Relationship between the anti-inflammatory properties of salmeterol/fluticasone and the expression of CD4+CD25+Foxp3+ regulatory T cells in COPD

Background

Salmeterol and fluticasone combination (SFC) has anti-inflammatory effects and improves clinical symptoms in patients with chronic obstructive pulmonary disease (COPD). However, the anti-inflammatory mechanism of SFC remains unclear. In this study, we investigated the inflammatory responses of COPD, as well as the relationship of the inflammatory factors with the levels of CD4⁺CD25⁺Foxp3⁺ regulatory T cells (Foxp3⁺Tregs) after SFC therapy.

Methods

Twenty-one patients with moderate or severe COPD received treatment with 50/500 μg of SFC twice a day for 12 weeks. Before and after treatment, the patients were evaluated using the Modified Medical Research Council (MMRC) dyspnea scale and by conducting a 6-min walk test. The number of neutrophils, monocytes and lymphocytes in induced sputum were counted. Levels of cytokines, including pre-inflammatory IL-8, TNF-α, IL-17A and cytokine IL-10, in the sputum supernatant and peripheral blood were measured by ELISA. The proportion of Foxp3⁺Tregs in the total CD4⁺ T cell of the peripheral blood was determined by flow cytometry. The relationship between IL-17A levels and the percentage of Foxp3⁺Tregs was analyzed by statistical analysis.

Results

After treatment with SFC, the forced expiratory volume in 1 s as a percentage of predicted values (FEV1%) and the 6-min walk distance in the COPD patients significantly increased, while dyspnea scores decreased. The total number of cells, neutrophils, and the percentage of neutrophils in induced sputum reduced notably, while the proportion of monocytes was significantly increased. Levels of the inflammatory cytokines IL-8, TNF-α, and IL-17A in the sputum supernatant and in the blood were markedly lowered, while IL-10 levels were unchanged. The proportion of Foxp3⁺Tregs in the total CD4⁺T cell population in the peripheral blood was drastically higher than that before treatment. The level of IL-17A was negatively correlated with the proportion of Foxp3⁺Tregs in CD4⁺T cells.

Conclusion

SFC can reduce the levels of inflammatory factors and improve symptoms of COPD. The levels of inflammatory factors are associated with the variation of Foxp3⁺Tregs in COPD.

Trial registration

This study was registered with http://www.chictr.org (Chinese Clinical Trial Register) as follows: ChiCTR-TNC-10001270     

Functional diversity of T lymphocytes due to secretion of different cytokine patterns.

Different helper T cell subsets secrete different patterns of cytokines when stimulated by antigen. The TH1 and TH2 subsets differ in the secretion of at least eight cytokines, and three or more other cytokine secretion patterns also exist among both mouse and human T cell clones. Several properties of strong immune responses suggest that at least the TH1 and TH2 phenotypes can be present in vivo. As cytokines are major determinants of the functions of the T cells that produce them, these patterns lead to different properties of the T cell subsets. TH1 cells mediate several functions connected with cytotoxicity and local inflammatory reactions, and so these T cells are particularly effective at combating viruses and intracellular bacteria and parasites. TH2 cells are much more effective at stimulating B cells to produce antibody, and so should be more effective against free-living bacteria, and in inducing protective humoral immunity. Antibody and delayed inflammatory reactions are often mutually exclusive during immune responses, and this can be at least partially explained by cross-inhibition of TH1 and TH2 cells. A newly discovered cytokine, IL10, has been implicated as one of the cross-regulatory cytokines, as this TH2 product inhibits cytokine synthesis by TH1 cells.     

