney, Cliona M

    2012-01-01

    Infections with a range of common community viruses remain a major cause of mortality and morbidity after allogeneic hematopoietic stem cell transplantation. T cells specific for cytomegalovirus (CMV), Epstein-Barr virus (EBV) and adenoviruses can safely prevent and infections with these three most common culprits, but the manufacture of individual T cell lines for each virus would be prohibitive in terms of time and cost. We have demonstrated that T cells specific for all three viruses can be manufactured in a single culture using monocytes and EBV-transformed B lymphoblastoid cell lines (LCLs), both transduced with an adenovirus vector expressing pp65 of CMV, as antigen-presenting cells. Trivirus-specific T cell lines produced from healthy stem cell donors could prevent and treat infections with all three viruses, not only in the designated recipient, but in unrelated, partially-HLA-matched third party recipients. We now provide the details and logistics of T cell manufacture.

  4. Dendritic Cells in the Cancer Microenvironment

    Directory of Open Access Journals (Sweden)

    Yang Ma, Galina V. Shurin, Zhu Peiyuan, Michael R. Shurin

    2013-01-01

    Full Text Available The complexity of the tumor immunoenvironment is underscored by the emergence and discovery of different subsets of immune effectors and regulatory cells. Tumor-induced polarization of immune cell differentiation and function makes this unique environment even more intricate and variable. Dendritic cells (DCs represent a special group of cells that display different phenotype and activity at the tumor site and exhibit differential pro-tumorigenic and anti-tumorigenic functions. DCs play a key role in inducing and maintaining the antitumor immunity, but in the tumor environment their antigen-presenting function may be lost or inefficient. DCs might be also polarized into immunosuppressive/tolerogenic regulatory DCs, which limit activity of effector T cells and support tumor growth and progression. Although various factors and signaling pathways have been described to be responsible for abnormal functioning of DCs in cancer, there are still no feasible therapeutic modalities available for preventing or reversing DC malfunction in tumor-bearing hosts. Thus, better understanding of DC immunobiology in cancer is pivotal for designing novel or improved therapeutic approaches that will allow proper functioning of DCs in patients with cancer.

  5. Regulation of Natural Killer Cell Function by STAT3

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    Nicholas eCacalano

    2016-04-01

    Full Text Available Natural killer (NK cells, key members of a distinct hempatopoietic lineage, innate lymphoid cells (ILCs, are critical effectors that mediate cytotoxicity toward tumor and virally-infected cells but also regulate inflammation, antigen presentation and the adaptive immune response. It has been shown that NK cells can regulate the development and activation of many other components of the immune response such as dendritic cells, which in turn, modulate the function of NK cells in multiple synergistic feed back loops driven by cell-cell contact and the secretion of cytokines and chemokines that control effector function and migration of cells to sites of immune activation. The Signal Transducer and Activator of Transcription (STAT-3 is involved in driving almost all of the pathways that control NK cytolytic activity as well as the reciprocal regulatory interactions between NK cells and other components of the immune system. In the context of tumor immunology, NK cells are a first line of defense that eliminates pre-cancerous and transformed cells early in the process of carcinogenesis, through a mechanism of immune surveillance. Even after tumors become established, NK cells are critical components of anti-cancer immunity: dysfunctional NK cells are often found in the peripheral blood of cancer patients and the lack of NK cells in the tumor microenvironment often correlates with poor prognosis. The pathways and soluble factors activated in tumor-associated NK cells, cancer cells, and regulatory myeloid cells which determine the outcome of cancer immunity are all critically regulated by STAT3. Using the tumor microenvironment as a paradigm, we present here an overview of the research that has revealed fundamental mechanisms through which STAT3 regulates all aspects of natural killer cell biology, including NK development, activation, target cell killing, and fine tuning of the innate and adaptive immune responses.

  6. Dendritic cells induce immunological tolerance after organ transplantation%树突状细胞诱导的器官移植后免疫耐受

    Institute of Scientific and Technical Information of China (English)

    余昆; 苟欣

    2009-01-01

    Dendritic cell (DC) is the most efficient kind of antigen-presenting cell (APC) at present. As the primer and controller of T cellular immunologic response, DC has become a research hotspot in the domain of organ transplantation nowadays. This paper reviewed the biological feature, culture in vitro and the mechanism of inducing immunological tolerance of dendritic cells.%树突状细胞(dendritic cell,DC)是当前发现的功能最强的专职抗原提呈细胞(antigen-presenting cell,APC),其作为机体适应性T细胞免疫应答的始动者和调控者,已成为目前器官移植领域的研究热点.本文就树突状细胞的生物学特性、体外扩增培养、诱导移植免疫耐受的机制等方面的研究进展做一综述.

  7. D-Alanylation of Teichoic Acids and Loss of Poly-N-Acetyl Glucosamine in Staphylococcus aureus during Exponential Growth Phase Enhance IL-12 Production in Murine Dendritic Cells

    DEFF Research Database (Denmark)

    Lund, Lisbeth Drozd; Ingmer, Hanne; Frokiaer, Hanne

    2016-01-01

    about their role in immune stimulation and evasion. Depending on the growth phase, S. aureus may affect antigen presenting cells differently. Here, the impact of growth phases and the surface molecules lipoteichoic acid, peptidoglycan and poly-N-acetyl glucosamine on the induction of IL-12 imperative...... peptidoglycan to EP S. aureus stimulated cells increased bacterial uptake but abrogated IL-12 induction, while addition of lipoteichoic acid increased IL-12 production but had no effect on the bacterial uptake. Depletion of the capability to produce poly-N-acetyl glucosamine increased the IL-12 inducing...

  8. 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.

