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Sample records for cd4 t-cell count

  1. The BD FACSPresto Point of Care CD4 Test Accurately Enumerates CD4+ T Cell Counts

    PubMed Central

    Bwana, Priska; Vojnov, Lara; Adhiambo, Maureen; Akinyi, Catherine; Mwende, Joy; Prescott, Marta; Mwau, Matilu

    2015-01-01

    Objective Currently 50% of ART eligible patients are not yet receiving life-saving antiretroviral therapy (ART). Financial constraints do not allow most developing countries to adopt a universal test and offer ART strategy. Decentralizing CD4+ T cell testing may, therefore, provide greater access to testing, ART, and better patient management. We evaluated the technical performance of a new point-of-care CD4+ T cell technology, the BD FACSPresto, in a field methods comparison study. Methods 264 HIV-positive patients were consecutively enrolled and included in the study. The BD FACSPresto POC CD4+ T cell technology was placed in two rural health care facilities and operated by health care facility staff. We compared paired finger-prick and venous samples using the BD FACSPresto and several existing reference technologies, respectively. Results The BD FACSPresto had a mean bias of 67.29 cells/ul and an r2 of 0.9203 compared to the BD FACSCalibur. At ART eligibility thresholds of 350 and 500 cells/ul, the sensitivity to define treatment eligibility were 81.5% and 77.2% and the specificities were 98.9% and 100%, respectively. Similar results were observed when the BD FACSPresto was compared to the BD FACSCount and Alere Pima. The coefficient of variation (CV) was less than 7% for both the BD FACSCalibur and BD FACSPresto. CD4+ T cell testing by nurses using the BD FACSPresto at rural health care facilities showed high technical similarity to test results generated by laboratory technicians using the BD FACSPresto in a high functioning laboratory. Conclusions The BD FACSPresto performed favorably in the laboratory setting compared to the conventional reference standard technologies; however, the lower sensitivities indicated that up to 20% of patients tested in the field in need of treatment would be missed. The BD FACSPresto is a technology that can allow for greater decentralization and wider access to CD4+ T cell testing and ART. PMID:26720601

  2. Interleukin-2 Therapy Induces CD4 Downregulation, Which Decreases Circulating CD4 T Cell Counts, in African Green Monkeys

    PubMed Central

    Mudd, Joseph C.; Perkins, Molly R.; DiNapoli, Sarah R.; Hirsch, Vanessa M.

    2016-01-01

    ABSTRACT African green monkeys (AGMs) are natural hosts of simian immunodeficiency virus (SIVAGM). Because these animals do not develop simian AIDS despite maintaining high viral loads, there is considerable interest in determining how these animals have evolved to avoid SIV disease progression. Unlike nonnatural hosts of SIV, adult AGMs maintain low levels of CD4+ T cells at steady states and also have a large population of virus-resistant CD8αα T cells that lack CD4 expression despite maintaining T helper cell functionalities. In recent work, we have shown that homeostatic cytokines can induce CD4 downregulation in AGM T cells in vitro. Through administering therapeutic doses of recombinant human interleukin-2 (IL-2) to AGMs, we show here that this mechanism is operative in vivo. IL-2 therapy induced transient yet robust proliferation in all major T cell subsets. Within the CD4+ T cell population, those that were induced into cycle by IL-2 exhibited characteristics of CD4-to-CD8αα conversion. In all animals receiving IL-2, circulating CD4+ T cell counts and proportions tended to be lower and CD4− CD8αα+ T cell counts tended to be higher. Despite reductions in circulating target cells, the viral load was unaffected over the course of study. IMPORTANCE The data in this study identify that homeostatic cytokines can downregulate CD4 in vivo and, when given therapeutically, can induce AGMs to sustain very low levels of circulating CD4+ T cells without showing signs of immunodeficiency. PMID:27053558

  3. Piecewise HIV virus dynamic model with CD4+ T cell count-guided therapy: I

    PubMed Central

    Tang, Sanyi; Xiao, Yanni; Wang, Ning; Wu, Hulin

    2012-01-01

    The strategies of structured treatment interruptions (STIs) of antiretroviral therapies have been proposed for clinical management of HIV infected patients, but clinical studies on STIs failed to achieve a consistent conclusion for this strategy. To evaluate the STI strategies, in particular, CD4+ T cell count-guided STIs, and explain these controversial conclusions from different clinical studies, in this paper we propose to use piecewise HIV virus dynamic models to quantitatively explore the STI strategies and investigate their dynamic behaviors. Our analysis results indicate that CD4+ T cell counts can be maintained above a safe level using the STI with a single threshold or a threshold window. Numerical simulations show that the CD4+ T cell counts either fluctuate or approach a stable level for a patient, depending on the prescribed upper or lower threshold values. In particular, the CD4+ T cell counts can be stabilized at a desired level if the threshold policy control is applied. The durations of drug-on and drug-off are very sensitive to the prescribed upper or lower threshold levels, which possibly explains why the on-off strategy with fixed schedule or a STI strategy with frequent switches is associated with the high rate of failure. Our findings suggest that it is critical to carefully choose the thresholds of CD4+ T cell count and individualize the STIs for each individual patient based on initial CD4+ T cell counts. PMID:22659043

  4. The performance of BD FACSPresto™ for CD4 T-cell count, CD4% and hemoglobin concentration test in Ethiopia.

    PubMed

    Gebremicael, Gebremedhin; Belay, Yohanes; Girma, Fitsum; Abreha, Yemane; Gebreegziabxier, Atsbeha; Tesfaye, Simret; Messele, Zelalem; Assefa, Yibeltal; Bellete, Bahrie; Kassa, Desta; Vojnov, Lara

    2017-01-01

    In Ethiopia, CD4+ T-cell counting is still required for all patients at baseline before antiretroviral therapy (ART) and to determine eligibility and follow-up of opportunistic infection prophylaxis. However, access to CD4+ T cell count in rural health facilities remains a major challenge in Ethiopia like other resource-limited settings. Both capillary and venous blood was drawn from each of 325 study participant recruited in Addis Ababa and surroundings. The CD4+ T-cell count, CD4%, and hemoglobin (Hgb) were tested at one of the four study health facilities using capillary blood and BD FACSPresto™ device. These tests were also done at the national HIV reference laboratory, using venous blood with BD FACSCalibur™, Sysmex XT-1800i™, and BD FACSPresto™. BD FACSPresto™ had an absolute mean bias of -13.3 cells/ul (-2.99%) and 28.3 cells/μl (6.4%) using venous and capillary blood, respectively, compared with BD FACSCalibur™. The absolute CD4 assay on the BD FACSPresto™ had a regression coefficient (R2) of 0.87 and 0.92 using capillary blood and venous blood samples, respectively, compared with BD FACSCalibur™. The percentage similarity of the BD FACSPresto™ using capillary and venous blood was 105.2% and 99.3%, respectively. The sensitivity of the FACSPresto™ using threshold of 500 cells/μl for ART eligibility using capillary and venous blood was 87.9 and 94.3%, while the specificity was 91.4 and 83.8%, respectively. Furthermore, the BD FACSPresto™ had an absolute mean bias of -0.2 dl/μl (0.0%) (95% LOA: -1.7, 1.3) and -0.59 dl/μl (0.1%) (95% LOA: -1.49, 0.31) for Hgb using capillary and venous blood compared with the Sysmex XT-1800i™, respectively. Our results showed acceptable agreement between the BD FACSPresto™ and BD FACSCalibur™ for CD4+ T-cell counting and CD4%; and between the BD FACSPresto™ and Sysmex XT-1800i™for measuring Hgb concentration.

  5. Restoring Cytokine Balance in HIV-Positive Individuals with Low CD4 T Cell Counts

    PubMed Central

    Valdivia, Anddre; Ly, Judy; Gonzalez, Leslie; Hussain, Parveen; Saing, Tommy; Islamoglu, Hicret; Pearce, Daniel; Ochoa, Cesar

    2017-01-01

    Abstract HIV infects and destroys CD4+ T cells leading to a compromised immune system. In a double-blinded study, a group of HIV-infected individuals with CD4+ T cell counts below 350 cells/mm3 were given either an empty liposomal supplement or a liposomal glutathione (L-GSH) supplement to take over a 3-month period. Baseline measurements in HIV-positive subjects show a significant decrease in levels of interleukin (IL)-12, IL-2, and interferon (IFN)-γ, along with a substantial increase in the levels of IL-6, IL-10, transforming growth factor (TGF)-β, and free radicals, compared to healthy individuals. Supplementation of HIV-positive subjects with L-GSH for 3 months resulted in a notable increase in the levels of IL-12, IL-2, and IFN-γ, with a concomitant decrease in the levels of IL-6, IL-10, and free radicals, and stabilization in the levels of TGF-β, IL-1, and IL-17, compared to their placebo counterparts. Levels of free radicals in CD4+ T cells stabilized, while GSH levels increased in the treatment group. Those in the placebo group showed no significant difference throughout the study. In summary, supplementation with L-GSH in HIV-infected individuals with CD4+ T cell counts below 350 cells/mm3 can help restore redox homeostasis and cytokine balance, therefore aiding the immune system to control opportunistic infections. PMID:28398068

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

    PubMed Central

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

    2016-01-01

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

  7. Limited CD4+ T cell proliferation leads to preservation of CD4+ T cell counts in SIV-infected sooty mangabeys.

    PubMed

    Chan, Ming Liang; Petravic, Janka; Ortiz, Alexandra M; Engram, Jessica; Paiardini, Mirko; Cromer, Deborah; Silvestri, Guido; Davenport, Miles P

    2010-12-22

    Human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections result in chronic virus replication and progressive depletion of CD4+ T cells, leading to immunodeficiency and death. In contrast, 'natural hosts' of SIV experience persistent infection with high virus replication but no severe CD4+ T cell depletion, and remain AIDS-free. One important difference between pathogenic and non-pathogenic infections is the level of activation and proliferation of CD4+ T cells. We analysed the relationship between CD4+ T cell number and proliferation in HIV, pathogenic SIV in macaques, and non-pathogenic SIV in sooty mangabeys (SMs) and mandrills. We found that CD4+ T cell proliferation was negatively correlated with CD4+ T cell number, suggesting that animals respond to the loss of CD4+ T cells by increasing the proliferation of remaining cells. However, the level of proliferation seen in pathogenic infections (SIV in rhesus macaques and HIV) was much greater than in non-pathogenic infections (SMs and mandrills). We then used a modelling approach to understand how the host proliferative response to CD4+ T cell depletion may impact the outcome of infection. This modelling demonstrates that the rapid proliferation of CD4+ T cells in humans and macaques associated with low CD4+ T cell levels can act to 'fuel the fire' of infection by providing more proliferating cells for infection. Natural host species, on the other hand, have limited proliferation of CD4+ T cells at low CD4+ T cell levels, which allows them to restrict the number of proliferating cells susceptible to infection.

  8. Long-term increase in CD4+ T-cell counts during combination antiretroviral therapy for HIV-1 infection.

    PubMed

    Lok, Judith J; Bosch, Ronald J; Benson, Constance A; Collier, Ann C; Robbins, Gregory K; Shafer, Robert W; Hughes, Michael D

    2010-07-31

    To inform guidelines concerning when to initiate combination antiretroviral therapy (ART), we investigated whether CD4(+) T-cell counts (CD4 cell counts) continue to increase over long periods of time on ART. Losses-to-follow-up and some patients discontinuing ART at higher CD4 cell counts hamper such evaluation, but novel statistical methods can help address these issues. We estimated the long-term CD4 cell count trajectory accounting for losses-to-follow-up and treatment discontinuations. The study population included 898 US patients first initiating ART in a randomized trial (AIDS Clinical Trials Group 384); 575 were subsequently prospectively followed in an observational study (AIDS Clinical Trials Group Longitudinal Linked Randomized Trials). Inverse probability of censoring weighting statistical methods were used to estimate the CD4 cell count trajectory accounting for losses-to-follow-up and ART discontinuations, overall and for pretreatment CD4 cell count categories (500 cells/microl). Median CD4 cell count increased from 270 cells/microl pre-ART to an estimated 556 cells/microl at 3 and 532 cells/microl at 7 years after starting ART in analyses ignoring treatment discontinuations, and to 570 and 640 cells/microl, respectively, had all patients continued ART. However, even had ART been continued, an estimated 25, 9, 3, and 2% of patients with pretreatment CD4 cell counts of 200 or less, 201-350, 351-500, and more than 500 cells/microl would have had CD4 cell counts of 350 cells/microl or less after 7 years. If patients remain on ART, CD4 cell counts increase in most patients for at least 7 years. However, the substantial percentage of patients starting therapy at low CD4 cell counts who still had low CD4 cell counts after 7 years provides support for ART initiation at higher CD4 cell counts.

  9. 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

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

    PubMed

    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.

  11. Negative prognostic impact of low absolute CD4(+) T cell counts in peripheral blood in mantle cell lymphoma.

    PubMed

    Zhang, Xin-Yu; Xu, Ji; Zhu, Hua-Yuan; Wang, Yan; Wang, Li; Fan, Lei; Wu, Yu-Jie; Li, Jian-Yong; Xu, Wei

    2016-10-01

    Tumor microenvironment and host immunity are closely related to outcome in patients with mantle cell lymphoma (MCL). However, few researchers have focused on the prognostic value of peripheral blood lymphocyte subsets counts. The purpose of this study was to investigate the prognostic value of lymphocyte subsets and absolute monocyte counts. Sixty-eight patients were analyzed retrospectively. Absolute CD4(+) T cell counts (ACD4C), CD8(+) T cell counts, nature killer cell counts, and CD4/CD8 ratios were assessed by peripheral blood flow cytometry and correlated with clinical parameters and long-term outcomes. The median follow-up for all patients was 21 months and the median survival time was 44 months. The overall survival (OS) rate at 1, 3, and 5 years was 80%, 51%, and 41%, respectively. In our cohort, high absolute monocyte count, and low ACD4C and CD4/CD8 ratio were associated with unfavorable OS (P = 0.029, P = 0.027, and P = 0.045, respectively) by univariate analysis. Multivariate analysis indicated that low ACD4C was a significant predictor of unfavorable OS (P = 0.004) independent of the simplified MCL International Prognostic Index (P = 0.048) in patients treated with or without rituximab (P = 0.011). Low CD4(+) T cell counts proved to be a significant predictor of unfavorable OS in patients with MCL.

  12. HIV-2 viral tropism influences CD4+ T cell count regardless of viral load.

    PubMed

    Treviño, Ana; Soriano, Vicente; Poveda, Eva; Parra, Patricia; Cabezas, Teresa; Caballero, Estrella; Roc, Lourdes; Rodríguez, Carmen; Eiros, Jose M; Lopez, Mariola; De Mendoza, Carmen

    2014-08-01

    HIV-2 infection is characterized by low plasma viraemia and slower progression to AIDS in comparison with HIV-1 infection. However, antiretroviral therapy in patients with HIV-2 is less effective and often fails to provide optimal CD4 recovery. We examined viral tropism in persons with HIV-2 infection enrolled in the HIV-2 Spanish cohort. Viral tropism was estimated based on V3 sequences obtained from plasma RNA and/or proviral DNA. From a total of 279 individuals with HIV-2 infection recorded in the Spanish national register, 58 V3 sequences belonging to 42 individuals were evaluated. X4 viruses were recognized in 14 patients (33%). Patients with X4 viruses had lower median CD4+ cell counts than patients with R5 viruses [130 (17-210) versus 359 (180-470) cells/mm(3); P = 0.007]. This was true even considering only the subset of 19 patients on antiretroviral therapy [94 (16-147) versus 184 (43-368) cells/mm(3); P = 0.041]. In multivariate analysis, significant differences in CD4+ cell counts between patients with X4 and R5 viruses remained after adjusting for age, gender, antiretroviral therapy and viral load. The presence of X4-tropic viruses in HIV-2 infection is associated with low CD4+ cell counts, regardless of antiretroviral treatment. Along with CD4+ cell counts, viral tropism testing may assist decisions about when to initiate antiretroviral therapy in HIV-2-infected individuals. © The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  13. The severity, extent and recurrence of necrotizing periodontal disease in relation to HIV status and CD4+ T cell count.

    PubMed

    Phiri, Reality; Feller, Liviu; Blignaut, Elaine

    2010-10-01

    South Africa ranks among the three countries with the highest prevalence of HIV infection in sub-Saharan Africa, with an estimated 29.5% of women attending antenatal clinics being infected. Necrotizing periodontal disease is a well recognized HIV-associated oral condition. The objective of this investigation was to determine a possible correlation between the extent, severity and treatment outcome of necrotizing periodontal disease in relation to a person's HIV status and CD4+ T cell count. Data from 105 consecutive patients presenting with necrotizing periodontal disease at an academic oral health centre in South Africa were analysed. All patients were provided with an opportunity to undergo voluntary counseling and testing for HIV infection, were treated for necrotizing periodontal disease and followed over a period of nine months. The mean age of the cohort was 28 years old (range 12 - 52). Of 98 (93.3%) patients unaware of their HIV serostatus at the initial visit, 59 (56.2%) consented to testing. In total 45 (42.9%) were HIV-seropositive with a mean CD4+ T cell count of 222.7 cells/microl and 14 (13.3%) were HIV-seronegative, with a significantly higher mean CD4+ T cell count of 830 cells/microl (Fisher's exact test, p < 0.001), while the status of 46 (43.8%) remained unknown. In 101 (96.2%) patients, > or = 5 tooth sites were affected, and in 27 (26%) > or = 4 mm of gingival tissue were affected. This study, which included HIV-seropositive, HIV-seronegative and persons of unknown HIV status, revealed no statistical evidence that HIV infection was associated with the extent, severity or relapse of necrotizing periodontal disease. No statistically significant association could be demonstrated between the extent, severity and recurrence of necrotizing periodontal disease and a CD4+ T cell count < or = 200 cells/microl among HIV-seropositive patients.

  14. Validation of a single-platform, volumetric, flow cytometry for CD4 T cell count monitoring in therapeutic mobile unit

    PubMed Central

    2012-01-01

    Background A mobile health unit may be useful to follow up adult and pediatric patients on antiretroviral treatment and living in remote areas devoid of laboratory facilities. The study evaluated the use of the simplified, robust, single-plateform, volumetric, pan-leucogating Auto40 flow cytometer (Apogee Flow Systems Ltd, Hemel Hempstead, UK) for CD4 T cell numeration in a mobile unit, compared against a reference flow cytometry method. Methods The therapeutic mobile unit of the Laboratoire National de Santé Hygiène Mobile, Yaoundé, Cameroon, was equipped with the Auto40. A FACSCalibur flow cytometer (Becton Dickinson Immuno-cytometry System, San Jose, CA, USA) was used as reference method. EDTA-blood samples from volunteers were first subjected to CD4 T cell count in the mobile unit, and an aliquot was sent within 4 hours to Centre International de Référence Chantal Biya, Yaoundé, for FACSCalibur assay. Results Two HIV screening campaigns with the mobile unit were organised in December 2009 and January 2010. The campaign in the suburb of Yaoundé which was 20 km from the reference laboratory included 188 volunteers comprising 93 children less than 5 years old. The campaign in Ambang Bikok (53 km far from Yaoundé) included 69 adult volunteers. In Yaoundé suburb, mean ± standard deviation (SD) CD4 T cell count was 996 ± 874 cells/μl by Auto40, and 989 ± 883 cells/μl by FACSCalibur; in Ambang Bikok, mean ± SD CD4 T cell count was 1041 ± 317 cells/μl by Auto40, and 1032 ± 294 cells/μl by FACSCalibur. Results by Auto40 and FACSCalibur were highly correlated in Yaoundé (r2 = 0.982) as in Ambang Bikok (r2 = 0.921). Bland-Altman analysis showed a close agreement between Auto40 and FACSCalibur results expressed in absolute count as in percentage in Yaoundé and Ambang Bikok. When pooling the 257 CD4 T cell count measurements, the Auto40 yielded a mean difference of +7.6 CD4 T cells/μl higher than by reference flow cytometry; and the sensitivity and

  15. IVIg immune reconstitution treatment alleviates the state of persistent immune activation and suppressed CD4 T cell counts in CVID.

    PubMed

    Paquin-Proulx, Dominic; Santos, Bianca A N; Carvalho, Karina I; Toledo-Barros, Myrthes; Barreto de Oliveira, Ana Karolina; Kokron, Cristina M; Kalil, Jorge; Moll, Markus; Kallas, Esper G; Sandberg, Johan K

    2013-01-01

    Common variable immunodeficiency (CVID) is characterized by defective B cell function, impaired antibody production, and increased susceptibility to bacterial infections. Here, we addressed the hypothesis that poor antibody-mediated immune control of infections may result in substantial perturbations in the T cell compartment. Newly diagnosed CVID patients were sampled before, and 6-12 months after, initiation of intravenous immunoglobulin (IVIg) therapy. Treatment-naïve CVID patients displayed suppressed CD4 T cell counts and myeloid dendritic cell (mDC) levels, as well as high levels of immune activation in CD8 T cells, CD4 T cells, and invariant natural killer T (iNKT) cells. Expression of co-stimulatory receptors CD80 and CD83 was elevated in mDCs and correlated with T cell activation. Levels of both FoxP3+ T regulatory (Treg) cells and iNKT cells were low, whereas soluble CD14 (sCD14), indicative of monocyte activation, was elevated. Importantly, immune reconstitution treatment with IVIg partially restored the CD4 T cell and mDC compartments. Treatment furthermore reduced the levels of CD8 T cell activation and mDC activation, whereas levels of Treg cells and iNKT cells remained low. Thus, primary deficiency in humoral immunity with impaired control of microbial infections is associated with significant pathological changes in cell-mediated immunity. Furthermore, therapeutic enhancement of humoral immunity with IVIg infusions alleviates several of these defects, indicating a relationship between poor antibody-mediated immune control of infections and the occurrence of abnormalities in the T cell and mDC compartments. These findings help our understanding of the immunopathogenesis of primary immunodeficiency, as well as acquired immunodeficiency caused by HIV-1 infection.

  16. IVIg Immune Reconstitution Treatment Alleviates the State of Persistent Immune Activation and Suppressed CD4 T Cell Counts in CVID

    PubMed Central

    Carvalho, Karina I.; Toledo-Barros, Myrthes; Barreto de Oliveira, Ana Karolina; Kokron, Cristina M.; Kalil, Jorge; Moll, Markus; Kallas, Esper G.; Sandberg, Johan K.

    2013-01-01

    Common variable immunodeficiency (CVID) is characterized by defective B cell function, impaired antibody production, and increased susceptibility to bacterial infections. Here, we addressed the hypothesis that poor antibody-mediated immune control of infections may result in substantial perturbations in the T cell compartment. Newly diagnosed CVID patients were sampled before, and 6–12 months after, initiation of intravenous immunoglobulin (IVIg) therapy. Treatment-naïve CVID patients displayed suppressed CD4 T cell counts and myeloid dendritic cell (mDC) levels, as well as high levels of immune activation in CD8 T cells, CD4 T cells, and invariant natural killer T (iNKT) cells. Expression of co-stimulatory receptors CD80 and CD83 was elevated in mDCs and correlated with T cell activation. Levels of both FoxP3+ T regulatory (Treg) cells and iNKT cells were low, whereas soluble CD14 (sCD14), indicative of monocyte activation, was elevated. Importantly, immune reconstitution treatment with IVIg partially restored the CD4 T cell and mDC compartments. Treatment furthermore reduced the levels of CD8 T cell activation and mDC activation, whereas levels of Treg cells and iNKT cells remained low. Thus, primary deficiency in humoral immunity with impaired control of microbial infections is associated with significant pathological changes in cell-mediated immunity. Furthermore, therapeutic enhancement of humoral immunity with IVIg infusions alleviates several of these defects, indicating a relationship between poor antibody-mediated immune control of infections and the occurrence of abnormalities in the T cell and mDC compartments. These findings help our understanding of the immunopathogenesis of primary immunodeficiency, as well as acquired immunodeficiency caused by HIV-1 infection. PMID:24130688

  17. CD4+ T cell counts in initiation of antiretroviral therapy in HIV infected asymptomatic individuals; controversies and inconsistencies.

    PubMed

    Maina, E K; Bonney, E Y; Bukusi, E A; Sedegah, M; Lartey, M; Ampofo, W K

    2015-12-01

    The primary goal when devising strategies to define the start of therapy in HIV infected individuals is to avoid HIV disease progression and toxicity from antiretroviral therapy (ART). Intermediate goals includes, avoiding resistance by suppressing HIV replication, reducing transmission, limiting spread and diversity of HIV within the body and protecting the immune system from harm. The question of how early or late to start ART and achieve both primary and intermediate goals has dominated HIV research. The distinction between early and late treatment of HIV infection is currently a matter of CD4+ T cells count, a marker of immune status, rather than on viral load, a marker of virus replication. Discussions about respective benefits of early or delayed therapy, as well as the best CD4+ T cell threshold during the course of HIV infection at which ART is initiated remains inconclusive. Guidelines issued by various agencies, provide different initiation recommendations. This can be confusing for clinicians and policy-makers when determining the best time to initiate therapy. Optimizing ART initiation strategies are clearly complex and must be balanced between individual and broader public health needs. This review assesses available data that contributes to the debate on optimal time to initiate therapy in HIV-infected asymptomatic individuals. We also review reports on CD4+ T cell threshold to guide initiation of ART and finally discuss arguments for and against early or late initiation of ART.

  18. Immune Activation, Cd4+ T Cell Counts, and Viremia Exhibit Oscillatory Patterns over Time in Patients with Highly Resistant HIV Infection

    PubMed Central

    Kitchen, Christina M. R.; Yeghiazarian, Lilit; Hoh, Rebecca; McCune, Joseph M.; Sinclair, Elizabeth; Martin, Jeffrey N.; Deeks, Steven G.

    2011-01-01

    The rates of immunologic and clinical progression are lower in patients with drug-resistant HIV compared to wild-type HIV. This difference is not fully explained by viral load. It has been argued that reductions in T cell activation and/or viral fitness might result in preserved target cells and an altered relationship between the level of viremia and the rate of CD4+ T cell loss. We tested this hypothesis over time in a cohort of patients with highly resistant HIV. Fifty-four antiretroviral-treated patients with multi-drug resistant HIV and detectable plasma HIV RNA were followed longitudinally. CD4+ T cell counts and HIV RNA levels were measured every 4 weeks and T cell activation (CD38/HLA-DR) was measured every 16 weeks. We found that the levels of CD4+ T cell activation over time were a strong independent predictor of CD4+ T cell counts while CD8+ T cell activation was more strongly associated with viremia. Using spectral analysis, we found strong evidence for oscillatory (or cyclic) behavior in CD4+ T cell counts, HIV RNA levels, and T cell activation. Each of the cell populations exhibited an oscillatory behavior with similar frequencies. Collectively, these data suggest that there may be a mechanistic link between T cell activation, CD4+ T cell counts, and viremia and lends support for the hypothesis of altered predator-prey dynamics as a possible explanation of the stability of CD4+ T cell counts in the presence of sustained multi-drug resistant viremia. PMID:21701594

  19. Predictors of CD4(+) T-cell counts of HIV type 1-infected persons after virologic failure of all 3 original antiretroviral drug classes.

    PubMed

    Costagliola, Dominique; Ledergerber, Bruno; Torti, Carlo; van Sighem, Ard; Podzamczer, Daniel; Mocroft, Amanda; Dorrucci, Maria; Masquelier, Bernard; de Luca, Andrea; Jansen, Klaus; De Wit, Stephane; Obel, Niels; Fätkenheuer, Gerd; Touloumi, Giota; Mussini, Cristina; Castagna, Antonella; Stephan, Cristoph; García, Federico; Zangerle, Robert; Duval, Xavier; Perez-Hoyos, Santiago; Meyer, Laurence; Ghosn, Jade; Fabre-Colin, Céline; Kjaer, Jesper; Chêne, Genevieve; Grarup, Jesper; Phillips, Andrew; Lodwick, Rebecca; Torti, Carlo; Dorrucci, Maria; Günthard, Huldrych F; Michalik, Claudia; Chrysos, George; Castagna, Antonella

    2013-03-01

    Low CD4(+) T-cell counts are the main factor leading to clinical progression in human immunodeficiency virus type 1 (HIV-1) infection. We aimed to investigate factors affecting CD4(+) T-cell counts after triple-class virological failure. We included individuals from the COHERE database who started antiretroviral therapy from 1998 onward and who experienced triple-class virological failure. CD4(+) T-cell counts obtained after triple-class virologic failure were analyzed using generalized estimating equations. The analyses included 2424 individuals with a total of 23 922 CD4(+) T-cell count measurements. In adjusted models (excluding current viral load and year), CD4(+) T-cell counts were higher with regimens that included boosted protease inhibitors (increase, 22 cells/µL [95% confidence interval {CI}, 3.9-41]; P = .017) or drugs from the new classes (increase, 39 cells/µL [95% CI, 15-62]; P = .001), compared with nonnucleoside reverse-transcriptase inhibitor-based regimens. These associations disappeared when current viral load and/or calendar year were included. Compared with viral levels of <2.5 log(10) copies/mL, levels of 2.5-3.5, 3.5-4.5, 4.5-5.5, and >5.5 log(10) copies/mL were associated with CD4(+) T-cell count decreases of 51, 84, 137, and 186 cells/µL, respectively (P < .001). The approximately linear inverse relationship between log(10) viral load and CD4(+) T-cell count indicates that there are likely immunologic benefits from lowering viral load even by modest amounts that do not lead to undetectable viral loads. This is important for patients with low CD4(+) T-cell counts and few drug options.

  20. Intestinal Parasitosis in Relation to Anti-Retroviral Therapy, CD4+ T-cell Count and Diarrhea in HIV Patients

    PubMed Central

    Khalil, Shehla; Mirdha, Bijay Ranjan; Sinha, Sanjeev; Panda, Ashutosh; Singh, Yogita; Joseph, Anju; Deb, Manorama

    2015-01-01

    Intestinal parasitic infections are one of the major causes of diarrhea in human immunodeficiency virus (HIV) seropositive individuals. Antiretroviral therapy has markedly reduced the incidence of many opportunistic infections, but parasite-related diarrhea still remains frequent and often underestimated especially in developing countries. The present hospital-based study was conducted to determine the spectrum of intestinal parasitosis in adult HIV/AIDS (acquired immunodeficiency syndrome) patients with or without diarrhea with the levels of CD4+ T-cell counts. A total of 400 individuals were enrolled and were screened for intestinal parasitosis. Of these study population, 200 were HIV seropositives, and the remaining 200 were HIV uninfected individuals with or without diarrhea. Intestinal parasites were identified by using microscopy as well as PCR assay. A total of 130 (32.5%) out of 400 patients were positive for any kinds of intestinal parasites. The cumulative number of parasite positive patients was 152 due to multiple infections. A significant association of Cryptosporidium (P<0.001) was detected among individuals with CD4+ T-cell counts less than 200 cells/μl. PMID:26797437

  1. Intestinal Parasitosis in Relation to Anti-Retroviral Therapy, CD4(+) T-cell Count and Diarrhea in HIV Patients.

    PubMed

    Khalil, Shehla; Mirdha, Bijay Ranjan; Sinha, Sanjeev; Panda, Ashutosh; Singh, Yogita; Joseph, Anju; Deb, Manorama

    2015-12-01

    Intestinal parasitic infections are one of the major causes of diarrhea in human immunodeficiency virus (HIV) seropositive individuals. Antiretroviral therapy has markedly reduced the incidence of many opportunistic infections, but parasite-related diarrhea still remains frequent and often underestimated especially in developing countries. The present hospital-based study was conducted to determine the spectrum of intestinal parasitosis in adult HIV/AIDS (acquired immunodeficiency syndrome) patients with or without diarrhea with the levels of CD4(+) T-cell counts. A total of 400 individuals were enrolled and were screened for intestinal parasitosis. Of these study population, 200 were HIV seropositives, and the remaining 200 were HIV uninfected individuals with or without diarrhea. Intestinal parasites were identified by using microscopy as well as PCR assay. A total of 130 (32.5%) out of 400 patients were positive for any kinds of intestinal parasites. The cumulative number of parasite positive patients was 152 due to multiple infections. A significant association of Cryptosporidium (P<0.001) was detected among individuals with CD4(+) T-cell counts less than 200 cells/μl.

  2. Connectivity and HIV-1 infection: role of CD4(+) T-cell counts and HIV-1 RNA copy number.

    PubMed

    Padierna-Olivos, L; Moreno-Altamirano, M M; Sánchez-Colón, S; Massó-Rojas, F; Sánchez-García, F J

    2000-12-01

    Following primary infection with human immunodeficiency virus (HIV)-1, antibodies against specific HIV-1 epitopes are elicited. However, non-HIV-1 specific antibodies, including autoantibodies, also arise. In fact, it has been proposed that such autoantibodies have an important role in the pathogenesis of HIV-1 infection. Because an imbalance in connectivity has been associated with autoimmune processes, we investigated the connectivity status of HIV-1-infected individuals. Moreover, we tested the possible role of viral load and CD4(+) T-cell counts, in connectivity, because these parameters appear to be important in the prognosis of HIV-1 infection. Results show that indeed, there is an alteration in connectivity in these patients, both for immunoglobulin (Ig)G and IgM, which is an immune alteration not previously identified in HIV-1 infection. In addition, our results show that viral load and CD4(+) T-cell counts are both equally important in defining the characteristic pattern of connectivity in HIV-1-infected individuals, and that neither is independently responsible for alterations in patient connectivity status.

  3. Fluorescent intensity-based differential counting of FITC-doped silica nanoparticles: applications of CD4+ T-cell detection in microchip-type flowcytometers

    NASA Astrophysics Data System (ADS)

    Yun, Hoyoung; Bang, Hyunwoo; Lee, Won Gu; Lim, Hyunchang; Park, Junha; Lee, Joonmo; Riaz, Asif; Cho, Keunchang; Chung, Chanil; Han, Dong-Chul; Chang, Jun Keun

    2007-12-01

    Although CD4+ T-cells are an important target of HIV detection, there have been still major problems in making a diagnosis and monitoring in the third world and the region with few medical facilities. Then, it is necessary to use portable diagnosis devices at low cost when you put an enumeration of CD4+ T-cells. In general, the counting of CD4 below 200cells/uL makes it necessary to initiate antiretroviral treatment in adults (over 13 years old). However, lymphocyte subsets (including CD4 counts) of infants and young children are higher than those of adults. This fact shows the percentage of CD4+ T-cells of blood subsets, i.e., CD4/CD45%, CD4/CD8% or CD4/CD3% means a more reliable indicator of HIV infection than absolute counts in children. To know the percentage of CD4+ T-cell by using two fluorescent dyes of different emission wavelength, at least, one laser and two PMT detectors are in general needed. Then, it is so hard to develop a portable device like a 'toaster size' because this makes such a device more complex including many peripheral modules. In this study, we developed a novel technique to control the intensity of fluorescent dye-doped silica nanoparticles. I synthesized FITC-doped silica nanoparticles conjugated CD4 antibody 10 times brighter than FITC-conjugated CD45 antibody. With the difference of intensity of two fluorescent dyes, we measured two parameters by using only a single detector and laser. Most experiments were achieved with uFACS (microfabricated fluorescence-activated cell sorter) on an inverted microscope (IX71, Olympus). In conclusion, this method enables us to discriminate the difference between CD4 and CD45 in an intensity domain simultaneously. Furthermore, this technique would make it possible develop much cheaper and smaller devices which can count the number of CD4 T-cells.

  4. CD4+ T-cell Count may not be a Useful Strategy to Monitor Antiretroviral Therapy Response in HTLV-1/HIV Co-infected Patients.

    PubMed

    Vandormael, Alain; Rego, Filipe; Danaviah, Siva; Carlos Junior Alcantara, Luiz; Boulware, David R; de Oliveira, Tulio

    2017-01-01

    HTLV-1/HIV co-infection is known to elevate the CD4+ T-cell counts of treatment-naïve persons. We investigated whether HTLV-1/HIV co-infected patients continued to have elevated CD4+ T-cell counts after developing virologic failure on antiretroviral therapy (ART). The data is taken from a drug resistance study located in the KwaZulu-Natal province of South Africa. All participants (N=383) presented for repeated CD4+ T-cell count and HIV viral load level testing between January 2006 and March 2014. We used a random-coefficient model to estimate the change in CD4+ T-cell count and HIV viral load level by HTLV-1/HIV co-infection status over time, adjusting for age, sex, and duration of virologic failure. HTLV-1/HIV co-infected participants (n=8) had higher CD4+ T-cell counts, with a positive difference of 117.2 cells/μL at the ART initiation date (p-value=0.001), 114.7 cells/μL (pvalue< 0.001) 12 months after this date, and 112.3 cells/μL (p-value=0.005) 24 months after this date, holding all else constant. In contrast, there was no difference in the HIV viral load level by HTLV-1/HIV co-infected status throughout the observation period. We show that HTLV-1/HIV co-infected participants continued to have elevated CD4+ T-cell counts after developing virologic failure on ART, despite no difference in their HIV viral load levels when compared with HIV mono-infected participants. Our results indicate that CD4+ T-cell count testing may not be a useful strategy to monitor ART response in the presence of HTLV-1/HIV co-infection. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Enhancing the performance of a point-of-care CD4+ T-cell counting microchip through monocyte depletion for HIV/AIDS diagnostics.

    PubMed

    Cheng, Xuanhong; Gupta, Amit; Chen, Chihchen; Tompkins, Ronald G; Rodriguez, William; Toner, Mehmet

    2009-05-21

    CD4+ T cell counts are important tests used to stage HIV-positive patients, enabling clinicians to make informed antiretroviral treatment decisions and to monitor the therapeutic outcomes. However, state-of-the-art CD4 counting methods based on flow cytometry are not applicable in resource-limited settings, due to their high cost and technical requirements. In previous work, we reported the development of a cell isolation microchip that can be used at the point of care for CD4 counts. In that microfluidic chip, CD4+ T cells were separated from 10 microL of whole blood, and enumerated via either light microscopy or impedance sensing. The microchip counts matched flow cytometry results in the intermediate CD4 count range, between 200-800 cells/microL, but displayed a positive bias at absolute CD4 counts below 200 cells/microL, due largely to monocyte contamination. To enhance the performance in the low CD4 count range, we report here an improved design of a two-stage microfluidic device to deplete monocytes from whole blood, followed by CD4+ T cell capture. Using the double-stage device combined with a high viscosity rinsing solution, we obtained microchip CD4 counts comparable to flow cytometry results in the full clinically relevant range. In addition to CD4 counting, the strategy of contaminant depletion prior to target cell isolation can be easily adapted to immunoaffinity capture of other cell types that lack a unique surface marker from a complex biological fluid.

  6. Increase in CD4+ T-Cell Count at the Time of HIV Diagnosis and Antiretroviral Treatment Initiation Among Persons With HIV in New York City.

    PubMed

    Braunstein, Sarah L; Robertson, McKaylee M; Myers, Julie; Abraham, Bisrat; Nash, Denis

    2016-12-01

     Trends in CD4(+) T-cell count at human immunodeficiency virus (HIV) infection diagnosis and antiretroviral therapy (ART) initiation can be characterized using laboratory tests from surveillance.  We used CD4(+) T-cell counts and viral loads from New York City for persons who received a diagnosis of HIV infection during 2006-2012.  From 2006 to 2012, the median CD4(+) T-cell count increased from 325 to 379 cells/µL at diagnosis and from 178 to 360 cells/μL at ART initiation. CD4(+) T-cell counts were consistently lower in women, blacks, Hispanics, persons who inject drugs, and heterosexuals.  Increases in CD4(+) T-cell count at diagnosis and ART initiation suggest that the time from HIV infection to ART initiation has been reduced substantially in New York City. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  7. Reference curves for CD4 T-cell count response to combination antiretroviral therapy in HIV-1-infected treatment-naïve patients.

    PubMed

    Bouteloup, V; Sabin, C; Mocroft, A; Gras, L; Pantazis, N; Le Moing, V; d'Arminio Monforte, A; Mary-Krause, M; Roca, B; Miro, J M; Battegay, M; Brockmeyer, N; Berenguer, J; Morlat, P; Obel, N; De Wit, S; Fätkenheuer, G; Zangerle, R; Ghosn, J; Pérez-Hoyos, S; Campbell, M; Prins, M; Chêne, G; Meyer, L; Dorrucci, M; Torti, C; Thiébaut, R

    2017-01-01

    The aim of this work was to provide a reference for the CD4 T-cell count response in the early months after the initiation of combination antiretroviral therapy (cART) in HIV-1-infected patients. All patients in the Collaboration of Observational HIV Epidemiological Research Europe (COHERE) cohort who were aged ≥ 18 years and started cART for the first time between 1 January 2005 and 1 January 2010 and who had at least one available measurement of CD4 count and a viral load ≤ 50 HIV-1 RNA copies/mL at 6 months (± 3 months) after cART initiation were included in the study. Unadjusted and adjusted references curves and predictions were obtained using quantile regressions. A total of 28 992 patients were included in the study. The median CD4 T-cell count at treatment initiation was 249 [interquartile range (IQR) 150, 336] cells/μL. The median observed CD4 counts at 6, 9 and 12 months were 382 (IQR 256, 515), 402 (IQR 274, 543) and 420 (IQR 293, 565) cells/μL. The two main factors explaining the variation of CD4 count at 6 months were AIDS stage and CD4 count at cART initiation. A CD4 count increase of ≥ 100 cells/mL is generally required in order that patients stay 'on track' (i.e. with a CD4 count at the same percentile as when they started), with slightly higher gains required for those starting with CD4 counts in the higher percentiles. Individual predictions adjusted for factors influencing CD4 count were more precise. Reference curves aid the evaluation of the immune response early after antiretroviral therapy initiation that leads to viral control. © 2016 British HIV Association.

  8. Responsiveness of T Cells to Interleukin-7 Is Associated with Higher CD4+ T Cell Counts in HIV1-Positive Individuals with Highly Active Antiretroviral Therapy-Induced Viral Load Suppression

    PubMed Central

    Camargo, Jose F.; Kulkarni, Hemant; Agan, Brian K.; Gaitan, Alvaro A.; Beachy, Lisa A.; Srinivas, Sowmya; He, Weijing; Anderson, Stephanie; Marconi, Vincent C.; Dolan, Matthew J.; Ahuja, Sunil K.

    2013-01-01

    Background Despite suppression of the human immunodeficiency virus type 1(HIV-1) load by highly active antiretroviral therapy (HAART), recovery of CD4+ T cell counts can be impaired. We investigated whether this impairment may be associated with hyporesponsiveness of T cells to γ-chain (γc) cytokines known to influence T cell homeostasis. Methods The responsiveness of T cells to interleukin (IL)-2, IL-7, and IL-15 was determined by assessing cytokine-induced phosphorylation of the signal transducer and activator of transcription 5 (STAT5) in peripheral T cells obtained from 118 HIV-positive subjects and 13 HIV-negative subjects. Results The responsiveness of T cells to interleukin (IL)-7 but not to IL-2 or IL-15 was lower among HIV-positive subjects than among HIV-negative subjects. Among subjects with viral load suppression, the degree of IL-7 responsiveness (1) correlated with naive CD4+ T cell counts and was a better immune correlate of the prevailing CD4+ T cell count than were levels of human leukocyte antigen-DR1 or programmed death-1, which are predictors of T cell homeostasis during HIV infection; and (2) was greater in subjects with complete (i.e., attainment of ≥500 CD4+ T cells/mm3 ≥5 years after initiation of HAART) versus incomplete immunologic responses. The correlation between plasma levels of IL-7 and CD4+ T cell counts during HAART was maximal in subjects with increased IL-7 responsiveness. Conclusions Responsiveness of T cells to IL-7 is associated with higher CD4+ T cell counts during HAART and thus may be a determinant of the extent of immune reconstitution. PMID:19432535

  9. Evaluation of Baseline CD4+ T Cell Counts and ART Requirement in Newly Diagnosed HIV Seropositive Individuals in a Tertiary Care Hospital of Northern India.

    PubMed

    Bhattar, Sonali; Mehra, Bhanu; Bhalla, Preena; Rawat, Deepti

    2016-11-01

    Antiretroviral Therapy (ART) has changed the outlook of Human Immune-deficiency Virus (HIV)/Acquired Immuno Deficiency Syndrome (AIDS) patients worldwide. To analyse the trends in baseline CD4+ T cell counts and ART requirements in newly diagnosed HIV seropositive individuals in a Tertiary care hospital of Northern India. Out of 1263 HIV seropositive clients identified from January 2012 to June 2014, the baseline CD4+ T cell counts of only those 470 clients were analysed, who registered at the linked ART centre. The mean baseline CD4+ count of the study group was 249.77±216.0cells/mm(3) and that of male and female were 300.31±240.47cells/mm(3) and 232.38±204.25cells/mm(3) respectively. A total of 259 of 334 (77.54%) HIV reactive males, 83 of 130 (63.85%) HIV reactive females and overall 348 of 470 (74.04%) required antiretroviral treatment on enrolment. In the present study, about three-fourth of newly diagnosed HIV positive Indian patients required initiation of ART at registration. The relatively low baseline CD4+ T cell counts in this population highlights the need for timely baseline CD4+ counts testing of HIV positive patients and the urgency of initiating treatment in HIV reactive individuals in Indian health care settings.

  10. Evaluation of Baseline CD4+ T Cell Counts and ART Requirement in Newly Diagnosed HIV Seropositive Individuals in a Tertiary Care Hospital of Northern India

    PubMed Central

    Bhattar, Sonali; Mehra, Bhanu; Rawat, Deepti

    2016-01-01

    Introduction Antiretroviral Therapy (ART) has changed the outlook of Human Immune-deficiency Virus (HIV)/Acquired Immuno Deficiency Syndrome (AIDS) patients worldwide. Aim To analyse the trends in baseline CD4+ T cell counts and ART requirements in newly diagnosed HIV seropositive individuals in a Tertiary care hospital of Northern India. Materials and Methods Out of 1263 HIV seropositive clients identified from January 2012 to June 2014, the baseline CD4+ T cell counts of only those 470 clients were analysed, who registered at the linked ART centre. Results The mean baseline CD4+ count of the study group was 249.77±216.0cells/mm3 and that of male and female were 300.31±240.47cells/mm3 and 232.38±204.25cells/mm3 respectively. A total of 259 of 334 (77.54%) HIV reactive males, 83 of 130 (63.85%) HIV reactive females and overall 348 of 470 (74.04%) required antiretroviral treatment on enrolment. Conclusion In the present study, about three-fourth of newly diagnosed HIV positive Indian patients required initiation of ART at registration. The relatively low baseline CD4+ T cell counts in this population highlights the need for timely baseline CD4+ counts testing of HIV positive patients and the urgency of initiating treatment in HIV reactive individuals in Indian health care settings. PMID:28050367

  11. Enumeration of CD4+ T-Cells Using a Portable Microchip Count Platform in Tanzanian HIV-Infected Patients

    PubMed Central

    Moon, SangJun; Gurkan, Umut Atakan; Blander, Jeffrey; Fawzi, Wafaie W.; Aboud, Said; Mugusi, Ferdinand; Kuritzkes, Daniel R.; Demirci, Utkan

    2011-01-01

    Background CD4+ T-lymphocyte count (CD4 count) is a standard method used to monitor HIV-infected patients during anti-retroviral therapy (ART). The World Health Organization (WHO) has pointed out or recommended that a handheld, point-of-care, reliable, and affordable CD4 count platform is urgently needed in resource-scarce settings. Methods HIV-infected patient blood samples were tested at the point-of-care using a portable and label-free microchip CD4 count platform that we have developed. A total of 130 HIV-infected patient samples were collected that included 16 de-identified left over blood samples from Brigham and Women's Hospital (BWH), and 114 left over samples from Muhimbili University of Health and Allied Sciences (MUHAS) enrolled in the HIV and AIDS care and treatment centers in the City of Dar es Salaam, Tanzania. The two data groups from BWH and MUHAS were analyzed and compared to the commonly accepted CD4 count reference method (FACSCalibur system). Results The portable, battery operated and microscope-free microchip platform developed in our laboratory (BWH) showed significant correlation in CD4 counts compared with FACSCalibur system both at BWH (r = 0.94, p<0.01) and MUHAS (r = 0.49, p<0.01), which was supported by the Bland-Altman methods comparison analysis. The device rapidly produced CD4 count within 10 minutes using an in-house developed automated cell counting program. Conclusions We obtained CD4 counts of HIV-infected patients using a portable platform which is an inexpensive (<$1 material cost) and disposable microchip that uses whole blood sample (<10 µl) without any pre-processing. The system operates without the need for antibody-based fluorescent labeling and expensive fluorescent illumination and microscope setup. This portable CD4 count platform displays agreement with the FACSCalibur results and has the potential to expand access to HIV and AIDS monitoring using fingerprick volume of whole blood and helping people who suffer

  12. Clinical Outcome of HIV Viraemic Controllers and Noncontrollers with Normal CD4 Counts Is Exclusively Determined by Antigen-Specific CD8+ T-Cell-Mediated HIV Suppression

    PubMed Central

    Tansiri, Yada; Rowland-Jones, Sarah L.; Ananworanich, Jintanat; Hansasuta, Pokrath

    2015-01-01

    In this cross-sectional study we evaluated T-cell responses using several assays to determine immune correlates of HIV control that distinguish untreated viraemic controllers (VC) from noncontrollers (NC) with similar CD4 counts. Samples were taken from 65 ART-naïve chronically HIV-infected VC and NC from Thailand with matching CD4 counts in the normal range (>450 cells/μl). We determined HIVp24-specific T-cell responses using standard Interferon-gamma (IFNγ) ELISpot assays, and compared the functional quality of HIVp24-specific CD8+ T-cell responses using polychromatic flow cytometry. Finally, in vitro HIV suppression assays were performed to evaluate directly the activity of CD8+ T cells in HIV control. Autologous CD4+ T cells were infected with primary patient-derived HIV isolates and the HIV suppressive activity of CD8+ T cells was determined after co-culture, measuring production of HIVp24 Ag by ELISA. The HIVp24-specific T-cell responses of VC and NC could not completely be differentiated through measurement of IFNγ-producing cells using ELISpot assays, nor by the absolute cell numbers of polyfunctional HIVp24-specific CD8+ T cells. However, in vitro HIV suppression assays showed clear differences between VC and NC. HIV suppressive activity, mediated by either ex vivo unstimulated CD8+ T cells or HIVp24-specific T-cell lines, was significantly greater using cells from VC than NC cells. Additionally, we were able to demonstrate a significant correlation between the level of HIV suppressive activity mediated by ex vivo unstimulated CD8+ T cells and plasma viral load (pVL) (Spearman r = -0.7345, p = 0.0003). This study provides evidence that in vitro HIV suppression assays are the most informative in the functional evaluation of CD8+ T-cell responses and can distinguish between VC and NC. PMID:25764310

  13. Effect of Nadir CD4+ T Cell Count on Clinical Measures of Periodontal Disease in HIV+ Adults before and during Immune Reconstitution on HAART

    PubMed Central

    Vernon, Lance T.; Demko, Catherine A.; Babineau, Denise C.; Wang, Xuelei; Toossi, Zahra; Weinberg, Aaron; Rodriguez, Benigno

    2013-01-01

    Background The contribution of HIV-infection to periodontal disease (PD) is poorly understood.  We proposed that immunological markers would be associated with improved clinical measures of PD. Methods We performed a longitudinal cohort study of HIV-infected adults who had started highly active antiretroviral therapy (HAART) <2 years. PD was characterized clinically as the percent of teeth with ≥1 site with periodontal probing depth (PPD) ≥5.0mm, recession (REC) >0mm, clinical attachment level (CAL) ≥4.0mm, and bleeding on probing (BOP) at ≥4 sites/tooth and microbiologically as specific periodontopathogen concentration. Linear mixed-effects models were used to assess the associations between immune function and PD. Results Forty (40) subjects with median 2.7 months on HAART and median nadir CD4+ T-cell count of 212 cells/μl completed a median 3 visits. Over 24 months, CD4+ T-cell count increased by a mean 173 cells/µl (p<0.001) and HIV RNA decreased by 0.5 log10 copies/ml (p<0.001); concurrently, PPD, CAL and BOP decreased by a mean 11.7%, 12.1%, and 14.7% respectively (all p<0.001). Lower nadir CD4+ T-cell count was associated with worse baseline REC (-6.72%; p=0.04) and CAL (9.06%; p<0.001). Further, lower nadir CD4+ T-cell count was associated with a greater relative longitudinal improvement in PPD in subjects with higher baseline levels of Porphyromonas gingivalis (p=0.027), and BOP in subjects with higher baseline levels of Porphyromonas gingivalis or Treponema denticola (p=0.001 and p=0.006 respectively). Longitudinal changes from baseline in CD4+ T-cell count and level of HIV RNA were not independently associated with longitudinal changes in any clinical markers of PD. Conclusion Degree of immunosuppression was associated with baseline gingival recession. After HAART initiation, measures of active PD improved most in those with lower nadir CD4+ T-cell counts and higher baseline levels of specific periodontopathogens. Nadir CD4+ T-cell count

  14. Mitochondrial genomics and CD4 T-cell count recovery after antiretroviral therapy initiation in AIDS clinical trials group study 384.

    PubMed

    Grady, Benjamin J; Samuels, David C; Robbins, Gregory K; Selph, Doug; Canter, Jeffrey A; Pollard, Richard B; Haas, David W; Shafer, Robert; Kalams, Spyros A; Murdock, Deborah G; Ritchie, Marylyn D; Hulgan, Todd

    2011-12-01

    Mitochondrial DNA (mtDNA) variation has been associated with time to progression to AIDS and adverse effects from antiretroviral therapy (ART). In this study, full mitochondrial DNA (mtDNA) sequence data from US-based adult participants in the AIDS Clinical Trials Group study 384 was used to assess associations between mtDNA variants and CD4 T-cell recovery with ART. Full mtDNA sequence was determined using chip-based array sequencing. Sequence and CD4 cell count data was available at baseline and after ART initiation for 423 subjects with HIV RNA levels <400 copies per milliliter plasma. The primary outcome was change in CD4 count of ≥100 cells per cubic millimeter from baseline. Analyses were adjusted for baseline age, CD4 cell count, HIV RNA, and naive:memory CD4 cell ratio. Race-stratified analysis of mtDNA variants with a minor allele frequency >1% revealed multiple mtDNA variants marginally associated (P < 0.05 before Bonferroni correction) with CD4 cell recovery. The most significant single nucleotide polymorphism associations were those tagging the African L2 haplogroup, which was associated with a decreased likelihood of ≥100 cells per cubic millimeter CD4 count increase at week 48 in non-Hispanic blacks (adjusted odds ratio = 0.17; 95% confidence interval = 0.06 to 0.53; P = 0.002). An African mtDNA haplogroup was associated with CD4 cell recovery after ART in this clinical trial population. These initial findings warrant replication and further investigation to confirm the role of mtDNA variation in CD4 cell recovery during ART.

  15. EBV and HHV-6 Circulating Subtypes in People Living with HIV in Burkina Faso, Impact on CD4 T cell count and HIV Viral Load

    PubMed Central

    Traore, Lassina; Nikiema, Ouéogo; Ouattara, Abdoul Karim; Compaore, Tegwindé Rébéca; Soubeiga, Serge Théophile; Diarra, Birama; Obiri-Yeboah, Dorcas; Sorgho, Pegdwendé Abel; Djigma, Florencia Wendkuuni; Bisseye, Cyrille; Yonli, Albert Théophane; Simpore, Jacques

    2017-01-01

    Epstein Barr Virus (EBV) and Human Herpes Virus 6 (HHV-6) are responsible for severe diseases, particularly in immunocompromised persons. There is limited data of the infection of these opportunistic viruses in Burkina Faso. The purpose of this study was to characterize EBV and HHV-6 subtypes and to assess their impact on CD4 T cell count, HIV-1 viral load and antiretroviral treatment in people living with HIV-1. The study population consisted of 238 HIV-positive patients with information on the CD4 T cell count, HIV-1 viral load and HAART. Venous blood samples collected in EDTA tubes were used for EBV and HHV-6 Real Time PCR subtyping. An infection rate of 6.7% (16/238) and 7.1% (17/238) were found respectively for EBV and HHV-6 in the present study. Among EBV infections, similar prevalence was noted for both subtypes (3.9% (9/238) for EBV-1 vs 4.6% (11/238) for EBV-2) with 2.1% (5/238) of co-infection. HHV-6A infection represented 6.3% (15/238) of the study population against 5.0% (12/238) for HHV-6B. EBV-2 infection was significantly higher in patients with CD4 T cell count ≥ 500 compared to those with CD4 T cell count less than 500 cells (1.65% vs 8.56%, p = 0,011). The prevalence of EBV and HHV-6 infections was almost similar in HAART-naive and HAART-experienced patients. The present study provides information on the prevalence of EBV and HHV-6 subtypes in people living with HIV-1 in Burkina Faso. The study also suggests that HAART treatment has no effect on infection with these opportunistic viruses in people living with HIV-1.