Mechanism for normal splenic T lymphocyte functions in proestrus females after trauma: enhanced local synthesis of 17beta-estradiol

Trauma-hemorrhage and resuscitation (TH) produces profound immunodepression and enhances susceptibility to sepsis in males but not in proestrus females, suggesting gender dimorphism in the immune responses. However, the mechanism responsible for the maintenance of immune functions in proestrus females after TH is unclear. Splenic T lymphocytes express receptors for estrogen (ER), contain enzymes involved in estrogen metabolism, and are the major source of cytokine production; the metabolism of 17-estradiol was assessed in the splenic T lymphocytes of proestrus and ovariectomized mice by using appropriate substrates after TH. Analysis for aromatase and 17-hydroxysteroid dehydrogenases indicated increased 17-estradiol synthesis and low conversion into estrone in T lymphocytes of proestrus but not of ovariectomized mice. The effect of 17-estradiol on T lymphocyte cytokine release was reliant on ER expressions. This was apparent in the differences of ER expression, especially that of ER-, and an association between increased 17-estradiol synthesis and sustained release of IL-2 and IL-6 in T lymphocytes of proestrus females after TH. Because 17-estradiol is able to regulate cytokine genes, and the splenic T lymphocyte cytokine releases is altered after TH, continued synthesis of 17-estradiol in proestrus females appears to be responsible for the maintenance of T lymphocyte cytokine release associated with the protection of immune functions after TH. inflammation; immune suppression; steroid synthesis; T lymphocytes; cytokines     

Relationship between Regulatory T Cells and Immune Activation in Human Immunodeficiency Virus-Infected Patients Interrupting Antiretroviral Therapy

Persistent immune activation plays a central role in driving Human Immunodeficiency Virus (HIV) disease progression. Whether CD4+CD25+ regulatory T cells (Tregs) are harmful by suppressing HIV-specific immune responses and/or beneficial through a decrease in immune activation remains debatable. We analysed the relationship between proportion and number of regulatory T cells (Tregs) and immune activation in HIV-infected patients interrupting an effective antiretroviral therapy (ART). Twenty-five patients were included in a substudy of a prospective multicenter trial of treatment interruption (TI) (ANRS 116). Proportions and numbers of Tregs and the proportion of activated CD4 and CD8 T cells were assessed at baseline and month 12 (M12) of TI. Specific anti-HIV CD4 and CD8 responses were investigated at baseline and M12. Non parametric univariate analyses and multivariate linear regression models were conducted. At baseline, the proportion of Tregs negatively correlated with the proportion of HLA-DR⁺CD8⁺T cells (r = −0.519). Following TI, the proportion of Tregs increased from 6.3% to 7.2% (p = 0.029); absolute numbers of Tregs decreased. The increase in the proportion of HLA-DR⁺CD38⁺CD8⁺T cells was significantly related to the increase in proportion of Tregs (p = 0.031). At M12, the proportion of Tregs did not negatively correlate with CD8 T-cell activation. Nevertheless, Tregs retain a suppressive function since depletion of Treg-containing CD4⁺CD25⁺ cells led to an increase in lymphoproliferative responses in most patients studied. Our data suggest that Tregs are efficient in controlling residual immune activation in patients with ART-mediated viral suppression. However, the insufficient increase in the proportion and/or the decrease in the absolute number of Tregs result in a failure to control immune activation following TI.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00118677","term_id":"NCT00118677"}}NCT00118677     

Dynamics of Immune Reconstitution and Activation Markers in HIV+ Treatment-Na?ve Patients Treated with Raltegravir,Tenofovir Disoproxil Fumarate and Emtricitabine

Background

The dynamics of CD4+ T cell reconstitution and changes in immune activation and inflammation in HIV-1 disease following initiation of antiretroviral therapy (ART) are incompletely defined and their underlying mechanisms poorly understood.

Methods

Thirty-nine treatment-naïve patients were treated with raltegravir, tenofovir DF and emtricitabine. Immunologic and inflammatory indices were examined in persons with sustained virologic control during 48 weeks of therapy.

Results

Initiation of ART increased CD4+ T cell numbers and decreased activation and cell cycle entry among CD4+ and CD8+ T cell subsets, and attenuated markers of coagulation (D-dimer levels) and inflammation (IL-6 and TNFr1). These indices decayed at different rates and almost all remained elevated above levels measured in HIV-seronegatives through 48 weeks of viral control. Greater first and second phase CD4+ T cell restoration was related to lower T cell activation and cell cycling at baseline, to their decay with treatment, and to baseline levels of selected inflammatory indices, but less so to their changes on therapy.

