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Sample records for antigens cd4

  1. The role of CD4 in antigen-independent activation of isolated single T lymphocytes

    DEFF Research Database (Denmark)

    Kelso, A; Owens, T

    1988-01-01

    The membrane molecule CD4 (L3T4) is thought to facilitate activation of Class II H-2-restricted T cells by binding to Ia determinants on antigen-presenting cells. Recent reports suggest that CD4 can also contribute to antigen-independent activation by anti-T cell receptor (TCR) antibodies. An assay...

  2. The generation and antigen-specificity of CD4+CD25+ regulatory T cells.

    Science.gov (United States)

    Taams, Leonie S; Curnow, S John; Vukmanovic-Stejic, M; Akbar, Arne N

    2006-09-01

    CD4+CD25+ regulatory T cells are essential components of the immune system. They help to maintain immune tolerance by exerting suppressive effects on cells of the adaptive and innate immune system. In the last few years there has been an abundance of papers addressing the suppressive effects of CD4+CD25+ regulatory T cells and their putative role in various experimental disease models and human diseases. Despite the enormous amounts of data on these cells a number of controversial issues still exists. CD4+CD25+ regulatory T cells were originally described as thymus-derived anergic/suppressive T cells. Recent papers however indicate that these cells might also be generated in the periphery. Due to the thymic development of CD4+CD25+ regulatory T cells it was thought that these cells were specific for self-antigens. Indeed it was shown that CD4+CD25+ regulatory T cells could be positively selected upon high affinity interaction with self-antigens. However, evidence is accumulating that these cells might also interact with non-self antigens. Finally, in the literature there is conflicting evidence regarding the role of soluble factors versus cell-contact in the mechanism of suppression. The aim of this review is to summarize the evidence supporting these opposing viewpoints and to combine them into a general model for the origin, function and antigen-specificity of CD4+CD25+ regulatory T cells. PMID:16918478

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

  4. Antigen-Specific CD4+ T Cells Recognize Epitopes of Protective Antigen following Vaccination with an Anthrax Vaccine

    OpenAIRE

    Laughlin, Elsa M.; Miller, Joseph D.; James, Eddie; Fillos, Dimitri; Ibegbu, Chris C.; Mittler, Robert S.; Akondy, Rama; Kwok, William; Ahmed, Rafi; Nepom, Gerald,

    2007-01-01

    Detection of antigen-specific CD4+ T cells is facilitated by the use of fluorescently labeled soluble peptide-major histocompatibility complex (MHC) multimers which mirror the antigen specificity of T-cell receptor recognition. We have used soluble peptide-MHC class II tetramers containing peptides from the protective antigen (PA) of Bacillus anthracis to detect circulating T cells in peripheral blood of subjects vaccinated with an anthrax vaccine. PA-specific HLA class II-restricted T lympho...

  5. AFM force measurements of the gp120-sCD4 and gp120 or CD4 antigen-antibody interactions

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    Chen, Yong, E-mail: dr_yongchen@hotmail.com [Institute for Advanced Study, Nanchang University, Nanchang, Jiangxi 330031 (China); Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Zeng, Gucheng [Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Chen, Sherry Shiyi [Department of Biomedical Engineering, Duke University, Durham, NC 27708 (United States); Feng, Qian [Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612 (United States); Chen, Zheng Wei, E-mail: zchen@uic.edu [Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612 (United States)

    2011-04-08

    Highlights: {yields} The unbinding force of sCD4-gp120 interaction was 25.45 {+-} 20.46 pN. {yields} The unbinding force of CD4 antigen-antibody interaction was 51.22 {+-} 34.64 pN. {yields} The unbinding force of gp120 antigen-antibody interaction was 89.87 {+-} 44.63 pN. {yields} The interaction forces between various HIV inhibitors and the target molecules are significantly different. {yields} Functionalizing on AFM tip or substrate of an interaction pair caused different results. -- Abstract: Soluble CD4 (sCD4), anti-CD4 antibody, and anti-gp120 antibody have long been regarded as entry inhibitors in human immunodeficiency virus (HIV) therapy. However, the interactions between these HIV entry inhibitors and corresponding target molecules are still poorly understood. In this study, atomic force microscopy (AFM) was utilized to investigate the interaction forces among them. We found that the unbinding forces of sCD4-gp120 interaction, CD4 antigen-antibody interaction, and gp120 antigen-antibody interaction were 25.45 {+-} 20.46, 51.22 {+-} 34.64, and 89.87 {+-} 44.63 pN, respectively, which may provide important mechanical information for understanding the effects of viral entry inhibitors on HIV infection. Moreover, we found that the functionalization of an interaction pair on AFM tip or substrate significantly influenced the results, implying that we must perform AFM force measurement and analyze the data with more caution.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

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

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

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    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.

  8. Hsp70 enhances presentation of FMDV antigen to bovine CD4+ T cells in vitro

    OpenAIRE

    McLaughlin, Kerry; Seago, Julian; Robinson, Lucy; Kelly, Charles; Charleston, Bryan

    2010-01-01

    International audience Foot-and-mouth disease virus (FMDV) is the causative agent of a highly contagious acute vesicular disease affecting cloven-hoofed animals, including cattle, sheep and pigs. The current vaccine induces a rapid humoral response, but the duration of the protective antibody response is variable, possibly associated with a variable specific CD4+ T cell response. We investigated the use of heat shock protein 70 (Hsp70) as a molecular chaperone to target viral antigen to th...

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

    Science.gov (United States)

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

    2016-03-01

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

  10. Antigen recognition by autoreactive CD4⁺ thymocytes drives homeostasis of the thymic medulla.

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    Magali Irla

    Full Text Available The thymic medulla is dedicated for purging the T-cell receptor (TCR repertoire of self-reactive specificities. Medullary thymic epithelial cells (mTECs play a pivotal role in this process because they express numerous peripheral tissue-restricted self-antigens. Although it is well known that medulla formation depends on the development of single-positive (SP thymocytes, the mechanisms underlying this requirement are incompletely understood. We demonstrate here that conventional SP CD4⁺ thymocytes bearing autoreactive TCRs drive a homeostatic process that fine-tunes medullary plasticity in adult mice by governing the expansion and patterning of the medulla. This process exhibits strict dependence on TCR-reactivity with self-antigens expressed by mTECs, as well as engagement of the CD28-CD80/CD86 costimulatory axis. These interactions induce the expression of lymphotoxin α in autoreactive CD4⁺ thymocytes and RANK in mTECs. Lymphotoxin in turn drives mTEC development in synergy with RANKL and CD40L. Our results show that Ag-dependent interactions between autoreactive CD4⁺ thymocytes and mTECs fine-tune homeostasis of the medulla by completing the signaling axes implicated in mTEC expansion and medullary organization.

  11. 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

  12. Antigen presentation by small intestinal epithelial cells uniquely enhances IFN-γ secretion from CD4{sup +} intestinal intraepithelial lymphocytes

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    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.

  13. Performance of cryptococcal antigen lateral flow assay using saliva in Ugandans with CD4 <100.

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    Richard Kwizera

    Full Text Available Cryptococcal meningitis can best be diagnosed by cerebrospinal fluid India ink microscopy, cryptococcal antigen detection, or culture. These require invasive lumbar punctures. The utility of cryptococcal antigen detection in saliva is unknown. We evaluated the diagnostic performance of the point-of-care cryptococcal antigen lateral flow assay (CrAg LFA in saliva.We screened HIV-infected, antiretroviral therapy naïve persons with symptomatic meningitis (n = 130 and asymptomatic persons with CD4+<100 cells/µL entering into HIV care (n = 399 in Kampala, Uganda. The diagnostic performance of testing saliva was compared to serum/plasma cryptococcal antigen as the reference standard.The saliva lateral flow assay performance was overall more sensitive in symptomatic patients (88% than in asymptomatic patients (27%. The specificity of saliva lateral flow assay was excellent at 97.8% in the symptomatic patients and 100% in asymptomatic patients. The degree of accuracy of saliva in diagnosing cryptococcosis and the level of agreement between the two sample types was better in symptomatic patients (C-statistic 92.9, κ-0.82 than in asymptomatic patients (C-statistic 63.5, κ-0.41. Persons with false negative salvia CrAg tests had lower levels of peripheral blood CrAg titers (P<0.001.There was poor diagnostic performance in testing saliva for cryptococcal antigen, particularly among asymptomatic persons screened for preemptive treatment of cryptococcosis.

  14. Spontaneous loss and alteration of antigen receptor expression in mature CD4+ T cells

    International Nuclear Information System (INIS)

    The T-cell receptor CD3 (TCR/CD3) complex plays a central role in antigen recognition and activation of mature T cells, and therefore abnormalities in the expression of the complex should induce unresponsiveness of T cells to antigen stimulus. Using flow cytometry, we detected and enumerated variant cells with loss or alteration of surface TCR/CD3 expression among human mature CD4+ T cells. The presence of variant CD4+ T cells was demonstrated by isolating and cloning them from peripheral blood, and their abnormalities can be accounted for by alterations in TCR expression such as defects of protein expression and partial protein deletion. The variant frequency in peripheral blood increased with aging in normal donors and was highly elevated in patients with ataxia telangiectasia, an autosomal recessive inherited disease with defective DNA repair and variable T-cell immunodeficiency. These findings suggest that such alterations in TCR expression are induced by somatic mutagenesis of TCR genes and can be important factors related to age-dependent and genetic disease-associated T-cell dysfunction. (author)

  15. Antigen-Experienced CD4lo T Cells Are Linked to Deficient Contraction of the Immune Response in Autoimmune Diabetes

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    Sean Linkes

    2010-01-01

    Full Text Available Following proper activation, naïve “CD4lo” T cells differentiate into effector T cells with enhanced expression of CD4 -“CD4hi” effectors. Autoimmune diabetes-prone NOD mice display a unique set of antigen-experienced “CD4lo” T cells that persist after primary stimulation. Here, we report that a population of such cells remained after secondary and tertiary TCR stimulation and produced cytokines upon antigenic challenge. However, when NOD blasts were induced in the presence of rIL-15, the number of antigen-experienced “CD4lo” T cells was significantly reduced. Clonal contraction, mediated in part by CD95-dependent activation-induced cell death (AICD, normally regulates the accumulation of “CD4hi” effectors. Interestingly, CD95 expression was dramatically reduced on the AICD-resistant NOD “CD4lo” T cells. Thus, while autoimmune disease has often been attributed to the engagement of robust autoimmunity, we suggest that the inability to effectively contract the immune response distinguishes benign autoimmunity from progressive autoimmune diseases that are characterized by chronic T cell-mediated inflammation.

  16. Independent clinical significance of HIV antigen determination and CD4 counts in anti-HIV positive patients

    DEFF Research Database (Denmark)

    Skinhøj, P; Hofmann, B; Jacobsen, K D;

    1989-01-01

    HIV antigenemia was found in 52/243 HIV antibody positive individuals attending 2 AIDS-screening clinics, giving a prevalence of 13, 25 and 76% in CDC groups II, III and IV, respectively. No correlation was found to decreased CD4 lymphocyte values in the individual groups. HIV antigen therefore...... identified a separate subpopulation. For 138 asymptomatic patients followed prospectively both laboratory parameters predicted HIV-related events, the relative risk factor being 4 for low CD4 value and 6 for presence of HIV antigen. Individuals presenting with HIV antigen and decreased CD4 count all...... developed disease within 18 months, the relative risk factor being 24. Thus the 2 markers, when measured together, effectively separated asymptomatic HIV-infected patients into 1 of 3 risk categories....

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

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

    2012-01-01

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

  18. Antigen-specific and non-specific CD4+ T cell recruitment and proliferation during influenza infection

    International Nuclear Information System (INIS)

    To track epitope-specific CD4+ T cells at a single-cell level during influenza infection, the MHC class II-restricted OVA323-339 epitope was engineered into the neuraminidase stalk of influenza/A/WSN, creating a surrogate viral antigen. The recombinant virus, influenza A/WSN/OVAII, replicated well, was cleared normally, and stimulated both wild-type and DO11.10 or OT-II TCR transgenic OVA-specific CD4+ T cells. OVA-specific CD4 T cells proliferated during infection only when the OVA epitope was present. However, previously primed (but not naive) transgenic CD4+ T cells were recruited to the infected lung both in the presence and absence of the OVA323-339 epitope. These data show that, when primed, CD4+ T cells may traffic to the lung in the absence of antigen, but do not proliferate. These results also document a useful tool for the study of CD4 T cells in influenza infection

  19. A false expression of CD8 antigens on CD4+ T cells in a routine flow cytometry analysis.

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    Danuta Kowalczyk

    2006-09-01

    Full Text Available The two-colour flow cytometry method applied in a routine enumeration of peripheral blood T lymphocyte subsets reveals that in some patients the entire population of CD4+ lymphocytes seems to express CD8 determinants as well. However, expression of the CD8 antigens on the cell surface is much lower in comparison with typical CD8+ cells. Moreover, in one-colour staining with an anti-CD8 antibody, cells with weak CD8 expression are not observed and only one typical population of CD8+ lymphocytes is seen. Investigating this phenomenon, we showed that after washing patient cells in RPMI before CD4/CD8 staining, the CD4+ T cell population did not show CD8 "co-expression". These results suggest that CD4+ lymphocytes, which seem to co-express CD8 antigen, in fact do not have this antigen on their surface. Moreover, after the addition of patient plasma to healthy donor cells prior to CD4/CD8 staining, a weak CD8 expression on normal CD4+ cells was noticed. Therefore we can assume that the agent(s causing this phenomenon is/are present in the plasma of some patients. Altogether, these observations suggest that this phenomenon is nonspecific and probably results from cross-linking of anti-CD8 mAbs with anti-CD4 mAbs caused by factor(s present in plasma of some patient. However, identification of that/these factor(s requires further research.

  20. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells.

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    Yukiko Kiniwa

    Full Text Available Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8(+ T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4(+ T helper (Th cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4(+ T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1 as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4(+ Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4(+ T cell-mediated immunotherapy in melanoma.

  1. Role of CD4 molecule in the induction of interleukin 2 and interleukin 2 receptor in class II major histocompatibility complex-restricted antigen-specific T helper clones. T cell receptor/CD3 complex transmits CD4-dependent and CD4-independent signals.

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    Oyaizu, N; Chirmule, N; Pahwa, S.

    1992-01-01

    The CD4 molecule plays an essential role in antigen-induced activation of T helper (Th) cells, but its contribution to signal transduction events resulting in physiologic T cell function is ill defined. By utilizing anti-CD4 monoclonal antibodies (MAbs) that recognize distinct epitopes of CD4, we have investigated the role of CD4 molecule in antigen-induced interleukin 2 (IL-2) and IL-2 receptor (IL-2R) alpha chain expression in class II major histocompatibility complex-restricted antigen-spe...

  2. Blocking of HIV-1 Infectivity by a Soluble, Secreted Form of the CD4 Antigen

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    Smith, Douglas H.; Byrn, Randal A.; Marsters, Scot A.; Gregory, Timothy; Groopman, Jerome E.; Capon, Daniel J.

    1987-12-01

    The initial event in the infection of human T lymphocytes, macrophages, and other cells by human immunodeficiency virus (HIV-1) is the attachment of the HIV-1 envelope glycoprotein gp120 to its cellular receptor, CD4. As a step toward designing antagonists of this binding event, soluble, secreted forms of CD4 were produced by transfection of mammalian cells with vectors encoding versions of CD4 lacking its transmembrane and cytoplasmic domains. The soluble CD4 so produced binds gp120 with an affinity and specificity comparable to intact CD4 and is capable of neutralizing the infectivity of HIV-1. These studies reveal that the high-affinity CD4-gp120 interaction does not require other cell or viral components and may establish a novel basis for therapeutic intervention in the acquired immune deficiency syndrome (AIDS).

  3. 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.

  4. GM-CSF production allows the identification of immunoprevalent antigens recognized by human CD4+ T cells following smallpox vaccination.

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    Valeria Judkowski

    Full Text Available The threat of bioterrorism with smallpox and the broad use of vaccinia vectors for other vaccines have led to the resurgence in the study of vaccinia immunological memory. The importance of the role of CD4+ T cells in the control of vaccinia infection is well known. However, more CD8+ than CD4+ T cell epitopes recognized by human subjects immunized with vaccinia virus have been reported. This could be, in part, due to the fact that most of the studies that have identified human CD4+ specific protein-derived fragments or peptides have used IFN-γ production to evaluate vaccinia specific T cell responses. Based on these findings, we reasoned that analyzing a large panel of cytokines would permit us to generate a more complete analysis of the CD4 T cell responses. The results presented provide clear evidence that TNF-α is an excellent readout of vaccinia specificity and that other cytokines such as GM-CSF can be used to evaluate the reactivity of CD4+ T cells in response to vaccinia antigens. Furthermore, using these cytokines as readout of vaccinia specificity, we present the identification of novel peptides from immunoprevalent vaccinia proteins recognized by CD4+ T cells derived from smallpox vaccinated human subjects. In conclusion, we describe a "T cell-driven" methodology that can be implemented to determine the specificity of the T cell response upon vaccination or infection. Together, the single pathogen in vitro stimulation, the selection of CD4+ T cells specific to the pathogen by limiting dilution, the evaluation of pathogen specificity by detecting multiple cytokines, and the screening of the clones with synthetic combinatorial libraries, constitutes a novel and valuable approach for the elucidation of human CD4+ T cell specificity in response to large pathogens.

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

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    Wolfram Osen

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

  6. Dendritic cells cross-present HIV antigens from live as well as apoptotic infected CD4+ T lymphocytes

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    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.

  7. CD4+ T Cells and Toll-Like Receptors Recognize Salmonella Antigens Expressed in Bacterial Surface Organelles

    OpenAIRE

    Bergman, Molly A.; Cummings, Lisa A.; Barrett, Sara L. Rassoulian; Smith, Kelly D.; Lara, J. Cano; Aderem, Alan; Cookson, Brad T.

    2005-01-01

    A better understanding of immunity to infection is revealed from the characteristics of microbial ligands recognized by host immune responses. Murine infection with the intracellular bacterium Salmonella generates CD4+ T cells that specifically recognize Salmonella proteins expressed in bacterial surface organelles such as flagella and membrane vesicles. These natural Salmonella antigens are also ligands for Toll-like receptors (TLRs) or avidly associated with TLR ligands such as lipopolysacc...

  8. Identification of broadly conserved cross-species protective Leishmania antigen and its responding CD4+ T cells.

    Science.gov (United States)

    Mou, Zhirong; Li, Jintao; Boussoffara, Thouraya; Kishi, Hiroyuki; Hamana, Hiroshi; Ezzati, Peyman; Hu, Chuanmin; Yi, Weijing; Liu, Dong; Khadem, Forough; Okwor, Ifeoma; Jia, Ping; Shitaoka, Kiyomi; Wang, Shufeng; Ndao, Momar; Petersen, Christine; Chen, Jianping; Rafati, Sima; Louzir, Hechmi; Muraguchi, Atsushi; Wilkins, John A; Uzonna, Jude E

    2015-10-21

    There is currently no clinically effective vaccine against leishmaniasis because of poor understanding of the antigens that elicit dominant T cell immunity. Using proteomics and cellular immunology, we identified a dominant naturally processed peptide (PEPCK335-351) derived from Leishmania glycosomal phosphoenolpyruvate carboxykinase (PEPCK). PEPCK was conserved in all pathogenic Leishmania, expressed in glycosomes of promastigotes and amastigotes, and elicited strong CD4(+) T cell responses in infected mice and humans. I-A(b)-PEPCK335-351 tetramer identified protective Leishmania-specific CD4(+) T cells at a clonal level, which comprised ~20% of all Leishmania-reactive CD4(+) T cells at the peak of infection. PEPCK335-351-specific CD4(+) T cells were oligoclonal in their T cell receptor usage, produced polyfunctional cytokines (interleukin-2, interferon-γ, and tumor necrosis factor), and underwent expansion, effector activities, contraction, and stable maintenance after lesion resolution. Vaccination with PEPCK peptide, DNA expressing full-length PEPCK, or rPEPCK induced strong durable cross-species protection in both resistant and susceptible mice. The effectiveness and durability of protection in vaccinated mice support the development of a broadly cross-species protective vaccine against different forms of leishmaniasis by targeting PEPCK. PMID:26491077

  9. Human CD4+ lymphocytes for antigen quantification: characterization using conventional flow cytometry and mass cytometry.

    Science.gov (United States)

    Wang, Lili; Abbasi, Fatima; Ornatsky, Olga; Cole, Kenneth D; Misakian, Martin; Gaigalas, Adolfas K; He, Hua-Jun; Marti, Gerald E; Tanner, Scott; Stebbings, Richard

    2012-07-01

    To transform the linear fluorescence intensity scale obtained with fluorescent microspheres to an antibody bound per cell (ABC) scale, a biological cell reference material is needed. Optimally, this material should have a reproducible and tight ABC value for the expression of a known clinical reference biomarker. In this study, we characterized commercially available cryopreserved peripheral blood mononuclear cells (PBMCs) and two lyophilized PBMC preparations, Cyto-Trol and PBMC-National Institute for Biological Standard and Control (NIBSC) relative to freshly prepared PBMC and whole blood samples. It was found that the ABC values for CD4 expression on cryopreserved PBMC were consistent with those of freshly obtained PBMC and whole blood samples. By comparison, the ABC value for CD4 expression on Cyto-Trol is lower and the value on PBMC-NIBSC is much lower than those of freshly prepared cell samples using both conventional flow cytometry and CyTOF™ mass cytometry. By performing simultaneous surface and intracellular staining measurements on these two cell samples, we found that both cell membranes are mostly intact. Moreover, CD4(+) cell diameters from both lyophilized cell preparations are smaller than those of PBMC and whole blood. This could result in steric interference in antibody binding to the lyophilized cells. Further investigation of the fixation effect on the detected CD4 expression suggests that the very low ABC value obtained for CD4(+) cells from lyophilized PBMC-NIBSC is largely due to paraformaldehyde fixation; this significantly decreases available antibody binding sites. This study provides confirmation that the results obtained from the newly developed mass cytometry are directly comparable to the results from conventional flow cytometry when both methods are standardized using the same ABC approach. PMID:22539147

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

    Science.gov (United States)

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

    2012-01-16

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

  11. CD4 lymphocyte counts and serum p24 antigen of no diagnostic value in monitoring HIV-infected patients with pulmonary symptoms

    DEFF Research Database (Denmark)

    Orholm, M; Nielsen, T L; Nielsen, Jens Ole;

    1990-01-01

    The diagnostic value of the CD4 cell counts and the HIV p24 antigen were evaluated in a consecutive series of 105 HIV-infected patients experiencing 128 episodes of pulmonary symptoms which required bronchoscopy. One-third of patients with opportunistic infection (OI) had CD4 counts greater than 0....... In conclusion, the CD4 cell counts and the presence of p24 antigen in serum had a very limited predictive value for the presence of OI in HIV-infected patients with pulmonary symptoms....

  12. Allergic Sensitization Underlies Hyperreactive Antigen-Specific CD4+ T Cell Responses in Coincident Filarial Infection.

    Science.gov (United States)

    Gazzinelli-Guimarães, Pedro H; Bonne-Année, Sandra; Fujiwara, Ricardo T; Santiago, Helton C; Nutman, Thomas B

    2016-10-01

    Among the various hypotheses put forward to explain the modulatory influence of helminth infection on allergic effector responses in humans, the IL-10-induced suppression of Th2-associated responses has been the leading candidate. To explore this helminth/allergy interaction more fully, parasite- and allergen-specific CD4(+) T cell responses in 12 subjects with filarial infections, and coincident allergic sensitization (filarial [Fil](+)allergy [A](+)) were compared with the responses to three appropriate control groups (Fil(-)A(-) [n = 13], Fil(-)A(+) [n = 12], Fil(+)A(-) [n = 11]). The most important findings revealed that Fil(+)A(+) had marked (p eosinophils (p eosinophil-derived neurotoxin [p < 0.01, r = 0.7059]). CD4(+) responses to allergen were not different (to a large extent) among the groups. Taken together, our data suggest that allergic sensitization coincident with filarial infection drives parasite Ag-specific T cell hyperresponsiveness, which is characterized largely by an augmented Th2-dominated immune response. PMID:27566825

  13. Circulating HIV-Specific Interleukin-21(+)CD4(+) T Cells Represent Peripheral Tfh Cells with Antigen-Dependent Helper Functions.

    Science.gov (United States)

    Schultz, Bruce T; Teigler, Jeffrey E; Pissani, Franco; Oster, Alexander F; Kranias, Gregory; Alter, Galit; Marovich, Mary; Eller, Michael A; Dittmer, Ulf; Robb, Merlin L; Kim, Jerome H; Michael, Nelson L; Bolton, Diane; Streeck, Hendrik

    2016-01-19

    A central effort in HIV vaccine development is to generate protective broadly neutralizing antibodies, a process dependent on T follicular helper (Tfh) cells. The feasibility of using peripheral blood counterparts of lymph node Tfh cells to assess the immune response and the influence of viral and vaccine antigens on their helper functions remain obscure. We assessed circulating HIV-specific IL-21(+)CD4(+) T cells and showed transcriptional and phenotypic similarities to lymphoid Tfh cells, and hence representing peripheral Tfh (pTfh) cells. pTfh cells were functionally active and B cell helper quality differed depending on antigen specificity. Furthermore, we found higher frequency of pTfh cells in peripheral blood mononuclear cell specimens from the ALVAC+AIDSVAX (RV144) HIV vaccine trial associated with protective antibody responses compared to the non-protective DNA+Ad5 vaccine trial. Together, we identify IL-21(+)CD4(+) T cells as pTfh cells, implicating them as key populations in the generation of vaccine-evoked antibody responses. PMID:26795249

  14. 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.

  15. Antigen dynamics govern the induction of CD4(+) T cell tolerance during autoimmunity.

    Science.gov (United States)

    Challa, Dilip K; Mi, Wentao; Lo, Su-Tang; Ober, Raimund J; Ward, E Sally

    2016-08-01

    Antigen-specific T cell tolerance holds great promise for the treatment of autoimmune diseases. However, strategies to induce durable tolerance using high doses of soluble antigen have to date been unsuccessful, due to lack of efficacy and the risk of hypersensitivity. In the current study we have overcome these limitations by developing a platform for tolerance induction based on engineering the immunoglobulin Fc region to modulate the dynamic properties of low doses (1 μg/mouse; ∼50 μg/kg) of Fc-antigen fusions. Using this approach, we demonstrate that antigen persistence is a dominant factor governing the elicitation of tolerance in the model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE), induced by immunizing B10.PL mice with the N-terminal epitope of myelin basic protein. Unexpectedly, our analyses reveal a stringent threshold of antigen persistence for both prophylactic and therapeutic treatments, although distinct mechanisms lead to tolerance in these two settings. Importantly, the delivery of tolerogenic Fc-antigen fusions during ongoing disease results in the downregulation of T-bet and CD40L combined with amplification of Foxp3(+) T cell numbers. The generation of effective, low dose tolerogens using Fc engineering has potential for the regulation of autoreactive T cells. PMID:27236506

  16. 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...

  17. Dexamethasone and Monophosphoryl Lipid A-Modulated Dendritic Cells Promote Antigen-Specific Tolerogenic Properties on Naive and Memory CD4+ T Cells

    Science.gov (United States)

    Maggi, Jaxaira; Schinnerling, Katina; Pesce, Bárbara; Hilkens, Catharien M.; Catalán, Diego; Aguillón, Juan C.

    2016-01-01

    Tolerogenic dendritic cells (DCs) are a promising tool to control T cell-mediated autoimmunity. Here, we evaluate the ability of dexamethasone-modulated and monophosphoryl lipid A (MPLA)-activated DCs [MPLA-tolerogenic DCs (tDCs)] to exert immunomodulatory effects on naive and memory CD4+ T cells in an antigen-specific manner. For this purpose, MPLA-tDCs were loaded with purified protein derivative (PPD) as antigen and co-cultured with autologous naive or memory CD4+ T cells. Lymphocytes were re-challenged with autologous PPD-pulsed mature DCs (mDCs), evaluating proliferation and cytokine production by flow cytometry. On primed-naive CD4+ T cells, the expression of regulatory T cell markers was evaluated and their suppressive ability was assessed in autologous co-cultures with CD4+ effector T cells and PPD-pulsed mDCs. We detected that memory CD4+ T cells primed by MPLA-tDCs presented reduced proliferation and proinflammatory cytokine expression in response to PPD and were refractory to subsequent stimulation. Naive CD4+ T cells were instructed by MPLA-tDCs to be hyporesponsive to antigen-specific restimulation and to suppress the induction of T helper cell type 1 and 17 responses. In conclusion, MPLA-tDCs are able to modulate antigen-specific responses of both naive and memory CD4+ T cells and might be a promising strategy to “turn off” self-reactive CD4+ effector T cells in autoimmunity.

  18. Equivalence of human and mouse CD4 in enhancing antigen responses by a mouse class II-restricted T cell hybridoma

    OpenAIRE

    1989-01-01

    We have examined the ability of hCD4 to interact functionally with mouse class II MHC molecules using the mouse T cell hybridoma BI-141, specific for beef insulin. We have previously shown that expression of mouse CD4 results in a marked enhancement of IL-2 release by BI-141 cells in response to beef insulin or, in a cross-reactive response, to pork insulin, on the appropriate mouse APCs. We now demonstrate that expression of hCD4 results in an equivalent stimulation of antigen responses by t...

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

    Directory of Open Access Journals (Sweden)

    Nagatani Katsuya

    2005-05-01

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

  20. Nonclassical antigen-processing pathways are required for MHC class II-restricted direct tumor recognition by NY-ESO-1-specific CD4(+) T cells.

    Science.gov (United States)

    Matsuzaki, Junko; Tsuji, Takemasa; Luescher, Immanuel; Old, Lloyd J; Shrikant, Protul; Gnjatic, Sacha; Odunsi, Kunle

    2014-04-01

    Tumor antigen-specific CD4(+) T cells that directly recognize cancer cells are important for orchestrating antitumor immune responses at the local tumor sites. However, the mechanisms of direct MHC class II (MHC-II) presentation of intracellular tumor antigen by cancer cells are poorly understood. We found that two functionally distinct subsets of CD4(+) T cells were expanded after HLA-DPB1*04 (DP04)-binding NY-ESO-1157-170 peptide vaccination in patients with ovarian cancer. Although both subsets recognized exogenous NY-ESO-1 protein pulsed on DP04(+) target cells, only one type recognized target cells with intracellular expression of NY-ESO-1. The tumor-recognizing CD4(+) T cells more efficiently recognized the short 8-9-mer peptides than the non-tumor-recognizing CD4(+) T cells. In addition to endosomal/lysosomal proteases that are typically involved in MHC-II antigen presentation, several pathways in the MHC class I presentation pathways, such as the proteasomal degradation and transporter-associated with antigen-processing-mediated peptide transport, were also involved in the presentation of intracellular NY-ESO-1 on MHC-II. The presentation was inhibited significantly by primaquine, a small molecule that inhibits endosomal recycling, consistent with findings that pharmacologic inhibition of new protein synthesis enhances antigen presentation. Together, our data demonstrate that cancer cells selectively present peptides from intracellular tumor antigens on MHC-II by multiple nonclassical antigen-processing pathways. Harnessing the direct tumor-recognizing ability of CD4(+) T cells could be a promising strategy to enhance antitumor immune responses in the immunosuppressive tumor microenvironment.

  1. 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...

  2. CD4 binding to major histocompatibility complex class II antigens induces LFA-1-dependent and -independent homotypic adhesion of B lymphocytes.

    Science.gov (United States)

    Kansas, G S; Cambier, J C; Tedder, T F

    1992-01-01

    T helper cells recognize processed antigen (Ag) in the context of major histocompatibility complex (MHC) class II antigens present on the surface of B cells and other Ag-presenting cells. This interaction is mediated through the T cell receptor complex with associate recognition of class II molecules by the CD4 molecule. In this study, the binding of a soluble recombinant CD4/Ig heavy chain fusion protein (CD4-gamma 3) or monoclonal antibody (mAb) to class II antigens on human B cells was shown to induce rapid and specific homotypic adhesion of B cells and most B lymphoblastoid cell lines. mAb reactive with CD4 inhibited CD4-gamma 3-induced adhesion and a mutant B lymphoblastoid cell line deficient in class II antigens failed to respond. Induction of homotypic adhesion was dependent on energy metabolism and a functional cytoskeleton, and class II+ pre-B cells did not exhibit adhesion in response to these stimuli, suggesting that cross-linking of class II molecules generated a transmembrane signal and did not simply aggregate cells. In addition, MHC class II-induced adhesion was Fc receptor independent, as 15 mAb of different Ig isotypes reactive with HLA-D or HLA-DQ gene products induced adhesion. Anti-class II mAb and CD4-gamma 3 were able to induce adhesion at concentrations as low as 10 ng/ml and 100 ng/ml, respectively. Suboptimal stimulation of B cell lines through HLA-D antigens induced homotypic adhesion that was dependent on the activation of LFA-1 (CD11a/CD18), and which could be blocked by specific mAb. However, at greater signal strengths, adhesion was not blocked by mAb against the known adhesion receptors, suggesting the induction of a novel adhesion pathway. Consistent with this, homotypic adhesion induced by engagement of MHC class II antigens was observed with LFA-1-deficient B cell lines, and was independent of CD49d or CD18 expression. Thus, the direct engagement of B cell class II antigens by CD4 is likely to generate transmembrane signals which

  3. Targeting CLEC9A delivers antigen to human CD141+ DC for CD4+ and CD8+T cell recognition

    Science.gov (United States)

    Tullett, Kirsteen M.; Leal Rojas, Ingrid M.; Minoda, Yoshihito; Tan, Peck S.; Zhang, Jian-Guo; Smith, Corey; Shortman, Ken; Caminschi, Irina; Lahoud, Mireille H.; Radford, Kristen J.

    2016-01-01

    DC-based vaccines that initiate T cell responses are well tolerated and have demonstrated efficacy for tumor immunotherapy, with the potential to be combined with other therapies. Targeting vaccine antigens (Ag) directly to the DCs in vivo is more effective than cell-based therapies in mouse models and is therefore a promising strategy to translate to humans. The human CD141+ DCs are considered the most clinically relevant for initiating CD8+ T cell responses critical for killing tumors or infected cells, and they specifically express the C-type lectin-like receptor CLEC9A that facilitates presentation of Ag by these DCs. We have therefore developed a human chimeric Ab that specifically targets CLEC9A on CD141+ DCs in vitro and in vivo. These human chimeric Abs are highly effective at delivering Ag to DCs for recognition by both CD4+ and CD8+ T cells. Given the importance of these cellular responses for antitumor or antiviral immunity, and the superior specificity of anti-CLEC9A Abs for this DC subset, this approach warrants further development for vaccines.

  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. HIV-infected CD4+ T Cells Use T-bet-dependent Pathway for Production of IL-10 Upon Antigen Recognition.

    Science.gov (United States)

    Shete, A; Suryawanshi, P; Godbole, S; Pawar, J; Paranjape, R; Thakar, M

    2016-04-01

    Interleukin (IL)-10 has been implicated in persistence of pathogens in a number of chronic infections. Infected CD4+ cells upon reactivation with HIV antigens were also shown to produce IL-10, which might contribute to their persistence. Hence, it is crucial to determine mechanisms regulating IL-10 production after activation with HIV antigens for devising effective blocking strategies. In this study, ERK-, T-bet- and FoxP3-dependent pathways were evaluated for their possible roles in IL-10 production by infected CD4+ cells after reactivation with HIV Env. Intracellular and secreted IL-10 levels were determined by flow cytometry and Bioplex assay after treating PBMCs with PD98059, tipifarnib and cyclosporin A for blocking of ERK-, T-bet-and FoxP3-dependent pathways, respectively. Baseline levels of T-bet, pERK were higher in P24+ CD4+ cells as compared to uninfected CD4+ cells, which increased further after activation with Env. Inhibition of T-bet resulted in 2.3-fold reduction of IL-10 expression whereas ERK and FoxP3 inhibition failed to cause suppression of IL-10 expression. Conversely, IL-10 secreted by PBMCs was inhibited maximally after ERK inhibition suggesting its role in regulation of cytokine secretory pathway. IFN-γ was found to be suppressed after treatment with inhibitors of all these pathways. Thus, the study highlighted need for IL-10 blockade along with the use of antigens for therapeutic vaccinations or latency reversal and identified the T-bet-dependent pathway as an important pathway regulating IL-10 production by infected CD4+ cells. However, simultaneous blockade of IFN-γ precludes use of inhibitor of this pathway as an IL-10 blocking strategy. PMID:27028319

  6. Immunohistochemical detection of SWC3, CD2, CD3, CD4 and CD8 antigens in paraformaldehyde fixed and paraffin embedded porcine lymphoid tissue

    DEFF Research Database (Denmark)

    Tingstedt, Jens Erik; Tornehave, Ditte; Lind, Peter;

    2003-01-01

    porcine tissue sections using the highly sensitive tyramide signal amplification system. Combining this method with different antigen retrieval techniques enabled us to detect CD2, CD3, CD4, CD8 and SWC3 antigen expressing cells in porcine lymphoid tissue. Thus, we describe herein methods......Identification of the different cell types of the immune system is important for in situ studies on the pathogenesis of infectious diseases in various animals, including the pig. Unfortunately, many monoclonal anti-leukocyte antibodies are only useful for staining frozen tissue sections...... for the detection of several major cell types of the porcine immune system in fixed tissue with optimal preservation of histological details....

  7. CXCR3 Directs Antigen-Specific Effector CD4+ T Cell Migration to the Lung During Parainfluenza Virus Infection

    DEFF Research Database (Denmark)

    Kohlmeier, Jacob E; Cookenham, Tres; Miller, Shannon C;

    2009-01-01

    Effector T cells are a crucial component of the adaptive immune response to respiratory virus infections. Although it was previously reported that the chemokine receptors CCR5 and CXCR3 affect trafficking of respiratory virus-specific CD8(+) T cells, it is unclear whether these receptors govern...... effector CD4(+) T cell migration to the lungs. To assess the role of CCR5 and CXCR3 in vivo, we directly compared the migration of Ag-specific wild-type and chemokine receptor-deficient effector T cells in mixed bone marrow chimeric mice during a parainfluenza virus infection. CXCR3-deficient effector CD4......(+) T cells were 5- to 10-fold less efficient at migrating to the lung compared with wild-type cells, whereas CCR5-deficient effector T cells were not impaired in their migration to the lung. In contrast to its role in trafficking, CXCR3 had no impact on effector CD4(+) T cell proliferation, phenotype...

  8. A Simple Proteomics-Based Approach to Identification of Immunodominant Antigens from a Complex Pathogen: Application to the CD4 T Cell Response against Human Herpesvirus 6B.

    Science.gov (United States)

    Becerra-Artiles, Aniuska; Dominguez-Amorocho, Omar; Stern, Lawrence J; Calvo-Calle, J Mauricio

    2015-01-01

    Most of humanity is chronically infected with human herpesvirus 6 (HHV-6), with viral replication controlled at least in part by a poorly characterized CD4 T cell response. Identification of viral epitopes recognized by CD4 T cells is complicated by the large size of the herpesvirus genome and a low frequency of circulating T cells responding to the virus. Here, we present an alternative to classical epitope mapping approaches used to identify major targets of the T cell response to a complex pathogen like HHV-6B. In the approach presented here, extracellular virus preparations or virus-infected cells are fractionated by SDS-PAGE, and eluted fractions are used as source of antigens to study cytokine responses in direct ex vivo T cell activation studies. Fractions inducing significant cytokine responses are analyzed by mass spectrometry to identify viral proteins, and a subset of peptides from these proteins corresponding to predicted HLA-DR binders is tested for IFN-γ production in seropositive donors with diverse HLA haplotypes. Ten HHV-6B viral proteins were identified as immunodominant antigens. The epitope-specific response to HHV-6B virus was complex and variable between individuals. We identified 107 peptides, each recognized by at least one donor, with each donor having a distinctive footprint. Fourteen peptides showed responses in the majority of donors. Responses to these epitopes were validated using in vitro expanded cells and naturally expressed viral proteins. Predicted peptide binding affinities for the eight HLA-DRB1 alleles investigated here correlated only modestly with the observed CD4 T cell responses. Overall, the response to the virus was dominated by peptides from the major capsid protein U57 and major antigenic protein U11, but responses to other proteins including glycoprotein H (U48) and tegument proteins U54 and U14 also were observed. These results provide a means to follow and potentially modulate the CD4 T-cell immune response to HHV-6

  9. 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.

  10. Modified tumour antigen-encoding mRNA facilitates the analysis of naturally occurring and vaccine-induced CD4 and CD8 T cells in cancer patients.

    Science.gov (United States)

    Knights, Ashley J; Nuber, Natko; Thomson, Christopher W; de la Rosa, Olga; Jäger, Elke; Tiercy, Jean-Marie; van den Broek, Maries; Pascolo, Steve; Knuth, Alexander; Zippelius, Alfred

    2009-03-01

    The development of effective anti-cancer vaccines requires precise assessment of vaccine-induced immunity. This is often hampered by low ex vivo frequencies of antigen-specific T cells and limited defined epitopes. This study investigates the applicability of modified, in vitro-transcribed mRNA encoding a therapeutically relevant tumour antigen to analyse T cell responses in cancer patients. In this study transfection of antigen presenting cells, by mRNA encoding the tumour antigen NY-ESO-1, was optimised and applied to address spontaneous and vaccine-induced T cell responses in cancer patients. Memory CD8+ T cells from lung cancer patients having detectable humoral immune responses directed towards NY-ESO-1 could be efficiently detected in peripheral blood. Specific T cells utilised a range of different T cell receptors, indicating a polyclonal response. Specific killing of a panel of NY-ESO-1 expressing tumour cell lines indicates recognition restricted to several HLA allelic variants, including a novel HLA-B49 epitope. Using a modified mRNA construct targeting the translated antigen to the secretory pathway, detection of NY-ESO-1-specific CD4+ T cells in patients could be enhanced, which allowed the in-depth characterisation of established T cell clones. Moreover, broad CD8+ and CD4+ T cell responses covering multiple epitopes were detected following mRNA stimulation of patients treated with a recombinant vaccinia/fowlpox NY-ESO-1 vaccine. This approach allows for a precise monitoring of responses to tumour antigens in a setting that addresses the breadth and magnitude of antigen-specific T cell responses, and that is not limited to a particular combination of known epitopes and HLA-restrictions. PMID:18663444

  11. Local CD4 and CD8 T-cell reactivity to HSV-1 antigens documents broad viral protein expression and immune competence in latently infected human trigeminal ganglia.

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    Monique van Velzen

    2013-08-01

    Full Text Available Herpes simplex virus type 1 (HSV-1 infection results in lifelong chronic infection of trigeminal ganglion (TG neurons, also referred to as neuronal HSV-1 latency, with periodic reactivation leading to recrudescent herpetic disease in some persons. HSV-1 proteins are expressed in a temporally coordinated fashion during lytic infection, but their expression pattern during latent infection is largely unknown. Selective retention of HSV-1 reactive T-cells in human TG suggests their role in controlling reactivation by recognizing locally expressed HSV-1 proteins. We characterized the HSV-1 proteins recognized by virus-specific CD4 and CD8 T-cells recovered from human HSV-1-infected TG. T-cell clusters, consisting of both CD4 and CD8 T-cells, surrounded neurons and expressed mRNAs and proteins consistent with in situ antigen recognition and antiviral function. HSV-1 proteome-wide scans revealed that intra-TG T-cell responses included both CD4 and CD8 T-cells directed to one to three HSV-1 proteins per person. HSV-1 protein ICP6 was targeted by CD8 T-cells in 4 of 8 HLA-discordant donors. In situ tetramer staining demonstrated HSV-1-specific CD8 T-cells juxtaposed to TG neurons. Intra-TG retention of virus-specific CD4 T-cells, validated to the HSV-1 peptide level, implies trafficking of viral proteins from neurons to HLA class II-expressing non-neuronal cells for antigen presentation. The diversity of viral proteins targeted by TG T-cells across all kinetic and functional classes of viral proteins suggests broad HSV-1 protein expression, and viral antigen processing and presentation, in latently infected human TG. Collectively, the human TG represents an immunocompetent environment for both CD4 and CD8 T-cell recognition of HSV-1 proteins expressed during latent infection. HSV-1 proteins recognized by TG-resident T-cells, particularly ICP6 and VP16, are potential HSV-1 vaccine candidates.

  12. The Tumor Antigen NY-ESO-1 Mediates Direct Recognition of Melanoma Cells by CD4+ T Cells after Intercellular Antigen Transfer.

    Science.gov (United States)

    Fonteneau, Jean Francois; Brilot, Fabienne; Münz, Christian; Gannagé, Monique

    2016-01-01

    NY-ESO-1-specific CD4(+) T cells are of interest for immune therapy against tumors, because it has been shown that their transfer into a patient with melanoma resulted in tumor regression. Therefore, we investigated how NY-ESO-1 is processed onto MHC class II molecules for direct CD4(+) T cell recognition of melanoma cells. We could rule out proteasome and autophagy-dependent endogenous Ag processing for MHC class II presentation. In contrast, intercellular Ag transfer, followed by classical MHC class II Ag processing via endocytosis, sensitized neighboring melanoma cells for CD4(+) T cell recognition. However, macroautophagy targeting of NY-ESO-1 enhanced MHC class II presentation. Therefore, both elevated NY-ESO-1 release and macroautophagy targeting could improve melanoma cell recognition by CD4(+) T cells and should be explored during immunotherapy of melanoma.

  13. 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...

  14. Blood feeding by the Rocky Mountain spotted fever vector, Dermacentor andersoni, induces interleukin-4 expression by cognate antigen responding CD4+ T cells

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    Wikel Stephen K

    2009-10-01

    Full Text Available Abstract Background Tick modulation of host defenses facilitates both blood feeding and pathogen transmission. Several tick species deviate host T cell responses toward a Th2 cytokine profile. The majority of studies of modulation of T cell cytokine expression by ticks were performed with lymphocytes from infested mice stimulated in vitro with polyclonal T cell activators. Those reports did not examine tick modulation of antigen specific responses. We report use of a transgenic T cell receptor (TCR adoptive transfer model reactive with influenza hemagglutinin peptide (110-120 to examine CD4+ T cell intracellular cytokine responses during infestation with the metastriate tick, Dermacentor andersoni, or exposure to salivary gland extracts. Results Infestation with pathogen-free D. andersoni nymphs or administration of an intradermal injection of female or male tick salivary gland extract induced significant increases of IL-4 transcripts in skin and draining lymph nodes of BALB/c mice as measured by quantitative real-time RT-PCR. Furthermore, IL-10 transcripts were significantly increased in skin while IL-2 and IFN-γ transcripts were not significantly changed by tick feeding or intradermal injection of salivary gland proteins, suggesting a superimposed Th2 response. Infestation induced TCR transgenic CD4+ T cells to divide more frequently as measured by CFSE dilution, but more notably these CD4+ T cells also gained the capacity to express IL-4. Intracellular levels of IL-4 were significantly increased. A second infestation administered 14 days after a primary exposure to ticks resulted in partially reduced CFSE dilution with no change in IL-4 expression when compared to one exposure to ticks. Intradermal inoculation of salivary gland extracts from both male and female ticks also induced IL-4 expression. Conclusion This is the first report of the influence of a metastriate tick on the cytokine profile of antigen specific CD4+ T cells. Blood feeding

  15. A Simple Proteomics-Based Approach to Identification of Immunodominant Antigens from a Complex Pathogen: Application to the CD4 T Cell Response against Human Herpesvirus 6B.

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    Aniuska Becerra-Artiles

    Full Text Available Most of humanity is chronically infected with human herpesvirus 6 (HHV-6, with viral replication controlled at least in part by a poorly characterized CD4 T cell response. Identification of viral epitopes recognized by CD4 T cells is complicated by the large size of the herpesvirus genome and a low frequency of circulating T cells responding to the virus. Here, we present an alternative to classical epitope mapping approaches used to identify major targets of the T cell response to a complex pathogen like HHV-6B. In the approach presented here, extracellular virus preparations or virus-infected cells are fractionated by SDS-PAGE, and eluted fractions are used as source of antigens to study cytokine responses in direct ex vivo T cell activation studies. Fractions inducing significant cytokine responses are analyzed by mass spectrometry to identify viral proteins, and a subset of peptides from these proteins corresponding to predicted HLA-DR binders is tested for IFN-γ production in seropositive donors with diverse HLA haplotypes. Ten HHV-6B viral proteins were identified as immunodominant antigens. The epitope-specific response to HHV-6B virus was complex and variable between individuals. We identified 107 peptides, each recognized by at least one donor, with each donor having a distinctive footprint. Fourteen peptides showed responses in the majority of donors. Responses to these epitopes were validated using in vitro expanded cells and naturally expressed viral proteins. Predicted peptide binding affinities for the eight HLA-DRB1 alleles investigated here correlated only modestly with the observed CD4 T cell responses. Overall, the response to the virus was dominated by peptides from the major capsid protein U57 and major antigenic protein U11, but responses to other proteins including glycoprotein H (U48 and tegument proteins U54 and U14 also were observed. These results provide a means to follow and potentially modulate the CD4 T-cell immune

  16. Impact of adjuvants on CD4(+) T cell and B cell responses to a protein antigen vaccine: Results from a phase II, randomized, multicenter trial.

    Science.gov (United States)

    Leroux-Roels, Geert; Marchant, Arnaud; Levy, Jack; Van Damme, Pierre; Schwarz, Tino F; Horsmans, Yves; Jilg, Wolfgang; Kremsner, Peter G; Haelterman, Edwige; Clément, Frédéric; Gabor, Julian J; Esen, Meral; Hens, Annick; Carletti, Isabelle; Fissette, Laurence; Tavares Da Silva, Fernanda; Burny, Wivine; Janssens, Michel; Moris, Philippe; Didierlaurent, Arnaud M; Van Der Most, Robbert; Garçon, Nathalie; Van Belle, Pascale; Van Mechelen, Marcelle

    2016-08-01

    Immunogenicity and safety of different adjuvants combined with a model antigen (HBsAg) were compared. Healthy HBV-naïve adults were randomized to receive HBs adjuvanted with alum or Adjuvant Systems AS01B, AS01E, AS03A or AS04 at Days 0 and 30. Different frequencies of HBs-specific CD4+ T cells 14days post dose 2 but similar polyfunctionality profiles were induced by the different adjuvants with frequencies significantly higher in the AS01B and AS01E groups than in the other groups. Antibody concentrations 30days post-dose 2 were significantly higher in AS01B, AS01E and AS03A than in other groups. Limited correlations were observed between HBs-specific CD4+ T cell and antibody responses. Injection site pain was the most common solicited local symptom and was more frequent in AS groups than in alum group. Different adjuvants formulated with the same antigen induced different adaptive immune responses and reactogenicity patterns in healthy naïve adults. The results summary for this study (GSK study number 112115 - NCT# NCT00805389) is available on the GSK Clinical Study Register and can be accessed at www.gsk-clinicalstudyregister.com.

  17. Impact of adjuvants on CD4(+) T cell and B cell responses to a protein antigen vaccine: Results from a phase II, randomized, multicenter trial.

    Science.gov (United States)

    Leroux-Roels, Geert; Marchant, Arnaud; Levy, Jack; Van Damme, Pierre; Schwarz, Tino F; Horsmans, Yves; Jilg, Wolfgang; Kremsner, Peter G; Haelterman, Edwige; Clément, Frédéric; Gabor, Julian J; Esen, Meral; Hens, Annick; Carletti, Isabelle; Fissette, Laurence; Tavares Da Silva, Fernanda; Burny, Wivine; Janssens, Michel; Moris, Philippe; Didierlaurent, Arnaud M; Van Der Most, Robbert; Garçon, Nathalie; Van Belle, Pascale; Van Mechelen, Marcelle

    2016-08-01

    Immunogenicity and safety of different adjuvants combined with a model antigen (HBsAg) were compared. Healthy HBV-naïve adults were randomized to receive HBs adjuvanted with alum or Adjuvant Systems AS01B, AS01E, AS03A or AS04 at Days 0 and 30. Different frequencies of HBs-specific CD4+ T cells 14days post dose 2 but similar polyfunctionality profiles were induced by the different adjuvants with frequencies significantly higher in the AS01B and AS01E groups than in the other groups. Antibody concentrations 30days post-dose 2 were significantly higher in AS01B, AS01E and AS03A than in other groups. Limited correlations were observed between HBs-specific CD4+ T cell and antibody responses. Injection site pain was the most common solicited local symptom and was more frequent in AS groups than in alum group. Different adjuvants formulated with the same antigen induced different adaptive immune responses and reactogenicity patterns in healthy naïve adults. The results summary for this study (GSK study number 112115 - NCT# NCT00805389) is available on the GSK Clinical Study Register and can be accessed at www.gsk-clinicalstudyregister.com. PMID:27236001

  18. 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

    ABSTRACT 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 better defined. Here we demonstrate that in vitro blockade of PD-L1 and/or IL-10Rα results in markedly different profiles of HIV-1-specific CD4 T cell restoration. Whereas PD-L1 blockade leads to balanced increase in gamma interferon (IFN-γ), IL-2, and IL-13 secretion, IL-10Rα blockade preferentially restores IFN-γ production. In viremic subjects, combined PD-L1/IL-10Rα blockade results in a striking 10-fold increase in IFN-γ secretion by HIV-1-specific CD4 T cells that is not observed in subjects with spontaneous (elite controllers) or therapy-induced control of viral replication. In contrast to the dramatic increase in IFN-γ production, concurrent blockade has a marginal additive effect on IL-2 production, IL-13 secretion, and HIV-1-specific CD4 T cell proliferation. IFN-γ produced by Thelper cells upregulates PD-L1, HLA I/II, and IL-12 expression by monocytes. The effect of combined blockade on IFN-γ was dependent on reciprocal reinforcement through IL-12. These studies provide crucial information on the different immunoregulatory qualities of PD-1 and IL-10 in progressive disease and link exhausted virus-specific CD4 T cells and monocytes in the regulation of IFN-γ and IL-12 secretion. IMPORTANCE Infection with HIV results in most people in uncontrolled viral replication and progressive weakening of the body defenses. In the absence of antiviral therapy, this process results in clinical disease, or AIDS. An important reason why HIV continues to multiply is

  19. Cooperation between CD4+ T Cells and Humoral Immunity Is Critical for Protection against Dengue Using a DNA Vaccine Based on the NS1 Antigen.

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    Antônio J S Gonçalves

    2015-12-01

    Full Text Available Dengue virus (DENV is spread through most tropical and subtropical areas of the world and represents a serious public health problem. At present, the control of dengue disease is mainly hampered by the absence of antivirals or a vaccine, which results in an estimated half worldwide population at risk of infection. The immune response against DENV is not yet fully understood and a better knowledge of it is now recognized as one of the main challenge for vaccine development. In previous studies, we reported that a DNA vaccine containing the signal peptide sequence from the human tissue plasminogen activator (t-PA fused to the DENV2 NS1 gene (pcTPANS1 induced protection against dengue in mice. In the present work, we aimed to elucidate the contribution of cellular and humoral responses elicited by this vaccine candidate for protective immunity. We observed that pcTPANS1 exerts a robust protection against dengue, inducing considerable levels of anti-NS1 antibodies and T cell responses. Passive immunization with anti-NS1 antibodies conferred partial protection in mice infected with low virus load (4 LD50, which was abrogated with the increase of viral dose (40 LD50. The pcTPANS1 also induced activation of CD4+ and CD8+ T cells. We detected production of IFN-γ and a cytotoxic activity by CD8+ T lymphocytes induced by this vaccine, although its contribution in the protection was not so evident when compared to CD4+ cells. Depletion of CD4+ cells in immunized mice completely abolished protection. Furthermore, transfer experiments revealed that animals receiving CD4+ T cells combined with anti-NS1 antiserum, both obtained from vaccinated mice, survived virus infection with survival rates not significantly different from pcTPANS1-immunized animals. Taken together, results showed that the protective immune response induced by the expression of NS1 antigen mediated by the pcTPANS1 requires a cooperation between CD4+ T cells and the humoral immunity.

  20. Transforming growth factor-beta inhibits human antigen-specific CD4(+) T cell proliferation without modulating the cytokine response

    NARCIS (Netherlands)

    Tiemessen, MM; Kunzmann, S; Schmidt-Weber, CB; Garssen, J; Bruijnzeel-Koomen, CAFM; Knol, EF; Van Hoffen, E

    2003-01-01

    Transforming growth factor (TGF)-beta has been demonstrated to play a key role in the regulation of the immune response, mainly by its suppressive function towards cells of the immune system. In humans, the effect of TGF-beta on antigen-specific established memory T cells has not been investigated y

  1. Synthetic TLR4 agonists enhance functional antibodies and CD4+ T-cell responses against the Plasmodium falciparum GMZ2.6C multi-stage vaccine antigen.

    Science.gov (United States)

    Baldwin, Susan L; Roeffen, Will; Singh, Susheel K; Tiendrebeogo, Regis W; Christiansen, Michael; Beebe, Elyse; Carter, Darrick; Fox, Christopher B; Howard, Randall F; Reed, Steven G; Sauerwein, Robert; Theisen, Michael

    2016-04-27

    A subunit vaccine targeting both transmission and pathogenic asexual blood stages of Plasmodium falciparum, i.e., a multi-stage vaccine, could be a powerful tool to combat malaria. Here, we report production and characterization of the recombinant protein GMZ2.6C, which contains a fragment of the sexual-stage protein Pfs48/45-6C genetically fused to GMZ2, an asexual vaccine antigen in advanced clinical development. To select the most suitable vaccine formulation for downstream clinical studies, GMZ2.6C was tested with various immune modulators in different adjuvant formulations (stable emulsions, liposomes, and alum) in C57BL/6 mice. Some, but not all, formulations containing either the synthetic TLR4 agonist GLA or SLA elicited the highest parasite-specific antibody titers, the greatest IFN-γ responses in CD4+ TH1 cells, and the highest percentage of multifunctional CD4+ T cells expressing IFN-γ and TNF in response to GMZ2.6C. Both of these agonists have good safety records in humans. PMID:26994314

  2. CD85/LIR-1/ILT2 and CD152 (Cytotoxic T Lymphocyte Antigen 4) Inhibitory Molecules Down-Regulate the Cytolytic Activity of Human CD4+ T-Cell Clones Specific for Mycobacterium tuberculosis

    OpenAIRE

    Merlo, Andrea; Saverino, Daniele; Tenca, Claudya; Grossi, Carlo Enrico; Bruno, Silvia; Ciccone, Ermanno

    2001-01-01

    Antigen-specific cytolytic CD4+ T lymphocytes control Mycobacterium tuberculosis infection by secreting cytokines and by killing macrophages that have phagocytosed the pathogen. However, lysis of the latter cells promotes microbial dissemination, and other macrophages engulf the released bacteria. Subsequently, CD4+ T-cell-mediated killing of macrophages goes on, and this persistent process may hamper control of infection, unless regulatory mechanisms maintain a subtle balance between lysis o...

  3. Establishment of HLA-DR4 transgenic mice for the identification of CD4+ T cell epitopes of tumor-associated antigens.

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    Junji Yatsuda

    Full Text Available Reports have shown that activation of tumor-specific CD4(+ helper T (Th cells is crucial for effective anti-tumor immunity and identification of Th-cell epitopes is critical for peptide vaccine-based cancer immunotherapy. Although computer algorithms are available to predict peptides with high binding affinity to a specific HLA class II molecule, the ability of those peptides to induce Th-cell responses must be evaluated. We have established HLA-DR4 (HLA-DRA*01:01/HLA-DRB1*04:05 transgenic mice (Tgm, since this HLA-DR allele is most frequent (13.6% in Japanese population, to evaluate HLA-DR4-restricted Th-cell responses to tumor-associated antigen (TAA-derived peptides predicted to bind to HLA-DR4. To avoid weak binding between mouse CD4 and HLA-DR4, Tgm were designed to express chimeric HLA-DR4/I-E(d, where I-E(d α1 and β1 domains were replaced with those from HLA-DR4. Th cells isolated from Tgm immunized with adjuvant and HLA-DR4-binding cytomegalovirus-derived peptide proliferated when stimulated with peptide-pulsed HLA-DR4-transduced mouse L cells, indicating chimeric HLA-DR4/I-E(d has equivalent antigen presenting capacity to HLA-DR4. Immunization with CDCA155-78 peptide, a computer algorithm-predicted HLA-DR4-binding peptide derived from TAA CDCA1, successfully induced Th-cell responses in Tgm, while immunization of HLA-DR4-binding Wilms' tumor 1 antigen-derived peptide with identical amino acid sequence to mouse ortholog failed. This was overcome by using peptide-pulsed syngeneic bone marrow-derived dendritic cells (BM-DC followed by immunization with peptide/CFA booster. BM-DC-based immunization of KIF20A494-517 peptide from another TAA KIF20A, with an almost identical HLA-binding core amino acid sequence to mouse ortholog, successfully induced Th-cell responses in Tgm. Notably, both CDCA155-78 and KIF20A494-517 peptides induced human Th-cell responses in PBMCs from HLA-DR4-positive donors. Finally, an HLA-DR4 binding DEPDC1191

  4. Bispecificity for myelin and neuronal self-antigens is a common feature of CD4 T cells in C57BL/6 mice.

    Science.gov (United States)

    Lucca, Liliana E; Desbois, Sabine; Ramadan, Abdulraouf; Ben-Nun, Avraham; Eisenstein, Miriam; Carrié, Nadège; Guéry, Jean-Charles; Sette, Alessandro; Nguyen, Phuong; Geiger, Terrence L; Mars, Lennart T; Liblau, Roland S

    2014-10-01

    The recognition of multiple ligands by a single TCR is an intrinsic feature of T cell biology, with important consequences for physiological and pathological processes. Polyspecific T cells targeting distinct self-antigens have been identified in healthy individuals as well as in the context of autoimmunity. We have previously shown that the 2D2 TCR recognizes the myelin oligodendrocyte glycoprotein epitope (MOG)35-55 as well as an epitope within the axonal protein neurofilament medium (NF-M15-35) in H-2(b) mice. In this study, we assess whether this cross-reactivity is a common feature of the MOG35-55-specific T cell response. To this end, we analyzed the CD4 T cell response of MOG35-55-immunized C57BL/6 mice for cross-reactivity with NF-M15-35. Using Ag recall responses, we established that an important proportion of MOG35-55-specific CD4 T cells also responded to NF-M15-35 in all mice tested. To study the clonality of this response, we analyzed 22 MOG35-55-specific T cell hybridomas expressing distinct TCR. Seven hybridomas were found to cross-react with NF-M15-35. Using an alanine scan of NF-M18-30 and an in silico predictive model, we dissected the molecular basis of cross-reactivity between MOG35-55 and NF-M15-35. We established that NF-M F24, R26, and V27 proved important TCR contacts. Strikingly, the identified TCR contacts are conserved within MOG38-50. Our data indicate that due to linear sequence homology, part of the MOG35-55-specific T cell repertoire of all C57BL/6 mice also recognizes NF-M15-35, with potential implications for CNS autoimmunity. PMID:25135834

  5. Immunotherapy of non-Hodgkin's lymphoma with a defined ratio of CD8+ and CD4+ CD19-specific chimeric antigen receptor-modified T cells.

    Science.gov (United States)

    Turtle, Cameron J; Hanafi, Laïla-Aïcha; Berger, Carolina; Hudecek, Michael; Pender, Barbara; Robinson, Emily; Hawkins, Reed; Chaney, Colette; Cherian, Sindhu; Chen, Xueyan; Soma, Lorinda; Wood, Brent; Li, Daniel; Heimfeld, Shelly; Riddell, Stanley R; Maloney, David G

    2016-09-01

    CD19-specific chimeric antigen receptor (CAR)-modified T cells have antitumor activity in B cell malignancies, but factors that affect toxicity and efficacy have been difficult to define because of differences in lymphodepletion and heterogeneity of CAR-T cells administered to individual patients. We conducted a clinical trial in which CD19 CAR-T cells were manufactured from defined T cell subsets and administered in a 1:1 CD4(+)/CD8(+) ratio of CAR-T cells to 32 adults with relapsed and/or refractory B cell non-Hodgkin's lymphoma after cyclophosphamide (Cy)-based lymphodepletion chemotherapy with or without fludarabine (Flu). Patients who received Cy/Flu lymphodepletion had increased CAR-T cell expansion and persistence, and higher response rates [50% complete remission (CR), 72% overall response rate (ORR)] than patients who received Cy-based lymphodepletion without Flu (8% CR, 50% ORR). The CR rate in patients treated with Cy/Flu at the maximally tolerated dose was 64% (82% ORR; n = 11). Cy/Flu minimized the effects of an immune response to the murine single-chain variable fragment component of the CAR, which limited CAR-T cell expansion and clinical efficacy in patients who received Cy-based lymphodepletion without Flu. Severe cytokine release syndrome (sCRS) and grade ≥3 neurotoxicity were observed in 13 and 28% of all patients, respectively. Serum biomarkers, one day after CAR-T cell infusion, correlated with subsequent sCRS and neurotoxicity. Immunotherapy with CD19 CAR-T cells in a defined CD4(+)/CD8(+) ratio allowed identification of correlative factors for CAR-T cell expansion, persistence, and toxicity, and facilitated optimization of lymphodepletion that improved disease response and overall and progression-free survival. PMID:27605551

  6. 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.

  7. 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.

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

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    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. Orally-Induced Intestinal CD4+ CD25+ FoxP3+ Treg Controlled Undesired Responses towards Oral Antigens and Effectively Dampened Food Allergic Reactions.

    Directory of Open Access Journals (Sweden)

    Paola Lorena Smaldini

    Full Text Available The induction of peripheral tolerance may constitute a disease-modifying treatment for allergic patients. We studied how oral immunotherapy (OIT with milk proteins controlled allergy in sensitized mice (cholera toxin plus milk proteins upon exposure to the allergen. Symptoms were alleviated, skin test was negativized, serum specific IgE and IgG1 were abrogated, a substantial reduction in the secretion of IL-5 and IL-13 by antigen-stimulated spleen cells was observed, while IL-13 gene expression in jejunum was down-regulated, and IL-10 and TGF-β were increased. In addition, we observed an induction of CD4+CD25+FoxP3+ cells and IL-10- and TGF-β-producing regulatory T cells in the lamina propria. Finally, transfer experiments confirmed the central role of these cells in tolerance induction. We demonstrated that the oral administration of milk proteins pre- or post-sensitization controlled the Th2-immune response through the elicitation of mucosal IL-10- and TGF-β-producing Tregs that inhibited hypersensitivity symptoms and the allergic response.

  10. The use of anti-CD4 antibodies and down-regulatory mechanism of CD4 antigen in Th1/Th2 polarization detection%CD4单抗选择对于流式细胞术分析Th1/Th2极化的有效性评价

    Institute of Scientific and Technical Information of China (English)

    严茹红; 张萍; 朱雪明

    2007-01-01

    选择13B8.2和S3.5两株商品化的CD4单克隆抗体用于Th1/Th2极化的流式细胞术评价,分析PMA、Ionomycin和BFA单独或联合作用于外周血CD4抗原表达水平的变化,以确定Th1/Th2极化评价时有效的CD4设门单抗,并试图揭示CD4抗原降调的机制.结果表明,13B8.2可作为CD4的设门单抗. PMA和Ionomycin联合刺激会导致外周血CD4抗原的明显降低,而PMA单独刺激不能,且BFA与PMA和Iononmycin同时加入外周血中可部分抑制PMA和Ionomycin刺激引起的CD4抗原内吞和降解.

  11. Collaborative interactions between type 2 innate lymphoid cells and antigen-specific CD4+ Th2 cells exacerbate murine allergic airway diseases with prominent eosinophilia.