  16. EBV and HHV-6 Circulating Subtypes in People Living with HIV in Burkina Faso, Impact on CD4 T cell count and HIV Viral Load.

    PubMed

    Traore, Lassina; Nikiema, Ouéogo; Ouattara, Abdoul Karim; Compaore, Tegwindé Rébéca; Soubeiga, Serge Théophile; Diarra, Birama; Obiri-Yeboah, Dorcas; Sorgho, Pegdwendé Abel; Djigma, Florencia Wendkuuni; Bisseye, Cyrille; Yonli, Albert Théophane; Simpore, Jacques

    2017-01-01

    Epstein Barr Virus (EBV) and Human Herpes Virus 6 (HHV-6) are responsible for severe diseases, particularly in immunocompromised persons. There is limited data of the infection of these opportunistic viruses in Burkina Faso. The purpose of this study was to characterize EBV and HHV-6 subtypes and to assess their impact on CD4 T cell count, HIV-1 viral load and antiretroviral treatment in people living with HIV-1. The study population consisted of 238 HIV-positive patients with information on the CD4 T cell count, HIV-1 viral load and HAART. Venous blood samples collected in EDTA tubes were used for EBV and HHV-6 Real Time PCR subtyping. An infection rate of 6.7% (16/238) and 7.1% (17/238) were found respectively for EBV and HHV-6 in the present study. Among EBV infections, similar prevalence was noted for both subtypes (3.9% (9/238) for EBV-1 vs 4.6% (11/238) for EBV-2) with 2.1% (5/238) of co-infection. HHV-6A infection represented 6.3% (15/238) of the study population against 5.0% (12/238) for HHV-6B. EBV-2 infection was significantly higher in patients with CD4 T cell count ≥ 500 compared to those with CD4 T cell count less than 500 cells (1.65% vs 8.56%, p = 0,011). The prevalence of EBV and HHV-6 infections was almost similar in HAART-naive and HAART-experienced patients. The present study provides information on the prevalence of EBV and HHV-6 subtypes in people living with HIV-1 in Burkina Faso. The study also suggests that HAART treatment has no effect on infection with these opportunistic viruses in people living with HIV-1.

  17. Lower Viral Loads and Slower CD4+ T-Cell Count Decline in MRKAd5 HIV-1 Vaccinees Expressing Disease-Susceptible HLA-B*58:02.

    PubMed

    Leitman, Ellen M; Hurst, Jacob; Mori, Masahiko; Kublin, James; Ndung'u, Thumbi; Walker, Bruce D; Carlson, Jonathan; Gray, Glenda E; Matthews, Philippa C; Frahm, Nicole; Goulder, Philip J R

    2016-08-01

    HLA strongly influences human immunodeficiency virus type 1 (HIV-1) disease progression. A major contributory mechanism is via the particular HLA-presented HIV-1 epitopes that are recognized by CD8(+) T-cells. Different populations vary considerably in the HLA alleles expressed. We investigated the HLA-specific impact of the MRKAd5 HIV-1 Gag/Pol/Nef vaccine in a subset of the infected Phambili cohort in whom the disease-susceptible HLA-B*58:02 is highly prevalent. Viral loads, CD4(+) T-cell counts, and enzyme-linked immunospot assay-determined anti-HIV-1 CD8(+) T-cell responses for a subset of infected antiretroviral-naive Phambili participants, selected according to sample availability, were analyzed. Among those expressing disease-susceptible HLA-B*58:02, vaccinees had a lower chronic viral set point than placebo recipients (median, 7240 vs 122 500 copies/mL; P = .01), a 0.76 log10 lower longitudinal viremia level (P = .01), and slower progression to a CD4(+) T-cell count of <350 cells/mm(3) (P = .02). These differences were accompanied by a higher Gag-specific breadth (4.5 vs 1 responses; P = .04) and magnitude (2300 vs 70 spot-forming cells/10(6) peripheral blood mononuclear cells; P = .06) in vaccinees versus placebo recipients. In addition to the known enhancement of HIV-1 acquisition resulting from the MRKAd5 HIV-1 vaccine, these findings in a nonrandomized subset of enrollees show an HLA-specific vaccine effect on the time to CD4(+) T-cell count decline and viremia level after infection and the potential for vaccines to differentially alter disease outcome according to population HLA composition. NCT00413725, DOH-27-0207-1539. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

  18. Estimated Costs for Delivery of HIV Antiretroviral Therapy to Individuals with CD4+ T-Cell Counts >350 cells/uL in Rural Uganda

    PubMed Central

    Jain, Vivek; Chang, Wei; Byonanebye, Dathan M.; Owaraganise, Asiphas; Twinomuhwezi, Ellon; Amanyire, Gideon; Black, Douglas; Marseille, Elliot; Kamya, Moses R.; Havlir, Diane V.; Kahn, James G.

    2015-01-01

    Background Evidence favoring earlier HIV ART initiation at high CD4+ T-cell counts (CD4>350/uL) has grown, and guidelines now recommend earlier HIV treatment. However, the cost of providing ART to individuals with CD4>350 in Sub-Saharan Africa has not been well estimated. This remains a major barrier to optimal global cost projections for accelerating the scale-up of ART. Our objective was to compute costs of ART delivery to high CD4+count individuals in a typical rural Ugandan health center-based HIV clinic, and use these data to construct scenarios of efficient ART scale-up. Methods Within a clinical study evaluating streamlined ART delivery to 197 individuals with CD4+ cell counts >350 cells/uL (EARLI Study: NCT01479634) in Mbarara, Uganda, we performed a micro-costing analysis of administrative records, ART prices, and time-and-motion analysis of staff work patterns. We computed observed per-person-per-year (ppy) costs, and constructed models estimating costs under several increasingly efficient ART scale-up scenarios using local salaries, lowest drug prices, optimized patient loads, and inclusion of viral load (VL) testing. Findings Among 197 individuals enrolled in the EARLI Study, median pre-ART CD4+ cell count was 569/uL (IQR 451–716). Observed ART delivery cost was $628 ppy at steady state. Models using local salaries and only core laboratory tests estimated costs of $529/$445 ppy (+/-VL testing, respectively). Models with lower salaries, lowest ART prices, and optimized healthcare worker schedules reduced costs by $100–200 ppy. Costs in a maximally efficient scale-up model were $320/$236 ppy (+/- VL testing). This included $39 for personnel, $106 for ART, $130/$46 for laboratory tests, and $46 for administrative/other costs. A key limitation of this study is its derivation and extrapolation of costs from one large rural treatment program of high CD4+ count individuals. Conclusions In a Ugandan HIV clinic, ART delivery costs—including VL testing

  19. Association of KIR3DL1/S1 and HLA-Bw4 with CD4 T cell counts in HIV-infected Mexican mestizos.

    PubMed

    Hernández-Ramírez, Daniel; Esparza-Pérez, Mario A; Ramirez-Garcialuna, José L; Arguello, J Rafael; Mandeville, Peter B; Noyola, Daniel E; García-Sepúlveda, Christian A

    2015-08-01

    Certain genotypic combinations of killer-cell immunoglobulin-like receptors (KIR) and human leukocyte antigens (HLA) have been associated with favourable outcomes after exposure to human immunodeficiency virus in Caucasoid and African populations. Human immunodeficiency virus (HIV) infection is characterized by a rapid exhaustion of CD4 cells, which results in impaired cellular immunity. During this early phase of infection, it is thought that the natural killer (NK) cells represent the main effector arm of the host immune response to HIV. This study investigates whether KIR and HLA factors are associated to CD4 T cell numbers after HIV infection in Mexican mestizos as assessed at the time of initial medical evaluation and subsequent clinical follow-up. KIR and HLA-B gene carrier frequency differences were compared between groups of patients stratified by CD4 T cell numbers as assessed during their first medical evaluation (a point in time at which all patients were anti-retroviral therapy naïve). In addition, the influence that these genetic factors have on averaged historical CD4 cell counts in patients subjected to follow-up (mostly therapy-experienced) was also evaluated. Our results suggest a protective role for the HLA-Bw4 and KIR3D + Bw4 combination in both therapy-naïve and therapy-experienced patients. This report furthers our understanding on the way that immune genes modulate HIV disease progression in less-studied human populations such as the Mexican mestizos with a special focus on CD4 T cell number and behaviour.

  20. Pregnancy and Other Factors Associated With Higher CD4+ T-Cell Counts at HIV Diagnosis in Southeast Michigan, 1992–2002

    PubMed Central

    Wotring, Linda L.; Montgomery, JoLynn P.; Mokotoff, Eve D.; Inungu, Joseph N.; Markowitz, Norman; Crane, Lawrence R.

    2005-01-01

    Abstract and Introduction Abstract Background Early diagnosis of HIV infection provides the opportunity for treatment to prevent progression to AIDS and for intervention to prevent further transmission. The impact of routine screening of pregnant women and other factors on the stage of HIV disease at diagnosis were evaluated. Methods Data were collected in 1992–2002 from the medical records of persons presenting for HIV-related care at 2 major medical centers in Detroit, Michigan. Patients were included in the analysis if they had a CD4+ T-cell count recorded within 6 months of their first positive HIV test (N = 1858). Results Half of the patients (49%) had a first CD4+ T-cell count of < 200 cells/mm3 and 19% had an AIDS-defining illness at the time of HIV diagnosis. In the multivariate model, pregnant women were less likely than nonpregnant women to enter care with a CD4+ T-cell count of < 200 cells/mm3 (odds ratio, .24; 95% confidence interval, .14–.41). Even after adjusting for pregnancy, female sex was protective, as was age < 30 years. HIV-transmission risk factors, race, and time period of HIV diagnosis were not significantly associated with first CD4+ T-cell counts of < 200 cells/mm3. Conclusion Routinely offering HIV testing in prenatal care, as required by Michigan law, resulted in earlier diagnoses of HIV in pregnant women, as indicated by their higher CD4+ T-cell counts. Increasing routine HIV testing of all persons seeking medical care may increase the overall proportion of HIV diagnoses that are made early in the disease process. Introduction Increasing the proportions of HIV-positive persons who know their status and receive care is a strategic goal of the US Centers for Disease Control and Prevention (CDC).[1] As one of the tactics for achieving this goal, the CDC's recommendation on routinely offering HIV testing has recently been expanded to include all persons seeking healthcare in all clinical settings where the prevalence of HIV in the

  1. Relaxation of adaptive evolution during the HIV-1 infection owing to reduction of CD4+ T cell counts.

    PubMed

    Leal, Élcio; Casseb, Jorge; Hendry, Michael; Busch, Michael P; Diaz, Ricardo Sobhie

    2012-01-01

    The first stages of HIV-1 infection are essential to establish the diversity of virus population within host. It has been suggested that adaptation to host cells and antibody evasion are the leading forces driving HIV evolution at the initial stages of AIDS infection. In order to gain more insights on adaptive HIV-1 evolution, the genetic diversity was evaluated during the infection time in individuals contaminated by the same viral source in an epidemic cluster. Multiple sequences of V3 loop region of the HIV-1 were serially sampled from four individuals: comprising a single blood donor, two blood recipients, and another sexually infected by one of the blood recipients. The diversity of the viral population within each host was analyzed independently in distinct time points during HIV-1 infection. Phylogenetic analysis identified multiple HIV-1 variants transmitted through blood transfusion but the establishing of new infections was initiated by a limited number of viruses. Positive selection (d(N)/d(S)>1) was detected in the viruses within each host in all time points. In the intra-host viruses of the blood donor and of one blood recipient, X4 variants appeared respectively in 1993 and 1989. In both patients X4 variants never reached high frequencies during infection time. The recipient, who X4 variants appeared, developed AIDS but kept narrow and constant immune response against HIV-1 during the infection time. Slowing rates of adaptive evolution and increasing diversity in HIV-1 are consequences of the CD4+ T cells depletion. The dynamic of R5 to X4 shift is not associated with the initial amplitude of humoral immune response or intensity of positive selection.

  2. HIV-1-specific T cell precursors with high proliferative capacity correlate with low viremia and high CD4 counts in untreated individuals.

    PubMed

    Calarota, Sandra A; Foli, Andrea; Maserati, Renato; Baldanti, Fausto; Paolucci, Stefania; Young, Mary A; Tsoukas, Christos M; Lisziewicz, Julianna; Lori, Franco

    2008-05-01

    Evidences have recently suggested that the preservation of vaccine-induced memory rather than effector T cells is essential for better outcome and survival following pathogenic SIV challenge in macaques. However, an equivalent demonstration in humans is missing, and the immune correlates of HIV-1 control have been only partially characterized. We focused on the quantification of Ag-specific T cell precursors with high proliferative capacity (PHPC) using a peptide-based cultured IFN-gamma ELISPOT assay (PHPC assay), which has been shown to identify expandable memory T cells. To determine which responses correlate with viral suppression and positive immunologic outcome, PBMC from 32 chronically untreated HIV-1-infected individuals were evaluated in response to peptide pools, representing the complete HIV-1 Gag, Nef, and Rev proteins, by PHPC and IFN-gamma ELISPOT assay, which instead identifies effector T cells with low proliferative capacity. High magnitude of Gag-specific PHPC, but not ELISPOT, responses significantly correlated with low plasma viremia, due to responses directed toward p17 and p15 subunits. Only Gag p17-specific PHPC response significantly correlated with high CD4 counts. Analysis of 20 additional PBMC samples from an independent cohort of chronically untreated HIV-1-infected individuals confirmed the correlation between Gag p17-specific PHPC response and either plasma viremia (inverse correlation) or CD4 counts (direct correlation). Our results indicate that the PHPC assay is quantitatively and qualitatively different from the ELISPOT assay, supporting that different T cell populations are being evaluated. The PHPC assay might be an attractive option for individual patient management and for the design and testing of therapeutic and prophylactic vaccines.

  3. Impaired hepatitis C virus (HCV)-specific interferon-γ responses in individuals with HIV who acquire HCV infection: correlation with CD4(+) T-cell counts.

    PubMed

    Flynn, Jacqueline K; Dore, Gregory J; Matthews, Gail; Hellard, Margaret; Yeung, Barbara; Rawlinson, William D; White, Peter A; Kaldor, John M; Lloyd, Andrew R; Ffrench, Rosemary A

    2012-11-15

    Studies examining the effect of coinfection with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) on the HCV-specific immune response in acute HCV infection are limited. This study directly compared acute HCV-specific T-cell responses and cytokine profiles between 20 HIV/HCV-coinfected and 20 HCV-monoinfected subjects, enrolled in the Australian Trial in Acute Hepatitis C (ATAHC), using HCV peptide enzyme-linked immunospot (ELISPOT) and multiplex in vitro cytokine production assays. HIV/HCV coinfection had a detrimental effect on the HCV-specific cytokine production in acute HCV infection, particularly on HCV-specific interferon γ (IFN-γ) production (magnitude P = .004; breadth P = .046), which correlated with peripheral CD4(+) T-cell counts (ρ = 0.605; P = .005) but not with detectable HIV viremia (ρ = 0.152; P = .534).

  4. CD4+ T-cell counts and interleukin-8 and CCL-5 plasma concentrations discriminate disease severity in children with RSV infection.

    PubMed

    Brand, Hanne K; Ferwerda, Gerben; Preijers, Frank; de Groot, Ronald; Neeleman, Chris; Staal, Frank J T; Warris, Adilia; Hermans, Peter W M

    2013-02-01

    Current tools to predict the severity of respiratory syncytial virus (RSV) infection might be improved by including immunological parameters. We hypothesized that a combination of inflammatory markers would differentiate between severe and mild disease in RSV-infected children. Blood and nasopharyngeal samples from 52 RSV-infected children were collected during acute infection and after recovery. Retrospectively, patients were categorized into three groups based on disease severity: mild (no supportive treatment), moderate (supplemental oxygen and/or nasogastric feeding), and severe (mechanical ventilation). Clinical data, number of flow-defined leukocyte subsets, and cytokine concentrations were compared. Children with severe RSV infection were characterized by young age; lymphocytopenia; increased interleukin (IL)-8, granulocyte colony-stimulating factor (G-CSF), and IL-6 concentrations; and decreased chemokine (C-C motif) ligand (CCL-5) concentrations in plasma. The combination of plasma levels of IL-8 and CCL-5, and CD4+ T-cell counts, with cutoff values of 67 pg/ml, 13 ng/ml, and 2.3 × 10(6)/ml, respectively, discriminated severe from mild RSV infection with 82% sensitivity and 96% specificity. This study demonstrates that the combination of CD4+ T-cell counts and IL-8 and CCL-5 plasma concentrations correlates with disease severity in RSV-infected children. In addition to clinical features, these immunological markers may be used to assess severity of RSV infection and guide clinical management.

  5. Hierarchy Low CD4+/CD8+ T-Cell Counts and IFN-γ Responses in HIV-1+ Individuals Correlate with Active TB and/or M.tb Co-Infection.

    PubMed

    Shao, Lingyun; Zhang, Xinyun; Gao, Yan; Xu, Yunya; Zhang, Shu; Yu, Shenglei; Weng, Xinhua; Shen, Hongbo; Chen, Zheng W; Jiang, Weimin; Zhang, Wenhong

    2016-01-01

    Detailed studies of correlation between HIV-M.tb co-infection and hierarchy declines of CD8+/CD4+ T-cell counts and IFN-γ responses have not been done. We conducted case-control studies to address this issue. 164 HIV-1-infected individuals comprised of HIV-1+ATB, HIV-1+LTB and HIV-1+TB- groups were evaluated. Immune phenotyping and complete blood count (CBC) were employed to measure CD4+ and CD8+ T-cell counts; T.SPOT.TB and intracellular cytokine staining (ICS) were utilized to detect ESAT6, CFP10 or PPD-specific IFN-γ responses. There were significant differences in median CD4+ T-cell counts between HIV-1+ATB (164/μL), HIV-1+LTB (447/μL) and HIV-1+TB- (329/μL) groups. Hierarchy low CD4+ T-cell counts (<200/μL, 200-500/μL, >500/μL) were correlated significantly with active TB but not M.tb co-infection. Interestingly, hierarchy low CD8+ T-cell counts were not only associated significantly with active TB but also with M.tb co-infection (P<0.001). Immunologically, HIV-1+ATB group showed significantly lower numbers of ESAT-6-/CFP-10-specific IFN-γ+ T cells than HIV-1+LTB group. Consistently, PPD-specific IFN-γ+CD4+/CD8+ T effector cells in HIV-1+ATB group were significantly lower than those in HIV-1+LTB group (P<0.001). Hierarchy low CD8+ T-cell counts and effector function in HIV-1-infected individuals are correlated with both M.tb co-infection and active TB. Hierarchy low CD4+ T-cell counts and Th1 effector function in HIV-1+ individuals are associated with increased frequencies of active TB, but not M.tb co-infection.

  6. The Factors Related to CD4+ T-Cell Recovery and Viral Suppression in Patients Who Have Low CD4+ T Cell Counts at the Initiation of HAART: A Retrospective Study of the National HIV Treatment Sub-Database of Zhejiang Province, China, 2014

    PubMed Central

    He, Lin; Pan, Xiaohong; Dou, Zhihui; Huang, Peng; Zhou, Xin; Peng, Zhihang; Zheng, Jinlei; Zhang, Jiafeng; Yang, Jiezhe; Xu, Yun; Jiang, Jun; Chen, Lin; Jiang, Jianmin; Wang, Ning

    2016-01-01

    Background Since China has a unique system of delivering HIV care that includes all patients’ records. The factors related to CD4+ T-cell recovery and viral suppression in patients who have low CD4+ T cell counts at the initiation of HAART are understudied in the China despite subsequent virological suppression (viral load < 50 copies/mL) is unknown. Methods The authors conducted a retrospective cohort study using data from the national HIV treatment sub-database of Zhejiang province to identify records of HIV+ patients. Patient records were included if they were ≥ 16 years of age, had an initial CD4 count < 100 cells/μL, were on continuous HAART for at least one year by the end of December 31, 2014; and achieved and maintained continued maximum virological suppression (MVS) (< 50 copies/ml) by 9 months after starting HAART. The primary endpoint for analysis was time to first CD4+ T cell count recovery (≥ 200, 350, 500 cells/μL). Cox proportional hazard regression was used to identify the risk factors for CD4+ T cell count recovery to key thresholds (200–350, 350–500, ≥ 500 cells/μL) by the time of last clinical follow-up (whichever occurred first), key thresholds (follow-up date for analysis), with patients still unable to reach the endpoints being censored by the end December 31, 2014 (follow-up date for analysis). Results Of the 918 patients who were included in the study, and the median CD4+ T cell count was 39 cells/μL at the baseline. At the end of follow-up, 727 (79.2%), 363 (39.5%) and 149 (16.2%) patients had return to ≥ 200, 350, and 500 cells/μL, respectively. Kaplan-Meier analysis demonstrated that the rate of patients with CD4+ count recovery to ≥ 200, 350, and 500 cells/μL after 1 year on HAART was 43.6, 8.6, and 2.5%, respectively, after 3 years on treatment was 90.8, 46.3, and 17.9%, respectively, and after 5 years on HAART was 97.1, 72.2, and 36.4%, respectively. The median time to return to 200–350, 350–500, ≥ 500cells

  7. Risk of Severe Non AIDS Events Is Increased among Patients Unable to Increase their CD4+ T-Cell Counts >200+/μl Despite Effective HAART.

    PubMed

    Lapadula, Giuseppe; Chatenoud, Liliane; Gori, Andrea; Castelli, Francesco; Di Giambenedetto, Simona; Fabbiani, Massimiliano; Maggiolo, Franco; Focà, Emanuele; Ladisa, Nicoletta; Sighinolfi, Laura; Di Pietro, Massimo; Pan, Angelo; Torti, Carlo

    2015-01-01

    Immunological non-response (INR) despite virological suppression is associated with AIDS-defining events/death (ADE). Little is known about its association with serious non-AIDS-defining events (nADE). Patients highly-active antiretroviral therapy (HAART) with <200 CD4+/μl and achieving HIV-RNA <50 copies/ml within 12 (±3) months were categorized as INR if CD4+ T-cell count at year 1 was <200/μl. Predictors of nADE (malignancies, severe infections, renal failure--ie, estimated glomerular filtration rate <30 ml/min, cardiovascular events and liver decompensation) were assessed using multivariable Cox models. Follow-up was right-censored in case of HAART discontinuation or confirmed HIV-RNA>50. 1221 patients were observed for a median of 3 (IQR: 1.3-6.1) years. Pre-HAART CD4+ were 77/μl (IQR: 28-142) and 56% of patients had experienced an ADE. After 1 year, CD4+ increased to 286 (IQR: 197-387), but 26.1% of patients were INR. Thereafter, 86 nADE (30.2% malignancies, 27.9% infectious, 17.4% renal, 17.4% cardiovascular, 7% hepatic) were observed, accounting for an incidence of 1.83 events (95%CI: 1.73-2.61) per 100 PYFU. After adjusting for measurable confounders, INR had a significantly greater risk of nADE (HR 1.65; 95%CI: 1.06-2.56). Older age (per year, HR 1.03; 95%CI: 1.01-1.05), hepatitis C co-infection (HR 2.09; 95%CI: 1.19-3.7), a history of previous nADE (HR 2.16; 95%CI: 1.06-4.4) and the occurrence of ADE during the follow-up (HR 2.2; 95%CI: 1.15-4.21) were other independent predictors of newly diagnosed nADE. Patients failing to restore CD4+ to >200 cells/μl run a greater risk of serious nADE, which is intertwined or predicted by AIDS progression. Improved management of this fragile population and innovative therapy able to induce immune-reconstitution are urgently needed. Also, our results strengthen the importance of earlier diagnosis and HAART introduction.

  8. B cell depletion in HIV-1 subtype A infected Ugandan adults: relationship to CD4 T cell count, viral load and humoral immune responses.

    PubMed

    Oballah, Peter; Flach, Britta; Eller, Leigh A; Eller, Michael A; Ouma, Benson; de Souza, Mark; Kibuuka, Hannah N; Wabwire-Mangen, Fred; Brown, Bruce K; Michael, Nelson L; Robb, Merlin L; Montefiori, David; Polonis, Victoria R

    2011-01-01

    To better understand the nature of B cell dysfunctions in subjects infected with HIV-1 subtype A, a rural cohort of 50 treatment-naïve Ugandan patients chronically infected with HIV-1 subtype A was studied, and the relationship between B cell depletion and HIV disease was assessed. B cell absolute counts were found to be significantly lower in HIV-1+ patients, when compared to community matched negative controls (p<0.0001). HIV-1-infected patients displayed variable functional and binding antibody titers that showed no correlation with viral load or CD4+ T cell count. However, B cell absolute counts were found to correlate inversely with neutralizing antibody (NAb) titers against subtype A (p = 0.05) and subtype CRF02_AG (p = 0.02) viruses. A positive correlation was observed between subtype A gp120 binding antibody titers and NAb breadth (p = 0.02) and mean titer against the 10 viruses (p = 0.0002). In addition, HIV-1 subtype A sera showed preferential neutralization of the 5 subtype A or CRF02_AG pseudoviruses, as compared with 5 pseudoviruses from subtypes B, C or D (p<0.001). These data demonstrate that in patients with chronic HIV-1 subtype A infection, significant B cell depletion can be observed, the degree of which does not appear to be associated with a decrease in functional antibodies. These findings also highlight the potential importance of subtype in the specificity of cross-clade neutralization in HIV-1 infection.

  9. Elevated granzyme B+ B-cell level in SIV-infection correlate with viral load and low CD4 T-cell count

    PubMed Central

    Kotb, Ahmad; Klippert, Antonina; Daskalaki, Maria; Sauermann, Ulrike; Stahl-Hennig, Christiane; Neumann, Berit

    2017-01-01

    Granzyme B-expressing (GrB+) B cells are thought to contribute to immune dysfunctions in HIV patients, but so far their exact role is unknown. This report demonstrates for the first time the existence of GrB+ B cells in SIV-infected rhesus macaques, which represent the most commonly used nonhuman primate model for HIV research. Similar to HIV patients, we found significantly higher frequencies of these cells in the blood of chronically SIV-infected rhesus monkeys compared with uninfected healthy ones. These frequencies correlated with plasma viral load and inversely with absolute CD4 T-cell counts. When investigating GrB+ B cells in different compartments, levels were highest in blood, spleen and bone marrow, but considerably lower in lymph nodes and tonsils. Analysis of expression of various surface markers on this particular B-cell subset in SIV-infected macaques revealed differences between the phenotype in macaques and in humans. GrB+ B cells in SIV-infected rhesus macaques exhibit an elevated expression of CD5, CD10, CD25 and CD27, while expression of CD19, CD185 and HLA-DR is reduced. In contrast to human GrB+ B cells, we did not observe a significantly increased expression of CD43 and CD86. B-cell receptor stimulation in combination with IL-21 of purified B cells from healthy animals led to the induction of GrB expression. Furthermore, initial functional analyses indicated a regulatory role on T-cell proliferation. Overall, our data pave the way for longitudinal analyses including studies on the functionality of GrB+ B cells in the nonhuman primate model for AIDS. PMID:27779180

  10. Reliable and Accurate CD4+ T Cell Count and Percent by the Portable Flow Cytometer CyFlow MiniPOC and “CD4 Easy Count Kit-Dry”, as Revealed by the Comparison with the Gold Standard Dual Platform Technology

    PubMed Central

    Nasi, Milena; De Biasi, Sara; Bianchini, Elena; Gibellini, Lara; Pinti, Marcello; Scacchetti, Tiziana; Trenti, Tommaso; Borghi, Vanni; Mussini, Cristina; Cossarizza, Andrea

    2015-01-01

    Background An accurate and affordable CD4+ T cells count is an essential tool in the fight against HIV/AIDS. Flow cytometry (FCM) is the “gold standard” for counting such cells, but this technique is expensive and requires sophisticated equipment, temperature-sensitive monoclonal antibodies (mAbs) and trained personnel. The lack of access to technical support and quality assurance programs thus limits the use of FCM in resource-constrained countries. We have tested the accuracy, the precision and the carry-over contamination of Partec CyFlow MiniPOC, a portable and economically affordable flow cytometer designed for CD4+ count and percentage, used along with the “CD4% Count Kit-Dry”. Materials and Methods Venous blood from 59 adult HIV+ patients (age: 25–58 years; 43 males and 16 females) was collected and stained with the “MiniPOC CD4% Count Kit-Dry”. CD4+ count and percentage were then determined in triplicate by the CyFlow MiniPOC. In parallel, CD4 count was performed using mAbs and a CyFlow Counter, or by a dual platform system (from Beckman Coulter) based upon Cytomic FC500 (“Cytostat tetrachrome kit” for mAbs) and Coulter HmX Hematology Analyzer (for absolute cell count). Results The accuracy of CyFlow MiniPOC against Cytomic FC500 showed a correlation coefficient (CC) of 0.98 and 0.97 for CD4+ count and percentage, respectively. The accuracy of CyFlow MiniPOC against CyFlow Counter showed a CC of 0.99 and 0.99 for CD4 T cell count and percentage, respectively. CyFlow MiniPOC showed an excellent repeatability: CD4+ cell count and percentage were analyzed on two instruments, with an intra-assay precision below ±5% deviation. Finally, there was no carry-over contamination for samples at all CD4 values, regardless of their position in the sequence of analysis. Conclusion The cost-effective CyFlow MiniPOC produces rapid, reliable and accurate results that are fully comparable with those from highly expensive dual platform systems. PMID:25622041

  11. Efficient Nef-Mediated Downmodulation of TCR-CD3 and CD28 Is Associated with High CD4+ T Cell Counts in Viremic HIV-2 Infection

    PubMed Central

    Yu, Hangxing; Sauter, Daniel; Usmani, Shariq M.; Schmokel, Jan; Feldman, Jerome; Gruters, Rob A.; van der Ende, Marchina E.; Geyer, Matthias; Rowland-Jones, Sarah; Osterhaus, Albert D.

    2012-01-01

    The role of the multifunctional accessory Nef protein in the immunopathogenesis of HIV-2 infection is currently poorly understood. Here, we performed comprehensive functional analyses of 50 nef genes from 21 viremic (plasma viral load, >500 copies/ml) and 16 nonviremic (<500) HIV-2-infected individuals. On average, nef alleles from both groups were equally active in modulating CD4, TCR-CD3, CD28, MHC-I, and Ii cell surface expression and in enhancing virion infectivity. Thus, many HIV-2-infected individuals efficiently control the virus in spite of efficient Nef function. However, the potency of nef alleles in downmodulating TCR-CD3 and CD28 to suppress the activation and apoptosis of T cells correlated with high numbers of CD4+ T cells in viremic patients. No such correlations were observed in HIV-2-infected individuals with undetectable viral load. Further functional analyses showed that the Nef-mediated downmodulation of TCR-CD3 suppressed the induction of Fas, Fas-L, PD-1, and CTLA-4 cell surface expression as well as the secretion of gamma interferon (IFN-γ) by primary CD4+ T cells. Moreover, we identified a single naturally occurring amino acid variation (I132T) in the core domain of HIV-2 Nef that selectively disrupts its ability to downmodulate TCR-CD3 and results in functional properties highly reminiscent of HIV-1 Nef proteins. Taken together, our data suggest that the efficient Nef-mediated downmodulation of TCR-CD3 and CD28 help viremic HIV-2-infected individuals to maintain normal CD4+ T cell homeostasis by preventing T cell activation and by suppressing the induction of death receptors that may affect the functionality and survival of both virally infected and uninfected bystander cells. PMID:22345473

  12. Efficient Nef-mediated downmodulation of TCR-CD3 and CD28 is associated with high CD4+ T cell counts in viremic HIV-2 infection.

    PubMed

    Khalid, Mohammad; Yu, Hangxing; Sauter, Daniel; Usmani, Shariq M; Schmokel, Jan; Feldman, Jerome; Gruters, Rob A; van der Ende, Marchina E; Geyer, Matthias; Rowland-Jones, Sarah; Osterhaus, Albert D; Kirchhoff, Frank

    2012-05-01

    The role of the multifunctional accessory Nef protein in the immunopathogenesis of HIV-2 infection is currently poorly understood. Here, we performed comprehensive functional analyses of 50 nef genes from 21 viremic (plasma viral load, >500 copies/ml) and 16 nonviremic (<500) HIV-2-infected individuals. On average, nef alleles from both groups were equally active in modulating CD4, TCR-CD3, CD28, MHC-I, and Ii cell surface expression and in enhancing virion infectivity. Thus, many HIV-2-infected individuals efficiently control the virus in spite of efficient Nef function. However, the potency of nef alleles in downmodulating TCR-CD3 and CD28 to suppress the activation and apoptosis of T cells correlated with high numbers of CD4(+) T cells in viremic patients. No such correlations were observed in HIV-2-infected individuals with undetectable viral load. Further functional analyses showed that the Nef-mediated downmodulation of TCR-CD3 suppressed the induction of Fas, Fas-L, PD-1, and CTLA-4 cell surface expression as well as the secretion of gamma interferon (IFN-γ) by primary CD4(+) T cells. Moreover, we identified a single naturally occurring amino acid variation (I132T) in the core domain of HIV-2 Nef that selectively disrupts its ability to downmodulate TCR-CD3 and results in functional properties highly reminiscent of HIV-1 Nef proteins. Taken together, our data suggest that the efficient Nef-mediated downmodulation of TCR-CD3 and CD28 help viremic HIV-2-infected individuals to maintain normal CD4(+) T cell homeostasis by preventing T cell activation and by suppressing the induction of death receptors that may affect the functionality and survival of both virally infected and uninfected bystander cells.

  13. 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.

  14. Atypical manifestation of progressive outer retinal necrosis in AIDS patient with CD4+ T-cell counts more than 100 cells/microL on highly active antiretroviral therapy.

    PubMed

    Vichitvejpaisal, Pornpattana; Reeponmahar, Somporn; Tantisiriwat, Woraphot

    2009-06-01

    Typical progressive outer retinal necrosis (PORN) is an acute ocular infectious disease in acquired immunodeficiency syndrome (AIDS) patients with extremely low CD4+ T-cell counts. It is a form of the Varicella- zoster virus (VZV) infection. This destructive infection has an extremely rapid course that may lead to blindness in affected eyes within days or weeks. Attempts at its treatment have had limited success. We describe the case of a bilateral PORN in an AIDS patient with an initial CD4+ T-cell count >100 cells/microL that developed after initiation of highly active antiretroviral therapy (HAART). A 29-year-old Thai female initially diagnosed with human immunodeficiency virus (HIV) in 1998, presented with bilaterally decreased visual acuity after initiating HAART two months earlier. Multiple yellowish spots appeared in the deep retina without evidence of intraocular inflammation or retinal vasculitis. Her CD4+ T-cell count was 127 cells/microL. She was diagnosed as having PORN based on clinical features and positive VZV in the aqueous humor and vitreous by polymerase chain reaction (PCR). Despite combined treatment with intravenous acyclovir and intravitreous ganciclovir, the patient's visual acuity worsened with no light-perception in either eye. This case suggests that PORN should be included in the differential diagnosis of reduced visual acuity in AIDS patients initiating HAART with higher CD4+ T-cell counts. PORN may be a manifestation of the immune reconstitution syndrome.

  15. Development of promyelocytic leukemia zinc finger-expressing innate CD4 T cells requires stronger T-cell receptor signals than conventional CD4 T cells.

    PubMed

    Qiao, Yu; Zhu, Lingqiao; Sofi, Hanief; Lapinski, Philip E; Horai, Reiko; Mueller, Kristen; Stritesky, Gretta L; He, Xi; Teh, Hung-Sia; Wiest, David L; Kappes, Dietmar J; King, Philip D; Hogquist, Kristin A; Schwartzberg, Pamela L; Sant'Angelo, Derek B; Chang, Cheong-Hee

    2012-10-02

    MHC class II-expressing thymocytes and thymic epithelial cells can mediate CD4 T-cell selection resulting in functionally distinct thymocyte-selected CD4 (T-CD4) and epithelial-selected CD4 (E-CD4) T cells, respectively. However, little is known about how T-cell receptor (TCR) signaling influences the development of these two CD4 T-cell subsets. To study TCR signaling for T-CD4 T-cell development, we used a GFP reporter system of Nur77 in which GFP intensity directly correlates with TCR signaling strength. T-CD4 T cells expressed higher levels of GFP than E-CD4 T cells, suggesting that T-CD4 T cells received stronger TCR signaling than E-CD4 T cells during selection. Elimination of Ras GTPase-activating protein enhanced E-CD4 but decreased T-CD4 T-cell selection efficiency, suggesting a shift to negative selection. Conversely, the absence of IL-2-inducible T-cell kinase that causes poor E-CD4 T-cell selection due to insufficient TCR signaling improved T-CD4 T-cell generation, consistent with rescue from negative selection. Strong TCR signaling during T-CD4 T-cell development correlates with the expression of the transcription factor promyelocytic leukemia zinc finger protein. However, although modulation of the signaling strength affected the efficiency of T-CD4 T-cell development during positive and negative selection, the signaling strength is not as important for the effector function of T-CD4 T cells. These findings indicate that innate T-CD4 T cells, together with invariant natural killer T cells and γδ T cells, receive strong TCR signals during their development and that signaling requirements for the development and the effector functions are distinct.

  16. Immune memory in CD4+ CD45RA+ T cells.

    PubMed Central

    Richards, D; Chapman, M D; Sasama, J; Lee, T H; Kemeny, D M

    1997-01-01

    This study addresses the question of whether human peripheral CD4+ CD45RA+ T cells possess antigen-specific immune memory. CD4+ CD45RA+ T cells were isolated by a combination of positive and negative selection. Putative CD4+ CD45RA+ cells expressed CD45RA (98.9%) and contained < 0.1% CD4+ CD45RO+ and < 0.5% CD4+ CD45RA+ CD45RO+ cells. Putative CD45RO+ cells expressed CD45RO (90%) and contained 9% CD45RA+ CD45RO+ and < 0.1% CD4+ CD45RA+ cells. The responder frequency of Dermatophagoides pteronyssinus-stimulated CD4+ CD45RA+ and CD4+ CD45RO+ T cells was determined in two atopic donors and found to be 1:11,314 and 1:8031 for CD4+ CD45RA+ and 1:1463 and 1:1408 for CD4+ CD45RO+ T cells. The responder frequencies of CD4+ CD45RA+ and CD4+ CD45RO+ T cells from two non-atopic, but exposed, donors were 1:78031 and 1:176,903 for CD4+ CD45RA+ and 1:9136 and 1:13,136 for CD4+ CD45RO+ T cells. T cells specific for D. pteronyssinus were cloned at limiting dilution following 10 days of bulk culture with D. pteronyssinus antigen. Sixty-eight clones were obtained from CD4+ CD45RO+ and 24 from CD4+ CD45RA+ T cells. All clones were CD3+ CD4+ CD45RO+ and proliferated in response to D. pteronyssinus antigens. Of 40 clones tested, none responded to Tubercule bacillus purified protein derivative (PPD). No difference was seen in the pattern of interleukin-4 (IL-4) or interferon-gamma (IFN-gamma) producing clones derived from CD4+ CD45RA+ and CD4+ CD45RO+ precursors, although freshly isolated and polyclonally activated CD4+ CD45RA+ T cells produced 20-30-fold lower levels of IL-4 and IFN-gamma than their CD4+ CD45RO+ counterparts. Sixty per cent of the clones used the same pool of V beta genes. These data support the hypothesis that immune memory resides in CD4+ CD45RA+ as well as CD4+ CD45RO+ T cells during the chronic immune response to inhaled antigen. PMID:9301520

  17. Long-term CD4+ T-cell count evolution after switching from regimens including HIV nucleoside reverse transcriptase inhibitors (NRTI) plus protease inhibitors to regimens containing NRTI plus non-NRTI or only NRTI

    PubMed Central

    2011-01-01

    Background Data regarding CD4+ recovery after switching from protease inhibitor (PI)-based regimens to regimens not containing PI are scarce. Methods Subjects with virological success on first-PI-regimens who switched to NNRTI therapy (NNRTI group) or to nucleoside reverse transcriptase (NRTI)-only (NRTI group) were studied. The effect of the switch on the ongoing CD4+ trend was assessed by two-phase linear regression (TPLR), allowing us to evaluate whether a change in the CD4+ trend (hinge) occurred and the time of its occurrence. Furthermore, we described the evolution of the frequencies in CD4-count classes across four relevant time-points (baseline, before and immediately after the switch, and last visit). Finally, we explored whether the CD4+ counts evolved differently in patients who switched to NNRTI or NRTI-only regimens by considering: the overall CD4+ trends, the time to CD4+≥ 500/mm3 after the switch, and the area-under-the-curve (AUC) of the CD4+ after the switch. Results Eight hundred and ninety-six patients, followed for a median of 2,121 days, were included. At TPLR, hinges occurred in 581/844 (68.9%), but in only 40/581 (6.9%) within a time interval (180 days) compatible with a possible relationship to the switch; furthermore, in 19/40 cases, CD4+ counts appeared to decrease after the hinges. In comparison with the NNRTI group, the NRTI group showed CD4+ count greater at baseline (P = 0.0234) and before the switch (P ≤ 0.0001), superior CD4+ T-cell increases after HAART was started, lower probability of not achieving CD4+ ≥ 500/mm3 (P = 0.0024), and, finally, no significant differences in the CD4+ T-cell AUC after the switch after adjusting for possible confounders (propensity score and pre-switch AUC). Persistence at CD4+ < 200/mm3 was observed in 34/435 (7.5%) patients, and a decrease below this level was found in only 10/259 (3.9%) with baseline CD4+ ≥ 350/mm3. Conclusions Switching from first-line PI to NNRTI- or NRTI-based regimens did

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

    PubMed Central

    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

    2016-01-01

    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

  19. Chemokine receptor CCR2b 64I polymorphism and its relation to CD4 T-cell counts and disease progression in a Danish cohort of HIV-infected individuals. Copenhagen AIDS cohort.

    PubMed

    Eugen-Olsen, J; Iversen, A K; Benfield, T L; Koppelhus, U; Garred, P

    1998-06-01

    We have investigated the role of the recently described mutation in CCR2b named 64I in relation to HIV resistance, CD4 T-cell counts, and disease progression in Danish individuals by polymerase chain reaction (PCR)-based methods as well as sequenced full-length CXCR4 and CCR5 genes from HIV-infected long-term nonprogressors for possible mutations. In total, 215 Danish individuals were analyzed for 64I allele frequency; disease progression was followed in 105 HIV-1-positive homosexual Danish men from their first known positive HIV-1 test result and up to 11 years. In 87 individuals, the CD4 T-cell count was monitored closely. We found no significant difference in 64I allele frequency between HIV-1-seropositive persons (0.08), high-risk HIV-1-seronegative persons (0.11), and blood donors (0.06). No significant difference was observed in annual CD4 T-cell decline, CD4 T-cell counts at the time of AIDS, in AIDS-free survival as well as survival with AIDS, between 64I allele carriers and wild-type individuals. Among 9 long-term nonprogressors, 2 carried the 64I allele, while none of 9 fast progressors carried the 64I allele. However, this was not significantly different (p=.47). Long-term nonprogression could not be explained by CXCR4 polymorphism or other polymorphisms in the CCR5 gene than the CCR5delta32 allele. Furthermore, we were not able to detect any significant independent effect of the 64I allele on development to AIDS, overall survival, and annual CD4 T-cell decline in this cohort.

  20. 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. Copyright © 2016 by The American Association of Immunologists, Inc.

  1. 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

  2. Integration of semiconductor quantum dots into nano-bio-chip systems for enumeration of CD4+ T cell counts at the point-of-need†‡

    PubMed Central

    Jokerst, Jesse V.; Floriano, Pierre N.; Christodoulides, Nicolaos; Simmons, Glennon W.; McDevitt, John T.

    2010-01-01

    Recent humanitarian efforts have led to the widespread release of antiretroviral drugs for the treatment of the more than 33 million HIV afflicted people living in resource-scarce settings. Here, the enumeration of CD4+ T lymphocytes is required to establish the level at which the immune system has been compromised. The gold standard method used in developed countries, based on flow cytometry, though widely accepted and accurate, is precluded from widespread use in resource-scarce settings due to its high expense, high technical requirements, difficulty in operation-maintenance and the lack of portability for these sophisticated laboratory-confined systems. As part of continuing efforts to develop practical diagnostic instrumentation, the integration of semiconductor nanocrystals (quantum dots, QDs) into a portable microfluidic-based lymphocyte capture and detection device is completed. This integrated system is capable of isolating and counting selected lymphocyte sub-populations (CD3+CD4+) from whole blood samples. By combining the unique optical properties of the QDs with the sample handling capabilities and cost effectiveness of novel microfluidic systems, a practical, portable lymphocyte measurement modality that correlates nicely with flow cytometry (R2 = 0.97) has been developed. This QD-based system reduces the optical requirements significantly relative to molecular fluorophores and the mini-CD4 counting device is projected to be suitable for use in both point-of-need and resource-scarce settings. PMID:19023471

  3. Occurrence of enteric parasitic infections among HIV-infected individuals and its relation to CD4 T-cell counts with a special emphasis on coccidian parasites at a tertiary care centre in South India.

    PubMed

    Swathirajan, Chinnambedu R; Vignesh, Ramachandran; Pradeep, Ambrose; Solomon, Sunil S; Solomon, Suniti; Balakrishnan, Pachamuthu

    2017-01-01

    Diarrhoea is one of the major complications occurring in over 90% of HIV-infected individuals in developing countries. Coccidian group of parasites, being opportunistic pathogens, have been implicated as the most common causative agents of diarrhoea among HIV-infected population. The aim was to study the magnitude of parasitic diarrhoea with special context to coccidian parasitic infections in HIV-infected individuals and their association with the patient's immunological status measured by CD4 T-cell counts. This investigation was performed between January 2002 and December 2014 at a tertiary HIV care centre in Chennai, South India. Stool samples were collected and microscopically observed for parasites using direct, formal-ether-concentrated wet mounts and modified acid-fast staining for coccidian parasites. CD4 T-cell counts were done by FACScount. All statistical analyses were performed using GraphPad Prism software, version 5.0, andP < 0.05 was considered statistically significant. Coccidian parasitic infection accounted for about 23.4% of parasitic infections, and of these, Cystoisospora belli was observed to be the most common cause of diarrhoea (88.8%), followed by Cryptosporidium spp. (9.9%) and Cyclospora spp. (1.3%). Trend analysis of coccidian aetiology during the study period revealed a significant rise in the positivity of C. belli and Cryptosporidium spp. (P = 0.001). Among the HIV patients with CD4+ T-cell counts <200 cells/μL, Cryptosporidium infection was most common (90%), followed by infection with C. belli(61.4%). Coccidian parasites continue to be the most common aetiological agent of diarrhoea among patients with HIV. The increasing trend of positivity of both cystoisosporiasis and cryptosporidiosis over the study period and the high positivity of cryptosporidiosis in patients with lower CD4+ T-cell counts are issues of serious concern. The findings call for the need for the early diagnosis of coccidian parasites and appropriate intervention

  4. The CYP2B6 G516T polymorphism influences CD4(+) T-cell counts in HIV-positive patients receiving antiretroviral therapy in an ethnically diverse region of the Amazon.

    PubMed

    Queiroz, Maria Alice Freitas; Laurentino, Rogério Valois; da Silva Graça Amoras, Ednelza; Araújo, Mauro Sérgio Moura de; Gomes, Samara Tatielle Monteiro; Lima, Sandra Souza; Vallinoto, Antonio Carlos Rosário; de Oliveira Guimarães Ishak, Marluísa; Ishak, Ricardo; Machado, Luiz Fernando Almeida

    2017-02-01

    Cytochrome P450 (CYP) enzyme polymorphisms seem to significantly influence the variability of the responses to certain antiretroviral drugs and their toxicity levels. The objective of this study was to evaluate the influence of the CYP2B6 G516T polymorphism on hepatic, renal, immunological, and viral marker changes in HIV-1-positive patients receiving treatment in an ethnically diverse region of the Amazon. CYP2B6 G516T genotyping was performed by real-time PCR (RT-PCR) in samples from 185 patients. Urea, creatinine, aspartate aminotransferase (AST), alanine aminotransferase (ALT), CD4(+)/CD8(+) T-cell counts, and HIV-1 plasma viral load were measured. The polymorphic CYP2B6 G516T allele frequency was 0.36, which is different from the frequencies in other ethnic groups. The polymorphic genotype was associated with changes in the urea and ALT levels, although the median values were within the normal range. The TT genotype was also associated with significantly lower CD4(+) T-cell counts in patients using efavirenz. The CYP2B6 G516T polymorphism seems to affect the response to efavirenz treatment by reducing CD4(+) T-cell counts in patients with a high degree of miscegenation who use this antiretroviral agent. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

    PubMed Central

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

    2013-01-01

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

  6. CD4 CTL, a Cytotoxic Subset of CD4+ T Cells, Their Differentiation and Function

    PubMed Central

    Takeuchi, Arata; Saito, Takashi

    2017-01-01

    CD4+ T cells with cytotoxic activity (CD4 CTL) have been observed in various immune responses. These cells are characterized by their ability to secrete granzyme B and perforin and to kill the target cells in an MHC class II-restricted fashion. Although CD4 CTLs were once thought to be an in vitro artifact associated with long-term culturing, they have since been identified in vivo and shown to play important roles in antiviral and antitumor immunity, as well as in inflammation. Functional characterization of CD4 CTL suggests their potential significance for therapeutic purposes. However, in order to develop effective CD4 CTL therapy it is necessary to understand the differentiation and generation of these cells. Although the mechanisms regulating development of various CD4+ Th subsets have been clarified in terms of the cytokine and transcription factor requirement, the CD4 CTL differentiation mechanism remains elusive. These cells are thought to be most closely related to Th1 cells secreting IFNγ and regulated by eomesodermin and/or T-bet transcription factors for their differentiation. However, our studies and those of others have identified CD4 CTLs within other CD4+ T cell subsets, including naïve T cells. We have identified class I-restricted T cell-associated molecule as a marker of CD4 CTL and, by using this marker, we detected a subset of naïve T cells that have the potential to differentiate into CD4 CTL. CD4 CTL develops at sites of infections as well as inflammation. In this review, we summarize recent findings about the generation of CD4 CTL and propose a model with several differentiation pathways. PMID:28280496

  7. The investigation of CD4+T-cell functions in primary HIV infection with antiretroviral therapy

    PubMed Central

    Sun, Yu; Fu, Yajing; Zhang, Zining; Tang, Tian; Liu, Jing; Ding, Haibo; Han, Xiaoxu; Xu, Junjie; Chu, Zhenxing; Shang, Hong; Jiang, Yongjun

    2017-01-01

    Abstract Human immunodeficiency virus (HIV) infection leads to reduced CD4+T-cell counts and immune dysfunction. Initiation of antiretroviral therapy (ART) in HIV primary infection has been recommended to achieve an optimal clinical outcome, but a comprehensive study on restoration of CD4+T-cell function in primary HIV-infected individuals with ART still needs to be eluciated. We investigated longitudinal changes in the CD4+T-cell counts, phenotypes, and functions in HIV-infected individuals with early ART (initiated within 6 months after HIV infection) or later ART (initiated more than 12 months after HIV infection). Patients from early ART and later ART groups had received ART for at least 1 year. Individuals with early ART had more CD4+T cells, a faster rate of CD4+T-cell recovery than those receiving later ART; the levels of CD4+T-cell activation and senescence were lower in early ART compared to those with later ART (P = .031; P = .016), but the activation was higher than normal controls (NC) (P = .001); thymic emigrant function was more upregulated in early ART than in later ART (P = .015), but still lower than NC (P = .027); proliferative capacity and interferon-γ secretion of CD4+T cells were significantly decreased in primary infection (P < .001; P = .029), and early ART restored these CD4+T-cell functions, there is no difference with NC, later ART could partially restore the functions of CD4+T cells, but it remained lower than that of NC (P = .005; P = .019). Early ART could better improve CD4+T-cell function. PMID:28700479

  8. Differential T cell receptor-mediated signaling in naive and memory CD4 T cells.

    PubMed

    Farber, D L; Acuto, O; Bottomly, K

    1997-08-01

    Naive and memory CD4 T cells differ in cell surface phenotype, function, activation requirements, and modes of regulation. To investigate the molecular bases for the dichotomies between naive and memory CD4 T cells and to understand how the T cell receptor (TCR) directs diverse functional outcomes, we investigated proximal signaling events triggered through the TCR/CD3 complex in naive and memory CD4 T cell subsets isolated on the basis of CD45 isoform expression. Naive CD4 T cells signal through TCR/CD3 similar to unseparated CD4 T cells, producing multiple tyrosine-phosphorylated protein species overall and phosphorylating the T cell-specific ZAP-70 tyrosine kinase which is recruited to the CD3zeta subunit of the TCR. Memory CD4 T cells, however, exhibit a unique pattern of signaling through TCR/CD3. Following stimulation through TCR/CD3, memory CD4 T cells produce fewer species of tyrosine-phosphorylated substrates and fail to phosphorylate ZAP-70, yet unphosphorylated ZAP-70 can associate with the TCR/CD3 complex. Moreover, a 26/28-kDa phosphorylated doublet is associated with CD3zeta in resting and activated memory but not in naive CD4 T cells. Despite these differences in the phosphorylation of ZAP-70 and CD3-associated proteins, the ZAP-70-related kinase, p72syk, exhibits similar phosphorylation in naive and memory T cell subsets, suggesting that this kinase could function in place of ZAP-70 in memory CD4 T cells. These results indicate that proximal signals are differentially coupled to the TCR in naive versus memory CD4 T cells, potentially leading to distinct downstream signaling events and ultimately to the diverse functions elicited by these two CD4 T cell subsets.