Conclusions

ART initiation results in dynamic changes in viral replication, T cell restoration, and indices of immune activation, inflammation, and coagulation. These findings suggest that determinants of T cell activation/cycling and inflammation/coagulation may have distinguishable impact on immune homeostasis.

Trial Registration

Clinicaltrials.gov NCT00660972     

The Effect of Leflunomide on Cycling and Activation of T-Cells in HIV-1-Infected Participants

Background

The pathogenesis of immunodeficiency due to human immunodeficiency virus (HIV)-1 is incompletely understood, but immune activation is believed to play a central role. Immunomodulatory agents that decrease immune activation may be useful in the treatment of HIV-1 infection.

Methodology

A randomized, double blind, placebo-controlled pilot study of leflunomide for 28 days was performed in participants with HIV-1 infection who were not receiving antiretroviral therapy. Participants randomized to leflunomide were subsequently treated with cholestyramine until leflunomide levels were below detection limit.

Findings

Treatment with leflunomide was well tolerated with mostly low-grade adverse events. Leflunomide administration reduced cycling of CD4 T cells (by ex vivo bromodeoxyuridine uptake and Ki67 expression) and decreased expression of activation markers (HLA-DR/CD38 co-expression) on CD8 T cells in peripheral blood. In addition, decreased expression of HIV-1 co-receptors was observed in both CD4 and CD8 T cells in the leflunomide group. There were no significant changes in naïve and memory T cell subsets, apoptosis of T cells or markers of microbial translocation.

Conclusions

Leflunomide was effective in reducing immune activation in the setting of chronic HIV-1 infection suggesting that targeting immune activation with immunomodulatory agents may be a feasible strategy.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00101374","term_id":"NCT00101374"}}NCT00101374     

Correlation between frequencies of blood monocytic myeloid-derived suppressor cells,regulatory T cells and negative prognostic markers in patients with castration-resistant metastatic prostate cancer

Myeloid-derived suppressor cells (MDSC) are believed to play a role in immune suppression and subsequent failure of T cells to mount an efficient anti-tumor response, by employing both direct T-cell inhibition as well as induction of regulatory T cells (Tregs). Investigating the frequency and function of immune suppressive cell subsets in the peripheral blood of 41 patients with prostate cancer (PC) and 36 healthy donors (HD) showed a significant increase in circulating CD14⁺ HLA-DR^low/neg monocytic MDSC (M-MDSC) and Tregs in patients with PC compared to HD. Furthermore, M-MDSC frequencies correlated positively with Treg levels. In vitro proliferation assay with autologous T cells confirmed M-MDSC-mediated T-cell suppression, and intracellular staining of immune suppressive enzyme iNOS revealed a higher expression in M-MDSC from patients with PC. Increased frequencies of M-MDSC correlated with known negative prognostic markers in patients with PC including elevated levels of lactate dehydrogenase and prostate-specific antigen. Accordingly, high levels of M-MDSC were associated with a shorter median overall survival. Our data strongly suggest that M-MDSC, possibly along with Tregs, play a role in establishing an immune suppressive environment in patients with PC. Moreover, correlation of M-MDSC frequency with known prognostic markers and the observed impact on OS could reflect a possible role in tumor progression. Further insight into the generation and function of MDSC and their interplay with Tregs and other cell types may suggest ways to tackle their induction and/or function to improve immunological tumor control.     