  9. Immune Privilege as an Intrinsic CNS Property: Astrocytes Protect the CNS against T-Cell-Mediated Neuroinflammation

    Directory of Open Access Journals (Sweden)

    Ulrike Gimsa

    2013-01-01

    Full Text Available Astrocytes have many functions in the central nervous system (CNS. They support differentiation and homeostasis of neurons and influence synaptic activity. They are responsible for formation of the blood-brain barrier (BBB and make up the glia limitans. Here, we review their contribution to neuroimmune interactions and in particular to those induced by the invasion of activated T cells. We discuss the mechanisms by which astrocytes regulate pro- and anti-inflammatory aspects of T-cell responses within the CNS. Depending on the microenvironment, they may become potent antigen-presenting cells for T cells and they may contribute to inflammatory processes. They are also able to abrogate or reprogram T-cell responses by inducing apoptosis or secreting inhibitory mediators. We consider apparently contradictory functions of astrocytes in health and disease, particularly in their interaction with lymphocytes, which may either aggravate or suppress neuroinflammation.

  10. Increasing the efficacy of antitumor glioma vaccines by photodynamic therapy and local injection of allogeneic glioma cells

    Science.gov (United States)

    Christie, Catherine E.; Peng, Qian; Madsen, Steen J.; Uzal, Francisco A.; Hirschberg, Henry

    2016-03-01

    Immunotherapy of brain tumors involves the stimulation of an antitumor immune response. This type of therapy can be targeted specifically to tumor cells thus sparing surrounding normal brain. Due to the presence of the blood-brain barrier, the brain is relatively isolated from the systemic circulation and, as such, the initiation of significant immune responses is more limited than other types of cancers. The purpose of this study was to show that the efficacy of tumor primed antigen presenting macrophage vaccines could be increased by: (1) PDT of the priming tumor cells, and (2) injection of allogeneic glioma cells directly into brain tumors. Experiments were conducted in an in vivo brain tumor model using Fisher rats and BT4C (allogeneic) and F98 (syngeneic) glioma cells. Preliminary results showed that vaccination alone had significantly less inhibitory effect on F98 tumor growth compared to the combination of vaccination and allogeneic cell (BT4C) injection.

  11. Rotavirus activates lymphocytes from non-obese diabetic mice by triggering toll-like receptor 7 signaling and interferon production in plasmacytoid dendritic cells.

    Directory of Open Access Journals (Sweden)

    Jessica A Pane

    2014-03-01

    Full Text Available It has been proposed that rotavirus infection promotes the progression of genetically-predisposed children to type 1 diabetes, a chronic autoimmune disease marked by infiltration of activated lymphocytes into pancreatic islets. Non-obese diabetic (NOD mice provide a model for the human disease. Infection of adult NOD mice with rhesus monkey rotavirus (RRV accelerates diabetes onset, without evidence of pancreatic infection. Rather, RRV spreads to the pancreatic and mesenteric lymph nodes where its association with antigen-presenting cells, including dendritic cells, induces cellular maturation. RRV infection increases levels of the class I major histocompatibility complex on B cells and proinflammatory cytokine expression by T cells at these sites. In autoimmunity-resistant mice and human mononuclear cells from blood, rotavirus-exposed plasmacytoid dendritic cells contribute to bystander polyclonal B cell activation through type I interferon expression. Here we tested the hypothesis that rotavirus induces bystander activation of lymphocytes from NOD mice by provoking dendritic cell activation and proinflammatory cytokine secretion. NOD mouse splenocytes were stimulated with rotavirus and assessed for activation by flow cytometry. This stimulation activated antigen-presenting cells and B cells independently of virus strain and replicative ability. Instead, activation depended on virus dose and was prevented by blockade of virus decapsidation, inhibition of endosomal acidification and interference with signaling through Toll-like receptor 7 and the type I interferon receptor. Plasmacytoid dendritic cells were more efficiently activated than conventional dendritic cells by RRV, and contributed to the activation of B and T cells, including islet-autoreactive CD8+ T cells. Thus, a double-stranded RNA virus can induce Toll-like receptor 7 signaling, resulting in lymphocyte activation. Our findings suggest that bystander activation mediated by type I

  12. Regulatory T Cells and Their Role in Animal Disease.

    Science.gov (United States)

    Veiga-Parga, T

    2016-07-01

    In humans and mouse models, Foxp3(+) regulatory T cells are known to control all aspects of immune responses. However, only limited information exists on these cells' role in diseases of other animals. In this review, we cover the most important features and different types of regulatory T cells, which include those that are thymus-derived and peripherally induced, the mechanisms by which they control immune responses by targeting effector T cells and antigen-presenting cells, and most important, their role in animal health and diseases including cancer, infections, and other conditions such as hypersensitivities and autoimmunity. Although the literature regarding regulatory T cells in domestic animal species is still limited, multiple articles have recently emerged and are discussed. Moreover, we also discuss the evidence suggesting that regulatory T cells might limit the magnitude of effector responses, which can have either a positive or negative result, depending on the context of animal and human disease. In addition, the issue of plasticity is discussed because plasticity in regulatory T cells can result in the loss of their protective function in some microenvironments during disease. Lastly, the manipulation of regulatory T cells is discussed in assessing the possibility of their use as a treatment in the future. PMID:26945003

  13. Stimulation of Natural Killer T Cells by Glycolipids

    Directory of Open Access Journals (Sweden)

    Brian L. Anderson

    2013-12-01

    Full Text Available Natural killer T (NKT cells are a subset of T cells that recognize glycolipid antigens presented by the CD1d protein. The initial discovery of immunostimulatory glycolipids from a marine sponge and the T cells that respond to the compounds has led to extensive research by chemists and immunologists to understand how glycolipids are recognized, possible responses by NKT cells, and the structural features of glycolipids necessary for stimulatory activity. The presence of this cell type in humans and most mammals suggests that it plays critical roles in antigen recognition and the interface between innate and adaptive immunity. Both endogenous and exogenous natural antigens for NKT cells have been identified, and it is likely that glycolipid antigens remain to be discovered. Multiple series of structurally varied glycolipids have been synthesized and tested for stimulatory activity. The structural features of glycolipids necessary for NKT cell stimulation are moderately well understood, and designed compounds have proven to be much more potent antigens than their natural counterparts. Nevertheless, control over NKT cell responses by designed glycolipids has not been optimized, and further research will be required to fully reveal the therapeutic potential of this cell type.

