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Sample records for circulating cd4 t-cells

  1. Characterization and clinical relevance of circulating CD4+CD28- T cells in Graves' disease.

    PubMed

    Wang, Fengming; Chen, Lei; Shen, Qiong; Liu, Tong; Jiang, Lian; Gu, Xinhua; Chen, Lujun; Sun, Jing; Liu, Cuiping

    2015-05-01

    During autoimmune disease the fraction of CD4+CD28- T cells in the peripheral blood of has been found to be elevated. In the present study, peripheral blood was collected from 61 patients with Graves' disease (GD) and 30 healthy control participants. Serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), free thyroxine (FT4) and thyrotropin receptor autoantibody (TRAb) were measured and peripheral blood mononuclear cell (PBMC) surface expression of CD4 and CD28 molecules was detected by flow cytometry. CD4+CD28- cells were sorted from six patients undergoing subtotal thyroidectomy and cultured ex vivo. The influence of TSH pretreated thyroid follicular cells on CD4+CD28- cell proliferation was evaluated using the agonist CD40 mAb 5C11, the blocking CD40L mAb 4F1 or B7-1 mAb 4E5 in 3H-TdR assays. Our data showed that the fraction of CD4+CD28- T cells was higher in GD patients than healthy donors (10.21%±8.56% vs. 2.33%±1.94%; P<0.001), and further elevated in 24 of 61 patients with Graves' ophthalmopathy (GO) (7.00±6.57% vs. 15.21±8.96%; P<0.001). A higher proportion of CD4+CD28- cells was detected in patients with degree II or III goiter than those with degree I goiter (11.53±9.18% vs. 6.11±3.97%; P<0.05 and 14.50±10.41% vs. 6.11±3.97%; P<0.01). The percentage of CD4+CD28- T cells correlated positively with serum levels of FT3 (r=0.354, P<0.01) and TRAb (r=0.304, P<0.05), but did not correlate with serum FT4 or TSH. Ex vivo, 5C11 enhanced proliferation of CD4+CD28+ cells (P<0.05), but did not influence the proliferation of CD4+CD28- cells. 4F1 inhibited the proliferation of both CD4+CD28+ (P<0.05) and CD4+CD28- (P<0.01) cells, and 4E5 inhibited proliferation of CD4+CD28+ cells (P<0.05). The elevation in circulating CD4+CD28- cells in GD patients correlates with disease severity and maybe plays an important role in the pathogenesis of GD. PMID:25839128

  2. Statins Increase the Frequency of Circulating CD4+FOXP3+ Regulatory T Cells in Healthy Individuals

    PubMed Central

    Rodríguez-Perea, Ana Lucía; Montoya, Carlos J.; Olek, Sven; Chougnet, Claire A.; Velilla, Paula A.

    2015-01-01

    Statins have been shown to modulate the number and the suppressive function of CD4+FOXP3+ T cells (Treg) in inflammatory conditions. However, it is not well established whether statin could also affect Treg in absence of inflammation. To address this question, eighteen normocholesterolemic male subjects were treated with lovastatin or atorvastatin daily for 45 days. The frequency and phenotype of circulating Treg were evaluated at days 0, 7, 30, and 45. mRNA levels of FOXP3, IDO, TGF-β, and IL-10 were measured in CD4+ T cells. We found that both statins significantly increased Treg frequency and FOXP3 mRNA levels at day 30. At day 45, Treg numbers returned to baseline values; however, TGF-β and FOXP3 mRNA levels remained high, accompanied by increased percentages of CTLA-4- and GITR-expressing Treg. Treg Ki-67 expression was decreased upon statin treatment. Treg frequency positively correlated with plasma levels of high-density lipoprotein cholesterol (HDL-c), suggesting a role for HDL-c in Treg homeostasis. Therefore, statins appear to have inflammation-independent immune-modulatory effects. Thus, the increase in Treg cells frequency likely contributes to immunomodulatory effect of statins, even in healthy individuals. PMID:25759848

  3. Skin CD4+ memory T cells exhibit combined cluster-mediated retention and equilibration with the circulation

    PubMed Central

    Collins, Nicholas; Jiang, Xiaodong; Zaid, Ali; Macleod, Bethany L.; Li, Jane; Park, Chang Ook; Haque, Ashraful; Bedoui, Sammy; Heath, William R.; Mueller, Scott N.; Kupper, Thomas S.; Gebhardt, Thomas; Carbone, Francis R.

    2016-01-01

    Although memory T cells within barrier tissues can persist as permanent residents, at least some exchange with blood. The extent to which this occurs is unclear. Here we show that memory CD4+ T cells in mouse skin are in equilibrium with the circulation at steady state. These cells are dispersed throughout the inter-follicular regions of the dermis and form clusters with antigen presenting cells around hair follicles. After infection or administration of a contact sensitizing agent, there is a sustained increase in skin CD4+ T-cell content, which is confined to the clusters, with a concomitant CCL5-dependent increase in CD4+ T-cell recruitment. Skin CCL5 is derived from CD11b+ cells and CD8+ T cells, with the elimination of the latter decreasing CD4+ T-cell numbers. These results reveal a complex pattern of tissue-retention and equilibration for CD4+ memory T cells in skin, which is altered by infection and inflammation history. PMID:27160938

  4. Prevalence, clinical relevance and characterization of circulating cytotoxic CD4+CD28- T cells in ankylosing spondylitis

    PubMed Central

    Duftner, Christina; Goldberger, Christian; Falkenbach, Albrecht; Würzner, Reinhard; Falkensammer, Barbara; Pfeiffer, Karl P; Maerker-Hermann, Elisabeth; Schirmer, Michael

    2003-01-01

    Circulating CD3+CD4+CD28- cells exhibit reduced apoptosis and were found to be more enriched in patients with ankylosing spondylitis than in age-matched healthy control individuals (7.40 ± 6.6% versus 1.03 ± 1.0%; P < 0.001). Levels of CD4+CD28- T cells correlate with disease status as measured using a modified metrology score, but they are independent of age and duration of ankylosing spondylitis. CD4+CD28- T cells produce IFN-γ and perforin, and thus they must be considered proinflammatory and cytotoxic. These T cells share phenotypic and functional properties of natural killer cells, strongly expressing CD57 but lacking the lymphocyte marker CD7. MHC class I recognizing and activating natural killer cell receptors on the surface of CD4+CD28- T cells may be involved in a HLA-B27 mediated co-stimulation of these proinflammatory and cytotoxic cells. PMID:12932293

  5. The Majority of HIV Type 1 DNA in Circulating CD4+ T Lymphocytes Is Present in Non-Gut-Homing Resting Memory CD4+ T Cells

    PubMed Central

    Xu, Yin; Bailey, Michelle; Seddiki, Nabila; Suzuki, Kazuo; Murray, John M.; Gao, Yuan; Yan, Celine; Cooper, David A.; Kelleher, Anthony D.; Koelsch, Kersten K.; Zaunders, John

    2013-01-01

    Abstract Memory CD4+ T lymphocytes in peripheral blood that express integrins α4ß7 preferentially recirculate through gut-associated lymphoid tissue (GALT), a proposed site of significant HIV-1 replication. Tregs and activated CD4+ T cells in GALT could also be particularly susceptible to infection. We therefore hypothesized that infection of these subsets of memory CD4+ T cells may contribute disproportionately to the HIV-1 reservoir. A cross-sectional study of CD4+ T cell subsets of memory CD45RO+ cells in peripheral blood mononuclear cells (PBMCs) was conducted using leukapheresis from eight subjects with untreated chronic HIV-1 infection. Real-time polymerase chain reaction (PCR) was used to quantify total and integrated HIV-1 DNA levels from memory CD4+ T cells sorted into integrin β7+ vs. β7−, CD25+CD127low Treg vs. CD127high, and activated CD38+ vs. CD38−. More than 80% of total HIV-1 DNA was found to reside in the integrin β7-negative non-gut-homing subset of CD45RO+ memory CD4+ T cells. Less than 10% was found in highly purified Tregs or CD38+ activated memory cells. Similarly, integrated HIV-1 DNA copies were found to be more abundant in resting non-gut-homing memory CD4+ T cells (76%) than in their activated counterparts (23%). Our investigations showed that the majority of both total and integrated HIV-1 DNA was found within non-gut-homing resting CD4+ T cells. PMID:23971972

  6. Human Blood-Circulating Basophils Capture HIV-1 and Mediate Viral trans-Infection of CD4+ T Cells

    PubMed Central

    Jiang, Ai-Ping; Jiang, Jin-Feng; Guo, Ming-Gao; Jin, Yong-Mei; Li, Yu-Ye

    2015-01-01

    ABSTRACT Cell-associated HIV-1 infection has been proposed to play a pivotal role in the spread of HIV-1 infection. Granulocytes are a category of white blood cells, comprising mainly basophils, neutrophils, and eosinophils, and participate in various inflammatory reactions and defense against pathogens. Here, we investigated the role of human blood granulocytes in the dissemination of HIV-1. These cells were found to express a variety of HIV-1 attachment factors (HAFs). Basophils expressed HAFs dendritic cell (DC)-specific intercellular adhesion molecule 3 (ICAM3)-grabbing nonintegrin (DC-SIGN), DC immunoreceptor (DCIR), heparan sulfate proteoglycan (HSPG), and α4β7 integrin and mediated the most efficient capture of HIV-1 on the cell surface. Neutrophils were found to express DCIR and demonstrated limited efficiency of viral capture. Eosinophils expressed α4β7 integrin but exhibited little or no virus-binding capacity. Intriguingly, following direct contact with CD4+ T cells, viruses harbored on the surface of basophils were transferred to T cells. The contact between basophils and CD4+ T cells and formation of infectious synapses appeared necessary for efficient HIV-1 spread. In HIV-1-infected individuals, the frequency of basophils remained fairly stable over the course of disease, regardless of CD4+ T depletion or the emergence of AIDS-associated opportunistic infections. Collectively, our results provide novel insights into the roles of granulocytes, particularly basophils, in HIV-1 dissemination. Thus, strategies designed to prevent basophil-mediated viral capture and transfer may be developed into a new form of therapy. IMPORTANCE Cell-associated HIV-1 infection has been proposed to play a pivotal role in the spread of HIV-1 infection. Here, we demonstrated that human blood-circulating granulocytes, particularly basophils, can capture HIV-1 and mediate viral trans-infection of CD4+ T cells. The expression of a variety of HIV-1 attachment factors, such

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

    PubMed

    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

  8. The Expression of Programmed Death-1 in Circulating CD4+ and CD8+ T Cells during Hepatitis B Virus Infection Progression and Its Correlation with Clinical Baseline Characteristics

    PubMed Central

    Xu, Ping; Chen, Yong-Jing; Chen, Hui; Zhu, Xiao-Yan; Song, Hua-Feng; Cao, Li-Juan

    2014-01-01

    Background/Aims Programmed death-1 (PD-1) expression was investigated in CD4+ and CD8+ T cells from hepatitis B virus (HBV)-infected patients at the chronic hepatitis B (CHB) infection, liver cirrhosis (LC), and hepatocellular carcinoma (HCC) stages. Methods PD-1 expression in circulating CD4+ and CD8+ T cells was detected by flow cytometry. The correlations between PD-1 expression and HBV viral load, alanine aminotransaminase (ALT) levels and aspartate aminotransferase (AST) levels were analyzed using GraphPad Prism 5.0. Results PD-1 expression in CD4+ and CD8+ T cells was significantly increased in both the CHB group and advanced-stage group (LC plus HCC). In the CHB group, PD-1 expression in both CD4+ and CD8+ T cells was positively correlated with the HBV viral load, ALT, and AST levels. However, in the LC plus HCC group, significant correlations between PD-1 expression and the clinical parameters were nearly absent. Conclusions PD-1 expression in peripheral CD4+ and CD8+ T cells is dynamic, changes with HBV infection progression, and is related to HBV viral load and liver function, especially in CHB. PD-1 expression could be utilized as a potential clinical indicator to determine the extent of virus replication and liver injury. PMID:24672661

  9. Memory CD4 T cells in influenza.

    PubMed

    Zens, Kyra D; Farber, Donna L

    2015-01-01

    Influenza A virus is a significant cause of morbidity and mortality worldwide, particularly among young children and the elderly. Current vaccines induce neutralizing antibody responses directed toward highly variable viral surface proteins, resulting in limited heterosubtypic protection to new viral serotypes. By contrast, memory CD4 T cells recognize conserved viral proteins and are cross-reactive to multiple influenza strains. In humans, virus-specific memory CD4 T cells were found to be the protective correlate in human influenza challenge studies, suggesting their key role in protective immunity. In mouse models, memory CD4 T cells can mediate protective responses to secondary influenza infection independent of B cells or CD8 T cells, and can influence innate immune responses. Importantly, a newly defined, tissue-resident CD4 memory population has been demonstrated to be retained in lung tissue and promote optimal protective responses to an influenza infection. Here, we review the current state of results regarding the generation of memory CD4 T cells following primary influenza infection, mechanisms for their enhanced efficacy in protection from secondary challenge including their phenotype, localization, and function in the context of both mouse models and human infection. We also discuss the generation of memory CD4 T cells in response to influenza vaccines and its future implications for vaccinology. PMID:25005927

  10. Levels of circulating myeloid subpopulations and of heme oxygenase-1 do not predict CD4+ T cell recovery after the initiation of antiretroviral therapy for HIV disease

    PubMed Central

    2014-01-01

    The level (or frequency) of circulating monocyte subpopulations such as classical (CD14hiCD16-) and non-classical (CD14dimCD16+) monocytes varies during the course of HIV disease progression and antiretroviral therapy (ART). We hypothesized that such variation and/or differences in the degree to which these cells expressed the immunoregulatory enzyme, heme oxygenase-1 (HO-1), would be associated with CD4+ T cell recovery after the initiation of ART. This hypothesis was tested in a cross-sectional study of four groups of HIV-infected subjects, including those who were seronegative, untreated virologic controllers [detectable viral load (VL) of <1000 copies/mL], untreated virologic non-controllers [VL > 10,000 copies/mL], and ART-mediated virologic controllers [VL < 75 copies/mL]. A longitudinal analysis of ART-treated subjects was also performed along with regression analysis to determine which biomarkers were associated with and/or predictive of CD4+ T cell recovery. Suppressive ART was associated with increased levels of classical monocyte subpopulations (CD14hiCD16-) and decreased levels of non-classical monocyte populations (CD14dimCD16+). Among peripheral blood mononuclear cells (PBMCs), HO-1 was found to be most highly up-regulated in CD14+ monocytes after ex vivo stimulation. Neither the levels of monocyte subpopulations nor of HO-1 expression in CD14+ monocytes were significantly associated with the degree of CD4+ T cell recovery. Monocyte subpopulations and HO-1 gene expression were, however, restored to normal levels by suppressive ART. These results suggest that the level of circulating monocyte subpopulations and their expression of HO-1 have no evident relationship to CD4+ T cell recovery after the initiation of ART. PMID:25180041

  11. Functional and Phenotypic Plasticity of CD4+ T Cell Subsets

    PubMed Central

    Caza, Tiffany; Landas, Steve

    2015-01-01

    The remarkable plasticity of CD4+ T cells allows individuals to respond to environmental stimuli in a context-dependent manner. A balance of CD4+ T cell subsets is critical to mount responses against pathogen challenges to prevent inappropriate activation, to maintain tolerance, and to participate in antitumor immune responses. Specification of subsets is a process beginning in intrathymic development and continuing within the circulation. It is highly flexible to adapt to differences in nutrient availability and the tissue microenvironment. CD4+ T cell subsets have significant cross talk, with the ability to “dedifferentiate” given appropriate environmental signals. This ability is dependent on the metabolic status of the cell, with mTOR acting as the rheostat. Autoimmune and antitumor immune responses are regulated by the balance between regulatory T cells and Th17 cells. When a homeostatic balance of subsets is not maintained, immunopathology can result. CD4+ T cells carry complex roles within tumor microenvironments, with context-dependent immune responses influenced by oncogenic drivers and the presence of inflammation. Here, we examine the signals involved in CD4+ T cell specification towards each subset, interconnectedness of cytokine networks, impact of mTOR signaling, and cellular metabolism in lineage specification and provide a supplement describing techniques to study these processes. PMID:26583116

  12. Increase in frequencies of circulating Th-17 cells correlates with microbial translocation, immune activation and exhaustion in HIV-1 infected patients with poor CD4 T-cell reconstitution.

    PubMed

    Valiathan, Ranjini; Asthana, Deshratn

    2016-05-01

    We analyzed the association of circulating Th-17 cells (cTh-17) with immune activation (IA), immune exhaustion (IE) and regulatory T-cells (T-regs) in 20 human immunodeficiency virus-1 (HIV-1) infected patients with impaired restoration of CD4 T-cell counts despite prolonged suppression of plasma viremia (discordant) and compared it with 20 HIV-1 infected patients showing good immunologic and virologic responses (concordant) following highly active antiretroviral therapy (HAART). Discordant HIV-1 infected patients showed significantly higher frequencies of cTh-17 cells compared to concordant patients and healthy controls after PMA+Ionomicin stimulation. Discordant patients also showed higher CD4 T-cell immune activation (HLA-DR+CD38+) than concordant patients which directly correlated with microbial translocation. Additionally, CD4 T-cells of discordant patients showed higher frequencies of CD4 T-cells expressing multiple immune exhaustion markers (Tim3+PD-1+) which correlated with immune activation indicating that combined analysis of inhibitory molecules along with PD-1 might be a better predictor for immune exhaustion of CD4 T-cells. Increased cTh-17 cell frequency correlated inversely with CD4 T-cell percentages and absolute counts and directly with CD4 T-cell immune activation and T-reg frequencies. Persistent CD4 T-cell immune activation might favor differentiation of activated CD4 T-cells toward cTh-17 phenotype in discordant patients. Discordant patients had significantly lower baseline CD4 T-cell counts and higher viral load at the initiation of HAART and higher immune activation and immune exhaustion after being on HAART for long time indicating that these factors might be associated with an increase in cTh-17 cell frequency, thus, increasing the risk of disease progression despite virologic control. PMID:26817581

  13. A circulating reservoir of pathogenic-like CD4+ T cells shares a genetic and phenotypic signature with the inflamed synovial micro-environment

    PubMed Central

    Spreafico, Roberto; van Loosdregt, Jorg; Wallace, Carol A; Massa, Margherita; Magni-Manzoni, Silvia; Gattorno, Marco; Martini, Alberto; Lovell, Daniel J; Albani, Salvatore

    2016-01-01

    Objectives Systemic immunological processes are profoundly shaped by the micro-environments where antigen recognition occurs. Identifying molecular signatures distinctive of such processes is pivotal to understand pathogenic immune responses and manipulate them for therapeutic purposes. Unfortunately, direct investigation of peripheral tissues, enriched in pathogenic T cells, is often impossible or imposingly invasive in humans. Conversely, blood is easily accessible, but pathogenic signatures are diluted systemically as a result of the strict compartmentalisation of immune responses. In this work, we aimed at defining immune mediators shared between the bloodstream and the synovial micro-environment, and relevant for disease activity in autoimmune arthritis. Methods CD4+ T cells from blood and synovium of patients with juvenile idiopathic arthritis (JIA) were immunophenotyped by flow cytometry. The TCR repertoire of a circulating subset showing similarity with the synovium was analysed through next-generation sequencing of TCR β-chain CDR3 to confirm enrichment in synovial clonotypes. Finally, clinical relevance was established by monitoring the size of this subset in the blood of patients with JIA and rheumatoid arthritis (RA). Results We identified a small subset of circulating CD4+ T cells replicating the phenotypical signature of lymphocytes infiltrating the inflamed synovium. These circulating pathogenic-like lymphocytes (CPLs) were enriched in synovial clonotypes and they exhibited strong production of pro-inflammatory cytokines. Importantly, CPLs were expanded in patients with JIA, who did not respond to therapy, and also correlated with disease activity in patients with RA. Conclusions CPLs provide an accessible reservoir of pathogenic cells recirculating into the bloodstream and correlating with disease activity, to be exploited for diagnostic and research purposes. PMID:25498120

  14. A Subset of Circulating Blood Mycobacteria-Specific CD4 T Cells Can Predict the Time to Mycobacterium tuberculosis Sputum Culture Conversion

    PubMed Central

    Lugongolo, Masixole; Gwala, Thabisile; Kiravu, Agano; Deniso, Pamela; Stewart-Isherwood, Lynsey; Omar, Shaheed Vally; Grobusch, Martin P.; Coetzee, Gerrit; Conradie, Francesca; Ismail, Nazir; Kaplan, Gilla; Fallows, Dorothy

    2014-01-01

    We investigated 18 HIV-negative patients with MDR-TB for M. tuberculosis (Mtb)- and PPD-specific CD4 T cell responses and followed them over 6 months of drug therapy. Twelve of these patients were sputum culture (SC) positive and six patients were SC negative upon enrollment. Our aim was to identify a subset of mycobacteria-specific CD4 T cells that would predict time to culture conversion. The total frequency of mycobacteria-specific CD4 T cells at baseline could not distinguish patients showing positive or negative SC. However, a greater proportion of late-differentiated (LD) Mtb- and PPD-specific memory CD4 T cells was found in SC positive patients than in those who were SC negative (p = 0.004 and p = 0.0012, respectively). Similarly, a higher co-expression of HLA-DR+Ki67+ on Mtb- and PPD-specific CD4 T cells could also discriminate between sputum SC positive versus SC negative (p = 0.004 and p = 0.001, respectively). Receiver operating characteristic (ROC) analysis revealed that baseline levels of Ki67+HLA-DR+ Mtb- and PPD-specific CD4 T cells were predictive of the time to sputum culture conversion, with area-under-the-curve of 0.8 (p = 0.027). Upon treatment, there was a significant decline of these Ki67+HLA-DR+ T cell populations in the first 2 months, with a progressive increase in mycobacteria-specific polyfunctional IFNγ+IL2+TNFα+ CD4 T cells over 6 months. Thus, a subset of activated and proliferating mycobacterial-specific CD4 T cells (Ki67+HLA-DR+) may provide a valuable marker in peripheral blood that predicts time to sputum culture conversion in TB patients at the start of treatment. PMID:25048802

  15. A subset of circulating blood mycobacteria-specific CD4 T cells can predict the time to Mycobacterium tuberculosis sputum culture conversion.

    PubMed

    Riou, Catherine; Gray, Clive M; Lugongolo, Masixole; Gwala, Thabisile; Kiravu, Agano; Deniso, Pamela; Stewart-Isherwood, Lynsey; Omar, Shaheed Vally; Grobusch, Martin P; Coetzee, Gerrit; Conradie, Francesca; Ismail, Nazir; Kaplan, Gilla; Fallows, Dorothy

    2014-01-01

    We investigated 18 HIV-negative patients with MDR-TB for M. tuberculosis (Mtb)- and PPD-specific CD4 T cell responses and followed them over 6 months of drug therapy. Twelve of these patients were sputum culture (SC) positive and six patients were SC negative upon enrollment. Our aim was to identify a subset of mycobacteria-specific CD4 T cells that would predict time to culture conversion. The total frequency of mycobacteria-specific CD4 T cells at baseline could not distinguish patients showing positive or negative SC. However, a greater proportion of late-differentiated (LD) Mtb- and PPD-specific memory CD4 T cells was found in SC positive patients than in those who were SC negative (p = 0.004 and p = 0.0012, respectively). Similarly, a higher co-expression of HLA-DR+ Ki67+ on Mtb- and PPD-specific CD4 T cells could also discriminate between sputum SC positive versus SC negative (p = 0.004 and p = 0.001, respectively). Receiver operating characteristic (ROC) analysis revealed that baseline levels of Ki67+ HLA-DR+ Mtb- and PPD-specific CD4 T cells were predictive of the time to sputum culture conversion, with area-under-the-curve of 0.8 (p = 0.027). Upon treatment, there was a significant decline of these Ki67+ HLA-DR+ T cell populations in the first 2 months, with a progressive increase in mycobacteria-specific polyfunctional IFNγ+ IL2+ TNFα+ CD4 T cells over 6 months. Thus, a subset of activated and proliferating mycobacterial-specific CD4 T cells (Ki67+ HLA-DR+) may provide a valuable marker in peripheral blood that predicts time to sputum culture conversion in TB patients at the start of treatment. PMID:25048802

  16. The effect of extracorporeal photopheresis alone or in combination therapy on circulating CD4+Foxp3+CD25- T-cells in patients with leukemic cutaneous T-cell lymphoma

    PubMed Central

    Shiue, Lisa H.; Couturier, Jacob; Lewis, Dorothy E.; Wei, Caimiao; Ni, Xiao; Duvic, Madeleine

    2015-01-01

    Purpose Extracorporeal photopheresis (ECP) alone or in combination therapy is effective for treatment of leukemic cutaneous T-cell lymphoma (L-CTCL), but its mechanism(s) of action remain unclear. This study was designed to investigate the effect of ECP on regulatory T-cell and CD8+ T-cells in L-CTCL patients. Experimental Design Peripheral blood from 18 L-CTCL patients at baseline, Day 2, 1-month, 3-month, and 6-month post-ECP therapy were analyzed by flow cytometry for CD4+CD25+/high, CD4+Foxp3+CD25+/-, CD3+CD8+, CD3+CD8+CD69+, and CD3+CD8+IFN-γ+ T-cells. Clinical responses were assessed and correlated with changes in these T-cell subsets. Results Twelve of 18 patients achieved clinical responses. The average baseline number of CD4+CD25+/high T-cells of PBMCs in L-CTCL patients was normal (2.2%), but increased at 6-month post-therapy (4.3%, p<0.01). The average baseline number of CD4+Foxp3+ T-cells out of CD4+ T-cells in 9 evaluable patients was high (66.8±13.7%), mostly CD25 negative. The levels of CD4+Foxp3+ T cells in responders were higher (n=6, 93.1±5.7%) than non-responders (n=3, 14.2±16.0%, p<0.01), and they declined in parallel with malignant T-cells. The numbers of CD3+CD8+CD69+ and CD3+CD8+ IFN-γ+ T-cells increased at 3-month post-therapy in 5 of 6 patients studied. Conclusions ECP alone or in combination therapy might be effective in L-CTCL patients whose malignant T-cells have a CD4+Foxp3+CD25- phenotype. PMID:25772268

  17. Oral immunization with a Salmonella enterica serovar typhi vaccine induces specific circulating mucosa-homing CD4(+) and CD8(+) T cells in humans.

    PubMed

    Lundin, B Samuel; Johansson, Camilla; Svennerholm, Ann-Mari

    2002-10-01

    The kinetics and homing characteristics of T-cell responses in humans after mucosal immunizations have not been well characterized. Therefore, we have investigated the magnitude and duration of such responses as well as the homing receptor expression of antigen-specific peripheral blood T cells by using an oral model vaccine, i.e., the live, attenuated Salmonella enterica serovar Typhi vaccine (Ty21a). Eight volunteers were each given three doses of the vaccine 2 days apart, and blood samples, from which CD4(+) and CD8(+) T cells were selected by the use of magnetic beads, were collected before vaccination and at regular intervals thereafter. To purify the potentially antigen-specific gut-homing T cells, CD45RA(-) integrin beta(7)(+) cells were further sorted by flow cytometry. The sorted cells were then stimulated in vitro with the serovar Typhi vaccine strain, and the proliferation of cells and the cytokine production were measured. Following vaccination, there was a large increase in both the proliferation of and the gamma interferon (IFN-gamma) production by blood T cells stimulated with the vaccine strain. The responses were seen among both CD4(+) and CD8(+) T cells, although the CD8(+) cells produced the largest amounts of IFN-gamma. Peak responses were seen 7 to 14 days after the onset of vaccination. Furthermore, most of the IFN-gamma produced by both CD4(+) and CD8(+) cells emanated from cells with the potential to home to mucosal tissues, as the integrin beta(7)-expressing memory T cells produced around 10-fold more IFN-gamma than the remaining populations. In conclusion, we demonstrate that oral vaccination with a live oral bacterial vaccine induces antigen-specific CD4(+) and CD8(+) memory T cells, almost all of which express the gut-homing integrin beta(7). PMID:12228290

  18. Canine CD4(+)CD8(+) double-positive T cells can develop from CD4(+) and CD8(+) T cells.

    PubMed

    Bismarck, Doris; Moore, Peter F; Alber, Gottfried; von Buttlar, Heiner

    2014-12-15

    For a long time the expression of the CD4 and CD8 receptor on peripheral blood T cells was thought to be mutually exclusive. However, in canine peripheral blood, similar to other species as swine or human for example, mature CD4(+)CD8(+) double-positive (dp) T cells exist which simultaneously express both surface receptors and have features of activated T cells. Canine CD4(+)CD8(+)dp T cells are heterogeneous and can be divided into three subpopulations by their intensity of CD4 and CD8α expression: CD4(bright)CD8α(bright), CD4(dim)CD8α(bright) and CD4(dim)CD8α(dim). The number of CD4(+)CD8α(+)dp T cells increases after in vitro stimulation of canine peripheral blood mononuclear cells (PBMC) raising the question of their progenitor(s). Thus, the aim of our study was to characterize the progenitor(s) of canine CD4(+)CD8α(+)dp T cells. By cell tracing experiments we identified both CD4(+) single-positive (sp) and also CD8α(+)sp T cells as progenitors of canine CD4(+)CD8α(+)dp T cells after in vitro stimulation. CD4(+)sp T cells almost exclusively upregulate a CD8αα homodimer, whereas CD8α(+)sp T cells can become CD4(+)CD8αβ(+) or CD4(+)CD8αα(+). Even in the absence of other cells, highly purified CD4(+)sp T cells can become double-positive upon in vitro stimulation, whereas highly purified CD8α(+)sp T cells fail to do so. However, CD8α(+)sp T cells can additionally express CD4 when stimulated in the presence of CD4(-)CD8α(-) double-negative (dn) cells or more efficiently when stimulated in the presence of CD4(+)sp T cells. Soluble factors secreted by CD4(+)sp T cells are sufficient for the upregulation of CD4 on CD8α(+)sp T cells, but direct cell-cell contact between CD4(+)sp and CD8α(+)sp T cells is more efficient. mRNA analysis shows that additional CD4 expression on CD8α(+)sp T cells results from de novo synthesis. Thus, uptake of soluble CD4 or trogocytosis is less likely as mechanism for generation of canine double-positive T cells. CD4(+)CD

  19. Administration of interleukin-7 increases CD4 T cells in idiopathic CD4 lymphocytopenia.

    PubMed

    Sheikh, Virginia; Porter, Brian O; DerSimonian, Rebecca; Kovacs, Stephen B; Thompson, William L; Perez-Diez, Ainhoa; Freeman, Alexandra F; Roby, Gregg; Mican, JoAnn; Pau, Alice; Rupert, Adam; Adelsberger, Joseph; Higgins, Jeanette; Bourgeois, Jeffrey S; Jensen, Stig M R; Morcock, David R; Burbelo, Peter D; Osnos, Leah; Maric, Irina; Natarajan, Ven; Croughs, Therese; Yao, Michael D; Estes, Jacob D; Sereti, Irini

    2016-02-25

    Idiopathic CD4 lymphopenia (ICL) is a rare syndrome defined by low CD4 T-cell counts (<300/µL) without evidence of HIV infection or other known cause of immunodeficiency. ICL confers an increased risk of opportunistic infections and has no established treatment. Interleukin-7 (IL-7) is fundamental for thymopoiesis, T-cell homeostasis, and survival of mature T cells, which provides a rationale for its potential use as an immunotherapeutic agent for ICL. We performed an open-label phase 1/2A dose-escalation trial of 3 subcutaneous doses of recombinant human IL-7 (rhIL-7) per week in patients with ICL who were at risk of disease progression. The primary objectives of the study were to assess safety and the immunomodulatory effects of rhIL-7 in ICL patients. Injection site reactions were the most frequently reported adverse events. One patient experienced a hypersensitivity reaction and developed non-neutralizing anti-IL-7 antibodies. Patients with autoimmune diseases that required systemic therapy at screening were excluded from the study; however, 1 participant developed systemic lupus erythematosus while on study and was excluded from further rhIL-7 dosing. Quantitatively, rhIL-7 led to an increase in the number of circulating CD4 and CD8 T cells and tissue-resident CD3 T cells in the gut mucosa and bone marrow. Functionally, these T cells were capable of producing cytokines after mitogenic stimulation. rhIL-7 was well tolerated at biologically active doses and may represent a promising therapeutic intervention in ICL. This trial was registered at www.clinicaltrials.gov as #NCT00839436. PMID:26675348

  20. EFFECT OF GM-CSF ON CIRCULATING CD8+ AND CD4+ T CELL RESPONSES TO A MULTIPEPTIDE MELANOMA VACCINE: OUTCOME OF A MULTICENTER RANDOMIZED TRIAL

    PubMed Central

    Slingluff, Craig L.; Petroni, Gina R.; Olson, Walter C.; Smolkin, Mark E.; Ross, Merrick I.; Haas, Naomi B.; Grosh, William W.; Boisvert, Marc E; Kirkwood, John M.; Chianese-Bullock, Kimberly A.

    2009-01-01

    Purpose GM-CSF administered locally together with vaccines can augment T cell responses in animal models. Human experience has been limited to small and uncontrolled trials. Thus, a multicenter randomized phase II trial was performed to determine whether local administration of GM-CSF augments immunogenicity of a multipeptide vaccine. It also assessed immunogenicity of administration in one vs. two vaccine sites. Experimental Design 121 eligible patients with resected stage IIB-IV melanoma were vaccinated with 12 MHC Class I-restricted melanoma peptides (12MP) to stimulate CD8+ T cells, plus an HLA-DR restricted tetanus helper peptide to stimulate CD4+ T cells, emulsified in incomplete Freund’s adjuvant, with or without 110 mcg GM-CSF. Among 119 evaluable patients, T cell responses were assessed by IFN-gamma ELIspot assay and tetramer analysis. Clinical outcomes were recorded. Results CD8+ T cell response rates to the 12MP (by day 50), with or without GM-CSF were 34% and 73%, respectively (p<0.001) by direct ELIspot assay. Tetramer analyses corroborated the functional data. CD4+ T cell responses to tetanus helper peptide were higher without GM-CSF (95% vs. 77%, p=0.005). There was no significant difference by number of vaccine sites. Three-year overall and disease-free survival estimates [95% CI] were 76% [67, 83%] and 52% [43, 61%] respectively, with too few events to assess differences by study group. Conclusions High immune response rates for this multipeptide vaccine were achieved, but CD8+ and CD4+ T cell responses were lower when administered with GM-CSF. These data challenge the value of local GM-CSF as a vaccine adjuvant in humans. PMID:19903780

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

    PubMed

    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

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

    PubMed

    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

  3. Impact of sepsis on CD4 T cell immunity

    PubMed Central

    Cabrera-Perez, Javier; Condotta, Stephanie A.; Badovinac, Vladimir P.; Griffith, Thomas S.

    2014-01-01

    Sepsis remains the primary cause of death from infection in hospital patients, despite improvements in antibiotics and intensive-care practices. Patients who survive severe sepsis can display suppressed immune function, often manifested as an increased susceptibility to (and mortality from) nosocomial infections. Not only is there a significant reduction in the number of various immune cell populations during sepsis, but there is also decreased function in the remaining lymphocytes. Within the immune system, CD4 T cells are important players in the proper development of numerous cellular and humoral immune responses. Despite sufficient clinical evidence of CD4 T cell loss in septic patients of all ages, the impact of sepsis on CD4 T cell responses is not well understood. Recent findings suggest that CD4 T cell impairment is a multipronged problem that results from initial sepsis-induced cell loss. However, the subsequent lymphopenia-induced numerical recovery of the CD4 T cell compartment leads to intrinsic alterations in phenotype and effector function, reduced repertoire diversity, changes in the composition of naive antigen-specific CD4 T cell pools, and changes in the representation of different CD4 T cell subpopulations (e.g., increases in Treg frequency). This review focuses on sepsis-induced alterations within the CD4 T cell compartment that influence the ability of the immune system to control secondary heterologous infections. The understanding of how sepsis affects CD4 T cells through their numerical loss and recovery, as well as function, is important in the development of future treatments designed to restore CD4 T cells to their presepsis state. PMID:24791959

  4. CD4 (T-Cell) Tests

    MedlinePlus

    ... 3 to 6 months when starting antiretroviral therapy (ART, see fact sheet 403 ). Once treatment has increased ... Fact Sheet 514 ) Monitoring treatment success: With successful ART, CD4 counts rise. Sometimes they rise quickly. Other ...

  5. Blind T-cell homeostasis in CD4-deficient mice.

    PubMed

    Adleman, L M; Wofsy, D

    1996-04-01

    Recently, it has been proposed that normal T-cell count is maintained by a homeostatic mechanism which is "blind" to the distinction between CD4+ T cells and CD8+ T cells. Interest in this blind homeostasis hypothesis (BHH) stems in part from its implications regarding the pathogenesis and treatment of HIV infection. In this report, BHH was tested in CD4-deficient mice. We found that as predicted by BHH, despite the absence of CD4+ T cells, CD4-deficient mice maintain normal absolute T-cell counts in the blood and spleen primarily through a marked increase in CD8+ T cells. These findings provide strong new support for BHH. PMID:8601219

  6. Low SAMHD1 expression following T-cell activation and proliferation renders CD4+ T cells susceptible to HIV-1

    PubMed Central

    Ruffin, Nicolas; Brezar, Vedran; Ayinde, Diana; Lefebvre, Cécile; Wiesch, Julian Schulze Zur; van Lunzen, Jan; Bockhorn, Maximilian; Schwartz, Olivier; Hocini, Hakim; Lelievre, Jean-Daniel; Banchereau, Jacques; Levy, Yves; Seddiki, Nabila

    2015-01-01

    Objectives: HIV-1 replication depends on the state of cell activation and division. It is established that SAMHD1 restricts HIV-1 infection of resting CD4+ T cells. The modulation of SAMHD1 expression during T-cell activation and proliferation, however, remains unclear, as well as a role for SAMHD1 during HIV-1 pathogenesis. Methods: SAMHD1 expression was assessed in CD4+ T cells after their activation and in-vitro HIV-1 infection. We performed phenotype analyzes using flow cytometry on CD4+ T cells from peripheral blood and lymph nodes from cohorts of HIV-1-infected individuals under antiretroviral treatment or not, and controls. Results: We show that SAMHD1 expression decreased during CD4+ T-cell proliferation in association with an increased susceptibility to in-vitro HIV-1 infection. Additionally, circulating memory CD4+ T cells are enriched in cells with low levels of SAMHD1. These SAMHD1low cells are highly differentiated, exhibit a large proportion of Ki67+ cycling cells and are enriched in T-helper 17 cells. Importantly, memory SAMHD1low cells were depleted from peripheral blood of HIV-infected individuals. We also found that follicular helper T cells present in secondary lymphoid organs lacked the expression of SAMHD1, which was accompanied by a higher susceptibility to HIV-1 infection in vitro. Conclusion: We demonstrate that SAMHD1 expression is decreased during CD4+ T-cell activation and proliferation. Also, CD4+ T-cell subsets known to be more susceptible to HIV-1 infection, for example, T-helper 17 and follicular helper T cells, display lower levels of SAMHD1. These results pin point a role for SAMHD1 expression in HIV-1 infection and the concomitant depletion of CD4+ T cells. PMID:25715102

  7. SAMHD1 restricts HIV-1 infection in resting CD4+ T cells

    PubMed Central

    Baldauf, Hanna-Mari; Pan, Xiaoyu; Erikson, Elina; Schmidt, Sarah; Daddacha, Waaqo; Burggraf, Manja; Schenkova, Kristina; Ambiel, Ina; Wabnitz, Guido; Gramberg, Thomas; Panitz, Sylvia; Flory, Egbert; Landau, Nathaniel R; Sertel, Serkan; Rutsch, Frank; Lasitschka, Felix; Kim, Baek; König, Renate; Fackler, Oliver T; Keppler, Oliver T

    2013-01-01

    Unlike activated CD4+ T cells, resting CD4+ T cells are highly resistant to productive HIV-1 infection1–8. Early after HIV-1 entry, a major block limits reverse transcription of incoming viral genomes. Here we show that the deoxynucleoside triphosphate triphosphohydrolase SAMHD1 prevents reverse transcription of HIV-1 RNA in resting CD4+ T cells. SAMHD1 is abundantly expressed in resting CD4+ T cells circulating in peripheral blood and residing in lymphoid organs. The early restriction to infection in unstimulated CD4+ T cells is overcome by HIV-1 or HIV-2 virions into which viral Vpx is artificially or naturally packaged, respectively, or by addition of exogenous deoxynucleosides. Vpx-mediated proteasomal degradation of SAMHD1 and elevation of intracellular deoxynucleotide pools precede successful infection by Vpx-carrying HIV. Resting CD4+ T cells from healthy donors following SAMHD1 silencing or from a patient with Aicardi-Goutières syndrome homozygous for a nonsense mutation in SAMHD1 were permissive for HIV-1 infection. Thus, SAMHD1 imposes an effective restriction to HIV-1 infection in the large pool of noncycling CD4+ T cells in vivo. Bypassing SAMHD1 was insufficient for the release of viral progeny, implicating other barriers at later stages of HIV replication. Together, these findings may unveil new ways to interfere with the immune evasion and T cell immunopathology of pandemic HIV-1. PMID:22972397

  8. Memory CD4 T cells emerge from effector T-cell progenitors.

    PubMed

    Harrington, Laurie E; Janowski, Karen M; Oliver, James R; Zajac, Allan J; Weaver, Casey T

    2008-03-20

    A hallmark of adaptive immunity is the generation of memory T cells that confer long-lived, antigen-specific protection against repeat challenges by pathogens. Understanding the mechanisms by which memory T cells arise is important for rational vaccination strategies and improved therapeutic interventions for chronic infections and autoimmune disorders. The large clonal expansion of CD8 T cells in response to some infections has made the development of CD8 T-cell memory more amenable to study, giving rise to a model of memory cell differentiation in which a fraction of fully competent effector T cells transition into long-lived memory T cells. Delineation of CD4 T-cell memory development has proved more difficult as a result of limitations on tracking the smaller populations of CD4 effector T cells generated during a pathogenic challenge, complicating efforts to determine whether CD4 memory T cells are direct descendants of effector T cells or whether they develop by alternative pathways. Here, using two complementary cytokine reporter mouse models to identify interferon (IFN)-gamma-positive effector T cells and track their fate, we show that the lineage relationship between effector and memory CD4 T cells resembles that for CD8 T cells responding to the same pathogen. We find that, in parallel with effector CD8 T cells, IFN-gamma-positive effector CD4 T cells give rise to long-lived memory T cells capable of anamnestic responses to antigenic rechallenge. PMID:18322463

  9. Plasticity of human CD4 T cell subsets.

    PubMed

    Geginat, Jens; Paroni, Moira; Maglie, Stefano; Alfen, Johanna Sophie; Kastirr, Ilko; Gruarin, Paola; De Simone, Marco; Pagani, Massimiliano; Abrignani, Sergio

    2014-01-01

    Human beings are exposed to a variety of different pathogens, which induce tailored immune responses and consequently generate highly diverse populations of pathogen-specific T cells. CD4(+) T cells have a central role in adaptive immunity, since they provide essential help for both cytotoxic T cell- and antibody-mediated responses. In addition, CD4(+) regulatory T cells are required to maintain self-tolerance and to inhibit immune responses that could damage the host. Initially, two subsets of CD4(+) helper T cells were identified that secrete characteristic effector cytokines and mediate responses against different types of pathogens, i.e., IFN-γ secreting Th1 cells that fight intracellular pathogens, and IL-4 producing Th2 cells that target extracellular parasites. It is now well established that this dichotomy is insufficient to describe the complexity of CD4(+) T cell differentiation, and in particular the human CD4 compartment contains a myriad of T cell subsets with characteristic capacities to produce cytokines and to home to involved tissues. Moreover, it has become increasingly clear that these T cell subsets are not all terminally differentiated cells, but that the majority is plastic and that in particular central memory T cells can acquire different properties and functions in secondary immune responses. In addition, there is compelling evidence that helper T cells can acquire regulatory functions upon chronic stimulation in inflamed tissues. The plasticity of antigen-experienced human T cell subsets is highly relevant for translational medicine, since it opens new perspectives for immune-modulatory therapies for chronic infections, autoimmune diseases, and cancer. PMID:25566245

  10. Plasticity of Human CD4 T Cell Subsets

    PubMed Central

    Geginat, Jens; Paroni, Moira; Maglie, Stefano; Alfen, Johanna Sophie; Kastirr, Ilko; Gruarin, Paola; De Simone, Marco; Pagani, Massimiliano; Abrignani, Sergio

    2014-01-01

    Human beings are exposed to a variety of different pathogens, which induce tailored immune responses and consequently generate highly diverse populations of pathogen-specific T cells. CD4+ T cells have a central role in adaptive immunity, since they provide essential help for both cytotoxic T cell- and antibody-mediated responses. In addition, CD4+ regulatory T cells are required to maintain self-tolerance and to inhibit immune responses that could damage the host. Initially, two subsets of CD4+ helper T cells were identified that secrete characteristic effector cytokines and mediate responses against different types of pathogens, i.e., IFN-γ secreting Th1 cells that fight intracellular pathogens, and IL-4 producing Th2 cells that target extracellular parasites. It is now well established that this dichotomy is insufficient to describe the complexity of CD4+ T cell differentiation, and in particular the human CD4 compartment contains a myriad of T cell subsets with characteristic capacities to produce cytokines and to home to involved tissues. Moreover, it has become increasingly clear that these T cell subsets are not all terminally differentiated cells, but that the majority is plastic and that in particular central memory T cells can acquire different properties and functions in secondary immune responses. In addition, there is compelling evidence that helper T cells can acquire regulatory functions upon chronic stimulation in inflamed tissues. The plasticity of antigen-experienced human T cell subsets is highly relevant for translational medicine, since it opens new perspectives for immune-modulatory therapies for chronic infections, autoimmune diseases, and cancer. PMID:25566245

  11. Transcriptional Regulatory Networks for CD4 T Cell Differentiation

    PubMed Central

    Zhu, Jinfang

    2015-01-01

    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, Th1, Th2, Th17, and inducible regulatory 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 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. PMID:24839135

  12. Human regulatory T cells control TCR signaling and susceptibility to suppression in CD4+ T cells.

    PubMed

    Chellappa, Stalin; Lieske, Nora V; Hagness, Morten; Line, Pål D; Taskén, Kjetil; Aandahl, Einar M

    2016-07-01

    Human CD4(+)CD25(hi)FOXP3(+) regulatory T cells maintain immunologic tolerance and prevent autoimmune and inflammatory immune responses. Regulatory T cells undergo a similar activation cycle as conventional CD4(+) T cells upon antigen stimulation. Here, we demonstrate that T cell receptors and costimulation are required to activate the regulatory T cell suppressive function. Regulatory T cells suppressed the T cell receptor signaling in effector T cells in a time-dependent manner that corresponded with inhibition of cytokine production and proliferation. Modulation of the activation level and thereby the suppressive capacity of regulatory T cells imposed distinct T cell receptor signaling signatures and hyporesponsiveness in suppressed and proliferating effector T cells and established a threshold for effector T cell proliferation. The immune suppression of effector T cells was completely reversible upon removal of regulatory T cells. However, the strength of prior immune suppression by regulatory T cells and corresponding T cell receptor signaling in effector T cells determined the susceptibility to suppression upon later reexposure to regulatory T cells. These findings demonstrate how the strength of the regulatory T cell suppressive function determines intracellular signaling, immune responsiveness, and the later susceptibility of effector T cells to immune suppression and contribute to unveiling the complex interactions between regulatory T cells and effector T cells. PMID:26715685

  13. A novel differentiation pathway from CD4+ T cells to CD4T cells for maintaining immune system homeostasis

    PubMed Central

    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

  14. CD4+ T cell activation in multiple sclerosis.

    PubMed

    Verselis, S J; Goust, J M

    1987-02-01

    Interleukin-2 (IL-2) production by CD4-enriched T cells from multiple sclerosis (MS) patients and normal individuals stimulated with concanavalin A (conA) and/or autologous and allogeneic B lymphoid cell lines (B-LCL) was evaluated 24, 48 and 96 h after stimulation. ConA-stimulated CD4+ cells from MS patients did not produce significantly more IL-2 than normal CD4+ cells. In contrast, autologous B-LCL-induced IL-2 production by MS CD4+ cells significantly (P = 0.026) exceeded that produced by normal CD4+ cells identically stimulated after 24 h in culture. Differences in IL-2 production by CD4+ cells from MS patients reached highest significance using allogeneic B-LCL, whose stimulatory capacity was similar, whether established from normal individuals or MS patients. This increased IL-2 production in response to B-LCL may represent a supranormal response of CD4+ cells from MS patients to class II major histocompatibility (MHC)-associated stimuli. It suggests that the deficiency of suppressor T cell functions postulated to play a role in MS does not arise from a lack of IL-2 induction and might indicate that bursts of IL-2 production could play a role in MS. PMID:3492511

  15. Defective CD8 T Cell Memory Following Acute Infection Without CD4 T Cell Help

    NASA Astrophysics Data System (ADS)

    Sun, Joseph C.; Bevan, Michael J.

    2003-04-01

    The CD8+ cytotoxic T cell response to pathogens is thought to be CD4+ helper T cell independent because infectious agents provide their own inflammatory signals. Mice that lack CD4+ T cells mount a primary CD8 response to Listeria monocytogenes equal to that of wild-type mice and rapidly clear the infection. However, protective memory to a challenge is gradually lost in the former animals. Memory CD8+ T cells from normal mice can respond rapidly, but memory CD8+ T cells that are generated without CD4 help are defective in their ability to respond to secondary encounters with antigen. The results highlight a previously undescribed role for CD4 help in promoting protective CD8 memory development.

  16. Roscovitine Suppresses CD4+ T Cells and T Cell-Mediated Experimental Uveitis

    PubMed Central

    Zhang, Zili; Liu, Qi; Leskov, Konstantin S.; Wu, Xiumei; Duan, Jie; Zhang, Gary L.; Hall, Mark; Rosenbaum, James T.

    2013-01-01

    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. PMID:24260551

  17. CD4+ T cell anergy prevents autoimmunity and generates regulatory T cell precursors

    PubMed Central

    Kalekar, Lokesh A.; Schmiel, Shirdi E.; Nandiwada, Sarada L.; Lam, Wing Y.; Barsness, Laura O.; Zhang, Na; Stritesky, Gretta L.; Malhotra, Deepali; Pauken, Kristen E.; Linehan, Jonathan L.; O’Sullivan, M. Gerard; Fife, Brian T.; Hogquist, Kristin A.; Jenkins, Marc K.; Mueller, Daniel L.

    2015-01-01

    The role that anergy, an acquired state of T cell functional unresponsiveness, plays in natural peripheral tolerance remains unclear. In this study, we demonstrate that anergy is selectively induced in fetal antigen-specific maternal CD4+ T cells during pregnancy. A naturally occurring subpopulation of anergic polyclonal CD4+ T cells, enriched in self antigen-specific T cell receptors, is also observed in healthy hosts. Neuropilin-1 expression in anergic conventional CD4+ T cells is associated with thymic regulatory T cell (Treg cell)-related gene hypomethylation, and this correlates with their capacity to differentiate into Foxp3+ Treg cells that suppress immunopathology. Thus, our data suggest that not only is anergy induction important in preventing autoimmunity, but it also generates the precursors for peripheral Treg cell differentiation. PMID:26829766

  18. Microbial exposure alters HIV-1-induced mucosal CD4+ T cell death pathways Ex vivo

    PubMed Central

    2014-01-01

    Background Early HIV-1 infection causes massive CD4+ T cell death in the gut and translocation of bacteria into the circulation. However, the programmed cell death (PCD) pathways used by HIV-1 to kill CD4+ T cells in the gut, and the impact of microbial exposure on T cell loss, remain unclear. Understanding mucosal HIV-1 triggered PCD could be advanced by an ex vivo system involving lamina propria mononuclear cells (LPMCs). We therefore modeled the interactions of gut LPMCs, CCR5-tropic HIV-1 and a commensal gut bacterial species, Escherichia coli. In this Lamina Propria Aggregate Culture (LPAC) model, LPMCs were infected with HIV-1BaL by spinoculation and cultured in the presence or absence of heat killed E.coli. CD4+ T cell numbers derived from flow cytometry and viable cell counts were reported relative to mock infection. Viable cells were identified by viability dye exclusion (AqVi), and intracellular HIV-1 Gag p24 protein was used to identify infected cells. Annexin V and AqVi were used to identify apoptotic versus necrotic cells. Caspase-1 and Caspase-3 activities were blocked using specific inhibitors YVAD and DEVD, respectively. Results CD4+ T cell depletion following HIV-1 infection was reproducibly observed by 6 days post infection (dpi). Depletion at 6 dpi strongly correlated with infection frequency at 4 dpi, was significantly blocked by Efavirenz treatment, and was primarily driven by p24-negative cells that were predominantly necrotic. HIV-1 infection significantly induced CD4+ T-cell intrinsic Caspase-1 activity, whereas Caspase-1 inhibition, but not Caspase-3 inhibition, significantly blocked CD4+ T cell depletion. Exposure to E.coli enhanced HIV-1 infection and CD4+ T depletion, and significantly increased the number of apoptotic p24+ cells. Notably, CD4+ T cell depletion in the presence of E.coli was partially blocked by Caspase-3, but not by Caspase-1 inhibition. Conclusions In the LPAC model, HIV-1 induced Caspase-1 mediated pyroptosis in

  19. Access of protective antiviral antibody to neuronal tissues requires CD4 T-cell help.

    PubMed

    Iijima, Norifumi; Iwasaki, Akiko

    2016-05-26

    Circulating antibodies can access most tissues to mediate surveillance and elimination of invading pathogens. Immunoprivileged tissues such as the brain and the peripheral nervous system are shielded from plasma proteins by the blood-brain barrier and blood-nerve barrier, respectively. Yet, circulating antibodies must somehow gain access to these tissues to mediate their antimicrobial functions. Here we examine the mechanism by which antibodies gain access to neuronal tissues to control infection. Using a mouse model of genital herpes infection, we demonstrate that both antibodies and CD4 T cells are required to protect the host after immunization at a distal site. We show that memory CD4 T cells migrate to the dorsal root ganglia and spinal cord in response to infection with herpes simplex virus type 2. Once inside these neuronal tissues, CD4 T cells secrete interferon-γ and mediate local increase in vascular permeability, enabling antibody access for viral control. A similar requirement for CD4 T cells for antibody access to the brain is observed after intranasal challenge with vesicular stomatitis virus. Our results reveal a previously unappreciated role of CD4 T cells in mobilizing antibodies to the peripheral sites of infection where they help to limit viral spread. PMID:27225131

  20. Distinct Translational Control in CD4+ T Cell Subsets

    PubMed Central

    Yurchenko, Ekaterina; Zheng, Lei; Gandin, Valentina; Topisirovic, Ivan; Li, Shui; Wagner, Carston R.; Sonenberg, Nahum; Piccirillo, Ciriaco A.

    2013-01-01

    Regulatory T cells expressing the transcription factor Foxp3 play indispensable roles for the induction and maintenance of immunological self-tolerance and immune homeostasis. Genome-wide mRNA expression studies have defined canonical signatures of T cell subsets. Changes in steady-state mRNA levels, however, often do not reflect those of corresponding proteins due to post-transcriptional mechanisms including mRNA translation. Here, we unveil a unique translational signature, contrasting CD4+Foxp3+ regulatory T (TFoxp3+) and CD4+Foxp3− non-regulatory T (TFoxp3−) cells, which imprints subset-specific protein expression. We further show that translation of eukaryotic translation initiation factor 4E (eIF4E) is induced during T cell activation and, in turn, regulates translation of cell cycle related mRNAs and proliferation in both TFoxp3− and TFoxp3+ cells. Unexpectedly, eIF4E also affects Foxp3 expression and thereby lineage identity. Thus, mRNA–specific translational control directs both common and distinct cellular processes in CD4+ T cell subsets. PMID:23658533

  1. Heterogeneity of Human CD4(+) T Cells Against Microbes.

    PubMed

    Sallusto, Federica

    2016-05-20

    CD4(+) T helper (Th) cells play a central role in the adaptive immune response by providing help to B cells and cytotoxic T cells and by releasing different types of cytokines in tissues to mediate protection against a wide range of pathogenic microorganisms. These functions are performed by different types of Th cells endowed with distinct migratory capacities and effector functions. Here we discuss how studies of the human T cell response to microbes have advanced our understanding of Th cell functional heterogeneity, in particular with the discovery of a distinct Th1 subset involved in the response to Mycobacteria and the characterization of two types of Th17 cells specific for extracellular bacteria or fungi. We also review new approaches to dissect at the clonal level the human CD4(+) T cell response induced by pathogens or vaccines that have revealed an unexpected degree of intraclonal diversification and propose a progressive and selective model of CD4(+) T cell differentiation. PMID:27168241

  2. CD4+ and CD8+ T Cell Activation Are Associated with HIV DNA in Resting CD4+ T Cells

    PubMed Central

    Cockerham, Leslie R.; Siliciano, Janet D.; Sinclair, Elizabeth; O'Doherty, Una; Palmer, Sarah; Yukl, Steven A.; Strain, Matt C.; Chomont, Nicolas; Hecht, Frederick M.; Siliciano, Robert F.; Richman, Douglas D.; Deeks, Steven G.

    2014-01-01

    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. PMID:25340755

  3. Human CD4+ T-Cells: A Role for Low-Affinity Fc Receptors

    PubMed Central

    Chauhan, Anil K.

    2016-01-01

    Both lymphoid and myeloid cells express Fc receptors (FcRs). Low-affinity FcRs engage circulating immune complexes, which results in the cellular activation and pro-inflammatory cytokine production. FcRs participate in the internalization, transport, and/or recycling of antibodies and antigens. Cytosolic FcRs also route these proteins to proteasomes and antigen-presentation pathways. Non-activated CD4+ T-cells do not express FcRs. Once activated, naive CD4+ T-cells express FcγRIIIa, which, upon IC ligation, provide a costimulatory signal for the differentiation of these cells into effector cell population. FcγRIIIa present on CD4+ T-cell membrane could internalize nucleic acid-containing ICs and elicit a cross-talk with toll-like receptors. FcγRIIIa common γ-chain forms a heterodimer with the ζ-chain of T-cell receptor complex, suggesting a synergistic role for these receptors. This review first summarizes our current understanding of FcRs on CD4+ T-cells. Thereafter, I will attempt to correlate the findings from the recent literature on FcRs and propose a role for these receptors in modulating adaptive immune responses via TLR signaling, nucleic acid sensing, and epigenetic changes in CD4+ T-cells. PMID:27313579

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

    PubMed

    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. PMID:26526988

  5. The potential role of cell surface complement regulators and circulating CD4+ CD25+ T-cells in the development of autoimmune myasthenia gravis

    PubMed Central

    Hamdoon, Mohamed Nasreldin Thabit; Fattouh, Mona; El-din, Asmaa Nasr; Elnady, Hassan M.

    2016-01-01

    Introduction CD4+CD25+ regulatory T-lymphocytes (T-regs) and regulators of complement activity (RCA) involving CD55 and CD59 play an important role in the prevention of autoimmune diseases. However, their role in the pathogenesis of human autoimmune myasthenia gravis (MG) remains unclear. This study aimed to determine the frequency of peripheral blood T-regs and CD4+ T-helper (T-helper) cells and the red blood cells (RBCs) level of expression of CD55 and CD59 in MG patients. Methods Fourteen patients with MG in neurology outpatient clinics of Sohag University Hospital and Sohag General Hospital from March 2014 to December 2014, and 10 age-matched healthy controls participated in this case-control study. We did flowcytometric assessments of the percentage of peripheral T-regs and T-helper cells and the level of expression of CD55 and CD59 on RBCs in the peripheral blood of patients and controls. Results There was a statistically significant decrease in the percentage of peripheral blood T-regs and T-regs/T-helper cell ratio in the MG patients group. Moreover, the level of expression of CD55, CD59, and dual expression of CD55/CD59 on RBCs were statistically significantly lower in MG patients than those of healthy controls. However, regression analysis indicated that there was no significant correlation between all the measured parameters and disease duration or staging. Conclusion Functional defects in the T-regs and RCA may play a role in the pathogenesis of autoimmune MG and their functional modulation may represent an alternative therapeutic strategy for MG treatment. PMID:26955441

  6. Determinants of immunodominance for CD4 T cells.

    PubMed

    Kim, AeRyon; Sadegh-Nasseri, Scheherazade

    2015-06-01

    The term immunodominance was originally defined as a restricted T cell response to a short peptide sequence derived from a given protein. The question of what determines immunodominance has been a longstanding battle for the past two decades. Hundreds of papers have been written on different aspects of epitope selection during antigen processing documenting the complexity of the process. Antigen processing machinery involves several accessory molecules and chaperons coevolved with proteins of Major Histocompatibility Complex (MHC) molecules that each plays its part in epitope selection. These molecules are targeted to specialized vesicular compartments that also accommodate antigen processing enzymes called cathepsins. Within the antigen processing compartments, highly regulated pH gradient and reducing conditions and enzymes necessary for denaturation of the antigens are available and function to optimize processing of antigen and selection of the fittest for transport to the cell membrane and presentation to T cells. Despite the complexity, a cell free reductionist antigen processing system was recently reported that included only few purified proteins, but was shown to process and select physiologically relevant epitopes from full length protein antigens. Due to its minimalist nature the system has been quite helpful in dissecting the factors that contribute to epitope selection during antigen processing. In this review, we would summarize and highlight models that may explain how the dominant epitope may be selected for presentation to CD4(+) helper T cells. PMID:25576665

  7. Antibody induced CD4 down-modulation of T cells is site-specifically mediated by CD64+ cells

    PubMed Central

    Vogel, Stephanie; Grabski, Elena; Buschjäger, Daniela; Klawonn, Frank; Döring, Marius; Wang, Junxi; Fletcher, Erika; Bechmann, Ingo; Witte, Torsten; Durisin, Martin; Schraven, Burkhart; Mangsbo, Sara M.; Schönfeld, Kurt; Czeloth, Niklas; Kalinke, Ulrich

    2015-01-01

    Treatment of PBMC with the CD4-specific mAb BT-061 induces CD4 down-modulation of T cells. Here we report that addition of BT-061 to purified T cells did not confer this effect, whereas incubation of T cells in BT-061 coated wells restored CD4 down-modulation. These results implied that Fcγ receptor mediated cell-cell interactions played a role. In consistence with this hypothesis PBMC depleted of CD64+ monocytes did not confer CD4 down-modulation of BT-061 decorated T cells. Strikingly, CD4 down-modulation was observed in BT-061 treated synovial fluid punctuated from patients’ inflamed joints that comprised enhanced numbers of CD64+ cells. In contrast, in a circulating whole blood system injection of BT-061 did not induce CD4 down-modulation, due to CD64 saturation by serum IgG. Similarly, tonsil derived mononuclear cells devoid of CD64+ cells did not show CD4 down-modulation, whereas addition of blood derived monocytes restored the effect. Thus, the interaction of BT-061 decorated T cells with CD64+ cells is needed for CD4 down-modulation, implying that in patients BT-061 would primarily induce CD4 down-modulation at inflammatory sites. These results highlight the need not only to examine the interaction of a given mAb with single FcγR, but also the immunological environment that is appropriate to support such interactions. PMID:26670584

  8. Antibody induced CD4 down-modulation of T cells is site-specifically mediated by CD64(+) cells.

    PubMed

    Vogel, Stephanie; Grabski, Elena; Buschjäger, Daniela; Klawonn, Frank; Döring, Marius; Wang, Junxi; Fletcher, Erika; Bechmann, Ingo; Witte, Torsten; Durisin, Martin; Schraven, Burkhart; Mangsbo, Sara M; Schönfeld, Kurt; Czeloth, Niklas; Kalinke, Ulrich

    2015-01-01

    Treatment of PBMC with the CD4-specific mAb BT-061 induces CD4 down-modulation of T cells. Here we report that addition of BT-061 to purified T cells did not confer this effect, whereas incubation of T cells in BT-061 coated wells restored CD4 down-modulation. These results implied that Fcγ receptor mediated cell-cell interactions played a role. In consistence with this hypothesis PBMC depleted of CD64(+) monocytes did not confer CD4 down-modulation of BT-061 decorated T cells. Strikingly, CD4 down-modulation was observed in BT-061 treated synovial fluid punctuated from patients' inflamed joints that comprised enhanced numbers of CD64(+) cells. In contrast, in a circulating whole blood system injection of BT-061 did not induce CD4 down-modulation, due to CD64 saturation by serum IgG. Similarly, tonsil derived mononuclear cells devoid of CD64(+) cells did not show CD4 down-modulation, whereas addition of blood derived monocytes restored the effect. Thus, the interaction of BT-061 decorated T cells with CD64(+) cells is needed for CD4 down-modulation, implying that in patients BT-061 would primarily induce CD4 down-modulation at inflammatory sites. These results highlight the need not only to examine the interaction of a given mAb with single FcγR, but also the immunological environment that is appropriate to support such interactions. PMID:26670584

  9. Skin-resident memory CD4+ T cells enhance protection against Leishmania major infection

    PubMed Central

    Glennie, Nelson D.; Yeramilli, Venkata A.; Beiting, Daniel P.; Volk, Susan W.; Weaver, Casey T.