    Science.gov (United States)

    Liu, Bo; Lee, Jee-Boong; Chen, Chun-Yu; Hershey, Gurjit K Khurana; Wang, Yui-Hsi

    2015-04-15

    Type-2 innate lymphoid cells (ILC2s) and the acquired CD4(+) Th2 and Th17 cells contribute to the pathogenesis of experimental asthma; however, their roles in Ag-driven exacerbation of chronic murine allergic airway diseases remain elusive. In this study, we report that repeated intranasal rechallenges with only OVA Ag were sufficient to trigger airway hyperresponsiveness, prominent eosinophilic inflammation, and significantly increased serum OVA-specific IgG1 and IgE in rested mice that previously developed murine allergic airway diseases. The recall response to repeated OVA inoculation preferentially triggered a further increase of lung OVA-specific CD4(+) Th2 cells, whereas CD4(+) Th17 and ILC2 cell numbers remained constant. Furthermore, the acquired CD4(+) Th17 cells in Stat6(-/-)/IL-17-GFP mice, or innate ILC2s in CD4(+) T cell-ablated mice, failed to mount an allergic recall response to OVA Ag. After repeated OVA rechallenge or CD4(+) T cell ablation, the increase or loss of CD4(+) Th2 cells resulted in an enhanced or reduced IL-13 production by lung ILC2s in response to IL-25 and IL-33 stimulation, respectively. In return, ILC2s enhanced Ag-mediated proliferation of cocultured CD4(+) Th2 cells and their cytokine production, and promoted eosinophilic airway inflammation and goblet cell hyperplasia driven by adoptively transferred Ag-specific CD4(+) Th2 cells. Thus, these results suggest that an allergic recall response to recurring Ag exposures preferentially triggers an increase of Ag-specific CD4(+) Th2 cells, which facilitates the collaborative interactions between acquired CD4(+) Th2 cells and innate ILC2s to drive the exacerbation of a murine allergic airway diseases with an eosinophilic phenotype. PMID:25780046

  12. CD85/LIR-1/ILT2 and CD152 (cytotoxic T lymphocyte antigen 4) inhibitory molecules down-regulate the cytolytic activity of human CD4+ T-cell clones specific for Mycobacterium tuberculosis.

    Science.gov (United States)

    Merlo, A; Saverino, D; Tenca, C; Grossi, C E; Bruno, S; Ciccone, E

    2001-10-01

    Antigen-specific cytolytic CD4+ T lymphocytes control Mycobacterium tuberculosis infection by secreting cytokines and by killing macrophages that have phagocytosed the pathogen. However, lysis of the latter cells promotes microbial dissemination, and other macrophages engulf the released bacteria. Subsequently, CD4+ T-cell-mediated killing of macrophages goes on, and this persistent process may hamper control of infection, unless regulatory mechanisms maintain a subtle balance between lysis of macrophages by cytolytic CD4+ cells and activation of cytolytic CD4+ cells by infected macrophages. We asked whether inhibitory molecules expressed by CD4+ cytolytic T lymphocytes could play a role in such a balance. To this end, human CD4+ T-cell clones specific for M. tuberculosis were produced that displayed an autologous major histocompatibility complex class II-restricted lytic ability against purified protein derivative (PPD)-pulsed antigen-presenting cells. All T-cell clones expressed CD152 (cytotoxic T-lymphocyte antigen 4 [CTLA-4]) and CD85/leukocyte immunoglobulin-like receptor 1 (LIR-1)/immunoglobulin-like transcript 2 (ILT2) inhibitory receptors, but not CD94 and the killer inhibitory receptor (or killer immunoglobulin-like receptor [KIR]) p58.2. CD3-mediated activation of the clones was inhibited in a redirected killing assay in which CD152 and CD85/LIR-1/ILT2 were cross-linked. Specific antigen-mediated proliferation of the clones was also sharply reduced when CD152 and CD85/LIR-1/ILT2 were cross-linked by specific monoclonal antibody (MAb) followed by goat anti-mouse antiserum. In contrast, blockade of the receptors by specific MAb only increased their proliferation. Production of interleukin 2 (IL-2) and gamma interferon (IFN-gamma) by the T-cell clones was also strongly reduced when CD152 and CD85/LIR-1/ILT2 were cross-linked. The lytic activity of the T-cell clones against PPD-pulsed autologous monocytes or Epstein-Barr virus-activated B cells was increased

  13. CD4+ T Cells Recognizing PE/PPE Antigens Directly or via Cross Reactivity Are Protective against Pulmonary Mycobacterium tuberculosis Infection.

    Science.gov (United States)

    Sayes, Fadel; Pawlik, Alexandre; Frigui, Wafa; Gröschel, Matthias I; Crommelynck, Samuel; Fayolle, Catherine; Cia, Felipe; Bancroft, Gregory J; Bottai, Daria; Leclerc, Claude; Brosch, Roland; Majlessi, Laleh

    2016-07-01

    Mycobacterium tuberculosis (Mtb), possesses at least three type VII secretion systems, ESX-1, -3 and -5 that are actively involved in pathogenesis and host-pathogen interaction. We recently showed that an attenuated Mtb vaccine candidate (Mtb Δppe25-pe19), which lacks the characteristic ESX-5-associated pe/ppe genes, but harbors all other components of the ESX-5 system, induces CD4+ T-cell immune responses against non-esx-5-associated PE/PPE protein homologs. These T cells strongly cross-recognize the missing esx-5-associated PE/PPE proteins. Here, we characterized the fine composition of the functional cross-reactive Th1 effector subsets specific to the shared PE/PPE epitopes in mice immunized with the Mtb Δppe25-pe19 vaccine candidate. We provide evidence that the Mtb Δppe25-pe19 strain, despite its significant attenuation, is comparable to the WT Mtb strain with regard to: (i) its antigenic repertoire related to the different ESX systems, (ii) the induced Th1 effector subset composition, (iii) the differentiation status of the Th1 cells induced, and (iv) its particular features at stimulating the innate immune response. Indeed, we found significant contribution of PE/PPE-specific Th1 effector cells in the protective immunity against pulmonary Mtb infection. These results offer detailed insights into the immune mechanisms underlying the remarkable protective efficacy of the live attenuated Mtb Δppe25-pe19 vaccine candidate, as well as the specific potential of PE/PPE proteins as protective immunogens.

  14. The number of responding CD4 T cells and the dose of antigen conjointly determine the TH1/TH2 phenotype by modulating B7/CD28 interactions.

    Science.gov (United States)

    Rudulier, Christopher D; McKinstry, K Kai; Al-Yassin, Ghassan A; Kroeger, David R; Bretscher, Peter A

    2014-06-01

    Our previous in vivo studies show that both the amount of Ag and the number of available naive CD4 T cells affect the Th1/Th2 phenotype of the effector CD4 T cells generated. We examined how the number of OVA-specific CD4 TCR transgenic T cells affects the Th1/Th2 phenotype of anti-SRBC CD4 T cells generated in vivo upon immunization with different amounts of OVA-SRBC. Our observations show that a greater number of Ag-dependent CD4 T cell interactions are required to generate Th2 than Th1 cells. We established an in vitro system that recapitulates our main in vivo findings to more readily analyze the underlying mechanism. The in vitro generation of Th2 cells depends, as in vivo, upon both the number of responding CD4 T cells and the amount of Ag. We demonstrate, using agonostic/antagonistic Abs to various costimulatory molecules or their receptors, that the greater number of CD4 T cell interactions, required to generate Th2 over Th1 cells, does not involve CD40, OX40, or ICOS costimulation, but does involve B7/CD28 interactions. A comparison of the level of expression of B7 molecules by APC and CD4 T cells, under different conditions resulting in the substantial generation of Th1 and Th2 cells, leads us to propose that the critical CD28/B7 interactions, required to generate Th2 cells, may directly occur between CD4 T cells engaged with the same B cell acting as an APC.

  15. Homeostatic Cytokines Induce CD4 Downregulation in African Green Monkeys Independently of Antigen Exposure To Generate Simian Immunodeficiency Virus-Resistant CD8αα T Cells

    OpenAIRE

    Molly R Perkins; Briant, Judith A.; Calantone, Nina; Whitted, Sonya; Vinton, Carol L.; Klatt, Nichole R.; Ourmanov, Ilnour; Ortiz, Alexandra M.; Vanessa M Hirsch; Brenchley, Jason M.

    2014-01-01

    African green monkeys (AGMs; genus Chlorocebus) are a natural host of simian immunodeficiency virus (SIVAGM). As they do not develop simian AIDS, there is great interest in understanding how this species has evolved to avoid immunodeficiency. Adult African green monkeys naturally have low numbers of CD4 T cells and a large population of major histocompatibility complex class II-restricted CD8αdim T cells that are generated through CD4 downregulation in CD4+ T cells. Mechanisms that drive this...

  16. Allo-antigen stimulated CD8+ T-cells suppress NF-κB and Ets-1 DNA binding activity, and inhibit phosphorylated NF-κB p65 nuclear localization in CD4+ T-cells.

    Science.gov (United States)

    Nagashima, Ryuichi; Kawakami, Fumitaka; Takahashi, Shinichiro; Obata, Fumiya; Kubo, Makoto

    2014-08-01

    CD8+ T-cells of asymptomatic HIV-1 carriers (AC) suppress human immunodeficiency virus type 1 (HIV-1) replication in a class I major histocompatibility complex (MHC-I)-restricted and -unrestricted manner. In order to investigate the mechanism of MHC-I-unrestricted CD8+ T-cell-mediated HIV-1 suppression, we previously established allo-antigen stimulated CD8+T-cells from HIV-1-uninfected donors. These allo-antigen stimulated CD8+ T-cells suppressed HIV-1 replication in acutely infected autologous CD4+ T-cells when directly co-cultured. To elucidate the mechanism of HIV-1 replication suppression, we analyzed DNA-binding activity and phosphorylation of transcriptional factors associated with HIV-1 replication by electrophoresis mobility shift assay and Western blotting. When CD4+ T-cells were cultured with allo-antigen stimulated CD8+ T-cells, the reduction of NF-κB and Ets-1 DNA-binding activity was observed. Nuclear localization of NF-κB p65 and Ets-1 was suppressed in CD4+ T-cells. Although NF-κB p65 and Ets-1 are known to be regulated by protein kinase A (PKA), no difference was observed in the expression and phosphorylation of the PKA catalytic subunit in CD4+ T-cells cultured with PHA-treated CD8+ T-cells or allo-antigen stimulated CD8+ T-cells. Cyclic AMP is also known to enter through gap junctions, but the suppression of HIV-1 replication mediated by allo-antigen stimulated CD8+ T-cells was not affected by the gap junction inhibitor. The nuclear transport of phosphorylated NF-κB p65 (Ser276) was inhibited only in CD4+ T-cells cultured with allo-antigen stimulated CD8+ T-cells. Our results indicate that allo-antigen stimulated CD8+ T-cells suppress the transcriptional activity of NF-κB p65 or Ets-1 in an antigen-nonspecific manner, and inhibit the nuclear transport of phosphorylated NF-κB p65 (Ser276).

  17. Characterization of the antigen-specific CD4+ T cell response induced by prime-boost strategies with CAF01 and CpG adjuvants administered by the intranasal and subcutaneous routes

    Directory of Open Access Journals (Sweden)

    Annalisa eCiabattini

    2015-08-01

    Full Text Available The design of heterologous prime-boost vaccine combinations that optimally shape the immune response is of critical importance for the development of next generation vaccines. Here we tested different prime-boost combinations using the tuberculosis vaccine antigen H56 with CAF01 or CpG ODN 1821 adjuvants, administered by the parenteral and nasal routes. By using peptide-MHC class II tetramers, antigen-specific CD4+ T cells were tracked following primary and booster immunizations. Both parenteral priming with H56 plus CAF01 and nasal priming with H56 plus CpG elicited significant expansion of CD4+ tetramer-positive T cells in the spleen, however only parenterally primed cells responded to booster immunization. Subcutaneous priming with H56 and CAF01 followed by nasal boosting with H56 and CpG showed the greater expansion of CD4+ tetramer-positive T cells in the spleen and lungs compared to all the other homologous and heterologous prime-boost combinations. Nasal boosting exerted a recruitment of primed CD4+ T cells into lungs that was stronger in subcutaneously than nasally primed mice, in accordance with different chemokine receptor expression induced by primary immunization. These data demonstrate that subcutaneous priming is fundamental for eliciting CD4+ T cells that can be efficiently boosted by the nasal route and results in the recruitment of antigen-experienced cells into the lungs. Combination of different vaccine formulations and routes of delivery for priming and boosting is a strategic approach for improving and directing vaccine-induced immune responses.

  18. A study of the effects of Schistosoma japonicum soluble egg antigen on CD4+CD25+regulatory T cells in patients with asthma%CD4+CD25+调节性T细胞在血吸虫可溶性虫卵抗原影响哮喘中的作用研究

    Institute of Scientific and Technical Information of China (English)

    朱云娟; 刘佩梅; 杨秀珍; 刘霞; 吴增强; 纪伟华; 安桂珍; 沈悦云; 刘金霞; 李健

    2011-01-01

    Objective To study the relationship between Schistosoma japonicum soluble egg antigen (SEA) and asthma and the effects of SEA on CD4+ CD25+ regulatory T cells (CD4+ CD25+ Treg) and expression of the Foxp3 gene. Methods BALB/C mice were each injected with 50 μg SEA peritoneally and through the foot pad once a week for 4 weeks. In the control group, all injections were with normal saline. Then asthma was induced with ovalbumin (OVA) in all mice. After mice were sacrificed, the lungs were subjected to pathologic examination; the bronchoalveolar lavage fluid (BALF) was collected and different cells were classified and counted after smearing and staining. Spleen cells were separated and the percentage of CD4+ CD25+ Treg out of total CD4+ T cells was determined using flow cytometry. Total spleen RNA was prepared and synthesized into cDNA through reverse transcription; cDNA was subjected to PCR amplification to determine the level of Foxp3 mRNA expression. Results Mild pulmonary inflammation was observed in the SEA immunization group, whereas severe inflammation was observed in the control group. Staining of the BALF revealed that the SEA immunization group had a much lower BALF cell density than did the control group. In the SEA immunization group, the percentage of eosinophils out of total cells was(2. 22± 1. 52)% while it was (19. 93±4. 08)% in the control group. The difference between the 2 groups was statistically significant (P<0. 05). Flow cytometry revealed that the percentage of CD4+ CD25+ Treg out of total CD4+ T cells was (32. 24±2. 19) % in the SEA immunization group while it was (27. 41±2. 87) % in the control group. The difference between the 2 groups was statistically significant (P<0. 05). The level of Foxp3 mRNA expression was higher than that in the control group as well. Conclusion SEA inhibits the development of asthma to some extent and it seems influence immune regulation through its effect on CD4+CD25+Treg.%目的 研究血吸虫可溶性虫

  19. 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

  20. 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.

  1. Activation of a heterogeneous hepatitis B (HB) core and e antigen-specific CD4+ T-cell population during seroconversion to anti-HBe and anti-HBs in hepatitis B virus infection.

    OpenAIRE

    Jung, M C; Diepolder, H M; Spengler, U; Wierenga, E A; Zachoval, R; Hoffmann, R M; Eichenlaub, D; Frösner, G; Will, H; Pape, G. R.

    1995-01-01

    Overcoming hepatitis B virus infection essentially depends on the appropriate immune response of the infected host. Among the hepatitis B virus antigens, the core (HBcAg) and e (HBeAg) proteins appear highly immunogenic and induce important lymphocyte effector functions. In order to investigate the importance of HBcAg/HBeAg-specific T lymphocytes in patients with acute and chronic hepatitis B and to identify immunodominant epitopes within the HBcAg/HBeAg, CD4+ T-cell responses to hepatitis B ...

  2. Active treatment of murine tumors with a highly attenuated vaccinia virus expressing the tumor associated antigen 5T4 (TroVax) is CD4+ T cell dependent and antibody mediated.

    Science.gov (United States)

    Harrop, Richard; Ryan, Matthew G; Myers, Kevin A; Redchenko, Irina; Kingsman, Susan M; Carroll, Miles W

    2006-09-01

    5T4 is a tumor associated antigen that is expressed on the surface of a wide spectrum of human adenocarcinomas. The highly attenuated virus, modified vaccinia Ankara, has been engineered to express human 5T4 (h5T4). In a pre-clinical murine model, the recombinant virus (TroVax) induces protection against challenge with CT26-h5T4 (a syngeneic tumor line expressing h5T4). Anti-tumor activity is long lived, with protection still evident 6 months after the final vaccination. In a therapeutic setting, injection of mice with TroVax results in a reduction in tumor burden of >90%. Depletion of CD8+ T cells has no effect upon therapy in the active treatment model, whereas depletion of CD4+ T cells completely abrogates anti-tumor activity. In a prophylactic setting, depletion of CD4+ and CD8+ T cells after the induction of a h5T4 immune response has no deleterious effect on protection following challenge with CT26-h5T4. In light of these studies, the role of antibodies in protection against tumor challenge was investigated. 5T4 specific polyclonal serum decreased tumor burden by approximately 70%. Thus, we conclude that CD4+ T cells are essential for the induction of a protective immune response and that antibodies are the likely effector moiety in this xenogeneic murine tumor model. PMID:16311730

  3. Brugia malayi Antigen (BmA Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells.

    Directory of Open Access Journals (Sweden)

    Emily E I M Mouser

    Full Text Available One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA and excretory-secretory product 62 (ES-62 from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs.

  4. Impact of tuberculosis treatment on CD4 cell count, HIV RNA, and p24 antigen in patients with HIV and tuberculosis

    DEFF Research Database (Denmark)

    Wejse, Christian; Furtado, A; Camara, C;

    2013-01-01

    To describe HIV RNA levels during tuberculosis (TB) infection in patients co-infected with TB and HIV. Moreover, to examine the p24 antigen profile during TB treatment.......To describe HIV RNA levels during tuberculosis (TB) infection in patients co-infected with TB and HIV. Moreover, to examine the p24 antigen profile during TB treatment....

  5. Circulating precursor CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells indicate Tfh cell activity and promote antibody responses upon antigen reexposure.

    Science.gov (United States)

    He, Jing; Tsai, Louis M; Leong, Yew Ann; Hu, Xin; Ma, Cindy S; Chevalier, Nina; Sun, Xiaolin; Vandenberg, Kirsten; Rockman, Steve; Ding, Yan; Zhu, Lei; Wei, Wei; Wang, Changqi; Karnowski, Alexander; Belz, Gabrielle T; Ghali, Joanna R; Cook, Matthew C; Riminton, D Sean; Veillette, André; Schwartzberg, Pamela L; Mackay, Fabienne; Brink, Robert; Tangye, Stuart G; Vinuesa, Carola G; Mackay, Charles R; Li, Zhanguo; Yu, Di

    2013-10-17

    Follicular B helper T (Tfh) cells support high affinity and long-term antibody responses. Here we found that within circulating CXCR5⁺ CD4⁺ T cells in humans and mice, the CCR7(lo)PD-1(hi) subset has a partial Tfh effector phenotype, whereas CCR7(hi)PD-1(lo) cells have a resting phenotype. The circulating CCR7(lo)PD-1(hi) subset was indicative of active Tfh differentiation in lymphoid organs and correlated with clinical indices in autoimmune diseases. Thus the CCR7(lo)PD-1(hi) subset provides a biomarker to monitor protective antibody responses during infection or vaccination and pathogenic antibody responses in autoimmune diseases. Differentiation of both CCR7(hi)PD-1(lo) and CCR7(lo)PD-1(hi) subsets required ICOS and BCL6, but not SAP, suggesting that circulating CXCR5⁺ helper T cells are primarily generated before germinal centers. Upon antigen reencounter, CCR7(lo)PD-1(hi) CXCR5⁺ precursors rapidly differentiate into mature Tfh cells to promote antibody responses. Therefore, circulating CCR7(lo)PD-1(hi) CXCR5⁺ CD4⁺ T cells are generated during active Tfh differentiation and represent a new mechanism of immunological early memory.

  6. 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...

  7. Further characterization of protective Trypanosoma cruzi-specific CD4+ T-cell clones: T helper type 1-like phenotype and reactivity with shed trypomastigote antigens.

    Science.gov (United States)

    Nickell, S P; Keane, M; So, M

    1993-01-01

    We previously reported the isolation from immune mice of a panel of murine clonal T-cell lines which specifically recognize antigens expressed by the trypomastigote stage of the protozoan parasite Trypanosoma cruzi, the causative agent of human Chagas' disease. Our analysis indicated that distinct clones which recognize common as well as strain-specific antigenic determinants were represented. The immunoprotective potential of several of these T-cell clones was demonstrated by adoptive transfer of protection to naive syngeneic recipients. Here we report that these T-cell clones are all of the TH1 phenotype, as determined from their lymphokine secretion patterns. Significant levels of stimulatory activity for each clone were detected in trypomastigote supernatants, and the release of this activity was time and temperature dependent. Seven of 10 T-cell clones tested responded to nitrocellulose-immunoblotted trypomastigote proteins in the range of 90 to 47 kDa; no fewer than six distinct epitopes residing on at least five distinct polypeptide species were recognized by this panel of clones. Two clones (2G8 and 4B10) previously shown to protect in vivo responded to immunoblotted proteins in the range of 65 to 53 and 90 to 80 kD, respectively. Stimulatory activity for the latter clone was shown to be expressed on the surface of trypomastigotes and to bind specifically to wheat germ agglutinin, indicating that its target antigen is an 85-kDa trypomastigote surface glycoprotein. PMID:8335358

  8. 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.

  9. Identification of a type 1 diabetes-associated CD4 promoter haplotype with high constitutive activity

    DEFF Research Database (Denmark)

    Kristiansen, O P; Karlsen, A E; Larsen, Z M;

    2004-01-01

    CD4 is a candidate gene in autoimmune diseases, including Type 1 diabetes mellitus (T1DM), because the CD4 receptor is crucial for appropriate antigen responses of CD4(+) T cells. We previously found linkage between a CD4-1188(TTTTC)(5-14) promoter polymorphism and T1DM. In the present study, we ...

  10. Vaccination with an adenoviral vector encoding the tumor antigen directly linked to invariant chain induces potent CD4(+) T-cell-independent CD8(+) T-cell-mediated tumor control

    DEFF Research Database (Denmark)

    Sorensen, Maria R; Holst, Peter J; Pircher, Hanspeter;

    2009-01-01

    of the vaccine antigen to invariant chain (Ii). To evaluate this strategy we used a mouse model, in which an immunodominant epitope (GP33) of the LCMV glycoprotein (GP) represents the tumor-associated neoantigen. Prophylactic vaccination of C57BL/6 mice with a replication-deficient human adenovirus 5 vector...... vaccination with adenovirus expressing GP alone (Ad-GP), or GP and Ii unlinked (Ad-GP+Ii). Ad-Ii-GP- induced tumor control depended on an improved generation of the tumor-associated neoantigen-specific CD8(+) T-cell response and was independent of CD4(+) T cells. IFN-gamma was shown to be a key player during...

  11. The self-antigen, thyroglobulin, induces antigen-experienced CD4+ T cells from healthy donors to proliferate and promote production of the regulatory cytokine, interleukin-10, by monocytes

    DEFF Research Database (Denmark)

    Nielsen, Claus Kim Hostein; Galdiers, Marcel P; Hedegaard, Chris Juul;

    2010-01-01

    monocytes were prime producers of IL-10 in the early TG response, a few IL-10-secreting CD4(+) T cells, primarily with CD45RO(+) memory phenotype, were also detected. Furthermore, T-cell depletion from the mononuclear cell preparation abrogated monocyte IL-10 production. Our findings indicate active...

  12. The self-antigen, thyroglobulin, induces antigen-experienced CD4+ T cells from healthy donors to proliferate and promote production of the regulatory cytokine, interleukin-10, by monocytes

    DEFF Research Database (Denmark)

    Nielsen, Claus H; Galdiers, Marcel P; Hedegaard, Chris J;

    2010-01-01

    monocytes were prime producers of IL-10 in the early TG response, a few IL-10-secreting CD4(+) T cells, primarily with CD45RO(+) memory phenotype, were also detected. Furthermore, T-cell depletion from the mononuclear cell preparation abrogated monocyte IL-10 production. Our findings indicate active....... Whereas TT induced pro-inflammatory cytokines [interleukin-2 (IL-2)/interferon-gamma (IFN-gamma)/IL-4/IL-5], TG evoked persistent release of the regulatory IL-10. Some donors, however, also responded with late IFN-gamma production, suggesting that the regulation by IL-10 could be overridden. Although...

  13. Synthetic TLR4 agonists enhance functional antibodies and CD4+ T-cell responses against the Plasmodium falciparum GMZ2.6C multi-stage vaccine antigen

    DEFF Research Database (Denmark)

    Baldwin, Susan L; Roeffen, Will; Singh, Susheel K;

    2016-01-01

    , liposomes, and alum) in C57BL/6 mice. Some, but not all, formulations containing either the synthetic TLR4 agonist GLA or SLA elicited the highest parasite-specific antibody titers, the greatest IFN-γ responses in CD4+ TH1 cells, and the highest percentage of multifunctional CD4+ T cells expressing IFN...

  14. HuMax-CD4

    DEFF Research Database (Denmark)

    Skov, Lone; Kragballe, Knud; Zachariae, Claus;

    2003-01-01

    BACKGROUND: Psoriasis is characterized by infiltration with mononuclear cells. Especially activated memory CD4+ T cells are critical in the pathogenesis. Interaction between the CD4 receptor and the major histocompatibility complex class II molecule is important for T-cell activation. OBJECTIVE: To...... dose level, 6 (38%) of 16 patients obtained more than 25% reduction of PASI and 3 (19%) obtained more than 50% reduction of PASI. A dose-dependent decrease in total lymphocyte count was seen and was parallel to a dose-dependent decrease in CD4+ T cells. This decrease was due to a decrease in the memory...

  15. IL-12和CpG疫苗佐剂体内对特异性CD4+T细胞免疫应答的影响%The role of IL-12 and CpG as adjuvants on the immune responses of antigen-specific CD4+T cells in vivo

    Institute of Scientific and Technical Information of China (English)

    杨滨燕; 吴长有

    2005-01-01

    目的:观察IL-12和CpG作为疫苗佐剂在体内促进抗原特异性CD4+T细胞的分化和IFN-γ的产生异同.方法:自CD4+T细胞受体转基因(TCR-Tg)小鼠脾和淋巴结分离CD4+T细胞,体外利用CFSE进行标记,然后被动输给相同基因的正常小鼠.经OVA、OVA+IL-12或OVA+CpG免疫后,观察抗原特异性CD4+T细胞的组织分布,IFN-γ的表达以及与细胞分裂之间的关系.结果:未经OVA抗原免疫的小鼠,抗原特异性CD4+T细胞未见有增殖反应.当经OVA抗原免疫后,可见脾和肺组织中细胞增殖;IFN-γ+细胞在脾脏、淋巴结和肺组织表达的阳性率很低,其范围为0.93%~2.17%.当经OVA+IL-12免疫后,IL-12促进IFN-γ的表达,阳性率为4.53%~26.79%;而经OVA+CpG免疫后,CpG只促进淋巴结中IFN-γ的表达(3.84%).IFN-γ表达的细胞主要为分裂3~5次的细胞.结论:IL-12和CpG作为疫苗佐剂均可促进IFN-γ产生,促进细胞免疫应答.

  16. 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....

  17. Depletion of the surface CD4 molecule by the envelope protein of human immunodeficiency virus expressed in a human CD4+ monocytoid cell line

    International Nuclear Information System (INIS)

    A CD4+ human monocytoid cell line, U937, was transfected with a constructed plasmid which has the envelope gene of human immunodeficiency virus under the transcriptional control of the human metallothionein IIA promoter and was cloned thereafter. These cloned cell lines (EH and EL cells) expressed the viral gp160 in the cytoplasm. The expression of surface CD4 antigen examined by Leu3a and OKT4 monoclonal antibodies, however, disappeared completely in EH cells, which produce a larger amount of gp160, while diminishing only partly in EL cells, which produce a smaller amount of gp160. These results indicate that the level of expression of surface CD4 antigen correlates inversely with the amount of intracellular gp160. Moreover, immunoprecipitation studies using lysate from EH cells showed that OKT4 monoclonal antibody precipitated a significant number of CD4 molecules even after surface CD4 disappeared. However, Leu3a monoclonal antibody, which recognizes the binding site for envelope protein, could not precipitate any CD4 molecules in the same cell lysate. Taken together, these results suggested that CD4 molecules are still synthesized normally after the augmented production of gp160 in the cells but form a complex with the envelope protein in the cytoplasm and become unable to be transported to the cell surface, resulting in the observed depletion of surface CD4 antigen. This mechanism may explain the decrease or absence of surface CD4 antigens in human lymphocytes infected with human immunodeficiency virus

  18. Antibody-targeted NY-ESO-1 to mannose receptor or DEC-205 in vitro elicits dual human CD8+ and CD4+ T cell responses with broad antigen specificity.

    Science.gov (United States)

    Tsuji, Takemasa; Matsuzaki, Junko; Kelly, Marcus P; Ramakrishna, Venky; Vitale, Laura; He, Li-Zhen; Keler, Tibor; Odunsi, Kunle; Old, Lloyd J; Ritter, Gerd; Gnjatic, Sacha

    2011-01-15

    Immunization of cancer patients with vaccines containing full-length tumor Ags aims to elicit specific Abs and both CD4(+) and CD8(+) T cells. Vaccination with protein Ags, however, often elicits only CD4(+) T cell responses without inducing Ag-specific CD8(+) T cells, as exogenous protein is primarily presented to CD4(+) T cells. Recent data revealed that Ab-mediated targeting of protein Ags to cell surface receptors on dendritic cells could enhance the induction of both CD4(+) and CD8(+) T cells. We investigated in this study if these observations were applicable to NY-ESO-1, a cancer-testis Ag widely used in clinical cancer vaccine trials. We generated two novel targeting proteins consisting of the full-length NY-ESO-1 fused to the C terminus of two human mAbs against the human mannose receptor and DEC-205, both internalizing molecules expressed on APC. These targeting proteins were evaluated for their ability to activate NY-ESO-1-specific human CD4(+) and CD8(+) T cells in vitro. Both targeted NY-ESO-1 proteins rapidly bound to their respective targets on APC. Whereas nontargeted and Ab-targeted NY-ESO-1 proteins similarly activated CD4(+) T cells, cross-presentation to CD8(+) T cells was only efficiently induced by targeted NY-ESO-1. In addition, both mannose receptor and DEC-205 targeting elicited specific CD4(+) and CD8(+) T cells from PBLs of cancer patients. Receptor-specific delivery of NY-ESO-1 to APC appears to be a promising vaccination strategy to efficiently generate integrated and broad Ag-specific immune responses against NY-ESO-1 in cancer patients.

  19. APL1, an altered peptide ligand derived from human heat-shock protein 60, increases the frequency of Tregs and its suppressive capacity against antigen responding effector CD4 + T cells from rheumatoid arthritis patients.

    Science.gov (United States)

    Barberá, Ariana; Lorenzo, Noraylis; van Kooten, Peter; van Roon, Joel; de Jager, Wilco; Prada, Dinorah; Gómez, Jorge; Padrón, Gabriel; van Eden, Willem; Broere, Femke; Del Carmen Domínguez, María

    2016-07-01

    Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by a chronic relapsing-remitting joint inflammation. Perturbations in the balance between CD4 + T cells producing IL-17 and CD4 + CD25(high)FoxP3 + Tregs correlate with irreversible bone and cartilage destruction in RA. APL1 is an altered peptide ligand derived from a CD4+ T-cell epitope of human HSP60, an autoantigen expressed in the inflamed synovium, which increases the frequency of CD4 + CD25(high)FoxP3+ Tregs in peripheral blood mononuclear cells from RA patients. The aim of this study was to evaluate the suppressive capacity of Tregs induced by APL1 on proliferation of effector CD4+ T cells using co-culture experiments. Enhanced Treg-mediated suppression was observed in APL1-treated cultures compared with cells cultured only with media. Subsequent analyses using autologous cross-over experiments showed that the enhanced Treg suppression in APL1-treated cultures could reflect increased suppressive function of Tregs against APL1-responsive T cells. On the other hand, APL1-treatment had a significant effect reducing IL-17 levels produced by effector CD4+ T cells. Hence, this peptide has the ability to increase the frequency of Tregs and their suppressive properties whereas effector T cells produce less IL-17. Thus, we propose that APL1 therapy could help to ameliorate the pathogenic Th17/Treg balance in RA patients. PMID:27241313

  20. Natural autoantibodies and complement promote the uptake of a self antigen, human thyroglobulin, by B cells and the proliferation of thyroglobulin-reactive CD4(+) T cells in healthy individuals

    DEFF Research Database (Denmark)

    Nielsen, C H; Leslie, R G; Jepsen, B S;

    2001-01-01

    of complement receptor types 1 (CR1, CD35) and 2 (CR2, CD21). T cell responsiveness to Tg was examined in a preparation of peripheral blood mononuclear cells (PBMC) cultured in the presence of autologous serum. A subset of CD4(+) T cells exhibited a dose-dependent proliferative response to Tg, which...

  1. 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....

  2. File list: ALL.Bld.10.AllAg.CD4-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.10.AllAg.CD4-Positive_T-Lymphocytes hg19 All antigens Blood CD4-Positive T-...16 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Bld.10.AllAg.CD4-Positive_T-Lymphocytes.bed ...

  3. File list: ALL.Bld.10.AllAg.CD4-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.10.AllAg.CD4-Positive_T-Lymphocytes mm9 All antigens Blood CD4-Positive T-L...SRX832476,SRX832474,SRX832478,SRX832479,SRX832475 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Bld.10.AllAg.CD4-Positive_T-Lymphocytes.bed ...

  4. File list: ALL.Bld.20.AllAg.CD4-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.20.AllAg.CD4-Positive_T-Lymphocytes hg19 All antigens Blood CD4-Positive T-...31 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Bld.20.AllAg.CD4-Positive_T-Lymphocytes.bed ...

  5. File list: ALL.Bld.05.AllAg.CD4-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  6. File list: ALL.Bld.50.AllAg.CD4-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  7. File list: ALL.Bld.05.AllAg.CD4-Positive_T-Lymphocytes [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.05.AllAg.CD4-Positive_T-Lymphocytes hg19 All antigens Blood CD4-Positive T-...99 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/ALL.Bld.05.AllAg.CD4-Positive_T-Lymphocytes.bed ...

  8. Interleukin 1-induced down-regulation of antibody binding to CD4 molecules on human lymphocytes

    DEFF Research Database (Denmark)

    Tvede, N; Christensen, L D; Ødum, Niels;

    1988-01-01

    Interleukin 1 (IL-1) is involved in the early activation of T lymphocytes. The CD4 antigen, described as a phenotypic marker of helper T cells, is also important in early T-cell activation by its ability to bind to MHC class II molecules on antigen-presenting cells, and to transmit positive (and......+ cells. Under optimal growth conditions, the initial reduction in antibody binding to CD4 was followed by an apparent re-expression of the CD4 antigen even in the presence of high concentrations of IL-1. This re-expression did not occur if the cells were cultured at 4 degrees C, or after treatment...

  9. 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.

  10. Production of Primary Human CD4+ T Cell Lines and Clones

    OpenAIRE

    Matthis, Jessica; Reijonen, Helena

    2013-01-01

    Tetramer staining of CD4+ T cells is a valuable technique in immunology for detecting rare auto-reactive T cells. Generating clones or cell lines from auto-antigen tetramer positive CD4+ T cells allows further characterization and phenotyping of auto-reactive cells.

  11. Reactivity of naive CD4+CD25- T cells against gut microflora in healthy mice

    DEFF Research Database (Denmark)

    Gad, Monika; Lundsgaard, Dorthe; Kjellev, Stine;

    2006-01-01

    We have previously shown that conventional as well as germ-free CD4+ T cells depleted of CD25+ cells from the gut-associated lymphoid tissue and the periphery proliferate specifically in response to enterobacterial antigen exposure whereas unfractionated CD4+ T cells are not reactive under these ...

  12. Multifunctional CD4 T Cell Responses in Patients with Active Tuberculosis

    OpenAIRE

    Qiu, Zhengang; Zhang, Mingxia; Zhu, Yuzhen; Zheng, Feiqun; Lu, Puxuan; Liu, Haiying; Michael W Graner; Zhou, Boping; Chen, Xinchun

    2012-01-01

    The roles of multifunctional CD4 T cells in human tuberculosis are not well defined. In this study, we found that patients with tuberculosis had decreased PMA/ionomycin stimulated multifunctional CD4 T cells, and increased Mycobacterium tuberculosis antigen-specific multifunctional CD4 T cells, when compared to individuals with latent tuberculosis infection and healthy controls. PMA/ionomycin stimulated IFN-γ+IL-2+TNF-α+ CD4 T cell responses were decreased in patients with smear-positive tube...

  13. HIV-1 induces DCIR expression in CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Alexandra A Lambert

    Full Text Available The C-type lectin receptor DCIR, which has been shown very recently to act as an attachment factor for HIV-1 in dendritic cells, is expressed predominantly on antigen-presenting cells. However, this concept was recently challenged by the discovery that DCIR can also be detected in CD4(+ T cells found in the synovial tissue from rheumatoid arthritis (RA patients. Given that RA and HIV-1 infections share common features such as a chronic inflammatory condition and polyclonal immune hyperactivation status, we hypothesized that HIV-1 could promote DCIR expression in CD4(+ T cells. We report here that HIV-1 drives DCIR expression in human primary CD4(+ T cells isolated from patients (from both aviremic/treated and viremic/treatment naive persons and cells acutely infected in vitro (seen in both virus-infected and uninfected cells. Soluble factors produced by virus-infected cells are responsible for the noticed DCIR up-regulation on uninfected cells. Infection studies with Vpr- or Nef-deleted viruses revealed that these two viral genes are not contributing to the mechanism of DCIR induction that is seen following acute infection of CD4(+ T cells with HIV-1. Moreover, we report that DCIR is linked to caspase-dependent (induced by a mitochondria-mediated generation of free radicals and -independent intrinsic apoptotic pathways (involving the death effector AIF. Finally, we demonstrate that the higher surface expression of DCIR in CD4(+ T cells is accompanied by an enhancement of virus attachment/entry, replication and transfer. This study shows for the first time that HIV-1 induces DCIR membrane expression in CD4(+ T cells, a process that might promote virus dissemination throughout the infected organism.

  14. CD4+CD25hiFOXP3+ cells in cord blood of neonates born from filaria infected mother are negatively associated with CD4+Tbet+ and CD4+RORγt+ T cells.

    Directory of Open Access Journals (Sweden)

    Ulysse Ateba-Ngoa

    Full Text Available BACKGROUND: Children who have been exposed in utero to maternal filarial infection are immunologically less responsive to filarial antigens, have less pathology, and are more susceptible to acquire infection than offspring of uninfected mothers. Moreover children from filaria infected mothers have been shown to be less responsive to vaccination as a consequence of an impairment of their immune response. However, it is not well known how in utero exposure to parasite antigens affects cellular immune responses. METHODOLOGY: Here, 30 pregnant women were examined for the presence of microfilaria of Loa loa and Mansonella perstans in peripheral blood. At delivery, cord blood mononuclear cells (CBMC were obtained and the CD4+T cells were phenotyped by expression of the transcription factors Tbet, RORγt, and FOXP3. RESULTS: No significant difference was observed between newborns from infected versus uninfected mothers in the frequencies of total CD4+T cells and CD4+T cells subsets including CD4+Tbet+, CD4+RORγt+ T and CD4+CD25hiFOXP3+ T cells. However, there was a negative association between CD4+CD25hiFOXP3+T cells and CD4+Tbet+ as well as CD4+RORγt+ T cells in the infected group only (B = -0.242, P = 0.002; B = -0.178, P = 0.013 respectively. CONCLUSION: Our results suggest that filarial infection during pregnancy leads to an expansion of functionally active regulatory T cells that keep TH1 and TH17 in check.

  15. CD4-regulatory cells in COPD patients

    DEFF Research Database (Denmark)

    Smyth, Lucy J C; Starkey, Cerys; Vestbo, Jørgen;

    2007-01-01

    BACKGROUND: The numbers of airway CD8 and B lymphocytes are increased in COPD patients, suggesting an autoimmune process. CD4-regulatory T cells control autoimmunity but have not been studied in patients with COPD. OBJECTIVE: To compare T-regulatory cell numbers in the BAL from COPD patients......, smokers with normal lung function, and healthy nonsmokers (HNS). METHODS: BAL and peripheral blood mononuclear cell (PBMC) samples were obtained from 26 COPD patients, 19 smokers, and 8 HNS. Flow cytometry was performed for regulatory phenotypic markers. RESULTS: COPD patients had increased BAL CD8...... numbers compared to smokers and HNS. CD4 numbers were similar between groups. There was increased BAL CD4CD25(bright) expression in smokers (median 28.8%) and COPD patients (median 23.1%) compared to HNS (median 0%). Increased FoxP3 expression was confirmed in BAL CD4CD25(bright) cells. BAL CD4CD25 cells...

  16. 妊娠期父源抗原特异性激活调节性T细胞的研究%Study on role of paternal antigens-specific CD4+CD25+T regulatory cells during pregnancy

    Institute of Scientific and Technical Information of China (English)

    屠海燕; 寿张飞

    2016-01-01

    Objective To investigate that the pregnancy induced T regulatory (Treg) cells are generated by aiming at pa-ternal antigens or induced by in vivo hormone change. Methods The 4 mice model groups were set up:normal pregnancy(n=15), abortion trend(n=15),third party mating(n=15) and false pregnancy(n=6). The change of Treg cells level and hormone content were observed. The Treg cells originated from paternal antigen premunity mice was adoptively instilled into the pregnant mice by the antigens-specific verification for observing its protective effect on embryonic mouse. Results The in vivo progesterone,E2 and E3 levels had no statistical differences between the abortion trend group and the normal pregnancy group (P>0.05). After in-stilling Treg cells of paternal antigen specific activation or adoptive transfer paternal antigens-specific Treg cells,the abortion rate of pregnant mice was decreased,while Treg cells level was increased. Conclusion The Treg cell amplification playing the pro-tective role during pregnancy is paternal antigens specific activation ,which is not caused by the single hormone content change.%目的:探讨妊娠诱导调节性T细胞扩增与父源抗原的关系。方法建立正常妊娠(n=15)、流产倾向(n=15)、第三方交配(n=15)及假孕(n=6)共四组小鼠模型,观察调节性T细胞水平和激素含量变化。通过抗原特异性验证将父源抗原预免疫小鼠来源的调节性T细胞过继滴注到孕鼠体内,观察其对胚鼠的保护作用。结果流产倾向组与正常妊娠组孕鼠体内黄体酮、雌二醇、雌三醇水平比较,差异均无统计学意义(P>0.05)。滴注父源抗原特异性激活调节性T细胞或经父源抗原预免疫的调节性T细胞后,孕鼠流产率下降,调节性T细胞水平升高。结论妊娠期调节性T细胞扩增发挥保护作用的是父源抗原特异性激活,并非单一激素含量变化引起。

  17. File list: ALL.Bld.20.AllAg.CD4_CD8_double_negative_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  3. File list: ALL.Bld.50.AllAg.CD4_CD8_double_positive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

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  4. File list: ALL.Bld.05.AllAg.CD4_CD8_double_positive_cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ALL.Bld.05.AllAg.CD4_CD8_double_positive_cells mm9 All antigens Blood CD4 CD8 double...X692962,SRX692956 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/ALL.Bld.05.AllAg.CD4_CD8_double_positive_cells.bed ...

  5. Temporal expression of bacterial proteins instructs host CD4 T cell expansion and Th17 development.

    Directory of Open Access Journals (Sweden)

    Seung-Joo Lee

    2012-01-01

    Full Text Available Pathogens can substantially alter gene expression within an infected host depending on metabolic or virulence requirements in different tissues, however, the effect of these alterations on host immunity are unclear. Here we visualized multiple CD4 T cell responses to temporally expressed proteins in Salmonella-infected mice. Flagellin-specific CD4 T cells expanded and contracted early, differentiated into Th1 and Th17 lineages, and were enriched in mucosal tissues after oral infection. In contrast, CD4 T cells responding to Salmonella Type-III Secretion System (TTSS effectors steadily accumulated until bacterial clearance was achieved, primarily differentiated into Th1 cells, and were predominantly detected in systemic tissues. Thus, pathogen regulation of antigen expression plays a major role in orchestrating the expansion, differentiation, and location of antigen-specific CD4 T cells in vivo.

  6. 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 (...

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

    Science.gov (United States)

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

    2011-01-01

    SUMMARY 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 (200 μg) of a murine anti-mouse CD4 monoclonal IgG (clone GK1·5). CD4+ T-cell-depleted hamsters infected with the hookworm Ancylostoma ceylanicum exhibited a threefold higher mean intestinal worm burden and more severe anaemia than animals that received isotype control IgG. In addition, depletion of CD4+ T cells was associated with impaired cellular and humoral (serum and mucosal) immune responses to hookworm antigens. These data demonstrate an effector role for CD4+ T cells in hookworm immunity and disease pathogenesis. Ultimately, these studies may yield important insights into the relationship between intestinal nematode infections and diseases that are associated with CD4+ T-cell depletion, including HIV. PMID:20500671

  8. Predicting AIDS-related events using CD4 percentage or CD4 absolute counts

    Directory of Open Access Journals (Sweden)

    Donabedian Haig

    2006-08-01

    Full Text Available Abstract Background The extent of immunosuppression and the probability of developing an AIDS-related complication in HIV-infected people is usually measured by the absolute number of CD4 positive T-cells. The percentage of CD4 positive cells is a more easily measured and less variable number. We analyzed sequential CD4 and CD8 numbers, percentages and ratios in 218 of our HIV infected patients to determine the most reliable predictor of an AIDS-related event. Results The CD4 percentage was an unsurpassed predictor of the occurrence of AIDS-related events when all subsets of patients are considered. The CD4 absolute count was the next most reliable, followed by the ratio of CD4/CD8 percentages. The value of CD4 percentage over the CD4 absolute count was seen even after the introduction of highly effective HIV therapy. Conclusion The CD4 percentage is unsurpassed as a parameter for predicting the onset of HIV-related diseases. The extra time and expense of measuring the CD4 absolute count may be unnecessary.

  9. Antiretroviral therapy suppressed participants with low CD4+ T-cell counts segregate according to opposite immunological phenotypes

    Science.gov (United States)

    Pérez-Santiago, Josué; Ouchi, Dan; Urrea, Victor; Carrillo, Jorge; Cabrera, Cecilia; Villà-Freixa, Jordi; Puig, Jordi; Paredes, Roger; Negredo, Eugènia; Clotet, Bonaventura; Massanella, Marta; Blanco, Julià

    2016-01-01

    Background: The failure to increase CD4+ T-cell counts in some antiretroviral therapy suppressed participants (immunodiscordance) has been related to perturbed CD4+ T-cell homeostasis and impacts clinical evolution. Methods: We evaluated different definitions of immunodiscordance based on CD4+ T-cell counts (cutoff) or CD4+ T-cell increases from nadir value (ΔCD4) using supervised random forest classification of 74 immunological and clinical variables from 196 antiretroviral therapy suppressed individuals. Unsupervised clustering was performed using relevant variables identified in the supervised approach from 191 individuals. Results: Cutoff definition of CD4+ cell count 400 cells/μl performed better than any other definition in segregating immunoconcordant and immunodiscordant individuals (85% accuracy), using markers of activation, nadir and death of CD4+ T cells. Unsupervised clustering of relevant variables using this definition revealed large heterogeneity between immunodiscordant individuals and segregated participants into three distinct subgroups with distinct production, programmed cell-death protein-1 (PD-1) expression, activation and death of T cells. Surprisingly, a nonnegligible number of immunodiscordant participants (22%) showed high frequency of recent thymic emigrants and low CD4+ T-cell activation and death, very similar to immunoconcordant participants. Notably, human leukocyte antigen - antigen D related (HLA-DR) PD-1 and CD45RA expression in CD4+ T cells allowed reproducing subgroup segregation (81.4% accuracy). Despite sharp immunological differences, similar and persistently low CD4+ values were maintained in these participants over time. Conclusion: A cutoff value of CD4+ T-cell count 400 cells/μl classified better immunodiscordant and immunoconcordant individuals than any ΔCD4 classification. Immunodiscordance may present several, even opposite, immunological patterns that are identified by a simple immunological follow-up. Subgroup

  10. 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....

  11. The Differentiation and Protective Function of Cytolytic CD4 T Cells in Influenza Infection

    Directory of Open Access Journals (Sweden)

    Deborah M. Brown

    2016-03-01

    Full Text Available CD4 T cells that recognize peptide antigen in the context of Class II MHC can differentiate into various subsets that are characterized by their helper functions. However, increasing evidence indicates that CD4 cells with direct cytolytic activity (CD4 CTL play a role in chronic, as well as, acute infections such as influenza A virus (IAV infection. In the last couple of decades, techniques to measure the frequency and activity of these cytolytic cells has demonstrated their abundance in infections such as HIV, mouse pox, murine gamma herpes virus, CMV, EBV and influenza among others. We now appreciate a greater role for CD4 CTL as direct effectors in viral infections and anti-tumor immunity through their ability to acquire perforin mediated cytolytic activity and contribution to lysis of virally infected targets or tumors. As early as the 1980s, CD4 T cell clones with cytolytic potential were identified after influenza virus infection, yet much of this early work was dependent on in vitro culture and little was known about the physiological relevance of CD4 CTL. Here, we discuss the direct role CD4 CTL play in protection against lethal IAV infection and the factors that drive the generation of perforin mediated lytic activity in CD4 cells in vivo during IAV infection. While focusing on CD4 CTL generated during IAV infection, we pull comparisons from the literature in other anti-viral and anti-tumor systems. Further, we highlight what is currently known about CD4 CTL secondary and memory responses, as well as vaccination strategies to induce these potent killer cells that provide an extra layer of cell mediated immune protection against heterosubtypic IAV infection.

  12. Involvement of CD244 in regulating CD4+ T cell immunity in patients with active tuberculosis.

    Directory of Open Access Journals (Sweden)

    Bingfen Yang

    Full Text Available CD244 (2B4 is a member of the signaling lymphocyte activation molecule (SLAM family of immune cell receptors and it plays an important role in modulating NK cell and CD8(+ T cell immunity. In this study, we investigated the expression and function of CD244/2B4 on CD4(+ T cells from active TB patients and latent infection individuals. Active TB patients had significantly elevated CD244/2B4 expression on M. tuberculosis antigen-specific CD4(+ T cells compared with latent infection individuals. The frequencies of CD244/2B4-expressing antigen-specific CD4(+ T cells were significantly higher in retreatment active TB patients than in new active TB patients. Compared with CD244/2B4-dull and -middle CD4(+ T cells, CD244/2B4-bright CD4(+ T cell subset had significantly reduced expression of IFN-γ, suggesting that CD244/2B4 expression may modulate IFN-γ production in M. tuberculosis antigen-responsive CD4(+ T cells. Activation of CD244/2B4 signaling by cross-linking led to significantly decreased production of IFN-γ. Blockage of CD244/2B4 signaling pathway of T cells from patients with active TB resulted in significantly increased production of IFN-γ, compared with isotype antibody control. In conclusion, CD244/2B4 signaling pathway has an inhibitory role on M. tuberculosis antigen-specific CD4(+ T cell function.

  13. Cd4As2Br3

    Directory of Open Access Journals (Sweden)

    Mohammed Kars

    2014-03-01

    Full Text Available Single crystals of Cd4As2Br3 (tetracadmium biarsenide tribromide were grown by a chemical transport reaction. The structure is isotypic with the members of the cadmium and mercury pnictidohalides family with general formula M4A2X3 (M = Cd, Hg; A = P, As, Sb; X = Cl, Br, I and contains two independent As atoms on special positions with site symmetry -3 and two independent Cd atoms, of which one is on a special position with site symmetry -3. The Cd4As2Br3 structure consists of AsCd4 tetrahedra sharing vertices with isolated As2Cd6 octahedra that contain As–As dumbbells in the centre of the octahedron. The Br atoms are located in the voids of this three-dimensional arrangement and bridge the different polyhedra through Cd...Br contacts.

  14. Idiopathic CD4 lymphocytopenia with sensorimotor polyneuropathy.

    Science.gov (United States)

    Puri, Vinod; Duggal, Ashish Kumar; Chaudhry, Neera

    2016-01-01

    A, 21-years-old, male, presented with acute onset, gradually progressive, predominantly distal, symmetrical weakness of both upper and lower limbs with arreflexia. He had impaired sensations in glove and stocking distribution with distal gradient. He was found to have absolute CD4 + cell count of 188 cells/μL, absolute CD8 cell count, 532 cells/μL and CD4: CD8 ratio of 0.35. Electrophysiology revealed reduced to absent CMAP amplitude as well as SNAPs in various nerves of upper and lower limbs, along with normal conduction velocity and normal F wave latencies. Pattern evoked visual potentials were prolonged, on both sides, P100 being 130 ms, on right and 108 ms, on left side. In the follow up of 2 years, he showed spontaneous but gradual clinical improvement but his electrophysiological parameters as well as CD 4+ cells count did not show any significant improvement. PMID:27570393

  15. Idiopathic CD4 lymphocytopenia with sensorimotor polyneuropathy

    Directory of Open Access Journals (Sweden)

    Vinod Puri

    2016-01-01

    Full Text Available A, 21-years-old, male, presented with acute onset, gradually progressive, predominantly distal, symmetrical weakness of both upper and lower limbs with arreflexia. He had impaired sensations in glove and stocking distribution with distal gradient. He was found to have absolute CD4 + cell count of 188 cells/μL, absolute CD8 cell count, 532 cells/μL and CD4: CD8 ratio of 0.35. Electrophysiology revealed reduced to absent CMAP amplitude as well as SNAPs in various nerves of upper and lower limbs, along with normal conduction velocity and normal F wave latencies. Pattern evoked visual potentials were prolonged, on both sides, P100 being 130 ms, on right and 108 ms, on left side. In the follow up of 2 years, he showed spontaneous but gradual clinical improvement but his electrophysiological parameters as well as CD 4+ cells count did not show any significant improvement.

  16. Reconstitution of CD4 T Cells in Bronchoalveolar Lavage Fluid after Initiation of Highly Active Antiretroviral Therapy▿

    Science.gov (United States)

    Knox, Kenneth S.; Vinton, Carol; Hage, Chadi A.; Kohli, Lisa M.; Twigg, Homer L.; Klatt, Nichole R.; Zwickl, Beth; Waltz, Jeffrey; Goldman, Mitchell; Douek, Daniel C.; Brenchley, Jason M.

    2010-01-01

    The massive depletion of gastrointestinal-tract CD4 T cells is a hallmark of the acute phase of HIV infection. In contrast, the depletion of the lower-respiratory-tract mucosal CD4 T cells as measured in bronchoalveolar lavage (BAL) fluid is more moderate and similar to the depletion of CD4 T cells observed in peripheral blood (PB). To understand better the dynamics of disease pathogenesis and the potential for the reconstitution of CD4 T cells in the lung and PB following the administration of effective antiretroviral therapy, we studied cell-associated viral loads, CD4 T-cell frequencies, and phenotypic and functional profiles of antigen-specific CD4 T cells from BAL fluid and blood before and after the initiation of highly active antiretroviral therapy (HAART). The major findings to emerge were the following: (i) BAL CD4 T cells are not massively depleted or preferentially infected by HIV compared to levels for PB; (ii) BAL CD4 T cells reconstitute after the initiation of HAART, and their infection frequencies decrease; (iii) BAL CD4 T-cell reconstitution appears to occur via the local proliferation of resident BAL CD4 T cells rather than redistribution; and (iv) BAL CD4 T cells are more polyfunctional than CD4 T cells in blood, and their functional profile is relatively unchanged after the initiation of HAART. Taken together, these data suggest mechanisms for mucosal CD4 T-cell depletion and interventions that might aid in the reconstitution of mucosal CD4 T cells. PMID:20610726

  17. Adoptive immunotherapy of cancer with polyclonal, 108-fold hyperexpanded, CD4+ and CD8+ T cells

    Directory of Open Access Journals (Sweden)

    Kim Julian A

    2004-11-01

    Full Text Available Abstract T cell-mediated cancer immunotherapy is dose dependent and optimally requires participation of antigen-specific CD4+ and CD8+ T cells. Here, we isolated tumor-sensitized T cells and activated them in vitro using conditions that led to greater than 108-fold numerical hyperexpansion of either the CD4+ or CD8+ subset while retaining their capacity for in vivo therapeutic efficacy. Murine tumor-draining lymph node (TDLN cells were segregated to purify the CD62Llow subset, or the CD4+ subset thereof. Cells were then propagated through multiple cycles of anti-CD3 activation with IL-2 + IL-7 for the CD8+ subset, or IL-7 + IL-23 for the CD4+ subset. A broad repertoire of TCR Vβ families was maintained throughout hyperexpansion, which was similar to the starting population. Adoptive transfer of hyper-expanded CD8+ T cells eliminated established pulmonary metastases, in an immunologically specific fashion without the requirement for adjunct IL-2. Hyper-expanded CD4+ T cells cured established tumors in intracranial or subcutaneous sites that were not susceptible to CD8+ T cells alone. Because accessibility and antigen presentation within metastases varies according to anatomic site, maintenance of a broad repertoire of both CD4+ and CD8+ T effector cells will augment the overall systemic efficacy of adoptive immunotherapy.

  18. CD4~+Foxp3~+ regulatory T cells converted by rapamycin from peripheral CD4~+ CD25~-naive T cells display more potent regulatory ability in vitro

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-fei; GAO Jie; ZHANG Dong; WANG Zi-han; ZHU Ji-ye

    2010-01-01

    Background Rapamycin (RAPA) is a relatively new immunosuppressant drug that functions as a serine/threonine kinase inhibitor to prevent rejection in organ transplantation. RAPA blocks activation of T-effector (Teff) cells by inhibiting the response to interleukin-2. Recently, RAPA was also shown to selectively expand the T-regulator (Treg) cell population. To date, no studies have examined the mechanism by which RAPA converts Teff cells to Treg cells. Methods Peripheral CD4~+CD25~- naive T cells were cultivated with RAPA and B cells as antigen-presenting cells (APCs) in vitro. CD4~+CD25~- T cells were harvested after 6 days and analyzed for expression of forkhead box protein 3 (Foxp3) using flow cytometry. CD4~+CD25~+CD127~- subsets as the converted Tregs were isolated from the mixed lymphocyte reactions (MLR) with CD127 negative selection, followed by CD4 and CD25 positive selection using microbeads and magnetic separation column (MSC). Moreover, mRNA was extracted from converted Tregs and C57BL/6 naive CD4~+CD25~+ T cells and Foxp3 levels were examined by quantitative real-time polymerase chain reaction (rt-PCR). A total of 1×10~5 carboxyfluorescein succinimidyl ester (CFSE)-labeled naive CD4~+CD25~- T cells/well from C57BL/6 mice were cocultured with DBA/2 or C3H maturation of dendritic cells (mDCs) (0.25×10~5/well) in 96-well round-bottom plates for 6 days. Then 1×10~5 or 0.25×10~5 converted Treg cells were added to every well as regulatory cells. Cells were harvested after 6 days of culture and analyzed for proliferation of CFSE-labeled naive CD4~+CD25~- T cells using flow cytometry. Data were analyzed using CellQuest software.Results We found that RAPA can convert peripheral CD4~+CD25~- naive T Cells to CD4~+Foxp3~+ Treg cells using B cells as APCs, and this subtype of Treg can potently suppress Teff proliferation and maintain antigenic specificity. Conclusion Our findings provide evidence that RAPA induces Treg cell conversion from Teff cells and

  19. Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

    International Nuclear Information System (INIS)

    Highlights: ► Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. ► We hypothesize that CD4i antibodies could induce conformational changes in gp120. ► CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. ► CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

  20. How do CD4+ T cells detect and eliminate tumor cells that either lack or express MHC class II molecules?

    Directory of Open Access Journals (Sweden)

    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.

  1. Surface membrane CD4 turnover in phorbol ester stimulated T-lymphocytes. Evidence of degradation and increased synthesis

    DEFF Research Database (Denmark)

    Møller, B K; Andresen, B S; Christensen, E I;

    1990-01-01

    Down-regulation of surface membrane CD4 (smCD4) in phorbol ester stimulated T-cells resulted from internalization. Internalization (T1/2 = 15 min at 50 ng PMA/ml) was followed by degradation of CD4-bound antibodies. Degradation in unstimulated T-cells was comparatively insignificant. Release of d...... than recycling contributed to an accelerated smCD4 turnover in activated cells.......Down-regulation of surface membrane CD4 (smCD4) in phorbol ester stimulated T-cells resulted from internalization. Internalization (T1/2 = 15 min at 50 ng PMA/ml) was followed by degradation of CD4-bound antibodies. Degradation in unstimulated T-cells was comparatively insignificant. Release...... of degradation products was PMA dose-dependent and could be inhibited by methylamine. Uptake and degradation continued after maximal down-regulation of surface membrane CD4, and methylamine did not inhibit reappearance of smCD4 antigens. Metabolic labelling of T-cells further showed that ongoing synthesis rather...

  2. Memory CD4+ T cells do not induce graft-versus-host disease.

    Science.gov (United States)

    Anderson, Britt E; McNiff, Jennifer; Yan, Jun; Doyle, Hester; Mamula, Mark; Shlomchik, Mark J; Shlomchik, Warren D

    2003-07-01

    Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality in allogeneic stem cell transplantation (alloSCT). Donor T cells that accompany stem cell grafts cause GVHD by attacking recipient tissues; therefore, all patients receive GVHD prophylaxis by depletion of T cells from the allograft or through immunosuppressant drugs. In addition to providing a graft-versus-leukemia effect, donor T cells are critical for reconstituting T cell-mediated immunity. Ideally, immunity to infectious agents would be transferred from donor to host without GVHD. Most donors have been exposed to common pathogens and have an increased precursor frequency of memory T cells against pathogenic antigens. We therefore asked whether memory CD62L-CD44+ CD4+ T cells would induce less GVHD than unfractionated or naive CD4+ T cells. Strikingly, we found that memory CD4 cells induced neither clinical nor histologic GVHD. This effect was not due to the increased number of CD4+CD25+ regulatory T cells found in the CD62L-CD44+ fraction because memory T cells depletion of these cells did not cause GVHD. Memory CD4 cells engrafted and responded to antigen both in vivo and in vitro. If these murine results are applicable to human alloSCT, selective administration of memory T cells could greatly improve post-transplant immune reconstitution.

  3. CD4+ T cell effects on CD8+ T cell location defined using bioluminescence.

    Directory of Open Access Journals (Sweden)

    Mitra Azadniv

    Full Text Available T lymphocytes of the CD8+ class are critical in delivering cytotoxic function and in controlling viral and intracellular infections. These cells are "helped" by T lymphocytes of the CD4+ class, which facilitate their activation, clonal expansion, full differentiation and the persistence of memory. In this study we investigated the impact of CD4+ T cells on the location of CD8+ T cells, using antibody-mediated CD4+ T cell depletion and imaging the antigen-driven redistribution of bioluminescent CD8+ T cells in living mice. We documented that CD4+ T cells influence the biodistribution of CD8+ T cells, favoring their localization to abdominal lymph nodes. Flow cytometric analysis revealed that this was associated with an increase in the expression of specific integrins. The presence of CD4+ T cells at the time of initial CD8+ T cell activation also influences their biodistribution in the memory phase. Based on these results, we propose the model that one of the functions of CD4+ T cell "help" is to program the homing potential of CD8+ T cells.

  4. Methodologies for the analysis of HCV-specific CD4+ T cells

    Directory of Open Access Journals (Sweden)

    Megha eLokhande

    2015-02-01

    Full Text Available Virus-specific CD4+ T cells play a major role in viral infections, such as hepatitis C virus (HCV. Viral clearance is associated with vigorous and multispecific CD4+ T cell responses, while chronic infection has been shown to be associated with weak or absent T cell responses. Most of these studies have used functional assays to analyse virus-specific CD4+ T cell responses; however, these and other detection methods have various limitations. Therefore, the important question of whether virus-specific CD4+ T cells are completely absent or primarily impaired in specific effector functions during chronic infection, has yet to be analysed in detail. A novel assay, in which virus-specific CD4+ T cell frequencies can be determined by de novo CD154 (CD40 ligand expression in response to viral antigens, can help to overcome some of the limitations of functional assays and restrictions of multimer-based methods. This and other current established methods for the detection of HCV-specific CD4+ T cells will be discussed in this review.

  5. Naturally Occurring Self-Reactive CD4+CD25+ Regulatory T Cells: Universal Immune Code

    Institute of Scientific and Technical Information of China (English)

    Nafiseh Pakravan; Agheel Tabar Molla Hassan; Zuhair Muhammad Hassan

    2007-01-01

    Naturally occurring thymus-arisen CD4+CD25+ regulatory T (Treg) cells are considered to play a central role in self-tolerance. Precise signals that promote the development of Treg cells remain elusive, but considerable evidence suggests that costimulatory molecules, cytokines, the nature of the TCR and the niche or the context in which the T cell encounters antigen in the thymus play important roles. Analysis of TCR from Treg cells has demonstrated that a large proportion of this population has a higher avidity to self-antigen in comparison with TCR from CD4+CD25- cells and that peripheral antigen is required for their development, maintenance, or expansion. Treg cells have been shown to undergo expansion in the periphery, likely regulated by the presence of self-antigen. Many studies have shown that the involvement of Treg cells in the tolerance induction is antigen-specific, even with MHC-mismatched,in transplantation/graft versus host disease (GVHD), autoimmunity, cancer, and pregnancy. Theses studies concluded a vital role for self-reactive Treg cells in maintenance of the body integrity. Based on those studies, we hypothesize that self-reactive Treg cells are shared among all healthy individuals and recognize same self-antigens and their TCR encodes for few dominant antigens of each organ which defines the healthy self. These dominant self antigens can be regarded as "universal immune code".

  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. Change of paradigm: CD8+ T cells as important helper for CD4+ T cells during asthma and autoimmune encephalomyelitis

    OpenAIRE

    Huber, Magdalena; Lohoff, Michael

    2015-01-01

    Summary The activation of naive CD4+ and CD8+ T cells in response to antigen and their subsequent proliferation and differentiation into effectors are important features of a cell-mediated immune response. CD4+ T cells (also known as T helper cells, Th) differentiate into several subpopulations including Th1, Th2, Th9, Th17, Tfh and Treg cells, characterized by specific cytokine profiles and effector functions. However, recent evidence indicates that CD8+ T cells (termed cytotoxic T lymphocyt...

  8. Characterisation of CD4 T cells in healthy and diseased koalas (Phascolarctos cinereus) using cell-type-specific monoclonal antibodies.