  9. Normalization of CD4+ T Cell Metabolism Reverses Lupus

    PubMed Central

    Yin, Yiming; Choi, Seung-Chul; Xu, Zhiwei; Perry, Daniel J.; Seay, Howard; Croker, Byron P.; Sobel, Eric S.; Brusko, Todd M.; Morel, Laurence

    2015-01-01

    Systemic Lupus Erythematosus (SLE) is an autoimmune disease in which autoreactive CD4+ T cells play an essential role. CD4+ T cells rely on glycolysis for inflammatory effector functions, but recent studies have shown that mitochondrial metabolism supports their chronic activation. How these processes contribute to lupus is unclear. Here, we show that both glycolysis and mitochondrial oxidative metabolism are elevated in CD4+ T cells from lupus-prone B6.Sle1.Sle2.Sle3 (TC) mice as compared to non-autoimmune controls. In vitro, both the mitochondrial metabolism inhibitor metformin and the glucose metabolism inhibitor 2-Deoxy-D-glucose (2DG) reduced IFNγ production, although at different stages of activation. Metformin also restored the defective IL-2 production by TC CD4+ T cells. In vivo, treatment of TC mice and other lupus models with a combination of metformin and 2DG normalized T cell metabolism and reversed disease biomarkers. Further, CD4+ T cells from SLE patients also exhibited enhanced glycolysis and mitochondrial metabolism that correlated with their activation status, and their excessive IFNγ production was significantly reduced by metformin in vitro. These results suggest that normalization of T cell metabolism through the dual inhibition of glycolysis and mitochondrial metabolism is a promising therapeutic venue for SLE. PMID:25673763

  10. Dysregulation of CD4(+) T Cell Subsets in Intracranial Aneurysm.

    PubMed

    Zhang, Hai-Feng; Zhao, Ming-Guang; Liang, Guo-Biao; Yu, Chun-Yong; He, Wenxiu; Li, Zhi-Qing; Gao, Xu

    2016-02-01

    Intracranial aneurysms (IAs) and potential IA rupture are one of the direct causes of permanent brain damage and mortality. Interestingly, the major risk factors of IA development, including hemodynamic stress, hypertension, smoking, and genetic predispositions, are closely associated with a proinflammatory immune status. Therefore, we examined the roles of CD4(+) T cells in IA pathogenesis. IA patients exhibited peripheral CD4(+) T-cell imbalance, with overrepresented T helper 1 (Th1) and Th17 activities and underrepresented Th2 and regulatory T (Treg) activities, including increased IFN-γ, TNF-α, and IL-17 production and decreased IL-10 production from total CD4(+) T cells. Chemokine receptors CXCR3 and CCR6 were used to identify Th1, Th2, and Th17 cell subsets, and CD4(+)CD25(hi) was used to identify Treg cells. Based on these markers, the data then showed altered cytokine production by each cell type and shifted subpopulation frequency. Moreover, this shift in frequency was directly correlated with IA severity. To examine the underlying mechanism of CD4(+) T cell skewing, we cocultured CD4(+) T cells with autologous monocytes and found that coculture with monocytes could significantly increase IFN-γ and IL-17 production through contact-independent mechanisms, demonstrating that monocytes could potentially contribute to the altered CD4(+) T cell composition in IA. Analyzing mRNA transcripts revealed significantly upregulated IL-1β and TNF-α expression by monocytes from IA patients. We found a loss of CD4(+) T cell subset balance that was likely to promote a higher state of inflammation in IA, which may exacerbate the disease through a positive feedback loop.

  11. 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

  12. 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

  13. HIV-specific cytolytic CD4 T cell responses during acute HIV infection predict disease outcome

    PubMed Central

    Soghoian, Damien Z.; Jessen, Heiko; Flanders, Michael; Sierra-Davidson, Kailan; Cutler, Sam; Pertel, Thomas; Ranasinghe, Srinika; Lindqvist, Madelene; Davis, Isaiah; Lane, Kimberly; Rychert, Jenna; Rosenberg, Eric S.; Piechocka-Trocha, Alicja; Brass, Abraham L.; Brenchley, Jason M.; Walker, Bruce D.; Streeck, Hendrik

    2013-01-01

    Early immunological events during acute HIV infection are thought to fundamentally influence long-term disease outcome. Whereas the contribution of HIV-specific CD8 T cell responses to early viral control is well established, the role of HIV-specific CD4 T cell responses in the control of viral replication following acute infection is unknown. A growing body of evidence suggests that CD4 T cells - besides their helper function - have the capacity to directly recognize and kill virally infected cells. In a longitudinal study of a cohort of individuals acutely infected with HIV, we observed that subjects able to spontaneously control HIV replication in the absence of antiretroviral therapy showed a significant expansion of HIV-specific CD4 T cell responses—but not CD8 T cell responses–compared to subjects who progressed to a high viral set point (p=0.038). Strikingly, this expansion occurred prior to differences in viral load or CD4 T cell count and was characterized by robust cytolytic activity and expression of a distinct profile of perforin and granzymes at the earliest time point. Kaplan-Meier analysis revealed that the emergence of Granzyme A+ HIV-specific CD4 T cell responses at baseline was highly predictive of slower disease progression and clinical outcome (average days to CD4 T cell count <350/μl was 575 versus 306, p=0.001). These data demonstrate that HIV-specific CD4 T cell responses can be used during the earliest phase of HIV infection as an immunological predictor of subsequent viral set point and disease outcome. Moreover, these data suggest that expansion of Granzyme A+ HIV-specific cytolytic CD4 T cell responses early during acute HIV infection contributes substantially to the control of viral replication. PMID:22378925

  14. Priming of CD4+ T cells and development of CD4+ T cell memory; lessons for malaria.

    PubMed

    Stephens, R; Langhorne, J

    2006-01-01

    CD4 T cells play a central role in the immune response to malaria. They are required to help B cells produce the antibody that is essential for parasite clearance. They also produce cytokines that amplify the phagocytic and parasitocidal response of the innate immune system, as well as dampening this response later on to limit immunopathology. Therefore, understanding the mechanisms by which T helper cells are activated and the requirements for development of specific, and effective, T cell memory and immunity is essential in the quest for a malaria vaccine. In this paper on the CD4 session of the Immunology of Malaria Infections meeting, we summarize discussions of CD4 cell priming and memory in malaria and in vaccination and outline critical future lines of investigation. B. Stockinger and M.K. Jenkins proposed cutting edge experimental systems to study basic T cell biology in malaria. Critical parameters in T cell activation include the cell types involved, the route of infection and the timing and location and cell types involved in antigen presentation. A new generation of vaccines that induce CD4 T cell activation and memory are being developed with new adjuvants. Studies of T cell memory focus on differentiation and factors involved in maintenance of antigen specific T cells and control of the size of that population. To improve detection of T cell memory in the field, efforts will have to be made to distinguish antigen-specific responses from cytokine driven responses.

  15. CD4+ regulatory T cell responses induced by T cell vaccination in patients with multiple sclerosis

    PubMed Central

    Hong, Jian; Zang, Ying C. Q.; Nie, Hong; Zhang, Jingwu Z.

    2006-01-01

    Immunization with irradiated autologous T cells (T cell vaccination) is shown to induce regulatory T cell responses that are poorly understood. In this study, CD4+ regulatory T cell lines were generated from patients with multiple sclerosis that received immunization with irradiated autologous myelin basic protein-reactive T cells. The resulting CD4+ regulatory T cell lines had marked inhibition on autologous myelin basic protein-reactive T cells and displayed two distinctive patterns distinguishable by the expression of transcription factor Foxp3 and cytokine profile. The majority of the T cell lines had high Foxp3 expression and secreted both IFN-γ and IL-10 as compared with the other pattern characteristic of low Foxp3 expression and predominant production of IL-10 but not IFN-γ. CD4+ regulatory T cell lines of both patterns expressed CD25 and reacted with activated autologous T cells but not resting T cells, irrespective of antigen specificity of the target T cells. It was evident that they recognized preferentially a synthetic peptide corresponding to residues 61–73 of the IL-2 receptor α chain. T cell vaccination correlated with increased Foxp3 expression and T cell reactivity to peptide 61–73. The findings have important implications in the understanding of the role of CD4+ regulatory T cell response induced by T cell vaccination. PMID:16547138

  16. Prolonged CD4 T Cell Lymphopenia Increases Morbidity and Mortality after Renal Transplantation

    PubMed Central

    Courivaud, Cécile; Bamoulid, Jamal; Vivet, Bérengère; Chabroux, Aline; Deschamps, Marina; Rebibou, Jean-Michel; Ferrand, Christophe; Chalopin, Jean-Marc; Tiberghien, Pierre; Saas, Philippe

    2010-01-01

    Prolonged CD4 T cell lymphopenia after administration of polyclonal anti-thymocyte globulins increases the rate of posttransplantation morbidity, but whether impaired immune reconstitution affects survival is unknown. We studied the effect of CD4 T cell lymphopenia on survival in 302 consecutive prevalent renal transplant recipients and the role of thymic function in CD4 T cell reconstitution and posttransplantation outcomes in 100 consecutive incident renal transplant recipients. We followed the prevalent cohort for a mean duration of 92 months. Of these 302 patients, 81 (27%) had persistent CD4 T cell counts <300/mm3 and 36 (12%) died during follow-up. We observed a higher death rate in patients with CD4 T cell lymphopenia persisting for >1 year (24.1 versus 7.6%; P < 0.001). Furthermore, in Cox regression analysis, CD4 T cell lymphopenia associated with a nearly five-fold risk for death (adjusted hazard ratio [HR] 4.63; 95% confidence interval [CI] 1.91 to 10.65; P = 0.001). In the incident cohort, we estimated thymic function by T cell receptor excision circles (TRECs) per 150,000 CD3+ cells, which predicted efficient CD4 T cell reconstitution. Higher pretransplantation TREC values associated with lower risks for cancer (adjusted HR 0.39; 95% CI 0.15 to 0.97; P = 0.046) and infection (HR 0.29; 95% CI 0.11 to 0.78; P = 0.013). In summary, prolonged polyclonal anti-thymocyte globulin–induced CD4 T cell lymphopenia is an independent risk factor for death. Determination of pretransplantation thymic function may identify patients at higher risk for CD4 T cell lymphopenia and posttransplantation morbidity, including cancer and infections. PMID:20203160

  17. Prolonged CD4 T cell lymphopenia increases morbidity and mortality after renal transplantation.

    PubMed

    Ducloux, Didier; Courivaud, Cécile; Bamoulid, Jamal; Vivet, Bérengère; Chabroux, Aline; Deschamps, Marina; Rebibou, Jean-Michel; Ferrand, Christophe; Chalopin, Jean-Marc; Tiberghien, Pierre; Saas, Philippe

    2010-05-01

    Prolonged CD4 T cell lymphopenia after administration of polyclonal anti-thymocyte globulins increases the rate of posttransplantation morbidity, but whether impaired immune reconstitution affects survival is unknown. We studied the effect of CD4 T cell lymphopenia on survival in 302 consecutive prevalent renal transplant recipients and the role of thymic function in CD4 T cell reconstitution and posttransplantation outcomes in 100 consecutive incident renal transplant recipients. We followed the prevalent cohort for a mean duration of 92 months. Of these 302 patients, 81 (27%) had persistent CD4 T cell counts <300/mm3 and 36 (12%) died during follow-up. We observed a higher death rate in patients with CD4 T cell lymphopenia persisting for >1 year (24.1 versus 7.6%; P < 0.001). Furthermore, in Cox regression analysis, CD4 T cell lymphopenia associated with a nearly five-fold risk for death (adjusted hazard ratio [HR] 4.63; 95% confidence interval [CI] 1.91 to 10.65; P = 0.001). In the incident cohort, we estimated thymic function by T cell receptor excision circles (TRECs) per 150,000 CD3+ cells, which predicted efficient CD4 T cell reconstitution. Higher pretransplantation TREC values associated with lower risks for cancer (adjusted HR 0.39; 95% CI 0.15 to 0.97; P = 0.046) and infection (HR 0.29; 95% CI 0.11 to 0.78; P = 0.013). In summary, prolonged polyclonal anti-thymocyte globulin-induced CD4 T cell lymphopenia is an independent risk factor for death. Determination of pretransplantation thymic function may identify patients at higher risk for CD4 T cell lymphopenia and posttransplantation morbidity, including cancer and infections.

  18. 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

  19. Addition of maraviroc to antiretroviral therapy decreased interferon-γ mRNA in the CD4+ T cells of patients with suboptimal CD4+ T-cell recovery.

    PubMed

    Minami, Rumi; Takahama, Soichiro; Kaku, Yu; Yamamoto, Masahiro

    2017-01-01

    The CCR5 antagonist, maraviroc (MVC), is associated with an enhanced CD4+ T-cell response independent of virological suppression; however, its mechanism of action has not been elucidated. In this study, we confirmed the effect of MVC on CD4+ T-cell count recovery in immunological non-responders, and compared the conventional combination antiretroviral therapy (cART) with MVC-intensified cART. We also investigated the effect of MVC on interferon-γ (IFN-γ) production in CD4+ T cells in vitro and in vivo, and evaluated the relationship between the mRNA level of IFN-γ and the degree of CD4+ T-cell count recovery. In vitro analysis indicated that MVC significantly decreased mRNA levels of IFN-γ in HIV-Tat stimulated CD4+ T cells from healthy donor peripheral blood mononuclear cells. Of the 18 HIV-infected patients treated with MVC-intensified cART, 12 had a significantly increased CD4+ T-cell count after 24 weeks of additional treatment with MVC. In patients exhibiting a response in CD4+ T-cell counts, mRNA levels of IFN-γ in CD4+ T cells were lower than those in patients showing a non-response at baseline and at week 24, while mRNA levels of IFN-γ decreased in both groups at 24 weeks. In conclusion, MVC decreased the mRNA level of IFN-γ in CD4+ T cells in vitro and in vivo, especially in patients whose CD4+ T-cell count increased significantly. We also found that the lower baseline IFN-γ mRNA level and the larger decreased rate of IFN-γ mRNA in CD4+ T cells were associated with a good response to MVC regarding CD4+ T-cell recovery.

  20. CD4+ T Cells: guardians of the phagosome.

    PubMed

    Tubo, Noah J; Jenkins, Marc K

    2014-04-01

    CD4(+) T cells are key cells of the adaptive immune system that use T cell antigen receptors to recognize peptides that are generated in endosomes or phagosomes and displayed on the host cell surface bound to major histocompatibility complex molecules. These T cells participate in immune responses that protect hosts from microbes such as Mycobacterium tuberculosis, Cryptococcus neoformans, Leishmania major, and Salmonella enterica, which have evolved to live in the phagosomes of macrophages and dendritic cells. Here, we review studies indicating that CD4(+) T cells control phagosomal infections asymptomatically in most individuals by secreting cytokines that activate the microbicidal activities of infected phagocytes but in a way that inhibits the pathogen but does not eliminate it. Indeed, we make the case that localized, controlled, persistent infection is necessary to maintain large numbers of CD4(+) effector T cells in a state of activation needed to eradicate systemic and more pathogenic forms of the infection. Finally, we posit that current vaccines for phagosomal infections fail because they do not produce this "periodic reminder" form of CD4(+) T cell-mediated immune control.

  1. CD4 T cells: fates, functions, and faults

    PubMed Central

    2008-01-01

    In 1986, Mosmann and Coffman identified 2 subsets of activated CD4 T cells, Th1 and Th2 cells, which differed from each other in their pattern of cytokine production and their functions. Our understanding of the importance of the distinct differentiated forms of CD4 T cells and of the mechanisms through which they achieve their differentiated state has greatly expanded over the past 2 decades. Today at least 4 distinct CD4 T-cell subsets have been shown to exist, Th1, Th2, Th17, and iTreg cells. Here we summarize much of what is known about the 4 subsets, including the history of their discovery, their unique cytokine products and related functions, their distinctive expression of cell surface receptors and their characteristic transcription factors, the regulation of their fate determination, and the consequences of their abnormal activation. PMID:18725574

  2. Apoptotic depletion of CD4+ T cells in idiopathic CD4+ T lymphocytopenia.

    PubMed Central

    Laurence, J; Mitra, D; Steiner, M; Lynch, D H; Siegal, F P; Staiano-Coico, L

    1996-01-01

    Progressive loss of CD4+ T lymphocytes, accompanied by opportunistic infections characteristic of the acquired immune deficiency syndrome, ahs been reported in the absence of any known etiology. The pathogenesis of this syndrome, a subset of idiopathic CD4+ T lymphocytopenia (ICL), is uncertain. We report that CD4+ T cells from seven of eight ICL patients underwent accelerated programmed cell death, a process facilitated by T cell receptor cross-linking. Apoptosis was associated with enhanced expression of Fas and Fas ligand in unstimulated cell populations, and partially inhibited by soluble anti-Fas mAb. In addition, apoptosis was suppressed by aurintricarboxylic acid, an inhibitor of calcium-dependent endonucleases and proteases, in cells from four of seven patients, The in vivo significance of these findings was supported by three factors: the absence of accelerated apoptosis in persons with stable, physiologic CD4 lymphopenia without clinical immune deficiency; detection of serum antihistone H2B autoantibodies, one consequence of DNA fragmentation, in some patients; and its selectivity, with apoptosis limited to the CD4 population in some, and occurring among CD8+ T cells predominantly in those individuals with marked depletion of both CD4+ T lymphocytes linked to clinical immune suppression have evidence for accelerated T cell apoptosis in vitro that may be pathophysiologic and amenable to therapy with apoptosis inhibitors. PMID:8609222

  3. Primary antitumor immune response mediated by CD4+ T cells.

    PubMed

    Corthay, Alexandre; Skovseth, Dag K; Lundin, Katrin U; Røsjø, Egil; Omholt, Hilde; Hofgaard, Peter O; Haraldsen, Guttorm; Bogen, Bjarne

    2005-03-01

    Gene-targeted mice have recently revealed a role for lymphocytes and interferon-gamma (IFNgamma) in conferring protection against cancer, but the mechanisms remain unclear. Here, we have characterized a successful primary antitumor immune response initiated by naive CD4+ T cells. Major histocompatibility complex class II (MHC-II)-negative myeloma cells injected subcutaneously into syngeneic mice were surrounded within 3 days by macrophages that captured tumor antigens. Within 6 days, naive myeloma-specific CD4+ T cells became activated in draining lymph nodes and subsequently migrated to the incipient tumor site. Upon recognition of tumor-derived antigenic peptides presented on MHC-II by macrophages, the myeloma-specific CD4+ T cells were reactivated and started to secrete cytokines. T cell-derived IFNgamma activated macrophages in close proximity to the tumor cells. Tumor cell growth was completely inhibited by such locally activated macrophages. These data indicate a mechanism for immunosurveillance of MHC-II-negative cancer cells by tumor-specific CD4+ T cells through collaboration with macrophages.

  4. Cellular Plasticity of CD4+ T Cells in the Intestine

    PubMed Central

    Brucklacher-Waldert, Verena; Carr, Edward J.; Linterman, Michelle A.; Veldhoen, Marc

    2014-01-01

    Barrier sites such as the gastrointestinal tract are in constant contact with the environment, which contains both beneficial and harmful components. The immune system at the epithelia must make the distinction between these components to balance tolerance, protection, and immunopathology. This is achieved via multifaceted immune recognition, highly organized lymphoid structures, and the interaction of many types of immune cells. The adaptive immune response in the gut is orchestrated by CD4+ helper T (Th) cells, which are integral to gut immunity. In recent years, it has become apparent that the functional identity of these Th cells is not as fixed as initially thought. Plasticity in differentiated T cell subsets has now been firmly established, in both health and disease. The gut, in particular, utilizes CD4+ T cell plasticity to mold CD4+ T cell phenotypes to maintain its finely poised balance of tolerance and inflammation and to encourage biodiversity within the enteric microbiome. In this review, we will discuss intestinal helper T cell plasticity and our current understanding of its mechanisms, including our growing knowledge of an evolutionarily ancient symbiosis between microbiota and malleable CD4+ T cell effectors. PMID:25339956

  5. 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.

  6. Association of CD4+ T-cell Count, HIV-1 RNA Viral Load, and Antiretroviral Therapy With Kaposi Sarcoma Risk Among HIV-infected Persons in the United States and Canada.

    PubMed

    Dubrow, Robert; Qin, Li; Lin, Haiqun; Hernández-Ramírez, Raúl U; Neugebauer, Romain S; Leyden, Wendy; Althoff, Keri N; Achenbach, Chad J; Hessol, Nancy A; Modur, Sharada P; DʼSouza, Gypsyamber; Bosch, Ronald J; Grover, Surbhi; Horberg, Michael A; Kitahata, Mari M; Mayor, Angel M; Novak, Richard M; Rabkin, Charles S; Sterling, Timothy R; Goedert, James J; Justice, Amy C; Engels, Eric A; Moore, Richard D; Silverberg, Michael J

    2017-08-01

    Kaposi sarcoma (KS) remains common among HIV-infected persons. To better understand KS etiology and to help target prevention efforts, we comprehensively examined a variety of CD4 T-cell count and HIV-1 RNA viral load (VL) measures, as well as antiretroviral therapy (ART) use, to determine independent predictors of KS risk. North American AIDS Cohort Collaboration on Research and Design. We followed HIV-infected persons during 1996-2009 from 18 cohorts. We used time-updated Cox regression to model relationships between KS risk and recent, lagged, trajectory, and cumulative CD4 count or VL measures, as well as ART use. We used Akaike's information criterion and global P values to derive a final model. In separate models, the relationship between each measure and KS risk was highly significant (P < 0.0001). Our final mutually adjusted model included recent CD4 count [hazard ratio (HR) for <50 vs. ≥500 cells/μL = 12.4; 95% confidence interval (CI): 6.5 to 23.8], recent VL (HR for ≥100,000 vs. ≤500 copies/mL = 3.8; 95% CI: 2.0 to 7.3), and cumulative (time-weighted mean) VL (HR for ≥100,000 vs. ≤500 copies/mL = 2.5; 95% CI: 1.0 to 5.9). Each P-trend was <0.0001. After adjusting for these measures, we did not detect an independent association between ART use and KS risk. Our results suggested a multifactorial etiology for KS, with early and late phases of development. The cumulative VL effect suggested that controlling HIV replication promptly after HIV diagnosis is important for KS prevention. We observed no evidence for direct anti-KS activity of ART, independent of CD4 count and VL.

  7. Altered Intracellular ATP Production by Activated CD4+ T-Cells in Very Preterm Infants

    PubMed Central

    Corvaglia, Luigi; Gabrielli, Liliana; Chiereghin, Angela; Lazzarotto, Tiziana

    2016-01-01

    Background. The neonatal immune system is not fully developed at birth; newborns have adequate lymphocytes counts but these cells lack function. Objective. To assess the activity of T-cells and the influence of the main perinatal factors in very preterm infants (birth weight < 1500 g). Design. Blood samples from 59 preterm infants (21/59 were dizygotic twins) were collected at birth and at 30 days of life to measure CD4+ T-cell activity using the ImmuKnow™ assay. Fifteen healthy adults were included as a control group. Results. CD4+ T-cell activity was lower in VLBW infants compared with adults (p < 0.001). Twins showed lower immune activity compared to singletons (p = 0.005). Infants born vaginally showed higher CD4+ T-cell activity compared to those born by C-section (p = 0.031); infants born after prolonged Premature Rupture of Membranes (pPROM) showed higher CD4+ T-cell activity at birth (p = 0.002) compared to infants born without pPROM. Low CD4+ T-cell activity at birth is associated with necrotizing enterocolitis (NEC) in the first week of life (p = 0.049). Conclusions. Preterm infants show a lack in CD4+ T-cell activity at birth. Perinatal factors such as intrauterine inflammation, mode of delivery, and zygosity can influence the adaptive immune activation capacity at birth and can contribute to exposing these infants to serious complications such as NEC. PMID:28070527

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

    PubMed Central

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

    2012-01-01

    Following primary infection, human herpesvirus 6 (HHV-6) establishes a persistent infection for life. HHV-6 reactivation has been associated with transplant rejection, delayed engraftment, encephalitis, muscular dystrophy, and drug-induced hypersensitivity syndrome. The poor understanding of the targets and outcome of the cellular immune response to HHV-6 makes it difficult to outline the role of HHV-6 in human disease. To fill in this gap, we characterized CD4 T cell responses to HHV-6 using peripheral blood mononuclear cell (PBMC) and T cell lines generated from healthy donors. CD4+ T cells responding to HHV-6 in peripheral blood were observed at frequencies below 0.1% of total T cells but could be expanded easily in vitro. Analysis of cytokines in supernatants of PBMC and T cell cultures challenged with HHV-6 preparations indicated that gamma interferon (IFN-γ) and interleukin-10 (IL-10) were appropriate markers of the HHV-6 cellular response. Eleven CD4+ T cell epitopes, all but one derived from abundant virion components, were identified. The response was highly cross-reactive between HHV-6A and HHV-6B variants. Seven of the CD4+ T cell epitopes do not share significant homologies with other known human pathogens, including the closely related human viruses human herpesvirus 7 (HHV-7) and human cytomegalovirus (HCMV). Major histocompatibility complex (MHC) tetramers generated with these epitopes were able to detect HHV-6-specific T cell populations. These findings provide a window into the immune response to HHV-6 and provide a basis for tracking HHV-6 cellular immune responses. PMID:22357271

  9. Helicobacter pylori Infection Is Associated with Higher CD4 T Cell Counts and Lower HIV-1 Viral Loads in ART-Naïve HIV-Positive Patients in Ghana.

    PubMed

    Sarfo, Fred Stephen; Eberhardt, Kirsten Alexandra; Dompreh, Albert; Kuffour, Edmund Osei; Soltau, Mareike; Schachscheider, Marei; Drexler, Jan Felix; Eis-Hübinger, Anna Maria; Häussinger, Dieter; Oteng-Seifah, Emelia Efua; Bedu-Addo, George; Phillips, Richard Odame; Norman, Betty; Burchard, Gerd; Feldt, Torsten

    2015-01-01

    Worldwide, there is a high co-endemicity of HIV and H. pylori infection and there is growing evidence that H. pylori co-infection is associated with parameters of HIV disease progression. The objective of this study was to investigate the prevalence of H. pylori infection, and the association with clinical, immunological and virological parameters in a large cohort of HIV-infected individuals and uninfected controls in a West African country. HIV-patients (n = 1,095) and HIV-negative individuals (n = 107) were recruited at a university hospital in Ghana. H. pylori status was determined using stool antigen testing. HIV-related, clinical and socio-demographic parameters were recorded and analyzed according to H. pylori status. The prevalence of H. pylori infection was significantly lower in HIV-positive compared to HIV-negative individuals (51.5 vs. 88%, p<0.0001). In HIV patients, H. pylori prevalence decreased in parallel with CD4+ T cell counts. In ART-naïve HIV-infected individuals, but not in those taking ART, H. pylori infection was associated with higher CD4 cell counts (312 vs. 189 cells/μL, p<0.0001) and lower HIV-1 viral loads (4.92 vs. 5.21 log10 copies/mL, p = 0.006). The findings could not be explained by socio-demographic confounders or reported use of antibiotics. Having no access to tap water and higher CD4+ T cell counts were identified as risk factors for H. pylori infection. H. pylori prevalence was inversely correlated with the degree of immunosuppression. In ART-naïve individuals, H. pylori infection is associated with favorable immunological and virological parameters. The underlying mechanisms for this association are unclear and warrant investigation.

  10. STAT5 and CD4 + T Cell Immunity

    PubMed Central

    Owen, David L.; Farrar, Michael A.

    2017-01-01

    STAT5 plays a critical role in the development and function of many cell types. Here, we review the role of STAT5 in the development of T lymphocytes in the thymus and its subsequent role in the differentiation of distinct CD4 + helper and regulatory T-cell subsets. PMID:28163905

  11. CD4+ T cells memorize obesity and promote weight regain.

    PubMed

    Zou, Jianghuan; Lai, Beibei; Zheng, Mingzhu; Chen, Qin; Jiang, Shujun; Song, Anying; Huang, Zan; Shi, Peiliang; Tu, Xin; Wang, Di; Lu, Linrong; Lin, Zhaoyu; Gao, Xiang

    2017-06-19

    Body weight regain often causes failure of obesity therapies while the underlying mechanism remains largely unknown. In this study, we report that immune cells, especially CD4+ T cells, mediate the 'memory' of previous obese status. In a weight gain-loss-regain model, we found that C57BL/6J mice with an obesity history showed a much faster rate of body weight regain. This obesity memory could last for at least 2 months after previously obese mice were kept at the same body weight as non-obese mice. Surprisingly, such obesity memory was abrogated by dexamethasone treatment, whereas immunodeficient Rag1(-/-) and H2A(-/-) mice failed to establish such memory. Rag1(-/-) mice repossessed the obesity memory when immune cells or CD4+ T cells isolated from previously obese mice were transferred. Furthermore, depletion of CD4+ T cells led to obesity memory ablation. Taken together, we conclude that CD4+ T cells mediate obesity memory and promote weight regain.Cellular &Molecular Immunology advance online publication, 19 June 2017; doi:10.1038/cmi.2017.36.

  12. Monoclonal antibody to CD4+ T cells abrogates genetic resistance to Haemonchus contortus in sheep.

    PubMed Central

    Gill, H S; Watson, D L; Brandon, M R

    1993-01-01

    The roles of CD4+ and CD8+ T cells in genetically determined resistance of sheep to Haemonchus contortus (a natural host-parasite relationship) was investigated by selectively depleting genetically resistant merino lambs of their CD4+ or CD8+ T cells by treatment with mouse monoclonal antibody (mAb) specific for the appropriate determinant before and during challenge infection. Administration of anti-CD4 mAb to genetically resistant lambs completely abrogated their expression of genetic resistance as indicated by significantly higher faecal egg output and worm burdens found in the CD4+ T-cell-depleted lambs compared with those of controls. Host responses associated with resistance to H. contortus including mucosal mast cell hyperplasia and tissue eosinophilia were also significantly suppressed in CD4-depleted lambs. The development of anamnestic anti-parasite antibody responses were also significantly inhibited by anti-CD4 mAb. Furthermore, anti-CD4 mAb abolished differences in host responses between genetically resistant and random-bred (susceptible) lambs. In contrast, depletion of CD8+ T cells had no effect on genetic resistance; faecal egg output, worm counts, mast cells and eosinophil responses in CD8-depleted lambs were not significantly different from those in controls. Together, these results suggest that CD4+ T cells play a pivotal role in mediating genetic resistance to H. contortus, and in the generation of mucosal mast cell hyperplasia, tissue eosinophilia and anti-Haemonchus antibody. CD8+ T cells appear to play no protective role. The possible mechanisms by which CD4+ T cells might mediate anti-parasite resistance are discussed. PMID:8094709

  13. Roscovitine suppresses CD4+ T cells and T cell-mediated experimental uveitis.

    PubMed

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

    2013-01-01

    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. 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. 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. 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.

  14. 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

  15. CD4 T-Cell Memory Generation and Maintenance

    PubMed Central

    Gasper, David J.; Tejera, Melba Marie; Suresh, M.

    2014-01-01

    Immunologic memory is the adaptive immune system's powerful ability to remember a previous antigen encounter and react with accelerated vigor upon antigen re-exposure. It provides durable protection against reinfection with pathogens and is the foundation for vaccine-induced immunity. Unlike the relatively restricted immunologic purview of memory B cells and CD8 T cells, the field of CD4 T-cell memory must account for multiple distinct lineages with diverse effector functions, the issue of lineage commitment and plasticity, and the variable distribution of memory cells within each lineage. Here, we discuss the evidence for lineage-specific CD4 T-cell memory and summarize the known factors contributing to memory-cell generation, plasticity, and long-term maintenance. PMID:24940912

  16. CD4 T-cell memory generation and maintenance.

    PubMed

    Gasper, David J; Tejera, Melba Marie; Suresh, M

    2014-01-01

    Immunologic memory is the adaptive immune system's powerful ability to remember a previous antigen encounter and react with accelerated vigor upon antigen re-exposure. It provides durable protection against reinfection with pathogens and is the foundation for vaccine-induced immunity. Unlike the relatively restricted immunologic purview of memory B cells and CD8 T cells, the field of CD4 T-cell memory must account for multiple distinct lineages with diverse effector functions, the issue of lineage commitment and plasticity, and the variable distribution of memory cells within each lineage. Here, we discuss the evidence for lineage-specific CD4 T-cell memory and summarize the known factors contributing to memory-cell generation, plasticity, and long-term maintenance.

  17. Perturbations in B cell responsiveness to CD4+ T cell help in HIV-infected individuals

    PubMed Central

    Moir, Susan; Ogwaro, Kisani M.; Malaspina, Angela; Vasquez, Joshua; Donoghue, Eileen T.; Hallahan, Claire W.; Liu, Shuying; Ehler, Linda A.; Planta, Marie A.; Kottilil, Shyamasundaran; Chun, Tae-Wook; Fauci, Anthony S.

    2003-01-01

    HIV infection induces a wide array of B cell dysfunctions. We have characterized the effect of plasma viremia on the responsiveness of B cells to CD4+ T cell help in HIV-infected patients. In HIV-negative donors, B cell proliferation correlated with CD154 expression on activated CD4+ T cells and with the availability of IL-2, whereas in HIV-infected viremic patients, reduced B cell proliferation was observed despite normal CD154 expression on activated CD4+ T cells. Reduced triggering of B cells by activated CD4+ T cells was clearly observed in HIV-infected viremic patients compared with aviremic patients with comparable CD4+ T cell counts, and a dramatic improvement in B cell function was observed in patients whose plasma viremia was controlled by effective antiretroviral therapy. The degree of B cell dysfunction in viremic patients correlated strongly with the inability of B cells to express CD25 in response to activated CD4+ T cells, resulting in an inability to mount a normal proliferative response to IL-2. Similar defects in responsiveness to IL-2 were observed in the B cells of HIV-infected viremic patients in the context of B cell receptor stimulation. These data provide new insight into the mechanisms associated with ineffective humoral responses in HIV disease. PMID:12730375

  18. 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

  19. An atlas of mouse CD4(+) T cell transcriptomes.

    PubMed

    Stubbington, Michael Jt; Mahata, Bidesh; Svensson, Valentine; Deonarine, Andrew; Nissen, Jesper K; Betz, Alexander G; Teichmann, Sarah A

    2015-04-03

    CD4(+) T cells are key regulators of the adaptive immune system and can be divided into T helper (Th) cells and regulatory T (Treg) cells. During an immune response Th cells mature from a naive state into one of several effector subtypes that exhibit distinct functions. The transcriptional mechanisms that underlie the specific functional identity of CD4(+) T cells are not fully understood. To assist investigations into the transcriptional identity and regulatory processes of these cells we performed mRNA-sequencing on three murine T helper subtypes (Th1, Th2 and Th17) as well as on splenic Treg cells and induced Treg (iTreg) cells. Our integrated analysis of this dataset revealed the gene expression changes associated with these related but distinct cellular identities. Each cell subtype differentially expresses a wealth of 'subtype upregulated' genes, some of which are well known whilst others promise new insights into signalling processes and transcriptional regulation. We show that hundreds of genes are regulated purely by alternative splicing to extend our knowledge of the role of post-transcriptional regulation in cell differentiation. This CD4(+) transcriptome atlas provides a valuable resource for the study of CD4(+) T cell populations. To facilitate its use by others, we have made the data available in an easily accessible online resource at www.th-express.org.

  20. Rate and Predictors of Non-AIDS Events in a Cohort of HIV-Infected Patients with a CD4 T Cell Count Above 500 Cells/mm3

    PubMed Central

    Lucero, Constanza; Torres, Berta; León, Agathe; Calvo, Marta; Leal, Lorna; Pérez, Iñaki; Plana, Montserrat; Arnedo, Mireia; Mallolas, Josep; Gatell, Josep M.

    2013-01-01

    Abstract The reduction of risk of non-AIDS events after combined antiretroviral therapy (cART) initiation and the crude incidence rate (CIR) of these events in patients who control the viral load without cART (controllers) in a cohort of 574 antiretroviral-naive patients with a baseline CD4 T cell count above 500 cells/mm3 were assessed. Non-AIDS severe events were defined as a first admission to the hospital due to non-AIDS-defining malignancies, cardiovascular, neuropsychiatric, liver-related, or end-stage renal disease events. Potential determinants of non-AIDS/death events were studied using Cox regression models. Eighty-five non-AIDS/death events occurred during 6,062 persons-years of follow-up (PYFU) with a CIR of 1.4 per 100 PYFU. Factors associated with non-AIDS/death event were age (HR 3.4; 95% CI: 1.6–6.9), nadir CD4 below 350 cells/mm3 (HR 2.5; 95% CI: 1.4–4.6), and a last determination of viral load above the median (HR 1.9; 95% CI: 1.0–3.3). The CIR of non-AIDS/death events was 2.1 and 1.8 per 100 PYFU before and after cART in patients who started cART (n=446). A reduction of CIR of non-AIDS events after cART initiation was observed only in patients with a nadir of CD4 above 350 cells/mm3 (2.5 vs. 0.6 per 100 PYFU, p=0.004, and remained stable after cART in patients with a median nadir of CD4 below 350 cells/mm3. CIR was similar in elite, viremic, and noncontrollers (1.1, 1.0, and 1.5 per 100 PYFU, respectively, p=0.25). Reduction of CIR of non-AIDS events after cART initiation depends on nadir CD4 T cell count. Most of the controllers patients had a CIR similar to noncontrollers. These data support the early initiation of cART in HIV-infected patients. PMID:23530980

  1. A rapid manual method for CD4+ T-cell quantitation for use in developing countries.

    PubMed

    Landay, A; Ho, J L; Hom, D; Russell, T; Zwerner, R; Minuty, J G; Kataaha, P; Mmiro, F; Jackson, B

    1993-12-01

    Clinicians took blood samples from 294 HIV-1 seropositive patients and 88 HIV-1 seronegative patients at Cornell University Medical College and The New York Hospital in New York City, Rush-Presbyterian-St. Luke's Medical Center in Chicago, and Makerere University Medical school in Kampala, Uganda, to assess a manual method's (Cytosphere) ability to accurately determine the CD4+ T-cell count. The Cytosphere assay uses latex beads coated with CD4 antibody which are combined with anticoagulated whole blood followed by red cell lysis. A hemacytometer then counts the bead-coated cells. The average technologist only needs 1-3 days of training (20 CD4 practice assays/days) in the Cytosphere assay. The minimal equipment required for the assay are a pipette, a hemacytometer, and a light microscope. The lysing agent inactivates HIV-1. The overall correlation between the standard flow cytometry method and the Cytosphere assay stood at 0.912 and was significant (p .001). When the researchers stratified the samples based on CD4+ T-cell counts defined by flow cytometry, the predictive values of the Cytosphere assay for correctly identifying patients with CD4 T-cell counts greater or less than 200 x 1 million/1 were 96% and 92%, respectively. These findings suggested that the Cytosphere assay has the potential to quantify CD4 cells in the limited laboratories in developing countries. Larger longitudinal studies of HIV seropositive people in developing countries are needed to test the reliability and reproducibility of the assay.

  2. Conditions That Induce Tolerance in Mature CD4+ T Cells

    PubMed Central

    Lanoue, Astrid; Bona, Constantin; von Boehmer, Harald; Sarukhan, Adelaida

    1997-01-01

    Establishment of antigen-specific tolerance among mature T cells has been a long debated, yet poorly understood issue. In this study we have used transgenic mice bearing a class II–restricted TCR specific for the hemmagglutinin of the influenza virus in order to test the behavior of CD4+ T cells upon exposure to antigen in different forms and doses. We first studied the fate of T cells expressing the transgenic TCR (6.5) in double transgenic mice where HA was expressed as a self antigen by hemapoietic cells. In these mice, we found some mature T cells in periphery that had escaped thymic deletion and that showed signs of activation but which were anergic. Mature CD4+6.5+ cells that were transferred into antigen-containing recipients went through an initial phase of expansion after which most cells were deleted and those remaining became unresponsive, as previously described for CD8+ cells. Inducing tolerance in CD4+6.5+ cells in situ in single transgenic mice proved a difficult task: classical protocols using single doses of soluble or deaggregated antigen as well as feeding antigen all failed to induce antigen-specific unresponsiveness. It was only after decreasing cell numbers by CD4 antibody treatment and by repeatedly reintroducing antigen thereafter that unresponsiveness of 6.5+ cells was achieved and maintained. In no case could we observe the appearance of antigen-specific T cells with a Th2 cytokine profile among the remaining cells and therefore conclude that deletion and anergy represent the major mechanisms of tolerance in our studies. PMID:9053441

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

    PubMed

    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

    2014-07-01

    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 24weeks of MVC intensification in 32 subjects. Median changes of CD4+ T cell counts over 24weeks of MVC compared to baseline were 38cells/mm(3) (p<0.001). The median slope of CD4+ T cell recovery was 39cells/mm(3) per year before initiation of MVC and 76cells/mm(3) 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.

  4. Human CD4low CD25high regulatory T cells indiscriminately kill autologous activated T cells

    PubMed Central

    Bryl, Ewa; Daca, Agnieszka; Jóźwik, Agnieszka; Witkowski, Jacek M

    2009-01-01

    The interest of the scientific community in regulatory CD4+ T cells has reached an enormously high level. Common agreement is that they inhibit not only the proliferation of CD4 and CD8 lymphocytes, but also the activities of natural killer cells and macrophages. However, very important issues concerning actual mechanism(s) and specificity of the action of regulatory T cells (Tregs) upon responder cells are still unsolved or vague. The best known marker for Tregs is the expression of transcription factor FoxP3, widely used for their enumeration. It is known that FoxP3 inhibits cytokine production so the most probable action of Tregs is direct. However, FoxP3 expression cannot be used for functional studies in humans. Therefore we identified human peripheral blood Tregs as a distinct, very well-defined population of peripheral blood T cells with reduced CD4 and high CD25 expression (CD4low CD25high), which fulfils the current phenotypic criteria identifying the Tregs by simultaneously expressing high amounts of FoxP3. We conclude that the definition of a CD4low CD25high phenotype is enough to unambiguously detect and study the regulatory function of these cells. On the functional level, the CD4low Tregs are able to non-specifically suppress the proliferation of autologous, previously polyclonally activated CD4+ and CD4− lymphocytes and to kill them by direct contact, probably utilizing intracellular granzyme B and perforin. PMID:19016909

  5. Human CD4low CD25high regulatory T cells indiscriminately kill autologous activated T cells.

    PubMed

    Bryl, Ewa; Daca, Agnieszka; Jóźwik, Agnieszka; Witkowski, Jacek M

    2009-09-01

    The interest of the scientific community in regulatory CD4(+) T cells has reached an enormously high level. Common agreement is that they inhibit not only the proliferation of CD4 and CD8 lymphocytes, but also the activities of natural killer cells and macrophages. However, very important issues concerning actual mechanism(s) and specificity of the action of regulatory T cells (Tregs) upon responder cells are still unsolved or vague. The best known marker for Tregs is the expression of transcription factor FoxP3, widely used for their enumeration. It is known that FoxP3 inhibits cytokine production so the most probable action of Tregs is direct. However, FoxP3 expression cannot be used for functional studies in humans. Therefore we identified human peripheral blood Tregs as a distinct, very well-defined population of peripheral blood T cells with reduced CD4 and high CD25 expression (CD4(low) CD25(high)), which fulfils the current phenotypic criteria identifying the Tregs by simultaneously expressing high amounts of FoxP3. We conclude that the definition of a CD4(low) CD25(high) phenotype is enough to unambiguously detect and study the regulatory function of these cells. On the functional level, the CD4(low) Tregs are able to non-specifically suppress the proliferation of autologous, previously polyclonally activated CD4(+) and CD4(-) lymphocytes and to kill them by direct contact, probably utilizing intracellular granzyme B and perforin.

  6. Single wall carbon nanotube electrode system capable of quantitative detection of CD4(+) T cells.

    PubMed

    Kim, Joonhyub; Park, Gayoung; Lee, Seoho; Hwang, Suk-Won; Min, Namki; Lee, Kyung-Mi

    2017-04-15

    Development of CNT-based CD4(+) T cell imunosensors remains in its infancy due to the poor immobilization efficiency, lack of reproducibility, and difficulty in providing linear quantification. Here, we developed a fully-integrated single wall carbon nanotube (SWCNT)-based immunosensor capable of selective capture and linear quantification of CD4(+) T cells with greater dynamic range. By employing repeated two-step oxygen (O2) plasma treatment processes with 35 days of recovery periods, we achieved the enhanced functionalization of the CNT surface and the removal of the byproduct of spray-coated SWCNTs that hinders charge transfer and stable CD4(+) T cell sensing. As a result, a linear electrochemical signal was generated in direct proportion to the bound cells. The slope of a SWCNT electrode in a target concentration range (10(2)~10(6)cells/mL) was 4.55×10(-2)μA per concentration decade, with the lowest detection limit of 1×10(2)cells/mL. Since the reduced number of CD4(+) T cell counts in patients' peripheral blood corresponds to the progression of HIV disease, our CD4(+) T cell-immunosensor provides a simple and low-cost platform which can fulfill the requirement for the development of point-of-care (POC) diagnostic technologies for human immunodeficiency virus (HIV) patients in resource-limited countries.

  7. CD4 T cells promote CD8 T cell immunity at the priming and effector site during viral encephalitis.

    PubMed

    Phares, Timothy W; Stohlman, Stephen A; Hwang, Mihyun; Min, Booki; Hinton, David R; Bergmann, Cornelia C

    2012-03-01

    CD4 T cell activation during peripheral infections not only is essential in inducing protective CD8 T cell memory but also promotes CD8 T cell function and survival. However, the contributions of CD4 T cell help to antiviral CD8 T cell immunity during central nervous system (CNS) infection are not well established. Encephalitis induced by the sublethal coronavirus JHMV was used to identify when CD4 T cells regulate CD8 T cell responses following CNS infection. Peripheral expansion of virus-specific CD8 T cells was impaired when CD4 T cells were ablated prior to infection but not at 4 days postinfection. Delayed CD4 T cell depletion abrogated CD4 T cell recruitment to the CNS but only slightly diminished CD8 T cell recruitment. Nevertheless, the absence of CNS CD4 T cells was associated with reduced gamma interferon (IFN-γ) and granzyme B expression by infiltrating CD8 T cells, increased CD8 T cell apoptosis, and impaired control of infectious virus. CD4 T cell depletion subsequent to CD4 T cell CNS migration restored CD8 T cell activity and virus control. Analysis of γc-dependent cytokine expression indicated interleukin-21 (IL-21) as a primary candidate optimizing CD8 T cell activity within the CNS. These results demonstrate that CD4 T cells play critical roles in both enhancing peripheral activation of CD8 T cells and prolonging their antiviral function within the CNS. The data highlight the necessity for temporally and spatially distinct CD4 T cell helper functions in sustaining CD8 T cell activity during CNS infection.

  8. Respiratory Syncytial Virus (RSV) Infects CD4+ T Cells: Frequency of Circulating CD4+ RSV+ T Cells as a Marker of Disease Severity in Young Children.

    PubMed

    Raiden, Silvina; Sananez, Inés; Remes-Lenicov, Federico; Pandolfi, Julieta; Romero, Cecilia; De Lillo, Leonardo; Ceballos, Ana; Geffner, Jorge; Arruvito, Lourdes

    2017-04-01

    Although human airway epithelial cells are the main target of respiratory syncytial virus (RSV), it also infects immune cells, such as macrophages and B cells. Whether T cells are permissive to RSV infection is unknown. We sought to analyze the permissiveness of CD4+ T cells to RSV infection. CD4+ and CD8+ T cells from cord blood, healthy young children, and adults were challenged by RSV or cocultured with infected HEp-2 cells. Infection, phenotype, and cytokine production by T cells were analyzed by flow cytometry or enzyme-linked immunosorbent assay. Expression of RSV antigens by circulating CD4+ T cells from infected children was analyzed by flow cytometry, and disease severity was defined by standard criteria. CD4+ and CD8+ T cells were productively infected by RSV. Infection decreased interleukin 2 and interferon γ production as well as the expression of CD25 and Ki-67 by activated CD4+ T cells. Respiratory syncytial virus antigens were detected in circulating CD4+ and CD8+ T cells during severe RSV infection of young children. Interestingly, the frequency of CD4+ RSV+ T cells positively correlated with disease severity. Respiratory syncytial virus infects CD4+ and CD8+ T cells and compromises T-cell function. The frequency of circulating CD4+ RSV+ T cells might represent a novel marker of severe infection.

  9. Short-term antiretroviral therapy to prevent mother-to-child transmission is safe and results in a sustained increase in CD4 T-cell counts in HIV-1-infected mothers.

    PubMed

    Palacios, R; Senise, Jf; Vaz, Mjr; Diaz, Rs; Castelo, A

    2009-03-01

    Short-term antiretroviral therapy (START) to prevent mother-to-child transmission (MTCT) is currently recommended for all HIV-1-infected pregnant women. The objective of this study was to assess the effect on CD4 cell counts and viral load dynamics the withdrawal of START after birth could generate. This was a 5-year cohort study involving HIV-1-infected pregnant women who presented with CD4 counts >300 cells/microL and had received START to prevent MTCT. Seventy-five pregnancies were assessed. In 24 cases, there was a history of antiretroviral therapy prior to prophylaxis. The median baseline CD4 count was 573 cells/microL. In 75% of cases, prophylaxis was started after 26.6 weeks of gestation. The median CD4 cell count increase over baseline during prophylaxis was 24.5%. In only five cases did HIV-1 viral load remain detectable during prophylaxis. After START, CD4 cell counts did not drop significantly, and the HIV-1 viral load plateau was near the baseline level. The estimated mean time for CD4 count to fall below 300 cells/microL was 3.5 years and was directly associated with high baseline CD4 cell count, as well as with CD4 increase after prophylaxis, whereas it was negatively correlated with previous use of antiretroviral (ARV) drugs and persistence of detectable HIV-1 viral load during prophylaxis. A potent, well-tolerated prophylactic ARV regimen can improve CD4 cell counts during and after START. In women receiving such prophylaxis, there is a remarkable time interval for CD4 cell counts to drop to levels that indicate treatment.

  10. Unrecognised tuberculosis at antiretroviral therapy initiation is associated with lower CD4+ T cell recovery.

    PubMed

    Hermans, Sabine M; van Leth, Frank; Kiragga, Agnes N; Hoepelman, Andy I M; Lange, Joep M A; Manabe, Yukari C

    2012-12-01

    To investigate whether an unrecognised diagnosis of tuberculosis (TB) at the start of antiretroviral therapy (ART) influences subsequent CD4+ T cell (CD4) count recovery in an urban HIV clinic in Uganda. In a retrospective cohort study, a multivariable polynomial mixed effects model was used to estimate CD4 recovery in the first 96 weeks of ART in two groups of patients: prevalent TB (started ART while on TB treatment), unrecognised TB (developed TB within 6 months after start ART). Included were 511 patients with a median baseline CD4 count of 57 cells/mm(3) (interquartile range: 22-130), of whom 368 (72%) had prevalent TB and 143 (28%) had unrecognised TB. Compared with prevalent TB, unrecognised TB was associated with lower CD4 count recovery at 96 weeks: -22.3 cells/mm(3) (95% confidence interval -43.2 to -1.5, P = 0.036). These estimates were adjusted for gender, age, baseline CD4 count and the use of zidovudine-based regimen. Unrecognised TB at the time of ART initiation resulted in impaired CD4 recovery compared with TB treated before ART initiation. More vigilant screening with more sensitive and rapid TB diagnostics prior to ART initiation is needed to decrease the risk of ART-associated TB and sub-optimal immune reconstitution. © 2012 Blackwell Publishing Ltd.

  11. Transporters for Antiretroviral Drugs in Colorectal CD4+ T Cells and Circulating α4β7 Integrin CD4+ T Cells: Implications for HIV Microbicides.

    PubMed

    Mukhopadhya, Indrani; Murray, Graeme I; Duncan, Linda; Yuecel, Raif; Shattock, Robin; Kelly, Charles; Iannelli, Francesco; Pozzi, Gianni; El-Omar, Emad M; Hold, Georgina L; Hijazi, Karolin

    2016-09-06

    CD4+ T lymphocytes in the colorectal mucosa are key in HIV-1 transmission and dissemination. As such they are also the primary target for antiretroviral (ARV)-based rectal microbicides for pre-exposure prophylaxis. Drug transporters expressed in mucosal CD4+ T cells determine ARV distribution across the cell membrane and, most likely, efficacy of microbicides. We describe transporters for antiretroviral drugs in colorectal mucosal CD4+ T lymphocytes and compare gene expression with circulating α4β7+CD4+ T cells, which traffic to the intestine and have been shown to be preferentially infected by HIV-1. Purified total CD4+ T cells were obtained from colorectal tissue and blood samples by magnetic separation. CD4+ T cells expressing α4β7 integrin were isolated by fluorescence-activated cell sorting from peripheral blood mononuclear cells of healthy volunteers. Expressions of 15 efflux and uptake drug transporter genes were quantified using Taqman qPCR assays. Expression of efflux transporters MRP3, MRP5, and BCRP and uptake transporter CNT2 were significantly higher in colorectal CD4+ T cells compared to circulating CD4+ T cells (p = 0.01-0.03). Conversely, circulating α4β7+CD4+ T cells demonstrated significantly higher expression of OATPD compared to colorectal CD4+ T cells (p = 0.001). To the best of our knowledge this is the first report of drug transporter gene expression in colorectal CD4+ and peripheral α4β7+CD4+ T cells. The qualitative and quantitative differences in drug transporter gene expression profiles between α4β7+CD4+ T cells and total mucosal CD4+ T cells may have significant implications for the efficacy of rectally delivered ARV-microbicides. Most notably, we have identified efflux drug transporters that could be targeted by selective inhibitors or beneficial drug-drug interactions to enhance intracellular accumulation of antiretroviral drugs.

  12. Control of inflammatory heart disease by CD4+ T cells.

    PubMed

    Barin, Jobert G; Čiháková, Daniela

    2013-05-01

    This review focuses on autoimmune myocarditis and its sequela, inflammatory dilated cardiomyopathy (DCMI), and the inflammatory and immune mechanisms underlying the pathogenesis of these diseases. Several mouse models of myocarditis and DCMI have improved our knowledge of the pathogenesis of these diseases, informing more general problems of cardiac remodeling and heart failure. CD4(+) T cells are critical in driving the pathogenesis of myocarditis. We discuss in detail the role of T helper cell subtypes in the pathogenesis of myocarditis, the biology of T cell-derived effector cytokines, and the participation of other leukocytic effectors in mediating disease pathophysiology. We discuss interactions between these subsets in both suppressive and collaborative fashions. These findings indicate that cardiac inflammatory disease, and autoimmunity in general, may be more diverse in divergent effector mechanisms than has previously been appreciated.

  13. Gene Editing of CCR5 in Autologous CD4 T Cells of Persons Infected with HIV

    PubMed Central

    Tebas, Pablo; Stein, David; Tang, Winson W.; Frank, Ian; Wang, Shelley Q.; Lee, Gary; Spratt, S. Kaye; Surosky, Richard T.; Giedlin, Martin A.; Nichol, Geoff; Holmes, Michael C.; Gregory, Philip D.; Ando, Dale G.; Kalos, Michael; Collman, Ronald G.; Binder-Scholl, Gwendolyn; Plesa, Gabriela; Hwang, Wei-Ting; Levine, Bruce L.; June, Carl H.

    2014-01-01

    BACKGROUND CCR5 is the major coreceptor for human immunodeficiency virus (HIV). We investigated whether site-specific modification of the gene (“gene editing”) — in this case, the infusion of autologous CD4 T cells in which the CCR5 gene was rendered permanently dysfunctional by a zinc-finger nuclease (ZFN) — is safe. METHODS We enrolled 12 patients in an open-label, nonrandomized, uncontrolled study of a single dose of ZFN-modified autologous CD4 T cells. The patients had chronic aviremic HIV infection while they were receiving highly active antiretroviral therapy. Six of them underwent an interruption in antiretroviral treatment 4 weeks after the infusion of 10 billion autologous CD4 T cells, 11 to 28% of which were genetically modified with the ZFN. The primary outcome was safety as assessed by treatment-related adverse events. Secondary outcomes included measures of immune reconstitution and HIV resistance. RESULTS One serious adverse event was associated with infusion of the ZFN-modified autologous CD4 T cells and was attributed to a transfusion reaction. The median CD4 T-cell count was 1517 per cubic millimeter at week 1, a significant increase from the preinfusion count of 448 per cubic millimeter (P<0.001). The median concentration of CCR5-modified CD4 T cells at 1 week was 250 cells per cubic millimeter. This constituted 8.8% of circulating peripheral-blood mononuclear cells and 13.9% of circulating CD4 T cells. Modified cells had an estimated mean half-life of 48 weeks. During treatment interruption and the resultant viremia, the decline in circulating CCR5-modified cells (−1.81 cells per day) was significantly less than the decline in unmodified cells (−7.25 cells per day) (P = 0.02). HIV RNA became undetectable in one of four patients who could be evaluated. The blood level of HIV DNA decreased in most patients. CONCLUSIONS CCR5-modified autologous CD4 T-cell infusions are safe within the limits of this study. (Funded by the National

  14. Gene editing of CCR5 in autologous CD4 T cells of persons infected with HIV.

    PubMed

    Tebas, Pablo; Stein, David; Tang, Winson W; Frank, Ian; Wang, Shelley Q; Lee, Gary; Spratt, S Kaye; Surosky, Richard T; Giedlin, Martin A; Nichol, Geoff; Holmes, Michael C; Gregory, Philip D; Ando, Dale G; Kalos, Michael; Collman, Ronald G; Binder-Scholl, Gwendolyn; Plesa, Gabriela; Hwang, Wei-Ting; Levine, Bruce L; June, Carl H

    2014-03-06

    CCR5 is the major coreceptor for human immunodeficiency virus (HIV). We investigated whether site-specific modification of the gene ("gene editing")--in this case, the infusion of autologous CD4 T cells in which the CCR5 gene was rendered permanently dysfunctional by a zinc-finger nuclease (ZFN)--is safe. We enrolled 12 patients in an open-label, nonrandomized, uncontrolled study of a single dose of ZFN-modified autologous CD4 T cells. The patients had chronic aviremic HIV infection while they were receiving highly active antiretroviral therapy. Six of them underwent an interruption in antiretroviral treatment 4 weeks after the infusion of 10 billion autologous CD4 T cells, 11 to 28% of which were genetically modified with the ZFN. The primary outcome was safety as assessed by treatment-related adverse events. Secondary outcomes included measures of immune reconstitution and HIV resistance. One serious adverse event was associated with infusion of the ZFN-modified autologous CD4 T cells and was attributed to a transfusion reaction. The median CD4 T-cell count was 1517 per cubic millimeter at week 1, a significant increase from the preinfusion count of 448 per cubic millimeter (P<0.001). The median concentration of CCR5-modified CD4 T cells at 1 week was 250 cells per cubic millimeter. This constituted 8.8% of circulating peripheral-blood mononuclear cells and 13.9% of circulating CD4 T cells. Modified cells had an estimated mean half-life of 48 weeks. During treatment interruption and the resultant viremia, the decline in circulating CCR5-modified cells (-1.81 cells per day) was significantly less than the decline in unmodified cells (-7.25 cells per day) (P=0.02). HIV RNA became undetectable in one of four patients who could be evaluated. The blood level of HIV DNA decreased in most patients. CCR5-modified autologous CD4 T-cell infusions are safe within the limits of this study. (Funded by the National Institute of Allergy and Infectious Diseases and others

  15. Cycling Memory CD4+ T Cells in HIV Disease Have a Diverse T Cell Receptor Repertoire and a Phenotype Consistent with Bystander Activation

    PubMed Central

    Jiang, Wei; Younes, Souheil-Antoine; Funderburg, Nicholas T.; Mudd, Joseph C.; Espinosa, Enrique; Davenport, Miles P.; Babineau, Denise C.; Sieg, Scott F.