  14. High epitope expression levels increase competition between T cells.

    Directory of Open Access Journals (Sweden)

    Almut Scherer

    2006-08-01

    Full Text Available Both theoretical predictions and experimental findings suggest that T cell populations can compete with each other. There is some debate on whether T cells compete for aspecific stimuli, such as access to the surface on antigen-presenting cells (APCs or for specific stimuli, such as their cognate epitope ligand. We have developed an individual-based computer simulation model to study T cell competition. Our model shows that the expression level of foreign epitopes per APC determines whether T cell competition is mainly for specific or aspecific stimuli. Under low epitope expression, competition is mainly for the specific epitope stimuli, and, hence, different epitope-specific T cell populations coexist readily. However, if epitope expression levels are high, aspecific competition becomes more important. Such between-specificity competition can lead to competitive exclusion between different epitope-specific T cell populations. Our model allows us to delineate the circumstances that facilitate coexistence of T cells of different epitope specificity. Understanding mechanisms of T cell coexistence has important practical implications for immune therapies that require a broad immune response.

  15. How do CD4+ T cells detect and eliminate tumor cells that either lack or express MHC class II molecules?

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    Ole Audun Werner Haabeth

    2014-04-01

    Full Text Available CD4+ T cells contribute to tumor eradication, even in the absence of CD8+ T cells. Cytotoxic CD4+ T cells can directly kill MHC class II positive tumor cells. More surprisingly, CD4+ T cells can indirectly eliminate tumor cells that lack MHC class II expression. Here, we review the mechanisms of direct and indirect CD4+ T cell-mediated elimination of tumor cells. An emphasis is put on T cell receptor (TCR transgenic models, where anti-tumor responses of naïve CD4+ T cells of defined specificity can be tracked. Some generalizations can tentatively be made. For both MHCIIPOS and MHCIINEG tumors, presentation of tumor specific antigen by host antigen presenting cells (APCs appears to be required for CD4+ T cell priming. This has been extensively studied in a myeloma model (MOPC315, where host APCs in tumor-draining lymph nodes are primed with secreted tumor antigen. Upon antigen recognition, naïve CD4+ T cells differentiate into Th1 cells and migrate to the tumor. At the tumor site, the mechanisms for elimination of MHCIIPOS and MHCIINEG tumor cells differ. In a TCR transgenic B16 melanoma model, MHCIIPOS melanoma cells are directly killed by cytotoxic CD4+ T cells in a perforin/granzyme B-dependent manner. By contrast, MHCIINEG myeloma cells are killed by IFN-g stimulated M1-like macrophages. In summary, while the priming phase of CD4+ T cells appears similar for MHCIIPOS and MHCIINEG tumors, the killing mechanisms are different. Unresolved issues and directions for future research are addressed.

  16. Full restoration of Brucella-infected dendritic cell functionality through Vγ9Vδ2 T helper type 1 crosstalk.

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    Ming Ni

    Full Text Available Vγ9Vδ2 T cells play an important role in the immune response to infectious agents but the mechanisms contributing to this immune process remain to be better characterized. Following their activation, Vγ9Vδ2 T cells develop cytotoxic activity against infected cells, secrete large amounts of cytokines and influence the function of other effectors of immunity, notably cells playing a key role in the initiation of the adaptive immune response such as dendritic cells. Brucella infection dramatically impairs dendritic cell maturation and their capacity to present antigens to T cells. Herein, we investigated whether V T cells have the ability to restore the full functional capacities of Brucella-infected dendritic cells. Using an in vitro multicellular infection model, we showed that: 1/Brucella-infected dendritic cells activate Vγ9Vδ2 T cells through contact-dependent mechanisms, 2/activated Vγ9Vδ2 T cells induce full differentiation into IL-12 producing cells of Brucella-infected dendritic cells with functional antigen presentation activity. Furthermore, phosphoantigen-activated Vγ9Vδ2 T cells also play a role in triggering the maturation process of dendritic cells already infected for 24 h. This suggests that activated Vγ9Vδ2 T cells could be used to modulate the outcome of infectious diseases by promoting an adjuvant effect in dendritic cell-based cellular therapies.

  17. Generation of Adducts of 4-Hydroxy-2-nonenal with Heat Shock 60 kDa Protein 1 in Human Promyelocytic HL-60 and Monocytic THP-1 Cell Lines

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    Alessia Arcaro

    2015-01-01

    Full Text Available Heat shock 60 kDa protein 1 (HSP60 is a chaperone and stress response protein responsible for protein folding and delivery of endogenous peptides to antigen-presenting cells and also a target of autoimmunity implicated in the pathogenesis of atherosclerosis. By two-dimensional electrophoresis and mass spectrometry, we found that exposure of human promyelocytic HL-60 cells to a nontoxic concentration (10 μM of 4-hydroxy-2-nonenal (HNE yielded a HSP60 modified with HNE. We also detected adducts of HNE with putative uncharacterized protein CXorf49, the product of an open reading frame identified in various cell and tissue proteomes. Moreover, exposure of human monocytic THP-1 cells differentiated with phorbol 12-myristate 13-acetate to 10 μM HNE, and to light density lipoprotein modified with HNE (HNE-LDL or by copper-catalyzed oxidation (oxLDL, but not to native LDL, stimulated the formation of HNE adducts with HSP60, as detected by immunoprecipitation and western blot, well over basal levels. The identification of HNE-HSP60 adducts outlines a framework of mutually reinforcing interactions between endothelial cell stressors, like oxLDL and HSP60, whose possible outcomes, such as the amplification of endothelial dysfunction, the spreading of lipoxidative damage to other proteins, such as CXorf49, the activation of antigen-presenting cells, and the breaking of tolerance to HSP60 are discussed.