Potential role of melatonin in autoimmune diseases

Autoimmune diseases are a broad spectrum of disorders involved in the imbalance of T-cell subsets, in which interplay or interaction of Th1, Th17 and Tregs are most important, resulting in prolonged inflammation and subsequent tissue damage. Pathogenic Th1 and Th17 cells can secrete signature proinflammatory cytokines, including interferon (IFN)-γ and IL-17, however Tregs can suppress effector cells and dampen a wide spectrum of immune responses. Melatonin (MLT) can regulate the humoral and cellular immune responses, as well as cell proliferation and immune mediators. Treatment with MLT directly interferes with T cell differentiation, controls the balance between pathogenic and regulatory T cells and regulates inflammatory cytokine release. MLT can promote the differentiation of type 1 regulatory T cells via extracellular signal regulated kinase 1/2 (Erk1/2) and retinoic acid-related orphan receptor-α (ROR-α) and suppress the differentiation of Th17 cells via the inhibition of ROR-γt and ROR-α expression through NFIL3. Moreover, MLT inhibits NF-κB signaling pathway to reduce TNF-α and IL-1β expression, promotes Nrf2 gene and protein expression to reduce oxidative and inflammatory states and regulates Bax and Bcl-2 to reduce apoptosis; all of which alleviate the development of autoimmune diseases. Thus, MLT can serve as a potential new therapeutic target, creating opportunities for the treatment of autoimmune diseases. This review aims to highlight recent advances in the role of MLT in several autoimmune diseases with particular focus given to novel signaling pathways involved in Th17 and Tregs as well as cell proliferation and apoptosis.     

Changes to the Natural Killer Cell Repertoire after Therapeutic Hepatitis B DNA Vaccination

Background

Improvements to the outcome of adaptive immune responses could be achieved by inducing specific natural killer (NK) cell subsets which can cooperate with dendritic cells to select efficient T cell responses. We previously reported the induction or reactivation of T cell responses in chronic hepatitis B patients vaccinated with a DNA encoding hepatitis B envelope proteins during a phase I clinical trial.

Methodology/Principal Findings

In this study, we examined changes in the peripheral NK cell populations occurring during this vaccine trial using flow cytometry analysis. Despite a constant number of NK cells in the periphery, a significant increase in the CD56^bright population was observed after each vaccination and during the follow up. Among the 13 different NK cell markers studied by flow cytometry analysis, the expression of CD244 and NKG2D increased significantly in the CD56^bright NK population. The ex vivo CD107a expression by CD56^bright NK cells progressively increased in the vaccinated patients to reach levels that were significantly higher compared to chronically HBV-infected controls. Furthermore, modifications to the percentage of the CD56^bright NK cell population were correlated with HBV-specific T cell responses detected by the ELISPOT assay.

Conclusions/Significance

These changes in the CD56^bright population may suggest a NK helper effect on T cell adaptive responses. Activation of the innate and adaptive arms of the immune system by DNA immunization may be of particular importance to the efficacy of therapeutic interventions in a context of chronic infections.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00988767","term_id":"NCT00988767"}}NCT00988767     

Expression and Function of TNF and IL-1 Receptors on Human Regulatory T Cells

Regulatory T cells (Tregs) suppress immune activation and are critical in preventing autoimmune diseases. While the ability of Tregs to inhibit proliferation of other T cells is well established, it is not yet clear whether Tregs also modulate inflammatory cytokines during an immune response. Here, we show that the expression of inflammatory cytokine receptors IL-1R1 and TNFR2 were higher on resting mature Tregs compared to naïve or memory T cells. While upon activation through the T cell receptor (TCR), expression of IL-1R1 and TNFR2 were upregulated on all T cell subsets, IL-1R1 maintained significantly higher expression on activated Tregs as compared to other T cell subsets. The decoy receptor for IL-1 (IL-1R2) was not expressed by any of the resting T cells but was rapidly upregulated and preferentially expressed upon TCR-stimulation on Tregs. In addition, we found that Tregs also expressed high levels of mRNA for IL-1 antagonist, IL-1RA. TCR-stimulation of naïve T cells in the presence of TGFβ, which induces FOXP3 expression, however did not result in upregulation of IL-1R1 or IL-1R2. In addition, ectopic expression of FOXP3 in non-Tregs, while causing significant upregulation of IL-1R1 and IL-1R2, did not achieve the levels seen in bona fide Tregs. We also determined that resting human Tregs expressing IL-1R1 did not have higher suppressive capacity compared to IL-1R1- Tregs, suggesting that IL-1R1 does not discriminate suppressive resting Tregs in healthy individuals. Functionally, activated human Tregs displayed a capacity to neutralize IL-1β, which suggests a physiological significance for the expression of IL-1 decoy receptor on Tregs. In conclusion, our findings that human Tregs preferentially express receptors for TNF and IL-1 suggest a potential function in sensing and dampening local inflammation.     