    2015-01-01

    Leishmaniasis causes a significant disease burden worldwide. Although Leishmania-infected patients become refractory to reinfection after disease resolution, effective immune protection has not yet been achieved by human vaccines. Although circulating Leishmania-specific T cells are known to play a critical role in immunity, the role of memory T cells present in peripheral tissues has not been explored. Here, we identify a population of skin-resident Leishmania-specific memory CD4+ T cells. These cells produce IFN-γ and remain resident in the skin when transplanted by skin graft onto naive mice. They function to recruit circulating T cells to the skin in a CXCR3-dependent manner, resulting in better control of the parasites. Our findings are the first to demonstrate that CD4+ TRM cells form in response to a parasitic infection, and indicate that optimal protective immunity to Leishmania, and thus the success of a vaccine, may depend on generating both circulating and skin-resident memory T cells. PMID:26216123

  10. Beta-catenin signaling mediates CD4 expression on mature CD8+ T cells.

    PubMed

    Schenkel, Jason M; Zloza, Andrew; Li, Wei; Narasipura, Srinivas D; Al-Harthi, Lena

    2010-08-15

    Upon activation, a subset of mature human CD8(+) T cells re-expresses CD4 dimly. This CD4(dim)CD8(bright) T cell population is genuine and enriched in antiviral CD8(+) T cell responses. The signaling pathway that leads to CD4 re-expression on mature CD8(+) T cells is not clear. Given that Wnt/beta-catenin signaling plays a critical role in the transition of CD4(-)CD8(-) to CD4(+)CD8(+) thymocytes, we determined whether beta-catenin mediates CD4 expression on mature CD8(+) T cells. We demonstrate that active beta-catenin expression is 20-fold higher on CD4(dim)CD8(bright) than CD4(-)CD8(+) T cells. Activation of beta-catenin signaling, through LiCl or transfection with a constitutively active construct of beta-catenin, induced CD4 on CD8(+) T cells by approximately 10-fold. Conversely, inhibition of beta-catenin signaling through transfection with a dominant-negative construct for T cell factor-4, a downstream effector of beta-catenin signaling, diminished CD4 expression on CD8(+) T cells by 50% in response to T cell activation. Beta-catenin-mediated induction of CD4 on CD8(+) T cells is transcriptionally regulated, as it induced CD4 mRNA, and T cell factor/lymphoid enhancer factor sites were identified within the human CD4 promoter. Further, beta-catenin expression induced the antiapoptotic factor BcL-xL, suggesting that beta-catenin may mediate protection against activation-induced cell death. Collectively, these data demonstrate that beta-catenin is critical in inducing CD4 expression on mature CD8(+) T cells, suggesting that it is a common pathway for CD4 upregulation among thymocytes and mature CD8(+) T cells. PMID:20631314

  11. Canine CD4+CD8+ double positive T cells in peripheral blood have features of activated T cells.

    PubMed

    Bismarck, Doris; Schütze, Nicole; Moore, Peter; Büttner, Mathias; Alber, Gottfried; Buttlar, Heiner v

    2012-10-15

    In dogs a CD4(+)CD8(+) double positive T cell subpopulation exists that has not been phenotypically defined yet. We demonstrate that canine CD4(+)CD8(+) T cells are mature CD1a(-) and TCRαβ(+) T cells. To analyse the activation potential of CD4(+)CD8(+) T cells, PBMC from dogs vaccinated against canine distemper virus (CDV) were re-stimulated with CDV. Upon antigen-specific stimulation, the CD4(+)CD8(+) T cell fraction increases and consists nearly exclusively of proliferated cells. Similarly, other features of activated effector/memory T cells such as up-regulation of CD25 and MHC-II as well as down-regulation of CD62L (L-selectin) were observed in CD4(+)CD8(+) T cells after stimulation. Canine CD4(+)CD8(+) T cells are less abundant, but more heterogeneous than porcine ones, comprising a small proportion expressing the β chain of CD8 in addition to the CD8α chain, like human CD4(+)CD8(+) T cells. In summary, this analysis provides the basis for functional characterisation of the in vivo relevance of CD4(+)CD8(+) T cells in T-cell mediated immunity. PMID:22789871

  12. Measurement of phenotype and absolute number of circulating heparin-binding hemagglutinin, ESAT-6 and CFP-10, and purified protein derivative antigen-specific CD4 T cells can discriminate active from latent tuberculosis infection.

    PubMed

    Hutchinson, Paul; Barkham, Timothy M S; Tang, Wenying; Kemeny, David M; Chee, Cynthia Bin-Eng; Wang, Yee T

    2015-02-01

    The tuberculin skin test (TST) and interferon gamma (IFN-γ) release assays (IGRAs) are used as adjunctive tests for the evaluation of suspected cases of active tuberculosis (TB). However, a positive test does not differentiate latent from active TB. We investigated whether flow cytometric measurement of novel combinations of intracellular cytokines and surface makers on CD4 T cells could differentiate between active and latent TB after stimulation with Mycobacterium tuberculosis-specific proteins. Blood samples from 60 patients referred to the Singapore Tuberculosis Control Unit for evaluation for active TB or as TB contacts were stimulated with purified protein derivative (PPD), ESAT-6 and CFP-10, or heparin-binding hemagglutinin (HBHA). The CD4 T cell cytokine response (IFN-γ, interleukin-2 [IL-2], interleukin-17A [IL-17A], interleukin-22 [IL-22], granulocyte-macrophage colony-stimulating factor [GM-CSF], and tumor necrosis factor alpha [TNF-α]) and surface marker expression (CD27, CXCR3, and CD154) were then measured. We found that the proportion of PPD-specific CD4 T cells, defined as CD154(+) TNF-α(+) cells that were negative for CD27 and positive for GM-CSF, gave the strongest discrimination between subjects with latent and those with active TB (area under the receiver operator characteristic [ROC] curve of 0.9277; P < 0.0001). Also, the proportions and absolute numbers of HBHA-specific CD4 T cells were significantly higher in those with latent TB infection, particularly CD154(+) TNF-α(+) IFN-γ(+) IL-2(+) and CD154(+) TNF-α(+) CXCR3(+). Finally, we found that the ratio of ESAT-6- and CFP-10-responding to HBHA-responding CD4 T cells was significantly different between the two study populations. In conclusion, we found novel markers of M. tuberculosis-specific CD4 cells which differentiate between active and latent TB. PMID:25520147

  13. Vaccine-Elicited CD4 T Cells Induce Immunopathology Following Chronic LCMV Infection

    PubMed Central

    Penaloza-MacMaster, Pablo; Barber, Daniel L.; Wherry, E. John; Provine, Nicholas M.; Teigler, Jeffrey E.; Parenteau, Lily; Blackmore, Stephen; Borducchi, Erica N.; Larocca, Rafael A.; Yates, Kathleen B.; Shen, Hao; Haining, W. Nicholas; Sommerstein, Rami; Pinschewer, Daniel D.; Ahmed, Rafi; Barouch, Dan. H.

    2015-01-01

    CD4 T cells promote innate and adaptive immune responses, but how vaccine-elicited CD4 T cells contribute to immune protection remains unclear. Here we evaluated whether induction of virus-specific CD4 T cells by vaccination would protect mice against infection with chronic lymphocytic choriomeningitis virus (LCMV). Immunization with vaccines that selectively induced CD4 T cell responses resulted in catastrophic inflammation and mortality following challenge with a persistent strain of LCMV. Immunopathology required antigen-specific CD4 T cells and was associated with a cytokine storm, generalized inflammation, and multi-organ system failure. Virus-specific CD8 T cells or antibodies abrogated the pathology. These data demonstrate that vaccine-elicited CD4 T cells in the absence of effective antiviral immune responses can trigger lethal immunopathology. PMID:25593185

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

    PubMed

    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

  15. Cooperativity of HIV-Specific Cytolytic CD4 T Cells and CD8 T Cells in Control of HIV Viremia

    PubMed Central

    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; Robb, Merlin L.; Michael, Nelson L.; Bolton, Diane

    2015-01-01

    ABSTRACT 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 transcriptional signature compared to Th1 CD4+ cells but shared similar features with HIV-specific cytolytic CD8+ T cells. Furthermore, HIV-specific cytolytic CD4+ T cells showed comparable killing activity relative to HIV-specific CD8+ T cells and worked cooperatively in the elimination of virally infected cells. Interestingly, we found that cytolytic CD4+ T cells emerge early during acute HIV infection and tightly follow acute viral load trajectory. This emergence was associated to the early viral set point, suggesting an involvement in early control, in spite of CD4 T cell susceptibility to HIV infection. Our data suggest cytolytic CD4+ T cells as an independent subset distinct from Th1 cells that show combined activity with CD8+ T cells in the long-term control of HIV infection. IMPORTANCE The ability of the immune system to control chronic HIV infection is of critical interest to both vaccine design and therapeutic approaches. Much research has focused on the effect of the ability of CD8+ T cells to control the virus, while CD4+ T cells have been overlooked as effectors in HIV control due to the fact that they are preferentially infected. We show here that a subset of HIV-specific CD4+ T cells cooperate in the cytolytic control of HIV replication. Moreover, these cells represent a distinct subset of CD4+ T cells showing significant transcriptional and phenotypic differences compared to HIV-specific Th1 cells but with similarities to CD8+ T cells. These findings are

  16. Blimp-1-mediated CD4 T cell exhaustion causes CD8 T cell dysfunction during chronic toxoplasmosis.

    PubMed

    Hwang, SuJin; Cobb, Dustin A; Bhadra, Rajarshi; Youngblood, Ben; Khan, Imtiaz A

    2016-08-22

    CD8, but not CD4, T cells are considered critical for control of chronic toxoplasmosis. Although CD8 exhaustion has been previously reported in Toxoplasma encephalitis (TE)-susceptible model, our current work demonstrates that CD4 not only become exhausted during chronic toxoplasmosis but this dysfunction is more pronounced than CD8 T cells. Exhausted CD4 population expressed elevated levels of multiple inhibitory receptors concomitant with the reduced functionality and up-regulation of Blimp-1, a transcription factor. Our data demonstrates for the first time that Blimp-1 is a critical regulator for CD4 T cell exhaustion especially in the CD4 central memory cell subset. Using a tamoxifen-dependent conditional Blimp-1 knockout mixed bone marrow chimera as well as an adoptive transfer approach, we show that CD4 T cell-intrinsic deletion of Blimp-1 reversed CD8 T cell dysfunction and resulted in improved pathogen control. To the best of our knowledge, this is a novel finding, which demonstrates the role of Blimp-1 as a critical regulator of CD4 dysfunction and links it to the CD8 T cell dysfunctionality observed in infected mice. The critical role of CD4-intrinsic Blimp-1 expression in mediating CD4 and CD8 T cell exhaustion may provide a rational basis for designing novel therapeutic approaches. PMID:27481131

  17. Nanotubes connect CD4+ T cells to airway smooth muscle cells: novel mechanism of T cell survival.

    PubMed

    Al Heialy, Saba; Zeroual, Melissa; Farahnak, Soroor; McGovern, Toby; Risse, Paul-André; Novali, Mauro; Lauzon, Anne-Marie; Roman, Horia N; Martin, James G

    2015-06-15

    Contact between airway smooth muscle (ASM) cells and activated CD4(+) T cells, a key interaction in diseases such as asthma, triggers ASM cell proliferation and enhances T cell survival. We hypothesized that direct contact between ASM and CD4(+) T cells facilitated the transfer of anti-apoptotic proteins via nanotubes, resulting in increased survival of activated CD4(+) T cells. CD4(+) T cells, isolated from PBMCs of healthy subjects, when activated and cocultured with ASM cells for 24 h, formed nanotubes that were visualized by immunofluorescence and atomic force microscopy. Cell-to-cell transfer of the fluorescent dye calcein-AM confirmed cytoplasmic communication via nanotubes. Immunoreactive B cell lymphoma 2 (Bcl-2) and induced myeloid leukemia cell differentiation protein (Mcl-1), two major anti-apoptotic proteins, were present within the nanotubes. Downregulation of Mcl-1 by small interfering RNA in ASM cells significantly increased T cell apoptosis, whereas downregulation of Bcl-2 had no effect. Transfer of GFP-tagged Mcl-1 from ASM cells to CD4(+) T cells via the nanotubes confirmed directionality of transfer. In conclusion, activated T cells communicate with ASM cells via nanotube formation. Direct transfer of Mcl-1 from ASM to CD(+) T cells via nanotubes is involved in T cell survival. This study provides a novel mechanism of survival of CD4(+) T cells that is dependent on interaction with a structural cell. PMID:25934863

  18. Micropatterning of costimulatory ligands enhances CD4+ T cell function

    PubMed Central

    Shen, Keyue; Thomas, V. Kaye; Dustin, Michael L.; Kam, Lance C.

    2008-01-01

    Spatial organization of signaling complexes is a defining characteristic of the immunological synapse (IS), but its impact on cell communication is unclear. In T cell–APC pairs, more IL-2 is produced when CD28 clusters are segregated from central supramolecular activation cluster (cSMAC)-localized CD3 and into the IS periphery. However, it is not clear in these cellular experiments whether the increased IL-2 is driven by the pattern itself or by upstream events that precipitate the patterns. In this article, we recapitulate key features of physiological synapses using planar costimulation arrays containing antibodies against CD3 and CD28, surrounded by ICAM-1, created by combining multiple rounds of microcontact printing on a single surface. Naïve T cells traverse these arrays, stopping at features of anti-CD3 antibodies and forming a stable synapse. We directly demonstrate that presenting anti-CD28 in the cell periphery, surrounding an anti-CD3 feature, enhances IL-2 secretion by naïve CD4+ T cells compared with having these signals combined in the center of the IS. This increased cytokine production correlates with NF-κB translocation and requires PKB/Akt signaling. The ability to arbitrarily and independently control the locations of anti-CD3 and anti-CD28 offered the opportunity to examine patterns not precisely attainable in cell–cell interfaces. With these patterns, we show that the peripheral presentation of CD28 has a larger impact on IL-2 secretion than CD3 colocalization/segregation. PMID:18505845

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

    PubMed Central

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

    2011-01-01

    Typhoid fever is a persistent infection caused by host-adapted Salmonella strains adept at circumventing immune-mediated host defences. Given the importance of T cells in protection, the culling of activated CD4+ T cells after primary infection has been proposed as a potential immune evasion strategy used by this pathogen. We demonstrate that the purging of activated antigen-specific CD4+ T cells after virulent Salmonella infection requires SPI-2 encoded virulence determinants, and is not restricted only to cells with specificity to Salmonella-expressed antigens, but extends to CD4+ T cells primed to expand by co-infection with recombinant Listeria monocytogenes. Unexpectedly, however, the loss of activated CD4+ T cells during Salmonella infection demonstrated using a monoclonal population of adoptively transferred CD4+ T cells was not reproduced among the endogenous repertoire of antigen-specific CD4+ T cells identified with MHC class II tetramer. Analysis of T-cell receptor variable segment usage revealed the selective loss and reciprocal enrichment of defined CD4+ T-cell subsets after Salmonella co-infection that is associated with the purging of antigen-specific cells with the highest intensity of tetramer staining. Hence, virulent Salmonella triggers the selective culling of high avidity activated CD4+ T-cell subsets, which re-shapes the repertoire of antigen-specific T cells that persist later after infection. PMID:22044420

  20. CD4+ primary T cells expressing HCV-core protein upregulate Foxp3 and IL-10, suppressing CD4 and CD8 T cells.

    PubMed

    Fernandez-Ponce, Cecilia; Dominguez-Villar, Margarita; Aguado, Enrique; Garcia-Cozar, Francisco

    2014-01-01

    Adaptive T cell responses are critical for controlling HCV infection. While there is clinical evidence of a relevant role for regulatory T cells in chronic HCV-infected patients, based on their increased number and function; mechanisms underlying such a phenomena are still poorly understood. Accumulating evidence suggests that proteins from Hepatitis C virus can suppress host immune responses. We and others have shown that HCV is present in CD4+ lymphocytes from chronically infected patients and that HCV-core protein induces a state of unresponsiveness in the CD4+ tumor cell line Jurkat. Here we show that CD4+ primary T cells lentivirally transduced with HCV-core, not only acquire an anergic phenotype but also inhibit IL-2 production and proliferation of bystander CD4+ or CD8+ T cells in response to anti-CD3 plus anti-CD28 stimulation. Core-transduced CD4+ T cells show a phenotype characterized by an increased basal secretion of the regulatory cytokine IL-10, a decreased IFN-γ production upon stimulation, as well as expression of regulatory T cell markers, CTLA-4, and Foxp3. A significant induction of CD4+CD25+CD127(low)PD-1(high)TIM-3(high) regulatory T cells with an exhausted phenotype was also observed. Moreover, CCR7 expression decreased in HCV-core expressing CD4+ T cells explaining their sequestration in inflamed tissues such as the infected liver. This work provides a new perspective on de novo generation of regulatory CD4+ T cells in the periphery, induced by the expression of a single viral protein. PMID:24465502

  1. Longitudinal Requirement for CD4+ T Cell Help for Adenovirus Vector–Elicited CD8+ T Cell Responses

    PubMed Central

    Provine, Nicholas M.; Larocca, Rafael A.; Penaloza-MacMaster, Pablo; Borducchi, Erica N.; McNally, Anna; Parenteau, Lily R.; Kaufman, David R.

    2014-01-01

    Despite the widespread use of replication-incompetent recombinant adenovirus (Ad) vectors as candidate vaccine platforms, the mechanism by which these vectors elicit CD8+ T cell responses remains poorly understood. Our data demonstrate that induction and maintenance of CD8+ T cell responses by Ad vector immunization is longitudinally dependent on CD4+ T cell help for a prolonged period. Depletion of CD4+ T cells in wild type mice within the first 8 d following Ad immunization resulted in dramatically reduced induction of Ag-specific CD8+ T cells, decreased T-bet and eomesodermin expression, impaired KLRG1+ effector differentiation, and atypical expression of the memory markers CD127, CD27, and CD62L. Moreover, these CD8+ T cells failed to protect against a lethal recombinant Listeria monocytogenes challenge. Depletion of CD4+ T cells between weeks 1 and 4 following immunization resulted in increased contraction of memory CD8+ T cells. These data demonstrate a prolonged temporal requirement for CD4+ T cell help for vaccine-elicited CD8+ T cell responses in mice. These findings have important implications in the design of vaccines aimed at eliciting CD8+ T cell responses and may provide insight into the impaired immunogenicity of vaccines in the context of AIDS and other CD4+ T cell immune deficiencies. PMID:24778441

  2. Pathogenic CD4 T cells in type 1 diabetes recognize epitopes formed by peptide fusion.

    PubMed

    Delong, Thomas; Wiles, Timothy A; Baker, Rocky L; Bradley, Brenda; Barbour, Gene; Reisdorph, Richard; Armstrong, Michael; Powell, Roger L; Reisdorph, Nichole; Kumar, Nitesh; Elso, Colleen M; DeNicola, Megan; Bottino, Rita; Powers, Alvin C; Harlan, David M; Kent, Sally C; Mannering, Stuart I; Haskins, Kathryn

    2016-02-12

    T cell-mediated destruction of insulin-producing β cells in the pancreas causes type 1 diabetes (T1D). CD4 T cell responses play a central role in β cell destruction, but the identity of the epitopes recognized by pathogenic CD4 T cells remains unknown. We found that diabetes-inducing CD4 T cell clones isolated from nonobese diabetic mice recognize epitopes formed by covalent cross-linking of proinsulin peptides to other peptides present in β cell secretory granules. These hybrid insulin peptides (HIPs) are antigenic for CD4 T cells and can be detected by mass spectrometry in β cells. CD4 T cells from the residual pancreatic islets of two organ donors who had T1D also recognize HIPs. Autoreactive T cells targeting hybrid peptides may explain how immune tolerance is broken in T1D. PMID:26912858

  3. Eomesodermin Expression in CD4+ T Cells Restricts Peripheral Foxp3 Induction.

    PubMed

    Lupar, Ekaterina; Brack, Maria; Garnier, Laure; Laffont, Sophie; Rauch, Katharina S; Schachtrup, Kristina; Arnold, Sebastian J; Guéry, Jean-Charles; Izcue, Ana

    2015-11-15

    CD4(+) T cells polarize into effector Th subsets characterized by signature transcription factors and cytokines. Although T-bet drives Th1 responses and represses the alternative Th2, Th17, and Foxp3(+) regulatory T cell fates, the role of the T-bet-related transcription factor eomesodermin (Eomes) in CD4(+) T cells is less well understood. In this study, we analyze the expression and effects of Eomes in mouse CD4(+) T lymphocytes. We find that Eomes is readily expressed in activated CD4(+) Th1 T cells in vivo. Eomes(+) CD4(+) T cells accumulated in old mice, under lymphopenic conditions in a T cell transfer model of colitis, and upon oral Ag administration. However, despite its expression, genetic deletion of Eomes in CD4(+) T cells did not impact on IFN-γ production nor increase Th2 or Th17 responses. In contrast, Eomes deficiency favored the accumulation of Foxp3(+) cells in old mice, after in vivo differentiation of Eomes-deficient naive CD4(+) T cells, and in response to oral Ag in a cell-intrinsic way. Enforced Eomes expression during in vitro regulatory T cell induction also reduced Foxp3 transcription. Likewise, bystander Eomes-deficient CD4(+) T cells were more efficient at protecting from experimental autoimmune encephalitis compared with wild-type CD4(+) T cells. This enhanced capacity of Eomes-deficient CD4(+) T cells to inhibit EAE in trans was associated with an enhanced frequency of Foxp3(+) cells. Our data identify a novel role for Eomes in CD4(+) T cells and indicate that Eomes expression may act by limiting Foxp3 induction, which may contribute to the association of EOMES to susceptibility to multiple sclerosis. PMID:26453746

  4. ESTABLISHING MEAN CD4+ T CELL VALUES AMONG HEALTHY JAVANESE ADULTS IN INDONESIA.

    PubMed

    Prasetyo, Afiono Agung; Zaini, Khilyat Ulin Nur

    2015-07-01

    The objective of this study was to establish mean CD4+ T cell values among healthy Javanese adults in Indonesia. Two hundred forty-one healthy adults (119 women and 122 men), aged 18-65 years, were enrolled in the study. CD4+ T cells were analyzed by immunophenotyping. The mean absolute CD4+ T cell count was 753.3 ± 270.3 cells/µl (median = 725.0 cells/µl) and the mean CD4+ T cell percentage was 32.6 ± 7.7%, (median = 31.0%). Women had a slightly higher mean absolute CD4+ T cell count and CD4+ T cell percentage (779.1 ± 271.0 cells/ µl; 33.4 ± 8.2%) than men (728.2 ± 268.3 cells/µl; 31.8 ± 7.1%), but the differences were not statistically significant (p = 0.126, p = 0.216, respectively). The mean absolute CD4+ T cell varied significantly by age group (p = 0.002). Sixty-one point seven percent of men studied (37/60) had a CD4+ T cell count less than 500 cells/µl (OR 1.8; 95% CI = 1.001-3.300). Absolute CD4+ T cell counts among Javanese Indonesians varied significantly by age. PMID:26867386

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

    PubMed

    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. Quantitative and qualitative characterization of expanded CD4+ T cell clones in rheumatoid arthritis patients

    PubMed Central

    Ishigaki, Kazuyoshi; Shoda, Hirofumi; Kochi, Yuta; Yasui, Tetsuro; Kadono, Yuho; Tanaka, Sakae; Fujio, Keishi; Yamamoto, Kazuhiko

    2015-01-01

    Rheumatoid arthritis (RA) is an autoimmune destructive arthritis associated with CD4+ T cell-mediated immunity. Although expanded CD4+ T cell clones (ECs) has already been confirmed, the detailed characteristics of ECs have not been elucidated in RA. Using combination of a single-cell analysis and next-generation sequencing (NGS) in TCR repertoire analysis, we here revealed the detailed nature of ECs by examining peripheral blood (PB) from 5 RA patients and synovium from 1 RA patient. When we intensively investigated the single-cell transcriptome of the most expanded clones in memory CD4+ T cells (memory-mECs) in RA-PB, senescence-related transcripts were up-regulated, indicating circulating ECs were constantly stimulated. Tracking of the transcriptome shift within the same memory-mECs between PB and the synovium revealed the augmentations in senescence-related gene expression and the up-regulation of synovium-homing chemokine receptors in the synovium. Our in-depth characterization of ECs in RA successfully demonstrated the presence of the specific immunological selection pressure, which determines the phenotype of ECs. Moreover, transcriptome tracking added novel aspects to the underlying sequential immune processes. Our approach may provide new insights into the pathophysiology of RA. PMID:26245356

  7. Immediate Dysfunction of Vaccine-Elicited CD8+ T Cells Primed in the Absence of CD4+ T Cells.

    PubMed

    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

    2016-09-01

    CD4(+) T cell help is critical for optimal CD8(+) T cell memory differentiation and maintenance in many experimental systems. In addition, many reports have identified reduced primary CD8(+) T cell responses in the absence of CD4(+) T cell help, which often coincides with reduced Ag or pathogen clearance. In this study, 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 d 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

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

    NASA Astrophysics Data System (ADS)

    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.

  9. CD4+ T cell-dependent and CD4+ T cell-independent cytokine-chemokine network changes in the immune responses of HIV-infected individuals.

    PubMed

    Arnold, Kelly B; Szeto, Gregory L; Alter, Galit; Irvine, Darrell J; Lauffenburger, Douglas A

    2015-10-20

    A vital defect in the immune systems of HIV-infected individuals is the loss of CD4(+) T cells, resulting in impaired immune responses. We hypothesized that there were CD4(+) T cell-dependent and CD4(+) T cell-independent alterations in the immune responses of HIV-1(+) individuals. To test this, we analyzed the secretion of cytokines and chemokines from stimulated peripheral blood mononuclear cell (PBMC) populations from HIV(+) donors, healthy donors, and healthy donors with CD4(+) T cells experimentally depleted. Multivariate analyses of 16 cytokines and chemokines at 6 and 72 hours after three stimuli (antibody-coated beads to stimulate T cells and R848 or lipopolysaccharide to stimulate innate immune cells) enabled integrative analysis of secreted profiles. Two major effects in HIV(+) PBMCs were not reproduced upon depletion of CD4(+) T cells in healthy PBMCs: (i) HIV(+) PBMCs maintained T cell-associated secreted profiles after T cell stimulation; (ii) HIV(+) PBMCs showed impaired interferon-γ (IFN-γ) secretion early after innate stimulation. These changes arose from hyperactive T cells and debilitated natural killer (NK) cell, respectively. Modeling and experiments showed that early IFN-γ secretion predicted later differences in secreted profiles in vitro. This effect was recapitulated in healthy PBMCs by blocking the IFN-γ receptor. Thus, we identified a critical deficiency in NK cell responses of HIV-infected individuals, independent of CD4(+) T cell depletion, which directs secreted profiles. Our findings illustrate a broad approach for identifying key disease-associated nodes in a multicellular, multivariate signaling network. PMID:26486173

  10. Development and Function of Protective and Pathologic Memory CD4 T Cells

    PubMed Central

    Jaigirdar, Shafqat Ahrar; MacLeod, Megan K. L.

    2015-01-01

    Immunological 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. PMID:26441961

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

    PubMed

    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

  12. Itk Signals Promote Neuroinflammation by Regulating CD4+ T-Cell Activation and Trafficking

    PubMed Central

    Kannan, Arun K.; Kim, Do-Geun

    2015-01-01

    Here we demonstrate that interleukin-2-inducible T-cell kinase (Itk) signaling in cluster of differentiation 4-positive (CD4+) T cells promotes experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis (MS). We show that Itk−/− mice exhibit reduced disease severity, and transfer of Itk−/− CD4+ T cells into T cell-deficient recipients results in lower disease severity. We observed a significant reduction of CD4+ T cells in the CNS of Itk−/− mice or recipients of Itk−/− CD4+ T cells during EAE, which is consistent with attenuated disease. Itk−/− CD4+ T cells exhibit defective response to myelin antigen stimulation attributable to displacement of filamentous actin from the CD4+ coreceptor. This results in inadequate transmigration of Itk−/− CD4+ T cells into the CNS and across brain endothelial barriers in vitro. Finally, Itk−/− CD4+ T cells show significant reduction in production of T-helper 1 (Th1) and Th17 cytokines and exhibit skewed T effector/T regulatory cell ratios. These results indicate that signaling by Itk promotes autoimmunity and CNS inflammation, suggesting that it may be a viable target for treatment of MS. PMID:25568116

  13. Immediate Dysfunction of Vaccine-Elicited CD8+ T Cells Primed in the Absence of CD4+ T Cells

    PubMed Central

    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

    2016-01-01

    CD4+ T cell help is critical for optimal CD8+ T cell memory differentiation and maintenance in many experimental systems. In addition, many reports have identified reduced primary CD8+ T cell responses in the absence of CD4+ T cell help, which often coincides with reduced Ag or pathogen clearance. In this study, 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 d 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

  14. CD31 is required on CD4+ T cells to promote T cell survival during Salmonella infection

    PubMed Central

    Ross, Ewan A; Coughlan, Ruth E; Flores-Langarica, Adriana; Bobat, Saeeda; Marshall, Jennifer L; Hussain, Khiyam; Charlesworth, James; Abhyankar, Nikita; Hitchcock, Jessica; Gil, Cristina; López-Macías, Constantino; Henderson, Ian R; Khan, Mahmood; Watson, Steve P; MacLennan, Ian C M; Buckley, Christopher D; Cunningham, Adam F

    2011-01-01

    Haematopoietic cells constitutively express CD31/PECAM1 a signalling, adhesion receptor associated with controlling responses to inflammatory stimuli. Although expressed on CD4+ T cells, its function on these cells is unclear. To address this we have used a model of systemic Salmonella infection that induces high levels of T cell activation and depends upon CD4+ T cells for resolution. Infection of CD31-deficient (CD31KO) mice demonstrates that these mice fail to control infection effectively. During infection, CD31KO mice have diminished numbers of total CD4+ T cells and IFN-γ-secreting Th1 cells. This is despite a higher proportion of CD31KO CD4+ T cells exhibiting an activated phenotype, and an undiminished capacity to prime normally and polarize to Th1. Reduced numbers of T cells reflected the increased propensity of naive and activated CD31KO T cells to undergo apoptosis after infection compared to wild-type (WT) T cells. Using adoptive transfer experiments we show that loss of CD31 on CD4+ T cells alone is sufficient to account for the defective CD31KO T cell accumulation. These data are consistent with CD31 helping to control T cell activation as in its absence T cells have a greater propensity to become activated, resulting in increased susceptibility to become apoptotic. The impact of CD31 loss on T cell homeostasis becomes most pronounced during severe, inflammatory and immunological stresses such as those caused by systemic Salmonella infection. This identifies a novel role for CD31 in regulating CD4 T cell homeostasis. PMID:21734076

  15. Increased CD4+/CD8+ Double-Positive T Cells in Chronic Chagasic Patients

    PubMed Central

    Giraldo, Nicolas A.; Bolaños, Natalia I.; Cuellar, Adriana; Guzman, Fanny; Uribe, Ana Maria; Bedoya, Astrid; Olaya, Natalia; Cucunubá, Zulma M.; Roa, Nubia; Rosas, Fernando; Velasco, Víctor; Puerta, Concepción J.; González, John M.

    2011-01-01

    Background CD4+/CD8+ double positive (DP) T cells have been described in healthy individuals as well as in patients with autoimmune and chronic infectious diseases. In chronic viral infections, this cell subset has effector memory phenotype and displays antigen specificity. No previous studies of double positive T cells in parasite infections have been carried out. Methodology/Principal Findings Seventeen chronic chagasic patients (7 asymptomatic and 10 symptomatic) and 24 non-infected donors, including 12 healthy and 12 with non-chagasic cardiomyopathy donors were analyzed. Peripheral blood was stained for CD3, CD4, CD8, HLA-DR and CD38, and lymphocytes for intracellular perforin. Antigen specificity was assessed using HLA*A2 tetramers loaded with T. cruzi K1 or influenza virus epitopes. Surface expression of CD107 and intracellular IFN-γ production were determined in K1-specific DP T cells from 11 chagasic donors. Heart tissue from a chronic chagasic patient was stained for both CD8 and CD4 by immunochemistry. Chagasic patients showed higher frequencies of DP T cells (2.1%±0.9) compared with healthy (1.1%±0.5) and non-chagasic cardiomyopathy (1.2%±0.4) donors. DP T cells from Chagasic patients also expressed more HLA-DR, CD38 and perforin and had higher frequencies of T. cruzi K1-specific cells. IFN-γ production in K1-specific cells was higher in asymptomatic patients after polyclonal stimulation, while these cells tended to degranulate more in symptomatic donors. Immunochemistry revealed that double positive T cells infiltrate the cardiac tissue of a chagasic donor. Conclusions Chagasic patients have higher percentages of circulating double positive T cells expressing activation markers, potential effector molecules and greater class I antigenic specificity against T. cruzi. Although K1 tetramer positive DP T cell produced little IFN-γ, they displayed degranulation activity that was increased in symptomatic patients. Moreover, K1-specific DP T cells can

  16. T Cell-Extrinsic CD18 Attenuates Antigen-Dependent CD4+ T cell Activation In Vivo1

    PubMed Central

    Wu, Xingxin; Lahiri, Amit; Sarin, Ritu; Abraham, Clara

    2015-01-01

    The β2 integrins (CD11/CD18) are heterodimeric leukocyte adhesion molecules expressed on hematopoietic cells. The role of T cell-intrinsic CD18 in trafficking of naïve T cells to secondary lymphoid organs, and in antigen-dependent T cell activation in vitro and in vivo has been well-defined. However, the T cell-extrinsic role for CD18, including on antigen presenting cells (APC), in contributing to T cell activation in vivo is less well understood. We examined the role for T cell-extrinsic CD18 in the activation of WT CD4+ T cells in vivo through the adoptive transfer of DO11.10 Ag-specific CD4+ T cells into CD18−/− mice. We found that T cell-extrinsic CD18 was required for attenuating OVA-induced T cell proliferation in peripheral lymph nodes (PLN). The increased proliferation of WT DO11.10 CD4+ T cells in CD18−/− PLN was associated with a higher percentage of APC, and these APC demonstrated an increased activation profile and increased Ag-uptake, in particular in F4/80+ APC. Depletion of F4/80+ cells both reduced and equalized antigen-dependent T cell proliferation in CD18−/− relative to littermate control PLN, demonstrating that these cells play a critical role in the enhanced T cell proliferation in CD18−/− mice. Consistently, CD11b blockade, which is expressed on F4/80+ macrophages, enhanced the proliferation of DO11.10+ T cells in CD18+/− PLN. Thus, in contrast to the T cell-intrinsic essential role for CD18 in T cell activation, T cell-extrinsic expression of CD18 attenuates antigen-dependent CD4+ T cell activation in PLN in vivo. PMID:25801431

  17. Use of MHC class II tetramers to investigate CD4+ T cell responses: problems and solutions.

    PubMed

    Cecconi, Virginia; Moro, Monica; Del Mare, Sara; Dellabona, Paolo; Casorati, Giulia

    2008-11-01

    MHC-class I tetramers technology enabled the characterization of peptide-specific T cells at the single cell level in a variety of studies. Several laboratories have also developed MHC-class II multimers to characterize Ag-specific CD4+ T cells. However, the generation and use of MHC-class II multimers seems more problematic than that of MHC-I multimers. We have generated HLA-DR*1101 tetramers in a versatile empty form, which can be loaded after purification with peptides of interest. We discuss the impact of critical biological and structural parameters for the optimal staining of Ag-specific CD4+ T cells using HLA-DR*1101 tetramers, such as: (i) activation state of CD4+ T cells; (ii) membrane trafficking in the target CD4+ T cells; (iii) binding characteristics of the loaded CD4 epitope. Our data indicate that reorganization of TCR on the plasma membrane upon CD4+ T cell activation, as well as an homogenous binding frame of the CD4 epitopes to the soluble HLA-DR monomer, are critical for a stable TCR/MHC-class II tetramer interaction. These factors, together with the low frequencies and affinities of specific CD4+ T cells, explain the need for in vitro expansion or ex vivo enrichment of specific T cells for the optimal visualization with MHC-class II tetramers. PMID:18612991

  18. Polyfunctional CD4 T cells in the response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), Interleukin-2 (IL-2) and Tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. However, the a...

  19. Polyfunctional cytokine responses by central memory CD4+T cells in response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. Mycobacterium ...

  20. Polyfunctional cytokine responses by central memory CD4*T cells in response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4 T cells are crucial in immunity to tuberculosis (TB). Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB. Mycobacterium bovis in...

  1. The Interplay Between Monocytes/Macrophages and CD4+ T Cell Subsets in Rheumatoid Arthritis

    PubMed Central

    Roberts, Ceri A.; Dickinson, Abigail K.; Taams, Leonie S.

    2015-01-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by inflammation of the synovial lining (synovitis). The inflammation in the RA joint is associated with and driven by immune cell infiltration, synovial hyperproliferation, and excessive production of proinflammatory mediators, such as tumor necrosis factor α (TNFα), interferon γ (IFNγ), interleukin (IL)-1β, IL-6, and IL-17, eventually resulting in damage to the cartilage and underlying bone. The RA joint harbors a wide range of immune cell types, including monocytes, macrophages, and CD4+ T cells (both proinflammatory and regulatory). The interplay between CD14+ myeloid cells and CD4+ T cells can significantly influence CD4+ T cell function, and conversely, effector vs. regulatory CD4+ T cell subsets can exert profound effects on monocyte/macrophage function. In this review, we will discuss how the interplay between CD4+ T cells and monocytes/macrophages may contribute to the immunopathology of RA. PMID:26635790

  2. The frequency of α4β7high memory CD4+ T cells correlates with susceptibility to rectal SIV infection

    PubMed Central

    Martinelli, Elena; Veglia, Filippo; Goode, Diana; Guerra-Perez, Natalia; Aravantinou, Meropi; Arthos, James; Piatak, Michael; Lifson, Jeffrey D.; Blanchard, James; Gettie, Agegnehu; Robbiani, Melissa

    2013-01-01

    Background Integrin α4β7 (α4β7) mediates the homing of CD4+ T cells to gut-associated lymphoid tissues (GALT), which constitute a highly favorable environment for HIV expansion and dissemination. HIV and SIV envelope proteins bind to and signal through α4β7 and during acute infection SIV preferentially infects α4β7high CD4+ T cells. We postulated that the availability of these cells at the time of challenge could influence mucosal SIV transmission and acute viral load (VL). Methods We challenged 17 rhesus macaques with 3000 TCID50 of SIVmac239 rectally and followed the subsets of α4β7+ T and dendritic cells (DCs) by flow cytometry in blood and tissues, before and after challenge. Results We found that the frequency of memory CD4+ T cells that expressed high levels of α4β7 (α4β7high memory CD4+ T cells) in blood before challenge correlated strongly with susceptibility to infection and acute VL. Notably, not only at the time of challenge, but also their frequency 3 weeks before challenge correlated with infection. This association extended to the rectal tissue as we observed a strong direct correlation between the frequency of α4β7high memory CD4+ T cells in blood and rectum before and after challenge. The frequency of α4β7+ myeloid DCs and α4β7high CD80+ DCs also correlated with infection and acute VL, while blood CCR5+ and CD69+ CD4+ T cells could not be associated with infection. Conclusions Our results suggest that animals with higher frequency of α4β7high CD4+ T cells in circulation and in rectal tissue could be more susceptible to SIV rectal transmission. PMID:23797688

  3. The ion channel TRPV1 regulates the activation and proinflammatory properties of CD4+ T cells

    PubMed Central

    Bertin, Samuel; Aoki-Nonaka, Yukari; de Jong, Petrus Rudolf; Stanwood, Shawna R.; Srikanth, Sonal; Lee, Jihyung; To, Keith; Abramson, Lior; Yu, Timothy; Han, Tiffany; Touma, Ranim; Li, Xiangli; González-Navajas, José M.; Herdman, Scott; Corr, Maripat; Fu, Guo; Dong, Hui; Gwack, Yousang; Franco, Alessandra; Jefferies, Wilfred A.; Raz, Eyal

    2016-01-01

    TRPV1 is a Ca2+-permeable channel mostly studied as a pain receptor in sensory neurons. However, its role in other cell types is poorly understood. Here, we demonstrate that TRPV1 is functionally expressed in CD4+ T cells where it acts as a non-store-operated Ca2+ channel and contributes to T cell receptor (TCR)-induced Ca2+ influx, TCR signaling and T cell activation. In models of T cell-mediated colitis, TRPV1 promotes colitogenic T cell responses and intestinal inflammation. Furthermore, genetic and pharmacological inhibition of TRPV1 in human CD4+ T cells recapitulates the phenotype of murine Trpv1−/− CD4+ T cells. These findings suggest that TRPV1 inhibition could represent a new therapeutic strategy to restrain proinflammatory T cell responses. PMID:25282159

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

    PubMed Central

    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

  5. Therapeutic Potential of Hyporesponsive CD4+ T Cells in Autoimmunity

    PubMed Central

    Maggi, Jaxaira; Schafer, Carolina; Ubilla-Olguín, Gabriela; Catalán, Diego; Schinnerling, Katina; Aguillón, Juan C.

    2015-01-01

    The interaction between dendritic cells (DCs) and T cells is crucial on immunity or tolerance induction. In an immature or semi-mature state, DCs induce tolerance through T-cell deletion, generation of regulatory T cells, and/or induction of T-cell anergy. Anergy is defined as an unresponsive state that retains T cells in an “off” mode under conditions in which immune activation is undesirable. This mechanism is crucial for the control of T-cell responses against self-antigens, thereby preventing autoimmunity. Tolerogenic DCs (tDCs), generated in vitro from peripheral blood monocytes of healthy donors or patients with autoimmune pathologies, were shown to modulate immune responses by inducing T-cell hyporesponsiveness. Animal models of autoimmune diseases confirmed the impact of T-cell anergy on disease development and progression in vivo. Thus, the induction of T-cell hyporesponsiveness by tDCs has become a promising immunotherapeutic strategy for the treatment of T-cell-mediated autoimmune disorders. Here, we review recent findings in the area and discuss the potential of anergy induction for clinical purposes. PMID:26441992

  6. The CD4(+) T cell methylome contributes to a distinct CD4(+) T cell transcriptional signature in Mycobacterium bovis-infected cattle.

    PubMed

    Doherty, Rachael; Whiston, Ronan; Cormican, Paul; Finlay, Emma K; Couldrey, Christine; Brady, Colm; O'Farrelly, Cliona; Meade, Kieran G

    2016-01-01

    We hypothesised that epigenetic regulation of CD4(+) T lymphocytes contributes to a shift toward a dysfunctional T cell phenotype which may impact on their ability to clear mycobacterial infection. Combined RNA-seq transcriptomic profiling and Reduced Representation Bisulfite Sequencing identified 193 significantly differentially expressed genes and 760 differentially methylated regions (DMRs), between CD4(+) T cells from M. bovis infected and healthy cattle. 196 DMRs were located within 10 kb of annotated genes, including GATA3 and RORC, both of which encode transcription factors that promote TH2 and TH17 T helper cell subsets respectively. Gene-specific DNA methylation and gene expression levels for the TNFRSF4 and Interferon-γ genes were significantly negatively correlated suggesting a regulatory relationship. Pathway analysis of DMRs identified enrichment of genes involved in the anti-proliferative TGF-β signaling pathway and TGFB1 expression was significantly increased in peripheral blood leukocytes from TB-infected cattle. This first analysis of the bovine CD4(+) T cell methylome suggests that DNA methylation directly contributes to a distinct gene expression signature in CD4(+) T cells from cattle infected with M. bovis. Specific methylation changes proximal to key inflammatory gene loci may be critical to the emergence of a non-protective CD4(+) T cell response during mycobacterial infection in cattle. PMID:27507428

  7. The CD4+ T cell methylome contributes to a distinct CD4+ T cell transcriptional signature in Mycobacterium bovis-infected cattle

    PubMed Central

    Doherty, Rachael; Whiston, Ronan; Cormican, Paul; Finlay, Emma K.; Couldrey, Christine; Brady, Colm; O’Farrelly, Cliona; Meade, Kieran G.

    2016-01-01

    We hypothesised that epigenetic regulation of CD4+ T lymphocytes contributes to a shift toward a dysfunctional T cell phenotype which may impact on their ability to clear mycobacterial infection. Combined RNA-seq transcriptomic profiling and Reduced Representation Bisulfite Sequencing identified 193 significantly differentially expressed genes and 760 differentially methylated regions (DMRs), between CD4+ T cells from M. bovis infected and healthy cattle. 196 DMRs were located within 10 kb of annotated genes, including GATA3 and RORC, both of which encode transcription factors that promote TH2 and TH17 T helper cell subsets respectively. Gene-specific DNA methylation and gene expression levels for the TNFRSF4 and Interferon-γ genes were significantly negatively correlated suggesting a regulatory relationship. Pathway analysis of DMRs identified enrichment of genes involved in the anti-proliferative TGF-β signaling pathway and TGFB1 expression was significantly increased in peripheral blood leukocytes from TB-infected cattle. This first analysis of the bovine CD4+ T cell methylome suggests that DNA methylation directly contributes to a distinct gene expression signature in CD4+ T cells from cattle infected with M. bovis. Specific methylation changes proximal to key inflammatory gene loci may be critical to the emergence of a non-protective CD4+ T cell response during mycobacterial infection in cattle. PMID:27507428

  8. Simian immunodeficiency virus selectively infects proliferating CD4+ T cells in neonatal rhesus macaques

    PubMed Central

    Wang, Xiaolei; Xu, Huanbin; Pahar, Bapi; Alvarez, Xavier; Green, Linda C.; Dufour, Jason; Moroney-Rasmussen, Terri; Lackner, Andrew A.

    2010-01-01

    Infants infected with HIV have a more severe course of disease and persistently higher viral loads than HIV-infected adults. However, the underlying pathogenesis of this exacerbation remains obscure. Here we compared the rate of CD4+ and CD8+ T-cell proliferation in intestinal and systemic lymphoid tissues of neonatal and adult rhesus macaques, and of normal and age-matched simian immunodeficiency virus (SIV)–infected neonates. The results demonstrate infant primates have much greater rates of CD4+ T-cell proliferation than adult macaques, and that these proliferating, recently “activated” CD4+ T cells are infected in intestinal and other lymphoid tissues of neonates, resulting in selective depletion of proliferating CD4+ T cells in acute infection. This depletion is accompanied by a marked increase in CD8+ T-cell activation and production, particularly in the intestinal tract. The data indicate intestinal CD4+ T cells of infant primates have a markedly accelerated rate of proliferation and maturation resulting in more rapid and sustained production of optimal target cells (activated memory CD4+ T cells), which may explain the sustained “peak” viremia characteristic of pediatric HIV infection. Eventual failure of CD4+ T-cell turnover in intestinal tissues may indicate a poorer prognosis for HIV-infected infants. PMID:20716768

  9. Intratumoral CD4+CD25+ regulatory T-cell-mediated suppression of infiltrating CD4+ T cells in B-cell non-Hodgkin lymphoma

    PubMed Central

    Yang, Zhi-Zhang; Novak, Anne J.; Stenson, Mary J.; Witzig, Thomas E.; Ansell, Stephen M.

    2006-01-01

    Most non-Hodgkin lymphomas (NHLs) are of B-cell origin, but the tumor tissue can be variably infiltrated with T cells. In the present study, we have identified a subset of CD4+CD25+ T cells with high levels of CTLA-4 and Foxp3 (intratumoral Treg cells) that are overrepresented in biopsy specimens of B-cell NHL (median of 17% in lymphoma biopsies, 12% in inflammatory tonsil, and 6% in tumor-free lymph nodes; P = .001). We found that these CD4+CD25+ T cells suppressed the proliferation and cytokine (IFN-γ and IL-4) production of infiltrating CD4+CD25- T cells in response to PHA stimulation. PD-1 was found to be constitutively and exclusively expressed on a subset of infiltrating CD4+CD25- T cells, and B7-H1 could be induced on intratumoral CD4+CD25+ T cells in B-cell NHL. Anti-B7-H1 antibody or PD-1 fusion protein partly restored the proliferation of infiltrating CD4+CD25- T cells when cocultured with intratumoral Treg cells. Finally, we found that CCL22 secreted by lymphoma B cells is involved in the chemotaxis and migration of intratumoral Treg cells that express CCR4, but not CCR8. Taken together, our results suggest that Treg cells are highly represented in the area of B-cell NHL and that malignant B cells are involved in the recruitment of these cells into the area of lymphoma. PMID:16403912

  10. Characterization of Regulatory T-Cell Markers in CD4+ T Cells of the Upper Airway Mucosa

    PubMed Central

    Ballke, Christina; Gran, Einar; Baekkevold, Espen S.; Jahnsen, Frode L.

    2016-01-01

    CD4+ T regulatory cells (Tregs) comprise a heterogeneous population of cells the regulate immune responses and prevent autoimmunity. Most reports on human Tregs are derived from studies of peripheral blood, although Tregs mainly exert their functions in the periphery. Here we performed a detailed analysis of Tregs in the human upper airway mucosa under non-inflammatory conditions, and found that 10% of all CD4+ T cells expressed the transcription factor FOXP3 and the memory marker CD45RO, as well as high levels of CTLA-4. The majority of FOXP3+CD4+ T cells co-expressed the transcription factor Helios and produced very little cytokines, compatible with being thymus-derived Tregs. FOXP3+Helios-CD4+ T cells were more heterogeneous. A mean of 24% produced the immunomodulatory cytokine IL-10, whereas a large fraction also produced IL-2, IFN-μ or IL-17. A significant population (6%) of FOXP3-negative T cells also produced IL-10, usually in combination with IFN-μ. Together, we found that CD4+ T cells in the upper airways differed functionally from their counterparts in peripheral blood, including higher expression of IL-10. Moreover, our findings suggest that several subsets of CD4+ T cells with functionally distinct regulatory properties reside in the upper airway mucosa which should be taken into account when targeting Tregs for therapy. PMID:26866695

  11. Expansion of regulatory T cells from umbilical cord blood and adult peripheral blood CD4(+)CD25 (+) T cells.

    PubMed

    Lin, Syh-Jae; Lu, Chun-Hao; Yan, Dah-Chin; Lee, Pei-Tzu; Hsiao, Hsiu-Shan; Kuo, Ming-Ling

    2014-10-01

    CD4(+)CD25(+) regulatory T cells (Treg), if properly expanded from umbilical cord blood (UCB), may provide a promising immunotherapeutic tool. Our previous data demonstrated that UCB CD4(+)CD25(+) T cells with 4-day stimulation have comparable phenotypes and suppressive function to that of adult peripheral blood (APB) CD4(+)CD25(+) T cells. We further examined whether 2-week culture would achieve higher expansion levels of Tregs. UCB CD4(+)CD25(+) T cells and their APB counterparts were stimulated with anti-CD3/anti-CD28 in the presence of IL-2 or IL-15 for 2 weeks. The cell proliferation and forkhead box P3 (FoxP3) expression were examined. The function of the expanded cells was then investigated by suppressive assay. IL-21 was applied to study whether it counteracts the function of UCB and APB CD4(+)CD25(+) T cells. The results indicate that UCB CD4(+)CD25(+) T cells expanded much better than their APB counterparts. IL-2 was superior to expand UCB and APB Tregs for 2 weeks than IL-15. FoxP3 expression which peaked on Day 10-14 was comparable. Most importantly, expanded UCB Tregs showed greater suppressive function in allogeneic mixed lymphocyte reaction. The addition of IL-21, however, counteracted the suppressive function of expanded UCB and APB Tregs. The results support using UCB as a source of Treg cells. PMID:24515612

  12. E protein transcription factors are required for the development of CD4(+) lineage T cells.

    PubMed

    Jones-Mason, Mary Elizabeth; Zhao, Xudong; Kappes, Dietmar; Lasorella, Anna; Iavarone, Antonio; Zhuang, Yuan

    2012-03-23

    The double-positive (DP) to single-positive (SP) transition during T cell development is initiated by downregulation of the E protein transcription factors HEB and E2A. Here, we have demonstrated that in addition to regulating the onset of this transition, HEB and E2A also play a separate role in CD4(+) lineage choice. Deletion of HEB and E2A in DP thymocytes specifically blocked the development of CD4(+) lineage T cells. Furthermore, deletion of the E protein inhibitors Id2 and Id3 allowed CD4(+) T cell development but blocked CD8(+) lineage development. Analysis of the CD4(+) lineage transcriptional regulators ThPOK and Gata3 placed HEB and E2A upstream of CD4(+) lineage specification. These studies identify an important role for E proteins in the activation of CD4(+) lineage differentiation as thymocytes undergo the DP to SP transition. PMID:22425249

  13. Dissecting How CD4 T Cells Are Lost During HIV Infection.

    PubMed

    Doitsh, Gilad; Greene, Warner C

    2016-03-01

    Although the replicative life cycle of HIV within CD4 T cells is understood in molecular detail, less is known about how this human retrovirus promotes the loss of CD4 T lymphocytes. It is this cell death process that drives clinical progression to acquired immune deficiency syndrome (AIDS). Recent studies have highlighted how abortive infection of resting and thus nonpermissive CD4 T cells in lymphoid tissues triggers a lethal innate immune response against the incomplete DNA products generated by inefficient viral reverse transcription in these cells. Sensing of these DNA fragments results in pyroptosis, a highly inflammatory form of programmed cell death, that potentially further perpetuates chronic inflammation and immune activation. As discussed here, these studies cast CD4 T cell death during HIV infection in a different light. Further, they identify drug targets that may be exploited to both block CD4 T cell demise and the chronic inflammatory response generated during pyroptosis. PMID:26962940

  14. CD4+NKG2D+ T Cells Exhibit Enhanced Migratory and Encephalitogenic Properties in Neuroinflammation

    PubMed Central

    Ruck, Tobias; Bittner, Stefan; Gross, Catharina C.; Breuer, Johanna; Albrecht, Stefanie; Korr, Sabrina; Göbel, Kerstin; Pankratz, Susann; Henschel, Christian M.; Schwab, Nicholas; Staszewski, Ori; Prinz, Marco; Kuhlmann, Tanja

    2013-01-01

    Migration of encephalitogenic CD4+ T lymphocytes across the blood-brain barrier is an essential step in the pathogenesis of multiple sclerosis (MS). We here demonstrate that expression of the co-stimulatory receptor NKG2D defines a subpopulation of CD4+ T cells with elevated levels of markers for migration, activation, and cytolytic capacity especially when derived from MS patients. Furthermore, CD4+NKG2D+ cells produce high levels of proinflammatory IFN-γ and IL-17 upon stimulation. NKG2D promotes the capacity of CD4+NKG2D+ cells to migrate across endothelial cells in an in vitro model of the blood-brain barrier. CD4+NKG2D+ T cells are enriched in the cerebrospinal fluid of MS patients, and a significant number of CD4+ T cells in MS lesions coexpress NKG2D. We further elucidated the role of CD4+NKG2D+ T cells in the mouse system. NKG2D blockade restricted central nervous system migration of T lymphocytes in vivo, leading to a significant decrease in the clinical and pathologic severity of experimental autoimmune encephalomyelitis, an animal model of MS. Blockade of NKG2D reduced killing of cultivated mouse oligodendrocytes by activated CD4+ T cells. Taken together, we identify CD4+NKG2D+ cells as a subpopulation of T helper cells with enhanced migratory, encephalitogenic and cytotoxic properties involved in inflammatory CNS lesion development. PMID:24282598

  15. Predictor for the effect of amino acid composition on CD4+ T cell epitopes preprocessing.

    PubMed

    Hoze, Ehud; Tsaban, Lea; Maman, Yaakov; Louzoun, Yoram

    2013-05-31

    Predictive tools for all levels of CD8+ T cell epitopes processing have reached a maturation level. Good prediction algorithms have been developed for proteasomal cleavage, TAP and MHC class I peptide binding. The same cannot be said of CD4+ T cell epitopes. While multiple algorithms of varying accuracy have been proposed for MHC class II peptide binding, the preprocessing of CD4+ T cell epitopes is still lacking a good prediction algorithm. CD4+ T cell epitopes generation includes several stages, not all which are well-defined. We here group these stages to produce a generic preprocessing stage predictor for the cleavage processes preceding the presentation of epitopes to CD4+ T cell. The predictor is learnt using a combination of in vitro cleavage experiments and observed naturally processed MHC class II binding peptides. The properties of the predictor highlight the effect of different factors on CD4+ T cell epitopes preprocessing. The most important factor emerging from the predictor is the secondary structure of the cleaved region in the protein. The effect of the secondary structure is expected since CD4+ T cell epitopes are not denatured before cleavage. A website developed based on this predictor is available at: http://peptibase.cs.biu.ac.il/PepCleave_cd4/. PMID:23481624

  16. Immunodominant HIV-1 Cd4+ T Cell Epitopes in Chronic Untreated Clade C HIV-1 Infection

    PubMed Central

    Ramduth, Danni; Day, Cheryl L.; Thobakgale, Christina F.; Mkhwanazi, Nompumelelo P.; de Pierres, Chantal; Reddy, Sharon; van der Stok, Mary; Mncube, Zenele; Nair, Kriebashne; Moodley, Eshia S.; Kaufmann, Daniel E.; Streeck, Hendrik; Coovadia, Hoosen M.; Kiepiela, Photini; Goulder, Philip J. R.; Walker, Bruce D.