    2014-01-01

    ABSTRACT The mechanisms of increased memory CD4+ T cell cycling in HIV disease are incompletely understood but have been linked to antigen stimulation, homeostatic signals, or exposure to microbial products and the inflammatory cytokines that they induce. We examined the phenotype and Vβ family distribution in cycling memory CD4+ T cells among 52 healthy and 59 HIV-positive (HIV+) donors. Cycling memory CD4+ T cells were proportionally more frequent in subjects with HIV infection than in controls, more often expressed CD38 and PD-1, and less frequently expressed OX40 and intracellular CD40L. OX40 expression on memory CD4+ T cells was induced in vitro by anti-CD3, interleukin-2 (IL-2), IL-7, or IL-15 but not by Toll-like receptor ligands. In HIV+ donors, memory CD4+ T cell cycling was directly related to plasma lipopolysaccharide (LPS) levels, to plasma HIV RNA levels, and to memory CD8+ T cell cycling and was inversely related to peripheral blood CD4+ T cell counts but not to the levels of IL-2, IL-7, or IL-15, while in HIV-negative donors, memory CD4+ T cell cycling was related to IL-7 levels and negatively related to the plasma levels of LPS. In both controls and HIV+ donors, cycling memory CD4+ T cells had a broad distribution of Vβ families comparable to that of noncycling cells. Increased memory CD4+ T cell cycling in HIV disease is reflective of generalized immune activation and not driven primarily by cognate peptide stimulation or exposure to common gamma-chain cytokines. This cycling may be a consequence of exposure to microbial products, to plasma viremia, or, otherwise, to proinflammatory cytokines. IMPORTANCE This work provides evidence that the increased memory CD4+ T cell cycling in HIV infection is not a result of cognate peptide recognition but, rather, is more likely related to the inflammatory environment of HIV infection. PMID:24522925

  16. CD4 T cell recovery is slower in patients experiencing viral load rebounds during HAART

    PubMed Central

    Scott-Algara, D; Aboulker, J-P; Durier, C; Badell, E; Marcellin, F; Prud'homme, M; Jouanne, C; Meiffredy, V; Brun-Vezinet, F; Pialoux, G; Raffi, F

    2001-01-01

    To determine whether viral load rebounds during HAART impact on CD4+ T cell recovery and immune reconstitution, we studied a prospective cohort of 355 antiretroviral naive patients enrolled to be randomized in a trial of three strategies of induction/maintenance HAART. The extent of immune reconstitution in blood through 72 weeks of antiretroviral treatment was evaluated. Lymphocyte subset markers (CD4, CD8, CD45RA, CD62L, CD16, CD19), activation markers (HLA-DR, CD38, CD25) were performed by cytometry analysis. Our results showed that plasma HIV-1 RNA was suppressed to below 500 copies per ml through week 72 in 240 patients (group 1) while the remaining 115 patients experienced at least one viral rebound (group 2). At baseline, CD4 cell count was higher and HIV-1 RNA was lower in group 1 than in group 2. Over 72 weeks, mean increase in CD4+ T cell count was 0·32 cell/mm3/day in group 1 and only 0·14 cell/mm3/day in group 2 (P < 0·0001). However, the patterns of changes in CD4+ and CD8+ T cell subsets during therapy were very similar across the two groups with only subtle and very limited differences. We conclude that permanent control of HIV replication could be necessary for faster immune reconstitution. PMID:11703374

  17. Interleukin-27 is differentially associated with HIV viral load and CD4+ T cell counts in therapy-naïve HIV-mono-infected and HIV/HCV-co-infected Chinese.

    PubMed

    He, Lai; Zhao, Jin; Wang, Maggie Haitian; Siu, Kenny K Y; Gan, Yong-Xia; Chen, Lin; Zee, Benny C Y; Yang, Li; Kung, Hsiang-Fu; Yang, Zheng-Rong; He, Ming-Liang

    2014-01-01

    Human Immunodeficiency Virus (HIV) infection and the resultant Acquired Immunodeficiency Syndrome (AIDS) epidemic are major global health challenges; hepatitis C virus (HCV) co-infection has made the HIV/AIDS epidemic even worse. Interleukin-27 (IL-27), a cytokine which inhibits HIV and HCV replication in vitro, associates with HIV infection and HIV/HCV co-infection in clinical settings. However, the impact of HIV and HCV viral loads on plasma IL-27 expression levels has not been well characterized. In this study, 155 antiretroviral therapy-naïve Chinese were recruited. Among them 80 were HIV- and HCV-negative healthy controls, 45 were HIV-mono-infected and 30 were HIV/HCV-co-infected. Plasma level HIV, HCV, IL-27 and CD4+ number were counted and their correlation, regression relationships were explored. We show that: plasma IL-27 level was significantly upregulated in HIV-mono-infected and HIV/HCV-co-infected Chinese; HIV viral load was negatively correlated with IL-27 titer in HIV-mono-infected subjects whereas the relationship was opposite in HIV/HCV-co-infected subjects; and the relationships between HIV viral loads, IL-27 titers and CD4+ T cell counts in the HIV mono-infection and HIV/HCV co-infection groups were dramatically different. Overall, our results suggest that IL-27 differs in treatment-naïve groups with HIV mono-infections and HIV/HCV co-infections, thereby providing critical information to be considered when caring and treating those with HIV mono-infection and HIV/HCV co-infection.

  18. CD4 aptamer-RORγt shRNA chimera inhibits IL-17 synthesis by human CD4(+) T cells.

    PubMed

    Song, Pingfang; Chou, Yuan K; Zhang, Xiaowei; Meza-Romero, Roberto; Yomogida, Kentaro; Benedek, Gil; Chu, Cong-Qiu

    2014-10-03

    Cell type specific delivery of RNAi to T cells has remained to be a challenge. Here we describe an aptamer mediated delivery of shRNA to CD4(+) T cells targeting RORγt to suppress Th17 cells. A cDNA encoding CD4 aptamer and RORγt shRNA was constructed and the chimeric CD4 aptamer-RORγt shRNA (CD4-AshR-RORγt) was generated using in vitro T7 RNA transcription. 2'-F-dCTP and 2'-F-dUTP were incorporated into CD4-AshR-RORγt for RNase resistance. CD4-AshR-RORγt was specifically uptaken by CD4(+) Karpas 299 cells and primary human CD4(+) T cells. The RORγt shRNA moiety of CD4-AshR-RORγt chimera was cleaved and released by Dicer. Furthermore, CD4-AshR-RORγt suppressed RORγt gene expression in Karpas 299 cells and CD4(+) T cells and consequently inhibited Th17 cell differentiation and IL-17 production. These results demonstrate that aptamer-facilitated cell specific delivery of shRNA represents a novel approach for efficient RNAi delivery and is potentially to be developed for therapeutics targeting specific T cells subtypes.

  19. Elevated humoral response to cytomegalovirus in HIV-infected individuals with poor CD4+ T-cell immune recovery.

    PubMed

    Gómez-Mora, Elisabet; Massanella, Marta; García, Elisabet; Giles, David; Bernadó, Marta; Urrea, Victor; Carrillo, Jorge; Ouchi, Dan; Puig, Jordi; Negredo, Eugenia; Clotet, Bonaventura; Blanco, Julià; Cabrera, Cecilia

    2017-01-01

    Some HIV-infected c-ART-suppressed individuals show incomplete CD4+ T-cell recovery, abnormal T-cell activation and higher mortality. One potential source of immune activation could be coinfection with cytomegalovirus (CMV). IgG and IgM levels, immune activation, inflammation and T-cell death in c-ART-suppressed individuals with CD4+ T-cell counts >350 cells/μL (immunoconcordant, n = 133) or <350 cells/μL (immunodiscordant, n = 95) were analyzed to evaluate the effect of CMV humoral response on immune recovery. In total, 27 HIV-uninfected individuals were included as controls. In addition, the presence of CMV IgM antibodies was retrospectively analyzed in 58 immunoconcordant individuals and 66 immunodiscordant individuals. Increased CMV IgG levels were observed in individuals with poor immune reconstitution (p = 0.0002). Increased CMV IgG responses were significantly correlated with lower nadir and absolute CD4+ T-cell counts. In contrast, CMV IgG responses were positively correlated with activation (HLA-DR+) and death markers in CD4+ T-cells and activated memory CD8+ T-cells (CD45RA-CD38+). Longitudinal subanalysis revealed an increased frequency of IgM+ samples in individuals with poor CD4+ T-cell recovery, and an association was observed between retrospective IgM positivity and the current level of IgG. The magnitude of the humoral immune response to CMV is associated with nadir CD4+ T-cell counts, inflammation, immune activation and CD4+ T-cell death, thus suggesting that CMV infection may be a relevant driving force in the increased morbidity/mortality observed in HIV+ individuals with poor CD4+ T-cell recovery.

  20. Aryl hydrocarbon receptor controls regulatory CD4+ T cell function.

    PubMed

    Pot, Caroline

    2012-05-31

    The ligand activated transcription factor aryl hydrocarbon receptor (AhR) has been studied for many decades in toxicology as the ligand for the environmental contaminant dioxin. However, AhR has recently emerged as a critical physiological regulator of immune responses affecting both innate and adaptive systems, and several AhR ligands with different pharmacological profiles have recently been studied. The current review discusses new insights into the role of AhR signalling and AhR ligands on the regulation of the immune system, with a focus on regulatory T cells which maintain immune tolerance. Notably, AhR is expressed and modulates the development of two induced regulatory CD4+ T cell subsets, the forkhead box P3-positive (Foxp3+) regulatory T cells (iTreg) and the IL-10-secreting type 1 regulatory T (T(R)1) cells, through different signalling pathways. We will finally discuss how AhR ligands could be exploited to alleviate human autoimmune diseases. Clearly, drugs targeted against AhR should promote the development of new strategies to fight against autoimmune diseases.

  1. Distinct CD4 T-cell effects on primary versus recall CD8 T-cell responses during viral encephalomyelitis.

    PubMed

    Hwang, Mihyun; Phares, Timothy W; Hinton, David R; Stohlman, Stephen A; Bergmann, Cornelia C; Min, Booki

    2015-03-01

    CD4 T-cell help is not a universal requirement for effective primary CD8 T cells but is essential to generate memory CD8 T cells capable of recall responses. This study examined how CD4 T cells affect primary and secondary anti-viral CD8 T-cell responses within the central nervous system (CNS) during encephalomyelitis induced by sublethal gliatropic coronavirus. CD4 T-cell depletion before infection did not impair peripheral expansion, interferon-γ production, CNS recruitment or initial CNS effector capacity of virus-specific CD8 T cells ex vivo. Nevertheless, impaired virus control in the absence of CD4 T cells was associated with gradually diminished CNS CD8 T-cell interferon-γ production. Furthermore, within the CD8 T-cell population short-lived effector cells were increased and memory precursor effector cells were significantly decreased, consistent with higher T-cell turnover. Transfer of memory CD8 T cells to reduce viral load in CD4-depleted mice reverted the recipient CNS CD8 T-cell phenotype to that in wild-type control mice. However, memory CD8 T cells primed without CD4 T cells and transferred into infected CD4-sufficient recipients expanded less efficiently and were not sustained in the CNS, contrasting with their helped counterparts. These data suggest that CD4 T cells are dispensable for initial expansion, CNS recruitment and differentiation of primary resident memory CD8 T cells as long as the duration of antigen exposure is limited. By contrast, CD4 T cells are essential to prolong primary CD8 T-cell function in the CNS and imprint memory CD8 T cells for recall responses. © 2014 John Wiley & Sons Ltd.

  2. Distinct CD4 T-cell effects on primary versus recall CD8 T-cell responses during viral encephalomyelitis

    PubMed Central

    Hwang, Mihyun; Phares, Timothy W; Hinton, David R; Stohlman, Stephen A; Bergmann, Cornelia C; Min, Booki

    2015-01-01

    CD4 T-cell help is not a universal requirement for effective primary CD8 T cells but is essential to generate memory CD8 T cells capable of recall responses. This study examined how CD4 T cells affect primary and secondary anti-viral CD8 T-cell responses within the central nervous system (CNS) during encephalomyelitis induced by sublethal gliatropic coronavirus. CD4 T-cell depletion before infection did not impair peripheral expansion, interferon-γ production, CNS recruitment or initial CNS effector capacity of virus-specific CD8 T cells ex vivo. Nevertheless, impaired virus control in the absence of CD4 T cells was associated with gradually diminished CNS CD8 T-cell interferon-γ production. Furthermore, within the CD8 T-cell population short-lived effector cells were increased and memory precursor effector cells were significantly decreased, consistent with higher T-cell turnover. Transfer of memory CD8 T cells to reduce viral load in CD4-depleted mice reverted the recipient CNS CD8 T-cell phenotype to that in wild-type control mice. However, memory CD8 T cells primed without CD4 T cells and transferred into infected CD4-sufficient recipients expanded less efficiently and were not sustained in the CNS, contrasting with their helped counterparts. These data suggest that CD4 T cells are dispensable for initial expansion, CNS recruitment and differentiation of primary resident memory CD8 T cells as long as the duration of antigen exposure is limited. By contrast, CD4 T cells are essential to prolong primary CD8 T-cell function in the CNS and imprint memory CD8 T cells for recall responses. PMID:25187405

  3. Viral Load and CD4+ T-Cell Dynamics in Primary HIV-1 Subtype C Infection

    PubMed Central

    Novitsky, Vladimir; Woldegabriel, Elias; Kebaabetswe, Lemme; Rossenkhan, Raabya; Mlotshwa, Busisiwe; Bonney, Caitlin; Finucane, Mariel; Musonda, Rosemary; Moyo, Sikhulile; Wester, Carolyn; van Widenfelt, Erik; Makhema, Joseph; Lagakos, Stephen; Essex, M.

    2009-01-01

    Background Most knowledge of primary HIV-1 infection is based on subtype B studies, whereas the evolution of viral parameters in the early phase of HIV-1 subtype C infection is not well characterized. Methods The kinetics of viral RNA, proviral DNA, CD4+ T-cell count, and subsets of CD4+ T cells expressing CCR5 or CXCR4 were characterized in 8 acute and 62 recent subtype C infections over the first year postseroconversion. Results The viral RNA peak was 6.25 ± 0.92 log10 copies per milliliter. After seroconversion, heterogeneity among acute cases was evident by patterns of change in viral load and CD4+ T-cell count over time. The patterns were supported by the rate of viral RNA decline from peak (P = 0.022), viral RNA means (P = 0.005), CD4 levels (P <0.001), and CD4 decline to 350 (P = 0.011) or 200 (P = 0.046). Proviral DNA had no apparent peak and its mean was 2.59 ± 0.69 log10 per 106 peripheral blood mononuclear cell. In recent infections, viral RNA set point was 4.00 ± 0.97 log10 and viral RNA correlated inversely with CD4+ T cells (P <0.001) and directly with proviral DNA (P <0.001). Conclusions Distinct patterns of viral RNA evolution may exist shortly after seroconversion in HIV-1 subtype C infection. The study provides better understanding of the early phase of subtype C infection. PMID:19295336

  4. Preserved immune functionality and high CMV-specific T-cell responses in HIV-infected individuals with poor CD4(+) T-cell immune recovery.

    PubMed

    Gómez-Mora, Elisabet; García, Elisabet; Urrea, Victor; Massanella, Marta; Puig, Jordi; Negredo, Eugenia; Clotet, Bonaventura; Blanco, Julià; Cabrera, Cecilia

    2017-09-15

    Poor CD4(+) T-cell recovery after cART has been associated with skewed T-cell maturation, inflammation and immunosenescence; however, T-cell functionality in those individuals has not been fully characterized. In the present study, we assessed T-cell function by assessing cytokine production after polyclonal, CMV and HIV stimulations of T-cells from ART-suppressed HIV-infected individuals with CD4(+) T-cell counts >350 cells/μL (immunoconcordants) or <350 cells/μL (immunodiscordants). A group of HIV-uninfected individuals were also included as controls. Since CMV co-infection significantly affected T-cell maturation and polyfunctionality, only CMV(+) individuals were analyzed. Despite their reduced and skewed CD4(+) T-cell compartment, immunodiscordant individuals showed preserved polyclonal and HIV-specific responses. However, CMV response in immunodiscordant participants was significantly different from immunoconcordant or HIV-seronegative individuals. In immunodiscordant subjects, the magnitude of IFN-γ(+) CD8(+) and IL-2(+) CD4(+) T-cells in response to CMV was higher and differently associated with the CD4(+) T-cell maturation profile., showing an increased frequency of naïve, central memory and EMRA CMV-specific CD4(+) T-cells. In conclusion, CD4(+) and CD8(+) T-cell polyfunctionality was not reduced in immunodiscordant individuals, although heightened CMV-specific immune responses, likely related to subclinical CMV reactivations, may be contributing to the skewed T-cell maturation and the higher risk of clinical progression observed in those individuals.

  5. CD4+ regulatory T cells in solid organ transplantation

    PubMed Central

    Issa, Fadi; Wood, Kathryn J.

    2011-01-01

    Purpose of review: Solid organ transplantation is the most effective treatment for end-stage organ failure, but the long-term outcomes remain suboptimal. CD4+ regulatory T cells (Treg) are emerging as a potential therapy to facilitate long-term allograft survival. This review provides a general overview of the biology of CD4+ Treg and then goes on to discuss the most relevant and recent experimental and clinical evidence for their therapeutic use in solid organ transplantation. Recent findings: There have been major advances in our understanding of Treg, including improvements in methods for their isolation and expansion. Experimental models are providing very important data on the in vitro and in vivo behaviour of Treg in transplantation, while recent clinical trials of Treg cellular therapy in graft-versus-host disease are offering a valuable insight into the efficacy of Treg adoptive cellular therapy. Summary: Data in favour of Treg cellular therapy in transplantation are mounting, and we predict that their use in clinical trials is on the horizon. PMID:20881492

  6. Macrophages overexpressing Aire induce CD4+Foxp3+ T cells.

    PubMed

    Sun, Jitong; Fu, Haiying; Wu, Jing; Zhu, Wufei; Li, Yi; Yang, Wei

    2013-01-01

    Aire plays an important role in central immune tolerance by regulating the transcription of thousands of genes. However, the role of Aire in the peripheral immune system is poorly understood. Regulatory T (Treg) cells are considered essential for the maintenance of peripheral tolerance, but the effect of Aire on Treg cells in the peripheral immune system is currently unknown. In this study, we investigated the effects of macrophages overexpressing Aire on CD4+Foxp3+ Treg cells by co-culturing Aire-overexpressing RAW264.7 cells or their supernatant with splenocytes. The results show that macrophages overexpressing Aire enhanced the expression of Foxp3 mRNA and induced different subsets of Treg cells in splenocytes through cell-cell contact or a co-culture supernatants. TGF-β is a key molecule in the increases of CD4+CD45RA+Foxp3hi T cell and activating Treg (aTreg) levels observed following cell‑supernatant co-culturing. Subsets of Treg cells were induced by Aire-overexpressing macrophages, and the manipulation of Treg cells by the targeting of Aire may provide a method for the treatment of inflammatory or autoimmune diseases.

  7. Activation requirements and responses to TLR ligands in human CD4+ T cells: comparison of two T cell isolation techniques.

    PubMed

    Lancioni, Christina L; Thomas, Jeremy J; Rojas, Roxana E

    2009-05-15

    Direct regulation of T cell function by microbial ligands through Toll-like receptors (TLR) is an emerging area of T cell biology. Currently either immunomagnetic cell sorting (IMACS) or fluorescence-activated cell sorting (FACS), are utilized to isolate T-cell subsets for such studies. However, it is unknown to what extent differences in T cell purity between these isolation techniques influence T cell functional assays. We compared the purity, response to mitogen, activation requirements, and response to TLR ligands between human CD4(+) T cells isolated either by IMACS (IMACS-CD4(+)) or by IMACS followed by FACS (IMACS/FACS-CD4(+)). As expected, IMACS-CD4(+) were less pure than IMACS/FACS-CD4(+) (92.5%+/-1.4% versus 99.7%+/-0.2%, respectively). Consequently, IMACS-CD4(+) proliferated and produced cytokines in response to mitogen alone and had lower activation requirements compared to IMACS/FACS-CD4(+). In addition IMACS-CD4(+) but not IMACS/FACS-CD4(+) responses were upregulated by the TLR-4 ligand lipopolysaccharide (LPS). On the other hand, TLR-2 and TLR-5 engagement induced costimulation in both IMACS-CD4(+) and highly purified IMACS-/FACS-CD4(+). Altogether these results indicate that small differences in cell purity can significantly alter T cell responses to TLR ligands. This study stresses the importance of a stringent purification method when investigating the role of microbial ligands in T cell function.

  8. CD4+ T-cell deficiency in HIV patients responding to antiretroviral therapy is associated with increased expression of interferon-stimulated genes in CD4+ T cells.

    PubMed

    Fernandez, Sonia; Tanaskovic, Sara; Helbig, Karla; Rajasuriar, Reena; Kramski, Marit; Murray, John M; Beard, Michael; Purcell, Damian; Lewin, Sharon R; Price, Patricia; French, Martyn A

    2011-12-15

    Most patients with human immunodeficiency virus (HIV) who remain CD4(+) T-cell deficient on antiretroviral therapy (ART) exhibit marked immune activation. As CD4(+) T-cell activation may be mediated by microbial translocation or interferon-alpha (IFN-α), we examined these factors in HIV patients with good or poor CD4(+) T-cell recovery on long-term ART. Messenger RNA levels for 3 interferon-stimulated genes were increased in CD4(+) T cells of patients with poor CD4(+) T-cell recovery, whereas levels in patients with good recovery did not differ from those in healthy controls. Poor CD4(+) T-cell recovery was also associated with CD4(+) T-cell expression of markers of activation, senescence, and apoptosis, and with increased serum levels of the lipopolysaccharide receptor and soluble CD14, but these were not significantly correlated with expression of the interferon-stimulated genes. Therefore, CD4(+) T-cell recovery may be adversely affected by the effects of IFN-α, which may be amenable to therapeutic intervention.

  9. Human CD4+ central and effector memory T cells produce IL-21: effect on cytokine-driven proliferation of CD4+ T cell subsets.

    PubMed

    Onoda, Tadashi; Rahman, Mizanur; Nara, Hidetoshi; Araki, Akemi; Makabe, Koki; Tsumoto, Kouhei; Kumagai, Izumi; Kudo, Toshio; Ishii, Naoto; Tanaka, Nobuyuki; Sugamura, Kazuo; Hayasaka, Kiyoshi; Asao, Hironobu

    2007-10-01

    IL-21 regulates certain functions of T cells, B cells, NK cells and dendritic cells. Although activated CD4(+) T cells produce IL-21, data identifying the specific CD4(+) T cell subsets that produce IL-21 are conflicting. In a previous study, mouse IL-21 message was detected in T(H)2, whereas human IL-21 (hIL-21) message was found in both T(H)1 and follicular helper T cells. To identify the IL-21-secreting cell populations in human, we established a hybridoma cell line producing an anti-hIL-21 mAb. Intracellular hIL-21-staining experiments showed that hIL-21 was mainly expressed in activated CD4(+) central memory T cells and in activated CD4(+) effector memory T cells, but not in activated CD4(+) naive T cells. Moreover, IL-21 was produced upon activation by some IFN-gamma-producing T(H)1-polarized cells and some IL-17-producing T(H)17-polarized cells, but not by IL-4-producing T(H)2-polarized cells. These results suggest that specific CD4(+) T cell populations produce IL-21. In the functional analysis, we found that IL-21 significantly enhanced the cytokine-driven proliferation of CD4(+) helper T cells synergistically with IL-7 and IL-15 without T cell activation stimuli. Taken together, IL-21 produced from CD4(+) memory T cells may have a supportive role in the maintenance of CD4(+) T cell subsets.

  10. Memory CD4+ T cells are suppressed by CD8+ regulatory T cells in vitro and in vivo

    PubMed Central

    Long, Xin; Cheng, Qi; Liang, Huifang; Zhao, Jianping; Wang, Jian; Wang, Wei; Tomlinson, Stephen; Chen, Lin; Atkinson, Carl; Zhang, Bixiang; Chen, Xiaoping; Zhu, Peng

    2017-01-01

    Background: Acute graft rejection mediated by alloreactive memory CD4+ T cells is a major obstacle to transplantation tolerance. It has been reported that CD8+ T regulatory cells (Tregs) have the ability to induce graft tolerance by restraining the function of activated CD4+ T cells, but not including memory T cells. The aim of this study is to elucidate the effect of CD8+ Tregs on alloreactive memory CD4+ T cells. Methods: We detected Qa-1 expression and performed proliferative assay on memory CD4+ T cells. All memory CD4+ T cells were purified from mice receiving skin allografts. We performed inhibitory and cytotoxic assays on CD8+ Tregs, which were isolated from a T cell vaccination mouse model, and IL-2, IL-4, IL-10 and IFN-γ levels were measured in co-culture supernatants by ELISA. To confirm CD8+ Tregs inhibition of memory CD4+ T cells in-vivo, we utilized a murine model of cardiac allograft transplantation. Results: Memory CD4+ T cells mediated acute allograft rejection, and CD8+ Tregs suppressed the proliferation of memory CD4+ T cells. In vitro, memory CD4+ T cells were inhibited and lysed by CD8+ Tregs. There was a positive correlation between IFN-γ levels, and cell lysis rate induced by CD8+ Tregs. In-vivo studies demonstrated CD8+ Tregs prolonged graft survival times, by inhibiting CD4+ memory T cells, through a Qa-1-peptide-TCR pathway. Conclusions: CD8+ Tregs inhibit CD4+ memory T cell-mediated acute murine cardiac allograft rejection, and further prolong graft survival times. These results provide new insights into immune regulation of organ rejection. PMID:28123634

  11. The Transcription Factor Hobit Identifies Human Cytotoxic CD4+ T Cells

    PubMed Central

    Oja, Anna E.; Vieira Braga, Felipe A.; Remmerswaal, Ester B. M.; Kragten, Natasja A. M.; Hertoghs, Kirsten M. L.; Zuo, Jianmin; Moss, Paul A.; van Lier, René A. W.; van Gisbergen, Klaas P. J. M.; Hombrink, Pleun

    2017-01-01

    The T cell lineage is commonly divided into CD4-expressing helper T cells that polarize immune responses through cytokine secretion and CD8-expressing cytotoxic T cells that eliminate infected target cells by virtue of the release of cytotoxic molecules. Recently, a population of CD4+ T cells that conforms to the phenotype of cytotoxic CD8+ T cells has received increased recognition. These cytotoxic CD4+ T cells display constitutive expression of granzyme B and perforin at the protein level and mediate HLA class II-dependent killing of target cells. In humans, this cytotoxic profile is found within the human cytomegalovirus (hCMV)-specific, but not within the influenza- or Epstein–Barr virus-specific CD4+ T cell populations, suggesting that, in particular, hCMV infection induces the formation of cytotoxic CD4+ T cells. We have previously described that the transcription factor Homolog of Blimp-1 in T cells (Hobit) is specifically upregulated in CD45RA+ effector CD8+ T cells that arise after hCMV infection. Here, we describe the expression pattern of Hobit in human CD4+ T cells. We found Hobit expression in cytotoxic CD4+ T cells and accumulation of Hobit+ CD4+ T cells after primary hCMV infection. The Hobit+ CD4+ T cells displayed highly overlapping characteristics with Hobit+ CD8+ T cells, including the expression of cytotoxic molecules, T-bet, and CX3CR1. Interestingly, γδ+ T cells that arise after hCMV infection also upregulate Hobit expression and display a similar effector phenotype as cytotoxic CD4+ and CD8+ T cells. These findings suggest a shared differentiation pathway in CD4+, CD8+, and γδ+ T cells that may involve Hobit-driven acquisition of long-lived cytotoxic effector function. PMID:28392788

  12. Regulation of CD4 T cells and their effects on immunopathological inflammation following viral infection.

    PubMed

    Bhattacharyya, Mitra; Madden, Patrick; Henning, Nathan; Gregory, Shana; Aid, Malika; Martinot, Amanda J; Barouch, Dan H; Penaloza-MacMaster, Pablo

    2017-10-01

    CD4 T cells help immune responses, but knowledge of how memory CD4 T cells are regulated and how they regulate adaptive immune responses and induce immunopathology is limited. Using adoptive transfer of virus-specific CD4 T cells, we show that naive CD4 T cells undergo substantial expansion following infection, but can induce lethal T helper type 1-driven inflammation. In contrast, memory CD4 T cells exhibit a biased proliferation of T follicular helper cell subsets and were able to improve adaptive immune responses in the context of minimal tissue damage. Our analyses revealed that type I interferon regulates the expansion of primary CD4 T cells, but does not seem to play a critical role in regulating the expansion of secondary CD4 T cells. Strikingly, blockade of type I interferon abrogated lethal inflammation by primary CD4 T cells following viral infection, despite that this treatment increased the numbers of primary CD4 T-cell responses. Altogether, these data demonstrate important aspects of how primary and secondary CD4 T cells are regulated in vivo, and how they contribute to immune protection and immunopathology. These findings are important for rational vaccine design and for improving adoptive T-cell therapies against persistent antigens. © 2017 John Wiley & Sons Ltd.

  13. Measuring T cell receptor and T cell gene expression diversity in antigen-responsive human CD4+ T cells.

    PubMed

    Eugster, Anne; Lindner, Annett; Heninger, Anne-Kristin; Wilhelm, Carmen; Dietz, Sevina; Catani, Mara; Ziegler, Anette-G; Bonifacio, Ezio

    2013-12-31

    T cells have diversity in TCR, epitope recognition, and cytokine production, and can be used for immune monitoring. Furthermore, clonal expansion of TCR families in disease may provide opportunities for TCR-directed therapies. We developed methodology for sequencing expressed genes of TCR alpha and beta chains from single cells and applied this to vaccine (tetanus-toxoid)-responsive CD4(+) T cells. TCR alpha and beta chains were both successfully sequenced in 1309 (43%) of 3038 CD4(+) T cells yielding 677 different receptors. TRAV and TRBV gene usage differed between tetanus-toxoid-responsive and non-responsive cells (p=0.004 and 0.0002), and there was extensive TCR diversity in tetanus-toxoid-responsive cells within individuals. Identical TCRs could be recovered in different samples from the same subject: TCRs identified after booster vaccination were frequent in pre-booster memory T cells (31% of pre-booster TCR), and also identified in pre-booster vaccination naïve cells (6.5%). No TCR was shared between subjects, but tetanus toxoid-responsive cells sharing one of their TCR chains were observed within and between subjects. Coupling single-cell gene expression profiling to TCR sequencing revealed examples of distinct cytokine profiles in cells bearing identical TCR. Novel molecular methodology demonstrates extensive diversity of Ag-responsive CD4(+) T cells within and between individuals. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. CD4 cell count and CD4/CD8 ratio increase during rituximab maintenance in granulomatosis with polyangiitis patients

    PubMed Central

    Nossent, Johannes C.

    2016-01-01

    Introduction Rituximab (RTX) is a B cell-depleting agent approved for the treatment of granulomatosis with polyangiitis (GPA). RTX reduces antibody producing precursor plasma cells and inhibits B and T cells interaction. Infections related to T cell immunodeficiency are not infrequent during RTX treatment. Our study investigated CD4 cell count and CD4/CD8 ratio in GPA patients during the first two years of long-term RTX treatment. Methods A single centre cohort study of 35 patients who received median total cumulative dose of cyclophosphamide (CYC) of 15 g and were treated with RTX 2 g followed by retreatment with either 2 g once annually or 1 g biannually. Serum levels of total immunoglobulin (Ig) and lymphocytes subsets were recorded at RTX initiation and at 3, 6, 12, 18 and 24 months. Low CD4 count and inverted CD4/CD8 ratio were defined as CD4 < 0.3 × 109/l and ratio < 1. Results The CD4 cell count and CD4/CD8 ratio decreased slightly following the initial RTX treatment and then increased gradually during maintenance treatment. While the proportion of patients with low CD4 cell count decreased from 43% at baseline to 18% at 24 months, the ratio remained inverted in 40%. Oral daily prednisolone dose at baseline, CYC exposure and the maintenance regimen did not influence the CD4 cell count and ratio. Being older (p = 0.012) and having a higher CRP (p = 0.044) and ESR (p = 0.024) at baseline significantly increased the risk of inverted CD4/CD8 ratio at 24 months. Inverted ratio at baseline associated with lower total Ig levels during the study. Conclusions Overall, the CD4 and CD4/CD8 ratio increased during maintenance RTX therapy in GPA with no discernible impact of other immunosuppressive therapy. However the increase in CD4 was not followed by an increase in the CD4/CD8 ratio, especially in older patients. Inverted CD4/CD8 ratio associated with lower Ig levels, suggesting a more profound B cell depleting effect of RTX with a relative increase in CD8

  15. A quantitative comparison of anti-HIV gene therapy delivered to hematopoietic stem cells versus CD4+ T cells.

    PubMed

    Savkovic, Borislav; Nichols, James; Birkett, Donald; Applegate, Tanya; Ledger, Scott; Symonds, Geoff; Murray, John M

    2014-06-01

    Gene therapy represents an alternative and promising anti-HIV modality to highly active antiretroviral therapy. It involves the introduction of a protective gene into a cell, thereby conferring protection against HIV. While clinical trials to date have delivered gene therapy to CD4+T cells or to CD34+ hematopoietic stem cells (HSC), the relative benefits of each of these two cellular targets have not been conclusively determined. In the present analysis, we investigated the relative merits of delivering a dual construct (CCR5 entry inhibitor + C46 fusion inhibitor) to either CD4+T cells or to CD34+ HSC. Using mathematical modelling, we determined the impact of each scenario in terms of total CD4+T cell counts over a 10 year period, and also in terms of inhibition of CCR5 and CXCR4 tropic virus. Our modelling determined that therapy delivery to CD34+ HSC generally resulted in better outcomes than delivery to CD4+T cells. An early one-off therapy delivery to CD34+ HSC, assuming that 20% of CD34+ HSC in the bone marrow were gene-modified (G+), resulted in total CD4+T cell counts ≥ 180 cells/ µL in peripheral blood after 10 years. If the uninfected G+ CD4+T cells (in addition to exhibiting lower likelihood of becoming productively infected) also exhibited reduced levels of bystander apoptosis (92.5% reduction) over non gene-modified (G-) CD4+T cells, then total CD4+T cell counts of ≥ 350 cells/ µL were observed after 10 years, even if initially only 10% of CD34+ HSC in the bone marrow received the protective gene. Taken together our results indicate that: 1.) therapy delivery to CD34+ HSC will result in better outcomes than delivery to CD4+T cells, and 2.) a greater impact of gene therapy will be observed if G+ CD4+T cells exhibit reduced levels of bystander apoptosis over G- CD4+T cells.

  16. A Quantitative Comparison of Anti-HIV Gene Therapy Delivered to Hematopoietic Stem Cells versus CD4+ T Cells

    PubMed Central

    Savkovic, Borislav; Nichols, James; Birkett, Donald; Applegate, Tanya; Ledger, Scott; Symonds, Geoff; Murray, John M.

    2014-01-01

    Gene therapy represents an alternative and promising anti-HIV modality to highly active antiretroviral therapy. It involves the introduction of a protective gene into a cell, thereby conferring protection against HIV. While clinical trials to date have delivered gene therapy to CD4+T cells or to CD34+ hematopoietic stem cells (HSC), the relative benefits of each of these two cellular targets have not been conclusively determined. In the present analysis, we investigated the relative merits of delivering a dual construct (CCR5 entry inhibitor + C46 fusion inhibitor) to either CD4+T cells or to CD34+ HSC. Using mathematical modelling, we determined the impact of each scenario in terms of total CD4+T cell counts over a 10 year period, and also in terms of inhibition of CCR5 and CXCR4 tropic virus. Our modelling determined that therapy delivery to CD34+ HSC generally resulted in better outcomes than delivery to CD4+T cells. An early one-off therapy delivery to CD34+ HSC, assuming that 20% of CD34+ HSC in the bone marrow were gene-modified (G+), resulted in total CD4+T cell counts ≥180 cells/ µL in peripheral blood after 10 years. If the uninfected G+ CD4+T cells (in addition to exhibiting lower likelihood of becoming productively infected) also exhibited reduced levels of bystander apoptosis (92.5% reduction) over non gene-modified (G-) CD4+T cells, then total CD4+T cell counts of ≥350 cells/ µL were observed after 10 years, even if initially only 10% of CD34+ HSC in the bone marrow received the protective gene. Taken together our results indicate that: 1.) therapy delivery to CD34+ HSC will result in better outcomes than delivery to CD4+T cells, and 2.) a greater impact of gene therapy will be observed if G+ CD4+T cells exhibit reduced levels of bystander apoptosis over G- CD4+T cells. PMID:24945407

  17. Baseline Naive CD4+ T-cell Level Predicting Immune Reconstitution in Treated HIV-infected Late Presenters

    PubMed Central

    Guo, Fu-Ping; Li, Yi-Jia; Qiu, Zhi-Feng; Lv, Wei; Han, Yang; Xie, Jing; Li, Yan-Ling; Song, Xiao-Jing; Du, Shan-Shan; Mehraj, Vikram; Li, Tai-Sheng; Routy, Jean-Pierre

    2016-01-01

    Background: Among HIV-infected patients initiating antiretroviral therapy (ART), early changes in CD4+ T-cell subsets are well described. However, HIV-infected late presenters initiating treatment present with a suboptimal CD4+ T-cell reconstitution and remain at a higher risk for AIDS and non-AIDS events. Therefore, factors associated with CD4+ T-cell reconstitution need to be determined in this population, which will allow designing effective immunotherapeutic strategies. Methods: Thirty-one adult patients with baseline CD4+ T-cell count <350 cells/mm3 exhibiting viral suppression after ART initiation were followed in the HIV/AIDS research center of Peking Union Medical College Hospital in Beijing, China, from October 2002 to September 2013. Changes in T-cell subsets and associated determinants were measured. Results: Median baseline CD4+ T-cell count was 70 cells/mm3. We found a biphasic reconstitution of T-cell subsets and immune activation: a rapid change during the first 6 months followed by a more gradual change over the subsequent 8 years. Baseline CD4+ T-cell count >200 cells/mm3 in comparison to CD4+ T-cell count ≤200 cells/mm3 was associated with more complete immune Reconstitution (77.8% vs. 27.3% respectively; P = 0.017) and normalized CD4/CD8 ratio. We showed that the baseline percentage of naive CD4+ T-cell was a predictive marker for complete immune reconstitution (area under receiver operating characteristic curve 0.907), and 12.4% as cutoff value had a sensitivity of 84.6% and a specificity of 88.2%. Conclusions: Baseline naive CD4+ T-cell percentage may serve as a predictive marker for optimal immune reconstitution during long-term therapy. Such study findings suggest that increasing thymic output should represent an avenue to improve patients who are diagnosed late in the course of infection. PMID:27824000

  18. Persistence of integrated HIV DNA in CXCR3+CCR6+ memory CD4+ T-cells in HIV-infected individuals on antiretroviral therapy

    PubMed Central

    Khoury, Gabriela; Anderson, Jenny L; Fromentin, Rémi; Hartogensis, Wendy; Smith, Miranda Z; Bacchetti, Peter; Hecht, Frederick M; Chomont, Nicolas; Cameron, Paul U; Deeks, Steven G; Lewin, Sharon R

    2016-01-01

    Background HIV latent infection can be established in vitro by treating resting CD4+ T-cells with chemokines (CK) that bind to chemokine receptors (CKR), CCR7, CXCR3 and CCR6, highly expressed on T-cells. Objective To determine if CKR identify CD4+ T-cells enriched for HIV in HIV-infected individuals receiving suppressive antiretroviral therapy (ART). Design A cross-sectional study of CKR expression and HIV persistence in blood from HIV-infected individuals on suppressive ART for >3 years (n=48). A subset of 20 individuals underwent leukapheresis and sorting of specific CD4+ T-cell subsets. Methods We used flow cytometry to quantify CCR5, CCR6, CXCR3 and CXCR5 expression on CD4+ T-cells. HIV persistence was quantified using real time PCR to detect total, integrated HIV DNA, 2-LTR circles and cell-associated HIV RNA in total CD4+ T-cells from blood or sorted T-cell subsets. Associations between CKR and HIV persistence in CD4+ T-cells in blood were determined using regression models and adjusted for current and nadir CD4+ T-cell counts. Results The frequency of cells harbouring integrated HIV DNA was inversely associated with current CD4+ T-cell count and positively associated with CCR5+ CD4+ T-cells, CXCR3+CCR6+ and CXCR3+CCR6- expression on total memory CD4+ T-cells (p<0.001, 0.048, 0.015 and 0.016 respectively). CXCR3+CCR6+ CM CD4+ T-cells contained the highest amount of integrated HIV DNA compared to all T-cell subsets examined (p=0.001). Conclusion CXCR3 and CCR6 co-expression defines a subset of CD4+ T-cells that are preferentially enriched for HIV DNA in HIV-infected individuals on ART. PMID:26807971

  19. Association of CD4+ T cell subpopulations and psychological stress measures in women living with HIV.

    PubMed

    Rehm, Kristina E; Konkle-Parker, Deborah

    2017-01-24

    Psychological stress is a known immunomodulator. In individuals with HIV, depression, the most common manifestation of increased psychological stress, can affect immune function with lower CD4+ T cell counts correlating with higher levels of depression. It is unknown how other forms of psychological stress can impact immune markers in people living with HIV. We conducted a cross-sectional study to determine how CD4+ T cell subpopulations correlated with different forms of psychological stress. We recruited 50 HIV-positive women as part of the Women's Interagency HIV Study. We assessed perceived stress, worry, acute anxiety, trait anxiety, and depression through self-report questionnaires and CD4+ T cell subpopulations using flow cytometry. Our sample was 96% African-American with a mean ± SD age and body mass index of 42 ± 8.8 years and 36.6 ± 11.5 kg/m(2), respectively. The mean ± SD scores on the psychological measures were as follows: Perceived Stress Scale (PSS), 16.5 ± 6.4; Penn State Worry Questionnaire (PSWQ), 47.7 ± 13.8; State-Trait Anxiety Inventory - State (STAIS), 39.1 ± 12.3; State-Trait Anxiety Inventory - Trait (STAIT), 40.2 ± 11.4; Center for Epidemiological Studies Depression Scale (CES-D), 15.6 ± 11.4. The mean + SD values for the immune parameters were as follows: regulatory T cells (Treg), 1.25% ± 0.7; T helper 1 (Th1), 14.9% ± 6.1; T helper 2 (Th2), 3.8% ± 2; Th1/Th2 ratio, 4.6 ± 3; and CD4+ T cell count (cells/mm(3)), 493 ± 251. Treg levels positively correlated with PSS, STAIS, and STAIT. CD4+ T cell count negatively correlated with PSS, PSWQ, STAIS, STAIT, and CES-D. These data suggest that immune function may be impacted by various forms of psychological stress in HIV-positive women. Interventions that target stress reduction may be useful in improving immune parameters and quality of life.

  20. Decreased Numbers of CD4+ Naive and Effector Memory T Cells, and CD8+ Naïve T Cells, are Associated with Trichloroethylene Exposure

    PubMed Central

    Hosgood, H. Dean; Zhang, Luoping; Tang, Xiaojiang; Vermeulen, Roel; Qiu, Chuangyi; Shen, Min; Smith, Martyn T.; Ge, Yichen; Ji, Zhiying; Xiong, Jun; He, Jian; Reiss, Boris; Liu, Songwang; Xie, Yuxuan; Guo, Weihong; Galvan, Noe; Li, Laiyu; Hao, Zhenyue; Rothman, Nathaniel; Huang, Hanlin; Lan, Qing

    2012-01-01

    Trichloroethylene (TCE) is a volatile chlorinated organic compound that is commonly used as a solvent for lipophilic compounds. Although recognized as an animal carcinogen, TCE’s carcinogenic potential in humans is still uncertain. We have carried out a cross-sectional study of 80 workers exposed to TCE and 96 unexposed controls matched on age and sex in Guangdong, China to study TCE’s early biologic effects. We previously reported that the total lymphocyte count and each of the major lymphocyte subsets (i.e., CD4+ T cells, CD8+ T cells, natural killer cells, and B cells) were decreased in TCE-exposed workers compared to controls, suggesting a selective effect on lymphoid progenitors, and/or lymphocyte survival. To explore which T lymphocyte subsets are affected in the same study population, we investigated the effect of TCE exposure on the numbers of CD4+ naïve and memory T cells, CD8+ naïve and memory T cells, and regulatory T cells by FACS analysis. Linear regression of each subset was used to test for differences between exposed workers and controls adjusting for potential confounders. We observed that CD4+ and CD8+ naïve T cell counts were about 8% (p = 0.056) and 17% (p = 0.0002) lower, respectively, among exposed workers. CD4+ effector memory T cell counts were decreased by about 20% among TCE-exposed workers compared to controls (p = 0.001). The selective targeting of TCE on CD8+ naive and possibly CD4+ naive T cells, and CD4+ effector memory T cells, provide further insights into the immunosuppression-related response of human immune cells upon TCE exposure. PMID:22649769

  1. 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.

  2. CD4+ Primary T Cells Expressing HCV-Core Protein Upregulate Foxp3 and IL-10, Suppressing CD4 and CD8 T Cells

    PubMed Central

    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+CD127lowPD-1highTIM-3high 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

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

    PubMed

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

    2011-12-01

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

  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.

  5. 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

  6. 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

  7. [In vitro amplification of CD4(+) CD25(+) regulatory T cells and identification of amplified T cell immunosuppressive function].

    PubMed

    Weng, Wen-Jun; Pan, Li; Fang, Jian-Pei; Xu, Lv-Hong

    2013-10-01

    This study was purposed to compare the effect of 3 different cell components for expanding CD4(+) CD25(+) Treg in vitro, and identify their immunosuppressive function. CD4(+) T cells, CD4(+) CD25(-)T cells and CD4(+) CD25(+)T cells were isolated from mouse splenocytes by MACS and then expanded in vitro. Phenotype of the T cell lines and expression of the FOXP3 was determined by flow cytometry. The inhibitory effect of expanded CD4(+) CD25(+) T cells on CD4(+) CD25(-)T cells was tested by MLR method. The results showed that the Treg cells from all the three groups were expanded significantly after culture for 2 weeks. In the CD4(+) T cells group, the proliferation rate was (77.8 ± 5.32) folds with a percentage of Treg cells increasing from (6.61 ± 1.00)% to (15.33 ± 1.31)%. The proliferation rate in the CD4(+) CD25(-) T cells group was (95.20 ± 7.67) folds, with the percentage of CD4(+) CD25(+) T cells raising from (0.37 ± 0.13)% to (9.84 ± 0.98)%. The proliferation rate in the CD4(+) CD25(+) T cells group was (41.20 ± 6.92) folds, the proportion of Treg cells decreased from (86.75 ± 1.25)% to (85.32 ± 1.62)%, and the expression of Foxp3 decreased from (76.92 ± 1.72)% to (75.33 ± 2.11)% during the culture, there were not significant differences in the cell purity and the expression of Foxp3, compared with pre-amplification. The inhibitory test showed that the expanded CD4(+) CD25(+) T cells could inhibit the proliferation of CD4(+) CD25(-) T cells in vitro in a cell dose-dependent manner. It is concluded that the amplification of CD4(+) CD25(+) Treg cells is successful in vitro, especially in the CD4(+) CD25(+) T cells group, the cell purity and Foxp3 gene is not obviously changes after amplification.

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

    PubMed Central

    Cobb, Dustin A.; Bhadra, Rajarshi

    2016-01-01

    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

  9. Orchestration of CD4 T cell epitope preferences after multi-peptide immunization

    PubMed Central

    Tung, Jacqueline; Sant, Andrea J.

    2013-01-01

    A detailed understanding of the molecular and cellular mechanisms that underlie epitope preferences in T cell priming is important for vaccines designed to elicit a broad T cell response. Protein vaccinations generally elicit CD4 T cell responses that are skewed toward a small fraction of epitopes, a phenomenon known as immunodominance. This characteristic of T cell responses, that limits the diversity of CD4 T cell recognition, is generally attributed to intracellular antigen processing. However, we recently discovered that immunodominance hierarchies persist even after vaccination with synthetic peptides. In this study, we probed the regulatory mechanisms that cause diminished CD4 T cell responses to subdominant peptides after such multi-peptide immunization in mice. We have found that the delivery of subdominant and dominant epitopes on separate dendritic cells rescues expansion of less favored CD4 T cells. Furthermore, through the use of genetic models and inhibitors, we have found that selective losses in CD4 T cell responses are mediated by an IFN-γ-induced pathway, involving indoleamine 2,3-dioxygenase (IDO), and that regulatory T cell (Treg) activities may also regulate preferences in CD4 T cell specificity. We propose that after multi-peptide immunization, the expansion and differentiation of dominant T cells initiate complex regulatory events that determine the final peptide specificity of the elicited CD4 T cell response. PMID:23772029

  10. Quantifying and predicting the effect of exogenous interleukin-7 on CD4+ T cells in HIV-1 infection.

    PubMed

    Thiébaut, Rodolphe; Drylewicz, Julia; Prague, Mélanie; Lacabaratz, Christine; Beq, Stéphanie; Jarne, Ana; Croughs, Thérèse; Sekaly, Rafick-Pierre; Lederman, Michael M; Sereti, Irini; Commenges, Daniel; Lévy, Yves

    2014-05-01

    Exogenous Interleukin-7 (IL-7), in supplement to antiretroviral therapy, leads to a substantial increase of all CD4+ T cell subsets in HIV-1 infected patients. However, the quantitative contribution of the several potential mechanisms of action of IL-7 is unknown. We have performed a mathematical analysis of repeated measurements of total and naive CD4+ T cells and their Ki67 expression from HIV-1 infected patients involved in three phase I/II studies (N = 53 patients). We show that, besides a transient increase of peripheral proliferation, IL-7 exerts additional effects that play a significant role in CD4+ T cell dynamics up to 52 weeks. A decrease of the loss rate of the total CD4+ T cell is the most probable explanation. If this effect could be maintained during repeated administration of IL-7, our simulation study shows that such a strategy may allow maintaining CD4+ T cell counts above 500 cells/µL with 4 cycles or fewer over a period of two years. This in-depth analysis of clinical data revealed the potential for IL-7 to achieve sustained CD4+ T cell restoration with limited IL-7 exposure in HIV-1 infected patients with immune failure despite antiretroviral therapy.

  11. Preferential loss of gut-homing α4β7 CD4+ T cells and their circulating functional subsets in acute HIV-1 infection

    PubMed Central

    Lu, Xiaofan; Li, Zhen; Li, Qunhui; Jiao, Yanmei; Ji, Yunxia; Zhang, Hongwei; Liu, Zhuoming; Li, Wei; Wu, Hao

    2016-01-01

    Preferential infection and depletion of gut-homing α4β7 CD4+ T cells in the blood are observed in chronic HIV/SIV infection. The dynamic change in gut-homing α4β7 CD4+ T cells and their functional subsets during the acute stages of HIV-1 infection are less documented. Therefore, we conducted a cohort study to investigate whether acute HIV-1 infection induced abnormalities in gut-homing α4β7 CD4+ T cells and their functional subsets. We examined the frequency, absolute number, and functionality of gut-homing α4β7 CD4+ T cells in 26 acute HIV-1-infected patients compared with 20 healthy individuals. We found that circulating gut-homing α4β7 CD4+ T cells were preferentially depleted during acute HIV-1 infection and were positively correlated with absolute CD4+ T-cell count in blood. Notably, Th17 and Th1 cell subsets of gut-homing CD4+ T cells were also decreased, which resulted in an imbalance of T helper cells (Th1):regulatory T cells (Treg) and Treg:Th17 ratios. Gut-homing Th17 and Th1 cells were also positively correlated with the absolute number of total CD4+ T cells and gut-homing CD4+ T cells. The gut-homing Treg:Th17 ratio was inversely correlated with the CD4+ T-cell count. Taken together, the analyses of our acute HIV-1 cohort demonstrate that gut-homing α4β7 CD4+ T cells and their functional subsets were profoundly depleted during acute HIV-1 infection, which may have resulted in the persistent loss of circulating CD4+ T cells and an imbalance of Th1:Treg and Treg:Th17 ratios and contribute to HIV-1 disease pathogenesis. PMID:26277899

  12. Viral persistence redirects CD4 T cell differentiation toward T follicular helper cells

    PubMed Central

    Fahey, Laura M.; Wilson, Elizabeth B.; Elsaesser, Heidi; Fistonich, Chris D.; McGavern, Dorian B.

    2011-01-01

    CD4 T cell responses are crucial to prevent and control viral infection; however, virus-specific CD4 T cell activity is considered to be rapidly lost during many persistent viral infections. This is largely caused by the fact that during viral persistence CD4 T cells do not produce the classical Th1 cytokines associated with control of acute viral infections. Considering that CD4 T cell help is critical for both CD8 T cell and B cell functions, it is unclear how CD4 T cells can lose responsiveness but continue to sustain long-term control of persistent viral replication. We now demonstrate that CD4 T cell function is not extinguished as a result of viral persistence. Instead, viral persistence and prolonged T cell receptor stimulation progressively redirects CD4 T cell development away from the Th1 response induced during an acute infection toward T follicular helper cells. Importantly, this sustained CD4 T cell functionality is critical to maintain immunity and ultimately aid in the control of persistent viral infection. PMID:21536743

  13. Polyfunctional and IFN-γ monofunctional human CD4+ T cell populations are molecularly distinct

    PubMed Central

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

    2017-01-01

    Pathogen-specific polyfunctional T cell responses have been associated with favorable clinical outcomes, but it is not known whether molecular differences exist between polyfunctional and monofunctional cytokine-producing T cells. Here, we report that polyfunctional CD4+ T cells induced during Plasmodium falciparum (P. falciparum) blood-stage infection in humans have a unique transcriptomic profile compared with IFN-γ monofunctional CD4+ T cells and, thus, are molecularly distinct. The 14-gene signature revealed in P. falciparum–reactive polyfunctional T cells is associated with cytokine signaling and lymphocyte chemotaxis, and systems biology analysis identified IL-27 as an upstream regulator of the polyfunctional gene signature. Importantly, the polyfunctional gene signature is largely conserved in Influenza-reactive polyfunctional CD4+ T cells, suggesting that polyfunctional T cells have core characteristics independent of pathogen specificity. This study provides the first evidence to our knowledge that consistent molecular differences exist between polyfunctional and monofunctional CD4+ T cells. PMID:28194431

  14. Low Double-Negative CD3(+)CD4(-)CD8(-) T Cells Are Associated with Incomplete Restoration of CD4(+) T Cells and Higher Immune Activation in HIV-1 Immunological Non-Responders.