Long-Term Effects of Interprofessional Biopsychosocial Rehabilitation for Adults with Chronic Non-Specific Low Back Pain: A Multicentre,Quasi-Experimental Study

Background

Improvement of the long-term effectiveness of multidisciplinary ortho-paedic rehabilitation (MOR) in the management of chronic non-specific low back pain (CLBP) remains a central issue for health care in Germany. We developed an interprofessional and interdisciplinary, biopsychosocial rehabilitation concept named “PASTOR” to promote self-management in adults with CLBP and compared its effectiveness with the current model of MOR.

Methods

A multicentre quasi-experimental study with three measurement time points was implemented. 680 adults aged 18 to 65 with CLBP were assed for eligibil-ity in three inpatient rehabilitation centres in Germany. At first the effects of the MOR, with a total extent of 48 hours (control group), were assessed. Thereafter, PASTOR was implemented and evaluated in the same centres (intervention group). It consisted of six interprofessional modules, which were provided on 12 days in fixed groups, with a total extent of 48 hours. Participants were assessed with self-report measures at baseline, discharge, and 12 months for functional ability (primary outcome) using the Hannover Functional Ability Questionnaire (FFbH-R) and vari-ous secondary outcomes (e.g. pain, health status, physical activity, pain coping, pain-related cognitions).

Results

In total 536 participants were consecutively assigned to PASTOR (n=266) or MOR (n=270). At 12 months, complete data of 368 participants was available. The adjusted between-group difference in the FFbH-R at 12 months was 6.58 (95% CI 3.38 to 9.78) using complete data and 3.56 (95% CI 0.45 to 6.67) using available da-ta, corresponding to significant small-to-medium effect sizes of d=0.42 (p<0.001) and d=0.10 (p=0.025) in favour of PASTOR. Further improvements in secondary out-comes were also observed in favour of PASTOR.

Conclusion

The interprofessional and interdisciplinary, biopsychosocial rehabilita-tion program PASTOR shows some improvements of the long-term effectiveness of inpatient rehabilitation in the management of adults with CLBP. Further insights into mechanisms of action of complex intervention programs are required.

Trial Registration

ClinicalTrials.gov NCT02056951     

The interaction between regulatory T cells and NKT cells in the liver: a CD1d bridge links innate and adaptive immunity

Background/Aims

Regulatory T cells (Tregs) and natural killer T (NKT) cells are two distinct lymphocyte subsets that independently regulate hepatic adaptive and innate immunity, respectively. In the current study, we examine the interaction between Tregs and NKT cells to understand the mechanisms of cross immune regulation by these cells.

Methods

The frequency and function of Tregs were evaluated in wild type and NKT cell deficient (CD1dko) mice. In vitro lymphocyte proliferation and apoptosis assays were performed with NKT cells co-cultured with Tregs. The ability of Tregs to inhibit NKT cells in vivo was examined by adoptive transfer of Tregs in a model of NKT cell mediated hepatitis.

Results

CD1dko mice have a significant reduction in hepatic Tregs. Although, the Tregs from CD1dko mice remain functional and can suppress conventional T cells, their ability to suppress activation induced NKT cell proliferation and to promote NKT cell apoptosis is greatly diminished. These effects are CD1d dependent and require cell to cell contact. Adoptive transfer of Tregs inhibits NKT cell-mediated liver injury.

Conclusions

NKT cells promote Tregs, and Tregs inhibit NKT cells in a CD1d dependent manner requiring cell to cell contact. These cross-talk immune regulations provide a linkage between innate and adaptive immunity.     

Cigarette Smoking Promotes Inflammation in Patients with COPD by Affecting the Polarization and Survival of Th/Tregs through Up-Regulation of Muscarinic Receptor 3 and 5 Expression

Background

CD4⁺ T cells in the lung are involved in the pathogenesis of chronic obstructive pulmonary disease (COPD), although CD4⁺ T cell subsets and the direct effect of smoking on these cells, especially the expression of MRs, have not been comprehensively examined.