  18. Assessing T cell clonal size distribution: a non-parametric approach.

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    Olesya V Bolkhovskaya

    Full Text Available Clonal structure of the human peripheral T-cell repertoire is shaped by a number of homeostatic mechanisms, including antigen presentation, cytokine and cell regulation. Its accurate tuning leads to a remarkable ability to combat pathogens in all their variety, while systemic failures may lead to severe consequences like autoimmune diseases. Here we develop and make use of a non-parametric statistical approach to assess T cell clonal size distributions from recent next generation sequencing data. For 41 healthy individuals and a patient with ankylosing spondylitis, who undergone treatment, we invariably find power law scaling over several decades and for the first time calculate quantitatively meaningful values of decay exponent. It has proved to be much the same among healthy donors, significantly different for an autoimmune patient before the therapy, and converging towards a typical value afterwards. We discuss implications of the findings for theoretical understanding and mathematical modeling of adaptive immunity.

  19. Prospects for a nonliving vaccine against Schistosomiasis based on cell-mediated immune resistance mechanisms

    Directory of Open Access Journals (Sweden)

    Stephanie L. James

    1987-01-01

    Full Text Available We have designed a vaccine model based on induction of cell-mediated immunity and shown that it protects mice against Schistosoma mansoni infection. Mice are immunized by intradermal injection with schistosome antigens plus BCG. Resistance is dependent on the route of antigen presentation and the adjuvant chosen. The pattern of resistance correlates with sensitization of T lymphocytes for production of gamma interferon, a macrophage activating lymphokine that stimulates the cellular effector mechanism of protection. Purified schistosome paramyosin, a muscle cell component present in soluble parasite antigenic preparations, is immunogenic for T lymphocytes and induces resistance when given intradermally with BCG. It is likely that this protein, and possibly other soluble molecules that are released by the parasites of a challenge infection, induce a cellular inflammatory response resulting in larval trapping and/or killing by activated macrophages. These results verify the feasibility of a vaccine against schistosomiasis based on induction of cell-mediated immune resistance mechanisms.

  20. Dynamic Behavior and Function of Foxp3+ Regulatory T Cells in Tumor Bearing Host

    Institute of Scientific and Technical Information of China (English)

    F. Xiao-Feng Qin

    2009-01-01

    Regulatory T cells (Tregs) expressing forkhead/winged-helix transcription factor Foxp3 represent a distinct lineage of lymphocytes which play a central role in protecting the host from autoimmune diseases. However, Tregs also pose a major problem to anti-tumor immunity. Growing body of evidence from both laboratory and clinical investigations has demonstrated that expansion and accumulation of these immunosuppressive cells correlates with advanced tumor growth and predicts poor disease prognosis. How tumor development subverts normal self-tolerance function of Tregs thereby thwarts host anti-tumor immunity remains elusive. This review will discuss our current knowledge in understanding the dynamics and plasticity of Foxp3+ Treg activation and induction in tumor bearing hosts and their interaction with various antigen presenting cells (APCs) in tumor microenvironment leading to the establishment of active local and systemic immune suppression.

  1. Assessing T cell clonal size distribution: a non-parametric approach.

    Science.gov (United States)

    Bolkhovskaya, Olesya V; Zorin, Daniil Yu; Ivanchenko, Mikhail V

    2014-01-01

    Clonal structure of the human peripheral T-cell repertoire is shaped by a number of homeostatic mechanisms, including antigen presentation, cytokine and cell regulation. Its accurate tuning leads to a remarkable ability to combat pathogens in all their variety, while systemic failures may lead to severe consequences like autoimmune diseases. Here we develop and make use of a non-parametric statistical approach to assess T cell clonal size distributions from recent next generation sequencing data. For 41 healthy individuals and a patient with ankylosing spondylitis, who undergone treatment, we invariably find power law scaling over several decades and for the first time calculate quantitatively meaningful values of decay exponent. It has proved to be much the same among healthy donors, significantly different for an autoimmune patient before the therapy, and converging towards a typical value afterwards. We discuss implications of the findings for theoretical understanding and mathematical modeling of adaptive immunity. PMID:25275470

  2. Assessing T cell clonal size distribution: a non-parametric approach.

    Science.gov (United States)

    Bolkhovskaya, Olesya V; Zorin, Daniil Yu; Ivanchenko, Mikhail V

    2014-01-01

    Clonal structure of the human peripheral T-cell repertoire is shaped by a number of homeostatic mechanisms, including antigen presentation, cytokine and cell regulation. Its accurate tuning leads to a remarkable ability to combat pathogens in all their variety, while systemic failures may lead to severe consequences like autoimmune diseases. Here we develop and make use of a non-parametric statistical approach to assess T cell clonal size distributions from recent next generation sequencing data. For 41 healthy individuals and a patient with ankylosing spondylitis, who undergone treatment, we invariably find power law scaling over several decades and for the first time calculate quantitatively meaningful values of decay exponent. It has proved to be much the same among healthy donors, significantly different for an autoimmune patient before the therapy, and converging towards a typical value afterwards. We discuss implications of the findings for theoretical understanding and mathematical modeling of adaptive immunity.