    Science.gov (United States)

    Mangar, Chandan; Armitage, Charles W; Timms, Peter; Corcoran, Lynn M; Beagley, Kenneth W

    2016-07-01

    The koala (Phascolarctos cinereus) is an arboreal herbivorous marsupial that is an Australian icon. Koalas in many parts of Australia are under multiple threats including habitat destruction, dog attacks, vehicular accidents, and infectious diseases such as Chlamydia spp. and the koala retrovirus (KoRV), which may contribute to the incidence of lymphoma and leukaemia in this species. Due to a lack of koala-specific immune reagents and assays there is currently no way to adequately analyse the immune response in healthy, diseased or vaccinated animals. This paper reports the production and characterisation of the first anti-koala CD4 monoclonal antibody (mAb). The koala CD4 gene was identified and used to develop recombinant proteins for mAb production. Fluorochrome-conjugated anti-CD4 mAb was used to measure the levels of CD4(+) lymphocytes collected from koala spleens (41.1%, range 20-45.1%) lymph nodes (36.3%, range 19-55.9%) and peripheral blood (23.8%, range 17.3-35%) by flow cytometry. Biotin-conjugated anti-CD4 mAb was used for western blot to determine an approximate size of 52 kDa for the koala CD4 molecule and used in immunohistochemistry to identify CD4(+) cells in the paracortical region and germinal centres of spleen and lymph nodes. Using the anti-CD4 mab we showed that CD4 cells from vaccinated, but not control, koalas proliferated following in vitro stimulation with UV-inactivated Chlamydia pecorum and recombinant chlamydial antigens. Since CD4(+) T cells have been shown to play a pivotal role in clearing chlamydial infection in both human and mouse infections, using this novel antibody will help determine the role CD4(+) T cells play in protection against chlamydial infection in koalas and also enhance our knowledge of how KoRV affects the koala immune system. PMID:26905635

  9. CELLULAR AND POPULATION PLASTICITY OF HELPER CD4 T CELL RESPONSES

    Directory of Open Access Journals (Sweden)

    Gesham eMagombedze

    2013-08-01

    Full Text Available Vertebrates are constantly exposed to pathogens, and the adaptive immunity has most likely evolved to control and clear such infectious agents. CD4 T cells are the major players in the adaptive immune response to pathogens. Following recognition of pathogen-derived antigens naïve CD4 T cells differentiate into effectors which then control pathogen replication either directly by killing pathogen-infected cells or by assisting with generation of cytotoxic T lymphocytes or pathogen-specific antibodies. Pathogen-specific effector CD4 T cells are highly heterogeneous in terms of cytokines they produce. Three major subtypes of effector CD4 T cells have been identified: T-helper 1 (Th1 cells producing IFN-g and TNF-α, Th2 cells producing IL-4 and IL-10, and Th17 cells producing IL-17. How this heterogeneity is maintained and what regulates changes in effector T cell composition during chronic infections remains poorly understood. In this review we discuss recent advances in our understanding of CD4 T cell differentiation in response to microbial infections. We propose that a change in the phenotype of pathogen-specific effector CD4 T cells during chronic infections, for example, from Th1 to Th2 response as observed in Mycobacteriumavium ssp. paratuberculosis (MAP infection of ruminants, can be achieved by conversion of T cells from one effector subset to another (cellular plasticity or due to differences in kinetics (differentiation, proliferation, death of different effector T cell subsets (population plasticity. We also shortly review mathematical models aimed at describing CD4 T cell differentiation and outline areas for future experimental and theoretical research.

  10. Coinhibitory receptor PD-1H preferentially suppresses CD4+ T cell–mediated immunity

    Science.gov (United States)

    Flies, Dallas B.; Han, Xue; Higuchi, Tomoe; Zheng, Linghua; Sun, Jingwei; Ye, Jessica Jane; Chen, Lieping

    2014-01-01

    T cell activation is regulated by the interactions of surface receptors with stimulatory and inhibitory ligands. Programmed death-1 homolog (PD-1H, also called VISTA) is a member of the CD28 family of proteins and has been shown to act as a coinhibitory ligand on APCs that suppress T cell responses. Here, we determined that PD-1H functions as a coinhibitory receptor for CD4+ T cells. CD4+ T cells in mice lacking PD-1H exhibited a dramatically increased response to antigen stimulation. Furthermore, delivery of a PD-1H–specific agonist mAb directly inhibited CD4+ T cell activation both in vitro and in vivo, validating a coinhibitory function of PD-1H. In a murine model of acute hepatitis, administration of a PD-1H agonist mAb suppressed CD4+ T cell–mediated acute inflammation. PD-1H–deficient animals were highly resistant to tumor induction in a murine brain glioma model, and depletion of CD4+ T cells, but not CD8+ T cells, promoted tumor formation. Together, our findings suggest that PD-1H has potential as a target of immune modulation in the treatment of human inflammation and malignancies. PMID:24743150

  11. IL-21-producer CD4+ T cell kinetics during primary simian immunodeficiency virus infection.

    Science.gov (United States)

    Shi, Shoi; Seki, Sayuri; Matano, Tetsuro; Yamamoto, Hiroyuki

    2013-01-01

    IL-21 signaling is important for T cell and B cell-mediated clearance of chronic viral infections. While non-cognate follicular helper CD4+ T cells (TFH) are indicated to be pivotal in providing IL-21-mediated help to activated B cells within germinal centers, how this signaling may be disrupted in early AIDS virus infection is not clear. In this study, we assessed the lineage and kinetics of peripheral blood IL-21-producing CD4+ T cells in primary simian immunodeficiency virus (SIV) infection of rhesus macaques. After SIV challenge, antigen-nonspecific IL-21 production was observed in Th1, Th2 and Th17 cells with Th1 dominance. While IL-21+ Th2 and IL-21+ Th17 showed variable kinetics, an increase in total IL-21+ CD4+ T cells and IL-21+ Th1 from week 3 to week 8 was observed, preceding plasma SIV-specific IgG development from week 5 to week 12. SIV Gag-specific IL-21+ CD4+ T cells detectable at week 2 were decreased in frequencies at week 5. Results imply that kinetics of IL-21+ CD4+ T cells comprised of multiple lineages, potentially targeted by SIV with a bias of existing frequencies during their precursor stage, associate with availability of cooperative B-cell help provided through a proportionate precursor pool developing into TFH and subsequent anti-SIV antibody responses. PMID:23791954

  12. Lack of IL-15 results in the suboptimal priming of CD4+ T cell response against an intracellular parasite.

    Science.gov (United States)

    Combe, Crescent L; Moretto, Magali M; Schwartzman, Joseph D; Gigley, Jason P; Bzik, David J; Khan, Imtiaz A

    2006-04-25

    IFN-gamma-producing CD4+ T cells, although important for protection against acute Toxoplasma gondii infection, can cause gut pathology, which may prove to be detrimental for host survival. Here we show that mice lacking IL-15 gene develop a down-regulated IFN-gamma-producing CD4+ T cell response against the parasite, which leads to a reduction in gut necrosis and increased level of survival against infection. Moreover, transfer of immune CD4+ T cells from WT to IL-15-/- mice reversed inhibition of gut pathology and caused mortality equivalent to levels of parental WT mice. Down-regulated CD4+ T cell response in the absence of IL-15, manifested as reduced antigen-specific proliferation, was due to defective priming of the T cell subset by dendritic cells (DCs) of these animals. When stimulated with antigen-pulsed DCs from WT mice, CD4+ T cells from IL-15-/- mice were primed optimally, and robust proliferation of these cells was observed. A defect in the DCs of knockout mice was further confirmed by their reduced ability to produce IL-12 upon stimulation with Toxoplasma lysate antigen. Addition of exogenous IL-15 to DC cultures from knockout mice led to increased IL-12 production by these cells and restored their ability to prime an optimal parasite-specific CD4+ T cell response. To our knowledge, this is the first demonstration of the role of IL-15 in the development of CD4+ T cell immunity against an intracellular pathogen. Furthermore, based on these observations, targeting of IL-15 should have a beneficial effect on individuals suffering from CD4+ T cell-mediated autoimmune diseases. PMID:16614074

  13. CD4+/CD8+ double-positive T cells

    DEFF Research Database (Denmark)

    Overgaard, Nana H; Jung, Ji-Won; Steptoe, Raymond J;

    2015-01-01

    CD4(+)/CD8(+) DP thymocytes are a well-described T cell developmental stage within the thymus. However, once differentiated, the CD4(+) lineage or the CD8(+) lineage is generally considered to be fixed. Nevertheless, mature CD4(+)/CD8(+) DP T cells have been described in the blood and peripheral...... cells, CD4(+)/CD8(+) T cell populations, outside of the thymus, have recently been described to express concurrently ThPOK and Runx3. Considerable heterogeneity exists within the CD4(+)/CD8(+) DP T cell pool, and the function of CD4(+)/CD8(+) T cell populations remains controversial, with conflicting...... reports describing cytotoxic or suppressive roles for these cells. In this review, we describe how transcriptional regulation, lineage of origin, heterogeneity of CD4 and CD8 expression, age, species, and specific disease settings influence the functionality of this rarely studied T cell population....

  14. The early activation marker CD69 regulates the expression of chemokines and CD4 T cell accumulation in intestine.

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    Katarina Radulovic

    Full Text Available Migration of naïve and activated lymphocytes is regulated by the expression of various molecules such as chemokine receptors and ligands. CD69, the early activation marker of C-type lectin domain family, is also shown to regulate the lymphocyte migration by affecting their egress from the thymus and secondary lymphoid organs. Here, we aimed to investigate the role of CD69 in accumulation of CD4 T cells in intestine using murine models of inflammatory bowel disease. We found that genetic deletion of CD69 in mice increases the expression of the chemokines CCL-1, CXCL-10 and CCL-19 in CD4(+ T cells and/or CD4(- cells. Efficient in vitro migration of CD69-deficient CD4 T cells toward the chemokine stimuli was the result of increased expression and/or affinity of chemokine receptors. In vivo CD69(-/- CD4 T cells accumulate in the intestine in higher numbers than B6 CD4 T cells as observed in competitive homing assay, dextran sodium sulphate (DSS-induced colitis and antigen-specific transfer colitis. In DSS colitis CD69(-/- CD4 T cell accumulation in colonic lamina propria (cLP was associated with increased expression of CCL-1, CXCL-10 and CCL-19 genes. Furthermore, treatment of DSS-administrated CD69(-/- mice with the mixture of CCL-1, CXCL-10 and CCL-19 neutralizing Abs significantly decreased the histopathological signs of colitis. Transfer of OT-II×CD69(-/- CD45RB(high CD4 T cells into RAG(-/- hosts induced CD4 T cell accumulation in cLP. This study showed CD69 as negative regulator of inflammatory responses in intestine as it decreases the expression of chemotactic receptors and ligands and reduces the accumulation of CD4 T cells in cLP during colitis.

  15. Autocrine production of beta-chemokines protects CMV-Specific CD4 T cells from HIV infection.

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    Joseph P Casazza

    2009-10-01

    Full Text Available Induction of a functional subset of HIV-specific CD4+ T cells that is resistant to HIV infection could enhance immune protection and decrease the rate of HIV disease progression. CMV-specific CD4+ T cells, which are less frequently infected than HIV-specific CD4+ T cells, are a model for such an effect. To determine the mechanism of this protection, we compared the functional response of HIV gag-specific and CMV pp65-specific CD4+ T cells in individuals co-infected with CMV and HIV. We found that CMV-specific CD4+ T cells rapidly up-regulated production of MIP-1alpha and MIP-1beta mRNA, resulting in a rapid increase in production of MIP-1alpha and MIP-1beta after cognate antigen stimulation. Production of beta-chemokines was associated with maturational phenotype and was rarely seen in HIV-specific CD4+ T cells. To test whether production of beta-chemokines by CD4+ T cells lowers their susceptibility to HIV infection, we measured cell-associated Gag DNA to assess the in vivo infection history of CMV-specific CD4+ T cells. We found that CMV-specific CD4+ T cells which produced MIP-1beta contained 10 times less Gag DNA than did those which failed to produce MIP-1beta. These data suggest that CD4+ T cells which produce MIP-1alpha and MIP-1beta bind these chemokines in an autocrine fashion which decreases the risk of in vivo HIV infection.

  16. Detection of circulating tumor lysate-reactive CD4+ T cells in melanoma patients

    DEFF Research Database (Denmark)

    Ladekarl, Morten; Agger, Ralf; Fleischer, Charlotte C;

    2004-01-01

    donors with high background levels of spontaneous IFN-gamma production, indicating an inhibitory effect of the lysate. CONCLUSIONS: This method for detection of a peripheral T-cell immune response in melanoma patients has several advantages for clinical use. The tumor lysate preparations may contain......PURPOSE: We wanted to study whether an allogeneic melanoma lysate would be a feasible stimulatory antigen source for detection of a peripheral CD4+ T-cell immune response in patients with medically untreated malignant melanoma. The lysate was produced from a melanoma cell line (FM3.29) which...... expresses high amounts of melanoma antigens. METHODS: Fresh peripheral blood was incubated with and without lysate for 6 h in the presence of anti-CD28/anti-CD49d MoAb (for costimulation). After flow cytometric estimation of the frequency of CD69+/IFN-gamma+ cells in the CD4+ population, the response to...

  17. CD4+ T-cell priming as biomarker to study immune response to preventive vaccines

    Directory of Open Access Journals (Sweden)

    Annalisa eCiabattini

    2013-12-01

    Full Text Available T-cell priming is a critical event in the initiation of the immune response to vaccination since it deeply influences both the magnitude and the quality of the immune response induced. CD4+ T-cell priming, required for the induction of high-affinity antibodies and immune memory, represents a key target for improving and modulating vaccine immunogenicity. A major challenge in the study of in vivo T-cell priming is due to the low frequency of antigen-specific T cells. This review discusses the current knowledge on antigen-specific CD4+ T-cell priming in the context of vaccination, as well as the most advanced tools for the characterization of the in vivo T-cell priming and the opportunities offered by the application of systems biology.

  18. Regulation and gene expression profiling of NKG2D positive human cytomegalovirus-primed CD4+ T-cells.

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    Helle Jensen

    Full Text Available NKG2D is a stimulatory receptor expressed by natural killer (NK cells, CD8(+ T-cells, and γδ T-cells. NKG2D expression is normally absent from CD4(+ T-cells, however recently a subset of NKG2D(+ CD4(+ T-cells has been found, which is specific for human cytomegalovirus (HCMV. This particular subset of HCMV-specific NKG2D(+ CD4(+ T-cells possesses effector-like functions, thus resembling the subsets of NKG2D(+ CD4(+ T-cells found in other chronic inflammations. However, the precise mechanism leading to NKG2D expression on HCMV-specific CD4(+ T-cells is currently not known. In this study we used genome-wide analysis of individual genes and gene set enrichment analysis (GSEA to investigate the gene expression profile of NKG2D(+ CD4(+ T-cells, generated from HCMV-primed CD4(+ T-cells. We show that the HCMV-primed NKG2D(+ CD4(+ T-cells possess a higher differentiated phenotype than the NKG2D(- CD4(+ T-cells, both at the gene expression profile and cytokine profile. The ability to express NKG2D at the cell surface was primarily determined by the activation or differentiation status of the CD4(+ T-cells and not by the antigen presenting cells. We observed a correlation between CD94 and NKG2D expression in the CD4(+ T-cells following HCMV stimulation. However, knock-down of CD94 did not affect NKG2D cell surface expression or signaling. In addition, we show that NKG2D is recycled at the cell surface of activated CD4(+ T-cells, whereas it is produced de novo in resting CD4(+ T-cells. These findings provide novel information about the gene expression profile of HCMV-primed NKG2D(+ CD4(+ T-cells, as well as the mechanisms regulating NKG2D cell surface expression.

  19. Analysis of purine metabolic enzymes in human CD4 Leu 8- and CD4 Leu 8+ lymphocyte subpopulations.

    Science.gov (United States)

    Fernandez-Mejia, C; Polmar, S H; Peralta-Zaragoza, O; Madrid-Marina, V

    1993-02-01

    1. Specific activities of adenosine deaminase, purine nucleoside phosphorylase, adenosine kinase, 5'-nucleotidase, S-adenosyl-L-homocysteine hydrolase, AMP deaminase, adenine phosphoribosyl transferase, and hypoxanthine phosphoribosyl transferase were analyzed in human CD4 T-lymphocyte subsets. 2. CD4 Leu 8- (helper/inducer) and CD4 Leu 8+ (suppressor/inducer) subpopulations were obtained by panning or fluorescence activated cell sorting techniques using specific monoclonal antibodies. 3. A 45% decrease of 5'-NT AMP activity in the CD4 Leu 8- cells (suppressor/inducer) compared with CD4 total cell population. 4. No statistical significant differences in enzyme activity were found between the subsets analyzed in other purine enzymes. 5. These results suggest that the distribution of purine metabolic enzymes is homogeneous in CD4 Leu 8- and CD4 Leu 8+ T-lymphocyte subpopulations. PMID:8444317

  20. Intratumoral convergence of the TCR repertoires of effector and Foxp3+ CD4+ T cells.

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    Michal Kuczma

    Full Text Available The presence of Foxp3(+ regulatory CD4(+ T cells in tumor lesions is considered one of the major causes of ineffective immune response in cancer. It is not clear whether intratumoral T(reg cells represent T(reg cells pre-existing in healthy mice, or arise from tumor-specific effector CD4(+ T cells and thus representing adaptive T(reg cells. The generation of T(reg population in tumors could be further complicated by recent evidence showing that both in humans and mice the peripheral population of T(reg cells is heterogenous and consists of subsets which may differentially respond to tumor-derived antigens. We have studied T(reg cells in cancer in experimental mice that express naturally selected, polyclonal repertoire of CD4(+ T cells and which preserve the heterogeneity of the T(reg population. The majority of T(reg cells present in healthy mice maintained a stable suppressor phenotype, expressed high level of Foxp3 and an exclusive set of TCRs not used by naive CD4(+ T cells. A small T(reg subset, utilized TCRs shared with effector T cells and expressed a lower level of Foxp3. We show that response to tumor-derived antigens induced efficient clonal recruitment and expansion of antigen-specific effector and T(reg cells. However, the population of T(reg cells in tumors was dominated by cells expressing TCRs shared with effector CD4(+ T cells. In contrast, T(reg cells expressing an exclusive set of TCRs, that dominate in healthy mice, accounted for only a small fraction of all T(reg cells in tumor lesions. Our results suggest that the T(reg repertoire in tumors is generated by conversion of effector CD4(+ T cells or expansion of a minor subset of T(reg cells. In conclusion, successful cancer immunotherapy may depend on the ability to block upregulation of Foxp3 in effector CD4(+ T cells and/or selectively inhibiting the expansion of a minor T(reg subset.

  1. TCR repertoire and Foxp3 expression define functionally distinct subsets of CD4+ Treg cells1

    OpenAIRE

    Kuczma, Michal; Pawlikowska, Iwona; Kopij, Magdalena; Podolsky, Robert; Rempala, Grzegorz A.; Kraj, Piotr

    2009-01-01

    Despite extensive research efforts to characterize peripheral regulatory T cells (Treg) expressing transcription factor Foxp3, their subset complexity, phenotypic characteristics, TCR repertoire and antigen specificities remain ambiguous. Here, we identify and define two subsets of peripheral Treg cells differing in Foxp3 expression level and TCR repertoires. Treg cells expressing a high level of Foxp3 and TCRs not utilized by naive CD4+ T cells present a stable suppressor phenotype and domin...

  2. CD4+ T cell immunity to the Burkholderia pseudomallei ABC transporter LolC in melioidosis

    OpenAIRE

    Chu, Karen K.; Tippayawat, Patcharaporn; Walker, Nicola J.; Harding, Sarah V.; Atkins, Helen S.; Maillere, Bernard; Bancroft, Gregory J; Lertmemongkolchai, Ganjana; Altmann, Daniel M

    2010-01-01

    Burkholderia pseudomallei (Bp) causes melioidosis, a disease with a wide range of possible outcomes, from seroconversion and dormancy to sepsis and death. This spectrum of host-pathogen interactions poses challenging questions about heterogeneity in immunity to Bp. Models show protection to be dependent on CD4+ cells and IFNγ, but little is known about specific target antigens. Having previously implicated the ABC transporter, LolC, in protective immunity, we here use epitope prediction, HLA ...

  3. CRTAM determines the CD4+ cytotoxic T lymphocyte lineage.

    Science.gov (United States)

    Takeuchi, Arata; Badr, Mohamed El Sherif Gadelhaq; Miyauchi, Kosuke; Ishihara, Chitose; Onishi, Reiko; Guo, Zijin; Sasaki, Yoshiteru; Ike, Hiroshi; Takumi, Akiko; Tsuji, Noriko M; Murakami, Yoshinori; Katakai, Tomoya; Kubo, Masato; Saito, Takashi

    2016-01-11

    Naive T cells differentiate into various effector T cells, including CD4(+) helper T cell subsets and CD8(+) cytotoxic T cells (CTL). Although cytotoxic CD4(+) T cells (CD4 +: CTL) also develop from naive T cells, the mechanism of development is elusive. We found that a small fraction of CD4(+) T cells that express class I-restricted T cell-associated molecule (CRTAM) upon activation possesses the characteristics of both CD4(+) and CD8(+) T cells. CRTAM(+) CD4(+) T cells secrete IFN-γ, express CTL-related genes, such as eomesodermin (Eomes), Granzyme B, and perforin, after cultivation, and exhibit cytotoxic function, suggesting that CRTAM(+) T cells are the precursor of CD4(+)CTL. Indeed, ectopic expression of CRTAM in T cells induced the production of IFN-γ, expression of CTL-related genes, and cytotoxic activity. The induction of CD4(+)CTL and IFN-γ production requires CRTAM-mediated intracellular signaling. CRTAM(+) T cells traffic to mucosal tissues and inflammatory sites and developed into CD4(+)CTL, which are involved in mediating protection against infection as well as inducing inflammatory response, depending on the circumstances, through IFN-γ secretion and cytotoxic activity. These results reveal that CRTAM is critical to instruct the differentiation of CD4(+)CTL through the induction of Eomes and CTL-related gene.

  4. Calpain 4 is not necessary for LFA-1-mediated function in CD4+ T cells.

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    Sarah A Wernimont

    Full Text Available BACKGROUND: T cell activation and immune synapse formation require the appropriate activation and clustering of the integrin, LFA-1. Previous work has reported that the calpain family of calcium-dependent proteases are important regulators of integrin activation and modulate T cell adhesion and migration. However, these studies have been limited by the use of calpain inhibitors, which have known off-target effects. METHODOLOGY/PRINCIPAL FINDINGS: Here, we used a LoxP/CRE system to specifically deplete calpain 4, a small regulatory calpain subunit required for expression and activity of ubiquitously expressed calpains 1 and 2, in CD4+ T cells. CD4+ and CD8+ T cells developed normally in Capn4(F/F:CD4-CRE mice and had severely diminished expression of Calpain 1 and 2, diminished talin proteolysis and impaired casein degradation. Calpain 4-deficient T cells showed no difference in adhesion or migration on the LFA-1 ligand ICAM-1 compared to control T cells. Moreover, there was no impairment in conjugation between Capn4(F/F:CD4-CRE T cells and antigen presenting cells, and the conjugates were still capable of polarizing LFA-1, PKC-theta and actin to the immune synapse. Furthermore, T cells from Capn4(F/F:CD4-CRE mice showed normal proliferation in response to either anti-CD3/CD28 coated beads or cognate antigen-loaded splenocytes. Finally, there were no differences in the rates of apoptosis following extrinsic and intrinsic apoptotic stimuli. CONCLUSION/SIGNIFICANCE: Our findings demonstrate that calpain 4 is not necessary for LFA-1-mediated adhesion, conjugation or migration. These results challenge previous reports that implicate a central role for calpains in the regulation of T cell LFA-1 function.

  5. Human Memory CD4+ T Cell Immune Responses against Giardia lamblia.

    Science.gov (United States)

    Saghaug, Christina Skår; Sørnes, Steinar; Peirasmaki, Dimitra; Svärd, Staffan; Langeland, Nina; Hanevik, Kurt

    2016-01-01

    The intestinal protozoan parasite Giardia lamblia may cause severe prolonged diarrheal disease or pass unnoticed as an asymptomatic infection. T cells seem to play an important role in the immune response to Giardia infection, and memory responses may last years. Recently, TH17 responses have been found in three animal studies of Giardia infection. The aim of this study was to characterize the human CD4(+) T cell responses to Giardia. Peripheral blood mononuclear cells (PBMCs) were obtained from 21 returning travelers with recent or ongoing giardiasis and 12 low-risk healthy controls and stimulated in vitro with Giardia lamblia proteins. Production of tumor necrosis factor alpha (TNF-α), gamma interferon, interleukin-17A (IL-17A), IL-10, and IL-4 was measured in CD4(+) effector memory (EM) T cells after 24 h by flow cytometry. After 6 days of culture, activation and proliferation were measured by flow cytometry, while an array of inflammatory cytokine levels in supernatants were measured with multiplex assays. We found the number of IL-17A-producing CD4(+) EM T cells, as well as that of cells simultaneously producing both IL-17A and TNF-α, to be significantly elevated in the Giardia-exposed individuals after 24 h of antigen stimulation. In supernatants of PBMCs stimulated with Giardia antigens for 6 days, we found inflammation-associated cytokines, including 1L-17A, as well as CD4(+) T cell activation and proliferation, to be significantly elevated in the Giardia-exposed individuals. We conclude that symptomatic Giardia infection in humans induces a CD4(+) EM T cell response of which IL-17A production seems to be an important component. PMID:26376930

  6. Immunosuppression of canine renal allograft recipients by CD4 and CD8 monoclonal antibodies

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    Watson, C.J.E.; Davies, H.S.; Rebello, P.R.U.B.; McNair, R.; Rasmussen, A.; Calne, R.Y.; Metcalfe, S.M. (Department of Surgery, University of Cambridge (United Kingdom)); Cobbold, S.P.; Thiru, S.; Waldmann, H. (Department of Pathology, University of Cambridge (United Kingdom))

    1994-01-01

    A state of tolerance to MHC mismatched allografts can be generated in rodents by treatment with CD4 and CD8 monoclonal antibodies (mAb). In order to transpose this type of therapy to large animals and ultimately to the clinic, a suitable model is required. To this end we have generated a series of mAb to the canine CD4, CD8, and Thy-l antigens and have tested their ability to prevent rejection of renal allografts. Donor-recipient pairs were selected from a colony of mongrel dogs in which untreated rejection of two haplotype-mismatched kidneys occurred by day 7 (defined as a serum creatinine > 300 [mu]mol/l). Therapy with either the CD4 or the CD8 mAb, using no other immunosuppression, did not prolong graft survival. Depletion of T cells by a Thy-l mAb prior to surgery only extended graft survival to day 9. However, treating with combinations of mAb up to day 10 (CD4 plus Thy-l; CD4 plus CD8; or CD4 plus CD8 plus Thy-l) prolonged renal allograft function up to 25 days. Combination of the triple mAb therapy with a sub-therapeutic immunosuppressive drug regimen (cyclosporin A plus azathioprine that alone gave a median survival of 15 days) favored survival to a median of 38 days. This protocol also inhibited the antiglobulin response that had curtailed the effects of mAb treatment, opening the way to more extended, and potentially tolerizing, mAb plus drug regimens. (au) (23 refs.).

  7. Monoclonal Anti—CD4 Antibody MT310 Binds HIV-1 gp120 Binding Site on CD4

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Tests show the monoclonal anti—CD4 antibody (mAb) MT310 recognizes the gp120-binding site on CD4 as part of its mechanism for strongly inhibiting human immunodeficiency virus type 1 (HIV-1) infection of CD4+ T cells. In competition tests, mAb MT310 and mAb Leu3a (an anti-CD4 mAb recognizing the gp120-binding site) all inhibited gp120-binding to CD4+ T lymphocytes, while mAb MT405 did not. This result suggests that MT310, like Leu3a, recognizes the gp120-binding site on CD4. To further confirm whether MT310 recognizes the gp120-binding site on CD4, we prepared rabbit anti-idiotypic antisera (Ab2) against MT310 (Ab1). The anti-idiotypic antisera against MT310 inhibited binding of MT310 and Leu3a to human CD4+ T lymphocytes, but did not block binding of MT151 with the second domain of CD4, while rabbit anti-idiotypic antisera to MT151 could block binding of itself to these cells, but could not inhibit the binding of MT310 and Leu3a, further indicating that MT310 recognized the gp120-binding site on CD4.

  8. CD4(+CD25(-Nrp1(+ T cells synergize with rapamycin to prevent murine cardiac allorejection in immunocompetent recipients.

    Directory of Open Access Journals (Sweden)

    Qing Yuan

    Full Text Available Besides CD4(+CD25(+Foxp3(+ regulatory T cells (Tregs, other immunosuppressive T cells also participated in the regulation of immune tolerance. Reportedly, neuropilin-1 (Nrp1 might be one of the molecules by which regulatory cells exert their suppressive effects. Indeed, CD4(+CD25(-Nrp1(+ T cells exhibit potent suppressive function in autoimmune inflammatory responses. Here we investigated the specific role of CD4(+CD25(-Nrp1(+ T cells in the setting of the transplant immune response. Through MLR assays, we found that CD4(+CD25(-Nrp1(+ T cells suppressed the proliferation of naive CD4(+CD25(- T cells activated by allogeneic antigen-stimulation. Adoptive transfer of CD4(+CD25(-Nrp1(+ T cells synergized with rapamycin to induce long-term graft survival in fully MHC-mismatched murine heart transplantation, which was associated with decreased IFN-γ, IL-17 and increased IL-10, TGF-β, Foxp3 and Nrp1 expression in the grafts. Importantly, our data indicated that CD4(+CD25(-Nrp1(+ T cell transfer augments the accumulation of Tregs in the recipient, and creates conditions that favored induction of hyporesponsiveness of the T effector cells. In conclusion, this translational study indicates the possible therapeutic potential of CD4(+CD25(-Nrp1(+ T cells in preventing allorejection. CD4(+Nrp1(+ T cells might therefore be used in bulk as a population of immunosuppressive cells with more beneficial properties concerning ex vivo isolation as compared to Foxp3(+ Tregs.

  9. Identification of CD4-Binding Site Dependent Plasma Neutralizing Antibodies in an HIV-1 Infected Indian Individual.

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    Lubina Khan

    Full Text Available Dissecting antibody specificities in the plasma of HIV-1 infected individuals that develop broadly neutralizing antibodies (bNAbs is likely to provide useful information for refining target epitopes for vaccine design. Several studies have reported CD4-binding site (CD4bs antibodies as neutralization determinants in the plasma of subtype B-infected individuals; however there is little information on the prevalence of CD4bs specificities in HIV-infected individuals in India. Here, we report on the presence of CD4bs antibodies and their contribution to virus neutralization in the plasma from a cohort of HIV-1 infected Indian individuals. Plasma from 11 of the 140 HIV-1 infected individuals (7.9% studied here exhibited cross-neutralization activity against a panel of subtype B and C viruses. Analyses of these 11 plasma samples for the presence of CD4bs antibodies using two CD4bs-selective probes (antigenically resurfaced HXB2gp120 core protein RSC3 and hyperglycosylated JRFLgp120 mutant ΔN2mCHO revealed that five (AIIMS 617, 619, 627, 642, 660 contained RSC3-reactive plasma antibodies and only one (AIIMS 660 contained ΔN2mCHO-reactive antibodies. Plasma antibody depletion and competition experiments confirmed that the neutralizing activity in the AIIMS 660 plasma was dependent on CD4bs antibodies. To the best of our knowledge, this is the first study to report specifically on the presence of CD4bs antibodies in the plasma of a cohort of HIV-1 infected Indian donors. The identification of CD4bs dependent neutralizing antibodies in an HIV-1 infected Indian donor is a salient finding of this study and is supportive of ongoing efforts to induce similar antibodies by immunization.

  10. Thymic Nurse Cells Support CD4-CD8+ Thymocytes to Differentiate into CD4+CD8+ Cells

    Institute of Scientific and Technical Information of China (English)

    Aidong Li; Xueli Liu; Baochun Duan; Jie Ma

    2005-01-01

    Thymic nurse cells (TNCs) represent a unique microenvironment in the thymus for T cell maturation. In order to investigate the role of thymic nurse cells during T cell differentiation, a TNC clone, RWTE-1, which formed a typical complex with fetal thymocytes in vitro was established from normal Wistar rat. Hanging drop culture method was applied to reveal the interaction between TNCs and thymocytes. Our result revealed that eighty percent of immature CD4-CD8+ cells differentiated into CD4+CD8+ cells after a 12-hour hanging drop culture with RWTE-1. However, in a 12-hour culture of immature CD4-CD8+ cells with or without RWTE-1 supernatant, only 30% of the cells differentiated into CD4+CD8+ cells spontaneously. This observation led to the conclusion that RWTE-1 cell has the capacity to facilitate immature CD4-CD8+ thymocytes to differentiate into CD4+CD8+ T cells by direct interaction.

  11. Sialylation regulates peripheral tolerance in CD4+ T cells.

    Science.gov (United States)

    Brennan, Patrick J; Saouaf, Sandra J; Van Dyken, Steve; Marth, Jamey D; Li, Bin; Bhandoola, Avinash; Greene, Mark I

    2006-05-01

    Decreased binding by the 6C10 auto-antibody serves as a unique marker for CD4+ T cell unresponsiveness after the induction of T cell tolerance in Vbeta8.1 TCR transgenic mice. We further define the nature of the epitope recognized by the 6C10 antibody to be a subset of Thy-1 bearing incompletely sialylated N-linked glycans, and furthermore, we demonstrate that tolerant CD4+ T cells have an increased degree of cell-surface sialylation. To test the significance of the altered glycosylation state identified by the 6C10 auto-antibody in the tolerant CD4+ T cell population, surface sialic acid was cleaved enzymatically. Treatment of purified peripheral CD4+ T cells with Vibrio cholerae sialidase (VCS) leads to increased 6C10 binding, significantly enhances proliferation in the tolerant CD4+ population and corrects defects in phosphotyrosine signaling observed in the tolerant CD4+ T cell. Furthermore, in vivo administration of VCS enhances proliferation in both tolerant and naive CD4+ T cell subsets. These studies suggest that sialylation of glycoproteins on the surface of the CD4+ T cell contributes to the regulation of T cell responsiveness in the tolerant state. PMID:16291658

  12. Allergen-Specific CD4(+) T Cells in Human Asthma.

    Science.gov (United States)

    Ling, Morris F; Luster, Andrew D

    2016-03-01

    In allergic asthma, aeroallergen exposure of sensitized individuals mobilizes robust innate and adaptive airway immune responses, stimulating eosinophilic airway inflammation and the activation and infiltration of allergen-specific CD4(+) T cells into the airways. Allergen-specific CD4(+) T cells are thought to be central players in the asthmatic response as they specifically recognize the allergen and initiate and orchestrate the asthmatic inflammatory response. In this article, we briefly review the role of allergen-specific CD4(+) T cells in the pathogenesis of human allergic airway inflammation in allergic individuals, discuss the use of allergen-major histocompatibility complex class II tetramers to characterize allergen-specific CD4(+) T cells, and highlight current gaps in knowledge and directions for future research pertaining to the role of allergen-specific CD4(+) T cells in human asthma. PMID:27027948

  13. The role of CD4 T cell memory in generating protective immunity to novel and potentially pandemic strains of influenza

    Directory of Open Access Journals (Sweden)

    Anthony eDiPiazza

    2016-01-01

    Full Text Available Recent events have made it clear that potentially pandemic strains of influenza regularly pose a threat to human populations. Therefore, it is essential that we develop better strategies to enhance vaccine design and evaluation, to predict those that will be poor responders to vaccination and to identify those that are at particular risk of disease-associated complications following infection. Simplified animal models have revealed the discrete functions that CD4 T cells play in the developing immune response and to influenza immunity. However, humans have a complex immunological history with influenza through periodic infection and vaccination with seasonal variants, leading to the establishment of heterogeneous memory populations of CD4 T cells that participate in subsequent responses. The continual evolution of the influenza-specific CD4 T cell repertoire involves both specificity and function and overlays other restrictions on CD4 T cell activity derived from viral antigen handling and MHC class II:peptide epitope display. Together, these complexities in the influenza-specific CD4 T cell repertoire constitute a formidable obstacle to predicting protective immune response to potentially pandemic strains of influenza and in devising optimal vaccine strategies to potentiate these responses. We suggest that more precise efforts to identify and enumerate both the positive and negative contributors within the CD4 T cell compartment will aid significantly in achievement of these goals.

  14. Induction of prolonged survival of CD4+ T lymphocytes by intermittent IL-2 therapy in HIV-infected patients

    Science.gov (United States)

    Kovacs, Joseph A.; Lempicki, Richard A.; Sidorov, Igor A.; Adelsberger, Joseph W.; Sereti, Irini; Sachau, William; Kelly, Grace; Metcalf, Julia A.; Davey, Richard T.; Falloon, Judith; Polis, Michael A.; Tavel, Jorge; Stevens, Randy; Lambert, Laurie; Hosack, Douglas A.; Bosche, Marjorie; Issaq, Haleem J.; Fox, Stephen D.; Leitman, Susan; Baseler, Michael W.; Masur, Henry; Di Mascio, Michele; Dimitrov, Dimiter S.; Lane, H. Clifford

    2005-01-01

    HIV infection leads to decreases in the number of CD4+ T lymphocytes and an increased risk for opportunistic infections and neoplasms. The administration of intermittent cycles of IL-2 to HIV-infected patients can lead to profound increases (often greater than 100%) in CD4 cell number and percentage. Using in vivo labeling with 2H-glucose and BrdU, we have been able to demonstrate that, although therapy with IL-2 leads to high levels of proliferation of CD4 as well as CD8 lymphocytes, it is a remarkable preferential increase in survival of CD4 cells (with half-lives that can exceed 3 years) that is critical to the sustained expansion of these cells. This increased survival was time-dependent: the median half-life, as determined by semiempirical modeling, of labeled CD4 cells in 6 patients increased from 1.7 weeks following an early IL-2 cycle to 28.7 weeks following a later cycle, while CD8 cells showed no change in the median half-life. Examination of lymphocyte subsets demonstrated that phenotypically naive (CD27+CD45RO–) as well as central memory (CD27+CD45RO+) CD4 cells were preferentially expanded, suggesting that IL-2 can help maintain cells important for host defense against new antigens as well as for long-term memory to opportunistic pathogens. PMID:16025158

  15. SA-4-1BBL costimulation inhibits conversion of conventional CD4+ T cells into CD4+ FoxP3+ T regulatory cells by production of IFN-γ.

    Directory of Open Access Journals (Sweden)

    Shravan Madireddi

    Full Text Available Tumors convert conventional CD4(+ T cells into induced CD4(+CD25(+FoxP3(+ T regulatory (iTreg cells that serve as an effective means of immune evasion. Therefore, the blockade of conventional CD4(+ T cell conversion into iTreg cells represents an attractive target for improving the efficacy of various immunotherapeutic approaches. Using a novel form of 4-1BBL molecule, SA-4-1BBL, we previously demonstrated that costimulation via 4-1BB receptor renders both CD4(+and CD8(+ T effector (Teff cells refractory to inhibition by Treg cells and increased intratumoral Teff/Treg cell ratio that correlated with therapeutic efficacy in various preclinical tumor models. Building on these studies, we herein show for the first time, to our knowledge, that signaling through 4-1BB inhibits antigen- and TGF-β-driven conversion of naïve CD4(+FoxP3(- T cells into iTreg cells via stimulation of IFN-γ production by CD4(+FoxP3(- T cells. Importantly, treatment with SA-4-1BBL blocked the conversion of CD4(+FoxP3(- T cells into Treg cells by EG.7 tumors. Taken together with our previous studies, these results show that 4-1BB signaling negatively modulate Treg cells by two distinct mechanisms: i inhibiting the conversion of CD4(+FoxP3(- T cells into iTreg cells and ii endowing Teff cells refractory to inhibition by Treg cells. Given the dominant role of Treg cells in tumor immune evasion mechanisms, 4-1BB signaling represents an attractive target for favorably tipping the Teff:Treg balance toward Teff cells with important implications for cancer immunotherapy.

  16. Cancer immunotherapy employing an innovative strategy to enhance CD4+ T cell help in the tumor microenvironment.

    Directory of Open Access Journals (Sweden)

    Liwen Song

    Full Text Available Chemotherapy and/or radiation therapy are widely used as cancer treatments, but the antitumor effects they produce can be enhanced when combined with immunotherapies. Chemotherapy kills tumor cells, but it also releases tumor antigen and allows the cross-presentation of the tumor antigen to trigger antigen-specific cell-mediated immune responses. Promoting CD4+ T helper cell immune responses can be used to enhance the cross-presentation of the tumor antigen following chemotherapy. The pan HLA-DR binding epitope (PADRE peptide is capable of generating antigen-specific CD4+ T cells that bind various MHC class II molecules with high affinity and has been widely used in conjunction with vaccines to improve their potency by enhancing CD4+ T cell responses. Here, we investigated whether intratumoral injection of PADRE and the adjuvant CpG into HPV16 E7-expressing TC-1 tumors following cisplatin chemotherapy could lead to potent antitumor effects and antigen-specific cell-mediated immune responses. We observed that treatment with all three agents produced the most potent antitumor effects compared to pairwise combinations. Moreover, treatment with cisplatin, CpG and PADRE was able to control tumors at a distant site, indicating that our approach is able to induce cross-presentation of the tumor antigen. Treatment with cisplatin, CpG and PADRE also enhanced the generation of PADRE-specific CD4+ T cells and E7-specific CD8+ T cells and decreased the number of MDSCs in tumor loci. The treatment regimen presented here represents a universal approach to cancer control.

  17. Effect of Natalizumab on Circulating CD4(+) T-Cells in Multiple Sclerosis

    DEFF Research Database (Denmark)

    Börnsen, Lars; Christensen, Jeppe Romme; Ratzer, Rikke;

    2012-01-01

    In multiple sclerosis (MS), treatment with the monoclonal antibody natalizumab effectively reduces the formation of acute lesions in the central nervous system (CNS). Natalizumab binds the integrin very late antigen (VLA)-4, expressed on the surface of immune cells, and inhibits VLA-4 dependent......-cells due to reduced extravasation of activated and pro-inflammatory T-cells or due to induction of VLA-4 mediated co-stimulatory signals by natalizumab. In this study we examined how natalizumab treatment altered the distribution of effector and memory T-cell subsets in the blood compartment and if T......(HIGH) T-cells, in blood, and natalizumab decreased the expression of CD134 on MBP-reactive CD26(HIGH)CD4(+) T-cells in vitro. Otherwise CD4(+) T-cells from natalizumab-treated and untreated MS patients showed similar responses to MBP. In conclusion natalizumab treatment selectively increased...

  18. Glycan-modified liposomes boost CD4+ and CD8+ T-cell responses by targeting DC-SIGN on dendritic cells

    NARCIS (Netherlands)

    W.W.J. Unger; A.J. van Beelen; S.C. Bruijns; M. Joshi; C.M. Fehres; L. van Bloois; M.I. Verstege; M. Ambrosini; H. Kalay; K. Nazmi; J.G. Bolscher; E. Hooiberg; T.D. de Gruijl; G. Storm; Y. van Kooyk

    2012-01-01

    Cancer immunotherapy requires potent tumor-specific CD8+ and CD4+ T-cell responses, initiated by dendritic cells (DCs). Tumor antigens can be specifically targeted to DCs in vivo by exploiting their expression of C-type lectin receptors (CLR), which bind carbohydrate structures on antigens, resultin

  19. Isolation and Characterization of Salmonid CD4+ T Cells.

    Science.gov (United States)

    Maisey, Kevin; Montero, Ruth; Corripio-Miyar, Yolanda; Toro-Ascuy, Daniela; Valenzuela, Beatriz; Reyes-Cerpa, Sebastián; Sandino, Ana María; Zou, Jun; Wang, Tiehui; Secombes, Christopher J; Imarai, Mónica

    2016-05-15

    This study reports the isolation and functional characterization of rainbow trout (Oncorhynchus mykiss) CD4-1(+) T cells and the establishment of an IL-15-dependent CD4-1(+) T cell line. By using Abs specific for CD4-1 and CD3ε it was possible to isolate the double-positive T cells in spleen and head kidney. The morphology and the presence of transcripts for T cell markers in the sorted CD4-1(+)CD3ε(+) cells were studied next. Cells were found to express TCRα, TCRβ, CD152 (CTLA-4), CD154 (CD40L), T-bet, GATA-3, and STAT-1. The sorted CD4-1(+) T cells also had a distinctive functional attribute of mammalian T lymphocytes, namely they could undergo Ag-specific proliferation, using OVA as a model Ag. The OVA-stimulated cells showed increased expression of several cytokines, including IFN-γ1, IL-4/13A, IL-15, IL-17D, IL-10, and TGF-β1, perhaps indicating that T cell proliferation led to differentiation into distinct effector phenotypes. Using IL-15 as a growth factor, we have selected a lymphoid cell line derived from rainbow trout head kidney cells. The morphology, cell surface expression of CD4-1, and the presence of transcripts of T cell cytokines and transcription factors indicated that this is a CD4-1(+) T cell line. To our knowledge, this is the first demonstration of the presence of CD4-1(+)CD3ε(+) T cells in salmonids. As in mammals, CD4-1(+) T cells may be the master regulators of immune responses in fish, and therefore these findings and the new model T cell line developed will contribute to a greater understanding of T cell function and immune responses in teleost fish. PMID:27053758

  20. CD4~+CD56~+ hematodermic neoplasm in a child

    Institute of Scientific and Technical Information of China (English)

    GUO Xia; LI Qiang; ZHOU Chen-yan

    2010-01-01

    @@ CD4~+CD56~+ hematodermic neoplasm (HN) is a rare, highly aggressive systemic neoplasm, which had been described under various names including lymphoblastic lymphoma of natural killer (NK) phenotype, blastic NK cell lymphoma (BNK), leukemic lymphoma of immature NK lineage and CD4~+CD56~+ HN. This malignancy is mainly involved in elderly people and usually a rapidly fatal disease, since consistently effective treatments have not yet been developed. It is relatively rare in children.~(1-6) Herein we report a boy with CD4~+CD56~+ HN.

  1. Adoptive immunotherapy of cancer using CD4+ T cells

    OpenAIRE

    Muranski, Pawel; Restifo, Nicholas P

    2009-01-01

    CD4+ T cells are central to the function of the immune system but their role in tumor immunity remains underappreciated. It is becoming clear that there is an enormous diversity of CD4+ T cell polarization patterns including Th1, Th2, Th17, and regulatory T cells (Tregs). These functionally divergent T cell subsets can have opposing effects — they can trigger tumor rejection or inhibit treatment after adoptive cell transfer. Some polarized CD4+ cells have plasticity, and their phenotypes and ...

  2. Flow-cytometric measurement of CD4-8- T cells bearing T-cell receptor αβ chains, 1

    International Nuclear Information System (INIS)

    In this study we detected rare, possibly abnormal, T cells bearing CD3 surface antigen and T-cell receptor (TCR) αβ chains but lacking both CD4 and CD8 antigens (viz., TCRαβ+CD4-8- cells, as determined by flow cytometry). The TCRαβ+CD4-8-T cells were detected at a mean frequency of 0.63 ± 0.35 % (mean ± standard deviation) in peripheral blood TCRαβ+ cells of 119 normal persons. Two unusual cases besides the 119 normal persons showed extremely elevated frequencies of TCRαβ+CD4-8-T cells, viz., approximately 5 % to 10 % and 14 % to 19 % in whole TCRαβ+ cells. Both individuals were males who were otherwise physiologically quite normal with no history of severe illness, and these high frequencies were also observed in blood samples collected 2 or 8 years prior to the current measurements. The TCRαβ+CD4-8-T cells of the two individuals were found to express mature T-cell markers such as CD2,3, and 5 antigens, as well as natural killer (NK) cell markers, viz., CD11b, 16, 56, and 57 antigens, when peripheral blood lymphocytes were subjected to three-color flow cytometry. Lectin-dependent or redirected antibody-dependent cell-mediated cytotoxicities were observed for both freshly sorted TCRαβ+CD4-8- cells and in vitro established clones. Nevertheless, NK-like activity was not detected. Further, Southern blot analysis of TCRβ and γ genes revealed identical rearrangement patterns for all the TCRαβ+CD4-8- clones established in vitro. These results suggest that the TCRαβ+CD4-8-T cells from these two mean exhibit unique characteristics and proliferate clonally in vivo. (author)

  3. High numbers of differentiated effector CD4 T cells are found in patients with cancer and correlate with clinical response after neoadjuvant therapy of breast cancer.

    Science.gov (United States)

    Péguillet, Isabelle; Milder, Maud; Louis, Delphine; Vincent-Salomon, Anne; Dorval, Thierry; Piperno-Neumann, Sophie; Scholl, Suzy M; Lantz, Olivier

    2014-04-15

    CD4(+) T cells influence tumor immunity in complex ways that are not fully understood. In this study, we characterized a population of human differentiated effector CD4(+) T cells that is defined by low levels of the interleukin (IL)-2 and IL-7 receptors (CD25(-)CD127(-)). We found that this cell population expands in patients with various types of cancer, including breast cancer, to represent 2% to 20% of total CD4(+) blood T lymphocytes as compared with only 0.2% to 2% in healthy individuals. Notably, these CD25(-)CD127(-)CD4 T cells expressed effector markers such as CD244 and CD11b with low levels of CD27, contrasting with the memory phenotype dominating this population in healthy individuals. These cells did not cycle in patients, nor did they secrete IL-10 or IL-17, but instead displayed cytotoxic features. Moreover, they encompassed oligoclonal expansions paralleling an expansion of effector CD8(+) T cells that included tumor antigen-specific T cells. During neoadjuvant chemotherapy in patients with breast cancer, we found that the increase in CD25(-)CD127(-) CD4(+) T cells correlated with tumor regression. This observation suggested that CD4(+) T cells included tumor antigen-specific cells, which may be generated by or participate in tumor regressions during chemotherapy. In summary, our results lend support to the hypothesis that CD4(+) T cells are involved in human antitumor responses.

  4. Dysregulated cytokine expression by CD4+ T cells from post-septic mice modulates both Th1 and Th2-mediated granulomatous lung inflammation.

    Directory of Open Access Journals (Sweden)

    William F Carson

    Full Text Available Previous epidemiological studies in humans and experimental studies in animals indicate that survivors of severe sepsis exhibit deficiencies in the activation and effector function of immune cells. In particular, CD4+ T lymphocytes can exhibit reduced proliferative capacity and improper cytokine responses following sepsis. To further investigate the cell-intrinsic defects of CD4+ T cells following sepsis, splenic CD4+ T cells from sham surgery and post-septic mice were transferred into lymphopenic mice. These recipient mice were then subjected to both TH1-(purified protein derivative and TH2-(Schistosoma mansoni egg antigen driven models of granulomatous lung inflammation. Post-septic CD4+ T cells mediated smaller TH1 and larger TH2 lung granulomas as compared to mice receiving CD4+ T cells from sham surgery donors. However, cytokine production by lymph node cells in antigen restimulation assays indicated increased pan-specific cytokine expression by post-septic CD4+ T cell recipient mice in both TH1 and TH2 granuloma models. These include increased production of T(H2 cytokines in TH1 inflammation, and increased production of T(H1 cytokines in TH2 inflammation. These results suggest that cell-intrinsic defects in CD4+ T cell effector function can have deleterious effects on inflammatory processes post-sepsis, due to a defect in the proper regulation of TH-specific cytokine expression.

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

    Science.gov (United States)

    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.

  6. CD4:CD8 lymphocyte ratio as a quantitative measure of immunologic health in HIV-1 infection: findings from an African cohort with prospective data

    Science.gov (United States)

    Tang, Jianming; Li, Xuelin; Price, Matthew A.; Sanders, Eduard J.; Anzala, Omu; Karita, Etienne; Kamali, Anatoli; Lakhi, Shabir; Allen, Susan; Hunter, Eric; Kaslow, Richard A.; Gilmour, Jill

    2015-01-01

    In individuals with human immunodeficiency virus type 1 (HIV-1) infection, CD4:CD8 lymphocyte ratio is often recognized as a quantitative outcome that reflects the critical role of both CD4+ and CD8+ T-cells in HIV-1 pathogenesis or disease progression. Our work aimed to first establish the dynamics and clinical relevance of CD4:CD8 ratio in a cohort of native Africans and then to examine its association with viral and host factors, including: (i) length of infection, (ii) demographics, (iii) HIV-1 viral load (VL), (iv) change in CD4+ T-lymphocyte count (CD4 slope), (v) HIV-1 subtype, and (vi) host genetics, especially human leukocyte antigen (HLA) variants. Data from 499 HIV-1 seroconverters with frequent (monthly to quarterly) follow-up revealed that CD4:CD8 ratio was stable in the first 3 years of infection, with a modest correlation with VL and CD4 slope. A relatively normal CD4:CD8 ratio (>1.0) in early infection was associated with a substantial delay in disease progression to severe immunodeficiency (hazards ratio (HR) = 0.43, 95% confidence interval (CI) = 0.29-0.63, P 1.0, but HLA variants (e.g., HLA-B*57 and HLA-B*81) previously associated with VL and/or CD4 trajectories in eastern and southern Africans had no obvious impact on CD4:CD8 ratio. Collectively, these findings suggest that CD4:CD8 ratio is a robust measure of immunologic health with both clinical and epidemiological implications. PMID:26191056

  7. Cyclotriazadisulfonamides: promising new CD4-targeted anti-HIV drugs.

    Science.gov (United States)

    Vermeire, Kurt; Schols, Dominique

    2005-08-01

    It is imperative to continue efforts to identify novel effective therapies that can assist in containing the spread of HIV. Recently acquired knowledge about the HIV entry process points to new strategies to block viral entry. For most HIV strains, the successful infection of their target cells is mainly dependent on the presence of the CD4 surface molecule, which serves as the primary virus receptor. The attachment of the viral envelope to this cellular CD4 receptor can be considered as an ideal target with multiple windows of opportunity for therapeutic intervention. Therefore, drugs that interfere with the CD4 receptor, and thus inhibit viral entry, may be promising agents for the treatment of AIDS. The CD4-targeted HIV entry inhibitors cyclotriazadisulfonamides represent a novel class of small molecule antiviral agents with a unique mode of action. The lead compound, CADA, specifically interacts with the cellular CD4 receptor and is active against a wide variety of HIV strains at submicromolar levels when evaluated in different cell-types such as T cells, monocytes and dendritic cells. Moreover, a strict correlation has been demonstrated between anti-HIV activity and CD4 interaction of about 20 different CADA analogues. In addition, CADA acted synergistically in combination with all other FDA-approved anti-HIV drugs as well as with compounds that target the main HIV co-receptors. In this article, the characteristics of cyclotriazadisulfonamide compounds are presented and the possible application of CADA as a microbicide is also discussed. PMID:15980096

  8. Reduced Plasmodium Parasite Burden Associates with CD38+ CD4+ T Cells Displaying Cytolytic Potential and Impaired IFN-γ Production

    Science.gov (United States)

    Burel, Julie G.; Apte, Simon H.; Groves, Penny L.; Klein, Kerenaftali; McCarthy, James S.; Doolan, Denise L.

    2016-01-01

    Using a unique resource of samples from a controlled human malaria infection (CHMI) study, we identified a novel population of CD4+ T cells whose frequency in the peripheral blood was inversely correlated with parasite burden following P. falciparum infection. These CD4+ T cells expressed the multifunctional ectoenzyme CD38 and had unique features that distinguished them from other CD4+ T cells. Specifically, their phenotype was associated with proliferation, activation and cytotoxic potential as well as significantly impaired production of IFN-γ and other cytokines and reduced basal levels of activated STAT1. A CD38+ CD4+ T cell population with similar features was identified in healthy uninfected individuals, at lower frequency. CD38+ CD4+ T cells could be generated in vitro from CD38- CD4+ T cells after antigenic or mitogenic stimulation. This is the first report of a population of CD38+ CD4+ T cells with a cytotoxic phenotype and markedly impaired IFN-γ capacity in humans. The expansion of this CD38+ CD4+ T population following infection and its significant association with reduced blood-stage parasite burden is consistent with an important functional role for these cells in protective immunity to malaria in humans. Their ubiquitous presence in humans suggests that they may have a broad role in host-pathogen defense. Trial Registration ClinicalTrials.gov clinical trial numbers ACTRN12612000814875, ACTRN12613000565741 and ACTRN12613001040752 PMID:27662621

  9. Peripheral tolerance through clonal deletion of mature CD4-CD8+ T cells.

    Science.gov (United States)

    Carlow, D A; Teh, S J; van Oers, N S; Miller, R G; Teh, H S

    1992-05-01

    Transgenic mice bearing the alpha beta transgenes encoding a defined T cell receptor specific for the male (H-Y) antigen presented by the H-2Db class I MHC molecule were used to study mechanisms of peripheral tolerance. Female transgenic mice produce large numbers of functionally homogeneous CD8+ male antigen-reactive T cells in the thymus that subsequently accumulate in the peripheral lymphoid organs. We have used three experimental approaches to show that male reactive CD8+ T cells can be eliminated from peripheral lymphoid organs after exposure to male antigen. (i) In female transgenic mice that were neonatally tolerized with male spleen cells, male reactive CD8+ T cells continued to be produced in large numbers in the thymus but were virtually absent in the lymph nodes. (ii) Injection of thymocytes from female transgenic mice into female mice neonatally tolerized with the male antigen, or into normal male mice, led to the specific elimination of male-reactive CD8+ T cells in the lymph nodes. (iii) Four days after male lymphoid cells were injected intravenously into female transgenic mice, male antigen-reactive CD8+ T cells recovered from the lymph nodes of recipient mice were highly apoptotic when compared to CD4+ (non-male reactive) T cells. These data indicate that tolerance to extrathymic antigen can be achieved through elimination of mature T cells in the peripheral lymphoid organs.

  10. Multidimensional Clusters of CD4+T Cell Dysfunction Are Primarily Associated with the CD4/CD8 Ratio in Chronic HIV Infection

    DEFF Research Database (Denmark)

    Frederiksen, Juliet Wairimu; Buggert, Marcus; Noyan, Kajsa;

    2015-01-01

    correlation analyses between laboratory parameters and pathological CD4+ clusters revealed that the CD4/CD8 ratio was the preeminent surrogate marker of CD4+ T cells dysfunction using all three methods. Increased frequencies of an early-differentiated CD4+ T cell cluster with high CD38, HLA-DR and PD-1...

  11. Direct ex vivo detection of HLA-DR3-restricted cytomegalovirus- and Mycobacterium tuberculosis-specific CD4+ T cells.

    Science.gov (United States)

    Bronke, Corine; Palmer, Nanette M; Westerlaken, Geertje H A; Toebes, Mireille; van Schijndel, Gijs M W; Purwaha, Veenu; van Meijgaarden, Krista E; Schumacher, Ton N M; van Baarle, Debbie; Tesselaar, Kiki; Geluk, Annemieke

    2005-09-01

    In order to detect epitope-specific CD4+ T cells in mycobacterial or viral infections in the context of human class II major histocompatibility complex protein human leukocyte antigen (HLA)-DR3, two HLA-DR3 tetrameric molecules were successfully produced. One contained an immunodominant HLA-DR3-restricted T-cell epitope derived from the 65-kDa heat-shock protein of Mycobacterium tuberculosis, peptide 1-13. For the other tetramer, we used an HLA-DR3-restricted T-cell epitope derived from cytomegalovirus (CMV) pp65 lower matrix protein, peptide 510-522, which induced high levels of interferon (IFN)-gamma-producing CD4+ T cells in three of four HLA-DR3-positive CMV-seropositive individuals up to 0.84% of CD4+ T cells by intracellular cytokine staining. In peripheral blood mononuclear cells from M. tuberculosis-exposed, Mycobacterium bovis bacille Calmette-Guérin (BCG)-vaccinated, or CMV-seropositive individuals, we were able to directly detect with both tetramers epitope-specific T cells up to 0.62% and 0.45% of the CD4+ T-cell population reactive to M. tuberculosis and CMV, respectively. After a 6-day culture with peptide p510-522, the frequency of CMV-specific tetramer-binding T cells was expanded up to 9.90% tetramer+ CFSElow (5,6-carboxyfluorescein diacetate succinimidyl ester) cells within the CD4+ T-cell population, further confirming the specificity of the tetrameric molecules. Thus, HLA-DR3/peptide tetrameric molecules can be used to investigate HLA-DR3-restricted antigen-specific CD4+ T cells in clinical disease or after vaccination.

  12. Oct1 and OCA-B are selectively required for CD4 memory T cell function.

    Science.gov (United States)

    Shakya, Arvind; Goren, Alon; Shalek, Alex; German, Cody N; Snook, Jeremy; Kuchroo, Vijay K; Yosef, Nir; Chan, Raymond C; Regev, Aviv; Williams, Matthew A; Tantin, Dean

    2015-11-16

    Epigenetic changes are crucial for the generation of immunological memory. Failure to generate or maintain these changes will result in poor memory responses. Similarly, augmenting or stabilizing the correct epigenetic states offers a potential method of enhancing memory. Yet the transcription factors that regulate these processes are poorly defined. We find that the transcription factor Oct1 and its cofactor OCA-B are selectively required for the in vivo generation of CD4(+) memory T cells. More importantly, the memory cells that are formed do not respond properly to antigen reencounter. In vitro, both proteins are required to maintain a poised state at the Il2 target locus in resting but previously stimulated CD4(+) T cells. OCA-B is also required for the robust reexpression of multiple other genes including Ifng. ChIPseq identifies ∼50 differentially expressed direct Oct1 and OCA-B targets. We identify an underlying mechanism involving OCA-B recruitment of the histone lysine demethylase Jmjd1a to targets such as Il2, Ifng, and Zbtb32. The findings pinpoint Oct1 and OCA-B as central mediators of CD4(+) T cell memory. PMID:26481684

  13. Human CD4+ T cell epitopes from vaccinia virus induced by vaccination or infection.

    Directory of Open Access Journals (Sweden)

    J Mauricio Calvo-Calle

    2007-10-01

    Full Text Available Despite the importance of vaccinia virus in basic and applied immunology, our knowledge of the human immune response directed against this virus is very limited. CD4(+ T cell responses are an important component of immunity induced by current vaccinia-based vaccines, and likely will be required for new subunit vaccine approaches, but to date vaccinia-specific CD4(+ T cell responses have been poorly characterized, and CD4(+ T cell epitopes have been reported only recently. Classical approaches used to identify T cell epitopes are not practical for large genomes like vaccinia. We developed and validated a highly efficient computational approach that combines prediction of class II MHC-peptide binding activity with prediction of antigen processing and presentation. Using this approach and screening only 36 peptides, we identified 25 epitopes recognized by T cells from vaccinia-immune individuals. Although the predictions were made for HLA-DR1, eight of the peptides were recognized by donors of multiple haplotypes. T cell responses were observed in samples of peripheral blood obtained many years after primary vaccination, and were amplified after booster immunization. Peptides recognized by multiple donors are highly conserved across the poxvirus family, including variola, the causative agent of smallpox, and may be useful in development of a new generation of smallpox vaccines and in the analysis of the immune response elicited to vaccinia virus. Moreover, the epitope identification approach developed here should find application to other large-genome pathogens.

  14. Public T cell receptors confer high-avidity CD4 responses to HIV controllers.

    Science.gov (United States)

    Benati, Daniela; Galperin, Moran; Lambotte, Olivier; Gras, Stéphanie; Lim, Annick; Mukhopadhyay, Madhura; Nouël, Alexandre; Campbell, Kristy-Anne; Lemercier, Brigitte; Claireaux, Mathieu; Hendou, Samia; Lechat, Pierre; de Truchis, Pierre; Boufassa, Faroudy; Rossjohn, Jamie; Delfraissy, Jean-François; Arenzana-Seisdedos, Fernando; Chakrabarti, Lisa A

    2016-06-01

    The rare patients who are able to spontaneously control HIV replication in the absence of therapy show signs of a particularly efficient cellular immune response. To identify the molecular determinants that underlie this response, we characterized the T cell receptor (TCR) repertoire directed at Gag293, the most immunoprevalent CD4 epitope in the HIV-1 capsid. HIV controllers from the ANRS CODEX cohort showed a highly skewed TCR repertoire that was characterized by a predominance of TRAV24 and TRBV2 variable genes, shared CDR3 motifs, and a high frequency of public clonotypes. The most prevalent public clonotypes generated TCRs with affinities at the higher end of values reported for naturally occurring TCRs. The high-affinity Gag293-specific TCRs were cross-restricted by up to 5 distinct HLA-DR alleles, accounting for the expression of these TCRs in HIV controllers of diverse genetic backgrounds. Transfer of these TCRs to healthy donor CD4+ T cells conferred high antigen sensitivity and polyfunctionality, thus recapitulating key features of the controller CD4 response. Transfer of a high-affinity Gag293-specific TCR also redirected CD8+ T cells to target HIV-1 capsid via nonconventional MHC II restriction. Together, these findings indicate that TCR clonotypes with superior functions are associated with HIV control. Amplification or transfer of such clonotypes may contribute to immunotherapeutic approaches aiming at a functional HIV cure. PMID:27111229

  15. Novel function of perforin in negatively regulating CD4+T cell activation by affecting calcium signaling

    Institute of Scientific and Technical Information of China (English)

    Enguang Bi; Kairui Mao; Jia Zou; Yuhan Zheng; Bing Sun; Chunjian Huang; Yu Hu; Xiaodong Wu; Weiwen Deng; Guomei Lin; Zhiduo Liu; Lin Tian; Shuhui Sun

    2009-01-01

    Perforin is a pore-forming protein engaged mainly in mediating target T cell death and is employed by cytotoxic Tlymphocytes (CTLs) and natural killer cells. However, whether it also plays a role in conventional CD4+ T cell func-tion remains unclear. Here we report that in perforin-deficient (PKO) mice, CD4+ T cells are hyperproliferative in response to T cell receptor (TCR) stimulation. This feature of hyperproliferation is accompanied by the enhancement both in cell division and in IL-2 secretion. It seems that the perforin deficiency does not influence T cell development in thymus spleen and lymph node. In vivo, perforin deficiency results in increased antigen-specific T cell prolifera-tion and antibody production. Furthermore, PKO mice are more susceptible to experimental autoimmune uveitis. To address the molecular mechanism, we found that after TCR stimulation, CD44 T cells from PKO mice display an increased intracellular calcium flux and subsequently enhance activation of transcription factor NFATI. Our results indicate that perforin plays a negative role in regulating CD4+ T cell activation and immune response by affecting TCR-dependent Ca2+ signaling.

  16. Immediate dysfunction of vaccine-elicited CD8+ T cells primed in the absence of CD4+ T cells

    Science.gov (United States)

    Provine, Nicholas M.; Larocca, Rafael A.; Aid, Malika; Penaloza-MacMaster, Pablo; Badamchi-Zadeh, Alexander; Borducchi, Erica N.; Yates, Kathleen B.; Abbink, Peter; Kirilova, Marinela; Ng’ang’a, David; Bramson, Jonathan; Haining, W. Nicholas; Barouch, Dan H.

    2016-01-01

    CD4+ T cell help is critical for optimal CD8+ T cell memory differentiation and maintenance in many experimental systems. Additionally, many reports have identified reduced primary CD8+ T cell responses in the absence of CD4+ T cell help, which often coincides with reduced antigen or pathogen clearance. Here we demonstrate that absence of CD4+ T cells at the time of adenovirus vector immunization of mice led to immediate impairments in early CD8+ T cell functionality and differentiation. Unhelped CD8+ T cells exhibited a reduced effector phenotype, decreased ex vivo cytotoxicity, and decreased capacity to produce cytokines. This dysfunctional state was imprinted within 3 days of immunization. Unhelped CD8+ T cells expressed elevated levels of inhibitory receptors and exhibited transcriptomic exhaustion and anergy profiles by gene set enrichment analysis. Dysfunctional, impaired effector differentiation also occurred following immunization of CD4+ T cell-deficient mice with a poxvirus vector. This study demonstrates that following priming with viral vectors, CD4+ T cell help is required to promote both the expansion and acquisition of effector functions by CD8+ T cells, which is accomplished by preventing immediate dysfunction. PMID:27448585

  17. Innate lymphoid cells regulate CD4+ T-cell responses to intestinal commensal bacteria.

    Science.gov (United States)

    Hepworth, Matthew R; Monticelli, Laurel A; Fung, Thomas C; Ziegler, Carly G K; Grunberg, Stephanie; Sinha, Rohini; Mantegazza, Adriana R; Ma, Hak-Ling; Crawford, Alison; Angelosanto, Jill M; Wherry, E John; Koni, Pandelakis A; Bushman, Frederic D; Elson, Charles O; Eberl, Gérard; Artis, David; Sonnenberg, Gregory F

    2013-06-01

    Innate lymphoid cells (ILCs) are a recently characterized family of immune cells that have critical roles in cytokine-mediated regulation of intestinal epithelial cell barrier integrity. Alterations in ILC responses are associated with multiple chronic human diseases, including inflammatory bowel disease, implicating a role for ILCs in disease pathogenesis. Owing to an inability to target ILCs selectively, experimental studies assessing ILC function have predominantly used mice lacking adaptive immune cells. However, in lymphocyte-sufficient hosts ILCs are vastly outnumbered by CD4(+) T cells, which express similar profiles of effector cytokines. Therefore, the function of ILCs in the presence of adaptive immunity and their potential to influence adaptive immune cell responses remain unknown. To test this, we used genetic or antibody-mediated depletion strategies to target murine ILCs in the presence of an adaptive immune system. We show that loss of retinoic-acid-receptor-related orphan receptor-γt-positive (RORγt(+)) ILCs was associated with dysregulated adaptive immune cell responses against commensal bacteria and low-grade systemic inflammation. Remarkably, ILC-mediated regulation of adaptive immune cells occurred independently of interleukin (IL)-17A, IL-22 or IL-23. Genome-wide transcriptional profiling and functional analyses revealed that RORγt(+) ILCs express major histocompatibility complex class II (MHCII) and can process and present antigen. However, rather than inducing T-cell proliferation, ILCs acted to limit commensal bacteria-specific CD4(+) T-cell responses. Consistent with this, selective deletion of MHCII in murine RORγt(+) ILCs resulted in dysregulated commensal bacteria-dependent CD4(+) T-cell responses that promoted spontaneous intestinal inflammation. These data identify that ILCs maintain intestinal homeostasis through MHCII-dependent interactions with CD4(+) T cells that limit pathological adaptive immune cell responses to commensal

  18. Human cerebrospinal fluid contains CD4+ memory T cells expressing gut- or skin-specific trafficking determinants: relevance for immunotherapy

    Directory of Open Access Journals (Sweden)

    Campbell James J

    2006-07-01

    Full Text Available Abstract Background Circulating memory T cells can be divided into tissue-specific subsets, which traffic through distinct tissue compartments during physiologic immune surveillance, based on their expression of adhesion molecules and chemokine receptors. We reasoned that a bias (either enrichment or depletion of CSF T cell expression of known organ-specific trafficking determinants might suggest that homing of T cells to the subarachnoid space could be governed by a CNS-specific adhesion molecule or chemokine receptor. Results The expression of cutaneous leukocyte antigen (CLA and CC-chemokine receptor 4 (CCR4; associated with skin-homing as well as the expression of integrin α4β7 and CCR9 (associated with gut-homing was analyzed on CD4+ memory T cells in CSF from individuals with non-inflammatory neurological diseases using flow cytometry. CSF contained similar proportions of CD4+ memory T cells expressing CLA, CCR4, integrin α4β7 and CCR9 as paired blood samples. Conclusion The results extend our previous findings that antigen-experienced CD4+ memory T cells traffic through the CSF in proportion to their abundance in the peripheral circulation. Furthermore, the ready access of skin- and gut-homing CD4+ memory T cells to the CNS compartment via CSF has implications for the mechanisms of action of immunotherapeutic strategies, such as oral tolerance or therapeutic immunization, where immunogens are administered using an oral or subcutaneous route.