    2009-01-01

    Background A dominance of Gag-specific CD8+ T cell responses is significantly associated with a lower viral load in individuals with chronic, untreated clade C human immunodeficiency virus type 1 (HIV-1) infection. This association has not been investigated in terms of Gag-specific CD4+ T cell responses, nor have clade C HIV-1–specific CD4+ T cell epitopes, likely a vital component of an effective global HIV-1 vaccine, been identified. Methodology/Principal Findings Intracellular cytokine staining was conducted on 373 subjects with chronic, untreated clade C infection to assess interferon-gamma (IFN-γ) responses by CD4+ T cells to pooled Gag peptides and to determine their association with viral load and CD4 count. Gag-specific IFN-γ–producing CD4+ T cell responses were detected in 261/373 (70%) subjects, with the Gag responders having a significantly lower viral load and higher CD4 count than those with no detectable Gag response (p<0.0001 for both parameters). To identify individual peptides targeted by HIV-1–specific CD4+ T cells, separate ELISPOT screening was conducted on CD8-depleted PBMCs from 32 chronically infected untreated subjects, using pools of overlapping peptides that spanned the entire HIV-1 clade C consensus sequence, and reconfirmed by flow cytometry to be CD4+ mediated. The ELISPOT screening identified 33 CD4+ peptides targeted by 18/32 patients (56%), with 27 of the 33 peptides located in the Gag region. Although the breadth of the CD4+ responses correlated inversely with viral load (p = 0.015), the magnitude of the response was not significantly associated with viral load. Conclusions/Significance These data indicate that in chronic untreated clade C HIV-1 infection, IFN-γ–secreting Gag-specific CD4+ T cell responses are immunodominant, directed at multiple distinct epitopes, and associated with viral control. PMID:19352428

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

    PubMed Central

    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 susceptibility of mucosal Treg to viral infection and the longitudinal effect of HIV/SIV infection on Treg dynamics. In this study, we determined the level of SIV infection in Treg and nonregulatory CD4+ T cells (non-Treg) isolated from the colon of SIV-infected rhesus macaques. The dynamics of mucosal Treg and alterations in the mucosal CD4+ T-cell pool were examined longitudinally. Our findings indicate that mucosal Treg were less susceptible to productive SIV infection than non-Treg and thus were selectively spared from SIV-mediated cell death. In addition to improved survival, local expansion of Treg by SIV-induced proliferation of the mucosal CD4+ T-cell pool facilitated the accumulation of mucosal Treg during the course of infection. High frequency of mucosal Treg in chronic SIV infection was strongly related to a reduction of perforin-expressing cells. In conclusion, this study suggests that mucosal Treg are less affected by productive SIV infection than non-Treg and therefore spared from depletion. Although SIV production is limited in mucosal Treg, Treg accumulation may indirectly contribute to viral persistence by suppressing antiviral immune responses. PMID:20071575

  18. Interleukin-7 is required for CD4(+) T cell activation and autoimmune neuroinflammation.

    PubMed

    Lawson, Brian R; Gonzalez-Quintial, Rosana; Eleftheriadis, Theodoros; Farrar, Michael A; Miller, Stephen D; Sauer, Karsten; McGavern, Dorian B; Kono, Dwight H; Baccala, Roberto; Theofilopoulos, Argyrios N

    2015-12-01

    IL-7 is known to be vital for T cell homeostasis but has previously been presumed to be dispensable for TCR-induced activation. Here, we show that IL-7 is critical for the initial activation of CD4(+) T cells in that it provides some of the necessary early signaling components, such as activated STAT5 and Akt. Accordingly, short-term in vivo IL-7Rα blockade inhibited the activation and expansion of autoantigen-specific CD4(+) T cells and, when used to treat experimental autoimmune encephalomyelitis (EAE), prevented and ameliorated disease. Our studies demonstrate that IL-7 signaling is a prerequisite for optimal CD4(+) T cell activation and that IL-7R antagonism may be effective in treating CD4(+) T cell-mediated neuroinflammation and other autoimmune inflammatory conditions. PMID:26319414

  19. IL-10-producing CD4+ T cells negatively regulate fucosylation of epithelial cells in the gut

    PubMed Central

    Goto, Yoshiyuki; Lamichhane, Aayam; Kamioka, Mariko; Sato, Shintaro; Honda, Kenya; Kunisawa, Jun; Kiyono, Hiroshi

    2015-01-01

    Fucosylated glycans on the surface of epithelial cells (ECs) regulate intestinal homeostasis by serving as attachment receptors and a nutrient source for some species of bacteria. We show here that epithelial fucosylation in the ileum is negatively regulated by IL-10-producing CD4+ T cells. The number of fucosylated ECs was increased in the ileum of mice lacking T cells, especially those expressing αβ T cell receptor (TCR), CD4, and IL-10. No such effect was observed in mice lacking B cells. Adoptive transfer of αβTCR+ CD4+ T cells from normal mice, but not IL-10-deficient mice, normalized fucosylation of ECs. These findings suggest that IL-10-producing CD4+ T cells contribute to the maintenance of the function of ECs by regulating their fucosylation. PMID:26522513

  20. CD4 T Cell Responses in Latent and Chronic Viral Infections

    PubMed Central

    Walton, Senta; Mandaric, Sanja; Oxenius, Annette

    2013-01-01

    The spectrum of tasks which is fulfilled by CD4 T cells in the setting of viral infections is large, ranging from support of CD8 T cells and humoral immunity to exertion of direct antiviral effector functions. While our knowledge about the differentiation pathways, plasticity, and memory of CD4 T cell responses upon acute infections or immunizations has significantly increased during the past years, much less is still known about CD4 T cell differentiation and their beneficial or pathological functions during persistent viral infections. In this review we summarize current knowledge about the differentiation, direct or indirect antiviral effector functions, and the regulation of virus-specific CD4 T cells in the setting of persistent latent or active chronic viral infections with a particular emphasis on herpes virus infections for the former and chronic lymphocytic choriomeningitis virus infection for the latter. PMID:23717308

  1. Pathogenic CD4 T cells in type 1 diabetes recognize epitopes formed by peptide fusion

    PubMed Central

    Delong, Thomas; Wiles, Timothy A.; Baker, Rocky L.; Bradley, Brenda; Barbour, Gene; Reisdorph, Richard; Kumar, Nitesh; Elso, Colleen M.; Armstrong, Michael; Powell, Roger L.; Reisdorph, Nichole; DeNicola, Megan; Bottino, Rita; Powers, Alvin C.; Harlan, David M.; Kent, Sally C.; Mannering, Stuart I.; Haskins, Kathryn

    2016-01-01

    Type 1 diabetes (T1D) is caused by T cell mediated destruction of the insulin-producing β cells. CD4 T cell responses play a central role in β-cell destruction but the identity of the epitopes recognized by pathogenic CD4 T cells remains unknown. To address this we used a panel of diabetes triggering CD4 T cell clones isolated from non-obese diabetic (NOD) mice. Here we show that these pathogenic CD4 T cells target peptide ligands that are formed by covalent crosslinking of proinsulin peptides to other peptides present in β-cell secretory granules. These hybrid insulin peptides (HIPs) are highly antigenic for CD4 T cells and can be detected by mass spectrometry in β-cells. CD4 T cells from the residual pancreatic islets of two organ donors who had T1D also recognize HIPs. The discovery that autoreactive T cells target hybrid peptides may explain how immune tolerance is broken in T1D. PMID:26912858

  2. Coordinated Changes in DNA Methylation in Antigen-Specific Memory CD4 T Cells

    PubMed Central

    Ogoshi, Katsumi; Sasaki, Atsushi; Abe, Jun; Qu, Wei; Nakatani, Yoichiro; Ahsan, Budrul; Oshima, Kenshiro; Shand, Francis H. W.; Ametani, Akio; Suzuki, Yutaka; Kaneko, Shuichi; Wada, Takashi; Hattori, Masahira; Sugano, Sumio; Morishita, Shinichi; Matsushima, Kouji

    2013-01-01

    Memory CD4+ T cells are central regulators of both humoral and cellular immune responses. T cell differentiation results in specific changes in chromatin structure and DNA methylation of cytokine genes. Although the methylation status of a limited number of gene loci in T cells has been examined, the genome-wide DNA methylation status of memory CD4+ T cells remains unexplored. To further elucidate the molecular signature of memory T cells, we conducted methylome and transcriptome analyses of memory CD4+ T cells generated using T cells from TCR-transgenic mice. The resulting genome-wide DNA methylation profile revealed 1144 differentially methylated regions (DMRs) across the murine genome during the process of T cell differentiation, 552 of which were associated with gene loci. Interestingly, the majority of these DMRs were located in introns. These DMRs included genes such as CXCR6, Tbox21, Chsy1, and Cish, which are associated with cytokine production, homing to bone marrow, and immune responses. Methylation changes in memory T cells exposed to specific Ag appeared to regulate enhancer activity rather than promoter activity of immunologically relevant genes. In addition, methylation profiles differed between memory T cell subsets, demonstrating a link between T cell methylation status and T cell differentiation. By comparing DMRs between naive and Ag-specific memory T cells, this study provides new insights into the functional status of memory T cells. PMID:23509353

  3. Natural CD4+ T-Cell Responses against Indoleamine 2,3-Dioxygenase

    PubMed Central

    Munir, Shamaila; Larsen, Stine Kiaer; Iversen, Trine Zeeberg; Donia, Marco; Klausen, Tobias Wirenfeldt; Svane, Inge Marie; Straten, Per thor; Andersen, Mads Hald

    2012-01-01

    Background The enzyme indoleamine 2,3-dioxygenase (IDO) contributes to immune tolerance in a variety of settings. In cancer IDO is expressed within the tumor itself as well as in antigen-presenting cells in tumor-draining lymph nodes, where it endorses the establishment of peripheral immune tolerance to tumor antigens. Recently, we described cytotoxic CD8+ T-cell reactivity towards IDO-derived peptides. Methods and Findings In the present study, we show that CD4+ helper T cells additionally spontaneously recognize IDO. Hence, we scrutinized the vicinity of the previously described HLA-A*0201-restricted IDO-epitope for CD4+ T-cell epitopes. We demonstrated the presence of naturally occurring IDO-specific CD4+ T cells in cancer patients and to a lesser extent in healthy donors by cytokine release ELISPOT. IDO-reactive CD4+ T cells released IFN-γ, TNF-α, as well as IL-17. We confirm HLA class II-restriction by the addition of HLA class II specific blocking antibodies. In addition, we detected a trend between class I- and class II-restricted IDO responses and detected an association between IDO-specific CD4+ T cells and CD8+ CMV-responses. Finally, we could detect IL-10 releasing IDO-reactive CD4+ T cells. Conclusion IDO is spontaneously recognized by HLA class II-restricted, CD4+ T cells in cancer patients and in healthy individuals. IDO-specific T cells may participate in immune-regulatory networks where the activation of pro-inflammatory IDO-specific CD4+ responses may well overcome or delay the immune suppressive actions of the IDO-protein, which are otherwise a consequence of the early expression of IDO in maturing antigen presenting cells. In contrast, IDO-specific regulatory T cells may enhance IDO-mediated immune suppression. PMID:22539948

  4. Sequestration from Immune CD4^+ T Cells of Mycobacteria Growing in Human Macrophages

    NASA Astrophysics Data System (ADS)

    Pancholi, Preeti; Mirza, Asra; Bhardwaj, Nina; Steinman, Ralph M.

    1993-05-01

    CD4^+ helper T cells mediate resistance to tuberculosis, presumably by enhancing the antimicrobial activity of macrophages within which the Mycobacterium tuberculosis organism grows. A first step in resistance should be the presentation of mycobacterial antigens by macrophages to CD4^+ T cells. However, when the antigenic stimulus is limited to organisms growing in human monocytes, the organisms become sequestered from immune CD4^+ T cells. This block in presentation is selective for growing mycobacteria and not for other stimuli. Sequestration would allow replicating organisms to persist in infected individuals and may contribute to virulence.

  5. Clonal Structure of Rapid-Onset MDV-Driven CD4+ Lymphomas and Responding CD8+ T Cells

    PubMed Central

    Mwangi, William N.; Smith, Lorraine P.; Baigent, Susan J.; Beal, Richard K.; Nair, Venugopal; Smith, Adrian L.

    2011-01-01

    Lymphoid oncogenesis is a life threatening complication associated with a number of persistent viral infections (e.g. EBV and HTLV-1 in humans). With many of these infections it is difficult to study their natural history and the dynamics of tumor formation. Marek's Disease Virus (MDV) is a prevalent α-herpesvirus of poultry, inducing CD4+ TCRαβ+ T cell tumors in susceptible hosts. The high penetrance and temporal predictability of tumor induction raises issues related to the clonal structure of these lymphomas. Similarly, the clonality of responding CD8 T cells that infiltrate the tumor sites is unknown. Using TCRβ repertoire analysis tools, we demonstrated that MDV driven CD4+ T cell tumors were dominated by one to three large clones within an oligoclonal framework of smaller clones of CD4+ T cells. Individual birds had multiple tumor sites, some the result of metastasis (i.e. shared dominant clones) and others derived from distinct clones of transformed cells. The smaller oligoclonal CD4+ cells may represent an anti-tumor response, although on one occasion a low frequency clone was transformed and expanded after culture. Metastatic tumor clones were detected in the blood early during infection and dominated the circulating T cell repertoire, leading to MDV associated immune suppression. We also demonstrated that the tumor-infiltrating CD8+ T cell response was dominated by large oligoclonal expansions containing both “public” and “private” CDR3 sequences. The frequency of CD8+ T cell CDR3 sequences suggests initial stimulation during the early phases of infection. Collectively, our results indicate that MDV driven tumors are dominated by a highly restricted number of CD4+ clones. Moreover, the responding CD8+ T cell infiltrate is oligoclonal indicating recognition of a limited number of MDV antigens. These studies improve our understanding of the biology of MDV, an important poultry pathogen and a natural infection model of virus-induced tumor

  6. Clonal structure of rapid-onset MDV-driven CD4+ lymphomas and responding CD8+ T cells.

    PubMed

    Mwangi, William N; Smith, Lorraine P; Baigent, Susan J; Beal, Richard K; Nair, Venugopal; Smith, Adrian L

    2011-05-01

    Lymphoid oncogenesis is a life threatening complication associated with a number of persistent viral infections (e.g. EBV and HTLV-1 in humans). With many of these infections it is difficult to study their natural history and the dynamics of tumor formation. Marek's Disease Virus (MDV) is a prevalent α-herpesvirus of poultry, inducing CD4+ TCRαβ+ T cell tumors in susceptible hosts. The high penetrance and temporal predictability of tumor induction raises issues related to the clonal structure of these lymphomas. Similarly, the clonality of responding CD8 T cells that infiltrate the tumor sites is unknown. Using TCRβ repertoire analysis tools, we demonstrated that MDV driven CD4+ T cell tumors were dominated by one to three large clones within an oligoclonal framework of smaller clones of CD4+ T cells. Individual birds had multiple tumor sites, some the result of metastasis (i.e. shared dominant clones) and others derived from distinct clones of transformed cells. The smaller oligoclonal CD4+ cells may represent an anti-tumor response, although on one occasion a low frequency clone was transformed and expanded after culture. Metastatic tumor clones were detected in the blood early during infection and dominated the circulating T cell repertoire, leading to MDV associated immune suppression. We also demonstrated that the tumor-infiltrating CD8+ T cell response was dominated by large oligoclonal expansions containing both "public" and "private" CDR3 sequences. The frequency of CD8+ T cell CDR3 sequences suggests initial stimulation during the early phases of infection. Collectively, our results indicate that MDV driven tumors are dominated by a highly restricted number of CD4+ clones. Moreover, the responding CD8+ T cell infiltrate is oligoclonal indicating recognition of a limited number of MDV antigens. These studies improve our understanding of the biology of MDV, an important poultry pathogen and a natural infection model of virus-induced tumor formation. PMID

  7. Requirement for CD4 T Cell Help in Generating Functional CD8 T Cell Memory

    NASA Astrophysics Data System (ADS)

    Shedlock, Devon J.; Shen, Hao

    2003-04-01

    Although primary CD8 responses to acute infections are independent of CD4 help, it is unknown whether a similar situation applies to secondary responses. We show that depletion of CD4 cells during the recall response has minimal effect, whereas depletion during the priming phase leads to reduced responses by memory CD8 cells to reinfection. Memory CD8 cells generated in CD4+/+ mice responded normally when transferred into CD4-/- hosts, whereas memory CD8 cells generated in CD4-/- mice mounted defective recall responses in CD4+/+ adoptive hosts. These results demonstrate a previously undescribed role for CD4 help in the development of functional CD8 memory.

  8. SAMHD1 restricts HIV-1 reverse transcription in quiescent CD4+ T-cells

    PubMed Central

    2012-01-01

    Background Quiescent CD4+ T lymphocytes are highly refractory to HIV-1 infection due to a block at reverse transcription. Results Examination of SAMHD1 expression in peripheral blood lymphocytes shows that SAMHD1 is expressed in both CD4+ and CD8+ T cells at levels comparable to those found in myeloid cells. Treatment of CD4+ T cells with Virus-Like Particles (VLP) containing Vpx results in the loss of SAMHD1 expression that correlates with an increased permissiveness to HIV-1 infection and accumulation of reverse transcribed viral DNA without promoting transcription from the viral LTR. Importantly, CD4+ T-cells from patients with Aicardi-Goutières Syndrome harboring mutation in the SAMHD1 gene display an increased susceptibility to HIV-1 infection that is not further enhanced by VLP-Vpx-treatment. Conclusion Here, we identified SAMHD1 as the restriction factor preventing efficient viral DNA synthesis in non-cycling resting CD4+ T-cells. These results highlight the crucial role of SAMHD1 in mediating restriction of HIV-1 infection in quiescent CD4+ T-cells and could impact our understanding of HIV-1 mediated CD4+ T-cell depletion and establishment of the viral reservoir, two of the HIV/AIDS hallmarks. PMID:23092122

  9. Regulatory T cells prevent CD8 T cell maturation by inhibiting CD4 Th cells at tumor sites.

    PubMed

    Chaput, Nathalie; Darrasse-Jèze, Guillaume; Bergot, Anne-Sophie; Cordier, Corinne; Ngo-Abdalla, Stacie; Klatzmann, David; Azogui, Orly

    2007-10-15

    Natural regulatory T cells (Tregs) are present in high frequencies among tumor-infiltrating lymphocytes and in draining lymph nodes, supposedly facilitating tumor development. To investigate their role in controlling local immune responses, we analyzed intratumoral T cell accumulation and function in the presence or absence of Tregs. Tumors that grew in normal BALB/c mice injected with the 4T1 tumor cell line were highly infiltrated by Tregs, CD4 and CD8 cells, all having unique characteristics. Most infiltrating Tregs expressed low levels of CD25Rs and Foxp3. They did not proliferate even in the presence of IL-2 but maintained a strong suppressor activity. CD4 T cells were profoundly anergic and CD8 T cell proliferation and cytotoxicity were severely impaired. Depletion of Tregs modified the characteristics of tumor infiltrates. Tumors were initially invaded by activated CD4(+)CD25(-) T cells, which produced IL-2 and IFN-gamma. This was followed by the recruitment of highly cytotoxic CD8(+) T cells at tumor sites leading to tumor rejection. The beneficial effect of Treg depletion in tumor regression was abrogated when CD4 helper cells were also depleted. These findings indicate that the massive infiltration of tumors by Tregs prevents the development of a successful helper response. The Tregs in our model prevent Th cell activation and subsequent development of efficient CD8 T cell activity required for the control of tumor growth. PMID:17911581

  10. Methodologies for the Analysis of HCV-Specific CD4+ T Cells

    PubMed Central

    Lokhande, Megha U.; Thimme, Robert; Klenerman, Paul; Semmo, Nasser

    2015-01-01

    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 multi-specific 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 analyze 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 analyzed 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. PMID:25767470

  11. CD4+ and CD8+ T cells have opposing roles in breast cancer progression and outcome

    PubMed Central

    Zhang, Qunyuan; Ye, Jian; Wang, Fang; Zhang, Yanping; Hunborg, Pamela; Varvares, Mark A.; Hoft, Daniel F.; Hsueh, Eddy C.; Peng, Guangyong

    2015-01-01

    The Cancer Immunoediting concept has provided critical insights suggesting dual functions of immune system during the cancer initiation and development. However, the dynamics and roles of CD4+ and CD8+ T cells in the pathogenesis of breast cancer remain unclear. Here we utilized two murine breast cancer models (4T1 and E0771) and demonstrated that both CD4+ and CD8+ T cells were increased and involved in immune responses, but with distinct dynamic trends in breast cancer development. In addition to cell number increases, CD4+ T cells changed their dominant subsets from Th1 in the early stages to Treg and Th17 cells in the late stages of the cancer progression. We also analyzed CD4+ and CD8+ T cell infiltration in primary breast cancer tissues from cancer patients. We observed that CD8+ T cells are the key effector cell population mediating effective anti-tumor immunity resulting in better clinical outcomes. In contrast, intra-tumoral CD4+ T cells have negative prognostic effects on breast cancer patient outcomes. These studies indicate that CD4+ and CD8+ T cells have opposing roles in breast cancer progression and outcomes, which provides new insights relevant for the development of effective cancer immunotherapeutic approaches. PMID:25968569

  12. Aire-Overexpressing Dendritic Cells Induce Peripheral CD4+ T Cell Tolerance

    PubMed Central

    Li, Dongbei; Li, Haijun; Fu, Haiying; Niu, Kunwei; Guo, Yantong; Guo, Chuan; Sun, Jitong; Li, Yi; Yang, Wei

    2015-01-01

    Autoimmune regulator (Aire) can promote the ectopic expression of peripheral tissue-restricted antigens (TRAs) in thymic medullary epithelial cells (mTECs), which leads to the deletion of autoreactive T cells and consequently prevents autoimmune diseases. However, the functions of Aire in the periphery, such as in dendritic cells (DCs), remain unclear. This study’s aim was to investigate the effect of Aire-overexpressing DCs (Aire cells) on the functions of CD4+ T cells and the treatment of type 1 diabetes (T1D). We demonstrated that Aire cells upregulated the mRNA levels of the tolerance-related molecules CD73, Lag3, and FR4 and the apoptosis of CD4+ T cells in STZ-T1D mouse-derived splenocytes. Furthermore, following insulin stimulation, Aire cells decreased the number of CD4+ IFN-γ+ T cells in both STZ-T1D and WT mouse-derived splenocytes and reduced the expression levels of TCR signaling molecules (Ca2+ and p-ERK) in CD4+ T cells. We observed that Aire cells-induced CD4+ T cells could delay the development of T1D. In summary, Aire-expressing DCs inhibited TCR signaling pathways and decreased the quantity of CD4+IFN-γ+ autoreactive T cells. These data suggest a mechanism for Aire in the maintenance of peripheral immune tolerance and provide a potential method to control autoimmunity by targeting Aire. PMID:26729097

  13. CD4+ and CD8+ T cells have opposing roles in breast cancer progression and outcome.

    PubMed

    Huang, Yi; Ma, Chunling; Zhang, Qunyuan; Ye, Jian; Wang, Fang; Zhang, Yanping; Hunborg, Pamela; Varvares, Mark A; Hoft, Daniel F; Hsueh, Eddy C; Peng, Guangyong

    2015-07-10

    The Cancer Immunoediting concept has provided critical insights suggesting dual functions of immune system during the cancer initiation and development. However, the dynamics and roles of CD4+ and CD8+ T cells in the pathogenesis of breast cancer remain unclear. Here we utilized two murine breast cancer models (4T1 and E0771) and demonstrated that both CD4+ and CD8+ T cells were increased and involved in immune responses, but with distinct dynamic trends in breast cancer development. In addition to cell number increases, CD4+ T cells changed their dominant subsets from Th1 in the early stages to Treg and Th17 cells in the late stages of the cancer progression. We also analyzed CD4+ and CD8+ T cell infiltration in primary breast cancer tissues from cancer patients. We observed that CD8+ T cells are the key effector cell population mediating effective anti-tumor immunity resulting in better clinical outcomes. In contrast, intra-tumoral CD4+ T cells have negative prognostic effects on breast cancer patient outcomes. These studies indicate that CD4+ and CD8+ T cells have opposing roles in breast cancer progression and outcomes, which provides new insights relevant for the development of effective cancer immunotherapeutic approaches. PMID:25968569

  14. Tissue adaptation of regulatory and intraepithelial CD4T cells controls gut inflammation.

    PubMed

    Sujino, Tomohisa; London, Mariya; Hoytema van Konijnenburg, David P; Rendon, Tomiko; Buch, Thorsten; Silva, Hernandez M; Lafaille, Juan J; Reis, Bernardo S; Mucida, Daniel

    2016-06-24

    Foxp3(+) regulatory T cells in peripheral tissues (pT(regs)) are instrumental in limiting inflammatory responses to nonself antigens. Within the intestine, pT(regs) are located primarily in the lamina propria, whereas intraepithelial CD4(+) T cells (CD4(IELs)), which also exhibit anti-inflammatory properties and depend on similar environmental cues, reside in the epithelium. Using intravital microscopy, we show distinct cell dynamics of intestinal T(regs) and CD4(IELs) Upon migration to the epithelium, T(regs) lose Foxp3 and convert to CD4(IELs) in a microbiota-dependent manner, an effect attributed to the loss of the transcription factor ThPOK. Finally, we demonstrate that pT(regs) and CD4(IELs) perform complementary roles in the regulation of intestinal inflammation. These results reveal intratissue specialization of anti-inflammatory T cells shaped by discrete niches of the intestine. PMID:27256884

  15. Spontaneous Proliferation of H2M-/- CD4 T Cells Results in Unusual Acute Hepatocellular Necrosis

    PubMed Central

    Do, Jeong-su; Baldwin, William M.; Min, Booki

    2014-01-01

    Naïve CD4 T cells are triggered to undergo spontaneous proliferation, a proliferative response induced in response to homeostatic stimulation, when exposed to severe lymphopenic environments. They spontaneously acquire proinflammatory effector phenotypes, playing a major role in inducing chronic inflammation in the intestine that is believed to be induced by T cell recognition of commensal antigens. While the antigens inducing the T cell responses and inflammation are being extensively investigated, the role of clonality of T cells involved in this process remains poorly understood. In this study, we utilized naïve CD4 T cells isolated from B6 H2M−/− mice, in which MHCII molecules are complexed with a single CLIP molecule, and examined spontaneous proliferation and intestinal inflammation of CD4 T cells expressing limited T cell receptor repertoire diversity. We found that H2M−/− CD4 T cells undergo robust spontaneous proliferation, differentiate into IFNγ-producing Th1 type effector cells, and, most unexpectedly, induce severe acute hepatocellular necrosis. T cell interaction with MHCII molecule on cells of hematopoietic origin was essential to induce the pathology. Interestingly, B cells are fully capable of preventing necrotic inflammation via IL-10-independent and B7-H1-dependent mechanism. This could be a useful animal model to examine T cell-mediated liver inflammation and B cell-mediated immune regulation. PMID:25313460

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

    PubMed

    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. PMID:26858442

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

    PubMed Central

    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

    2016-01-01

    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. PMID:26858442

  18. Nuclear Retention of Multiply Spliced HIV-1 RNA in Resting CD4+ T Cells

    PubMed Central

    Lassen, Kara G; Ramyar, Kasra X; Bailey, Justin R; Zhou, Yan; Siliciano, Robert F

    2006-01-01

    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. PMID:16839202

  19. Gut Microbial Membership Modulates CD4 T Cell Reconstitution and Function after Sepsis.

    PubMed

    Cabrera-Perez, Javier; Babcock, Jeffrey C; Dileepan, Thamotharampillai; Murphy, Katherine A; Kucaba, Tamara A; Badovinac, Vladimir P; Griffith, Thomas S

    2016-09-01

    Transient lymphopenia is one hallmark of sepsis, and emergent data indicate the CD4 T cell compartment in sepsis survivors is numerically and functionally altered (when examined at the Ag-specific level) compared with nonseptic control subjects. Previous data from our laboratory demonstrated Ag-independent, lymphopenia-induced homeostatic proliferation to be a contributing mechanism by which CD4 T cells numerically recover in sepsis survivors. However, we reasoned it is also formally possible that some CD4 T cells respond directly to Ag expressed by gut-resident microbes released during polymicrobial sepsis. The effect of gut microbiome leakage on CD4 T cells is currently unknown. In this study, we explored the number and function of endogenous CD4 T cells specific for segmented filamentous bacterium (SFB) after cecal ligation and puncture (CLP)-induced sepsis using mice that either contained or lacked SFB as a normal gut-resident microbe. Interestingly, SFB-specific CD4 T cells underwent Ag-driven proliferation in CLP-treated SFB(+), but not in SFB(-), mice. Moreover, CLP-treated SFB(+) mice showed resistance to secondary lethal infection with recombinant SFB Ag-expressing virulent Listeria (but not wild-type virulent Listeria), suggesting the CLP-induced polymicrobial sepsis primed for a protective response by the SFB-specific CD4 T cells. Thus, our data demonstrate that the numerical recovery and functional responsiveness of Ag-specific CD4 T cells in sepsis survivors is, in part, modulated by the intestinal barrier's health discreetly defined by individual bacterial populations of the host's microbiome. PMID:27448587

  20. The differentiation and protective function of cytolytic CD4 T cells in influenza infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 play a role in chronic, as well as, acute infections...

  1. CD4+ follicular helper T cell infiltration predicts breast cancer survival

    PubMed Central

    Gu-Trantien, Chunyan; Loi, Sherene; Garaud, Soizic; Equeter, Carole; Libin, Myriam; de Wind, Alexandre; Ravoet, Marie; Le Buanec, Hélène; Sibille, Catherine; Manfouo-Foutsop, Germain; Veys, Isabelle; Haibe-Kains, Benjamin; Singhal, Sandeep K.; Michiels, Stefan; Rothé, Françoise; Salgado, Roberto; Duvillier, Hugues; Ignatiadis, Michail; Desmedt, Christine; Bron, Dominique; Larsimont, Denis; Piccart, Martine; Sotiriou, Christos; Willard-Gallo, Karen

    2013-01-01

    CD4+ T cells are critical regulators of immune responses, but their functional role in human breast cancer is relatively unknown. The goal of this study was to produce an image of CD4+ T cells infiltrating breast tumors using limited ex vivo manipulation to better understand the in vivo differences associated with patient prognosis. We performed comprehensive molecular profiling of infiltrating CD4+ T cells isolated from untreated invasive primary tumors and found that the infiltrating T cell subpopulations included follicular helper T (Tfh) cells, which have not previously been found in solid tumors, as well as Th1, Th2, and Th17 effector memory cells and Tregs. T cell signaling pathway alterations included a mixture of activation and suppression characterized by restricted cytokine/chemokine production, which inversely paralleled lymphoid infiltration levels and could be reproduced in activated donor CD4+ T cells treated with primary tumor supernatant. A comparison of extensively versus minimally infiltrated tumors showed that CXCL13-producing CD4+ Tfh cells distinguish extensive immune infiltrates, principally located in tertiary lymphoid structure germinal centers. An 8-gene Tfh signature, signifying organized antitumor immunity, robustly predicted survival or preoperative response to chemotherapy. Our identification of CD4+ Tfh cells in breast cancer suggests that they are an important immune element whose presence in the tumor is a prognostic factor. PMID:23778140

  2. The Story of CD4+CD28− T Cells Revisited: Solved or Still Ongoing?

    PubMed Central

    Maly, Kathrin

    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

  3. Impact of nicotine on the interplay between human periodontal ligament cells and CD4+ T cells.

    PubMed

    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

  4. IL-33 enhances retinoic acid signaling on CD4+ T cells.

    PubMed

    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

  5. The BMP Pathway Participates in Human Naive CD4+ T Cell Activation and Homeostasis

    PubMed Central

    Martínez, Víctor G.; Sacedón, Rosa; Hidalgo, Laura; Valencia, Jaris; Fernández-Sevilla, Lidia M.; Hernández-López, Carmen

    2015-01-01

    Bone Morphogenetic Proteins (BMPs) form a group of secreted factors that belongs to the TGF-β superfamily. Among different roles in a number of immune cell types, BMPs are known to regulate T cell development within the thymus, although the role of BMP signaling in human mature T cells remains elusive. In this study, we demonstrate that canonical BMP signaling is necessary during two critical events that regulate the size and function of human naive CD4+ T cell population: activation and homeostasis. Upon stimulation via TCR, naive CD4+ T cells upregulate the expression of BMP ligands triggering canonical BMP signaling in CD25+ cells. Blockade of BMP signaling severely impairs CD4+ T cell proliferation after activation mainly through regulation of IL-2, since the addition of this cytokine recuperates normal T cell expansion after inhibition of BMP signaling. Similarly, activation of canonical BMP pathway is required for both the maintenance of cell survival and the homeostatic proliferation induced by IL-7, a key factor for T cell homeostasis. Moreover, upregulation of two critical receptors for T cell homeostasis, CXCR4 and CCR9, triggered by IL-7 is also abrogated in the absence of BMP signaling. Collectively, we describe important roles of the canonical BMP signaling in human naive CD4+ T cell activation and homeostasis that could be valuable for clinical application. PMID:26110906

  6. Heterologous vaccination against human tuberculosis modulates antigen-specific CD4+ T-cell function.

    PubMed

    Dintwe, One B; Day, Cheryl L; Smit, Erica; Nemes, Elisa; Gray, Clive; Tameris, Michele; McShane, Helen; Mahomed, Hassan; Hanekom, Willem A; Scriba, Thomas J

    2013-09-01

    Heterologous prime-boost strategies hold promise for vaccination against tuberculosis. However, the T-cell characteristics required for protection are not known. We proposed that boost vaccines should induce long-lived functional and phenotypic changes to T cells primed by Bacille Calmette Guerin (BCG) and/or natural exposure to mycobacteria. We characterized changes among specific CD4(+) T cells after vaccination with the MVA85A vaccine in adults, adolescents, and children. CD4(+) T cells identified with Ag85A peptide-bearing HLA class II tetramers were characterized by flow cytometry. We also measured proliferative potential and cytokine expression of Ag85A-specific CD4(+) T cells. During the effector phase, MVA85A-induced specific CD4(+) T cells coexpressed IFN-γ and IL-2, skin homing integrins, and the activation marker CD38. This was followed by contraction and a transition to predominantly IL-2-expressing, CD45RA(-) CCR7(+) CD27(+) or CD45RA(+) CCR7(+) CD27(+) specific CD4(+) T cells. These surface phenotypes were similar to Ag85A-specific T cells prior to MVA85A. However, functional differences were observed postvaccination: specific proliferative capacity was markedly higher after 6-12 months than before vaccination. Our data suggest that MVA85A vaccination may modulate Ag85A-specific CD4(+) T-cell function, resulting in greater recall potential. Importantly, surface phenotypes commonly used as proxies for memory T-cell function did not associate with functional effects of vaccination. PMID:23737382

  7. Expression of CD39 by human peripheral blood CD4+CD25+ T cells denotes a regulatory memory phenotype

    PubMed Central

    Dwyer, Karen M.; Hanidziar, Dusan; Putheti, Prabhakar; Hill, Prue A; Pommey, Sandra; McRae, Jennifer L; Winterhalter, Adam; Doherty, Glen; Deaglio, Silvia; Koulmanda, Maria; Gao, Wenda; Robson, Simon C.; Strom, Terry B.

    2010-01-01

    We have shown that CD39 and CD73 are co-expressed on the surface of murine CD4+Foxp3+ regulatory T cells (Treg) and generate extracellular adenosine, contributing to Treg immunosuppressive activity. We now describe that CD39, independently of CD73, is expressed by a subset of blood derived human CD4+CD25+CD127lo T regulatory cells (Treg), defined by robust expression of Foxp3. A further distinct population of CD4+CD39+ T lymphocytes can be identified, which do not express CD25 and FoxP3 and exhibit the memory effector cellular phenotype. Differential expression of CD25 and CD39 on circulating CD4+ T cells distinguishes between Treg and pathogenic cellular populations that secrete pro-inflammatory cytokines such as IFNγ and IL-17. These latter cell populations are increased, with a concomitant decrease in the CD4+CD25+CD39+ Tregs, in the peripheral blood of patients with renal allograft rejection. We conclude that the ectonucleotidase CD39 is a useful and dynamic lymphocytes surface marker that can be used to identify different peripheral blood T cell populations to allow tracking of these in health and disease, as in renal allograft rejection. PMID:20977632

  8. CD137 Agonist Therapy Can Reprogram Regulatory T Cells into Cytotoxic CD4+ T Cells with Antitumor Activity.

    PubMed

    Akhmetzyanova, Ilseyar; Zelinskyy, Gennadiy; Littwitz-Salomon, Elisabeth; Malyshkina, Anna; Dietze, Kirsten K; Streeck, Hendrik; Brandau, Sven; Dittmer, Ulf

    2016-01-01

    Recent successes in immune therapeutic strategies aimed to improve control over tumor growth have sparked hope that long-lived control of cancer through stimulation of the immune system can be possible. However, the underlying immunological mechanisms that are induced by immunotherapeutic strategies are not well understood. In this study, we used the highly immunogenic Friend virus-induced FBL-3 tumor as a model to study the mechanisms of immunological tumor control by CD4(+) T cells in the course of CD137 (4-1BB) agonist immunotherapy in the absence of a CD8 T cell response. We demonstrate that treatment with a CD137 agonist resulted in complete FBL-3 tumor regression in CD8(+) T cell-deficient mice. CD137 signaling enhanced the production of proinflammatory cytokines and cytotoxic molecules in tumor-specific CD4(+) T cells. Interestingly, a subset of CD4(+)Foxp3(+) regulatory T cells was reprogrammed to eliminate immunogenic virus-induced tumor cells in response to CD137 agonist treatment. These cells expressed markers characteristic for Th cells (CD154) and produced the cytokine TNF-α or the T-box transcriptional factor Eomesodermin and granzyme B without loss of Foxp3 expression. Foxp3 Eomes double-positive CD4(+) T cells were capable of eliminating immunogenic virus-induced tumor cells in vivo. Thus, our data show that tumor-induced Foxp3(+)CD4(+) T cells can be reprogrammed into cytotoxic effector cells upon therapeutic costimulatory signaling and restore antitumor immunity. PMID:26608920

  9. Measurement of CD8 and CD4 T Cell Responses in Mouse Lungs

    PubMed Central

    Fett, Craig; Zhao, Jincun; Perlman, Stanley

    2016-01-01

    Study of the adaptive immune response to a viral challenge in an animal model often includes analysis of the T cell response. Here we discuss in detail the methods that are used to characterize the CD8 and CD4 T cell response following viral challenge in the lung.

  10. High avidity autoreactive CD4+ T cells induce host CTL, overcome Tregs and mediate tumor destruction

    PubMed Central

    Brandmaier, Andrew G.; Leitner, Wolfgang W.; Ha, Sung P.; Sidney, John; Restifo, Nicholas P.; Touloukian, Christopher E.

    2009-01-01

    Despite progress made over the past 25 years, existing immunotherapies have limited clinical effectiveness in patients with cancer. Immune tolerance consistently blunts the generated immune response, and the largely solitary focus on CD8+ T cell immunity has proven ineffective in the absence of CD4+ T cell help. To address these twin-tier deficiencies, we developed a translational model of melanoma immunotherapy focused on the exploitation of high avidity CD4+ T cells that become generated in germline antigen deficient mice. We had previously identified a TRP-1 specific HLA-DRB1*0401-restricted epitope. Using this epitope in conjunction with a newly described TRP-1 germline-knockout, we demonstrate that endogenous TRP-1 expression alters the functionality of the auto-reactive T cell repertoire. More importantly, we show, by using MHC-mismatched combinations, that CD4+ T cells derived from the self-antigen deficient host indirectly triggers the eradication of established B16 lung metastases. We demonstrate that the treatment effect is mediated entirely by endogenous CD8+ T cells and is not affected by the depletion of host Tregs. These findings suggest that high avidity CD4+ T cells can overcome endogenous conditions and mediate their anti-tumor effects exclusively through the elicitation of CD8+ T cell immunity. PMID:19561540

  11. Increased Mucosal CD4+ T Cell Activation in Rhesus Macaques following Vaccination with an Adenoviral Vector

    PubMed Central

    Bukh, Irene; Calcedo, Roberto; Roy, Soumitra; Carnathan, Diane G.; Grant, Rebecca; Qin, Qiuyue; Boyd, Surina; Ratcliffe, Sarah J.; Veeder, Christin L.; Bellamy, Scarlett L.; Betts, Michael R.

    2014-01-01

    ABSTRACT The possibility that vaccination with adenovirus (AdV) vectors increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of HIV acquisition within the Step trial. Modeling this within rhesus macaques is complicated because human adenoviruses, including human adenovirus type 5 (HAdV-5), are not endogenous to macaques. Here, we tested whether vaccination with a rhesus macaque-derived adenoviral vector (simian adenovirus 7 [SAdV-7]) enhances mucosal T cell activation within rhesus macaques. Following intramuscular SAdV-7 vaccination, we observed a pronounced increase in SAdV-7-specific CD4+ T cell responses in peripheral blood and, more dramatically, in rectal mucosa tissue. Vaccination also induced a significant increase in the frequency of activated memory CD4+ T cells in SAdV-7- and HAdV-5-vaccinated animals in the rectal mucosa but not in peripheral blood. These fluctuations within the rectal mucosa were also associated with a pronounced decrease in the relative frequency of naive resting CD4+ T cells. Together, these results indicate that peripheral vaccination with an AdV vector can increase the activation of mucosal CD4+ T cells, potentially providing an experimental model to further evaluate the role of host-vector interactions in increased HIV acquisition after AdV vector vaccination. IMPORTANCE The possibility that vaccination with a human adenovirus 5 vector increased mucosal T cell activation remains a central hypothesis to explain the potential enhancement of human immunodeficiency virus (HIV) acquisition within the Step trial. In this study, we tested whether vaccination with a rhesus macaque-derived adenoviral vector in rhesus macaques enhances mucosal CD4+ T cell activation, the main cell target of simian immunodeficiency virus (SIV)/HIV. The results showed that vaccination with an adenoviral vector indeed increases activation of mucosal CD4+ T cells and potentially increases susceptibility to SIV

  12. Novel autoantigens for diabetogenic CD4 T cells in autoimmune diabetes

    PubMed Central

    Delong, Thomas; Baker, Rocky L; He, Jing; Haskins, Kathryn

    2013-01-01

    Autoreactive CD4 T cells play a central role in the development of type 1 diabetes. The BDC-panel of diabetogenic T cell clones was originally isolated from non-obese diabetic (NOD) mice and has been used to study the role of autoreactive CD4 T cells and T cell autoantigens in the development of diabetes. Recent studies by our group have led to the identification of two new target antigens for clones of this panel. This review describes the proteomic strategy used for antigen identification, the antigens identified, and the potential contribution of post-translational modification to autoantigen generation. In addition, we compare peptide epitopes for the T cell clones and discuss their potential applications in investigating the role of T cell autoantigens in the pathogenesis and regulation of disease. PMID:22971988

  13. CD4+ T Cell Priming as Biomarker to Study Immune Response to Preventive Vaccines

    PubMed Central

    Ciabattini, Annalisa; Pettini, Elena; Medaglini, Donata

    2013-01-01

    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. PMID:24363656

  14. CD4+ T-cell subsets and host defense in the lung

    PubMed Central

    Kolls, Jay K.

    2012-01-01

    Summary CD4+ T-helper subsets are lineages of T cells that have effector function in the lung and control critical aspects of lung immunity. Depletion of these cells experimentally or by drugs or human immunodeficiency virus (HIV) infection in humans leads to the development of opportunistic infections as well as increased rates of bacteremia with certain bacterial pneumonias. Recently, it has been proposed that CD4+ T-cell subsets may also be excellent targets for mucosal vaccination to prevent pulmonary infections in susceptible hosts. Here we review recent findings that increase our understanding of T-cell subsets and their effector cytokines in the context of pulmonary infection. PMID:23405903

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

    PubMed

    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

  16. F protein increases CD4+CD25+ T cell population in patients with chronic hepatitis C.

    PubMed

    Hashempour, Tayebeh; Bamdad, Taravat; Bergamini, Alberto; Lavergne, Jean Pierre; Haj-Sheykholeslami, Arghavan; Brakier-Gingras, Léa; Ajorloo, Mehdi; Merat, Shahin

    2015-06-01

    HCV is a global health problem with an estimated 230 million chronically infected people worldwide. It has been reported that a 17-kd protein translated from core-encoding genomic region can contribute to immune-mediated mechanisms associated with the development of the chronic disease. Also, Treg cells can be contributed to an inadequate response against the viruses, leading to chronic infection. Here we evaluated the ability of protein F to modulate the frequency of CD4+CD25+FoxP3+T and IL-10+T cells in patients with chronic HCV infection. F gene was amplified and cloned in the expression vector. The protein was purified and used for stimulation of PBMCs in the HCV chronic patients and the control groups. The frequency of CD4+CD25+FoxP3+ T cell-like populations and IL-10-producing CD4+CD25+ T cells was assessed in the HCV-infected patients and in the healthy controls by flow cytometry, which showed an increase of both CD4+CD25+FoxP3+ T cell-like population and IL-10-producing CD4+CD25+ T cells in the HCV-infected patients positive for anti-F antibody. Our results suggest the potential involvement of F and core antigens in increasing the frequency of CD4+CD25+FoxP3+ T cell-like population and IL-10-producing CD4+CD25+ T cells which may be associated with HCV-persistent infection. PMID:25862675

  17. Control of HPV-associated tumors by innovative therapeutic HPV DNA vaccine in the absence of CD4+ T cells

    PubMed Central

    2014-01-01

    Human papillomavirus (HPV) infections are particularly problematic for HIV + and solid organ transplant patients with compromised CD4+ T cell-dependent immunity as they produce more severe and progressive disease compared to healthy individuals. There are no specific treatments for chronic HPV infection, resulting in an urgent unmet need for a modality that is safe and effective for both immunocompromised and otherwise normal patients with recalcitrant disease. DNA vaccination is attractive because it avoids the risks of administration of live vectors to immunocompromised patients, and can induce potent HPV-specific cytotoxic T cell responses. We have developed a DNA vaccine (pNGVL4a-hCRTE6E7L2) encoding calreticulin (CRT) fused to E6, E7 and L2 proteins of HPV-16, the genotype associated with approximately 90% vaginal, vulvar, anal, penile and oropharyngeal HPV-associated cancers and the majority of cervical cancers. Administration of the DNA vaccine by intramuscular (IM) injection followed by electroporation induced significantly greater HPV-specific immune responses compared to IM injection alone or mixed with alum. Furthermore, pNGVL4a-hCRTE6E7L2 DNA vaccination via electroporation of mice carrying an intravaginal HPV-16 E6/E7-expressing syngeneic tumor demonstrated more potent therapeutic effects than IM vaccination alone. Of note, administration of the DNA vaccine by IM injection followed by electroporation elicited potent E6 and E7-specific CD8+ T cell responses and antitumor effects despite CD4+ T cell-depletion, although no antibody response was detected. While CD4+ T cell-depletion did reduce the E6 and E7-specific CD8+ T cell response, it remained sufficient to prevent subcutaneous tumor growth and to eliminate circulating tumor cells in a model of metastatic HPV-16+ cancer. Thus, the antibody response was CD4-dependent, whereas CD4+ T cell help enhanced the E6/E7-specific CD8+ T cell immunity, but was not required. Taken together, our data suggest that

  18. CD4(+)CD25 (+)CD127 (low/-) T cells: a more specific Treg population in human peripheral blood.

    PubMed

    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

  19. Exhaustion of bacteria-specific CD4 T cells and microbial translocation in common variable immunodeficiency disorders.

    PubMed

    Perreau, Matthieu; Vigano, Selena; Bellanger, Florence; Pellaton, Céline; Buss, Guillaume; Comte, Denis; Roger, Thierry; Lacabaratz, Christine; Bart, Pierre-Alexandre; Levy, Yves; Pantaleo, Giuseppe

    2014-09-22

    In the present study, we have investigated the functional profile of CD4 T cells from patients with common variable immunodeficiency (CVID), including production of cytokines and proliferation in response to bacteria and virus-derived antigens. We show that the functional impairment of CD4 T cells, including the reduced capacity to proliferate and to produce IFN-γ and IL-2, was restricted to bacteria-specific and not virus-specific CD4 T cells. High levels of endotoxins were found in the plasma of patients with CVID, suggesting that CD4 T cell dysfunction might be caused by bacterial translocation. Of note, endotoxemia was associated with significantly higher expression of programmed death 1 (PD-1) on CD4 T cells. The blockade of the PD-1-PD-L1/2 axis in vitro restored CD4 T cell proliferation capacity, thus indicating that PD-1 signaling negatively regulates CD4 T cell functions. Finally, we showed that intravenous immunoglobulin G (IVIG) treatment significantly reduced endotoxemia and the percentage of PD-1(+) CD4 T cells, and restored bacteria-specific CD4 T cell cytokine production and proliferation. In conclusion, the present study demonstrates that the CD4 T cell exhaustion and functional impairment observed in CVID patients is associated with bacterial translocation and that IVIG treatment resolves bacterial translocation and restores CD4 T cell functions. PMID:25225461

  20. Oligoclonal CD4+ T Cells Promote Host Memory Immune Responses to Zwitterionic Polysaccharide of Streptococcus pneumoniae▿

    PubMed Central

    Groneck, Laura; Schrama, David; Fabri, Mario; Stephen, Tom Li; Harms, Fabian; Meemboor, Sonja; Hafke, Helena; Bessler, Martina; Becker, Jürgen C.; Kalka-Moll, Wiltrud M.

    2009-01-01

    Zwitterionic polysaccharides of the normal flora bacteria represent a novel class of antigens in that they correct systemic CD4+ T-cell deficiencies and direct lymphoid organogenesis during colonization of the host. Presentation of these polysaccharides to CD4+ T cells depends on major histocompatibility complex class II- and DM-dependent retrograde transport from lysosomes to the cell surface. Yet the phenotype and clonality of the immune response to the polysaccharide in the mature host immune system have not been studied. Using the zwitterionic capsular polysaccharide Sp1 of Streptococcus pneumoniae, a transient member of the bacterial flora, in an experimental mouse model of cellular immunity, we demonstrated the accumulation of TH1- and TH17-polarized CD4+ CD44high CD62low CD25− memory T cells. Subcutaneous immunization with Sp1 resulted in an increase of serum immunoglobulin G (IgG), predominantly of the IgG1 subclass, and suggested the presence of a humoral memory response to the polysaccharide. CD4+ T cells stimulated with polysaccharide in vitro and in vivo showed a nonrestricted pattern for the T-cell receptor (TCR) β-chain variable region, as demonstrated by semiquantitative reverse transcription-PCR and flow cytometry. Clonotype mapping of in vivo and in vitro polysaccharide-activated CD4+ T cells revealed clonotypic TCR transcripts. Taken together, the data show the induction of clonal expansion of CD4+ T cells by polysaccharides of commensal bacteria. Cellular and humoral memory host responses imply the ability of these polysaccharides to mediate the expansion of T cells via recognition within the CDR3 region of the TCR. PMID:19546196

  1. Adenoviral transduction of naive CD4 T cells to study Treg differentiation.

    PubMed

    Warth, Sebastian C; Heissmeyer, Vigo

    2013-01-01

    Regulatory T cells (Tregs) are essential to provide immune tolerance to self as well as to certain foreign antigens. Tregs can be generated from naive CD4 T cells in vitro with TCR- and co-stimulation in the presence of TGFβ and IL-2. This bears enormous potential for future therapies, however, the molecules and signaling pathways that control differentiation are largely unknown. Primary T cells can be manipulated through ectopic gene expression, but common methods fail to target the most important naive state of the T cell prior to primary antigen recognition. Here, we provide a protocol to express ectopic genes in naive CD4 T cells in vitro before inducing Treg differentiation. It applies transduction with the replication-deficient adenovirus and explains its generation and production. The adenovirus can take up large inserts (up to 7 kb) and can be equipped with promoters to achieve high and transient overexpression in T cells. It effectively transduces naive mouse T cells if they express a transgenic Coxsackie adenovirus receptor (CAR). Importantly, after infection the T cells remain naive (CD44(low), CD62L(high)) and resting (CD25(-), CD69(-)) and can be activated and differentiated into Tregs similar to non-infected cells. Thus, this method enables manipulation of CD4 T cell differentiation from its very beginning. It ensures that ectopic gene expression is already in place when early signaling events of the initial TCR stimulation induces cellular changes that eventually lead into Treg differentiation. PMID:23979424

  2. Transcription regulates HIF-1α expression in CD4(+) T cells.

    PubMed

    Bollinger, Thomas; Bollinger, Annalena; Gies, Sydney; Feldhoff, Lea; Solbach, Werner; Rupp, Jan

    2016-01-01

    The transcription factor hypoxia inducible factor-1α (HIF-1α) mediates the metabolic adaptation of cells to hypoxia and T-helper cell fate. However, HIF-1α regulation in CD4(+) T cells (T cells) remains elusive. Here we observed that depletion of oxygen (O2⩽2%) alone was not sufficient to induce HIF-1α expression in T cells. However, when hypoxic T cells were stimulated, HIF-1α was expressed and this was dependent on nuclear factor-κB- and nuclear factor of activated T cell (NFAT)-mediated transcriptional upregulation of Hif-1α mRNA. HIF-1α upregulation could be blocked by drugs inhibiting NF-κB, NFAT or mammalian target of rapamycin precluding CD4(+) T-cell stimulation or translation in T cells, as well as by blocking transcription. CD3, CD28, phorbol-12-myristat-13-acetat (PMA) or ionomycin-stimulated T cells did not express HIF-1α under normoxic conditions. In conclusion, regulation of HIF-1α expression in CD4(+) T cells in hypoxia gravely relies on its transcriptional upregulation and subsequent enhanced protein stabilization. PMID:26150319

  3. NK cell regulation of CD4 T cell-mediated graft-versus-host disease.

    PubMed

    Noval Rivas, Magali; Hazzan, Marc; Weatherly, Kathleen; Gaudray, Florence; Salmon, Isabelle; Braun, Michel Y

    2010-06-15

    CD3-negative NK cells are granular lymphocytes capable of producing inflammatory cytokines and killing malignant, infected, or stressed cells. We have recently observed a new role for NK cells in the control of the proliferation of CD4 T cells under persistent antigenic stimulation. Monoclonal anti-male CD4 T cells transferred into Rag2-/- male recipients did not expand or were rapidly eliminated. Remarkably, T cells transferred into NK cell-deficient Rag2-/- Il-2Rgammac-/- male hosts expanded extensively and mediated tissue lesions usually observed in chronic graft-versus-host disease (GVHD). T cell failure to proliferate and to induce chronic GVHD was the result of NK cell activity, because depletion of the recipient's NK1.1+ cells by Ab treatment induced T cell expansion and chronic GVHD. T cells under chronic Ag stimulation upregulated ligands of the activating receptor NKG2D, and regulatory activity of NK cells was inhibited by the injection of Abs directed to NKG2D. On the contrary, blocking NKG2A inhibitory receptors did not increase NK cell regulatory activity. Finally, we show that NK regulation of T cell expansion did not involve perforin-mediated lytic activity of NK cells, but depended on T cell surface expression of a functional Fas molecule. These results highlight the potential role played by NK cells in controlling the Ag-specific CD4+ T cells responsible for chronic GVHD. PMID:20488796

  4. Identification of beryllium-dependent peptides recognized by CD4+ T cells in chronic beryllium disease

    PubMed Central

    Falta, Michael T.; Mack, Douglas G.; Tinega, Alex N.; Crawford, Frances; Giulianotti, Marc; Santos, Radleigh; Clayton, Gina M.; Wang, Yuxiao; Zhang, Xuewu; Maier, Lisa A.; Marrack, Philippa; Kappler, John W.

    2013-01-01

    Chronic beryllium disease (CBD) is a granulomatous disorder characterized by an influx of beryllium (Be)-specific CD4+ T cells into the lung. The vast majority of these T cells recognize Be in an HLA-DP–restricted manner, and peptide is required for T cell recognition. However, the peptides that stimulate Be-specific T cells are unknown. Using positional scanning libraries and fibroblasts expressing HLA-DP2, the most prevalent HLA-DP molecule linked to disease, we identified mimotopes and endogenous self-peptides that bind to MHCII and Be, forming a complex recognized by pathogenic CD4+ T cells in CBD. These peptides possess aspartic and glutamic acid residues at p4 and p7, respectively, that surround the putative Be-binding site and cooperate with HLA-DP2 in Be coordination. Endogenous plexin A peptides and proteins, which share the core motif and are expressed in lung, also stimulate these TCRs. Be-loaded HLA-DP2–mimotope and HLA-DP2–plexin A4 tetramers detected high frequencies of CD4+ T cells specific for these ligands in all HLA-DP2+ CBD patients tested. Thus, our findings identify the first ligand for a CD4+ T cell involved in metal-induced hypersensitivity and suggest a unique role of these peptides in metal ion coordination and the generation of a common antigen specificity in CBD. PMID:23797096

  5. Identification of beryllium-dependent peptides recognized by CD4+ T cells in chronic beryllium disease.

    PubMed

    Falta, Michael T; Pinilla, Clemencia; Mack, Douglas G; Tinega, Alex N; Crawford, Frances; Giulianotti, Marc; Santos, Radleigh; Clayton, Gina M; Wang, Yuxiao; Zhang, Xuewu; Maier, Lisa A; Marrack, Philippa; Kappler, John W; Fontenot, Andrew P

    2013-07-01

    Chronic beryllium disease (CBD) is a granulomatous disorder characterized by an influx of beryllium (Be)-specific CD4T cells into the lung. The vast majority of these T cells recognize Be in an HLA-DP–restricted manner, and peptide is required for T cell recognition. However, the peptides that stimulate Be-specific T cells are unknown. Using positional scanning libraries and fibroblasts expressing HLA-DP2, the most prevalent HLA-DP molecule linked to disease, we identified mimotopes and endogenous self-peptides that bind to MHCII and Be, forming a complex recognized by pathogenic CD4T cells in CBD. These peptides possess aspartic and glutamic acid residues at p4 and p7, respectively, that surround the putative Be-binding site and cooperate with HLA-DP2 in Be coordination. Endogenous plexin A peptides and proteins, which share the core motif and are expressed in lung, also stimulate these TCRs. Be-loaded HLA-DP2–mimotope and HLA-DP2–plexin A4 tetramers detected high frequencies of CD4T cells specific for these ligands in all HLADP2+ CBD patients tested. Thus, our findings identify the first ligand for a CD4T cell involved in metal-induced hypersensitivity and suggest a unique role of these peptides in metal ion coordination and the generation of a common antigen specificity in CBD. PMID:23797096

  6. CD8+ T cell migration to the skin requires CD4+ help in a murine model of contact hypersensitivity.

    PubMed

    Fyhrquist, Nanna; Wolff, Henrik; Lauerma, Antti; Alenius, Harri

    2012-01-01

    The relative roles of CD4+ and CD8+ T cells in contact hypersensitivity responses have not been fully solved, and remain an important question. Using an adoptive transfer model, we investigated the role of the respective T cell subset. Magnetic bead separated CD4+ and CD8+ T cells from oxazolone sensitized C57BL/6 mice were transferred into RAG-/- mice, followed by hapten challenge and analysis of inflammatory parameters at 24 hours post exposure. The CD4+ T cell recipient mice developed partial contact hypersensitivity responses to oxazolone. CD8+ T cells caused significant amplification of the response in recipients of both CD4+ and CD8+ T cells including ear swelling, type 1 inflammatory mediators, and cell killing. Unexpectedly, CD8+ T cells were not sufficient to mediate contact hypersensitivity, although abundantly present in the lymph nodes in the CD8+ T cell reconstituted mice. There were no signs of inflammation at the site of hapten exposure, indicating impaired recruitment of CD8+ T cells in the absence of CD4+ T cells. These data show that CD4+ T cells mediate contact hypersensitivity to oxazolone, but CD8+ T cells contribute with the most potent effector mechanisms. Moreover, our results suggest that CD4+ T cell function is required for the mobilization of CD8+ effector T cells to the site of hapten exposure. The results shed new light on the relative importance of CD4+ and CD8+ T cells during the effector phase of contact hypersensitivity. PMID:22916101

  7. Tolerance induction in memory CD4 T cells requires two rounds of antigen-specific activation.

    PubMed

    David, Alexandria; Crawford, Frances; Garside, Paul; Kappler, John W; Marrack, Philippa; MacLeod, Megan

    2014-05-27

    A major goal for immunotherapy is to tolerize the immune cells that coordinate tissue damage in autoimmune and alloantigen responses. CD4 T cells play a central role in many of these conditions and improved antigen-specific regulation or removal of these cells could revolutionize current treatments. A confounding factor is that little is known about whether and how tolerance is induced in memory CD4 T cells. We used MHC class II tetramers to track and analyze a population of endogenous antigen-specific memory CD4 T cells exposed to soluble peptide in the absence of adjuvant. We found that such memory T cells proliferated and reentered the memory pool apparently unperturbed by the incomplete activation signals provided by the peptide. Upon further restimulation in vivo, CD4 memory T cells that had been previously exposed to peptide proliferated, provided help to primary responding B cells, and migrated to inflamed sites. However, these reactivated memory cells failed to survive. The reduction in T-cell number was marked by low expression of the antiapoptotic molecule B cell lymphoma 2 (Bcl2) and increased expression of activated caspase molecules. Consequently, these cells failed to sustain a delayed-type hypersensitivity response. Moreover, following two separate exposures to soluble antigen, no T-cell recall response and no helper activity for B cells could be detected. These results suggest that the induction of tolerance in memory CD4 T cells is possible but that deletion and permanent removal of the antigen-specific T cells requires reactivation following exposure to the tolerogenic antigen. PMID:24821788

  8. Cell death by pyroptosis drives CD4 T-cell depletion in HIV-1 infection

    NASA Astrophysics Data System (ADS)

    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.