    PubMed

    Lu, Xiaofan; Su, Bin; Xia, Huan; Zhang, Xin; Liu, Zhiying; Ji, Yunxia; Yang, Zixuan; Dai, Lili; Mayr, Luzia M; Moog, Christiane; Wu, Hao; Huang, Xiaojie; Zhang, Tong

    2016-01-01

    Failure of immune reconstitution increases the risk of AIDS or non-AIDS related morbidity and mortality in HIV-1-infected patients. CD3(+)CD4(-)CD8(-) T cells, which are usually described as double-negative (DN) T cells, display CD4-like helper and immunoregulatory functions. Here, we have measured the percentage of DN T cells in the immune reconstituted vs. non-immune reconstituted HIV-1-infected individuals. We observed that immunological non-responders (INRs) had a low number of DN T cells after long-term antiretroviral therapy (ART), and the number of these cells positively correlated with the CD4(+) T cell count. The ART did not result in complete suppression of immune activation recorded by the percentage of CD38(+)HLA-DR(+)CD8(+) T cells in INRs, and a strong inverse correlation was observed between DN T cells and immune activation. A low proportion of TGF-β1(+)DN T cells was found in INRs. Further mechanism study demonstrated that the level of TGF-β1-producing DN T cells and immune activation had a negative correlation after ART. Taken together, our study suggests that DN T cells control the immunological response in HIV-1-infected patients. These findings expand our understanding of the mechanism of immune reconstitution and could develop specific treatments to return the immune system to homeostasis following initiation of HIV-1 therapy.

  15. Low Double-Negative CD3+CD4−CD8− T Cells Are Associated with Incomplete Restoration of CD4+ T Cells and Higher Immune Activation in HIV-1 Immunological Non-Responders

    PubMed Central

    Lu, Xiaofan; Su, Bin; Xia, Huan; Zhang, Xin; Liu, Zhiying; Ji, Yunxia; Yang, Zixuan; Dai, Lili; Mayr, Luzia M.; Moog, Christiane; Wu, Hao; Huang, Xiaojie; Zhang, Tong

    2016-01-01

    Failure of immune reconstitution increases the risk of AIDS or non-AIDS related morbidity and mortality in HIV-1-infected patients. CD3+CD4−CD8− T cells, which are usually described as double-negative (DN) T cells, display CD4-like helper and immunoregulatory functions. Here, we have measured the percentage of DN T cells in the immune reconstituted vs. non-immune reconstituted HIV-1-infected individuals. We observed that immunological non-responders (INRs) had a low number of DN T cells after long-term antiretroviral therapy (ART), and the number of these cells positively correlated with the CD4+ T cell count. The ART did not result in complete suppression of immune activation recorded by the percentage of CD38+HLA-DR+CD8+ T cells in INRs, and a strong inverse correlation was observed between DN T cells and immune activation. A low proportion of TGF-β1+DN T cells was found in INRs. Further mechanism study demonstrated that the level of TGF-β1-producing DN T cells and immune activation had a negative correlation after ART. Taken together, our study suggests that DN T cells control the immunological response in HIV-1-infected patients. These findings expand our understanding of the mechanism of immune reconstitution and could develop specific treatments to return the immune system to homeostasis following initiation of HIV-1 therapy. PMID:28018346

  16. Small intestine CD11c+ CD8+ T cells suppress CD4+ T cell-induced immune colitis

    PubMed Central

    Fujiwara, Daisuke; Chen, Ling; Wei, Bo

    2011-01-01

    The large (LI) and small intestine (SI) differ in patterns of susceptibility to chronic mucosal inflammation. In this study, we evaluated whether this might, in part, reflect differences in resident mucosal CD11c+ T cells. These cells comprised 39–48% (SI) and 12–17% (LI) of the intraepithelial compartment, most of which were T-cell receptor-αβ+. In the SI, the majority of these cells were CD103+ CD8+ NK1.1−, whereas the opposite phenotype prevailed in the LI. In transfer models of CD4+ T cell-induced colitis, small numbers (2.5 × 105) of SI CD11c+ CD8+ T cells suppressed proinflammatory cytokine-producing CD4+ T cells in mesenteric lymph nodes and mucosa-associated lymphoid compartments (SI and LI) and protected mice from chronic inflammation. On a per-cell basis, the regulatory function of SI CD11c+ T cells in CD4+ T cell colitis was potent compared with other reported regulatory CD4+ or CD8+ T cells. In contrast, neither LI CD11c+ T cells nor SI CD11c− T cells were effective in such immunoregulation. SI CD11c+ CD8+ T cells were similarly effective in suppressing CD4+CD45RBhi T cell colitis, as evidenced by inhibition of intracellular proinflammatory cytokine expression and histological inflammation. These findings indicate that SI CD11c+ CD8+ T cells are a distinct intestinal T cell population that plays an immunoregulatory role in control of proinflammatory CD4+ T cells and maintenance of intestinal mucosal homeostasis. PMID:21436315

  17. Small intestine CD11c+ CD8+ T cells suppress CD4+ T cell-induced immune colitis.

    PubMed

    Fujiwara, Daisuke; Chen, Ling; Wei, Bo; Braun, Jonathan

    2011-06-01

    The large (LI) and small intestine (SI) differ in patterns of susceptibility to chronic mucosal inflammation. In this study, we evaluated whether this might, in part, reflect differences in resident mucosal CD11c(+) T cells. These cells comprised 39-48% (SI) and 12-17% (LI) of the intraepithelial compartment, most of which were T-cell receptor-αβ(+). In the SI, the majority of these cells were CD103(+) CD8(+) NK1.1(-), whereas the opposite phenotype prevailed in the LI. In transfer models of CD4(+) T cell-induced colitis, small numbers (2.5 × 10(5)) of SI CD11c(+) CD8(+) T cells suppressed proinflammatory cytokine-producing CD4(+) T cells in mesenteric lymph nodes and mucosa-associated lymphoid compartments (SI and LI) and protected mice from chronic inflammation. On a per-cell basis, the regulatory function of SI CD11c(+) T cells in CD4(+) T cell colitis was potent compared with other reported regulatory CD4(+) or CD8(+) T cells. In contrast, neither LI CD11c(+) T cells nor SI CD11c(-) T cells were effective in such immunoregulation. SI CD11c(+) CD8(+) T cells were similarly effective in suppressing CD4(+)CD45RB(hi) T cell colitis, as evidenced by inhibition of intracellular proinflammatory cytokine expression and histological inflammation. These findings indicate that SI CD11c(+) CD8(+) T cells are a distinct intestinal T cell population that plays an immunoregulatory role in control of proinflammatory CD4(+) T cells and maintenance of intestinal mucosal homeostasis.

  18. Frequency of beryllium-specific, central memory CD4+ T cells in blood determines proliferative response

    PubMed Central

    Fontenot, Andrew P.; Palmer, Brent E.; Sullivan, Andrew K.; Joslin, Fenneke G.; Wilson, Cara C.; Maier, Lisa A.; Newman, Lee S.; Kotzin, Brian L.

    2005-01-01

    Beryllium exposure can lead to the development of beryllium-specific CD4+ T cells and chronic beryllium disease (CBD), which is characterized by the presence of lung granulomas and a CD4+ T cell alveolitis. Studies have documented the presence of proliferating and cytokine-secreting CD4+ T cells in blood of CBD patients after beryllium stimulation. However, some patients were noted to have cytokine-secreting CD4+ T cells in blood in the absence of beryllium-induced proliferation, and overall, the correlation between the 2 types of responses was poor. We hypothesized that the relative proportion of memory T cell subsets determined antigen-specific proliferation. In most CBD patients, the majority of beryllium-specific CD4+ T cells in blood expressed an effector memory T cell maturation phenotype. However, the ability of blood cells to proliferate in the presence of beryllium strongly correlated with the fraction expressing a central memory T cell phenotype. In addition, we found a direct correlation between the percentage of beryllium-specific CD4+ TEM cells in blood and T cell lymphocytosis in the lung. Together, these findings indicate that the functional capability of antigen-specific CD4+ T cells is determined by the relative proportion of memory T cell subsets, which may reflect internal organ involvement. PMID:16151531

  19. 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. Copyright © 2015, American Association for the Advancement of Science.

  20. 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.

  1. 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

  2. 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

  3. Human CD4−8− T cells are a distinctive immunoregulatory subset

    PubMed Central

    Huang, Mei-Chuan; Patel, Kalpesh; Taub, Dennis D.; Longo, Dan L.; Goetzl, Edward J.

    2010-01-01

    Human CD4−8− T cells are a minor subset quantitatively but potentially important in immunity because they are predominantly distributed at body surfaces, and their number and activities increase in autoimmune diseases and decrease with aging. Distinguishing characteristics of CD4−8− T cells are found to include a unique profile of cytokines, including Serpin E1, which is not generated by other T cells, MIF, and TGF-β. At 2–5% of the total in mixtures with CD4 + CD8 T cells, CD4−8− T cells enhance the generation of IFN-γ and IL-17 by up to 12- and 5-fold, respectively, without contributing either cytokine or affecting cytokine production by NK/NKT cells. CD4−8− T cell-derived MIF is their major enhancer and TGFβ their principal inhibitor of CD4 and CD8 T cell cytokine production. Decreases in CD4−8− T cell effects may diminish protective immunity in aging, whereas increases may augment the severity of autoimmune diseases.—Huang, M.-C., Patel, K., Taub, D. D., Longo, D. L., Goetzl, E. J. Human CD4−8− T cells are a distinctive immunoregulatory subset. PMID:20154266

  4. 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

  5. Circumvention of regulatory CD4(+) T cell activity during cross-priming strongly enhances T cell-mediated immunity.

    PubMed

    Heit, Antje; Gebhardt, Friedemann; Lahl, Katharina; Neuenhahn, Michael; Schmitz, Frank; Anderl, Florian; Wagner, Hermann; Sparwasser, Tim; Busch, Dirk H; Kastenmüller, Kathrin

    2008-06-01

    Immunization with purified antigens is a safe and practical vaccination strategy but is generally unable to induce sustained CD8(+) T cell-mediated protection against intracellular pathogens. Most efforts to improve the CD8(+) T cell immunogenicity of these vaccines have focused on co-administration of adjuvant to support cross-presentation and dendritic cell maturation. In addition, it has been shown that CD4(+) T cell help during the priming phase contributes to the generation of protective CD8(+) memory T cells. In this report we demonstrate that the depletion of CD4(+) T cells paradoxically enhances long-lasting CD8-mediated protective immunity upon protein vaccination. Functional and genetic in vivo inactivation experiments attribute this enhancement primarily to MHC class II-restricted CD4(+) regulatory T cells (Treg), which appear to physiologically suppress the differentiation process towards long-living effector memory T cells. Since, in functional terms, this suppression by Treg largely exceeds the positive effects of conventional CD4(+) T cell help, even the absence of all CD4(+) T cells or lack of MHC class II-mediated interactions on priming dendritic cells result in enhanced CD8(+) T cell immunogenicity. These findings have important implications for the improvement of vaccines against intracellular pathogens or tumors, especially in patients with highly active Treg.

  6. 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

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

    PubMed

    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

    2011-08-15

    Hematopoietic cells constitutively express CD31/PECAM1, a signaling 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 on 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 postinfection compared with wild-type 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, because 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.

  8. CD137 is a Useful Marker for Identifying CD4(+) T Cell Responses to Mycobacterium tuberculosis.

    PubMed

    Yan, Z-H; Zheng, X-F; Yi, L; Wang, J; Wang, X-J; Wei, P-J; Jia, H-Y; Zhou, L-J; Zhao, Y-L; Zhang, H-T

    2017-05-01

    Upregulation of CD137 on recently activated CD8(+) T cells has been used to identify rare viral and tumour antigen-specific T cells from the peripheral blood. We aimed to evaluate the accuracy of CD137 for identifying Mycobacterium tuberculosis (Mtb)-reactive CD4(+) T cells in the peripheral blood of infected individuals by flow cytometry and to investigate the characteristics of these CD137(+) CD4(+) T cells. We initially enrolled 31 active tuberculosis (TB) patients, 31 individuals with latent TB infection (LTBI) and 25 healthy donors. The intracellular CD137 and interferon-γ (IFN-γ) production by CD4(+) T cells was simultaneously detected under unstimulated and CFP10-stimulated (culture filtrate protein 10, a Mtb-specific antigen) conditions. In unstimulated CD4(+) T cells, we found that the CD137 expression in the TB group was significantly higher than that in the LTBI group. Stimulation with CFP10 largely increased the CD4(+) T cell CD137 expression in both the TB and LTBI groups. After CFP10 stimulation, the frequency of CD137(+) CD4(+) T cells was higher than that of IFN-γ(+) CD4(+) T cells in both the TB and LTBI groups. Most of the CFP10-activated IFN-γ-secreting cells were CD137-positive, but only a small fraction of the CD137-positive cells expressed IFN-γ. An additional 20 patients with TB were enrolled to characterize the CD45RO(+) CCR7(+) , CD45RO(+) CCR7(-) and CD45RO(-) subsets in the CD137(+) CD4(+) T cell populations. The Mtb-specific CD137(+) CD4(+) T cells were mainly identified as having an effector memory phenotype. In conclusion, CD137 is a useful marker that can be used for identifying Mtb-reactive CD4(+) T cells by flow cytometry. © 2017 The Foundation for the Scandinavian Journal of Immunology.

  9. A novel differentiation pathway from CD4T cells to CD4T cells for maintaining immune system homeostasis.

    PubMed

    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

    2016-04-14

    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.

  10. ImmunoPET Imaging of Murine CD4(+) T Cells Using Anti-CD4 Cys-Diabody: Effects of Protein Dose on T Cell Function and Imaging.

    PubMed

    Freise, Amanda C; Zettlitz, Kirstin A; Salazar, Felix B; Lu, Xiang; Tavaré, Richard; Wu, Anna M

    2017-08-01

    Molecular imaging of CD4(+) T cells throughout the body has implications for monitoring autoimmune disease and immunotherapy of cancer. Given the key role of these cells in regulating immunity, it is important to develop a biologically inert probe. GK1.5 cys-diabody (cDb), a previously developed anti-mouse CD4 antibody fragment, was tested at different doses to assess its effects on positron emission tomography (PET) imaging and CD4(+) T cell viability, proliferation, CD4 expression, and function. The effect of protein dose on image contrast (lymphoid tissue-to-muscle ratio) was assessed by administering different amounts of (89)Zr-labeled GK1.5 cDb to mice followed by PET imaging and ex vivo biodistribution analysis. To assess impact of GK1.5 cDb on T cell biology, GK1.5 cDb was incubated with T cells in vitro or administered intravenously to C57BL/6 mice at multiple protein doses. CD4 expression and T cell proliferation were analyzed with flow cytometry and cytokines were assayed. For immunoPET imaging, the lowest protein dose of 2 μg of (89)Zr-labeled GK1.5 cDb resulted in significantly higher % injected dose/g in inguinal lymph nodes (ILN) and spleen compared to the 12-μg protein dose. In vivo administration of GK1.5 cDb at the high dose of 40 μg caused a transient decrease in CD4 expression in spleen, blood, lymph nodes, and thymus, which recovered within 3 days postinjection; this effect was reduced, although not abrogated, when 2 μg was administered. Proliferation was inhibited in vivo in ILN but not the spleen by injection of 40 μg GK1.5 cDb. Concentrations of GK1.5 cDb in excess of 25 nM significantly inhibited CD4(+) T cell proliferation and interferon-γ production in vitro. Overall, using low-dose GK1.5 cDb minimized biological effects on CD4(+) T cells. Low-dose GK1.5 cDb yields high-contrast immunoPET images with minimal effects on T cell biology in vitro and in vivo and may be a useful tool for investigating CD4(+) T cells in the context

  11. Molecular control of CD4(+) T cell lineage plasticity and integrity.

    PubMed

    Ellmeier, Wilfried

    2015-10-01

    CD4(+) helper T cells and CD8(+) cytotoxic T cells form the two major subsets of peripheral T lymphocytes. Helper T cells fulfill crucial roles in the activation and coordination of the immune response, while cytotoxic T cells kill virus-infected or tumor cells. Recent data suggest that the lineage identify of helper T cells is not fixed and that CD4(+) T cells under certain physiological conditions can be reprogrammed to express CD8 lineage genes and to develop into intestinal intraepithelial CD4(+) cytotoxic T lymphocytes that lack the expression of the key helper T cell lineage commitment factor ThPOK. Moreover, the analysis of mice with a conditional deletion of the transcription factor ThPOK or the histone deacetylases HDAC1 and HDAC2 indicated that CD8 lineage genes are actively repressed in CD4(+) T cells in order to maintain the lineage integrity of helper T cells. In this review I summarize recent studies that indicate plasticity of CD4(+) T cells towards a CTL program and that demonstrate that ThPOK and HDAC1-HDAC2 are part of a transcriptional regulatory circuit that counteracts the activity of the transcription factor Runx3 to maintain CD4(+) T cell lineage integrity. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Decision making during the conception and career of CD4+ T cells.

    PubMed

    Reiner, Steven L

    2009-02-01

    The mechanisms by which thymocytes commit to becoming CD4+ T cells and how these cells subsequently can adopt various cell fates are becoming important paradigms of developmental programming. Understanding how such CD4+ T-cell diversity accommodates both immune reaction against various challenges and the suppression of undesirable responses is also revealing new therapeutic options.

  13. Chronic exposure to trichloroethylene increases DNA methylation of the Ifng promoter in CD4(+) T cells.

    PubMed

    Gilbert, Kathleen M; Blossom, Sarah J; Erickson, Stephen W; Broadfoot, Brannon; West, Kirk; Bai, Shasha; Li, Jingyun; Cooney, Craig A

    2016-10-17

    CD4(+) T cells in female MRL+/+ mice exposed to solvent and water pollutant trichloroethylene (TCE) skew toward effector/memory CD4(+) T cells, and demonstrate seemingly non-monotonic alterations in IFN-γ production. In the current study we examined the mechanism for this immunotoxicity using effector/memory and naïve CD4(+) T cells isolated every 6 weeks during a 40 week exposure to TCE (0.5mg/ml in drinking water). A time-dependent effect of TCE exposure on both Ifng gene expression and IFN-γ protein production was observed in effector/memory CD4(+) T cells, with an increase after 22 weeks of exposure and a decrease after 40 weeks of exposure. No such effect of TCE was observed in naïve CD4(+) T cells. A cumulative increase in DNA methylation in the CpG sites of the promoter of the Ifng gene was observed in effector/memory, but not naïve, CD4(+) T cells over time. Also unique to the Ifng promoter was an increase in methylation variance in effector/memory compared to naïve CD4(+) T cells. Taken together, the CpG sites of the Ifng promoter in effector/memory CD4(+) T cells were especially sensitive to the effects of TCE exposure, which may help explain the regulatory effect of the chemical on this gene.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  17. 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

  18. Transmission of survival signals through Delta-like 1 on activated CD4+ T cells

    PubMed Central

    Furukawa, Takahiro; Ishifune, Chieko; Tsukumo, Shin-ichi; Hozumi, Katsuto; Maekawa, Yoichi; Matsui, Naoko; Kaji, Ryuji; Yasutomo, Koji

    2016-01-01

    Notch expressed on CD4+ T cells transduces signals that mediate their effector functions and survival. Although Notch signaling is known to be cis-inhibited by Notch ligands expressed on the same cells, the role of Notch ligands on T cells remains unclear. In this report we demonstrate that the CD4+ T cell Notch ligand Dll1 transduces signals required for their survival. Co-transfer of CD4+ T cells from Dll1−/− and control mice into recipient mice followed by immunization revealed a rapid decline of CD4+ T cells from Dll1−/− mice compared with control cells. Dll1−/− mice exhibited lower clinical scores of experimental autoimmune encephalitis than control mice. The expression of Notch target genes in CD4+ T cells from Dll1−/− mice was not affected, suggesting that Dll1 deficiency in T cells does not affect cis Notch signaling. Overexpression of the intracellular domain of Dll1 in Dll1-deficient CD4+ T cells partially rescued impaired survival. Our data demonstrate that Dll1 is an independent regulator of Notch-signaling important for the survival of activated CD4+ T cells, and provide new insight into the physiological roles of Notch ligands as well as a regulatory mechanism important for maintaining adaptive immune responses. PMID:27659682

  19. Production of CD4+ and CD8+ T Cell Hybridomas

    PubMed Central

    Canaday, David H.

    2015-01-01

    T cell hybridomas are very useful tools to investigate antigen presenting cell (APC) function. They were developed based on the fusion technology that led to monoclonal antibody section. Antigen-specific primary T cells are generated and fused to an immortal thymoma line. Unfused thymoma cells are eliminated by engineered metabolic selection. Antigen-specific hybridomas are identified and may be characterized in detail. Primary T cells are preferable for studies of the regulatory mechanisms intrinsic to T cells, but for study of antigen presentation T cell hybridomas have advantages over primary T cell clones, including their relative uniformity, stability over time, and ready availability in large numbers for extensive antigen presentation experiments. PMID:23329495

  20. Perforin-dependent CD4+ T-cell cytotoxicity contributes to control a murine poxvirus infection

    PubMed Central

    Fang, Min; Siciliano, Nicholas A.; Hersperger, Adam R.; Roscoe, Felicia; Hu, Angela; Ma, Xueying; Shamsedeen, Ahamed R.; Eisenlohr, Laurence C.; Sigal, Luis J.

    2012-01-01

    CD4+ T cells are generally regarded as helpers and regulators of the immune response. Although cytolytic CD4+ T cells have been described, whether those generated during the course of a viral infection play a role in virus control remains unknown. Here we show that during acute infection with ectromelia virus, the mouse homolog of the human virus of smallpox, large numbers of CD4+ T cells in the draining lymph node and liver of resistant mice have a cytotoxic phenotype. We also show that these cells kill targets in vivo in a perforin-dependent manner and that mice with specific deficiency of perforin in CD4+ T cells have impaired virus control. Thus, perforin-dependent CD4+ T-cell killing of infected cells is an important mechanism of antiviral defense. PMID:22665800

  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. Modelling CD4 T Cell Recovery in Hepatitis C and HIV Co-infected Children Receiving Antiretroviral Therapy

    PubMed Central

    Thorne, Claire; Malyuta, Ruslan; Volokha, Alla; Callard, Robin E.; Klein, Nigel J.; Lewis, Joanna

    2017-01-01

    Background: The effect of hepatitis C virus (HCV) coinfection on CD4+ T cell recovery in treated HIV-infected children is poorly understood. Objective: To compare CD4+ T cell recovery in HIV/HCV coinfected children with recovery in HIV monoinfected children. Method: We studied 355 HIV monoinfected and 46 HIV/HCV coinfected children receiving antiretroviral therapy (ART) during a median follow-up period of 4.2 years (interquartile range: 2.7–5.3 years). Our dataset came from the Ukraine pediatric HIV Cohort and the HIV/HCV coinfection study within the European Pregnancy and Paediatric HIV Cohort Collaboration. We fitted an asymptotic nonlinear mixed-effects model of CD4+ T cell reconstitution to age-standardized CD4 counts in all 401 children and investigated factors predicting the speed and extent of recovery. Results: We found no significant impact of HCV coinfection on either pre-ART or long-term age-adjusted CD4 counts (z scores). However, the rate of increase in CD4 z score was slower in HIV/HCV coinfected children when compared with their monoinfected counterparts (P < 0.001). Both monoinfected and coinfected children starting ART at younger ages had higher pre-ART (P < 0.001) and long-term (P < 0.001) CD4 z scores than those who started when they were older. Conclusions: HIV/HCV coinfected children receiving ART had slower CD4+ T cell recovery than HIV monoinfected children. HIV/HCV coinfection had no impact on pre-ART or long-term CD4 z scores. Early treatment of HIV/HCV coinfected children with ART should be encouraged. PMID:28403051

  3. Chronic Human Infection with Trypanosoma cruzi Drives CD4+ T Cells to Immune Senescence1

    PubMed Central

    Albareda, María Cecilia; Olivera, Gabriela Carina; Laucella, Susana A.; Alvarez, María Gabriela; Fernandez, Esteban Rodrigo; Lococo, Bruno; Viotti, Rodolfo; Tarleton, Rick L.; Postan, Miriam

    2011-01-01

    Previously we found that the frequency of IFN-γ-producing CD8+ T cells specific for Trypanosoma cruzi inversely correlates with disease severity in chronic human Chagas disease along with low levels of IL-2-secreting CD8+ T cells in all clinical stages. This impairment of the parasite-specific T cell responses was associated with phenotypic features of immune senescence of the CD8+ T cell compartment. These data prompted us to address the question of whether the CD4+ T cell compartment also experiences signs of exhaustion. Thus, we performed a functional and phenotypical characterization of T. cruzi-specific and overall CD4+ T cells in chronically infected subjects with different degrees of cardiac dysfunction. The results show an inverse association between disease severity and the frequency of T. cruzi-specific IFN-γ-producing CD4+ T cells. The high expression of CD27 and CD28 with a relative low expression of CD57 found on CD4+IFN-γ + T cells suggests that the effector T cell pool in chronic T. cruzi infection includes a high proportion of newly recruited T cells, but a low frequency of long-term memory cells. The total CD4+ T cell compartment shows signs of senescence and later stages of differentiation associated with more severe stages of the disease. These findings support the hypothesis that long-term T. cruzi infection in humans might exhaust long-lived memory T cells. PMID:19692645

  4. Defining Features of Protective CD4 T cell responses to Mycobacterium tuberculosis

    PubMed Central

    Sakai, Shunsuke; Mayer-Barber, Katrin D.; Barber, Daniel L.

    2014-01-01

    CD4 T cells are critical for control of Mycobacterium tuberculosis (Mtb) infection and represent the best hope for vaccine-elicited protection. However, little is understood about the properties of Mtb-specific CD4 T cells that mediate control, and the lack of correlates of protection present a significant barrier to the rational development of new vaccination and therapeutic strategies which are sorely needed. Here we discuss the features of protective CD4 T cells including recent evidence for IFN-γ dependent and independent mechanisms of protection, poor protection by terminally differentiated cells and the importance of T cell migratory capacity for the control of Mtb infection. PMID:25000593

  5. 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

  6. Myeloid Dendritic Cells Induce HIV-1 Latency in Non-proliferating CD4+ T Cells

    PubMed Central

    Evans, Vanessa A.; Kumar, Nitasha; Filali, Ali; Procopio, Francesco A.; Yegorov, Oleg; Goulet, Jean-Philippe; Saleh, Suha; Haddad, Elias K.; da Fonseca Pereira, Candida; Ellenberg, Paula C.; Sekaly, Rafick-Pierre; Cameron, Paul U.; Lewin, Sharon R.

    2013-01-01

    Latently infected resting CD4+ T cells are a major barrier to HIV cure. Understanding how latency is established, maintained and reversed is critical to identifying novel strategies to eliminate latently infected cells. We demonstrate here that co-culture of resting CD4+ T cells and syngeneic myeloid dendritic cells (mDC) can dramatically increase the frequency of HIV DNA integration and latent HIV infection in non-proliferating memory, but not naïve, CD4+ T cells. Latency was eliminated when cell-to-cell contact was prevented in the mDC-T cell co-cultures and reduced when clustering was minimised in the mDC-T cell co-cultures. Supernatants from infected mDC-T cell co-cultures did not facilitate the establishment of latency, consistent with cell-cell contact and not a soluble factor being critical for mediating latent infection of resting CD4+ T cells. Gene expression in non-proliferating CD4+ T cells, enriched for latent infection, showed significant changes in the expression of genes involved in cellular activation and interferon regulated pathways, including the down-regulation of genes controlling both NF-κB and cell cycle. We conclude that mDC play a key role in the establishment of HIV latency in resting memory CD4+ T cells, which is predominantly mediated through signalling during DC-T cell contact. PMID:24339779

  7. Myeloid dendritic cells induce HIV-1 latency in non-proliferating CD4+ T cells.

    PubMed

    Evans, Vanessa A; Kumar, Nitasha; Filali, Ali; Procopio, Francesco A; Yegorov, Oleg; Goulet, Jean-Philippe; Saleh, Suha; Haddad, Elias K; da Fonseca Pereira, Candida; Ellenberg, Paula C; Sekaly, Rafick-Pierre; Cameron, Paul U; Lewin, Sharon R

    2013-01-01

    Latently infected resting CD4(+) T cells are a major barrier to HIV cure. Understanding how latency is established, maintained and reversed is critical to identifying novel strategies to eliminate latently infected cells. We demonstrate here that co-culture of resting CD4(+) T cells and syngeneic myeloid dendritic cells (mDC) can dramatically increase the frequency of HIV DNA integration and latent HIV infection in non-proliferating memory, but not naïve, CD4(+) T cells. Latency was eliminated when cell-to-cell contact was prevented in the mDC-T cell co-cultures and reduced when clustering was minimised in the mDC-T cell co-cultures. Supernatants from infected mDC-T cell co-cultures did not facilitate the establishment of latency, consistent with cell-cell contact and not a soluble factor being critical for mediating latent infection of resting CD4(+) T cells. Gene expression in non-proliferating CD4(+) T cells, enriched for latent infection, showed significant changes in the expression of genes involved in cellular activation and interferon regulated pathways, including the down-regulation of genes controlling both NF-κB and cell cycle. We conclude that mDC play a key role in the establishment of HIV latency in resting memory CD4(+) T cells, which is predominantly mediated through signalling during DC-T cell contact.

  8. Implementation of Point-of-Care Diagnostics Leads to Variable Uptake of Syphilis, Anemia and CD4+ T-Cell Count Testing in Rural Maternal and Child Health Clinics

    PubMed Central

    De Schacht, Caroline; Lucas, Carlota; Sitoe, Nádia; Machekano, Rhoderick; Chongo, Patrina; Temmerman, Marleen; Tobaiwa, Ocean; Guay, Laura; Kassaye, Seble; Jani, Ilesh V.

    2015-01-01

    Introduction Anemia, syphilis and HIV are high burden diseases among pregnant women in sub-Saharan Africa. A quasi-experimental study was conducted in four health facilities in Southern Mozambique to evaluate the effect of point-of-care technologies for hemoglobin quantification, syphilis testing and CD4+ T-cell enumeration performed within maternal and child health services on testing and treatment coverage, and assessing acceptability by health workers. Methods Demographic and testing data on women attending first antenatal care services were extracted from existing records, before (2011; n = 865) and after (2012; n = 808) introduction of point-of-care testing. Study outcomes per health facility were compared using z-tests (categorical variables) and Wilcoxon rank-sum test (continuous variables), while inverse variance weights were used to adjust for possible cluster effects in the pooled analysis. A structured acceptability-assessment interview was conducted with health workers before (n = 22) and after (n = 19). Results After implementation of point-of-care testing, there was no significant change in uptake of overall hemoglobin screening (67.9% to 83.0%; p = 0.229), syphilis screening (80.8% to 87.0%; p = 0.282) and CD4+ T-cell testing (84.9% to 83.5%; p = 0.930). Initiation of antiretroviral therapy for treatment eligible women was similar in the weighted analysis before and after, with variability among the sites. Time from HIV diagnosis to treatment initiation decreased (median of 44 days to 17 days; p<0.0001). A generally good acceptability for point-of-care testing was seen among health workers. Conclusions Point-of-care CD4+ T-cell enumeration resulted in a decreased time to initiation of antiretroviral therapy among treatment eligible women, without significant increase in testing coverage. Overall hemoglobin and syphilis screening increased. Despite the perception that point-of-care technologies increase access to health services, the variability in

  9. Role of LAP(+)CD4(+) T cells in the tumor microenvironment of colorectal cancer.

    PubMed

    Zhong, Wu; Jiang, Zhi-Yuan; Zhang, Lei; Huang, Jia-Hao; Wang, Shi-Jun; Liao, Cun; Cai, Bin; Chen, Li-Sheng; Zhang, Sen; Guo, Yun; Cao, Yun-Fei; Gao, Feng

    2017-01-21

    To investigate the abundance and potential functions of LAP(+)CD4(+) T cells in colorectal cancer (CRC). Proportions of LAP(+)CD4(+) T cells were examined in peripheral blood and tumor/paratumor tissues of CRC patients and healthy controls using flow cytometry. Expression of phenotypic markers such as forkhead box (Fox)p3, cytotoxic T-lymphocyte-associated protein (CTLA)-4, chemokine CC receptor (CCR)4 and CCR5 was measured using flow cytometry. LAP(-)CD4(+) and LAP(+)CD4(+) T cells were isolated using a magnetic cell-sorting system and cell purity was analyzed by flow cytometry. Real-time quantitative polymerase chain reaction was used to measure expression of cytokines interleukin (IL)-10 and transforming growth factor (TGF)-β. The proportion of LAP(+)CD4(+) T cells was significantly higher in peripheral blood from patients (9.44% ± 3.18%) than healthy controls (1.49% ± 1.00%, P < 0.001). Among patients, the proportion of LAP(+)CD4(+) T cells was significantly higher in tumor tissues (11.76% ± 3.74%) compared with paratumor tissues (3.87% ± 1.64%, P < 0.001). We also observed positive correlations between the proportion of LAP(+)CD4(+) T cells and TNM stage (P < 0.001), distant metastasis (P < 0.001) and serum level of carcinoembryonic antigen (P < 0.05). Magnetic-activated cell sorting gave an overall enrichment of LAP(+)CD4(+) T cells (95.02% ± 2.87%), which was similar for LAP(-)CD4(+) T cells (94.75% ± 2.76%). In contrast to LAP(-)CD4(+) T cells, LAP(+)CD4(+) T cells showed lower Foxp3 expression but significantly higher levels of CTLA-4, CCR4 and CCR5 (P < 0.01). LAP(+)CD4(+) T cells expressed significantly larger amounts of IL-10 and TGF-β but lower levels of IL-2, IL-4, IL-17 and interferon-γ, compared with LAP(-)CD4(+) T cells. LAP(+)CD4(+) T cells accumulated in the tumor microenvironment of CRC patients and were involved in immune evasion mediated by IL-10 and TGF-β.

  10. Role of LAP+CD4+ T cells in the tumor microenvironment of colorectal cancer

    PubMed Central

    Zhong, Wu; Jiang, Zhi-Yuan; Zhang, Lei; Huang, Jia-Hao; Wang, Shi-Jun; Liao, Cun; Cai, Bin; Chen, Li-Sheng; Zhang, Sen; Guo, Yun; Cao, Yun-Fei; Gao, Feng

    2017-01-01

    AIM To investigate the abundance and potential functions of LAP+CD4+ T cells in colorectal cancer (CRC). METHODS Proportions of LAP+CD4+ T cells were examined in peripheral blood and tumor/paratumor tissues of CRC patients and healthy controls using flow cytometry. Expression of phenotypic markers such as forkhead box (Fox)p3, cytotoxic T-lymphocyte-associated protein (CTLA)-4, chemokine CC receptor (CCR)4 and CCR5 was measured using flow cytometry. LAP-CD4+ and LAP+CD4+ T cells were isolated using a magnetic cell-sorting system and cell purity was analyzed by flow cytometry. Real-time quantitative polymerase chain reaction was used to measure expression of cytokines interleukin (IL)-10 and transforming growth factor (TGF)-β. RESULTS The proportion of LAP+CD4+ T cells was significantly higher in peripheral blood from patients (9.44% ± 3.18%) than healthy controls (1.49% ± 1.00%, P < 0.001). Among patients, the proportion of LAP+CD4+ T cells was significantly higher in tumor tissues (11.76% ± 3.74%) compared with paratumor tissues (3.87% ± 1.64%, P < 0.001). We also observed positive correlations between the proportion of LAP+CD4+ T cells and TNM stage (P < 0.001), distant metastasis (P < 0.001) and serum level of carcinoembryonic antigen (P < 0.05). Magnetic-activated cell sorting gave an overall enrichment of LAP+CD4+ T cells (95.02% ± 2.87%), which was similar for LAP-CD4+ T cells (94.75% ± 2.76%). In contrast to LAP-CD4+ T cells, LAP+CD4+ T cells showed lower Foxp3 expression but significantly higher levels of CTLA-4, CCR4 and CCR5 (P < 0.01). LAP+CD4+ T cells expressed significantly larger amounts of IL-10 and TGF-β but lower levels of IL-2, IL-4, IL-17 and interferon-γ, compared with LAP-CD4+ T cells. CONCLUSION LAP+CD4+ T cells accumulated in the tumor microenvironment of CRC patients and were involved in immune evasion mediated by IL-10 and TGF-β. PMID:28210081

  11. 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

  12. Differentiation of naive CD4+ T cells into CD4+CD25+FOXP3+ regulatory T cells by continuous antigen stimulation.

    PubMed

    Mahic, Milada; Yaqub, Sheraz; Bryn, Tone; Henjum, Karen; Eide, Dag M; Torgersen, Knut M; Aandahl, Einar M; Taskén, Kjetil

    2008-05-01

    Human CD4+CD25+ regulatory T (T(R)) cells express the transcription factor forkhead box p3 (FOXP3) and have potent immunosuppressive properties. While naturally occurring T(R) cells develop in the thymus, adaptive T(R) cells develop in the periphery from naive CD4+ T cells. Adaptive T(R) cells may express cyclooxygenase type 2 (COX-2) and suppress effector T cells by a PGE(2)-dependent mechanism, which is reversible with COX inhibitors. In this study we have characterized the differentiation of naive CD4+ T cells into adaptive T(R) cells in detail during 7 days of continuous antigen stimulation. After 2 days of stimulation of CD4+CD25- T cells, the cells expressed FOXP3 and COX-2 and displayed potent immunosuppressive properties. The suppressive phenotype was present at all observed time-points from Day 2, although suppression was merely present at Day 7. The adaptive T(R) cells expressed cell surface markers consistent with an activated phenotype and secreted high levels of TGF-beta, IL-10, and PGE(2). However, the suppressive phenotype was found exclusively in cells that proliferated upon activation. These data support the notion that activation of naive CD4+ T cells leads to concomitant acquisition of effector and suppressive properties.

  13. Selective Expansion of Memory CD4+ T cells By Mitogenic Human CD28 Generates Inflammatory Cytokines and Regulatory T cells

    PubMed Central

    Singh, Manisha; Basu, Sreemanti; Camell, Christina; Couturier, Jacob; Nudelman, Rodolfo J.; Medina, Miguel A.; Rodgers, John R.; Lewis, Dorothy E.

    2009-01-01

    Co-stimulatory signals are important for development of effector and regulatory T cells. In this case, CD28 signaling is usually considered inert in the absence of signaling through the TCR. By contrast, mitogenic rat CD28 mAbs reportedly expand regulatory T cells without TCR stimulation. We found that a commercially available human CD28 mAb (ANC28) stimulated PBMCs without TCR co-ligation or cross-linking; ANC28 selectively expanded CD4+CD25+FoxP3−(T effector) and CD4+CD25+FoxP3+ (Treg) cells. ANC28 stimulated the CD45RO+ CD4+ (memory) population whereas CD45RA+CD4+ (naïve) cells did not respond. ANC28 also induced inflammatory cytokines. Treg induced by ANC28 retain the Treg phenotype longer than did co-stimulated Treg. Treg induced by ANC28 suppressed CD25− T cells through a contact-dependent mechanism. Purity influenced the response of CD4+CD25+ cells because bead-purified CD4+CD25+ cells (85–90% pure) responded strongly to ANC28, whereas 98% pure FACS-sorted CD4+CD25 bright (T-reg) did not respond. Purified CD4+CD25int cells responded similarly to the bead-purified CD4+CD25+ cells. Thus, pre-activated CD4+ T cells (CD25int) respond to ANC28 rather than Treg (CD25bright). The ability of ANC28 to expand both effectors producing inflammatory cytokines as well as suppressive regulatory T cells might be useful for ex vivo expansion of therapeutic T cells. PMID:18446791

  14. Human CD4- 8- T cells are a distinctive immunoregulatory subset.

    PubMed

    Huang, Mei-Chuan; Patel, Kalpesh; Taub, Dennis D; Longo, Dan L; Goetzl, Edward J

    2010-07-01

    Human CD4(-)8(-) T cells are a minor subset quantitatively but potentially important in immunity because they are predominantly distributed at body surfaces, and their number and activities increase in autoimmune diseases and decrease with aging. Distinguishing characteristics of CD4(-)8(-) T cells are found to include a unique profile of cytokines, including Serpin E1, which is not generated by other T cells, MIF, and TGF-beta. At 2-5% of the total in mixtures with CD4 + CD8 T cells, CD4(-)8(-) T cells enhance the generation of IFN-gamma and IL-17 by up to 12- and 5-fold, respectively, without contributing either cytokine or affecting cytokine production by NK/NKT cells. CD4(-)8(-) T cell-derived MIF is their major enhancer and TGFbeta their principal inhibitor of CD4 and CD8 T cell cytokine production. Decreases in CD4(-)8(-) T cell effects may diminish protective immunity in aging, whereas increases may augment the severity of autoimmune diseases.

  15. Frequency of CD4+CD161+ T Cell and Interleukin-10 Expression in Inflammatory Bowel Diseases

    PubMed Central

    Tsuchiya, Kazuyo; Ikeda, Takuto; Batmunkh, Baatarsuren; Choijookhuu, Narantsog; Ishizaki, Hidenobu; Hotokezaka, Masayuki; Hishikawa, Yoshitaka; Nanashima, Atsushi

    2017-01-01

    Mucosal immune dysregulation associated with T cells plays a critical role in the development of inflammatory bowel diseases (IBD). However, the definite significances of these cells in IBD still remain unclear. Therefore, we investigated the population and expression of CD4+CD161+ T cells in the colonic lamina propria mononuclear cells (LPMCs) in patients with IBD by analyses using flow cytometry and immunohistochemistry. Interleukin-10 (IL-10) mRNA levels in both LPMCs and CD4+ T cells in lamina propria (LP-CD4+ T cells) were measured using a real-time quantitative reverse transcription-polymerase chain reaction. IL-10 production was investigated with immunohistochemistry. The results revealed that the population of CD4+CD161+ T cells was significantly decreased in active ulcerative colitis (UC) compared with inactive UC (P < 0.05). The CD4+CD161+ T cell population was inversely correlated with disease activity in patients with UC (r = −0.6326, P = 0.0055), but there was no significant correlation in those with Crohn’s disease. Over-expression of IL-10 mRNA in both LPMCs and LP-CD4+ T cells were detected in active UC. Immunohistochemistry revealed decreased frequency of CD161+ cells and increased IL-10 positive cells in active UC. The frequency of CD4+CD161+ T cells and IL-10 expression was supposed to be associated with the pathological status of mucosal immunoregulation in IBD. PMID:28386147

  16. In situ depletion of CD4+ T cells in human skin by Zanolimumab.

    PubMed

    Villadsen, L S; Skov, L; Dam, T N; Dagnaes-Hansen, F; Rygaard, J; Schuurman, J; Parren, P W H I; van de Winkel, J G J; Baadsgaard, O

    2007-02-01

    CD4(+) T cells, in activated or malignant form, are involved in a number of diseases including inflammatory skin diseases such as psoriasis, and T cell lymphomas such as the majority of cutaneous T cell lymphomas (CTCL). Targeting CD4 with an antibody that inhibits and/or eliminates disease-driving T cells in situ may therefore be a useful approach in the treatment of inflammatory and malignant skin diseases. Depletion of CD4(+) T cells in intact inflamed human skin tissue by Zanolimumab, a fully human therapeutic monoclonal antibody (IgG1, kappa) against CD4, was studied in a human psoriasis xenograft mouse model. Zanolimumab treatment was shown to induce a significant reduction in the numbers of inflammatory mononuclear cells in upper dermis. This reduction in inflammatory mononuclear cells in situ was primarily due to a significant reduction in the numbers of skin-infiltrating CD4(+), but not CD8(+) CD3(+) T cells. The capacity of Zanolimumab to deplete the CD4(+) T cells in the skin may be of importance in diseases where CD4(+) T cells play a central role. Indeed, in a phase II clinical trial Zanolimumab has shown a dose-dependent clinical response in patients with CTCL and the antibody is currently in a phase III clinical trial for CTCL, a disease for which there is no safe and effective treatment available today.

  17. Upregulation of peripheral CD4+CXCR5+ T cells in osteosarcoma.

    PubMed

    Xiao, Hong; Luo, Gang; Son, Haihang; Zhou, Yue; Zheng, Wenjie

    2014-06-01

    Immune dysregulation plays a key role in the development of osteosarcoma (OS). Peripheral blood CD4+CXCR5+ T cells can induce B-cell activation and produce various cytokines and therefore may play critical roles in tumorigenesis. The purpose of the study was to investigate changes of peripheral CD4+CXCR5+ T cells in OS. Peripheral CD4+CXCR5+ T cells and its subtypes were determined by measuring CD3, CD4, CXCR5, CXCR3, and CCR6 in 38 OS patients and 42 healthy controls using flow cytometry. Data demonstrated that percentage of peripheral CD4+CXCR5+ T cells was significantly increased in OS patients (13.9 %) than in controls (8.6 %, p<0.001). Further analysis identified a profound skewing of peripheral CD4+CXCR5+ T cell subsets toward Th2 and Th17 cells in OS patients. Investigating clinical status of the patients showed that prevalence of peripheral CD4+CXCR5+ T cells was significantly elevated in cases with metastasis (17.4 %) than those without metastasis (12.7 %). Similarly, patients with high tumor grade revealed increased percentage of CD4+CXCR5+ T cells compared to those with low tumor grade (15.3 versus 11.0 %). Interestingly, the upregulation of peripheral CD4+CXCR5+ T cells in patients with metastasis or high tumor grade was contributed by Th1 and Th17 subtypes. This study suggests the involvement of peripheral CD4+CXCR5+ T cells in the pathogenesis and progression of OS and provides novel knowledge for understanding this disease.

  18. Stephanthraniline A suppressed CD4(+) T cell-mediated immunological hepatitis through impairing PKCθ function.

    PubMed

    Chen, Feng-Yang; Zhou, Li-Fei; Li, Xiao-Yu; Zhao, Jia-Wen; Xu, Shi-Fang; Huang, Wen-Hai; Gao, Li-Juan; Hao, Shu-Juan; Ye, Yi-Ping; Sun, Hong-Xiang

    2016-10-15

    Stephanthraniline A (STA), a C21 steroid isolated from Stephanotis mucronata (Blanco) Merr., was previously shown to inhibit T cells activation and proliferation in vitro and in vivo. The purpose of this study was to further evaluate the in vivo immunosuppressive activity of STA and to elucidate its potential mechanisms. The results showed that pretreatment with STA significantly attenuated concanavalin A (Con A)-induced hepatitis and reduced CD4(+) T cells activation and aggregation in hepatic tissue in mice. STA directly suppressed the activation and proliferation of Con A-induced CD4(+) T cells, and inhibited NFAT, NFκB and MAPK signaling cascades in activated CD4(+) T cells in vitro. Moreover, it was proved that STA inhibited T cells activation and proliferation through proximal T cell-receptor (TCR) signaling- and Ca(2+) signaling-independent way. The molecular docking studies predicted that STA could tight bind to PKCθ via five hydrogen. The further findings indicated STA directly inhibited PKCθ kinase activity, and its phosphorylation in activated CD4(+) T cells in vitro. Collectively, the present study indicated that STA could protect against CD4(+) T cell-mediated immunological hepatitis in mice through PKCθ and its downstream NFAT, NFκB and MAPK signaling cascades. These results highlight the potential of STA as an effective leading compound for use in the treatment of CD4(+) T cell-mediated inflammatory and autoimmune diseases.

  19. CCR5 promoter activity correlates with HIV disease progression by regulating CCR5 cell surface expression and CD4 T cell apoptosis.

    PubMed

    Joshi, Anjali; Punke, Erin B; Sedano, Melina; Beauchamp, Bethany; Patel, Rima; Hossenlopp, Cassady; Alozie, Ogechika K; Gupta, Jayanta; Mukherjee, Debabrata; Garg, Himanshu

    2017-03-22

    CCR5 is the major co-receptor for HIV and polymorphisms in the CCR5 gene as well as promoter region that alter cell surface expression have been associated with disease progression. We determined the relationship between CCR5 promoter polymorphisms and CD4 decline and other immunopathological features like immune activation and CD4+ T cell apoptosis in HIV patients. CCR5 promoter haplotype HHC was significantly associated with higher CD4 counts in patients. The relative promoter activity (RPA) of each haplotype was determined in vitro and combined promoter activity based on both alleles (CRPA) was assigned to each patients. Interestingly, CCR5 CRPA correlated inversely with CD4 counts and CD4:CD8 ratio specifically in viremic patients. In normal individuals, the CRPA correlated with the number of CCR5+ CD4+ T cells in the peripheral blood suggesting an effect on CCR5 expression. In a subset of high viremic patients harboring R5 tropic HIV, there was a strong correlation between CCR5 CRPA and both CD4 counts and CD4 T cell apoptosis. Our study demonstrates that, CCR5 promoter polymorphisms correlate with CD4 T cell loss possibly by regulating CD4 T cell apoptosis in HIV patients. Furthermore, assigning CRPAs to each patient is a new method of translating genotype to phenotype.

  20. Old Mice Accumulate Activated Effector CD4 T Cells Refractory to Regulatory T Cell-Induced Immunosuppression

    PubMed Central

    Harpaz, Idan; Bhattacharya, Udayan; Elyahu, Yehezqel; Strominger, Itai; Monsonego, Alon

    2017-01-01

    Chronic low-grade inflammation and reduced lymphocyte potency are implicated in the pathogenesis of major illnesses associated with aging. Whether this immune phenotype results from a loss of cell-mediated regulation or intrinsic dysregulated function of effector T cells (Teffs) requires further research. Here, we report that, as compared with young C57BL6 mice, old mice show an increased frequency of CD4+CD62L− Teffs with a dysregulated activated phenotype and markedly increased effector functions. Analysis of the frequency and suppressive function of CD4+FoxP3+ regulatory T cells (Tregs) indicates an increase in the frequency of FoxP3+ T cells with aging which, however, occurs within the CD4+CD25− T cells. Furthermore, whereas Tregs from young and old mice similarly suppress Teffs from young mice, both have a compromised suppressive capacity of Teffs from old mice, a phenomenon which is partially recovered in the presence of IL-2-producing CD4+CD62L+ non-Teffs. Finally, we observed that Teff subsets from old mice are enriched with IL-17A-producing T cells and exhibit intrinsically dysregulated expression of genes encoding cell-surface molecules and transcription factors, which play a key role in T-cell activation and regulation. We, thus, demonstrate an age-related impairment in the regulation of effector CD4 T cells, which may underlie the higher risk for destructive inflammation associated with aging. PMID:28382033

  1. Old Mice Accumulate Activated Effector CD4 T Cells Refractory to Regulatory T Cell-Induced Immunosuppression.

    PubMed

    Harpaz, Idan; Bhattacharya, Udayan; Elyahu, Yehezqel; Strominger, Itai; Monsonego, Alon

    2017-01-01

    Chronic low-grade inflammation and reduced lymphocyte potency are implicated in the pathogenesis of major illnesses associated with aging. Whether this immune phenotype results from a loss of cell-mediated regulation or intrinsic dysregulated function of effector T cells (Teffs) requires further research. Here, we report that, as compared with young C57BL6 mice, old mice show an increased frequency of CD4+CD62L- Teffs with a dysregulated activated phenotype and markedly increased effector functions. Analysis of the frequency and suppressive function of CD4+FoxP3+ regulatory T cells (Tregs) indicates an increase in the frequency of FoxP3+ T cells with aging which, however, occurs within the CD4+CD25- T cells. Furthermore, whereas Tregs from young and old mice similarly suppress Teffs from young mice, both have a compromised suppressive capacity of Teffs from old mice, a phenomenon which is partially recovered in the presence of IL-2-producing CD4+CD62L+ non-Teffs. Finally, we observed that Teff subsets from old mice are enriched with IL-17A-producing T cells and exhibit intrinsically dysregulated expression of genes encoding cell-surface molecules and transcription factors, which play a key role in T-cell activation and regulation. We, thus, demonstrate an age-related impairment in the regulation of effector CD4 T cells, which may underlie the higher risk for destructive inflammation associated with aging.

  2. Key role for CD4 T cells during mixed antibody mediated rejection of renal allografts

    PubMed Central

    Gaughan, A.; Wang, J.; Pelletier, R.P.; Nadasdy, T.; Brodsky, S.; Roy, S.; Lodder, M.; Bobek, D.; Mofatt-Bruce, S.; Fairchild, R.L.; Henry, M.L.; Hadley, G.A.

    2014-01-01

    We utilized mouse models to elucidate the immunologic mechanisms of functional graft loss during mixed antibody mediated rejection of renal allografts (mixed AMR), in which humoral and cellular responses to the graft occur concomitantly. Although the majority of T cells in the graft at the time of rejection were CD8 T cells with only a minor population of CD4 T cells, depletion of CD4 but not CD8 cells prevented acute graft loss during mixed AMR. CD4 depletion eliminated anti-donor alloantibodies and conferred protection from destruction of renal allografts. ELISPOT revealed that CD4 T effectors responded to donor alloantigens by both the direct and indirect pathways of allorecognition. In transfer studies, CD4 T effectors primed to donor alloantigens were highly effective at promoting acute graft dysfunction, and exhibited the attributes of effector T cells. Laser capture microdissection and confirmatory immunostaining studies revealed that CD4 T cells infiltrating the graft produced effector molecules with graft destructive potential. Bioluminescent imaging confirmed that CD4 T effectors traffic to the graft site in immune replete hosts. These data document that host CD4 T cells can promote acute dysfunction of renal allografts by directly mediating graft injury in addition to facilitating anti-donor alloantibody responses. PMID:24410909

  3. CD4 T-Cell Subsets in Malaria: TH1/TH2 Revisited

    PubMed Central

    Perez-Mazliah, Damian; Langhorne, Jean

    2015-01-01

    CD4+ T-cells have been shown to play a central role in immune control of infection with Plasmodium parasites. At the erythrocytic stage of infection, IFN-γ production by CD4+ T-cells and CD4+ T-cell help for the B-cell response are required for control and elimination of infected red blood cells. CD4+ T-cells are also important for controlling Plasmodium pre-erythrocytic stages through the activation of parasite-specific CD8+ T-cells. However, excessive inflammatory responses triggered by the infection have been shown to drive pathology. Early classical experiments demonstrated a biphasic CD4+ T-cell response against erythrocytic stages in mice, in which T helper (Th)1 and antibody-helper CD4+ T-cells appear sequentially during a primary infection. While IFN-γ-producing Th1 cells do play a role in controlling acute infections, and they contribute to acute erythrocytic-stage pathology, it became apparent that a classical Th2 response producing IL-4 is not a critical feature of the CD4+ T-cell response during the chronic phase of infection. Rather, effective CD4+ T-cell help for B-cells, which can occur in the absence of IL-4, is required to control chronic parasitemia. IL-10, important to counterbalance inflammation and associated with protection from inflammatory-mediated severe malaria in both humans and experimental models, was originally considered be produced by CD4+ Th2 cells during infection. We review the interpretations of CD4+ T-cell responses during Plasmodium infection, proposed under the original Th1/Th2 paradigm, in light of more recent advances, including the identification of multifunctional T-cells such as Th1 cells co-expressing IFN-γ and IL-10, the identification of follicular helper T-cells (Tfh) as the predominant CD4+ T helper subset for B-cells, and the recognition of inherent plasticity in the fates of different CD4+ T-cells. PMID:25628621

  4. CD4(+)CD26(-) lymphocytes are useful to assess blood involvement and define B ratings in cutaneous T cell lymphoma.

    PubMed

    Vonderheid, Eric C; Hou, J Steve

    2018-02-01

    Bernengo et al. reported that >30% CD4(+)CD26(-) lymphocytes detect blood involvement in patients with mycosis fungoides (MF) and Sézary syndrome. In addition, the ISCL/EORTC suggested that this threshold might serve as a criterion for the B2 blood rating for staging. In this manuscript, we report our experience with measurement of CD4(+)CD26(-) and CD4(+)CD7(-) cells, Sézary cell counts, and aberrant T cells with diminished expression of CD2, CD3, or CD5 antigens. CD4(+)CD26(-) ≥30% occurred in 15 of 373 (4.0%) patients with MF, 33 of 47 (70%) patients with erythrodermic cutaneous T cell lymphoma (ECTCL) and 2 of 54 (4%) patients with inflammatory skin diseases. CD4(+)CD26(-) measurements provided a more reliable assessment of neoplastic cell numbers in the blood than Sézary cell or CD4(+)CD7(-) percentages. CD4(+)CD26(-) measurements may be used to define B ratings for staging with B2 defined as CD4(+)CD26(-) ≥ 1000/μL, plus clonality or phenotypically abnormal cells.