  19. Idiopathic CD4+ lymphocytopenia: natural history and prognostic factors

    Science.gov (United States)

    Falloon, Judith; Bennett, John E.; Shaw, Pamela A.; Chaitt, Doreen; Baseler, Michael W.; Adelsberger, Joseph W.; Metcalf, Julia A.; Polis, Michael A.; Kovacs, Stephen J.; Kovacs, Joseph A.; Davey, Richard T.; Lane, H. Clifford; Masur, Henry

    2008-01-01

    Idiopathic CD4+ lymphocytopenia (ICL) is a rare non–HIV-related syndrome with unclear natural history and prognosis. This prospective natural history cohort study describes the clinical course, CD4 T lymphocyte kinetics, outcome, and prognostic factors of ICL. Thirty-nine patients (17 men, 22 women) 25 to 85 years old with ICL were evaluated between 1992 and 2006, and 36 were followed for a median of 49.5 months. Cryptococcal and nontuberculous mycobacterial infections were the major presenting opportunistic infections. Seven patients presented with no infection. In 32, CD4 T-cell counts remained less than 300/mm3 throughout the study period and in 7 normalized after an average of 31 months. Overall, 15 (41.6%) developed an opportunistic infection in follow-up, 5 (13.8%) of which were “AIDS-defining clinical conditions,” and 4 (11.1%) developed autoimmune diseases. Seven patients died, 4 from ICL-related opportunistic infections, within 42 months after diagnosis. Immunologic analyses revealed increased activation and turnover in CD4 but not CD8 T lymphocytes. CD8 T lymphocytopenia (< 180/mm3) and the degree of CD4 T cell activation (measured by HLA-DR expression) at presentation were associated with adverse outcome (opportunistic infection-related death; P = .003 and .02, respectively). This trial is registered at http://clinicaltrials.gov as #NCT00001319. PMID:18456875

  20. Adoptive immunotherapy via CD4+ versus CD8+ T cells

    Directory of Open Access Journals (Sweden)

    Vy Phan-Lai

    2016-04-01

    Full Text Available The goal of cancer immunotherapy is to induce specific and durable antitumor immunity. Adoptive T cell therapy (ACT has garnered wide interest, particularly in regard to strategies to improve T cell efficacy in trials. There are many types of T cells (and subsets which can be selected for use in ACT. CD4+ T cells are critical for the regulation, activation and aid of host defense mechanisms and, importantly, for enhancing the function of tumor-specific CD8+ T cells. To date, much research in cancer immunotherapy has focused on CD8+ T cells, in melanoma and other cancers. Both CD4+ T cells and CD8+ T cells have been evaluated as ACT in mice and humans, and both are effective at eliciting antitumor responses. IL-17 producing CD4+ T cells are a new subset of CD4+ T cells to be evaluated in ACT models. This review discusses the benefits of adoptive immunotherapy mediated by CD8+ and CD4+ cells. It also discusses the various type of T cells, source of T cells, and ex vivo cytokine growth factors for augmenting clinical efficacy of ACT. [Biomed Res Ther 2016; 3(4.000: 588-595

  1. CD4+ T cell responses in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Nasser Semmo; Paul Klenerman

    2007-01-01

    Hepatitis C virus (HCV) infection is a major cause of liver damage, with virus-induced end-stage disease such as liver cirrhosis and hepatocellular carcinoma resulting in a high rate of morbidity and mortality worldwide. Evidence that CD4+ T cell responses to HCV play an important role in the outcome of acute infection has been shown in several studies. However, the mechanisms behind viral persistence and the failure of CD4+ T cell responses to contain virus are poorly understood. During chronic HCV infection, HCV-specific CD4+ T cell responses are relatively weak or absent whereas in resolved infection these responses are vigorous and multispecific. Persons with a T-helper type Ⅰ profile, which promotes cellular effector mechanisms are thought to be more likely to experience viral clearance, but the overall role of these cells in the immunopathogenesis of chronic liver disease is not known. To define this, much more data is required on the function and specificity of virus-specific CD4+ T cells,especially in the early phases of acute disease and in the liver during chronic infection. The role and possible mechanisms of action of CD4+ T cell responses in determining the outcome of acute and chronic HCV infection will be discussed in this review.

  2. Circulating subsets and CD4(+)CD25(+) regulatory T cell function in chronic inflammatory demyelinating polyradiculoneuropathy.

    Science.gov (United States)

    Sanvito, Lara; Makowska, Anna; Gregson, Norman; Nemni, Raffaello; Hughes, Richard A C

    2009-01-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an inflammatory disease of the peripheral nervous system that is probably autoimmune in origin. Different components of the adaptive and innate immunity may be responsible for the aberrant response towards nerve antigens. To investigate this, we examined lymphocyte subsets and regulatory T cell (Treg) function in the blood of CIDP patients, healthy controls (HC) and subjects with non-immune mediated neuropathies (other neuropathies, ON). We used flow cytometry to determine the frequency of monocytes, B cells, natural killer (NK) and NK-T cells, total and activated CD4(+) and CD8(+) T cells, effector memory and central memory CD4(+) and CD8(+) T cells, and CD4(+)CD25(high)Foxp3(+) Tregs. Treg function was studied after polyclonal stimulation and antigen specific stimulation with myelin protein peptides in CIDP and HC. There was an increased frequency of monocytes (p = 0.02) and decreased frequency of NK cells (p = 0.02) in CIDP compared with HC but not ON. There were no significant differences in other populations. Treg function was impaired in CIDP compared to HC (p = 0.02), whilst T cell proliferation to myelin protein peptides before and after depletion of Tregs was not different between patients and controls. This study shows increased circulating monocytes and reduced NK cells in CIDP. Although Treg frequency was not altered, we confirm that Tregs display a defect of suppressive function. Myelin protein peptides were not the target of the altered peripheral regulation of the immune response. The mechanisms of peripheral immune tolerance in CIDP and their relevance to the pathogenesis deserve further exploration.

  3. Affinity and dose of TCR engagement yield proportional enhancer and gene activity in CD4+ T cells

    Science.gov (United States)

    Allison, Karmel A; Sajti, Eniko; Collier, Jana G; Gosselin, David; Troutman, Ty Dale; Stone, Erica L; Hedrick, Stephen M; Glass, Christopher K

    2016-01-01

    Affinity and dose of T cell receptor (TCR) interaction with antigens govern the magnitude of CD4+ T cell responses, but questions remain regarding the quantitative translation of TCR engagement into downstream signals. We find that while the response of mouse CD4+ T cells to antigenic stimulation is bimodal, activated cells exhibit analog responses proportional to signal strength. Gene expression output reflects TCR signal strength, providing a signature of T cell activation. Expression changes rely on a pre-established enhancer landscape and quantitative acetylation at AP-1 binding sites. Finally, we show that graded expression of activation genes depends on ERK pathway activation, suggesting that an ERK-AP-1 axis plays an important role in translating TCR signal strength into proportional activation of enhancers and genes essential for T cell function. DOI: http://dx.doi.org/10.7554/eLife.10134.001 PMID:27376549

  4. Transcriptional regulatory networks for CD4 T cell differentiation.

    Science.gov (United States)

    Christie, Darah; Zhu, Jinfang

    2014-01-01

    CD4(+) T cells play a central role in controlling the adaptive immune response by secreting cytokines to activate target cells. Naïve CD4(+) T cells differentiate into at least four subsets, Th1Th1 , Th2Th2 , Th17Th17 , and inducible regulatory T cellsregulatory T cells , each with unique functions for pathogen elimination. The differentiation of these subsets is induced in response to cytokine stimulation, which is translated into Stat activation, followed by induction of master regulator transcription factorstranscription factors . In addition to these factors, multiple other transcription factors, both subset specific and shared, are also involved in promoting subset differentiation. This review will focus on the network of transcription factors that control CD4(+) T cell differentiation.

  5. TSCOT+ thymic epithelial cell-mediated sensitive CD4 tolerance by direct presentation.

    Directory of Open Access Journals (Sweden)

    Sejin Ahn

    2008-08-01

    Full Text Available Although much effort has been directed at dissecting the mechanisms of central tolerance, the role of thymic stromal cells remains elusive. In order to further characterize this event, we developed a mouse model restricting LacZ to thymic stromal cotransporter (TSCOT-expressing thymic stromal cells (TDLacZ. The thymus of this mouse contains approximately 4,300 TSCOT+ cells, each expressing several thousand molecules of the LacZ antigen. TSCOT+ cells express the cortical marker CDR1, CD40, CD80, CD54, and major histocompatibility complex class II (MHCII. When examining endogenous responses directed against LacZ, we observed significant tolerance. This was evidenced in a diverse T cell repertoire as measured by both a CD4 T cell proliferation assay and an antigen-specific antibody isotype analysis. This tolerance process was at least partially independent of Autoimmune Regulatory Element gene expression. When TDLacZ mice were crossed to a novel CD4 T cell receptor (TCR transgenic reactive against LacZ (BgII, there was a complete deletion of double-positive thymocytes. Fetal thymic reaggregate culture of CD45- and UEA-depleted thymic stromal cells from TDLacZ and sorted TCR-bearing thymocytes excluded the possibility of cross presentation by thymic dendritic cells and medullary epithelial cells for the deletion. Overall, these results demonstrate that the introduction of a neoantigen into TSCOT-expressing cells can efficiently establish complete tolerance and suggest a possible application for the deletion of antigen-specific T cells by antigen introduction into TSCOT+ cells.

  6. Human cytomegalovirus latency-associated proteins elicit immune-suppressive IL-10 producing CD4⁺ T cells.

    Directory of Open Access Journals (Sweden)

    Gavin M Mason

    Full Text Available Human cytomegalovirus (HCMV is a widely prevalent human herpesvirus, which, after primary infection, persists in the host for life. In healthy individuals, the virus is well controlled by the HCMV-specific T cell response. A key feature of this persistence, in the face of a normally robust host immune response, is the establishment of viral latency. In contrast to lytic infection, which is characterised by extensive viral gene expression and virus production, long-term latency in cells of the myeloid lineage is characterised by highly restricted expression of viral genes, including UL138 and LUNA. Here we report that both UL138 and LUNA-specific T cells were detectable directly ex vivo in healthy HCMV seropositive subjects and that this response is principally CD4⁺ T cell mediated. These UL138-specific CD4⁺ T cells are able to mediate MHC class II restricted cytotoxicity and, importantly, show IFNγ effector function in the context of both lytic and latent infection. Furthermore, in contrast to CDCD4⁺ T cells specific to antigens expressed solely during lytic infection, both the UL138 and LUNA-specific CD4⁺ T cell responses included CD4⁺ T cells that secreted the immunosuppressive cytokine cIL-10. We also show that cIL-10 expressing CD4⁺ T-cells are directed against latently expressed US28 and UL111A. Taken together, our data show that latency-associated gene products of HCMV generate CD4⁺ T cell responses in vivo, which are able to elicit effector function in response to both lytic and latently infected cells. Importantly and in contrast to CD4⁺ T cell populations, which recognise antigens solely expressed during lytic infection, include a subset of cells that secrete the immunosuppressive cytokine cIL-10. This suggests that HCMV skews the T cell responses to latency-associated antigens to one that is overall suppressive in order to sustain latent carriage in vivo.

  7. Differentiation of Effector CD4 T Cell Populations*

    OpenAIRE

    Zhu, Jinfang; Yamane, Hidehiro; Paul, William E.

    2010-01-01

    CD4 T cells play critical roles in mediating adaptive immunity to a variety of pathogens. They are also involved in autoimmunity, asthma, and allergic responses as well as in tumor immunity. During TCR activation in a particular cytokine milieu, naive CD4 T cells may differentiate into one of several lineages of T helper (Th) cells, including Th1, Th2, Th17, and iTreg, as defined by their pattern of cytokine production and function. In this review, we summarize the discovery, functions, and r...

  8. THE EFFECT OF VIRGIN COCONUT OIL ON LYMPHOCYTE AND CD4 IN CHICKEN VACCINATED AGAINST Avian Influenza VIRUS

    Directory of Open Access Journals (Sweden)

    E.Y.W. Yuniwarti

    2014-10-01

    Full Text Available This research aimed to find preventing alternative of avian influenza (AI disease in broiler chickenby increasing body immune. Lymphocyte T would directly react to antigen presented to the cell surfaceby antigen presenting cell (APC. Th-CD4 interaction functioned to maintain Th-APC bond intactduring specific antigen activation. Fatty acid in virgin coconut oil (VCO was potential asimmunostimulant, which therefore could increase chicken immunity through the increase of lymphocyteT and Th-CD4. This research used 40 one-day-old broiler chickens. The method applied was CompletelyRandomized Factorial Design in which the first factor was two levels of vaccine, namely groups of AIvaccinated and unvaccinated. The second factor was four levels of VCO namely 0, 5, 10, 15 mL/kg feed.Day Old Chick (DOC were divided into eight treatment groups and repeated five times. Feed and waterwere given ad libitum for four weeks. The result showed that the number of lymphocyte and Th-CD4 inchickens given 10 mL per kg feed and vaccinated with AI was higher than that in chickens given VCOwithout AI vaccine.

  9. THE EFFECT OF VIRGIN COCONUT OIL ON LYMPHOCYTE AND CD4 IN CHICKEN VACCINATED AGAINST Avian Influenza VIRUS

    Directory of Open Access Journals (Sweden)

    E. Y. W. Yuniwarti

    2012-03-01

    Full Text Available This research aimed to find preventing alternative of avian influenza (AI disease in broiler chicken by increasing body immune. Lymphocyte T would directly react to antigen presented to the cell surface by antigen presenting cell (APC. Th-CD4 interaction functioned to maintain Th-APC bond intact during specific antigen activation. Fatty acid in virgin coconut oil (VCO was potential as immunostimulant, which therefore could increase chicken immunity through the increase of lymphocyte T and Th-CD4. This research used 40 one-day-old broiler chickens. The method applied was Completely Randomized Factorial Design in which the first factor was two levels of vaccine, namely groups of AI vaccinated and unvaccinated. The second factor was four levels of VCO namely 0, 5, 10, 15 mL/kg feed. Day Old Chick (DOC were divided into eight treatment groups and repeated five times. Feed and water were given ad libitum for four weeks. The result showed that the number of lymphocyte and Th-CD4 in chickens given 10 mL per kg feed and vaccinated with AI was higher than that in chickens given VCO without AI vaccine.

  10. Abundance and specificity of influenza reactive circulating memory follicular helper and non-follicular helper CD4 T cells in healthy adults.

    Science.gov (United States)

    Leddon, Scott A; Richards, Katherine A; Treanor, John J; Sant, Andrea J

    2015-09-01

    CD4 T-cell responses are functionally complex and regulate many aspects of innate and adaptive immunity. Follicular helper (Tfh) cells are CD4 T cells specialized to support B-cell production of isotype-switched, high-affinity antibody. So far, studies of Tfh cells in humans have focused on their differentiation requirements, with little research devoted to their antigen specificity. Here, after separating circulating human memory CD4 T cells based on expression of CXCR5, a signature marker of Tfh, we have quantified and assayed the influenza protein antigen specificity of blood Tfh cells and CD4 T cells lacking this marker. Through the use of peptide pools derived from nucleoprotein (NP) or haemagglutinin (HA) and a panel of human donors, we have discovered that circulating Tfh cells preferentially recognize peptide epitopes from HA while cells lacking CXCR5 are enriched for specificity toward NP. These studies suggest that reactive CD4 T cells specific for distinct viral antigens may have generalized differences in their functional potential due to their previous stimulation history. PMID:26094691

  11. Cellular plasticity of CD4+ T cells in the intestine

    Directory of Open Access Journals (Sweden)

    Verena eBrucklacher-Waldert

    2014-10-01

    Full Text Available Barrier sites such as the gastrointestinal tract are in constant contact with the environment which contains both beneficial and harmful components. The immune system at the epithelia must make the distinction between these components to balance tolerance, protection and immunopathology. This is achieved via multifaceted immune recognition, highly organised lymphoid structures and the interaction of many types of immune cells. The adaptive immune response in the gut is orchestrated by CD4+ helper T (Th cells which are integral to gut immunity. In recent years it has become apparent that the functional identity of these Th cells is not as fixed as initially thought. Plasticity in differentiated T cell subsets has now been firmly established, in both health and disease. The gut, in particular, utilises CD4+ T cell plasticity to mould CD4+ T cell phenotypes to maintain its finely poised balance of tolerance and inflammation and to encourage biodiversity within the enteric microbiome. In this review we will discuss intestinal helper T cell plasticity and our current understanding of its mechanisms, including our growing knowledge of an evolutionarily ancient symbiosis between microbiota and malleable CD4+ T cell effectors.

  12. Biomarkers of CD4+ CTL cell Mediated Immunity to Tuberculosis

    Science.gov (United States)

    The immune responses mediated by interactions between T-lymphocyte subsets and mycobacteria-infected macrophages are critical for control of tuberculosis. In these studies, the bovine model was used to characterize the cytolytic and mycobactericidal CD4+ T cell response induced by BCG vaccination. ...

  13. Requirement of cognate CD4+ T-cell recognition for the regulation of allospecific CTL by human CD4+ CD127- CD25+ FOXP3+ cells generated in MLR.

    Directory of Open Access Journals (Sweden)

    Yuming Yu

    Full Text Available Although immunoregulation of alloreactive human CTLs has been described, the direct influence of CD4(+ Tregs on CD8(+ cytotoxicity and the interactive mechanisms have not been well clarified. Therefore, human CD4(+CD127(-CD25(+FOXP3(+ Tregs were generated in MLR, immunoselected and their allospecific regulatory functions and associated mechanisms were then tested using modified (51Chromium release assays (Micro-CML, MLRs and CFSE-based multi-fluorochrome flow cytometry proliferation assays. It was observed that increased numbers of CD4(+CD127(-CD25(+FOXP3(+ cells were generated after a 7 day MLR. After immunoselection for CD4(+CD127(-CD25(+ cells, they were designated as MLR-Tregs. When added as third component modulators, MLR-Tregs inhibited the alloreactive proliferation of autologous PBMC in a concentration dependent manner. The inhibition was quasi-antigen specific, in that the inhibition was non-specific at higher MLR-Treg modulator doses, but non-specificity disappeared with lower numbers at which specific inhibition was still significant. When tested in micro-CML assays CTL inhibition occurred with PBMC and purified CD8(+ responders. However, antigen specificity of CTL inhibition was observed only with unpurified PBMC responders and not with purified CD8(+ responders or even with CD8(+ responders plus Non-T "APC". However, allospecificity of CTL regulation was restored when autologous purified CD4(+ T cells were added to the CD8(+ responders. Proliferation of CD8(+ cells was suppressed by MLR-Tregs in the presence or absence of IL-2. Inhibition by MLR-Tregs was mediated through down-regulation of intracellular perforin, granzyme B and membrane-bound CD25 molecules on the responding CD8(+ cells. Therefore, it was concluded that human CD4(+CD127(-CD25(+FOXP3(+ MLR-Tregs down-regulate alloreactive cytotoxic responses. Regulatory allospecificity, however, requires the presence of cognate responding CD4(+ T cells. CD8(+ CTL regulatory

  14. Association of high CD4-positive T cell infiltration with mutations in HLA class II-regulatory genes in microsatellite-unstable colorectal cancer.

    Science.gov (United States)

    Surmann, Eva-Maria; Voigt, Anita Y; Michel, Sara; Bauer, Kathrin; Reuschenbach, Miriam; Ferrone, Soldano; von Knebel Doeberitz, Magnus; Kloor, Matthias

    2015-03-01

    Besides being expressed on professional antigen-presenting cells, HLA class II antigens are expressed on various tumors of non-lymphoid origin, including a subset of colorectal cancers (CRC). Information about the regulation of HLA class II antigen expression is important for a better understanding of their role in the interactions between tumor and immune cells. Whether lack of HLA class II antigen expression in tumors reflects the selective immune destruction of HLA class II antigen-expressing tumor cells is unknown. To address this question, we tested whether lack of HLA class II antigen expression in CRC was associated with immune cell infiltration. We selected microsatellite-unstable (MSI-H) CRC, because they show pronounced tumor antigen-specific immune responses and, in a subset of tumors, lack of HLA class II antigen expression due to mutations inactivating HLA class II-regulatory genes. We examined HLA class II antigen expression, mutations in regulatory genes, and CD4-positive T cell infiltration in 69 MSI-H CRC lesions. Mutations in RFX5, CIITA, and RFXAP were found in 13 (28.9%), 3 (6.7%), and 1 (2.2%) out of 45 HLA class II antigen-negative tumors. CD4-positive tumor-infiltrating lymphocyte counts were significantly higher in HLA class II antigen-negative tumors harboring mutations in HLA class II-regulatory genes (107.4 T cells per 0.25 mm(2)) compared to tumors without mutations (55.5 T cells per 0.25 mm(2), p = 0.008). Our results suggest that the outgrowth of tumor cells lacking HLA class II antigen expression due to mutations of regulatory genes is favored in an environment of dense CD4-positive T cell infiltration.

  15. CD4+ T-cell lines used to evaluate a Mycobacterium avium subsp. paratuberculosis (MAP) peptide vaccine

    DEFF Research Database (Denmark)

    Lybeck, Kari; Sjurseth, Siri K.; Al-Touama, Zainab;

    The aim of the study was to establish a protocol for generation of MAP-specific T-cell lines and to use these lines for evaluation of a peptide vaccine. A protocol for culturing T-cell lines from peripheral blood of goats naturally infected with MAP was established. CD4+ T cells were positively...... selected using an anti CD4 mAb and Dynabeads. Sorted CD4+ cells were cultivated with purified protein derivative from MAP (PPDj) or E. coli sonicate, IL-2, and IL-15. After two cultivation cycles, T cells were tested for recall responses in a proliferative T-cell assay. T-cell line responses were in...... antigens. T-cell lines were now generated by cultivating CD4+ cells with peptides instead of PPDj. Initially, both healthy and MAP-infected goats were vaccinated with 119 peptides defined by in silico analysis. Cellular responses to the peptides were not detected using standard IFN- γ plasma ELISA. However...

  16. Complement receptor type 2 mediates infection of the human CD4-negative Raji B-cell line with opsonized HIV.

    Science.gov (United States)

    Boyer, V; Delibrias, C; Noraz, N; Fischer, E; Kazatchkine, M D; Desgranges, C

    1992-12-01

    Opsonization of the HTLV-RF and HTLV-IIIB strains of HIV-1 with normal human HIV seronegative serum under conditions that allow complement activation resulted in the productive infection of cells of the Raji B lymphoblastoid cell line. Under the same experimental conditions, no infection of Raji cells was observed with unopsonized virus. Infection of Raji cells with complement-opsonized HIV-1 was totally suppressed by preblocking the function of CR2 (the C3dg receptor, CD21) on the cells with a monoclonal anti-CR2 antibody cross-linked with rabbit F(ab')2 anti-mouse immunoglobulin antibodies. Infection of Raji cells occurred independently of CD4 since the cells lacked the expression of CD4 antigen and of CD4 transcripts. Thus, Raji cells may be infected with complement-opsonized HIV independently of CD4 and in the absence of antibodies. By mediating and/or enhancing HIV infection, complement and complement receptors contribute to extend the range of target cells to the virus and may increase infection in patients with a low viral load. PMID:1281336

  17. Heat Shock Proteins 60 and 70 Specific Proinflammatory and Cytotoxic Response of CD4+CD28null Cells in Chronic Kidney Disease

    Directory of Open Access Journals (Sweden)

    Ashok K. Yadav

    2013-01-01

    Full Text Available Background. CD4+CD28null T cells are expanded in peripheral blood of patients with chronic kidney disease and associated with subclinical atherosclerosis. However, triggers for the oligoclonal expansion and activation of these cells are not clear. Methods. We investigated twenty-five stage V-IV chronic kidney disease (CKD patients and eight healthy subjects (HC. Peripheral mononuclear cells were isolated and incubated with heat shock protein- (HSP 60 and 70. CD4+CD28null and CD4+CD28+ cells were sorted by flowcytometry and antigen specific response was assessed by the mRNA and protein expression of interferon (IFN-γ, perforin, and granzyme B using qRT-PCR and Elispot. Results. The basal mRNA expression of IFN-γ, perforin, and granzyme B in CD4+CD28null cells was higher in subjects with CKD compared to that in HC (P<0.0001. Subjects with CKD also showed expression of IFN-γ, perforin, and granzyme B in the CD4+CD28+ subset, but this was much weaker than that seen in the CD4+CD28null population (P<0.0001. We did not note the expression of these molecules at mRNA or protein level in either subset of CD4 cells in HC. After incubation with HSP60 and HSP70, CD4+CD28null cells showed increased expression at mRNA (P<0.001 and protein level (P<0.001. CD4+CD28+ cells also showed a weak increase in expression. No antigen-specific response was noted in HC. Conclusion. These data show that CD4+CD28null cells in subjects with CKD react with HSP60 and HSP70 by upregulating the expression of IFN-γ, perforin and granzyme B. Increased circulating level of HSP60 and HSP70 might play a role in initiation and/or progression of atherosclerosis in CKD subjects through perturbation of CD4+CD28null cells.

  18. Methotrexate induces poly(ADP-ribose) polymerase-dependent, caspase 3-independent apoptosis in subsets of proliferating CD4+ T cells

    DEFF Research Database (Denmark)

    Nielsen, C H; Albertsen, L; Bendtzen, K;

    2007-01-01

    The mechanism of action of methotrexate (MTX) in autoimmune diseases (AID) is unclear. A pro-apoptotic effect has been demonstrated in mitogen-stimulated peripheral blood mononuclear cells (PBMC), but studies employing conventional antigens have disputed a pro-apoptotic effect. CD4+ T helper (Th...

  19. Guanine Nucleotide-Binding Proteins of the G(12) Family Shape Immune Functions by Controlling CD4(+) T Cell Adhesiveness and Motility

    NARCIS (Netherlands)

    S. Herroeder; P. Reichardt; A. Sassmann; B. Zimmermann; D. Jaeneke; J. Hoeckner; M.W. Hollmann; K.D. Fischer; S. Vogt; R. Grosse; N. Hogg; M. Gunzer; S. Offermanns; N. Wettschureck

    2009-01-01

    Integrin-mediated adhesion plays a central role in T cell trafficking and activation. Genetic inactivation of the guanine nucleotide-binding (G) protein alpha-subunits G alpha(12) and G alpha(13) resulted in an increased activity of integrin leukocyte-function-antigen-1 in murine CD4(+) T cells. The

  20. The effect of beta-interferon therapy on myelin basic protein-elicited CD4+ T cell proliferation and cytokine production in multiple sclerosis

    DEFF Research Database (Denmark)

    Hedegaard, Chris J; Krakauer, Martin; Bendtzen, Klaus;

    2008-01-01

    Interferon (IFN)-beta therapy has well-established clinical benefits in multiple sclerosis (MS), but the underlying modulation of cytokine responses to myelin self-antigens remains poorly understood. We analysed the CD4+ T cell proliferation and cytokine responses elicited by myelin basic protein...

  1. 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

  2. Human CD4+ T Cell Response to Human Herpesvirus 6

    OpenAIRE

    Nastke, Maria-D.; Becerra, Aniuska; Yin, Liusong; Dominguez-Amorocho, Omar; Gibson, Laura; Stern, Lawrence J.; Calvo-Calle, J. Mauricio

    2012-01-01

    Following primary infection, human herpesvirus 6 (HHV-6) establishes a persistent infection for life. HHV-6 reactivation has been associated with transplant rejection, delayed engraftment, encephalitis, muscular dystrophy, and drug-induced hypersensitivity syndrome. The poor understanding of the targets and outcome of the cellular immune response to HHV-6 makes it difficult to outline the role of HHV-6 in human disease. To fill in this gap, we characterized CD4 T cell responses to HHV-6 using...

  3. Lentiviral Nef-mediated CD4 and CD28 downmodulation

    OpenAIRE

    Heilmann, Jessica

    2014-01-01

    Different properties allow HIV-1 and SIV to establish a chronic disease, e.g. genome insertion into long living quiescent T cells, high genome mutations and evasion of the immune system. The lentiviral Nef protein undertakes important functions of evading the immune system. One of these functions is the downregulation of CD4 receptors from infected cell surfaces. Downregulation of the main entry receptor of HIV-1 prevents superinfection and related cell death, enhances release and infectivity...

  4. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity

    Directory of Open Access Journals (Sweden)

    Karen A.O. Martins

    2016-01-01

    Full Text Available Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection from Ebola virus challenge. Adjuvants tested include poly-ICLC (Hiltonol, MPLA, CpG 2395, and alhydrogel. We compared and contrasted antibody responses, neutralizing antibody responses, effector T cell responses, and T follicular helper (Tfh cell frequencies with each adjuvant's impact on durable protection. We demonstrate that in this system, the most effective adjuvant elicits a Th1-skewed antibody response and strong CD4 T cell responses, including an increase in Tfh frequency. Using immune-deficient animals and adoptive transfer of serum and cells from vaccinated animals into naïve animals, we further demonstrate that serum and CD4 T cells play a critical role in conferring protection within effective vaccination regimens. These studies inform on the requirements of long term immune protection, which can potentially be used to guide screening of clinical-grade adjuvants for vaccine clinical development.

  5. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity.

    Science.gov (United States)

    Martins, Karen A O; Cooper, Christopher L; Stronsky, Sabrina M; Norris, Sarah L W; Kwilas, Steven A; Steffens, Jesse T; Benko, Jacqueline G; van Tongeren, Sean A; Bavari, Sina

    2016-01-01

    Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP) as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection from Ebola virus challenge. Adjuvants tested include poly-ICLC (Hiltonol), MPLA, CpG 2395, and alhydrogel. We compared and contrasted antibody responses, neutralizing antibody responses, effector T cell responses, and T follicular helper (Tfh) cell frequencies with each adjuvant's impact on durable protection. We demonstrate that in this system, the most effective adjuvant elicits a Th1-skewed antibody response and strong CD4 T cell responses, including an increase in Tfh frequency. Using immune-deficient animals and adoptive transfer of serum and cells from vaccinated animals into naïve animals, we further demonstrate that serum and CD4 T cells play a critical role in conferring protection within effective vaccination regimens. These studies inform on the requirements of long term immune protection, which can potentially be used to guide screening of clinical-grade adjuvants for vaccine clinical development. PMID:26870818

  6. Adjuvant-enhanced CD4 T Cell Responses are Critical to Durable Vaccine Immunity

    Science.gov (United States)

    Martins, Karen A.O.; Cooper, Christopher L.; Stronsky, Sabrina M.; Norris, Sarah L.W.; Kwilas, Steven A.; Steffens, Jesse T.; Benko, Jacqueline G.; van Tongeren, Sean A.; Bavari, Sina

    2015-01-01

    Protein-based vaccines offer a safer alternative to live-attenuated or inactivated vaccines but have limited immunogenicity. The identification of adjuvants that augment immunogenicity, specifically in a manner that is durable and antigen-specific, is therefore critical for advanced development. In this study, we use the filovirus virus-like particle (VLP) as a model protein-based vaccine in order to evaluate the impact of four candidate vaccine adjuvants on enhancing long term protection from Ebola virus challenge. Adjuvants tested include poly-ICLC (Hiltonol), MPLA, CpG 2395, and alhydrogel. We compared and contrasted antibody responses, neutralizing antibody responses, effector T cell responses, and T follicular helper (Tfh) cell frequencies with each adjuvant's impact on durable protection. We demonstrate that in this system, the most effective adjuvant elicits a Th1-skewed antibody response and strong CD4 T cell responses, including an increase in Tfh frequency. Using immune-deficient animals and adoptive transfer of serum and cells from vaccinated animals into naïve animals, we further demonstrate that serum and CD4 T cells play a critical role in conferring protection within effective vaccination regimens. These studies inform on the requirements of long term immune protection, which can potentially be used to guide screening of clinical-grade adjuvants for vaccine clinical development. PMID:26870818

  7. When aging reaches CD4+ T-cells: phenotypic and functional changes

    Directory of Open Access Journals (Sweden)

    Marco Antonio Moro-García

    2013-05-01

    Full Text Available Beyond midlife, the immune system shows aging features and its defensive capability becomes impaired, by a process known as immunosenescence that involves many changes in the innate and adaptive responses. Innate immunity seems to be better preserved globally, while the adaptive immune response exhibits profound age-dependent modifications. Elderly people display a decline in numbers of naïve T-cells in peripheral blood and lymphoid tissues, while, in contrast, their proportion of highly differentiated effector and memory T-cells, such as the CD28null T-cells, increases markedly. Naïve and memory CD4+ T-cells constitute a highly dynamic system with constant homeostatic and antigen-driven proliferation, influx, and loss of T-cells. Thymic activity dwindles with age and essentially ceases in the later decades of life, severely constraining the generation of new T-cells. Homeostatic control mechanisms are very effective at maintaining a large and diverse subset of naïve CD4+ T-cells throughout life, but although later than in CD8+T-cell compartment, these mechanisms ultimately fail with age.

  8. Docosahexaenoic acid reduces suppressive and migratory functions of CD4CD25 regulatory T-cells

    Science.gov (United States)

    Yessoufou, Akadiri; Plé, Aude; Moutairou, Kabirou; Hichami, Aziz; Khan, Naim Akhtar

    2009-01-01

    Immunological tolerance is one of the fundamental aspects of the immune system. The CD4+CD25+ regulatory T (Treg) cells have emerged as key players in the development of tolerance to self and foreign antigens. However, little is known about the endogenous factors and mechanisms controlling their suppressive capacity on immune response. In this study, we observed that docosahexaenoic acid (DHA), an n-3 polyunsaturated fatty acid, diminished, in a dose-dependent manner, the capacity of Treg cells to inhibit the CD4+CD25− effector T-cell proliferation. DHA not only reduced the migration of Treg cells toward chemokines but also downregulated the mRNA expression of CCR-4 and CXCR-4 in Treg cells. DHA also curtailed ERK1/2 and Akt phosphorylation and downregulated the Smad7 levels in these cells. Contradictorily, DHA upregulated the mRNA expression of Foxp3, CTLA-4, TGF-β, and IL-10; nonetheless, this fatty acid increased the expression of p27KIP1 mRNA, known to be involved in Treg cell unresponsiveness. In Foxp3-immunoprepitated nuclear proteins, DHA upregulated histone desacetylase 7 levels that would again participate in the unresposnsiveness of these cells. Finally, a DHA-enriched diet also diminished, ex vivo, the suppressive capacity of Treg cells. Altogether, these results suggest that DHA, by diminishing Treg cell functions, may play a key role in health and disease. PMID:19561360

  9. Functional heterogeneity in CD4+ T cell responses against a bacterial pathogen

    Directory of Open Access Journals (Sweden)

    Ashley eViehmann Milam

    2015-12-01

    Full Text Available To investigate how CD4+ T cells function against a bacterial pathogen, we generated a Listeria monocytogenes-specific CD4+ T cell model. In this system, two TCRtg mouse lines, LLO56 and LLO118 recognize the same immunodominant epitope (LLO190-205 of Listeria monocytogenes and have identical in vitro responses. However, in vivo LLO56 and LLO118 display vastly different responses during both primary and secondary infection. LLO118 dominates in the primary response and in providing CD8 T cell help. LLO56 predominates in the secondary response. We have also shown that both specific (TCR-mediated and nonspecific stimuli (bypassing the TCR elicit distinct responses from the two transgenics, leading us to conclude that the strength of self-pMHC signaling during development tightly dictates the cell’s future response in the periphery. Herein, we review our findings in this transfer system, focusing on the contribution of the immunomodulatory molecule CD5 and the importance of self-interaction in peripheral maintenance of the cell. We also discuss the manner in which individual TCR affinities to foreign and self-pMHC contribute to the outcome of an immune response; our assertion is that there exists a spectrum of possible T cell responses to recognition of cognate antigen during infection, adding immense diversity to the immune system’s response to pathogens.

  10. Early Postseroconversion CD4 Cell Counts Independently Predict CD4 Cell Count Recovery in HIV-1–Postive Subjects Receiving Antiretroviral Therapy

    Science.gov (United States)

    Kulkarni, Hemant; Okulicz, Jason F.; Grandits, Greg; Crum-Cianflone, Nancy F.; Landrum, Michael L.; Hale, Braden; Wortmann, Glenn; Tramont, Edmund; Polis, Michael; Dolan, Matthew; Lifson, Alan R.; Agan, Brian K.; Ahuja, Sunil K.; Marconi, Vincent C.

    2013-01-01

    Background The relationship between CD4+ T-cell counts determined soon after seroconversion with HIV-1 (baseline CD4), nadir CD4, and CD4 levels attained during highly active antiretroviral therapy (HAART) is unknown. Methods Longitudinal, including baseline (at or soon after HIV diagnosis), intermediate (nadir), and distal (post-HAART) CD4+ T-cell counts were assessed in 1085 seroconverting subjects who achieved viral load suppression from a large well-characterized cohort. The association of baseline with post-HAART CD4+ T-cell count was determined after adjustment for other relevant covariates. Results A higher baseline CD4+ T-cell count predicted a greater post- HAART CD4+ T-cell count, independent of the nadir and other explanatory variables. Together, baseline and nadir strongly predicted the post-HAART CD4+ count such that a high baseline and lower nadir were associated with a maximal immune recovery after HAART. Likelihood of recovery of the baseline count after HAART was significantly higher when the nadir/baseline count ratio was consistently ≥0.6. Conclusions Among viral load suppressing seroconverters, the absolute CD4+ T-cell count attained post-HAART is highly dependent on both baseline and nadir CD4+ T-cell counts. These associations further support the early diagnosis and initiation of HAART among HIV-infected persons. PMID:21546844

  11. Deficiency of Mouse CD4+CD25+Foxp3+Regulatory T Cells in Xenogeneic Pig Thymus-Grafted Nude Mice Suffering from Autoimmune Diseases

    Institute of Scientific and Technical Information of China (English)

    Baojun Zhang; Chenming Sun; Yanyan Qu; Aijun Zhang; Jun Liu; Lianjun Zhang; Zeqing Niu; Yong Zhao

    2008-01-01

    Xenogeneic thymus transplantation can efficiently induce specific immune tolerance to donor antigens in athymic recipients.However,many nude mice snffer from autoimmune diseases(AID) for over 10 weeks after xenogeneic thymus transplantation.CD4+CD25+Foxp3+ regulatory T (Treg)cells were recently determined to play a pivotal role in keeping immune tolerance in humans and mice.Thus,we investigated this subpopulation of Treg cells in the periphery of pig thymus-grafted nude mice suffering from AID.Our results showed that the expression of Foxp3, CTLA-4 and GITR on mouse CD4+CD25+T cells and the ratio of CD4+CD25+Foxp3+Treg cells to CD4+T cells were significantly decreased in the periphery of pig thymus-grafted nude mice snfiering from AID,compared with healthy pig or mouse thymus-grafted nude mice.Furthermore,mouse CD4+CD25+T cells in pig thymus-grafted nude mice Sufiering from AID showed more severe deficiency in immunosuppressive function compared with the counterpart in xenogeneic pig or syngeneic thymus-grafted nude mice without AID.Thus,the decreased frequency, altered phenotype and functional deficiency of mouse CD4+CD25+Treg cells in pig thymus-grafted nude mice may contribute to the development of AID in this model.

  12. Both CD4+ and CD8+ Lymphocytes Participate in the IFN-γ Response to Filamentous Hemagglutinin from Bordetella pertussis in Infants, Children, and Adults

    Directory of Open Access Journals (Sweden)

    Violette Dirix

    2012-01-01

    Full Text Available Infant CD4+ T-cell responses to bacterial infections or vaccines have been extensively studied, whereas studies on CD8+ T-cell responses focused mainly on viral and intracellular parasite infections. Here we investigated CD8+ T-cell responses upon Bordetella pertussis infection in infants, children, and adults and pertussis vaccination in infants. Filamentous hemagglutinin-specific IFN-γ secretion by circulating lymphocytes was blocked by anti-MHC-I or -MHC-II antibodies, suggesting that CD4+ and CD8+ T lymphocytes are involved in IFN-γ production. Flow cytometry analyses confirmed that both cell types synthesized antigen-specific IFN-γ, although CD4+ lymphocytes were the major source of this cytokine. IFN-γ synthesis by CD8+ cells was CD4+ T cell dependent, as evidenced by selective depletion experiments. Furthermore, IFN-γ synthesis by CD4+ cells was sometimes inhibited by CD8+ lymphocytes, suggesting the presence of CD8+ regulatory T cells. The role of this dual IFN-γ secretion by CD4+ and CD8+ T lymphocytes in pertussis remains to be investigated.

  13. CD4 Variability in Malawi: Implications for Use of a CD4 Threshold of 500 Cells/mm3 Versus Universal Eligibility for Antiretroviral Therapy

    Science.gov (United States)

    Schooley, Alan L.; Kamudumuli, Pocha Samuel; Vangala, Sitaram; Tseng, Chi-hong; Soko, Chifundo; Parent, Julie; Phiri, Khumbo; Jahn, Andreas; Namarika, Dan; Hoffman, Risa M.

    2016-01-01

    Background. Given the uncertainty about the ability of a single CD4 count to accurately classify a patient as antiretroviral therapy (ART) eligible, we sought to understand the extent to which CD4 variability results in misclassification at a CD4 threshold of 500 cells/mm3. Methods. We performed a prospective study of CD4 variability in Malawian human immunodeficiency virus-infected, ART-naive, World Health Organization (WHO) stage 1 or 2, nonpregnant adults. CD4 counts were performed daily for 8 days. We fit a Bayesian linear mixed-effects model of log-transformed CD4 cell counts to the data. We used Monte Carlo approximations to estimate misclassification rates for different observed values of CD4. The misclassification rate was calculated based on the conditional probability of true CD4 given the geometric mean of observed CD4 measurements. Results. Fifty patients were enrolled from 2 sites. The median age was 33.5 years (interquartile range, 27.5–40.0) and 34 (68%) were female. Misclassification rates were <1% when the observed CD4 counts were ≤250 or ≥750 cells/mm3. Rates of misclassification were high at observed CD4 counts between 350 and 650 cells/mm3, particularly when a single measurement was used (up to 46.7%). Conclusions. Our data show that ART eligibility based on a single CD4 count results in highest risk of misclassification when observed CD4 counts are in the range of 350–650 cells/mm3. Given the benefits of early ART, countries should weigh the costs and complexity of CD4 testing using a 500 cell/mm3 threshold against the cost savings and public health benefits of universal eligibility. PMID:27704028

  14. CD4+ and CD8+ T cell activation are associated with HIV DNA in resting CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Leslie R Cockerham

    Full Text Available The association between the host immune environment and the size of the HIV reservoir during effective antiretroviral therapy is not clear. Progress has also been limited by the lack of a well-accepted assay for quantifying HIV during therapy. We examined the association between multiple measurements of HIV and T cell activation (as defined by markers including CD38, HLA-DR, CCR5 and PD-1 in 30 antiretroviral-treated HIV-infected adults. We found a consistent association between the frequency of CD4+ and CD8+ T cells expressing HLA-DR and the frequency of resting CD4+ T cells containing HIV DNA. This study highlights the need to further examine this relationship and to better characterize the biology of markers commonly used in HIV studies. These results may also have implications for reactivation strategies.

  15. Neoplasia hematodérmica CD4+ CD56+ en la infancia Hematodermic CD4+ CD56+ neoplasm in childhood

    Directory of Open Access Journals (Sweden)

    Erica A. Rojas Bilbao

    2008-04-01

    Full Text Available La neoplasia hematodérmica CD4+ CD56+ con fenotipo de célula dendrítica plasmocitoide es una rara y agresiva neoplasia recientemente reconocida por la WHO-EORTC classification. Afecta adultos de edad media y ancianos, siendo muy pocos los casos descriptos en niños. Presentamos el caso de una niña de 12 años con grave retraso mental, estigmas genéticos y múltiples lesiones cutáneas localizadas en miembros inferiores y superiores. Histológicamente se observó un infiltrado dérmico difuso de células pequeñas y medianas con expresión de CD4, CD56, CD43 y S100 así como de marcadores dendríticos plasmocitoides: CD 123 y BDCA-2 confirmados por citometría de flujo, sin compromiso de sangre periférica ni médula ósea. Cumpliendo dos semanas de tratamiento para leucemia linfoblástica aguda evolucionó con remisión clínica de las lesiones cutaneas.Hematodermic CD4+ CD56+ neoplasm with plasmacytoid dendritic cell phenotype is a rare and aggressive neoplasm recently recognized by the WHO-EORTC classification. It generally appears in elderly adults, exceptionally in childhood. We present a 12-year-old girl with severe mental retardation, genetic clinical features and multiple nodular cutaneous lesions on legs and arms. Histologically the nodules showed diffuse dermal infiltrate of medium and small cells and expression of CD4, CD56, CD43, S100 and plasmacytoid dendritic markers: CD123, BDCA-2 under flow cytometry study. Peripheral blood and bone marrow were not involved. Clinical remission of cutaneous lesions was observed after two weeks of acute lymphoblastic leukemia therapy.

  16. Characterization of HIV-Specific CD4+T Cell Responses against Peptides Selected with Broad Population and Pathogen Coverage

    DEFF Research Database (Denmark)

    Buggert, Marcus; Norstrom, Melissa M.; Czarnecki, Chris;

    2012-01-01

    for the identification of HIV-specific CD4+ T cells targeting broadly reactive epitopes in populations with diverse ethnic background stems from the vast genomic variation of HIV and the diversity of the host cellular immune system. Here, we describe a novel epitope selection strategy, PopCover, that aims to resolve...... this challenge, and identify a set of potential HLA class II-restricted HIV epitopes that in concert will provide optimal viral and host coverage. Using this selection strategy, we identified 64 putative epitopes (peptides) located in the Gag, Nef, Env, Pol and Tat protein regions of HIV. In total, 73...... II-restricted epitopes. All together, selection strategies, such as PopCover, might with success be used for the evaluation of antigen-specific CD4+ T cell responses and design of future vaccines....

  17. ZnT8-Specific CD4+ T cells display distinct cytokine expression profiles between type 1 diabetes patients and healthy adults.

    Directory of Open Access Journals (Sweden)

    Daisuke Chujo

    Full Text Available Determination of antigen-specific T cell repertoires in human blood has been a challenge. Here, we show a novel integrated approach that permits determination of multiple parameters of antigen-specific T cell repertoires. The approach consists of two assays: the Direct assay and the Cytokine-driven assay. Briefly, human PBMCs are first stimulated with overlapping peptides encoding a given antigen for 48 hours to measure cytokine secretion (Direct assay. Peptide-reactive T cells are further expanded by IL-2 for 5 days; and after overnight starvation, expanded cells are stimulated with the same peptides from the initial culture to analyze cytokine secretion (Cytokine-driven assay. We first applied this integrated approach to determine the type of islet-antigen-specific T cells in healthy adults. Out of ten donors, the Direct assay identified GAD65-specific CD4(+ T cells in three adults and zinc transporter 8 (ZnT8-specific CD4(+ T cells in five adults. The intracytoplasmic cytokine staining assay showed that these islet-antigen-specific CD4(+ T cells belonged to the CD45RO(+ memory compartment. The Cytokine-driven assay further revealed that islet-antigen-specific CD4(+ T cells in healthy adults were capable of secreting various types of cytokines including type 1 and type 2 cytokines as well as IL-10. We next applied our integrated assay to determine whether the type of ZnT8-specific CD4(+ T cells is different between Type 1 diabetes patients and age/gender/HLA-matched healthy adults. We found that ZnT8-specific CD4(+ T cells were skewed towards Th1 cells in T1D patients, while Th2 and IL-10-producing cells were prevalent in healthy adults. In conclusion, the Direct assay and the Cytokine-driven assay complement each other, and the combination of the two assays provides information of antigen-specific T cell repertoires on the breadth, type, and avidity. This strategy is applicable to determine the differences in the quality of antigen-specific T

  18. Utility of the point of care CD4 analyzer, PIMA, to enumerate CD4 counts in the field settings in India

    Directory of Open Access Journals (Sweden)

    Thakar Madhuri

    2012-09-01

    Full Text Available Abstract Background In resource limited settings non-availability of CD4 count facility at the site could adversely affect the ART roll out programme. Point of care CD4 enumerating equipments can make the CD4 count available at the site of care and improve the patients’ management considerably. This study is aimed at determining the utility of a Point of Care PIMA CD4 analyzer (Alere, Germany in the field settings in India. Method The blood samples were collected from 1790 participants at 21 ART centers from different parts of the country and tested using PIMA and the reference methods (FACSCalibur, FACSCount and CyFlow SL3. The paired finger prick and venous blood samples from 175 participants were tested by the PIMA CD4 Analyzer and then by FACSCalibur. Result The CD4 counts obtained by PIMA CD4 analyzer showed excellent correlation with the counts obtained by the reference methods; for venous blood the Pearson’s r was 0.921, p 500 cells/mm3, the differences in the median CD4 counts obtained by the reference method and the PIMA analyzer were not significant (P > 0.05 and the relative bias were low (−7 to 5.1%. The Intermachine comparison showed variation within the acceptable limit of%CV of 10%. Conclusion In the field settings, the POC PIMA CD4 analyzer gave CD4 counts comparable to the reference methods for all CD4 ranges. The POC equipment could identify the patients eligible for ART in 91% cases. Adequate training is necessary for finger prick sample collection for optimum results. Decentralization of CD4 testing by making the CD4 counts available at primary health centers, especially in remote areas with minimum or no infrastructure would reduce the missed visits and improve adherence of the patients.

  19. Memory T follicular helper CD4 T cells

    Directory of Open Access Journals (Sweden)

    J. Scott eHale

    2015-02-01

    Full Text Available T follicular helper (Tfh cells are the subset of CD4 T helper cells that are required for generation and maintenance of germinal center reactions and the generation of long-lived humoral immunity. This specialized T helper subset provides help to cognate B cells via their expression of CD40 ligand, IL-21, IL-4, and other molecules. Tfh cells are characterized by their expression of the chemokine receptor CXCR5, expression of the transcriptional repressor Bcl6, and their capacity to migrate to the follicle and promote germinal center B cell responses. Until recently, it remained unclear whether Tfh cells differentiated into memory cells and whether they maintain their Tfh commitment at the memory phase. This review will highlight several recent studies that support the idea of Tfh-committed CD4 T cells at the memory stage of the immune response. The implication of these findings is that memory Tfh cells retain their capacity to recall their Tfh-specific effector functions upon reactivation to provide help for B cell responses and play an important role in prime and boost vaccination or during recall responses to infection. The markers that are useful for distinguishing Tfh effector and memory cells, as well as the limitations of using these markers will be discussed. Tfh effector and memory generation, lineage maintenance, and plasticity relative to other T helper lineages (Th1, Th2, Th17, etc will also be discussed. Ongoing discoveries regarding the maintenance and lineage stability versus plasticity of memory Tfh cells will improve strategies that utilize CD4 T cell memory to modulate antibody responses during prime and boost vaccination.

  20. Gut Mucosal FOXP3+ Regulatory CD4+ T Cells and Nonregulatory CD4+ T Cells Are Differentially Affected by Simian Immunodeficiency Virus Infection in Rhesus Macaques▿

    OpenAIRE

    Allers, Kristina; Loddenkemper, Christoph; Hofmann, Jörg; Unbehaun, Anett; Kunkel, Désirée; Moos, Verena; Kaup, Franz-Josef; Stahl-Hennig, Christiane; Sauermann, Ulrike; Epple, Hans-Jörg; Schneider, Thomas

    2010-01-01

    The gastrointestinal tract represents a major site for human and simian immunodeficiency virus (HIV and SIV) replication and CD4+ T-cell depletion. Despite severe depletion of mucosal CD4+ T cells, FOXP3+ regulatory CD4+ T cells (Treg) are highly increased in the gut mucosa of chronically HIV-infected individuals and may contribute to HIV pathogenesis, either by their immunosuppressive function or as a significant target cell population for virus production. Little is known about the suscepti...

  1. CTLA-4 is Required by CD4+CD25+ Treg to Control CD4+ T Cell Lymphopenia-Induced Proliferation

    OpenAIRE

    Sojka, Dorothy K.; Hughson, Angela; Fowell, Deborah J.

    2009-01-01

    CTLA-4 is constitutively expressed by CD4+CD25+Foxp3+ regulatory T cells (Treg) but its precise role in Treg function is not clear. Although blockade of CTLA-4 interferes with Treg function, studies using CTLA-4 deficient Treg have failed to reveal an essential requirement for CTLA-4 in Treg suppression in vivo. Conditional deletion of CTLA-4 in Foxp3+ T cells disrupts immune homeostasis in vivo but the immune processes disrupted by CTLA-4 deletion have not been determined. We demonstrate tha...

  2. Neoplasia hematodérmica CD4+ CD56+ en la infancia Hematodermic CD4+ CD56+ neoplasm in childhood

    OpenAIRE

    Erica A. Rojas Bilbao; Ana María Chirife; Darío Llorio; Lliliana B. Giménez; Lina Marino; Diego A. Rosso

    2008-01-01

    La neoplasia hematodérmica CD4+ CD56+ con fenotipo de célula dendrítica plasmocitoide es una rara y agresiva neoplasia recientemente reconocida por la WHO-EORTC classification. Afecta adultos de edad media y ancianos, siendo muy pocos los casos descriptos en niños. Presentamos el caso de una niña de 12 años con grave retraso mental, estigmas genéticos y múltiples lesiones cutáneas localizadas en miembros inferiores y superiores. Histológicamente se observó un infiltrado dérmico difuso de célu...

  3. CD4+ T Lymphocytes are Not Necessary for the Acute Rejection of Vascularized Mouse Lung Transplants

    OpenAIRE

    Gelman, Andrew E.; Okazaki, Mikio; Lai, Jiaming; Kornfeld, Christopher G.; Kreisel, Friederike H.; Richardson, Steven B.; Sugimoto, Seiichiro; Tietjens, Jeremy R.; Patterson, G. Alexander; Krupnick, Alexander S.; Kreisel, Daniel

    2008-01-01

    Acute rejection continues to present a major obstacle to successful lung transplantation. While CD4+ T lymphocytes are critical for the rejection of some solid organ grafts the role of CD4+ T cells in the rejection of lung allografts is largely unknown. In this study we demonstrate in a novel model of orthotopic vascularized mouse lung transplantation that acute rejection of lung allografts is independent of CD4+ T cell-mediated allorecognition pathways. CD4+ T cell-independent rejection occu...

  4. In vitro activated CD4+ T cells from interferon-gamma (IFN-gamma)-deficient mice induce intestinal inflammation in immunodeficient hosts

    DEFF Research Database (Denmark)

    Bregenholt, S; Brimnes, J; Nissen, Mogens Holst;

    1999-01-01

    To investigate the role of IFN-gamma in the immunopathogenesis of inflammatory bowel disease (IBD), severe combined immunodeficient (SCID) mice were transplanted with in vitro activated CD4+ T cells from either wild-type (WT) or IFN-gamma-deficient (IFN-gammaKO) BALB/c mice. In vitro, the two types...... intestinal inflammation with moderate weight loss. Intracellular cytokine staining of lamina propria lymphocytes (LPL) revealed comparable fractions of CD4+ T cells positive for TNF-alpha, IL-2 and IL-10 in the two groups of transplanted SCID mice, whereas a two-to-three-fold increase in the fraction of IL-4...... and subsequently enhanced by the ability of IFN-gamma to induce de novo MHC class II expression in the colonic epithelium, a change which could lead to increased antigen processing and production of local proinflammatory cytokines, CD4+ T cell turnover and thereby to exaggeration of disease....

  5. Inhibition of HIV replication by pokeweed antiviral protein targeted to CD4+ cells by monoclonal antibodies

    Science.gov (United States)

    Zarling, Joyce M.; Moran, Patricia A.; Haffar, Omar; Sias, Joan; Richman, Douglas D.; Spina, Celsa A.; Myers, Dorothea E.; Kuebelbeck, Virginia; Ledbetter, Jeffrey A.; Uckun, Fatih M.

    1990-09-01

    FUNCTIONAL impairment and selective depletion of CD4+ T cells, the hallmark of AIDS, are at least partly caused by human immunodeficiency virus (HIV-1) type 1 binding to the CD4 molecule and infecting CD4+ cells1,2. It may, therefore, be of therapeutic value to target an antiviral agent to CD4+ cells to prevent infection and to inhibit HIV-1 production in patients' CD4+ cells which contain proviral DNA3,4. We report here that HIV-1 replication in normal primary CD4+ T cells can be inhibited by pokeweed antiviral protein, a plant protein of relative molecular mass 30,000 (ref. 5), which inhibits replication of certain plant RNA viruses6-8, and of herpes simplex virus, poliovirus and influenza virus9-11. Targeting pokeweed antiviral protein to CD4+ T cells by conjugating it to monoclonal antibodies reactive with CDS, CD7 or CD4 expressed on CD4+ cells, increased its anti-HIV potency up to 1,000-fold. HIV-1 replication is inhibited at picomolar concentrations of conjugates of pokeweed antiviral protein and monoclonal antibodies, which do not inhibit proliferation of normal CD4+ T cells or CD4-dependent responses. These conjugates inhibit HIV-1 protein synthesis and also strongly inhibit HIV-1 production in activated CD4+ T cells from infected patients.

  6. IKK2dn转染树突状细胞诱导产生的CD4+CD25-T细胞的筛选及鉴定%Screening and function identification of CD4 + CD25 - T cells induced by immature dendritic cells transfected with IKK2dn

    Institute of Scientific and Technical Information of China (English)

    樊彩斌; 张东兴; 温端改; 侯建全; 欧阳骏; 杜科霖

    2012-01-01

    Objective To investigate the method of screening CD4 + CD25 - T cells from regulatory T cells (Treg) induced by recipient-derived immature dendritic cells (imDC) transfected by IKK2dn and loaded with donor antigens,and assess their immunologic function.Methods Rat bone marrow-derived imDC were transfected by IKK2dn and loaded by BN antigen,then cultured with Lewis rats T cells in vitro.From these Treg,CD4 + CD25 T cells were screened by magnetic active cell sorting (MACS),then incubated in secondary mixed lymphocyte reaction ( MLR),with Lewis rat T lymphocytes.Results By MACS,the purity of CD4 + CD25 - T cells was more than 95%.The result of secondary MLR displayed the absorbance value was significantly lower in the CD4 + CD25 - T cells group ( 0.106 ± 0.006 ) than that in BN antigen group (0.189 ± 0.007 ),Adv0-CD4 +T cells group (0.419 ± 0.014) and the third donor group (0.200 ± 0.008) (P <0.05).Conclusion By MACS sereening,we can obtain high purity of CD4 + CD25-T cells from Treg induced by imDC transfected with IKK2dn and loaded by BN rat antigen and recipient Lewis rats T cells.And these T cells can inhibit T cell proliferation with the donor antigen specificity.%目的 探讨从转染IKK2dn并负载供者抗原的未成熟树突状细胞(imDC)诱导产生的调节性T细胞(Treg)中筛选CD4+ CD25 - Treg的方法,并进行鉴定.方法 Lewis大鼠骨髓源性imDC,转染IKK2dn后负载供者BN大鼠抗原,与Lewis大鼠T细胞进行体外混合淋巴细胞反应(MLR)诱导产生Treg,用免疫磁珠法(MACS)筛选出CD4+ CD25 -T细胞,流式细胞仪(FCM)检测细胞纯度.加入CD4+ CD25 -T细胞行再次MLR检测其抑制T细胞增殖的作用.结果 经MACS筛选,CD4+ CD25 -T细胞纯度为(95.78±1.25)%.再次MLR结果显示CD4+ CD25 -T细胞组的吸光度值为(0.106±0.006),低于BN抗原组(0.189±0.007)、Adv0-CD4+T细胞组(0.419±0.014)及第三方供者抗原组(0.200±0.008),差异有统计学意义(P<0.05).结论 转染IKK2dn并负载

  7. 人白介素16与HIV-1的CD4受体的相互作用%Interaction between human interleukin-16 and CD4 receptorof HIV- 1

    Institute of Scientific and Technical Information of China (English)

    杨洁; 刘次全

    2000-01-01

    目的:研究人白介素-16和HIV-1病毒受体CD4(T淋巴细胞分化抗原)的作用机理.方法:人白介素-16的结构保守区由SYBYL软件中的Biopolymer模块建立,其非保守区由LOOP SEARCH方法建立.结果:人白介素-16首先形成二聚体,然后与CD4的二聚体进一步形成HIL-16与CD4的复合物二聚体。接着,该复合物二聚体通过二硫键(Cys31-Cys31)形成HIL-16与CD4复合物的四聚体。结论:该相互作用模型有助于推测白介素-16的作用机制,也有益于全新抗艾滋病药物的合理设计。%AIM: To study the interaction between human inter-leukin-16 (IL-16) and the receptor CD4 (T-lymphocytedifferentiation antigen) of human immunodeficiency virustype 1 (HIV-1). METHODS: Two structurally con-served regions (SCRs) of human IL-16 were built by theSYBYL/Biopolymer module using the correspondingtransmembrane (TM) domain of human interleukin-4(H IL-4) and HIL-2 as the templates. The coordinatesfor amino-terminal residue sequence, carboxyl-terminalresidue sequences, and cytoplasm loops were generatedusing Biopolymer's LOOP SEARCH algorithm. RE-SULTS: HIL-16 first formed a homodimer, then contacted with CD4 dimer further forming a dimeric complex. Subsequently, the dimeric complex constructed the tetrameric complex by two disulfide bridges between the cysteines of HIL-16 (Cys31-Cys31). CONCLUSION:The interaction model is useful to propose the action mechanism of HIL-16 and is beneficial for rational designing of novel anti-HIV drags.

  8. Enhancement of CD4(+) T cell response and survival via coexpressed OX40/OX40L in Graves' disease.

    Science.gov (United States)

    Wang, Qin; Shi, Bi-Min; Xie, Fang; Fu, Zhao-Yang; Chen, Yong-Jing; An, Jing-Nan; Ma, Yu; Liu, Cui-Ping; Zhang, Xue-Kun; Zhang, Xue-Guang

    2016-07-15

    OX40/OX40L pathway plays a very important role in the antigen priming T cells and effector T cells. In the present study, we aimed to examine the involvement of OX40/OX40L pathway in the activation of autoreactive T cells in patients with Grave's disease (GD). We found that OX40 and OX40L were constitutively coexpressed on peripheral CD4(+) T cells from GD patients using flow cytometry analysis. The levels of OX40 and OX40L coexpression on CD4(+) T cells were shown to be correlated with TRAbs. Cell proliferation assay showed that blocking OX40/OX40L signal inhibited T cell proliferation and survival, which suggested that OX40/OX40L could enhance CD4(+) T cell proliferation and maintain their long-term survival in GD by self-enhancing loop of T cell activation independent of APCs. Confocal microscopy and coimmunoprecipitation analysis further revealed that OX40 and OX40L formed a functional complex, which may facilitate signal transduction from OX40L to OX40 and contribute to the pathogenesis of GD. PMID:27107937

  9. CD4+ T Cells Are Not Required for Suppression of Hepatitis B Virus Replication in the Liver of Vaccinated Chimpanzees.

    Science.gov (United States)

    Rybczynska, Jolanta; Campbell, Katherine; Kamili, Saleem; Locarnini, Stephen; Krawczynski, Krzysztof; Walker, Christopher M

    2016-01-01

    Humans vaccinated with hepatitis B virus (HBV) surface antigen (HBsAg) sometimes develop humoral and cellular immunity to HBV proteins such as core and polymerase that are not vaccine components, providing indirect evidence that vaccine-induced immunity is not sterilizing. We previously described CD4(+) T-cell immunity against HBsAg and polymerase in chimpanzees after vaccination and HBV challenge. Here, vaccinated chimpanzees with protective levels of anti-HBsAg antibodies were rechallenged with HBV after antibody-mediated CD4(+) T-cell depletion. HBV DNA was detected in liver for at least 3 months after rechallenge, but virus replication was suppressed, as revealed by the absence of HBV DNA and HBsAg in serum. These observations provide direct virological evidence for nonsterilizing immunity in individuals with anti-HBsAg antibodies and are consistent with translation of HBV proteins to prime immune responses. They also indicate that CD4(+) T cells were not required for suppression of HBV replication in previously vaccinated individuals. PMID:26324781

  10. Gut-homing CD4+ T cell receptor alpha beta+ T cells in the pathogenesis of murine inflammatory bowel disease

    DEFF Research Database (Denmark)

    Rudolphi, A; Boll, G; Poulsen, S S;

    1994-01-01

    We studied which T cell subsets from the gut-associated lymphoid tissue (GALT) can migrate out of the gut mucosa and repopulate GALT compartments of an immunodeficient (semi)syngeneic host. Many distinct lymphocyte subsets were found in GALT of immunocompetent H-2d (BALB/c, BALB/cdm2, C.B-17......+/+) mice. No antigen receptor-expressing lymphoid cells were found in GALT of congenic C.B-17 scid/scid (scid) mice. The heterotopic transplantation of a full-thickness gut wall graft from the ileum or colon of immunocompetent (C.B-17+/+, BALB/cdm2) donor mice onto immunodeficient scid mice selectively...... reconstituted a CD3+ T cell receptor alpha beta+ CD4+ T cell subset. CD4+ cells of this subset expressed the surface phenotype of mucosa-seeking, memory T cells. In the immunodeficient scid host, this gut-derived CD4+ T cell subset was found in spleen, peritoneal cavity, mesenteric lymph nodes (LN), epithelial...

  11. Keratinocytes-associated chemokines and enzymatically quiescent heparanase induce the binding of resting CD4+ T cells.