Methods

First, circulating CD4⁺ T cell subsets in healthy nonsmokers, patients with SCOPD and patients with AECOPD were evaluated by flow cytometry. Then, differentiation experiments were carried out using RT-PCR, and Ki-67/Annexin V antibodies were used to measure proliferation and apoptosis. We also explored the impact of CSE on the differentiation and survival of CD4⁺Th/Tregs and examined the expression of MRs in healthy nonsmokers and patients with SCOPD.

Results

We found the percentages of circulating Th1 and Th17 cells were increased in patients with AECOPD, while the percentage of Th2 cells was decreased in patients with SCOPD. The percentages of Th10 cells were decreased in both patients with SCOPD and patients with AECOPD, while the percentages of Tregs were increased. In addition, the percentages of CD4⁺α-7⁺ T cells were decreased in patients with SCOPD and patients with AECOPD. However, only the decrease observed in patients with AECOPD was significant. In vitro studies also revealed MR expression affected the polarization of T cells, with different CD4⁺ T cell subtypes acquiring different MR expression profiles. The addition of CSE facilitated CD4⁺ T cell polarization towards pro-inflammatory subsets (Th1 and Th17) and affected the survival of CD4⁺ T cells and Treg cells by up-regulating the expression of MR3 and 5, resulting in an imbalance of CD4⁺ T cell subsets.

Conclusions

Our findings suggest an imbalance of circulating CD4⁺ T cell subsets is involved in COPD pathogenesis in smokers. Cigarette smoking may contribute to this imbalance by affecting the polarization and survival of Th/Tregs through the up-regulation of MR3 and MR5.     

Elevated proinflammatory cytokine production by a skewed T cell compartment requires monocytes and promotes inflammation in type 2 diabetes

An appropriate balance between proinflammatory (Th17 and Th1) and anti-inflammatory (regulatory T cells [Tregs] and Th2) subsets of T cells is critical to maintain homeostasis and avoid inflammatory disease. Type 2 diabetes (T2D) is a chronic inflammatory disease promoted by changes in immune cell function. Recent work indicates T cells are important mediators of inflammation in a mouse model of T2D. These studies identified an elevation in the Th17 and Th1 subsets with a decrease in the Treg subset, which culminates in inflammation and insulin resistance. Based on these data, we tested the hypothesis that T cells in T2D patients are skewed toward proinflammatory subsets. Our data show that blood from T2D patients has increased circulating Th17 cells and elevated activation of Th17 signature genes. Importantly, T cells required culture with monocytes to maintain Th17 signatures, and fresh ex vivo T cells from T2D patients appeared to be poised for IL-17 production. T cells from T2D patients also have increased production of IFN-γ, but produce healthy levels of IL-4. In contrast, T2D patients had decreased percentages of CD4(+) Tregs. These data indicate that T cells in T2D patients are naturally skewed toward proinflammatory subsets that likely promote chronic inflammation in T2D through elevated cytokine production. Potential therapies targeted toward resetting this balance need to be approached with caution due to the reciprocal relationship between Th17 cells and Tregs. Understanding the unique aspects of T2D T cells is essential to predict outcomes of such treatments.     

First insight into the kinome of human regulatory T cells

Regulatory T cells (Tregs) are essential for controlling peripheral tolerance by the active suppression of various immune cells including conventional T effector cells (Teffs). Downstream of the T cell receptor (TCR), more than 500 protein kinases encoded by the human genome have to be considered in signaling cascades regulating the activation of Tregs and Teffs, respectively. Following TCR engagement, Tregs posses a number of unique attributes, such as constitutive expression of Foxp3, hyporesponsiveness and poor cytokine production. Furthermore, recent studies showed that altered regulation of protein kinases is important for Treg function. These data indicate that signaling pathways in Tregs are distinctly organized and alterations at the level of protein kinases contribute to the unique Treg phenotype. However, kinase-based signaling networks in Tregs are poorly understood and necessitate further systematic characterization. In this study, we analyzed the differential expression of kinases in Tregs and Teffs by using a kinase-selective proteome strategy. In total, we revealed quantitative information on 185 kinases expressed in the human CD4(+) T cell subsets. The majority of kinases was equally abundant in both T cell subsets, but 11 kinases were differentially expressed in Tregs. Most strikingly, Tregs showed an altered expression of cell cycle kinases including CDK6. Quantitative proteomics generates first comparative insight into the kinase complements of the CD4(+) Teff and Treg subset. Treg-specific expression pattern of 11 protein kinases substantiate the current opinion that TCR-mediated signaling cascades are altered in Tregs and further suggests that Tregs exhibit significant specificities in cell-cycle control and progression.     