  9. Role of miRNAs in CD4 T cell plasticity during inflammation and tolerance.

    PubMed

    Sethi, Apoorva; Kulkarni, Neeraja; Sonar, Sandip; Lal, Girdhari

    2013-01-01

    Gene expression is tightly regulated in a tuneable, cell-specific and time-dependent manner. Recent advancement in epigenetics and non-coding RNA (ncRNA) revolutionized the concept of gene regulation. In order to regulate the transcription, ncRNA can promptly response to the extracellular signals as compared to transcription factors present in the cells. microRNAs (miRNAs) are ncRNA (~22 bp) encoded in the genome, and present as intergenic or oriented antisense to neighboring genes. The strategic location of miRNA in coding genes helps in the coupled regulation of its expression with host genes. miRNA together with complex machinery called RNA-induced silencing complex (RISC) interacts with target mRNA and degrade the mRNA or inhibits the translation. CD4 T cells play an important role in the generation and maintenance of inflammation and tolerance. Cytokines and chemokines present in the inflamed microenvironment controls the differentiation and function of various subsets of CD4 T cells [Th1, Th2, Th17, and regulatory CD4 T cells (Tregs)]. Recent studies suggest that miRNAs play an important role in the development and function of all subsets of CD4 T cells. In current review, we focused on how various miRNAs are regulated by cell's extrinsic and intrinsic signaling, and how miRNAs affect the transdifferentiation of subsets of CD4 T cell and controls their plasticity during inflammation and tolerance. PMID:23386861

  10. Temporal requirements for B cells in the establishment of CD4 T cell memory.

    PubMed

    Mollo, Sarah B; Zajac, Allan J; Harrington, Laurie E

    2013-12-15

    CD4 T cell memory generation is shaped by a number of factors, including the strength and duration of TCR signaling, as well as the priming environment, all of which can be modified by B cells. Studies using B cell-deficient mice indicate B cells play a critical role in generating effector and memory CD4 T cells; however, when and how B cells are acting to promote these responses has not yet been ascertained. In this study, we use anti-CD20 Ab depletion of B cells at different times following Listeria monocytogenes infection to show that B cells are necessary for the induction of optimal CD4 T cell memory, but not for the transition and maintenance of this population. Importantly, the prerequisite of B cells early postinfection is partially dependent on their expression of MHC class II. B cells are not only required during the priming phase, but also necessary for the initiation of robust secondary responses by memory CD4 T cells. Interestingly, the requirement during the recall response is independent of B cell Ag presentation. Overall, these studies demonstrate the temporally and functionally distinct roles for B cells in regulating CD4 T cell responses. PMID:24218454

  11. Role of miRNAs in CD4 T cell plasticity during inflammation and tolerance

    PubMed Central

    Sethi, Apoorva; Kulkarni, Neeraja; Sonar, Sandip; Lal, Girdhari

    2013-01-01

    Gene expression is tightly regulated in a tuneable, cell-specific and time-dependent manner. Recent advancement in epigenetics and non-coding RNA (ncRNA) revolutionized the concept of gene regulation. In order to regulate the transcription, ncRNA can promptly response to the extracellular signals as compared to transcription factors present in the cells. microRNAs (miRNAs) are ncRNA (~22 bp) encoded in the genome, and present as intergenic or oriented antisense to neighboring genes. The strategic location of miRNA in coding genes helps in the coupled regulation of its expression with host genes. miRNA together with complex machinery called RNA-induced silencing complex (RISC) interacts with target mRNA and degrade the mRNA or inhibits the translation. CD4 T cells play an important role in the generation and maintenance of inflammation and tolerance. Cytokines and chemokines present in the inflamed microenvironment controls the differentiation and function of various subsets of CD4 T cells [Th1, Th2, Th17, and regulatory CD4 T cells (Tregs)]. Recent studies suggest that miRNAs play an important role in the development and function of all subsets of CD4 T cells. In current review, we focused on how various miRNAs are regulated by cell's extrinsic and intrinsic signaling, and how miRNAs affect the transdifferentiation of subsets of CD4 T cell and controls their plasticity during inflammation and tolerance. PMID:23386861

  12. Exogenous and endogenous hyaluronic acid reduces HIV infection of CD4+ T cells

    PubMed Central

    Li, Peilin; Fujimoto, Katsuya; Bourguingnon, Lilly; Yukl, Steven; Deeks, Steven; Wong, Joseph K

    2014-01-01

    Preventing mucosal transmission of HIV is critical to halting the HIV epidemic. Novel approaches to preventing mucosal transmission are needed. Hyaluronic acid (HA) is a major extracellular component of mucosa and the primary ligand for the cell surface receptor CD44. CD44 enhances HIV infection of CD4+ T cells, but the role of HA in this process is not clear. To study this, virions were generated with CD44 (HIVCD44) or without CD44 (HIVmock). Exogenous HA reduced HIV infection of unstimulated CD4+ T cells in a CD44-dependent manner. Conversely, hyaluronidase-mediated reduction of endogenous HA on the cell surface enhanced HIV binding to and infection of unstimulated CD4+ T cells. Exogenous HA treatment reduced activation of protein kinase C alpha via CD44 on CD4+ T cells during infection with HIVCD44. These results reveal new roles for HA during the interaction of HIV with CD4+ T cells that may be relevant to mucosal HIV transmission and could be exploitable as a future strategy to prevent HIV infection. PMID:24957217

  13. Reviving function in CD4+ T cells adapted to persistent systemic antigen.

    PubMed

    Noval Rivas, Magali; Weatherly, Kathleen; Hazzan, Marc; Vokaer, Benoit; Dremier, Sarah; Gaudray, Florence; Goldman, Michel; Salmon, Isabelle; Braun, Michel Y

    2009-10-01

    In bone marrow-transplanted patients, chronic graft-versus-host disease is a complication that results from the persistent stimulation of recipient minor histocompatibility Ag (mHA)-specific T cells contained within the graft. In this study, we developed a mouse model where persistent stimulation of donor T cells by recipient's mHA led to multiorgan T cell infiltration. Exposure to systemic mHA, however, deeply modified T cell function and chronically stimulated T cells developed a long-lasting state of unresponsiveness, or immune adaptation, characterized by their inability to mediate organ immune damages in vivo. However, analysis of the gene expression profile of adapted CD4+ T cells revealed the specific coexpression of genes known to promote differentiation and function of Th1 effector cells as well as genes coding for proteins that control T cell activity, such as cell surface-negative costimulatory molecules and regulatory cytokines. Strikingly, blockade of negative costimulation abolished T cell adaptation and stimulated strong IFN-gamma production and severe multiorgan wasting disease. Negative costimulation was also shown to control lethal LPS-induced toxic shock in mice with adapted T cells, as well as the capacity of adapted T cells to reject skin graft. Our results demonstrate that negative costimulation is the molecular mechanism used by CD4+ T cells to adapt their activity in response to persistent antigenic stimulation. The effector function of CD4+ T cells that have adapted to chronic Ag presentation can be activated by stimuli strong enough to overcome regulatory signals delivered to the T cells by negative costimulation. PMID:19734216

  14. CD4(+) T-cell help amplifies innate signals for primary CD8(+) T-cell immunity.

    PubMed

    Bedoui, Sammy; Heath, William R; Mueller, Scott N

    2016-07-01

    CD8(+) T cells provide an important component of protection against intracellular infections and cancer. Immune responses by these T cells involve a primary phase of effector expansion and differentiation, followed by a contraction phase leading to memory formation and, if antigen is re-encountered, a secondary expansion phase with more rapid differentiation. Both primary and secondary phases of CD8(+) T-cell immunity have been shown to depend on CD4(+) T-cell help, although during certain infections the primary phase is variable in this requirement. One explanation for such variability relates to the strength of associated inflammatory signals, with weak signals requiring help. Here, we focus on our studies that have dissected the requirements for help in the primary phase of the CTL response to herpes simplex virus, elucidating intricate interactions and communications between CD4(+) T cells, various dendritic cell subsets, and CD8(+) T cells. We place our studies in the context of others and describe a simple model of help where CD40 signaling amplifies innate signals to enable efficient CD8(+) T-cell expansion and differentiation. This model facilitates CTL induction to various different agents, without altering the qualitative innate signals that direct other important arms of immunity. PMID:27319342

  15. CD4+ T Cell Depletion in Human Immunodeficiency Virus (HIV) Infection: Role of Apoptosis

    PubMed Central

    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

  16. Identifying the target cell in primary simian immunodeficiency virus (SIV) infection: highly activated memory CD4(+) T cells are rapidly eliminated in early SIV infection in vivo.

    PubMed

    Veazey, R S; Tham, I C; Mansfield, K G; DeMaria, M; Forand, A E; Shvetz, D E; Chalifoux, L V; Sehgal, P K; Lackner, A A

    2000-01-01

    It has recently been shown that rapid and profound CD4(+) T-cell depletion occurs almost exclusively within the intestinal tract of simian immunodeficiency virus (SIV)-infected macaques within days of infection. Here we demonstrate (by three- and four-color flow cytometry) that this depletion is specific to a definable subset of CD4(+) T cells, namely, those having both a highly and/or acutely activated (CD69(+) CD38(+) HLA-DR(+)) and memory (CD45RA(-) Leu8(-)) phenotype. Moreover, we demonstrate that this subset of helper T cells is found primarily within the intestinal lamina propria. Viral tropism for this particular cell type (which has been previously suggested by various studies in vitro) could explain why profound CD4(+) T-cell depletion occurs in the intestine and not in peripheral lymphoid tissues in early SIV infection. Furthermore, we demonstrate that an acute loss of this specific subset of activated memory CD4(+) T cells may also be detected in peripheral blood and lymph nodes in early SIV infection. However, since this particular cell type is present in such small numbers in circulation, its loss does not significantly affect total CD4(+) T cell counts. This finding suggests that SIV and, presumably, human immunodeficiency virus specifically infect, replicate in, and eliminate definable subsets of CD4(+) T cells in vivo. PMID:10590091

  17. Blind T-cell homeostasis and the CD4/CD8 ratio in the thymus and peripheral blood.

    PubMed

    Mehr, R; Perelson, A S

    1997-04-15

    We present a model of the dynamics of CD4 and CD8 T-cell subsets in the thymus and peripheral blood and use it to study the blind homeostasis hypothesis, which states that the total T-cell population in the periphery is subject to regulation rather than regulation of the CD4 or CD8 subsets individually. Our model reconstructs experimental observations by Adleman and Wofsy on the effects of CD4+ T-cell depletion in mice. Our results point to the importance of the thymus in recovery from CD4+ T-cell depletion and particularly to the need to hypothesize an intrathymic feedback regulation of T-cell production exerted by CD4+ T cells. Our results support the blind homeostasis hypothesis for regulation of the peripheral blood levels of CD4+ and CD8- T cells. PMID:9170412

  18. DNA methylation analysis of CD4+ T cells in patients with psoriasis.

    PubMed

    Park, Geon Tae; Han, Jihye; Park, Sin-Gi; Kim, Sangsoo; Kim, Tae-Yoon

    2014-04-01

    Psoriasis is a chronic inflammatory skin disease that is characterized by aberrant cross-talk between keratinocytes and immune cells such as CD4+ T cells, resulting in keratinocyte hyperproliferation in the epidermis. DNA methylation, one of several epigenetic mechanisms, plays an important role in gene expression without changing the DNA sequence. Several studies have suggested the involvement of epigenetic regulation in skin lesions from patients with psoriasis. In this study, we investigated the genome-wide DNA methylation status of CD4+ T cells in patients with psoriasis compared with healthy subjects using methylated DNA immunoprecipitation sequencing (MeDIP-Seq). The results of MeDIP-Seq showed that the global methylation values of CD4+ T cells are higher in patients with psoriasis than in healthy controls, particularly in the promoter regions. Among the most hypermethylated genes in the promoter regions, we selected the genes whose expression is significantly reduced in the CD4+ T cells of psoriasis patients. Studies using the methylation inhibitor 5-azacytidine in vitro methylation assays have shown that the differential expression levels were associated with the methylation status of each gene. Bisulfite sequencing of the transcription start region of phosphatidic acid phosphatase type 2 domain containing 3 (PPAPDC3), one of the selected genes, showed hypermethylation in the CD4+ T cells of psoriasis patients. These results suggested that the methylation status, which is identified by MeDIP-Seq of the genes, was correlated with the mRNA expression level of the genes. Collectively, the DNA methylation status in CD4+ T cells might be associated with the pathogenesis of psoriasis. PMID:24323136

  19. Induction of CD4+ Regulatory and Polarized Effector/helper T Cells by Dendritic Cells

    PubMed Central

    2016-01-01

    Dendritic cells (DCs) are considered to play major roles during the induction of T cell immune responses as well as the maintenance of T cell tolerance. Naive CD4+ T cells have been shown to respond with high plasticity to signals inducing their polarization into effector/helper or regulatory T cells. Data obtained from in vitro generated bone-marrow (BM)-derived DCs as well as genetic mouse models revealed an important but not exclusive role of DCs in shaping CD4+ T cell responses. Besides the specialization of some conventional DC subsets for the induction of polarized immunity, also the maturation stage, activation of specialized transcription factors and the cytokine production of DCs have major impact on CD4+ T cells. Since in vitro generated BM-DCs show a high diversity to shape CD4+ T cells and their high similarity to monocyte-derived DCs in vivo, this review reports data mainly on BM-DCs in this process and only touches the roles of transcription factors or of DC subsets, which have been discussed elsewhere. Here, recent findings on 1) the conversion of naive into anergic and further into Foxp3− regulatory T cells (Treg) by immature DCs, 2) the role of RelB in steady state migratory DCs (ssmDCs) for conversion of naive T cells into Foxp3+ Treg, 3) the DC maturation signature for polarized Th2 cell induction and 4) the DC source of IL-12 for Th1 induction are discussed. PMID:26937228

  20. CD4(+) T-Cell-Independent Secondary Immune Responses to Pneumocystis Pneumonia.

    PubMed

    de la Rua, Nicholas M; Samuelson, Derrick R; Charles, Tysheena P; Welsh, David A; Shellito, Judd E

    2016-01-01

    Pneumocystis pneumonia is a major cause of morbidity and mortality among immunocompromised patients, especially in the context of HIV/AIDS. In the murine model of Pneumocystis pneumonia, CD4(+) T-cells are required for clearance of a primary infection of Pneumocystis, but not the memory recall response. We hypothesized that the memory recall response in the absence of CD4(+) T-cells is mediated by a robust memory humoral response, CD8(+) T-cells, and IgG-mediated phagocytosis by alveolar macrophages. To investigate the role of CD8(+) T-cells and alveolar macrophages in the immune memory response to Pneumocystis, mice previously challenged with Pneumocystis were depleted of CD8(+) T-cells or alveolar macrophages prior to re-infection. Mice depleted of CD4(+) T-cells prior to secondary challenge cleared Pneumocystis infection within 48 h identical to immunocompetent mice during a secondary memory recall response. However, loss of CD8(+) T-cells or macrophages prior to the memory recall response significantly impaired Pneumocystis clearance. Specifically, mice depleted of CD8(+) T-cells or alveolar macrophages had significantly higher fungal burden in the lungs. Furthermore, loss of alveolar macrophages significantly skewed the lung CD8(+) T-cell response toward a terminally differentiated effector memory population and increased the percentage of IFN-γ(+) CD8(+) T-cells. Finally, Pneumocystis-infected animals produced significantly more bone marrow plasma cells and Pneumocystis-specific IgG significantly increased macrophage-mediated killing of Pneumocystis in vitro. These data suggest that secondary immune memory responses to Pneumocystis are mediated, in part, by CD8(+) T-cells, alveolar macrophages, and the production of Pneumocystis-specific IgG. PMID:27242785

  1. CD4+ T-Cell-Independent Secondary Immune Responses to Pneumocystis Pneumonia

    PubMed Central

    de la Rua, Nicholas M.; Samuelson, Derrick R.; Charles, Tysheena P.; Welsh, David A.; Shellito, Judd E.

    2016-01-01

    Pneumocystis pneumonia is a major cause of morbidity and mortality among immunocompromised patients, especially in the context of HIV/AIDS. In the murine model of Pneumocystis pneumonia, CD4+ T-cells are required for clearance of a primary infection of Pneumocystis, but not the memory recall response. We hypothesized that the memory recall response in the absence of CD4+ T-cells is mediated by a robust memory humoral response, CD8+ T-cells, and IgG-mediated phagocytosis by alveolar macrophages. To investigate the role of CD8+ T-cells and alveolar macrophages in the immune memory response to Pneumocystis, mice previously challenged with Pneumocystis were depleted of CD8+ T-cells or alveolar macrophages prior to re-infection. Mice depleted of CD4+ T-cells prior to secondary challenge cleared Pneumocystis infection within 48 h identical to immunocompetent mice during a secondary memory recall response. However, loss of CD8+ T-cells or macrophages prior to the memory recall response significantly impaired Pneumocystis clearance. Specifically, mice depleted of CD8+ T-cells or alveolar macrophages had significantly higher fungal burden in the lungs. Furthermore, loss of alveolar macrophages significantly skewed the lung CD8+ T-cell response toward a terminally differentiated effector memory population and increased the percentage of IFN-γ+ CD8+ T-cells. Finally, Pneumocystis-infected animals produced significantly more bone marrow plasma cells and Pneumocystis-specific IgG significantly increased macrophage-mediated killing of Pneumocystis in vitro. These data suggest that secondary immune memory responses to Pneumocystis are mediated, in part, by CD8+ T-cells, alveolar macrophages, and the production of Pneumocystis-specific IgG. PMID:27242785

  2. Extensive CD4 and CD8 T Cell Cross-Reactivity between Alphaherpesviruses.

    PubMed

    Jing, Lichen; Laing, Kerry J; Dong, Lichun; Russell, Ronnie M; Barlow, Russell S; Haas, Juergen G; Ramchandani, Meena S; Johnston, Christine; Buus, Soren; Redwood, Alec J; White, Katie D; Mallal, Simon A; Phillips, Elizabeth J; Posavad, Christine M; Wald, Anna; Koelle, David M

    2016-03-01

    The Alphaherpesvirinae subfamily includes HSV types 1 and 2 and the sequence-divergent pathogen varicella zoster virus (VZV). T cells, controlled by TCR and HLA molecules that tolerate limited epitope amino acid variation, might cross-react between these microbes. We show that memory PBMC expansion with either HSV or VZV enriches for CD4 T cell lines that recognize the other agent at the whole-virus, protein, and peptide levels, consistent with bidirectional cross-reactivity. HSV-specific CD4 T cells recovered from HSV-seronegative persons can be explained, in part, by such VZV cross-reactivity. HSV-1-reactive CD8 T cells also cross-react with VZV-infected cells, full-length VZV proteins, and VZV peptides, as well as kill VZV-infected dermal fibroblasts. Mono- and cross-reactive CD8 T cells use distinct TCRB CDR3 sequences. Cross-reactivity to VZV is reconstituted by cloning and expressing TCRA/TCRB receptors from T cells that are initially isolated using HSV reagents. Overall, we define 13 novel CD4 and CD8 HSV-VZV cross-reactive epitopes and strongly imply additional cross-reactive peptide sets. Viral proteins can harbor both CD4 and CD8 HSV/VZV cross-reactive epitopes. Quantitative estimates of HSV/VZV cross-reactivity for both CD4 and CD8 T cells vary from 10 to 50%. Based on these findings, we hypothesize that host herpesvirus immune history may influence the pathogenesis and clinical outcome of subsequent infections or vaccinations for related pathogens and that cross-reactive epitopes and TCRs may be useful for multi-alphaherpesvirus vaccine design and adoptive cellular therapy. PMID:26810224

  3. MHCII-independent CD4+ T cells protect injured CNS neurons via IL-4.

    PubMed

    Walsh, James T; Hendrix, Sven; Boato, Francesco; Smirnov, Igor; Zheng, Jingjing; Lukens, John R; Gadani, Sachin; Hechler, Daniel; Gölz, Greta; Rosenberger, Karen; Kammertöns, Thomas; Vogt, Johannes; Vogelaar, Christina; Siffrin, Volker; Radjavi, Ali; Fernandez-Castaneda, Anthony; Gaultier, Alban; Gold, Ralf; Kanneganti, Thirumala-Devi; Nitsch, Robert; Zipp, Frauke; Kipnis, Jonathan

    2015-02-01

    A body of experimental evidence suggests that T cells mediate neuroprotection following CNS injury; however, the antigen specificity of these T cells and how they mediate neuroprotection are unknown. Here, we have provided evidence that T cell-mediated neuroprotection after CNS injury can occur independently of major histocompatibility class II (MHCII) signaling to T cell receptors (TCRs). Using two murine models of CNS injury, we determined that damage-associated molecular mediators that originate from injured CNS tissue induce a population of neuroprotective, IL-4-producing T cells in an antigen-independent fashion. Compared with wild-type mice, IL-4-deficient animals had decreased functional recovery following CNS injury; however, transfer of CD4+ T cells from wild-type mice, but not from IL-4-deficient mice, enhanced neuronal survival. Using a culture-based system, we determined that T cell-derived IL-4 protects and induces recovery of injured neurons by activation of neuronal IL-4 receptors, which potentiated neurotrophin signaling via the AKT and MAPK pathways. Together, these findings demonstrate that damage-associated molecules from the injured CNS induce a neuroprotective T cell response that is independent of MHCII/TCR interactions and is MyD88 dependent. Moreover, our results indicate that IL-4 mediates neuroprotection and recovery of the injured CNS and suggest that strategies to enhance IL-4-producing CD4+ T cells have potential to attenuate axonal damage in the course of CNS injury in trauma, inflammation, or neurodegeneration. PMID:25607842

  4. The Control of the Specificity of CD4 T Cell Responses: Thresholds, Breakpoints, and Ceilings

    PubMed Central

    Sant, Andrea J.; Chaves, Francisco A.; Leddon, Scott A.; Tung, Jacqueline

    2013-01-01

    It has been known for over 25 years that CD4 T cell responses are restricted to a finite number of peptide epitopes within pathogens or protein vaccines. These selected peptide epitopes are termed “immunodominant.” Other peptides within the antigen that can bind to host MHC molecules and recruit CD4 T cells as single peptides are termed “cryptic” because they fail to induce responses when expressed in complex proteins or when in competition with other peptides during the immune response. In the last decade, our laboratory has evaluated the mechanisms that underlie the preferential specificity of CD4 T cells and have discovered that both intracellular events within antigen presenting cells, particular selective DM editing, and intercellular regulatory pathways, involving IFN-γ, indoleamine 2,3-dioxygenase, and regulatory T cells, play a role in selecting the final peptide specificity of CD4 T cells. In this review, we summarize our findings, discuss the implications of this work on responses to pathogens and vaccines and speculate on the logic of these regulatory events. PMID:24167504

  5. Conventional and Regulatory CD4+ T Cells That Share Identical TCRs Are Derived from Common Clones

    PubMed Central

    Emerson, Ryan O.; Pingel, Jeanette; Buller, R. Mark; DiPaolo, Richard J.

    2016-01-01

    Results from studies comparing the diversity and specificity of the TCR repertoires expressed by conventional (Tconv) and regulatory (Treg) CD4+ T cell have varied depending on the experimental system employed. We developed a new model in which T cells express a single fixed TCRα chain, randomly rearranged endogenous TCRβ chains, and a Foxp3-GFP reporter. We purified CD4+Foxp3- and CD4+Foxp3+ cells, then performed biased controlled multiplex PCR and high throughput sequencing of endogenous TCRβ chains. We identified >7,000 different TCRβ sequences in the periphery of 5 individual mice. On average, ~12% of TCR sequences were expressed by both conventional and regulatory populations within individual mice. The CD4+ T cells that expressed shared TCR sequences were present at higher frequencies compared to T cells expressing non-shared TCRs. Furthermore, nearly all (>90%) of the TCR sequences that were shared within mice were identical at the DNA sequence level, indicating that conventional and regulatory T cells that express shared TCRs are derived from common clones. Analysis of TCR repertoire overlap in the thymus reveals that a large proportion of Tconv and Treg sharing observed in the periphery is due to clonal expansion in the thymus. Together these data show that there are a limited number of TCR sequences shared between Tconv and Tregs. Also, Tconv and Tregs sharing identical TCRs are found at relatively high frequencies and are derived from common progenitors, of which a large portion are generated in the thymus. PMID:27100298

  6. TCRVγ9 γδ T Cell Response to IL-33: A CD4 T Cell-Dependent Mechanism.

    PubMed

    Duault, Caroline; Franchini, Don Marc; Familliades, Julien; Cayrol, Corinne; Roga, Stéphane; Girard, Jean-Philippe; Fournié, Jean-Jacques; Poupot, Mary

    2016-01-01

    The availability of specific stimuli to induce the anticancer cytotoxicity of human TCRVγ9-expressing T lymphocytes has allowed the development of γδ T cell-based cancer immunotherapies. However, the stringent dependence of such strategies on the inherently toxic IL-2 has raised safety concerns for patients, justifying a search for alternative methods for inducing γδ T cell stimulation. IL-33 is a γ-chain receptor-independent cytokine of the IL-1 superfamily that is expressed by endothelial cells from a tumor microenvironment and can sustain Th1 and Th2 immune responses. Therefore, we investigated its ability to support the stimulation of human TCRVγ9(+) γδ T cells. In this study, we report that IL-33 efficiently sustained the in vitro activation of Vγ9 T lymphocytes by synthetic phosphoantigens, zoledronate, and a BTN3A1 Ab in the absence of an exogenous supply of IL-2. IL-33 was as potent as IL-2 in allowing the proliferative amplification of Vγ9 T cells isolated from PBMC following activation by the synthetic phosphoantigen bromohydrin pyrophosphate. IL-33 also induced an identical maturation into TNF-α- and IFN-γ-producing Th1 effector memory cells, and IL-33-stimulated cells showed an equivalent cytotoxicity for various tumor cells in vitro. Finally, we found that the bioactivity of IL-33 on the Vγ9 T cell was indirectly mediated through contact with CD4 T cells and IL-2 production by CD4 T cells and Vγ9 T cells themselves. These data posit IL-33 as an alternative to IL-2 for Vγ9 T cell-based cancer immunotherapies. PMID:26608919

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

    PubMed Central

    Brown, Deborah M.; Lampe, Anna T.; Workman, Aspen M.

    2016-01-01

    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 human immunodeficiency virus, mouse pox, murine gamma herpes virus, cytomegalovirus, Epstein–Barr virus, and influenza among others. We now appreciate a greater role for CD4 CTL as direct effectors in viral infections and antitumor 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 antiviral and antitumor 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. PMID:27014272

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

    PubMed

    Brown, Deborah M; Lampe, Anna T; Workman, Aspen M

    2016-01-01

    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 human immunodeficiency virus, mouse pox, murine gamma herpes virus, cytomegalovirus, Epstein-Barr virus, and influenza among others. We now appreciate a greater role for CD4 CTL as direct effectors in viral infections and antitumor 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 antiviral and antitumor 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. PMID:27014272

  9. CD4+ T-cell survival in the GI tract requires dectin-1 during fungal infection

    PubMed Central

    Drummond, R A; Dambuza, I M; Vautier, S; Taylor, J A; Reid, D M; Bain, C C; Underhill, D M; Masopust, D; Kaplan, D H; Brown, G D

    2016-01-01

    Dectin-1 is an innate antifungal C-type lectin receptor necessary for protective antifungal immunity. We recently discovered that Dectin-1 is involved in controlling fungal infections of the gastrointestinal (GI) tract, but how this C-type lectin receptor mediates these activities is unknown. Here, we show that Dectin-1 is essential for driving fungal-specific CD4+ T-cell responses in the GI tract. Loss of Dectin-1 resulted in abrogated dendritic cell responses in the mesenteric lymph nodes (mLNs) and defective T-cell co-stimulation, causing substantial increases in CD4+ T-cell apoptosis and reductions in the cellularity of GI-associated lymphoid tissues. CD8+ T-cell responses were unaffected by Dectin-1 deficiency. These functions of Dectin-1 have significant implications for our understanding of intestinal immunity and susceptibility to fungal infections. PMID:26349660

  10. Decreased CD127 Expression on CD4+ T-Cells and Elevated Frequencies of CD4+CD25+CD127− T-Cells in Children with Long-Lasting Type 1 Diabetes

    PubMed Central

    Glowinska-Olszewska, Barbara; Rusak, Malgorzata; Jeznach, Marta; Grubczak, Kamil; Lipinska, Danuta; Milewska, Anna Justyna; Dabrowska, Milena; Jablonska, Ewa; Kretowski, Adam; Gorska, Maria; Bodzenta-Lukaszyk, Anna; Bossowski, Artur

    2013-01-01

    Pathobiology of type 1 diabetes (T1D) is predominantly associated with T-cell-related actions. Homeostasis of majority of T-cells is critically dependent on signals mediated by CD127 (interleukin-7 receptor, IL-7R). In contrast, regulatory T-cells express very little CD127 and thereby may be delineated by CD4+CD25+CD127− phenotype. Here we aimed to analyze CD127 expression on CD4+ and CD8+ T-cells and enumerate CD4+CD25+CD127− T-cells in long-lasting T1D. T-cells were analyzed by flow cytometry and immunologic data were correlated with vascular, metabolic, and inflammatory parameters. We demonstrated significantly decreased CD127 levels on CD4+, but not CD8+, T cells in T1D pediatric patients. Interestingly, frequencies of CD4+CD25+CD127− T-cells were significantly enhanced in T1D children and correlated well with frequencies of CD34+CD144+ endothelial progenitor cells and CD4+CD25− T-cells. Levels of CD127 on both CD4+ and CD8+ T-cells in T1D patients were not correlated to each other or HbA1C. Interestingly, however, CD127 levels on CD4+ T-cells were significantly correlated to frequencies of CD4+CD25+CD127− T-cells, whereas CD127 levels on CD8+ T-cells were significantly correlated to concentrations of VEGF and triglycerides. Our data indicate that CD127 expression is differentially modulated on CD4+ and CD8+ T-cells in the course of T1D. Moreover, we demonstrated that, in contrast to recent-onset T1D, long-lasting T1D is associated with enhancement of T-cells with regulatory phenotype. PMID:24348676

  11. High CD4+ T cell density is associated with poor prognosis in patients with non-muscle-invasive bladder cancer

    PubMed Central

    Zhang, Qinglei; Hao, Chongli; Cheng, Guangzhou; Wang, Lei; Wang, Xiang; Li, Chang; Qiu, Juhui; Ding, Kejia

    2015-01-01

    Purpose: The aim of this study was to investigate the clinical significance of CD4+ T cells in non-muscle-invasive bladder cancer (NMIBC) tissues in situ. Methods: Immunohistochemistry was used to examine the distribution of CD4+ T cells in 131 NMIBC tissues. Kaplan-Meier analysis and Cox proportional hazards regression models were applied to estimate overall survival (OS) and recurrence-free survival (RFS). Results: NMIBC patients were divided into two groups based on the median frequency of CD4+ T cells (median, 1/×400 high resolution). On univariate analysis, CD4+ T cell density was inversely associated with overall survival (P = 0.01). In those patients with high CD4+ T density, 5-year OS rates was only 77%, compared with 86% in those with low density, respectively. Although CD4+ T cell density showed no prognostic significance for RFS (P = 0.36), 5-year RFS rates of patients with high CD4+ T density (58%) was lower than those of patients with low CD4+ T density (65%, respectively). By multivariate analysis, tumor infiltrating CD4+ T cell density emerged as an independent prognostic factor for OS (HR, 2.75; P = 0.004). In addition, no association was found between CD4+ T cell density and any clinicopathological variables (P > 0.05). Conclusion: Our findings suggest that CD4+ T cells could potentially serve as a poor prognostic marker for patients with NMIBC. PMID:26617883

  12. Human Peripheral CD4(+) Vδ1(+) γδT Cells Can Develop into αβT Cells.

    PubMed

    Ziegler, Hendrik; Welker, Christian; Sterk, Marco; Haarer, Jan; Rammensee, Hans-Georg; Handgretinger, Rupert; Schilbach, Karin

    2014-01-01

    The lifelong generation of αβT cells enables us to continuously build immunity against pathogens and malignancies despite the loss of thymic function with age. Homeostatic proliferation of post-thymic naïve and memory T cells and their transition into effector and long-lived memory cells balance the decreasing output of naïve T cells, and recent research suggests that also αβT-cell development independent from the thymus may occur. However, the sites and mechanisms of extrathymic T-cell development are not yet understood in detail. γδT cells represent a small fraction of the overall T-cell pool, and are endowed with tremendous phenotypic and functional plasticity. γδT cells that express the Vδ1 gene segment are a minor population in human peripheral blood but predominate in epithelial (and inflamed) tissues. Here, we characterize a CD4(+) peripheral Vδ1(+) γδT-cell subpopulation that expresses stem-cell and progenitor markers and is able to develop into functional αβT cells ex vivo in a simple culture system and in vivo. The route taken by this process resembles thymic T-cell development. However, it involves the re-organization of the Vδ1(+) γδTCR into the αβTCR as a consequence of TCR-γ chain downregulation and the expression of surface Vδ1(+)Vβ(+) TCR components, which we believe function as surrogate pre-TCR. This transdifferentiation process is readily detectable in vivo in inflamed tissue. Our study provides a conceptual framework for extrathymic T-cell development and opens up a new vista in immunology that requires adaptive immune responses in infection, autoimmunity, and cancer to be reconsidered. PMID:25709606

  13. CD8 T cell memory recall is enhanced by novel direct interactions with CD4 T cells enabled by MHC class II transferred from APCs.

    PubMed

    Romagnoli, Pablo A; Premenko-Lanier, Mary F; Loria, Gilbert D; Altman, John D

    2013-01-01

    Protection against many intracellular pathogens is provided by CD8 T cells, which are thought to need CD4 T cell help to develop into effective memory CD8 T cells. Because murine CD8 T cells do not transcribe MHC class II (MHC-II) genes, several models have proposed antigen presenting cells (APCs) as intermediaries required for CD4 T cells to deliver their help to CD8 T cells. Here, we demonstrate the presence of MHC-II molecules on activated murine CD8 T cells in vitro as well as in vivo. These MHC-II molecules are acquired via trogocytosis by CD8 T cells from their activating APCs, particularly CD11c positive dendritic cells (DCs). Transferred MHC-II molecules on activated murine CD8 T cells were functionally competent in stimulating specific indicator CD4 T cells. CD8 T cells that were "helped" in vitro and subsequently allowed to rest in vivo showed enhanced recall responses upon challenge compared to "helpless" CD8 T cells; in contrast, no differences were seen upon immediate challenge. These data indicate that direct CD8:CD4 T cell interactions may significantly contribute to help for CD8 T cells. Furthermore, this mechanism may enable CD8 T cells to communicate with different subsets of interacting CD4 T cells that could modulate immune responses. PMID:23441229

  14. Inflammation Enhances IL-2 Driven Differentiation of Cytolytic CD4 T Cells

    PubMed Central

    Workman, Aspen M.; Jacobs, Ashley K.; Vogel, Alexander J.; Condon, Shirley; Brown, Deborah M.

    2014-01-01

    Cytolytic CD4 T cells (CD4 CTL) have been identified in vivo in response to viral infections; however, the factors necessary for driving the cytolytic phenotype have not been fully elucidated. Our previously published work suggests IL-2 may be the master regulator of perforin-mediated cytotoxicity in CD4 effectors. To further dissect the role of IL-2 in CD4 CTL generation, T cell receptor transgenic mice deficient in the ability to produce IL-2 or the high affinity IL-2 receptor (IL-2Rα, CD25) were used. Increasing concentrations of IL-2 were necessary to drive perforin (Prf) expression and maximal cytotoxicity. Granzyme B (GrB) expression and killing correlated with STAT5 activation and CD25 expression in vitro, suggesting that signaling through the high affinity IL-2R is critical for full cytotoxicity. IL-2 signaling was also necessary in vivo for inducing the Th1 phenotype and IFN-γ expression in CD4 T cells during influenza A (IAV) infection. In addition, GrB expression, as measured by mean fluorescent intensity, was decreased in CD25 deficient cells; however, the frequency of CD4 cells expressing GrB was unchanged. Similarly, analysis of cytolytic markers such as CD107a/b and Eomesodermin indicate high IL-2Rα expression is not necessary to drive the CD4 CTL phenotype during IAV infection. Thus, inflammatory signals induced by viral infection may overcome the need for strong IL-2 signals in driving cytotoxicity in CD4 cells. PMID:24586481

  15. Identification of novel Mycobacterium tuberculosis CD4 T-cell antigens via high throughput proteome screening

    PubMed Central

    Nayak, Kaustuv; Jing, Lichen; Russell, Ronnie M.; Davies, D. Huw; Hermanson, Gary; Molina, Douglas M.; Liang, Xiaowu; Sherman, David R.; Kwok, William W.; Yang, Junbao; Kenneth, John; Ahamed, Syed F.; Chandele, Anmol; Kaja, Murali-Krishna; Koelle, David M.

    2015-01-01

    Elicitation of CD4 IFN-gamma T cell responses to Mycobacterium tuberculosis (MTB) is a rational vaccine strategy to prevent clinical tuberculosis. Diagnosis of MTB infection is based on T-cell immune memory to MTB antigens. The MTB proteome contains over four thousand open reading frames (ORFs). We conducted a pilot antigen identification study using 164 MTB proteins and MTB-specific T-cells expanded in vitro from 12 persons with latent MTB infection. Enrichment of MTB-reactive T-cells from PBMC used cell sorting or an alternate system compatible with limited resources. MTB proteins were used as single antigens or combinatorial matrices in proliferation and cytokine secretion readouts. Overall, our study found that 44 MTB proteins were antigenic, including 27 not previously characterized as CD4 T-cell antigens. Antigen truncation, peptide, NTM homology, and HLA class II tetramer studies confirmed malate synthase G (encoded by gene Rv1837) as a CD4 T-cell antigen. This simple, scalable system has potential utility for the identification of candidate MTB vaccine and biomarker antigens. PMID:25857935

  16. Alternative splicing of MALT1 controls signalling and activation of CD4+ T cells

    PubMed Central

    Meininger, Isabel; Griesbach, Richard A.; Hu, Desheng; Gehring, Torben; Seeholzer, Thomas; Bertossi, Arianna; Kranich, Jan; Oeckinghaus, Andrea; Eitelhuber, Andrea C.; Greczmiel, Ute; Gewies, Andreas; Schmidt-Supprian, Marc; Ruland, Jürgen; Brocker, Thomas; Heissmeyer, Vigo; Heyd, Florian; Krappmann, Daniel

    2016-01-01

    MALT1 channels proximal T-cell receptor (TCR) signalling to downstream signalling pathways. With MALT1A and MALT1B two conserved splice variants exist and we demonstrate here that MALT1 alternative splicing supports optimal T-cell activation. Inclusion of exon7 in MALT1A facilitates the recruitment of TRAF6, which augments MALT1 scaffolding function, but not protease activity. Naive CD4+ T cells express almost exclusively MALT1B and MALT1A expression is induced by TCR stimulation. We identify hnRNP U as a suppressor of exon7 inclusion. Whereas selective depletion of MALT1A impairs T-cell signalling and activation, downregulation of hnRNP U enhances MALT1A expression and T-cell activation. Thus, TCR-induced alternative splicing augments MALT1 scaffolding to enhance downstream signalling and to promote optimal T-cell activation. PMID:27068814

  17. CD4+ T Cells Promote Antibody Production but Not Sustained Affinity Maturation during Borrelia burgdorferi Infection

    PubMed Central

    Elsner, Rebecca A.; Hastey, Christine J.

    2014-01-01

    CD4 T cells are crucial for enhancing B cell-mediated immunity, supporting the induction of high-affinity, class-switched antibody responses, long-lived plasma cells, and memory B cells. Previous studies showed that the immune response to Borrelia burgdorferi appears to lack robust T-dependent B cell responses, as neither long-lived plasma cells nor memory B cells form for months after infection, and nonswitched IgM antibodies are produced continuously during this chronic disease. These data prompted us to evaluate the induction and functionality of B. burgdorferi infection-induced CD4 TFH cells. We report that CD4 T cells were effectively primed and TFH cells induced after B. burgdorferi infection. These CD4 T cells contributed to the control of B. burgdorferi burden and supported the induction of B. burgdorferi-specific IgG responses. However, while affinity maturation of antibodies against a prototypic T-dependent B. burgdorferi protein, Arthritis-related protein (Arp), were initiated, these increases were reversed later, coinciding with the previously observed involution of germinal centers. The cessation of affinity maturation was not due to the appearance of inhibitory or exhausted CD4 T cells or a strong induction of regulatory T cells. In vitro T-B cocultures demonstrated that T cells isolated from B. burgdorferi-infected but not B. burgdorferi-immunized mice supported the rapid differentiation of B cells into antibody-secreting plasma cells rather than continued proliferation, mirroring the induction of rapid short-lived instead of long-lived T-dependent antibody responses in vivo. The data further suggest that B. burgdorferi infection drives the humoral response away from protective, high-affinity, and long-lived antibody responses and toward the rapid induction of strongly induced, short-lived antibodies of limited efficacy. PMID:25312948

  18. Identification of two regulatory elements controlling Fucosyltransferase 7 transcription in murine CD4+ T cells.

    PubMed

    Pink, Matthias; Ratsch, Boris A; Mardahl, Maibritt; Schröter, Micha F; Engelbert, Dirk; Triebus, Julia; Hamann, Alf; Syrbe, Uta

    2014-11-01

    Fucosyltransferase VII encoded by the gene Fut7 is essential in CD4(+) T cells for the generation of E- and P-selectin ligands (E- and P-lig) which facilitate recruitment of lymphocytes into inflamed tissues and into the skin. This study aimed to identify regulatory elements controlling the inducible Fut7 expression in CD4(+) T cells that occurs upon activation and differentiation of naive T cells into effector cells. Comparative analysis of the histone modification pattern in non-hematopoetic cells and CD4(+) T cell subsets revealed a differential histone modification pattern within the Fut7 locus including a conserved non-coding sequence (CNS) identified by cross-species conservation comparison suggesting that regulatory elements are confined to this region. Cloning of the CNS located about 500 bp upstream of the Fut7 locus, into a luciferase reporter vector elicited reporter activity after transfection of the αβ-WT T cell line, but not after transfection of primary murine CD4(+) Th1 cells. As quantification of different Fut7 transcripts revealed a predominance of transcripts lacking the first exons in primary Th1 cells we searched for an alternative promoter. Cloning of an intragenic region spanning a 1kb region upstream of exon 4 into an enhancer-containing vector indeed elicited promoter activity. Interestingly, also the CNS enhanced activity of this intragenic minimal promoter in reporter assays in primary Th1 cells suggesting that both elements interact in primary CD4(+) T cells to induce Fut7 transcription. PMID:24915132

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

    PubMed Central

    Sørnes, Steinar; Peirasmaki, Dimitra; Svärd, Staffan; Langeland, Nina

    2015-01-01

    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

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

    PubMed

    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

  1. IL-15 induces CD4+ effector memory T cell production and tissue emigration in nonhuman primates

    PubMed Central

    Picker, Louis J.; Reed-Inderbitzin, Edward F.; Hagen, Shoko I.; Edgar, John B.; Hansen, Scott G.; Legasse, Alfred; Planer, Shannon; Piatak, Michael; Lifson, Jeffrey D.; Maino, Vernon C.; Axthelm, Michael K.; Villinger, Francois

    2006-01-01

    HIV infection selectively targets CD4+ effector memory T (TEM) cells, resulting in dramatic depletion of CD4+ T cells in mucosal effector sites in early infection. Regeneration of the TEM cell compartment is slow and incomplete, even when viral replication is controlled by antiretroviral therapy (ART). Here, we demonstrate that IL-15 dramatically increases in vivo proliferation of rhesus macaque (RM) CD4+ and CD8+ TEM cells with little effect on the naive or central memory T (TCM) cell subsets, a response pattern that is quite distinct from that of either IL-2 or IL-7. TEM cells produced in response to IL-15 did not accumulate in blood. Rather, 5-bromo-2′-deoxyuridine (BrdU) labeling studies suggest that many of these cells rapidly disperse to extralymphoid effector sites, where they manifest (slow) decay kinetics indistinguishable from that of untreated controls. In RMs with uncontrolled SIV infection and highly activated immune systems, IL-15 did not significantly increase CD4+ TEM cell proliferation, but with virologic control and concomitant reduction in immune activation by ART, IL-15 responsiveness was again observed. These data suggest that therapeutic use of IL-15 in the setting of ART might facilitate specific restoration of the CD4+ T cell compartment that is the primary target of HIV with less risk of exhausting precursor T cell compartments or generating potentially deleterious regulatory subsets. PMID:16691294

  2. The chromatin remodeler Mi-2beta is required for CD4 expression and T cell development.

    PubMed

    Williams, Christine J; Naito, Taku; Arco, Pablo Gómez-Del; Seavitt, John R; Cashman, Susan M; De Souza, Beverly; Qi, Xiaoqing; Keables, Piper; Von Andrian, Ulrich H; Georgopoulos, Katia

    2004-06-01

    Changes in chromatin structure underlie the activation or silencing of genes during development. The chromatin remodeler Mi-2beta is highly expressed in thymocytes and is presumed to be a transcriptional repressor because of its presence in the nucleosome remodeling deacetylase (NuRD) complex. Using conditional inactivation, we show that Mi-2beta is required at several steps during T cell development: for differentiation of beta selected immature thymocytes, for developmental expression of CD4, and for cell divisions in mature T cells. We further show that Mi-2beta plays a direct role in promoting CD4 gene expression. Mi-2beta associates with the CD4 enhancer as well as the E box binding protein HEB and the histone acetyltransferase (HAT) p300, enabling their recruitment to the CD4 enhancer and causing histone H3-hyperacetylation to this regulatory region. These findings provide important insights into the regulation of CD4 expression during T cell development and define a role for Mi-2beta in gene activation. PMID:15189737

  3. Vaccine-Induced CD107a+ CD4+ T Cells Are Resistant to Depletion following AIDS Virus Infection

    PubMed Central

    Terahara, Kazutaka; Ishii, Hiroshi; Nomura, Takushi; Takahashi, Naofumi; Takeda, Akiko; Shiino, Teiichiro; Tsunetsugu-Yokota, Yasuko

    2014-01-01

    ABSTRACT CD4+ T-cell responses are crucial for effective antibody and CD8+ T-cell induction following virus infection. However, virus-specific CD4+ T cells can be preferential targets for human immunodeficiency virus (HIV) infection. HIV-specific CD4+ T-cell induction by vaccination may thus result in enhancement of virus replication following infection. In the present study, we show that vaccine-elicited CD4+ T cells expressing CD107a are relatively resistant to depletion in a macaque AIDS model. Comparison of virus-specific CD107a, macrophage inflammatory protein-1β, gamma interferon, tumor necrosis factor alpha, and interleukin-2 responses in CD4+ T cells of vaccinated macaques prechallenge and 1 week postchallenge showed a significant reduction in the CD107a− but not the CD107a+ subset after virus exposure. Those vaccinees that failed to control viremia showed a more marked reduction and exhibited significantly higher viral loads at week 1 than unvaccinated animals. Our results indicate that vaccine-induced CD107a− CD4+ T cells are depleted following virus infection, suggesting a rationale for avoiding virus-specific CD107a− CD4+ T-cell induction in HIV vaccine design. IMPORTANCE Induction of effective antibody and/or CD8+ T-cell responses is a principal vaccine strategy against human immunodeficiency virus (HIV) infection. CD4+ T-cell responses are crucial for effective antibody and CD8+ T-cell induction. However, virus-specific CD4+ T cells can be preferential targets for HIV infection. Here, we show that vaccine-induced virus-specific CD107a− CD4+ T cells are largely depleted following infection in a macaque AIDS model. While CD4+ T-cell responses are important in viral control, our results indicate that virus-specific CD107a− CD4+ T-cell induction by vaccination may not lead to efficient CD4+ T-cell responses following infection but rather be detrimental and accelerate viral replication in the acute phase. This suggests that HIV vaccine design

  4. Polyfunctional CD4 T cells in the response to bovine tuberculosis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyfunctional CD4 T cells simultaneously produce interferon-gamma (IFN-gamma), interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) and play relevant roles in several chronic infections, including human TB and HIV. However, the assessment of this response in bovine infections was not fe...

  5. Alternatively expressed genes identified in the CD4+ T cells of allograft rejection mice.

    PubMed

    Xu, Jia; Wang, Dan; Zhang, Chao; Song, Jing; Liang, Ting; Jin, Weirong; Kim, Yeong C; Wang, San Ming; Hou, Guihua

    2011-01-01

    Allograft rejection is a leading cause for the failure of allotransplantation. CD4(+) T cells play critical roles in this process. The identification of genes that alternatively expressed in CD4(+) T cells during allograft rejection will provide critical information for studying the mechanism of allograft rejection, finding specific gene markers for monitoring, predicting allograft rejection, and opening new ways to regulate and prevent allograft rejection. Here, we established allograft and isograft transplantation models by adoptively transferring wild-type BALB/c mouse CD4(+) T cells into severe combined immunodeficient (SCID) mice with a C57BL/6 or BALB/c mouse skin graft. Using the whole transcriptome sequencing-based serial analysis of gene expression (SAGE) technology, we identified 97 increasingly and 88 decreasingly expressed genes that may play important roles in allograft rejection and tolerance. Functional classification of these genes shows that apoptosis, transcription regulation, cell growth and maintenance, and signal transduction are among the frequently changed functional groups. This study provides a genome-wide view for the candidate genes of CD4(+) T cells related to allotransplantation, and this report is a good resource for further microarray studies and for identifying the specific markers that are associated with clinical organ transplantations. PMID:21294963

  6. HIV-1 gp120 induces NFAT nuclear translocation in resting CD4+ T-cells

    SciTech Connect

    Cicala, Claudia . E-mail: ccicala@nih.gov; Arthos, James; Censoplano, Nina; Cruz, Catherine; Chung, Eva; Martinelli, Elena; Lempicki, Richard A.; Natarajan, Ven; VanRyk, Donald; Daucher, Marybeth; Fauci, Anthony S.

    2006-02-05

    The replication of human immunodeficiency virus (HIV) in CD4+ T-cells is strongly dependent upon the state of activation of infected cells. Infection of sub-optimally activated cells is believed to play a critical role in both the transmission of virus and the persistence of CD4+ T-cell reservoirs. There is accumulating evidence that HIV can modulate signal-transduction pathways in a manner that may facilitate replication in such cells. We previously demonstrated that HIV gp120 induces virus replication in resting CD4+ T cells isolated from HIV-infected individuals. Here, we show that in resting CD4+ T-cells, gp120 activates NFATs and induces their translocation into the nucleus. The HIV LTR encodes NFAT recognition sites, and NFATs may play a critical role in promoting viral replication in sub-optimally activated cells. These observations provide insight into a potential mechanism by which HIV is able to establish infection in resting cells, which may have implications for both transmission of HIV and the persistence of viral reservoirs.

  7. ADAR1 Facilitates HIV-1 Replication in Primary CD4+ T Cells

    PubMed Central

    van Hamme, John L.; Jansen, Machiel H.; van Dort, Karel A.; Vanderver, Adeline; Rice, Gillian I.; Crow, Yanick J.; Kootstra, Neeltje A.; Kuijpers, Taco W.

    2015-01-01

    Unlike resting CD4+ T cells, activated CD4+T cells are highly susceptible to infection of human immunodeficiency virus 1 (HIV-1). HIV-1 infects T cells and macrophages without activating the nucleic acid sensors and the anti-viral type I interferon response. Adenosine deaminase acting on RNA 1 (ADAR1) is an RNA editing enzyme that displays antiviral activity against several RNA viruses. Mutations in ADAR1 cause the autoimmune disorder Aicardi-Goutieères syndrome (AGS). This disease is characterized by an inappropriate activation of the interferon-stimulated gene response. Here we show that HIV-1 replication, in ADAR1-deficient CD4+T lymphocytes from AGS patients, is blocked at the level of protein translation. Furthermore, viral protein synthesis block is accompanied by an activation of interferon-stimulated genes. RNA silencing of ADAR1 in Jurkat cells also inhibited HIV-1 protein synthesis. Our data support that HIV-1 requires ADAR1 for efficient replication in human CD4+T cells. PMID:26629815

  8. Blockade of the Programmed Death-1 Pathway Restores Sarcoidosis CD4+ T-Cell Proliferative Capacity

    PubMed Central

    Braun, Nicole A.; Celada, Lindsay J.; Herazo-Maya, Jose D.; Abraham, Susamma; Shaginurova, Guzel; Sevin, Carla M.; Grutters, Jan; Culver, Daniel A.; Dworski, Ryszard; Sheller, James; Massion, Pierre P.; Polosukhin, Vasiliy V.; Johnson, Joyce E.; Kaminski, Naftali; Wilkes, David S.; Oswald-Richter, Kyra A.

    2014-01-01

    Rationale: Effective therapeutic interventions for chronic, idiopathic lung diseases remain elusive. Normalized T-cell function is an important contributor to spontaneous resolution of pulmonary sarcoidosis. Up-regulation of inhibitor receptors, such as programmed death-1 (PD-1) and its ligand, PD-L1, are important inhibitors of T-cell function. Objectives: To determine the effects of PD-1 pathway blockade on sarcoidosis CD4+ T-cell proliferative capacity. Methods: Gene expression profiles of sarcoidosis and healthy control peripheral blood mononuclear cells were analyzed at baseline and follow-up. Flow cytometry was used to measure ex vivo expression of PD-1 and PD-L1 on systemic and bronchoalveolar lavage–derived cells of subjects with sarcoidosis and control subjects, as well as the effects of PD-1 pathway blockade on cellular proliferation after T-cell receptor stimulation. Immunohistochemistry analysis for PD-1/PD-L1 expression was conducted on sarcoidosis, malignant, and healthy control lung specimens. Measurements and Main Results: Microarray analysis demonstrates longitudinal increase in PDCD1 gene expression in sarcoidosis peripheral blood mononuclear cells. Immunohistochemistry analysis revealed increased PD-L1 expression within sarcoidosis granulomas and lung malignancy, but this was absent in healthy lungs. Increased numbers of sarcoidosis PD-1+ CD4+ T cells are present systemically, compared with healthy control subjects (P < 0.0001). Lymphocytes with reduced proliferative capacity exhibited increased proliferation with PD-1 pathway blockade. Longitudinal analysis of subjects with sarcoidosis revealed reduced PD-1+ CD4+ T cells with spontaneous clinical resolution but not with disease progression. Conclusions: Analogous to the effects in other chronic lung diseases, these findings demonstrate that the PD-1 pathway is an important contributor to sarcoidosis CD4+ T-cell proliferative capacity and clinical outcome. Blockade of the PD-1 pathway may be a

  9. CD4+ T cell responses to self- and mutated p53 determinants during tumorigenesis in mice.

    PubMed

    Fedoseyeva, E V; Boisgérault, F; Anosova, N G; Wollish, W S; Arlotta, P; Jensen, P E; Ono, S J; Benichou, G

    2000-06-01

    We analyzed CD4+ T helper responses to wild-type (wt) and mutated (mut) p53 protein in normal and tumor-bearing mice. In normal mice, we observed that although some self-p53 determinants induced negative selection of p53-reactive CD4+ T cells, other p53 determinants (cryptic) were immunogenic. Next, BALB/c mice were inoculated with J774 syngeneic tumor cell line expressing mut p53. BALB/c tumor-bearing mice mounted potent CD4+ T cell responses to two formerly cryptic peptides on self-p53. This response was characterized by massive production of IL-5, a Th2-type lymphokine. Interestingly, we found that T cell response was induced by different p53 peptides depending upon the stage of cancer. Mut p53 gene was shown to contain a single mutation resulting in the substitution of a tyrosine by a histidine at position 231 of the protein. Two peptides corresponding to wt and mutated sequences of this region were synthesized. Both peptides bound to the MHC class II-presenting molecule (Ed) with similar affinities. However, only mut p53.225-239 induced T cell responses in normal BALB/c mice, a result strongly suggesting that high-affinity wt p53.225-239 autoreactive T cells had been eliminated in these mice. Surprisingly, CD4+ T cell responses to both mut and wt p53.225-239 peptides were recorded in J774 tumor-bearing mice, a phenomenon attributed to the recruitment of low-avidity p53.225-239 self-reactive T cells. PMID:10820239

  10. Elevated expression of T-bet in mycobacterial antigen-specific CD4(+) T cells from patients with tuberculosis.

    PubMed

    Yang, Bingfen; Zhai, Fei; Jiang, Jing; Wang, Xinjing; Cao, Zhihong; Cheng, Xiaoxing

    2015-01-01

    T-bet is a T-box transcriptional factor that controls the differentiation and effector functions of CD4 T cells. In this study, we studied the role of T-bet in regulating CD4(+) T cell immunity against tuberculosis (TB). T-bet expression in Mycobacterium tuberculosis antigen-specific CD4(+) T cells was significantly higher in patients with active TB than in individuals with latent TB infection (p<0.0001). Comparison of T-bet expression in TCM and TEM subsets showed that CD4(+)T-bet(+)M. tuberculosis antigen-specific CD4(+) T cells had significantly lower frequency of TCM (p=0.003) and higher frequency of TEM (p=0.003) than CD4(+)T-bet(-) cells. The expression of PD-1 in antigen-specific CD4(+) T cells was significantly higher in patients with TB than in individuals with latent TB infection (p=0.006). CD4(+)CD154(+)T-bet(+) T cells had significantly higher expression of PD-1 than CD4(+)CD154(+)T-bet(-) T cells (p=0.0028). It is concluded that T-bet expression might be associated with differentiation into effector memory cells and PD-1 expression in mycobacterial antigen-specific CD4(+) T cells. PMID:26302932

  11. Novel Insights into the Regulatory Architecture of CD4+ T Cells in Rheumatoid Arthritis

    PubMed Central

    Aterido, Adrià; Palacio, Carlos; Marsal, Sara; Ávila, Gabriela; Julià, Antonio

    2014-01-01

    Rheumatoid arthritis (RA) is the most frequent autoimmune chronic inflammatory disease of the joints and it is characterized by the inflammation of the synovial membrane and the subsequent destruction of the joints. In RA, CD4+ T cells are the main drivers of disease initiation and the perpetuation of the damaging inflammatory process. To date, however, the genetic regulatory mechanisms of CD4+ T cells associated with RA etiology are poorly understood. The genome-wide analysis of expression quantitative trait loci (eQTL) in disease-relevant cell types is a recent genomic integration approach that is providing significant insights into the genetic regulatory mechanisms of many human pathologies. The objective of the present study was to analyze, for the first time, the genome-wide genetic regulatory mechanisms associated with the gene expression of CD4+ T cells in RA. Whole genome gene expression profiling of CD4+ T cells and the genome-wide genotyping (598,258 SNPs) of 29 RA patients with an active disease were performed. In order to avoid the excessive burden of multiple testing associated with genome-wide trans-eQTL analysis, we developed and implemented a novel systems genetics approach. Finally, we compared the genomic regulation pattern of CD4+ T cells in RA with the genomic regulation observed in reference lymphoblastoid cell lines (LCLs). We identified a genome-wide significant cis-eQTL associated with the expression of FAM66C gene (P = 6.51e−9). Using our new systems genetics approach we identified six statistically significant trans-eQTLs associated with the expression of KIAA0101 (P<7.4e−8) and BIRC5 (P = 5.35e−8) genes. Finally, comparing the genomic regulation profiles between RA CD4+ T cells and control LCLs we found 20 genes showing differential regulatory patterns between both cell types. The present genome-wide eQTL analysis has identified new genetic regulatory elements that are key to the activity of CD4+ T cells in RA. PMID:24959711

  12. Absence of CD4(+) T cell help generates corrupt CD8(+) effector T cells in sarcoma-bearing Swiss mice treated with NLGP vaccine.

    PubMed

    Ghosh, Sarbari; Sarkar, Madhurima; Ghosh, Tithi; Guha, Ipsita; Bhuniya, Avishek; Biswas, Jaydip; Mallick, Atanu; Bose, Anamika; Baral, Rathindranath

    2016-07-01

    One of the prime objectives of cancer immunology and immunotherapy is to study the issues related to rescue and/or maintenance of the optimum effector CD8(+) T cell functions by minimizing tumor-induced negative factors. In this regard the influence of host intrinsic CD4(+) helper T cells towards generation and maintenance of CD8(+) effector T cells appears controversial in different experimental settings. Therefore, the present study was aimed to re-analyze the influence of CD4(+) helper T cells towards effector T cells during neem leaf glycoprotein (NLGP)-vaccine-mediated tumor growth restriction. CD4 depletion (mAb; Clone GK1.5) surprisingly resulted in significant increase in CD8(+) T cells in different immune organs from NLGP-treated sarcoma-bearing mice. However, such CD8 surge could not restrict the sarcoma growth in NLGP-treated CD4-depleted mice. Furthermore, CD4 depletion in early phase hinders CD8(+) T cell activation and terminal differentiation by targeting crucial transcription factor Runx3. CD4 depletion decreases accumulation of CD8α(+) dendritic cells within tumor draining lymph node, hampers antigen cross priming and CD86-CD28 interactions for optimum CD8(+) T cell functions. In order to search the mechanism of CD4(+) T cell help on NLGP-mediated CD8 effector functions, the role of CD4(+) helper T cell-derived IL-2 on optimization of CD8 functions was found using STAT5 signaling, but complete response requires physical contact of CD4(+) helper T cells with its CD8 counterpart. In conclusion, it was found that CD4(+) T cell help is not required to generate CD8(+) T cells but was found to be an integral phenomenon in maintenance of its anti-tumor functions even in NLGP-vaccine-mediated sarcoma growth restriction. PMID:27178306

  13. CD4+ T cells provide protection against acute lethal encephalitis caused by Venezuelan equine encephalitis virus

    PubMed Central

    Yun, Nadezhda E.; Peng, Bi-Hung; Bertke, Andrea S.; Borisevich, Viktoriya; Smith, Jennifer K.; Smith, Jeanon N.; Poussard, Allison L.; Salazar, Milagros; Judy, Barbara M.; Zacks, Michele A.; Estes, D. Mark; Paessler, Slobodan

    2009-01-01

    Studying the mechanisms of host survival resulting from viral encephalitis is critical to the development of vaccines. Here we have shown in several independent studies that high-dose treatment with neutralizing antibody prior to intranasal infection with Venezuelan equine encephalitis virus had an antiviral effect in the visceral organs and prolonged survival time of infected mice, even in the absence of alpha beta T cells. Nevertheless, the antibody treatment did not prevent the development of lethal encephalitis. In contrary, the adoptive transfer of primed CD4+ T cells is necessary to prevent lethal encephalitis in mice lacking alpha beta T cell receptor. PMID:19446933

  14. The Immune-Metabolic Basis of Effector Memory CD4+ T Cell Function under Hypoxic Conditions.

    PubMed

    Dimeloe, Sarah; Mehling, Matthias; Frick, Corina; Loeliger, Jordan; Bantug, Glenn R; Sauder, Ursula; Fischer, Marco; Belle, Réka; Develioglu, Leyla; Tay, Savaş; Langenkamp, Anja; Hess, Christoph

    2016-01-01

    Effector memory (EM) CD4(+) T cells recirculate between normoxic blood and hypoxic tissues to screen for cognate Ag. How mitochondria of these cells, shuttling between normoxia and hypoxia, maintain bioenergetic efficiency and stably uphold antiapoptotic features is unknown. In this study, we found that human EM CD4(+) T cells had greater spare respiratory capacity (SRC) than did naive counterparts, which was immediately accessed under hypoxia. Consequently, hypoxic EM cells maintained ATP levels, survived and migrated better than did hypoxic naive cells, and hypoxia did not impair their capacity to produce IFN-γ. EM CD4(+) T cells also had more abundant cytosolic GAPDH and increased glycolytic reserve. In contrast to SRC, glycolytic reserve was not tapped under hypoxic conditions, and, under hypoxia, glucose metabolism contributed similarly to ATP production in naive and EM cells. However, both under normoxic and hypoxic conditions, glucose was critical for EM CD4(+) T cell survival. Mechanistically, in the absence of glycolysis, mitochondrial membrane potential (ΔΨm) of EM cells declined and intrinsic apoptosis was triggered. Restoring pyruvate levels, the end product of glycolysis, preserved ΔΨm and prevented apoptosis. Furthermore, reconstitution of reactive oxygen species (ROS), whose production depends on ΔΨm, also rescued viability, whereas scavenging mitochondrial ROS exacerbated apoptosis. Rapid access of SRC in hypoxia, linked with built-in, oxygen-resistant glycolytic reserve that functionally insulates ΔΨm and mitochondrial ROS production from oxygen tension changes, provides an immune-metabolic basis supporting survival, migration, and function of EM CD4(+) T cells in normoxic and hypoxic conditions. PMID:26621861

  15. Role of acid sphingomyelinase bioactivity in human CD4+ T-cell activation and immune responses

    PubMed Central

    Bai, A; Kokkotou, E; Zheng, Y; Robson, S C

    2015-01-01

    Acid sphingomyelinase (ASM), a lipid hydrolase enzyme, has the potential to modulate various cellular activation responses via the generation of ceramide and by interaction with cellular receptors. We have hypothesized that ASM modulates CD4+ T-cell receptor activation and impacts immune responses. We first observed interactions of ASM with the intracellular domains of both CD3 and CD28. ASM further mediates T-cell proliferation after anti-CD3/CD28 antibody stimulation and alters CD4+ T-cell activation signals by generating ceramide. We noted that various pharmacological inhibitors of ASM or knockdown of ASM using small hairpin RNA inhibit CD3/CD28-mediated CD4+ T-cell proliferation and activation. Furthermore, such blockade of ASM bioactivity by biochemical inhibitors and/or molecular-targeted knockdown of ASM broadly abrogate T-helper cell responses. In conclusion, we detail immune, pivotal roles of ASM in adaptive immune T-cell responses, and propose that these pathways might provide novel targets for the therapy of autoimmune and inflammatory diseases. PMID:26203857

  16. Control of Experimental Autoimmune Encephalomyelitis by CD4+ Suppressor T Cells: Peripheral versus in situ Immunoregulation

    PubMed Central

    Bynoe, Margaret S.; Bonorino, Paula; Viret, Christophe

    2007-01-01

    The pathogenesis of experimental autoimmune encephalomyelitis (EAE) can be efficiently kept under control by specialized subsets of CD4+ T lymphocytes able to negatively regulate the function of T cells with encephalitogenic potential. A number of observations support a role for such suppressor T cells in controlling early phases of disease development at the level of peripheral lymphoid organs but there is also evidence suggesting immunoregulation within the central nervous system (CNS) microenvironment itself. This review evaluates the sites of regulation based on available data from distinct experimental models. We then discuss these aspects with reference to suppressor CD4+ T cells induced through the epicutaneous application of pure CNS antigens that confer long term protection against EAE. Finally, we give an overview of genes recently discovered to be important in regulation of the immune system that may also prove to be key players in the modulation of EAE and MS. PMID:17900707

  17. Ubiquitin Ligases and Deubiquitinating Enzymes in CD4+ T Cell Effector Fate Choice and Function.

    PubMed

    Layman, Awo A K; Oliver, Paula M

    2016-05-15

    The human body is exposed to potentially pathogenic microorganisms at barrier sites such as the skin, lungs, and gastrointestinal tract. To mount an effective response against these pathogens, the immune system must recruit the right cells with effector responses that are appropriate for the task at hand. Several types of CD4(+) T cells can be recruited, including Th cells (Th1, Th2, and Th17), T follicular helper cells, and regulatory T cells. These cells help to maintain normal immune homeostasis in the face of constantly changing microbes in the environment. Because these cells differentiate from a common progenitor, the composition of their intracellular milieu of proteins changes to appropriately guide their effector function. One underappreciated process that impacts the levels and functions of effector fate-determining factors is ubiquitylation. This review details our current understanding of how ubiquitylation regulates CD4(+) T cell effector identity and function. PMID:27183634

  18. New insights into CD4(+) T cell abnormalities in systemic sclerosis.

    PubMed

    Liu, Mengguo; Wu, Wenyu; Sun, Xinfen; Yang, Ji; Xu, Jinhua; Fu, Wenwen; Li, Ming

    2016-04-01

    Systemic sclerosis (SSc) is an autoimmune connective tissue disease that is characterized by vasculopathy and excessive deposition of extracellular matrix, which causes fibrosis of the skin and internal organs and eventually leads to multiorgan dysfunction. Studies have shown that CD4(+) T cell activation is a key factor in the pathogenesis of scleroderma because activated T cells can release various cytokines, resulting in inflammation, microvascular damage and fibrosis. T helper cell 17 (Th17) and regulatory T (Treg) cell activities are a hallmark SSc, as Th17-type cytokines can induce both inflammation and fibrosis. More recently, several studies have reported new T cell subsets, including Th9 and Th22 cells, along with their respective cytokines in the peripheral blood, serum and skin lesions of individuals with SSc. Herein, we review recent data on various CD4(+) T helper cell subsets in SSc, and discuss potential roles of these cells in promoting inflammation and fibrosis. PMID:26724976

  19. Absence of β2 Integrins Impairs Regulatory T Cells and Exacerbates CD4+ T cell-Dependent Autoimmune Carditis1

    PubMed Central

    Haasken, Stefanie; Auger, Jennifer L.; Binstadt, Bryce A.