    Science.gov (United States)

    Hershkoviz, R; Marikovsky, M; Gilat, D; Lider, O

    1996-02-01

    Whether the chemokines macrophage inflammatory protein-1 beta (MIP-1 beta) and regulated on activation normal T expressed and secreted (RANTES), which interact specifically with glycosaminoglycans and thus mediate the recruitment, attachment, and migration of leukocytes to vascular endothelia and extracellular matrix, are also involved in interactions between CD4+ murine T lymphocytes and keratinocytes was examined. We have previously observed that depending on the local pH, a mammalian extracellular matrix-degrading enzyme, endo-beta-D glucuronidase (heparanase), which cleaves heparin sulfate proteoglycans, can function wither as an enzyme or as an adhesion molecule for CD4+ T lymphocytes. Herein, the involvement of heparanase in T cell-keratinocyte interactions was also probed. At 37 degree C and pH 7.2, radioactively labeled MIP-1 beta, RANTES, and heparanase bound to confluent layers of resting keratinocytes in a saturable and an heparan sulfate- or heparin-dependent manner, and thereby induced the adhesion of resting CD4+ T cells to keratinocytes. At a relatively acidic pH characteristic of inflammatory milieu, enzymatically active heparanase did not bind to the keratinocytes but, rather, inhibited the binding of MIP-1beta, RANTES, and the enzymatically quiescent heparanase to keratinocytes. These results suggest that certain chemokines and heparanase may function to restrict passing leukocytes, notable T lymphocytes, in the cutaneous micro-environment, a site which is continuously challenged with antigens. These keratinocyte-bound lymphocytes can serve as a reservoir of immediate responders to immunological stimuli. PMID:8601723

  12. Elicitation of neutralizing antibodies directed against CD4-induced epitope(s using a CD4 mimetic cross-linked to a HIV-1 envelope glycoprotein.

    Directory of Open Access Journals (Sweden)

    Antu K Dey

    Full Text Available The identification of HIV-1 envelope glycoprotein (Env structures that can generate broadly neutralizing antibodies (BNAbs is pivotal to the development of a successful vaccine against HIV-1 aimed at eliciting effective humoral immune responses. To that end, the production of novel Env structure(s that might induce BNAbs by presentation of conserved epitopes, which are otherwise occluded, is critical. Here, we focus on a structure that stabilizes Env in a conformation representative of its primary (CD4 receptor-bound state, thereby exposing highly conserved "CD4 induced" (CD4i epitope(s known to be important for co-receptor binding and subsequent virus infection. A CD4-mimetic miniprotein, miniCD4 (M64U1-SH, was produced and covalently complexed to recombinant, trimeric gp140 envelope glycoprotein (gp140 using site-specific disulfide linkages. The resulting gp140-miniCD4 (gp140-S-S-M64U1 complex was recognized by CD4i antibodies and the HIV-1 co-receptor, CCR5. The gp140-miniCD4 complex elicited the highest titers of CD4i binding antibodies as well as enhanced neutralizing antibodies against Tier 1 viruses as compared to gp140 protein alone following immunization of rabbits. Neutralization against HIV-2(7312/V434M and additional serum mapping confirm the specific elicitation of antibodies directed to the CD4i epitope(s. These results demonstrate the utility of structure-based approach in improving immunogenic response against specific region, such as the CD4i epitope(s here, and its potential role in vaccine application.

  13. Tuberculosis Therapy Modifies the Cytokine Profile, Maturation State, and Expression of Inhibitory Molecules on Mycobacterium tuberculosis-Specific CD4+ T-Cells.

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    Kapil K Saharia

    Full Text Available Little is known about the expression of inhibitory molecules cytotoxic T-lymphocyte antigen-4 (CTLA-4 and programmed-death-1 (PD-1 on Mycobacterium tuberculosis (Mtb-specific CD4 T-cells and how their expression is impacted by TB treatment.Cryopreserved PBMCs from HIV-TB co-infected and TB mono-infected patients with untreated and treated tuberculosis (TB disease were stimulated for six hours with PPD and stained. Using polychromatic flow cytometry, we characterized the differentiation state, cytokine profile, and inhibitory molecule expression on PPD-specific CD4 T-cells.In our HIV-TB co-infected cohort, TB treatment increased the proportion of PPD-specific CD4 T-cells co-producing IFN-γ+IL-2+TNF-α+ and IFN-γ+IL-2+ (p = 0.0004 and p = 0.0002, respectively while decreasing the proportion of PPD-specific CD4 T-cells co-producing IFN-γ+MIP1-β+TNF-α+ and IFN-γ+MIP1-β+. The proportion of PPD-specific CD4 T-cells expressing an effector memory phenotype decreased (63.6% vs 51.6%, p = 0.0015 while the proportion expressing a central memory phenotype increased (7.8% vs. 21.7%, p = 0.001 following TB treatment. TB treatment reduced the proportion of PPD-specific CD4 T-cells expressing CTLA-4 (72.4% vs. 44.3%, p = 0.0005 and PD-1 (34.5% vs. 29.2%, p = 0.03. Similar trends were noted in our TB mono-infected cohort.TB treatment alters the functional profile of Mtb-specific CD4 T-cells reflecting shifts towards a less differentiated maturational profile and decreases PD-1 and CTLA-4 expression. These could serve as markers of reduced mycobacterial burden. Further study is warranted.

  14. Cytomegalovirus Infection Leads to Development of High Frequencies of Cytotoxic Virus-Specific CD4+ T Cells Targeted to Vascular Endothelium.

    Science.gov (United States)

    Pachnio, Annette; Ciaurriz, Miriam; Begum, Jusnara; Lal, Neeraj; Zuo, Jianmin; Beggs, Andrew; Moss, Paul

    2016-09-01

    Cytomegalovirus (CMV) infection elicits a very strong and sustained intravascular T cell immune response which may contribute towards development of accelerated immune senescence and vascular disease in older people. Virus-specific CD8+ T cell responses have been investigated extensively through the use of HLA-peptide tetramers but much less is known regarding CMV-specific CD4+ T cells. We used a range of HLA class II-peptide tetramers to investigate the phenotypic and transcriptional profile of CMV-specific CD4+ T cells within healthy donors. We show that such cells comprise an average of 0.45% of the CD4+ T cell pool and can reach up to 24% in some individuals (range 0.01-24%). CMV-specific CD4+ T cells display a highly differentiated effector memory phenotype and express a range of cytokines, dominated by dual TNF-α and IFN-γ expression, although substantial populations which express IL-4 were seen in some donors. Microarray analysis and phenotypic expression revealed a profile of unique features. These include the expression of CX3CR1, which would direct cells towards fractalkine on activated endothelium, and the β2-adrenergic receptor, which could permit rapid response to stress. CMV-specific CD4+ T cells display an intense cytotoxic profile with high level expression of granzyme B and perforin, a pattern which increases further during aging. In addition CMV-specific CD4+ T cells demonstrate strong cytotoxic activity against antigen-loaded target cells when isolated directly ex vivo. PD-1 expression is present on 47% of cells but both the intensity and distribution of the inhibitory receptor is reduced in older people. These findings reveal the marked accumulation and unique phenotype of CMV-specific CD4+ T cells and indicate how such T cells may contribute to the vascular complications associated with CMV in older people. PMID:27606804

  15. Variation in HIV-1 R5 macrophage-tropism correlates with sensitivity to reagents that block envelope: CD4 interactions but not with sensitivity to other entry inhibitors

    Directory of Open Access Journals (Sweden)

    Simmonds Peter

    2008-01-01

    Full Text Available Abstract Background HIV-1 R5 viruses cause most of the AIDS cases worldwide and are preferentially transmitted compared to CXCR4-using viruses. Furthermore, R5 viruses vary extensively in capacity to infect macrophages and highly macrophage-tropic variants are frequently identified in the brains of patients with dementia. Here, we investigated the sensitivity of R5 envelopes to a range of inhibitors and antibodies that block HIV entry. We studied a large panel of R5 envelopes, derived by PCR amplification without culture from brain, lymph node, blood and semen. These R5 envelopes conferred a wide range of macrophage tropism and included highly macrophage-tropic variants from brain and non-macrophage-tropic variants from lymph node. Results R5 macrophage-tropism correlated with sensitivity to inhibition by reagents that inhibited gp120:CD4 interactions. Thus, increasing macrophage-tropism was associated with increased sensitivity to soluble CD4 and to IgG-CD4 (PRO 542, but with increased resistance to the anti-CD4 monoclonal antibody (mab, Q4120. These observations were highly significant and are consistent with an increased affinity of envelope for CD4 for macrophage-tropic envelopes. No overall correlations were noted between R5 macrophage-tropism and sensitivity to CCR5 antagonists or to gp41 specific reagents. Intriguingly, there was a relationship between increasing macrophage-tropism and increased sensitivity to the CD4 binding site mab, b12, but decreased sensitivity to 2G12, a mab that binds a glycan complex on gp120. Conclusion Variation in R5 macrophage-tropism is caused by envelope variation that predominantly influences sensitivity to reagents that block gp120:CD4 interactions. Such variation has important implications for therapy using viral entry inhibitors and for the design of envelope antigens for vaccines.

  16. The influence of CD 4+t cells, hiv disease stage and zidovudine on hiv isolation in Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Carlos Brites

    1996-02-01

    Full Text Available HIV-l isolation was attempted on 72 individuais, including persons with knoum HIV infection and five without proven HIV infection but with indeterminate Western blot patterns, as well as on low-risk HIV seronegative persons. The ahility to detect HIV- 1 frorn culture supernatant by p24 antigen capture assay was evaluated by segregating patients by absolute CD4+ cell counts, clinicai stage of disease, p24 antigenemia and zidovudine use. The likelihood of a p24 positive HIV culture was highest among patients with CD4+ T-cell counts below 200/ul and patients with advanced clinical disease. Use of zidovudine did not affect the rate ofHIV positwity in cultures.Tentativa de isolamento do vírus tipo 1 da imunodeficiência adquirida (VIH-1 foi realizada em 72 indivíduos sendo 51 pacientes com sorologia positiva para o VIH-1, confirmada por Western blot; 5 doadores de sangue com padrão indeterminado ao Western blot; 3 indivíduos com diagnóstico clínico de AIDS, porém com sorologia negativa, e 13 profissionais de saúde soronegativos. Os pacientes foram estratificados de acordo com a contagem de células CD4+, estágio clínico , antigenemia (p24 e uso de zidovudine. As culturas para o VIH-1 foram positivas em 45/50 (90% tentativas. Houve uma correlação inversa entre o número de células CD4+ e a freqüência de isolamento do VIH-1. As culturas foram positivas em 84% dos indivíduos com CD4+ <200, contra 48% d positividade naqueles com contagem de célula CD4+ acima deste valor. O uso de zidovudine não interferiu na positividade das culturas. Concluímo. que a sensibilidade dos métodos de culture qualitativo e quantitativo é similar para a detecção do VIH-1. A taxa de positividade das culturas não foi afetada pelo uso prévio de zidovudine, mas foi diretamente proporcional ao grau de imunodeficiência dos pacientes.

  17. IFNγ/IL-10 co-producing cells dominate the CD4 response to malaria in highly exposed children.

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    Prasanna Jagannathan

    2014-01-01

    Full Text Available Although evidence suggests that T cells are critical for immunity to malaria, reliable T cell correlates of exposure to and protection from malaria among children living in endemic areas are lacking. We used multiparameter flow cytometry to perform a detailed functional characterization of malaria-specific T cells in 78 four-year-old children enrolled in a longitudinal cohort study in Tororo, Uganda, a highly malaria-endemic region. More than 1800 episodes of malaria were observed in this cohort, with no cases of severe malaria. We quantified production of IFNγ, TNFα, and IL-10 (alone or in combination by malaria-specific T cells, and analyzed the relationship of this response to past and future malaria incidence. CD4(+ T cell responses were measurable in nearly all children, with the majority of children having CD4(+ T cells producing both IFNγ and IL-10 in response to malaria-infected red blood cells. Frequencies of IFNγ/IL10 co-producing CD4(+ T cells, which express the Th1 transcription factor T-bet, were significantly higher in children with ≥2 prior episodes/year compared to children with <2 episodes/year (P<0.001 and inversely correlated with duration since malaria (Rho = -0.39, P<0.001. Notably, frequencies of IFNγ/IL10 co-producing cells were not associated with protection from future malaria after controlling for prior malaria incidence. In contrast, children with <2 prior episodes/year were significantly more likely to exhibit antigen-specific production of TNFα without IL-10 (P = 0.003. While TNFα-producing CD4(+ T cells were not independently associated with future protection, the absence of cells producing this inflammatory cytokine was associated with the phenotype of asymptomatic infection. Together these data indicate that the functional phenotype of the malaria-specific T cell response is heavily influenced by malaria exposure intensity, with IFNγ/IL10 co-producing CD4(+ T cells dominating this response among

  18. Increased frequency of CD4 and CD8 regulatory T cells in individuals under 15 years with multibacillary leprosy.

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    Camila Fernandes

    Full Text Available BACKGROUND: Leprosy is a chronic disease, caused by Mycobacterium leprae, which poses a serious public health problem worldwide. Its high incidence in people under 15 years old in Ceará state, Brazil, reflects the difficulty of its control. The spectrum of clinical manifestations is associated with the immune response developed, with the Th1 and Th2 responses being related to the paucibacillary and multibacillary forms, respectively. Regulatory T cells (Treg, which can suppress Th1 and Th2 response, have received special attention in the literature and have been associated with development of chronic infections. However, their role in leprosy in individuals under 15 years old has not yet been elucidated. We evaluated the frequency of CD4(+/CD8(+CD25(highFOXP3(+ and CD4(+/CD8(+CD25(highFOXP3(high cells in leprosy patients and household contacts, in both cases under 15 years old. METHODOLOGY/PRINCIPAL FINDINGS: PBMC from 12 patients and 17 contacts were cultured for 72 hours with anti-CD3 and anti-CD28 (activators or with activators associated with total sonicated fraction of M. leprae. After culture, the frequency of CD4(+/CD8(+ Treg was identified by flow cytometry. Cells stimulated by activators and antigen from multibacillary patients showed Treg frequencies almost two times that of the contacts: CD4(+FOXP3(+ (21.93±8.43 vs. 13.79±8.19%, p = 0.0500, CD4(+FOXP3(high (10.33±5.69 vs. 5.57±4.03%, p = 0.0362, CD8(+FOXP3(+ (13.88±9.19 vs. 6.18±5.56%, p = 0.0230 and CD8(+FOXP3(high (5.36±4.17 vs. 2.23±2.68%, p = 0.0461. Furthermore, the mean fluorescence intensity of FOXP3 in Treg was higher in multibacillary patients than in the contacts. Interestingly, there was a positive correlation of the bacillary index and number of lesions with the frequency of all Treg evaluated in patients. CONCLUSIONS/SIGNIFICANCE: We have demonstrated for the first time that multibacillary leprosy patients under 15 years old have greater CD4(+ and

  19. CD4 T cell epitope specificity determines follicular versus non-follicular helper differentiation in the polyclonal response to influenza infection or vaccination

    Science.gov (United States)

    Knowlden, Zackery A. G.; Sant, Andrea J.

    2016-01-01

    Follicular helper T cells (Tfh) are essential for B cell production of high-affinity, class-switched antibodies. Much interest in Tfh development focuses on the priming environment of CD4 T cells. Here we explored the role that peptide specificity plays in the partitioning of the polyclonal CD4 T cell repertoire between Tfh and NonTfh lineages during the response to influenza. Surprisingly, we found that CD4 T cells specific for different epitopes exhibited distinct tendencies to segregate into Tfh or NonTfh. To alter the microenvironment and abundance, viral antigens were introduced as purified recombinant proteins in adjuvant as native proteins. Also, the most prototypical epitopes were expressed in a completely foreign protein. In many cases, the epitope-specific response patterns of Tfh vs. NonTfh persisted. The functional TcR avidity of only a subset of epitope-specific cells correlated with the tendency to drive a Tfh response. Thus, we conclude that in a polyclonal CD4 T cell repertoire, features of TcR-peptide:MHC class II complex have a strong deterministic influence on the ability of CD4 T cells to become a Tfh or a NonTfh. Our data is most consistent with at least 2 checkpoints of Tfh selection that include both TcR affinity and B cell presentation. PMID:27329272

  20. CD4 T cell epitope specificity determines follicular versus non-follicular helper differentiation in the polyclonal response to influenza infection or vaccination.

    Science.gov (United States)

    Knowlden, Zackery A G; Sant, Andrea J

    2016-01-01

    Follicular helper T cells (Tfh) are essential for B cell production of high-affinity, class-switched antibodies. Much interest in Tfh development focuses on the priming environment of CD4 T cells. Here we explored the role that peptide specificity plays in the partitioning of the polyclonal CD4 T cell repertoire between Tfh and NonTfh lineages during the response to influenza. Surprisingly, we found that CD4 T cells specific for different epitopes exhibited distinct tendencies to segregate into Tfh or NonTfh. To alter the microenvironment and abundance, viral antigens were introduced as purified recombinant proteins in adjuvant as native proteins. Also, the most prototypical epitopes were expressed in a completely foreign protein. In many cases, the epitope-specific response patterns of Tfh vs. NonTfh persisted. The functional TcR avidity of only a subset of epitope-specific cells correlated with the tendency to drive a Tfh response. Thus, we conclude that in a polyclonal CD4 T cell repertoire, features of TcR-peptide:MHC class II complex have a strong deterministic influence on the ability of CD4 T cells to become a Tfh or a NonTfh. Our data is most consistent with at least 2 checkpoints of Tfh selection that include both TcR affinity and B cell presentation. PMID:27329272

  1. Protein kinase C θ regulates the phenotype of murine CD4+ Th17 cells.

    Directory of Open Access Journals (Sweden)

    Katarzyna Wachowicz

    Full Text Available Protein kinase C θ (PKCθ is involved in signaling downstream of the T cell antigen receptor (TCR and is important for shaping effector T cell functions and inflammatory disease development. Acquisition of Th1-like effector features by Th17 cells has been linked to increased pathogenic potential. However, the molecular mechanisms underlying Th17/Th1 phenotypic instability remain largely unknown. In the current study, we address the role of PKCθ in differentiation and function of Th17 cells by using genetic knock-out mice. Implementing in vitro (polarizing T cell cultures and in vivo (experimental autoimmune encephalomyelitis model, EAE techniques, we demonstrated that PKCθ-deficient CD4+ T cells show normal Th17 marker gene expression (interleukin 17A/F, RORγt, accompanied by enhanced production of the Th1-typical markers such as interferon gamma (IFN-γ and transcription factor T-bet. Mechanistically, this phenotype was linked to aberrantly elevated Stat4 mRNA levels in PKCθ-/- CD4+ T cells during the priming phase of Th17 differentiation. In contrast, transcription of the Stat4 gene was suppressed in Th17-primed wild-type cells. This change in cellular effector phenotype was reflected in vivo by prolonged neurological impairment of PKCθ-deficient mice during the course of EAE. Taken together, our data provide genetic evidence that PKCθ is critical for stabilizing Th17 cell phenotype by selective suppression of the STAT4/IFN-γ/T-bet axis at the onset of differentiation.

  2. Auditing National HIV Guidelines and Policies: The United Kingdom CD4 Surveillance Scheme

    OpenAIRE

    Brown, Alison E; Kall, Meaghan M; Smith, Ruth D; Yin, Zheng; Hunter, Alan; Valerie C Delpech

    2012-01-01

    The United Kingdom’s CD4 surveillance scheme monitors CD4 cell counts among HIV patients and is a national resource for HIV surveillance. It has driven public health policy and allowed auditing of national HIV testing, treatment and care guidelines. We demonstrate its utility through four example outputs: median CD4 count at HIV diagnosis; late HIV diagnosis and short-term mortality; the timing of first CD4 count to indicate entry into HIV care; and the proportion of patients with CD4 counts

  3. Immunity to experimental Salmonella typhimurium infections in rats. Transfer of immunity with primed CD4+CD25high and CD4+CD25low T lymphocytes

    DEFF Research Database (Denmark)

    Thygesen, P; Brandt, L; Jørgensen, T;

    1994-01-01

    The protective effect of primed CD4+ T lymphocytes against a lethal dose of 10(8) viable Salmonella typhimurium was studied in Lewis rats. Primed CD4+ T lymphocytes were obtained by inoculating Lewis rats with a non-lethal dose of 10(6) viable S. typhimurium. Four weeks after the infection, splee...

  4. Acquisition of pneumococci specific effector and regulatory Cd4+ T cells localising within human upper respiratory-tract mucosal lymphoid tissue.

    Directory of Open Access Journals (Sweden)

    Jeffrey Pido-Lopez

    2011-12-01

    Full Text Available The upper respiratory tract mucosa is the location for commensal Streptococcus (S. pneumoniae colonization and therefore represents a major site of contact between host and bacteria. The CD4(+ T cell response to pneumococcus is increasingly recognised as an important mediator of immunity that protects against invasive disease, with data suggesting a critical role for Th17 cells in mucosal clearance. By assessing CD4 T cell proliferative responses we demonstrate age-related sequestration of Th1 and Th17 CD4(+ T cells reactive to pneumococcal protein antigens within mucosal lymphoid tissue. CD25(hi T cell depletion and utilisation of pneumococcal specific MHCII tetramers revealed the presence of antigen specific Tregs that utilised CTLA-4 and PDL-1 surface molecules to suppress these responses. The balance between mucosal effector and regulatory CD4(+ T cell immunity is likely to be critical to pneumococcal commensalism and the prevention of unwanted pathology associated with carriage. However, if dysregulated, such responses may render the host more susceptible to invasive pneumococcal infection and adversely affect the successful implementation of both polysaccharide-conjugate and novel protein-based pneumococcal vaccines.

  5. CD4 T-cell enumeration in a field setting: evaluation of CyFlow counter using the CD4 easy count kit-dry and Pima CD4 systems.

    Directory of Open Access Journals (Sweden)

    Djibril Wade

    Full Text Available BACKGROUND: Flow Cytometry (FCM is still considered to be the method of choice for accurate CD4 enumeration. However, the use of FCM in developing countries is problematic due to their cost and complexity. Lower-cost technologies have been introduced. We evaluated CyFlow Counter together with its lyophilized reagents, and Pima CD4 in high-temperature area, using FACSCount as reference. MATERIALS AND METHODS: Whole blood samples were consecutively collected by venipuncture from 111 HIV+ patients and 17 HIV-negative donors. CD4 T-cell enumeration was performed on CyFlow Counter, Pima CD4 and FACSCount. RESULTS: CyFlow Counter and Pima CD4 systems showed good correlation with FACSCount (slope of 0.82 and 0.90, and concordance ρc of 0.94 and 0.98, respectively. CyFlow Counter showed absolute or relative biases (LOA of -63 cells/mm(3 (-245 to 120 or -9.8% (-38.1 to 18.4 respectively, and Pima CD4 showed biases (LOA of -30 cells/mm(3 (-160 to 101 or -3.5% (-41.0 to 33.9%. CyFlow Counter and Pima CD4 showed respectively 106.7% and 105.9% of similarity with FACSCount. According to WHO-2010 ART initiation threshold of 350 cells/mm(3, CyFlow Counter and Pima CD4 showed respectively sensibility of 100% and 97%, and specificity of 91% and 93%. CyFlow Counter and Pima CD4 were strongly correlated (slope of 1.09 and ρc of 0.95. These alternative systems showed good agreement with bias of 33 cells/mm(3 (-132 to 203 or 6.3% (-31.2 to 43.8, and similarity of 104.3%. CONCLUSION: CyFlow Counter using CD4 easy count kit-dry and Pima CD4 systems can accurately provide CD4 T-cell counts with acceptable agreement to those of FACSCount.

  6. Defect density in multiwalled carbon nanotubes influences ovalbumin adsorption and promotes macrophage activation and CD4(+) T-cell proliferation.

    Science.gov (United States)

    Bai, Wei; Raghavendra, Achyut; Podila, Ramakrishna; Brown, Jared M

    2016-01-01

    Carbon nanotubes (CNTs) are of great interest for the development of drugs and vaccines due to their unique physicochemical properties. The high surface area to volume ratio and delocalized pi-electron cloud of CNTs promote binding of proteins to the surface forming a protein corona. This unique feature of CNTs has been recognized for potential delivery of antigens for strong and long-lasting antigen-specific immune responses. Based on an earlier study that demonstrated increased protein binding, we propose that carboxylated multiwalled CNTs (MWCNTs) can function as an improved carrier to deliver antigens such as ovalbumin (OVA). To test this hypothesis, we coated carboxylated MWCNTs with OVA and measured uptake and activation of antigen-presenting cells (macrophages) and their ability to stimulate CD4(+) T-cell proliferation. We employed two types of carboxylated MWCNTs with different surface areas and defects (MWCNT-2 and MWCNT-30). MWCNT-2 and MWCNT-30 have surface areas of ~215 m(2)/g and 94 m(2)/g, respectively. The ratios of D- to G-band areas (I D/I G) were 0.97 and 1.37 for MWCNT-2 and MWCNT-30, respectively, samples showing that MWCNT-30 contained more defects. The increase in defects in MWCNT-30 led to increased binding of OVA as compared to MWCNT-2 (1,066±182 μg/mL vs 582±41 μg/mL, respectively). Both types of MWCNTs, along with MWCNT-OVA complexes, showed no observable toxicity to bone-marrow-derived macrophages up to 5 days. Surprisingly, we found that MWCNT-OVA complex significantly increased the expression of major histocompatibility complex class II on macrophages and production of pro-inflammatory cytokines (tumor necrosis factor-α and interleukin 6), while MWCNTs without OVA protein corona did not. The coculture of MWCNT-OVA-complex-treated macrophages and OVA-specific CD4(+) T-cells isolated from OT-II mice demonstrated robust proliferation of CD4(+) T-cells. This study provides strong evidence for a role for defects in carboxylated MWCNTs

  7. Defect density in multiwalled carbon nanotubes influences ovalbumin adsorption and promotes macrophage activation and CD4+ T-cell proliferation

    Science.gov (United States)

    Bai, Wei; Raghavendra, Achyut; Podila, Ramakrishna; Brown, Jared M

    2016-01-01

    Carbon nanotubes (CNTs) are of great interest for the development of drugs and vaccines due to their unique physicochemical properties. The high surface area to volume ratio and delocalized pi-electron cloud of CNTs promote binding of proteins to the surface forming a protein corona. This unique feature of CNTs has been recognized for potential delivery of antigens for strong and long-lasting antigen-specific immune responses. Based on an earlier study that demonstrated increased protein binding, we propose that carboxylated multiwalled CNTs (MWCNTs) can function as an improved carrier to deliver antigens such as ovalbumin (OVA). To test this hypothesis, we coated carboxylated MWCNTs with OVA and measured uptake and activation of antigen-presenting cells (macrophages) and their ability to stimulate CD4+ T-cell proliferation. We employed two types of carboxylated MWCNTs with different surface areas and defects (MWCNT-2 and MWCNT-30). MWCNT-2 and MWCNT-30 have surface areas of ~215 m2/g and 94 m2/g, respectively. The ratios of D- to G-band areas (ID/IG) were 0.97 and 1.37 for MWCNT-2 and MWCNT-30, respectively, samples showing that MWCNT-30 contained more defects. The increase in defects in MWCNT-30 led to increased binding of OVA as compared to MWCNT-2 (1,066±182 μg/mL vs 582±41 μg/mL, respectively). Both types of MWCNTs, along with MWCNT–OVA complexes, showed no observable toxicity to bone-marrow-derived macrophages up to 5 days. Surprisingly, we found that MWCNT–OVA complex significantly increased the expression of major histocompatibility complex class II on macrophages and production of pro-inflammatory cytokines (tumor necrosis factor-α and interleukin 6), while MWCNTs without OVA protein corona did not. The coculture of MWCNT–OVA-complex-treated macrophages and OVA-specific CD4+ T-cells isolated from OT-II mice demonstrated robust proliferation of CD4+ T-cells. This study provides strong evidence for a role for defects in carboxylated MWCNTs and

  8. Self-reactive CD4+ T cells and B cells in the blood in health and autoimmune disease: increased frequency of thyroglobulin-reactive cells in Graves' disease

    DEFF Research Database (Denmark)

    Nielsen, Claus H; Moeller, Ane Christine; Hegedüs, Laszlo;

    2006-01-01

    with autoimmune thyroiditis. In Hashimoto's thyroiditis, B cells bound increased amounts of thyroglobulin in a complement- and autoantibody-dependent manner, and the thyroglobulin-elicited proliferation of CD4(+) T cells and B cells was complement dependent. Increased proportions of Tg-responsive CD4......(+) T cells and B cells were found in patients with Graves' disease. Notably, both patient groups and healthy controls exhibited higher proliferative responses to thyroglobulin than to a foreign recall antigen, tetanus toxoid. Our results suggest that self-tolerance can be broken by exposure of...... circulating lymphocytes to high local concentrations of self-antigen, and that complement plays a role in the maintenance of autoimmune processes, at least in Hashimoto's thyroiditis....

  9. CD4-specific designed ankyrin repeat proteins are novel potent HIV entry inhibitors with unique characteristics.

    Directory of Open Access Journals (Sweden)

    Andreas Schweizer

    2008-07-01

    Full Text Available Here, we describe the generation of a novel type of HIV entry inhibitor using the recently developed Designed Ankyrin Repeat Protein (DARPin technology. DARPin proteins specific for human CD4 were selected from a DARPin DNA library using ribosome display. Selected pool members interacted specifically with CD4 and competed with gp120 for binding to CD4. DARPin proteins derived in the initial selection series inhibited HIV in a dose-dependent manner, but showed a relatively high variability in their capacity to block replication of patient isolates on primary CD4 T cells. In consequence, a second series of CD4-specific DARPins with improved affinity for CD4 was generated. These 2nd series DARPins potently inhibit infection of genetically divergent (subtype B and C HIV isolates in the low nanomolar range, independent of coreceptor usage. Importantly, the actions of the CD4 binding DARPins were highly specific: no effect on cell viability or activation, CD4 memory cell function, or interference with CD4-independent virus entry was observed. These novel CD4 targeting molecules described here combine the unique characteristics of DARPins-high physical stability, specificity and low production costs-with the capacity to potently block HIV entry, rendering them promising candidates for microbicide development.

  10. DC-SIGN increases the affinity of HIV-1 envelope glycoprotein interaction with CD4.

    Directory of Open Access Journals (Sweden)

    Karolin Hijazi

    Full Text Available Mannose-binding C-type lectin receptors, expressed on Langerhans cells and subepithelial dendritic cells (DCs of cervico-vaginal tissues, play an important role in HIV-1 capture and subsequent dissemination to lymph nodes. DC-SIGN has been implicated in both productive infection of DCs and the DC-mediated trans infection of CD4(+ T cells that occurs in the absence of replication. However, the molecular events that underlie this efficient transmission have not been fully defined. In this study, we have examined the effect of the extracellular domains of DC-SIGN and Langerin on the stability of the interaction of the HIV-1 envelope glycoprotein with CD4 and also on replication in permissive cells. Surface plasmon resonance analysis showed that DC-SIGN increases the binding affinity of trimeric gp140 envelope glycoproteins to CD4. In contrast, Langerin had no effect on the stability of the gp140:CD4 complex. In vitro infection experiments to compare DC-SIGN enhancement of CD4-dependent and CD4-independent strains demonstrated significantly lower enhancement of the CD4-independent strain. In addition DC-SIGN increased the relative rate of infection of the CD4-dependent strain but had no effect on the CD4-independent strain. DC-SIGN binding to the HIV envelope protein effectively increases exposure of the CD4 binding site, which in turn contributes to enhancement of infection.

  11. Generation of the First TCR Transgenic Mouse with CD4+ T Cells Recognizing an Anti-inflammatory Regulatory T Cell-Inducing Hsp70 Peptide

    Science.gov (United States)

    Jansen, Manon A. A.; van Herwijnen, Martijn J. C.; van Kooten, Peter J. S.; Hoek, Aad; van der Zee, Ruurd; van Eden, Willem; Broere, Femke

    2016-01-01

    Antigen-specific regulatory T cells (Tregs) directed at self-antigens are difficult to study since suitable specific tools to isolate and characterize these cells are lacking. A T cell receptor (TCR)-transgenic mouse would generate possibilities to study such ­antigen-specific T cells. As was shown previously, immunization with the mycobacterial heat shock protein (Hsp) 70-derived peptide B29 and its mouse homologs mB29a and mB29b induced anti-inflammatory responses. Furthermore, B29 induced antigen-­specific Tregs in vivo. To study mB29b-specific Tregs, we isolated the TCR from T cell hybridomas generated against mB29b and produced a TCR transgenic mouse that expresses a MHC-class II restricted mB29b-specific TCR. These TCR transgenic CD4+ T cells were found to cross-react with the B29 epitope as identified with peptide-induced proliferation and IL-2 production. Thus, we have successfully generated a novel mouse model with antigen-specific CD4+ T cells that recognize self and bacterial Hsp 70-derived peptides. With this novel mouse model, it will be possible to study primary antigen-specific T cells with specificity for a regulatory Hsp70 T cell epitope. This will enable the isolation and characterization CD4+CD25+ Tregs with a proven specificity. This will provide useful knowledge of the induction, activation, and mode of action of Hsp70-specific Tregs, for instance, during experimental arthritis. PMID:27014269

  12. Generation of the First TCR Transgenic Mouse with CD4(+) T Cells Recognizing an Anti-inflammatory Regulatory T Cell-Inducing Hsp70 Peptide.

    Science.gov (United States)

    Jansen, Manon A A; van Herwijnen, Martijn J C; van Kooten, Peter J S; Hoek, Aad; van der Zee, Ruurd; van Eden, Willem; Broere, Femke

    2016-01-01

    Antigen-specific regulatory T cells (Tregs) directed at self-antigens are difficult to study since suitable specific tools to isolate and characterize these cells are lacking. A T cell receptor (TCR)-transgenic mouse would generate possibilities to study such -antigen-specific T cells. As was shown previously, immunization with the mycobacterial heat shock protein (Hsp) 70-derived peptide B29 and its mouse homologs mB29a and mB29b induced anti-inflammatory responses. Furthermore, B29 induced antigen--specific Tregs in vivo. To study mB29b-specific Tregs, we isolated the TCR from T cell hybridomas generated against mB29b and produced a TCR transgenic mouse that expresses a MHC-class II restricted mB29b-specific TCR. These TCR transgenic CD4(+) T cells were found to cross-react with the B29 epitope as identified with peptide-induced proliferation and IL-2 production. Thus, we have successfully generated a novel mouse model with antigen-specific CD4(+) T cells that recognize self and bacterial Hsp 70-derived peptides. With this novel mouse model, it will be possible to study primary antigen-specific T cells with specificity for a regulatory Hsp70 T cell epitope. This will enable the isolation and characterization CD4(+)CD25(+) Tregs with a proven specificity. This will provide useful knowledge of the induction, activation, and mode of action of Hsp70-specific Tregs, for instance, during experimental arthritis. PMID:27014269

  13. HIV/AIDS合并妊娠的CD4+T淋巴细胞临床观察%HIVIAIDS in pregnancy the CD4+lymphocytes in clinical observation

    Institute of Scientific and Technical Information of China (English)

    郭晓峰; 唐小平; 蔡卫平; 何浩岚

    2009-01-01

    目的 探讨HIV/AIDS合并妊娠规范使用抗病毒药物后CD4+T淋巴细胞的变化规律.方法 回顾性分析36例HIV/AIDS孕产妇CD4+T淋巴细胞计数及CD4+/CD8+比值变化,其中具有孕期、产后(3个月内)连续的CD4+、CD8+T淋巴细胞计数及CD4+/CD8+比值资料的有1 7例.结果 36例患者CD4+计数最小值80个/uL,最大值743个/uL,中位数367个/uL.其中17例患者孕期CD4+计数最小值80个/uL,最大值588个/uL,中位教313个/uL;产后(3个月内)CD4+计数最小值139个/uL,最大值737个/uL,中位数391个/uL;孕期CD4+/CD8+比值最低0.13,最高0.89,中位数0.41,产后CD4+/CD8+比值最低0.17,最高1.2,中位数0.51. 结论 本组17名HIV/AIDS孕产妇孕期、产后CD4+T淋巴细胞计数及CD4+/CD8+比值变化为产后有逐渐上升的趋势,但x 2检验差异无统计学意义.

  14. Increased cytotoxicity of CD4+ invariant NKT cells against CD4+CD25hiCD127lo/− regulatory T cells in allergic asthma

    OpenAIRE

    Nguyen, Khoa D.; Vanichsarn, Chris; Nadeau, Kari C.

    2008-01-01

    CD4+CD25hiCD127lo/− regulatory T cells (Treg) have been implicated in the resolution of asthma-associated inflammation while the opposite role of CD4+ invariant NKT (iNKT) cells has been the subject of recent investigations. Studies here focused on mechanisms of interaction between CD4+ iNKT cells and Treg to further explore their roles in allergic asthma (AA). Flow cytometry analysis revealed a significant increase in the expression of the natural cytotoxicity receptors NKp30 and NKp46 by CD...

  15. Decreased percentage of CD4+Foxp3+TGF-β+ and increased percentage of CD4+IL-17+ cells in bronchoalveolar lavage of asthmatics

    OpenAIRE

    Barczyk, Adam; Pierzchala, Wladyslaw; Caramori, Gaetano; Wiaderkiewicz, Ryszard; Kaminski, Marcin; Barnes, Peter J; Adcock, Ian M.

    2014-01-01

    Background Asthma is a chronic inflammatory disorder of the airways with the proven role of Th2 cells in its pathogenesis. The role and characteristic of different subsets of CD4+ cells is much less known. Aim The aim of the study was to analyze the incidence of different subsets of CD4+ T cells, in particular different subsets of CD4+ cells with the co-expression of different cytokines. Methods Twenty five stable asthmatic and twelve age-matched control subjects were recruited to the study. ...

  16. Long-term exposure to high levels of decabrominated diphenyl ether inhibits CD4 T-cell functions in C57Bl/6 mice.

    Science.gov (United States)

    Feng, Yan; Zeng, Weihong; Wang, Ying; Shen, Hao; Wang, Yan

    2016-09-01

    In recent years, the adverse health effects of decabrominated diphenyl ether (BDE-209) have raised more concerns as a growing number of studies reported its persistence in the environment and abundance in the human population, especially in occupational environmental compartments and exposed personnel. This study applies our previous animal model simulating occupational exposure to BDE-209 to investigate its potential adverse effects on CD4 T cells. Female C57Bl/6 mice were orally gavaged with BDE-209 at a dose of 800 mg kg(-1) every 2 days for 10 months and the blood of each mouse was collected for analysis. Kinetic changes of the peripheral immune system were investigated from 1 to 5 months of exposure. The chronic effects on cytokine production, proliferation and the antigen-specific responses of CD4 T cells were evaluated at 7, 9 and 10 months, respectively. The results have shown that impaired proliferation and cytokine (IFN-γ, IL-2 or TNF-α) production of CD4 T cells were observed in BDE-209-exposed mice, accompanied by increased T regulatory cells in the blood. BDE-209 exposure in vitro also suppressed the reactivity of CD4 T cells at concentrations of 0.01, 0.1, 1 and 10 μM. Furthermore, we observed weaker antigen-specific CD4 T-cell responses to Listeria monocytogenes infection in the mice exposed to BDE-209, suggesting decreased resistance to exogenous pathogens. Taken together, these observations indicate an impaired cellular immunity after long-term and relative high-dose exposure to BDE-209 in adult mice. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26682527

  17. Development of an antibody to bovine IL-2 reveals multifunctional CD4 T(EM cells in cattle naturally infected with bovine tuberculosis.

    Directory of Open Access Journals (Sweden)

    Adam O Whelan

    Full Text Available Gaining a better understanding of the T cell mechanisms underlying natural immunity to bovine tuberculosis would help to identify immune correlates of disease progression and facilitate the rational design of improved vaccine and diagnostic strategies. CD4 T cells play an established central role in immunity to TB, and recent interest has focussed on the potential role of multifunctional CD4 T cells expressing IFN-γ, IL-2 and TNF-α. Until now, it has not been possible to assess the contribution of these multifunctional CD4 T cells in cattle due to the lack of reagents to detect bovine IL-2 (bIL-2. Using recombinant phage display technology, we have identified an antibody that recognises biologically active bIL-2. Using this antibody, we have developed a polychromatic flow cytometric staining panel that has allowed the investigation of multifunctional CD4 T-cells responses in cattle naturally infected with M. bovis. Assessment of the frequency of antigen specific CD4 T cell subsets reveals a dominant IFN-γ(+IL-2(+TNF-α(+ and IFN-γ(+ TNF-α(+ response in naturally infected cattle. These multifunctional CD4 T cells express a CD44(hiCD45RO(+CD62L(lo T-effector memory (T(EM phenotype and display higher cytokine median fluorescence intensities than single cytokine producers, consistent with an enhanced 'quality of response' as reported for multifunctional cells in human and murine systems. Through our development of these novel immunological bovine tools, we provide the first description of multifunctional T(EM cells in cattle. Application of these tools will improve our understanding of protective immunity in bovine TB and allow more direct comparisons of the complex T cell mediated immune responses between murine models, human clinical studies and bovine TB models in the future.

  18. Elevated IL-6 Receptor Expression on CD4+ T Cells contributes to the increased Th17 Responses in patients with Chronic Hepatitis B

    Directory of Open Access Journals (Sweden)

    Gao Zhiliang

    2011-06-01

    Full Text Available Abstract Background Increased numbers of Interleukin-17-producing CD4+ T cells (Th17 have been found in association with hepatitis B virus (HBV-induced liver injury. However, the mechanism underlying the increase of Th17 responses in patients with HBV infection remains unclear. In this study, we investigate the possible regulatory mechanisms of increased Th17 responses in patients with chronic hepatitis B(CHB. Methods Th17 response and IL-6R expression on CD4+ T cells in peripheral blood samples were determined by flow cytometry. Cytokines TGF-β, IL-1β, IL-6 and IL-17 in plasma and/or supernatant samples were determined by ELISA and the IL-17 and IL-6R mRNA levels were quantified by quantitative real-time reverse polymerase chain reaction. Results All these data indicated that the frequency of periphery Th17 cells is significantly correlated with the percentage of CD4+ T cells expressing IL-6R in CHB patients. CD4+ T cells from patients with CHB, but not those from healthy donors, produced higher levels of IL-17 and had more IL-6R expression upon stimulation with the HBV core antigen (HBcAg in vitro. The PMA/ionomycin and HBcAg -stimulated up-regulation of IL-17 production by CD4+ T cells could be reversed by a neutralizing antibody against IL-6R. Conclusion we showed that enhancement of IL-6R expression on CD4+ T cells upon HBV infection contributes to increased Th17 response in patients with CHB.

  19. Specificity analysis of human CD4+ T-cell clones directed against human herpesvirus 6 (HHV-6), HHV-7, and human cytomegalovirus.

    OpenAIRE

    Yasukawa, M; Yakushijin, Y; Furukawa, M; Fujita, S.

    1993-01-01

    In order to clarify antigenic variations among various isolates of human herpesvirus 6 (HHV-6) and cross-reactivity among HHV-6, HHV-7, and human cytomegalovirus (HCMV) in the T-cell immune response, the antigenic specificity of the proliferative response mediated by 232 CD4+ human T-cell clones directed against HHV-6, HHV-7, or HCMV was examined. The results obtained were as follows. (i) Although the majority of T-cell clones directed against HHV-6 proliferated in response to stimulation wit...

  20. Micro-RNA-155-mediated control of heme oxygenase 1 (HO-1) is required for restoring adaptively tolerant CD4+ T-cell function in rodents.

    OpenAIRE

    Zhang, Jinyu; Vandevenne, Patricia; Hamdi, Haifa; Van Puyvelde, Merry; Zucchi, Alessandro; Bettonville, Marie; Weatherly, Kathleen; Braun, Michel Y

    2015-01-01

    T cells chronically stimulated by a persistent antigen often become dysfunctional and lose effector functions and proliferative capacity. To identify the importance of micro-RNA-155 (miR-155) in this phenomenon, we analyzed mouse miR-155-deficient CD4(+) T cells in a model where the chronic exposure to a systemic antigen led to T-cell functional unresponsiveness. We found that miR-155 was required for restoring function of T cells after programmed death receptor 1 blockade. Heme oxygenase 1 (...

  1. NAD+ protects against EAE by regulating CD4+ T-cell differentiation

    Science.gov (United States)

    Tullius, Stefan G.; Biefer, Hector Rodriguez Cetina; Li, Suyan; Trachtenberg, Alexander J.; Edtinger, Karoline; Quante, Markus; Krenzien, Felix; Uehara, Hirofumi; Yang, Xiaoyong; Kissick, Haydn T.; Kuo, Winston P.; Ghiran, Ionita; de la Fuente, Miguel A.; Arredouani, Mohamed S.; Camacho, Virginia; Tigges, John C.; Toxavidis, Vasilis; El Fatimy, Rachid; Smith, Brian D.; Vasudevan, Anju; ElKhal, Abdallah

    2014-01-01

    CD4+ T cells are involved in the development of autoimmunity, including multiple sclerosis (MS). Here we show that nicotinamide adenine dinucleotide (NAD+) blocks experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by inducing immune homeostasis through CD4+IFNγ+IL-10+ T cells and reverses disease progression by restoring tissue integrity via remyelination and neuroregeneration. We show that NAD+ regulates CD4+ T-cell differentiation through tryptophan hydroxylase-1 (Tph1), independently of well-established transcription factors. In the presence of NAD+, the frequency of T-bet−/− CD4+IFNγ+ T cells was twofold higher than wild-type CD4+ T cells cultured in conventional T helper 1 polarizing conditions. Our findings unravel a new pathway orchestrating CD4+ T-cell differentiation and demonstrate that NAD+ may serve as a powerful therapeutic agent for the treatment of autoimmune and other diseases. PMID:25290058

  2. Lack of permissivity of human monoclonal CD4+ lymphocytes to HIV.

    Science.gov (United States)

    Chapel, A; Bourges, J F; Bensussan, A; d'Auriol, L; Vilmer, E; Dormont, D

    1990-01-01

    Although knowledge has accumulated about GP110-CD4 interaction, viral penetration into human CD4+ lymphocytes remains unclear, in spite of the fact that all studies on HIV infection were performed on cell-transformed lineages, or on human polyclonal CD4+ cells. In order to investigate this viral entrance into susceptible cells, we studied the permissivity of 13 human monoclonal CD4+ lymphocytes by means of reverse transcriptase (RT) assay and immunocapture. We demonstrated a differential susceptibility to HIV of these CD4+ clones. In a second experiment, HIV infection was studied: (1) sequentially by RT assay and P24 immunocapture on several clones; (2) by cocultivation of infected clones with umbilical cord lymphocytes. These experiments suggested existence of permissive and "nonpermissive" CD4+ monoclonal lymphocytes. Slot blot, then PCR, revealed that proviral DNA sequences were detectable in all clones, but were present at lower levels in nonpermissive clones.

  3. Cord blood CD4+ T cells respond to self heat shock protein 60 (HSP60.

    Directory of Open Access Journals (Sweden)

    Joost A Aalberse

    Full Text Available BACKGROUND: To prevent harmful autoimmunity most immune responses to self proteins are controlled by central and peripheral tolerance. T cells specific for a limited set of self-proteins such as human heat shock protein 60 (HSP60 may contribute to peripheral tolerance. It is not known whether HSP60-specific T cells are present at birth and thus may play a role in neonatal tolerance. We studied whether self-HSP60 reactive T cells are present in cord blood, and if so, what phenotype these cells have. METHODOLOGY/PRINCIPAL FINDINGS: Cord blood mononuclear cells (CBMC of healthy, full term neonates (n = 21, were cultured with HSP60 and Tetanus Toxoid (TT to study antigen specific proliferation, cytokine secretion and up-regulation of surface markers. The functional capacity of HSP60-induced T cells was determined with in vitro suppression assays. Stimulation of CBMC with HSP60 led to CD4(+ T cell proliferation and the production of various cytokines, most notably IL-10, Interferon-gamma, and IL-6. HSP60-induced T cells expressed FOXP3 and suppressed effector T cell responses in vitro. CONCLUSION: Self-reactive HSP60 specific T cells are already present at birth. Upon stimulation with self-HSP60 these cells proliferate, produce cytokines and express FOXP3. These cells function as suppressor cells in vitro and thus they may be involved in the regulation of neonatal immune responses.

  4. NAD+ protects against EAE by regulating CD4+ T-cell differentiation

    OpenAIRE

    Tullius, Estefan G.; Biefer, Hector Rodriguez Cetina; Li, Suyan; Trachtenberg, Alexander J.; Edtinger, Karoline; Quante, Markus; Krenzien, Felix; Uehara, Hirofumi; Yang, Xiaoyong; Kissick, Haydn T.; Kuo, Winston P.; Ghiran, Ionita; Fuente García, Miguel Ángel de la; Arredouani, Mohamed S.; Camacho, Virginia

    2014-01-01

    Producción Científica CD4(+) T cells are involved in the development of autoimmunity, including multiple sclerosis (MS). Here we show that nicotinamide adenine dinucleotide (NAD(+)) blocks experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by inducing immune homeostasis through CD4(+)IFNγ(+)IL-10(+) T cells and reverses disease progression by restoring tissue integrity via remyelination and neuroregeneration. We show that NAD(+) regulates CD4(+) T-cell differentiation th...

  5. CD4+CD25bright T cells in human intestinal lamina propria as regulatory cells.

    Science.gov (United States)

    Makita, Shin; Kanai, Takanori; Oshima, Shigeru; Uraushihara, Koji; Totsuka, Teruji; Sawada, Taisuke; Nakamura, Tetsuya; Koganei, Kazutaka; Fukushima, Tsuneo; Watanabe, Mamoru

    2004-09-01

    It is well known that immune responses in the intestine remain in a state of controlled inflammation, suggesting that not only active suppression by regulatory T cells plays an important role in the normal intestinal homeostasis, but also its dysregulation leads to the development of inflammatory bowel disease. In this study, we demonstrate that the CD4(+)CD25(bright) T cells reside in the human intestinal lamina propria (LP) and functionally retain regulatory activities. All human LP CD4(+) T cells regardless of CD25 expression constitutively expressed CTLA-4, glucocorticoid-induced TNFR family-related protein, and Foxp3 and proliferate poorly. Although LP CD4(+)CD25(-) T cells showed an activated and anergic/memory phenotype, they did not retain regulatory activity. In LP CD4(+)CD25(+) T cells, however, cells expressing CD25 at high levels (CD4(+)CD25(bright)) suppressed the proliferation and various cytokine productions of CD4(+)CD25(-) T cells. LP CD4(+)CD25(bright) T cells by themselves produced fewer amounts of IL-2, IFN-gamma, and IL-10. Interestingly, LP CD4(+)CD25(bright) T cells with regulatory T activity were significantly increased in patients with active inflammatory bowel disease. These results suggest that CD4(+)CD25(bright) T cells found in the normal and inflamed intestinal mucosa selectively inhibit the host immune response and therefore may contribute to the intestinal immune homeostasis. PMID:15322172

  6. TNF-α blockade induces IL-10 expression in human CD4+ T cells

    Science.gov (United States)

    Evans, Hayley G.; Roostalu, Urmas; Walter, Gina J.; Gullick, Nicola J.; Frederiksen, Klaus S.; Roberts, Ceri A.; Sumner, Jonathan; Baeten, Dominique L.; Gerwien, Jens G.; Cope, Andrew P.; Geissmann, Frederic; Kirkham, Bruce W.; Taams, Leonie S.

    2014-02-01

    IL-17+ CD4+ T (Th17) cells contribute to the pathogenesis of several human inflammatory diseases. Here we demonstrate that TNF inhibitor (TNFi) drugs induce the anti-inflammatory cytokine IL-10 in CD4+ T cells including IL-17+ CD4+ T cells. TNFi-mediated induction of IL-10 in IL-17+ CD4+ T cells is Treg-/Foxp3-independent, requires IL-10 and is overcome by IL-1β. TNFi-exposed IL-17+ CD4+ T cells are molecularly and functionally distinct, with a unique gene signature characterized by expression of IL10 and IKZF3 (encoding Aiolos). We show that Aiolos binds conserved regions in the IL10 locus in IL-17+ CD4+ T cells. Furthermore, IKZF3 and IL10 expression levels correlate in primary CD4+ T cells and Aiolos overexpression is sufficient to drive IL10 in these cells. Our data demonstrate that TNF-α blockade induces IL-10 in CD4+ T cells including Th17 cells and suggest a role for the transcription factor Aiolos in the regulation of IL-10 in CD4+ T cells.

  7. Exploration of the Partial Different Roles of CD4 + CD25 + Tregs and CD4 + CD25HighTregs in Sero-resistance Syphilitic Patients%梅毒血清固定患者CD4+CD25+Treg细胞和CD4+CD25High Treg细胞功能的差异探讨

    Institute of Scientific and Technical Information of China (English)

    张明海; 赵建斌

    2013-01-01

    目的 探讨梅毒血清固定患者外周血CD4+ CD25+ Treg细胞和CD4+ CD25HighTreg细胞功能是否发生变化.方法 采用流式细胞术(FCM)检测28例梅毒血清固定患者和28例梅毒转阴患者外周血CD4+CD25+ Treg细胞和CD4+ CD25High Treg细胞中FOXP3和CTLA-4的水平;采用免疫磁珠细胞分选技术(MACS)和Realtime-PCR技术检测CD4+ CD25+ Treg细胞的FOXP3和CTLA-4mRNA水平.结果 梅毒血清固定组外周血CD4+ CD25+Treg细胞功能增强,而梅毒血清转阴组外周血CD4+ CD25HighTreg细胞功能稳定.结论 CD4+CD25+Treg和CD4+ CD25HighTreg细胞在梅毒血清固定形成中作用的方式或途径存在部分差异.

  8. Clinical Evaluation of the BD FACSPresto™ Near-Patient CD4 Counter in Kenya

    Science.gov (United States)

    Angira, Francis; Akoth, Benta; Omolo, Paul; Opollo, Valarie; Bornheimer, Scott; Judge, Kevin; Tilahun, Henok; Lu, Beverly; Omana-Zapata, Imelda; Zeh, Clement

    2016-01-01

    Background The BD FACSPresto™ Near-Patient CD4 Counter was developed to expand HIV/AIDS management in resource-limited settings. It measures absolute CD4 counts (AbsCD4), percent CD4 (%CD4), and hemoglobin (Hb) from a single drop of capillary or venous blood in approximately 23 minutes, with throughput of 10 samples per hour. We assessed the performance of the BD FACSPresto system, evaluating accuracy, stability, linearity, precision, and reference intervals using capillary and venous blood at KEMRI/CDC HIV-research laboratory, Kisumu, Kenya, and precision and linearity at BD Biosciences, California, USA. Methods For accuracy, venous samples were tested using the BD FACSCalibur™ instrument with BD Tritest™ CD3/CD4/CD45 reagent, BD Trucount™ tubes, and BD Multiset™ software for AbsCD4 and %CD4, and the Sysmex™ KX-21N for Hb. Stability studies evaluated duration of staining (18–120-minute incubation), and effects of venous blood storage <6–24 hours post-draw. A normal cohort was tested for reference intervals. Precision covered multiple days, operators, and instruments. Linearity required mixing two pools of samples, to obtain evenly spaced concentrations for AbsCD4, total lymphocytes, and Hb. Results AbsCD4 and %CD4 venous/capillary (N = 189/ N = 162) accuracy results gave Deming regression slopes within 0.97–1.03 and R2 ≥0.96. For Hb, Deming regression results were R2 ≥0.94 and slope ≥0.94 for both venous and capillary samples. Stability varied within 10% 2 hours after staining and for venous blood stored less than 24 hours. Reference intervals results showed that gender—but not age—differences were statistically significant (p<0.05). Precision results had <3.5% coefficient of variation for AbsCD4, %CD4, and Hb, except for low AbsCD4 samples (<6.8%). Linearity was 42–4,897 cells/μL for AbsCD4, 182–11,704 cells/μL for total lymphocytes, and 2–24 g/dL for Hb. Conclusions The BD FACSPresto system provides accurate, precise clinical

  9. Palmitic acid analogs exhibit nanomolar binding affinity for the HIV-1 CD4 receptor and nanomolar inhibition of gp120-to-CD4 fusion.

    Directory of Open Access Journals (Sweden)

    Elena E Paskaleva

    Full Text Available BACKGROUND: We recently reported that palmitic acid (PA is a novel and efficient CD4 fusion inhibitor to HIV-1 entry and infection. In the present report, based on in silico modeling of the novel CD4 pocket that binds PA, we describe discovery of highly potent PA analogs with increased CD4 receptor binding affinities (K(d and gp120-to-CD4 inhibition constants (K(i. The PA analogs were selected to satisfy Lipinski's rule of drug-likeness, increased solubility, and to avoid potential cytotoxicity. PRINCIPAL FINDINGS: PA analog 2-bromopalmitate (2-BP was most efficacious with K(d approximately 74 nM and K(i approximately 122 nM, ascorbyl palmitate (6-AP exhibited slightly higher K(d approximately 140 nM and K(i approximately 354 nM, and sucrose palmitate (SP was least efficacious binding to CD4 with K(d approximately 364 nM and inhibiting gp120-to-CD4 binding with K(i approximately 1486 nM. Importantly, PA and its analogs specifically bound to the CD4 receptor with the one to one stoichiometry. SIGNIFICANCE: Considering observed differences between K(i and K(d values indicates clear and rational direction for improving inhibition efficacy to HIV-1 entry and infection. Taken together this report introduces a novel class of natural small molecules fusion inhibitors with nanomolar efficacy of CD4 receptor binding and inhibition of HIV-1 entry.

  10. OX40对溃疡性结肠炎CD4+T细胞分泌细胞因子功能的影响%The role of OX40 in CD4+T cells cytokines production in ulcerative colitis

    Institute of Scientific and Technical Information of China (English)

    王晓娣; 吴铁镛

    2008-01-01

    Objective To investigate the expression of OX40 on CD4+T cells in patients with ulcerative colitis (UC)and the role of OX40/OX40L interaction for the cytokine production of lamina propria(LP)-CD4+T cells from UC.Methotis LP-CD4+T cells were purified.The expression of OX40 molecule was measured with FACS.LP-CD4+T cells were cultured with different stimuli and proliferation was assessed.The cytokines concentrations of the culture supernatant were detected.Results No difference of the OX40 expression was observed among the CD4+T cells from peripheral blood(PB)of UC patients,LP of non-inflammatory colonic tissue in UC patients and control PB.However.the expression of OX40 was significantly higher on LP-CD4+T cells from inflammatory colonic tissue in UC patients.In vitro culture with antigen presenting cells,the levels of IFNγ and TNFα secreted by LP-CD4+T cells from the inflammatory colonic tissue were significantly higher than those from the non-inflammatory colonic tissue(both P<0.01).The levels of IFNγ and TNFα secreted by LP-CD4+T cells from the inflammatory colonic tissue were further increased by anti-OX40 MoAb stimulation.but suppressed significantly by adding anti-OX40L MoAb (compared with non stimulation,P<0.01,respectively).The IFNγ and TNFα secretion of the LP-CD4+T cells from the non-inflammatory colonic tissue were not significantly different with and without anti-OX40 or anti-OX40L MoAbs stimulation.IL-4 and IL-10 produced by LP-CD4+T cells from the inflammatory or non-inflammatory colonic tissue were not significantly changed when adding different stimuli.Conclusions OX40 is highly expressed on LP-CD4+T cells from inflammatory colonic tissue in patients with UC.AntiOX40L MoAb can inhibit the proinflammatory cytokines secreted by these cells.It is indicated that OX40+T cells are involved in the immunopathological process in UC and blockage of the interaction of OX40 and OX40Lis a new strategy to be considered for the treatment of the disease

  11. Amaranthus leucocarpus lectin recognizes a moesin-like O-glycoprotein and costimulates murine CD3-activated CD4(+) T cells.

    Science.gov (United States)

    Arenas-Del Ángel, Maria; Legorreta-Herrera, Martha; Mendoza-Hernández, Guillermo; Garfias, Yonathan; Chávez, Raul; Zenteno, Edgar; Lascurain, Ricardo

    2015-09-01

    The Galβ1,3GalNAcα1,O-Ser/Thr specific lectin from Amaranthus leucocarpus (ALL) binds a ∼70 kDa glycoprotein on murine T cell surface. We show that in the absence of antigen presenting cells, murine CD4(+) T cells activated by an anti-CD3 antibody plus ALL enhanced cell proliferation similar to those cells activated via CD3/CD28 at 48 h of culture. Moreover, ALL induced the production of IL-4, IL-10, TNF-alpha, and TGF-beta in CD3-activated cells. Proteomic assay using two-dimensional electrophoresis and far-Western blotting, ALL recognized two prominent proteins associated to the lipid raft microdomains in CD3/CD28-activated CD4(+) T cells. By mass spectrometry, the peptide fragments from ALL-recognized proteins showed sequences with 33% homology to matricin (gi|347839 NCBInr) and 41% identity to an unnamed protein related to moesin (gi|74186081 NCBInr). Confocal microscopy analysis of CD3/CD28-activated CD4(+) T cells confirmed that staining by ALL colocalized with anti-moesin FERM domain antibody along the plasma membrane and in the intercellular contact sites. Our findings suggest that a moesin-like O-glycoprotein is the ALL-recognized molecule in lipid rats, which induces costimulatory signals on CD4(+) T cells. PMID:26417436

  12. HIV-1 Nef targets MHC-I and CD4 for degradation via a final common beta-COP-dependent pathway in T cells.

    Directory of Open Access Journals (Sweden)

    Malinda R Schaefer

    Full Text Available To facilitate viral infection and spread, HIV-1 Nef disrupts the surface expression of the viral receptor (CD4 and molecules capable of presenting HIV antigens to the immune system (MHC-I. To accomplish this, Nef binds to the cytoplasmic tails of both molecules and then, by mechanisms that are not well understood, disrupts the trafficking of each molecule in different ways. Specifically, Nef promotes CD4 internalization after it has been transported to the cell surface, whereas Nef uses the clathrin adaptor, AP-1, to disrupt normal transport of MHC-I from the TGN to the cell surface. Despite these differences in initial intracellular trafficking, we demonstrate that MHC-I and CD4 are ultimately found in the same Rab7(+ vesicles and are both targeted for degradation via the activity of the Nef-interacting protein, beta-COP. Moreover, we demonstrate that Nef contains two separable beta-COP binding sites. One site, an arginine (RXR motif in the N-terminal alpha helical domain of Nef, is necessary for maximal MHC-I degradation. The second site, composed of a di-acidic motif located in the C-terminal loop domain of Nef, is needed for efficient CD4 degradation. The requirement for redundant motifs with distinct roles supports a model in which Nef exists in multiple conformational states that allow access to different motifs, depending upon which cellular target is bound by Nef.

  13. Peripheral canine CD4(+)CD8(+) double-positive T cells - unique amongst others.

    Science.gov (United States)

    von Buttlar, Heiner; Bismarck, Doris; Alber, Gottfried

    2015-12-15

    T lymphocytes co-expressing CD4 and CD8 ("double-positive T cells") are commonly associated with a thymic developmental stage of T cells. Their first description in humans and pigs as extrathymic T cells with a memory phenotype almost 30 years ago came as a surprise. Meanwhile peripheral double-positive T cells have been described in a growing number of different species. In this review we highlight novel data from our very recent studies on canine peripheral double-positive T cells which point to unique features of double-positive T cells in the dog. In contrast to porcine CD4(+)CD8(+) T cells forming a homogenous cellular population based on their expression of CD4 and CD8α, canine CD4(+)CD8(+) T cells can be divided into three different cellular subsets with distinct expression levels of CD4 and CD8α. Double-positive T cells expressing CD8β are present in humans and dogs but absent in swine. Moreover, canine CD4(+)CD8(+) T cells can not only develop from CD4(+) single-positive T cells but also from CD8(+) single-positive T cells. Together, this places canine CD4(+)CD8(+) T cells closer to their human than porcine counterparts since human double-positive T cells also appear to be heterogeneous in their CD4 and CD8α expression and have both CD4(+) and CD8(+) T cells as progenitor cells. However, CD4(+) single-positive T cells are the more potent progenitors for canine double-positive T cells, whereas CD8(+) single-positive T cells are more potent progenitors for human double-positive T cells. Canine double-positive T cells have an activated phenotype and may have as yet unrecognized roles in vivo in immunity to infection or in inflammatory diseases such as chronic infection, autoimmunity, allergy, or cancer.

  14. Auditing national HIV guidelines and policies: The United Kingdom CD4 Surveillance Scheme.

    Science.gov (United States)

    Brown, Alison E; Kall, Meaghan M; Smith, Ruth D; Yin, Zheng; Hunter, Alan; Hunter, Alan; Delpech, Valerie C

    2012-01-01

    The United Kingdom's CD4 surveillance scheme monitors CD4 cell counts among HIV patients and is a national resource for HIV surveillance. It has driven public health policy and allowed auditing of national HIV testing, treatment and care guidelines. WE DEMONSTRATE ITS UTILITY THROUGH FOUR EXAMPLE OUTPUTS: median CD4 count at HIV diagnosis; late HIV diagnosis and short-term mortality; the timing of first CD4 count to indicate entry into HIV care; and the proportion of patients with CD4 counts <350 cells/mm3 receiving anti-retroviral therapy (ARV). In 2009, 95% (61,502/64,420) of adults living with diagnosed HIV infection had CD4 counts available. The median CD4 count at diagnosis increased from 276 to 335 cells/mm3 between 2000 and 2009, indicating modest improvements in HIV testing. In 2009, 52% of patients were diagnosed at a late stage of HIV infection (CD4 <350 cells/mm(3)); these individuals had a ten-fold risk of dying within a year of their diagnosis compared to those diagnosed promptly. In 2008, the national target of performing a CD4 count within 14 days of diagnosis was met for 61% of patients. National treatment guidelines have largely been met with 83% patients with CD4 <350 cells/mm(3) receiving ARV. The monitoring of CD4 counts is critical to HIV surveillance in the United Kingdom enabling the close monitoring of efforts to reduce morbidity and mortality associated with late diagnosis and underpins the auditing of policies and guidelines. These routine surveillance outputs can be generated at national and local levels to drive and monitor public health policy and prevention efforts. PMID:23049663

  15. Effects of human respiratory syncytial virus, metapneumovirus, parainfluenza virus 3 and influenza virus on CD4+ T cell activation by dendritic cells.

    Directory of Open Access Journals (Sweden)

    Cyril Le Nouën

    Full Text Available BACKGROUND: Human respiratory syncytial virus (HRSV, and to a lesser extent human metapneumovirus (HMPV and human parainfluenza virus type 3 (HPIV3, re-infect symptomatically throughout life without antigenic change, suggestive of incomplete immunity. One causative factor is thought to be viral interference with dendritic cell (DC-mediated stimulation of CD4+ T cells. METHODOLOGY, PRINCIPAL FINDINGS: We infected human monocyte-derived DC with purified HRSV, HMPV, HPIV3, or influenza A virus (IAV and compared their ability to induce activation and proliferation of autologous CD4+ T cells in vitro. IAV was included because symptomatic re-infection without antigenic change is less frequent, suggesting that immune protection is more complete and durable. We examined virus-specific memory responses and superantigen-induced responses by multiparameter flow cytometry. Live virus was more stimulatory than inactivated virus in inducing DC-mediated proliferation of virus-specific memory CD4+ T cells, suggesting a lack of strong suppression by live virus. There were trends of increasing proliferation in the order: HMPVCD4+ T cell proliferation in response to secondary stimulus with superantigen, but the effect was transitory and greatest for IAV. T cell cytokine production was similar, with no evidence of Th2 or Th17 skewing. CONCLUSIONS, SIGNIFICANCE: Understanding the basis for the ability of HRSV in particular to symptomatically re-infect without significant antigenic change is of considerable interest. The present results show that these common respiratory viruses are similar in their ability to induce DC to activate CD4+ T cells. Thus, the results do not support the common model in which viral suppression of CD4+ T cell activation and

  16. Characterization of memory CD4+ IL-21+ T cells in human PBMC%人外周血CD4+IL-21+记忆T细胞的特征

    Institute of Scientific and Technical Information of China (English)

    刘昀; 李丽; 黄凤玉; 吴长有

    2010-01-01

    目的:探讨人外周血中白细胞介索21(IL-21)的产生细胞及其特征.方法:分离人外周血单个核细胞(PBMC),分为不刺激或anti-CD3(OKT3)、OKT3+anti-CD28、PMA+ionomycin刺激四个组,流式细胞术(FCM)检测产生IL-21的细胞亚群.PMA+ionomycin刺激PBMC、纯化CD4+、CD4+CD45RA-、CD4+CD45RA+细胞、脐带血单个核细胞(CB-MC),FCM分析产生IL-21细胞的表型特征和IL-21与Th1、Th2、Th17和Th22细胞因子之间的关系.结果:与OKT3、OKT3+anti-CD28相比,PMA+ionomycin能诱导最高量的IL-21产生.产生IL-21的主要细胞为CD4+T细胞,少数CD8+T细胞.CD4+IL-21+T细胞表达CD45RO,不表达CD45RA,其中部分细胞表达CCR6、CCR7或CXCR5.CD4+CD45RA-细胞表达IL-21远高于CIM+CD45RA+细胞.进一步研究表明,PBMC产生IL-21,而CBMC不产生.此外,大约24%的CD4+IL-21+细胞表达IFN-γ,小于10%CD4+IL21+细胞表达IL-4、IL-17或IL-22.结论:人PBMC在多克隆刺激的条件下,可以诱导IL-21的产生.产生IL-21的主要细胞亚群具有记忆CD4+T细胞的表型.其中一部分CD4+IL-21+T细胞的表型独立于Th1、Th2、Th17和Th22细胞亚群.