  3. The TNF receptor and Ig superfamily members form an integrated signaling circuit controlling dendritic cell homeostasis

    Science.gov (United States)

    De Trez, Carl; Ware, Carl F.

    2008-01-01

    Dendritic cells (DC) constitute the most potent antigen presenting cells of the immune system, playing a key role bridging innate and adaptive immune responses. Specialized DC subsets differ depending on their origin, tissue location and the influence of trophic factors, the latter remain to be fully understood. Stromal cell and myeloid-associated Lymphotoxin-β receptor (LTβR) signaling is required for the local proliferation of lymphoid tissue DC. This review focuses the LTβR signaling cascade as a crucial positive trophic signal in the homeostasis of DC subsets. The noncanonical coreceptor pathway comprised of the Immunoglobulin (Ig) superfamily member, B and T lymphocyte attenuator (BTLA) and TNFR superfamily member, Herpesvirus entry mediator (HVEM) counter regulates the trophic signaling by LTβR. Together both pathways form an integrated signaling circuit achieving homeostasis of DC subsets. PMID:18511331

  4. Dendritic Cells as Vectors for Immunotherapy of Tumor and Its Application for Gastric Cancer Therapy

    Institute of Scientific and Technical Information of China (English)

    YugangWu; LiangWang; YanyunZhang

    2004-01-01

    Dendritic cells (DCs) are recognized as the most potent antigen-presenting cells (APCs) with the ability to stimulate naive resting T cells and initiate primary immune responses. DCs are poised to capture antigen (Ag),migrate to draining lymphoid organs, and, after a process of maturation, select Ag-specific lymphocytes to which they present the processed Ag, thereby inducing immune responses. Numerous studies indicated that immunotherapies utilizing DC-presenting tumor-associated antigens can safely be administered to cancer patients and induce significant immunologic and clinical responses. Moreover, it has been demonstrated that DCs are related to clinical stage, invasion, metastasis and prognosis of gastric cancer. DC-based tumor vaccines become a new effective immunoadjuvant therapy for gastric cancer. Cellular & Molecular Immunology. 2004;1(5):351-356.

  5. Dendritic Cells as Vectors for Immunotherapy of Tumor and Its Application for Gastric Cancer Therapy

    Institute of Scientific and Technical Information of China (English)

    Yugang Wu; Liang Wang; Yanyun Zhang

    2004-01-01

    Dendritic cells (DCs) are recognized as the most potent antigen-presenting cells (APCs) with the ability to stimulate na(i)ve resting T cells and initiate primary immune responses. DCs are poised to capture antigen (Ag),migrate to draining lymphoid organs, and, after a process of maturation, select Ag-specific lymphocytes to which they present the processed Ag, thereby inducing immune responses. Numerous studies indicated that immunotherapies utilizing DC-presenting tumor-associated antigens can safely be administered to cancer patients and induce significant immunologic and clinical responses. Moreover, it has been demonstrated that DCs are related to clinical stage, invasion, metastasis and prognosis of gastric cancer. DC-based tumor vaccines become a new effective immunoadjuvant therapy for gastric cancer. Cellular & Molecular Immunology. 2004;1(5):351-356.

  6. Mycobacterium bovis Bacillus Calmette-Guérin-Induced Macrophage Cytotoxicity against Bladder Cancer Cells

    Directory of Open Access Journals (Sweden)

    Yi Luo

    2010-01-01

    Full Text Available Many details of the molecular and cellular mechanisms involved in Mycobacterium bovis bacillus Calmette-Guérin (BCG immunotherapy of bladder cancer have been discovered in the past decades. However, information on a potential role for macrophage cytotoxicity as an effector mechanism is limited. Macrophages play pivotal roles in the host innate immunity and serve as a first line of defense in mycobacterial infection. In addition to their function as professional antigen-presenting cells, the tumoricidal activity of macrophages has also been studied with considerable interest. Studies have shown that activated macrophages are potent in killing malignant cells of various tissue origins. This review summarizes the current understanding of the BCG-induced macrophage cytotoxicity toward bladder cancer cells with an intention to inspire investigation on this important but underdeveloped research field.

  7. [Tissue and cell interactions in the oral mucosa after cytostatic drugs administration].

    Science.gov (United States)

    Bykov, V L; Leont'eva, I V

    2011-01-01

    In the preceding work ("Morphology", 2011, issue 2), the regularities of oral mucosal (OM) epithelium injury after the cytostatic drug (CSD) treatment and its further regeneration, were reviewed. This paper presents the systematized summary of current literature data and the authors' own findings on the regularities of CSD effect on non-epithelial OM cell populations and their interactions with each other and the epithelium. The changes of intraepithelial tissue homeostasis, associated with CSD effect on intraepithelial lymphocytes, granulocytes, dendritic antigen presenting cells and melanocytes, interacting with epitheliocytes, are described. The data are presented, indicating that along with the epithelium, the cell populations of lamina propria and submucosal connective tissue, as well as the small blood vessels, are important targets of CSD in the OM tissues. The concept of a unifying model, describing tissue, cellular and molecular mechanisms of the oral mucositis development after CSD treatment, is reviewed.

  8. Signaling and Dynamic Actin Responses of B Cells on Topographical Substrates

    Science.gov (United States)

    Ketchum, Christina; Sun, Xiaoyu; Fourkas, John; Song, Wenxia; Upadhyaya, Arpita

    B cells become activated upon physical contact with antigen on the surface of antigen presenting cells, such as dendritic cells. Binding of the B cell receptor with antigen initiates actin-mediated spreading of B cells, signaling cascades and eventually infection fighting antibodies. Lymphocytes, including B cells and T cells, have been shown to be responsive to the physical parameters of the contact surface, such as antigen mobility and substrate stiffness. However the roll of surface topography on lymphocyte function is unknown. Here we investigate the degree to which substrate topography controls actin-mediated spreading and B cell activation using nano-fabricated surfaces and live cell imaging. The model topographical system consists of 600 nanometer tall ridges with spacing varying between 800 nanometers and 5 micrometers. Using TIRF imaging we observe actin dynamics, B cell receptor motion and calcium signaling of B cells as they spread on the ridged substrates. We show that the spacing between ridges had a strong effect on the dynamics of actin and calcium influx on B cells. Our results indicate that B cells are highly sensitive to surface topography during cell spreading and signaling activation.