  5. Cytotoxic activity of CD4+ T cells against autologous tumor cells.

    PubMed

    Konomi, Y; Sekine, T; Takayama, T; Fuji, M; Tanaka, T

    1995-09-01

    The 51Cr-release assay is mostly applied to detecting the cytotoxic activity of CD8+ T cells, and little is known about the activity of CD4+ T cells. Therefore, the correlation between the cytotoxic activity of CD4+ or CD8+ T cells and the incubation period with autologous tumor cells was analyzed by two methods. The incubation periods were 4 and 20 h (4 h and 20 h assay) for the 51Cr-release assay. Eight pairs of tumor cells and T cells were assayed. T cells were fractionated into CD4+ and CD8+ T cells by using magnetic beads and panning methods, and those cells were activated by culture with recombinant interleukin-2 and immobilized anti-CD3 monoclonal antibody. In 6 out of 8 cases, no cytotoxic activity of CD4+ T cells was detected by the 4 h assay, whereas cytotoxic activity was detected in all cases in the 20 h assay. The cytotoxic activities in 20 h assay of CD4+ T cells were increased 67-fold in comparison with the activities in 4 h assay (range: 5-197). In the case of CD8+ T cells, cytotoxic activities were detected in 6 out of 8 cases in the 4 h assay. The lytic unit ratio of CD4+ and CD8+ T cells was calculated as 1.5 in the 20 h assay (range: 0.2- > 7.2) versus 0.4 in the 4 h assay (range: < 0.1-1.3). Cytotoxic activities in colorimetric assay using Crystal Violet with a 24 h incubation were similar to those in the 20 h 51Cr-release assay in all eight cases. These results indicate that CD4+ T cells have cytotoxic activity as strong as that of CD8+ T cells towards autologous tumor cells.

  6. Development of a device for selective removal of CD4+ T cells.

    PubMed

    Onodera, Hirokazu; Ninomiya, Kasumi; Yoshida, Makoto; Matsuo, Hidenori; Shibuya, Noritoshi

    2003-06-01

    To control antigen (Ag)-specific immune cells is important in the treatment of autoimmune diseases. In particular, controlling the immune response of autoimmune T cells is effective in the treatment of these diseases. The development of a device that can remove CD4+ T cells specifically by extracorporeal circulation is now in progress, with the aim to deplete autoimmune T cells. We developed a removal material made of polypropylene non-woven fabrics with anti human CD4 monoclonal antibody immobilized on the surface. Using a column packed with the removal material, we succeeded in removing CD4+ T cells specifically from peripheral whole blood by direct perfusion. Moreover, CD4+ T cells can be specifically removed even from blood with lower surface antigen density by in vitro activation.

  7. IL-21 induces IL-22 production in CD4+ T cells.

    PubMed

    Yeste, Ada; Mascanfroni, Ivan D; Nadeau, Meghan; Burns, Evan J; Tukpah, Ann-Marcia; Santiago, Andrezza; Wu, Chuan; Patel, Bonny; Kumar, Deepak; Quintana, Francisco J

    2014-05-06

    Interleukin (IL)-22 produced by innate lymphoid cells (ILCs) and CD4+ T cells plays an important role in host defence and mucosal homeostasis, thus it is important to investigate the mechanisms that regulate IL-22 production. We investigated the regulation IL-22 production by CD4+ T cells. Here we show that IL-21 triggers IL-22, but not IL-17 production by CD4+ T cells. STAT3, activated by IL-21, controls the epigenetic status of the il22 promoter and its interaction with the aryl hydrocarbon receptor (AhR). Moreover, IL-21 and AhR signalling in T cells control IL-22 production and the development of dextran sodium sulphate-induced colitis in ILC-deficient mice. Thus, we have identified IL-21 as an inducer of IL-22 production in CD4+ T cells in vitro and in vivo.

  8. Revealing the role of CD4+ T cells in viral immunity

    PubMed Central

    2012-01-01

    Protective immunity to chronic and acute viral infection relies on both the innate and adaptive immune response. Although neutralizing antibody production by B cells and cytotoxic activity of CD8+ T cells are well-accepted components of the adaptive immune response to viruses, identification of the specific role of CD4+ T cells in protection has been more challenging to establish. Delineating the contribution of CD4+ T cells has been complicated by their functional heterogeneity, breadth in antigen specificity, transient appearance in circulation, and sequestration in tissue sites of infection. In this minireview, we discuss recent progress in identifying the multiple roles of CD4+ T cells in orchestrating and mediating the immune responses against viral pathogens. We highlight several recent reports, including one published in this issue, that have employed comprehensive and sophisticated approaches to provide new evidence for CD4+ T cells as direct effectors in antiviral immunity. PMID:22851641

  9. Interleukin-7 is required for CD4+ T cell activation and autoimmune neuroinflammation

    PubMed Central

    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.

    2015-01-01

    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

  10. DJ-1/Park7 Sensitive Na(+) /H(+) Exchanger 1 (NHE1) in CD4(+) T Cells.

    PubMed

    Zhou, Yuetao; Shi, Xiaolong; Chen, Hong; Zhang, Shaqiu; Salker, Madhuri S; Mack, Andreas F; Föller, Michael; Mak, Tak W; Singh, Yogesh; Lang, Florian

    2016-08-10

    DJ-1/Park7 is a redox-sensitive chaperone protein counteracting oxidation and presumably contributing to the control of oxidative stress responses and thus inflammation. DJ-1 gene deletion exacerbates the progression of Parkinson's disease presumably by augmenting oxidative stress. Formation of reactive oxygen species (ROS) is paralleled by activation of the Na(+) /H(+) exchanger 1 (NHE1). ROS formation in CD4(+) T cells plays a decisive role in regulating inflammatory responses. In the present study we explored whether DJ-1 is expressed in CD4(+) T cells and affects ROS production as well as NHE1 in those cells. To this end, DJ-1 and NHE1 transcript and protein levels were quantified by qRT-PCR and Western blotting respectively, intracellular pH (pHi) utilizing bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) fluorescence, NHE activity from realkalinization after an ammonium pulse, and ROS production utilizing 2',7' -dichlorofluorescin diacetate (DCFDA) fluorescence. As a result DJ-1 was expressed in CD4(+) T cells. ROS formation, NHE1 transcript levels, NHE1 protein, and NHE activity were higher in CD4(+) T cells from DJ-1 deficient mice than in CD4(+) T cells from wild type mice. Antioxidant N-acetyl-cysteine (NAC) and protein tyrosine kinase (PTK) inhibitor staurosporine decreased the NHE activity in DJ-1 deficient CD4(+) T cells, and blunted the difference between DJ-1(-/-) and DJ-1(+/+) CD4(+) T cells, an observation pointing to a role of ROS in the up-regulation of NHE1 in DJ-1(-/-) CD4(+) T cells. In conclusion, DJ-1 is a powerful regulator of ROS production as well as NHE1 expression and activity in CD4(+) T cells. This article is protected by copyright. All rights reserved.

  11. 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

  12. Virologic and immunologic effects of adding maraviroc to suppressive ART in subjects with suboptimal CD4+ T-cell recovery

    PubMed Central

    Cillo, Anthony R.; Hilldorfer, Benedict B.; Lalama, Christina M.; McKinnon, John E.; Coombs, Robert W.; Tenorio, Allan R.; Fox, Lawrence; Gandhi, Rajesh T.; Ribaudo, Heather; Currier, Judith S.; Gulick, Roy M.; Wilkin, Timothy J.; Mellors, John W.

    2015-01-01

    Background Combination antiretroviral therapy (ART) suppresses HIV-1 replication, but does not restore CD4+ T-cell counts in all subjects. To investigate the effects of maraviroc on HIV-1 persistence and the relations between virologic and immunologic parameters in subjects with incomplete CD4+ T-cell recovery, we performed a prospective, open-label pilot trial in which maraviroc was added to a suppressive ART regimen for 24 weeks. Design A5256 was a single-arm trial in which subjects on suppressive ART with incomplete CD4+ T-cell recovery added maraviroc for 24 weeks. Methods We quantified low-level, residual viremia in plasma and total HIV-1 DNA and 2-LTR circles in peripheral blood mononuclear cells before and after maraviroc intensification. We also evaluated markers of CD4+ and CD8+ T-cell immune activation (%CD38+HLA-DR+) and apoptosis (%caspase3+/Bcl-2−). Results No effect of maraviroc was found on the probability of detectable plasma viremia (≥1 copy/mL; n=31, exact McNemar p=1.0) or detectable 2-LTR circles (n=28, p=0.25) or on total HIV-1 DNA (n=28, 90% confidence interval: −0.1, +0.3 log10 copies/106 CD4+ T-cells). Pre-maraviroc HIV-1 DNA levels were inversely related to pre-maraviroc %CD38+HLA-DR+ CD4+ T-cells (Spearman=−0.52, p=0.004), and lower pre-maraviroc HIV-1 DNA levels were associated with larger decreases in %CD38+HLA-DR+ CD4+ T-cells during maraviroc intensification (Spearman=0.44, p=0.018). Conclusions In subjects on suppressive ART with incomplete CD4+ T-cell recovery, maraviroc intensification did not affect measures of HIV-1 persistence but did decrease persistent CD4+ T-cell immune activation especially in subjects with low pre-intensification levels of HIV-1 DNA. PMID:26544577

  13. Tracking Virus-Specific CD4+ T Cells during and after Acute Hepatitis C Virus Infection

    PubMed Central

    Pfafferot, Katja; Heeg, Malte H.J.; Gaudieri, Silvana; Grüner, Norbert; Rauch, Andri; Gerlach, J. Tilman; Jung, Maria-Christina; Zachoval, Reinhart; Pape, Gerd R.; Schraut, Winfried; Santantonio, Teresa; Nitschko, Hans; Obermeier, Martin; Phillips, Rodney; Scriba, Thomas J.; Semmo, Nasser; Day, Cheryl; Weber, Jonathan N.; Fidler, Sarah; Thimme, Robert; Haberstroh, Anita; Baumert, Thomas F.; Klenerman, Paul; Diepolder, Helmut M.

    2007-01-01

    Background CD4+ T cell help is critical in maintaining antiviral immune responses and such help has been shown to be sustained in acute resolving hepatitis C. In contrast, in evolving chronic hepatitis C CD4+ T cell helper responses appear to be absent or short-lived, using functional assays. Methodology/Principal Findings Here we used a novel HLA-DR1 tetramer containing a highly targeted CD4+ T cell epitope from the hepatitis C virus non-structural protein 4 to track number and phenotype of hepatitis C virus specific CD4+ T cells in a cohort of seven HLA-DR1 positive patients with acute hepatitis C in comparison to patients with chronic or resolved hepatitis C. We observed peptide-specific T cells in all seven patients with acute hepatitis C regardless of outcome at frequencies up to 0.65% of CD4+ T cells. Among patients who transiently controlled virus replication we observed loss of function, and/or physical deletion of tetramer+ CD4+ T cells before viral recrudescence. In some patients with chronic hepatitis C very low numbers of tetramer+ cells were detectable in peripheral blood, compared to robust responses detected in spontaneous resolvers. Importantly we did not observe escape mutations in this key CD4+ T cell epitope in patients with evolving chronic hepatitis C. Conclusions/Significance During acute hepatitis C a CD4+ T cell response against this epitope is readily induced in most, if not all, HLA-DR1+ patients. This antiviral T cell population becomes functionally impaired or is deleted early in the course of disease in those where viremia persists. PMID:17653276

  14. A transcriptome-based model of central memory CD4 T cell death in HIV infection.

    PubMed

    Olvera-García, Gustavo; Aguilar-García, Tania; Gutiérrez-Jasso, Fany; Imaz-Rosshandler, Iván; Rangel-Escareño, Claudia; Orozco, Lorena; Aguilar-Delfín, Irma; Vázquez-Pérez, Joel A; Zúñiga, Joaquín; Pérez-Patrigeon, Santiago; Espinosa, Enrique

    2016-11-22

    Human central memory CD4 T cells are characterized by their capacity of proliferation and differentiation into effector memory CD4 T cells. Homeostasis of central memory CD4 T cells is considered a key factor sustaining the asymptomatic stage of Human Immunodeficiency Virus type 1 (HIV-1) infection, while progression to acquired immunodeficiency syndrome is imputed to central memory CD4 T cells homeostatic failure. We investigated if central memory CD4 T cells from patients with HIV-1 infection have a gene expression profile impeding proliferation and survival, despite their activated state. Using gene expression microarrays, we analyzed mRNA expression patterns in naive, central memory, and effector memory CD4 T cells from healthy controls, and naive and central memory CD4 T cells from patients with HIV-1 infection. Differentially expressed genes, defined by Log2 Fold Change (FC) ≥ |0.5| and Log (odds) > 0, were used in pathway enrichment analyses. Central memory CD4 T cells from patients and controls showed comparable expression of differentiation-related genes, ruling out an effector-like differentiation of central memory CD4 T cells in HIV infection. However, 210 genes were differentially expressed in central memory CD4 T cells from patients compared with those from controls. Expression of 75 of these genes was validated by semi quantitative RT-PCR, and independently reproduced enrichment results from this gene expression signature. The results of functional enrichment analysis indicated movement to cell cycle phases G1 and S (increased CCNE1, MKI67, IL12RB2, ADAM9, decreased FGF9, etc.), but also arrest in G2/M (increased CHK1, RBBP8, KIF11, etc.). Unexpectedly, the results also suggested decreased apoptosis (increased CSTA, NFKBIA, decreased RNASEL, etc.). Results also suggested increased IL-1β, IFN-γ, TNF, and RANTES (CCR5) activity upstream of the central memory CD4 T cells signature, consistent with the demonstrated milieu in HIV infection. Our

  15. In-Depth Analysis of Citrulline Specific CD4 T-Cells in Rheumatoid Arthritis

    DTIC Science & Technology

    2017-01-01

    AWARD NUMBER: W81XWH-15-1-0004 TITLE: In-Depth Analysis of Citrulline-Specific CD4 T-Cells in Rheumatoid Arthritis PRINCIPAL INVESTIGATOR...2016 4. TITLE AND SUBTITLE In-Depth Analysis of Citrulline-Specific CD4 T Cells in Rheumatoid Arthritis 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH...NOTES 14. ABSTRACT The goal of this project is to test the hypothesis that cit-specific CD4 T cells present in rheumatoid arthritis (RA) patients

  16. In Depth Analysis of Citrulline Specific CD4 T Cells in Rheumatoid Arthritis

    DTIC Science & Technology

    2017-01-01

    AWARD NUMBER: W81XWH-15-1-0003 TITLE: In-Depth Analysis of Citrulline-Specific CD4 T Cells in Rheumatoid Arthritis PRINCIPAL INVESTIGATOR...TITLE AND SUBTITLE In-Depth Analysis of Citrulline-Specific CD4 T Cells in Rheumatoid Arthritis 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-15-1-0003...NOTES 14. ABSTRACT The goal of this project is to test the hypothesis that cit-specific CD4 T cells present in rheumatoid arthritis (RA) patients

  17. Immune activation induces immortalization of HTLV-1 LTR-Tax transgenic CD4+ T cells

    PubMed Central

    Swaims, Alison Y.; Khani, Francesca; Zhang, Yingyu; Roberts, Arthur I.; Devadas, Satish

    2010-01-01

    Infection with the human T-cell leukemia virus-1 (HTLV-1) results in a variety of diseases including adult T-cell leukemia/lymphoma (ATL). Although the pathogenesis of these disorders is poorly understood, it involves complex interactions with the host immune system. Activation of infected T cells may play an important role in disease pathogenesis through induction of the oncogenic HTLV-1 Tax transactivator protein. To test this hypothesis, we employed transgenic mice in which Tax is regulated by the HTLV-1 LTR. T-cell receptor stimulation of LTR-Tax CD4+ T cells induced Tax expression, hyper-proliferation, and immortalization in culture. The transition to cellular immortalization was accompanied by markedly increased expression of the antiapoptotic gene, mcl-1, previously implicated as important in T-cell survival. Immortalized cells exhibited a CD4+CD25+CD3− phenotype commonly observed in ATL. Engraftment of activated LTR-Tax CD4+ T cells into NOD/Shi-scid/IL-2Rγ null mice resulted in a leukemia-like phenotype with expansion and tissue infiltration of Tax+, CD4+ lymphocytes. We suggest that immune activation of infected CD4+ T cells plays an important role in the induction of Tax expression, T-cell proliferation, and pathogenesis of ATL in HTLV-1–infected individuals. PMID:20634377

  18. The Degree of CD4+ T Cell Autoreactivity Determines Cellular Pathways Underlying Inflammatory Arthritis

    PubMed Central

    Perng, Olivia A.; Aitken, Malinda; Rankin, Andrew L.; Garcia, Victoria; Kropf, Elizabeth; Erikson, Jan; Garlick, David S.; Caton, Andrew J.

    2014-01-01

    Although therapies targeting distinct cellular pathways (e.g. anti-cytokine versus anti-B cell therapy) have been found to be an effective strategy for at least some patients with inflammatory arthritis, the mechanisms that determine which pathways promote arthritis development are poorly understood. We have used a transgenic mouse model to examine how variations in the CD4+ T cell response to a surrogate self-peptide can affect the cellular pathways that are required for arthritis development. CD4+ T cells that are highly reactive with the self-peptide induce inflammatory arthritis that affects male and female mice equally. Arthritis develops by a B cell-independent mechanism, although it can be suppressed by an anti-TNF treatment, which prevented the accumulation of effector CD4+ Th17 cells in the joints of treated mice. By contrast, arthritis develops with a significant female bias in the context of a more weakly autoreactive CD4+ T cell response, and B cells play a prominent role in disease pathogenesis. In this setting of lower CD4+ T cell autoreactivity, B cells promote the formation of autoreactive CD4+ effector T cells (including Th17 cells), and IL-17 is required for arthritis development. These studies show that the degree of CD4+ T cell reactivity for a self-peptide can play a prominent role in determining whether distinct cellular pathways can be targeted to prevent the development of inflammatory arthritis. PMID:24591372

  19. EBV Latency II-derived peptides induce a specific CD4+ cytotoxic T-cell activity and not a CD4+ regulatory T-cell response.

    PubMed

    Moralès, Olivier; Depil, Stéphane; Mrizak, Dhafer; Martin, Nathalie; Ndour, Papa Alioune; Dufosse, Françoise; Miroux, Céline; Coll, Jean; de Launoit, Yvan; Auriault, Claude; Pancre, Véronique; Delhem, Nadira

    2012-04-01

    Epstein-Barr virus (EBV) is associated with several malignant diseases that can be distinguished by their patterns of viral latent gene expression. We developed here an original peptidic approach to favor the induction of a specific CD4+ T-cell response against EBV latency II malignancies (Hodgkin's lymphoma, nasopharyngeal carcinoma, T/NK lymphoma). Previously, we selected 6 peptides derived from EBV nuclear antigen-1, latency membrane proteins (LMP)-1, and LMP-2 highly promiscuous for major histocompatibility complex class II molecules and showed their ability to induce interferon-γ-secreting CD4+ T cells. We confirmed here that all peptides used in cocktail are recognized by human CD4+ memory T cells from healthy donors, inducing a broad T-helper (Th)1 cytokine secretion interferon-γ, interleukin-2. Furthermore, we have generated EBV-specific CD4+ T-cell lines and proved their cytotoxic potential, not only on original models expressing latency II antigens (EBV-transformed T cell or monocyte), but also on lymphoblastoid cell lines expressing latency III antigens (lymphoblastoid cell lines). In addition, granzyme B enzyme-linked immunospot assays suggested that a part of this specific cytotoxic activity could be linked to the granule lytic pathway. Very importantly, we have showed that neither phenotypical changes nor functional activities of CD4+CD25+CD127(low)-regulatory T cells were observed in response to EBV+ peptides, avoiding any risk of aggravation of the preexisting immunosuppressive environment reported in EBV-associated malignancies. In conclusion, our promiscuous peptide cocktail could be used safely in immunotherapeutic approaches against EBV latency II malignancies, mainly to prevent relapse in high-risk patients further to classic treatments.

  20. Differential CD4+ cell count increase and CD4+ :CD8+ ratio normalization with maraviroc compared with tenofovir

    PubMed Central

    CHAN, Ellen S.; LANDAY, Alan L.; BROWN, Todd T.; RIBAUDO, Heather J.; MIRMONSEF, Paria; OFOTOKUN, Igho; WEITZMANN, M. Neale; MARTINSON, Jeffrey; KLINGMAN, Karin L.; ERON, Joseph J.; FICHTENBAUM, Carl J.; PLANTS, Jill; TAIWO, Babafemi O.

    2016-01-01

    Objective Studies exploring the immunologic effects of maraviroc (MVC) have produced mixed results; hence it remains unclear whether MVC has unique immunologic effects in comparison to other antiretroviral drugs. We sought to determine whether MVC has differential effects compared to tenofovir disoproxil fumarate (TDF) during initial antiretroviral therapy. Design Prospective study in AIDS Clinical Trials Group A5303, a double-blind, placebo-controlled trial (N=262) of MVC versus TDF, each combined with boosted darunavir and emtricitabine Methods A total of 31 cellular and soluble biomarkers were assayed at weeks 0 and 48. Polychromatic flow cytometry was performed on cryopreserved peripheral blood mononuclear cells (PBMC). Soluble markers were assayed in plasma using ELISA kits. Analyses were as-treated. Results Analyses included 230 participants (119 in MVC arm and 111 in TDF arm). Over 48 weeks of treatment, no significant differences were detected in declines in markers of inflammation and activation with MVC versus TDF. A greater CD4+ T-cell count increase (median +234 cells/μl vs. +188 cells/μl, p=0.036), a smaller CD8+ T-cell count decrease (−6 cells/μl vs. −109 cells/μl, p=0.008) and a smaller CD4+:CD8+ ratio increase (0.26 vs. 0.39, p=0.003) occurred with MVC. Among participants with baseline CD4+:CD8+ ratio<1, smaller proportion of MVC group normalized to ratio >1 at week 48 (15% and 36%, p<0.001). Conclusions MVC resulted in less improvement in CD4+:CD8+ ratio driven by greater increase in CD4+ count but smaller decline in CD8+ count. Changes in soluble or cellular biomarkers of inflammation and immune activation were not different between MVC and TDF. PMID:27281061

  1. Definition of target antigens for naturally occurring CD4(+) CD25(+) regulatory T cells.

    PubMed

    Nishikawa, Hiroyoshi; Kato, Takuma; Tawara, Isao; Saito, Kanako; Ikeda, Hiroaki; Kuribayashi, Kagemasa; Allen, Paul M; Schreiber, Robert D; Sakaguchi, Shimon; Old, Lloyd J; Shiku, Hiroshi

    2005-03-07

    The antigenic targets recognized by naturally occurring CD4(+) CD25(+) regulatory T cells (T reg cells) have been elusive. We have serologically defined a series of broadly expressed self-antigens derived from chemically induced mouse sarcomas by serological identification of antigens by recombinant expression cloning (SEREX). CD4(+) CD25(+) T cells from mice immunized with SEREX-defined self-antigens had strong suppressive activity on peptide-specific proliferation of CD4(+) CD25(-) T cells and CD8(+) T cells. The suppressive effect was observed without in vitro T cell stimulation. Foxp3 expression in these CD4(+) CD25(+) T cells from immunized mice was 5-10 times greater than CD4(+) CD25(+) T cells derived from naive mice. The suppressive effect required cellular contact and was blocked by anti-glucocorticoid-induced tumor necrosis factor receptor family-related gene antibody. In vitro suppressive activity essentially disappeared 8 wk after the last immunization. However, it was regained by in vitro restimulation with cognate self-antigen protein but not with control protein. We propose that SEREX-defined self-antigens such as those used in this study represent self-antigens that elicit naturally occurring CD4(+) CD25(+) T reg cells.

  2. Functional Exhaustion Limits CD4+ and CD8+ T-Cell Responses to Congenital Cytomegalovirus Infection.

    PubMed

    Huygens, Ariane; Lecomte, Sandra; Tackoen, Marie; Olislagers, Véronique; Delmarcelle, Yves; Burny, Wivine; Van Rysselberge, Michel; Liesnard, Corinne; Larsen, Martin; Appay, Victor; Donner, Catherine; Marchant, Arnaud

    2015-08-01

    Cytomegalovirus (CMV) infection during fetal life causes severe symptoms and is associated with prolonged viral excretion. Previous studies reported low CD4(+) T-cell responses to CMV infection in early life, contrasting with large responses of effector CD8(+) T cells. The mechanisms underlying the defective CD4(+) T-cell responses and the possible dissociation with CD8(+) T-cell responses have not been clarified. The magnitude and the quality of the fetal CD8(+) and CD4(+) T-cell responses to CMV infection were compared to those of adults with primary or chronic infection. In utero CMV infection induced oligoclonal expansions of fetal CD4(+) and CD8(+) T lymphocytes expressing a T-helper type 1 or Tc1 effector phenotype similar to that of adult CMV-specific cells. However, the effector cytokine responses and the polyfunctionality of newborn CD4(+) and CD8(+) T cells were markedly lower than those of adult cells. This reduced functionality was associated with a higher expression of the programmed death 1 inhibitory receptor, and blockade of this receptor increased newborn T-cell responses. Functional exhaustion limits effector CD4(+) and CD8(+) T-lymphocyte responses to CMV during fetal life. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  3. 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

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

    PubMed

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

    2006-09-01

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

  5. 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

  6. A colitogenic memory CD4+ T cell population mediates gastrointestinal graft-versus-host disease

    PubMed Central

    Zhou, Vivian; Agle, Kimberle; Chen, Xiao; Beres, Amy; Komorowski, Richard; Belle, Ludovic; Taylor, Carolyn; Zhu, Fenlu; Haribhai, Dipica; Williams, Calvin B.; Verbsky, James; Blumenschein, Wendy; Sadekova, Svetlana; Bowman, Eddie; Ballantyne, Christie; Weaver, Casey; Serody, David A.; Vincent, Benjamin; Serody, Jonathan; Cua, Daniel J.; Drobyski, William R.

    2016-01-01

    Damage to the gastrointestinal tract is a major cause of morbidity and mortality in graft-versus-host disease (GVHD) and is attributable to T cell–mediated inflammation. In this work, we identified a unique CD4+ T cell population that constitutively expresses the β2 integrin CD11c and displays a biased central memory phenotype and memory T cell transcriptional profile, innate-like properties, and increased expression of the gut-homing molecules α4β7 and CCR9. Using several complementary murine GVHD models, we determined that adoptive transfer and early accumulation of β2 integrin–expressing CD4+ T cells in the gastrointestinal tract initiated Th1-mediated proinflammatory cytokine production, augmented pathological damage in the colon, and increased mortality. The pathogenic effect of this CD4+ T cell population critically depended on coexpression of the IL-23 receptor, which was required for maximal inflammatory effects. Non–Foxp3-expressing CD4+ T cells produced IL-10, which regulated colonic inflammation and attenuated lethality in the absence of functional CD4+Foxp3+ T cells. Thus, the coordinate expression of CD11c and the IL-23 receptor defines an IL-10–regulated, colitogenic memory CD4+ T cell subset that is poised to initiate inflammation when there is loss of tolerance and breakdown of mucosal barriers. PMID:27500496

  7. Peripheral CD4(+)CD8(+) T cells are differentiated effector memory cells with antiviral functions.

    PubMed

    Nascimbeni, Michelina; Shin, Eui-Cheol; Chiriboga, Luis; Kleiner, David E; Rehermann, Barbara

    2004-07-15

    Although an increased frequency of CD4(+)CD8(+) T cells has been observed in the peripheral blood during viral infections, their role, function, and biologic significance are still poorly understood. Here we demonstrate that the circulating CD4(+)CD8(+) T-cell population contains mature effector memory lymphocytes specific for antigens of multiple past, latent, and high-level persistent viral infections. Upon in vitro antigenic challenge, a higher frequency of CD4(+)CD8(+) than single-positive cells displayed a T helper 1/T cytotoxic 1 (Th1/Tc1) cytokine profile and proliferated. Ex vivo, more double-positive than single-positive cells exhibited a differentiated phenotype. Accordingly, their lower T-cell receptor excision circles (TREC) content and shorter telomeres proved they had divided more frequently than single-positive cells. Consistent with expression of the tissue-homing marker CXCR3, CD4(+)CD8(+) T cells were demonstrated in situ at the site of persistent viral infection (ie, in the liver during chronic hepatitis C). Finally, a prospective analysis of hepatitis C virus (HCV) infection in a chimpanzee, the only animal model for HCV infection, showed a close correlation between the frequency of activated CD4(+)CD8(+) T cells and viral kinetics. Collectively, these findings demonstrate that peripheral CD4(+)CD8(+) T cells take part in the adaptive immune response against infectious pathogens and broaden the perception of the T-cell populations involved in antiviral immune responses.

  8. T cell Activation does not drive CD4 decline in longitudinally followed HIV-infected Elite Controllers

    PubMed Central

    2011-01-01

    Background Elite controllers (EC) are a rare subset of HIV infected individuals who control viral load below 50 copies/ml of plasma without treatment. Methods Thirty four EC were studied. The slope of CD4 count change was available for 25 of these subjects. We assessed immune activation by measuring the percent of CD38+HLA-DR+CD8+ T cells in the EC group and comparing it with that in 24 treatment-naïve HIV disease progressors and 13 HIV uninfected healthy controls. Results Compared to HIV uninfected subjects, EC had higher percentages of CD38+HLA-DR+CD8+ T cells (p < 0.001) that was lower than that observed in progressors (p < 0.01). Fifteen of 25 EC had a slope of CD4 count change that was not significantly different from 0 while 3 had a positive and 7 a negative CD4 count slope. Immune activation did not distinguish EC subsets with stable/increasing versus declining CD4 counts. Conclusions Elevated immune activation in ECs is not associated with a faster rate of CD4 decline PMID:21679427

  9. Innate-like CD4 T cells selected by thymocytes suppress adaptive immune responses against bacterial infections

    PubMed Central

    Qiao, Yu; Gray, Brian M.; Sofi, Mohammed H.; Bauler, Laura D.; Eaton, Kathryn A.; O'Riordan, Mary X. D.; Chang, Cheong-Hee

    2012-01-01

    We have reported a new innate-like CD4 T cell population that expresses cell surface makers of effector/memory cells and produce Th1 and Th2 cytokines immediately upon activation. Unlike conventional CD4 T cells that are selected by thymic epithelial cells, these CD4 T cells, named T-CD4 T cells, are selected by MHC class II expressing thymocytes. Previously, we showed that the presence of T-CD4 T cells protected mice from airway inflammation suggesting an immune regulatory role of T-CD4 T cells. To further understand the function of T-CD4 T cells, we investigated immune responses mediated by T-CD4 T cells during bacterial infection because the generation of antigen specific CD4 T cells contributes to clearance of infection and for the development of immune memory. The current study shows a suppressive effect of T-CD4 T cells on both CD8 and CD4 T cell-mediated immune responses during Listeria and Helicobacter infections. In the mouse model of Listeria monocytogenes infection, T-CD4 T cells resulted in decreasedfrequency of Listeria-specific CD8 T cells and the killing activity of them. Furthermore, mice with T-CD4 T cells developed poor immune memory, demonstrated by reduced expansion of antigen-specific T cells and high bacterial burden upon re-infection. Similarly, the presence of T-CD4 T cells suppressed the generation of antigen-specific CD4 T cells in Helicobacter pylori infected mice. Thus, our studies reveal a novel function of T-CD4 T cells in suppressing anti-bacterial immunity. PMID:23264931

  10. Liver fibrosis progression and clinical outcomes are intertwined: role of CD4+ T-cell count and NRTI exposure from a large cohort of HIV/HCV-coinfected patients with detectable HCV-RNA

    PubMed Central

    Focà, Emanuele; Fabbiani, Massimiliano; Prosperi, Mattia; Quiros Roldan, Eugenia; Castelli, Francesco; Maggiolo, Franco; Di Filippo, Elisa; Di Giambenedetto, Simona; Gagliardini, Roberta; Saracino, Annalisa; Di Pietro, Massimo; Gori, Andrea; Sighinolfi, Laura; Pan, Angelo; Postorino, Maria Concetta; Torti, Carlo

    2016-01-01

    Abstract Introduction: Patients coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) suffer from faster progression of liver fibrosis (LF) and have greater risk of worse clinical outcomes. We evaluated predictors and incidence of these events in a large multicentre cohort. Methods: We selected all HIV-infected patients starting a first-line combination antiretroviral therapy (cART), with detectable HCV-RNA, without exposure to interferon/ribavirin, with ≥2 fibrosis-4 index (FIB-4) classifications before cART. Kaplan–Meier analysis was used to estimate incidence of clinical events (AIDS, non-AIDS related, deaths) and LF progression (via transitions: from FIB-4 class 1 to 2 or 3, from class 2 to class 3, and worsening by 0.5 point). Multivariate Cox regression was used to assess predictors, baseline, or time updated. Results: One thousand four hundred thirty-three patients were selected. Overall, 745 clinical events occurred, with an incidence of 7.6% over 9811 person-year of follow-up (PYFU) and a median survival time of 9.36 years. Incidence of LF progression from FIB-4 class 1 to 2 or 3 was 12.4%, and from FIB-4 class 2 to 3 was 7% with a median survival time of 5.67 and 10.35 years, respectively. At multivariate analyses, intravenous drug use and time-updated gamma-glutamyl transferase (γGT) were negative predictors for any outcomes, either clinical or FIB-4 progression. Higher CD4+ T-cell protected from clinical events, and lower HIV-RNA and higher CD4+ T-cell appeared to protect from FIB-4 transitions. Moreover, independently from the viro-immunological status, current FIB-4 class 3 predicted clinical events. Occurrence of AIDS and cardiovascular/kidney events were significant predictors of 0.5 point worsening and transitions of FIB-4, respectively. Prolonged exposure to nucleos(t)ide reverse transcriptase inhibitors (NRTI) was a negative predictor for any outcomes. Conclusion: Both clinical and LF progression in HIV

  11. Tissue adaptation of regulatory and intraepithelial CD4+ T cells controls gut inflammation

    PubMed Central

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

    2016-01-01

    Foxp3+ regulatory T cells in peripheral tissues (pTregs) are instrumental in limiting inflammatory responses to non-self antigens. Within the intestine, pTregs are located primarily in the lamina propria, while intraepithelial CD4+ T cells (CD4IELs), 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 Tregs and CD4IELs. Upon migration to the epithelium, Tregs lose Foxp3 and convert to CD4IELs in a microbiota-dependent fashion, an effect attributed to the loss of the transcription factor ThPOK. Finally, we demonstrate that pTregs and CD4IELs perform complementary roles in the regulation of intestinal inflammation. These results reveal intra-tissue specialization of anti-inflammatory T cells shaped by discrete niches of the intestine. PMID:27256884

  12. Studies on the T cell receptor (TCR) revision of autoantibody-inducing CD4 T (aiCD4 T) cell.

    PubMed

    Shiozawa, Shunichi; Uto, Kenichi

    2014-01-01

    Our recent studies into the role of autoantibody-inducing CD4 T cells in autoimmune disease have necessitated studies on the mechanism of TCR revision, a phenomenon that has been difficult to approach experimentally. Here we describe a detailed experimental technique to investigate the molecular events involved in TCR revision.

  13. Abrogation of Rbpj Attenuates Experimental Autoimmune Uveoretinitis by Inhibiting IL-22-Producing CD4+ T Cells

    PubMed Central

    Ishifune, Chieko; Maekawa, Yoichi; Shimada, Mitsuo; Yasutomo, Koji

    2014-01-01

    Experimental autoimmune uveoretinitis (EAU) is an organ-specific T cell-mediated disease induced by immunizing mice with interphotoreceptor retinoid binding protein (IRBP). Autoaggressive CD4+ T cells are the major pathogenic population for EAU. We investigated the contribution of Notch signaling in T cells to EAU pathogenesis because Notch signaling regulates various aspects of CD4+ T cell functions. Rbpj is required for Notch signaling, and Rbpj deficiency in T cells inhibited EAU disease severity. The amelioration of EAU in T cell-specific Rbpj-deficient mice correlated with low levels of IL-22 production from CD4+ T cells, although IRBP-specific CD4+ T cell proliferation and Th17 differentiation were unaffected. Administration of recombinant IL-22 during the late phase, but not the early phase, of EAU increased EAU clinical scores in T cell-specific Rbpj-deficient mice. Notch inhibition in mice immunized with IRBP with a γ-secretase inhibitor (GSI) suppressed EAU progression, even when GSI was administered as late as 13 days after IRBP immunization. Our data demonstrate that Rbpj/Notch-mediated IL-22 production in T cells has a key pathological role in the late phase of EAU, and suggest that Notch blockade might be a useful therapeutic approach for treating EAU. PMID:24586644

  14. 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.

  15. 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

  16. Fighting Viral Infections and Virus-Driven Tumors with Cytotoxic CD4+ T Cells

    PubMed Central

    Muraro, Elena; Merlo, Anna; Martorelli, Debora; Cangemi, Michela; Dalla Santa, Silvia; Dolcetti, Riccardo; Rosato, Antonio

    2017-01-01

    CD4+ T cells have been and are still largely regarded as the orchestrators of immune responses, being able to differentiate into distinct T helper cell populations based on differentiation signals, transcription factor expression, cytokine secretion, and specific functions. Nonetheless, a growing body of evidence indicates that CD4+ T cells can also exert a direct effector activity, which depends on intrinsic cytotoxic properties acquired and carried out along with the evolution of several pathogenic infections. The relevant role of CD4+ T cell lytic features in the control of such infectious conditions also leads to their exploitation as a new immunotherapeutic approach. This review aims at summarizing currently available data about functional and therapeutic relevance of cytotoxic CD4+ T cells in the context of viral infections and virus-driven tumors. PMID:28289418

  17. Target organ localization of memory CD4+ T cells in patients with chronic beryllium disease

    PubMed Central

    Fontenot, Andrew P.; Canavera, Scott J.; Gharavi, Laia; Newman, Lee S.; Kotzin, Brian L.

    2002-01-01

    Chronic beryllium disease (CBD) is caused by exposure to beryllium in the workplace, and it remains an important public health concern. Evidence suggests that CD4+ T cells play a critical role in the development of this disease. Using intracellular cytokine staining, we found that the frequency of beryllium-specific CD4+ T cells in the lungs (bronchoalveolar lavage) of 12 CBD patients ranged from 1.4% to 29% (mean 17.8%), and these T cells expressed a Th1-type phenotype in response to beryllium sulfate (BeSO4). Few, if any, beryllium-specific CD8+ T cells were identified. In contrast, the frequency of beryllium-responsive CD4+ T cells in the blood of these subjects ranged from undetectable to 1 in 500. No correlation was observed between the frequency of beryllium-responsive bronchoalveolar lavage (BAL) CD4+ T cells as detected by intracellular staining and lymphocyte proliferation in culture after BeSO4 exposure. Staining for surface marker expression showed that nearly all BAL T cells exhibit an effector memory cell phenotype. These results demonstrate a dramatically high frequency and compartmentalization of antigen-specific effector memory CD4+ cells in the lungs of CBD patients. These studies provide insight into the phenotypic and functional characteristics of antigen-specific T cells invading other inaccessible target organs in human disease. PMID:12438445

  18. IL-12 is required for anti-OX40-mediated CD4 T cell survival.

    PubMed

    Ruby, Carl E; Montler, Ryan; Zheng, Rongxui; Shu, Suyu; Weinberg, Andrew D

    2008-02-15

    Engagement of OX40 greatly improves CD4 T cell function and survival. Previously, we showed that both OX40 engagement and CTLA-4 blockade led to enhanced CD4 T cell expansion, but only OX40 signaling increased survival. To identify pathways associated with OX40-mediated survival, the gene expression of Ag-activated CD4 T cells isolated from mice treated with anti-OX40 and -CTLA-4 was compared. This comparison revealed a potential role for IL-12 through increased expression of the IL-12R-signaling subunit (IL-12Rbeta2) on T cells activated 3 days previously with Ag and anti-OX40. The temporal expression of IL-12Rbeta2 on OX40-stimulated CD4 T cells was tightly regulated and peaked approximately 4-6 days after initial activation/expansion, but before the beginning of T cell contraction. IL-12 signaling, during this window of IL-12Rbeta2 expression, was required for enhanced T cell survival and survival was associated with STAT4-specific signaling. The findings from these observations were exploited in several different mouse tumor models where we found that the combination of anti-OX40 and IL-12 showed synergistic therapeutic efficacy. These results may lead to the elucidation of the molecular pathways involved with CD4 T cell survival that contribute to improved memory, and understanding of these pathways could lead to greater efficacy of immune stimulatory Abs in tumor-bearing individuals.

  19. CD4 T cell activation by B cells in human Leishmania (Viannia) infection

    PubMed Central

    2014-01-01

    Background An effective adaptive immune response requires activation of specific CD4 T cells. The capacity of B cells to activate CD4 T cells in human cutaneous leishmaniasis caused by Leishmania (Viannia) has not been evaluated. Methods CD4 T cell activation by B cells of cutaneous leishmaniasis patients was evaluated by culture of PBMCs or purified B cells and CD4 T cells with Leishmania panamensis antigens. CD4 T cell and B cell activation markers were evaluated by flow cytometry and 13 cytokines were measured in supernatants with a bead-based capture assay. The effect of Leishmania antigens on BCR-mediated endocytosis of ovalbumin was evaluated in the Ramos human B cell line by targeting the antigen with anti-IgM-biotin and anti-biotin-ovalbumin-FITC. Results Culture of PBMCs from cutaneous leishmaniasis patients with Leishmania antigens resulted in upregulation of the activation markers CD25 and CD69 as well as increased frequency of CD25hiCD127- cells among CD4 T cells. Concomitantly, B cells upregulated the costimulatory molecule CD86. These changes were not observed in PBMCs from healthy subjects, indicating participation of Leishmania-specific lymphocytes expanded in vivo. Purified B cells from these patients, when interacting with purified CD4 T cells and Leishmania antigens, were capable of inducing significant increases in CD25 and CD69 expression and CD25hiCD127- frequency in CD4 T cells. These changes were associated with upregulation of CD86 in B cells. Comparison of changes in CD4 T cell activation parameters between PBMC and B cell/CD4 T cell cultures showed no statistically significant differences; further, significant secretion of IFN-γ, TNF-α, IL-6 and IL-13 was induced in both types of cultures. Additionally, culture with Leishmania antigens enhanced BCR-mediated endocytosis of ovalbumin in Ramos human B cells. Conclusions The capacity of B cells specific for Leishmania antigens in peripheral blood of cutaneous leishmaniasis patients to

  20. The transcriptome of HIV-1 infected intestinal CD4+ T cells exposed to enteric bacteria.

    PubMed

    Yoder, Alyson C; Guo, Kejun; Dillon, Stephanie M; Phang, Tzu; Lee, Eric J; Harper, Michael S; Helm, Karen; Kappes, John C; Ochsenbauer, Christina; McCarter, Martin D; Wilson, Cara C; Santiago, Mario L

    2017-02-01

    Global transcriptome studies can help pinpoint key cellular pathways exploited by viruses to replicate and cause pathogenesis. Previous data showed that laboratory-adapted HIV-1 triggers significant gene expression changes in CD4+ T cell lines and mitogen-activated CD4+ T cells from peripheral blood. However, HIV-1 primarily targets mucosal compartments during acute infection in vivo. Moreover, early HIV-1 infection causes extensive depletion of CD4+ T cells in the gastrointestinal tract that herald persistent inflammation due to the translocation of enteric microbes to the systemic circulation. Here, we profiled the transcriptome of primary intestinal CD4+ T cells infected ex vivo with transmitted/founder (TF) HIV-1. Infections were performed in the presence or absence of Prevotella stercorea, a gut microbe enriched in the mucosa of HIV-1-infected individuals that enhanced both TF HIV-1 replication and CD4+ T cell death ex vivo. In the absence of bacteria, HIV-1 triggered a cellular shutdown response involving the downregulation of HIV-1 reactome genes, while perturbing genes linked to OX40, PPAR and FOXO3 signaling. However, in the presence of bacteria, HIV-1 did not perturb these gene sets or pathways. Instead, HIV-1 enhanced granzyme expression and Th17 cell function, inhibited G1/S cell cycle checkpoint genes and triggered downstream cell death pathways in microbe-exposed gut CD4+ T cells. To gain insights on these differential effects, we profiled the gene expression landscape of HIV-1-uninfected gut CD4+ T cells exposed to bacteria. Microbial exposure upregulated genes involved in cellular proliferation, MAPK activation, Th17 cell differentiation and type I interferon signaling. Our findings reveal that microbial exposure influenced how HIV-1 altered the gut CD4+ T cell transcriptome, with potential consequences for HIV-1 susceptibility, cell survival and inflammation. The HIV-1- and microbe-altered pathways unraveled here may serve as a molecular blueprint

  1. Cytomegalovirus (CMV) Epitope-Specific CD4(+) T Cells Are Inflated in HIV(+) CMV(+) Subjects.

    PubMed

    Abana, Chike O; Pilkinton, Mark A; Gaudieri, Silvana; Chopra, Abha; McDonnell, Wyatt J; Wanjalla, Celestine; Barnett, Louise; Gangula, Rama; Hager, Cindy; Jung, Dae K; Engelhardt, Brian G; Jagasia, Madan H; Klenerman, Paul; Phillips, Elizabeth J; Koelle, David M; Kalams, Spyros A; Mallal, Simon A

    2017-10-02

    Select CMV epitopes drive life-long CD8(+) T cell memory inflation, but the extent of CD4 memory inflation is poorly studied. CD4(+) T cells specific for human CMV (HCMV) are elevated in HIV(+) HCMV(+) subjects. To determine whether HCMV epitope-specific CD4(+) T cell memory inflation occurs during HIV infection, we used HLA-DR7 (DRB1*07:01) tetramers loaded with the glycoprotein B DYSNTHSTRYV (DYS) epitope to characterize circulating CD4(+) T cells in coinfected HLA-DR7(+) long-term nonprogressor HIV subjects with undetectable HCMV plasma viremia. DYS-specific CD4(+) T cells were inflated among these HIV(+) subjects compared with those from an HIV(-) HCMV(+) HLA-DR7(+) cohort or with HLA-DR7-restricted CD4(+) T cells from the HIV-coinfected cohort that were specific for epitopes of HCMV phosphoprotein-65, tetanus toxoid precursor, EBV nuclear Ag 2, or HIV gag protein. Inflated DYS-specific CD4(+) T cells consisted of effector memory or effector memory-RA(+) subsets with restricted TCRβ usage and nearly monoclonal CDR3 containing novel conserved amino acids. Expression of this near-monoclonal TCR in a Jurkat cell-transfection system validated fine DYS specificity. Inflated cells were polyfunctional, not senescent, and displayed high ex vivo levels of granzyme B, CX3CR1, CD38, or HLA-DR but less often coexpressed CD38(+) and HLA-DR(+) The inflation mechanism did not involve apoptosis suppression, increased proliferation, or HIV gag cross-reactivity. Instead, the findings suggest that intermittent or chronic expression of epitopes, such as DYS, drive inflation of activated CD4(+) T cells that home to endothelial cells and have the potential to mediate cytotoxicity and vascular disease. Copyright © 2017 by The American Association of Immunologists, Inc.

  2. A simple theoretical framework for understanding heterogeneous differentiation of CD4+ T cells

    PubMed Central

    2012-01-01

    Background CD4+ T cells have several subsets of functional phenotypes, which play critical yet diverse roles in the immune system. Pathogen-driven differentiation of these subsets of cells is often heterogeneous in terms of the induced phenotypic diversity. In vitro recapitulation of heterogeneous differentiation under homogeneous experimental conditions indicates some highly regulated mechanisms by which multiple phenotypes of CD4+ T cells can be generated from a single population of naïve CD4+ T cells. Therefore, conceptual understanding of induced heterogeneous differentiation will shed light on the mechanisms controlling the response of populations of CD4+ T cells under physiological conditions. Results We present a simple theoretical framework to show how heterogeneous differentiation in a two-master-regulator paradigm can be governed by a signaling network motif common to all subsets of CD4+ T cells. With this motif, a population of naïve CD4+ T cells can integrate the signals from their environment to generate a functionally diverse population with robust commitment of individual cells. Notably, two positive feedback loops in this network motif govern three bistable switches, which in turn, give rise to three types of heterogeneous differentiated states, depending upon particular combinations of input signals. We provide three prototype models illustrating how to use this framework to explain experimental observations and make specific testable predictions. Conclusions The process in which several types of T helper cells are generated simultaneously to mount complex immune responses upon pathogenic challenges can be highly regulated, and a simple signaling network motif can be responsible for generating all possible types of heterogeneous populations with respect to a pair of master regulators controlling CD4+ T cell differentiation. The framework provides a mathematical basis for understanding the decision-making mechanisms of CD4+ T cells, and it can be

  3. The transcriptome of HIV-1 infected intestinal CD4+ T cells exposed to enteric bacteria

    PubMed Central

    Dillon, Stephanie M.; Phang, Tzu; Lee, Eric J.; Helm, Karen; Kappes, John C.; McCarter, Martin D.

    2017-01-01

    Global transcriptome studies can help pinpoint key cellular pathways exploited by viruses to replicate and cause pathogenesis. Previous data showed that laboratory-adapted HIV-1 triggers significant gene expression changes in CD4+ T cell lines and mitogen-activated CD4+ T cells from peripheral blood. However, HIV-1 primarily targets mucosal compartments during acute infection in vivo. Moreover, early HIV-1 infection causes extensive depletion of CD4+ T cells in the gastrointestinal tract that herald persistent inflammation due to the translocation of enteric microbes to the systemic circulation. Here, we profiled the transcriptome of primary intestinal CD4+ T cells infected ex vivo with transmitted/founder (TF) HIV-1. Infections were performed in the presence or absence of Prevotella stercorea, a gut microbe enriched in the mucosa of HIV-1-infected individuals that enhanced both TF HIV-1 replication and CD4+ T cell death ex vivo. In the absence of bacteria, HIV-1 triggered a cellular shutdown response involving the downregulation of HIV-1 reactome genes, while perturbing genes linked to OX40, PPAR and FOXO3 signaling. However, in the presence of bacteria, HIV-1 did not perturb these gene sets or pathways. Instead, HIV-1 enhanced granzyme expression and Th17 cell function, inhibited G1/S cell cycle checkpoint genes and triggered downstream cell death pathways in microbe-exposed gut CD4+ T cells. To gain insights on these differential effects, we profiled the gene expression landscape of HIV-1-uninfected gut CD4+ T cells exposed to bacteria. Microbial exposure upregulated genes involved in cellular proliferation, MAPK activation, Th17 cell differentiation and type I interferon signaling. Our findings reveal that microbial exposure influenced how HIV-1 altered the gut CD4+ T cell transcriptome, with potential consequences for HIV-1 susceptibility, cell survival and inflammation. The HIV-1- and microbe-altered pathways unraveled here may serve as a molecular blueprint

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

    USDA-ARS?s Scientific Manuscript database

    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...

  5. TNFAIP3 promotes survival of CD4 T cells by restricting MTOR and promoting autophagy.

    PubMed

    Matsuzawa, Yu; Oshima, Shigeru; Takahara, Masahiro; Maeyashiki, Chiaki; Nemoto, Yasuhiro; Kobayashi, Masanori; Nibe, Yoichi; Nozaki, Kengo; Nagaishi, Takashi; Okamoto, Ryuichi; Tsuchiya, Kiichiro; Nakamura, Tetsuya; Ma, Averil; Watanabe, Mamoru

    2015-01-01

    Autophagy plays important roles in metabolism, differentiation, and survival in T cells. TNFAIP3/A20 is a ubiquitin-editing enzyme that is thought to be a negative regulator of autophagy in cell lines. However, the role of TNFAIP3 in autophagy remains unclear. To determine whether TNFAIP3 regulates autophagy in CD4 T cells, we first analyzed Tnfaip3-deficient naïve CD4 T cells in vitro. We demonstrated that Tnfaip3-deficient CD4 T cells exhibited reduced MAP1LC3/LC3 (microtubule-associated protein 1 light chain 3) puncta formation, increased mitochondrial content, and exaggerated reactive oxygen species (ROS) production. These results indicate that TNFAIP3 promotes autophagy after T cell receptor (TCR) stimulation in CD4 T cells. We then investigated the mechanism by which TNFAIP3 promotes autophagy signaling. We found that TNFAIP3 bound to the MTOR (mechanistic target of rapamycin) complex and that Tnfaip3-deficient cells displayed enhanced ubiquitination of the MTOR complex and MTOR activity. To confirm the effects of enhanced MTOR activity in Tnfaip3-deficient cells, we analyzed cell survival following treatment with Torin1, an MTOR inhibitor. Tnfaip3-deficient CD4 T cells exhibited fewer cell numbers than the control cells in vitro and in vivo. In addition, the impaired survival of Tnfaip3-deficient cells was ameliorated with Torin1 treatment in vitro and in vivo. The effect of Torin1 was abolished by Atg5 deficiency. Thus, enhanced MTOR activity regulates the survival of Tnfaip3-deficient CD4 T cells. Taken together, our findings illustrate that TNFAIP3 restricts MTOR signaling and promotes autophagy, providing new insight into the manner in which MTOR and autophagy regulate survival in CD4 T cells.

  6. 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

  7. 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. © The Author(s) 2015.

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

    PubMed

    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

    2013-07-01

    CD4T 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 CD4T 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 CD4T 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 CD4T 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.

  9. 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

  10. IL-15 amplifies the pathogenic properties of CD4+CD28- T cells in multiple sclerosis.

    PubMed

    Broux, Bieke; Mizee, Mark R; Vanheusden, Marjan; van der Pol, Susanne; van Horssen, Jack; Van Wijmeersch, Bart; Somers, Veerle; de Vries, Helga E; Stinissen, Piet; Hellings, Niels

    2015-03-01

    CD4(+)CD28(-) T cells arise through repeated antigenic stimulation and are present in diseased tissues of patients with various autoimmune disorders, including multiple sclerosis (MS). These cells are believed to have cytotoxic properties that contribute to the pathogenic damaging of the target organ. Endogenous cues that are increased in the diseased tissue may amplify the activity of CD4(+)CD28(-) T cells. In this study, we focused on IL-15, a cytotoxicity-promoting cytokine that is increased in the serum and cerebrospinal fluid of MS patients. Using immunohistochemistry, we demonstrate that IL-15 is mainly produced by astrocytes and infiltrating macrophages in inflammatory lesions of MS patients. Moreover, in vitro transmigration studies reveal that IL-15 selectively attracts CD4(+)CD28(-) T cells of MS patients, but not of healthy individuals. IL-15 further induces the expression of chemokine receptors and adhesion molecules on CD4(+)CD28(-) T cells, as investigated using flow cytometry, resulting in enhanced migration over a monolayer of human brain endothelial cells. Finally, flow cytometric analyses revealed that IL-15 increases the proliferation and production of GM-CSF, expression of cytotoxic molecules (NKG2D, perforin, and granzyme B), and degranulation capacity of CD4(+)CD28(-) T cells. Taken together, these findings indicate that increased peripheral and local levels of IL-15 amplify the pathogenic potential of CD4(+)CD28(-) T cells, thus contributing to tissue damage in MS brain lesions. Copyright © 2015 by The American Association of Immunologists, Inc.