  17. ICOS Promotes the Function of CD4+ Effector T Cells during Anti-OX40-Mediated Tumor Rejection.

    Science.gov (United States)

    Metzger, Todd C; Long, Hua; Potluri, Shobha; Pertel, Thomas; Bailey-Bucktrout, Samantha L; Lin, John C; Fu, Tihui; Sharma, Padmanee; Allison, James P; Feldman, Reid M R

    2016-07-01

    ICOS is a T-cell coregulatory receptor that provides a costimulatory signal to T cells during antigen-mediated activation. Antitumor immunity can be improved by ICOS-targeting therapies, but their mechanism of action remains unclear. Here, we define the role of ICOS signaling in antitumor immunity using a blocking, nondepleting antibody against ICOS ligand (ICOS-L). ICOS signaling provided critical support for the effector function of CD4(+) Foxp3(-) T cells during anti-OX40-driven tumor immune responses. By itself, ICOS-L blockade reduced accumulation of intratumoral T regulatory cells (Treg), but it was insufficient to substantially inhibit tumor growth. Furthermore, it did not impede antitumor responses mediated by anti-4-1BB-driven CD8(+) T cells. We found that anti-OX40 efficacy, which is based on Treg depletion and to a large degree on CD4(+) effector T cell (Teff) responses, was impaired with ICOS-L blockade. In contrast, the provision of additional ICOS signaling through direct ICOS-L expression by tumor cells enhanced tumor rejection and survival when administered along with anti-OX40 therapy. Taken together, our results showed that ICOS signaling during antitumor responses acts on both Teff and Treg cells, which have opposing roles in promoting immune activation. Thus, effective therapies targeting the ICOS pathway should seek to promote ICOS signaling specifically in effector CD4(+) T cells by combining ICOS agonism and Treg depletion. Cancer Res; 76(13); 3684-9. ©2016 AACR. PMID:27197182

  18. Systemic BCG immunization induces persistent lung mucosal multifunctional CD4 T(EM cells which expand following virulent mycobacterial challenge.

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    Daryan A Kaveh

    Full Text Available To more closely understand the mechanisms of how BCG vaccination confers immunity would help to rationally design improved tuberculosis vaccines that are urgently required. Given the established central role of CD4 T cells in BCG induced immunity, we sought to characterise the generation of memory CD4 T cell responses to BCG vaccination and M. bovis infection in a murine challenge model. We demonstrate that a single systemic BCG vaccination induces distinct systemic and mucosal populations of T effector memory (T(EM cells in vaccinated mice. These CD4+CD44(hiCD62L(loCD27⁻ T cells concomitantly produce IFN-γ and TNF-α, or IFN-γ, IL-2 and TNF-α and have a higher cytokine median fluorescence intensity MFI or 'quality of response' than single cytokine producing cells. These cells are maintained for long periods (>16 months in BCG protected mice, maintaining a vaccine-specific functionality. Following virulent mycobacterial challenge, these cells underwent significant expansion in the lungs and are, therefore, strongly associated with protection against M. bovis challenge. Our data demonstrate that a persistent mucosal population of T(EM cells can be induced by parenteral immunization, a feature only previously associated with mucosal immunization routes; and that these multifunctional T(EM cells are strongly associated with protection. We propose that these cells mediate protective immunity, and that vaccines designed to increase the number of relevant antigen-specific T(EM in the lung may represent a new generation of TB vaccines.

  19. CD4+CD25+Treg细胞与支气管哮喘%CD4+ CD25+ Treg cells and bronchial asthma

    Institute of Scientific and Technical Information of China (English)

    鞠云飞; 孙立锋; 胡华

    2011-01-01

    The main function of CD4+ CD25+ Treg cells are immunological anergy and inhibition,which is essential to the maintenance of immunological tolerance in the host.CD4+ CD25+ Treg cells produce inhibitory cytokines (TGF-β and IL-10),express membrane molecules (CTLA-4,GITR,etc) and Foxp3.There are abnormal in function and quantity of CD4+ CD25+ Treg cells of peripheral blood from asthmatic patients,which maybe one of the pathogenesis of asthma.Glucocorticoids can inhibit the airway inflamation of asthma by impacting CD4+ CD25+ Treg cells.%CD4+ CD25+ Treg细胞的主要作用表现为免疫无能性和免疫抑制性,是外周免疫耐受形成机制的主要组成部分.其主要作用机制为分泌抑制性细胞因子(IL-10和TGF-β)、表达细胞表面分子(CTLA-4、GITR等)及Foxp3等.支气管哮喘患者外周血CD4+ CD25+ Treg功能及数量存在异常,这可能是支气管哮喘发病机制之一.糖皮质激素可以通过影响CD4+ CD25+ Treg的状态起到抑制支气管哮喘气道炎症的作用.

  20. Combination effect on HIV infection in vitro of soluble CD4 and HIV-neutralizing antibodies

    DEFF Research Database (Denmark)

    Hansen, J E; Sørensen, A M; Olofsson, S;

    1994-01-01

    In combination with HIV gp120 V3-loop antibody, two carbohydrate specific neutralizing antibodies (83D4 and 2G12) had a synergistic neutralizing effect on HIV infection. However, sCD4 and an antibody which blocks gp 120/CD4 binding (1B1) both displayed antagonism....

  1. HIV-specific CD4(+) T cells and viremia: who's in control?

    NARCIS (Netherlands)

    C.A. Jansen; D. van Baarle; F. Miedema

    2006-01-01

    It has been proposed that HIV-specific CD4(+) T cells with a central memory phenotype might be involved in controlling HIV replication. Based on recent data (lack of protective effects of HIV-specific CD4+ T-cell responses in acutely infected patients undergoing treatment interruptions; loss of init

  2. CD4-independent use of the CCR5 receptor by sequential primary SIVsm isolates

    Directory of Open Access Journals (Sweden)

    Thorstensson Rigmor

    2007-07-01

    Full Text Available Abstract Background CD4-independence has been taken as a sign of a more open envelope structure that is more accessible to neutralizing antibodies and may confer altered cell tropism. In the present study, we analyzed SIVsm isolates for CD4-independent use of CCR5, mode of CCR5-use and macrophage tropism. The isolates have been collected sequentially from 13 experimentally infected cynomolgus macaques and have previously been shown to use CCR5 together with CD4. Furthermore, viruses obtained early after infection were neutralization sensitive, while neutralization resistance appeared already three months after infection in monkeys with progressive immunodeficiency. Results Depending whether isolated early or late in infection, two phenotypes of CD4-independent use of CCR5 could be observed. The inoculum virus (SIVsm isolate SMM-3 and reisolates obtained early in infection often showed a pronounced CD4-independence since virus production and/or syncytia induction could be detected directly in NP-2 cells expressing CCR5 but not CD4 (CD4-independent-HIGH. Conversely, late isolates were often more CD4-dependent in that productive infection in NP-2/CCR5 cells was in most cases weak and was revealed only after cocultivation of infected NP-2/CCR5 cells with peripheral blood mononuclear cells (CD4-independent-LOW. Considering neutralization sensitivity of these isolates, newly infected macaques often harbored virus populations with a CD4-independent-HIGH and neutralization sensitive phenotype that changed to a CD4-independent-LOW and neutralization resistant virus population in the course of infection. Phenotype changes occurred faster in progressor than long-term non-progressor macaques. The phenotypes were not reflected by macrophage tropism, since all isolates replicated efficiently in macrophages. Infection of cells expressing CCR5/CXCR4 chimeric receptors revealed that SIVsm used the CCR5 receptor in a different mode than HIV-1. Conclusion Our

  3. Absence of cross-presenting cells in the salivary gland and viral immune evasion confine cytomegalovirus immune control to effector CD4 T cells.

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    Senta M Walton

    2011-08-01

    Full Text Available Horizontal transmission of cytomegaloviruses (CMV occurs via prolonged excretion from mucosal surfaces. We used murine CMV (MCMV infection to investigate the mechanisms of immune control in secretory organs. CD4 T cells were crucial to cease MCMV replication in the salivary gland (SG via direct secretion of IFNγ that initiated antiviral signaling on non-hematopoietic cells. In contrast, CD4 T cell helper functions for CD8 T cells or B cells were dispensable. Despite SG-resident MCMV-specific CD8 T cells being able to produce IFNγ, the absence of MHC class I molecules on infected acinar glandular epithelial cells due to viral immune evasion, and the paucity of cross-presenting antigen presenting cells (APCs prevented their local activation. Thus, local activation of MCMV-specific T cells is confined to the CD4 subset due to exclusive presentation of MCMV-derived antigens by MHC class II molecules on bystander APCs, resulting in IFNγ secretion interfering with viral replication in cells of non-hematopoietic origin.

  4. CD4+ natural regulatory T cells prevent experimental cerebral malaria via CTLA-4 when expanded in vivo.

    Directory of Open Access Journals (Sweden)

    Ashraful Haque

    Full Text Available Studies in malaria patients indicate that higher frequencies of peripheral blood CD4(+ Foxp3(+ CD25(+ regulatory T (Treg cells correlate with increased blood parasitemia. This observation implies that Treg cells impair pathogen clearance and thus may be detrimental to the host during infection. In C57BL/6 mice infected with Plasmodium berghei ANKA, depletion of Foxp3(+ cells did not improve parasite control or disease outcome. In contrast, elevating frequencies of natural Treg cells in vivo using IL-2/anti-IL-2 complexes resulted in complete protection against severe disease. This protection was entirely dependent upon Foxp3(+ cells and resulted in lower parasite biomass, impaired antigen-specific CD4(+ T and CD8(+ T cell responses that would normally promote parasite tissue sequestration in this model, and reduced recruitment of conventional T cells to the brain. Furthermore, Foxp3(+ cell-mediated protection was dependent upon CTLA-4 but not IL-10. These data show that T cell-mediated parasite tissue sequestration can be reduced by regulatory T cells in a mouse model of malaria, thereby limiting malaria-induced immune pathology.

  5. Targeting of liposomes to HIV-1-infected cells by peptides derived from the CD4 receptor.

    Science.gov (United States)

    Slepushkin, V A; Salem, I I; Andreev, S M; Dazin, P; Düzgüneş, N

    1996-10-23

    Liposomes can be targeted to HIV-infected cells by either reconstituting transmembrane CD4 in the membrane or covalently coupling soluble CD4 to modified lipids. We investigated whether synthetic peptides could be used as ligands for targeting liposomes. A synthetic peptide from the complementarity determining region 2 (CDR-2)-like domain of CD4 could bind specifically to HIV-infected cells and mediate the binding of peptide-coupled liposomes to these cells. A peptide from the CDR-3-like domain of CD4 inhibited HIV-induced syncytia formation, but failed to target liposomes to infected cells. This apparent discrepancy may be due to the requirement for a conformational change in the CD4 receptor for the CDR-3 region to interact with the HIV envelope protein. Our results demonstrate the feasibility of using synthetic peptides to target liposomes containing antiviral drugs to HIV-infected cells.

  6. Development and function of protective and pathologic memory CD4 T cells

    Directory of Open Access Journals (Sweden)

    Megan KL Macleod

    2015-09-01

    Full Text Available IImmunological memory is one of the defining features of the adaptive immune system. As key orchestrators and mediators of immunity, CD4 T cells are central to the vast majority of adaptive immune responses. Generated following an immune response, memory CD4 T cells retain pertinent information about their activation environment enabling them to make rapid effector responses upon reactivation. These responses can either benefit the host by hastening the control of pathogens or cause damaging immunopathology. Here, we will discuss the diversity of the memory CD4 T cell pool, the signals that influence the transition of activated T cells into that pool, and highlight how activation requirements differ between naïve and memory CD4 T cells. A greater understanding of these factors has the potential to aid the design of more effective vaccines and to improve regulation of pathologic CD4 T cells, such as in the context of autoimmunity and allergy.

  7. In situ depletion of CD4(+) T cells in human skin by Zanolimumab

    DEFF Research Database (Denmark)

    Villadsen, L.S.; Skov, L.; Dam, T.N.;

    2007-01-01

    -driving T cells in situ may therefore be a useful approach in the treatment of inflammatory and malignant skin diseases. Depletion of CD4(+) T cells in intact inflamed human skin tissue by Zanolimumab, a fully human therapeutic monoclonal antibody (IgG1, kappa) against CD4, was studied in a human psoriasis......CD4(+) T cells, in activated or malignant form, are involved in a number of diseases including inflammatory skin diseases such as psoriasis, and T cell lymphomas such as the majority of cutaneous T cell lymphomas (CTCL). Targeting CD4 with an antibody that inhibits and/or eliminates disease...... xenograft mouse model. Zanolimumab treatment was shown to induce a significant reduction in the numbers of inflammatory mononuclear cells in upper dermis. This reduction in inflammatory mononuclear cells in situ was primarily due to a significant reduction in the numbers of skin-infiltrating CD4(+), but not...

  8. Label Free Detection of CD4+ and CD8+ T Cells Using the Optofluidic Ring Resonator

    Directory of Open Access Journals (Sweden)

    John T. Gohring

    2010-06-01

    Full Text Available We have demonstrated label free detection of CD4+ and CD8+ T-Lymphocyte whole cells and CD4+ T-Lymphocyte cell lysis using the optofluidic ring resonator (OFRR sensor. The OFRR sensing platform incorporates microfluidics and photonics in a setup that utilizes small sample volume and achieves a fast detection time. In this work, white blood cells were isolated from healthy blood and the concentrations were adjusted to match T-Lymphocyte levels of individuals infected with HIV. Detection was accomplished by immobilizing CD4 and CD8 antibodies on the inner surface of the OFRR. Sensing results show excellent detection of CD4+ and CD8+ T-Lymphocyte cells at medically significant concentrations with a detection time of approximately 30 minutes. This work will lead to a rapid and low-cost sensing device that can provide a CD4 and CD8 count as a measure of HIV progression.

  9. Clinical significance of CD4 + and CD8 + T lymphocytes in infectious mononucleosis%CD4+、CD8+T细胞检测对传染性单核细胞增多症的临床意义

    Institute of Scientific and Technical Information of China (English)

    马强; 刘正娟

    2011-01-01

    [ Objective] To study the clinical meanings of CD4 + and CD8 + T lymphocytes in children with infectious mononucleosis (IM). [ Methods] By using the flow cytometry, the antigens of CD4 and CD8 on T lymphocytes in peripheral blood of 27 children with IM( the IM group)were examined ,and then were compared with those in 16 children with atypical EB virus infections (the atypical group) ,20 children with infectious mononucleosis syndrome (the infectious mononucleosis syndrome group) and 23 healthy children ( the control group). [ Results] By comparing to those of atypical EB virus infections,infectious mononucleosis syndrome and other healthy children, the percentage of CD4 + T lymphocytes ( 26.76 ±8.98)% and CD4/CD8 ratio (0.64 ±0.31 ) in IM decreased,while the percentage of CD8+ T lymphocytes (46.36 ± 12.15 )% increased. There were statistically significant differences between IM and other three groups (P <0.05 ). [ Conclusion] Detecting CD4+ and CD8 + T lymphocytes in peripheral blood of children with IM is helpful in the diagnosis and evaluation of immunologic function.%[目的]探讨CD4+、CD8+T细胞检测对传染性单核细胞增多症(IM)的临床意义.[方法]应用流式细胞仪检测IM患儿27例(IM组)外周血CIM+、CD8+T细胞,同时检测非典型EB病毒感染患儿16例(非典型EB病毒感染组)、传染性单核细胞增多综合征惠儿20例(传单综合征组)、正常儿童23例(正常对照组),进行统计分析.[结果]IM组CD4+T细胞(26.76±8.98)%和CD4/CD8比值(0.64±0.31)明显降低,CD8+T细胞(46.36±12.15)%明显升高,与非典型EB病毒感染组、传单综合征组、正常对照组比较差异均有显著性意义(P<0.05).[结论]检测外周血CD4+、CD8+T细胞可协助IM诊断及患儿免疫功能状况评估.

  10. Ectopic expression of anti-HIV-1 shRNAs protects CD8{sup +} T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Kamata, Masakazu, E-mail: masa3k@ucla.edu [Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Kim, Patrick Y. [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Ng, Hwee L. [Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Ringpis, Gene-Errol E.; Kranz, Emiko; Chan, Joshua; O' Connor, Sean [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Yang, Otto O. [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); UCLA AIDS Institute, Los Angeles, CA (United States); AIDS Healthcare Foundation, Los Angeles, CA (United States); Chen, Irvin S.Y. [Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); UCLA AIDS Institute, Los Angeles, CA (United States)

    2015-07-31

    Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8{sup +} T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To test this possibility, highly purified CD8{sup +} T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8{sup +} T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24{sup Gag} in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8{sup +} T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8{sup +} T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8{sup +} T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance. - Highlights: • Ectopic expression of CD4ζ CAR in CD8{sup +} T cells renders them susceptible to HIV-1 infection. • Co-expression of two anti-HIV-1 shRNAs protects CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection. • Protecting CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection suppresses its cytopathic effect.

  11. Ectopic expression of anti-HIV-1 shRNAs protects CD8+ T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation

    International Nuclear Information System (INIS)

    Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8+ T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To test this possibility, highly purified CD8+ T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8+ T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24Gag in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8+ T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8+ T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8+ T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance. - Highlights: • Ectopic expression of CD4ζ CAR in CD8+ T cells renders them susceptible to HIV-1 infection. • Co-expression of two anti-HIV-1 shRNAs protects CD4ζ CAR-modified CD8+ T cells from HIV-1 infection. • Protecting CD4ζ CAR-modified CD8+ T cells from HIV-1 infection suppresses its cytopathic effect

  12. Expansion of Parasite-Specific CD4+ and CD8+ T Cells Expressing IL-10 Superfamily Cytokine Members and Their Regulation in Human Lymphatic Filariasis

    Science.gov (United States)

    Anuradha, Rajamanickam; George, Parakkal Jovvian; Hanna, Luke E.; Kumaran, Paul; Chandrasekaran, Vedachalam; Nutman, Thomas B.; Babu, Subash

    2014-01-01

    Background Lymphatic filariasis (LF) is known to be associated with an increased production of IL-10. The role of the other IL-10 family members in the pathogenesis of infection and/or disease is not known. Methodology/Principal Findings We examined the expression patterns of IL-10 family members – IL-19, IL-24 and IL-26 in LF. We demonstrate that both CD4+ and CD8+ T cells express IL-19, IL-24 and IL-26 and that the frequency of CD4+ T cells expressing IL-19 and IL-24 (as well as IL-10) is significantly increased at baseline and following filarial antigen stimulation in patients with LF in comparison to individuals with filarial lymphedema and uninfected individuals. This CD4+ T cell expression pattern was associated with increased production of IL-19 and IL-24 by filarial – antigen stimulated PBMC. Moreover, the frequency of CD4+ and CD8+ T cells expressing IL-26 was significantly increased following filarial antigen stimulation in filarial lymphedema individuals. Interestingly, IL-10 blockade resulted in diminished frequencies of IL-19+ and IL-24+ T cells, whereas the addition of recombinant IL-10 resulted in significantly increased frequency of IL-19+ and IL-24+ T cells as well as significantly up regulated IL-19 and IL-24 gene expression, suggesting that IL-10 regulates IL-19 and IL-24 expression in T cells. In addition, IL-1β and IL-23 blockade also induced a diminution in the frequency of IL-19+ and IL-24+ T cells, indicating a novel role for these cytokines in the induction of IL-19 and IL-24 expressing T cells. Finally, elimination of infection resulted in significantly decreased frequencies of antigen – specific CD4+ T cells expressing IL-10, IL-19 and IL-24. Conclusions Our findings, therefore, suggest that IL-19 and IL-24 are associated with the regulation of immune responses in active filarial infection and potentially with protection against development of pathology, while IL-26 is predominantly associated with pathology in LF. PMID:24699268

  13. Diminished CD4+/CD25+ T cell and increased IFN-gamma levels occur in dogs vaccinated with Leishmune in an endemic area for visceral leishmaniasis.

    Science.gov (United States)

    de Lima, Valéria Marçal Felix; Ikeda, Fabiana Augusta; Rossi, Cláudio N; Feitosa, Mary Marcondes; Vasconcelos, Rosemeride Oliveira; Nunes, Caris Maroni; Goto, Hiro

    2010-06-15

    The Leishmune vaccine has been used in endemic areas to prevent canine visceral leishmaniasis in Brazil, but cytokine production induced by vaccination has rarely been investigated in dogs. This study aimed to evaluate the immune response of dogs vaccinated with Leishmune FML vaccine (Fort Dodge) against total antigen of Leishmania (Leishmania) chagasi (TAg) and FML. Twenty healthy dogs from Araçatuba, São Paulo, Brazil, an endemic leishmaniasis area, received three consecutive subcutaneous injection of Leishmune vaccine at 21-day intervals. PBMC were isolated before and 10 days after completing vaccination and lymphoproliferative response and antibody production against FML or total promastigote antigen were tested. Cytokines IFN-gamma, IL-4 and TNF-alpha were measured in culture supernatant and CD4+/CD25+ and CD8+/CD25+ T cell presence was determined. Analysis of the data indicated that the vaccine conferred humoral responses (100%) against both antigens and cellular immunity to FML (85%) and total antigen (80%), the supernatant of cultured cells stimulated with TAg and FML showed an increase in IFN-gamma (P<0.05), and the vaccine reduced CD4+/CD25+ T cell presence compared to that observed before vaccination. These responses may constitute part of the immune mechanism induced by Leishmune.

  14. Correlation between Total Lymphocyte Count, Hemoglobin, Hematocrit and CD4 Count in HIV/AIDS Patients

    Directory of Open Access Journals (Sweden)

    Alavi S.M

    2009-04-01

    Full Text Available Lymphocyte CD4+count, a standard laboratory test for staging of HIV infection, is expensive and unavailable in resource-restricted countries. Total lymphocyte count (TLC and hemoglobin (Hb are recommended as simple & inexpensive surrogates. The aim of this study was to assess the correlation, sensitivity and predictive power of these parameters as substitutes for CD4 count. One hundred HIV patients enrolled in this analytic descriptive study in Ahvaz, a city in the South of Iran, from 2005 to 2006. They were tested for CD4 count, TLC, Hb, and hematocrit (Hct. The cutoffs were determined as: 200 cells/µL, 1200 cells/µL, 12 g/dl and 30%, respectively. We used Sys Max SE 9500 for CBC and Flow cytometry for CD4 count. The correlation coefficient established correlation between values. Sensitivity, specificity and positive predictive values were calculated. 2 females (%2 and 98 males (%98 of the mean age of 32±5 years were studied. 87 cases (%87 were IV drug users, the majority having a history of imprisonment. The mean CD4 count, TLC, Hb and Hct were 279±225, 2102±1250, 10.7±2.4 and 30.4±9.0, respectively. A strong correlation was observed between CD4 count and TLC (R = 0.645, P = 0.001, but no correlation was seen between CD4 count and Hb or Hct (R= 0.451, P=0.056 and R= 0.375, P=0.816 respectively. This study shows that TLC is a suitable surrogate marker for CD4 count. Hb and Hct are of limited value in predicting CD4 counts and should not be substituted for CD4counts.

  15. TRAIL对肿瘤侵润CD4+CD25+Treg的调节作用%Regulation of TRAIL on tumor infiltrating CD4+CD25+Treg

    Institute of Scientific and Technical Information of China (English)

    袁海芹; 刁智娟; 周剑锁; 刘彦信; 史娟; 郑德先

    2011-01-01

    0bjective:To investigate the regulation of TRAIL on tumor infiltrating CD 4+ CD25 +Treg cells.Methods:The inpact of TRAL on CCL22 secretion of tumor cells was detected by ELISA .Recam binant soluble TRAL was adminsttated into subcutaneous solid 4T1 tumor and tumor volum e was measured .Tumor infiltrating lym phocytes w ere isolated and assayed by flow cytam etry to evaluate the change of CD4+ CD25+ Treg cells in umor.Results:rsTRAIL increased CCL22 secretion into supematant of tumor cell 4Tl and B16 cells.TRAIL treat ment did notinhibit the s .C.4T1 tumor growth ,but turmor infiltrating CD 4+ CD25+ Treg increased obviously .Conclusion :Augmention in CCL22 secretion of 4T1 cancer cells might recruit Tregs,therefore, leading to turmor infiltrating CD 4+CD 25+Treg increase .This study provides novel data tor the physiological function research of TRAIL and cancer therapy application .%目的:探讨TRAIL对肿瘤侵润CD4+CD25+Treg细胞的调节作用.方法:ELISA检测TRAIL对肿瘤细胞分泌CCL22的影响;建立对TRAIL耐受的4T1肿瘤细胞皮下实体瘤模型,瘤内给予重组TRAIL蛋白,检测肿瘤体积的变化;分离肿瘤侵润的淋巴细胞,采用流式细胞术检测瘤内CD4+CD25+Treg细胞的变化.结果:TRAIL引起肿瘤细胞4T1和B16培养上清中CCL22水平增加;TRAIL治疗组与对照组相比,对TRAIL耐受的4T1移植瘤体积没有明显变化,但TRAIL治疗组的肿瘤侵润CD4+CD25+Treg细胞显著增加.结论:TRAIL引起肿瘤细胞分泌CCL22,可因此诱导CD4+CD25+Treg细胞趋化至肿瘤部位导致肿瘤侵润的CD4+CD25+Treg比例增加,为TRAIL的生理功能和在肿瘤治疗中的应用提供了新的资料.

  16. A novel differentiation pathway from CD4⁺ T cells to CD4⁻ T cells for maintaining immune system homeostasis.

    Science.gov (United States)

    Zhao, X; Sun, G; Sun, X; Tian, D; Liu, K; Liu, T; Cong, M; Xu, H; Li, X; Shi, W; Tian, Y; Yao, J; Guo, H; Zhang, D

    2016-01-01

    CD4(+) T lymphocytes are key players in the adaptive immune system and can differentiate into a variety of effector and regulatory T cells. Here, we provide evidence that a novel differentiation pathway of CD4(+) T cells shifts the balance from a destructive T-cell response to one that favors regulation in an immune-mediated liver injury model. Peripheral CD4(-)CD8(-)NK1.1(-) double-negative T cells (DNT) was increased following Concanavalin A administration in mice. Adoptive transfer of DNT led to significant protection from hepatocyte necrosis by direct inhibition on the activation of lymphocytes, a process that occurred primarily through the perforin-granzyme B route. These DNT converted from CD4(+) rather than CD8(+) T cells, a process primarily regulated by OX40. DNT migrated to the liver through the CXCR3-CXCL9/CXCL10 interaction. In conclusion, we elucidated a novel differentiation pathway from activated CD4(+) T cells to regulatory DNT cells for maintaining homeostasis of the immune system in vivo, and provided key evidence that utilizing this novel differentiation pathway has potential application in the prevention and treatment of autoimmune diseases. PMID:27077809

  17. Tuberculosis treatment in HIV infected Ugandans with CD4 counts>350 cells/mm reduces immune activation with no effect on HIV load or CD4 count.

    Directory of Open Access Journals (Sweden)

    C Scott Mahan

    Full Text Available BACKGROUND: Both HIV and TB cause a state of heightened immune activation. Immune activation in HIV is associated with progression to AIDS. Prior studies, focusing on persons with advanced HIV, have shown no decline in markers of cellular activation in response to TB therapy alone. METHODOLOGY: This prospective cohort study, composed of participants within a larger phase 3 open-label randomized controlled clinical trial, measured the impact of TB treatment on immune activation in persons with non-advanced HIV infection (CD4>350 cells/mm3 and pulmonary TB. HIV load, CD4 count, and markers of immune activation (CD38 and HLA-DR on CD4 and CD8 T cells were measured prior to starting, during, and for 6 months after completion of standard 6 month anti-tuberculosis (TB therapy in 38 HIV infected Ugandans with smear and culture confirmed pulmonary TB. RESULTS: Expression of CD38, and co-expression of CD38 and HLA-DR, on CD8 cells declined significantly within 3 months of starting standard TB therapy in the absence of anti-retroviral therapy, and remained suppressed for 6 months after completion of therapy. In contrast, HIV load and CD4 count remained unchanged throughout the study period. CONCLUSION: TB therapy leads to measurable decreases in immune activation in persons with HIV/TB co-infection and CD4 counts>350 cells/mm3.

  18. Dextran Sulfate Suppression of Viruses in the HIV Family: Inhibition of Virion Binding to CD4+ Cells

    Science.gov (United States)

    Mitsuya, Hiroaki; Looney, David J.; Kuno, Sachiko; Ueno, Ryuji; Wong-Staal, Flossie; Broder, Samuel

    1988-04-01

    The first step in the infection of human T lymphocytes by human immunodeficiency virus type 1 (HIV-1) is attachment to the target cell receptor, the CD4 antigen. This step may be vulnerable to attack by antibodies, chemicals, or small peptides. Dextran sulfate (molecular weight approximately 8000), which has been given to patients as an anticoagulant or antilipemic agent for more than two decades, was found to block the binding of virions to various target T lymphocytes, inhibit syncytia formation, and exert a potent inhibitory effect against HIV-1 in vitro at concentrations that may be clinically attainable in human beings. This drug also suppressed the replication of HIV-2 in vitro. These observations could have theoretical and clinical implications in the strategy to develop drugs against HIV types 1 and 2.

  19. 老年脓毒症休克患者CD4+CD25+调节性T细胞的变化及对预后的影响%Effects of changes of CD4+ CD25+ regulatory T cells on prognosis in elderly patients with septic shock

    Institute of Scientific and Technical Information of China (English)

    呼邦传; 孙仁华; 徐云祥; 杨向红; 李茜; 韩芳

    2010-01-01

    目的 探讨老年脓毒症休克患者CD4+CD25+调节性T淋巴细胞(CD4+CD25+Treg)的变化及对预后的影响.方法 选择老年脓毒症休克患者75例,采用流式细胞仪检测患者外周血第1、4天和第7~10天CD4+CD25+叉头转录基因P3(FoxP3)/CD4+比例和白细胞DR抗原(HLA-DR)表达.结果 老年脓毒症休克患者平均年龄(69.2±7.5)岁,28 d病死率为53.3%.(1)休克死亡组与生存组CD4+CD25+FoxP3/CD4+比较,第1天(1.76±0.31)对(1.68±0.24)%,第4天(1.94±0.32)%对(1.82±0.28)%,差异均无统计学意义(P>0.05),第7~10天休克死亡组(2.65±0.28)%,明显高于存活组(1.79±0.27)%,差异有统计学意义(t=11.30,P<0.01);(2)死亡组第4天和第7~10天HLA-DR表达持续低下,显著低于生存组(t=7.29,t=16.80,均P<0.01),并分别与CD4+CD25+FoxP3/CD4+比例呈显著负相关(r=-0.39,P<0.05;r=-0.58,P<0.01);(3)多元Logistic回归分析显示,脓毒症休克患者第7~10天CD4+CD25+FoxP3/CD4+(OR=3.47,95%CI:1.33~10.0)和HLA-DR(OR=0.27,95%CI:0.14~0.73)是影响其死亡的独立危险因素.结论 老年脓毒症休克患者CD4+CD25+Treg持续上升,提示机体免疫功能抑制,脓毒症休克死亡的危险性增加.%Objective To investigate the changes of CD4+CD25+ regulatory T (Treg) cells in elderly patients with septic shock, and to evaluate the effects of the changes on 28-day mortality rate.Methods The 75 consecutive elderly patients with septic shock were recruited from December 2006to December 2008, and the general states and clinical characteristics of them were analyzed. The CD4+ CD25+ FoxP3 regulatory T cells and human leucocyte antigen DR (HLA-DR) were measured by flow cytometer at the 1st, 4th and 7-10th day of septic shock after being diagnosed. Results The patients were at an average age of (69.2±7.5) years, and the 28-day mortality rate was 53.3%.There were no significant differences in the percentage of CD4 + CD25+ FoxP3/CD4+T cells between the survivors and the non-survivors at

  20. 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

  1. HIV-1 induces IL-10 production in human monocytes via a CD4-independent pathway.

    Science.gov (United States)

    Ji, Jiaxiang; Sahu, Gautam K; Braciale, Vivian L; Cloyd, Miles W

    2005-06-01

    In HIV-infected patients, increased levels of IL-10, mainly produced by virally infected monocytes, were reported to be associated with impaired cell-mediated immune responses. In this study, we investigated how HIV-1 induces IL-10 production in human monocytes. We found that CD14(+) monocytes infected by either HIV-1(213) (X4) or HIV-1(BaL) (R5) produced IL-10, IL-6, tumor necrosis factor-alpha (TNF-alpha), and to a lesser extent, IFN-gamma. However, the capacity of HIV-1 to induce these cytokines was not dependent on virus replication since UV-inactivated HIV-1 induced similar levels of these cytokines. In addition, soluble HIV-1 gp160 could induce CD14(+) monocytes to produce IL-10 but at lower levels. Cross-linking CD4 molecules (XLCD4) with anti-CD4 mAbs and goat anti-mouse IgG (GAM) resulted in high levels of IL-6, TNF-alpha and IFN-gamma but no IL-10 production by CD14(+) monocytes. Interestingly, neither anti-CD4 mAbs nor recombinant soluble CD4 (sCD4) receptor could block IL-10 secretion induced by HIV-1(213), HIV-1(BaL) or HIV-1 gp160 in CD14(+) monocytes, whereas anti-CD4 mAb or sCD4 almost completely blocked the secretion of the other cytokines. Furthermore, HIV-1(213) could induce IL-10 mRNA expression in CD14(+) monocytes while XLCD4 by anti-CD4 mAb and GAM failed to do so. As with IL-10 protein levels, HIV-1(213)-induced IL-10 mRNA expression in CD14(+) monocytes could not be inhibited by anti-CD4 mAb or sCD4. Taken together, HIV-1 binding to CD14(+) monocytes can induce CD4-independent IL-10 production at both mRNA and protein levels. This finding suggests that HIV induces the immunosuppressive IL-10 production in monocytes and is not dependent on CD4 molecules and that interference with HIV entry through CD4 molecules may have no impact on counteracting the effects of IL-10 during HIV infection. PMID:15937058

  2. Mycobacterium avium and purified protein derivative-specific cytotoxicity mediated by CD4+ lymphocytes from healthy HIV-seropositive and-seronegative individuals

    DEFF Research Database (Denmark)

    Ravn, P; Pedersen, B K

    1996-01-01

    HIV is the greatest single risk factor for the development of tuberculosis. Diseases caused by M. tuberculosis and mycobacteria are the most common opportunistic infections in HIV-infected persons, which may stem from a functional defect of the CD4+ T-cell-mediated killing of macrophages harboring...... mycobacteria. Our objective was to investigate the M.tuberculosis-and M. avium-specific cytotoxic capacity of T cells from healthy, bacille Calmette-Guérin-vaccinated, HIV-seropositive individuals. Blood mononuclear cells were obtained from 10 healthy HIV-seropositive and 10 healthy seronegative persons...... stimulation and by using purified CD4+ and CD8+ cell subsets. Substantial, but reduced antigen-specific cytotoxicity was observed in patients with asymptomatic HIV infection. The immunological dysfunction leading to reduced cytotoxic activity in healthy HIV-seropositive subjects could not be explained...

  3. A vaccine encoding conserved promiscuous HIV CD4 epitopes induces broad T cell responses in mice transgenic to multiple common HLA class II molecules.

    Directory of Open Access Journals (Sweden)

    Susan Pereira Ribeiro

    Full Text Available Current HIV vaccine approaches are focused on immunogens encoding whole HIV antigenic proteins that mainly elicit cytotoxic CD8+ responses. Mounting evidence points toward a critical role for CD4+ T cells in the control of immunodeficiency virus replication, probably due to cognate help. Vaccine-induced CD4+ T cell responses might, therefore, have a protective effect in HIV replication. In addition, successful vaccines may have to elicit responses to multiple epitopes in a high proportion of vaccinees, to match the highly variable circulating strains of HIV. Using rational vaccine design, we developed a DNA vaccine encoding 18 algorithm-selected conserved, "promiscuous" (multiple HLA-DR-binding B-subtype HIV CD4 epitopes - previously found to be frequently recognized by HIV-infected patients. We assessed the ability of the vaccine to induce broad T cell responses in the context of multiple HLA class II molecules using different strains of HLA class II- transgenic mice (-DR2, -DR4, -DQ6 and -DQ8. Mice displayed CD4+ and CD8+ T cell responses of significant breadth and magnitude, and 16 out of the 18 encoded epitopes were recognized. By virtue of inducing broad responses against conserved CD4+ T cell epitopes that can be recognized in the context of widely diverse, common HLA class II alleles, this vaccine concept may cope both with HIV genetic variability and increased population coverage. The vaccine may thus be a source of cognate help for HIV-specific CD8+ T cells elicited by conventional immunogens, in a wide proportion of vaccinees.

  4. CD4+CD25+Treg细胞与支气管哮喘%CD4+CD25+Treg cells and bronchial asthma

    Institute of Scientific and Technical Information of China (English)

    鞠云飞; 孙立锋; 胡华

    2011-01-01

    CD4+CD25+Treg细胞的主要作用表现为免疫无能性和免疫抑制性,是外周免疫耐受形成机制的主要组成部分.其主要作用机制为分泌抑制性细胞因子(IL-10和TGF-β)、表达细胞表面分子(CTLA-4、GITR等)及Foxp3等.支气管哮喘患者外周血CD4+CD25+Treg功能及数量存在异常,这可能是支气管哮喘发病机制之一.糖皮质激素可以通过影响CD4+CD25+Treg的状态起到抑制支气管哮喘气道炎症的作用.

  5. Parasite fate and involvement of infected cells in the induction of CD4+ and CD8+ T cell responses to Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Christopher D Dupont

    2014-04-01

    Full Text Available During infection with the intracellular parasite Toxoplasma gondii, the presentation of parasite-derived antigens to CD4+ and CD8+ T cells is essential for long-term resistance to this pathogen. Fundamental questions remain regarding the roles of phagocytosis and active invasion in the events that lead to the processing and presentation of parasite antigens. To understand the most proximal events in this process, an attenuated non-replicating strain of T. gondii (the cpsII strain was combined with a cytometry-based approach to distinguish active invasion from phagocytic uptake. In vivo studies revealed that T. gondii disproportionately infected dendritic cells and macrophages, and that infected dendritic cells and macrophages displayed an activated phenotype characterized by enhanced levels of CD86 compared to cells that had phagocytosed the parasite, thus suggesting a role for these cells in priming naïve T cells. Indeed, dendritic cells were required for optimal CD4+ and CD8+ T cell responses, and the phagocytosis of heat-killed or invasion-blocked parasites was not sufficient to induce T cell responses. Rather, the selective transfer of cpsII-infected dendritic cells or macrophages (but not those that had phagocytosed the parasite to naïve mice potently induced CD4+ and CD8+ T cell responses, and conferred protection against challenge with virulent T. gondii. Collectively, these results point toward a critical role for actively infected host cells in initiating T. gondii-specific CD4+ and CD8+ T cell responses.

  6. NADPH Oxidase-Derived Superoxide Provides a Third Signal for CD4 T Cell Effector Responses.

    Science.gov (United States)

    Padgett, Lindsey E; Tse, Hubert M

    2016-09-01

    Originally recognized for their direct induced toxicity as a component of the innate immune response, reactive oxygen species (ROS) can profoundly modulate T cell adaptive immune responses. Efficient T cell activation requires: signal 1, consisting of an antigenic peptide-MHC complex binding with the TCR; signal 2, the interaction of costimulatory molecules on T cells and APCs; and signal 3, the generation of innate immune-derived ROS and proinflammatory cytokines. This third signal, in particular, has proven essential in generating productive and long-lasting immune responses. Our laboratory previously demonstrated profound Ag-specific hyporesponsiveness in the absence of NADPH oxidase-derived superoxide. To further examine the consequences of ROS deficiency on Ag-specific T cell responses, our laboratory generated the OT-II.Ncf1(m1J) mouse, possessing superoxide-deficient T cells recognizing the nominal Ag OVA323-339 In this study, we demonstrate that OT-II.Ncf1(m1J) CD4 T cells displayed a severe reduction in Th1 T cell responses, in addition to blunted IL-12R expression and severely attenuated proinflammatory chemokine ligands. Conversely, IFN-γ synthesis and IL-12R synthesis were rescued by the addition of exogenous superoxide via the paramagnetic superoxide donor potassium dioxide or superoxide-sufficient dendritic cells. Ultimately, these data highlight the importance of NADPH oxidase-derived ROS in providing a third signal for adaptive immune maturation by modulating the IL-12/IL-12R pathway and the novelty of the OT-II.Ncf1(m1J) mouse model to determine the role of redox-dependent signaling on effector responses. Thus, targeting ROS represents a promising therapeutic strategy in dampening Ag-specific T cell responses and T cell-mediated autoimmune diseases, such as type 1 diabetes. PMID:27474077

  7. Hierarchical Cd4SiS6/SiO2 Heterostructure Nanowire Arrays

    Directory of Open Access Journals (Sweden)

    Liu Jian

    2009-01-01

    Full Text Available Abstract Novel hierarchical Cd4SiS6/SiO2 based heterostructure nanowire arrays were fabricated on silicon substrates by a one-step thermal evaporation of CdS powder. The as-grown products were characterized using scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. Studies reveal that a typical hierarchical Cd4SiS6/SiO2 heterostructure nanowire is composed of a single crystalline Cd4SiS6 nanowire core sheathed with amorphous SiO2 sheath. Furthermore, secondary nanostructures of SiO2 nanowires are highly dense grown on the primary Cd4SiS6 core-SiO2 sheath nanowires and formed hierarchical Cd4SiS6/SiO2 based heterostructure nanowire arrays which stand vertically on silicon substrates. The possible growth mechanism of hierarchical Cd4SiS6/SiO2 heterostructure nanowire arrays is proposed. The optical properties of hierarchical Cd4SiS6/SiO2 heterostructure nanowire arrays are investigated using Raman and Photoluminescence spectroscopy.

  8. Involvement of CD4+CD25+ regulatory T cells in the pathogenesis of polycythaemia vera

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wen-bo; LI Ying; LIU Xin; ZHANG Ling-yan; WANG Xin

    2008-01-01

    Background Regulatory T cells (Treg) have been shown to play an important role in the regulation of hematopoietic activity. However, there is no information about the effect of Treg cells in the pathogenesis of polycythaemia vera (PV).Methods In this study, we investigated the percentage and function of Treg cells in the peripheral blood of 21 PV patients and 25 healthy donors. Treg cells were identified and characterized as CD4+CD25+FOXP3+ by flow cytometry.The suppressive activity of CD4+CD25+ Treg cells was assessed by the proliferation and cytokine secretion of the co-cultured CD4+CD25- fractions.Results The results showed that the percentage of Treg cells in the peripheral blood of PV patients significantly increased compared to healthy controls ((10.93±4.02)% vs (5.86±1.99)%, P <0.05). Moreover, the mRNA and protein expression of FOXP3 was higher in CD4+CD25+ Treg cells. Coordinately, when co-cultured with the activated CD4+CD25-cells, the CD4+CD25+ Treg cells showed enhanced suppressive function in PV. Yet, the underlying mechanism for the increased frequency and function of CD4+CD25+ Treg cells is still to be clarified.Conclusion Treg cells expansion might account for the abnormal T cell immunity in PV patients and thus contribute to the pathogenesis of PV.

  9. Natural polymorphisms in Tap2 influence negative selection and CD4∶CD8 lineage commitment in the rat.

    Directory of Open Access Journals (Sweden)

    Jonatan Tuncel

    2014-02-01

    Full Text Available Genetic variation in the major histocompatibility complex (MHC affects CD4∶CD8 lineage commitment and MHC expression. However, the contribution of specific genes in this gene-dense region has not yet been resolved. Nor has it been established whether the same genes regulate MHC expression and T cell selection. Here, we assessed the impact of natural genetic variation on MHC expression and CD4∶CD8 lineage commitment using two genetic models in the rat. First, we mapped Quantitative Trait Loci (QTLs associated with variation in MHC class I and II protein expression and the CD4∶CD8 T cell ratio in outbred Heterogeneous Stock rats. We identified 10 QTLs across the genome and found that QTLs for the individual traits colocalized within a region spanning the MHC. To identify the genes underlying these overlapping QTLs, we generated a large panel of MHC-recombinant congenic strains, and refined the QTLs to two adjacent intervals of ∼0.25 Mb in the MHC-I and II regions, respectively. An interaction between these intervals affected MHC class I expression as well as negative selection and lineage commitment of CD8 single-positive (SP thymocytes. We mapped this effect to the transporter associated with antigen processing 2 (Tap2 in the MHC-II region and the classical MHC class I gene(s (RT1-A in the MHC-I region. This interaction was revealed by a recombination between RT1-A and Tap2, which occurred in 0.2% of the rats. Variants of Tap2 have previously been shown to influence the antigenicity of MHC class I molecules by altering the MHC class I ligandome. Our results show that a restricted peptide repertoire on MHC class I molecules leads to reduced negative selection of CD8SP cells. To our knowledge, this is the first study showing how a recombination between natural alleles of genes in the MHC influences lineage commitment of T cells.

  10. CD4 lymphocyte dynamics in Tanzanian pulmonary tuberculosis patients with and without hiv co-infection

    Directory of Open Access Journals (Sweden)

    Andersen Aase B

    2012-03-01

    Full Text Available Abstract Background The interaction of HIV and tuberculosis (TB on CD4 levels over time is complex and has been divergently reported. Methods CD4 counts were assessed from time of diagnosis till the end of TB treatment in a cohort of pulmonary TB patients with and without HIV co-infection and compared with cross-sectional data on age- and sex-matched non-TB controls from the same area. Results Of 1,605 study participants, 1,250 were PTB patients and 355 were non-TB controls. At baseline, HIV was associated with 246 (95% CI: 203; 279 cells per μL lower CD4 counts. All PTB patients had 100 cells per μL lower CD4 counts than the healthy controls. The CD4 levels were largely unchanged during a five-month of TB treatment. HIV infected patients not receiving ART at any time and those already on ART at baseline had no increase in CD4 counts after 5 months of TB treatment, whereas those prescribed ART between baseline and 2 months, and between 2 and 5 months increased by 69 (22;117 and 110 (52; 168 CD4 cells per μL after 5 months. Conclusions The increase in circulating CD4 levels observed in PTB in patients is acquired after 2 months of treatment irrespective of HIV status. Initiation of ART is the strongest factor correlated with CD4 increase during TB treatment. Trial registration number Clinical trials.gov: NCT00311298

  11. Distribution of CD4 lymphocyte cells among apparently healthy HIV seropositive and seronegative populations

    Directory of Open Access Journals (Sweden)

    Abdulazeez A Abubakar

    2012-01-01

    Full Text Available Background: CD4 lymphocyte cells are often used as prognostic markers for monitoring the progression of immunosupression such as HIV infection. Aim: This study was conducted to assess the distribution of CD4 lymphocytes among apparently healthy human immunodeficiency virus (HIV seronegative and seropositive populations in a Nigerian state. Materials and Methods: A total of 1520 apparently healthy subjects aged 18-64 years, composed of 800 males and 720 females attending some selected health institutions in the state, participated in the study. Ten milliliters of blood was collected from each subject; 5 ml of this was used for HIV antibodies sero-typing while the remaining 5 ml was anticoagulated and used for CD4 lymphocytes level determination. Only samples tested positive both with Capillus and Determine HIV test kits were further differentiated into sero-types with a standard diagnostic HIV test kit. The CD4 lymphocyte levels of all the sample were determined; mean CD4 levels of 205.1±0.09 and 287.4±0.3 cells/μl were recorded among females seropositives and seronagatives respectively. Statistical analysis by the Student t-test showed a significant difference in the mean CD4 lymphocyte count by gender. Results: Findings showed a mean CD4 level of 311.7±1.2 cells/μl among seropositive males while 399.3±0.6 cells/μl was recorded among seronegatives (t=5.86. The study also recorded a CD4 lymphocyte range of 232-464 cells/μl among apparently healthy seronegative population in this locality. Conclusion: The findings showed a significantly higher mean CD4 lymphocyte count among adult male HIV seronegatives (χ2= 9.22 and seropositives (χ2=15.07 than their female counterparts. Further research work using the automation technique is suggested to confirm this new range for monitoring HIV subjects on antiretroviral therapy.

  12. Mannose-Capped Lipoarabinomannan from Mycobacterium tuberculosis Induces CD4+ T Cell Anergy via GRAIL.

    Science.gov (United States)

    Sande, Obondo J; Karim, Ahmad F; Li, Qing; Ding, Xuedong; Harding, Clifford V; Rojas, Roxana E; Boom, W Henry

    2016-01-15

    Mycobacterium tuberculosis cell wall glycolipid, lipoarabinomannan, can inhibit CD4(+) T cell activation by downregulating the phosphorylation of key proximal TCR signaling molecules: Lck, CD3ζ, ZAP70, and LAT. Inhibition of proximal TCR signaling can result in T cell anergy, in which T cells are inactivated following an Ag encounter, yet remain viable and hyporesponsive. We tested whether mannose-capped lipoarabinomannan (LAM)-induced inhibition of CD4(+) T cell activation resulted in CD4(+) T cell anergy. The presence of LAM during primary stimulation of P25 TCR-transgenic murine CD4(+) T cells with M. tuberculosis Ag85B peptide resulted in decreased proliferation and IL-2 production. P25 TCR-transgenic CD4(+) T cells primed in the presence of LAM also exhibited decreased response upon restimulation with Ag85B. The T cell anergic state persisted after the removal of LAM. Hyporesponsiveness to restimulation was not due to apoptosis, generation of Foxp3-positive regulatory T cells, or inhibitory cytokines. Acquisition of the anergic phenotype correlated with upregulation of gene related to anergy in lymphocytes (GRAIL) protein in CD4(+) T cells. Inhibition of human CD4(+) T cell activation by LAM also was associated with increased GRAIL expression. Small interfering RNA-mediated knockdown of GRAIL before LAM treatment abrogated LAM-induced hyporesponsiveness. In addition, exogenous IL-2 reversed defective proliferation by downregulating GRAIL expression. These results demonstrate that LAM upregulates GRAIL to induce anergy in Ag-reactive CD4(+) T cells. Induction of CD4(+) T cell anergy by LAM may represent one mechanism by which M. tuberculosis evades T cell recognition. PMID:26667170

  13. Tuberculosis Therapy Modifies the Cytokine Profile, Maturation State, and Expression of Inhibitory Molecules on Mycobacterium tuberculosis-Specific CD4+ T-Cells

    Science.gov (United States)

    Saharia, Kapil K.; Petrovas, Constantinos; Ferrando-Martinez, Sara; Leal, Manuel; Luque, Rafael; Ive, Prudence; Luetkemeyer, Anne; Havlir, Diane; Koup, Richard A.

    2016-01-01

    Background Little is known about the expression of inhibitory molecules cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed-death-1 (PD-1) on Mycobacterium tuberculosis (Mtb)-specific CD4 T-cells and how their expression is impacted by TB treatment. Methods Cryopreserved PBMCs from HIV-TB co-infected and TB mono-infected patients with untreated and treated tuberculosis (TB) disease were stimulated for six hours with PPD and stained. Using polychromatic flow cytometry, we characterized the differentiation state, cytokine profile, and inhibitory molecule expression on PPD-specific CD4 T-cells. Results In our HIV-TB co-infected cohort, TB treatment increased the proportion of PPD-specific CD4 T-cells co-producing IFN-γ+IL-2+TNF-α+ and IFN-γ+IL-2+ (p = 0.0004 and p = 0.0002, respectively) while decreasing the proportion of PPD-specific CD4 T-cells co-producing IFN-γ+MIP1-β+TNF-α+ and IFN-γ+MIP1-β+. The proportion of PPD-specific CD4 T-cells expressing an effector memory phenotype decreased (63.6% vs 51.6%, p = 0.0015) while the proportion expressing a central memory phenotype increased (7.8% vs. 21.7%, p = 0.001) following TB treatment. TB treatment reduced the proportion of PPD-specific CD4 T-cells expressing CTLA-4 (72.4% vs. 44.3%, p = 0.0005) and PD-1 (34.5% vs. 29.2%, p = 0.03). Similar trends were noted in our TB mono-infected cohort. Conclusion TB treatment alters the functional profile of Mtb-specific CD4 T-cells reflecting shifts towards a less differentiated maturational profile and decreases PD-1 and CTLA-4 expression. These could serve as markers of reduced mycobacterial burden. Further study is warranted. PMID:27367521

  14. Comprehensive Analysis of Contributions from Protein Conformational Stability and Major Histocompatibility Complex Class II-Peptide Binding Affinity to CD4+ Epitope Immunogenicity in HIV-1 Envelope Glycoprotein

    Science.gov (United States)

    Li, Tingfeng; Steede, N. Kalaya; Nguyen, Hong-Nam P.; Freytag, Lucy C.; McLachlan, James B.; Mettu, Ramgopal R.; Robinson, James E.

    2014-01-01

    ABSTRACT Helper T-cell epitope dominance in human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein gp120 is not adequately explained by peptide binding to major histocompatibility complex (MHC) proteins. Antigen processing potentially influences epitope dominance, but few, if any, studies have attempted to reconcile the influences of antigen processing and MHC protein binding for all helper T-cell epitopes of an antigen. Epitopes of gp120 identified in both humans and mice occur on the C-terminal flanks of flexible segments that are likely to be proteolytic cleavage sites. In this study, the influence of gp120 conformation on the dominance pattern in gp120 from HIV strain 89.6 was examined in CBA mice, whose MHC class II protein has one of the most well defined peptide-binding preferences. Only one of six dominant epitopes contained the most conserved element of the I-Ak binding motif, an aspartic acid. Destabilization of the gp120 conformation by deletion of single disulfide bonds preferentially enhanced responses to the cryptic I-Ak motif-containing sequences, as reported by T-cell proliferation or cytokine secretion. Conversely, inclusion of CpG in the adjuvant with gp120 enhanced responses to the dominant CD4+ T-cell epitopes. The gp120 destabilization affected secretion of some cytokines more than others, suggesting that antigen conformation could modulate T-cell functions through mechanisms of antigen processing. IMPORTANCE CD4+ helper T cells play an essential role in protection against HIV and other pathogens. Thus, the sites of helper T-cell recognition, the dominant epitopes, are targets for vaccine design; and the corresponding T cells may provide markers for monitoring infection and immunity. However, T-cell epitopes are difficult to identify and predict. It is also unclear whether CD4+ T cells specific for one epitope are more protective than T cells specific for other epitopes. This work shows that the three-dimensional (3D) structure of an

  15. A subset of dendritic cells induces CD4+ T cells to produce IFN-γ by an IL-12–independent but CD70-dependent mechanism in vivo

    OpenAIRE

    Soares, Helena; Waechter, HaeNa; Glaichenhaus, Nicholas; Mougneau, Evelyne; Yagita, Hideo; Mizenina, Olga; Dudziak, Diana; Nussenzweig, Michel C.; Steinman, Ralph M.

    2007-01-01

    Interferon (IFN)-γ, a cytokine critical for resistance to infection and tumors, is produced by CD4+ helper T lymphocytes after stimulation by cultured dendritic cells (DCs) that secrete a cofactor, interleukin (IL)-12. We have identified a major IL-12–independent pathway whereby DCs induce IFN-γ–secreting T helper (Th)1 CD4+ T cells in vivo. This pathway requires the membrane-associated tumor necrosis family member CD70 and was identified by targeting the LACK antigen from Leishmania major wi...

  16. Progressive multifocal leucoencephalopathy in a patient with idiopathic CD4+ lymphocytopenia.

    LENUS (Irish Health Repository)

    Moloney, F

    2012-03-01

    Progressive multifocal leucoencephalopathy (PML) is an opportunistic, demyelinating neurological disease caused by reactivation of the JC polyomavirus. PML occurs almost exclusively in immunosuppressed individuals, with only isolated case reports of PML occurring in patients without apparent immunosuppression. Idiopathic CD4+ lymohocytopenia (ICL) is a syndrome defined by the Centre for Disease Control and Prevention as a CD4+ count <300 cells\\/uL or <20% of total T cell count on >1 occasion, with no evidence of human immunodeficiency virus (HIV) infection, and the absence of other known immunodeficiency or therapy associated with lymphocytopenia. We describe a case of PML occurring in a patient with idiopathic CD4+ lymphocytopenia.

  17. Detection of resistance mutations and CD4 slopes in individuals experiencing sustained virological failure

    DEFF Research Database (Denmark)

    Schultze, Anna; Paredes, Roger; Sabin, Caroline;

    2014-01-01

    mutations on CD4 slopes in patients undergoing episodes of viral failure. MATERIALS AND METHODS: Patients from the EuroSIDA and UK CHIC cohorts undergoing at least one episode of virological failure (>3 consecutive RNA measurements >500 on ART) with at least three CD4 measurements and a resistance test...... during the episode were included. Mutations were identified using the IAS-US (2013) list, and were presumed to be present from detection until the end of an episode. Multivariable linear mixed models with a random intercept and slope adjusted for age, baseline CD4 count, hepatitis C, drug type, RNA (log...

  18. Genetic subspecies diversity of the chimpanzee CD4 virus-receptor gene

    DEFF Research Database (Denmark)

    Hvilsom, Christina; Carlsen, Frands; Siegismund, Hans R;

    2008-01-01

    Chimpanzees are naturally and asymptomatically infected by simian immunodeficiency virus (SIV). Pathogenic properties of SIV/HIV vary and differences in susceptibility and pathogenicity of SIV/HIV depend in part on host-specific factors such as virus-receptor/co-receptor interactions. Since CD4...... plays a primary role in virus binding and since SIVcpz have been found only in two African chimpanzee subspecies, we characterized the genetic diversity of CD4 receptors in all four recognized subspecies of chimpanzees. We found noticeable variation in the first variable region V1 of CD4 and in intron...

  19. Idiopathic CD4 lymphocytopenia with giant cell arteritis and pulmonary mucormycosis

    Directory of Open Access Journals (Sweden)

    Ryan A. Denu

    2014-10-01

    Full Text Available Idiopathic CD4 lymphocytopenia (ICL is characterized by a low CD4+ lymphocyte count in the absence of HIV or other underlying etiologies. We report a case of a 57-year old man with ICL and giant cell arteritis (GCA who developed pulmonary mucormycosis, which, to our knowledge, is the first report of these occurring in a patient with ICL. Abnormally low total lymphocyte or CD4+ cell counts occurring in patients with autoimmune disorders should alert clinicians to the possibility of ICL. Immunosuppressive treatment should be used with caution in this context.

  20. Deficient Fas expression by CD4+ CCR5+ T cells in multiple sclerosis

    DEFF Research Database (Denmark)

    Julià, Eva; Montalban, Xavier; Al-Zayat, Hammad;

    2006-01-01

    OBJECTIVE: To evaluate whether T cells expressing CCR5 and CXCR3 from multiple sclerosis (MS) patients are more resistant to apoptosis. METHODS: Expression of CD69, TNF-R1, Fas, FasL, bcl-2, and bax was investigated in 41 MS patients and 12 healthy controls by flow cytometry in CD4+ and CD8+ T...... cells expressing CCR5 and CXCR3. RESULTS: In MS patients, the percentage of CD69 was increased and Fas expression decreased in CD4+ CCR5+ T cells. INTERPRETATION: The lower Fas expression in activated CD4+ CCR5+ T cells might contribute to disease pathogenesis by prolonging cell survival and favoring...

  1. Do natural Treg become activated to antigen specific Treg in transplantation and in autoimmunity?

    OpenAIRE

    Bruce Milne Hall; Tran, Giang T.; Nirupama eVerma; Karren ePlain; Catherine M. Robinson; Masaru eNomura; Hodgkinson, Suzanne J.

    2013-01-01

    Antigen specific Treg are often CD4+CD25+FoxP3+T cells, with a phenotype similar to natural Treg (nTreg). It is assumed that nTreg cannot develop into an antigen specific Treg as repeated culture with IL-2 and a specific antigen does not increase the capacity or potency of nTreg to promote immune tolerance or suppress in vitro. This has led to an assumption that antigen specific Treg mainly develop from CD4+CD25-FoxP3- T cells, by activation with antigen and TGF-beta in the absence of infla...

  2. Interleukin-2 Enhances the Regulatory Functions of CD4(+)T Cell-Derived CD4(-)CD8(-) Double Negative T Cells.

    Science.gov (United States)

    Cong, Min; Liu, Tianhui; Tian, Dan; Guo, Hongbo; Wang, Ping; Liu, Kai; Lin, Jun; Tian, Yue; Shi, Wen; You, Hong; Jia, Jidong; Zhang, Dong

    2016-08-01

    CD4(+) T cells can be converted to CD4(-)CD8(-) double negative T cells (DN T cells) under appropriate conditions, and IL-2 enhanced the conversion. Here, we investigated the effect of IL-2 on the proliferation and function of converted DN T cells in vitro and in vivo. DN T cells were hyporesponsive when restimulated by mature dendritic cells (mDCs), IL-2 completely restored their responsiveness in vitro. In addition, IL-2 increased the resistance of DN T cells to apoptosis in vivo. DN T cells profoundly inhibited the proliferation of CD4(+)CD25(-) T effector cells triggered by mDCs in vitro, and this suppression was further enhanced by IL-2. Adoptively transferring of DN T cells, in combination with IL-2, inhibited the proliferation and enhanced apoptosis of alloreactive CD4(+) T cells, which resulted in significant prolongation of skin allograft survival time. Perforin plays a key role in the enhancement of DN T cells immune regulation by IL-2. In conclusion, we elucidated that IL-2 promoted DN T cell proliferation and suppressive function. The combination of DN T cells and exogenous IL-2 may represent a novel therapy in the clinical setting to prevent allograft rejection and induce immune tolerance. PMID:27135902

  3. Conformational alterations in the CD4 binding cavity of HIV-1 gp120 influencing gp120-CD4 interactions and fusogenicity of HIV-1 envelopes derived from brain and other tissues

    Directory of Open Access Journals (Sweden)

    Ramsland Paul A

    2011-06-01

    Full Text Available Abstract Background CD4-binding site (CD4bs alterations in gp120 contribute to HIV-1 envelope (Env mediated fusogenicity and the ability of gp120 to utilize low levels of cell-surface CD4. In a recent study, we constructed three-dimensional models of gp120 to illustrate CD4bs conformations associated with enhanced fusogenicity and enhanced CD4-usage of a modestly-sized panel of blood-derived HIV-1 Envs (n = 16. These conformations were characterized by a wider aperture of the CD4bs cavity, as constrained by the inner-most atoms at the gp120 V1V2 stem and the V5 loop. Here, we sought to provide further validation of the utility of these models for understanding mechanisms that influence Env function, by characterizing the structure-function relationships of a larger panel of Envs derived from brain and other tissues (n = 81. Findings Three-dimensional models of gp120 were generated by our recently validated homology modelling protocol. Analysis of predicted CD4bs structures showed correlations between the aperture width of the CD4bs cavity and ability of the Envs to mediate cell-cell fusion, scavenge low-levels of cell-surface CD4, bind directly to soluble CD4, and bind to the Env mAb IgG1b12 whose epitope overlaps the gp120 CD4bs. These structural alterations in the CD4bs cavity were associated with repositioning of the V5 loop. Conclusions Using a large, independent panel of Envs, we can confirm the utility of three-dimensional gp120 structural models for illustrating CD4bs alterations that can affect Env function. Furthermore, we now provide new evidence that these CD4bs alterations augment the ability of gp120 to interact with CD4 by increasing the exposure of the CD4bs.

  4. Clonally expanded CD4+ T cells can produce infectious HIV-1 in vivo.

    Science.gov (United States)

    Simonetti, Francesco R; Sobolewski, Michele D; Fyne, Elizabeth; Shao, Wei; Spindler, Jonathan; Hattori, Junko; Anderson, Elizabeth M; Watters, Sarah A; Hill, Shawn; Wu, Xiaolin; Wells, David; Su, Li; Luke, Brian T; Halvas, Elias K; Besson, Guillaume; Penrose, Kerri J; Yang, Zhiming; Kwan, Richard W; Van Waes, Carter; Uldrick, Thomas; Citrin, Deborah E; Kovacs, Joseph; Polis, Michael A; Rehm, Catherine A; Gorelick, Robert; Piatak, Michael; Keele, Brandon F; Kearney, Mary F; Coffin, John M; Hughes, Stephen H; Mellors, John W; Maldarelli, Frank

    2016-02-16

    Reservoirs of infectious HIV-1 persist despite years of combination antiretroviral therapy and make curing HIV-1 infections a major challenge. Most of the proviral DNA resides in CD4(+)T cells. Some of these CD4(+)T cells are clonally expanded; most of the proviruses are defective. It is not known if any of the clonally expanded cells carry replication-competent proviruses. We report that a highly expanded CD4(+) T-cell clone contains an intact provirus. The highly expanded clone produced infectious virus that was detected as persistent plasma viremia during cART in an HIV-1-infected patient who had squamous cell cancer. Cells containing the intact provirus were widely distributed and significantly enriched in cancer metastases. These results show that clonally expanded CD4(+)T cells can be a reservoir of infectious HIV-1.

  5. Human CD141+ DCs induce CD4+ T cells to produce type 2 cytokines1

    Science.gov (United States)

    Yu, Chun I; Becker, Christian; Metang, Patrick; Marches, Florentina; Wang, Yuanyuan; Toshiyuki, Hori; Banchereau, Jacques; Merad, Miriam; Palucka, Karolina

    2014-01-01

    Dendritic cells (DCs) play the central role in the priming of naïve T cells and the differentiation of unique effector T cells. Here, using lung tissues and blood from both humans and humanized mice, we analyzed the response of human CD1c+ and CD141+ DC subsets to live-attenuated influenza virus (LAIV). Specifically, we analyzed the type of CD4+ T cell immunity elicited by LAIV-exposed DCs. Both DC subsets induce proliferation of allogeneic naïve CD4+ T cells with capacity to secrete IFN-γ. However, CD141+ DCs are uniquely able to induce the differentiation of IL-4 and IL-13 producing CD4+ T cells. CD141+ DCs induce IL-4 and IL-13 secreting CD4+ T cells through OX40L. Thus, CD141+ DCs demonstrate remarkable plasticity in guiding adaptive immune responses. PMID:25246496

  6. Tapping CD4 T cells for cancer immunotherapy: the choice of personalized genomics.

    Science.gov (United States)

    Zanetti, Maurizio

    2015-03-01

    Cellular immune responses that protect against tumors typically have been attributed to CD8 T cells. However, CD4 T cells also play a central role. It was shown recently that, in a patient with metastatic cholangiocarcinoma, CD4 T cells specific for a peptide from a mutated region of ERBB2IP could arrest tumor progression. This and other recent findings highlight new opportunities for CD4 T cells in cancer immunotherapy. In this article, I discuss the role and regulation of CD4 T cells in response to tumor Ags. Emphasis is placed on the types of Ags and mechanisms that elicit tumor-protective responses. I discuss the advantages and drawbacks of cancer immunotherapy through personalized genomics. These considerations should help to guide the design of next-generation therapeutic cancer vaccines.