    2011-01-01

    The immunopathogenic mechanisms mediating inflammation in multi-organ autoimmune diseases may vary between the different target tissues. We utilized the K/BxN TCR transgenic mouse model to investigate the contribution of CD4+ T cells and β2 integrins in the pathogenesis of autoimmune arthritis and endocarditis. Depletion of CD4+ T cells following the onset of arthritis specifically prevented the development of cardiac valve inflammation. Genetic absence of β2 integrins had no effect on the severity of arthritis and unexpectedly increased the extent of cardiovascular pathology. The exaggerated cardiac phenotype of the β2 integrin-deficient K/BxN mice was accompanied by immune hyperactivation and was linked to a defect in regulatory T cells. These findings are consistent with a model in which the development of arthritis in K/BxN mice relies primarily on autoantibodies, whereas endocarditis depends on an additional contribution of effector T cells. Furthermore, strategies targeting β2 integrins for the treatment of systemic autoimmune conditions need to consider not only the role of these molecules in leukocyte recruitment to sites of inflammation, but also their impact on the regulation of immunological tolerance. PMID:21795599

  20. CD4(+)CD25(+) T Cells in primary malignant hypertension related kidney injury.

    PubMed

    Huang, Hongdong; Luo, Yang; Liang, Yumei; Long, Xidai; Peng, Youming; Liu, Zhihua; Wen, Xiaojun; Jia, Meng; Tian, Ru; Bai, Chengli; Li, Cui; He, Fuliang; Lin, Qiushi; Wang, Xueyan; Dong, Xiaoqun

    2016-01-01

    CD4(+)CD25(+) T cells are critical for maintenance of immunologic self-tolerance. We measured the number of CD4(+)CD25(+) cells in the patients with primary malignant hypertension related kidney injury, to explore the molecular pathogenesis of this disease. We selected 30 patients with primary malignant hypertension related kidney injury and 30 healthy volunteers. Information on clinical characteristics and laboratory tests was obtained from each subject. The number of CD4(+)CD25(+) cells and glomerular injury were assessed by flow cytometry and histopathology, respectively. Both serum IL-2, IL-4, and IL-6 and endothelial cell markers were analyzed by ELISA. ADAMTS13 antibody was detected by Western blotting. CD4(+)CD25(+) cells were significantly reduced in patients with primary malignant hypertension related kidney injury compared to controls (P < 0.05). The number of CD4(+)CD25(+) cells was negatively related to blood urea nitrogen, serum uric acid, proteinuria, and supernatant IL-4; whereas positively associated with estimated glomerular filtration rate in patients. Gradually decreasing CD4(+)CD25(+) cells were also found as increasing renal injury. Additionally, patients exhibited increasing supernatant IL-4, serum IL-2 and IL-6, endothelial cell markers, and anti-ADAMTS13 antibody compared with controls (all P < 0.05). CD4(+)CD25(+) cells may play a key role in the pathogenesis of primary malignant hypertension related kidney injury. PMID:27278520

  1. CD4+CD25+ T Cells in primary malignant hypertension related kidney injury

    PubMed Central

    Huang, Hongdong; Luo, Yang; Liang, Yumei; Long, Xidai; Peng, Youming; Liu, Zhihua; Wen, Xiaojun; Jia, Meng; Tian, Ru; Bai, Chengli; Li, Cui; He, Fuliang; Lin, Qiushi; Wang, Xueyan; Dong, Xiaoqun

    2016-01-01

    CD4+CD25+ T cells are critical for maintenance of immunologic self-tolerance. We measured the number of CD4+CD25+ cells in the patients with primary malignant hypertension related kidney injury, to explore the molecular pathogenesis of this disease. We selected 30 patients with primary malignant hypertension related kidney injury and 30 healthy volunteers. Information on clinical characteristics and laboratory tests was obtained from each subject. The number of CD4+CD25+ cells and glomerular injury were assessed by flow cytometry and histopathology, respectively. Both serum IL-2, IL-4, and IL-6 and endothelial cell markers were analyzed by ELISA. ADAMTS13 antibody was detected by Western blotting. CD4+CD25+ cells were significantly reduced in patients with primary malignant hypertension related kidney injury compared to controls (P < 0.05). The number of CD4+CD25+ cells was negatively related to blood urea nitrogen, serum uric acid, proteinuria, and supernatant IL-4; whereas positively associated with estimated glomerular filtration rate in patients. Gradually decreasing CD4+CD25+ cells were also found as increasing renal injury. Additionally, patients exhibited increasing supernatant IL-4, serum IL-2 and IL-6, endothelial cell markers, and anti-ADAMTS13 antibody compared with controls (all P < 0.05). CD4+CD25+ cells may play a key role in the pathogenesis of primary malignant hypertension related kidney injury. PMID:27278520

  2. Crystal structure of a complete ternary complex of T-cell receptor, peptide-MHC, and CD4

    SciTech Connect

    Yin, Yiyuan; Wang, Xin Xiang; Mariuzza, Roy A

    2012-07-11

    Adaptive immunity depends on specific recognition by a T-cell receptor (TCR) of an antigenic peptide bound to a major histocompatibility complex (pMHC) molecule on an antigen-presenting cell (APC). In addition, T-cell activation generally requires binding of this same pMHC to a CD4 or CD8 coreceptor. Here, we report the structure of a complete TCR-pMHC-CD4 ternary complex involving a human autoimmune TCR, a myelin-derived self-peptide bound to HLA-DR4, and CD4. The complex resembles a pointed arch in which TCR and CD4 are each tilted ~65° relative to the T-cell membrane. By precluding direct contacts between TCR and CD4, the structure explains how TCR and CD4 on the T cell can simultaneously, yet independently, engage the same pMHC on the APC. The structure, in conjunction with previous mutagenesis data, places TCR-associated CD3εγ and CD3εδ subunits, which transmit activation signals to the T cell, inside the TCR-pMHC-CD4 arch, facing CD4. By establishing anchor points for TCR and CD4 on the T-cell membrane, the complex provides a basis for understanding how the CD4 coreceptor focuses TCR on MHC to guide TCR docking on pMHC during thymic T-cell selection.

  3. HIV-1 Antibody Neutralization Breadth Is Associated with Enhanced HIV-Specific CD4+ T Cell Responses

    PubMed Central

    Soghoian, Damien Z.; Lindqvist, Madelene; Ghebremichael, Musie; Donaghey, Faith; Carrington, Mary; Seaman, Michael S.; Kaufmann, Daniel E.; Walker, Bruce D.

    2015-01-01

    ABSTRACT Antigen-specific CD4+ T helper cell responses have long been recognized to be a critical component of effective vaccine immunity. CD4+ T cells are necessary to generate and maintain humoral immune responses by providing help to antigen-specific B cells for the production of antibodies. In HIV infection, CD4+ T cells are thought to be necessary for the induction of Env-specific broadly neutralizing antibodies. However, few studies have investigated the role of HIV-specific CD4+ T cells in association with HIV neutralizing antibody activity in vaccination or natural infection settings. Here, we conducted a comprehensive analysis of HIV-specific CD4+ T cell responses in a cohort of 34 untreated HIV-infected controllers matched for viral load, with and without neutralizing antibody breadth to a panel of viral strains. Our results show that the breadth and magnitude of Gag-specific CD4+ T cell responses were significantly higher in individuals with neutralizing antibodies than in those without neutralizing antibodies. The breadth of Gag-specific CD4+ T cell responses was positively correlated with the breadth of neutralizing antibody activity. Furthermore, the breadth and magnitude of gp41-specific, but not gp120-specific, CD4+ T cell responses were significantly elevated in individuals with neutralizing antibodies. Together, these data suggest that robust Gag-specific CD4+ T cells and, to a lesser extent, gp41-specific CD4+ T cells may provide important intermolecular help to Env-specific B cells that promote the generation or maintenance of Env-specific neutralizing antibodies. IMPORTANCE One of the earliest discoveries related to CD4+ T cell function was their provision of help to B cells in the development of antibody responses. Yet little is known about the role of CD4+ T helper responses in the setting of HIV infection, and no studies to date have evaluated the impact of HIV-specific CD4+ T cells on the generation of antibodies that can neutralize

  4. Impact of ageing on the response and repertoire of influenza virus-specific CD4 T cells

    PubMed Central

    2014-01-01

    Background Ageing has been shown to reduce CD8 T cell repertoire diversity and immune responses against influenza virus infection in mice. In contrast, less is known about the impact of ageing on CD4 T cell repertoire diversity and immune response to influenza virus infection. Results The CD4 T cell response was followed after infection of young and aged C57BL/6 mice with influenza virus using a tetramer specific for an immunodominant MHC class II epitope of the influenza virus nucleoprotein. The appearance of virus-specific CD4 T cells in the lung airways of aged mice was delayed compared to young mice, but the overall peak number and cytokine secretion profile of responding CD4 T cells was not greatly perturbed. In addition, the T cell repertoire of responding cells, determined using T cell receptor Vβ analysis, failed to show the profound effect of age we previously described for CD8 T cells. The reduced impact of age on influenza-specific CD4 T cells was consistent with a reduced effect of age on the overall CD4 compared with the CD8 T cell repertoire in specific pathogen free mice. Aged mice that were thymectomized as young adults showed an enhanced loss of the epitope-specific CD4 T cell response after influenza virus infection compared with age-matched sham-thymectomized mice, suggesting that a reduced repertoire can contribute to impaired responsiveness. Conclusions The diversity of the CD4 T cell repertoire and response to influenza virus is not as profoundly impaired by ageing in C57BL/6 mice as previously shown for CD8 T cells. However, adult thymectomy enhanced the impact of ageing on the response. Understanding the impact of ageing on CD4 T cell responses to influenza virus infection is an important prerequisite for developing better vaccines for the elderly. PMID:24999367

  5. CD4+CD25hiCD127low Regulatory T Cells Are Increased in Oral Squamous Cell Carcinoma Patients

    PubMed Central

    Lim, Kue Peng; Chun, Nicole Ai Leng; Ismail, Siti Mazlipah; Abraham, Mannil Thomas; Yusoff, Mohd Nury; Zain, Rosnah Binti; Ngeow, Wei Cheong; Ponniah, Sathibalan; Cheong, Sok Ching

    2014-01-01

    Regulatory T cells (Tregs), a subset of CD4+ T cells plays a pivotal role in regulating the immune system. An increase in Treg numbers enables cancer progression by dampening the immune system and allowing tumor cells to evade immune detection and destruction. An increase in Treg numbers and expression of inhibitory cytokines including TGF-β and IL-10 are mechanisms by which Tregs exert their immune suppressive function. However, the presence of Tregs and inhibitory cytokines in oral cancer patients is still unclear. In this study, the presence of circulating Tregs in 39 oral cancer patients and 24 healthy donors was examined by studying the presence of the CD4+CD25hiCD127low cell population in their peripheral blood mononuclear cells using flow cytometry. Serum levels of TGF-β and IL-10 were measured by ELISA. T cell subsets of OSCC patients were found to differ significantly from healthy donors where a decrease in CD8+ cytotoxic T cells and an increase in Tregs (CD4+CD25hiCD127low) were observed. Further, the ratio of CD8+ T cells/Tregs was also decreased in patients compared to healthy donors. The presence of Tregs was accompanied by a decrease in IL-10 but not TGF-β secretion in OSCC patients when compared to donors; in addition, the analysis also revealed that an increased presence of Tregs was accompanied by better patient survival. Amongst OSCC patients, smokers had significantly higher levels of TGF-β. It is apparent that the immune system is compromised in OSCC patients and the characterization of the Treg subpopulation could form a basis for improving our understanding of the perturbations in the immune system that occur during OSCC tumorigenesis. PMID:25153698

  6. Activated CD4+ T cells preferentially take up lipid microspheres, but resting cells do not.

    PubMed Central

    Suzuki, K

    1995-01-01

    Lipid microspheres (LM) used as drug carriers increase the effectiveness and reduce the toxicity of incorporated drugs. The present study is designed to determine whether or not activated T lymphocytes, which were the cells chosen first from the 'inflammatory cells', can take up LM in vitro. LM were labelled with a fluorescent probe, DiI (DiI-LM), to examine the kinetics. Flow cytometric analysis demonstrated that in freshly isolated peripheral blood mononuclear cells (PBMC), monocytes principally took up DiI-LM, while lymphocytes and granulocytes did not. When PBMC were stimulated with immobilized anti-CD3 MoAb and IL-2, cells expressing CD3, CD4, CD8 and CD16 incorporated DiI-LM. Purified CD4+ T cells, obtained by positive panning selection, were stimulated with this system. They were CD25, CD71, LFA-1-positive, and also showed an ability to take up DiI-LM, which resting cells did not. The findings were confirmed by flow cytometry and quantitative analysis of DiI. Confocal micrographs showed fluorescent granules from the probe in the cytoplasm of stimulated CD4+ T cells after incubation with DiI-LM. These results suggest that immunomodulatory agents incorporated into LM might selectively regulate the function of CD4+ or CD8+ T cells when these are activated. Images Fig. 4 PMID:7882572

  7. Ectonucleotidase activity and immunosuppression in astrocyte-CD4 T cell bidirectional signaling.

    PubMed

    Filipello, Fabia; Pozzi, Davide; Proietti, Michele; Romagnani, Andrea; Mazzitelli, Sonia; Matteoli, Michela; Verderio, Claudia; Grassi, Fabio

    2016-02-01

    Astrocytes play a crucial role in neuroinflammation as part of the glia limitans, which regulates infiltration of the brain parenchyma by leukocytes. The signaling pathways and molecular events, which result from the interaction of activated T cells with astrocytes are poorly defined. Here we show that astrocytes promote the expression and enzymatic activity of CD39 and CD73 ectonucleotidases in recently activated CD4 cells by a contact dependent mechanism that is independent of T cell receptor interaction with class II major histocompatibility complex (MHC). Transforming growth factor-β (TGF-β) is robustly upregulated and sufficient to promote ectonucleotidases expression. T cell adhesion to astrocyte results in differentiation to an immunosuppressive phenotype defined by expression of the transcription factor Rorγt, which characterizes the CD4 T helper 17 subset. CD39 activity in T cells in turn inhibits spontaneous calcium oscillations in astrocytes that correlated with enhanced and reduced transcription of CCL2 chemokine and Sonic hedgehog (Shh), respectively. We hypothesize this TCR-independent interaction promote an immunosuppressive program in T cells to control possible brain injury by deregulated T cell activation during neuroinflammation. On the other hand, the increased secretion of CCL2 with concomitant reduction of Shh might promote leukocytes extravasation into the brain parenchyma. PMID:26784253

  8. Ectonucleotidase activity and immunosuppression in astrocyte-CD4 T cell bidirectional signaling

    PubMed Central

    Filipello, Fabia; Romagnani, Andrea; Mazzitelli, Sonia; Matteoli, Michela; Verderio, Claudia; Grassi, Fabio

    2016-01-01

    Astrocytes play a crucial role in neuroinflammation as part of the glia limitans, which regulates infiltration of the brain parenchyma by leukocytes. The signaling pathways and molecular events, which result from the interaction of activated T cells with astrocytes are poorly defined. Here we show that astrocytes promote the expression and enzymatic activity of CD39 and CD73 ectonucleotidases in recently activated CD4 cells by a contact dependent mechanism that is independent of T cell receptor interaction with class II major histocompatibility complex (MHC). Transforming growth factor-β (TGF-β) is robustly upregulated and sufficient to promote ectonucleotidases expression. T cell adhesion to astrocyte results in differentiation to an immunosuppressive phenotype defined by expression of the transcription factor Rorγt, which characterizes the CD4 T helper 17 subset. CD39 activity in T cells in turn inhibits spontaneous calcium oscillations in astrocytes that correlated with enhanced and reduced transcription of CCL2 chemokine and Sonic hedgehog (Shh), respectively. We hypothesize this TCR-independent interaction promote an immunosuppressive program in T cells to control possible brain injury by deregulated T cell activation during neuroinflammation. On the other hand, the increased secretion of CCL2 with concomitant reduction of Shh might promote leukocytes extravasation into the brain parenchyma. PMID:26784253

  9. Successful immunotherapy induces previously unidentified allergen-specific CD4+ T-cell subsets.

    PubMed

    Ryan, John F; Hovde, Rachel; Glanville, Jacob; Lyu, Shu-Chen; Ji, Xuhuai; Gupta, Sheena; Tibshirani, Robert J; Jay, David C; Boyd, Scott D; Chinthrajah, R Sharon; Davis, Mark M; Galli, Stephen J; Maecker, Holden T; Nadeau, Kari C

    2016-03-01

    Allergen immunotherapy can desensitize even subjects with potentially lethal allergies, but the changes induced in T cells that underpin successful immunotherapy remain poorly understood. In a cohort of peanut-allergic participants, we used allergen-specific T-cell sorting and single-cell gene expression to trace the transcriptional "roadmap" of individual CD4+ T cells throughout immunotherapy. We found that successful immunotherapy induces allergen-specific CD4+ T cells to expand and shift toward an "anergic" Th2 T-cell phenotype largely absent in both pretreatment participants and healthy controls. These findings show that sustained success, even after immunotherapy is withdrawn, is associated with the induction, expansion, and maintenance of immunotherapy-specific memory and naive T-cell phenotypes as early as 3 mo into immunotherapy. These results suggest an approach for immune monitoring participants undergoing immunotherapy to predict the success of future treatment and could have implications for immunotherapy targets in other diseases like cancer, autoimmune disease, and transplantation. PMID:26811452

  10. Successful immunotherapy induces previously unidentified allergen-specific CD4+ T-cell subsets

    PubMed Central

    Ryan, John F.; Hovde, Rachel; Glanville, Jacob; Lyu, Shu-Chen; Ji, Xuhuai; Gupta, Sheena; Tibshirani, Robert J.; Jay, David C.; Boyd, Scott D.; Chinthrajah, R. Sharon; Davis, Mark M.; Galli, Stephen J.; Maecker, Holden T.; Nadeau, Kari C.

    2016-01-01

    Allergen immunotherapy can desensitize even subjects with potentially lethal allergies, but the changes induced in T cells that underpin successful immunotherapy remain poorly understood. In a cohort of peanut-allergic participants, we used allergen-specific T-cell sorting and single-cell gene expression to trace the transcriptional “roadmap” of individual CD4+ T cells throughout immunotherapy. We found that successful immunotherapy induces allergen-specific CD4+ T cells to expand and shift toward an “anergic” Th2 T-cell phenotype largely absent in both pretreatment participants and healthy controls. These findings show that sustained success, even after immunotherapy is withdrawn, is associated with the induction, expansion, and maintenance of immunotherapy-specific memory and naive T-cell phenotypes as early as 3 mo into immunotherapy. These results suggest an approach for immune monitoring participants undergoing immunotherapy to predict the success of future treatment and could have implications for immunotherapy targets in other diseases like cancer, autoimmune disease, and transplantation. PMID:26811452

  11. Global intron retention mediated gene regulation during CD4+ T cell activation.

    PubMed

    Ni, Ting; Yang, Wenjing; Han, Miao; Zhang, Yubo; Shen, Ting; Nie, Hongbo; Zhou, Zhihui; Dai, Yalei; Yang, Yanqin; Liu, Poching; Cui, Kairong; Zeng, Zhouhao; Tian, Yi; Zhou, Bin; Wei, Gang; Zhao, Keji; Peng, Weiqun; Zhu, Jun

    2016-08-19

    T cell activation is a well-established model for studying cellular responses to exogenous stimulation. Using strand-specific RNA-seq, we observed that intron retention is prevalent in polyadenylated transcripts in resting CD4(+) T cells and is significantly reduced upon T cell activation. Several lines of evidence suggest that intron-retained transcripts are less stable than fully spliced transcripts. Strikingly, the decrease in intron retention (IR) levels correlate with the increase in steady-state mRNA levels. Further, the majority of the genes upregulated in activated T cells are accompanied by a significant reduction in IR. Of these 1583 genes, 185 genes are predominantly regulated at the IR level, and highly enriched in the proteasome pathway, which is essential for proper T cell proliferation and cytokine release. These observations were corroborated in both human and mouse CD4(+) T cells. Our study revealed a novel post-transcriptional regulatory mechanism that may potentially contribute to coordinated and/or quick cellular responses to extracellular stimuli such as an acute infection. PMID:27369383

  12. Small CD4 Mimetics Prevent HIV-1 Uninfected Bystander CD4 + T Cell Killing Mediated by Antibody-dependent Cell-mediated Cytotoxicity

    PubMed Central

    Richard, Jonathan; Veillette, Maxime; Ding, Shilei; Zoubchenok, Daria; Alsahafi, Nirmin; Coutu, Mathieu; Brassard, Nathalie; Park, Jongwoo; Courter, Joel R.; Melillo, Bruno; Smith, Amos B.; Shaw, George M.; Hahn, Beatrice H.; Sodroski, Joseph; Kaufmann, Daniel E.; Finzi, Andrés

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) infection causes a progressive depletion of CD4 + T cells. Despite its importance for HIV-1 pathogenesis, the precise mechanisms underlying CD4 + T-cell depletion remain incompletely understood. Here we make the surprising observation that antibody-dependent cell-mediated cytotoxicity (ADCC) mediates the death of uninfected bystander CD4 + T cells in cultures of HIV-1-infected cells. While HIV-1-infected cells are protected from ADCC by the action of the viral Vpu and Nef proteins, uninfected bystander CD4 + T cells bind gp120 shed from productively infected cells and are efficiently recognized by ADCC-mediating antibodies. Thus, gp120 shedding represents a viral mechanism to divert ADCC responses towards uninfected bystander CD4 + T cells. Importantly, CD4-mimetic molecules redirect ADCC responses from uninfected bystander cells to HIV-1-infected cells; therefore, CD4-mimetic compounds might have therapeutic utility in new strategies aimed at specifically eliminating HIV-1-infected cells. PMID:26870823

  13. Maraviroc intensification in patients with suppressed HIV viremia has limited effects on CD4+ T cell recovery and gene expression

    PubMed Central

    Beliakova-Bethell, Nadejda; Jain, Sonia; Woelk, Christopher H.; Witt, Mallory D.; Sun, Xiaoying; Lada, Steven M.; Spina, Celsa A.; Goicoechea, Miguel; Rought, Steffney E.; Haubrich, Richard; Dubé, Michael P.

    2014-01-01

    Addition of the CCR5 inhibitor Maraviroc (MVC) to ongoing antiretroviral therapy increases CD4+ T cell counts in some virologically suppressed patients with suboptimal CD4+ T cell recovery. To understand the mechanisms by which MVC elicits increases in CD4+ T cell counts, the present study was undertaken to identify host factors (i.e. genes) that are modulated and are correlated with CD4+ T cell recovery during the 24 weeks of MVC intensification in 32 subjects. Median changes of CD4+ T cell counts over 24 weeks of MVC compared to baseline were 38 cells/mm3 (p < 0.001). The median slope of CD4+ T cell recovery was 39 cells/mm3 per year before initiation of MVC and 76 cells/mm3 per year during MVC intensification, however, this increase was not statistically significant (p = 0.33). Microarray analysis (N = 31,426 genes) identified a single differentially expressed gene, tumor necrosis factor alpha (TNF), which was modestly (1.44-fold, p < 0.001) downregulated by MVC at week 24 compared to baseline. TNF differential expression was evaluated using an independent method of droplet digital PCR, but the difference was not significant (p = 0.6). Changes in gene expression did not correlate with CD4+ T cell recovery or any changes in the CD4+ T cell maturation, proliferation and activation phenotypes. In summary, our data suggest that modest improvements of CD4+ T cell counts during MVC intensification cannot be explained by changes in gene expression elicited by MVC. However, the modest changes in T cell composition, including reduction of the percentages of Tregs, proliferating CD4+ T cells and senescent CD8+ T cells, suggest immunologically favorable effects of MVC. PMID:24769244

  14. CD8+ T Cell Migration to the Skin Requires CD4+ Help in a Murine Model of Contact Hypersensitivity

    PubMed Central

    Fyhrquist, Nanna; Wolff, Henrik; Lauerma, Antti; Alenius, Harri

    2012-01-01

    The relative roles of CD4+ and CD8+ T cells in contact hypersensitivity responses have not been fully solved, and remain an important question. Using an adoptive transfer model, we investigated the role of the respective T cell subset. Magnetic bead separated CD4+ and CD8+ T cells from oxazolone sensitized C57BL/6 mice were transferred into RAG−/− mice, followed by hapten challenge and analysis of inflammatory parameters at 24 hours post exposure. The CD4+ T cell recipient mice developed partial contact hypersensitivity responses to oxazolone. CD8+ T cells caused significant amplification of the response in recipients of both CD4+ and CD8+ T cells including ear swelling, type 1 inflammatory mediators, and cell killing. Unexpectedly, CD8+ T cells were not sufficient to mediate contact hypersensitivity, although abundantly present in the lymph nodes in the CD8+ T cell reconstituted mice. There were no signs of inflammation at the site of hapten exposure, indicating impaired recruitment of CD8+ T cells in the absence of CD4+ T cells. These data show that CD4+ T cells mediate contact hypersensitivity to oxazolone, but CD8+ T cells contribute with the most potent effector mechanisms. Moreover, our results suggest that CD4+ T cell function is required for the mobilization of CD8+ effector T cells to the site of hapten exposure. The results shed new light on the relative importance of CD4+ and CD8+ T cells during the effector phase of contact hypersensitivity. PMID:22916101

  15. Expanding Roles for CD4 T Cells and Their Subpopulations in Tumor Immunity and Therapy

    PubMed Central

    Dobrzanski, Mark J.

    2013-01-01

    The importance of CD4 T cells in orchestrating the immune system and their role in inducing effective T cell-mediated therapies for the treatment of patients with select established malignancies are undisputable. Through a complex and balanced array of direct and indirect mechanisms of cellular activation and regulation, this functionally diverse family of lymphocytes can potentially promote tumor eradication, long-term tumor immunity, and aid in establishing and/or rebalancing immune cell homeostasis through interaction with other immune cell populations within the highly dynamic tumor environment. However, recent studies have uncovered additional functions and roles for CD4 T cells, some of which are independent of other lymphocytes, that can not only influence and contribute to tumor immunity but paradoxically promote tumor growth and progression. Here, we review the recent advances in our understanding of the various CD4 T cell lineages and their signature cytokines in disease progression and/or regression. We discuss their direct and indirect mechanistic interplay among themselves and with other responding cells of the antitumor response, their potential roles and abilities for “plasticity” and memory cell generation within the hostile tumor environment, and their potentials in cancer treatment and immunotherapy. PMID:23533029

  16. The role of CD4-Lck in T-cell receptor antagonism: evidence for negative signaling.

    PubMed Central

    Racioppi, L; Matarese, G; D'Oro, U; De Pascale, M; Masci, A M; Fontana, S; Zappacosta, S

    1996-01-01

    Small changes in the complex between a peptide and a molecule of the major histocompatibility complex generate ligands able to partially activate (partial agonist) or even inhibit (antagonist) T-cell functions. T-cell receptor engagement of antagonist complex results in a partial zeta chain phosphorylation without activation of the associated ZAP-70 kinase. Herein we show that, despite a strong inhibition of both inositol phospholipid hydrolysis and extracellular increasing antagonist concentrations increased the activity of the CD4-Lck kinase. Addition of anti-CD4 antibody to culture medium prevented inhibitory effects induced by antagonist ligand. We propose that CD4-Lck activation triggered by antagonist complexes may act in a dominant negative mode, thus overriding stimulatory signals coming from agonist ligand. These findings identify a new T-cell signaling profile that may explain the ability of some T-cell receptor variant ligands to inhibit specific biological activities or trigger alternative activation programs. Images Fig. 3 Fig. 4 PMID:8816805

  17. Transplantation of Tail Skin to Study Allogeneic CD4 T Cell Responses in Mice

    PubMed Central

    Rossi, Simona W.

    2014-01-01

    The study of T cell responses and their consequences during allo-antigen recognition requires a model that enables one to distinguish between donor and host T cells, to easily monitor the graft, and to adapt the system in order to answer different immunological questions. Medawar and colleagues established allogeneic tail-skin transplantation in mice in 1955. Since then, the skin transplantation model has been continuously modified and adapted to answer specific questions. The use of tail-skin renders this model easy to score for graft rejection, requires neither extensive preparation nor deep anesthesia, is applicable to animals of all genetic background, discourages ischemic necrosis, and permits chemical and biological intervention. In general, both CD4+ and CD8+ allogeneic T cells are responsible for the rejection of allografts since they recognize mismatched major histocompatibility antigens from different mouse strains. Several models have been described for activating allogeneic T cells in skin-transplanted mice. The identification of major histocompatibility complex (MHC) class I and II molecules in different mouse strains including C57BL/6 mice was an important step toward understanding and studying T cell-mediated alloresponses. In the tail-skin transplantation model described here, a three-point mutation (I-Abm12) in the antigen-presenting groove of the MHC-class II (I-Ab) molecule is sufficient to induce strong allogeneic CD4+ T cell activation in C57BL/6 mice. Skin grafts from I-Abm12 mice on C57BL/6 mice are rejected within 12-15 days, while syngeneic grafts are accepted for up to 100 days. The absence of T cells (CD3-/- and Rag2-/- mice) allows skin graft acceptance up to 100 days, which can be overcome by transferring 2 x 104 wild type or transgenic T cells. Adoptively transferred T cells proliferate and produce IFN-γ in I-Abm12-transplanted Rag2-/- mice. PMID:25147005

  18. Azithromycin suppresses CD4+ T-cell activation by direct modulation of mTOR activity

    PubMed Central

    Ratzinger, F.; Haslacher, H.; Poeppl, W.; Hoermann, G.; Kovarik, J. J.; Jutz, S.; Steinberger, P.; Burgmann, H.; Pickl, W. F.; Schmetterer, K. G.

    2014-01-01

    Advanced macrolides, such as azithromycin (AZM) or clarithromycin (CLM), are antibiotics with immunomodulatory properties. Here we have sought to evaluate their in vitro influence on the activation of CD4+ T-cells. Isolated CD4+ T-cells were stimulated with agonistic anti-CD3/anti-CD28 monoclonal antibodies in the presence of 0.6 mg/L, 2.5 mg/L, 10 mg/L or 40 mg/L AZM or CLM. Cell proliferation, cytokine level in supernatants and cell viability was assessed. Intracellular signaling pathways were evaluated using reporter cell lines, FACS analysis, immunoblotting and in vitro kinase assays. AZM inhibited cell proliferation rate and cytokine secretion of CD4+ T-cells in a dose-dependent manner. Similarly, high concentrations of CLM (40 mg/L) also suppressed these T-cell functions. Analysis of molecular signaling pathways revealed that exposure to AZM reduced the phosphorylation of the S6 ribosomal protein, a downstream target of mTOR. This effect was also observed at 40 mg/L CLM. In vitro kinase studies using recombinant mTOR showed that AZM inhibited mTOR activity. In contrast to rapamycin, this inhibition was independent of FKBP12. We show for the first time that AZM and to a lesser extent CLM act as immunosuppressive agents on CD4+ T-cells by inhibiting mTOR activity. Our results might have implications for the clinical use of macrolides. PMID:25500904

  19. Interferon-alpha stimulates production of interleukin-10 in activated CD4+ T cells and monocytes.

    PubMed

    Aman, M J; Tretter, T; Eisenbeis, I; Bug, G; Decker, T; Aulitzky, W E; Tilg, H; Huber, C; Peschel, C

    1996-06-01

    In the present study, we investigated the effect of interferon-alpha (IFN-alpha) on the expression of interleukin-10 (IL-10) mRNA and protein synthesis in human monocytes and CD4+ T cells. In mononuclear cells, IFN-alpha induced expression of IL-10 mRNA and further enhanced lipopolysaccharide (LPS)-stimulated IL-10 expression. In purified monocytes, a strong expression of IL-10 mRNA induced by LPS was not further enhanced by IFN-alpha. In highly purified CD4+ T cells, IFN-alpha upregulated IL-10 mRNA upon activation with phytohemagglutinin and phorbol myristate acetate. In purified monocytes, an effect of IFN-alpha on IL-10 protein synthesis was dependent on costimulation with LPS. Maximal stimulation of IL-10 protein by IFN-alpha was seen after prolonged incubation periods of 48 to 96 hours, whereas IFN-gamma reduced IL-10 production in the early incubation period. Similar effects of IFN-alpha were observed in CD4+ T cells activated with CD3 and CD28 monoclonal antibodies. Addition of IFN-alpha caused an increase of IL-10 in culture supernatants of activated T-helper cells of more than 100% after 96 hours of incubation. In contrast, other cytokines, including IFN-gamma and IL-4, had no influence on IL-10 secretion stimulated by CD3 and CD28 in CD4+ T cells. In serum samples of IFN-alpha-treated individuals, we failed to detect an influence of cytokine treatment on IL-10 serum levels, confirming the requirement of additional activating signals for IFN-alpha-mediated effects on IL-10 synthesis. In conclusion, IFN-alpha enhances the late induction of IL-10, which physiologically occurs upon stimulation of monocytes and T cells. Biologically, this effect might enhance the negative-feedback mechanism ascribed to IL-10, which limits inflammatory reactions. PMID:8639843

  20. E4BP4 overexpression: a protective mechanism in CD4+ T cells from SLE patients.

    PubMed

    Zhao, Ming; Liu, Qian; Liang, Gongping; Wang, Litao; Luo, Shuangyan; Tang, Qian; Zhao, Hongjun; Su, Yuwen; Yung, Susan; Chan, Tak Mao; Lu, Qianjin

    2013-03-01

    Systemic lupus erythematosus (SLE) is a prototype autoimmune disease characterized by various immunological abnormalities, including dysregulated activation of T and B lymphocytes, which trigger autoantibody production and immune-complex deposition. E4BP4, also known as NFIL3, has emerged as a major transcription factor that regulates the development and function of immune cells in a number of lineages. E4BP4 has been shown to regulate cytokines expression, and its synthesis is in turn controlled by various cytokines. To date, the roles of E4BP4 in immune dysregulation and autoimmune disorders are unclear. In this study, we demonstrated that E4BP4 expression is increased in CD4(+) T cells isolated from patients with active systemic lupus erythematosus (SLE), especially in patients treated with glucocorticoid (GC). Increased expression of E4BP4 inhibited the activation and self-reactivity of T cells stimulated by anti-CD3/CD28 antibodies. In contrast, the self-reactivity was enhanced in CD4(+) T cells from SLE patients following E4BP4 gene silencing and the production of autoantibody was increased in autologous B cells. We further demonstrated that E4BP4 directly regulated CD40L expression by binding to the promoter region and altering histone acetylation and methylation of the CD40L loci. Taken together, our data provide evidence that E4BP4 can inhibit CD40L expression through epigenetic modifications in the promoter region of CD40L, thus negatively regulating self-reactivity of SLE CD4(+) T cells. Furthermore, our data demonstrate that overexpression of E4BP4 initiates a protective mechanism in SLE CD4(+) T cells, which may be a promising target in the therapy for SLE. PMID:23340290

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

    PubMed

    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

  2. Antileukemia multifunctionality of CD4(+) T cells genetically engineered by HLA class I-restricted and WT1-specific T-cell receptor gene transfer.

    PubMed

    Fujiwara, H; Ochi, T; Ochi, F; Miyazaki, Y; Asai, H; Narita, M; Okamoto, S; Mineno, J; Kuzushima, K; Shiku, H; Yasukawa, M

    2015-12-01

    To develop gene-modified T-cell-based antileukemia adoptive immunotherapy, concomitant administration of CD4(+) and CD8(+) T cells that have been gene modified using identical HLA class I-restricted leukemia antigen-specific T-cell receptor (TCR) gene transfer has not yet been fully investigated. Here, using CD4(+) and CD8(+) T cells that had been gene modified with a retroviral vector expressing HLA-A*24:02-restricted and Wilms' tumor 1 (WT1)-specific TCR-α/β genes and siRNAs for endogenous TCRs (WT1-siTCR/CD4(+) T cells and WT1-siTCR/CD8(+) T cells), we examined the utility of this strategy. WT1-siTCR/CD4(+) T cells sufficiently recognized leukemia cells in an HLA class I-restricted manner and provided target-specific Th1 help for WT1-siTCR/CD8(+) T cells. By using a xenografted mouse model, we found that WT1-siTCR/CD4(+) T cells migrated to leukemia sites and subsequently attracted WT1-siTCR/CD8(+) T cells via chemotaxis. Therapy-oriented experiments revealed effective enhancement of leukemia suppression mediated by concomitant administration of WT1-siTCR/CD4(+) T cells and WT1-siTCR/CD8(+) T cells. Importantly, this augmented efficacy in the presence of WT1-siTCR/CD4(+) T cells was correlated with longer survival and enhanced formation of memory T cells by WT1-siTCR/CD8(+) T cells. Collectively, our experimental findings strongly suggest that this strategy would be clinically advantageous for the treatment of human leukemia. PMID:26104661

  3. Comparative Impact of Suppressive Antiretroviral Regimens on the CD4/CD8 T-Cell Ratio

    PubMed Central

    Masiá, Mar; Padilla, Sergio; Barber, Xavier; Sanchis, Marina; Terol, Gertrudis; Lidón, Fernando; Gutiérrez, Félix

    2016-01-01

    Abstract Although different factors have been implicated in the CD4/CD8 T-cell ratio recovery in HIV-infected patients who receive effective antiretroviral therapy (ART), limited information exists on the influence of the regimen composition. A longitudinal study carried out in a prospective, single-center cohort of HIV-infected patients. ART regimens including non-nucleoside reverse transcriptase inhibitors (NNRTI), protease inhibitors (PI), or integrase strand transfer inhibitors (INSTI) from patients who achieved long-term (≥6-month duration) virological suppression (HIV-RNA < 400 copies/mL) from January 1998 to June 2014 were analyzed. The impact of ART composition on the changes of the CD4/CD8 T-cell ratio was modeled using a mixed linear approach with adjustment for possible confounders. A total of 1068 ART regimens from 570 patients were analyzed. Mean (SD) age of the patients was 42.15 (10.68) years and 276 (48.42%) had hepatitis C virus (HCV) coinfection. Five hundred fifty-eight (52.25%) regimens were PI-based, 439 (40.10%) NNRTI-based, and 71 (6.65%) INSTI-based; 487 (45.60%) were initial regimens, 476 (44.57%) simplification, and 105 (9.83%) salvage regimens. Median (IQR) number of regimens was 1 (1–2) per patient, of 29 (14–58) months duration, and 4 (3–7) CD4/CD8 measurements per regimen. The median baseline CD4/CD8 ratio was 0.42, 0.50, and 0.54, respectively, with the PI-, NNRTI-, and INSTI-based regimens (P = 0.0073). Overall median (IQR) increase of CD4/CD8 ratio was 0.0245 (−0.0352–0.0690) per year, and a CD4/CD8 ratio ≥1 was achieved in 19.35% of the cases with PI-based, 25.97% with NNRTI-based, and 22.54% with INSTI-based regimens (P = 0.1406). In the adjusted model, the mean CD4/CD8 T-cell ratio increase was higher with NNRTI-based regimens compared for PI-based (estimated coefficient for PI [95% CI], −0.0912 [−0.1604 to −0.0219], P = 0.009). Also, a higher CD4/CD8 baseline ratio was associated with higher

  4. CD4-Negative Cells Bind Human Immunodeficiency Virus Type 1 and Efficiently Transfer Virus to T Cells

    PubMed Central

    Olinger, Gene G.; Saifuddin, Mohammed; Spear, Gregory T.

    2000-01-01

    The ability of human immunodeficiency virus strain MN (HIVMN), a T-cell line-adapted strain of HIV, and X4 and R5 primary isolates to bind to various cell types was investigated. In general, HIVMN bound to cells at higher levels than did the primary isolates. Virus bound to both CD4-positive (CD4+) and CD4-negative (CD4−) cells, including neutrophils, Raji cells, tonsil mononuclear cells, erythrocytes, platelets, and peripheral blood mononuclear cells (PBMC), although virus bound at significantly higher levels to PBMC. However, there was no difference in the amount of HIV that bound to CD4-enriched or CD4-depleted PBMC. Virus bound to CD4− cells was up to 17 times more infectious for T cells in cocultures than was the same amount of cell-free virus. Virus bound to nucleated cells was significantly more infectious than virus bound to erythrocytes or platelets. The enhanced infection of T cells by virus bound to CD4− cells was not due to stimulatory signals provided by CD4− cells or infection of CD4− cells. However, anti-CD18 antibody substantially reduced the enhanced virus replication in T cells, suggesting that virus that bound to the surface of CD4− cells is efficiently passed to CD4+ T cells during cell-cell adhesion. These studies show that HIV binds at relatively high levels to CD4− cells and, once bound, is highly infectious for T cells. This suggests that virus binding to the surface of CD4− cells is an important route for infection of T cells in vivo. PMID:10954556

  5. HIV-specific CD8+ T cell function in children with vertically acquired HIV-1 infection is critically influenced by age and the state of the CD4+ T cell compartment.

    PubMed

    Sandberg, Johan K; Fast, Noam M; Jordan, Kimberly A; Furlan, Scott N; Barbour, Jason D; Fennelly, Glenn; Dobroszycki, Joanna; Spiegel, Hans M L; Wiznia, Andrew; Rosenberg, Michael G; Nixon, Douglas F

    2003-04-15

    The immunology of vertical HIV transmission differs from that of adult infection in that the immune system of the infant is not fully matured, and the factors that influence the functionality of CD8(+) T cell responses against HIV in children remain largely undefined. We have investigated CD8(+) T cell responses in 65 pediatric subjects with vertically acquired HIV-1 infection. Vigorous, broad, and Ag dose-driven CD8(+) T cell responses against HIV Ags were frequently observed in children who were older than 3 years of age and maintained CD4(+) T cell counts >400 cells/ micro l. In contrast, younger age or a CD4(+) T cell count <400 cells/ micro l was associated with poor CD8(+) T cell responses and high HIV loads. Furthermore, subjects with a severely depleted and phenotypically altered CD4(+) T cell compartment had circulating Gag-specific CD8(+) T cells with impaired IFN-gamma production. When viral load was not suppressed by antiviral treatment, subjects that fell below the putative age and CD4(+) T cell count thresholds had significantly reduced CD8(+) T cell responses and significantly higher viral loads. Thus, the data suggest that fully effective HIV-specific CD8(+) T cell responses take years to develop despite an abundance of Ag in early life, and responses are further severely impaired, independent of age, in children who have a depleted or skewed CD4(+) T cell compartment. The results are discussed in relation to differences between the neonatal and adult immune systems in the ability to respond to HIV infection. PMID:12682278

  6. Bystander Activation and Anti-Tumor Effects of CD8+ T Cells Following Interleukin-2 Based Immunotherapy Is Independent of CD4+ T Cell Help

    PubMed Central

    Grossenbacher, Steven K.; Hsiao, Hui-Hua; Zamora, Anthony E.; Mirsoian, Annie; Koehn, Brent; Blazar, Bruce R.; Weiss, Jonathan M.; Wiltrout, Robert H.; Sckisel, Gail D.; Murphy, William J.

    2014-01-01

    We have previously demonstrated that immunotherapy combining agonistic anti-CD40 and IL-2 (IT) results in synergistic anti-tumor effects. IT induces expansion of highly cytolytic, antigen-independent “bystander-activated” (CD8+CD44high) T cells displaying a CD25−NKG2D+ phenotype in a cytokine dependent manner, which were responsible for the anti-tumor effects. While much attention has focused on CD4+ T cell help for antigen-specific CD8+ T cell expansion, little is known regarding the role of CD4+ T cells in antigen-nonspecific bystander-memory CD8+ T cell expansion. Utilizing CD4 deficient mouse models, we observed a significant expansion of bystander-memory T cells following IT which was similar to the non-CD4 depleted mice. Expanded bystander-memory CD8+ T cells upregulated PD-1 in the absence of CD4+ T cells which has been published as a hallmark of exhaustion and dysfunction in helpless CD8+ T cells. Interestingly, compared to CD8+ T cells from CD4 replete hosts, these bystander expanded cells displayed comparable (or enhanced) cytokine production, lytic ability, and in vivo anti-tumor effects suggesting no functional impairment or exhaustion and were enriched in an effector phenotype. There was no acceleration of the post-IT contraction phase of the bystander memory CD8+ response in CD4-depleted mice. The response was independent of IL-21 signaling. These results suggest that, in contrast to antigen-specific CD8+ T cell expansion, CD4+ T cell help is not necessary for expansion and activation of antigen-nonspecific bystander-memory CD8+ T cells following IT, but may play a role in regulating conversion of these cells from a central memory to effector phenotype. Additionally, the expression of PD-1 in this model appears to be a marker of effector function and not exhaustion. PMID:25119341

  7. Nod2 Activates NF-kB in CD4+ T Cells but Its Expression Is Dispensable for T Cell-Induced Colitis

    PubMed Central

    Zanello, Galliano; Goethel, Ashleigh; Forster, Katharina; Geddes, Kaoru; Philpott, Dana J.; Croitoru, Kenneth

    2013-01-01

    Although the etiology of Crohn's disease (CD) remains elusive this disease is characterized by T cell activation that leads to chronic inflammation and mucosal damage. A potential role for maladaptation between the intestinal microbiota and the mucosal immune response is suggested by the fact that mutations in the pattern recognition receptor Nod2 are associated with higher risks for developing CD. Although Nod2 deletion in CD4+ T cells has been shown to impair the induction of colitis in the murine T cell transfer model, the analysis of T cell intrinsic Nod2 function in T cell differentiation and T cell-mediated immunity is inconsistent between several studies. In addition, the role of T cell intrinsic Nod2 in regulatory T cell (Treg) development and function during colitis remain to be analyzed. In this study, we show that Nod2 expression is higher in activated/memory CD4+ T cells and its expression was inducible after T cell receptor (TCR) ligation. Nod2 stimulation with muramyl dipeptide (MDP) led to a nuclear accumulation of c-Rel NF-kB subunit. Although functionally active in CD4+ T cells, the deletion of Nod2 did not impair the induction and the prevention of colitis in the T cell transfer model. Moreover, Nod2 deletion did not affect the development of Foxp3+ Treg cells in the spleen of recipient mice and Nod2 deficient CD4 T cells expressing the OVA specific transgenic TCR were able to differentiate in Foxp3+ Treg cells after OVA feeding. In vitro, CD25+ Nod2 deficient T cells suppressed T cell proliferation as well as wild type counter parts and T cell stimulation with MDP did not affect the proliferation and the cytokine secretion of T cells. In conclusion, our data indicate that Nod2 is functional in murine CD4+ T cells but its expression is dispensable for the T cell regulation of colitis. PMID:24324812

  8. CD4(+)HLA-G(+) regulatory T cells: Molecular signature and pathophysiological relevance.

    PubMed

    Pankratz, Susann; Ruck, Tobias; Meuth, Sven G; Wiendl, Heinz

    2016-09-01

    The regulation of potentially harmful immune responses by regulatory T (Treg) cells is essential for maintaining peripheral immune tolerance and homeostasis. Especially CD4(+) Treg cells have been regarded as pivotal regulators of autoreactive and inflammatory responses as well as inducers of immune tolerance by using a variety of immune suppressive mechanisms. Besides the well-known classical CD4(+)CD25(+)FoxP3(+) Treg cells, CD4(+) T cells expressing the immune tolerizing molecule human leukocyte antigen G (HLA-G) have been recently described as another potent thymus-derived Treg (tTreg) cell subset. Albeit both tTreg subsets share common molecular characteristics, the mechanisms of their immunosuppressive function differ fundamentally. Dysfunction and numerical abnormalities of classical CD4(+) tTreg cells have been implicated in the pathogenesis of several immune-mediated diseases such as multiple sclerosis (MS). Clearly, a deeper understanding of the various CD4(+) tTreg subsets and also the underlying mechanisms of impaired immune tolerance in these disorders are essential for the development of potential therapeutic strategies. This review focuses on the current knowledge on defining features and functioning of HLA-G(+)CD4(+) tTreg cells as well as their emerging role in various pathologies with special emphasis on the pathogenesis of MS. Furthermore, future research possibilities together with potential therapeutic applications are discussed. PMID:26826445

  9. Expression of fas protein on CD4+T cells irradiated by low level He-Ne

    NASA Astrophysics Data System (ADS)

    Nie, Fan; Zhu, Jing; Zhang, Hui-Guo

    2005-07-01

    Objective: To investigate the influence on the Expression of Fas protein on CD4+ T cells irradiated by low level He-Ne laser in the cases of psoriasis. Methods:the expression of CD4+ T Fas protein was determined in the casee of psoriasis(n=5) pre and post-low level laser irradiation(30 min、60min and 120min)by flow cytometry as compared withthe control(n=5). Results:In the cases of psoriasis,the expression of CD4+T FAS protein 21.4+/-3.1% was increased significantly than that of control group 16.8+/-2.1% pre-irradiation, p<0.05in the control,there is no difference between pre and post- irradiation,p>0.05in the cases , the expression of CD4+T Fas protein wae positively corelated to the irradiation times, when the energy density arrived to 22.92J/cm2(60 minutes)and 45.84J/cm2(120minutes), the expression of CD4+ T Fas protein was increased significantly as compared with pre-irradiation,p<0.05.Conclusion: The expression of CD4+T Fas protein may be increased by low level He-Ne laser irradiation ,the uncontrolled status of apoptosis could be corrected.

  10. Green tea epigallocatechin-3-gallate modulates differentiation of naive CD4+ T cells into specific lineage effector cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    CD4+ T helper (Th) subsets Th1, Th9, and Th17 cells are implicated in inducing autoimmunity whereas regulatory T cells (Treg) have a protective effect. We previously showed that epigallocatechin-3-gallate (EGCG) attenuated experimental autoimmune encephalomyelitis (EAE) and altered CD4+ T cell subpo...

  11. Dynamics of CCR5 Expression by CD4+ T Cells in Lymphoid Tissues during Simian Immunodeficiency Virus Infection

    PubMed Central

    Veazey, Ronald S.; Mansfield, Keith G.; Tham, Irene C.; Carville, Angela C.; Shvetz, Daniel E.; Forand, Amy E.; Lackner, Andrew A.

    2000-01-01

    Early viral replication and profound CD4+ T-cell depletion occur preferentially in intestinal tissues of macaques infected with simian immunodeficiency virus (SIV). Here we show that a much higher percentage of CD4+ T cells in the intestine express CCR5 compared with those found in the peripheral blood, spleen, or lymph nodes. In addition, the selectivity and extent of the CD4+ T-cell loss in SIV infection may depend upon these cells coexpressing CCR5 and having a “memory” phenotype (CD45RA−). Following intravenous infection with SIVmac251, memory CD4+ CCR5+ T cells were selectively eliminated within 14 days in all major lymphoid tissues (intestine, spleen, and lymph nodes). However, the effect on CD4+ T-cell numbers was most profound in the intestine, where cells of this phenotype predominate. The CD4+ T cells that remain after 14 days of infection lacked CCR5 and/or were naive (CD45RA+). Furthermore, when animals in the terminal stages of SIV infection (with AIDS) were examined, virtually no CCR5-expressing CD4+ T cells were found in lymphoid tissues, and all of the remaining CD4+ T cells were naive and coexpressed CXCR4. These findings suggest that chemokine receptor usage determines which cells are targeted for SIV infection and elimination in vivo. PMID:11069995

  12. CD4+ T cells from MHC II-dependent thymocyte–thymocyte interaction provide efficient help for B cells

    PubMed Central

    Kim, Eun Ji; Choi, Bomi; Moon, Hana; Lee, You Jeong; Jeon, Yoon Kyeong; Park, Seong Hoe; Kim, Tae Jin; Jung, Kyeong Cheon

    2011-01-01

    Recently, a novel CD4+ T-cell developmental pathway was reported that generates thymocyte–thymocyte (T–T) CD4+ T cells. We established a mouse system (CIITAtgCIITApIV−/−) where thymic positive selection occurred only by major histocompatibility complex (MHC) class II+ thymocytes. T–T CD4+ T cells selected via MHC class II-dependent T–T interaction are comprised of PLZF-negative and innate PLZF-positive populations. Until recently, the functional role of the PLZF-negative population was unclear. In this study, we demonstrate that naïve T–T CD4+ T cells provide B-cell help to a level comparable with that of naïve conventional CD4+ T cells. Considering the absence of PLZF expression in naïve T–T CD4+ T cells, these results suggest that PLZF-negative naïve T–T CD4+ T cells are functionally equivalent to conventional naïve CD4+ T cells in terms of B-cell help. PMID:21358747

  13. Differential Expression of Immune Checkpoint Modulators on In Vitro Primed CD4+ and CD8+ T Cells

    PubMed Central

    Sabins, Nina C.; Harman, Benjamin C.; Barone, Linda R.; Shen, Shixue; Santulli-Marotto, Sandra

    2016-01-01

    PD-1, TIM-3, and LAG-3 are molecules shown to have immune modulatory properties, and although initially classified as indicators of T cell hyporesponsiveness, it has become clear that they are also associated with the normal course of T cell activation. Functional studies have focused mainly on CD8+ T cells during chronic inflammation due to interest in co-opting the cellular immune response to eliminate viral or cancerous threats; however, there remains a relative lack of data regarding the expression of these molecules on CD4+ T cells. Here, we report that expression of the immune checkpoint (IC) molecules PD-1, LAG-3, and TIM-3 are differentially expressed on CD4+ and CD8+ T cells in the allogeneic response resulting from a mixed lymphocyte reaction. In these studies, PD-1 expression is higher on CD4+ T cells compared to CD8+ T cells. In contrast, TIM-3 is expressed at higher levels on CD8+ T cells compared to CD4+ T cells with an apparent reciprocity in that PD-1+ CD4+ T cells are frequently TIM-3lo/−, while TIM-3-expressing CD8+ T cells are largely PD-1lo/−. In addition, there is a decrease in the frequency of TIM-3+ CD4+ cells producing IFN-γ and IL-5 compared to TIM-3+ CD8+ cells. Lastly, the memory T cell phenotype within each IC-expressing subset differs between CD4+ and CD8+ T cells. These findings highlight key differences in IC expression patterns between CD4+ and CD8+ T cells and may allow for more effective therapeutic targeting of these molecules in the future. PMID:27379090

  14. NF-κB: Roles and Regulation In Different CD4+ T cell subsets

    PubMed Central

    Oh, Hyunju; Ghosh, Sankar

    2012-01-01

    Summary The nuclear factor-κB (NF-κB) family of transcription factors plays important roles in various biological processes including apoptosis, stress response, immunity, and inflammation. NF-κB signaling is involved in both immune cell development and function, and it is critical in modulation of the immune response through the transcriptional regulation of cytokine and chemokine expression. An area of great interest in T-cell-mediated adaptive immunity is the ability of naive CD4+ T cells generated in the thymus to differentiate into various subsets including T-helper 1 (Th1), Th2, Th17, Th9, follicular helper T (Tfh), Th22 and regulatory T (Treg) cells, upon encountering different pathogens and microenvironments. In this review, we discuss the role of NF-κB pathway in the development and functional divergence of the different helper T-cell subsets as well as in regulatory T cells. PMID:23405894

  15. Tumour-specific CD4 T cells eradicate melanoma via indirect recognition of tumour-derived antigen.

    PubMed

    Shklovskaya, Elena; Terry, Alexandra M; Guy, Thomas V; Buckley, Adrian; Bolton, Holly A; Zhu, Erhua; Holst, Jeff; Fazekas de St. Groth, Barbara

    2016-07-01

    The importance of CD4 T cells in tumour immunity has been increasingly recognised, with recent reports describing robust CD4 T cell-dependent tumour control in mice whose immune-regulatory mechanisms have been disturbed by irradiation, chemotherapy, immunomodulatory therapy and/or constitutive immunodeficiency. Tumour control in such models has been attributed in large part to direct Major Histocompatibility Complex (MHC) class II-dependent CD4 T cell killing of tumour cells. To test whether CD4 T cells can eradicate tumours without directly killing tumour cells, we developed an animal model in which tumour-derived antigen could be presented to T-cell receptor (TCR)-transgenic CD4 T cells by host but not tumour MHC class II molecules. In I-E(+) mice bearing I-E(null) tumours, naive I-E-restricted CD4 T cells proliferated locally in tumour-draining lymph nodes after recognising tumour-derived antigen on migratory dendritic cells. In lymphopaenic but not immunosufficient hosts, CD4 T cells differentiated into polarised T helper type 1 (Th1) cells expressing interferon gamma (IFNγ), tumor necrosis factor alpha (TNFα) and interleukin (IL)-2 but little IL-17, and cleared established tumours. Tumour clearance was enhanced by higher TCR affinity for tumour antigen-MHC class II and was critically dependent on IFNγ, as demonstrated by early tumour escape in animals treated with an IFNγ blocking antibody. Thus, CD4 T cells and IFNγ can control tumour growth without direct T-cell killing of tumour cells, and without requiring additional adaptive immune cells such as CD8 T cells and B cells. Our results support a role for effective CD4 T cell-dependent tumour immunity against MHC class II-negative tumours. PMID:26837456

  16. Functional Heterogeneity in CD4(+) T Cell Responses Against a Bacterial Pathogen.

    PubMed

    Milam, Ashley Viehmann; Allen, Paul M

    2015-01-01

    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 L. 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 [T cell receptor (TCR)-mediated] and non-specific 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. PMID:26697015

  17. A novel SIV gag-specific CD4(+)T-cell clone suppresses SIVmac239 replication in CD4(+)T cells revealing the interplay between antiviral effector cells and their infected targets.

    PubMed

    Ayala, Victor I; Trivett, Matthew T; Coren, Lori V; Jain, Sumiti; Bohn, Patrick S; Wiseman, Roger W; O'Connor, David H; Ohlen, Claes; Ott, David E

    2016-06-01

    To study CD4(+)T-cell suppression of AIDS virus replication, we isolated nine rhesus macaque SIVGag-specific CD4(+)T-cell clones. One responding clone, Gag68, produced a typical cytotoxic CD8(+)T-cell response: induction of intracellular IFN-γ, MIP-1α, MIP-1β, and CD107a degranulation. Gag68 effectively suppressed the spread of SIVmac239 in CD4(+)T cells with a corresponding reduction of infected Gag68 effector cells, suggesting that CD4(+)effectors need to suppress their own infection in addition to their targets to be effective. Gag68 TCR cloning and gene transfer into CD4(+)T cells enabled additional experiments with this unique specificity after the original clone senesced. Our data supports the idea that CD4(+)T cells can directly limit AIDS virus spread in T cells. Furthermore, Gag68 TCR transfer into CD4(+)T-cell clones with differing properties holds promise to better understand the suppressive effector mechanisms used by this important component of the antiviral response using the rhesus macaque model. PMID:27017056

  18. Cell-intrinsic mechanism involving Siglec-5 associated with divergent outcomes of HIV-1 infection in human and chimpanzee CD4 T cells.