The Metalloprotease ADAM12 Regulates the Effector Function of Human Th17 Cells

A key modulator of immune homeostasis, TGFβ has an important role in the differentiation of regulatory T cells (Tregs) and IL-17-secreting T cells (Th17). How TGFβ regulates these functionally opposing T cell subsets is not well understood. We determined that an ADAM family metalloprotease called ADAM12 is specifically and highly expressed in both Tregs and CCR6+ Th17 cells. ADAM12 is induced in vitro upon differentiation of naïve T cells to Th17 cells or IL-17-secreting Tregs. Remarkably, silencing ADAM12 expression in CCR6+ memory T cells enhances the production of Th17 cytokines, similar to suppressing TGFβ signaling. Further, ADAM12 knockdown in naïve human T cells polarized towards Th17/Treg cells, or ectopically expressing RORC, greatly enhances IL-17-secreting cell differentiation, more potently then inhibiting TGFβ signals. Together, our findings reveal a novel regulatory role for ADAM12 in Th17 cell differentiation or function and may have implications in regulating their aberrant responses during immune pathologies.     

Phase I Clinical Trial of Fibronectin CH296-Stimulated T Cell Therapy in Patients with Advanced Cancer

Background

Previous studies have demonstrated that less-differentiated T cells are ideal for adoptive T cell transfer therapy (ACT) and that fibronectin CH296 (FN-CH296) together with anti-CD3 resulted in cultured cells that contain higher amounts of less-differentiated T cells. In this phase I clinical trial, we build on these prior results by assessing the safety and efficacy of FN-CH296 stimulated T cell therapy in patients with advanced cancer.

Methods

Patients underwent fibronectin CH296-stimulated T cell therapy up to six times every two weeks and the safety and antitumor activity of the ACT were assessed. In order to determine immune function, whole blood cytokine levels and the number of peripheral regulatory T cells were analyzed prior to ACT and during the follow up.

Results

Transferred cells contained numerous less-differentiated T cells greatly represented by CD27+CD45RA+ or CD28+CD45RA+ cell, which accounted for approximately 65% and 70% of the total, respectively. No ACT related severe or unexpected toxicities were observed. The response rate among patients was 22.2% and the disease control rate was 66.7%.

Conclusions

The results obtained in this phase I trial, indicate that FN-CH296 stimulated T cell therapy was very well tolerated with a level of efficacy that is quite promising. We also surmise that expanding T cell using CH296 is a method that can be applied to other T- cell-based therapies.

Trial Registration

UMIN UMIN000001835     

A Phase I Randomized Therapeutic MVA-B Vaccination Improves the Magnitude and Quality of the T Cell Immune Responses in HIV-1-Infected Subjects on HAART

Trial Design

Previous studies suggested that poxvirus-based vaccines might be instrumental in the therapeutic HIV field. A phase I clinical trial was conducted in HIV-1-infected patients on highly active antiretroviral therapy (HAART), with CD4 T cell counts above 450 cells/mm³ and undetectable viremia. Thirty participants were randomized (2:1) to receive either 3 intramuscular injections of MVA-B vaccine (coding for clade B HIV-1 Env, Gag, Pol and Nef antigens) or placebo, followed by interruption of HAART.

Methods

The magnitude, breadth, quality and phenotype of the HIV-1-specific T cell response were assayed by intracellular cytokine staining (ICS) in 22 volunteers pre- and post-vaccination.