  9. Activated human T cells secrete exosomes that participate in IL-2 mediated immune response signaling.

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    Jessica Wahlgren

    Full Text Available It has previously been shown that nano-meter sized vesicles (30-100 nm, exosomes, secreted by antigen presenting cells can induce T cell responses thus showing the potential of exosomes to be used as immunological tools. Additionally, activated CD3⁺ T cells can secrete exosomes that have the ability to modulate different immunological responses. Here, we investigated what effects exosomes originating from activated CD3⁺ T cells have on resting CD3⁺ T cells by studying T cell proliferation, cytokine production and by performing T cell and exosome phenotype characterization. Human exosomes were generated in vitro following CD3⁺ T cell stimulation with anti-CD28, anti-CD3 and IL-2. Our results show that exosomes purified from stimulated CD3⁺ T cells together with IL-2 were able to generate proliferation in autologous resting CD3⁺ T cells. The CD3⁺ T cells stimulated with exosomes together with IL-2 had a higher proportion of CD8⁺ T cells and had a different cytokine profile compared to controls. These results indicate that activated CD3⁺ T cells communicate with resting autologous T cells via exosomes.

  10. Autonomous T cell trafficking examined in vivo with intravital two-photon microscopy

    Science.gov (United States)

    Miller, Mark J.; Wei, Sindy H.; Cahalan, Michael D.; Parker, Ian

    2003-03-01

    The recirculation of T cells between the blood and secondary lymphoid organs requires that T cells are motile and sensitive to tissue-specific signals. T cell motility has been studied in vitro, but the migratory behavior of individual T cells in vivo has remained enigmatic. Here, using intravital two-photon laser microscopy, we imaged the locomotion and trafficking of naïve CD4+ T cells in the inguinal lymph nodes of anesthetized mice. Intravital recordings deep within the lymph node showed T cells flowing rapidly in the microvasculature and captured individual homing events. Within the diffuse cortex, T cells displayed robust motility with an average velocity of 11 μm·min1. T cells cycled between states of low and high motility roughly every 2 min, achieving peak velocities >25 μm·min1. An analysis of T cell migration in 3D space revealed a default trafficking program analogous to a random walk. Our results show that naïve T cells do not migrate collectively, as they might under the direction of pervasive chemokine gradients. Instead, they appear to migrate as autonomous agents, each cell taking an independent trafficking path. Our results call into question the role of chemokine gradients for basal T cell trafficking within T cell areas and suggest that antigen detection may result from a stochastic process through which a random walk facilitates contact with antigen-presenting dendritic cells.

  11. A Multi-Compartment Hybrid Computational Model Predicts Key Roles for Dendritic Cells in Tuberculosis Infection

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    Simeone Marino

    2016-10-01

    Full Text Available Tuberculosis (TB is a world-wide health problem with approximately 2 billion people infected with Mycobacterium tuberculosis (Mtb, the causative bacterium of TB. The pathologic hallmark of Mtb infection in humans and Non-Human Primates (NHPs is the formation of spherical structures, primarily in lungs, called granulomas. Infection occurs after inhalation of bacteria into lungs, where resident antigen-presenting cells (APCs, take up bacteria and initiate the immune response to Mtb infection. APCs traffic from the site of infection (lung to lung-draining lymph nodes (LNs where they prime T cells to recognize Mtb. These T cells, circulating back through blood, migrate back to lungs to perform their immune effector functions. We have previously developed a hybrid agent-based model (ABM, labeled GranSim describing in silico immune cell, bacterial (Mtb and molecular behaviors during tuberculosis infection and recently linked that model to operate across three physiological compartments: lung (infection site where granulomas form, lung draining lymph node (LN, site of generation of adaptive immunity and blood (a measurable compartment. Granuloma formation and function is captured by a spatio-temporal model (i.e., ABM, while LN and blood compartments represent temporal dynamics of the whole body in response to infection and are captured with ordinary differential equations (ODEs. In order to have a more mechanistic representation of APC trafficking from the lung to the lymph node, and to better capture antigen presentation in a draining LN, this current study incorporates the role of dendritic cells (DCs in a computational fashion into GranSim. Results: The model was calibrated using experimental data from the lungs and blood of NHPs. The addition of DCs allowed us to investigate in greater detail mechanisms of recruitment, trafficking and antigen presentation and their role in tuberculosis infection. Conclusion: The main conclusion of this study is

  12. Gene expression profiles identify inflammatory signatures in dendritic cells.

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    Anna Torri

    Full Text Available Dendritic cells (DCs constitute a heterogeneous group of antigen-presenting leukocytes important in activation of both innate and adaptive immunity. We studied the gene expression patterns of DCs incubated with reagents inducing their activation or inhibition. Total RNA was isolated from DCs and gene expression profiling was performed with oligonucleotide microarrays. Using a supervised learning algorithm based on Random Forest, we generated a molecular signature of inflammation from a training set of 77 samples. We then validated this molecular signature in a testing set of 38 samples. Supervised analysis identified a set of 44 genes that distinguished very accurately between inflammatory and non inflammatory samples. The diagnostic performance of the signature genes was assessed against an independent set of samples, by qRT-PCR. Our findings suggest that the gene expression signature of DCs can provide a molecular classification for use in the selection of anti-inflammatory or adjuvant molecules with specific effects on DC activity.