  11. Cocaine Enhances HIV-1–Induced CD4+ T-Cell Apoptosis

    PubMed Central

    Pandhare, Jui; Addai, Amma B.; Mantri, Chinmay K.; Hager, Cynthia; Smith, Rita M.; Barnett, Louis; Villalta, Fernando; Kalams, Spyros A.; Dash, Chandravanu

    2015-01-01

    Substance abuse is a major barrier in eradication of the HIV epidemic because it serves as a powerful cofactor for viral transmission, disease progression, and AIDS-related mortality. Cocaine, one of the commonly abused drugs among HIV-1 patients, has been suggested to accelerate HIV disease progression. However, the underlying mechanism remains largely unknown. Therefore, we tested whether cocaine augments HIV-1–associated CD4+ T-cell decline, a predictor of HIV disease progression. We examined apoptosis of resting CD4+ T cells from HIV-1–negative and HIV-1–positive donors in our study, because decline of uninfected cells plays a major role in HIV-1 disease progression. Treatment of resting CD4+ T cells with cocaine (up to 100 μmol/L concentrations) did not induce apoptosis, but 200 to 1000 μmol/L cocaine induced apoptosis in a dose-dependent manner. Notably, treatment of CD4+ T cells isolated from healthy donors with both HIV-1 virions and cocaine significantly increased apoptosis compared with the apoptosis induced by cocaine or virions alone. Most important, our biochemical data suggest that cocaine induces CD4+ T-cell apoptosis by increasing intracellular reactive oxygen species levels and inducing mitochondrial depolarization. Collectively, our results provide evidence of a synergy between cocaine and HIV-1 on CD4+ T-cell apoptosis that may, in part, explain the accelerated disease observed in HIV-1–infected drug abusers. PMID:24486327

  12. 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

  13. Long-Lived CD4+IFN-γ+ T Cells rather than Short-Lived CD4+IFN-γ+IL-10+ T Cells Initiate Rapid IL-10 Production To Suppress Anamnestic T Cell Responses during Secondary Malaria Infection

    PubMed Central

    Villegas-Mendez, Ana; Inkson, Colette A.; Shaw, Tovah N.; Strangward, Patrick

    2016-01-01

    CD4+ T cells that produce IFN-γ are the source of host-protective IL-10 during primary infection with a number of different pathogens, including Plasmodium spp. The fate of these CD4+IFN-γ+IL-10+ T cells following clearance of primary infection and their subsequent influence on the course of repeated infections is, however, presently unknown. In this study, utilizing IFN-γ–yellow fluorescent protein (YFP) and IL-10–GFP dual reporter mice, we show that primary malaria infection–induced CD4+YFP+GFP+ T cells have limited memory potential, do not stably express IL-10, and are disproportionately lost from the Ag-experienced CD4+ T cell memory population during the maintenance phase postinfection. CD4+YFP+GFP+ T cells generally exhibited a short-lived effector rather than effector memory T cell phenotype postinfection and expressed high levels of PD-1, Lag-3, and TIGIT, indicative of cellular exhaustion. Consistently, the surviving CD4+YFP+GFP+ T cell–derived cells were unresponsive and failed to proliferate during the early phase of secondary infection. In contrast, CD4+YFP+GFP− T cell–derived cells expanded rapidly and upregulated IL-10 expression during secondary infection. Correspondingly, CD4+ T cells were the major producers within an accelerated and amplified IL-10 response during the early stage of secondary malaria infection. Notably, IL-10 exerted quantitatively stronger regulatory effects on innate and CD4+ T cell responses during primary and secondary infections, respectively. The results in this study significantly improve our understanding of the durability of IL-10–producing CD4+ T cells postinfection and provide information on how IL-10 may contribute to optimized parasite control and prevention of immune-mediated pathology during repeated malaria infections. PMID:27630165

  14. Complementary Dendritic Cell–activating Function of CD8+ and CD4+ T Cells

    PubMed Central

    Mailliard, Robbie B.; Egawa, Shinichi; Cai, Quan; Kalinska, Anna; Bykovskaya, Svetlana N.; Lotze, Michael T.; Kapsenberg, Martien L.; Storkus, Walter J.; Kalinski, Pawel

    2002-01-01

    Dendritic cells (DCs) activated by CD40L-expressing CD4+ T cells act as mediators of “T helper (Th)” signals for CD8+ T lymphocytes, inducing their cytotoxic function and supporting their long-term activity. Here, we show that the optimal activation of DCs, their ability to produce high levels of bioactive interleukin (IL)-12p70 and to induce Th1-type CD4+ T cells, is supported by the complementary DC-activating signals from both CD4+ and CD8+ T cells. Cord blood– or peripheral blood–isolated naive CD8+ T cells do not express CD40L, but, in contrast to naive CD4+ T cells, they are efficient producers of IFN-γ at the earliest stages of the interaction with DCs. Naive CD8+ T cells cooperate with CD40L-expressing naive CD4+ T cells in the induction of IL-12p70 in DCs, promoting the development of primary Th1-type CD4+ T cell responses. Moreover, the recognition of major histocompatibility complex class I–presented epitopes by antigen-specific CD8+ T cells results in the TNF-α– and IFN-γ–dependent increase in the activation level of DCs and in the induction of type-1 polarized mature DCs capable of producing high levels of IL-12p70 upon a subsequent CD40 ligation. The ability of class I–restricted CD8+ T cells to coactivate and polarize DCs may support the induction of Th1-type responses against class I–presented epitopes of intracellular pathogens and contact allergens, and may have therapeutical implications in cancer and chronic infections. PMID:11854360

  15. Toll like Receptor 2 engagement on CD4(+) T cells promotes TH9 differentiation and function.

    PubMed

    Karim, Ahmad Faisal; Reba, Scott M; Li, Qing; Boom, W Henry; Rojas, Roxana E

    2017-09-01

    We have recently demonstrated that mycobacterial ligands engage Toll like receptor 2 (TLR2) on CD4(+) T cells and up-regulate T-cell receptor (TCR) triggered Th1 responses in vitro and in vivo. To better understand the role of T-cell expressed TLR2 on CD4(+) T-cell differentiation and function, we conducted a gene expression analysis of murine naïve CD4(+) T-cells stimulated in the presence or absence of TLR2 co-stimulation. Unexpectedly, naïve CD4(+) T-cells co-stimulated via TLR2 showed a significant up-regulation of Il9 mRNA compared to cells co-stimulated via CD28. Under TH9 differentiation, we observed up-regulation of TH9 differentiation, evidenced by increases in both percent of IL-9 secreting cells and IL-9 in culture supernatants in the presence of TLR2 agonist both in polyclonal and Ag85B cognate peptide specific stimulations. Under non-polarizing conditions, TLR2 engagement on CD4(+) T-cells had minimal effect on IL-9 secretion and TH9 differentiation, likely due to a prominent effect of TLR2 signaling on IFN-γ secretion and TH1 differentiation. We also report that, TLR2 signaling in CD4(+) T cells increased expression of transcription factors BATF and PU.1, known to positively regulate TH9 differentiation. These results reveal a novel role of T-cell expressed TLR2 in enhancing the differentiation and function of TH9 T cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The Induction and Maintenance of Transplant Tolerance Engages Both Regulatory and Anergic CD4(+) T cells.

    PubMed

    Besançon, Alix; Baas, Marije; Goncalves, Tania; Valette, Fabrice; Waldmann, Herman; Chatenoud, Lucienne; You, Sylvaine

    2017-01-01

    Therapeutic tolerance to self-antigens or foreign antigens is thought to depend on constant vigilance by Foxp3(+) regulatory T cells (Tregs). Previous work using a pancreatic islet allograft model and a short pulse of CD3 antibody therapy has shown that CD8(+) T cells become anergic and use TGFβ and coinhibitory signaling as their contribution to the tolerance process. Here, we examine the role of CD4(+) T cells in tolerization by CD3 antibodies. We show that both Foxp3(+) Tregs and CD4(+) T cell anergy play a role in the induction of tolerance and its maintenance. Foxp3(+) Tregs resisted CD3 antibody-mediated depletion, unlike intragraft Th1 CD4(+) lymphocytes coexpressing granzyme B and Tbx21, which were selectively eliminated. Tregs were mandatory for induction of tolerance as their depletion at the time of CD3 antibody therapy or for a short time thereafter, by an antibody to CD25 (PC61), led to graft rejection. Early treatment with CTLA-4 antibody gave the same outcome. In contrast, neither PC61 nor anti-CTLA-4 given late, at day 100 posttransplant, reversed tolerance once established. Ablation of Foxp3 T cells after diphtheria toxin injection in tolerant Foxp3(DTR) recipient mice provided the same outcome. Alloreactive T cells had been rendered intrinsically unresponsive as total CD4(+) or Treg-deprived CD4(+) T cells from tolerant recipients were unable to mount donor-specific IFN-γ responses. In addition, intragraft Treg-deprived CD4(+) T cells lacked proliferative capacities, expressed high levels of the inhibitory receptor PD-1, and exhibited a CD73(hi)FR4(hi) phenotype, thus reflecting a state of T cell anergy. We conclude that Tregs play a substantive and critical role in guiding the immune system toward tolerance of the allograft, when induced by CD3 antibody, but are less important for maintenance of the tolerant state, where T cell anergy appears sufficient.

  17. Hematopoietic progenitor cell regulation by CD4+CD25+ T cells.

    PubMed

    Urbieta, Maite; Barao, Isabel; Jones, Monica; Jurecic, Roland; Panoskaltsis-Mortari, Angela; Blazar, Bruce R; Murphy, William J; Levy, Robert B

    2010-06-10

    CD4(+)CD25(+)FoxP3(+) regulatory T cells (Tregs) possess the capacity to modulate both adaptive and innate immune responses. We hypothesized that Tregs could regulate hematopoiesis based on cytokine effector molecules they can produce. The studies here demonstrate that Tregs can affect the differentiation of myeloid progenitor cells. In vitro findings demonstrated the ability of Tregs to inhibit the differentiation of interleukin-3 (IL-3)/stem cell factor (colony-forming unit [CFU]-IL3)-driven progenitor cells. Inhibitory effects were mediated by a pathway requiring cell-cell contact, major histocompatibility complex class II expression on marrow cells, and transforming growth factor-beta. Importantly, depletion of Tregs in situ resulted in enhanced CFU-IL3 levels after bone marrow transplantation. Cotransplantation of CD4(+)FoxP3(+)(gfp) Tregs together with bone marrow was found to diminish CFU-IL3 responses after transplantation. To address the consequence of transplanted Tregs on differentiated progeny from these CFU 2 weeks after hematopoietic stem cell transplantation, peripheral blood complete blood counts were performed and examined for polymorphonuclear leukocyte content. Recipients of cotransplanted Tregs exhibited diminished neutrophil counts. Together, these findings illustrate that both recipient and donor Tregs can influence hematopoietic progenitor cell activity after transplantation and that these cells can alter responses outside the adaptive and innate immune systems.

  18. Defective circulating CD4+LAP+ regulatory T cells in patients with dilated cardiomyopathy.

    PubMed

    Zhu, Zheng-Feng; Tang, Ting-Ting; Dong, Wen-Yong; Li, Yuan-Yuan; Xia, Ni; Zhang, Wen-Cai; Zhou, Su-Feng; Yuan, Jing; Liao, Meng-Yang; Li, Jing-Jing; Jiao, Jiao; Nie, Shao-Fang; Wang, Qing; Tu, Xin; Xu, Cheng-Qi; Liao, Yu-Hua; Shi, Guo-Ping; Cheng, Xiang

    2015-04-01

    There has been increasing evidence that chronic immune activation plays critical roles in the pathogenesis of DCM. CD4(+) LAP(+) Tregs are a newly identified T cell subset with suppressive function on the immune response. This study was designed to investigate whether the circulating frequency and function of CD4(+)LAP(+) Tregs would be impaired in patients with DCM. The results demonstrated that DCM patients had a significantly lower frequency of circulating CD4(+)LAP(+) Tregs compared with control donors. CD4(+)LAP(+) Tregs from DCM patients showed compromised function to suppress proliferation of CD4(+) LAP(-)CD25(int/low) T cells and proliferation and IgG production of B cells. Moreover, B cell proliferation and IgG subset production could be directly suppressed by CD4(+) LAP(+) Tregs. TGF-β and contact-dependent mechanisms were involved in CD4(+)LAP(+) Treg-mediated suppression. Correlation analysis suggested that CD4(+)LAP(+) Treg frequency was positively correlated with LVEF and negatively correlated with serum IgG3 and NT-proBNP concentration in patients with DCM. Our results are the first to demonstrate that the frequencies of CD4(+)LAP(+) Tregs in patients with DCM are reduced and that their suppressive function is compromised. Defective CD4(+) LAP(+) Tregs may be an underlying mechanism of immune activation in DCM patients. © Society for Leukocyte Biology.

  19. Jug r 2-reactive CD4(+) T cells have a dominant immune role in walnut allergy.

    PubMed

    Archila, Luis Diego; Jeong, David; Pascal, Mariona; Bartra, Joan; Juan, Manel; Robinson, David; Farrington, Mary L; Kwok, William W

    2015-10-01

    Allergic reactions to walnut can be life-threatening. Although IgE epitopes of walnut have been studied, CD4(+) T cell-specific epitopes for walnut remain uncharacterized. In particular, the relationship of both phenotype and frequency of walnut-specific T cells to the disease have not been examined. We sought to provide a thorough phenotypic analysis for walnut-reactive T cells in allergic and nonallergic subjects, particularly the relationship of phenotypes and frequencies of walnut-specific T cells with the disease. The CD154 upregulation assay was used to examine CD4(+) T-cell reactivity toward the walnut allergens Jug r 1, Jug r 2, and Jug r 3. A tetramer-guided epitope mapping approach was used to identify HLA-restricted CD4(+) T-cell epitopes in Jug r 2. Direct ex vivo staining with peptide-major histocompatibility complex class II tetramers enabled comparison of the frequency and phenotype of Jug r 2-specific CD4(+) T cells between allergic and nonallergic subjects. Jug r 2-specific T-cell clones were also generated, and mRNA transcription factor levels were assessed by using quantitative RT-PCR. Intracellular cytokine staining assays were performed for further phenotypic analyses. Jug r 2 was identified as the major allergen that elicited CD4(+) T-cell responses. Multiple Jug r 2 T-cell epitopes were identified. The majority of these T cells in allergic subjects have a CCR4(+) phenotype. A subset of these T cells express CCR4(+)CCR6(+) irrespective of the asthmatic status of the allergic subjects. Intracellular cytokine staining confirmed these TH2-, TH2/TH17-, and TH17-like heterogenic profiles. Jug r 2-specific T-cell clones from allergic subjects mainly expressed GATA3, nonetheless, a portion of T-cell clones both GATA3 and RAR-related orphan receptor C (RORC) or RORC alone, confirming the presence of TH2, TH2/TH17, and TH17 cells. Jug r 2-specific responses dominate walnut T-cell responses in patients with walnut allergy. Jug r 2 central memory CD4

  20. Helper T cells down-regulate CD4 expression upon chronic stimulation giving rise to double-negative T cells.

    PubMed

    Grishkan, Inna V; Ntranos, Achilles; Calabresi, Peter A; Gocke, Anne R

    2013-01-01

    Double-negative T (DNT) cells are αβTCR(+)CD3(+)CD4(-)CD8(-)NK1.1(-) cells that constitute a small but significant proportion of the αβTCR(+) T cells. Their developmental pathway and pathological significance remain unclear. In the present study, we utilized chronic in vitro stimulation of CD4(+) T cells to mimic immune hyper-activation of autoimmune lymphoproliferative syndrome and systemic lupus erythematosus, conditions characterized by DNT cells accumulation. After approximately 4-5 rounds of stimulation, the CD3(+)CD4(-) population became apparent. These cells did not express CD8, NK1.1, γδTCR, or B220, exhibited a highly proliferative effector phenotype, and were dependent on T cell receptor (TCR) stimulation for survival. Moreover, CD3(+)CD4(-) cells expressed MHC class II-restricted αβTCR, indicative of their origin from a CD4(+) T cell population. The results presented herein illustrate a novel method of DNT cell generation in vitro and suggest that immune hyper-activation could also be implicated in the genesis of the disease-associated DNT cells in vivo.

  1. Persistent expansion of CD4+ effector memory T cells in Wegener's granulomatosis.

    PubMed

    Abdulahad, W H; van der Geld, Y M; Stegeman, C A; Kallenberg, C G M

    2006-09-01

    In order to test the hypothesis that Wegener's granulomatosis (WG) is associated with an ongoing immune effector response, even in remission, we examined the distribution of peripheral naive and memory T-lymphocytes in this disease, and analyzed the function-related phenotypes of the memory T-cell population. Peripheral blood mononuclear cells (PBMCs) were freshly isolated from WG-patients in remission (R-WG, n=40), active WG-patients (A-WG, n=17), and age-matched healthy controls (HCs, n=21). Expression of CD4, CD8, CD45RO, CCR7, interleukin (IL)-18Ralpha, ST2L, and FoxP3 were determined by four-color flow cytometric analysis. CD45RO and CCR7 were used for distinction between naive and memory T cells, IL-18Ralpha, ST2L, and FoxP3 for the assessment of Type1, Type2, and regulatory T-cells, respectively. In R-WG, the CD4+CD45RO+CCR7- effector memory T-cell subpopulation (TEM) was relatively increased, whereas the CD4+CD45RO-CCR7+ naive T-cell population (TNaive) was decreased as compared to HC. The distribution of naive and memory CD8+T cells did not differ between R-WG, A-WG, and HC, nor did CD4+CD45RO+CCR7+ central memory T cells (TCM). In contrast to HC, the percentage of CD4+TNaive cells in R-WG correlated negatively with age, whereas CD4+TEM cells showed a positive correlation. In R-WG, a skewing towards Type2 T cells was observed in CD4+TEM cells. No differences were detected in FoxP3+CD4+TEM cells between R-WG and A-WG, whereas the FoxP3-CD4+TEM cells were increased in R-WG and decreased in A-WG as compared to HC. Collectively, peripheral blood homeostasis of CD4+T cells is disturbed in R-WG with the persistent expansion of non-regulatory CD4+TEM cells. These cells might be involved in relapse and may constitute a target for therapy.

  2. 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

  3. Cryptotanshinone inhibits lung tumor growth by increasing CD4+ T cell cytotoxicity through activation of the JAK2/STAT4 pathway

    PubMed Central

    Man, Yonghong; Yang, Le; Zhang, Dongxian; Bi, Yongyi

    2016-01-01

    Cryptotanshinone is one of the fat-soluble phenanthrene quinone components. In vitro studies have shown that tanshinone compounds can inhibit the proliferation of various tumor cells and affect cell cycle distribution. The aim of the present study was to better understand the effect of cryptotanshinone on the inhibition of small cell lung cancer by cytotoxic cluster of differentiation (CD)4+ T cells through activation of the Janus kinase 2/signal transducer and activator of transcription 4 (JAK2/STAT4) pathway. The Cell Counting kit-8 assay and the lactate dehydrogenase assay were used to analyze the cell proliferation of H446 and CD4+ T cells, and the cell cytotoxicity of CD4+ and CD8+ T cells, respectively. JAK2 and STAT4 protein expression was measured by western blot analysis. Cryptotanshinone effectively inhibited the tumor growth of the H446 cells and the cell proliferation of the CD4+ T cells. Treatment with cryptotanshinone increased the cytotoxicity of the CD4+ T cells, but could not affect the cytotoxicity of the CD8+ T cells. Meanwhile, cryptotanshinone induced phosphorylated (p)-JAK2 and p-STAT4 protein expression in the CD4+ T cells. These results suggest that cryptotanshinone inhibits the cell growth of lung tumors by increasing CD4+ T cell toxicity through activation of the JAK2/STAT4 pathway. PMID:27895777

  4. Interleukin 4-producing CD4+ T cells in the skin of cats with allergic dermatitis.

    PubMed

    Roosje, P J; Dean, G A; Willemse, T; Rutten, V P M G; Thepen, T

    2002-03-01

    Lesional skin of cats with allergic dermatitis has a cellular infiltrate and a CD4/CD8 ratio comparable to that in humans with atopic dermatitis. CD4+ helper T cells and in particular cells belonging to the Th2 subset play an important role in disease pathogenesis in humans. We investigated the cytokine pattern of CD4+ T cells in situ, with special emphasis on the putative presence of cells producing interleukin 4 (IL4), in cats with allergic dermatitis. Immunohistochemical procedures were used to determine that CD4+ T cells in lesional and nonlesional skin of cats with allergic dermatitis can produce IL4, as occurs in humans. Lesional and nonlesional skin of cats with allergic dermatitis had significantly more IL4+ T cells (P = 0.001) than did skin of healthy control cats. Double staining indicated that all IL4+ cells were positive for pan-T or CD4 markers. Double labeling for mast cell chymase and IL4 stained primarily different cells. Western blotting demonstrated cross-reactivity between the antibody against human IL4 and a feline recombinant IL4. These results indicate that IL4 is primarily produced by CD4+ T cells and is also present in clinically uninvolved skin, indicating a role in the pathogenesis of allergic dermatitis in cats.

  5. Notch Signaling Regulates Antigen Sensitivity of Naive CD4+ T Cells by Tuning Co-stimulation

    PubMed Central

    Laky, Karen; Evans, Sharron; Perez-Diez, Ainhoa

    2015-01-01

    SUMMARY Adaptive immune responses begin when naive CD4+ T cells engage peptide+major histocompatibility complex class II and co-stimulatory molecules on antigen-presenting cells (APCs). Notch signaling can influence effector functions in differentiated CD4+ T helper and T regulatory cells. Whether and how ligand-induced Notch signaling influences the initial priming of CD4+ T cells has not been addressed. We have found that Delta Like Ligand 4 (DLL4)-induced Notch signaling potentiates phosphatidylinositol 3-OH kinase (PI3K)-dependent signaling downstream of the T cell receptor+CD28, allowing naive CD4+ T cells to respond to lower doses of antigen. In vitro, DLL4-deficient APCs were less efficient stimulators of CD4+ T cell activation, metabolism, proliferation, and cytokine secretion. With deletion of DLL4 from CD11c+ APCs in vivo, these deficits translated to an impaired ability to mount an effective CD4+-dependent anti-tumor response. These data implicate Notch signaling as an important regulator of adaptive immune responses. PMID:25607460

  6. 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

  7. Manipulating Antigenic Ligand Strength to Selectively Target Myelin-Reactive CD4+ T Cells in EAE

    PubMed Central

    Sabatino, Joseph J.; Rosenthal, Kristen M.

    2010-01-01

    The development of antigen-specific therapies for the selective tolerization of autoreactive T cells remains the Holy Grail for the treatment of T-cell-mediated autoimmune diseases such as multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE). This quest remains elusive, however, as the numerous antigen-specific strategies targeting myelin-specific T cells over the years have failed to result in clinical success. In this review, we revisit the antigen-based therapies used in the treatment of myelin-specific CD4+ T cells in the context of the functional avidity and the strength of signal of the encephalitogenic CD4+ T cell repertoire. In light of differences in activation thresholds, we propose that autoreactive T cells are not all equal, and therefore tolerance induction strategies must incorporate ligand strength in order to be successful in treating EAE and ultimately the human disease MS. PMID:19904613

  8. Regulators of Glucose Metabolism in CD4(+) and CD8(+) T Cells.

    PubMed

    Palmer, Clovis S; Hussain, Tabinda; Duette, Gabriel; Weller, Thomas J; Ostrowski, Matias; Sada-Ovalle, Isabel; Crowe, Suzanne M

    2016-11-01

    Much like cancer cells, activated T cells undergo various metabolic changes that allow them to grow and proliferate rapidly. By adopting aerobic glycolysis upon activation, T cells effectively prioritize efficiency in biosynthesis over energy generation. There are distinct differences in the way CD4(+) and CD8(+) T cells process activation signals. CD8(+) effector T cells are less dependent on Glut1 and oxygen levels compared to their CD4(+) counterparts. Similarly the downstream signaling by TCR also differs in both effector T cell types. Recent studies have explored PI3K/Akt, mTORC, HIF1α, p70S6K and Bcl-6 signaling in depth providing definition of the crucial roles of these regulators in glucose metabolism. These new insights may allow improved therapeutic manipulation against inflammatory conditions that are associated with dysfunctional T-cell metabolism such as autoimmune disorders, metabolic syndrome, HIV, and cancers.

  9. Identification of melanoma-reactive CD4+ T cell subsets from Human Melanoma Draining Lymph Nodes

    PubMed Central

    Zhang, Mei; Graor, Hallie; Yan, Lu; Kim, Julian

    2015-01-01

    Our laboratory has previously demonstrated that melanoma draining lymph node (MDLN) samples from stage III patients contained both CD4+ and CD8+ T cells that can be readily expanded to mediate tumor cell apoptosis in vitro and improve survival in mice bearing human melanoma xenografts. In this study, we investigated whether MDLN T cells contain melanoma-reactive CD4+ T cell compartment and what they are. In order to test this, we performed multi-parametric (11-color and 6-color) FACS analyses to monitor phenotypic and functional property of CD4+ T cells in response to melanoma cell antigen re-exposure. Our results have demonstrated that the antigen re-exposure could result in a generation of CD4+CCR7+CD62L+CD27− T cell subsets with various effector cell-like properties. Within the CD4+CCR7+CD62L+CD27− T cell compartment, in response to antigen re-exposure, some of the cells expressed significantly up-regulated CD40L and/or CXCR5, and some of them expressed significantly up-regulated IL-2 and/or TNF-α. This may suggest the existence of melanoma reactive CD4+ “effector-precursor” cells within the expanded MDLN cells and their differentiation into various effector lineages in response to antigen re-stimulation. Recent clinical trials have demonstrated that effective adoptive cellular immunotherapy (ACI) maybe enhanced by antigen specific CD4+ T cells. Therefore, results of this study may significantly benefit innovative design of ACI that can potentially mediate enhanced and durable clinical responses. PMID:26641258

  10. Quorum-Sensing in CD4+ T Cell Homeostasis: A Hypothesis and a Model

    PubMed Central

    Almeida, Afonso R. M.; Amado, Inês F.; Reynolds, Joseph; Berges, Julien; Lythe, Grant; Molina-París, Carmen; Freitas, Antonio A.

    2012-01-01

    Homeostasis of lymphocyte numbers is believed to be due to competition between cellular populations for a common niche of restricted size, defined by the combination of interactions and trophic factors required for cell survival. Here we propose a new mechanism: homeostasis of lymphocyte numbers could also be achieved by the ability of lymphocytes to perceive the density of their own populations. Such a mechanism would be reminiscent of the primordial quorum-sensing systems used by bacteria, in which some bacteria sense the accumulation of bacterial metabolites secreted by other elements of the population, allowing them to “count” the number of cells present and adapt their growth accordingly. We propose that homeostasis of CD4+ T cell numbers may occur via a quorum-sensing-like mechanism, where IL-2 is produced by activated CD4+ T cells and sensed by a population of CD4+ Treg cells that expresses the high-affinity IL-2Rα-chain and can regulate the number of activated IL-2-producing CD4+ T cells and the total CD4+ T cell population. In other words, CD4+ T cell populations can restrain their growth by monitoring the number of activated cells, thus preventing uncontrolled lymphocyte proliferation during immune responses. We hypothesize that malfunction of this quorum-sensing mechanism may lead to uncontrolled T cell activation and autoimmunity. Finally, we present a mathematical model that describes the key role of IL-2 and quorum-sensing mechanisms in CD4+ T cell homeostasis during an immune response. PMID:22654881

  11. Memory CD4 T Cells Induce Antibody-Mediated Rejection of Renal Allografts.

    PubMed

    Gorbacheva, Victoria; Fan, Ran; Fairchild, Robert L; Baldwin, William M; Valujskikh, Anna

    2016-11-01

    Despite advances in immunosuppression, antibody-mediated rejection is a serious threat to allograft survival. Alloreactive memory helper T cells can induce potent alloantibody responses and often associate with poor graft outcome. Nevertheless, the ability of memory T cells to elicit well characterized manifestations of antibody-mediated rejection has not been tested. We investigated helper functions of memory CD4 T cells in a mouse model of renal transplantation. Whereas the majority of unsensitized C57Bl/6 recipients spontaneously accepted fully MHC-mismatched A/J renal allografts, recipients containing donor-reactive memory CD4 T cells rapidly lost allograft function. Increased serum creatinine levels, high serum titers of donor-specific alloantibody, minimal T cell infiltration, and intense C4d deposition in the grafts of sensitized recipients fulfilled all diagnostic criteria for acute renal antibody-mediated rejection in humans. IFNγ neutralization did not prevent the renal allograft rejection induced by memory helper T cells, and CD8 T cell depletion at the time of transplantation or depletion of both CD4 and CD8 T cells also did not prevent the renal allograft rejection induced by memory helper T cells starting at day 4 after transplantation. However, B cell depletion inhibited alloantibody generation and significantly extended allograft survival, indicating that donor-specific alloantibodies (not T cells) were the critical effector mechanism of renal allograft rejection induced by memory CD4 T cells. Our studies provide direct evidence that recipient T cell sensitization may result in antibody-mediated rejection of renal allografts and introduce a physiologically relevant animal model with which to investigate mechanisms of antibody-mediated rejection and novel therapeutic approaches for its prevention and treatment. Copyright © 2016 by the American Society of Nephrology.

  12. Cell-to-cell transfer of M. tuberculosis antigens optimizes CD4 T cell priming.

    PubMed

    Srivastava, Smita; Ernst, Joel D

    2014-06-11

    During Mycobacterium tuberculosis and other respiratory infections, optimal T cell activation requires pathogen transport from the lung to a local draining lymph node (LN). However, the infected inflammatory monocyte-derived dendritic cells (DCs) that transport M. tuberculosis to the local lymph node are relatively inefficient at activating CD4 T cells, possibly due to bacterial inhibition of antigen presentation. We found that infected migratory DCs release M. tuberculosis antigens as soluble, unprocessed proteins for uptake and presentation by uninfected resident lymph node DCs. This transfer of bacterial proteins from migratory to local DCs results in optimal priming of antigen-specific CD4 T cells, which are essential in controlling tuberculosis. Additionally, this mechanism does not involve transfer of the whole bacterium and is distinct from apoptosis or exosome shedding. These findings reveal a mechanism that bypasses pathogen inhibition of antigen presentation by infected cells and generates CD4 T cell responses that control the infection.

  13. Changes in Reactivity In Vitro of CD4(+)CD25(+) and CD4(+)CD25(-) T Cell Subsets in Transplant Tolerance.

    PubMed

    Hall, Bruce M; Robinson, Catherine M; Plain, Karren M; Verma, Nirupama D; Tran, Giang T; Nomura, Masaru; Carter, Nicole; Boyd, Rochelle; Hodgkinson, Suzanne J

    2017-01-01

    Transplant tolerance induced in adult animals is mediated by alloantigen-specific CD4(+)CD25(+) T cells, yet in many models, proliferation of CD4(+) T cells from hosts tolerant to specific-alloantigen in vitro is not impaired. To identify changes that may diagnose tolerance, changes in the patterns of proliferation of CD4(+), CD4(+)CD25(+), and CD4(+)CD25(-) T cells from DA rats tolerant to Piebald Virol Glaxo rat strain (PVG) cardiac allografts and from naïve DA rats were examined. Proliferation of CD4(+) T cells from both naïve and tolerant hosts was similar to both PVG and Lewis stimulator cells. In mixed lymphocyte culture to PVG, proliferation of naïve CD4(+)CD25(-) T cells was greater than naïve CD4(+) T cells. In contrast, proliferation of CD4(+)CD25(-) T cells from tolerant hosts to specific-donor PVG was not greater than CD4(+) T cells, whereas their response to Lewis and self-DA was greater than CD4(+) T cells. Paradoxically, CD4(+)CD25(+) T cells from tolerant hosts did not proliferate to PVG, but did to Lewis, whereas naïve CD4(+)CD25(+) T cells proliferate to both PVG and Lewis but not to self-DA. CD4(+)CD25(+) T cells from tolerant, but not naïve hosts, expressed receptors for interferon (IFN)-γ and IL-5 and these cytokines promoted their proliferation to specific-alloantigen PVG but not to Lewis or self-DA. We identified several differences in the patterns of proliferation to specific-donor alloantigen between cells from tolerant and naïve hosts. Most relevant is that CD4(+)CD25(+) T cells from tolerant hosts failed to proliferate or suppress to specific donor in the absence of either IFN-γ or IL-5. The proliferation to third-party and self of each cell population from tolerant and naïve hosts was similar and not affected by IFN-γ or IL-5. Our findings suggest CD4(+)CD25(+) T cells that mediate transplant tolerance depend on IFN-γ or IL-5 from alloactivated Th1 and Th2 cells.

  14. Distinctive selection mechanisms govern the T cell receptor repertoire of peripheral CD4-CD8- alpha/beta T cells

    PubMed Central

    1992-01-01

    The T cell receptor (TCR) repertoire of CD4+ and CD8+ alpha/beta T cells is heavily influenced by positive and negative selection events that occur during T cell development in the thymus. The coreceptors CD4 and CD8 appear to be essential for this selection to occur. To gain insight into whether T cells that express TCR alpha/beta but lack either coreceptor (CD4- CD8- TCR alpha/beta or alpha/beta double- negative [DN] cells) are also subject to positive and negative selection, and whether selection can occur in the absence of coreceptors, we have performed an extensive immunogenetic analysis of the TCR V beta repertoire of alpha/beta DN cells in lymph nodes of normal mice. Our results show that alpha/beta DN cells appear to be unaffected by clonal deletion of V beta 5 and V beta 11 in I-E- expressing mice, and do not undergo deletion of V beta 6- and V beta 8.1-expressing T cells in Mls-1a-positive mice. They are also unaffected by positive selection of V beta 17a+ T cells in the context of I-Aq. The results suggest that most selection events require the participation of CD4 and CD8, while alpha/beta DN cells are unselected. This argues that most alpha/beta DN cells probably have never expressed CD4 or CD8. However, a unique form of repertoire selection occurs: enrichment of V beta 17a+ alpha/beta DN cells in I-E+ mice. This could be an instance of coreceptor-independent selection. PMID:1512537

  15. AFP-specific CD4+ Helper T-cell Responses in Healthy Donors and HCC Patients

    PubMed Central

    Evdokimova, Viktoria N.; Liu, Yang; Potter, Douglas M.; Butterfield, Lisa H.

    2013-01-01

    Summary Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and is often diagnosed at an advanced stage. We have investigated α-fetoprotein (AFP) as a tumor-associated antigen for HCC. We identified major histocompatibility complex class I-restricted peptide epitopes derived from AFP and studied CD8+ T-cell responses in vivo and in vitro in ongoing immunotherapy studies. Helper T cells are of critical importance in shaping the immune response; therefore, we investigated the frequency and function of AFP-specific CD4+ T cells in the general population and among HCC patients. CD4+ T-cell responses were assessed by direct ex vivo multicytokine enzyme-linked immunospot assay and by measurement of cytokine levels using a multicytokine assay. Our analysis indicates that healthy donors have very low frequencies of AFP-specific CD4+ T-cell responses, which are of TH1 type, detectable ex vivo. In contrast, these T cells were either reduced or eliminated in HCC patients at advanced stages of disease. To better activate these cells, we compared the stimulatory capacity of both AFP protein-fed and AdVhAFP-engineered dendritic cells (DC). Healthy donors have CD4+ T-cell responses, which were activated in response to AFP protein-fed DC whereas HCC patients do not demonstrate significant responses to AFP protein. AdVhAFP-transduced DC were capable of activating higher frequency TH1 CD4+ responses to AFP in both healthy donors and AFP-positive HCC patients. Importantly, CD4+ T-cell cytokine expression profiles were skewed towards interleukin-2 and interferon-γ production when activated by adenovirally engineered DC, which has therapeutic implications for vaccination efforts. PMID:17457217

  16. Homeostatically Maintained Resting Naive CD4+ T Cells Resist Latent HIV Reactivation

    PubMed Central

    Tsunetsugu-Yokota, Yasuko; Kobayahi-Ishihara, Mie; Wada, Yamato; Terahara, Kazutaka; Takeyama, Haruko; Kawana-Tachikawa, Ai; Tokunaga, Kenzo; Yamagishi, Makoto; Martinez, Javier P.; Meyerhans, Andreas

    2016-01-01

    Homeostatic proliferation (HSP) is a major mechanism by which long-lived naïve and memory CD4+ T cells are maintained in vivo and suggested to contribute to the persistence of the latent HIV-1 reservoir. However, while many in vitro latency models rely on CD4+ T cells that were initially differentiated via T-cell receptor (TCR) stimulation into memory/effector cells, latent infection of naïve resting CD4+ T cells maintained under HSP conditions has not been fully addressed. Here, we describe an in vitro HSP culture system utilizing the cytokines IL-7 and IL-15 that allows studying latency in naïve resting CD4+ T cells. CD4+ T cells isolated from several healthy donors were infected with HIV pseudotypes expressing GFP and cultured under HSP conditions or TCR conditions as control. Cell proliferation, phenotype, and GFP expression were analyzed by flow cytometry. RNA expression was quantified by qRT-PCR. Under HSP culture conditions, latently HIV-1 infected naïve cells are in part maintained in the non-dividing (= resting) state. Although a few HIV-1 provirus+ cells were present in these resting GFP negative cells, the estimated level of GFP transcripts per infected cell seems to indicate a block at the post-transcriptional level. Interestingly, neither TCR nor the prototypic HDAC inhibitor SAHA were able to reactivate HIV-1 provirus from these cells. This lack of reactivation was not due to methylation of the HIV LTR. These results point to a mechanism of HIV control in HSP-cultured resting naïve CD4+ T cells that may be distinct from that in TCR-stimulated memory/effector T cells. PMID:27990142

  17. 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

  18. Cytotoxic CD4 T Cells: Differentiation, Function, and Application to Dengue Virus Infection

    PubMed Central

    Tian, Yuan; Sette, Alessandro; Weiskopf, Daniela

    2016-01-01

    Dengue virus (DENV) has spread through most tropical and subtropical areas of the world and represents a serious public health problem. The control of DENV infection has not yet been fully successful due to lack of effective therapeutics or vaccines. Nevertheless, a better understanding of the immune responses against DENV infection may reveal new strategies for eliciting and improving antiviral immunity. T cells provide protective immunity against various viral infections by generating effector cells that cooperate to eliminate antigens and memory cells that can survive for long periods with enhanced abilities to control recurring pathogens. Following activation, CD8 T cells can migrate to sites of infection and kill infected cells, whereas CD4 T cells contribute to the elimination of pathogens by trafficking to infected tissues and providing help to innate immune responses, B cells, as well as CD8 T cells. However, it is now evident that CD4 T cells can also perform cytotoxic functions and induce the apoptosis of target cells. Importantly, accumulating studies demonstrate that cytotoxic CD4 T cells develop following DENV infections and may play a crucial role in protecting the host from severe dengue disease. We review our current understanding of the differentiation and function of cytotoxic CD4 T cells, with a focus on DENV infection, and discuss the potential of harnessing these cells for the prevention and treatment of DENV infection and disease. PMID:28003809

  19. 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.

  20. Cytotoxic CD4 T Cells: Differentiation, Function, and Application to Dengue Virus Infection.

    PubMed

    Tian, Yuan; Sette, Alessandro; Weiskopf, Daniela

    2016-01-01

    Dengue virus (DENV) has spread through most tropical and subtropical areas of the world and represents a serious public health problem. The control of DENV infection has not yet been fully successful due to lack of effective therapeutics or vaccines. Nevertheless, a better understanding of the immune responses against DENV infection may reveal new strategies for eliciting and improving antiviral immunity. T cells provide protective immunity against various viral infections by generating effector cells that cooperate to eliminate antigens and memory cells that can survive for long periods with enhanced abilities to control recurring pathogens. Following activation, CD8 T cells can migrate to sites of infection and kill infected cells, whereas CD4 T cells contribute to the elimination of pathogens by trafficking to infected tissues and providing help to innate immune responses, B cells, as well as CD8 T cells. However, it is now evident that CD4 T cells can also perform cytotoxic functions and induce the apoptosis of target cells. Importantly, accumulating studies demonstrate that cytotoxic CD4 T cells develop following DENV infections and may play a crucial role in protecting the host from severe dengue disease. We review our current understanding of the differentiation and function of cytotoxic CD4 T cells, with a focus on DENV infection, and discuss the potential of harnessing these cells for the prevention and treatment of DENV infection and disease.

  1. Effect of prolonged discontinuation of successful antiretroviral therapy on CD4+ T cell decline in human immunodeficiency virus-infected patients: implications for intermittent therapeutic strategies.

    PubMed

    Tebas, Pablo; Henry, Keith; Mondy, Kristin; Deeks, Steven; Valdez, Herman; Cohen, Cal; Powderly, William G

    2002-09-15

    This study evaluates the change in CD4(+) T cell counts among patients who achieved complete viral suppression and subsequently discontinued highly active antiretroviral therapy (HAART). We included 72 human immunodeficiency virus (HIV)-1-infected patients with plasma HIV RNA loads of <500 copies/mL for at least 3 months who then discontinued therapy for at least 12 weeks. The median CD4(+) T decay while off HAART was 16 cells/mm(3)/month (interquartile range, -6 to -34 cells/month). The mean follow-up after therapy ended was 45 weeks. The slope of the CD4(+) T cell decay was inversely correlated with the increase of CD4(+) T cells while receiving HAART, baseline virus load, CD4(+) T cell count at the time therapy was discontinued, age, and duration HIV RNA levels were undetectable. In a multiple regression analysis model, the increase of CD4(+) T cells while receiving therapy and age were independently associated with the rate of CD4(+) T cell loss.

  2. Altered frequency and phenotype of CD4+ forkhead box protein 3+ T cells and its association with autoantibody production in human immunodeficiency virus-infected paediatric patients

    PubMed Central

    Argüello, R J; Balbaryski, J; Barboni, G; Candi, M; Gaddi, E; Laucella, S

    2012-01-01

    The association between immune dysfunction and the development of autoimmune pathology in patients with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) is not clear. The frequency and phenotype of regulatory T cells, as well as the presence of autoantibodies, were evaluated in a paediatric cohort of HIV-infected patients without clinical evidence of autoimmune disease. Lower absolute counts but higher percentages of total CD4+ forkhead box protein 3 (FoxP3)+ T cells were recorded in children with severe immunosuppression than in those without evidence of immunosuppression. The frequencies of classical CD4+CD25+FoxP3+ regulatory T cells were not altered, whereas CD4+FoxP3+CD25- T cells were found increased significantly in patients with severe immunosuppression. Like classical regulatory T cells, CD4+FoxP3+CD25- T cells display higher cytotoxic T-lymphocyte antigen 4 (CTLA-4) but lower CD127 expression compared with CD4+FoxP3–CD25+ T cells. An improvement in CD4+ T cell counts, along with a decrease in viral load, was associated with a decrease in CD4+FoxP3+CD25- T cells. The majority of the patients with severe immunosuppression were positive for at least one out of seven autoantibodies tested and displayed hypergammaglobulinaemia. Conversely, HIV-infected children without evidence of immunosuppression had lower levels of autoantibodies and total immunoglobulins. A decline in CD4+FoxP3+ T cell numbers or a variation in their phenotype may induce a raise in antigen exposure with polyclonal B cell activation, probably contributing to the generation of autoantibodies in the absence of clinical autoimmune disease. PMID:22471284

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

    PubMed Central

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

    2014-01-01

    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

  4. Generation of CD4+ blastoid T cells in recipients of BP/IFA-sensitized spleen cells.

    PubMed

    Kira, J; Itoyama, Y; Goto, I

    1990-06-01

    While sensitization of Lewis rats with BP/IFA does not induce EAE, recipients given BP/IFA-sensitized cells after culture with BP do develop EAE. To clarify the pathophysiology responsible for this discrepancy, cell dynamics were studied in the recipients. The CD4+ T cells from BP/IFA-sensitized donors showed no proliferative response to BP and no change in cell size or surface molecule expression, even in the presence of BP in culture. On the other hand, the recipient cells proliferated vigorously, regardless of the presence or absence of BP. In this case, a large number of CD4+ blastoid T cells was generated only in the presence of BP in culture. Such cells showed marked upregulation of CD4, CD2, class I and II MHC, and IL2 receptor molecules, a finding we also observed in the case of BP-cultured cells from BP/CFA-sensitized rats with severe EAE. The proportion of CD4+ blastoid T cells generated after culture depended on the number of cells transferred and on the presence of BP in culture, and closely correlated with the severity of EAE in the recipients. These data suggest that BP/IFA-sensitization can also induce BP-reactive cells capable of becoming CD4+ blastoid T cells with marked upregulation of CD4, CD2, class I and II MHC, and IL2 receptor molecules directly related to potent encephalitogenicity, in vivo.

  5. Low-affinity CD4+ T cells are major responders in the primary immune response.

    PubMed

    Martinez, Ryan J; Andargachew, Rakieb; Martinez, Hunter A; Evavold, Brian D

    2016-12-15

    A robust primary immune response has been correlated with the precursor number of antigen-specific T cells, as identified using peptide MHCII tetramers. However, these tetramers identify only the highest-affinity T cells. Here we show the entire CD4+ T-cell repertoire, inclusive of low-affinity T cells missed by tetramers, using a T-cell receptor (TCR) signalling reporter and micropipette assay to quantify naive precursors and expanded populations. In vivo limiting dilution assays reveal hundreds more precursor T cells than previously thought, with higher-affinity tetramer-positive T cells, comprising only 5-30% of the total antigen-specific naive repertoire. Lower-affinity T cells maintain their predominance as the primary immune response progresses, with no enhancement of survival of T cells with high-affinity TCRs. These findings demonstrate that affinity for antigen does not control CD4+ T-cell entry into the primary immune response, as a diverse range in affinity is maintained from precursor through peak of T-cell expansion.

  6. Low-affinity CD4+ T cells are major responders in the primary immune response

    PubMed Central

    Martinez, Ryan J.; Andargachew, Rakieb; Martinez, Hunter A.; Evavold, Brian D.

    2016-01-01

    A robust primary immune response has been correlated with the precursor number of antigen-specific T cells, as identified using peptide MHCII tetramers. However, these tetramers identify only the highest-affinity T cells. Here we show the entire CD4+ T-cell repertoire, inclusive of low-affinity T cells missed by tetramers, using a T-cell receptor (TCR) signalling reporter and micropipette assay to quantify naive precursors and expanded populations. In vivo limiting dilution assays reveal hundreds more precursor T cells than previously thought, with higher-affinity tetramer-positive T cells, comprising only 5–30% of the total antigen-specific naive repertoire. Lower-affinity T cells maintain their predominance as the primary immune response progresses, with no enhancement of survival of T cells with high-affinity TCRs. These findings demonstrate that affinity for antigen does not control CD4+ T-cell entry into the primary immune response, as a diverse range in affinity is maintained from precursor through peak of T-cell expansion. PMID:27976744

  7. Functional and Developmental Analysis of CD4+CD25+ Regulatory T Cells under the Influence of Streptococcal M Protein in Rheumatic Heart Disease

    PubMed Central

    Abdul-Auhaimena, Nidhal; Al-Kaabi, Zaman I. L

    2011-01-01

    The purpose of this study was to determine the role of streptococcal M protein in naturally-occurring CD4+CD25+ regulatory T cells (nTregs) function and development in rheumatic heart disease in Iraqi patients. Streptococcus pyogenes was isolated for subsequent M protein extraction. Also, peripheral blood nTregs and CD4+ T cells were isolated by using Magnetic Cell Separation System. Tissue culture for isolated cells was performed in the presence and absence of M protein. Cell count was performed, and tumor necrosis factor alpha (TNF-α) and interleukin-4 (IL-4) were determined in culture supernatant using ELISA system. There was a significant positive correlation (P<0.01) between the number of proliferated nTregs and CD4+ T cells in the presence as well as the absence of streptococcal M protein. Moreover, there was a significant negative correlation between the mean number of nTregs and CD4+ T cells in mixed culture system in the absence of M protein (r=-0.995). There was also a positive, but not significant (P>0.05), association (r=0.353) between the mean number of nTregs and CD4+ T cells in the presence of M protein. The M protein stimulated CD4+ T cells to produce IL-4 in very little amount (<4 pg/ml) in all samples. Compared to the production of IL4, TNF-α was produced in higher concentrations in the culture supernatants. The findings of the study indicate that streptococcal M protein has an important role in increasing the proliferation of D4+CD25+regulatory T cells and CD4+ T cells. However, CD4+CD25+ regulatory T cells have lower suppressive activity against CD4+ T cells in the presence of M protein. PMID:23359747

  8. Increased ex vivo cell death of central memory CD4 T cells in treated HIV infected individuals with unsatisfactory immune recovery.

    PubMed

    Massanella, Marta; Gómez-Mora, Elisabet; Carrillo, Jorge; Curriu, Marta; Ouchi, Dan; Puig, Jordi; Negredo, Eugènia; Cabrera, Cecilia; Clotet, Bonaventura; Blanco, Julià

    2015-07-17

    High levels of ex vivo CD4 T-cell death and the accumulation of highly differentiated and/or immunosenescent T cells have been associated with poor CD4 T-cell recovery in treated HIV-infected individuals. However, the relationship between cell death and T-cell differentiation is still unclear. We have analyzed cell death, immunosenescence and differentiation parameters in HAART-treated subjects (VL <50 copies/mL for more than 2 years) with CD4 T-cell count <350 cells/μL (immunodiscordant, n = 23) or >400 cells/μL (immunoconcordant, n = 33). We included 11 healthy individuals as reference. As expected, suboptimal CD4 T-cell recovery was associated with low frequencies of naïve cells, high frequencies of transitional and effector memory cells and a subsequent low ratio of central/transitional memory cells in the CD4 compartment. These alterations correlated with spontaneous CD4 T-cell death. A deeper analysis of cell death in CD4 T-cell subsets showed increased cell death in memory cells of immunodiscordant individuals, mainly affecting central memory cells. Immunosenescence was also higher in immunodiscordant individuals albeit unrelated to cell death. The CD8 compartment was similar in both HIV-infected groups, except for an underrepresentation of naïve cells in immunodiscordant individuals. Immunodiscordant individuals show alterations in memory CD4 T-cell differentiation associated with a short ex vivo lifespan of central memory cells and an in vivo low central/transitional memory cell ratio. These alterations may contribute to poor CD4 T-cell repopulation.

  9. Computational modeling of heterogeneity and function of CD4+ T cells

    PubMed Central

    Carbo, Adria; Hontecillas, Raquel; Andrew, Tricity; Eden, Kristin; Mei, Yongguo; Hoops, Stefan; Bassaganya-Riera, Josep

    2014-01-01

    The immune system is composed of many different cell types and hundreds of intersecting molecular pathways and signals. This large biological complexity requires coordination between distinct pro-inflammatory and regulatory cell subsets to respond to infection while maintaining tissue homeostasis. CD4+ T cells play a central role in orchestrating immune responses and in maintaining a balance between pro- and anti- inflammatory responses. This tight balance between regulatory and effector reactions depends on the ability of CD4+ T cells to modulate distinct pathways within large molecular networks, since dysregulated CD4+ T cell responses may result in chronic inflammatory and autoimmune diseases. The CD4+ T cell differentiation process comprises an intricate interplay between cytokines, their receptors, adaptor molecules, signaling cascades and transcription factors that help delineate cell fate and function. Computational modeling can help to describe, simulate, analyze, and predict some of the behaviors in this complicated differentiation network. This review provides a comprehensive overview of existing computational immunology methods as well as novel strategies used to model immune responses with a particular focus on CD4+ T cell differentiation. PMID:25364738

  10. CD4+ T cells disarm or delete cytotoxic T lymphocytes under IL-17-polarizing conditions.

    PubMed

    Tsai, Jy-Ping; Lee, Meng-Hua; Hsu, Shu-Ching; Chen, Mei-Yu; Liu, Shih-Jen; Chang, Joseph T; Liao, Chun-Ta; Cheng, Ann-Joy; Chong, Pele; Chu, Ching-Liang; Shen, Chia-Rui; Chen, Hsin-Wei

    2012-08-15

    Previous studies have shown that TGF-β acts cooperatively with IL-6 to elicit a high frequency of IL-17-secreting CD4(+) T cells (termed Th17) and an elevated CD8(+)IL-17(+) T cell population (termed Tc17). These CD8(+) cells fail to behave like most cytotoxic T lymphocytes that express IFN-γ and granzyme B, but they exhibit a noncytotoxic phenotype. Although a significant increase in the number of these Tc17 cells was found in tumors, their role and interaction with other cell types remain unclear. In this study, we demonstrate that the presence of CD4(+)CD25(-) T cells, but not the CD4(+)CD25(+) (regulatory T [Treg]) cell population, significantly reduced the elicitation of Tc17 cells, possibly as a result of the induction of apoptotic signals. Importantly, these signals may be derived from soluble mediators, and the addition of anti-IL-2 restored the reduction of Tc17 cells in the presence of CD4(+)CD25(-) T cells. Finally, the elicited Tc17 and Treg cells exhibited a close association in patients with head and neck cancer, indicating that the surrounding Treg cells might maintain the survival of the Tc17 cells. Taken together, these results reveal an intriguing mechanism in which Tc17 cells are controlled by a finely tuned collaboration between the different types of CD4(+) T cells in distinct tumor microenvironments.

  11. Proportions of CD4+ memory T cells are altered in individuals chronically infected with Schistosoma haematobium

    PubMed Central

    Nausch, Norman; Bourke, Claire D.; Appleby, Laura J.; Rujeni, Nadine; Lantz, Olivier; Trottein, François; Midzi, Nicholas; Mduluza, Takafira; Mutapi, Francisca

    2012-01-01

    Characterisation of protective helminth acquired immunity in humans or experimental models has focused on effector responses with little work conducted on memory responses. Here we show for the first time, that human helminth infection is associated with altered proportions of the CD4+ memory T cells, with an associated alteration of TH1 responses. The reduced CD4+ memory T cell proportions are associated with a significantly lower ratio of schistosome-specific IgE/IgG4 (marker for resistance to infection/re-infection) in uninfected older people. Helminth infection does not affect the CD8+ memory T cell pool. Furthermore, we show for the first time in a helminth infection that the CD4+ memory T cell proportions decline following curative anti-helminthic treatment despite increased CD4+ memory cell replication. Reduced accumulation of the CD4+ memory T cells in schistosome-infected people has implications for the development of natural or vaccine induced schistosome-specific protective immunity as well as for unrelated pathogens. PMID:22737405

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

    PubMed

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

    2014-10-01

    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.

  13. Imaging CD4+ T cell interstitial migration in the inflamed dermis

    PubMed Central

    Gaylo, Alison; Overstreet, Michael G.; Fowell, Deborah J.

    2017-01-01

    The ability of CD4+ T cells to carry out effector functions is dependent upon the rapid and efficient migration of these cells in inflamed peripheral tissues through an as-yet undefined mechanism. The application of multiphoton microscopy to the study of the immune system provides a tool to measure the dynamics of immune responses within intact tissues. Here we present a protocol for non-invasive intravital multiphoton imaging of CD4+ T cells in the inflamed mouse ear dermis. Use of a custom imaging platform and a venous catheter allows for the visualization of CD4+ T cell dynamics in the dermal interstitium, with the ability to interrogate these cells in real-time via the addition of blocking antibodies to key molecular components involved in motility. This system provides advantages over both in vitro models and surgically invasive imaging procedures. Understanding the pathways used by CD4+ T cells for motility may ultimately provide insight into the basic function of CD4+ T cells as well as the pathogenesis of both autoimmune diseases and pathology from chronic infections. PMID:27078264

  14. 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

  15. 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.