  7. Quantifying CD4/CCR5 Usage Efficiency of HIV-1 Env Using the Affinofile System.

    Science.gov (United States)

    Webb, Nicholas E; Lee, Benhur

    2016-01-01

    Entry of HIV-1 into target cells involves the interaction of the HIV envelope (Env) with both a primary receptor (CD4) and a coreceptor (CXCR4 or CCR5). The relative efficiency with which a particular Env uses these receptors is a major component of cellular tropism in the context of entry and is related to a variety of pathological Env phenotypes (Chikere et al. Virology 435:81-91, 2013). The protocols outlined in this chapter describe the use of the Affinofile system, a 293-based dual-inducible cell line that expresses up to 25 distinct combinations of CD4 and CCR5, as well as the associated Viral Entry Receptor Sensitivity Assay (VERSA) metrics used to summarize the CD4/CCR5-dependent infectivity results. This system allows for high-resolution profiling of CD4 and CCR5 usage efficiency in the context of unique viral phenotypes.

  8. The SPL7013 dendrimer destabilizes the HIV-1 gp120-CD4 complex

    Science.gov (United States)

    Nandy, Bidisha; Saurabh, Suman; Sahoo, Anil Kumar; Dixit, Narendra M.; Maiti, Prabal K.

    2015-11-01

    The poly (l-lysine)-based SPL7013 dendrimer with naphthalene disulphonate surface groups blocks the entry of HIV-1 into target cells and is in clinical trials for development as a topical microbicide. Its mechanism of action against R5 HIV-1, the HIV-1 variant implicated in transmission across individuals, remains poorly understood. Using docking and fully atomistic MD simulations, we find that SPL7013 binds tightly to R5 gp120 in the gp120-CD4 complex but weakly to gp120 alone. Further, the binding, although to multiple regions of gp120, does not occlude the CD4 binding site on gp120, suggesting that SPL7013 does not prevent the binding of R5 gp120 to CD4. Using MD simulations to compute binding energies of several docked structures, we find that SPL7013 binding to gp120 significantly weakens the gp120-CD4 complex. Finally, we use steered molecular dynamics (SMD) to study the kinetics of the dissociation of the gp120-CD4 complex in the absence of the dendrimer and with the dendrimer bound in each of the several stable configurations to gp120. We find that SPL7013 significantly lowers the force required to rupture the gp120-CD4 complex and accelerates its dissociation. Taken together, our findings suggest that SPL7013 compromises the stability of the R5 gp120-CD4 complex, potentially preventing the accrual of the requisite number of gp120-CD4 complexes across the virus-cell interface, thereby blocking virus entry.The poly (l-lysine)-based SPL7013 dendrimer with naphthalene disulphonate surface groups blocks the entry of HIV-1 into target cells and is in clinical trials for development as a topical microbicide. Its mechanism of action against R5 HIV-1, the HIV-1 variant implicated in transmission across individuals, remains poorly understood. Using docking and fully atomistic MD simulations, we find that SPL7013 binds tightly to R5 gp120 in the gp120-CD4 complex but weakly to gp120 alone. Further, the binding, although to multiple regions of gp120, does not occlude

  9. Prevalence of human herpesvirus-8 salivary shedding in HIV increases with CD4 count.

    Science.gov (United States)

    Gandhi, M; Koelle, D M; Ameli, N; Bacchetti, P; Greenspan, J S; Navazesh, M; Anastos, K; Greenblatt, R M

    2004-08-01

    Human herpesvirus-8 (HHV-8) is the etiologic agent of Kaposi's sarcoma (KS), which occurs in epidemic form in human immunodeficiency virus(HIV)-infected individuals. Saliva is the only mucosal fluid in which infectious HHV-8 has been identified, although factors associated with HHV-8 salivary shedding remain unclear. Our study performed PCR analysis for HHV-8 DNA in saliva (and other body fluids) in 66 HIV- and HHV-8-co-infected women without KS so that we could examine predictors for HHV-8 DNA detection. CD4 count was the most significant predictor of HHV-8 salivary shedding, with increased prevalence of HHV-8 salivary DNA at higher CD4 counts. The odds of salivary HHV8 shedding at CD4 counts > = 350 cells/microL was 63 times the odds of shedding at CD4 200. Analysis of these data suggests an increased potential for HHV-8 transmission early in HIV infection, with implications for HHV-8 prevention.

  10. CD4+ lymphoid tissue inducer cells promote innate immunity in the gut

    OpenAIRE

    Sonnenberg, Gregory F.; Monticelli, Laurel A.; Elloso, M. Merle; Fouser, Lynette A.; Artis, David

    2010-01-01

    Fetal CD4+ lymphoid tissue inducer (LTi) cells play a critical role in the development of lymphoid-tissues. Recent studies identified that LTi cells persist in adults and are related to a heterogeneous population of innate lymphoid cells that have been implicated in inflammatory responses. However, whether LTi cells contribute to protective immunity remains poorly defined. We demonstrate that following infection with Citrobacter rodentium, CD4+ LTi cells were a dominant source of interleukin-...

  11. Effects of estrogen on CD4+CD25+ regulatory T cell in peripheral blood during pregnancy

    Institute of Scientific and Technical Information of China (English)

    Yuan-Huan Xiong; Zhen Yuan; Li He

    2013-01-01

    Objective:To investigate the effects of estrogen (E2) level on regulatory T cells (Treg) in peripheral blood during pregnancy. Methods:A total of 30 healthy non-pregnant women were selected as control group, 90 pregnant women of early, middle and late pregnancy and 30 postpartum women at 1 month after parturition were selected as experimental groups including early pregnancy group, middle pregnancy group and late pregnancy group;the proportions of CD4+CD25+Treg and CD4+CD25+CD127-Treg among CD4+T cells were detected by flow cytometry;the serum estrogen content in peripheral blood was detected by electrochemical immune luminescence method. Results: E2 level was coincident with the change of Tregs number during pregnancy. The estrogen content in peripheral blood increased gradually from early pregnancy to late pregnancy, then decreased significantly after parturition, and the level at 1 month after parturition down to the level in non-pregnancy group (P>0.05);the level of E2 in pregnancy groups were significantly higher than those in non-pregnancy group (P0.05);the proportions in middle and late pregnancy groups were significantly higher than those in early pregnancy group (P0.05). There was correlation between Tregs number with estrogen level during pregnancy. The proportion of CD4+CD25+ Treg and CD4+CD25+CD127- Treg were positively correlated with estrogen level. Conclusions:High proportion of CD4+CD25+Treg and CD4+CD25+CD127-Treg is closely related to the high level of E2 during pregnancy. It suggested that high level of estrogen may induce an increase of CD4+CD25+Treg in peripheral blood, and then influence the immune function of pregnant women. The results of this experiment might play an important role of estrogen in immune-modulation during pregnancy.

  12. Tracking virus-specific CD4+ T cells during and after acute hepatitis C virus infection.

    Directory of Open Access Journals (Sweden)

    Michaela Lucas

    Full Text Available BACKGROUND: CD4+ T cell help is critical in maintaining antiviral immune responses and such help has been shown to be sustained in acute resolving hepatitis C. In contrast, in evolving chronic hepatitis C CD4+ T cell helper responses appear to be absent or short-lived, using functional assays. METHODOLOGY/PRINCIPAL FINDINGS: Here we used a novel HLA-DR1 tetramer containing a highly targeted CD4+ T cell epitope from the hepatitis C virus non-structural protein 4 to track number and phenotype of hepatitis C virus specific CD4+ T cells in a cohort of seven HLA-DR1 positive patients with acute hepatitis C in comparison to patients with chronic or resolved hepatitis C. We observed peptide-specific T cells in all seven patients with acute hepatitis C regardless of outcome at frequencies up to 0.65% of CD4+ T cells. Among patients who transiently controlled virus replication we observed loss of function, and/or physical deletion of tetramer+ CD4+ T cells before viral recrudescence. In some patients with chronic hepatitis C very low numbers of tetramer+ cells were detectable in peripheral blood, compared to robust responses detected in spontaneous resolvers. Importantly we did not observe escape mutations in this key CD4+ T cell epitope in patients with evolving chronic hepatitis C. CONCLUSIONS/SIGNIFICANCE: During acute hepatitis C a CD4+ T cell response against this epitope is readily induced in most, if not all, HLA-DR1+ patients. This antiviral T cell population becomes functionally impaired or is deleted early in the course of disease in those where viremia persists.

  13. Nuclear retention of multiply spliced HIV-1 RNA in resting CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Kara G Lassen

    2006-07-01

    Full Text Available HIV-1 latency in resting CD4+ T cells represents a major barrier to virus eradication in patients on highly active antiretroviral therapy (HAART. We describe here a novel post-transcriptional block in HIV-1 gene expression in resting CD4+ T cells from patients on HAART. This block involves the aberrant localization of multiply spliced (MS HIV-1 RNAs encoding the critical positive regulators Tat and Rev. Although these RNAs had no previously described export defect, we show that they exhibit strict nuclear localization in resting CD4+ T cells from patients on HAART. Overexpression of the transcriptional activator Tat from non-HIV vectors allowed virus production in these cells. Thus, the nuclear retention of MS HIV-1 RNA interrupts a positive feedback loop and contributes to the non-productive nature of infection of resting CD4+ T cells. To define the mechanism of nuclear retention, proteomic analysis was used to identify proteins that bind MS HIV-1 RNA. Polypyrimidine tract binding protein (PTB was identified as an HIV-1 RNA-binding protein differentially expressed in resting and activated CD4+ T cells. Overexpression of PTB in resting CD4+ T cells from patients on HAART allowed cytoplasmic accumulation of HIV-1 RNAs. PTB overexpression also induced virus production by resting CD4+ T cells. Virus culture experiments showed that overexpression of PTB in resting CD4+ T cells from patients on HAART allowed release of replication-competent virus, while preserving a resting cellular phenotype. Whether through effects on RNA export or another mechanism, the ability of PTB to reverse latency without inducing cellular activation is a result with therapeutic implications.

  14. Costimulation of CD3/TcR complex with either integrin or nonintegrin ligands protects CD4+ allergen-specific T-cell clones from programmed cell death.

    Science.gov (United States)

    Agea, E; Bistoni, O; Bini, P; Migliorati, G; Nicoletti, I; Bassotti, G; Riccardi, C; Bertotto, A; Spinozzi, F

    1995-08-01

    An optimal stimulation of CD4+ cells in an immune response requires not only signals transduced via the TcR/CD3 complex, but also costimulatory signals delivered as a consequence of interactions between T-cell surface-associated costimulatory receptors and their counterparts on antigen-presenting cells (APC). The intercellular adhesion molecule-1 (ICAM-1, CD54) efficiently costimulates proliferation of resting, but not antigen-specific, T cells. In contrast, CD28 and CD2 support interleukin (IL)-2 synthesis and proliferation of antigen-specific T cells more efficiently than those of resting T cells. The molecular basis for this differential costimulation of T cells is poorly understood. Cypress-specific T-cell clones (TCC) were generated from four allergic subjects during in vivo seasonal exposure to the allergen. Purified cypress extract was produced directly from fresh collected pollen and incubated with the patients' mononuclear cells. Repeated allergen stimulation was performed in T-cell cultures supplemented with purified extract and autologous APC. The limiting-dilution technique was then adopted to generate allergen-specific TCC, which were also characterized by their cytokine secretion pattern as Th0 (IL-4 plus interferon-gamma) or Th2 (IL-4). Costimulation-induced proliferation or apoptosis was measured by propidium iodide cytofluorometric assay. By cross-linking cypress-specific CD4+ and CD8+ T-cell clones with either anti-CD3 or anti-CD2, anti-CD28, and anti-CD54 monoclonal antibodies, we demonstrated that CD4+ clones (with Th0- or Th2-type cytokine production pattern) undergo programmed cell death only after anti-CD3 stimulation, whereas costimulation with either anti-CD54 or anti-CD28 protects target cells from apoptosis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7503404

  15. Interfacial Cavity Filling To Optimize CD4-Mimetic Miniprotein Interactions with HIV-1 Surface Glycoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Morellato-Castillo, Laurence; Acharya, Priyamvada; Combes, Olivier; Michiels, Johan; Descours, Anne; Ramos, Oscar H.P.; Yang, Yongping; Vanham, Guido; Ariën, Kevin K.; Kwong, Peter D.; Martin, Loïc; Kessler, Pascal [ITM-Antwerp; (CEA-CNRS); (NIH)

    2013-08-05

    Ligand affinities can be optimized by interfacial cavity filling. A hollow (Phe43 cavity) between HIV-1 surface glycoprotein (gp120) and cluster of differentiation 4 (CD4) receptor extends beyond residue phenylalanine 43 of CD4 and cannot be fully accessed by natural amino acids. To increase HIV-1 gp120 affinity for a family of CD4-mimetic miniproteins (miniCD4s), we targeted the gp120 Phe43 cavity with 11 non-natural phenylalanine derivatives, introduced into a miniCD4 named M48 (1). The best derivative, named M48U12 (13), bound HIV-1 YU2 gp120 with 8 pM affinity and showed potent HIV-1 neutralization. It contained a methylcyclohexyl derivative of 4-aminophenylalanine, and its cocrystal structure with gp120 revealed the cyclohexane ring buried within the gp120 hydrophobic core but able to assume multiple orientations in the binding pocket, and the aniline nitrogen potentially providing a focus for further improvement. Altogether, the results provide a framework for filling the interfacial Phe43 cavity to enhance miniCD4 affinity.

  16. The Story of CD4+CD28− T Cells Revisited: Solved or Still Ongoing?

    Directory of Open Access Journals (Sweden)

    Kathrin Maly

    2015-01-01

    Full Text Available CD4+CD28− T cells are a unique type of proinflammatory T cells characterised by blockade of costimulatory CD28 receptor expression at the transcriptional level, which is still reversible by IL-12. In healthy individuals older than 65 years, these cells may accumulate to up to 50% of total CD4+ T lymphocytes as in many immune-mediated diseases, immunodeficiency, and specific infectious diseases. Here we focus on CD4+CD28− T cells in chronic immune-mediated diseases, summarizing various phenotypic and functional characteristics, which vary depending on the underlying disease, disease activity, and concurrent treatment. CD4+CD28− T cells present as effector/memory cells with increased replicative history and oligoclonality but reduced apoptosis. As an alternative costimulatory signal instead of CD28, not only natural killer cell receptors and Toll-like receptors, but also CD47, CTLA-4, OX40, and 4-1BB have to be considered. The proinflammatory and cytotoxic capacities of these cells indicate an involvement in progression and maintenance of chronic immune-mediated disease. So far it has been shown that treatment with TNF-α blockers, abatacept, statins, and polyclonal antilymphocyte globulins (ATG mediates reduction of the CD4+CD28− T cell level. The clinical relevance of targeting CD4+CD28− T cells as a therapeutic option has not been examined so far.

  17. Lymphoid tissue inducer cells: pivotal cells in the evolution of CD4 immunity and tolerance?

    Directory of Open Access Journals (Sweden)

    Peter John Lane

    2012-02-01

    Full Text Available Phylogeny suggests that the evolution of placentation in mammals was accompanied by substantial changes in the mammalian immune system: in particular lymph nodes and CD4 high affinity memory antibody responses co-evolved during the same period. Lymphoid tissue inducer cells (LTi are members of an emerging family of innate lymphoid cells (ILCs that are crucial for lymph node development, but our studies have indicated that they also play a pivotal role in the long-term maintenance of memory CD4 T cells in adult mammals through their expression of the tumor necrosis family members, OX40- and CD30-ligands. Additionally, our studies have shown that these two molecules are also key operators in CD4 effector function, as their absence obviates the need for the FoxP3-dependent regulatory T cells (Tregs that prevent CD4 driven autoimmune responses. In this perspective article, we summarize findings from our group over the last 10 years, and focus specifically on the role of LTi in thymus. We suggest that like memory CD4 T cells, LTi also play a role in the selection and maintenance of the Tregs that under normal circumstances are absolutely required to regulate CD4 effector cells.

  18. The story of CD4+ CD28- T cells revisited: solved or still ongoing?

    Science.gov (United States)

    Maly, Kathrin; Schirmer, Michael

    2015-01-01

    CD4(+)CD28(-) T cells are a unique type of proinflammatory T cells characterised by blockade of costimulatory CD28 receptor expression at the transcriptional level, which is still reversible by IL-12. In healthy individuals older than 65 years, these cells may accumulate to up to 50% of total CD4(+) T lymphocytes as in many immune-mediated diseases, immunodeficiency, and specific infectious diseases. Here we focus on CD4(+)CD28(-) T cells in chronic immune-mediated diseases, summarizing various phenotypic and functional characteristics, which vary depending on the underlying disease, disease activity, and concurrent treatment. CD4(+)CD28(-) T cells present as effector/memory cells with increased replicative history and oligoclonality but reduced apoptosis. As an alternative costimulatory signal instead of CD28, not only natural killer cell receptors and Toll-like receptors, but also CD47, CTLA-4, OX40, and 4-1BB have to be considered. The proinflammatory and cytotoxic capacities of these cells indicate an involvement in progression and maintenance of chronic immune-mediated disease. So far it has been shown that treatment with TNF-α blockers, abatacept, statins, and polyclonal antilymphocyte globulins (ATG) mediates reduction of the CD4(+)CD28(-) T cell level. The clinical relevance of targeting CD4(+)CD28(-) T cells as a therapeutic option has not been examined so far. PMID:25834833

  19. IL-17-Expressing CD4+ and CD8+ T Lymphocytes in Human Toxoplasmosis

    Directory of Open Access Journals (Sweden)

    Jéssica Líver Alves Silva

    2014-01-01

    Full Text Available This study aimed to measure the synthesis of Th1 and Th2 cytokines by mononuclear cells after culture with live T. gondii and identified Th17 (CD4+ and Tc17 (CD8+ cells in toxoplasma-seronegative and toxoplasma-seropositive parturient and nonpregnant women. Cytometric bead arrays were used to measure cytokine levels (IL-2, TNF-α, IFN-γ, IL-4, IL-5, and IL-10; immunophenotyping was used to characterize Th17 and Tc17 cells, and the cells were stained with antibodies against CD4+ and CD8+ T cells expressing IL-17. The addition of tachyzoites to cell cultures induced the synthesis of IL-5, IL-10, and TNF-α by cells from seronegative parturient women and of IL-5 and IL-10 by cells from seropositive, nonpregnant women. We observed a lower level of IL-17-expressing CD4+ and CD8+ T lymphocytes in cultures of cells from seronegative and seropositive parturient and nonpregnant women that were stimulated with tachyzoites, whereas analysis of the CD4+ and CD8+ T cell populations showed a higher level of CD4+ T cells compared with CD8+ T cells. These results suggest that the cytokine pattern and IL-17-expressing CD4+ and CD8+ T lymphocytes may have important roles in the inflammatory response to T. gondii, thus contributing to the maintenance of pregnancy and control of parasite invasion and replication.

  20. Impact of nicotine on the interplay between human periodontal ligament cells and CD4+ T cells.

    Science.gov (United States)

    Ge, Xin; Liu, Ying-Feng; Wong, Yong; Wu, Li-Zheng; Tan, Ling; Liu, Fen; Wang, Xiao-Jing

    2016-09-01

    Periodontitis is a common infectious disease associated with destruction of periodontal ligaments and alveolar bones. CD4(+) T cell-mediated immune response is involved in the progression of periodontitis. Tobacco consumption increases the risk of periodontal disease. However, the impact of nicotine on the interaction between human periodontal ligament (PDL) cells and CD4(+) T cells remains unrevealed. Our study aims to investigate the effect of nicotine on PDL cells and the cocultured CD4(+) T cells. The PDL cell cultures were established by explants from healthy individuals, exposed to nicotine or α-bungarotoxin (α-BTX), and incubated solely or in combination with CD4(+) T cells. Afterwards, cell viability, secreted cytokines, and matrix metalloproteinases (MMPs) were evaluated. In monoculture of PDL cells, nicotine dramatically repressed cell viability and increased apoptosis. Meanwhile, α-BTX largely reversed the nicotine-induced apoptosis and increased viability of PDL cells. Compared with the monoculture, MMP-1, MMP-3, interleukin (IL)-1β, IL-6, IL-17, and IL-21 in supernatant of cocultures were markedly elevated after treatment with nicotine. Moreover, α-BTX significantly attenuated nicotine-triggered production of these components either in mono- or co-cultures. In addition, PDL cell-derived CXCL12 following nicotine treatment recruited CD4(+) T cells. Above all, nicotine deteriorated periodontitis partially by promoting PDL cell-CD4(+) T cell-mediated inflammatory response and matrix degradation. PMID:26553320

  1. A dominant EV71-specific CD4+ T cell epitope is highly conserved among human enteroviruses.

    Directory of Open Access Journals (Sweden)

    Ruicheng Wei

    Full Text Available CD4+ T cell-mediated immunity plays a central role in determining the immunopathogenesis of viral infections. However, the role of CD4+ T cells in EV71 infection, which causes hand, foot and mouth disease (HFMD, has yet to be elucidated. We applied a sophisticated method to identify promiscuous CD4+ T cell epitopes contained within the sequence of the EV71 polyprotein. Fifteen epitopes were identified, and three of them are dominant ones. The most dominant epitope is highly conserved among enterovirus species, including HFMD-related coxsackieviruses, HFMD-unrelated echoviruses and polioviruses. Furthermore, the CD4+ T cells specific to the epitope indeed cross-reacted with the homolog of poliovirus 3 Sabin. Our findings imply that CD4+ T cell responses to poliovirus following vaccination, or to other enteroviruses to which individuals may be exposed in early childhood, may have a modulating effect on subsequent CD4+ T cell response to EV71 infection or vaccine.

  2. Correlation between total lymphocyte count, hemoglobin, hematocrit and CD4 count in HIV patients in Nigeria.

    Science.gov (United States)

    Emuchay, Charles Iheanyichi; Okeniyi, Shemaiah Olufemi; Okeniyi, Joshua Olusegun

    2014-04-01

    The expensive and technology limited setting of CD4 count testing is a major setback to the initiation of HAART in a resource limited country like Nigeria. Simple and inexpensive tools such as Hemoglobin (Hb) measurement and Total Lymphocyte Count (TLC) are recommended as substitute marker. In order to assess the correlations of these parameters with CD4 count, 100 "apparently healthy" male volunteers tested HIV positive aged ≥ 20 years but ≤ 40 years were recruited and from whom Hb, Hct, TLC and CD4 count were obtained. The correlation coefficients, R, the Nash-Sutcliffe Coefficient of Efficiency (CoE) and the p-values of the ANOVA model of Hb, Hct and TLC with CD4 count were assessed. The assessments show that there is no significant relationship of any of these parameters with CD4 count and the correlation coefficients are very weak. This study shows that Hb, Hct and TLC cannot be substitute for CD4 count as this might lead to certain individuals' deprivation of required treatment.

  3. CD4 lymphocyte dynamics in Tanzanian pulmonary tuberculosis patients with and without HIV co-infection

    DEFF Research Database (Denmark)

    Andersen, Aase B.; Range, Nyagosya; Changalucha, John;

    2012-01-01

    ABSTRACT: BACKGROUND: The interaction of HIV and tuberculosis (TB) on CD4 levels over time has previously been divergently reported and only in small study populations with short or no follow-up. METHODS: CD4 counts were assessed from time of diagnosis till the end of TB treatment in a cohort...... of pulmonary TB patients with and without HIV co-infection and compared with cross-sectional data on age- and sex-matched non-TB controls from the same area. RESULTS: Of 1605 study participants, 1250 were PTB patients and 355 were non-TB controls. At baseline, HIV was associated with 246 (95% CI: 203; 279......) cells per uL lower CD4 counts. All PTB patients had 100 cells per uL lower CD4 counts than the healthy controls. The CD4 levels were largely unchanged during five-months of TB treatment. HIV infected patients not receiving ART at any time and those already on ART at baseline had no increase in CD4...

  4. HLA Class-II Associated HIV Polymorphisms Predict Escape from CD4+ T Cell Responses.

    Directory of Open Access Journals (Sweden)

    Nathan Erdmann

    2015-08-01

    Full Text Available Antiretroviral therapy, antibody and CD8+ T cell-mediated responses targeting human immunodeficiency virus-1 (HIV-1 exert selection pressure on the virus necessitating escape; however, the ability of CD4+ T cells to exert selective pressure remains unclear. Using a computational approach on HIV gag/pol/nef sequences and HLA-II allelic data, we identified 29 HLA-II associated HIV sequence polymorphisms or adaptations (HLA-AP in an African cohort of chronically HIV-infected individuals. Epitopes encompassing the predicted adaptation (AE or its non-adapted (NAE version were evaluated for immunogenicity. Using a CD8-depleted IFN-γ ELISpot assay, we determined that the magnitude of CD4+ T cell responses to the predicted epitopes in controllers was higher compared to non-controllers (p<0.0001. However, regardless of the group, the magnitude of responses to AE was lower as compared to NAE (p<0.0001. CD4+ T cell responses in patients with acute HIV infection (AHI demonstrated poor immunogenicity towards AE as compared to NAE encoded by their transmitted founder virus. Longitudinal data in AHI off antiretroviral therapy demonstrated sequence changes that were biologically confirmed to represent CD4+ escape mutations. These data demonstrate an innovative application of HLA-associated polymorphisms to identify biologically relevant CD4+ epitopes and suggests CD4+ T cells are active participants in driving HIV evolution.

  5. Operational challenges in delivering CD4 diagnostics in sub-Saharan Africa.

    Science.gov (United States)

    Thairu, L; Katzenstein, D; Israelski, D

    2011-07-01

    Access to reliable and low cost CD4 T-cell enumeration to stage illness and monitor anti-retroviral therapy remains elusive in resource-limited settings. We report challenges in delivering CD4 testing using the microcapillary Fluorescence-Activated Cell Sorter (FACS) methodology (Guava EasyCD4 instrument Guava Technologies, Hayward) in Burkina Faso and Zimbabwe. Resources, instruments, reagents, and training were provided to local laboratories within the existing infrastructure and data on CD4 were collected from routine laboratory testing. Challenges encountered included frequent instrument breakdown; poor manufacturer maintenance; difficulties in managing reagent stocks; high technician turnover; reliance on antiquated data management systems; redundant service provision; and lack of repeat testing in male HIV+ patients and in patients with higher CD4 counts after initial staging. While adopting newer, less expensive technologies such as fluorescent platforms and point of care tests can facilitate access to lower cost CD4 testing, our experience suggests that supply chain, corporate commitment to implementation, and community factors also require consideration. PMID:21400312

  6. The effect of probiotics on CD4 counts among people living with HIV: a systematic review.

    Science.gov (United States)

    Miller, H; Ferris, R; Phelps, B R

    2016-06-01

    Probiotics are defined by the WHO as 'live microorganisms which when administered in adequate amounts confer a health benefit on the host'. Ongoing research has shown probiotics provide benefits to humans, including protection and restoration of the gastrointestinal and other mucosal tracts. As human immunodeficiency virus (HIV) activates gut-associated lymphoid tissue (GALT), several studies have investigated the effect of probiotics on CD4 cell count and related outcomes among those living with HIV. These studies are summarised here. Manuscripts were identified using the search terms 'probiotics', 'synbiotics', 'HIV', and 'CD4', and were reviewed for relevance and inclusion of CD4 count as an immunologic endpoint. Bibliographies of relevant manuscripts were also reviewed for additional studies matching inclusion and exclusion criteria. The search yielded 91 results; 13 included relevant outcomes. Seven of these studies produced beneficial CD4 outcomes, while the remaining 6 reported on insignificant beneficial or negative CD4 outcomes. The studies summarised here collectively suggest that daily consumption of probiotics over a prolonged period of time may improve CD4 count in people living with HIV.

  7. Restrictions to HIV-1 replication in resting CD4+T lymphocytes

    Institute of Scientific and Technical Information of China (English)

    Xiaoyu Pan; Hanna-Mari Baldauf; Oliver T Keppler; Oliver T Fackler

    2013-01-01

    CD4+ T lymphocytes represent the main target cell population of human immunodeficiency virus (HIV).In an activated state,CD4+ T cells residing in lymphoid organs are a major reservoir of ongoing HIV-1 replication in infected individuals.In contrast,resting CD4+ T cells are highly resistant to productive HIV-1 infection,yet are massively depleted during disease progression and represent a substantial latent reservoir for the virus in vivo.Barriers preventing replication of HIV-1 in resting CD4+ T cells include a rigid layer of cortical actin and,early after HIV-1entry,a block that limits reverse transcription of incoming viral RNA genomes.Defining the molecular bases of these restrictions has remained one of the central open questions in HIV research.Recent advances unraveled mechanisms by which HIV-1 bypasses the entry block and established the host cell restriction factor SAMHD1,a deoxynucleoside triphosphate triphosphohydrolase,as a central determinant of the cellular restriction to HIV-1 reverse transcription in resting CD4+ T cells.This review summarizes our current molecular and pathophysiological understanding of the multi-faceted interactions of HIV-1 with resting CD4+ T lymphocytes.

  8. Cytotoxic reactivity of gut lamina propria CD4+ alpha beta T cells in SCID mice with colitis

    DEFF Research Database (Denmark)

    Bonhagen, K; Thoma, S; Bland, P;

    1996-01-01

    SCID mice express the Fas ligand on the surface. Gut lamina propria CD4+ T cells show Fas-dependent cytotoxicity. A large fraction of gut lamina propria CD4+ T cells that infiltrate the inflamed colon in transplanted SCID mice are activated in situ and many CD4+ T cells are apoptotic. Hence, a large...... fraction of colitis-inducing CD4+ T cells undergo activation-induced cell death in situ and can damage other cells through Fas-dependent cytotoxicity....

  9. Human immunodeficiency virus type 1 envelope glycoprotein gp120 produces immune defects in CD4+ T lymphocytes by inhibiting interleukin 2 mRNA.

    OpenAIRE

    1990-01-01

    Envelope glycoprotein gp120 of human immunodeficiency virus type 1 (HIV-1) is known to inhibit T-cell function, but little is known about the mechanisms of this immunosuppression. Pretreatment of a CD4+ tetanus toxoid-specific T-cell clone with soluble gp120 was found to exert a dose-dependent inhibition of soluble antigen-driven or anti-CD3 monoclonal antibody-driven proliferative response, interleukin 2 (IL-2) production, and surface IL-2 receptor (IL-2R) alpha-chain expression, all of whic...

  10. IFN-γ and TNF-α producing CD4+ T-cells in the blood after Mycoplasma hyosynoviae challenge of vaccinated pigs

    DEFF Research Database (Denmark)

    Riber, Ulla; Hansen, Mette Sif; Lauritsen, Klara Tølbøll;

    In a vaccine trial against Mycoplasma hyosynoviae infection, pigs were vaccinated with formalin fixed whole-cell-antigen formulated with adjuvant DDA/TDB (SSI). Placebo pigs received adjuvant with saline. Vaccinations were performed at five and eight weeks of age, followed by an intranasal M......-α were rare. However, CD4+ cells producing IFN-γ or TNF-α after Ag-stimulation were detected in vaccinated pigs, and increased IFN-γ level (iMFI) in cells co-producing IFN-γ and TNF-α was more pronounced in vaccinated pigs compared to placebo pigs in response to M. hyosynoviae challenge (day 15 p...

  11. Enhanced normalisation of CD4/CD8 ratio with early antiretroviral therapy in primary HIV infection

    Directory of Open Access Journals (Sweden)

    John Thornhill

    2014-11-01

    Full Text Available Introduction: Despite normalization of total CD4 counts, ongoing immune dysfunction is noted amongst those on antiretroviral therapy (ART. Low CD4/CD8 ratio is associated with a high risk of AIDS and non-AIDS events and may act as a marker of immune senescence [1]. This ratio is improved by ART although normalization is uncommon (~7% [2]. The probability of normalization of CD4 count is improved with immediate ART initiation in primary HIV infection (PHI [3]. We examined whether CD4/CD8 ratio similarly normalized in immediate vs. deferred ART at PHI. Material and Methods: Using data from the SPARTAC trial and the UK Register of HIV Seroconverters, we examined the effect of ART with time (continuous from HIV seroconversion (SC on CD4/CD8 ratio (≥1 adjusted for sex, risk group, ethnicity, enrolment from an African site and both CD4 count and age at ART initiation. We also examined that effect by dichotomizing HIV duration at ART initiation (ART started within six months of SC: early ART; ART initiated>six months after SC: deferred. We also considered time to CD4 count normalization (≥900 cells/mm3. Results: In total, 353 initiated ART with median (IQR 97.9 (60.5, 384.5 days from estimated seroconversion; 253/353 early ART, 100 deferred ART. At one year after starting ART, 114/253 (45% early ART had normalized CD4/8 ratio, compared with 11/99 (11% in the deferred group, whilst 83/253 (33% of early ART had normalized CD4 counts, compared with 3/99 (3% in the deferred group. Individuals initiating within six months of PHI were significantly more likely to reach normal ratio than those initiating later (HR, 95% CI 2.96, 1.75 – 5.01, p<0.001. The longer after SC ART was initiated, the reduced likelihood of achieving normalization of CD4/CD8 ratio (HR 0.98, 95% CI 0.96 – 0.99 for each 30-day increase. CD4 count at ART initiation was also associated with normalization, as expected (HR 1.002, 95% CI 1.001 – 1.002, p<0.001. There was an

  12. Detection of CD4+/CD8+T Lymphocyte Ratio and CD4+CD25+ Treg in Peripheral Blood of Patients with Sporadic Vitiligo%散发型白癜风患者外周血CD4+/CD8+T细胞比值及CD4+CD25+T细胞的检测

    Institute of Scientific and Technical Information of China (English)

    叶蓉; 马刚; 胡小平; 彭曦

    2012-01-01

    目的 检测散发型白癜风患者外周血CD4+/CD8+T细胞比值及CD4+CD25+调节性T细胞水平,探讨其与散发型白癜风发病的关系.方法 散发型白癜风患者29例,男13例,女16例.通过流式细胞仪对散发型白癜风患者外周血CD4+/CD8+T细胞比值及CD4+CD25+调节性T细胞水平进行检测,并与20例健康人相比较.结果 与健康对照组相比,散发型白癜风患者外周血中CD4+/CD8+T细胞比值的差异无统计学意义(P>0.05),而CD4+CD25+调节性T细胞水平明显减少,差异有统计学意义(P<0.05),但在不同病程的患者中CD4+CD25+调节性T细胞数量的差异无统计学意义(P>0.05).结论 散发型白癜风患者外周血中存在CD4+CD25+调节性T细胞水平下降,可能与散发型白癜风的发生发展有一定关系.%Objective To detect the CD4+/CD8+ T lymphocyte ratio and the CD4+CD25+ Treg level in peripheral blood of patients with sporadic vitiligo, and to investigate its role in the pathogenesis of sporadic vitiligo. Methods Peripheral blood samples were taken from 29 outpatients with sporadic vitiligo, including 13 males and 16 females. The CD4+/CD8+ T lymphocyte ratio and the CD4+CD25+ Treg level was detected in peripheral blood of patients with sporadic vitiligo by flow cytometry, as well as controlled samples from 20 healthy human. Results There was no difference on the ratio of CD4+/CD8+ T lymphocyte between the patients with sporadic vitiligo and healthy people (P>0.05). Compared to the controlled group, the proportion of CD4+CD25+ Treg was significantly lower in sporadic vitiligo patients(P0.05). Conclusion The level of CD4+CD25+ Treg is lower in peripheral blood of sporadic vitiligo patients, which might play a role in the pathogenesis and development of sporadic vitiligo.

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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    Lifescience Database Archive (English)

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  10. Long-term Mortality in HIV-Positive Individuals Virally Suppressed for >3 Years With Incomplete CD4 Recovery

    DEFF Research Database (Denmark)

    Engsig, Frederik N; Zangerle, Robert; Katsarou, Olga;

    2014-01-01

    BACKGROUND: Some human immunodeficiency virus (HIV)-infected individuals initiating combination antiretroviral therapy (cART) with low CD4 counts achieve viral suppression but not CD4 cell recovery. We aimed to identify (1) risk factors for failure to achieve CD4 count >200 cells/µL after 3 years...

  11. In vitro separation and expansion of CD4 lymphocytes from HIV-infected individuals without activation of HIV infection

    DEFF Research Database (Denmark)

    Nielsen, S D; Nielsen, Jens Ole; Hansen, J E

    1997-01-01

    In order to offer a gene therapy-based treatment against AIDS, it is likely to be necessary to harvest and culture CD4 cells from HIV-positive patients without activating the HIV infection. We have used a magnetic cell sorting (MACS) system to enrich CD4 cells. Using positive selection, CD4 cells...

  12. BCG Vaccination Induces Robust CD4+ T Cell Responses to Mycobacterium tuberculosis Complex-Specific Lipopeptides in Guinea Pigs.

    Science.gov (United States)

    Kaufmann, Eva; Spohr, Christina; Battenfeld, Sibylle; De Paepe, Diane; Holzhauser, Thomas; Balks, Elisabeth; Homolka, Susanne; Reiling, Norbert; Gilleron, Martine; Bastian, Max

    2016-03-15

    A new class of highly antigenic, MHC-II-restricted mycobacterial lipopeptides that are recognized by CD4-positive T lymphocytes of Mycobacterium tuberculosis-infected humans has recently been described. To investigate the relevance of this novel class of mycobacterial Ags in the context of experimental bacille Calmette-Guérin (BCG) vaccination, Ag-specific T cell responses to mycobacterial lipid and lipopeptide-enriched Ag preparations were analyzed in immunized guinea pigs. Lipid and lipopeptide preparations as well as complex Ag mixtures, such as tuberculin, mycobacterial lysates, and culture supernatants, all induced a similar level of T cell proliferation. The hypothesis that lipopeptide-specific T cells dominate the early BCG-induced T cell response was corroborated in restimulation assays by the observation that Ag-expanded T cells specifically responded to the lipopeptide preparation. A comparative analysis of the responses to Ag preparations from different mycobacterial species revealed that the antigenic lipopeptides are specific for strains of the M. tuberculosis complex. Their intriguing conservation in pathogenic tuberculous bacteria and the fact that these highly immunogenic Ags seem to be actively released during in vitro culture and intracellular infection prompt the urgent question about their role in the fine-tuned interplay between the pathogen and its mammalian host, in particular with regard to BCG vaccination strategies. PMID:26889044

  13. 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

  14. CD4 + T cells in asthma pathogensis%CD4+ T细胞亚群在支气管哮喘病理机制中作用的新认识

    Institute of Scientific and Technical Information of China (English)

    张琳; 梁庆红; 王烨

    2013-01-01

    CD4 + T cells are regulated effective immune response to pathogens, Na? ve CD4 + T cells are active after interaction with antigen-MHC complex and differentiate into specific subtypes depending mainly on the cytoking milieu of the microenvironment. Ba-sides the classical T-helper 1 and T-helper 2, other subsets have been identified, including T-helper 17 , regulatory T cell, follicular help T cell, and T help-9, each with a characteristic cytoking profile. Regulatory T (Treg) cells are considered to inhibit the development of both type 1 (Thl) and type 2 helper T (Th2) cells. It is recently reported that there are reduced numbers of Treg cells in patients with allergic diseases and asthma. Therefore, Treg cells may suppress the onset of allergic disease and asthma by down-regulating other types of immune cells besides Thl and Th2 cells. The newly discovered interleukin 17 producing helper T cells that are responsible for autoimmune inflammatory diseases may counteract Treg cells even in allergic diseases and asthma. In this review, we further discuss the role of Th1, Th2, Thl7 , Th9 and Treg cells in allergic diseases and asthma.%CD4+T细胞对病原微生物可产生有效免疫应答,依据其产生细胞因子不同分为辅助Ⅰ型T细胞(Th1)和辅助Ⅱ型T细胞(Th2),目前其他亚型已被鉴定,包括Th17、调节性T细胞(Treg),滤泡型T细胞和Th9细胞等.调节性T细胞既抑制Th1,也抑制Th2发育.最近研究报道,在过敏性疾病和哮喘患者中Treg细胞数量减少,并认为是通过下调Th1和Th2细胞以外的其他亚类细胞而抑制过敏和哮喘发作的.在这篇综述中,我们将进一步探讨Th1、Th2、Th17、Th9以及Treg在过敏性和哮喘疾病中的作用.

  15. Visualization of the human CD4{sup +} T-cell response in humanized HLA-DR4-expressing NOD/Shi-scid/γc{sup null} (NOG) mice by retrogenic expression of the human TCR gene

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Takeshi, E-mail: takeshi-takahashi@ciea.or.jp; Katano, Ikumi; Ito, Ryoji; Ito, Mamoru

    2015-01-02

    Highlights: • β-Lactoglobulin (BLG) specific TCR genes were introduced to human HSC by retrovirus. • Human HSC with BLG-specific TCR were transplanted into NOG-HLA-DR4 I-A{sup −/−} mice. • BLG-specific TCR induced positive selection of thymocytes. • BLG-specific TCR positive CD4{sup +} T cells mediated immune responses in humanized mice. - Abstract: The development of severe immunodeficient mouse strains containing various human genes, including cytokines or HLA, has enabled the reconstitution of functional human immune systems after transplantation of human hematopoietic stem cells (HSC). Accumulating evidence has suggested that HLA-restricted antigen-specific human T-cell responses can be generated in these humanized mice. To directly monitor immune responses of human CD4{sup +} T cells, we introduced β-lactoglobulin (BLG)-specific T cell receptor (TCR) genes derived from CD4{sup +} T-cell clones of cow-milk allergy patients into HSCs, and subsequently transplanted them into NOG-HLA-DR4 transgenic/I-Aβ deficient mice (NOG-DR4/I-A{sup o}). In the thymus, thymocytes with BLG-specific TCR preferentially differentiated into CD4{sup +}CD8{sup −} single-positive cells. Adoptive transfer of mature CD4{sup +} T cells expressing the TCR into recipient NOG-DR4/I-A{sup o} mice demonstrated that human CD4{sup +} T cells proliferated in response to antigenic stimulation and produced IFN-γ in vivo, suggesting that functional T-cell reactions (especially Th1-skewed responses) were induced in humanized mice.

  16. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells

    Science.gov (United States)

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho

    2016-01-01

    Although CD4+ Foxp3+ T cells are largely described in the regulation of CD4+ T cell responses, their role in the suppression of CD8+ T cell priming is much less clear. Because the induction of CD8+ T cells during experimental infection with Trypanosoma cruzi is remarkably delayed and suboptimal, we raised the hypothesis that this protozoan parasite actively induces the regulation of CD8+ T cell priming. Using an in vivo assay that eliminated multiple variables associated with antigen processing and dendritic cell activation, we found that injection of bone marrow-derived dendritic cells exposed to T. cruzi induced regulatory CD4+ Foxp3+ T cells that suppressed the priming of transgenic CD8+ T cells by peptide-loaded BMDC. This newly described suppressive effect on CD8+ T cell priming was independent of IL-10, but partially dependent on CTLA-4 and TGF-β. Accordingly, depletion of Foxp3+ cells in mice infected with T. cruzi enhanced the response of epitope-specific CD8+ T cells. Altogether, our data uncover a mechanism by which T. cruzi suppresses CD8+ T cell responses, an event related to the establishment of chronic infections. PMID:27332899

  17. An MHC II-Dependent Activation Loop between Adipose Tissue Macrophages and CD4+ T Cells Controls Obesity-Induced Inflammation

    Directory of Open Access Journals (Sweden)

    Kae Won Cho

    2014-10-01

    Full Text Available An adaptive immune response triggered by obesity is characterized by the activation of adipose tissue CD4+ T cells by unclear mechanisms. We have examined whether interactions between adipose tissue macrophages (ATMs and CD4+ T cells contribute to adipose tissue metainflammation. Intravital microscopy identifies dynamic antigen-dependent interactions between ATMs and T cells in visceral fat. Mice deficient in major histocompatibility complex class II (MHC II showed protection from diet-induced obesity. Deletion of MHC II expression in macrophages led to an adipose tissue-specific decrease in the effector/memory CD4+ T cells, attenuation of CD11c+ ATM accumulation, and improvement in glucose intolerance by increasing adipose tissue insulin sensitivity. Ablation experiments demonstrated that the maintenance of proliferating conventional T cells is dependent on signals from CD11c+ ATMs in obese mice. These studies demonstrate the importance of MHCII-restricted signals from ATMs that regulate adipose tissue T cell maturation and metainflammation.

  18. Immunomodulatory Effects of Hemagglutinin- (HA- Modified A20 B-Cell Lymphoma Expanded as a Brain Tumor on Adoptively Transferred HA-Specific CD4+ T Cells

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    Valentin P. Shichkin

    2014-01-01

    Full Text Available Previously, the mouse A20 B-cell lymphoma engineered to express hemagglutinin (HA antigen (A20HA was used as a systemic tumor model. In this work, we used the A20HA cells as a brain tumor. HA-specific CD4+ T cells were transferred intravenously in a tail vein 5 days after A20HA intracranial inoculation and analyzed on days 2, 9, and 16 after the adoptive transfer by different methods. The transferred cells demonstrated state of activation as early as day 2 after the adoptive transfer and most the of viable HA-specific cells became anergic on day 16. Additionally, symptoms of systemic immunosuppression were observed in mice with massive brain tumors at a late stage of the brain tumor progression (days 20–24 after the A20HA inoculation. Despite that, a deal of HA-specific CD4+ T cells kept the functional activity even at the late stage of A20HA tumor growth. The activated HA-specific CD4+ T cells were found also in the brain of brain-tumor-bearing mice. These cells were still responding to reactivation with HA-peptide in vitro. Our data support an idea about sufficient role of both the tumor-specific and -nonspecific mechanisms inducing immunosuppression in cancer patients.

  19. HLA Class II Defects in Burkitt Lymphoma: Bryostatin-1-Induced 17 kDa Protein Restores CD4+ T-Cell Recognition

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    Azim Hossain

    2011-01-01

    Full Text Available While the defects in HLA class I-mediated Ag presentation by Burkitt lymphoma (BL have been well documented, CD4+ T-cells are also poorly stimulated by HLA class II Ag presentation, and the reasons underlying this defect(s have not yet been fully resolved. Here, we show that BL cells are deficient in their ability to optimally stimulate CD4+ T cells via the HLA class II pathway. The observed defect was not associated with low levels of BL-expressed costimulatory molecules, as addition of external co-stimulation failed to result in BL-mediated CD4+ T-cell activation. We further demonstrate that BL cells express the components of the class II pathway, and the defect was not caused by faulty Ag/class II interaction, because antigenic peptides bound with measurable affinity to BL-associated class II molecules. Treatment of BL with broystatin-1, a potent modulator of protein kinase C, led to significant improvement of functional class II Ag presentation in BL. The restoration of immune recognition appeared to be linked with an increased expression of a 17 kDa peptidylprolyl-like protein. These results demonstrate the presence of a specific defect in HLA class II-mediated Ag presentation in BL and reveal that treatment with bryostatin-1 could lead to enhanced immunogenicity.

  20. Establishment of reference CD4+ T cell values for adult Indian population

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    Ray Krishnangshu

    2011-10-01

    Full Text Available Abstract Background CD4+ T lymphocyte counts are the most important indicator of disease progression and success of antiretroviral treatment in HIV infection in resource limited settings. The nationwide reference range of CD4+ T lymphocytes was not available in India. This study was conducted to determine reference values of absolute CD4+ T cell counts and percentages for adult Indian population. Methods A multicentric study was conducted involving eight sites across the country. A total of 1206 (approximately 150 per/centre healthy participants were enrolled in the study. The ratio of male (N = 645 to female (N = 561 of 1.14:1. The healthy status of the participants was assessed by a pre-decided questionnaire. At all centers the CD4+ T cell count, percentages and absolute CD3+ T cell count and percentages were estimated using a single platform strategy and lyse no wash technique. The data was analyzed using the Statistical Package for the Social Scientist (SPSS, version 15 and Prism software version 5. Results The absolute CD4+ T cell counts and percentages in female participants were significantly higher than the values obtained in male participants indicating the true difference in the CD4+ T cell subsets. The reference range for absolute CD4 count for Indian male population was 381-1565 cells/μL and for female population was 447-1846 cells/μL. The reference range for CD4% was 25-49% for male and 27-54% for female population. The reference values for CD3 counts were 776-2785 cells/μL for Indian male population and 826-2997 cells/μL for female population. Conclusion The study used stringent procedures for controlling the technical variation in the CD4 counts across the sites and thus could establish the robust national reference ranges for CD4 counts and percentages. These ranges will be helpful in staging the disease progression and monitoring antiretroviral therapy in HIV infection in India.

  1. Human CD4-major histocompatibility complex class II (DQw6) transgenic mice in an endogenous CD4/CD8-deficient background: reconstitution of phenotype and human-restricted function

    OpenAIRE

    1994-01-01

    To reconstitute the human immune system in mice, transgenic mice expressing human CD4 and human major histocompatibility complex (MHC) class II (DQw6) molecules in an endogenous CD4- and CD8-deficient background (mCD4/8-/-), after homologous recombination, have been generated. We report that expression of human CD4 molecule in mCD4/8-/- mice rescues thymocyte development and completely restores the T cell compartment in peripheral lymphoid organs. Upon vesicular stomatitis virus (VSV) challen...

  2. Increased soluble CD4 in serum of rheumatoid arthritis patients is generated by matrix metalloproteinase (MMP-like proteinases.

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    Wen-Yi Tseng

    Full Text Available Higher soluble CD4 (sCD4 levels in serum have been detected in patients of infectious and chronic inflammatory diseases. However, how and why sCD4 is produced remains poorly understood. We establish sensitive ELISA and WB assays for sCD4 detection in conditioned medium of in vitro cell culture system and serum of chronic inflammatory patients. Serum samples from patients with systemic lupus erythematosus (SLE (n = 79, rheumatoid arthritis (RA (n = 59, ankylosing spondylitis (AS (n = 25, gout (n = 31, and normal controls (n = 99 were analyzed using ELISA for sCD4 detection. Results from each assay were analyzed by the Kruskal-Wallis test. Dunn's multiple comparison post-test was then applied between groups. We confirm that cells expressing exogenous CD4 produce sCD4 in a constitutive and PMA-induced manner. Importantly, sCD4 production in a heterologous expression system is inhibited by GM6001 and TAPI-0, suggesting receptor shedding by matrix metalloproteinase (MMP-like proteinases. Moreover, similar findings are recapitulated in human primary CD4(+ T cells. Finally, we show that serum sCD4 levels are increased in patients of chronic inflammatory diseases including RA and SLE, but not in those with gout. Intriguingly, sCD4 levels in RA patients are correlated positively with the disease activities and higher sCD4 levels seem to associate with poor prognosis. Taken together, we conclude that CD4 is shed from cell surface by a MMP-like sheddase and sCD4 level is closely related with the inflammatory condition in certain chronic diseases. Hence, sCD4 might be considered an important parameter for RA disease progression with potential diagnostic importance.

  3. Opioid growth factor and low-dose naltrexone impair central nervous system infiltration by CD4 + T lymphocytes in established experimental autoimmune encephalomyelitis, a model of multiple sclerosis.

    Science.gov (United States)

    Hammer, Leslie A; Waldner, Hanspeter; Zagon, Ian S; McLaughlin, Patricia J

    2016-01-01

    Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS), characterized by infiltrating myelin-reactive T lymphocytes and demyelinating lesions. Experimental autoimmune encephalomyelitis (EAE) is the animal model widely utilized to study MS. EAE is mediated by CD4(+) T cells and can be induced in EAE-susceptible mice through immunization with a myelin antigen, such as proteolipid protein 139-151 (PLP139-151) in SJL mice. In this PLP-induced EAE model, autoreactive CD4(+) T cells migrate from peripheral tissues into the CNS where they are reactivated resulting in CNS damage. Th1 and Th17 cells produce the pro-inflammatory cytokines IFNγ and IL-17, respectively, that have been shown to have pathogenic roles in EAE and MS. Anti-inflammatory Th2, IL-4 secreting cells, have been indicated to inhibit EAE exacerbation. However, given the inflammatory environment of EAE, Th2 effector cells are outnumbered by Th1/Th17 cells. Regulatory CD4(+) T cells suppress immune reactions and have been demonstrated to be dysfunctional in MS patients. Opioid growth factor (OGF), chemically termed [Met(5)]-enkephalin, is a negative growth factor that interacts with the OGF receptor. The OGF-OGFr axis can be activated through exogenous administration of OGF or a low dosage of naltrexone (LDN), an opioid antagonist. We have previously demonstrated that modulation of the OGF-OGFr axis results in alleviation from relapse-remitting EAE, and that CNS-infiltrating CD3(+) T cells are diminished with exogenous OGF or intermittent blockade with LDN administration. In this paper, we aimed to determine whether OGF or LDN alter the Th effector responses of CD4(+) T lymphocytes within the CNS in established EAE. We report in these studies that the numbers of CD4(+) T lymphocytes in the CNS of EAE mice are decreased following treatment with OGF for five days but not LDN. However, modulation of the OGF-OGFr axis did not result in changes to CD4(+) Th effector cell responses

  4. Increase in IFNγ(-IL-2(+ cells in recent human CD4 T cell responses to 2009 pandemic H1N1 influenza.

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    Jason M Weaver

    Full Text Available Human CD4 T cell recall responses to influenza virus are strongly biased towards Type 1 cytokines, producing IFNγ, IL-2 and TNFα. We have now examined the effector phenotypes of CD4 T cells in more detail, particularly focusing on differences between recent versus long-term, multiply-boosted responses. Peptides spanning the proteome of temporally distinct influenza viruses were distributed into pools enriched for cross-reactivity to different influenza strains, and used to stimulate antigen-specific CD4 T cells representing recent or long-term memory. In the general population, peptides unique to the long-circulating influenza A/New Caledonia/20/99 (H1N1 induced Th1-like responses biased toward the expression of IFNγ(+TNFα(+ CD4 T cells. In contrast, peptide pools enriched for non-cross-reactive peptides of the pandemic influenza A/California/04/09 (H1N1 induced more IFNγ(-IL-2(+TNFα(+ T cells, similar to the IFNγ(-IL-2(+ non-polarized, primed precursor T cells (Thpp that are a predominant response to protein vaccination. These results were confirmed in a second study that compared samples taken before the 2009 pandemic to samples taken one month after PCR-confirmed A/California/04/09 infection. There were striking increases in influenza-specific TNFα(+, IFNγ(+, and IL-2(+ cells in the post-infection samples. Importantly, peptides enriched for non-cross-reactive A/California/04/09 specificities induced a higher proportion of Thpp-like IFNγ(-IL-2(+TNFα(+ CD4 T cells than peptide pools cross-reactive with previous influenza strains, which induced more Th1 (IFNγ(+TNFα(+ responses. These IFNγ(-IL-2(+TNFα(+ CD4 T cells may be an important target population for vaccination regimens, as these cells are induced upon infection, may have high proliferative potential, and may play a role in providing future effector cells during subsequent infections.

  5. Preexisting CD4+ T-cell immunity in human population to avian influenza H7N9 virus: whole proteome-wide immunoinformatics analyses.

    Directory of Open Access Journals (Sweden)

    Venkata R Duvvuri

    Full Text Available In 2013, a novel avian influenza H7N9 virus was identified in human in China. The antigenically distinct H7N9 surface glycoproteins raised concerns about lack of cross-protective neutralizing antibodies. Epitope-specific preexisting T-cell immunity was one of the protective mechanisms in pandemic 2009 H1N1 even in the absence of cross-protective antibodies. Hence, the assessment of preexisting CD4+ T-cell immunity to conserved epitopes shared between H7N9 and human influenza A viruses (IAV is critical. A comparative whole proteome-wide immunoinformatics analysis was performed to predict the CD4+ T-cell epitopes that are commonly conserved within the proteome of H7N9 in reference to IAV subtypes (H1N1, H2N2, and H3N2. The CD4+ T-cell epitopes that are commonly conserved (∼ 556 were further screened against the Immune Epitope Database (IEDB to validate their immunogenic potential. This analysis revealed that 45.5% (253 of 556 epitopes are experimentally proven to induce CD4+ T-cell memory responses. In addition, we also found that 23.3% of CD4+ T-cell epitopes have ≥ 90% of sequence homology with experimentally defined CD8+ T-cell epitopes. We also conducted the population coverage analysis across different ethnicities using commonly conserved CD4+ T-cell epitopes and corresponding HLA-DRB1 alleles. Interestingly, the indigenous populations from Canada, United States, Mexico and Australia exhibited low coverage (28.65% to 45.62% when compared with other ethnicities (57.77% to 94.84%. In summary, the present analysis demonstrate an evidence on the likely presence of preexisting T-cell immunity in human population and also shed light to understand the potential risk of H7N9 virus among indigenous populations, given their high susceptibility during previous pandemic influenza events. This information is crucial for public health policy, in targeting priority groups for immunization programs.

  6. CD+4CD+25调节性T细胞与肿瘤的相关性研究%CD+4 CD+25 regulatory T cells and lung cancer

    Institute of Scientific and Technical Information of China (English)

    翟晋芳; 韩福才

    2009-01-01

    通过了解CD+4 CD+25调节性T细胞(CD+4 CD+25Treg)表面分子的特性和CD+4 CD+25Treg在外周血和组织中的表达,认识CD+4 CD+25 Treg在肿瘤免疫凋节中的作用,探索其作用的分子机制.%To know CD+4 CD+25 regulatory T cells' s function in tumor immunological regulation and to search for its functionary molecule mechanism by reviewing researches associated with the characteristics of CD+4 CD+25 regulatory T cells surface molecules and the expression of CD+4 CD+25 regulatory T cells in the peripheral blood and tissues.

  7. CD19 CAR–T cells of defined CD4+:CD8+ composition in adult B cell ALL patients

    Science.gov (United States)

    Turtle, Cameron J.; Hanafi, Laïla-Aïcha; Berger, Carolina; Gooley, Theodore A.; Cherian, Sindhu; Hudecek, Michael; Sommermeyer, Daniel; Melville, Katherine; Pender, Barbara; Budiarto, Tanya M.; Robinson, Emily; Steevens, Natalia N.; Chaney, Colette; Soma, Lorinda; Chen, Xueyan; Li, Daniel; Cao, Jianhong; Heimfeld, Shelly; Jensen, Michael C.; Riddell, Stanley R.; Maloney, David G.

    2016-01-01

    BACKGROUND. T cells that have been modified to express a CD19-specific chimeric antigen receptor (CAR) have antitumor activity in B cell malignancies; however, identification of the factors that determine toxicity and efficacy of these T cells has been challenging in prior studies in which phenotypically heterogeneous CAR–T cell products were prepared from unselected T cells. METHODS. We conducted a clinical trial to evaluate CD19 CAR–T cells that were manufactured from defined CD4+ and CD8+ T cell subsets and administered in a defined CD4+:CD8+ composition to adults with B cell acute lymphoblastic leukemia after lymphodepletion chemotherapy. RESULTS. The defined composition product was remarkably potent, as 27 of 29 patients (93%) achieved BM remission, as determined by flow cytometry. We established that high CAR–T cell doses and tumor burden increase the risks of severe cytokine release syndrome and neurotoxicity. Moreover, we identified serum biomarkers that allow testing of early intervention strategies in patients at the highest risk of toxicity. Risk-stratified CAR–T cell dosing based on BM disease burden decreased toxicity. CD8+ T cell–mediated anti-CAR transgene product immune responses developed after CAR–T cell infusion in some patients, limited CAR–T cell persistence, and increased relapse risk. Addition of fludarabine to the lymphodepletion regimen improved CAR–T cell persistence and disease-free survival. CONCLUSION. Immunotherapy with a CAR–T cell product of defined composition enabled identification of factors that correlated with CAR–T cell expansion, persistence, and toxicity and facilitated design of lymphodepletion and CAR–T cell dosing strategies that mitigated toxicity and improved disease-free survival. TRIAL REGISTRATION. ClinicalTrials.gov NCT01865617. FUNDING. R01-CA136551; Life Science Development Fund; Juno Therapeutics; Bezos Family Foundation. PMID:27111235

  8. Seroprevalence of Epstein-Barr virus among HIV positive patients moreover and its association with CD4 positive lymphocyte count.

    Science.gov (United States)

    Abdollahi, Alireza; Shoar, Saeed; Rasoulinejad, Mehrnaz; Sheikhbahaei, Sara

    2014-01-01

    Opportunistic infections are the leading cause of hospitalization and morbidity in human immunodeficiency virus (HIV) positive patients and are the most common cause of death between them. We aimed to measure IgG antibody against EBV viral capsid antigen (EBV-VCA IgG) to determine the seroprevalence of this infection in HIV-positive population. A case-control study between September 2011 and October 2012 was conducted in a teaching hospital enrolling 114 HIV-positive patients as case group and 114 healthy individuals as control with similar age and sex. Enzyme-linked immunosurbant assay (ELISA) technique was used for determination of EBV-VAC IgG in obtained samples. Of 114 serum samples obtained from HIV-positive patients, 103 (90.4%) samples were found positive for EBV-VCA IgG antibody. There was no significant difference in seroprevalence of EBV VCA IgG antibody between patients received antiretroviral therapy and naive patients (91.5% vs. 87.5%, P>0.05). There was no statistically significant difference in EBV-VCA IgG seroprevalence between three groups of CD4+ in HIV positive group. In conclusion current study showed that seroprevalence of EBV in HIV-positive patients is higher than HIV-negative healthy participants; however, administration of HAART and CD4+ lymphocyte count did not reveal a significant effect in seroprevalence of EBV. Due to the significance of this virus in mortality and morbidity and causing certain malignancies in patients with AIDS, these patients are strongly recommended to be tested for this virus.

  9. Seroprevalence of Epstein-Barr virus among HIV positive patients moreover and its association with CD4 positive lymphocyte count.

    Directory of Open Access Journals (Sweden)

    Alireza Abdollahi

    2014-12-01

    Full Text Available Opportunistic infections are the leading cause of hospitalization and morbidity in human immunodeficiency virus (HIV positive patients and are the most common cause of death between them. We aimed to measure IgG antibody against EBV viral capsid antigen (EBV-VCA IgG to determine the seroprevalence of this infection in HIV-positive population. A case-control study between September 2011 and October 2012 was conducted in a teaching hospital enrolling 114 HIV-positive patients as case group and 114 healthy individuals as control with similar age and sex. Enzyme-linked immunosurbant assay (ELISA technique was used for determination of EBV-VAC IgG in obtained samples. Of 114 serum samples obtained from HIV-positive patients, 103 (90.4% samples were found positive for EBV-VCA IgG antibody. There was no significant difference in seroprevalence of EBV VCA IgG antibody between patients received antiretroviral therapy and naive patients (91.5% vs. 87.5%, P>0.05. There was no statistically significant difference in EBV-VCA IgG seroprevalence between three groups of CD4+ in HIV positive group. In conclusion current study showed that seroprevalence of EBV in HIV-positive patients is higher than HIV-negative healthy participants; however, administration of HAART and CD4+ lymphocyte count did not reveal a significant effect in seroprevalence of EBV. Due to the significance of this virus in mortality and morbidity and causing certain malignancies in patients with AIDS, these patients are strongly recommended to be tested for this virus.

  10. Roscovitine suppresses CD4+ T cells and T cell-mediated experimental uveitis.

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    Zili Zhang

    Full Text Available BACKGROUND: T cells are essential for the development of uveitis and other autoimmune diseases. After initial activation, CD4+ lymphocytes express the co-stimulatory molecule OX40 that plays an important role in T cell proliferation. Cyclin dependent kinase 2 (CdK2 plays a pivotal role in the cell cycle transition from G1 to S phase. In addition, recent research has implicated CdK2 in T cell activation. Thus, we sought to test the immunosuppressive effect of roscovitine, a potent CdK2 inhibitor, on CD4+ T cell activation, proliferation, and function. DESIGN AND METHODS: Mouse CD4+ T cells were activated by anti-CD3 and anti-CD28 antibodies. The expression of OX40, CD44, and CdK2 were analyzed by flow cytometry. In addition, cell cycle progression and apoptosis of control and roscovitine-treated T lymphocytes were measured by BrdU incorporation and annexin V assay, respectively. Furthermore, the immunoregulatory effect of roscovitine was evaluated in both ovalbumin-induced uveitis and experimental autoimmune uveitis (EAU models. RESULTS: In this study, we found that T cell activation induced OX40 expression. Cell cycle analysis showed that more CD4+OX40+ cells entered S phase than OX40- T cells. Concurrently, CD4+OX40+ cells had a higher level of CdK2 expression. Roscovitine treatment blocked activated CD4+ cells from entering S phase. In addition, roscovitine not only reduced the viability of CD4+ lymphocytes but also suppressed T cell activation and cytokine production. Finally, roscovitine significantly attenuated the severity of T cell-dependent, OX40-enhanced uveitis. CONCLUSION: These results implicate CdK2 in OX40-augmented T cell response and expansion. Furthermore, this study suggests that roscovitine is a novel, promising, therapeutic agent for treating T cell-mediated diseases such as uveitis.

  11. TNFAIP3 promotes survival of CD4 T cells by restricting MTOR and promoting autophagy.

    Science.gov (United States)

    Matsuzawa, Yu; Oshima, Shigeru; Takahara, Masahiro; Maeyashiki, Chiaki; Nemoto, Yasuhiro; Kobayashi, Masanori; Nibe, Yoichi; Nozaki, Kengo; Nagaishi, Takashi; Okamoto, Ryuichi; Tsuchiya, Kiichiro; Nakamura, Tetsuya; Ma, Averil; Watanabe, Mamoru

    2015-01-01

    Autophagy plays important roles in metabolism, differentiation, and survival in T cells. TNFAIP3/A20 is a ubiquitin-editing enzyme that is thought to be a negative regulator of autophagy in cell lines. However, the role of TNFAIP3 in autophagy remains unclear. To determine whether TNFAIP3 regulates autophagy in CD4 T cells, we first analyzed Tnfaip3-deficient naïve CD4 T cells in vitro. We demonstrated that Tnfaip3-deficient CD4 T cells exhibited reduced MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) puncta formation, increased mitochondrial content, and exaggerated reactive oxygen species (ROS) production. These results indicate that TNFAIP3 promotes autophagy after T cell receptor (TCR) stimulation in CD4 T cells. We then investigated the mechanism by which TNFAIP3 promotes autophagy signaling. We found that TNFAIP3 bound to the MTOR (mechanistic target of rapamycin) complex and that Tnfaip3-deficient cells displayed enhanced ubiquitination of the MTOR complex and MTOR activity. To confirm the effects of enhanced MTOR activity in Tnfaip3-deficient cells, we analyzed cell survival following treatment with Torin1, an MTOR inhibitor. Tnfaip3-deficient CD4 T cells exhibited fewer cell numbers than the control cells in vitro and in vivo. In addition, the impaired survival of Tnfaip3-deficient cells was ameliorated with Torin1 treatment in vitro and in vivo. The effect of Torin1 was abolished by Atg5 deficiency. Thus, enhanced MTOR activity regulates the survival of Tnfaip3-deficient CD4 T cells. Taken together, our findings illustrate that TNFAIP3 restricts MTOR signaling and promotes autophagy, providing new insight into the manner in which MTOR and autophagy regulate survival in CD4 T cells.