    PubMed

    Soto, Paula C; Karris, Maile Y; Spina, Celsa A; Richman, Douglas D; Varki, Ajit

    2013-02-01

    Human and chimpanzee CD4+ T cells differ markedly in expression of the inhibitory receptor Siglec-5, which contributes towards differential responses to activating stimuli. While CD4+ T cells from both species are equally susceptible to HIV-1 infection, chimpanzee cells survive better, suggesting a cell-intrinsic difference. We hypothesized that Siglec-5 expression protects T cells from activation-induced and HIV-1-induced cell death. Transduction of human CEM T cells with Siglec-5 decreased cell responses to stimulation. Following HIV-1 infection, a higher percentage of Siglec-5-positive cells survived, suggesting relative resistance to virus-induced cell death. Consistent with this, we observed an increase in percentage of Siglec-5-positive cells surviving in mixed infected cultures. Siglec-5-transduced cells also showed decreased expression of apoptosis-related proteins following infection and reduced susceptibility to Fas-mediated cell death. Similar Siglec-5-dependent differences were seen when comparing infection outcomes in primary CD4+ T cells from humans and chimpanzees. A protective effect of Siglec-5 was further supported by observing greater proportions of circulating CD4+ T cells expressing Siglec-5 in acutely infected HIV-1 patients, compared to controls. Taken together, our results suggest that Siglec-5 expression protects T cells from HIV-1- and apoptosis-induced cell death and contributes to the different outcomes of HIV-1 infection in humans and chimpanzees. PMID:22945238

  19. Helminth Infections Coincident with Active Pulmonary Tuberculosis Inhibit Mono- and Multifunctional CD4+ and CD8+ T Cell Responses in a Process Dependent on IL-10

    PubMed Central

    George, Parakkal Jovvian; Anuradha, Rajamanickam; Kumar, Nathella Pavan; Sridhar, Rathinam; Banurekha, Vaithilingam V.; Nutman, Thomas B.; Babu, Subash

    2014-01-01

    Tissue invasive helminth infections and tuberculosis (TB) are co-endemic in many parts of the world and can trigger immune responses that might antagonize each other. We have previously shown that helminth infections modulate the Th1 and Th17 responses to mycobacterial-antigens in latent TB. To determine whether helminth infections modulate antigen-specific and non-specific immune responses in active pulmonary TB, we examined CD4+ and CD8+ T cell responses as well as the systemic (plasma) cytokine levels in individuals with pulmonary TB with or without two distinct helminth infections—Wuchereria bancrofti and Strongyloides stercoralis infection. By analyzing the frequencies of Th1 and Th17 CD4+ and CD8+ T cells and their component subsets (including multifunctional cells), we report a significant diminution in the mycobacterial–specific frequencies of mono- and multi–functional CD4+ Th1 and (to a lesser extent) Th17 cells when concomitant filarial or Strongyloides infection occurs. The impairment in CD4+ and CD8+ T cell cytokine responses was antigen-specific as polyclonal activated T cell frequencies were equivalent irrespective of helminth infection status. This diminution in T cell responses was also reflected in diminished circulating levels of Th1 (IFN-γ, TNF-α and IL-2)- and Th17 (IL-17A and IL-17F)-associated cytokines. Finally, we demonstrate that for the filarial co-infections at least, this diminished frequency of multifunctional CD4+ T cell responses was partially dependent on IL-10 as IL-10 blockade significantly increased the frequencies of CD4+ Th1 cells. Thus, co-existent helminth infection is associated with an IL-10 mediated (for filarial infection) profound inhibition of antigen-specific CD4+ T cell responses as well as protective systemic cytokine responses in active pulmonary TB. PMID:25211342

  20. Analysis of Virus-Specific CD4+ T Cells during Long-Term Gammaherpesvirus Infection

    PubMed Central

    Flaño, Emilio; Woodland, David L.; Blackman, Marcia A.; Doherty, Peter C.

    2001-01-01

    Major histocompatibility complex class II-mediated antigen presentation after intranasal infection with murine gammaherpesvirus 68 differs in mediastinal lymph nodes and spleen. Evidence that virus-specific CD4+ T cells were being stimulated was found as late as 6 to 8 months after infection, and cells specific for the viral gp15067–83 and ORF11168–180 peptides were maintained as a fairly stable proportion of the total response. PMID:11462049

  1. CD4+ T-cell epitope prediction using antigen processing constraints.

    PubMed

    Mettu, Ramgopal R; Charles, Tysheena; Landry, Samuel J

    2016-05-01

    T-cell CD4+ epitopes are important targets of immunity against infectious diseases and cancer. State-of-the-art methods for MHC class II epitope prediction rely on supervised learning methods in which an implicit or explicit model of sequence specificity is constructed using a training set of peptides with experimentally tested MHC class II binding affinity. In this paper we present a novel method for CD4+ T-cell eptitope prediction based on modeling antigen-processing constraints. Previous work indicates that dominant CD4+ T-cell epitopes tend to occur adjacent to sites of initial proteolytic cleavage. Given an antigen with known three-dimensional structure, our algorithm first aggregates four types of conformational stability data in order to construct a profile of stability that allows us to identify regions of the protein that are most accessible to proteolysis. Using this profile, we then construct a profile of epitope likelihood based on the pattern of transitions from unstable to stable regions. We validate our method using 35 datasets of experimentally measured CD4+ T cell responses of mice bearing I-Ab or HLA-DR4 alleles as well as of human subjects. Overall, our results show that antigen processing constraints provide a significant source of predictive power. For epitope prediction in single-allele systems, our approach can be combined with sequence-based methods, or used in instances where little or no training data is available. In multiple-allele systems, sequence-based methods can only be used if the allele distribution of a population is known. In contrast, our approach does not make use of MHC binding prediction, and is thus agnostic to MHC class II genotypes. PMID:26891811

  2. GITR ligand-costimulation activates effector and regulatory functions of CD4{sup +} T cells

    SciTech Connect

    Igarashi, Hanna; Cao, Yujia; Iwai, Hideyuki; Piao, Jinhua; Kamimura, Yosuke; Hashiguchi, Masaaki; Amagasa, Teruo; Azuma, Miyuki

    2008-05-16

    Engagement of glucocorticoid-induced TNFR-related protein (GITR) enables the costimulation of both CD25{sup -}CD4{sup +} effector (Teff) and CD25{sup +}CD4{sup +} regulatory (Treg) cells; however, the effects of GITR-costimulation on Treg function remain controversial. In this study, we examined the effects of GITR ligand (GITRL) binding on the respective functions of CD4{sup +} T cells. GITRL-P815 transfectants efficiently augmented anti-CD3-induced proliferation and cytokine production by Teff cells. Proliferation and IL-10 production in Treg were also enhanced by GITRL transfectants when exogenous IL-2 and stronger CD3 stimulation was provided. Concomitant GITRL-costimulation of Teff and Treg converted the anergic state of Treg into a proliferating state, maintaining and augmenting their function. Thus, GITRL-costimulation augments both effector and regulatory functions of CD4{sup +} T cells. Our results suggest that highly activated and increased ratios of Treg reverse the immune-enhancing effects of GITRL-costimulation in Teff, which may be problematic for therapeutic applications using strong GITR agonists.

  3. Mycobacterium tuberculosis-Specific IL-21+IFN-γ+CD4+ T Cells Are Regulated by IL-12

    PubMed Central

    Lao, Suihua; Yang, Binyan; Yu, Sifei; Zhang, Yannan; Wu, Changyou

    2016-01-01

    In the current study of Mycobacterium tuberculosis (MTB)-specific T and B cells, we found that MTB-specific peptides from early secreted antigenic target-6 (ESAT-6) and culture filtrate protein-10 (CFP-10) induced the expression of IL-21 predominantly in CD4+ T cells. A fraction of IL-21-expressing CD4+ T cells simultaneously expressed Th1 cytokines but did not secrete Th2 or Th17 cytokines, suggesting that MTB-specific IL-21-expressing CD4+ T cells were different from Th1, Th2 and Th17 subpopulations. The majority of MTB-specific IL-21-expressing CD4+ T cells co-expressed IFN-γ and IL-21+IFN-γ+CD4+ T cells exhibited obviously polyfunctionality. In addition, MTB-specific IL-21-expressing CD4+ T cells displayed a CD45RO+CD62LlowCCR7lowCD40LhighICOShigh phenotype. Bcl-6-expression was significantly higher in IL-21-expressing CD4+ T cells than IL-21-CD4+ T cells. Moreover, IL-12 could up-regulate MTB-specific IL-21 expression, especially the frequency of IL-21+IFN-γ+CD4+ T cells. Taken together, our results demonstrated that MTB-specific IL-21+IFN-γ+CD4+ T cells from local sites of tuberculosis (TB) infection could be enhanced by IL-12, which have the features of both Tfh and Th1 cells and may have an important role in local immune responses against TB infection. PMID:26785168

  4. The ion channel TRPV1 regulates the activation and proinflammatory properties of CD4T cells.

    PubMed

    Bertin, Samuel; Aoki-Nonaka, Yukari; de Jong, Petrus Rudolf; Nohara, Lilian L; Xu, Hongjian; Stanwood, Shawna R; Srikanth, Sonal; Lee, Jihyung; To, Keith; Abramson, Lior; Yu, Timothy; Han, Tiffany; Touma, Ranim; Li, Xiangli; González-Navajas, José M; Herdman, Scott; Corr, Maripat; Fu, Guo; Dong, Hui; Gwack, Yousang; Franco, Alessandra; Jefferies, Wilfred A; Raz, Eyal

    2014-11-01

    TRPV1 is a Ca(2+)-permeable channel studied mostly as a pain receptor in sensory neurons. However, its role in other cell types is poorly understood. Here we found that TRPV1 was functionally expressed in CD4(+) T cells, where it acted as a non-store-operated Ca(2+) channel and contributed to T cell antigen receptor (TCR)-induced Ca(2+) influx, TCR signaling and T cell activation. In models of T cell-mediated colitis, TRPV1 promoted colitogenic T cell responses and intestinal inflammation. Furthermore, genetic and pharmacological inhibition of TRPV1 in human CD4(+) T cells recapitulated the phenotype of mouse Trpv1(-/-) CD4(+) T cells. Our findings suggest that inhibition of TRPV1 could represent a new therapeutic strategy for restraining proinflammatory T cell responses. PMID:25282159

  5. Excess Lymphangiogenesis Cooperatively Induced by Macrophages and CD4(+) T Cells Drives the Pathogenesis of Lymphedema.

    PubMed

    Ogata, Fusa; Fujiu, Katsuhito; Matsumoto, Sahohime; Nakayama, Yukiteru; Shibata, Munehiko; Oike, Yuichi; Koshima, Isao; Watabe, Tetsuro; Nagai, Ryozo; Manabe, Ichiro

    2016-03-01

    Lymphedema is a debilitating progressive condition that severely restricts quality of life and is frequently observed after cancer surgery. The mechanism underlying lymphedema development remains poorly understood, and no effective pharmacological means to prevent or alleviate the ailment is currently available. Using a mouse model of lymphedema, we show here that excessive generation of immature lymphatic vessels is essential for initial edema development and that this early process is also important for later development of lymphedema pathology. We found that CD4(+) T cells interact with macrophages to promote lymphangiogenesis, and that both lymphangiogenesis and edema were greatly reduced in macrophage-depleted mice, lymphocyte-deficient Rag2(?/?) mice or CD4(+) T-cell-deficient mice. Mechanistically, T helper type 1 and T helper type 17 cells activate lesional macrophages to produce vascular endothelial growth factor-C, which promotes lymphangiogenesis, and inhibition of this mechanism suppressed not only early lymphangiogenesis, but also later development of lymphedema. Finally, we show that atorvastatin suppresses excessive lymphangiogenesis and lymphedema by inhibiting T helper type 1 and T helper type 17 cell activation. These results demonstrate that the interaction between CD4(+) T cells and macrophages is a potential therapeutic target for prevention of lymphedema after surgery. PMID:27015456

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

    PubMed

    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

  7. The DNA-binding inhibitor Id3 regulates IL-9 production in CD4(+) T cells.

    PubMed

    Nakatsukasa, Hiroko; Zhang, Dunfang; Maruyama, Takashi; Chen, Hua; Cui, Kairong; Ishikawa, Masaki; Deng, Lisa; Zanvit, Peter; Tu, Eric; Jin, Wenwen; Abbatiello, Brittany; Goldberg, Nathan; Chen, Qianming; Sun, Lingyun; Zhao, Keji; Chen, WanJun

    2015-10-01

    The molecular mechanisms by which signaling via transforming growth factor-β (TGF-β) and interleukin 4 (IL-4) control the differentiation of CD4(+) IL-9-producing helper T cells (TH9 cells) remain incompletely understood. We found here that the DNA-binding inhibitor Id3 regulated TH9 differentiation, as deletion of Id3 increased IL-9 production from CD4(+) T cells. Mechanistically, TGF-β1 and IL-4 downregulated Id3 expression, and this process required the kinase TAK1. A reduction in Id3 expression enhanced binding of the transcription factors E2A and GATA-3 to the Il9 promoter region, which promoted Il9 transcription. Notably, Id3-mediated control of TH9 differentiation regulated anti-tumor immunity in an experimental melanoma-bearing model in vivo and also in human CD4(+) T cells in vitro. Thus, our study reveals a previously unrecognized TAK1-Id3-E2A-GATA-3 pathway that regulates TH9 differentiation. PMID:26322481

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

    PubMed Central

    Shakya, Arvind; Goren, Alon; Shalek, Alex; German, Cody N.; Snook, Jeremy; Kuchroo, Vijay K.; Yosef, Nir; Chan, Raymond C.; Regev, Aviv

    2015-01-01

    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

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

    PubMed

    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

  10. Transient CD4+ T Cell Depletion Results in Delayed Development of Functional Vaccine-Elicited Antibody Responses

    PubMed Central

    Provine, Nicholas M.; Badamchi-Zadeh, Alexander; Bricault, Christine A.; Penaloza-MacMaster, Pablo; Larocca, Rafael A.; Borducchi, Erica N.; Seaman, Michael S.

    2016-01-01

    ABSTRACT We have recently demonstrated that CD4+ T cell help is required at the time of adenovirus (Ad) vector immunization for the development of functional CD8+ T cell responses, but the temporal requirement for CD4+ T cell help for the induction of antibody responses remains unclear. Here we demonstrate that induction of antibody responses in C57BL/6 mice can occur at a time displaced from the time of Ad vector immunization by depletion of CD4+ T cells. Transient depletion of CD4+ T cells at the time of immunization delays the development of antigen-specific antibody responses but does not permanently impair their development or induce tolerance against the transgene. Upon CD4+ T cell recovery, transgene-specific serum IgG antibody titers develop and reach a concentration equivalent to that in undepleted control animals. These delayed antibody responses exhibit no functional defects with regard to isotype, functional avidity, expansion after boosting immunization, or the capacity to neutralize a simian immunodeficiency virus (SIV) Env-expressing pseudovirus. The development of this delayed transgene-specific antibody response is temporally linked to the expansion of de novo antigen-specific CD4+ T cell responses, which develop after transient depletion of CD4+ T cells. These data demonstrate that functional vaccine-elicited antibody responses can be induced even if CD4+ T cell help is provided at a time markedly separated from the time of vaccination. IMPORTANCE CD4+ T cells have a critical role in providing positive help signals to B cells, which promote robust antibody responses. The paradigm is that helper signals must be provided immediately upon antigen exposure, and their absence results in tolerance against the antigen. Here we demonstrate that, in contrast to the current model that the absence of CD4+ T cell help at priming results in long-term antibody nonresponsiveness, antibody responses can be induced by adenovirus vector immunization or alum

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

    PubMed Central

    Rinaldo, Charles R.

    2013-01-01

    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. PMID:24278768

  12. Human CD4+ T cells require exogenous cystine for glutathione and DNA synthesis

    PubMed Central

    Levring, Trine B.; Kongsbak, Martin; Rode, Anna K. O.; Woetmann, Anders; Ødum, Niels; Bonefeld, Charlotte Menné; Geisler, Carsten

    2015-01-01

    Adaptive immune responses require activation and expansion of antigen-specific T cells. Whereas early T cell activation is independent of exogenous cystine (Cys2), T cell proliferation is dependent of Cys2. However, the exact roles of Cys2 in T cell proliferation still need to be determined. The aim of this study was to elucidate why activated human T cells require exogenous Cys2 in order to proliferate. We activated purified naïve human CD4+ T cells and found that glutathione (GSH) levels and DNA synthesis were dependent on Cys2 and increased in parallel with increasing concentrations of Cys2. Vice-versa, the GSH synthesis inhibitor L-buthionine-sulfoximine (BSO) and inhibition of Cys2 uptake with glutamate inhibited GSH and DNA synthesis in parallel. We further found that thioredoxin (Trx) can partly substitute for GSH during DNA synthesis. Finally, we show that GSH or Trx is required for the activity of ribonucleotide reductase (RNR), the enzyme responsible for generation of the deoxyribonucleotide DNA building blocks. In conclusion, we show that activated human T cells require exogenous Cys2 to proliferate and that this is partly explained by the fact that Cys2 is required for production of GSH, which in turn is required for optimal RNR-mediated deoxyribonucleotide synthesis and DNA replication. PMID:26392411

  13. Human T-cell lymphotropic virus type 1 Tax mediates enhanced transcription in CD4+ T lymphocytes.

    PubMed Central

    Newbound, G C; Andrews, J M; O'Rourke, J P; Brady, J N; Lairmore, M D

    1996-01-01

    Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia/lymphoma and is associated with a variety of immunoregulatory disorders. HTLV-1 has been shown to bind to and infect a variety of hematopoietic and nonhematopoietic cells. However, both in vivo and in vitro, the provirus is mostly detected in and preferentially transforms CD4+ T cells. The molecular mechanism that determines the CD4+ T-cell tropism of HTLV-1 has not been determined. Using cocultures of purified CD4+ and CD8+ T cells with an HTLV-1 producing cell line, we measured viral transcription by using Northern (RNA) blot analysis, protein production by using a p24 antigen capture assay and flow cytometric analysis for viral envelope, and proviral integration by using DNA slot blot analysis. We further measured HTLV-1 long terminal repeat-directed transcription in purified CD4+ and CD8+ T cells by using transient transfection assays and in vitro transcription. We demonstrate a higher rate of viral transcription in primary CD4+ T cells than in CD8+ T cells. HTLV-1 protein production was 5- to 25-fold greater in CD4+ cocultures and mRNA levels were 5-fold greater in these cultures than in the CD8+ cocultures. Transient transfection and in vitro transcription indicated a modest increase in basal transcription in CD4+ T cells, whereas there was a 20-fold increase in reporter gene activity in CD4+ T cells cotransfected with tax. These data suggest that unique or activated transcription factors, particularly Tax-responsive factors in CD4+ T cells, recognize regulatory sequences within the HTLV-1 long terminal repeat, and this mediates the observed enhanced viral transcription and ultimately the cell tropism and leukemogenic potential of the virus. PMID:8642630

  14. MHCII-independent CD4+ T cells protect injured CNS neurons via IL-4

    PubMed Central

    Walsh, James T.; Hendrix, Sven; Boato, Francesco; Smirnov, Igor; Zheng, Jingjing; Lukens, John R.; Gadani, Sachin; Hechler, Daniel; Gölz, Greta; Rosenberger, Karen; Kammertöns, Thomas; Vogt, Johannes; Vogelaar, Christina; Siffrin, Volker; Radjavi, Ali; Fernandez-Castaneda, Anthony; Gaultier, Alban; Gold, Ralf; Kanneganti, Thirumala-Devi; Nitsch, Robert; Zipp, Frauke; Kipnis, Jonathan

    2015-01-01

    A body of experimental evidence suggests that T cells mediate neuroprotection following CNS injury; however, the antigen specificity of these T cells and how they mediate neuroprotection are unknown. Here, we have provided evidence that T cell–mediated neuroprotection after CNS injury can occur independently of major histocompatibility class II (MHCII) signaling to T cell receptors (TCRs). Using two murine models of CNS injury, we determined that damage-associated molecular mediators that originate from injured CNS tissue induce a population of neuroprotective, IL-4–producing T cells in an antigen-independent fashion. Compared with wild-type mice, IL-4–deficient animals had decreased functional recovery following CNS injury; however, transfer of CD4+ T cells from wild-type mice, but not from IL-4–deficient mice, enhanced neuronal survival. Using a culture-based system, we determined that T cell–derived IL-4 protects and induces recovery of injured neurons by activation of neuronal IL-4 receptors, which potentiated neurotrophin signaling via the AKT and MAPK pathways. Together, these findings demonstrate that damage-associated molecules from the injured CNS induce a neuroprotective T cell response that is independent of MHCII/TCR interactions and is MyD88 dependent. Moreover, our results indicate that IL-4 mediates neuroprotection and recovery of the injured CNS and suggest that strategies to enhance IL-4–producing CD4+ T cells have potential to attenuate axonal damage in the course of CNS injury in trauma, inflammation, or neurodegeneration. PMID:25607842

  15. Helenalin suppresses essential immune functions of activated CD4+ T cells by multiple mechanisms.

    PubMed

    Berges, Carsten; Fuchs, Dominik; Opelz, Gerhard; Daniel, Volker; Naujokat, Cord

    2009-09-01

    Helenalin is a naturally occuring sesquiterpene lactone extracted from Arnica montana and Arnica chamissonis ssp. foliosa. Helenalin and its derivatives are known for anti-cancer and anti-inflammatory effects via inhibiting NF-kappaB and telomerase activity and impairing protein and DNA synthesis, suggesting that helenalin is a potential candidate for the treatment of deregulated and unwanted T cell-mediated immune responses. Here we show that helenalin induces apoptosis in activated CD4+ T cells by triggering the mitochondrial pathway of apoptosis. Induction of apoptosis is accompanied by rapid stabilization of p53, nuclear localization of p53 and AIF, and an increase in ROS production that results in loss of mitochondrial membrane potential (DeltaPsim). Activated CD4+ T cells which survive exposure to helenalin undergo inhibition of proliferation by induction of G2/M cell cycle arrest. Cell cycle arrest is accompanied by the accumulation of cell cycle regulator proteins p21(WAF/CIP1), p2(KIP1) and cyclin D2, whereas abundance of cyclin A and B(1) is decreased. Cell surface expression of the activation-associated receptors CD25, CD27, CD28, CD120b as well as production of IL-2 are impaired. Transcriptional activation of genes encoding for CD25, IL-2 and IFN-gamma is mediated by transcription factors of the NFAT family, and we demonstrate that helenalin suppresses nuclear translocation of NFATc2 in activated CD4+ T cells. Thus, helenalin can be defined as a new immunosuppressive compound suited for the treatment of deregulated and unwanted T cell-mediated immune responses. PMID:19656571

  16. Rv2468c, a novel Mycobacterium tuberculosis protein that costimulates human CD4+ T cells through VLA-5

    PubMed Central

    Li, Qing; Ding, Xuedong; Thomas, Jeremy J.; Harding, Clifford V.; Pecora, Nicole D.; Ziady, Assem G.; Shank, Samuel; Boom, W. Henry; Lancioni, Christina L.; Rojas, Roxana E.

    2012-01-01

    Mtb regulates many aspects of the host immune response, including CD4+ T lymphocyte responses that are essential for protective immunity to Mtb, and Mtb effects on the immune system are paradoxical, having the capacity to inhibit (immune evasion) and to activate (adjuvant effect) immune cells. Mtb regulates CD4+ T cells indirectly (e.g., by manipulation of APC function) and directly, via integrins and TLRs expressed on T cells. We now report that previously uncharacterized Mtb protein Rv2468c/MT2543 can directly regulate human CD4+ T cell activation by delivering costimulatory signals. When combined with TCR stimulation (e.g., anti-CD3), Rv2468c functioned as a direct costimulator for CD4+ T cells, inducing IFN-γ secretion and T cell proliferation. Studies with blocking antibodies and soluble RGD motifs demonstrated that Rv2468c engaged integrin VLA-5 (α5β1) on CD4+ T cells through its FN-like RGD motif. Costimulation by Rv2468c induced phosphorylation of FAKs and Pyk2. These results reveal that by expressing molecules that mimic host protein motifs, Mtb can directly engage receptors on CD4+ T cells and regulate their function. Rv2468c-induced costimulation of CD4+ T cells could have implications for TB immune pathogenesis and Mtb adjuvant effect. PMID:22158781

  17. Critical role of CD4 T cells in maintaining lymphoid tissue structure for immune cell homeostasis and reconstitution

    PubMed Central

    Zeng, Ming; Paiardini, Mirko; Engram, Jessica C.; Beilman, Greg J.; Chipman, Jeffrey G.; Schacker, Timothy W.; Silvestri, Guido

    2012-01-01

    Loss of the fibroblastic reticular cell (FRC) network in lymphoid tissues during HIV-1 infection has been shown to impair the survival of naive T cells and limit immune reconstitution after antiretroviral therapy. What causes this FRC loss is unknown. Because FRC loss correlates with loss of both naive CD4 and CD8 T-cell subsets and decreased lymphotoxin-β, a key factor for maintenance of FRC network, we hypothesized that loss of naive T cells is responsible for loss of the FRC network. To test this hypothesis, we assessed the consequences of antibody-mediated depletion of CD4 and CD8 T cells in rhesus macaques and sooty mangabeys. We found that only CD4 T-cell depletion resulted in FRC loss in both species and that this loss was caused by decreased lymphotoxin-β mainly produced by the CD4 T cells. We further found the same dependence of the FRC network on CD4 T cells in HIV-1–infected patients before and after antiretroviral therapy and in other immunodeficiency conditions, such as CD4 depletion in cancer patients induced by chemotherapy and irradiation. CD4 T cells thus play a central role in the maintenance of lymphoid tissue structure necessary for their own homeostasis and reconstitution. PMID:22613799

  18. Human bone marrow as a source to generate CMV-specific CD4+ T cells with multifunctional capacity.

    PubMed

    Na, Il-Kang; Letsch, Anne; Guerreiro, Manuel; Bauer, Sandra; Noack, Ines; Geginat, Jens; Reinke, Petra; Loesch, Michael; Kienapfel, Heino; Thiel, Eckhard; Volk, Hans Dieter; Scheibenbogen, Carmen

    2009-01-01

    The bone marrow (BM) is an important compartment for T cell memory. In cytomegalovirus (CMV)-seropositive individuals peripheral blood (PB) CMV-specific T cells constitute a large fraction of PB T cells but are mostly differentiated effector/effector memory T cells with limited survival and proliferative potential. In this study, we performed a comprehensive analysis of the CMV-specific T cell response in BM studying both CD4+ and CD8+ T cell responses against overlapping peptide pools of the CMV proteins pp65 and immediate early protein-1. CMV-specific T cell responses were characterized ex vivo and after in vitro expansion of paired PB/BM samples by multiparameter flow cytometry determining surface phenotype, cytokine profile, and cytotoxic capability. Comparable frequencies of CMV-specific T cells were found in un-manipulated PB and BM. Both total CD4+ and CD8+ T cells could be more rapidly expanded from BM. Expanded BM T cells contained significantly higher frequencies of CMV-specific CD4+ T cells than PB. Furthermore, higher frequencies of specific CD4+ T cells from BM were multifunctional, characterized by simultaneous production of interferon-gamma, tumor necrosis factor, and interleukin-2. Use of BM may thus facilitate more rapid generation of adoptive T cells with enhanced functionality. PMID:19816191

  19. The Early Activation Marker CD69 Regulates the Expression of Chemokines and CD4 T Cell Accumulation in Intestine

    PubMed Central

    Radulovic, Katarina; Rossini, Valerio; Manta, Calin; Holzmann, Karlheinz; Kestler, Hans A.; Niess, Jan Hendrik

    2013-01-01

    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−/− CD45RBhigh 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. PMID:23776480

  20. Vγ9Vδ2 T-Cell Polyfunctionality Is Differently Modulated in HAART-Treated HIV Patients according to CD4 T-Cell Count

    PubMed Central

    Casetti, Rita; De Simone, Gabriele; Sacchi, Alessandra; Rinaldi, Alessandra; Viola, Domenico; Agrati, Chiara; Bordoni, Veronica; Cimini, Eleonora; Tumino, Nicola; Besi, Francesca; Martini, Federico

    2015-01-01

    Alteration of γδ T-cell distribution and function in peripheral blood is among the earliest defects during HIV-infection. We asked whether the polyfunctional response could also be affected, and how this impairment could be associated to CD4 T-cell count. To this aim, we performed a cross-sectional study on HIV-infected individuals. In order to evaluate the polyfunctional-Vγ9Vδ2 T-cell response after phosphoantigen-stimulation, we assessed the cytokine/chemokine production and cytotoxicity by flow-cytometry in HAART-treated-HIV+ persons and healthy-donors. During HIV-infection Vγ9Vδ2-polyfunctional response quality is affected, since several Vγ9Vδ2 T-cell subsets resulted significantly lower in HIV+ patients in respect to healthy donors. Interestingly, we found a weak positive correlation between Vγ9Vδ2 T-cell-response and CD4 T-cell counts. By dividing the HIV+ patients according to CD4 T-cell count, we found that Low-CD4 patients expressed a lower number of two Vγ9Vδ2 T-cell subsets expressing MIP-1β in different combinations with other molecules (CD107a/IFNγ) in respect to High-CD4 individuals. Our results show that the Vγ9Vδ2 T-cell-response quality in Low-CD4 patients is specifically affected, suggesting a direct link between innate Vγ9Vδ2 T-cells and CD4 T-cell count. These findings suggest that Vγ9Vδ2 T-cell quality may be indirectly influenced by HAART therapy and could be included in a new therapeutical strategy which would perform an important role in fighting HIV infection. PMID:26161861

  1. Melanoma-specific CD4+ T cells recognize nonmutated HLA-DR-restricted tyrosinase epitopes.

    PubMed

    Topalian, S L; Gonzales, M I; Parkhurst, M; Li, Y F; Southwood, S; Sette, A; Rosenberg, S A; Robbins, P F

    1996-05-01

    Tyrosinase was the first melanoma-associated antigen shown to be recognized by CD4+ T cells. In this study, we have identified two HLA-DRB1*0401-restricted peptides recognized by these T cells: Ty 56-70 and Ty 448-462. As with many of the MHC class I-restricted melanoma epitopes, both are nonmutated self peptides that have intermediate and weak MHC binding affinities, respectively. Mutated and truncated versions of these peptides were used to define their MHC binding anchor residues. Anchor residues were then modified to derive peptides with increased MHC binding affinities and T cell stimulatory properties. Ty 56-70 and Ty 448-462 enhance the list of immunogenic HLA-A2-, A24-, and B44-restricted tyrosinase peptides already described. Thus, tyrosinase provides a model for anti-melanoma vaccines in which a single molecule can generate multivalent immunization incorporating both CD4+ and CD8+ T cell responses. PMID:8642306

  2. Human CD4+CD39+ regulatory T cells produce adenosine upon co-expression of surface CD73 or contact with CD73+ exosomes or CD73+ cells

    PubMed Central

    Schuler, P J; Saze, Z; Hong, C-S; Muller, L; Gillespie, D G; Cheng, D; Harasymczuk, M; Mandapathil, M; Lang, S; Jackson, E K; Whiteside, T L

    2014-01-01

    While murine CD4+CD39+ regulatory T cells (Treg) co-express CD73 and hydrolyze exogenous (e) adenosine triphosphate (ATP) to immunosuppressive adenosine (ADO), surface co-expression of CD73 on human circulating CD4+CD39+ Treg is rare. Therefore, the ability of human Treg to produce and utilize ADO for suppression remains unclear. Using mass spectrometry, we measured nucleoside production by subsets of human CD4+CD39+ and CD4+CD39(–)CD73+ T cells or CD19+ B cells isolated from blood of 30 volunteers and 14 cancer patients. CD39 and CD73 expression was evaluated by flow cytometry, Western blots, confocal microscopy or reverse transcription–polymerase chain reaction (RT–PCR). Circulating CD4+CD39+ Treg which hydrolyzed eATP to 5′-AMP contained few intracytoplasmic granules and had low CD73 mRNA levels. Only ∼1% of these Treg were CD39+CD73+. In contrast, CD4+CD39negCD73+ T cells contained numerous CD73+ granules in the cytoplasm and strongly expressed surface CD73. In vitro-generated Treg (Tr1) and most B cells were CD39+CD73+. All these CD73+ T cell subsets and B cells hydrolyzed 5′-AMP to ADO. Exosomes isolated from plasma of normal control (NC) or cancer patients carried enzymatically active CD39 and CD73+ and, when supplied with eATP, hydrolyzed it to ADO. Only CD4+CD39+ Treg co-incubated with CD4+CD73+ T cells, B cells or CD39+CD73+ exosomes produced ADO. Thus, contact with membrane-tethered CD73 was sufficient for ADO production by CD4+CD39+ Treg. In microenvironments containing CD4+CD73+ T cells, B cells or CD39+CD73+ exosomes, CD73 is readily available to CD4+CD39+CD73neg Treg for the production of immunosuppressive ADO. PMID:24749746

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

    PubMed Central

    Noyan, Kajsa; Nowak, Piotr; Sönnerborg, Anders; Lund, Ole; Karlsson, Annika C.

    2015-01-01

    HIV infection provokes a myriad of pathological effects on the immune system where many markers of CD4+ T cell dysfunction have been identified. However, most studies to date have focused on single/double measurements of immune dysfunction, while the identification of pathological CD4+ T cell clusters that is highly associated to a specific biomarker for HIV disease remain less studied. Here, multi-parametric flow cytometry was used to investigate immune activation, exhaustion, and senescence of diverse maturation phenotypes of CD4+ T cells. The traditional method of manual data analysis was compared to a multidimensional clustering tool, FLOw Clustering with K (FLOCK) in two cohorts of 47 untreated HIV-infected individuals and 21 age and sex matched healthy controls. In order to reduce the subjectivity of FLOCK, we developed an “artificial reference”, using 2% of all CD4+ gated T cells from each of the HIV-infected individuals. Principle component analyses demonstrated that using an artificial reference lead to a better separation of the HIV-infected individuals from the healthy controls as compared to using a single HIV-infected subject as a reference or analyzing data manually. Multiple 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 expression were best correlated (Rho = -0.80, P value = 1.96×10−11) with HIV disease progression as measured by the CD4/CD8 ratio. The novel approach described here can be used to identify cell clusters that distinguish healthy from HIV infected subjects and is biologically relevant for HIV disease progression. These results further emphasize that a simple measurement of the CD4/CD8 ratio is a useful biomarker for assessment of combined CD4+ T cell dysfunction in chronic HIV

  4. Fetal exposure to HIV-1 alters chemokine receptor expression by CD4+T cells and increases susceptibility to HIV-1.

    PubMed

    Bunders, Madeleine J; van Hamme, John L; Jansen, Machiel H; Boer, Kees; Kootstra, Neeltje A; Kuijpers, Taco W

    2014-01-01

    Absolute numbers of lymphocytes are decreased in uninfected infants born to HIV-1-infected women (HIV-1-exposed). Although the exact mechanism is unknown, fetal exposure to maternal HIV-1-infection could prime the immune system and affect T cell trafficking. We compared the expression of chemokine receptors on cord blood CD4(+) T cells from HIV-1-exposed children and healthy controls. At baseline CD4(+) T cells had a largely naïve phenotype. However, stimulation with cytokines resulted in an upregulation of inflammatory response-related chemokine receptors on CD4(+) T cells, with HIV-1-exposed infants having a significantly higher frequency of CD4(+) T cells expressing, in particularly Th2 associated chemokine receptors (CCR3 p < 0.01, CCR8 p = 0.03). Numbers of naive CCR7(+) CD4(+) T cells were reduced (p = 0.01) in HIV-1-exposed infants. We further assessed whether the inflammatory phenotype was associated with susceptibility to HIV-1 and detected higher levels of p24 upon in in vitro infection of stimulated CD4(+) T cells of HIV-1-exposed infants. In summary, fetal exposure to HIV-1 primes the immune system in the infant leading to an enhanced immune activation and altered T cell homing, with potential ramifications regarding T cell responses and the acquisition of HIV-1 as an infant. PMID:25341640

  5. CD4(+)B220(+)TCRγδ(+) T cells produce IL-17 in lupus-prone MRL/lpr mice.

    PubMed

    Qiu, Feng; Li, Tingting; Zhang, Kui; Wan, Jun; Qi, Xiaokun

    2016-09-01

    Systemic lupus erythematosus is an autoimmune disease with comprehensive immune cell disorders. Recent studies suggested that pro-inflammatory cytokine IL-17 plays important role in lupus, leaving the cellular sources and their pathogenic and physiologic characters largely unknown. In the current study, by using lupus-prone MRL/lpr mice, we demonstrated that Th17 response prevails in lupus disease regarding significantly accumulated serum IL-17, increased IL-17-producing splenocytes, and elevated phospho-STAT3 in CD4(+) T cells. Intracellular staining revealed that unusual CD4(+)B220(+) T cells are major IL-17-producing cells, whereas conventional CD4(+)B220(-) T cells are major IFN-γ-producing cells. Subsequent studies showed that CD4(+)B220(+) cells contains both αβ and γδ T cells in the spleen and thymus of MRL/lpr mice. Further study showed that around 60% of γδ T cells in MRL/lpr mice co-express both B220 and CD4 on their surface, and are the major RORγt(+) cells in MRL/lpr mice. Finally, CD4(+)B220(+) T cells alone do not proliferate, but could enhance the proliferation and IFN-γ-production of conventional CD4(+)B220(-) T cells. Our findings suggest the pathogenic role of unusual CD4(+)B220(+) T cells in lupus disease in MRL/lpr mice according to their IL-17-producing ability and stimulatory function for conventional CD4(+)B220(-) T cells. PMID:27235595

  6. A protective role for human IL-10-expressing CD4+ T cells in colitis

    PubMed Central

    Ranatunga, Dilini C.; Ramakrishnan, Amritha; Uprety, Priyanka; Wang, Fengying; Zhang, Hao; Margolick, Joseph B.; Brayton, Cory; Bream, Jay H.

    2012-01-01

    IL-10 is an immunoregulatory cytokine expressed by numerous cell-types. Studies in mice confirm that different IL-10-expressing cell subsets contribute differentially to disease phenotypes. However, little is known about the relationship between cell- or tissue-specific IL-10 expression and disease susceptibility in humans. Here, we utilized the previously described hIL10BAC transgenic model to examine the role of human IL-10 (hIL-10) in maintaining intestinal homeostasis. Genomically-controlled hIL-10 expression rescued Il10−/− mice from Helicobacter-induced colitis and was associated with control of pro-inflammatory cytokine expression and TH17 cell accumulation in gut tissues. Resistance to colitis was associated with an accumulation of hIL-10-expressing CD4+Foxp3+ T regulatory cells specifically within the lamina propria but not other secondary lymphoid tissues. Co-transfer of CD4+CD45RBlo cells from Il10−/−/hIL10BAC mice rescued Rag1−/− mice from colitis further suggesting that CD4+ T cells represent a protective source of hIL-10 in the colon. In concordance with an enhanced capacity to express IL-10, CD4+CD44+ T cells isolated from the lamina propria exhibited lower levels of the repressive histone mark H3K27Me3 and higher levels of the permissive histone mark AcH3 in both the human and mouse IL10 locus compared to the spleen. These results provide experimental evidence verifying the importance of T cell-derived human IL-10 expression in controlling inflammation within the colonic mucosa. We also provide molecular evidence suggesting the tissue microenvironment influences IL-10 expression patterns and chromatin structure in the human (and mouse) IL10 locus. PMID:22753934

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

    PubMed

    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

  8. Characteristics of differentiated CD8(+) and CD4 (+) T cells present in the human brain.

    PubMed

    Smolders, Joost; Remmerswaal, Ester B M; Schuurman, Karianne G; Melief, Jeroen; van Eden, Corbert G; van Lier, René A W; Huitinga, Inge; Hamann, Jörg

    2013-10-01

    Immune surveillance of the central nervous system (CNS) by T cells is important to keep CNS-trophic viruses in a latent state, yet our knowledge of the characteristics of CNS-populating T cells is incomplete. We performed a comprehensive, multi-color flow-cytometric analysis of isolated T cells from paired corpus callosum (CC) and peripheral blood (PB) samples of 20 brain donors. Compared to PB, CC T cells, which were mostly located in the perivascular space and sporadically in the parenchyma, were enriched for cells expressing CD8. Both CD4(+) and CD8(+) T cells in the CC had a late-differentiated phenotype, as indicated by lack of expression of CD27 and CD28. The CC contained high numbers of T cells expressing chemokine receptor CX3CR1 and CXCR3 that allow for homing to inflamed endothelium and tissue, but hardly cells expressing the lymph node-homing receptor CCR7. Despite the late-differentiated phenotype, CC T cells had high expression of the IL-7 receptor α-chain CD127 and did not contain the neurotoxic cytolytic enzymes perforin, granzyme A, and granzyme B. We postulate that CNS T cells make up a population of tissue-adapted differentiated cells, which use CX3CR1 and CXCR3 to home into the perivascular space, use IL-7 for maintenance, and lack immediate cytolytic activity, thereby preventing immunopathology in response to low or non-specific stimuli. The presence of these cells in this tightly regulated environment likely enables a fast response to local threats. Our results will enable future detailed exploration of T-cell subsets in the brain involved in neurological diseases. PMID:23880787

  9. Tolerance is established in polyclonal CD4(+) T cells by distinct mechanisms, according to self-peptide expression patterns.

    PubMed

    Malhotra, Deepali; Linehan, Jonathan L; Dileepan, Thamotharampillai; Lee, You Jeong; Purtha, Whitney E; Lu, Jennifer V; Nelson, Ryan W; Fife, Brian T; Orr, Harry T; Anderson, Mark S; Hogquist, Kristin A; Jenkins, Marc K

    2016-02-01

    Studies of repertoires of mouse monoclonal CD4(+) T cells have revealed several mechanisms of self-tolerance; however, which mechanisms operate in normal repertoires is unclear. Here we studied polyclonal CD4(+) T cells specific for green fluorescent protein expressed in various organs, which allowed us to determine the effects of specific expression patterns on the same epitope-specific T cells. Peptides presented uniformly by thymic antigen-presenting cells were tolerated by clonal deletion, whereas peptides excluded from the thymus were ignored. Peptides with limited thymic expression induced partial clonal deletion and impaired effector T cell potential but enhanced regulatory T cell potential. These mechanisms were also active for T cell populations specific for endogenously expressed self antigens. Thus, the immunotolerance of polyclonal CD4(+) T cells was maintained by distinct mechanisms, according to self-peptide expression patterns. PMID:26726812

  10. Vitamin D Actions on CD4+ T Cells in Autoimmune Disease

    PubMed Central

    Hayes, Colleen Elizabeth; Hubler, Shane L.; Moore, Jerott R.; Barta, Lauren E.; Praska, Corinne E.; Nashold, Faye E.

    2015-01-01

    This review summarizes and integrates research on vitamin D and CD4+ T-lymphocyte biology to develop new mechanistic insights into the molecular etiology of autoimmune disease. A deep understanding of molecular mechanisms relevant to gene–environment interactions is needed to deliver etiology-based autoimmune disease prevention and treatment strategies. Evidence linking sunlight, vitamin D, and the risk of multiple sclerosis and type 1 diabetes is summarized to develop the thesis that vitamin D is the environmental factor that most strongly influences autoimmune disease development. Evidence for CD4+ T-cell involvement in autoimmune disease pathogenesis and for paracrine calcitriol signaling to CD4+ T lymphocytes is summarized to support the thesis that calcitriol is sunlight’s main protective signal transducer in autoimmune disease risk. Animal modeling and human mechanistic data are summarized to support the view that vitamin D probably influences thymic negative selection, effector Th1 and Th17 pathogenesis and responsiveness to extrinsic cell death signals, FoxP3+CD4+ T-regulatory cell and CD4+ T-regulatory cell type 1 (Tr1) cell functions, and a Th1–Tr1 switch. The proposed Th1–Tr1 switch appears to bridge two stable, self-reinforcing immune states, pro- and anti-inflammatory, each with a characteristic gene regulatory network. The bi-stable switch would enable T cells to integrate signals from pathogens, hormones, cell–cell interactions, and soluble mediators and respond in a biologically appropriate manner. Finally, unanswered questions and potentially informative future research directions are highlighted to speed delivery of etiology-based strategies to reduce autoimmune disease. PMID:25852682

  11. Vitamin D Actions on CD4(+) T Cells in Autoimmune Disease.

    PubMed

    Hayes, Colleen Elizabeth; Hubler, Shane L; Moore, Jerott R; Barta, Lauren E; Praska, Corinne E; Nashold, Faye E

    2015-01-01

    This review summarizes and integrates research on vitamin D and CD4(+) T-lymphocyte biology to develop new mechanistic insights into the molecular etiology of autoimmune disease. A deep understanding of molecular mechanisms relevant to gene-environment interactions is needed to deliver etiology-based autoimmune disease prevention and treatment strategies. Evidence linking sunlight, vitamin D, and the risk of multiple sclerosis and type 1 diabetes is summarized to develop the thesis that vitamin D is the environmental factor that most strongly influences autoimmune disease development. Evidence for CD4(+) T-cell involvement in autoimmune disease pathogenesis and for paracrine calcitriol signaling to CD4(+) T lymphocytes is summarized to support the thesis that calcitriol is sunlight's main protective signal transducer in autoimmune disease risk. Animal modeling and human mechanistic data are summarized to support the view that vitamin D probably influences thymic negative selection, effector Th1 and Th17 pathogenesis and responsiveness to extrinsic cell death signals, FoxP3(+)CD4(+) T-regulatory cell and CD4(+) T-regulatory cell type 1 (Tr1) cell functions, and a Th1-Tr1 switch. The proposed Th1-Tr1 switch appears to bridge two stable, self-reinforcing immune states, pro- and anti-inflammatory, each with a characteristic gene regulatory network. The bi-stable switch would enable T cells to integrate signals from pathogens, hormones, cell-cell interactions, and soluble mediators and respond in a biologically appropriate manner. Finally, unanswered questions and potentially informative future research directions are highlighted to speed delivery of etiology-based strategies to reduce autoimmune disease. PMID:25852682

  12. CD4 on CD8+ T cells directly enhances effector function and is a target for HIV infection

    NASA Astrophysics Data System (ADS)

    Kitchen, Scott G.; Jones, Nicole R.; Laforge, Stuart; Whitmire, Jason K.; Vu, Bien-Aimee; Galic, Zoran; Brooks, David G.; Brown, Stephen J.; Kitchen, Christina M. R.; Zack, Jerome A.

    2004-06-01

    Costimulation of purified CD8+ T lymphocytes induces de novo expression of CD4, suggesting a previously unrecognized function for this molecule in the immune response. Here, we report that the CD4 molecule plays a direct role in CD8+ T cell function by modulating expression of IFN- and Fas ligand, two important CD8+ T cell effector molecules. CD4 expression also allows infection of CD8 cells by HIV, which results in down-regulation of the CD4 molecule and impairs the induction of IFN-, Fas ligand, and the cytotoxic responses of activated CD8+ T cells. Thus, the CD4 molecule plays a direct role in CD8 T cell function, and infection of these cells by HIV provides an additional reservoir for the virus and also may contribute to the immunodeficiency seen in HIV disease.

  13. Accelerated type 1 diabetes induction in mice by adoptive transfer of diabetogenic CD4+ T cells.

    PubMed

    Berry, Gregory; Waldner, Hanspeter

    2013-01-01

    The nonobese diabetic (NOD) mouse spontaneously develops autoimmune diabetes after 12 weeks of age and is the most extensively studied animal model of human Type 1 diabetes (T1D). Cell transfer studies in irradiated recipient mice have established that T cells are pivotal in T1D pathogenesis in this model. We describe herein a simple method to rapidly induce T1D by adoptive transfer of purified, primary CD4+ T cells from pre-diabetic NOD mice transgenic for the islet-specific T cell receptor (TCR) BDC2.5 into NOD.SCID recipient mice. The major advantages of this technique are that isolation and adoptive transfer of diabetogenic T cells can be completed within the same day, irradiation of the recipients is not required, and a high incidence of T1D is elicited within 2 weeks after T cell transfer. Thus, studies of pathogenesis and therapeutic interventions in T1D can proceed at a faster rate than with methods that rely on heterogenous T cell populations or clones derived from diabetic NOD mice. PMID:23685789

  14. Specific CD4+ T-Cell Reactivity and Cytokine Release in Different Clinical Presentations of Leptospirosis.

    PubMed

    Volz, Magdalena Sarah; Moos, Verena; Allers, Kristina; Luge, Enno; Mayer-Scholl, Anne; Nöckler, Karsten; Loddenkemper, Christoph; Jansen, Andreas; Schneider, Thomas

    2015-12-01

    Clinical manifestations of leptospirosis are highly variable: from asymptomatic to severe and potentially fatal. The outcome of the disease is usually determined in the immunological phase, beginning in the second week of symptoms. The underlying mechanisms, predictive factors, and individual immune responses that contribute to clinical variations are not well understood. The aim of this study was to determine the specifics of CD4(+) T-cell reactivity and cytokine release after stimulation with leptospiral antigens in patients with leptospirosis of different disease severities (patients with mild and severe symptoms) and in control subjects (with and without proven exposure to Leptospira). Whole-blood specimens were stimulated with Leptospira antigens in vitro. Subsequently, intracellular staining of cytokines was performed, and flow cytometry was used to assess the expression of CD40 ligand (CD40L) and the production of gamma interferon (IFN-γ), interleukin-10 (IL-10), IL-2, and tumor necrosis factor alpha (TNF-α) by CD4(+) T cells. The production of inflammatory cytokines such as TNF-α by CD4(+) T cells after stimulation with leptospiral antigens was highest in patients with severe disease. In contrast, the ratio of IL-10 production to TNF-α production was higher in exposed subjects than in patients with mild and severe disease. Levels of proinflammatory cytokines such as TNF-α may be useful markers of the severity of the immunological phase of leptospirosis. IL-10 production by T cells after antigen-specific stimulation may indicate a more successful downregulation of the inflammatory response and may contribute to an asymptomatic course of the disease. PMID:26491036

  15. Superantigenic Yersinia pseudotuberculosis induces the expression of granzymes and perforin by CD4+ T cells.

    PubMed

    Goubard, Agathe; Loïez, Caroline; Abe, Jun; Fichel, Caroline; Herwegh, Stéphanie; Faveeuw, Christelle; Porte, Rémi; Cayet, Delphine; Sebbane, Florent; Penet, Sylvie; Foligné, Benoit; Desreumaux, Pierre; Saito, Hirohisa; Sirard, Jean-Claude; Simonet, Michel; Carnoy, Christophe

    2015-05-01

    Bacterial superantigens (SAgs) are immunostimulatory toxins that induce acute diseases mainly through the massive release of inflammatory cytokines. Yersinia pseudotuberculosis is the only Gram-negative bacterium known to produce a SAg (Y. pseudotuberculosis-derived mitogen [YPM]). This SAg binds major histocompatibility complex class II molecules on antigen-presenting cells and T cell receptors (TcR) bearing the variable region Vβ3, Vβ9, Vβ13.1, or Vβ13.2 (in humans) and Vβ7 or Vβ8 (in mice). We have previously shown that YPM exacerbates the virulence of Y. pseudotuberculosis in mice. With a view to understanding the mechanism of YPM's toxicity, we compared the immune response in BALB/c mice infected with a YPM-producing Y. pseudotuberculosis or the corresponding isogenic, SAg-deficient mutant. Five days after infection, we observed strong CD4(+) Vβ7(+) T cell expansion and marked interleukin-4 (IL-4) production in mice inoculated with SAg-producing Y. pseudotuberculosis. These phenomena were correlated with the activation of ypm gene transcription in liver and spleen. A transcriptomic analysis revealed that the presence of YPM also increased expression of granzyme and perforin genes in the host's liver and spleen. This expression was attributed to a CD4(+) T cell subset, rather than to natural killer T (NKT) cells that display a TcR with a Vβ region that is potentially recognized by YPM. Increased production of cytotoxic molecules was correlated with hepatotoxicity, as demonstrated by an increase in plasma alanine aminotransferase activity. Our results demonstrate that YPM activates a potentially hepatotoxic CD4(+) T cell population. PMID:25754199

  16. Specific CD4+ T-Cell Reactivity and Cytokine Release in Different Clinical Presentations of Leptospirosis

    PubMed Central

    Moos, Verena; Allers, Kristina; Luge, Enno; Mayer-Scholl, Anne; Nöckler, Karsten; Loddenkemper, Christoph; Jansen, Andreas; Schneider, Thomas

    2015-01-01

    Clinical manifestations of leptospirosis are highly variable: from asymptomatic to severe and potentially fatal. The outcome of the disease is usually determined in the immunological phase, beginning in the second week of symptoms. The underlying mechanisms, predictive factors, and individual immune responses that contribute to clinical variations are not well understood. The aim of this study was to determine the specifics of CD4+ T-cell reactivity and cytokine release after stimulation with leptospiral antigens in patients with leptospirosis of different disease severities (patients with mild and severe symptoms) and in control subjects (with and without proven exposure to Leptospira). Whole-blood specimens were stimulated with Leptospira antigens in vitro. Subsequently, intracellular staining of cytokines was performed, and flow cytometry was used to assess the expression of CD40 ligand (CD40L) and the production of gamma interferon (IFN-γ), interleukin-10 (IL-10), IL-2, and tumor necrosis factor alpha (TNF-α) by CD4+ T cells. The production of inflammatory cytokines such as TNF-α by CD4+ T cells after stimulation with leptospiral antigens was highest in patients with severe disease. In contrast, the ratio of IL-10 production to TNF-α production was higher in exposed subjects than in patients with mild and severe disease. Levels of proinflammatory cytokines such as TNF-α may be useful markers of the severity of the immunological phase of leptospirosis. IL-10 production by T cells after antigen-specific stimulation may indicate a more successful downregulation of the inflammatory response and may contribute to an asymptomatic course of the disease. PMID:26491036

  17. CD4+ T Cell Help Guides Formation of CD103+ Lung-Resident Memory CD8+ T Cells during Influenza Viral Infection

    PubMed Central

    Laidlaw, Brian J.; Zhang, Nianzhi; Marshall, Heather D.; Staron, Mathew M.; Guan, Tianxia; Hu, Yinghong; Cauley, Linda S.; Craft, Joe; Kaech, Susan M.

    2014-01-01

    SUMMARY Tissue-resident memory T (Trm) cells provide enhanced protection against infection at mucosal sites. Here we found that CD4+ T cells are important for the formation of functional lung-resident CD8+ T cells after influenza virus infection. In the absence of CD4+ T cells, CD8+ T cells displayed reduced expression of CD103 (Itgae), were mislocalized away from airway epithelia, and demonstrated an impaired ability to recruit CD8+ T cells to the lung air-ways upon heterosubtypic challenge. CD4+ T cell-derived interferon-γ was necessary for generating lung-resident CD103+ CD8+ Trm CD8 T cells. Furthermore, expression of the transcription factor T-bet was increased in “unhelped” lung Trm cells, and a reduction in T-bet rescued CD103 expression in the absence of CD4+ T cell help. Thus, CD4+ T cell-dependent signals are important to limit expression of T-bet and allow for the development of CD103+ CD8+ Trm cells in the lung airways following respiratory infection. PMID:25308332

  18. Progressive CD4+ central–memory T cell decline results in CD4+ effector–memory insufficiency and overt disease in chronic SIV infection

    PubMed Central

    Okoye, Afam; Meier-Schellersheim, Martin; Brenchley, Jason M.; Hagen, Shoko I.; Walker, Joshua M.; Rohankhedkar, Mukta; Lum, Richard; Edgar, John B.; Planer, Shannon L.; Legasse, Alfred; Sylwester, Andrew W.; Piatak, Michael; Lifson, Jeffrey D.; Maino, Vernon C.; Sodora, Donald L.; Douek, Daniel C.; Axthelm, Michael K.; Grossman, Zvi; Picker, Louis J.

    2007-01-01

    Primary simian immunodeficiency virus (SIV) infections of rhesus macaques result in the dramatic depletion of CD4+ CCR5+ effector–memory T (TEM) cells from extra-lymphoid effector sites, but in most infections, an increased rate of CD4+ memory T cell proliferation appears to prevent collapse of effector site CD4+ TEM cell populations and acute-phase AIDS. Eventually, persistent SIV replication results in chronic-phase AIDS, but the responsible mechanisms remain controversial. Here, we demonstrate that in the chronic phase of progressive SIV infection, effector site CD4+ TEM cell populations manifest a slow, continuous decline, and that the degree of this depletion remains a highly significant correlate of late-onset AIDS. We further show that due to persistent immune activation, effector site CD4+ TEM cells are predominantly short-lived, and that their homeostasis is strikingly dependent on the production of new CD4+ TEM cells from central–memory T (TCM) cell precursors. The instability of effector site CD4+ TEM cell populations over time was not explained by increasing destruction of these cells, but rather was attributable to progressive reduction in their production, secondary to decreasing numbers of CCR5− CD4+ TCM cells. These data suggest that although CD4+ TEM cell depletion is a proximate mechanism of immunodeficiency, the tempo of this depletion and the timing of disease onset are largely determined by destruction, failing production, and gradual decline of CD4+ TCM cells. PMID:17724130

  19. Ndfip-mediated degradation of Jak1 tunes cytokine signalling to limit expansion of CD4+ effector T cells

    PubMed Central

    O'Leary, Claire E.; Riling, Christopher R.; Spruce, Lynn A.; Ding, Hua; Kumar, Suresh; Deng, Guoping; Liu, Yuhong; Seeholzer, Steven H.; Oliver, Paula M.

    2016-01-01

    Nedd4 family E3 ubiquitin ligases have been shown to restrict T-cell function and impact T-cell differentiation. We show here that Ndfip1 and Ndfip2, activators of Nedd4 family ligases, together limit accumulation and function of effector CD4+ T cells. Using a three-part proteomics approach in primary T cells, we identify stabilization of Jak1 in Ndfip1/2-deficient T cells stimulated through the TCR. Jak1 degradation is aborted in activated T cells that lack Ndfips. In wild-type cells, Jak1 degradation lessens CD4+ cell sensitivity to cytokines during TCR stimulation, while in Ndfip-deficient cells cytokine responsiveness persists, promoting increased expansion and survival of pathogenic effector T cells. Thus, Ndfip1/Ndfip2 regulate the cross talk between the T-cell receptor and cytokine signalling pathways to limit inappropriate T-cell responses. PMID:27088444

  20. The immune checkpoint regulator PD-L1 is a specific target for naturally occurring CD4(+) T cells.

    PubMed

    Munir, Shamaila; Andersen, Gitte Holmen; Svane, Inge Marie; Andersen, Mads Hald

    2013-04-01

    Programmed cell death 1 ligand 1 (PD-L1) is an important regulator of T-cell responses and may consequently limit anticancer immunity. We have recently identified PD-L1-specific, cytotoxic CD8(+) T cells. In the present study, we develop these findings and report that CD4(+) helper T cells spontaneously recognize PD-L1. We examined the locality of a previously identified HLA-A*0201-restricted PD-L1-epitope for the presence of possible CD4(+) T-cell epitopes. Thus, we identified naturally occurring PD-L1-specific CD4(+) T cells among the peripheral blood lymphocytes of cancer patients and - to lesser extents - healthy donors, by means of ELISPOT assays. PD-L1-specific CD4(+) T cells appeared to be TH17 cells exhibiting an effector T-cell cytokine profile. Hence, PD-L1-specific CD4(+) T cells released interferon γ (IFNγ), tumor necrosis factor α (TNFα) and interleukin-17 (IL-17) in response to a long PD-L1-derived peptide. Furthermore, we demonstrate that the specific recognition of PD-L1 by CD4(+) T cells is MHC class II-restricted. Natural T-cell responses against PD-L1 are noteworthy as they may play a prominent role in the regulation of the immune system. Thus, cytokine release from PD-L1-specific CD4(+) T cells may surmount the overall immunosuppressive actions of this immune checkpoint regulator. Moreover, PD-L1-specific T cells might be useful for anticancer immunotherapy, as they may counteract common mechanisms of immune escape mediated by the PD-L1/PD-1 pathway. PMID:23734334

  1. The immune checkpoint regulator PD-L1 is a specific target for naturally occurring CD4+ T cells

    PubMed Central

    Munir, Shamaila; Andersen, Gitte Holmen; Svane, Inge Marie; Andersen, Mads Hald

    2013-01-01

    Programmed cell death 1 ligand 1 (PD-L1) is an important regulator of T-cell responses and may consequently limit anticancer immunity. We have recently identified PD-L1-specific, cytotoxic CD8+ T cells. In the present study, we develop these findings and report that CD4+ helper T cells spontaneously recognize PD-L1. We examined the locality of a previously identified HLA-A*0201-restricted PD-L1-epitope for the presence of possible CD4+ T-cell epitopes. Thus, we identified naturally occurring PD-L1-specific CD4+ T cells among the peripheral blood lymphocytes of cancer patients and - to lesser extents - healthy donors, by means of ELISPOT assays. PD-L1-specific CD4+ T cells appeared to be TH17 cells exhibiting an effector T-cell cytokine profile. Hence, PD-L1-specific CD4+ T cells released interferon γ (IFNγ), tumor necrosis factor α (TNFα) and interleukin-17 (IL-17) in response to a long PD-L1-derived peptide. Furthermore, we demonstrate that the specific recognition of PD-L1 by CD4+ T cells is MHC class II-restricted. Natural T-cell responses against PD-L1 are noteworthy as they may play a prominent role in the regulation of the immune system. Thus, cytokine release from PD-L1-specific CD4+ T cells may surmount the overall immunosuppressive actions of this immune checkpoint regulator. Moreover, PD-L1-specific T cells might be useful for anticancer immunotherapy, as they may counteract common mechanisms of immune escape mediated by the PD-L1/PD-1 pathway. PMID:23734334

  2. Endogenous antigen processing drives the primary CD4+ T cell response to influenza

    PubMed Central

    Miller, Michael A.; Ganesan, Asha Purnima V.; Luckashenak, Nancy; Mendonca, Mark; Eisenlohr, Laurence C.

    2015-01-01

    By convention, CD4+ T lymphocytes recognize foreign and self peptides derived from internalized antigens in combination with MHC class II molecules. Alternative pathways of epitope production have been identified but their contributions to host defense have not been established. We show here in a mouse infection model that the CD4+ T cell response to influenza, critical for durable protection from the virus, is driven principally by unconventional processing of antigen synthesized within the infected antigen-presenting cell, not by classical processing of endocytosed virions or material from infected cells. Investigation of the cellular components involved, including the H2-M molecular chaperone, the proteasome, and gamma-interferon inducible lysosomal thiol reductase revealed considerable heterogeneity in the generation of individual epitopes, an arrangement that ensures peptide diversity and broad CD4+ T cell engagement. These results could fundamentally revise strategies for rational vaccine design and may lead to key insights into the induction of autoimmune and anti-tumor responses. PMID:26413780

  3. Multifunctional Analysis of CD4+ T-Cell Response as Immune-Based Model for Tuberculosis Detection

    PubMed Central

    Lichtner, Miriam; Mascia, Claudia; Sauzullo, Ilaria; Mengoni, Fabio; Vita, Serena; Marocco, Raffaella; Belvisi, Valeria; Russo, Gianluca; Vullo, Vincenzo; Mastroianni, Claudio M.