  16. Gene variation in IL-7 receptor (IL-7R)α affects IL-7R response in CD4+ T cells in HIV-infected individuals.

    PubMed

    Hartling, Hans Jakob; Ryder, Lars P; Ullum, Henrik; Ødum, Niels; Nielsen, Susanne Dam

    2017-02-09

    Optimal CD4+ T cell recovery after initiating combination antiretroviral treatment (cART) in HIV infection reduces risk of morbidity and mortality. T-allele homozygosity ('TT') in the single nucleotide polymorphism, rs6897932(C/T), in the IL-7 receptor α (IL-7RA) is associated with faster CD4+ T cell recovery after cART initiation compared to C-allele homozygosity in rs6897932 ('CC'). However, underlying mechanisms are unknown. We aimed to examine potential mechanisms explaining the association between rs6897932 and CD4+ T cell recovery. Ten 'TT' and 10 'CC' HIV-infected individuals matched on gender, age, and nadir and current CD4+ T cell counts were included in a cross-sectional study. 'TT' individuals had higher proportion of CD4+ T cells expressing pSTAT5 compared to 'CC' individuals after stimulating with IL-7, especially when co-stimulated with soluble IL7-RA (sIL-7RA). Furthermore, 'TT' individuals had a higher proportion of proliferating CD4+ T cells after 7 days of culture with IL-7 + sIL-7RA compared to 'CC' individuals. No differences between 'TT' and 'CC' in binding of biotinylated IL-7 were found. In conclusion, increased signal transduction and proliferation in response to IL-7 was found in 'TT' compared to 'CC' HIV-infected individuals providing a mechanistic explanation of the effect of rs6897932 T-allele on CD4+ T cell recovery in HIV infection.

  17. CD4 T cell knockout does not protect against kidney injury and worsens cancer.

    PubMed

    Ravichandran, Kameswaran; Wang, Qian; Ozkok, Abdullah; Jani, Alkesh; Li, Howard; He, Zhibin; Ljubanovic, Danica; Weiser-Evans, Mary C; Nemenoff, Raphael A; Edelstein, Charles L

    2016-04-01

    Most previous studies of cisplatin-induced acute kidney injury (AKI) have been in models of acute, high-dose cisplatin administration that leads to mortality in non-tumor-bearing mice. The aim of the study was to determine whether CD4 T cell knockout protects against AKI and cancer in a clinically relevant model of low-dose cisplatin-induced AKI in mice with cancer. Kidney function, serum neutrophil gelatinase-associated lipocalin (NGAL), acute tubular necrosis (ATN), and tubular apoptosis score were the same in wild-type and CD4 -/- mice with AKI. The lack of protection against AKI in CD4 -/- mice was associated with an increase in extracellular signal-regulated kinase (ERK), p38, CXCL1, and TNF-α, mediators of AKI and fibrosis, in both cisplatin-treated CD4 -/- mice and wild-type mice. The lack of protection was independent of the presence of cancer or not. Tumor size was double, and cisplatin had an impaired therapeutic effect on the tumors in CD4 -/- vs. wild-type mice. Mice depleted of CD4 T cells using the GK1.5 antibody were not protected against AKI and had larger tumors and lesser response to cisplatin. In summary, in a clinically relevant model of cisplatin-induced AKI in mice with cancer, (1) CD4 -/- mice were not protected against AKI; (2) ERK, p38, CXCL1, and TNF-α, known mediators of AKI, and interstitial fibrosis were increased in CD4 -/- kidneys; and (3) CD4 -/- mice had faster tumor growth and an impaired therapeutic effect of cisplatin on the tumors. The data warns against the use of CD4 T cell inhibition to attenuate cisplatin-induced AKI in patients with cancer. A clinically relevant low-dose cisplatin model of AKI in mice with cancer was used. CD4 -/- mice were not functionally or histologically protected against AKI. CD4 -/- mice had faster tumor growth. CD4 -/- mice had an impaired therapeutic effect of cisplatin on the tumors. Mice depleted of CD4 T cells were not protected against AKI and had larger tumors.

  18. Tyrosine kinase activity of CD4-associated p56lck may not be required for CD4-dependent T-cell activation.

    PubMed Central

    Collins, T L; Burakoff, S J

    1993-01-01

    The lymphoid-specific tyrosine kinase p56lck (Lck) is critical for the development and activation of T lymphocytes, and Lck kinase activity has been implicated in both T-cell antigen receptor/CD3- and CD4-mediated signaling. CD4-dependent T-cell activation has been demonstrated to be dependent upon the association of CD4 with Lck. To examine the role of the kinase activity of Lck in CD4-dependent T-cell activation, we have generated several kinase-deficient mutants of Lck. When transfected into CD4+ murine T-cell hybridoma cells, these mutants cause approximately 90% diminution in CD4-associated Lck kinase activity. Specifically, upon CD4 crosslinking there is decreased Lck autophosphorylation and decreased phosphorylation of an exogenous substrate. When CD4 is crosslinked to the T-cell antigen receptor-CD3 complex, decreased phosphorylation of associated substrates is also observed. In spite of this striking inhibition of Lck kinase function, cells expressing the kinase-deficient mutants demonstrate normal or enhanced CD4-dependent antigen responsiveness. These data demonstrate that the level of Lck kinase activity does not correlate with its CD4-associated function and suggest that the kinase activity of Lck may not be required for CD4-mediated signaling. Images Fig. 1 Fig. 2 Fig. 3 PMID:7505449

  19. Increased Regulatory T-Cell Percentage Contributes to Poor CD4(+) Lymphocytes Recovery: A 2-Year Prospective Study After Introduction of Antiretroviral Therapy.

    PubMed

    Saison, Julien; Maucort Boulch, Delphine; Chidiac, Christian; Demaret, Julie; Malcus, Christophe; Cotte, Laurent; Poitevin-Later, Francoise; Miailhes, Patrick; Venet, Fabienne; Trabaud, Mary Anne; Monneret, Guillaume; Ferry, Tristan

    2015-04-01

    Background.  The primary aim of this study was to determine the impact of regulatory T cells (Tregs) percentage on immune recovery in human immunodeficiency virus (HIV)-infected patients after antiretroviral therapy introduction. Methods.  A 2-year prospective study was conducted in HIV-1 chronically infected naive patients with CD4 count <500 cells/mm(3). Regulatory T cells were identified as CD4(+)CD25(high)CD127(low) cells among CD4(+) lymphocytes. Effect of Treg percentage at inclusion on CD4 evolution overtime was analyzed using a mixed-effect Poisson regression for count data. Results.  Fifty-eight patients were included (median CD4 = 293/mm(3), median Treg percentage = 6.1%). Percentage of Treg at baseline and CD4 nadir were independently related to the evolution of CD4 absolute value according to time: (1) at any given nadir CD4 count, 1% increase of initial Treg was associated with a 1.9% lower CD4 absolute value at month 24; (2) at any given Treg percentage at baseline, 10 cell/mm(3) increase of CD4 nadir was associated with a 2.4% increase of CD4 at month 24; and (3) both effects did not attenuate with time. The effect of Treg at baseline on CD4 evolution was as low as the CD4 nadir was high. Conclusions.  Regulatory T-cell percentage at baseline is a strong independent prognostic factor of immune recovery, particularly among patients with low CD4 nadir.

  20. Increased Regulatory T-Cell Percentage Contributes to Poor CD4+ Lymphocytes Recovery: A 2-Year Prospective Study After Introduction of Antiretroviral Therapy

    PubMed Central

    Saison, Julien; Maucort Boulch, Delphine; Chidiac, Christian; Demaret, Julie; Malcus, Christophe; Cotte, Laurent; Poitevin-Later, Francoise; Miailhes, Patrick; Venet, Fabienne; Trabaud, Mary Anne; Monneret, Guillaume; Ferry, Tristan

    2015-01-01

    Background. The primary aim of this study was to determine the impact of regulatory T cells (Tregs) percentage on immune recovery in human immunodeficiency virus (HIV)-infected patients after antiretroviral therapy introduction. Methods. A 2-year prospective study was conducted in HIV-1 chronically infected naive patients with CD4 count <500 cells/mm3. Regulatory T cells were identified as CD4+CD25highCD127low cells among CD4+ lymphocytes. Effect of Treg percentage at inclusion on CD4 evolution overtime was analyzed using a mixed-effect Poisson regression for count data. Results. Fifty-eight patients were included (median CD4 = 293/mm3, median Treg percentage = 6.1%). Percentage of Treg at baseline and CD4 nadir were independently related to the evolution of CD4 absolute value according to time: (1) at any given nadir CD4 count, 1% increase of initial Treg was associated with a 1.9% lower CD4 absolute value at month 24; (2) at any given Treg percentage at baseline, 10 cell/mm3 increase of CD4 nadir was associated with a 2.4% increase of CD4 at month 24; and (3) both effects did not attenuate with time. The effect of Treg at baseline on CD4 evolution was as low as the CD4 nadir was high. Conclusions. Regulatory T-cell percentage at baseline is a strong independent prognostic factor of immune recovery, particularly among patients with low CD4 nadir. PMID:26110165

  1. A role for the transcription factor Helios in human CD4+CD25+ regulatory T cells

    PubMed Central

    Getnet, Derese; Grosso, Joseph F.; Goldberg, Monica V.; Harris, Timothy J.; Yen, Hung-Rong; Bruno, Tullia C.; Durham, Nicholas M.; Hipkiss, Edward L.; Pyle, Kristin J.; Wada, Satoshi; Pan, Fan; Pardoll, Drew M.; Drake, Charles G.

    2010-01-01

    Relative up-regulation of the Ikaros family transcription factor Helios in natural regulatory T cells (Tregs) has been reported by several groups. However, a role for Helios in regulatory T cells has not yet been described. Here, we show that Helios is upregulated in CD4+CD25+ regulatory T cells. Chromatin Immunoprecipitation (ChIP) experiments indicated that Helios binds to the FoxP3 promoter. These data were further corroborated by experiments showing that knocking-down Helios with siRNA oligonucleotides results in down-regulation of FoxP3. Functionally, we found that suppression of Helios message in CD4+CD25+ T cells significantly attenuates their suppressive function. Taken together, these data suggest that Helios may play an important role in regulatory T cell function and support the concept that Helios may be a novel target to manipulate Treg activity in a clinical setting. PMID:20226531

  2. Aire-Overexpressing Dendritic Cells Induce Peripheral CD4T Cell Tolerance.

    PubMed

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

    2015-12-29

    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 CD4T 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 CD4T 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 (Ca(2+) and p-ERK) in CD4T cells. We observed that Aire cells-induced CD4T 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.

  3. Unusual CD4+CD28− T Cells and Their Pathogenic Role in Chronic Inflammatory Disorders

    PubMed Central

    Lee, Ga Hye

    2016-01-01

    CD28 is a primary co-stimulatory receptor that is essential for successful T cell activation, proliferation, and survival. While ubiquitously expressed on naive T cells, the level of CD28 expression on memory T cells is largely dependent on the T-cell differentiation stage in humans. Expansion of circulating T cells lacking CD28 was originally considered a hallmark of age-associated immunological changes in humans, with a progressive loss of CD28 following replicative senescence with advancing age. However, an increasing body of evidence has revealed that there is a significant age-inappropriate expansion of CD4+CD28− T cells in patients with a variety of chronic inflammatory diseases, suggesting that these cells play a role in their pathogenesis. In fact, expanded CD4+CD28− T cells can produce large amounts of proinflammatory cytokines such as IFN-γ and TNF-α and also have cytotoxic potential, which may cause tissue damage and development of pathogenesis in many inflammatory disorders. Here we review the characteristics of CD4+CD28− T cells as well as the recent advances highlighting the contribution of these cells to several disease conditions. PMID:28035207

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

    PubMed Central

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

    2010-01-01

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

  5. Multiparametric bioinformatics distinguish the CD4/CD8 ratio as a suitable laboratory predictor of combined T cell pathogenesis in HIV infection.

    PubMed

    Buggert, Marcus; Frederiksen, Juliet; Noyan, Kajsa; Svärd, Jenny; Barqasho, Babilonia; Sönnerborg, Anders; Lund, Ole; Nowak, Piotr; Karlsson, Annika C

    2014-03-01

    HIV disease progression is characterized by numerous pathological changes of the cellular immune system. Still, the CD4 cell count and viral load represent the laboratory parameters that are most commonly used in the clinic to determine the disease progression. In this study, we conducted an interdisciplinary investigation to determine which laboratory parameters (viral load, CD4 count, CD8 count, CD4 %, CD8 %, CD4/CD8) are most strongly associated with pathological changes of the immune system. Multiparametric flow cytometry was used to assess markers of CD4(+) and CD8(+) T cell activation (CD38, HLA-DR), exhaustion (PD-1, Tim-3), senescence (CD28, CD57), and memory differentiation (CD45RO, CD27) in a cohort of 47 untreated HIV-infected individuals. Using bioinformatical methods, we identified 139 unique populations, representing the "combined T cell pathogenesis," which significantly differed between the HIV-infected individuals and healthy control subjects. CD38, HLA-DR, and PD-1 were particularly expressed within these unique T cell populations. The CD4/CD8 ratio was correlated with more pathological T cell populations (n = 10) and had a significantly higher average correlation coefficient than any other laboratory parameters. We also reduced the dimensionalities of the 139-unique populations by Z-transformations and principal component analysis, which still identified the CD4/CD8 ratio as the preeminent surrogate of combined T cell pathogenesis. Importantly, the CD4/CD8 ratio at baseline was shown to be significantly associated with CD4 recovery 2 y after therapy initiation. These results indicate that the CD4/CD8 ratio would be a suitable laboratory predictor in future clinical and therapeutic settings to monitor pathological T cell events in HIV infection.

  6. A Pilot Trial of Adding Maraviroc to Suppressive Antiretroviral Therapy for Suboptimal CD4+ T-Cell Recovery Despite Sustained Virologic Suppression: ACTG A5256

    PubMed Central

    Wilkin, Timothy J.; Lalama, Christina M.; McKinnon, John; Gandhi, Rajesh T.; Lin, Nina; Landay, Alan; Ribaudo, Heather; Fox, Lawrence; Currier, Judith S.; Mellors, John W.; Gulick, Roy; Tenorio, Allan R.

    2012-01-01

    Background. Despite viral suppression, antiretroviral therapy (ART) does not restore CD4+ T-cell counts in many patients infected with human immunodeficiency virus type 1 (HIV-1). Methods. In a single-arm pilot trial involving ART recipients with suppressed plasma levels of HIV-1 RNA for at least 48 weeks and stable suboptimal CD4+ T-cell recovery, subjects added maraviroc, a CCR5 antagonist, to their existing ART for 24 weeks. After stopping maraviroc, they were followed for an additional 24 weeks. A Wilcoxon signed-rank test was used to evaluate whether maraviroc was associated with an increase of at least 20 cells/µL in the CD4+ T-cell count. Results. A total of 34 subjects were enrolled. The median age was 50 years, and the median baseline CD4+ T-cell count was 153 cells/µL. The median increase in CD4+ T-cell count from baseline to week 22/24 was 12 cells/µL (90% confidence interval, 1–22). A CD4+ T-cell count increase of at least 20 cells/µL was not detected (P = .97). Markers of immune activation and apoptosis decreased during maraviroc intensification; this decline partially reversed after discontinuing maraviroc. Conclusions. Adding maraviroc to suppressive ART for 24 weeks was not associated with an increase in CD4+ T-cell counts of at least 20 cells/µL. Further studies of CCR5 antagonists in the dampening of immune activation associated with HIV infection are warranted. Clinical Trials Registration. NCT 00709111. PMID:22740718

  7. A pilot trial of adding maraviroc to suppressive antiretroviral therapy for suboptimal CD4T-cell recovery despite sustained virologic suppression: ACTG A5256.

    PubMed

    Wilkin, Timothy J; Lalama, Christina M; McKinnon, John; Gandhi, Rajesh T; Lin, Nina; Landay, Alan; Ribaudo, Heather; Fox, Lawrence; Currier, Judith S; Mellors, John W; Gulick, Roy; Tenorio, Allan R

    2012-08-15

    Despite viral suppression, antiretroviral therapy (ART) does not restore CD4(+) T-cell counts in many patients infected with human immunodeficiency virus type 1 (HIV-1). In a single-arm pilot trial involving ART recipients with suppressed plasma levels of HIV-1 RNA for at least 48 weeks and stable suboptimal CD4(+) T-cell recovery, subjects added maraviroc, a CCR5 antagonist, to their existing ART for 24 weeks. After stopping maraviroc, they were followed for an additional 24 weeks. A Wilcoxon signed-rank test was used to evaluate whether maraviroc was associated with an increase of at least 20 cells/µL in the CD4(+) T-cell count. A total of 34 subjects were enrolled. The median age was 50 years, and the median baseline CD4(+) T-cell count was 153 cells/µL. The median increase in CD4(+) T-cell count from baseline to week 22/24 was 12 cells/µL (90% confidence interval, 1-22). A CD4(+) T-cell count increase of at least 20 cells/µL was not detected (P = .97). Markers of immune activation and apoptosis decreased during maraviroc intensification; this decline partially reversed after discontinuing maraviroc. Adding maraviroc to suppressive ART for 24 weeks was not associated with an increase in CD4(+) T-cell counts of at least 20 cells/µL. Further studies of CCR5 antagonists in the dampening of immune activation associated with HIV infection are warranted. Clinical Trials Registration. NCT 00709111.

  8. Proliferation of weakly suppressive regulatory CD4+ T cells is associated with over-active CD4+ T-cell responses in HIV-positive patients with mycobacterial immune restoration disease.

    PubMed

    Seddiki, Nabila; Sasson, Sarah C; Santner-Nanan, Brigitte; Munier, Meeling; van Bockel, David; Ip, Susanna; Marriott, Debbie; Pett, Sarah; Nanan, Ralph; Cooper, David A; Zaunders, John J; Kelleher, Anthony D

    2009-02-01

    The role of Treg in patients with late-stage HIV disease, who commence combination antiretroviral therapy (cART) and develop pathogen-specific immunopathology manifesting as immune restoration disease (IRD) remains unclear. We hypothesised that Treg could be defective in either numbers and/or function and therefore unable to ensure the physiological equilibrium of the immune system in patients with IRD. Phenotypic and functional CD4(+) T-cell subsets of eight late-stage HIV patients with nadir CD4 count <50 cells/microL, who developed mycobacterial IRD upon commencing cART were compared with six therapy naive HIV(+) patients (nadir CD4 count <50 cells/microL), who did not develop an IRD after cART. Mycobacterium-avium-specific CD4(+) T cells from IRD patients produced high levels of IFN-gamma and IL-2 compared with controls (p<0.001). Surprisingly, we found a significant expansion of CD127(lo)Foxp3(+)CD25(+) Treg in IRD patients and a higher ratio of Treg to effector/memory subsets (p<0.001). In vitro suppression assays demonstrated reduced functional capacity of suppressor cells and diminished IL-10 secretion in IRD patients. Plasma levels of IL-7 were increased in patients and, interestingly, exogenous IL-7 and other cytokines strongly inhibited Treg suppression. These data suggest that despite substantial Treg expansion in IRD, their ability to induce suppression, and thereby downregulate aberrant immune responses, is compromised.

  9. T cell receptor signaling pathway is overexpressed in CD4(+) T cells from HAM/TSP individuals.

    PubMed

    Pinto, Mariana Tomazini; Malta, Tathiane Maistro; Rodrigues, Evandra Strazza; Takayanagui, Osvaldo Massaiti; Tanaka, Yuetsu; Covas, Dimas Tadeu; Kashima, Simone

    2015-01-01

    Human T-lymphotropic virus type 1 (HTLV-1) is a human retrovirus related to the chronic neuroinflammatory disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). CD4(+) T cells activation appears to play a key role on HTLV-1 infection. Here we investigated the expression of genes associated to T cell activation CD3e molecule, epsilon (CD3ɛ), lymphocyte-specific protein tyrosine kinase (LCK), vav 1 guanine nucleotide exchange factor (VAV1), and zeta-chain (TCR) associated protein kinase 70kDa (ZAP70) on T lymphocytes of HTLV-1-infected individuals and compared to healthy uninfected individuals (CT). We observed that CD3ɛ, LCK, ZAP70, and VAV1 gene expression were increased in CD4(+) T cells from HAM/TSP group compared to HTLV-1 asymptomatic patients (HAC). Moreover, ZAP70 and VAV1 were also upregulated in HAM/TSP compared to CT group. We detected a positive correlation among all these genes. We also observed that CD3ɛ, LCK, and VAV1 genes had a positive correlation with the proviral load (PVL) and Tax expression. These results suggest that PVL and Tax protein could drive CD3ɛ, LCK, and VAV1 gene expression in CD4(+) T cells, and these genes function on a synchronized way on the CD4(+) T cell activation. The elucidation of the mechanisms underlying T cell receptor signaling pathway is of considerable interest and might lead to new insights into the mechanism of HAM/TSP. Copyright © 2015 Elsevier Editora Ltda. All rights reserved.

  10. Memory CD4+ T cells induce innate responses independently of pathogen.

    PubMed

    Strutt, Tara M; McKinstry, K Kai; Dibble, John P; Winchell, Caylin; Kuang, Yi; Curtis, Jonathan D; Huston, Gail; Dutton, Richard W; Swain, Susan L

    2010-05-01

    Inflammation induced by recognition of pathogen-associated molecular patterns markedly affects subsequent adaptive responses. We asked whether the adaptive immune system can also affect the character and magnitude of innate inflammatory responses. We found that the response of memory, but not naive, CD4(+) T cells enhances production of multiple innate inflammatory cytokines and chemokines (IICs) in the lung and that, during influenza infection, this leads to early control of virus. Memory CD4(+) T cell-induced IICs and viral control require cognate antigen recognition and are optimal when memory cells are either T helper type 1 (T(H)1) or T(H)17 polarized but are independent of interferon-gamma (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha) production and do not require activation of conserved pathogen recognition pathways. This represents a previously undescribed mechanism by which memory CD4(+) T cells induce an early innate response that enhances immune protection against pathogens.

  11. High Cell Surface Expression of CD4 Allows Distinction of CD4+CD25+ Antigen-specific Effector T Cells from CD4+CD25+ Regulatory T Cells in Murine Experimental Autoimmune Encephalomyelitis

    PubMed Central

    Li, Jinzhu; Ridgway, William; Fathman, C. Garrison; Tse, Harley Y.; Shaw, Michael K.

    2008-01-01

    Analysis of T regulatory cells (Treg) and T effector cells (Teff) in experimental autoimmune encephalomyelitis is complicated by the fact that both cell types express CD4 and CD25. We demonstrate that encephalitogenic T cells, following antigen recognition, up regulate cell surface expression of CD4. The CD4high sub-population contains all of the antigen response as shown by proliferation and cytokine secretion, and only these cells are capable of transferring EAE to naive animals. On the other hand, a FACS separable CD25+ sub-population of cells displayed consistent levels of CD4 prior to and after antigen stimulation. These cells displayed characteristics of Treg, such as expressing high levels of the Foxp3 gene and the ability to suppress mitogenic T cell responses. PMID:17920698

  12. Abdominal visceral adiposity influences CD4+ T cell cytokine production in pregnancy.

    PubMed

    Ozias, Marlies K; Li, Shengqi; Hull, Holly R; Brooks, William M; Petroff, Margaret G; Carlson, Susan E

    2015-02-01

    Women with pre-gravid obesity are at risk for pregnancy complications. While the macrophage response of obese pregnant women categorized by body mass index (BMI) has been documented, the relationship between the peripheral CD4(+) T cell cytokine profile and body fat compartments during pregnancy is unknown. In this study, third trimester peripheral CD4(+) T cell cytokine profiles were measured in healthy pregnant women [n=35; pre-pregnancy BMI: 18.5-40]. CD4(+) T cells were isolated from peripheral blood mononuclear cells and stimulated to examine their capacity to generate cytokines. Between 1 and 3weeks postpartum, total body fat was determined by dual-energy X-ray absorptiometry and abdominal subcutaneous and visceral fat masses were determined by magnetic resonance imaging. Pearson's correlation was performed to assess relationships between cytokines and fat mass. Results showed that greater abdominal visceral fat mass was associated with a decrease in stimulated CD4(+) T cell cytokine expression. IFN-gamma, TNF-alpha, IL-12p70, IL-10 and IL-17A were inversely related to visceral fat mass. Chemokines CCL3 and IL-8 and growth factors G-CSF and FLT-3L were also inversely correlated. Additionally, total body fat mass was inversely correlated with FGF-2 while abdominal subcutaneous fat mass and BMI were unrelated to any CD4(+) T cell cytokine. In conclusion, lower responsiveness of CD4(+) T cell cytokines associated with abdominal visceral fat mass is a novel finding late in gestation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. [The expression of CD(4+) T cells in different bacteria strain-induced mice periodontitis].

    PubMed

    Wang, Lin-yuan; Jin, Ying; Lin, Xiao-ping

    2014-02-01

    To compare the expression of CD(4+) T cells in mice periodontitis induced by two periodontal pathogen strains, and evaluate the role of CD(4+) T cells in periodontitis. Twelve C57BL/6 mice were divided into 3 groups at random including sham-infected, Porphyromonas gingivalis (P. gingivalis) W83-infected and P. gingivalis ATCC 33277-infected groups. All mice were sacrificed at the 4th week after the last infection. The analysis of alveolar bone resorption and the examination of histological staining were performed. The population of CD(4+) T cells in the gingivae and the cervical lymph nodes (CLNs) were analyzed by flow cytometry. SPSS 11.0 software package was used for statistical analysis. The levels of alveolar bone resorption were significantly high in both P. gingivalis W83-infected and P. gingivalis ATCC 33277-infected mice compared to sham-infected mice. Histological staining showed that the loss of periodontal attachment and osteoclasts-mediated alveolar bone resorption were found in both P. gingivalis W83-infected and P. gingivalis ATCC 33277-infected mice. Moreover, the periodontal destruction was severer in P. gingivalis W83-infected mice than in P. gingivalis ATCC 33277-infected mice. Flow cytometry showed that the percentage of CD(4+) T cells in the gingivae and CLNs in both P. gingivalis W83-infected and P. gingivalis ATCC 33277-infected mice were significantly higher than that in sham mice, and P. gingivalis W83-infected mice had a higher percentage of CD(4+) T cells compared to P. gingivalis ATCC 33277-infected mice. The population of CD(4+) T cells participates in the pathogenesis of periodontitis, and closely correlates with the periodontal destruction induced by periodontal pathogen infection. Supported by Higher School Specialized Research Fund for Doctoral Program(20112104110013) and Science and Technology Plan of Liaoning Province(2012225015).

  14. Epigenetic Alterations May Regulate Temporary Reversal of CD4+ T Cell Activation Caused by Trichloroethylene Exposure

    PubMed Central

    Gilbert, Kathleen M.; Nelson, Ashley R.; Cooney, Craig A.; Reisfeld, Brad; Blossom, Sarah J.

    2012-01-01

    Previous studies have shown that short-term (4 weeks) or chronic (32 weeks) exposure to trichloroethylene (TCE) in drinking water of female MRL+/+ mice generated CD4+ T cells that secreted increased levels of interferon (IFN)-γ and expressed an activated (CD44hiCD62Llo) phenotype. In contrast, the current study of subchronic TCE exposure showed that midway in the disease process both of these parameters of CD4+ T cell activation were reversed. This phase of the disease process may represent an attempt by the body to counteract the inflammatory effects of TCE. The decrease in CD4+ T cell production of IFN-γ following subchronic TCE exposure could not be attributed to skewing toward a Th2 or Th17 phenotype or to an increase in Treg cells. Instead, the suppression corresponded to alterations in markers used to assess DNA methylation, namely increased expression of retrotransposons Iap (intracisternal A particle) and Muerv (murine endogenous retrovirus). Also observed was an increase in the expression of Dnmt1 (DNA methyltransferase-1) and decreased expression of several genes known to be downregulated by DNA methylation, namely Ifng, Il2, and Cdkn1a. CD4+ T cells from a second study in which MRL+/+ mice were treated for 17 weeks with TCE showed a similar increase in Iap and decrease in Cdkn1a. In addition, DNA collected from the CD4+ T cells in the second study showed TCE-decreased global DNA methylation. Thus, these results described the biphasic nature of TCE-induced alterations in CD4+ T cell function and suggested that these changes represented potentially reversible alterations in epigenetic processes. PMID:22407948

  15. Immunological predictors of CD4+ T cell decline in antiretroviral treatment interruptions

    PubMed Central

    Seoane, Elena; Resino, Salvador; Moreno, Santiago; de Quiros, Juan Carlos Lopez Bernaldo; Moreno, Ana; Rubio, Rafael; Gonzalez-García, Juan; Arribas, José Ramón; Pulido, Federico; Muñoz-Fernández, Ma Ángeles

    2008-01-01

    Background The common response to stopping anti-HIV treatment is an increase of HIV-RNA load and decrease in CD4+, but not all the patients have similar responses to this therapeutic strategy. The aim was to identify predictive markers of CD4+ cell count declines to < 350/μL in CD4-guided antiretroviral treatment interruptions. Methods 27 HIV-infected patients participated in a prospective multicenter study in with a 24 month follow-up. Patients on stable highly active antiretroviral therapy (HAART), with CD4+ count > 600/μL, and HIV-RNA < 50 copies/ml for at least 6 months were offered the option to discontinue antiretroviral therapy. The main outcome was a decline in CD4+ cell count to < 350/μL. Results After 24 months of follow-up, 16 of 27 (59%) patients (who discontinued therapy) experienced declines in CD4+ cell count to < 350/μL. Patients with a CD4+ nadir of < 200 cells/μL had a greater risk of restarting therapy during the follow-up (RR (CI95%): 3.37 (1.07; 10.36)). Interestingly, lymphoproliferative responses to Mycobacterium tuberculosis purified protein derivative (PPD) below 10000 c.p.m. at baseline (4.77 (1.07; 21.12)), IL-4 production above 100 pg/mL at baseline (5.95 (1.76; 20.07)) in PBMC cultured with PPD, and increased IL-4 production of PBMC with p24 antigen at baseline (1.25 (1.01; 1.55)) were associated to declines in CD4+ cell count to < 350/μL. Conclusion Both the number (CD4+ nadir) and the functional activity of CD4+ (lymphoproliferative response to PPD) predict the CD4+ decrease associated with discontinuation of ART in patients with controlled viremia. PMID:18302775

  16. CD4+ T-Cell Reactivity to Orexin/Hypocretin in Patients With Narcolepsy Type 1.

    PubMed

    Ramberger, Melanie; Högl, Birgit; Stefani, Ambra; Mitterling, Thomas; Reindl, Markus; Lutterotti, Andreas

    2017-03-01

    Narcolepsy type 1 is accompanied by a selective loss of orexin/hypocretin (hcrt) neurons in the lateral hypothalamus caused by yet unknown mechanisms. Epidemiologic and genetic associations strongly suggest an immune-mediated pathogenesis of the disease. We compared specific T-cell reactivity to orexin/hcrt peptides in peripheral blood mononuclear cells of narcolepsy type 1 patients to healthy controls by a carboxyfluorescein succinimidyl ester proliferation assay. Orexin/hcrt-specific T-cell reactivity was also determined by cytokine (interferon gamma and granulocyte-macrophage colony-stimulating factor) analysis. Individuals were considered as responders if the cell division index of CD3+CD4+ T cells and both stimulation indices of cytokine secretion exceeded the cutoff 3. Additionally, T-cell reactivity to orexin/hcrt had to be confirmed by showing reactivity to single peptides present in different peptide pools. Using these criteria, 3/15 patients (20%) and 0/13 controls (0%) showed orexin/hcrt-specific CD4+ T-cell proliferation (p = .2262). The heterogeneous reactivity pattern did not allow the identification of a preferential target epitope. A significant role of orexin/hcrt-specific T cells in narcolepsy type 1 patients could not be confirmed in this study. Further studies are needed to assess the exact role of CD4+ T cells and possible target antigens in narcolepsy type 1 patients.

  17. Vaccination Produces CD4 T Cells with a Novel CD154-CD40-Dependent Cytolytic Mechanism.

    PubMed

    Coler, Rhea N; Hudson, Thomas; Hughes, Sean; Huang, Po-Wei D; Beebe, Elyse A; Orr, Mark T

    2015-10-01

    The discovery of new vaccines against infectious diseases and cancer requires the development of novel adjuvants with well-defined activities. The TLR4 agonist adjuvant GLA-SE elicits robust Th1 responses to a variety of vaccine Ags and is in clinical development for both infectious diseases and cancer. We demonstrate that immunization with a recombinant protein Ag and GLA-SE also induces granzyme A expression in CD4 T cells and produces cytolytic cells that can be detected in vivo. Surprisingly, these in vivo CTLs were CD4 T cells, not CD8 T cells, and this cytolytic activity was not dependent on granzyme A/B or perforin. Unlike previously reported CD4 CTLs, the transcription factors Tbet and Eomes were not necessary for their development. CTL activity was also independent of the Fas ligand-Fas, TRAIL-DR5, and canonical death pathways, indicating a novel mechanism of CTL activity. Rather, the in vivo CD4 CTL activity induced by vaccination required T cell expression of CD154 (CD40L) and target cell expression of CD40. Thus, vaccination with a TLR4 agonist adjuvant induces CD4 CTLs, which kill through a previously unknown CD154-dependent mechanism. Copyright © 2015 by The American Association of Immunologists, Inc.

  18. Heritable Gene Regulation in the CD4:CD8 T Cell Lineage Choice

    PubMed Central

    Issuree, Priya D. A.; Ng, Charles P.; Littman, Dan R.

    2017-01-01

    The adaptive immune system is dependent on functionally distinct lineages of T cell antigen receptor αβ-expressing T cells that differentiate from a common progenitor in the thymus. CD4+CD8+ progenitor thymocytes undergo selection following interaction with MHC class I and class II molecules bearing peptide self-antigens, giving rise to CD8+ cytotoxic and CD4+ helper or regulatory T cell lineages, respectively. The strict correspondence of CD4 and CD8 expression with distinct cellular phenotypes has made their genes useful surrogates for investigating molecular mechanisms of lineage commitment. Studies of Cd4 and Cd8 transcriptional regulation have uncovered cis-regulatory elements that are critical for mediating epigenetic modifications at distinct stages of development to establish heritable transcriptional programs. In this review, we examine the epigenetic mechanisms involved in Cd4 and Cd8 gene regulation during T cell lineage specification and highlight the features that make this an attractive system for uncovering molecular mechanisms of heritability. PMID:28382035

  19. 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.

  20. 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

  1. Human CD4+ T cell recent thymic emigrants are identified by protein tyrosine kinase 7 and have reduced immune function

    PubMed Central

    Haines, Christopher J.; Giffon, Thierry D.; Lu, Li-Sheng; Lu, Xiaowei; Tessier-Lavigne, Marc; Ross, Douglas T.

    2009-01-01

    CD4+ recent thymic emigrants (RTEs) comprise a clinically and immunologically important T cell population that indicates thymic output and that is essential for maintaining a diverse αβ–T cell receptor (TCR) repertoire of the naive CD4+ T cell compartment. However, their frequency and function are poorly understood because no known surface markers distinguish them from older non-RTE naive CD4+ T cells. We demonstrate that protein tyrosine kinase 7 (PTK7) is a novel marker for human CD4+ RTEs. Consistent with their recent thymic origin, human PTK7+ RTEs contained higher levels of signal joint TCR gene excision circles and were more responsive to interleukin (IL)-7 compared with PTK7− naive CD4+ T cells, and rapidly decreased after complete thymectomy. Importantly, CD4+ RTEs proliferated less and produced less IL-2 and interferon-γ than PTK7− naive CD4+ T cells after αβ-TCR/CD3 and CD28 engagement. This immaturity in CD4+ RTE effector function may contribute to the reduced CD4+ T cell immunity observed in contexts in which CD4+ RTEs predominate, such as in the fetus and neonate or after immune reconstitution. The ability to identify viable CD4+ RTEs by PTK7 staining should be useful for monitoring thymic output in both healthy individuals and in patients with genetic or acquired CD4+ T cell immunodeficiencies. PMID:19171767

  2. The α4 Nicotinic Receptor Promotes CD4+ T-Cell Proliferation and a Helper T-Cell Immune Response

    PubMed Central

    Nordman, Jacob C.; Muldoon, Pretal; Clark, Sarah; Damaj, M. Imad

    2014-01-01

    Smoking is a common addiction and a leading cause of disease. Chronic nicotine exposure is known to activate nicotinic acetylcholine receptors (nAChRs) in immune cells. We demonstrate a novel role for α4 nAChRs in the effect of nicotine on T-cell proliferation and immunity. Using cell-based sorting and proteomic analysis we define an α4 nAChR expressing helper T-cell population (α4+CD3+CD4+) and show that this group of cells is responsive to sustained nicotine exposure. In the circulation, spleen, bone marrow, and thymus, we find that nicotine promotes an increase in CD3+CD4+ cells via its activation of the α4 nAChR and regulation of G protein subunit o, G protein regulated–inducer of neurite outgrowth, and CDC42 signaling within T cells. In particular, nicotine is found to promote a helper T cell 2 adaptive immunologic response within T cells that is absent in α4−/− mice. We thus present a new mechanism of α4 nAChR signaling and immune regulation in T cells, possibly accounting for the effect of smoking on the immune system. PMID:24107512

  3. Extensive CD4 and CD8 T-cell cross-reactivity between alphaherpesviruses1

    PubMed Central

    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.

    2015-01-01

    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 bi-directional cross-reactivity. HSV-specific CD4 T cells recovered from HSV seronegative persons can be partially explained 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, and 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 10-50%. Based on these findings, we hypothesize 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

  4. 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.

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

    PubMed

    Wolf, Kyle J; 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.

  6. Longitudinal changes in CD4(+) T-cell memory responses induced by BCG vaccination of newborns.

    PubMed

    Soares, Andreia P; Kwong Chung, Cheong K C; Choice, Terry; Hughes, E Jane; Jacobs, Gail; van Rensburg, Esme Janse; Khomba, Gloria; de Kock, Marwou; Lerumo, Lesedi; Makhethe, Lebohang; Maneli, Mbulelo H; Pienaar, Bernadette; Smit, Erica; Tena-Coki, Nontobeko G; van Wyk, Leandre; Boom, W Henry; Kaplan, Gilla; Scriba, Thomas J; Hanekom, Willem A

    2013-04-01

    Improved vaccination strategies against tuberculosis are needed, such as approaches to boost immunity induced by the current vaccine, BCG. Design of these strategies has been hampered by a lack of knowledge of the kinetics of the human host response induced by neonatal BCG vaccination. Furthermore, the functional and phenotypic attributes of BCG-induced long-lived memory T-cell responses remain unclear. We assessed the longitudinal CD4 T-cell response following BCG vaccination of human newborns. The kinetics, function, and phenotype of these cells were measured using flow cytometric whole-blood assays. We showed that the BCG-specific CD4 T-cell response peaked 6-10 weeks after vaccination and gradually waned over the first year of life. Highly activated T-helper 1 cells, predominantly expressing interferon γ, tumor necrosis factor α, and/or interleukin 2, were present at the peak response. Following contraction, BCG-specific CD4 T cells expressed high levels of Bcl-2 and displayed a predominant CD45RACCR7 central memory phenotype. However, cytokine and cytotoxic marker expression by these cells was more characteristic of effector memory cells. Our findings suggest that boosting of BCG-primed CD4 T cells with heterologous tuberculosis vaccines may be best after 14 weeks of age, once an established memory response has developed.

  7. Longitudinal Changes in CD4+ T-Cell Memory Responses Induced by BCG Vaccination of Newborns

    PubMed Central

    Soares, Andreia P.; Kwong Chung, Cheong K. C.; Choice, Terry; Hughes, E. Jane; Jacobs, Gail; van Rensburg, Esme Janse; Khomba, Gloria; de Kock, Marwou; Lerumo, Lesedi; Makhethe, Lebohang; Maneli, Mbulelo H.; Pienaar, Bernadette; Smit, Erica; Tena-Coki, Nontobeko G.; van Wyk, Leandre; Boom, W. Henry; Kaplan, Gilla; Scriba, Thomas J.; Hanekom, Willem A.

    2013-01-01

    Background. Improved vaccination strategies against tuberculosis are needed, such as approaches to boost immunity induced by the current vaccine, BCG. Design of these strategies has been hampered by a lack of knowledge of the kinetics of the human host response induced by neonatal BCG vaccination. Furthermore, the functional and phenotypic attributes of BCG-induced long-lived memory T-cell responses remain unclear. Methods. We assessed the longitudinal CD4+ T-cell response following BCG vaccination of human newborns. The kinetics, function, and phenotype of these cells were measured using flow cytometric whole-blood assays. Results. We showed that the BCG-specific CD4+ T-cell response peaked 6–10 weeks after vaccination and gradually waned over the first year of life. Highly activated T-helper 1 cells, predominantly expressing interferon γ, tumor necrosis factor α, and/or interleukin 2, were present at the peak response. Following contraction, BCG-specific CD4+ T cells expressed high levels of Bcl-2 and displayed a predominant CD45RA–CCR7+ central memory phenotype. However, cytokine and cytotoxic marker expression by these cells was more characteristic of effector memory cells. Conclusions. Our findings suggest that boosting of BCG-primed CD4+ T cells with heterologous tuberculosis vaccines may be best after 14 weeks of age, once an established memory response has developed. PMID:23293360

  8. Increased TTS abrogates IDO-mediated CD4(+) T cells suppression in patients with Graves' disease.

    PubMed

    Wang, Shu; Mao, Chaoming; Zhao, Zefei; Gu, Qiaoli; Jin, Min; Xiao, Yichuan; Jiang, Xiaohua; Zhao, Yongju; Zhang, Yanyun; Ning, Guang

    2009-08-01

    Indoleamine 2,3-dioxygenase (IDO)-expression in antigen-presenting cells (APCs) may control autoimmune responses by depleting the available tryptophan, whereas tryptophanyl-tRNA synthetase (TTS) may counteract this effect. The study aims to determine whether abnormal IDO and TTS activities in autoreactive T, B and dendritic cells (DCs) lead to tryptophan metabolism disorder, inducing the immune imbalance in patients with Graves' disease (GD). The concentrations of serum kynurenine and tryptophan and the mRNA expressions of IDO and TTS were analyzed, and the mixed leukocyte reaction (MLR) was employed to assess the interaction of IDO-expressing DCs and TTS-expressing CD4(+) T cells. Compared with healthy donors (HD), the ratio of serum kynurenine to tryptophan (P < 0.0001) was increased in GD patients, which was associated with the increased IDO expression in B cells (P < 0.01) and DCs (P < 0.01). GD-derived CD4(+) T cells enhanced TTS expression (P < 0.01), and its proliferation was not inhibited in the presence of IDO-expressing DCs from the GD patients. In contrast, the proliferation of HD-derived CD4(+) T cells with low TTS expression was inhibited. Increased TTS expression from CD4(+) T cells resists IDO-mediated immunosuppression from DCs, which might link to a pathogenic mechanism involved in autoreactive T cells being sustained in vivo in GD patients.

  9. Bromelain treatment reduces CD25 expression on activated CD4+ T cells in vitro✩

    PubMed Central

    Secor, Eric R.; Singh, Anurag; Guernsey, Linda A.; McNamara, Jeff T.; Zhan, Lijun; Maulik, Nilanjana; Thrall, Roger S.

    2009-01-01

    Bromelain (Br), an extract from pineapple stem with cysteine protease activity, exerts anti-inflammatory effects in a number of inflammatory models. We have previously shown that Br treatment decreased activated CD4+ T cells and has a therapeutic role in an ovalbumin-induced murine model of allergic airway disease. The current study was designed to determine the effect of Br on CD4+ T cell activation, specifically the expression of CD25 in vitro. CD25 is up regulated upon T cell activation, found as a soluble fraction (sCD25) and is a therapeutic target in inflammation, autoimmunity and allergy. Br treatment of anti-CD3 stimulated CD4+ T cells reduced CD25 expression in a dose and time dependent manner. This reduction of CD25 was dependent on the proteolytic action of Br as the addition of E64 (a cysteine protease inhibitor) abrogated this response. The concentration of sCD25 was increased in supernatants of Br treated activated CD4+ T cells as compared to control cells, suggesting that Br proteolytically cleaved cell-surface CD25. This novel mechanism of action identifies how Br may exert its therapeutic benefits in inflammatory conditions. PMID:19162239

  10. 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

  11. Bromelain treatment reduces CD25 expression on activated CD4+ T cells in vitro.

    PubMed

    Secor, Eric R; Singh, Anurag; Guernsey, Linda A; McNamara, Jeff T; Zhan, Lijun; Maulik, Nilanjana; Thrall, Roger S

    2009-03-01

    Bromelain (Br), an extract from pineapple stem with cysteine protease activity, exerts anti-inflammatory effects in a number of inflammatory models. We have previously shown that Br treatment decreased activated CD4(+) T cells and has a therapeutic role in an ovalbumin-induced murine model of allergic airway disease. The current study was designed to determine the effect of Br on CD4(+) T cell activation, specifically the expression of CD25 in vitro. CD25 is up regulated upon T cell activation, found as a soluble fraction (sCD25) and is a therapeutic target in inflammation, autoimmunity and allergy. Br treatment of anti-CD3 stimulated CD4(+) T cells reduced CD25 expression in a dose and time dependent manner. This reduction of CD25 was dependent on the proteolytic action of Br as the addition of E64 (a cysteine protease inhibitor) abrogated this response. The concentration of sCD25 was increased in supernatants of Br treated activated CD4(+) T cells as compared to control cells, suggesting that Br proteolytically cleaved cell-surface CD25. This novel mechanism of action identifies how Br may exert its therapeutic benefits in inflammatory conditions.

  12. Restoring homeostasis of CD4+ T cells in hepatitis-B-virus-related liver fibrosis

    PubMed Central

    Cheng, Li-Sha; Liu, Yun; Jiang, Wei

    2015-01-01

    Immune-mediated liver injury is widely seen during hepatitis B virus (HBV) infection. Unsuccessful immune clearance of HBV results in chronic hepatitis and increases the risk of liver cirrhosis and hepatocellular carcinoma. HBV-related liver fibrosis (HBVLF), occurring as a result of HBV-induced chronic hepatitis, is a reversible, intermediate stage of chronic hepatitis B (CHB) and liver cirrhosis. Therefore, defining the pathogenesis of HBVLF is of practical significance for achieving better clinical outcomes. Recently, the homeostasis of CD4+ T cells was considered to be pivotal in the process of HBVLF. To better uncover the underlying mechanisms, in this review, we systematically retrospect the impacts of different CD4+ T-cell subsets on CHB and HBVLF. We emphasize CD4+ T-cell homeostasis and the important balance between regulatory T (Treg) and T helper 17 (Th17) cells. We discuss some cytokines associated with Treg and Th17 cells such as interleukin (IL)-17, IL-22, IL-21, IL-23, IL-10, IL-35 and IL-33, as well as surface molecules such as programmed cell death protein 1, cytotoxic T lymphocyte-associated antigen 4, T cell immunoglobulin domain and mucin domain-containing molecule 3 and cannabinoid receptor 2 that have potential therapeutic implications for the homeostasis of CD4+ T cells in CHB and HBVLF. PMID:26478664

  13. Memory CD4 T cell subsets are kinetically heterogeneous and replenished from naive T cells at high levels

    PubMed Central

    Gossel, Graeme; Hogan, Thea; Cownden, Daniel

    2017-01-01

    Characterising the longevity of immunological memory requires establishing the rules underlying the renewal and death of peripheral T cells. However, we lack knowledge of the population structure and how self-renewal and de novo influx contribute to the maintenance of memory compartments. Here, we characterise the kinetics and structure of murine CD4 T cell memory subsets by measuring the rates of influx of new cells and using detailed timecourses of DNA labelling that also distinguish the behaviour of recently divided and quiescent cells. We find that both effector and central memory CD4 T cells comprise subpopulations with highly divergent rates of turnover, and show that inflows of new cells sourced from the naive pool strongly impact estimates of memory cell lifetimes and division rates. We also demonstrate that the maintenance of CD4 T cell memory subsets in healthy mice is unexpectedly and strikingly reliant on this replenishment. DOI: http://dx.doi.org/10.7554/eLife.23013.001 PMID:28282024

  14. Regulatory T-cells are essential to promote proper CD4 T-cell priming upon mucosal infection

    PubMed Central

    Soerens, Andrew G.; Da Costa, Andreia; Lund, Jennifer M.

    2016-01-01

    Regulatory T-cells (Tregs) limit autoimmunity and immunopathology using a variety of suppressive mechanisms, but their roles during pathogen-directed immune responses remain unclear. Following Herpes Simplex virus-2 (HSV-2) infection, mice lacking Tregs fail to control viral replication, pointing to a role for Tregs in facilitating productive immune responses. Using adoptive transfer of TCR transgenic CD4 T-cells into Treg-sufficient or Treg-depleted mice prior to HSV-2 infection, we found that Tregs are required for timely accumulation of HSV-2-specific CD4 T-cells within the infected tissues. Further, Tregs are critical for appropriate trafficking of dendritic cells (DCs) from the vaginal mucosa to the dLN, which results in fully effective CD4 T-cell priming, activation, and ultimately migration to the infected tissues. Using CTLA-4 conditional knockout mice, we demonstrate that Tregs impact DC migration through a CTLA-4-mediated mechanism. Together, our data highlight the critical role of Tregs in proper potentiation of adaptive immune responses to microbial infection. PMID:27007674

  15. Differentiation of distinct long-lived memory CD4 T cells in intestinal tissues after oral Listeria monocytogenes infection.

    PubMed

    Romagnoli, P A; Fu, H H; Qiu, Z; Khairallah, C; Pham, Q M; Puddington, L; Khanna, K M; Lefrançois, L; Sheridan, B S

    2017-03-01

    Mucosal antigen-specific CD4 T-cell responses to intestinal pathogens remain incompletely understood. Here we examined the CD4 T-cell response after oral infection with an internalin A 'murinized' Listeria monocytogenes (Lm). Oral Lm infection induced a robust endogenous listeriolysin O (LLO)-specific CD4 T-cell response with distinct phenotypic and functional characteristics in the intestine. Circulating LLO-specific CD4 T cells transiently expressed the 'gut-homing' integrin α4β7 and accumulated in the intestinal lamina propria and epithelium where they were maintained independent of interleukin (IL)-15. The majority of intestinal LLO-specific CD4 T cells were CD27(-) Ly6C(-) and CD69(+) CD103(-) while the lymphoid LLO-specific CD4 T cells were heterogeneous based on CD27 and Ly6C expression and predominately CD69(-). LLO-specific effector CD4 T cells transitioned into a long-lived memory population that phenotypically resembled their parent effectors and displayed hallmarks of residency. In addition, intestinal effector and memory CD4 T cells showed a predominant polyfunctional Th1 profile producing IFNγ, TNFα, and IL-2 at high levels with minimal but detectable levels of IL-17A. Depletion of CD4 T cells in immunized mice led to elevated bacterial burden after challenge infection highlighting a critical role for memory CD4 T cells in controlling intestinal intracellular pathogens.

  16. Differentiation of distinct long-lived memory CD4 T cells in intestinal tissues after oral Listeria monocytogenes infection

    PubMed Central

    Romagnoli, PA; Fu, HH; Qiu, Z; Khairallah, C; Pham, QM; Puddington, L; Khanna, KM; Lefrançois, L; Sheridan, BS

    2016-01-01

    Mucosal antigen-specific CD4 T cell responses to intestinal pathogens remain incompletely understood. Here we examined the CD4 T cell response after oral infection with an internalin A ‘murinized’ Listeria monocytogenes (Lm). Oral Lm infection induced a robust endogenous listeriolysin O (LLO)-specific CD4 T cell response with distinct phenotypic and functional characteristics in the intestine. Circulating LLO-specific CD4 T cells transiently expressed the ‘gut-homing’ integrin α4β7 and accumulated in the intestinal lamina propria and epithelium where they were maintained independent of IL-15. The majority of intestinal LLO-specific CD4 T cells were CD27− Ly6C− and CD69+ CD103− while the lymphoid LLO-specific CD4 T cells were heterogeneous based on CD27 and Ly6C expression and predominately CD69−. LLO-specific effector CD4 T cells transitioned into a long-lived memory population that phenotypically resembled their parent effectors and displayed hallmarks of residency. In addition, intestinal effector and memory CD4 T cells showed a predominant polyfunctional Th1 profile producing IFNγ, TNFα and IL-2 at high levels with minimal but detectable levels of IL-17A. Depletion of CD4 T cells in immunized mice led to elevated bacterial burden after challenge infection highlighting a critical role for memory CD4 T cells in controlling intestinal intracellular pathogens. PMID:27461178

  17. Human memory, but not naive, CD4+ T cells expressing transcription factor T-bet might drive rapid cytokine production.

    PubMed

    Yu, Si-fei; Zhang, Yan-nan; Yang, Bin-yan; Wu, Chang-you

    2014-12-19

    We found that after stimulation for a few hours, memory but not naive CD4(+) T cells produced a large amount of IFN-γ; however, the mechanism of rapid response of memory CD4(+) T cells remains undefined. We compared the expression of transcription factors in resting or activated naive and memory CD4(+) T cells and found that T-bet, but not pSTAT-1 or pSTAT-4, was highly expressed in resting memory CD4(+) T cells and that phenotypic characteristics of T-bet(+)CD4(+) T cells were CD45RA(low)CD62L(low) CCR7(low). After short-term stimulation, purified memory CD4(+) T cells rapidly produced effector cytokines that were closely associated with the pre-existence of T-bet. By contrast, resting naive CD4(+) T cells did not express T-bet, and they produced cytokines only after sustained stimulation. Our further studies indicated that T-bet was expressed in the nuclei of resting memory CD4(+) T cells, which might have important implications for rapid IFN-γ production. Our results indicate that the pre-existence and nuclear mobilization of T-bet in resting memory CD4(+) T cells might be a possible transcriptional mechanism for rapid production of cytokines by human memory CD4(+) T cells.

  18. Defective response of CD4+ T cells to retinoic acid and TGFβ in systemic lupus erythematosus

    PubMed Central

    2011-01-01

    Introduction CD25+ FOXP3+ CD4+ regulatory T cells (Tregs) are induced by transforming growth factor β (TGFβ) and further expanded by retinoic acid (RA). We have previously shown that this process was defective in T cells from lupus-prone mice expressing the novel isoform of the Pbx1 gene, Pbx1-d. This study tested the hypothesis that CD4+ T cells from systemic lupus erythematosus (SLE) patients exhibited similar defects in Treg induction in response to TGFβ and RA, and that PBX1-d expression is associated with this defect. Methods Peripheral blood mononuclear cells (PBMCs) were collected from 142 SLE patients and 83 healthy controls (HCs). The frequency of total, memory and naïve CD4+ T cells was measured by flow cytometry on fresh cells. PBX1 isoform expression in purified CD4+ T cells was determined by reverse transcription polymerase chain reaction (RT-PCR). PBMCs were stimulated for three days with anti-CD3 and anti-CD28 in the presence or absence of TGFβ and RA. The expression of CD25 and FOXP3 on CD4+ T cells was then determined by flow cytometry. In vitro suppression assays were performed with sorted CD25+ and CD25- FOXP3+ T cells. CD4+ T cell subsets or their expansion were compared between patients and HCs with two-tailed Mann-Whitney tests and correlations between the frequencies of two subsets were tested with Spearman tests. Results The percentage of CD25- FOXP3+ CD4+ (CD25- Tregs) T cells was greater in SLE patients than in HCs, but these cells, contrary to their matched CD25+ counterparts, did not show a suppressive activity. RA-expansion of TGFβ-induced CD25+ Tregs was significantly lower in SLE patients than in HCs, although SLE Tregs expanded significantly more than HCs in response to either RA or TGFβ alone. Defective responses were also observed for the SLE CD25- Tregs and CD25+ FOXP3- activated CD4+ T cells as compared to controls. PBX1-d expression did not affect Treg induction, but it significantly reduced the expansion of CD25- Tregs

  19. 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, CD