  12. Quorum sensing in CD4+ T cell homeostasis: a hypothesis and a model.

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    Afonso R.M. Almeida

    2012-05-01

    Full Text Available Homeostasis of lymphocyte numbers is believed to be due to competition between cellular populations for a common niche of restricted size, defined by the combination of interactions and trophic factors required for cell survival. Here we propose a new mechanism: homeostasis of lymphocyte numbers could also be achieved by the ability of lymphocytes to perceive the density of their own populations. Such a mechanism would be reminiscent of the primordial quorum sensing systems used by bacteria, in which some bacteria sense the accumulation of bacterial metabolites secreted by other elements of the population, allowing them to count the number of cells present and adapt their growth accordingly. We propose that homeostasis of CD4+ T cell numbers may occur via a quorum-sensing-like mechanism, where IL-2 is produced by activated CD4+ T cells and sensed by a population of CD4+ Treg cells that expresses the high-affinity IL-2Rα-chain and can regulate the number of activated IL-2-producing CD4+ T cells and the total CD4+T cell population. In other words, CD4+ T cell populations can restrain their growth by monitoring the number of activated cells, thus preventing uncontrolled lymphocyte proliferation during immune responses. We hypothesize that malfunction of this quorum-sensing mechanism may lead to uncontrolled T cell activation and autoimmunity. Finally, we present a mathematical model that describes the role of IL-2 and quorum-sensing mechanisms in CD4+ T cell homeostasis during an immune response.

  13. Cooperativity of HIV-Specific Cytolytic CD4 T Cells and CD8 T Cells in Control of HIV Viremia

    OpenAIRE

    Johnson, Susan; Eller, Michael; Teigler, Jeffrey E.; Maloveste, Sebastien M.; Schultz, Bruce T.; Soghoian, Damien Z.; Lu, Richard; Oster, Alexander F.; Chenine, Agnès-Laurence; Alter, Galit; Dittmer, Ulf; Marovich, Mary; Merlin L Robb; Michael, Nelson L.; Bolton, Diane

    2015-01-01

    CD4+ T cells play a pivotal role in the control of chronic viral infections. Recently, nontraditional CD4+ T cell functions beyond helper effects have been described, and a role for cytolytic CD4+ T cells in the control of HIV infection has been suggested. We define here the transcriptional, phenotypic, and functional profiles of HIV-specific cytolytic CD4+ T cells. Fluidigm BioMark and multiparameter flow cytometric analysis of HIV-specific cytolytic CD4+ T cells revealed a distinct transcri...

  14. Neonatal bacillus Calmette-Guerin vaccination inhibits de novo allergic inflammatory response in mice via alteration of CD4+CD25+T-regulatory cells

    Institute of Scientific and Technical Information of China (English)

    Qian LI; Hua-hao SHEN

    2009-01-01

    Aim: The hygiene hypothesis suggests a lack of bacterial infections would favor the development of allergic diseases. My-cobacterium bovis bacille Calmette-Guerin (BCG) infection can inhibit allergen-induced asthma reactions, but the underly-hag mechanism of this infection on the immunological responses is unclear. T-regulatory (Treg) cells are thought to play a role as a crucial immunoregulatory cells that are capable of regulating adaptive immune responses. We conducted this study to investigate whether the protective effect of the BCG vaccination on allergic pulmonary inflammation is associated with the alteration of CD4+CD25+ Treg cells in a murine asthma model and the mechanisms of Treg cells. Methods: Newborn C57BL/6 mice were vaccinated 3 times with BCG on d 0, 7, and 14 and subsequently sensitized and challenged with ovalbumin. Eosinophil infiltration was investigated. The frequencies of spleen CD4+CD25+ Treg cells and the expression of specific transcriptional factor Foxp3 were assayed. The cytotoxic lymphocyte associated antigen (CTLA)-4 expression and cytokine interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) levels were measured. Results: We showed that treatment of mice with BCG inhibited de novo allergic inflammatory response in a mouse model of asthma. BCG treatments are associated with the increase of CD4+CD25+ Treg cells and Foxp3 expression, accompanied by an increased CTLA-4 expression and cytokine IL-10 and TGF-β levels (P<0.05). Conclusion: Neonatal BCG vaccinations ameliorate de novo local eosinophilic inflammation induced by allergen and in-crease the numbers of CD4+CD25+ Treg cells and Foxp3 expression. The cell-cell contact inhibition and regulatory cytokine production may be involved in the regulatory mechanism.

  15. Infection with host-range mutant adenovirus 5 suppresses innate immunity and induces systemic CD4+ T cell activation in rhesus macaques.

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    Huma Qureshi

    Full Text Available Ad5 is a common cause of respiratory disease and an occasional cause of gastroenteritis and conjunctivitis, and seroconversion before adolescence is common in humans. To gain some insight into how Ad5 infection affects the immune system of rhesus macaques (RM 18 RM were infected with a host-range mutant Ad5 (Ad5hr by 3 mucosal inoculations. There was a delay of 2 to 6 weeks after the first inoculation before plasmacytoid dendritic cell (pDC frequency and function increased in peripheral blood. Primary Ad5hr infection suppressed IFN-γ mRNA expression, but the second Ad5hr exposure induced a rapid increase in IFN-gamma mRNA in peripheral blood mononuclear cells (PBMC. Primary Ad5hr infection suppressed CCL20, TNF and IL-1 mRNA expression in PBMC, and subsequent virus exposures further dampened expression of these pro-inflammatory cytokines. Primary, but not secondary, Ad5hr inoculation increased the frequency of CXCR3+ CD4+ T cells in blood, while secondary, but not primary, Ad5hr infection transiently increased the frequencies of Ki67+, HLADR+ and CD95+/CCR5+ CD4+ T cells in blood. Ad5hr infection induced polyfunctional CD4 and CD8+ T cells specific for the Ad5 hexon protein in all of the animals. Thus, infection with Ad5hr induced a complex pattern of innate and adaptive immunity in RM that included transient systemic CD4+ T cell activation and suppressed innate immunity on re-exposure to the virus. The complex effects of adenovirus infection on the immune system may help to explain the unexpected results of testing Ad5 vector expressing HIV antigens in Ad5 seropositive people.

  16. Selective Loss of Innate CD4+ Vα24 Natural Killer T Cells in Human Immunodeficiency Virus Infection

    Science.gov (United States)

    Sandberg, Johan K.; Fast, Noam M.; Palacios, Emil H.; Fennelly, Glenn; Dobroszycki, Joanna; Palumbo, Paul; Wiznia, Andrew; Grant, Robert M.; Bhardwaj, Nina; Rosenberg, Michael G.; Nixon, Douglas F.

    2002-01-01

    Vα24 natural killer T (NKT) cells are innate immune cells involved in regulation of immune tolerance, autoimmunity, and tumor immunity. However, the effect of human immunodeficiency virus type 1 (HIV-1) infection on these cells is unknown. Here, we report that the Vα24 NKT cells can be subdivided into CD4+ or CD4− subsets that differ in their expression of the homing receptors CD62L and CD11a. Furthermore, both CD4+ and CD4− NKT cells frequently express both CXCR4 and CCR5 HIV coreceptors. We find that the numbers of NKT cells are reduced in HIV-infected subjects with uncontrolled viremia and marked CD4+ T-cell depletion. The number of CD4+ NKT cells is inversely correlated with HIV load, indicating depletion of this subset. In contrast, CD4− NKT-cell numbers are unaffected in subjects with high viral loads. HIV infection experiments in vitro show preferential depletion of CD4+ NKT cells relative to regular CD4+ T cells, in particular with virus that uses the CCR5 coreceptor. Thus, HIV infection causes a selective loss of CD4+ lymph node homing (CD62L+) NKT cells, with consequent skewing of the NKT-cell compartment to a predominantly CD4− CD62L− phenotype. These data indicate that the key immunoregulatory NKT-cell compartment is compromised in HIV-1-infected patients. PMID:12097565

  17. CD4(+)CD25 (+)CD127 (low/-) T cells: a more specific Treg population in human peripheral blood.

    Science.gov (United States)

    Yu, Ning; Li, Xiaomei; Song, Weiya; Li, Dongmei; Yu, Daliang; Zeng, Xiaofeng; Li, Mengtao; Leng, Xiaomei; Li, Xiangpei

    2012-12-01

    The quantitative identification and enrichment of viable regulatory T cells (Treg) requires reliable surface markers that are selectively expressed on Treg. Foxp3 is the accepted marker of nTreg, but it cannot be used to isolate cells for functional studies. In this study, we compared four staining profiles of Treg, including CD4(+)CD25(high) T cells, CD4(+)CD39(+) T cells, CD4(+)CD73(+) T cells, and CD4(+)CD25(+)CD127(low/-) T cells. We found that CD4(+)CD25(+)CD127(low/-) T cells expressed the highest level of Foxp3 and had the strongest correlation with CD4(+)CD25(+)Foxp3(+) T cells, the accepted identifying characteristics for "real" nTreg cells. Moreover, functional data showed that CD4(+)CD25(+)CD127(low/-) T cells could effectively suppress the proliferation of CD4(+)CD25(-) T cells, suggesting that compared with the other three populations, CD4(+)CD25(+)CD127(low/-) T cells best fit the definition of naturally occurring regulatory T cells in human peripheral blood. Finally, we showed that CD4(+)CD25(+)CD127(low/-) can be used to quantitate Treg cells in individuals with systemic lupus erythematosus supporting the use of CD4(+)CD25(+)CD127(low/-) to identify human Treg cells. PMID:22752562

  18. Improving therapeutic HPV peptide-based vaccine potency by enhancing CD4+ T help and dendritic cell activation

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    Hung Chien-Fu

    2010-11-01

    Full Text Available Abstract Background Effective vaccination against human papillomavirus (HPV represents an opportunity to control cervical cancer. Peptide-based vaccines targeting HPV E6 and/or E7 antigens while safe, will most likely require additional strategies to enhance the vaccine potency. Methods We tested the HPV-16 E7 peptide-based vaccine in combination with a strategy to enhance CD4+ T help using a Pan HLA-DR epitope (PADRE peptide and a strategy to enhance dendritic cell activation using the toll-like receptor 3 ligand, poly(I:C. Results We observed that mice vaccinated with E7 peptide-based vaccine in combination with PADRE peptide and poly(I:C generated better E7-specific CD8+ T cell immune responses as well as significantly improved therapeutic anti-tumor effects against TC-1 tumors compared to E7 peptide-based vaccine with either PADRE peptide or poly(I:C alone. Furthermore, we found that intratumoral vaccination with the E7 peptide in conjunction with PADRE peptide and poly(I:C generates a significantly higher frequency of E7-specific CD8+ T cells as well as better survival compared to subcutaneous vaccination with the same regimen in treated mice. Conclusions The combination of PADRE peptide and poly(I:C with antigenic peptide is capable of generating potent antigen-specific CD8+ T cell immune responses and antitumor effects in vaccinated mice. Our study has significant clinical implications for peptide-based vaccination.

  19. Access to CD4 Testing for Rural HIV Patients: Findings from a Cohort Study in Zimbabwe.

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    Florian Vogt

    Full Text Available CD4 cell count measurement remains an important diagnostic tool for HIV care in developing countries. Insufficient laboratory capacity in rural Sub-Saharan Africa is frequently mentioned but data on the impact at an individual patient level are lacking. Urban-rural discrepancies in CD4 testing have not been quantified to date. Such evidence is crucial for public health planning and to justify new yet more expensive diagnostic procedures that could circumvent access constraints in rural areas.To compare CD4 testing among rural and urban HIV patients during the first year of treatment.Records from 2,145 HIV positive adult patients from a Médecins sans Frontières (Doctors without Borders HIV project in Beitbridge, Zimbabwe, during 2011 and 2012 were used for a retrospective cohort analysis. Covariate-adjusted risk ratios were calculated to estimate the effects of area of residence on CD4 testing at treatment initiation, six and 12 months among rural and urban patients.While the proportion of HIV patients returning for medical consultations at six and 12 months decreased at a similar rate in both patient groups, CD4 testing during consultations dropped to 21% and 8% for urban, and 2% and 1% for rural patients at six and 12 months, respectively. Risk ratios for missing CD4 testing were 0.8 (95% CI 0.7-0.9, 9.2 (95% CI 5.5-15.3, and 7.6 (95% 3.7-17.1 comparing rural versus urban patients at treatment initiation, six and 12 months, respectively.CD4 testing was low overall, and particularly poor in rural patients. Difficulties with specimen transportation were probably a major factor underlying this difference and requires new diagnostic approaches. Our findings point to severe health system constraints in providing CD4 testing overall that need to be addressed if effective monitoring of HIV patients is to be achieved, whether by alternative CD4 diagnostics or newly-recommended routine viral load testing.

  20. The effect of CD4 receptor downregulation and its downstream signaling molecules on HIV-1 latency

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyung-Chang [National Institute of Health, Chungbuk (Korea, Republic of); School of Life Science and Biotechnology, Korea University, Seoul (Korea, Republic of); Kim, Hyeon Guk [National Institute of Health, Chungbuk (Korea, Republic of); Roh, Tae-Young [Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Gyeongbuk (Korea, Republic of); Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, Gyeongbuk (Korea, Republic of); Park, Jihwan [Division of Molecular and Life Science, Pohang University of Science and Technology, Pohang, Gyeongbuk (Korea, Republic of); Jung, Kyung-Min; Lee, Joo-Shil [National Institute of Health, Chungbuk (Korea, Republic of); Choi, Sang-Yun [School of Life Science and Biotechnology, Korea University, Seoul (Korea, Republic of); Kim, Sung Soon [National Institute of Health, Chungbuk (Korea, Republic of); Choi, Byeong-Sun, E-mail: byeongsun@korea.kr [National Institute of Health, Chungbuk (Korea, Republic of)

    2011-01-14

    Research highlights: {yields} CD4 receptors were downregulated on the surface of HIV-1 latently infected cells. {yields} CD4 downstream signaling molecules were suppressed in HIV-1 latently infected cells. {yields} HIV-1 progeny can be reactivated by induction of T-cell activation signal molecules. {yields} H3K4me3 and H3K9ac were highly enriched in CD4 downstream signaling molecules. {yields} HIV-1 latency can be maintained by the reduction of downstream signaling molecules. -- Abstract: HIV-1 can establish a latent infection in memory CD4 + T cells to evade the host immune response. CD4 molecules can act not only as the HIV-1 receptor for entry but also as the trigger in an intracellular signaling cascade for T-cell activation and proliferation via protein tyrosine kinases. Novel chronic HIV-1-infected A3.01-derived (NCHA) cells were used to examine the involvement of CD4 downstream signaling in HIV-1 latency. CD4 receptors in NCHA cells were dramatically downregulated on its surface but were slightly decreased in whole-cell lysates. The expression levels of CD4 downstream signaling molecules, including P56{sup Lck}, ZAP-70, LAT, and c-Jun, were sharply decreased in NCHA cells. The lowered histone modifications of H3K4me3 and H3K9ac correlated with the downregulation of P56{sup Lck}, ZAP-70, and LAT in NCHA cells. AP-1 binding activity was also reduced in NCHA cells. LAT and c-Jun suppressed in NCHA cells were highly induced after PMA treatment. In epigenetic analysis, other signal transduction molecules which are associated with active and/or latent HIV-1 infection showed normal states in HIV-1 latently infected cells compared to A3.01 cells. In conclusion, we demonstrated that the HIV-1 latent state is sustained by the reduction of downstream signaling molecules via the downregulation of CD4 and the attenuated activity of transcription factor as AP-1. The HIV-1 latency model via T-cell deactivation may provide some clues for the development of the new

  1. Computational modeling of heterogeneity and function of CD4+ T cells

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    Adria eCarbo

    2014-07-01

    Full Text Available The immune system is composed of many different cell types and hundreds of intersecting molecular pathways and signals. This large biological complexity requires coordination between distinct pro-inflammatory and regulatory cell subsets to respond to infection while maintaining tissue homeostasis. CD4+ T cells play a central role in orchestrating immune responses and in maintaining a balance between pro- and anti- inflammatory responses. This tight balance between regulatory and effector reactions depends on the ability of CD4+ T cells to modulate distinct pathways within large molecular networks, since dysregulated CD4+ T cell responses may result in chronic inflammatory and autoimmune diseases. The CD4+ T cell differentiation process comprises an intricate interplay between cytokines, their receptors, adaptor molecules, signaling cascades and transcription factors that help delineate cell fate and function. Computational modeling can help to describe, simulate, analyze, and predict some of the behaviors in this complicated differentiation network. This review provides a comprehensive overview of existing computational immunology methods as well as novel strategies used to model immune responses with a particular focus on CD4+ T cell differentiation.

  2. Specific interaction of aurintricarboxylic acid with the human immunodeficiency virus/CD4 cell receptor

    Energy Technology Data Exchange (ETDEWEB)

    Schols, D.; Baba, M.; Pauwels, R.; Desmyter, J.; De Clercq, E. (Katholieke Universiteit Leuven (Belgium))

    1989-05-01

    The triphenylmethane derivative aurintricarboxylic acid (ATA), but not aurin, selectively prevented the binding of OKT4A/Leu-3a monoclonal antibody (mAb) and, to a lesser extent, OKT4 mAb to the CD4 cell receptor for human immunodeficiency virus type 1 (HIV-1). The effect was seen within 1 min at an ATA concentration of 10 {mu}M in various T4{sup +} cells (MT-4, U-937, peripheral blood lymphocytes, and monocytes). It was dose-dependent and reversible. ATA prevented the attachment of radiolabeled HIV-1 particles to MT-4 cells, which could be expected as the result of its specific binding to the HIV/CD4 receptor. Other HIV inhibitors such as suramin, fuchsin acid, azidothymidine, dextran sulfate, heparin, and pentosan polysulfate did not affect OKT4A/Leu-3a mAb binding to the CD4 receptor, although the sulfated polysaccharides suppressed HIV-1 adsorption to the cells at concentrations required for complete protection against HIV-1 cytopathogenicity. Thus, ATA is a selective marker molecule for the CD4 receptor. ATA also interfered with the staining of membrane-associated HIV-1 glycoprotein gp120 by a mAb against it. These unusual properties of a small molecule of nonimmunological origin may have important implications for the study of CD4/HIV/AIDS pathogenesis and possibly treatment.

  3. Role of distinct CD4(+) T helper subset in pathogenesis of oral lichen planus.

    Science.gov (United States)

    Wang, Hui; Zhang, Dunfang; Han, Qi; Zhao, Xin; Zeng, Xin; Xu, Yi; Sun, Zheng; Chen, Qianming

    2016-07-01

    Oral lichen planus (OLP) is one of the most common chronic inflammatory oral mucosal diseases with T-cell-mediated immune pathogenesis. In subepithelial and lamina propria of OLP local lesions, the presence of CD4(+) T helper (CD4(+) Th) cells appeared as the major lymphocytes. These CD4(+) T lymphocytes can differentiate into distinct Th cell types such as Th1, Th2, Treg, Th17, Th22, Th9, and Tfh within the context of certain cytokines environment. Growing evidence indicated that Th1/Th2 imbalance may greatly participate into the cytokine network of OLP immunopathology. In addition, Th1/Th2 imbalance can be regulated by the Treg subset and also greatly influenced by the emerging novel CD4(+) Th subset Th17. Furthermore, the presence of novel subsets Th22, Th9 and Tfh in OLP patients is yet to be clarified. All these Th subsets and their specific cytokines may play a critical role in determining the character, extent and duration of immune responses in OLP pathogenesis. Therefore, we review the roles of distinct CD4(+) Th subsets and their signature cytokines in determining disease severity and susceptibility of OLP and also reveal the novel therapeutic strategies based on T lymphocytes subsets in OLP treatment. PMID:26693958

  4. Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection

    Science.gov (United States)

    Doitsh, Gilad; Galloway, Nicole L. K.; Geng, Xin; Yang, Zhiyuan; Monroe, Kathryn M.; Zepeda, Orlando; Hunt, Peter W.; Hatano, Hiroyu; Sowinski, Stefanie; Muñoz-Arias, Isa; Greene, Warner C.

    2014-01-01

    The pathway causing CD4 T-cell death in HIV-infected hosts remains poorly understood although apoptosis has been proposed as a key mechanism. We now show that caspase-3-mediated apoptosis accounts for the death of only a small fraction of CD4 T cells corresponding to those that are both activated and productively infected. The remaining over 95% of quiescent lymphoid CD4 T cells die by caspase-1-mediated pyroptosis triggered by abortive viral infection. Pyroptosis corresponds to an intensely inflammatory form of programmed cell death in which cytoplasmic contents and pro-inflammatory cytokines, including IL-1β, are released. This death pathway thus links the two signature events in HIV infection--CD4 T-cell depletion and chronic inflammation--and creates a pathogenic vicious cycle in which dying CD4 T cells release inflammatory signals that attract more cells to die. This cycle can be broken by caspase 1 inhibitors shown to be safe in humans, raising the possibility of a new class of `anti-AIDS' therapeutics targeting the host rather than the virus.

  5. The Fc and not CD4 Receptor Mediates Antibody Enhancement of HIV Infection in Human Cells

    Science.gov (United States)

    Homsy, Jacques; Meyer, Mia; Tateno, Masatoshi; Clarkson, Sarah; Levy, Jay A.

    1989-06-01

    Antibodies that enhance human immunodeficiency virus (HIV) infectivity have been found in the blood of infected individuals and in infected or immunized animals. These findings raise serious concern for the development of a safe vaccine against acquired immunodeficiency syndrome. To address the in vivo relevance and mechanism of this phenomenon, antibody-dependent enhancement of HIV infectivity in peripheral blood macrophages, lymphocytes, and human fibroblastoid cells was studied. Neither Leu3a, a monoclonal antibody directed against the CD4 receptor, nor soluble recombinant CD4 even at high concentrations prevented this enhancement. The addition of monoclonal antibody to the Fc receptor III (anti-FcRIII), but not of antibodies that react with FcRI or FcRII, inhibited HIV type 1 and HIV type 2 enhancement in peripheral blood macrophages. Although enhancement of HIV infection in CD4+ lymphocytes could not be blocked by anti-FcRIII, it was inhibited by the addition of human immunoglobulin G aggregates. The results indicate that the FcRIII receptor on human macrophages and possibly another Fc receptor on human CD4+ lymphocytes mediate antibody-dependent enhancement of HIV infectivity and that this phenomenon proceeds through a mechanism independent of the CD4 protein.

  6. Immune activation induces immortalization of HTLV-1 LTR-Tax transgenic CD4+ T cells.

    Science.gov (United States)

    Swaims, Alison Y; Khani, Francesca; Zhang, Yingyu; Roberts, Arthur I; Devadas, Satish; Shi, Yufang; Rabson, Arnold B

    2010-10-21

    Infection with the human T-cell leukemia virus-1 (HTLV-1) results in a variety of diseases including adult T-cell leukemia/lymphoma (ATL). Although the pathogenesis of these disorders is poorly understood, it involves complex interactions with the host immune system. Activation of infected T cells may play an important role in disease pathogenesis through induction of the oncogenic HTLV-1 Tax transactivator protein. To test this hypothesis, we employed transgenic mice in which Tax is regulated by the HTLV-1 LTR. T-cell receptor stimulation of LTR-Tax CD4(+) T cells induced Tax expression, hyper-proliferation, and immortalization in culture. The transition to cellular immortalization was accompanied by markedly increased expression of the antiapoptotic gene, mcl-1, previously implicated as important in T-cell survival. Immortalized cells exhibited a CD4(+)CD25(+)CD3(-) phenotype commonly observed in ATL. Engraftment of activated LTR-Tax CD4(+) T cells into NOD/Shi-scid/IL-2Rγ null mice resulted in a leukemia-like phenotype with expansion and tissue infiltration of Tax(+), CD4(+) lymphocytes. We suggest that immune activation of infected CD4(+) T cells plays an important role in the induction of Tax expression, T-cell proliferation, and pathogenesis of ATL in HTLV-1-infected individuals. PMID:20634377

  7. Homeostatic properties and phenotypic maturation of murine CD4+ pre-thymic emigrants in the thymus.

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    Jie Dong

    Full Text Available After a tightly regulated developmental program in the thymus, "mature" single positive (SP thymocytes leave the thymus and enter the periphery. These newly arrived recent thymic emigrants (RTEs are phenotypically and functionally immature, and will complete a dynamic maturation in the peripheral lymphoid organs before being licensed to be resident naïve T cells. To study the early events occurring in the RTE maturation process, we identified the phenotype of CD4(+ pre-RTEs, a population of CD4(+ SP thymocytes that have acquired the thymus egress capability. Compared to peripheral naïve T cells, CD4(+ pre-RTEs displayed superior survival capability in lymphoreplete mice and faster proliferation under lymphopenic condition. The differences in Bcl2/Bim expression and/or heightened IL-7 signaling pathway may account for the pre-RTEs' better responsiveness to homeostatic signals. Qa2, the expression of which indicates the phenotypic maturation of SPs and RTEs, was found to be upregulated in CD4(+ pre-RTEs in thymic perivascular space. Migratory dendritic cells that surround this region contribute to Qa2 expression in pre-RTEs. The dendritic cell-driven Qa2 induction of CD4(+ pre-RTEs is independent of MHC class II and Aire molecules.

  8. World Health Organization guidelines should not change the CD4 count threshold for antiretroviral therapy initiation

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    Nathan Geffen

    2013-03-01

    Full Text Available The World Health Organization (WHO currently recommends that HIV-positive adults start antiretroviral therapy (ART at CD4 counts <350 cells/μl. Several countries have changed their guidelines to recommend ART irrespective of CD4 count or at a threshold of 500 CD4 cells/μl. Consequently, WHO is currently revising its treatment guidelines and considering recommending ART initiation at CD4 counts <500 cells/μl. Such decisions are critically important, as WHO guidelines inform healthcare policies in developing countries and are used by activists in their advocacy work. Changing the CD4 initiation point from 350 to 500 cells/μl would, however, be premature and have profound cost implications on Global Fund, President’s Emergency Plan for AIDS Relief (PEPFAR and developing country health budgets. We should be willing to campaign for such a change in guidelines despite cost implications, if supported by evidence. However, the evidence remains outstanding. S Afr J HIV Med 2013;14(1:6-7. DOI:10.7196/SAJHIVMED.906

  9. Effects of BCG-polysaccharide nucleic acid on CD4+IL-17+ T cells and CD4+Foxp3+ Treg in asthmatic rats%卡介苗多糖核酸对哮喘大鼠CD4+IL-17+T细胞与CD4+Foxp3+调节性T细胞的影响

    Institute of Scientific and Technical Information of China (English)

    涂玲; 梁颖红; 魏明; 刘佳; 龚艳杰; 张俊华; 张宜花

    2015-01-01

    目的 观察卡介苗多糖核酸(BCG-PSN)对哮喘大鼠支气管肺泡灌洗液(BALF)、外周血和淋巴液中CD4+IL-17+T细胞(CD4+IL-17+T)与CD4+Foxp3+调节性T细胞(CD4+Foxp3+ Treg)百分比及IL-10、IL-17水平的影响及其可能机制.方法 SD大鼠60只随机分为对照组(n=15)、哮喘组(n=15)、BCG-PSN干预对照组(n=15)和BCG-PSN干预哮喘组(n=15).哮喘组和BCG-PSN干预哮喘组使用卵白蛋白建立大鼠哮喘模型,对照组和BCG-PSN干预对照组以等量生理盐水代替卵白蛋白,BCG-PSN干预哮喘组和BCG-PSN干预对照组均使用BCG-PSN进行干预.收集各组大鼠BALF、外周血和淋巴液,采用流式细胞术检测CD4+IL-17+T和CD4+Foxp3+ Treg百分比,酶联免疫吸附法(ELISA)检测IL-10和IL-17水平.结果 各组大鼠淋巴液中CD4+Foxp3+ Treg百分比、IL-10水平较BALF和外周血均明显升高(均P<0.01),CD4+IL-17+T百分比、IL-17水平较BALF和外周血均明显下降(均P<0.01).哮喘组大鼠BALF、淋巴液和外周血CD4+Foxp3+ Treg百分比、IL-10水平较其余3组均显著降低,而CD4+IL-17+T百分比、IL-17水平较其余3组均显著升高(均P<0.01).BCG-PSN干预哮喘组大鼠BALF、淋巴液和外周血CD4+Foxp3+ Treg百分比和IL-10水平较哮喘组显著升高(均P<0.01),与对照组和BCG-PSN干预对照组比较差异无统计学意义(均P>0.05).BCG-PSN干预哮喘组大鼠BALF、淋巴液和外周血CD4+IL-17+T细胞百分比、IL-17水平较哮喘组均显著下降(均P<0.01),与对照组和BCG-PSN干预对照组比较差异无统计学意义(P>0.05).结论 BCG-PSN可能通过调节哮喘大鼠外周血和淋巴液中CD4+Foxp3+ Treg和CD4+IL-17+T的百分比及相关细胞因子水平,改善机体免疫功能,从而减轻哮喘的炎性反应.%Objective To investigate the effect of BCG-polysaccharide nucleic acid (BCG-PSN) on the levels of CD4+IL-17+ T cells and CD4+Foxp3+ regulatory T cells(Treg),interleukin-10 (IL-10) and IL-17 in bronchoalveolar

  10. Correlation of memory T cell responses against TRAP with protection from clinical malaria, and CD4 CD25 high T cells with susceptibility in Kenyans.

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    Stephen M Todryk

    Full Text Available BACKGROUND: Immunity to malaria develops naturally in endemic regions, but the protective immune mechanisms are poorly understood. Many vaccination strategies aim to induce T cells against diverse pre-erythrocytic antigens, but correlates of protection in the field have been limited. The objective of this study was to investigate cell-mediated immune correlates of protection in natural malaria. Memory T cells reactive against thrombospondin-related adhesive protein (TRAP and circumsporozoite (CS protein, major vaccine candidate antigens, were measured, as were frequencies of CD4(+ CD25(high T cells, which may suppress immunity, and CD56(+ NK cells and gammadelta T cells, which may be effectors or may modulate immunity. METHODOLOGY AND PRINCIPAL FINDINGS: 112 healthy volunteers living in rural Kenya were entered in the study. Memory T cells reactive against TRAP and CS were measured using a cultured IFNgamma ELISPOT approach, whilst CD4(+ CD25(high T cells, CD56(+ NK cells, and gammadelta T cells were measured by flow cytometry. We found that T cell responses against TRAP were established early in life (<5 years in contrast to CS, and cultured ELISPOT memory T cell responses did not correlate with ex-vivo IFNgamma ELISPOT effector responses. Data was examined for associations with risk of clinical malaria for a period of 300 days. Multivariate logistic analysis incorporating age and CS response showed that cultured memory T cell responses against TRAP were associated with a significantly reduced incidence of malaria (p = 0.028. This was not seen for CS responses. Higher numbers of CD4(+ CD25(high T cells, potentially regulatory T cells, were associated with a significantly increased risk of clinical malaria (p = 0.039. CONCLUSIONS: These data demonstrate a role for central memory T cells in natural malarial immunity and support current vaccination strategies aimed at inducing durable protective T cell responses against the TRAP antigen. They also

  11. Dynamic transcription of long non-coding RNA genes during CD4+ T cell development and activation.

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    Fei Xia

    Full Text Available BACKGROUND: Recent evidence shows that long non-coding RNA (LncRNA play important regulatory roles in many biology process, including cell development, activation and oncogenesis. However, the roles of these LncRNAs in the development and activation of CD4+ T cells, which is an important component of immune response, remain unknown. RESULTS: To predict the function of LncRNA in the development and activation of CD4+ T cells, first, we examined the expression profiles of LncRNAs and mRNAs in CD4-CD8- (DN, CD4+CD8+ (DP, CD4+CD8-, and activated CD4+CD8- T cells in a microarray analysis and verified these results by real time PCRs (qPCR. We found that the expression of hundreds of LncRNAs significantly changed in each process of developmental transition, including DN into DP, DP into CD4+CD8-, and CD4+CD8- into activated CD4+ T cells. A Kendall distance analysis suggested that the expression of LncRNAs in DN, DP, CD4+CD8- T cells and activated CD4+ T cells were correlated with the expression of mRNAs in these T cells. The Blat algorithm and GO analysis suggested that LncRNAs may exert important roles in the development and activation of CD4+ T cells. These roles included proliferation, homeostasis, maturation, activation, migration, apoptosis and calcium ion transportation. CONCLUSION: The present study found that the expression profiles of LncRNAs in different stages of CD4+ T cells are distinguishable. LncRNAs are involved in the key biological process in CD4+ T cell development and activation.

  12. CD4+ T Cell Depletion in Human Immunodeficiency Virus (HIV Infection: Role of Apoptosis

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    Angelita Rebollo

    2011-05-01

    Full Text Available Human immunodeficiency virus (HIV infection is principally a mucosal disease and the gastrointestinal (GI tract is the major site of HIV replication. Loss of CD4+ T cells and systemic immune hyperactivation are the hallmarks of HIV infection. The end of acute infection is associated with the emergence of specific CD4+ and CD8+ T cell responses and the establishment of a chronic phase of infection. Abnormal levels of immune activation and inflammation persist despite a low steady state level of viremia. Although the causes of persistent immune hyperactivation remain incompletely characterized, physiological alterations of gastrointestinal tract probably play a major role. Failure to restore Th17 cells in gut-associated lymphoid tissues (GALT might impair the recovery of the gut mucosal barrier. This review discusses recent advances on understanding the contribution of CD4+ T cell depletion to HIV pathogenesis.

  13. CD4+ T Cell Depletion in Human Immunodeficiency Virus (HIV) Infection: Role of Apoptosis

    Science.gov (United States)

    Février, Michèle; Dorgham, Karim; Rebollo, Angelita

    2011-01-01

    Human immunodeficiency virus (HIV) infection is principally a mucosal disease and the gastrointestinal (GI) tract is the major site of HIV replication. Loss of CD4+ T cells and systemic immune hyperactivation are the hallmarks of HIV infection. The end of acute infection is associated with the emergence of specific CD4+ and CD8+ T cell responses and the establishment of a chronic phase of infection. Abnormal levels of immune activation and inflammation persist despite a low steady state level of viremia. Although the causes of persistent immune hyperactivation remain incompletely characterized, physiological alterations of gastrointestinal tract probably play a major role. Failure to restore Th17 cells in gut-associated lymphoid tissues (GALT) might impair the recovery of the gut mucosal barrier. This review discusses recent advances on understanding the contribution of CD4+ T cell depletion to HIV pathogenesis. PMID:21994747

  14. IL-33 enhances retinoic acid signaling on CD4+ T cells.

    Science.gov (United States)

    Gajardo, Tania; Pérez, Francisco; Terraza, Claudia; Campos-Mora, Mauricio; Noelle, Randolph J; Pino-Lagos, Karina

    2016-09-01

    Several molecules have been described as CD4+ T cells differentiation modulators and among them retinoic acid (RA) and more recently, IL-33, have been studied. Due to the similarities in T helper cell skewing properties between RA and IL-33, we asked whether IL-33 intersects, directly or indirectly, the RA signaling pathway. Total CD4+ T cells from DR5-luciferase mice were activated in the presence of RA with or without IL-33, and RA signaling was visualized using ex vivo imaging. Our results demonstrate that IL-33 itself is able to trigger RA signaling on CD4+ T cells, which is highly increased when IL-33 is added in conjunction with RA. This study presents IL-33 as a potential player that may synergize with RA in controlling T cell differentiation, and suggests that IL-33 may be an attractive target in controlling T cell differentiation in vivo. PMID:27322964

  15. Analisis perilaku dinamik pada sel T CD4+ dan sel T CD8+ terhadap infeksi mikobakterium

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    Alfi Nur Rochmatin

    2014-05-01

    Full Text Available Model matematika pada infeksi mikobakterium tuberkulosis yang berbentuk sistem persamaan diferensial nonlinear orde satu. Penelitian ini telah mengkonstruksi model matematika pada interaksi makrofag, sel T CD4+ dan sel T CD8+ dengan pengaruh usia. Solusi numerik pada model matematika ini dengan menggunakan ODE 45 berbantuan matlab. Analisis kestabilan diamati melalui titik tetap dengan mencari matriks jacobian dan nilai eigen dari titik tetap tersebut, maka dapat diperoleh bahwa semua titik tetap tersebut tidak stabil. Berdasarkan analisis perilaku dinamik pada sel T CD4+ dan sel T CD8+pada usia muda dan usia tua maka akan diperoleh bahwa sel T CD4+dan sel T CD8+ lebih banyak mempengaruhi populasi bakteri mikobakterium tuberkulosis dari pada saat usia muda

  16. CD4(+ cells regulate fibrosis and lymphangiogenesis in response to lymphatic fluid stasis.

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    Jamie C Zampell

    Full Text Available INTRODUCTION: Lymphedema is a chronic disorder that occurs commonly after lymph node removal for cancer treatment and is characterized by swelling, fibrosis, inflammation, and adipose deposition. Although previous histological studies have investigated inflammatory changes that occur in lymphedema, the precise cellular make up of the inflammatory infiltrate remains unknown. It is also unclear if this inflammatory response plays a causal role in the pathology of lymphedema. The purpose of this study was therefore to characterize the inflammatory response to lymphatic stasis and determine if these responses are necessary for the pathological changes that occur in lymphedema. METHODS: We used mouse-tail lymphedema and axillary lymph node dissection (ANLD models in order to study tissue inflammatory changes. Single cell suspensions were created and analyzed using multi-color flow cytometry to identify individual cell types. We utilized antibody depletion techniques to analyze the causal role of CD4+, CD8+, and CD25+ cells in the regulation of inflammation, fibrosis, adipose deposition, and lymphangiogenesis. RESULTS: Lymphedema in the mouse-tail resulted in a mixed inflammatory cell response with significant increases in T-helper, T-regulatory, neutrophils, macrophages, and dendritic cell populations. Interestingly, we found that ALND resulted in significant increases in T-helper cells suggesting that these adaptive immune responses precede changes in macrophage and dendritic cell infiltration. In support of this we found that depletion of CD4+, but not CD8 or CD25+ cells, significantly decreased tail lymphedema, inflammation, fibrosis, and adipose deposition. In addition, depletion of CD4+ cells significantly increased lymphangiogenesis both in our tail model and also in an inflammatory lymphangiogenesis model. CONCLUSIONS: Lymphedema and lymphatic stasis result in CD4+ cell inflammation and infiltration of mature T-helper cells. Loss of CD4+ but

  17. Differential role of CD4+ cells in the sensitization and effector phases of accelerated graft rejection.

    Science.gov (United States)

    Sablinski, T; Sayegh, M H; Hancock, W W; Kut, J P; Kwok, C A; Milford, E L; Tilney, N L; Kupiec-Weglinski, J W

    1991-01-01

    Although CD4-targeted therapy markedly prolongs survival of organ allografts in naive rodents, its effects in primed hosts have not been studied. In our model of accelerated rejection (ACCR) of cardiac Tx in rats, treatment with BWH-4, a CD4 mAb (IgG2a), in the sensitization (between skin and heart Tx) but not in the effector (after cardiac Tx) phase, abrogated fulminant less than 36 hr rejection response and prolonged Tx survival to ca. 11 days. This effect correlated with decreased frequency of circulating CD4+ cells, but it did not depend upon their total depletion. It was also related to BWH-4 mAb-mediated elimination/depression of strong anti-donor humoral responses and cellular responses as determined by lymphocyte-mediated cytotoxicity and mixed lymphocyte reaction and mounted otherwise at the time of engraftment by untreated sensitized hosts. Immunoperoxidase studies of cardiac Tx from BWH-4-conditioned recipients revealed reduced T and B cell activities, reflected in abolition/reduction in deposition of humoral mediators, infiltrating cells, intra-Tx elaboration of interleukin-2 and interferon-gamma, and cell activation. This first report of the successful use of CD4 mAb in sensitized recipients of vascularized organ Tx, stresses the role of CD4+ cells as potential targets for immunosuppression in the sensitization phase of accelerated Tx injury. The beneficial therapeutic effect, probably due to both depletion and functional inhibition of CD4+ T cells, has been achieved by using relatively low doses of BWH-4 mAb. PMID:1824805

  18. Dengue virus-specific, human CD4+ CD8- cytotoxic T-cell clones: multiple patterns of virus cross-reactivity recognized by NS3-specific T-cell clones.

    OpenAIRE

    Kurane, I; Brinton, M A; Samson, A L; Ennis, F A

    1991-01-01

    Thirteen dengue virus-specific, cytotoxic CD4+ CD8- T-cell clones were established from a donor who was infected with dengue virus type 3. These clones were examined for virus specificity and human leukocyte antigen (HLA) restriction in cytotoxic assays. Six patterns of virus specificities were determined. Two serotype-specific clones recognized only dengue virus type 3. Two dengue virus subcomplex-specific clones recognized dengue virus types 2, 3, and 4, and one subcomplex-specific clone re...

  19. Bromelain treatment reduces CD25 expression on activated CD4+ T cells in vitro✩

    OpenAIRE

    Secor, Eric R.; Singh, Anurag; Guernsey, Linda A.; McNamara, Jeff T.; Zhan, Lijun; Maulik, Nilanjana; Thrall, Roger S.

    2009-01-01

    Bromelain (Br), an extract from pineapple stem with cysteine protease activity, exerts anti-inflammatory effects in a number of inflammatory models. We have previously shown that Br treatment decreased activated CD4+ T cells and has a therapeutic role in an ovalbumin-induced murine model of allergic airway disease. The current study was designed to determine the effect of Br on CD4+ T cell activation, specifically the expression of CD25 in vitro. CD25 is up regulated upon T cell activation, f...

  20. IL-17-Expressing CD4 + and CD8 + T Lymphocytes in Human Toxoplasmosis

    OpenAIRE

    Jéssica Líver Alves Silva; Karine Rezende-Oliveira; Marcos Vinicius da Silva; César Gómez-Hernández; Bethânea Crema Peghini; Neide Maria Silva; José Roberto Mineo; Virmondes Rodrigues Júnior

    2014-01-01

    This study aimed to measure the synthesis of Th1 and Th2 cytokines by mononuclear cells after culture with live T. gondii and identified Th17 (CD4+) and Tc17 (CD8+) cells in toxoplasma-seronegative and toxoplasma-seropositive parturient and nonpregnant women. Cytometric bead arrays were used to measure cytokine levels (IL-2, TNF-α, IFN-γ, IL-4, IL-5, and IL-10); immunophenotyping was used to characterize Th17 and Tc17 cells, and the cells were stained with antibodies against CD4+ and CD8+ T c...

  1. CD26 + CD4 + T cell counts and attack risk in interferon-treated multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, F; Ross, C; Koch-Henriksen, Nils;

    2005-01-01

    patients with CD26 + CD4 + T cell counts above median, and this risk was independent of the risk conferred by neutralizing anti-IFN-beta antibodies. CD26 + CD4 + T cell counts may identify patients with MS at increased risk of attack during treatment with IFN-beta....... CCR5 on T cells is altered in patients with active MS. We studied the expression of these molecules by flow cytometry in patients followed for six months during immunomodulatory treatment. In interferon (IFN)-beta-treated patients, we found that the hazard ratio for developing an attack was 28 in...

  2. Differential human immunodeficiency virus expression in CD4+ cloned lymphocytes: from viral latency to replication.

    Science.gov (United States)

    Chapel, A; Bensussan, A; Vilmer, E; Dormont, D

    1992-06-01

    By using cloning methodology, 13 CD4+, CD8-, CD45RO+, and CD29+ clones, isolated from human immunodeficiency virus (HIV)-negative donors, have been characterized and tested regarding their susceptibility to two strains of HIV type 1 (HIV-1). Infected clones possess integrated provirus. Only six are able to replicate HIV-1, while seven may normally grow without cytopathic effect and without viral replication. These results argue that all CD4+ lymphocyte clones may be infectable but that a heterogeneity exists regarding their abilities to replicate HIV-1.

  3. The absolute lymphocyte count accurately estimates CD4 counts in HIV-infected adults with virologic suppression and immune reconstitution

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    Barnaby Young

    2014-11-01

    Full Text Available Introduction: The clinical value of monitoring CD4 counts in immune reconstituted, virologically suppressed HIV-infected patients is limited. We investigated if absolute lymphocyte counts (ALC from an automated blood counting machine could accurately estimate CD4 counts. Materials and Methods: CD4 counts, ALC and HIV viral load (VL were extracted from an electronic laboratory database for all patients in HIV care at the Communicable Diseases Centre, Tan Tock Seng Hospital, Singapore (2008–13. Virologic suppression was defined as consecutive HIV VLs 300 cells/mm3. CD4 counts were estimated using the CD4% from the first value >300 and an ALC 181–540 days later. Results: A total of 1215 periods of virologic suppression were identified from 1183 patients, with 2227 paired CD4-ALCs available for analysis. 98.3% of CD4 estimates were within 50% of the actual value. 83.3% within 25% and 40.5% within 10%. The error pattern was approximately symmetrically distributed around a mean of −6.5%, but significant peaked and with mild positive skew (kurtosis 4.45, skewness 1.07. Causes for these errors were explored. Variability between lymphocyte counts measured by ALC and flow cytometry did not follow an apparent pattern, and contributed to 32% of the total error (median absolute error 5.5%, IQR 2.6–9.3. The CD4% estimate was significantly lower than the actual value (t-test, p<0.0001. The magnitude of this difference was greater for lower values, and above 25%, there was no significant difference. Precision of the CD4 estimate was similar as baseline CD4% increased, however accuracy improved significantly: from a median 16% underestimation to 0% as baseline CD4% increased from 12 to 30. Above a CD4% baseline of 25, estimates of CD4 were within 25% of the actual value 90.2% of the time with a median 2% underestimation. A robust (bisqaure linear regression model was developed to correct for the rise in CD4% with time, when baseline was 14–24

  4. Antiretroviral treatment cohort analysis using time-updated CD4 counts: assessment of bias with different analytic methods.

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    Katharina Kranzer

    Full Text Available BACKGROUND: Survival analysis using time-updated CD4+ counts during antiretroviral therapy is frequently employed to determine risk of clinical events. The time-point when the CD4+ count is assumed to change potentially biases effect estimates but methods used to estimate this are infrequently reported. METHODS: This study examined the effect of three different estimation methods: assuming i a constant CD4+ count from date of measurement until the date of next measurement, ii a constant CD4+ count from the midpoint of the preceding interval until the midpoint of the subsequent interval and iii a linear interpolation between consecutive CD4+ measurements to provide additional midpoint measurements. Person-time, tuberculosis rates and hazard ratios by CD4+ stratum were compared using all available CD4+ counts (measurement frequency 1-3 months and 6 monthly measurements from a clinical cohort. Simulated data were used to compare the extent of bias introduced by these methods. RESULTS: The midpoint method gave the closest fit to person-time spent with low CD4+ counts and for hazard ratios for outcomes both in the clinical dataset and the simulated data. CONCLUSION: The midpoint method presents a simple option to reduce bias in time-updated CD4+ analysis, particularly at low CD4 cell counts and rapidly increasing counts after ART initiation.

  5. In vitro separation and expansion of CD4 lymphocytes from HIV-infected individuals without activation of HIV infection

    DEFF Research Database (Denmark)

    Nielsen, S D; Nielsen, Jens Ole; Hansen, J E

    1997-01-01

    In order to offer a gene therapy-based treatment against AIDS, it is likely to be necessary to harvest and culture CD4 cells from HIV-positive patients without activating the HIV infection. We have used a magnetic cell sorting (MACS) system to enrich CD4 cells. Using positive selection, CD4 cells...... from a total of 14 patients were enriched from a mean percentage of CD4 cells in PBMC of 18% to 91% CD4 cells in the enriched cell fraction. Furthermore, we found that this separation did not lead to an increase in viral load. The MACS performed equally well on cells from HIV-positive patients and HIV......-negative donors. CD4 cells from HIV-positive patients were readily expanded with PHA; 19-fold by day 10, 50-fold by day 20, and 156-fold by day 25. However, CD4 cells from HIV-positive patients grew at a slower rate than CD4 cells from HIV-negative donors. The expanded CD4 cells showed a high degree of CD4...

  6. Multiple in vitro and in vivo regulatory effects of budesonide in CD4+ T lymphocyte subpopulations of allergic asthmatics.

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    Elisabetta Pace

    Full Text Available BACKGROUND: Increased activation and increased survival of T lymphocytes characterise bronchial asthma. OBJECTIVES: In this study the effect of budesonide on T cell survival, on inducible co-stimulator T cells (ICOS, on Foxp3 and on IL-10 molecules in T lymphocyte sub-populations was assessed. METHODS: Cell survival (by annexin V binding and ICOS in total lymphocytes, in CD4+/CD25+ and in CD4+/CD25- and Foxp3 and IL-10 in CD4+/CD25+ and in CD4+/CD25-cells was evaluated, by cytofluorimetric analysis, in mild intermittent asthmatics (n = 19 and in controls (n = 15. Allergen induced T lymphocyte proliferation and the in vivo effects of budesonide in mild persistent asthmatics (n = 6 were also explored. RESULTS: Foxp3 was reduced in CD4+/CD25- and in CD4+/CD25+ cells and ICOS was reduced in CD4+/CD25+ cells but it was increased in CD4+CD25-in asthmatics when compared to controls. In asthmatics, in vitro, budesonide was able to: 1 increase annexin V binding and to reduce ICOS in total lymphocytes; 2 increase annexin V binding and Foxp3 and to reduce ICOS in CD4+/CD25- cells; 3 reduce annexin V binding and to increase IL-10 and ICOS in CD4+/CD25+ cells; 4 reduce cell allergen induced proliferation. In vivo, budesonide increased ICOS in CD4+/CD25+ while it increased Foxp3 and IL-10 in CD4+/CD25+ and in CD4+/CD25- cells. CONCLUSIONS: Budesonide modulates T cell survival, ICOS, Foxp3 and IL-10 molecules differently in T lymphocyte sub-populations. The findings provided shed light on new mechanisms by which corticosteroids, drugs widely used for the clinical management of bronchial asthma, control T lymphocyte activation.

  7. Brief Report: Enhanced Normalization of CD4/CD8 Ratio With Earlier Antiretroviral Therapy at Primary HIV Infection

    Science.gov (United States)

    Inshaw, Jamie; Kaleebu, Pontiano; Cooper, David; Ramjee, Gita; Schechter, Mauro; Tambussi, Giuseppe; Fox, Julie; Samuel, Miriam; Miro, Jose M.; Weber, Jonathan; Porter, Kholoud; Fidler, Sarah

    2016-01-01

    Background: Total CD4+ T-cell counts predict HIV disease progression but do not necessarily reflect normalization of immune function. CD4/CD8 ratio is a marker of immune dysfunction, a prognostic indicator for non-AIDS mortality, and reflects viral reservoir size. Despite antiretroviral therapy (ART), recovery of CD4/CD8 ratio in chronic HIV infection is incomplete; we hypothesize enhanced CD4/CD8 ratio recovery with earlier treatment initiation in recently infected individuals. Methods: CD4+ count and CD4/CD8 ratio were analyzed using data from 2 cohorts: SPARTAC trial and the UK HIV Seroconverters Cohort where primary HIV infection (PHI) was defined as within 6 months from estimated date of infection. Using time-to-event methods and Cox proportional hazard models, we examined the effect of CD4/CD8 ratio at seroconversion on disease progression (CD4 1.0). Findings: Of 573 seroconverters, 482 (84%) had abnormal CD4/CD8 ratios at HIV seroconversion. Individuals with higher CD4/CD8 ratio at seroconversion were significantly less likely to reach the disease progression endpoint [adjusted hazard ratio (aHR) (95% CI) = 0.52 (0.32 to 0.82), P = 0.005]. The longer the interval between seroconversion and ART initiation [HR (95% CI) = 0.98 per month increase (0.97, 0.99), P < 0.001], the less likely the CD4/CD8 ratio normalization. ART initiation within 6 months from seroconversion was significantly more likely to normalize [HR (95% CI) = 2.47 (1.67 to 3.67), P < 0.001] than those initiating later. Interpretation: Most individuals presenting in PHI have abnormal CD4/CD8 ratios. The sooner the ART is initiated in PHI, the greater the probability of achieving normal CD4/CD8 ratio. PMID:27070122

  8. Plasmodium falciparum-mediated induction of human CD25Foxp3 CD4 T cells is independent of direct TCR stimulation and requires IL-2, IL-10 and TGFbeta.

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    Anja Scholzen

    2009-08-01

    Full Text Available CD4(+CD25(+Foxp3(+ regulatory T cells (Tregs regulate disease-associated immunity and excessive inflammatory responses, and numbers of CD4(+CD25(+Foxp3(+ Tregs are increased during malaria infection. The mechanisms governing their generation, however, remain to be elucidated. In this study we investigated the role of commonly accepted factors for Foxp3 induction, TCR stimulation and cytokines such as IL-2, TGFbeta and IL-10, in the generation of human CD4(+CD25(+Foxp3(+ T cells by the malaria parasite Plasmodium falciparum. Using a co-culture system of malaria-infected red blood cells (iRBCs and peripheral blood mononuclear cells from healthy individuals, we found that two populations of Foxp3(hi and Foxp3(int CD4(+CD25(hi T cells with a typical Treg phenotype (CTLA-4(+, CD127(low, CD39(+, ICOS(+, TNFRII(+ were induced. Pro-inflammatory cytokine production was confined to the Foxp3(int subset (IFNgamma, IL-4 and IL-17 and inversely correlated with high relative levels of Foxp3(hi cells, consistent with Foxp3(hi CD4 T cell-mediated inhibition of parasite-induced effector cytokine T cell responses. Both Foxp3(hi and Foxp3(int cells were derived primarily from proliferating CD4(+CD25(- T cells with a further significant contribution from CD25(+Foxp3(+ natural Treg cells to the generation of the Foxp3(hi subset. Generation of Foxp3(hi, but not Foxp3(int, cells specifically required TGFbeta1 and IL-10. Add-back experiments showed that monocytes expressing increased levels of co-stimulatory molecules were sufficient for iRBC-mediated induction of Foxp3 in CD4 T cells. Foxp3 induction was driven by IL-2 from CD4 T cells stimulated in an MHC class II-dependent manner. However, transwell separation experiments showed that direct contact of monocytes with the cells that acquire Foxp3 expression was not required. This novel TCR-independent and therefore antigen-non specific mechanism for by-stander CD4(+CD25(hiFoxp3(+ cell induction is likely to reflect a

  9. Expression of regulatory CD4+CD25+ Treg,CD4+CD25higTreg cells and Foxp3 mRNA in wheezing infants and its clinical significance%CD4+CD25+、CD4+CD25hig调节性T细胞和Foxp3mRNA在婴幼儿喘息中的表达及意义

    Institute of Scientific and Technical Information of China (English)

    彭力; 钟礼立; 黄寒; 厉娟; 梁沫; 李云

    2012-01-01

    Objective To evaluate the changes of CD4+ CD25+ Treg,CD4 +CD25hig Treg and Foxp3 mRNA in peripheral blood from wheezing infantsMethods Fifty-one wheezing infants and twenty healthy volunteers were included in this study. The proportion of CD4 + CD25 + Treg and CD4 + CD25hig Treg population in total T cells was evaluated by flow cytometric analysis. The expression of Foxp3 mRNA was tested by flow cytometry. Total serum IgE of wheezy infants was detected by enzyme immunoassay. Results Compared with those of healthy control, the frequency of CD4 + CD25 + Treg and CD4 + CD25hig Treg in the peripheral blood from wheezing infants showed a significant increase (6. 31 + 2. 96) % / (3.52 + 1.46) % ,P<0. 01 ,P<0. 01, respectively).The expression of CD4 + CD25+ Treg,CD4 + CD25hig Treg and Foxp3 mRNA in peripheral blood from wheezing infants with atopy burden was lower than those from non-wheezing infants(P<0. 05). The correlation analysis showed that CD4 + CD25hig Treg (r= -0. 75 , P<0.01) and Foxp3 mRNA(r= -0. 61,P<0. 01) had significantly positive relation with total serum IgE,while CD4+CD25 + Treg had significantly negative relation with total serum IgE(r=0. 36,P<0. 05). Conclusion CD4+CD25+ Treg, CD4+CD25hig Treg and Foxp3 mRNA play an important role in activation of wheezing infants.%目的 探讨婴幼儿喘息CD4+CD25+、CD4+CD25hig调节性T细胞(Treg)和叉头/翼状螺旋转录因子(Foxp3)mRNA的表达及意义.方法 采用流式细胞术检测51例首次喘息婴幼儿外周血CD4+CD25+Treg和CD4+CD25higTreg的比例,RT-PCR检测Foxp3 mRNA的表达量,酶联免疫吸附法(ELASA)检测总IgE水平,并与正常婴幼儿对照.结果 喘息婴幼儿外周血CD4+CD25+Treg、CD4+CD25higTreg占CD4+T细胞的百分比分别为(6.31+2.96)%和(3.52+1.46)%,均明显低于健康对照组(P<0.01);特应征喘息组CD4+CD25+Treg、CD4+CD25higTreg及Foxp3 mRNA表达均低于非特应征喘息组(P<0.05).喘息患儿CD4+CD25higTreg百分率及Foxp3 mRNA表达与

  10. CD4+CD25+调节性T细胞对哮喘大鼠免疫功能影响%Effect of CD4+CD25+Regulatory T Cells on the Immunologic Function in Rats with Asthma

    Institute of Scientific and Technical Information of China (English)

    薛克营; 金卫国; 王成国; 程立; 杨中卫; 王正艳

    2009-01-01

    目的:观察CD4+CD25+调节性T细胞(CD4+CD25+Treg)对CD4+CD25-T细胞增殖和Th1/Th2细胞因子分泌的影响,探讨其在哮喘气道炎症中的作用机制.方法:将哮喘大鼠CD4+CD25-T细胞分别与卵白蛋白(OVA)免疫耐受大鼠CD4+Cd25+Treg细胞和哮喘大鼠CD4+CD25+Treg细胞联合培养,3H胸腺嘧啶核苷(3H-TdR)掺入法测量细胞增殖情况,ELISA检测细胞IL-4、IL-5和IFN-γ含量.结果:OVA耐受大鼠CD4+CD25+Treg细胞能抑制CD4+CD25-T细胞增殖和Th2细胞因子分泌(P<0.05);哮喘大鼠CD4+CD25+Treg细胞可明显抑制IFN-γ的分泌(P<0.05).结论:OVA免疫耐受大鼠CD4+CD25+Treg细胞可能通过抑制哮喘大鼠CD4+CD25-T细胞增殖和影响Th1/Th2平衡发挥作用,哮喘大鼠CD4+CD25+Treg细胞存在功能异常,可能与哮喘的发病有关.

  11. Immunity to intracellular Salmonella depends on surface-associated antigens.

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    Somedutta Barat

    Full Text Available Invasive Salmonella infection is an important health problem that is worsening because of rising antimicrobial resistance and changing Salmonella serovar spectrum. Novel vaccines with broad serovar coverage are needed, but suitable protective antigens remain largely unknown. Here, we tested 37 broadly conserved Salmonella antigens in a mouse typhoid fever model, and identified antigen candidates that conferred partial protection against lethal disease. Antigen properties such as high in vivo abundance or immunodominance in convalescent individuals were not required for protectivity, but all promising antigen candidates were associated with the Salmonella surface. Surprisingly, this was not due to superior immunogenicity of surface antigens compared to internal antigens as had been suggested by previous studies and novel findings for CD4 T cell responses to model antigens. Confocal microscopy of infected tissues revealed that many live Salmonella resided alone in infected host macrophages with no damaged Salmonella releasing internal antigens in their vicinity. In the absence of accessible internal antigens, detection of these infected cells might require CD4 T cell recognition of Salmonella surface-associated antigens that could be processed and presented even from intact Salmonella. In conclusion, our findings might pave the way for development of an efficacious Salmonella vaccine with broad serovar coverage, and suggest a similar crucial role of surface antigens for immunity to both extracellular and intracellular pathogens.

  12. Association of progressive CD4(+ T cell decline in SIV infection with the induction of autoreactive antibodies.

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    Takeo Kuwata

    2009-04-01

    Full Text Available The progressive decline of CD4(+ T cells is a hallmark of disease progression in human immunodeficiency virus (HIV and simian immunodeficiency virus (SIV infection. Whereas the acute phase of the infection is dominated by virus-mediated depletion of memory CD4(+ T cells, chronic infection is often associated with a progressive decline of total CD4(+ T cells, including the naïve subset. The mechanism of this second phase of CD4(+ T cell loss is unclear and may include immune activation-induced cell death, immune-mediated destruction, and regenerative or homeostatic failure. We studied patterns of CD4(+ T cell subset depletion in blood and tissues in a group of 20 rhesus macaques inoculated with derivatives of the pathogenic SIVsmE543-3 or SIVmac239. Phenotypic analysis of CD4(+ T cells demonstrated two patterns of CD4(+ T cell depletion, primarily affecting either naïve or memory CD4(+ T cells. Progressive decline of total CD4(+ T cells was observed only in macaques with naïve CD4(+ T cell depletion (ND, though the depletion of memory CD4(+ T cells was profound in macaques with memory CD4(+ T cell depletion (MD. ND macaques exhibited lower viral load and higher SIV-specific antibody responses and greater B cell activation than MD macaques. Depletion of naïve CD4(+ T cells was associated with plasma antibodies autoreactive with CD4(+ T cells, increasing numbers of IgG-coated CD4(+ T cells, and increased incidence of autoreactive antibodies to platelets (GPIIIa, dsDNA, and phospholipid (aPL. Consistent with a biological role of these antibodies, these latter antibodies were accompanied by clinical features associated with autoimmune disorders, thrombocytopenia, and catastrophic thrombotic events. More importantly for AIDS pathogenesis, the level of autoreactive antibodies significantly correlated with the extent of naïve CD4(+ T cell depletion. These results suggest an important role of autoreactive antibodies in the CD4(+ T cell decline

  13. Mesothelin virus-like particle immunization controls pancreatic cancer growth through CD8+ T cell induction and reduction in the frequency of CD4+ foxp3+ ICOS- regulatory T cells.

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    Sheng Zhang

    Full Text Available Our previous study has shown that mesothelin (MSLN is a potential immunotherapeutic target for pancreatic cancer. Here, we further studied the immunogenicity of chimeric murine MSLN-virus-like particles (mMSLN-VLPs, their ability to break tolerance to mMSLN, a self-antigen, and deciphered the mechanism of immune responses elicited by mMSLN-VLP immunization using a pancreatic cancer (PC mouse model. In addition to what we have found with xenogeneic human MSLN-VLP (hMSLN-VLP, mMSLN-VLP immunization was able to break the tolerance to intrinsic MSLN and mount mMSLN-specific, cytotoxic CD8(+ T cells which led to a significant reduction in tumor volume and prolonged survival in an orthotopic PC mouse model. Furthermore, CD4(+foxp3(+ regulatory T cells (Tregs were progressively decreased in both spleen and tumor tissues following mMSLN-VLP immunization and this was at least partly due to elevated levels of IL-6 production from activated plasmocytoid dendritic cell (pDC-like cells following mMSLN-VLP immunization. Moreover, mMSLN-VLP treatment mainly reduced the frequency of the CD4(+foxp3(+ICOS(- Treg subset. However, mMSLN-VLP induced IL-6 production also increased ICOSL expression on pDC-like cells which supported the proliferation of immunosuppressive CD4(+foxp3(+ICOS(+ Treg cells. This study reveals that mMSLN-VLP immunization is capable of controlling PC progression by effectively mounting an immune response against mMSLN, a tumor self-antigen, and altering the immunosuppressive tumor microenvironment via activation of pDCs-like cells and reduction in the frequency of CD4(+foxp3(+ICOS(- Treg cells. However, combination therapies will likely need to be used in order to target residual CD4(+foxp3(+ICOS(+ Treg cells.

  14. Murine CD4 T cells produce a new form of TGF-β as measured by a newly developed TGF-β bioassay.

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    Takatoku Oida

    Full Text Available BACKGROUND: It is generally assumed that T cells do not produce active TGF-β since active TGF-β as measured in supernatants by ELISA without acidification is usually not detectable. However, it is possible that active TGF-β from T cells may take a special form which is not detectable by ELISA. METHODOLOGY/PRINCIPAL FINDINGS: We constructed a TGF-β bioassay which can detect both soluble and membrane-bound forms of TGF-β from T cells. For this bioassay, 293T cells were transduced with (caga(12 Smad binding element-luciferase along with CD32 (Fc receptor and CD86. The resulting cells act as artificial antigen presenting cells in the presence of anti-CD3 and produce luciferase in response to biologically active TGF-β. We co-cultured pre-activated murine CD4(+CD25(- T cells or CD4(+CD25(+ T cells with the 293T-caga-Luc-CD32-CD86 reporter cells in the presence of anti-CD3 and IL-2. CD4(+CD25(- T cells induced higher luciferase in the reporter cells than CD4(+CD25(+ T cells. This T cell-produced TGF-β is in a soluble form since T cell culture supernatants contained the TGF-β activity. The TGF-β activity was neutralized with an anti-mouse LAP mAb or an anti-latent TGF-β/pro-TGF-β mAb, but not with anti-active TGF-β Abs. An anti-mouse LAP mAb removed virtually all acid activatable latent TGF-β from the T cell culture supernatant, but not the ability to induce TGF-β signaling in the reporter cells. The induction of TGF-β signaling by T cell culture supernatants was cell type-specific. CONCLUSIONS/SIGNIFICANCE: A newly developed 293T-caga-Luc-CD32-CD86 reporter cell bioassay demonstrated that murine CD4 T cells produce an unconventional form of TGF-β which can induce TGF-β signaling. This new form of TGF-β contains LAP as a component. Our finding of a new form of T cell-produced TGF-β and the newly developed TGF-β bioassay system will provide a new avenue to investigate T cell function of the immune system.

  15. Lysis of endogenously infected CD4+ T cell blasts by rIL-2 activated autologous natural killer cells from HIV-infected viremic individuals.

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    Manuela Fogli

    2008-07-01

    Full Text Available Understanding the cellular mechanisms that ensure an appropriate innate immune response against viral pathogens is an important challenge of biomedical research. In vitro studies have shown that natural killer (NK cells purified from healthy donors can kill heterologous cell lines or autologous CD4+ T cell blasts exogenously infected with several strains of HIV-1. However, it is not known whether the deleterious effects of high HIV-1 viremia interferes with the NK cell-mediated cytolysis of autologous, endogenously HIV-1-infected CD4+ T cells. Here, we stimulate primary CD4+ T cells, purified ex vivo from HIV-1-infected viremic patients, with PHA and rIL2 (with or without rIL-7. This experimental procedure allows for the significant expansion and isolation of endogenously infected CD4+ T cell blasts detected by intracellular staining of p24 HIV-1 core antigen. We show that, subsequent to the selective down-modulation of MHC class-I (MHC-I molecules, HIV-1-infected p24(pos blasts become partially susceptible to lysis by rIL-2-activated NK cells, while uninfected p24(neg blasts are spared from killing. This NK cell-mediated killing occurs mainly through the NKG2D activation pathway. However, the degree of NK cell cytolytic activity against autologous, endogenously HIV-1-infected CD4+ T cell blasts that down-modulate HLA-A and -B alleles and against heterologous MHC-I(neg cell lines is particularly low. This phenomenon is associated with the defective surface expression and engagement of natural cytotoxicity receptors (NCRs and with the high frequency of the anergic CD56(neg/CD16(pos subsets of highly dysfunctional NK cells from HIV-1-infected viremic patients. Collectively, our data demonstrate that the chronic viral replication of HIV-1 in infected individuals results in several phenotypic and functional aberrancies that interfere with the NK cell-mediated killing of autologous p24(pos blasts derived from primary T cells.

  16. IL-35, an anti-inflammatory cytokine which expands CD4+CD25+ Treg Cells.

    Science.gov (United States)

    Castellani, Maria Luisa; Anogeianaki, A; Felaco, P; Toniato, E; De Lutiis, M A; Shaik, B; Fulcheri, M; Vecchiet, J; Tetè, S; Salini, V; Theoharides, T C; Caraffa, A; Antinolfi, P; Frydas, I; Conti, P; Cuccurullo, C; Ciampoli, C; Cerulli, G; Kempuraj, D

    2010-01-01

    Interleukin 12 (IL 12) p35/p40 is a heterodimeric cytokine which plays a critical role in inflammation, immunity and tissue proliferation, and also plays a relevant function in T helper (Th) cell polarization and Th1 T-cell differentiation. IL-12 family members, IL-12p70, IL-23, IL-27 and IL-35, play an important role in influencing helper T-cell differentiation. EBV-induced gene 3 can be associated with the p35 subunit of IL-12 to form the EBI3/p35 heterodimer, also called IL-35. It has been shown that IL-35 has biological activity and able to expand