  13. Effects of dendritic cell vaccine activated with protein components of toxoplasma gondii on tumor specific CD8+ T-cells

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    Amari A

    2009-12-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: Dendritic Cell (DC is an important antigen-presenting cell that present tumor antigen to CD8+ and CD4+ T- Lymphocytes and induce specific anti-tumor immunity. In order to induce effective anti-tumor response, an option is increasing the efficiency of antigen presentation of dendritic cells and T cell activation capacity. The aim of the present study was to investigate the effect of dendritic cell maturation with protein components of toxoplasma gondii on cytotoxic T lymphocyte activity and their infiltration in to the tumor."n"nMethods: For DC generation, bone marrow cells were cultured in the presence of GM-CSF and IL-4 for five days. After that, LPS, protein components and whole extract of toxoplasma gondii were added to the culture media and incubated for another two days for DC maturation. To generate tumor, mices were injected subcutaneously with WEHI-164 cell line. For immunotherapy 106 DCs matured with different compounds were injected around the tumor site. Infiltration of CD8+ T cells were determined by flow cytometry and cytotoxic activity was measured by LDH detection kit."n"nResults: Immunotherapy with DCs treated with protein components of toxoplasma gondii led to a significant increase in the

  14. Cell-surface expression of Hsp70 on hematopoietic cancer cells after inhibition of HDAC activity

    DEFF Research Database (Denmark)

    Jensen, Helle

    The function of Hsp70 depends on its cellular location: When located intracellularly it exerts cytoprotective and anti-apoptotic functions, whereas it exerts immunostimulatory functions when located extracellularly. Secreted Hsp70 is for example involved in cross-presentation of cancer-derived an......The function of Hsp70 depends on its cellular location: When located intracellularly it exerts cytoprotective and anti-apoptotic functions, whereas it exerts immunostimulatory functions when located extracellularly. Secreted Hsp70 is for example involved in cross-presentation of cancer......-derived antigenic peptides, a function which is currently explored in immunotherapeutic approaches against cancer. Additionally, membrane-bound Hsp70 can stimulate antigen presenting cells to release proinflammatory cytokines and can provide a target structure for NK cell-mediated lysis. Human cancer cells...... frequently express Hsp70 on their cell surface, whereas the corresponding normal tissues do not. In addition, several clinically applied reagents, such as alkyl-lysophospholipides, chemotherapeutic agents, and anti-inflammatory reagents, have been found to enhance Hsp70 cell surface expression on cancer...

  15. Transcriptomic analysis of mouse EL4 T cells upon T cell activation and in response to protein synthesis inhibition via cycloheximide treatment.

    Science.gov (United States)

    Lim, Pek Siew; Hardy, Kristine; Peng, Kaiman; Shannon, Frances M

    2016-03-01

    T cell activation involves the recognition of a foreign antigen complexed to the major histocompatibility complex on the antigen presenting T cell to the T cell receptor. This leads to activation of signaling pathways, which ultimately leads to induction of key cytokine genes responsible for eradication of foreign antigens. We used the mouse EL4 T cell as a model system to study genes that are induced as a result of T cell activation using phorbol myristate acetate (PMA) and calcium ionomycin (I) as stimuli. We were also interested to examine the importance of new protein synthesis in regulating the expression of genes involved in T cell activation. Thus we have pre-treated mouse EL4 T cells with cycloheximide, a protein synthesis inhibitor, and left the cells unstimulated or stimulated with PMA/I for 4 h. We performed microarray expression profiling of these cells to correlate the gene expression with chromatin state of T cells upon T cell activation [1]. Here, we detail further information and analysis of the microarray data, which shows that T cell activation leads to differential expression of genes and inducible genes can be further classified as primary and secondary response genes based on their protein synthesis dependency. The data is available in the Gene Expression Omnibus under accession number GSE13278. PMID:26981393

  16. Mode of dendritic cell activation: the decisive hand in Th2/Th17 cell differentiation. Implications in asthma severity?

    Science.gov (United States)

    Vroman, Heleen; van den Blink, Bernt; Kool, Mirjam

    2015-02-01

    Asthma is a heterogeneous chronic inflammatory disease of the airways, with reversible airflow limitations and airway remodeling. The classification of asthma phenotypes was initially based on different combinations of clinical symptoms, but they are now unfolding to link biology to phenotype. As such, patients can suffer from a predominant eosinophilic, neutrophilic or even mixed eosinophilic/neutrophilic inflammatory response. In adult asthma patients, eosinophilic inflammation is usually seen in mild-to-moderate disease and neutrophilic inflammation in more severe disease. The underlying T cell response is predominated by T helper (Th) 2, Th17, or a mixed Th2/Th17 cell immune response. Dendritic cells (DCs) are "professional" antigen presenting cells (APCs), since their principal function is to present antigens and induce a primary immune response in resting naive T cells. DCs also drive the differentiation into distinctive Th subsets. The expression of co-stimulatory molecules and cytokines by DCs and surrounding cells determines the outcome of Th cell differentiation. The nature of DC activation will determine the expression of specific co-stimulatory molecules and cytokines, specifically needed for induction of the different Th cell programs. Thus DC activation is crucial for the subsequent effector Th immune responses. In this review, we will discuss underlying mechanisms that initiate DC activation in favor of Th2 differentiation versus Th1/Th17 and Th17 differentiation in the development of mild versus moderate to severe asthma. PMID:25245013

  17. Constitutive induction of intestinal Tc17 cells in the absence of hematopoietic cell-specific MHC class II expression.