Results

MVA-B vaccine induced newly detected HIV-1-specific CD4 T cell responses and expanded pre-existing responses (mostly against Gag, Pol and Nef antigens) that were high in magnitude, broadly directed and showed an enhanced polyfunctionality with a T effector memory (TEM) phenotype, while maintaining the magnitude and quality of the pre-existing HIV-1-specific CD8 T cell responses. In addition, vaccination also triggered preferential CD8⁺ T cell polyfunctional responses to the MVA vector antigens that increase in magnitude after two and three booster doses.

Conclusion

MVA-B vaccination represents a feasible strategy to improve T cell responses in individuals with pre-existing HIV-1-specific immunity.

Trial Registration

ClinicalTrials.gov NCT01571466     

Reconstitution of Intestinal CD4 and Th17 T Cells in Antiretroviral Therapy Suppressed HIV-Infected Subjects: Implication for Residual Immune Activation from the Results of a Clinical Trial

Introduction

During HIV infection the severe depletion of intestinal CD4⁺ T-cells is associated with microbial translocation, systemic immune activation, and disease progression. This study examined intestinal and peripheral CD4⁺ T-cell subsets reconstitution under combined antiretroviral therapy (cART), and systemic immune activation markers.

Methods

This longitudinal single-arm pilot study evaluates CD4⁺ T cells, including Th1 and Th17, in gut and blood and soluble markers for inflammation in HIV-infected individuals before (M0) and after eight (M8) months of cART. From January 2010 to December 2011, 10 HIV-1 naïve patients were screened and 9 enrolled. Blood and gut CD4⁺ T-cells subsets and cellular immune activation were determined by flow-cytometry and plasma soluble CD14 by ELISA. CD4⁺ Th17 cells were detected in gut biopsies by immunohistochemistry. Microbial translocation was measured by limulus-amebocyte-lysate assay to detect bacterial lipopolysaccharide (LPS) and PCR Real Time to detect plasma bacterial 16S rDNA.

Results

Eight months of cART increased intestinal CD4⁺ and Th17 cells and reduced levels of T-cell activation and proliferation. The magnitude of intestinal CD4⁺ T-cell reconstitution correlated with the reduction of plasma LPS. Importantly, the magnitude of Th17 cells reconstitution correlated directly with blood CD4⁺ T-cell recovery.

Conclusion

Short-term antiretroviral therapy resulted in a significant increase in the levels of total and Th17 CD4⁺ T-cells in the gut mucosa and in decline of T-cell activation. The observation that pre-treatment levels of CD4⁺ and of CD8⁺ T-cell activation are predictors of the magnitude of Th17 cell reconstitution following cART provides further rationale for an early initiation of cART in HIV-infected individuals.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT02097381","term_id":"NCT02097381"}}NCT02097381     

Blunted IL17/IL22 and Pro-Inflammatory Cytokine Responses in the Genital Tract and Blood of HIV-Exposed, Seronegative Female Sex Workers in Kenya

Background

Identifying the immune correlates of reduced susceptibility to HIV remains a key goal for the HIV vaccine field, and individuals who are HIV-exposed, seronegative (HESN) may offer important clues. Reduced systemic immune activation has been described in HESN individuals. Conversely, pro-inflammatory T cell subsets, particularly CD4+ T cells producing the cytokine IL17 (Th17 cells), may represent a highly susceptible target for HIV infection after sexual exposure. Therefore, we characterized the cellular pro-inflammatory and IL17/IL22 cytokine immune milieu in the genital mucosa and blood of HESN female sex workers (FSWs).

Methods and Results

Blinded lab personnel characterized basal and mitogen-induced gene and cytokine immune responses in the cervix and blood of HESN FSWs (n = 116) and non-FSW controls (n = 17) using qPCR and ELISA. IL17 and IL22 production was significantly reduced in both the cervix and blood of HESNs, both in resting cells and after mitogen stimulation. In addition, HESN participants demonstrated blunted production of both pro-inflammatory cytokines and β-chemokines.

Discussion and Conclusions

We conclude that HIV exposure without infection was associated with blunted IL17/IL22 and pro-inflammatory responses, both systemically and at the site of mucosal HIV exposure. It will be important for further studies to examine the causal nature of the association and to define the cell subsets responsible for these differences.