    2015-01-01

    Mono- and multifunctional specific CD4+ and CD8+ T-cell responses were evaluated to improve the immune-based detection of active tuberculosis (TB) and latent infection (LTBI). We applied flow cytometry to investigate cytokines profile (IFN-γ, TNF-α, and IL-2) of T cells after stimulation with TB antigens in 28 TB-infected subjects (18 active TB and 10 LTBI) and 10 uninfected controls. Cytokines production by CD4+ T cells at single-cell levels was higher in TB-infected subjects than uninfected controls (P < 0.0001). Assigning to activated CD4+ T cells, producing any of the three cytokines, a cut-off >0.45%, it was possible to differentiate TB-infected (>0.45%) by uninfected subjects (<0.45%). Among TB-infected subjects, the frequencies of multifunctional CD4+ T cells, simultaneously producing all 3 cytokines, are lower in active TB than LTBI subjects (P = 0.003). Thus, assigning to triple-positive CD4+ T cells a cut-off <0.182%, TB-infected individuals could be classified as active TB subjects (<0.182%) or LTBI subjects (>0.182%). The magnitude of CD8+ T-cell responses showed no differences between active TB and LTBI. Multifunctional CD4+ T-cell responses could have the potential to identify at single time point subjects without TB infection and patients having active or latent TB. PMID:26339657

  4. The role of TRPV1 in the CD4+ T cell-mediated inflammatory response of allergic rhinitis

    PubMed Central

    Son, Hye Ran; Rhee, Yun-Hee; Kim, Eun Hee; Kim, Ji Hye; Bae, Jun-Sang; Chung, Young-Jun; Chung, Phil-Sang; Raz, Eyal; Mo, Ji-Hun

    2016-01-01

    Transient receptor potential vanilloid 1 (TRPV1), which has been identified as a molecular target for the activation of sensory neurons by various painful stimuli, was reported to regulate the signaling and activation of CD4+ T cells. However, the role of TRPV1 in CD4+ T cell in allergic rhinitis remains poorly understood. In this study, TRPV1 expression was localized in CD4+ T cells. Both knockout and chemical inhibition of TRPV1 suppressed Th2/Th17 cytokine production in CD4 T cells and Jurkat T cells, respectively, and can suppress T cell receptor signaling pathways including NF-κB, MAP kinase, and NFAT. In TRPV1 knockout allergic rhinitis (AR) mice, eosinophil infiltration, Th2/Th17 cytokines in the nasal mucosa, and total and ova-specific IgE levels in serum decreased, compared with wild-type AR mice. The TRPV1 antagonists, BCTC or theobromine, showed similar inhibitory immunologic effects on AR mice models. In addition, the number of TRPV1+/CD4+ inflammatory cells increased in the nasal mucosa of patients with AR, compared with that of control subjects. Thus, TRPV1 activation on CD4+ T cells is involved in T cell receptor signaling, and it could be a novel therapeutic target in AR. PMID:26700618

  5. Ex vivo Enzymatic Treatment of Aged CD4 T Cells Restores Cognate T-cell Helper Function and Enhances Antibody Production in Mice

    PubMed Central

    Perkey, Eric; Miller, Richard A.; Garcia, Gonzalo G.

    2012-01-01

    Previous in vitro studies have shown that CD4 T cells from old mice have defects in T cell receptor (TCR) signaling, immune synapse formation, activation, and proliferation. We have reported that removing a specific set of surface glycoproteins by ex vivo treatment with O-sialoglycoprotein endopeptidase (OSGE) can reverse many aspects of the age-related decline in CD4 T cell function. However, the specific mechanism by which this process occurs remains unclear, and it is unknown whether this enzymatic treatment can also restore important aspects of adaptive immunity in vivo. By using an in vivo model of the immune response based on adoptive transfer of CD4 T cells from pigeon cytochrome C (PCC)-specific transgenic H-2(k/k) TCR-Vα11Vβ3 CD4+ mice to syngeneic hosts, we now demonstrat that aging diminishes CD28 costimulatory signals in CD4 T cells. These age-associated defects include changes in phosphorylation of AKT and expression of glucose transporter type I, inducible T-cell costimulatory molecule, and CD40 ligand, suggesting that the lack of CD28 costimulation contributes to age-dependent loss of CD4 function. All of these deficits can be reversed by ex vivo OSGE treatment. Blocking B7-CD28 interactions on T cells prevents OSGE-mediated restoration of T cell function, suggesting that changes in surface glycosylation, including CD28, may be responsible for age-related costimulation decline. Finally, we showed that the age-related decline in CD4 cognate helper function for immunoglobin G production and long-term humoral immunity can also be restored by OSGE treatments of CD4 T cells prior to adoptive transfer. PMID:23136198

  6. Helminth-conditioned dendritic cells prime CD4+ T cells to IL-4 production in vivo.

    PubMed

    Connor, Lisa M; Tang, Shiau-Choot; Camberis, Mali; Le Gros, Graham; Ronchese, Franca

    2014-09-15

    Dendritic cells (DC) are critical for the initiation of immune responses; however, their role in priming IL-4-producing Th2 cells in vivo is not fully understood. We used a model of intradermal injection with fluorescent-labeled, nonviable larvae from the helminth parasite nonviable Nippostrongylus brasiliensis L3 larvae (Nb), a strong inducer of Th2 responses, together with IL-4-GFP reporter mice that enable a sensitive detection of IL-4 production to examine the contribution of DC to the priming of IL-4-producing CD4(+) T cells in vivo. We found that parasite material is taken up by two distinct DC populations in draining lymph nodes: a mostly CD11c(int)MHC class II (MHCII)(hi)CD11b(+)Ly6C(-) dermal DC population and a CD11c(hi)MHCII(int)CD11b(+)Ly6C(+) monocyte-derived DC population. After Nb treatment, these two DC populations appeared in the draining lymph nodes in comparable numbers and with similar kinetics; however, treatment with pertussis toxin blocked the migration of dermal DC and the priming of IL-4-producing T cells, but only partially affected monocyte-derived DC numbers. In line with this observation, transfer of OVA-loaded CD11c(int)MHCII(hi) DC from Nb-treated mice into naive hosts could sensitize OVA-specific CD4(+) T cells to IL-4 production, whereas transfer of CD11c(int)MHCII(hi) DC from naive mice, or CD11c(hi)MHCII(int) DC from Nb-treated or naive mice, induced CD4(+) T cell expansion but no IL-4 production. Phenotypic analysis of Nb-loaded CD11c(int)MHCII(hi) DC revealed expression of programmed death ligand 2, CD301b, IFN regulatory factor 4, and moderate upregulation of OX40 ligand. However, thymic stromal lymphopoietin and OX40 ligand were not required for Th2 priming. Thus, our data suggest that appropriate stimuli can induce DC to express the unique signals sufficient to direct CD4(+) T cells to Th2 differentiation. PMID:25108019

  7. Comparative contribution of CD1 on the development of CD4+ and CD8+ T cell compartments.

    PubMed

    Wang, B; Chun, T; Wang, C R

    2000-01-15

    CD1 molecules are MHC class I-like glycoproteins whose expression is essential for the development of a unique subset of T cells, the NK T cells. To evaluate to what extent CD1 contributes to the development of CD4+ and CD8+ T cells, we generated CD1oIIo and CD1oTAPo mice and compared the generation of T cells in these double-mutant mice and IIo or TAPo mice. FACS analysis showed that the number of CD4+ T cells in CD1oIIo mice was reduced significantly compared with the corresponding population in IIo mice. Both CD4+ NK1.1+ and the CD4+ NK1.1- population were reduced in CD1oIIo mice, suggesting that CD1 can select not only CD4+ NK1.1+ T cells but also some NK1.1- CD4+ T cells. Functional analysis showed that the residual CD4+ cells in CD1oIIo can secrete large amounts of IFN-gamma and a significant amount of IL-4 during primary stimulation with anti-CD3, suggesting that this population may be enriched for NK T cells restricted by other class I molecules. In contrast to the CD4+ population, no significant differences in the CD8+ T cell compartment can be detected between TAPo and CD1oTAPo mice in all lymphoid tissues tested, including intestinal intraepithelial lymphocytes. Our data suggest that, unlike other MHC class I molecules, CD1 does not contribute in a major way to the development of CD8+ T cells. PMID:10623818

  8. Circulating rotavirus-specific T cells have a poor functional profile

    SciTech Connect

    Parra, Miguel; Herrera, Daniel; Jácome, María Fernanda; Mesa, Martha C.; Rodríguez, Luz-Stella; Guzmán, Carolina; Angel, Juana; Franco, Manuel A.

    2014-11-15

    Frequencies of circulating T cells producing IFN-γ, TNF-α, and IL-2, and percentages of T cells proliferating after stimulation with rotavirus (RV), tetanus toxoid, and influenza were evaluated in PBMC derived from healthy adults and children. In addition, the potential anergic state of RV-specific T cells was analyzed by stimulation of PBMC with RV antigen in the presence of three anergy inhibitors (rIL-2, rIL-12, or DGKα-i). The quality and magnitude of RV-T cell responses were significantly lower than those of tetanus toxoid and influenza antigens. RV-CD4 T cell response was enriched in monofunctional IFN-γ{sup +} cells, while influenza-CD4 and tetanus toxoid-CD4 T cell responses were enriched in multifunctional T cells. Moreover, rIL-2 – unlike rIL-12 or DGKα-i – increased the frequencies of RV-CD4 TNF-α{sup +}, CD4 IFN-γ{sup +}, and CD8 IFN-γ{sup +} cells. Thus, circulating RV-T cells seem to have a relatively poor functional profile that may be partially reversed in vitro by the addition of rIL-2. - Highlights: • The quality and magnitude of circulating RV-T cell responses are relatively poor. • Circulating RV-CD4 T cells are enriched in monofunctional IFN-γ+ cells. • Treatment with rIL-2 increased the frequencies of cytokine secreting RV-T cells.

  9. Polarization diversity of human CD4+ stem cell memory T cells.

    PubMed

    Takeshita, Masaru; Suzuki, Katsuya; Kassai, Yoshiaki; Takiguchi, Maiko; Nakayama, Yusuke; Otomo, Yuki; Morita, Rimpei; Miyazaki, Takahiro; Yoshimura, Akihiko; Takeuchi, Tsutomu

    2015-07-01

    T cells are considered to develop through three stages, from naïve T (Tn) into central memory T (Tcm) and finally into effector memory T (Tem). Among the subsets of Tn, stem cell memory T (Tscm) were recently found to be the least developed memory subset. While this subset was revealed to possess self-reproducibility and multipotentiality, little is known about the relationship between development and polarity. We conducted transcriptome analysis of human CD4(+) T subsets and found that Tscm was a clearly distinct subset, located between Tn and Tcm. Surface antigen analysis and differentiation assay showed that the flexibility of polarity and the cytokine production progressively changed as the differentiation of CD4(+) T cells advanced. Interestingly, we found that most cells of the CD45RO(-)CCR7(+)CCR6(+) subset, hitherto considered the naïve precursor of Th17, were in fact Tscm. These findings may advance our understanding of the highly heterogeneous human helper T cells. PMID:25931384

  10. HIV integration site distributions in resting and activated CD4+ T cells infected in culture

    PubMed Central

    Brady, Troy; Agosto, Luis M.; Malani, Nirav; Berry, Charles C.; O'Doherty, Una; Bushman, Frederic

    2010-01-01

    Objective The goal of this study was to investigate whether the location of HIV integration differs in resting versus activated T cells, a feature that could contribute to the formation of latent viral reservoirs via effects on integration targeting. Design Primary resting or activated CD4+ T cells were infected with purified X4-tropic HIV in the presence and absence of nucleoside triphosphates and genomic locations of integrated provirus determined. Methods We sequenced and analyzed a total of 2661 HIV integration sites using linker-mediated PCR and 454 sequencing. Integration site data sets were then compared to each other and to computationally generated random distributions. Results HIV integration was favored in active transcription units in both cell types, but integration sites from activated cells were found more often in genomic regions that were dense in genes, dense in CpG islands, and enriched in G/C bases. Integration sites from activated cells were also more strongly correlated with histone methylation patterns associated with active genes. Conclusion These data indicate that integration site distributions show modest but significant differences between resting and activated CD4+ T cells, and that integration in resting cells occurs more often in regions that may be suboptimal for proviral gene expression. PMID:19550285

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

    PubMed Central

    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

  12. Bioenergetics profile of CD4(+) T cells in relapsing remitting multiple sclerosis subjects.

    PubMed

    De Riccardis, Lidia; Rizzello, Antonia; Ferramosca, Alessandra; Urso, Emanuela; De Robertis, Francesca; Danieli, Antonio; Giudetti, Anna Maria; Trianni, Giorgio; Zara, Vincenzo; Maffia, Michele

    2015-05-20

    Multiple sclerosis (MS) is a chronic inflammatory autoimmune demyelinating disease of the central nervous system. There are four clinical forms of MS, the most common of which is characterized by a relapsing remitting course (RRMS). The etiology of MS is unknown, but many studies suggested that genetic, environmental and infectious agents may contribute to the development of this disease. In experimental autoimmune encephalomyelitis (EAE), the animal model for MS, it has been shown that CD4(+) T cells play a key role in MS pathogenesis. In fact, these cells are able to cross the blood-brain barrier and cause axonal damage with neuronal death. T cell activation critically depends on mitochondrial ATP synthesis and reactive oxygen species (ROS) production. Interestingly, lots of studies linked the oxidative damage arising from mitochondrial changes to neurodegenerative disorders, such as MS. Based on these evidences, this work focused on the metabolic reprogramming of CD4(+) T cells in MS subjects, being this cell population directly implicated in pathogenesis of disease, paying attention to mitochondrial function and response to oxidative stress. Such aspects, once clarified, may open new opportunities for a therapeutic metabolic modulation of MS disorder. PMID:25701681

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

    PubMed

    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

  14. TH2-Polarized CD4(+) T Cells and Macrophages Limit Efficacy of Radiotherapy.

    PubMed

    Shiao, Stephen L; Ruffell, Brian; DeNardo, David G; Faddegon, Bruce A; Park, Catherine C; Coussens, Lisa M

    2015-05-01

    Radiotherapy and chemotherapy following surgery are mainstays of treatment for breast cancer. Although multiple studies have recently revealed the significance of immune cells as mediators of chemotherapy response in breast cancer, less is known regarding roles for leukocytes as mediating outcomes following radiotherapy. To address this question, we utilized a syngeneic orthotopic murine model of mammary carcinogenesis to investigate if response to radiotherapy could be improved when select immune cells or immune-based pathways in the mammary microenvironment were inhibited. Treatment of mammary tumor-bearing mice with either a neutralizing mAb to colony-stimulating factor-1 (CSF-1) or a small-molecule inhibitor of the CSF-1 receptor kinase (i.e., PLX3397), resulting in efficient macrophage depletion, significantly delayed tumor regrowth following radiotherapy. Delayed tumor growth in this setting was associated with increased presence of CD8(+) T cells and reduced presence of CD4(+) T cells, the main source of the TH2 cytokine IL4 in mammary tumors. Selective depletion of CD4(+) T cells or neutralization of IL4 in combination with radiotherapy phenocopied results following macrophage depletion, whereas depletion of CD8(+) T cells abrogated improved response to radiotherapy following these therapies. Analogously, therapeutic neutralization of IL4 or IL13, or IL4 receptor alpha deficiency, in combination with the chemotherapy paclitaxel, resulted in slowed primary mammary tumor growth by CD8(+) T-cell-dependent mechanisms. These findings indicate that clinical responses to cytotoxic therapy in general can be improved by neutralizing dominant TH2-based programs driving protumorigenic and immune-suppressive pathways in mammary (breast) tumors to improve outcomes. PMID:25716473

  15. CD4+CD25hiFOXP3+ Cells in Cord Blood of Neonates Born from Filaria Infected Mother Are Negatively Associated with CD4+Tbet+ and CD4+RORγt+ T Cells

    PubMed Central

    Zettlmeissl, Eva; van der Vlugt, Luciën E. P. M.; de Jong, Sanne; Matsiegui, Pierre-Blaise; Ramharter, Michael; Kremsner, Peter G.; Yazdanbakhsh, Maria; Adegnika, Ayola Akim

    2014-01-01

    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. PMID:25531674

  16. Treatment of latent tuberculosis infection induces changes in multifunctional Mycobacterium tuberculosis-specific CD4+ T cells.

    PubMed

    Sauzullo, Ilaria; Mengoni, Fabio; Mascia, Claudia; Rossi, Raffaella; Lichtner, Miriam; Vullo, Vincenzo; Mastroianni, Claudio M

    2016-02-01

    To ascertain whether multiparametric flow cytometry assessment of multifunctional Mycobacterium tuberculosis (Mtb)-specific CD4(+) and CD8(+) T cells can distinguish between untreated and treated patients with latent tuberculosis infection (LTBI), we enrolled 14 LTBI subjects treated with isoniazid (INH) therapy, 16 untreated LTBI patients, and 25 healthy controls. The analysis of mono-functional CD4(+) and CD8(+) T cells producing single cytokines showed significant differences only between uninfected and infected LTBI subjects (both treated and untreated). Conversely, the analysis of multifunctional CD4(+) T cells revealed a significant reduction in the frequency of two CD4(+) T cells subsets, those producing IFN-γ, IL-2, and TNF-α simultaneously (triple positive; p = 0.005) and those producing IL-2 alone (p = 0.0359), as well as a shift towards T cells producing only one cytokine in treated as compared to untreated LTBI subjects. Assigning a triple-positive CD4(+) T cells a cut-off >0.082 %, 94 % of untreated LTBI patients were scored as positive, as compared to only 28 % of treated LTBI patients and none of the healthy controls. No significant differences between untreated and treated LTBI subjects in terms of Mtb-specific CD8(+) T cell cytokine profiles (p > 0.05) were identified. The significant changes in the cytokine profiles of Mtb-specific T cells after INH therapy suggest that analysis of multifunctional T cells may be a promising means for the monitoring of LTBI treatment success. PMID:26108901

  17. Intestinal lamina propria retaining CD4+CD25+ regulatory T cells is a suppressive site of intestinal inflammation.

    PubMed

    Makita, Shin; Kanai, Takanori; Nemoto, Yasuhiro; Totsuka, Teruji; Okamoto, Ryuichi; Tsuchiya, Kiichiro; Yamamoto, Masafumi; Kiyono, Hiroshi; Watanabe, Mamoru

    2007-04-15

    It is well known that immune responses in the intestine remain in a state of controlled inflammation, suggesting that not only does active suppression by regulatory T (T(REG)) cells play an important role in the normal intestinal homeostasis, but also that its dysregulation of immune response leads to the development of inflammatory bowel disease. In this study, we demonstrate that murine CD4(+)CD25(+) T cells residing in the intestinal lamina propria (LP) constitutively express CTLA-4, glucocorticoid-induced TNFR, and Foxp3 and suppress proliferation of responder CD4(+) T cells in vitro. Furthermore, cotransfer of intestinal LP CD4(+)CD25(+) T cells prevents the development of chronic colitis induced by adoptive transfer of CD4(+)CD45RB(high) T cells into SCID mice. When lymphotoxin (LT)alpha-deficient intercrossed Rag2 double knockout mice (LTalpha(-/-) x Rag2(-/-)), which lack mesenteric lymph nodes and Peyer's patches, are transferred with CD4(+)CD45RB(high) T cells, they develop severe wasting disease and chronic colitis despite the delayed kinetics as compared with the control LTalpha(+/+) x Rag2(-/-) mice transferred with CD4(+)CD45RB(high) T cells. Of note, when a mixture of splenic CD4(+)CD25(+) T(REG) cells and CD4(+)CD45RB(high) T cells are transferred into LTalpha(-/-) x Rag2(-/-) recipients, CD4(+)CD25(+) T(REG) cells migrate into the colon and prevent the development of colitis in LTalpha(-/-) x Rag2(-/-) recipients as well as in the control LTalpha(+/+) x Rag2(-/-) recipients. These results suggest that the intestinal LP harboring CD4(+)CD25(+) T(REG) cells contributes to the intestinal immune suppression. PMID:17404275

  18. Immunodominant CD4+ T-cell responses to influenza A virus in healthy individuals focus on matrix 1 and nucleoprotein.

    PubMed

    Chen, Li; Zanker, Damien; Xiao, Kun; Wu, Chao; Zou, Quanming; Chen, Weisan

    2014-10-01

    Antigen-specific CD4(+) T cells are essential for effective virus-specific host responses, with recent human challenge studies (in volunteers) establishing their importance for influenza A virus (IAV)-specific immunity. However, while many IAV CD4(+) T cell epitopes have been identified, few are known to stimulate immunodominant CD4(+) T cell responses. Moreover, much remains unclear concerning the major antigen(s) responded to by the human CD4(+) T cells and the extents and magnitudes of these responses. We initiated a systematic screen of immunodominant CD4(+) T cell responses to IAV in healthy individuals. Using in vitro expanded-multispecificity IAV-specific T cell lines and individual IAV protein antigens produced by recombinant vaccinia viruses, we found that the internal matrix protein 1 (M1) and nucleoprotein (NP) were the immunodominant targets of CD4(+) T cell responses. Ten epitopes derived from M1 and NP were definitively characterized. Furthermore, epitope sequence conservation analysis established that immunodominance correlated with an increased frequency of mutations, reflecting the fact that these prominent epitopes are under greater selective pressure. Such evidence that particular CD4(+) T cells are important for protection/recovery is of value for the development of novel IAV vaccines and for our understanding of different profiles of susceptibility to these major pathogens. Importance: Influenza virus causes half a million deaths annually. CD4(+) T cell responses have been shown to be important for protection against influenza and for recovery. CD4(+) T cell responses are also critical for efficient CD8(+) T cell response and antibody response. As immunodominant T cells generally play a more important role, characterizing these immunodominant responses is critical for influenza vaccine development. We show here that the internal matrix protein 1 (M1) and nucleoprotein (NP), rather than the surface proteins reported previously, are the

  19. Immunodominant CD4+ T-Cell Responses to Influenza A Virus in Healthy Individuals Focus on Matrix 1 and Nucleoprotein

    PubMed Central

    Chen, Li; Zanker, Damien; Xiao, Kun; Wu, Chao; Zou, Quanming

    2014-01-01

    ABSTRACT Antigen-specific CD4+ T cells are essential for effective virus-specific host responses, with recent human challenge studies (in volunteers) establishing their importance for influenza A virus (IAV)-specific immunity. However, while many IAV CD4+ T cell epitopes have been identified, few are known to stimulate immunodominant CD4+ T cell responses. Moreover, much remains unclear concerning the major antigen(s) responded to by the human CD4+ T cells and the extents and magnitudes of these responses. We initiated a systematic screen of immunodominant CD4+ T cell responses to IAV in healthy individuals. Using in vitro expanded-multispecificity IAV-specific T cell lines and individual IAV protein antigens produced by recombinant vaccinia viruses, we found that the internal matrix protein 1 (M1) and nucleoprotein (NP) were the immunodominant targets of CD4+ T cell responses. Ten epitopes derived from M1 and NP were definitively characterized. Furthermore, epitope sequence conservation analysis established that immunodominance correlated with an increased frequency of mutations, reflecting the fact that these prominent epitopes are under greater selective pressure. Such evidence that particular CD4+ T cells are important for protection/recovery is of value for the development of novel IAV vaccines and for our understanding of different profiles of susceptibility to these major pathogens. IMPORTANCE Influenza virus causes half a million deaths annually. CD4+ T cell responses have been shown to be important for protection against influenza and for recovery. CD4+ T cell responses are also critical for efficient CD8+ T cell response and antibody response. As immunodominant T cells generally play a more important role, characterizing these immunodominant responses is critical for influenza vaccine development. We show here that the internal matrix protein 1 (M1) and nucleoprotein (NP), rather than the surface proteins reported previously, are the immunodominant

  20. CD8α+ Dendritic cells prime TCR-peptide-reactive regulatory CD4+FOXP3− T cells

    PubMed Central

    Smith, Trevor R. F.; Maricic, Igor; Ria, Francesco; Schneider, Susan; Kumar, Vipin

    2011-01-01

    Summary CD4+ T cells with immune regulatory function can be either FOXP3+ or FOXP3−. We have previously shown that priming of naturally occurring TCR-peptide-reactive regulatory CD4+FOXP3− T cells (Treg) specifically controls Vβ8.2+CD4+ T cells mediating experimental autoimmune encephalomyelitis (EAE). However, the mechanism by which these Treg are primed to recognize their cognate antigenic determinant, which is derived from the TCRVβ8.2-chain, is not known. In this study we show that antigen presenting cells (APC) derived from splenocytes of naïve mice are able to stimulate cloned CD4+ Treg in the absence of exogenous antigen, and their stimulation capacity is augmented during EAE. Among the APC populations DC were the most efficient in stimulating the Treg. Stimulation of CD4+ Treg was dependent upon processing and presentation of TCR peptides from ingested Vβ8.2TCR+ CD4+ T cells. Additionally, dendritic cells pulsed with TCR peptide or apoptotic Vβ8.2+ T cells are able to prime Treg in vivo and mediate protection from disease in a CD8-dependent fashion. These data highlight a novel mechanism for the priming of CD4+ Treg by CD8α+ DC, and suggest a pathway that can be exploited to prime antigen-specific regulation of T cell-mediated inflammatory disease. PMID:20394075

  1. The Role of the PI3K Signaling Pathway in CD4+ T Cell Differentiation and Function

    PubMed Central

    Han, Jonathan M.; Patterson, Scott J.; Levings, Megan K.

    2012-01-01

    The relative activity of regulatory versus conventional CD4+ T cells ultimately maintains the delicate balance between immune tolerance and inflammation. At the molecular level, the activity of phosphatidylinositol 3-kinase (PI3K) and its downstream positive and negative regulators has a major role in controlling the balance between immune regulation and activation of different subsets of effector CD4+ T cells. In contrast to effector T cells which require activation of the PI3K to differentiate and mediate their effector function, regulatory T cells rely on minimal activation of this pathway to develop and maintain their characteristic phenotype, function, and metabolic state. In this review, we discuss the role of the PI3K signaling pathway in CD4+ T cell differentiation and function, and focus on how modulation of this pathway in T cells can alter the outcome of an immune response, ultimately tipping the balance between tolerance and inflammation. PMID:22905034

  2. Communication between Human Dendritic Cell Subsets in Tuberculosis: Requirements for Naive CD4+ T Cell Stimulation

    PubMed Central

    Lozza, Laura; Farinacci, Maura; Bechtle, Marina; Stäber, Manuela; Zedler, Ulrike; Baiocchini, Andrea; del Nonno, Franca; Kaufmann, Stefan H. E.

    2014-01-01

    Human primary dendritic cells (DCs) are heterogeneous by phenotype, function, and tissue localization and distinct from inflammatory monocyte-derived DCs. Current information regarding the susceptibility and functional role of primary human DC subsets to Mycobacterium tuberculosis (Mtb) infection is limited. Here, we dissect the response of different primary DC subsets to Mtb infection. Myeloid CD11c+ cells and pDCs (C-type lectin 4C+ cells) were located in human lymph nodes (LNs) of tuberculosis (TB) patients by histochemistry. Rare CD141hi DCs (C-type lectin 9A+ cells) were also identified. Infection with live Mtb revealed a higher responsiveness of myeloid CD1c+ DCs compared to CD141hi DCs and pDCs. CD1c+ DCs produced interleukin (IL)-6, tumor necrosis factor α, and IL-1β but not IL-12p70, a cytokine important for Th1 activation and host defenses against Mtb. Yet, CD1c+ DCs were able to activate autologous naïve CD4+ T cells. By combining cell purification with fluorescence-activated cell sorting and gene expression profiling on rare cell populations, we detected in responding CD4+ T cells, genes related to effector-cytolytic functions and transcription factors associated with Th1, Th17, and Treg polarization, suggesting multifunctional properties in our experimental conditions. Finally, immunohistologic analyses revealed contact between CD11c+ cells and pDCs in LNs of TB patients and in vitro data suggest that cooperation between Mtb-infected CD1c+ DCs and pDCs favors stimulation of CD4+ T cells. PMID:25071784

  3. Influence of phthiocerol dimycocerosate on CD4(+) T cell priming and persistence during Mycobacterium tuberculosis infection.

    PubMed

    Pinto, Rachel; Nambiar, Jonathan K; Leotta, Lisa; Counoupas, Claudio; Britton, Warwick J; Triccas, James A

    2016-07-01

    The characterisation of mycobacterial factors that influence or modulate the host immune response may aid the development of more efficacious TB vaccines. We have previously reported that Mycobacterium tuberculosis deficient in export of Phthiocerol Dimycocerosates (DIM) (MT103(ΔdrrC)) is more attenuated than wild type M. tuberculosis and provides sustained protective immunity compared to the existing BCG vaccine. Here we sought to define the correlates of immunity associated with DIM deficiency by assessing the impact of MT103(ΔdrrC) delivery on antigen presenting cell (APC) function and the generation of CD4(+) T cell antigen-specific immunity. MT103(ΔdrrC) was a potent activator of bone marrow derived dendritic cells, inducing significantly greater expression of CD86 and IL-12p40 compared to BCG or the MT103 parental strain. This translated to an increased ability to initiate early in vivo priming of antigen-specific CD4(+) T cells compared to BCG with enhanced release of IFN-γ and TNF upon antigen-restimulation. The heightened immunity induced by MT103(ΔdrrC) correlated with greater persistence within the spleen compared to BCG, however both MT103(ΔdrrC) and BCG were undetectable in the lung at 70 days post-vaccination. In immunodeficient RAG (-/-) mice, MT103(ΔdrrC) was less virulent than the parental MT103 strain, yet MT103(ΔdrrC) infected mice succumbed more rapidly compared to BCG-infected animals. These results suggest that DIM translocation plays a role in APC stimulation and CD4(+) T cell activation during M. tuberculosis infection and highlights the potential of DIM-deficient strains as novel TB vaccine candidates. PMID:27450001

  4. The impact of Nucleofection® on the activation state of primary human CD4 T cells

    PubMed Central

    Zhang, Mingce; Ma, Zhengyu; Selliah, Nithianandan; Weiss, Greta; Genin, Anna; Finkel, Terri H.; Cron, Randy Q.

    2014-01-01

    Gene transfer into primary human CD4 T lymphocytes is a critical tool in studying the mechanism of T cell-dependent immune responses and human immunodeficiency virus-1 (HIV-1) infection. Nucleofection® is an electroporation technique that allows efficient gene transfer into primary human CD4 T cells that are notoriously resistant to traditional electroporation. Despite its popularity in immunological research, careful characterization of its impact on the physiology of CD4 T cells has not been documented. Herein, using freshly-isolated primary human CD4 T cells, we examine the effects of Nucleofection® on CD4 T cell morphology, intracellular calcium levels, cell surface activation markers, and transcriptional activity. We find that immediately after Nucleofection®, CD4 T cells undergo dramatic morphological changes characterized by wrinkled and dilated plasma membranes before recovering 1 hour later. The intracellular calcium level also increases after Nucleofection®, peaking after 1 hour before recovering 8 hours post transfection. Moreover, Nucleofection® leads to increased expression of T cell activation markers, CD154 and CD69, for more than 24 hours, and enhances the activation effects of phytohemagglutinin (PHA) stimulation. In addition, transcriptional activity is increased in the first 24 hours after Nucleofection®, even in the absence of exogenous stimuli. Therefore, Nucleofection® significantly alters the activation state of primary human CD4 T cells. The effect of transferred gene products on CD4 T cell function by Nucleofection® should be assessed after sufficient resting time post transfection or analyzed in light of the activation caveats mentioned above. PMID:24910411

  5. Dopamine Receptor D3 Signaling on CD4+ T Cells Favors Th1- and Th17-Mediated Immunity.

    PubMed

    Contreras, Francisco; Prado, Carolina; González, Hugo; Franz, Dafne; Osorio-Barrios, Francisco; Osorio, Fabiola; Ugalde, Valentina; Lopez, Ernesto; Elgueta, Daniela; Figueroa, Alicia; Lladser, Alvaro; Pacheco, Rodrigo

    2016-05-15

    Dopamine receptor D3 (DRD3) expressed on CD4(+) T cells is required to promote neuroinflammation in a murine model of Parkinson's disease. However, how DRD3 signaling affects T cell-mediated immunity remains unknown. In this study, we report that TCR stimulation on mouse CD4(+) T cells induces DRD3 expression, regardless of the lineage specification. Importantly, functional analyses performed in vivo using adoptive transfer of OVA-specific OT-II cells into wild-type recipients show that DRD3 deficiency in CD4(+) T cells results in attenuated differentiation of naive CD4(+) T cells toward the Th1 phenotype, exacerbated generation of Th2 cells, and unaltered Th17 differentiation. The reciprocal regulatory effect of DRD3 signaling in CD4(+) T cells favoring Th1 generation and impairing the acquisition of Th2 phenotype was also reproduced using in vitro approaches. Mechanistic analysis indicates that DRD3 signaling evokes suppressor of cytokine signaling 5 expression, a negative regulator of Th2 development, which indirectly favors acquisition of Th1 phenotype. Accordingly, DRD3 deficiency results in exacerbated eosinophil infiltration into the airways of mice undergoing house dust mite-induced allergic response. Interestingly, our results show that, upon chronic inflammatory colitis induced by transfer of naive CD4(+) T cells into lymphopenic recipients, DRD3 deficiency not only affects Th1 response, but also the frequency of Th17 cells, suggesting that DRD3 signaling also contributes to Th17 expansion under chronic inflammatory conditions. In conclusion, our findings indicate that DRD3-mediated signaling in CD4(+) T cells plays a crucial role in the balance of effector lineages, favoring the inflammatory potential of CD4(+) T cells. PMID:27183640

  6. Overrepresentation of IL-10-Expressing B Cells Suppresses Cytotoxic CD4+ T Cell Activity in HBV-Induced Hepatocellular Carcinoma

    PubMed Central

    Tan, Hongwu; Zhu, Zun-Qiang; Zhang, Zhang-Yun; Zhao, Ludong

    2016-01-01

    Hepatocellular carcinoma (HCC) is a common cancer with poor prognosis and low five-year survival rate. A strong and effective CD4+ T cell-mediated cytotoxicity was associated with better survival and low recurrence rate in HCC, but the regulatory mechanism that controls CD4+ T cell cytotoxicity in HCC patients is not fully examined. Given that IL-10-expressing B cells could suppress the inflammation of cytotoxic CD8+ T cells, T helper 1 (Th1) cells and Th17 cells, while promoting regulatory T (Treg) cell differentiation, we examined the role of IL-10-expressing B cells in HBV-related HCC patients. We found that compared to healthy controls, HCC patients exhibited significantly higher frequencies of IL-10-expressing B cells, which were negatively correlated with the frequencies of granzyme A, granzyme B, and perforin expressing CD4+ T cells. Surface molecule Tim-1 was preferentially expressed on IL-10-expressing B cells. Therefore, we separated total B cells into Tim-1+ and Tim-1- B cells. CD4+ T cells incubated with Tim-1+ B cells exhibited significantly reduced levels of granzyme A, granzyme B and perforin expression, compared to the CD4+ T cells incubated with Tim-1- B cells. Antagonizing IL-10 in culture rescued CD4+ T cell cytotoxicity. Compared to that in peripheral blood, the level of IL-10-expressing B cells were further upregulated in resected tumor, while the level of CD4+ cytotoxic T cells was downregulated. The negative correlations between IL-10-expressing B cells and CD4+ cytotoxic T cells were also observed in tumor-infiltrating cells. Together, our data revealed an additional antitumor mechanism mediated by IL-10-expressing B cells. PMID:27136203

  7. Overrepresentation of IL-10-Expressing B Cells Suppresses Cytotoxic CD4+ T Cell Activity in HBV-Induced Hepatocellular Carcinoma.

    PubMed

    Xue, Hongwei; Lin, Fuhuang; Tan, Hongwu; Zhu, Zun-Qiang; Zhang, Zhang-Yun; Zhao, Ludong

    2016-01-01

    Hepatocellular carcinoma (HCC) is a common cancer with poor prognosis and low five-year survival rate. A strong and effective CD4+ T cell-mediated cytotoxicity was associated with better survival and low recurrence rate in HCC, but the regulatory mechanism that controls CD4+ T cell cytotoxicity in HCC patients is not fully examined. Given that IL-10-expressing B cells could suppress the inflammation of cytotoxic CD8+ T cells, T helper 1 (Th1) cells and Th17 cells, while promoting regulatory T (Treg) cell differentiation, we examined the role of IL-10-expressing B cells in HBV-related HCC patients. We found that compared to healthy controls, HCC patients exhibited significantly higher frequencies of IL-10-expressing B cells, which were negatively correlated with the frequencies of granzyme A, granzyme B, and perforin expressing CD4+ T cells. Surface molecule Tim-1 was preferentially expressed on IL-10-expressing B cells. Therefore, we separated total B cells into Tim-1+ and Tim-1- B cells. CD4+ T cells incubated with Tim-1+ B cells exhibited significantly reduced levels of granzyme A, granzyme B and perforin expression, compared to the CD4+ T cells incubated with Tim-1- B cells. Antagonizing IL-10 in culture rescued CD4+ T cell cytotoxicity. Compared to that in peripheral blood, the level of IL-10-expressing B cells were further upregulated in resected tumor, while the level of CD4+ cytotoxic T cells was downregulated. The negative correlations between IL-10-expressing B cells and CD4+ cytotoxic T cells were also observed in tumor-infiltrating cells. Together, our data revealed an additional antitumor mechanism mediated by IL-10-expressing B cells. PMID:27136203

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

    PubMed Central

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

    2006-01-01

    IFN-γ-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-γ-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

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

    PubMed

    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

  10. The impact of Nucleofection® on the activation state of primary human CD4 T cells.

    PubMed

    Zhang, Mingce; Ma, Zhengyu; Selliah, Nithianandan; Weiss, Greta; Genin, Anna; Finkel, Terri H; Cron, Randy Q

    2014-06-01

    Gene transfer into primary human CD4 T lymphocytes is a critical tool in studying the mechanism of T cell-dependent immune responses and human immunodeficiency virus-1 (HIV-1) infection. Nucleofection® is an electroporation technique that allows efficient gene transfer into primary human CD4 T cells that are notoriously resistant to traditional electroporation. Despite its popularity in immunological research, careful characterization of its impact on the physiology of CD4 T cells has not been documented. Herein, using freshly-isolated primary human CD4 T cells, we examine the effects of Nucleofection® on CD4 T cell morphology, intracellular calcium levels, cell surface activation markers, and transcriptional activity. We find that immediately after Nucleofection®, CD4 T cells undergo dramatic morphological changes characterized by wrinkled and dilated plasma membranes before recovering 1h later. The intracellular calcium level also increases after Nucleofection®, peaking after 1h before recovering 8h post transfection. Moreover, Nucleofection® leads to increased expression of T cell activation markers, CD154 and CD69, for more than 24h, and enhances the activation effects of phytohemagglutinin (PHA) stimulation. In addition, transcriptional activity is increased in the first 24h after Nucleofection®, even in the absence of exogenous stimuli. Therefore, Nucleofection® significantly alters the activation state of primary human CD4 T cells. The effect of transferred gene products on CD4 T cell function by Nucleofection® should be assessed after sufficient resting time post transfection or analyzed in light of the activation caveats mentioned above. PMID:24910411

  11. microRNA 184 regulates expression of NFAT1 in umbilical cord blood CD4+ T cells

    PubMed Central

    Weitzel, R. Patrick; Lesniewski, Mathew L.; Haviernik, Peter; Kadereit, Suzanne; Leahy, Patrick; Greco, Nicholas J.

    2009-01-01

    The reduced expression of nuclear factor of activated T cells-1 (NFAT1) protein in umbilical cord blood (UCB)–derived CD4+ T cells and the corresponding reduction in inflammatory cytokine secretion after stimulation in part underlies their phenotypic differences from adult blood (AB) CD4+ T cells. This muted response may contribute to the lower incidence and severity of high-grade acute graft-versus-host disease (aGVHD) exhibited by UCB grafts. Here we provide evidence that a specific microRNA, miR-184, inhibits NFAT1 protein expression elicited by UCB CD4+ T cells. Endogenous expression of miR-184 in UCB is 58.4-fold higher compared with AB CD4+ T cells, and miR-184 blocks production of NFAT1 protein through its complementary target sequence on the NFATc2 mRNA without transcript degradation. Furthermore, its negative effects on NFAT1 protein and downstream interleukin-2 (IL-2) transcription are reversed through antisense blocking in UCB and can be replicated via exogenous transfection of precursor miR-184 into AB CD4+ T cells. Our findings reveal a previously uncharacterized role for miR-184 in UCB CD4+ T cells and a novel function for microRNA in the early adaptive immune response. PMID:19286996

  12. Computational Analysis of the Model Describing HIV Infection of CD4+T Cells

    PubMed Central

    Atangana, Abdon

    2014-01-01

    An analysis of the model underpinning the description of the spread of HIV infection of CD4+T cells is examined in detail in this work. Investigations of the disease free and endemic equilibrium are done using the method of Jacobian matrix. An iteration technique, namely, the homotopy decomposition method (HDM), is implemented to give an approximate solution of nonlinear ordinary differential equation systems. The technique is described and illustrated with numerical examples. The approximated solution obtained via HDM is compared with those obtained via other methods to prove the trustworthiness of HDM. Moreover, the lessening and simplicity in calculations furnish HDM with a broader applicability. PMID:25136605

  13. Quantitation of Replication-Competent HIV-1 in Populations of Resting CD4+ T Cells

    PubMed Central

    Soriano-Sarabia, Natalia; Bateson, Rosalie E.; Dahl, Noelle P.; Crooks, Amanda M.; Kuruc, JoAnn D.; Margolis, David M.

    2014-01-01

    ABSTRACT Central memory (TCM) CD4+ T cells are the principal reservoir of latent HIV-1 infection that persists despite durable, successful antiretroviral therapy (ART). In a study that measured HIV DNA in 17 patients and replication-competent HIV in 4 patients, pools of resting and activated transitional memory (TTM) CD4+ T cells were found to be a reservoir for HIV infection. As defective viruses account for the majority of integrated HIV DNA and do not reflect the actual frequency of latent, replication-competent proviral infection, we assessed the specific contribution of resting TTM cells to latent HIV infection. We measured the frequency of replication-competent HIV in purified resting memory cell subpopulations by a limiting-dilution, quantitative viral outgrowth assay (QVOA). HIV was routinely detected within the resting central memory compartment but was infrequently detected within the resting TTM compartment. These observations suggest that prolonged ART may limit persistent latent infection in the TTM compartment. Our results confirm the importance of latent infection within the TCM compartment and again focus attention on these cells as the most important latent viral reservoir. While proliferation may drive expansion of detectable viral genomes in cells, the frequency of replication-competent HIV must be carefully assessed. Latent infection appears to wane within the transitional memory compartment in patients who have sustained successful viral suppression via ART or were treated very early in infection. IMPORTANCE Antiretroviral therapy (ART) has led to a significant decrease in morbidity and mortality among HIV-infected patients. However, HIV integrates into the genome of CD4+ T cells, generating pools of long-lived cells that are reservoirs of latent HIV. Two main subsets of CD4+ T cells, central memory and transitional memory cells, were reported to be major reservoirs of HIV infection. However, this study primarily measured the HIV DNA content

  14. CD4+CXCR3+ T cells and plasmacytoid dendritic cells drive accelerated atherosclerosis associated with systemic lupus erythematosus.

    PubMed

    Clement, Marc; Charles, Nicolas; Escoubet, Brigitte; Guedj, Kevin; Chauveheid, Marie-Paule; Caligiuri, Giuseppina; Nicoletti, Antonino; Papo, Thomas; Sacre, Karim

    2015-09-01

    Cardiovascular disease due to accelerated atherosclerosis is the leading cause of death in patients with systemic lupus erythematosus (SLE). Noteworthy, accelerated atherosclerosis in SLE patients appears to be independant of classical Framingham risk factors. This suggests that aggravated atherosclerosis in SLE patients may be a result of increased inflammation and altered immune responses. However, the mechanisms that mediate the acceleration of atherosclerosis in SLE remain elusive. Based on experimental data which includes both humans (SLE patients and control subjects) and rodents (ApoE-/- mice), we herein propose a multi-step model in which the immune dysfunction associated with SLE (i.e. high level of IFN-α production by TLR 9-stimulated pDCs) is associated with, first, an increased frequency of circulating pro inflammatory CD4+CXCR3+ T cells; second, an increased production of CXCR3 ligands by endothelial cells; third, an increased recruitment of pro-inflammatory CD4+CXCR3+ T cells into the arterial wall, and fourth, the development of atherosclerosis. In showing how SLE may promote accelerated atherosclerosis, our model also points to hypotheses for potential interventions, such as pDCs-targeted therapy, that might be studied in the future. PMID:26183767

  15. Donor CD4 T Cell Diversity Determines Virus Reactivation in Patients After HLA-Matched Allogeneic Stem Cell Transplantation

    PubMed Central

    Ritter, J; Seitz, V; Balzer, H; Gary, R; Lenze, D; Moi, S; Pasemann, S; Seegebarth, A; Wurdack, M; Hennig, S; Gerbitz, A; Hummel, M

    2015-01-01

    Delayed reconstitution of the T cell compartment in recipients of allogeneic stem cell grafts is associated with an increase of reactivation of latent viruses. Thereby, the transplanted T cell repertoire appears to be one of the factors that affect T cell reconstitution. Therefore, we studied the T cell receptor beta (TCRβ) gene rearrangements of flow cytometry–sorted CD4+ and CD8+ T cells from the peripheral blood of 23 allogeneic donors before G-CSF administration and on the day of apheresis. For this purpose, TCRβ rearrangements were amplified by multiplex PCR followed by high-throughput amplicon sequencing. Overall, CD4+ T cells displayed a significantly higher TCRβ diversity compared to CD8+ T cells irrespective of G-CSF administration. In line, no significant impact of G-CSF treatment on the TCR Vβ repertoire usage was found. However, correlation of the donor T cell repertoire with clinical outcomes of the recipient revealed that a higher CD4+ TCRβ diversity after G-CSF treatment is associated with lower reactivation of cytomegalovirus and Epstein–Barr virus. By contrast, no protecting correlation was observed for CD8+ T cells. In essence, our deep TCRβ analysis identifies the importance of the CD4+ T cell compartment for the control of latent viruses after allogeneic stem cell transplantation. PMID:25873100

  16. CD4+ T-cell dynamics and host predisposition to infection.

    PubMed Central

    Schweitzer, A N

    1993-01-01

    Resistance to infection is often associated with proliferative T-cell responses corresponding to activation of the Th1 CD4+ T-cell subset, while the proliferative responses of chronically infected individuals are often limited. A mathematical model of the interaction between Th1 cells and a replicating pathogen has been used to demonstrate that antigen dose-dependent inhibition of Th1-cell proliferation may differentially predispose the host to resistance or chronic infection according to the level of exposure. Furthermore, the rapidity of pathogen turnover dramatically influences the qualitative relationship between exposure level and outcome, the temporal progression of infection, and the extent to which superimposed regulation of effector function (distinct from proliferation) will alter the predicted predisposition. PMID:8095925

  17. HIV Susceptibility of human antigen-specific CD4 T cells in AIDS pathogenesis and vaccine response.

    PubMed

    Hu, Haitao; Liu, Fengliang; Kim, Jerome; Ratto-Kim, Silvia

    2016-06-01

    HIV causes infection and progressive depletion of human CD4 T cells. Emerging data have shown that antigen-specific CD4 T-cell subsets manifest differential susceptibility to HIV, potentially leading to pathogen-specific immune failure and opportunistic infections. This concept was recently explored in context of vectors utilized in HIV vaccine trials, and the data suggest that adenovirus type 5(Ad5)-specific CD4 T cells elicited by Ad5-HIV vaccine may be particularly susceptible to HIV, potentially rendering Ad5 vaccine recipients susceptible to HIV acquisition. We here examined recent data regarding the HIV susceptibility of antigen-specific CD4 T cells induced during infection or HIV vaccination and discussed its potential impact on HIV acquisition risk posed by HIV vaccination. PMID:26814372

  18. HIV-specific regulatory T cells are associated with higher CD4 cell counts in primary infection

    PubMed Central

    Kared, Hassen; Lelièvre, Jean-Daniel; Donkova-Petrini, Vladimira; Aouba, Albertine; Melica, Giovanna; Balbo, Michèle; Weiss, Laurence; Lévy, Yves

    2008-01-01

    Objective Expansion of Regulatory T (Treg) cells has been described in chronically HIV-infected subjects. We investigated whether HIV-suppressive Treg could be detected during primary HIV infection (PHI). Methods Seventeen patients diagnosed early after PHI (median: 13 days; 1–55) were studied. Median CD4 cell count was 480 cells/μl (33–1306) and plasma HIV RNA levels ranged between 3.3 to 5.7 log10 cp/mL. Suppressive capacity of blood purified CD4+CD25+ was evaluated in a co-culture assay. Fox-p3, IL-2 and IL-10 were quantified by RT-PCR and intra-cellular staining of ex vivo and activated CD4+CD25high T cells. Results The frequency of CD4+CD127lowCD25high T cells among CD4 T cells was lower in PHI compared to chronic patients (n=19). They exhibited a phenotype of memory T cells and expressed constitutively FoxP3. Similarly to chronic patients, Treg from PHI patients inhibited the proliferation of PPD and HIV p24 activated CD4+CD25− T cells. CD4+CD25high T cells from PHI patients responded specifically to p24 stimulation by expressing IL-10. In untreated PHI patients, the frequency, as well as HIV-specific activity of Treg decreased during a 24-month follow up. A positive correlation between percentages of Treg and both CD4 cell counts and the magnitude of p24-specific suppressive activity at diagnosis of PHI was found. Conclusions Our data showed that HIV drives Treg since PHI and that these cells persist throughout the course of the infection. A correlation between the frequency of Treg and CD4 T cell counts suggest that these cells may impact on the immune activation set point at PHI diagnosis. PMID:19005268

  19. Sequential Dysfunction and Progressive Depletion of Candida albicans-Specific CD4 T Cell Response in HIV-1 Infection

    PubMed Central

    Liu, Fengliang; Fan, Xiuzhen; Auclair, Sarah; Ferguson, Monique; Sun, Jiaren; Soong, Lynn; Hou, Wei; Redfield, Robert R.; Birx, Deborah L.; Ratto-Kim, Silvia; Robb, Merlin L.; Kim, Jerome H.; Michael, Nelson L.; Hu, Haitao

    2016-01-01

    Loss of immune control over opportunistic infections can occur at different stages of HIV-1 (HIV) disease, among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans) is one of the early and common manifestations in HIV-infected human subjects. The underlying immunological basis is not well defined. We have previously shown that compared to cytomegalovirus (CMV)-specific CD4 cells, C. albicans-specific CD4 T cells are highly permissive to HIV in vitro. Here, based on an antiretroviral treatment (ART) naïve HIV infection cohort (RV21), we investigated longitudinally the impact of HIV on C. albicans- and CMV-specific CD4 T-cell immunity in vivo. We found a sequential dysfunction and preferential depletion for C. albicans-specific CD4 T cell response during progressive HIV infection. Compared to Th1 (IFN-γ, MIP-1β) functional subsets, the Th17 functional subsets (IL-17, IL-22) of C. albicans-specific CD4 T cells were more permissive to HIV in vitro and impaired earlier in HIV-infected subjects. Infection history analysis showed that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo, harboring modestly but significantly higher levels of HIV DNA, than CMV-specific CD4 T cells. Longitudinal analysis of HIV-infected individuals with ongoing CD4 depletion demonstrated that C. albicans-specific CD4 T-cell response was preferentially and progressively depleted. Taken together, these data suggest a potential mechanism for earlier loss of immune control over mucosal candidiasis in HIV-infected patients and provide new insights into pathogen-specific immune failure in AIDS pathogenesis. PMID:27280548

  20. Sequential Dysfunction and Progressive Depletion of Candida albicans-Specific CD4 T Cell Response in HIV-1 Infection.

    PubMed

    Liu, Fengliang; Fan, Xiuzhen; Auclair, Sarah; Ferguson, Monique; Sun, Jiaren; Soong, Lynn; Hou, Wei; Redfield, Robert R; Birx, Deborah L; Ratto-Kim, Silvia; Robb, Merlin L; Kim, Jerome H; Michael, Nelson L; Hu, Haitao

    2016-06-01

    Loss of immune control over opportunistic infections can occur at different stages of HIV-1 (HIV) disease, among which mucosal candidiasis caused by the fungal pathogen Candida albicans (C. albicans) is one of the early and common manifestations in HIV-infected human subjects. The underlying immunological basis is not well defined. We have previously shown that compared to cytomegalovirus (CMV)-specific CD4 cells, C. albicans-specific CD4 T cells are highly permissive to HIV in vitro. Here, based on an antiretroviral treatment (ART) naïve HIV infection cohort (RV21), we investigated longitudinally the impact of HIV on C. albicans- and CMV-specific CD4 T-cell immunity in vivo. We found a sequential dysfunction and preferential depletion for C. albicans-specific CD4 T cell response during progressive HIV infection. Compared to Th1 (IFN-γ, MIP-1β) functional subsets, the Th17 functional subsets (IL-17, IL-22) of C. albicans-specific CD4 T cells were more permissive to HIV in vitro and impaired earlier in HIV-infected subjects. Infection history analysis showed that C. albicans-specific CD4 T cells were more susceptible to HIV in vivo, harboring modestly but significantly higher levels of HIV DNA, than CMV-specific CD4 T cells. Longitudinal analysis of HIV-infected individuals with ongoing CD4 depletion demonstrated that C. albicans-specific CD4 T-cell response was preferentially and progressively depleted. Taken together, these data suggest a potential mechanism for earlier loss of immune control over mucosal candidiasis in HIV-infected patients and provide new insights into pathogen-specific immune failure in AIDS pathogenesis. PMID:27280548

  1. Effector and Central Memory Poly-Functional CD4+ and CD8+ T Cells are Boosted upon ZOSTAVAX® Vaccination

    PubMed Central

    Sei, Janet J.; Cox, Kara S.; Dubey, Sheri A.; Antonello, Joseph M.; Krah, David L.; Casimiro, Danilo R.; Vora, Kalpit A.

    2015-01-01

    ZOSTAVAX® is a live attenuated varicella-zoster virus (VZV) vaccine that is licensed for the protection of individuals ≥50 years against shingles and its most common complication, postherpetic neuralgia. While IFNγ responses increase upon vaccination, the quality of the T cell response has not been elucidated. By using polychromatic flow cytometry, we characterized the breadth, magnitude, and quality of ex vivo CD4+ and CD8+ T cell responses induced 3–4 weeks after ZOSTAVAX vaccination of healthy adults. We show, for the first time that the highest frequencies of VZV-specific CD4+ T cells were poly-functional CD154+IFNγ+IL-2+TNFα+ cells, which were boosted upon vaccination. The CD4+ T cells were broadly reactive to several VZV proteins, with immediate early (IE) 63 ranking the highest among them in the fold rise of poly-functional cells, followed by IE62, gB, open reading frame (ORF) 9, and gE. We identified a novel poly-functional ORF9-specific CD8+ T cell population in 62% of the subjects, and these were boosted upon vaccination. Poly-functional CD4+ and CD8+ T cells produced significantly higher levels of IFNγ, IL-2, and TNFα compared to mono-functional cells. After vaccination, a boost in the expression of IFNγ by poly-functional IE63- and ORF9-specific CD4+ T cells and IFNγ, IL-2, and TNFα by ORF9-specific poly-functional CD8+ T cells was observed. Responding poly-functional T cells exhibited both effector (CCR7−CD45RA−CD45RO+), and central (CCR7+CD45RA−CD45RO+) memory phenotypes, which expressed comparable levels of cytokines. Altogether, our studies demonstrate that a boost in memory poly-functional CD4+ T cells and ORF9-specific CD8+ T cells may contribute toward ZOSTAVAX efficacy. PMID:26579128

  2. [Comparative analysis of the role of CD4(+) and CD8(+) T cells in severe asthma development].

    PubMed

    Wang, X; Wang, J; Xing, C-Y; Zang, R; Pu, Y-Y; Yin, Z-X

    2015-01-01

    The role of CD8^(+) T cells in asthma has not been fully discussed. The mechanisms of CD4^(+) and CD8^(+) cells in severe asthma (SA) development were compared. The microarray data (GSE31773) was downloaded from the Gene Expression Omnibus (GEO) database, including 20 samples of CD4^(+) and CD8^(+) T cells, which were collected from 8 health controls (HC), 4 non-severe asthma (NSA) and 8 SA patients. DEGs of CD4^(+) and CD8^(+) T cells in the HC vs. NSA and HC vs. SA groups were identified using the limma package in R. GO and pathway enrichment analysis of the common DEGs between the two groups were analyzed using DAVID. The interactive network of DEGs and significant modules were further explored. In CD4^(+) cells, there were 168 DEGs in HC vs. NSA group and 685 DEGs in HC vs. SA group, while for CD8^(+) T cells there were 719 DEGs in the HC vs. NSA groups and 1255 DEGs in the HC vs. SA groups. Besides, 80 common DEGs from CD4^(+) samples were enriched in the MAPKKK cascade and molecular metabolism, and 385 common DEGs of CD8^(+) T cells were significantly related with cell apoptosis and transformation. Moreover, two significant modules of DEGs in CD4^(+) were found to be involved with MPO and BPI. One module of CD8^(+) T cells containing PDHA1 and MRPL42 was identified to be related with glycolysis. In conclusion, MPO and BPI in CD4^(+), and PDHA1 and MRPL42 in CD8^(+) T cells might be used as specific biomarkers of SA progression. Therapy targeting the functions of CD4^(+) and CD8^(+) T cells may provide a novel perspective for SA treatment. PMID:26107902

  3. Analysis of the In Vivo Turnover of CD4+ T-Cell Subsets in Chronically SIV-Infected Sooty Mangabeys

    PubMed Central

    Ortiz, Alexandra M.; Carnathan, Diane G.; Yu, Joana; Sheehan, Katherine M.; Kim, Peter; Reynaldi, Arnold; Vanderford, Thomas H.; Klatt, Nichole R.; Brenchley, Jason M.; Davenport, Miles P.; Silvestri, Guido

    2016-01-01

    Aberrant turnover of memory CD4+ T-cells is central to Acquired Immunodeficiency Syndrome (AIDS) progression. Understanding the relationship between the turnover of CD4+ subsets and immunological homeostasis during simian immunodeficiency virus (SIV) infection in natural hosts may provide insight into mechanisms of immune regulation that may serve as models for therapeutic intervention in Human Immunodeficiency Virus (HIV)-infected persons. Sooty mangabeys (SMs) have naturally evolved with SIV to avoid AIDS progression while maintaining healthy peripheral CD4+ T-cell counts and thus represent a model by which therapeutic interventions for AIDS progression might be elucidated. To assess the relationship between the turnover of CD4+ subsets and immunological homeostasis during SIV infection in non-progressive hosts, we treated 6 SIV-uninfected and 9 SIV-infected SMs with 2’-bromo-5’-deoxyuridine (BrdU) for 14 days and longitudinally assessed CD4+ T-cell subset turnover by polychromatic flow cytometry. We observed that, in SIV-infected SMs, turnover of CD4+ T-cell naïve and central, transitional, and effector memory subsets is comparable to that in uninfected animals. Comparable turnover of CD4+ T-cell subsets irrespective of SIV-infection status likely contributes to the lack of aberrant immune activation and disease progression observed after infection in non-progressive hosts. PMID:27227993

  4. Analysis of the In Vivo Turnover of CD4+ T-Cell Subsets in Chronically SIV-Infected Sooty Mangabeys.

    PubMed

    Ortiz, Alexandra M; Carnathan, Diane G; Yu, Joana; Sheehan, Katherine M; Kim, Peter; Reynaldi, Arnold; Vanderford, Thomas H; Klatt, Nichole R; Brenchley, Jason M; Davenport, Miles P; Silvestri, Guido

    2016-01-01

    Aberrant turnover of memory CD4+ T-cells is central to Acquired Immunodeficiency Syndrome (AIDS) progression. Understanding the relationship between the turnover of CD4+ subsets and immunological homeostasis during simian immunodeficiency virus (SIV) infection in natural hosts may provide insight into mechanisms of immune regulation that may serve as models for therapeutic intervention in Human Immunodeficiency Virus (HIV)-infected persons. Sooty mangabeys (SMs) have naturally evolved with SIV to avoid AIDS progression while maintaining healthy peripheral CD4+ T-cell counts and thus represent a model by which therapeutic interventions for AIDS progression might be elucidated. To assess the relationship between the turnover of CD4+ subsets and immunological homeostasis during SIV infection in non-progressive hosts, we treated 6 SIV-uninfected and 9 SIV-infected SMs with 2'-bromo-5'-deoxyuridine (BrdU) for 14 days and longitudinally assessed CD4+ T-cell subset turnover by polychromatic flow cytometry. We observed that, in SIV-infected SMs, turnover of CD4+ T-cell naïve and central, transitional, and effector memory subsets is comparable to that in uninfected animals. Comparable turnover of CD4+ T-cell subsets irrespective of SIV-infection status likely contributes to the lack of aberrant immune activation and disease progression observed after infection in non-progressive hosts. PMID:27227993

  5. In Vivo Identification and Characterization of CD4+ Cytotoxic T Cells Induced by Virulent Brucella abortus Infection

    PubMed Central

    Martirosyan, Anna; Von Bargen, Kristine; Arce Gorvel, Vilma; Zhao, Weidong; Hanniffy, Sean; Bonnardel, Johnny; Méresse, Stéphane; Gorvel, Jean-Pierre

    2013-01-01

    CD4+ T cells display a variety of helper functions necessary for an efficient adaptive immune response against bacterial invaders. This work reports the in vivo identification and characterization of murine cytotoxic CD4+ T cells (CD4+ CTL) during Brucella abortus infection. These CD4+ CTLs express granzyme B and exhibit immunophenotypic features consistent with fully differentiated T cells. They express CD25, CD44, CD62L ,CD43 molecules at their surface and produce IFN-γ. Moreover, these cells express neither the co-stimulatory molecule CD27 nor the memory T cell marker CD127. We show here that CD4+ CTLs are capable of cytolytic action against Brucella-infected antigen presenting cells (APC) but not against Mycobacterium-infected APC. Cytotoxic CD4+ T cell population appears at early stages of the infection concomitantly with high levels of IFN-γ and granzyme B expression. CD4+ CTLs represent a so far uncharacterized immune cell sub-type triggered by early immune responses upon Brucella abortus infection. PMID:24367519

  6. In vivo identification and characterization of CD4⁺ cytotoxic T cells induced by virulent Brucella abortus infection.

    PubMed

    Martirosyan, Anna; Von Bargen, Kristine; Arce Gorvel, Vilma; Zhao, Weidong; Hanniffy, Sean; Bonnardel, Johnny; Méresse, Stéphane; Gorvel, Jean-Pierre

    2013-01-01

    CD4(+) T cells display a variety of helper functions necessary for an efficient adaptive immune response against bacterial invaders. This work reports the in vivo identification and characterization of murine cytotoxic CD4(+) T cells (CD4(+) CTL) during Brucella abortus infection. These CD4(+) CTLs express granzyme B and exhibit immunophenotypic features consistent with fully differentiated T cells. They express CD25, CD44, CD62L ,CD43 molecules at their surface and produce IFN-γ. Moreover, these cells express neither the co-stimulatory molecule CD27 nor the memory T cell marker CD127. We show here that CD4(+) CTLs are capable of cytolytic action against Brucella-infected antigen presenting cells (APC) but not against Mycobacterium-infected APC. Cytotoxic CD4(+) T cell population appears at early stages of the infection concomitantly with high levels of IFN-γ and granzyme B expression. CD4(+) CTLs represent a so far uncharacterized immune cell sub-type triggered by early immune responses upon Brucella abortus infection. PMID:24367519

  7. Virus-specific CD4+ memory phenotype T cells are abundant in unexposed adults

    PubMed Central

    Su, Laura F.; Kidd, Brian A.; Han, Arnold; Kotzin, Jonathan J.; Davis, Mark M.