    Science.gov (United States)

    Rubino, Stephen J; Geddes, Kaoru; Magalhaes, Joao G; Streutker, Catherine; Philpott, Dana J; Girardin, Stephen E

    2013-11-01

    The enteric pathogen Citrobacter rodentium induces a mucosal IL-17 response in CD4(+) T helper (Th17) cells that is dependent on the Nod-like receptors Nod1 and Nod2. Here, we sought to determine whether this early Th17 response required antigen presentation by major histocompatibility complex class II (MHCII) for full induction. At early phases of C. rodentium infection, we observed that the intestinal mucosal Th17 response was fully blunted in irradiated mice reconstituted with MHCII-deficient (MHCII(-/-) →WT) hematopoietic cells. Surprisingly, we also observed a substantial increase in the relative frequency of IL-17(+) CD8(+) CD4(-) TCR-β(+) cells (Tc17 cells) and FOXP3(+) CD8(+) CD4(-) TCR-β(+) cells in the lamina propria and intraepithelial lymphocyte compartment of MHCII(-/-) →WT mice compared with that in WT→WT counterparts. Moreover, MHCII(-/-) →WT mice displayed increased susceptibility, increased bacterial translocation to deeper organs, and more severe colonic histopathology after infection with C. rodentium. Finally, a similar phenotype was observed in mice deficient for CIITA, a transcriptional regulator of MHCII expression. Together, these results indicate that MHCII is required to mount early mucosal Th17 responses to an enteric pathogen, and that MHCII regulates the induction of atypical CD8(+) T-cell subsets, such as Tc17 cells and FOXP3(+) CD8(+) cells, in vivo. PMID:23881368

  18. Adenoviral transduction of mesenchymal stem cells: in vitro responses and in vivo immune responses after cell transplantation.

    Directory of Open Access Journals (Sweden)

    Oliver Treacy

    Full Text Available Adult mesenchymal stem cells (MSCs are non-hematopoietic cells with multi-lineage potential which makes them attractive targets for regenerative medicine applications. However, to date, therapeutic success of MSC-therapy is limited and the genetic modification of MSCs using viral vectors is one option to improve their therapeutic potential. Ex-vivo genetic modification of MSCs using recombinant adenovirus (Ad could be promising to reduce undesired immune responses as Ad will be removed before cell/tissue transplantation. In this regard, we investigated whether Ad-modification of MSCs alters their immunological properties in vitro and in vivo. We found that Ad-transduction of MSCs does not lead to up-regulation of major histocompatibility complex class I and II and co-stimulatory molecules CD80 and CD86. Moreover, Ad-transduction caused no significant changes in terms of pro-inflammatory cytokine expression, chemokine and chemokine receptor and Toll-like receptor expression. In addition, Ad-modification of MSCs had no affect on their ability to suppress T cell proliferation in vitro. In vivo injection of Ad-transduced MSCs did not change the frequency of various immune cell populations (antigen presenting cells, T helper and cytotoxic T cells, natural killer and natural killer T cells neither in the blood nor in tissues. Our results indicate that Ad-modification has no major influence on the immunological properties of MSCs and therefore can be considered as a suitable gene vector for therapeutic applications of MSCs.

  19. Rat monocyte-derived dendritic cells function and migrate in the same way as isolated tissue dendritic cells.

    Science.gov (United States)

    Richters, C D; Mayen, I; Havenith, C E G; Beelen, R H J; Kamperdijk, E W A

    2002-04-01

    Dendritic cells (DC) are the most potent antigen-presenting cells and are therefore useful to induce immune responses against tumor cells in patients. DC can be generated in vitro from monocytes using GM-CSF and IL-4, the so-called monocyte-derived DC (MoDC). To achieve antitumor responses, MoDC must be able to migrate to the draining lymph nodes after injection to induce cytotoxic T cells. Therefore, we studied migration of MoDC in a rat model. Functional rat MoDC were generated from PVG-RT7B rats and injected subcutaneously into PVG rats. These rat strains differ only at one epitope of the leukocyte-common antigen, which can be recognized by the antibody His 41. The advantage is that migrated cells can be detected in the draining lymph nodes by staining sections with His 41+; thus, migration is not influenced by labeling procedures. Rat MoDC migrated to the T-cell areas of the draining lymph nodes, just as isolated Langerhans cells or spleen DC do. In contrast, monocytes also migrated to the B-cell areas and the medulla. PMID:11927643

  20. CD28 ligation increases macrophage suppression of T-cell proliferation.

    Science.gov (United States)

    Silberman, Daniel; Bucknum, Amanda; Bartlett, Thomas; Composto, Gabriella; Kozlowski, Megan; Walker, Amanda; Werda, Amy; Cua, Jackelyn; Sharpe, Arlene H; Somerville, John E; Riggs, James E

    2012-07-01

    When compared to spleen or lymph node cells, resident peritoneal cavity cells respond poorly to T-cell activation in vitro. The greater proportional representation of macrophages in this cell source has been shown to actively suppress the T-cell response. Peritoneal macrophages exhibit an immature phenotype (MHC class II(lo), B7(lo)) that reduces their efficacy as antigen-presenting cells. Furthermore, these cells readily express inducible nitric oxide synthase (iNOS), an enzyme that promotes T-cell tolerance by catabolism of the limiting amino acid arginine. Here, we investigate the ability of exogenous T-cell costimulation to recover the peritoneal T-cell response. We show that CD28 ligation failed to recover the peritoneal T-cell response and actually suppressed responses that had been recovered by inhibiting iNOS. As indicated by cytokine ELISpot and neutralizing monoclonal antibody (mAb) treatment, this 'cosuppression' response was due to CD28 ligation increasing the number of interferon (IFN)-γ-secreting cells. Our results illustrate that cellular composition and cytokine milieu influence T-cell costimulation biology.Cellular & Molecular Immunology advance online publication, 23 April 2012; doi:10.1038/cmi.2012.13.