    2013-01-01

    While T cell memory is generally thought to require direct antigen exposure, we find an abundance of memory phenotype cells (20–90%, averaging over 50%) of CD4+ T cells specific for viral antigens in adults that have never been infected. These cells express the appropriate memory markers and genes, rapidly produce cytokines, and have clonally expanded. This contrasts with newborns where the same T cell receptor (TCR) specificities are almost entirely naïve, which may explain the vulnerability of young children to infections. One mechanism for this phenomenon is TCR cross-reactivity to environmental antigens and in support of this we find extensive cross-recognition by HIV-1 and influenza-reactive T lymphocytes to other microbial peptides and the expansion of one of these following influenza vaccination. Thus the presence of these memory phenotype T cells has significant implications for immunity to novel pathogens, child and adult health, and the influence of pathogen-rich versus hygienic environments. PMID:23395677

  8. Peripheral and central neuronal ATF3 precedes CD4+ T-cell infiltration in EAE.

    PubMed

    Frezel, Noémie; Sohet, Fabien; Daneman, Richard; Basbaum, Allan I; Braz, Joao M

    2016-09-01

    Experimental allergic encephalomyelitis (EAE), an animal model of multiple sclerosis produced by immunization with myelin oligodendrocyte glycoprotein (MOG) and adjuvants, results from profound T-cell mediated CNS demyelination. EAE is characterized by progressive, ascending motor dysfunction and symptoms of ongoing pain and hypersensitivity, in some cases preceding or concomitant with the motor deficits. In this regard, the EAE model mimics major features of multiple sclerosis, where a central neuropathic pain state is common. Although the latter condition is presumed to arise from a CNS loss of inhibitory controls secondary to the demyelination, dysfunction of sensory neurons may also contribute. Based on our previous studies that demonstrated the utility of monitoring expression of activating transcription factor 3 (ATF3), a sensitive marker of injured sensory neurons, here we followed both ATF3 and CD4+ T cells invasion of sensory ganglia (as well as the CNS) at different stages of the EAE model. We found that ATF3 is induced in peripheral sensory ganglia and brainstem well before the appearance of motor deficits. Unexpectedly, the ATF3 induction always preceded T cell infiltration, typically in adjacent, but non-overlapping regions. Surprisingly, control administration of the pertussis toxin and/or Complete Freund's adjuvants, without MOG, induced ATF3 in sensory neurons. In contrast, T cell infiltration only occurred with MOG. Taken together, our results suggest that the clinical manifestations in the EAE result not only from central demyelination but also from neuronal stress and subsequent pathophysiology of sensory neurons. PMID:27343802

  9. Two FOXP3(+)CD4(+) T cell subpopulations distinctly control the prognosis of colorectal cancers.

    PubMed

    Saito, Takuro; Nishikawa, Hiroyoshi; Wada, Hisashi; Nagano, Yuji; Sugiyama, Daisuke; Atarashi, Koji; Maeda, Yuka; Hamaguchi, Masahide; Ohkura, Naganari; Sato, Eiichi; Nagase, Hirotsugu; Nishimura, Junichi; Yamamoto, Hirofumi; Takiguchi, Shuji; Tanoue, Takeshi; Suda, Wataru; Morita, Hidetoshi; Hattori, Masahira; Honda, Kenya; Mori, Masaki; Doki, Yuichiro; Sakaguchi, Shimon

    2016-06-01

    CD4(+) T cells that express the forkhead box P3 (FOXP3) transcription factor function as regulatory T (Treg) cells and hinder effective immune responses against cancer cells. Abundant Treg cell infiltration into tumors is associated with poor clinical outcomes in various types of cancers. However, the role of Treg cells is controversial in colorectal cancers (CRCs), in which FOXP3(+) T cell infiltration indicated better prognosis in some studies. Here we show that CRCs, which are commonly infiltrated by suppression-competent FOXP3(hi) Treg cells, can be classified into two types by the degree of additional infiltration of FOXP3(lo) nonsuppressive T cells. The latter, which are distinguished from FOXP3(+) Treg cells by non-expression of the naive T cell marker CD45RA and instability of FOXP3, secreted inflammatory cytokines. Indeed, CRCs with abundant infiltration of FOXP3(lo) T cells showed significantly better prognosis than those with predominantly FOXP3(hi) Treg cell infiltration. Development of such inflammatory FOXP3(lo) non-Treg cells may depend on secretion of interleukin (IL)-12 and transforming growth factor (TGF)-β by tissues and their presence was correlated with tumor invasion by intestinal bacteria, especially Fusobacterium nucleatum. Thus, functionally distinct subpopulations of tumor-infiltrating FOXP3(+) T cells contribute in opposing ways to determining CRC prognosis. Depletion of FOXP3(hi) Treg cells from tumor tissues, which would augment antitumor immunity, could thus be used as an effective treatment strategy for CRCs and other cancers, whereas strategies that locally increase the population of FOXP3(lo) non-Treg cells could be used to suppress or prevent tumor formation. PMID:27111280

  10. Antigen-specific and non-specific CD4{sup +} T cell recruitment and proliferation during influenza infection

    SciTech Connect

    Chapman, Timothy J.; Castrucci, Maria R.; Padrick, Ryan C.; Bradley, Linda M.; Topham, David J. . E-mail: david_topham@urmc.rochester.edu

    2005-09-30

    To track epitope-specific CD4{sup +} T cells at a single-cell level during influenza infection, the MHC class II-restricted OVA{sub 323-339} epitope was engineered into the neuraminidase stalk of influenza/A/WSN, creating a surrogate viral antigen. The recombinant virus, influenza A/WSN/OVA{sub II}, replicated well, was cleared normally, and stimulated both wild-type and DO11.10 or OT-II TCR transgenic OVA-specific CD4{sup +} 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{sup +} T cells were recruited to the infected lung both in the presence and absence of the OVA{sub 323-339} epitope. These data show that, when primed, CD4{sup +} 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.

  11. Oral vaccination with lipid-formulated BCG induces a long-lived, multifunctional CD4(+) T cell memory immune response.

    PubMed

    Ancelet, Lindsay R; Aldwell, Frank E; Rich, Fenella J; Kirman, Joanna R

    2012-01-01

    Oral delivery of BCG in a lipid formulation (Liporale™-BCG) targets delivery of viable bacilli to the mesenteric lymph nodes and confers protection against an aerosol Mycobacterium tuberculosis challenge. The magnitude, quality and duration of the effector and memory immune response induced by Liporale™-BCG vaccination is unknown. Therefore, we compared the effector and memory CD4(+) T cell response in the spleen and lungs of mice vaccinated with Liporale™-BCG to the response induced by subcutaneous BCG vaccination. Liporale™-BCG vaccination induced a long-lived CD4(+) T cell response, evident by the detection of effector CD4(+) T cells in the lungs and a significant increase in the number of Ag85B tetramer-specific CD4(+) T cells in the spleen up to 30 weeks post vaccination. Moreover, following polyclonal stimulation, Liporale™-BCG vaccination, but not s.c. BCG vaccination, induced a significant increase in both the percentage of CD4(+) T cells in the lungs capable of producing IFNγ and the number of multifunctional CD4(+) T cells in the lungs at 30 weeks post vaccination. These results demonstrate that orally delivered Liporale™-BCG vaccine induces a long-lived multifunctional immune response, and could therefore represent a practical and effective means of delivering novel BCG-based TB vaccines. PMID:23049885

  12. The Role of CD4 T Cell Memory in Generating Protective Immunity to Novel and Potentially Pandemic Strains of Influenza

    PubMed Central

    DiPiazza, Anthony; Richards, Katherine A.; Knowlden, Zackery A. G.; Nayak, Jennifer L.; Sant, Andrea J.

    2016-01-01

    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. Animal models have revealed the discrete functions that CD4 T cells play in 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 the achievement of these goals. PMID:26834750

  13. Calnexin induces expansion of antigen-specific CD4(+) T cells that confer immunity to fungal ascomycetes via conserved epitopes.

    PubMed

    Wüthrich, Marcel; Brandhorst, Tristan T; Sullivan, Thomas D; Filutowicz, Hanna; Sterkel, Alana; Stewart, Douglas; Li, Mengyi; Lerksuthirat, Tassanee; LeBert, Vanessa; Shen, Zu Ting; Ostroff, Gary; Deepe, George S; Hung, Chiung Yu; Cole, Garry; Walter, Jennifer A; Jenkins, Marc K; Klein, Bruce

    2015-04-01

    Fungal infections remain a threat due to the lack of broad-spectrum fungal vaccines and protective antigens. Recent studies showed that attenuated Blastomyces dermatitidis confers protection via T cell recognition of an unknown but conserved antigen. Using transgenic CD4(+) T cells recognizing this antigen, we identify an amino acid determinant within the chaperone calnexin that is conserved across diverse fungal ascomycetes. Calnexin, typically an ER protein, also localizes to the surface of yeast, hyphae, and spores. T cell epitope mapping unveiled a 13-residue sequence conserved across Ascomycota. Infection with divergent ascomycetes, including dimorphic fungi, opportunistic molds, and the agent causing white nose syndrome in bats, induces expansion of calnexin-specific CD4(+) T cells. Vaccine delivery of calnexin in glucan particles induces fungal antigen-specific CD4(+) T cell expansion and resistance to lethal challenge with multiple fungal pathogens. Thus, the immunogenicity and conservation of calnexin make this fungal protein a promising vaccine target. PMID:25800545

  14. Calnexin induces expansion of antigen-specific CD4+ T cells that confer immunity to fungal ascomycetes via conserved epitopes

    PubMed Central

    Wüthrich, Marcel; Brandhorst, Tristan T.; Sullivan, Thomas D.; Filutowicz, Hanna; Sterkel, Alana; Stewart, Douglas; Li, Mengyi; Lerksuthirat, Tassanee; LeBert, Vanessa; Shen, Zu Ting; Ostroff, Gary; Deepe, George S.; Hung, Chiung Yu; Cole, Garry; Walter, Jennifer A.; Jenkins, Marc K.; Klein, Bruce

    2015-01-01

    Fungal infections remain a threat due to the lack of broad spectrum fungal vaccines and protective antigens. Recent studies showed that attenuated Blastomyces dermatitidis confers protection via T cell recognition of an unknown, but conserved antigen. Using transgenic CD4+ T cells recognizing this antigen, we identify an amino acid determinant within the chaperone calnexin that is conserved across diverse fungal ascomycetes. Calnexin, typically an ER protein, also localizes to the surface of yeast, hyphae and spores. T cell epitope mapping unveiled a 13-residue sequence conserved across Ascomycota. Infection with divergent ascomycetes including dimorphic fungi, opportunistic molds, and the agent causing white nose syndrome in bats induces expansion of calnexin-specific CD4+ T cells. Vaccine delivery of calnexin in glucan particles induces fungal antigen-specific CD4+ T cell expansion and resistance to lethal challenge with multiple fungal pathogens. Thus, the immunogeneticity and conservation of calnexin make this fungal protein a promising vaccine target. PMID:25800545

  15. Temporal Gene Regulation During HIV-1 Infection of Human CD4+ T Cells

    PubMed Central

    Corbeil, Jacques; Sheeter, Dennis; Genini, Davide; Rought, Steffney; Leoni, Lorenzo; Du, Pinyi; Ferguson, Mark; Masys, Daniel R.; Welsh, John B.; Fink, J. Lynn; Sasik, Roman; Huang, David; Drenkow, Jorg; Richman, Douglas D.; Gingeras, Thomas

    2001-01-01

    CD4+ T-cell depletion is a characteristic of human immunodeficiency virus type 1 (HIV-1) infection. In this study, modulation of mRNA expression of 6800 genes was monitored simultaneously at eight time points in a CD4+ T-cell line (CEM-GFP) during HIV infection. The responses to infection included: (1) >30% decrease at 72 h after infection in overall host-cell production of monitored mRNA synthesis, with the replacement of host-cell mRNA by viral mRNA, (2) suppression of the expression of selected mitochondrial and DNA repair gene transcripts, (3) increased expression of the proapoptotic gene and its gene p53-induced product Bax, and (4) activation of caspases 2, 3, and 9. The intense HIV-1 transcription resulted in the repression of much cellular RNA expression and was associated with the induction of apoptosis of infected cells but not bystander cells. This choreographed host gene response indicated that the subversion of the cell transcriptional machinery for the purpose of HIV-1 replication is akin to genotoxic stress and represents a major factor leading to HIV-induced apoptosis. PMID:11435401

  16. Dynamics of HIV Latency and Reactivation in a Primary CD4+ T Cell Model

    PubMed Central

    Muñoz, Miguel; Martinez, Raquel; Bartha, István; Cavassini, Matthias; Thorball, Christian; Fellay, Jacques; Beerenwinkel, Niko; Ciuffi, Angela; Telenti, Amalio

    2014-01-01

    HIV latency is a major obstacle to curing infection. Current strategies to eradicate HIV aim at increasing transcription of the latent provirus. In the present study we observed that latently infected CD4+ T cells from HIV-infected individuals failed to produce viral particles upon ex vivo exposure to SAHA (vorinostat), despite effective inhibition of histone deacetylases. To identify steps that were not susceptible to the action of SAHA or other latency reverting agents, we used a primary CD4+ T cell model, joint host and viral RNA sequencing, and a viral-encoded reporter. This model served to investigate the characteristics of latently infected cells, the dynamics of HIV latency, and the process of reactivation induced by various stimuli. During latency, we observed persistence of viral transcripts but only limited viral translation. Similarly, the reactivating agents SAHA and disulfiram successfully increased viral transcription, but failed to effectively enhance viral translation, mirroring the ex vivo data. This study highlights the importance of post-transcriptional blocks as one mechanism leading to HIV latency that needs to be relieved in order to purge the viral reservoir. PMID:24875931

  17. Memory programming in CD8+ T-cell differentiation is intrinsic and is not determined by CD4 help

    PubMed Central

    Kim, Juhyun; Jeong Ryu, Su; Oh, Keunhee; Ju, Ji-Min; Yeong Jeon, Ji; Nam, Giri; Lee, Dong-Sup; Kim, Hang-Rae; Young Kim, Joo; Chang, Jun; Sproule, Thomas; Choi, Kyungho; Roopenian, Derry; Young Choi, Eun

    2015-01-01

    CD8+ T cells activated without CD4+ T-cell help are impaired in memory expansion. To understand the underlying cellular mechanism, here we track the dynamics of helper-deficient CD8+ T-cell response to a minor histocompatibility antigen by phenotypic and in vivo imaging analyses. Helper-deficient CD8+ T cells show reduced burst expansion, rapid peripheral egress, delayed antigen clearance and continuous activation, and are eventually exhausted. Contrary to the general consensus that CD4 help encodes memory programmes in CD8+ T cells and helper-deficient CD8+ T cells are abortive, these cells can differentiate into effectors and memory precursors. Importantly, accelerating antigen clearance or simply increasing the burst effector size enables generation of memory cells by CD8+ T cells, regardless of CD4 help. These results suggest that the memory programme is CD8+ T-cell-intrinsic, and provide insight into the role of CD4 help in CD8+ T-cell responses. PMID:26272364

  18. Intranasal vaccination with proinsulin DNA induces regulatory CD4+ T cells that prevent experimental autoimmune diabetes.

    PubMed

    Every, Alison L; Kramer, David R; Mannering, Stuart I; Lew, Andrew M; Harrison, Leonard C

    2006-04-15

    Insulin, an autoantigen in type 1 diabetes, when administered mucosally to diabetes-prone NOD mice induces regulatory T cells (T(reg)) that protect against diabetes. Compared with protein, Ag encoded as DNA has potential advantages as a therapeutic agent. We found that intranasal vaccination of NOD mice with plasmid DNA encoding mouse proinsulin II-induced CD4+ T(reg) that suppressed diabetes development, both after adoptive cotransfer with "diabetogenic" spleen cells and after transfer into NOD mice given cyclophosphamide to accelerate diabetes onset. In contrast to prototypic CD4+ CD25+ T(reg), CD4+ T(reg) induced by proinsulin DNA were both CD25+ and CD25- and not defined by markers such as glucocorticoid-induced TNFR-related protein (GITR), CD103, or Foxp3. Intriguingly, despite induction of T(reg) and reduced islet inflammation, diabetes incidence in proinsulin DNA-treated mice was unchanged. However, diabetes was prevented when DNA vaccination was performed under the cover of CD40 ligand blockade, known to prevent priming of CTL by mucosal Ag. Thus, intranasal vaccination with proinsulin DNA has therapeutic potential to prevent diabetes, as demonstrated by induction of protective T(reg), but further modifications are required to improve its efficacy, which could be compromised by concomitant induction of pathogenic immunity. PMID:16585551

  19. 5-Hydroxymethylcytosine Remodeling Precedes Lineage Specification during Differentiation of Human CD4(+) T Cells.

    PubMed

    Nestor, Colm E; Lentini, Antonio; Hägg Nilsson, Cathrine; Gawel, Danuta R; Gustafsson, Mika; Mattson, Lina; Wang, Hui; Rundquist, Olof; Meehan, Richard R; Klocke, Bernward; Seifert, Martin; Hauck, Stefanie M; Laumen, Helmut; Zhang, Huan; Benson, Mikael

    2016-07-12

    5-methylcytosine (5mC) is converted to 5-hydroxymethylcytosine (5hmC) by the TET family of enzymes as part of a recently discovered active DNA de-methylation pathway. 5hmC plays important roles in regulation of gene expression and differentiation and has been implicated in T cell malignancies and autoimmunity. Here, we report early and widespread 5mC/5hmC remodeling during human CD4(+) T cell differentiation ex vivo at genes and cell-specific enhancers with known T cell function. We observe similar DNA de-methylation in CD4(+) memory T cells in vivo, indicating that early remodeling events persist long term in differentiated cells. Underscoring their important function, 5hmC loci were highly enriched for genetic variants associated with T cell diseases and T-cell-specific chromosomal interactions. Extensive functional validation of 22 risk variants revealed potentially pathogenic mechanisms in diabetes and multiple sclerosis. Our results support 5hmC-mediated DNA de-methylation as a key component of CD4(+) T cell biology in humans, with important implications for gene regulation and lineage commitment. PMID:27346350

  20. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells

    PubMed Central

    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

  1. A Human Trypanosome Suppresses CD8+ T Cell Priming by Dendritic Cells through the Induction of Immune Regulatory CD4+ Foxp3+ T Cells.

    PubMed

    Ersching, Jonatan; Basso, Alexandre Salgado; Kalich, Vera Lucia Garcia; Bortoluci, Karina Ramalho; Rodrigues, Maurício M

    2016-06-01

    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

  2. Idiopathic CD4 lymphocytopenia: a case of missing, wandering or ineffective T cells

    PubMed Central

    2012-01-01

    Idiopathic CD4 lymphocytopenia (ICL) is a presumed heterogenous syndrome with key element low CD4 T-cell counts (below 300/mm3) without evidence of HIV infection or other known immunodeficiency. The etiology, pathogenesis, and management of ICL remain poorly understood and inadequately defined. The clinical presentation can range from serious opportunistic infections to incidentally diagnosed asymptomatic individuals. Cryptococcal and non-tuberculous mycobacterial infections and progressive multifocal leukoencephalopathy are the most significant presenting infections, although the spectrum of opportunistic diseases can be similar to that in patients with lymphopenia and HIV infection. Malignancy is common and related to opportunistic pathogens with an oncogenic potential. Autoimmune diseases are also seen in ICL with an increased incidence. The etiology of ICL is unknown. Mechanisms implicated in CD4 reduction may include decreased production, increased destruction, and tissue sequestration. New distinct genetic defects have been identified in certain patients with ICL, supporting the hypothesis of the lack of a common etiology in this syndrome. The management of ICL is focused on the treatment of opportunistic infections, appropriate prophylactic antibiotics, and close monitoring. In selected patients with life-threatening infections or profound immunodeficiency, strategies to increase T-cell counts or enhance immune function could be considered and have included interleukin-2, interferon-gamma, interleukin-7, and hematopoietic stem cell transplantation. The prognosis is influenced by the accompanying opportunistic infections and may be affected by publication bias of severe cases with unfavorable outcomes. As newer laboratory investigation techniques are being developed and targeted experimental treatments become available, our comprehension and prognosis of this rare syndrome could be significantly improved. PMID:22971990

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

    PubMed

    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. PMID:16360834

  4. Importance of B cell co-stimulation in CD4(+) T cell differentiation: X-linked agammaglobulinaemia, a human model.

    PubMed

    Martini, H; Enright, V; Perro, M; Workman, S; Birmelin, J; Giorda, E; Quinti, I; Lougaris, V; Baronio, M; Warnatz, K; Grimbacher, B

    2011-06-01

    We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann-Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4(+)CD45RO(+) and CD4(+)CD45RO(+)CXCR5(+) cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans. PMID:21488866

  5. Importance of B cell co-stimulation in CD4+ T cell differentiation: X-linked agammaglobulinaemia, a human model

    PubMed Central

    Martini, H; Enright, V; Perro, M; Workman, S; Birmelin, J; Giorda, E; Quinti, I; Lougaris, V; Baronio, M; Warnatz, K; Grimbacher, B

    2011-01-01

    We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann–Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4+CD45RO+ and CD4+CD45RO+CXCR5+ cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans. PMID:21488866

  6. CD4+ and CD8+ TCRβ repertoires possess different potentials to generate extraordinarily high-avidity T cells

    PubMed Central

    Nakatsugawa, Munehide; Rahman, Muhammed A.; Yamashita, Yuki; Ochi, Toshiki; Wnuk, Piotr; Tanaka, Shinya; Chamoto, Kenji; Kagoya, Yuki; Saso, Kayoko; Guo, Tingxi; Anczurowski, Mark; Butler, Marcus O.; Hirano, Naoto

    2016-01-01

    Recent high throughput sequencing analysis has revealed that the TCRβ repertoire is largely different between CD8+ and CD4+ T cells. Here, we show that the transduction of SIG35α, the public chain-centric HLA-A*02:01(A2)/MART127–35 TCRα hemichain, conferred A2/MART127–35 reactivity to a substantial subset of both CD8+ and CD4+ T cells regardless of their HLA–A2 positivity. T cells individually reconstituted with SIG35α and different A2/MART127–35 TCRβ genes isolated from CD4+ or CD8+ T cells exhibited a wide range of avidity. Surprisingly, approximately half of the A2/MART127–35 TCRs derived from CD4+ T cells, but none from CD8+ T cells, were stained by A2/MART127–35 monomer and possessed broader cross-reactivity. Our results suggest that the differences in the primary structure of peripheral CD4+ and CD8+ TCRβ repertoire indeed result in the differences in their ability to form extraordinarily high avidity T cells which would otherwise have been deleted by central tolerance. PMID:27030642

  7. Characterization of the human CD4(+) T-cell repertoire specific for major histocompatibility class I-restricted antigens.

    PubMed

    Legoux, François; Gautreau, Laetitia; Hesnard, Leslie; Leger, Alexandra; Moyon, Melinda; Devilder, Marie-Claire; Bonneville, Marc; Saulquin, Xavier

    2013-12-01

    While CD4(+) T lymphocytes usually recognize antigens in the context of major histocompatibility (MHC) class II alleles, occurrence of MHC class-I restricted CD4(+) T cells has been reported sporadically. Taking advantage of a highly sensitive MHC tetramer-based enrichment approach allowing detection and isolation of scarce Ag-specific T cells, we performed a systematic comparative analysis of HLA-A*0201-restricted CD4(+) and CD8(+) T-cell lines directed against several immunodominant viral or tumoral antigens. CD4(+) T cells directed against every peptide-MHC class I complexes tested were detected in all donors. These cells yielded strong cytotoxic and T helper 1 cytokine responses when incubated with HLA-A2(+) target cells carrying the relevant epitopes. HLA-A2-restricted CD4(+) T cells were seldom expanded in immune HLA-A2(+) donors, suggesting that they are not usually engaged in in vivo immune responses against the corresponding peptide-MHC class I complexes. However, these T cells expressed TCR of very high affinity and were expanded following ex vivo stimulation by relevant tumor cells. Therefore, we describe a versatile and efficient strategy for generation of MHC class-I restricted T helper cells and high affinity TCR that could be used for adoptive T-cell transfer- or TCR gene transfer-based immunotherapies. PMID:23963968

  8. Cross-priming of long lived protective CD8+ T cells against Trypanosoma cruzi infection: importance of a TLR9 agonist and CD4+ T cells.

    PubMed

    de Alencar, Bruna C G; Araújo, Adriano F S; Penido, Marcus L O; Gazzinelli, Ricardo T; Rodrigues, Mauricio M

    2007-08-10

    We recently described that vaccination of mice with a glutathione S transferase fusion protein representing amino acids 261-500 of the Amastigote Surface Protein-2 efficiently cross-primed protective CD8+ T cells against a lethal challenge with the human protozoan parasite Trypanosoma cruzi. In this study, we initially established that this protective immunity was long lived. Subsequently, we studied the importance of TLR9 agonist CpG ODN 1826, TLR4 and CD4+ T cells for the generation of these protective CD8+ T cells. We found that: (i) the TLR9 agonist CpG ODN 1826 improved the efficiency of protective immunity; (ii) TLR4 is not relevant for priming of specific CD8+ T cells; (iii) CD4+ T cells are critical for priming of memory/protective CD8+ T cells. PMID:17629597

  9. Expression of S100 Protein in CD4-positive T-cell Lymphomas Is Often Associated With T-cell Prolymphocytic Leukemia.

    PubMed

    Aggarwal, Nidhi; Pongpruttipan, Tawatchai; Patel, Snehal; Bayerl, Michael G; Alkan, Serhan; Nathwani, Bharat; Surti, Urvashi; Kitahara, Sumire; Chinthammitr, Yingyong; Swerdlow, Steven H

    2015-12-01

    S100 T-cell lymphomas are infrequent, and except 1 all have been CD4 negative. On the basis of an index case of CD4 S100 T-cell prolymphocytic leukemia (T-PLL), we studied S100 protein expression in 19 additional T-PLLs and 56 other T-cell lymphomas that are usually CD4, including 15 angioimmunoblastic T-cell lymphomas, 24 anaplastic large cell lymphomas (16 ALK and 8 ALK), 7 mycosis fungoides/Sézary syndrome, and 10 peripheral T-cell lymphoma, not otherwise specified (PTCL, NOS). Two additional S100 CD4 PTCL, NOS cases were also reviewed. Thirty percent (6/20) of T-PLLs were S100 compared with 0/56 other T-cell lymphomas with previously unstudied S100 reactivity (40 CD4, 2 CD8, 11 CD4/CD8, 3 unknown) (P=0.0007). There were no significant differences between the S100 and S100 T-PLLs with regard to the male:female ratio (2:1 vs. 1:1), age (71.6±7.7 vs. 65.4±9.3), peripheral blood lymphocyte count (67.2±116.6 vs. 101.1±159.7×10/L), or median survival (463 vs. 578 d, where known). The 2 S100 PTCL, NOS cases occurred in a 7-year-old boy and a 45-year-old woman. Both had involvement of the bone marrow and peripheral blood but were morphologically unlike T-PLL and lacked TCL1 gene rearrangement. These results demonstrate that S100 T-cell lymphomas include a subset that are CD4 and most often, but not exclusively, are T-PLL. Although having diagnostic implications, there were no documented clinical differences between the S100 and S100 T-PLLs. PMID:26379148

  10. Depletion of CD8+ T Cells Exacerbates CD4+ T Cell-Induced Monocyte-to-Fibroblast Transition in Renal Fibrosis.

    PubMed

    Dong, Yanjun; Yang, Min; Zhang, Jing; Peng, Xiaogang; Cheng, Jizhong; Cui, Taigeng; Du, Jie

    2016-02-15

    Bone marrow-derived monocyte-to-fibroblast transition is a key step in renal fibrosis pathogenesis, which is regulated by the inflammatory microenvironment. However, the mechanism by which the inflammatory microenvironment regulates this transition is not fully understood. In this study, we examined how the CD8(+) T cell/IFN-γ microenvironment regulates the monocyte-to-fibroblast transition in renal fibrosis. Genetic ablation of CD8 promoted a monocyte-to-fibroblast transition and increased renal interstitial fibrosis, whereas reconstitution of CD8 knockout (KO) mice with CD8(+) T cells decreased fibrosis. However, depletion of CD4(+) T cells in CD8 KO mice also reduced fibrosis. To elucidate the role of CD4(+) T cells in mediating CD8-regulated monocyte-to-fibroblast transition, CD4(+) T cells were isolated from obstructed kidneys of CD8 KO or wild-type mice. CD4(+) T cells isolated from CD8 KO obstructed kidney expressed more IL-4 and GATA3 and less IFN-γ and T-bet and showed increased monocyte-to-fibroblast transition in vitro compared with those isolated from wild-type obstructed kidney. To examine the role of IFN-γ-expressing CD8(+) T cells, we reconstituted CD8 KO mice with CD8(+) T cells isolated from IFN-γ KO mice. The IFN-γ KO CD8(+) cells had no effect on IL-4, GATA3, IFN-γ, and T-bet mRNA expression in obstructed kidneys or renal fibrosis. Taken together, our findings identify the axis of CD8(+) T cells and IFN-γ-CD4(+) T cells as an important microenvironment for the monocyte-to-fibroblast transition, which negatively regulates renal fibrosis. PMID:26773152

  11. Suppression of CD4+ Effector Responses by Naturally Occurring CD4+ CD25+ Foxp3+ Regulatory T Cells Contributes to Experimental Cerebral Malaria

    PubMed Central

    Blanc, Anne-Laurence; Keswani, Tarun; Gorgette, Olivier; Bandeira, Antonio; Malissen, Bernard; Cazenave, Pierre-André

    2015-01-01

    The role of naturally occurring CD4+ CD25+ Foxp3+ regulatory T cells (nTreg) in the pathogenesis of cerebral malaria (CM), which involves both pathogenic T cell responses and parasite sequestration in the brain, is still unclear. To assess the contribution and dynamics of nTreg during the neuropathogenesis, we unbalanced the ratio between nTreg and naive CD4+ T cells in an attenuated model of Plasmodium berghei ANKA-induced experimental CM (ECM) by using a selective cell enrichment strategy. We found that nTreg adoptive transfer accelerated the onset and increased the severity of CM in syngeneic C57BL/6 (B6) P. berghei ANKA-infected mice without affecting the level of parasitemia. In contrast, naive CD4+ T cell enrichment prevented CM and promoted parasite clearance. Furthermore, early during the infection nTreg expanded in the spleen but did not efficiently migrate to the site of neuroinflammation, suggesting that nTreg exert their pathogenic action early in the spleen by suppressing the protective naive CD4+ T cell response to P. berghei ANKA infection in vivo in both CM-susceptible (B6) and CM-resistant (B6-CD4−/−) mice. However, their sole transfer was not sufficient to restore CM susceptibility in two CM-resistant congenic strains tested. Altogether, these results demonstrate that nTreg are activated and functional during P. berghei ANKA infection and that they contribute to the pathogenesis of CM. They further suggest that nTreg may represent an early target for the modulation of the immune response to malaria. PMID:26553468

  12. Protective Vaccine-Induced CD4+ T Cell-Independent B Cell Responses against Rabies Infection

    PubMed Central

    Dorfmeier, Corin L.; Lytle, Andrew G.; Dunkel, Amber L.; Gatt, Anthony

    2012-01-01

    A major goal in rabies virus (RV) research is to develop a single-dose postexposure prophylaxis (PEP) that would simplify vaccination protocols, reduce costs associated with rabies prevention in humans, and save lives. Live replication-deficient RV-based vaccines are emerging as promising single-dose vaccines to replace currently licensed inactivated RV-based vaccines. Nonetheless, little is known about how effective B cells develop in response to live RV-based vaccination. Understanding this fundamental property of rabies immunology may help in developing a single-dose RV vaccine. Typically, vaccines induce B cells secreting high-affinity, class-switched antibodies during germinal center (GC) reactions; however, there is a lag time between vaccination and the generation of GC B cells. In this report, we show that RV-specific antibodies are detected in mice immunized with live but not inactivated RV-based vaccines before B cells displaying a GC B cell phenotype (B220+GL7hiCD95hi) are formed, indicating a potential role for T cell-independent and early extrafollicular T cell-dependent antibody responses in the protection against RV infection. Using two mouse models of CD4+ T cell deficiency, we show that B cells secreting virus-neutralizing antibodies (VNAs) are induced via T cell-independent mechanisms within 4 days postimmunization with a replication-deficient RV-based vaccine. Importantly, mice that are completely devoid of T cells (B6.129P2-Tcrβtm1Mom Tcrδtm1Mom/J) show protection against pathogenic challenge shortly after immunization with a live replication-deficient RV-based vaccine. We show that vaccines that can exploit early pathways of B cell activation and development may hold the key for the development of a single-dose RV vaccine wherein the rapid induction of VNA is critical. PMID:22896601

  13. Expression of IL-37 contributes to the immunosuppressive property of human CD4+CD25+ regulatory T cells.

    PubMed

    Shuai, Xu; Wei-min, Li; Tong, Ya-lin; Dong, Ning; Sheng, Zhi-yong; Yao, Yong-ming

    2015-01-01

    Interleukin-37 (IL-37) possesses the function of down-regulate systemic and local inflammation. It is unknown whether IL-37 is expressed in human regulatory T cells (Tregs) and its role in modulating the immune response of Tregs. In the present study, cell surface molecules and secretory cytokines were analyzed in order to determine the function of IL-37 in regulating inhibitory effect of human CD4(+)CD25(+)Tregs. Meanwhile, the effects of IL-37 on T cell differentiation and proliferation as co-culture of CD4(+)CD25(+)Treg/CD4(+)CD25(-)T cell were also investigated. It was showed that IL-37 was expressed in cytoplasm of CD4(+)CD25(+)Tregs, and the levels of IL-37 were gradually elevated with the enhanced activity of CD4(+)CD25(+)Tregs. Secretory cytokines such as transforming growth factor (TGF)-β and interleukin (IL)-10, and expressions of cell surface molecules, including forkhead/winged helix transcription factor p3 (FOXP3) and cytotoxic T-lymphocyte associated antigen (CTLA)-4, were significantly decreased when IL-37 gene was silenced by siRNA. Furthermore, down-regulation of IL-37 expression in human CD4(+)CD25(+)Tregs obviously promoted proliferation of co-cultured T cell and differentiation, together with observably enhancement of IL-2 formation. These results demonstrated that IL-37 might manifest as a critical protein involving in immunosuppression of human CD4(+)CD25(+)Tregs. PMID:26411375

  14. Antigen-specific CD4{sup +} effector T cells: Analysis of factors regulating clonal expansion and cytokine production

    SciTech Connect

    Ohnuki, Kazunobu; Watanabe, Yuri; Takahashi, Yusuke; Kobayashi, Sakiko; Watanabe, Shiho; Ogawa, Shuhei; Kotani, Motoko; Kozono, Haruo; Tanabe, Kazunari; Abe, Ryo

    2009-03-20

    In order to fully understand T cell-mediated immunity, the mechanisms that regulate clonal expansion and cytokine production by CD4{sup +} antigen-specific effector T cells in response to a wide range of antigenic stimulation needs clarification. For this purpose, panels of antigen-specific CD4{sup +} T cell clones with different thresholds for antigen-induced proliferation were generated by repeated stimulation with high- or low-dose antigen. Differences in antigen sensitivities did not correlate with expression of TCR, CD4, adhesion or costimulatory molecules. There was no significant difference in antigen-dependent cytokine production by TG40 cells transfected with TCR obtained from either high- or low-dose-responding T cell clones, suggesting that the affinity of TCRs for their ligands is not primary determinant of T cell antigen reactivity. The proliferative responses of all T cell clones to both peptide stimulation and to TCR{beta} crosslinking revealed parallel dose-response curves. These results suggest that the TCR signal strength of effector T cells and threshold of antigen reactivity is determined by an intrinsic property, such as the TCR signalosome and/or intracellular signaling machinery. Finally, the antigen responses of high- and low-peptide-responding T cell clones reveal that clonal expansion and cytokine production of effector T cells occur independently of antigen concentration. Based on these results, the mechanisms underlying selection of high 'avidity' effector and memory T cells in response to pathogen are discussed.

  15. West Nile virus-specific CD4 T cells exhibit direct anti-viral cytokine secretion and cytotoxicity and are sufficient for antiviral protection

    PubMed Central

    Brien, James D.; Uhrlaub, Jennifer L.; Nikolich-Zugich, Janko

    2012-01-01

    CD4 T cells have been shown to be necessary for the prevention of encephalitis during West Nile virus infection. However, the mechanisms used by antigen-specific CD4 T cells to protect mice from West Nile virus encephalitis remain incompletely understood. Contrary to the belief that CD4 T cells are protective because they merely maintain the CD8 T cell response and improve antibody production, we here provide evidence for the direct anti-viral activity of CD4 T cells which functions to protect the host from WNV encephalitis. In adoptive transfers, naïve CD4 T cells protected a significant number of lethally infected RAG−/− mice, demonstrating the protective effect of CD4 T cells independent of B cells and CD8 T cells. To shed light on the mechanism of this protection, we defined the peptide specificities of the CD4 T cells responding to West Nile virus infection in C57BL/6 (H-2b) mice, and used these peptides to characterize the in vivo function of antiviral CD4 T cells. WNV-specific CD4 T cells produced IFN-γ and IL-2, but also showed potential for in vivo and ex vivo cytotoxicity. Furthermore, peptide vaccination using CD4 epitopes conferred protection against lethal West Nile virus infection in immunocompetent mice. These results demonstrate the role of direct effector function of antigen-specific CD4 T cell in preventing severe West Nile virus disease. PMID:19050276

  16. CD27 Agonism Plus PD-1 Blockade Recapitulates CD4+ T-cell Help in Therapeutic Anticancer Vaccination.

    PubMed

    Ahrends, Tomasz; Bąbała, Nikolina; Xiao, Yanling; Yagita, Hideo; van Eenennaam, Hans; Borst, Jannie

    2016-05-15

    While showing promise, vaccination strategies to treat cancer require further optimization. Likely barriers to efficacy involve cancer-associated immunosuppression and peripheral tolerance, which limit the generation of effective vaccine-specific cytotoxic T lymphocytes (CTL). Because CD4(+) T cells improve CTL responsiveness, next-generation vaccines include helper epitopes. Here, we demonstrate in mice how CD4(+) T-cell help optimizes the CTL response to a clinically relevant DNA vaccine engineered to combat human papillomavirus-expressing tumors. Inclusion of tumor-unrelated helper epitopes greatly increased CTL priming, effector, and memory T-cell programming. CD4(+) T-cell help optimized the CTL response in all these aspects via CD27/CD70 costimulation. Notably, administration of an agonistic CD27 antibody could largely replace helper epitopes in promoting primary and memory CTL responses, acting directly on CD8(+) T cells. CD27 agonism improved efficacy of the vaccine without helper epitopes, more so than combined PD-1 and CTLA-4 blockade. Combining CD27 agonism with CTLA-4 blockade improved vaccine-induced CTL priming and tumor infiltration, but only combination with PD-1 blockade was effective at eradicating tumors, thereby fully recapitulating the effect of CD4(+) T-cell help on vaccine efficacy. PD-1 blockade alone did not affect CTL priming or tumor infiltration, so these results implied that it cooperated with CD4(+) T-cell help by alleviating immune suppression against CTL in the tumor. Helper epitope inclusion or CD27 agonism did not stimulate regulatory T cells, and vaccine efficacy was also improved by CD27 agonism in the presence of CD4(+) T-cell help. Our findings provide a preclinical rationale to apply CD27 agonist antibodies, either alone or combined with PD-1 blockade, to improve the therapeutic efficacy of cancer vaccines and immunotherapy generally. Cancer Res; 76(10); 2921-31. ©2016 AACR. PMID:27020860

  17. CD4+ T cells promote the pathogenesis of Staphylococcus aureus pneumonia.

    PubMed

    Parker, Dane; Ryan, Chanelle L; Alonzo, Francis; Torres, Victor J; Planet, Paul J; Prince, Alice S

    2015-03-01

    We postulated that the activation of proinflammatory signaling by methicillin-resistant Staphylococcus aureus (MRSA) strain USA300 is a major factor in the pathogenesis of severe pneumonia and a target for immunomodulation. Local activation of T cells in the lung was a conserved feature of multiple strains of S. aureus, in addition to USA300. The pattern of Vβ chain activation was consistent with known superantigens, but deletion of SelX or SEK and SEQ was not sufficient to prevent T-cell activation, indicating the participation of multiple genes. Using Rag2(-/-), Cd4(-/-), and Cd28(-/-) mice, we observed significantly improved clearance of MRSA from the airways and decreased lung pathology, compared with findings for wild-type controls. The improved outcome correlated with decreased production of proinflammatory cytokines (tumor necrosis factor, KC, interleukin 6, and interleukin 1β). Our data suggest that T-cell-mediated hypercytokinemia induced by infection with MRSA strain USA300 contributes to pathogenesis and may be a therapeutic target for improving outcomes of this common infection in a clinical setting. PMID:25240171

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

    PubMed Central

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

    2011-01-01

    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 binding studies, HLA-transgenic models and studies of T cells from seropositive individuals to characterize HLA-restricted LolC responses. Immunized mice showed long-lasting memory to the protein, while predictive algorithms identified epitopes within LolC that subsequently demonstrated strong HLA class II binding. Immunization of HLA-DR transgenics with LolC stimulated T cell responses to four of these epitopes. Furthermore, responsiveness of HLA-transgenics to LolC revealed a hierarchy supportive of HLA polymorphism-determined differential susceptibility. Seropositive human donors of diverse HLA class II types showed T cell responses to LolC epitopes which are conserved among Burkholderia species including B. cenocepacia, associated with life-threatening cepacia complex in cystic fibrosis patients and B. mallei, which causes glanders. These findings suggest a role for LolC epitopes in multiepitope vaccine design for melioidosis and related diseases. PMID:21182082

  19. In Situ Peptide-MHC-II Tetramer Staining of Antigen-Specific CD4+ T Cells in Tissues.

    PubMed

    Dileepan, Thamotharampillai; Kim, Hyeon O; Cleary, P Patrick; Skinner, Pamela J

    2015-01-01

    The invention of peptide-MHC-tetramer technology to label antigen-specific T cells has led to an enhanced understanding of T lymphocyte biology. Here we describe the development of an in situ pMHC-II tetramer staining method to visualize antigen-specific CD4+ T cells in tissues. This method complements other methods developed that similarly use MHC class II reagents to stain antigen-specific CD4+ T cells in situ. In this study, we used group A streptococcus (GAS) expressing a surrogate peptide (2W) to inoculate C57BL/6 mice, and used fresh nasal-associated lymphoid tissues (NALT) in optimizing the in situ staining of 2W:I-Ab specific CD4+ T cells. The results showed 2W:I-Ab tetramer-binding CD4+ T cells in GAS-2W but not GAS infected mice. This method holds promise to be broadly applicable to study the localization, abundance, and phenotype of antigen-specific CD4+ T cells in undisrupted tissues. PMID:26067103

  20. Understanding Factors That Modulate the Establishment of HIV Latency in Resting CD4+ T-Cells In Vitro

    PubMed Central

    Anderson, Jenny L.; Mota, Talia M.; Evans, Vanessa A.; Kumar, Nitasha; Rezaei, Simin D.; Cheong, Karey; Solomon, Ajantha; Wightman, Fiona; Cameron, Paul U.; Lewin, Sharon R.

    2016-01-01

    Developing robust in vitro models of HIV latency is needed to better understand how latency is established, maintained and reversed. In this study, we examined the effects of donor variability, HIV titre and co-receptor usage on establishing HIV latency in vitro using two models of HIV latency. Using the CCL19 model of HIV latency, we found that in up to 50% of donors, CCL19 enhanced latent infection of resting CD4+ T-cells by CXCR4-tropic HIV in the presence of low dose IL-2. Increasing the infectious titre of CXCR4-tropic HIV increased both productive and latent infection of resting CD4+ T-cells. In a different model where myeloid dendritic cells (mDC) were co-cultured with resting CD4+ T-cells, we observed a higher frequency of latently infected cells in vitro than CCL19-treated or unstimulated CD4+ T-cells in the presence of low dose IL-2. In the DC-T-cell model, latency was established with both CCR5- and CXCR4-tropic virus but higher titres of CCR5-tropic virus was required in most donors. The establishment of latency in vitro through direct infection of resting CD4+ T-cells is significantly enhanced by CCL19 and mDC, but the efficiency is dependent on virus titre, co-receptor usage and there is significant donor variability. PMID:27383184

  1. A Combined Omics Approach to Generate the Surface Atlas of Human Naive CD4+ T Cells during Early T-Cell Receptor Activation*

    PubMed Central

    Graessel, Anke; Hauck, Stefanie M.; von Toerne, Christine; Kloppmann, Edda; Goldberg, Tatyana; Koppensteiner, Herwig; Schindler, Michael; Knapp, Bettina; Krause, Linda; Dietz, Katharina; Schmidt-Weber, Carsten B.; Suttner, Kathrin

    2015-01-01

    Naive CD4+ T cells are the common precursors of multiple effector and memory T-cell subsets and possess a high plasticity in terms of differentiation potential. This stem-cell-like character is important for cell therapies aiming at regeneration of specific immunity. Cell surface proteins are crucial for recognition and response to signals mediated by other cells or environmental changes. Knowledge of cell surface proteins of human naive CD4+ T cells and their changes during the early phase of T-cell activation is urgently needed for a guided differentiation of naive T cells and may support the selection of pluripotent cells for cell therapy. Periodate oxidation and aniline-catalyzed oxime ligation technology was applied with subsequent quantitative liquid chromatography-tandem MS to generate a data set describing the surface proteome of primary human naive CD4+ T cells and to monitor dynamic changes during the early phase of activation. This led to the identification of 173 N-glycosylated surface proteins. To independently confirm the proteomic data set and to analyze the cell surface by an alternative technique a systematic phenotypic expression analysis of surface antigens via flow cytometry was performed. This screening expanded the previous data set, resulting in 229 surface proteins, which were expressed on naive unstimulated and activated CD4+ T cells. Furthermore, we generated a surface expression atlas based on transcriptome data, experimental annotation, and predicted subcellular localization, and correlated the proteomics result with this transcriptional data set. This extensive surface atlas provides an overall naive CD4+ T cell surface resource and will enable future studies aiming at a deeper understanding of mechanisms of T-cell biology allowing the identification of novel immune targets usable for the development of therapeutic treatments. PMID:25991687

  2. Nef Neutralizes the Ability of Exosomes from CD4+ T Cells to Act as Decoys during HIV-1 Infection

    PubMed Central

    da Silva, Elaine Z. M.; Silveira, Paola P.; da Silva-Januário, Mara E.; Arruda, Eurico; Jamur, Maria C.; Oliver, Constance; Aguiar, Renato S.; daSilva, Luis L. P.

    2014-01-01

    Nef is an HIV-1 accessory protein that promotes viral replication and pathogenesis. A key function of Nef is to ensure sustained depletion of CD4 and MHC-I molecules in infected cells by inducing targeting of these proteins to multivesicular bodies (MVBs), and ultimately to lysosomes for degradation. Nef also affects cellular secretory routes promoting its own secretion via exosomes. To better understand the effects of Nef on the exocytic pathway, we investigated whether this viral factor modifies the composition of exosomes released by T lymphocytes. We showed that both CD4 and MHC-I molecules are secreted in exosomes from T cells and that the expression of Nef reduces the amount of these proteins in exosomes. To investigate the functional role for this novel activity of Nef, we performed in vitro HIV-1 infection assays in the presence of distinct populations of exosomes. We demonstrated that exosomes released by CD4+ T cells, but not CD4T cells, efficiently inhibit HIV-1 infection in vitro. Because CD4 is the main receptor for HIV-1 infection, these results suggest that CD4 molecules displayed on the surface of exosomes can bind to envelope proteins of HIV-1 hindering virus interaction with target cells and infection. Importantly, CD4-depleted exosomes released by CD4+ T cells expressing Nef have a reduced capacity to inhibit HIV-1 infection in vitro. These results provide evidence that Nef promotes HIV-1 infection by reducing the expression of CD4 in exosomes from infected cells, besides the original role of Nef in reducing the CD4 levels at the cell surface. PMID:25423108

  3. Neisseria gonorrhoeae enhances HIV-1 infection of primary resting CD4+ T cells through TLR2 activation.

    PubMed

    Ding, Jian; Rapista, Aprille; Teleshova, Natalia; Mosoyan, Goar; Jarvis, Gary A; Klotman, Mary E; Chang, Theresa L

    2010-03-15

    Sexually transmitted infections increase the likelihood of HIV-1 transmission. We investigated the effect of Neisseria gonorrheae (gonococcus [GC]) exposure on HIV replication in primary resting CD4(+) T cells, a major HIV target cell during the early stage of sexual transmission of HIV. GC and TLR2 agonists, such as peptidylglycan (PGN), Pam(3)CSK(4), and Pam(3)C-Lip, a GC-derived synthetic lipopeptide, but not TLR4 agonists including LPS or GC lipooligosaccharide enhanced HIV-1 infection of primary resting CD4(+) T cells after viral entry. Pretreatment of CD4(+) cells with PGN also promoted HIV infection. Anti-TLR2 Abs abolished the HIV enhancing effect of GC and Pam(3)C-Lip, indicating that GC-mediated enhancement of HIV infection of resting CD4(+) T cells was through TLR2. IL-2 was required for TLR2-mediated HIV enhancement. PGN and GC induced cell surface expression of T cell activation markers and HIV coreceptors, CCR5 and CXCR4. The maximal postentry HIV enhancing effect was achieved when PGN was added immediately after viral exposure. Kinetic studies and analysis of HIV DNA products indicated that GC exposure and TLR2 activation enhanced HIV infection at the step of nuclear import. We conclude that GC enhanced HIV infection of primary resting CD4(+) T cells through TLR2 activation, which both increased the susceptibility of primary CD4(+) T cells to HIV infection as well as enhanced HIV-infected CD4(+) T cells at the early stage of HIV life cycle after entry. This study provides a molecular mechanism by which nonulcerative sexually transmitted infections mediate enhancement of HIV infection and has implication for HIV prevention and therapeutics. PMID:20147631

  4. CD4+ T Cells Expressing PD-1, TIGIT and LAG-3 Contribute to HIV Persistence during ART.

    PubMed

    Fromentin, Rémi; Bakeman, Wendy; Lawani, Mariam B; Khoury, Gabriela; Hartogensis, Wendy; DaFonseca, Sandrina; Killian, Marisela; Epling, Lorrie; Hoh, Rebecca; Sinclair, Elizabeth; Hecht, Frederick M; Bacchetti, Peter; Deeks, Steven G; Lewin, Sharon R; Sékaly, Rafick-Pierre; Chomont, Nicolas

    2016-07-01

    HIV persists in a small pool of latently infected cells despite antiretroviral therapy (ART). Identifying cellular markers expressed at the surface of these cells may lead to novel therapeutic strategies to reduce the size of the HIV reservoir. We hypothesized that CD4+ T cells expressing immune checkpoint molecules would be enriched in HIV-infected cells in individuals receiving suppressive ART. Expression levels of 7 immune checkpoint molecules (PD-1, CTLA-4, LAG-3, TIGIT, TIM-3, CD160 and 2B4) as well as 4 markers of HIV persistence (integrated and total HIV DNA, 2-LTR circles and cell-associated unspliced HIV RNA) were measured in PBMCs from 48 virally suppressed individuals. Using negative binomial regression models, we identified PD-1, TIGIT and LAG-3 as immune checkpoint molecules positively associated with the frequency of CD4+ T cells harboring integrated HIV DNA. The frequency of CD4+ T cells co-expressing PD-1, TIGIT and LAG-3 independently predicted the frequency of cells harboring integrated HIV DNA. Quantification of HIV genomes in highly purified cell subsets from blood further revealed that expressions of PD-1, TIGIT and LAG-3 were associated with HIV-infected cells in distinct memory CD4+ T cell subsets. CD4+ T cells co-expressing the three markers were highly enriched for integrated viral genomes (median of 8.2 fold compared to total CD4+ T cells). Importantly, most cells carrying inducible HIV genomes expressed at least one of these markers (median contribution of cells expressing LAG-3, PD-1 or TIGIT to the inducible reservoir = 76%). Our data provide evidence that CD4+ T cells expressing PD-1, TIGIT and LAG-3 alone or in combination are enriched for persistent HIV during ART and suggest that immune checkpoint blockers directed against these receptors may represent valuable tools to target latently infected cells in virally suppressed individuals. PMID:27415008

  5. CD4+ T Cells Expressing PD-1, TIGIT and LAG-3 Contribute to HIV Persistence during ART

    PubMed Central

    Fromentin, Rémi; Bakeman, Wendy; Lawani, Mariam B.; Khoury, Gabriela; Hartogensis, Wendy; DaFonseca, Sandrina; Killian, Marisela; Epling, Lorrie; Hoh, Rebecca; Sinclair, Elizabeth; Hecht, Frederick M.; Bacchetti, Peter; Deeks, Steven G.; Lewin, Sharon R.; Sékaly, Rafick-Pierre; Chomont, Nicolas

    2016-01-01

    HIV persists in a small pool of latently infected cells despite antiretroviral therapy (ART). Identifying cellular markers expressed at the surface of these cells may lead to novel therapeutic strategies to reduce the size of the HIV reservoir. We hypothesized that CD4+ T cells expressing immune checkpoint molecules would be enriched in HIV-infected cells in individuals receiving suppressive ART. Expression levels of 7 immune checkpoint molecules (PD-1, CTLA-4, LAG-3, TIGIT, TIM-3, CD160 and 2B4) as well as 4 markers of HIV persistence (integrated and total HIV DNA, 2-LTR circles and cell-associated unspliced HIV RNA) were measured in PBMCs from 48 virally suppressed individuals. Using negative binomial regression models, we identified PD-1, TIGIT and LAG-3 as immune checkpoint molecules positively associated with the frequency of CD4+ T cells harboring integrated HIV DNA. The frequency of CD4+ T cells co-expressing PD-1, TIGIT and LAG-3 independently predicted the frequency of cells harboring integrated HIV DNA. Quantification of HIV genomes in highly purified cell subsets from blood further revealed that expressions of PD-1, TIGIT and LAG-3 were associated with HIV-infected cells in distinct memory CD4+ T cell subsets. CD4+ T cells co-expressing the three markers were highly enriched for integrated viral genomes (median of 8.2 fold compared to total CD4+ T cells). Importantly, most cells carrying inducible HIV genomes expressed at least one of these markers (median contribution of cells expressing LAG-3, PD-1 or TIGIT to the inducible reservoir = 76%). Our data provide evidence that CD4+ T cells expressing PD-1, TIGIT and LAG-3 alone or in combination are enriched for persistent HIV during ART and suggest that immune checkpoint blockers directed against these receptors may represent valuable tools to target latently infected cells in virally suppressed individuals. PMID:27415008

  6. Interleukin 27R regulates CD4+ T cell phenotype and impacts protective immunity during Mycobacterium tuberculosis infection.

    PubMed

    Torrado, Egidio; Fountain, Jeffrey J; Liao, Mingfeng; Tighe, Michael; Reiley, William W; Lai, Rachel P; Meintjes, Graeme; Pearl, John E; Chen, Xinchun; Zak, Daniel E; Thompson, Ethan G; Aderem, Alan; Ghilardi, Nico; Solache, Alejandra; McKinstry, K Kai; Strutt, Tara M; Wilkinson, Robert J; Swain, Susan L; Cooper, Andrea M

    2015-08-24

    CD4+ T cells mediate protection against Mycobacterium tuberculosis (Mtb); however, the phenotype of protective T cells is undefined, thereby confounding vaccination efforts. IL-27 is highly expressed during human tuberculosis (TB), and absence of IL-27R (Il27ra) specifically on T cells results in increased protection. IL-27R deficiency during chronic Mtb infection does not impact antigen-specific CD4+ T cell number but maintains programmed death-1 (PD-1), CD69, and CD127 expression while reducing T-bet and killer cell lectin-like receptor G1 (KLRG1) expression. Furthermore, T-bet haploinsufficiency results in failure to generate KLRG1+, antigen-specific CD4+ T cells, and in improved protection. T cells in Il27ra(-/-) mice accumulate preferentially in the lung parenchyma within close proximity to Mtb, and antigen-specific CD4+ T cells lacking IL-27R are intrinsically more fit than intact T cells and maintain IL-2 production. Improved fitness of IL-27R-deficient T cells is not associated with increased proliferation but with decreased expression of cell death-associated markers. Therefore, during Mtb infection, IL-27R acts intrinsically on T cells to limit protection and reduce fitness, whereas the IL-27R-deficient environment alters the phenotype and location of T cells. The significant expression of IL-27 in TB and the negative influence of IL-27R on T cell function demonstrate the pathway by which this cytokine/receptor pair is detrimental in TB. PMID:26282876

  7. Interleukin 27R regulates CD4+ T cell phenotype and impacts protective immunity during Mycobacterium tuberculosis infection

    PubMed Central

    Torrado, Egidio; Fountain, Jeffrey J.; Liao, Mingfeng; Tighe, Michael; Reiley, William W.; Lai, Rachel P.; Meintjes, Graeme; Pearl, John E.; Chen, Xinchun; Zak, Daniel E.; Thompson, Ethan G.; Aderem, Alan; Ghilardi, Nico; Solache, Alejandra; McKinstry, K. Kai; Strutt, Tara M.; Wilkinson, Robert J.; Swain, Susan L.

    2015-01-01

    CD4+ T cells mediate protection against Mycobacterium tuberculosis (Mtb); however, the phenotype of protective T cells is undefined, thereby confounding vaccination efforts. IL-27 is highly expressed during human tuberculosis (TB), and absence of IL-27R (Il27ra) specifically on T cells results in increased protection. IL-27R deficiency during chronic Mtb infection does not impact antigen-specific CD4+ T cell number but maintains programmed death-1 (PD-1), CD69, and CD127 expression while reducing T-bet and killer cell lectin-like receptor G1 (KLRG1) expression. Furthermore, T-bet haploinsufficiency results in failure to generate KLRG1+, antigen-specific CD4+ T cells, and in improved protection. T cells in Il27ra−/− mice accumulate preferentially in the lung parenchyma within close proximity to Mtb, and antigen-specific CD4+ T cells lacking IL-27R are intrinsically more fit than intact T cells and maintain IL-2 production. Improved fitness of IL-27R–deficient T cells is not associated with increased proliferation but with decreased expression of cell death–associated markers. Therefore, during Mtb infection, IL-27R acts intrinsically on T cells to limit protection and reduce fitness, whereas the IL-27R–deficient environment alters the phenotype and location of T cells. The significant expression of IL-27 in TB and the negative influence of IL-27R on T cell function demonstrate the pathway by which this cytokine/receptor pair is detrimental in TB. PMID:26282876

  8. Hoxb4 Overexpression in CD4 Memory Phenotype T Cells Increases the Central Memory Population upon Homeostatic Proliferation

    PubMed Central

    Fournier, Marilaine; Labrecque, Nathalie; Bijl, Janet J.

    2013-01-01

    Memory T cell populations allow a rapid immune response to pathogens that have been previously encountered and thus form the basis of success in vaccinations. However, the molecular pathways underlying the development and maintenance of these cells are only starting to be unveiled. Memory T cells have the capacity to self renew as do hematopoietic stem cells, and overlapping gene expression profiles suggested that these cells might use the same self-renewal pathways. The transcription factor Hoxb4 has been shown to promote self-renewal divisions of hematopoietic stem cells resulting in an expansion of these cells. In this study we investigated whether overexpression of Hoxb4 could provide an advantage to CD4 memory phenotype T cells in engrafting the niche of T cell deficient mice following adoptive transfer. Competitive transplantation experiments demonstrated that CD4 memory phenotype T cells derived from mice transgenic for Hoxb4 contributed overall less to the repopulation of the lymphoid organs than wild type CD4 memory phenotype T cells after two months. These proportions were relatively maintained following serial transplantation in secondary and tertiary mice. Interestingly, a significantly higher percentage of the Hoxb4 CD4 memory phenotype T cell population expressed the CD62L and Ly6C surface markers, characteristic for central memory T cells, after homeostatic proliferation. Thus Hoxb4 favours the maintenance and increase of the CD4 central memory phenotype T cell population. These cells are more stem cell like and might eventually lead to an advantage of Hoxb4 T cells after subjecting the cells to additional rounds of proliferation. PMID:24324706

  9. Requirement of CD30 expression on CD4 T cells in the pathogenesis of experimental autoimmune encephalomyelitis.

    PubMed

    Shinoda, Koji; Sun, Xun; Oyamada, Akiko; Yamada, Hisakata; Kira, Jun-Ichi; Yoshikai, Yasunobu