Impact Of CD4 Research Articles

Impact of CD4+ T lymphocytes on the cellular and molecular milieu of the vaginal mucosa following HSV-2 challenge of immune guinea pigs

CD4+ and CD8+ tissue resident memory cells (TRM) express many shared anti-viral activities upon re-exposure to virus. CD4+ T cells were depleted from HSV-immune guinea pigs to identify CD4-dependent functions in the vaginal mucosa following HSV-2 challenge. The incidence of animals shedding HSV-2 fell rapidly after challenge in control animals but remained significantly higher through day four post infection in CD4-depleted animals. Genes encoding CD14, IFN-γ, CCL2, and CCL5 were up-regulated in the vaginal mucosa of both groups following challenge. However, significantly higher expression of CD107b, IL-15, and TLR9 but lower expression of CD20, IL-21, and CCL5 was detected in CD4-depleted- compared to control-treated animals. Further, antigen stimulation of CD4+ TRM increased the expression of IFN-γ, IL-2, IL-21, IL-17A, and CCL5. The impact of these gene expression patterns on the recruitment and maintenance of the cellular milieu of the vaginal mucosa upon virus challenge is discussed.

A glance through the effects of CD4+ T cells, CD8+ T cells, and cytokines on Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia. Unfortunately, despite numerous studies, an effective treatment for AD has not yet been established. There is remarkable evidence indicating that the innate immune mechanism and adaptive immune response play significant roles in the pathogenesis of AD. Several studies have reported changes in CD8+ and CD4+ T cells in AD patients.This mini-review article discusses the potential contribution of CD4+ and CD8+ T cells reactivity to amyloid β (Aβ) protein in individuals with AD. Moreover, this mini-review examines the potential associations between T cells, heme oxygenase (HO), and impaired mitochondria in the context of AD. While current mathematical models of AD have not extensively addressed the inclusion of CD4+ and CD8+ T cells, there exist models that can be extended to consider AD as an autoimmune disease involving these T cell types. Additionally, the mini-review covers recent research that has investigated the utilization of machine learning models, considering the impact of CD4+ and CD8+ T cells.

CD4+ T-cell epitope-based heterologous prime-boost vaccination potentiates anti-tumor immunity and PD-1/PD-L1 immunotherapy

BackgroundAntitumor therapeutic vaccines are generally based on antigenic epitopes presented by major histocompatibility complex (MHC-I) molecules to induce tumor-specific CD8+ T cells. Paradoxically, continuous T cell receptor (TCR) stimulation from...

Harnessing Antitumor CD4+ T Cells for Cancer Immunotherapy.

Simple SummaryDiverse evidence revealed that CD4+ T cells play an important role in antitumor immunity by promoting or suppressing cytotoxic T cell responses. This review outlines the role of CD4+ T subsets within the tumor microenvironment and summarizes the latest progress regarding their potentials in cancer immunotherapy and methods for improving outcomes in cancer strategies by modulating CD4+ T responses.Over the past decades, CD4+ T cells have been considered as a supporting actor in the fields of cancer immunotherapy. Until recently, accumulating evidence has demonstrated the critical role of CD4+ T cells during antitumor immunity. CD4+ T cells can either suppress or promote the antitumor cytotoxic CD8+ T cell responses, either in secondary lymphoid organs or in the tumor. In this review, we provide an overview of the multifaceted role of different CD4+ T cell subsets in cancer immune response and their contribution during cancer therapies. Specifically, we focus on the latest progress regarding the impact of CD4+ T cell modulation on immunotherapies and other cancer therapies and discuss the prospect for harnessing CD4+ T cells to control tumor progression and prevent recurrence in patients.

Prevalence, risk factors and impact of cellular immunity on intestinal parasitosis among people living with HIV at Auchi, Edo State, Nigeria.

This study was sought to determine the impact of CD4+ T-cell count and associated risk factors with intestinal parasitosis in people living with HIV (PLHIV) in Central Hospital, Auchi, Edo State, Nigeria. One hundred and seventy (170) HIV-seropositive subjects were enrolled in the study from 24 August 2015 to 22 January 2016. Sociodemographic data were assessed using structured questionnaires. Blood and stool samples were collected from every participant. CD4+ T-cell count and stool parasitology were performed. The prevalence of intestinal parasites was 44.7%. Helminthiasis (67%) was a predominant infection in the study, while 32.9% had protozoasis. Specifically, Ancylostoma duodenale (33.3%) was the most common helminth, and Trichuristrichiura (7.8%), the least. However, Strongyloides stercoralis, Ascarislumbricoides and Hymenolepis nana were 13.7%, 31.5% and 13.7%, respectively. Cryptosporidium spp. (25.0%) was the only protozoan. Lower CD4+ T-cell count, ART naivety (OR = 2.62 p < 0.05), residence in a rural setting (OR = 0.89, p < 0.05), and farming occupation (OR = 1.70, p < 0.05) were associated with the prevalence of intestinal parasitosis among PLHIV. This study revealed a significantly high prevalence of intestinal parasitosis in ART naive PLHIV with reduced CD4+ count. Hence, it is recommended to frequently test for intestinal parasitosis and commencement of ART in all PLHIV to improve their health and longevity.

Early CD4+ T cell reconstitution as predictor of outcomes after allogeneic hematopoietic cell transplantation

Background: An association between early CD4+ T cell immune reconstitution (CD4+ IR) and survival after T-replete allogeneic hematopoietic cell transplantation (HCT) has been previously reported. Here we report validation of this relationship in a separate cohort that included recipients of ex vivo T-cell-depleted (TCD) HCT. We studied the relationship between CD4+ IR and clinical outcomes.Methods: A retrospective analysis of children/young adults receiving their first allogeneic HCT for any indication between January 2008 and December 2017 was performed. We related early CD4+ IR (defined as achieving >50 CD4+ T cells/µL on two consecutive measures within 100 days of HCT) to overall survival (OS), relapse, non-relapse mortality (NRM), event-free survival (EFS) and acute graft-versus-host disease (aGVHD). Fine and Gray competing risk models and Cox proportional hazard models were used.Results: In this analysis, 315 patients with a median age of 10.4 years (interquartile range 5.0–16.5 years) were included. The cumulative incidence of CD4+ IR at 100 days was 66.7% in the entire cohort, 54.7% in TCD (N = 208, hazard ratio [HR] 0.47, P < 0.001), 90.0% in uCB (N = 40) and 89.6% in T-replete (N = 47) HCT recipients. In multi-variate analyses, not achieving early CD4+ IR was a predictor of inferior OS (HR 2.35, 95% confidence interval [CI] 1.46–3.79, P < 0.001) and EFS (HR 1.80, 95% CI 1.20–2.69, P = 0.004) and increased NRM (HR 6.58, 95% CI 2.82–15.38, P < 0.001). No impact of CD4+ IR on relapse or aGVHD was found. Within the TCD group, similar associations were observed.Conclusion: In this HCT cohort, including recipients of TCD HCT, we confirmed that early CD4+ IR was an excellent predictor of outcomes. Finding strategies to predict or improve CD4+ IR may influence outcomes.

Early CD4+ T Cell Reconstruction As Predictor for Outcomes after Allogeneic Hematopoietic Cell Transplantation in Pediatric and Young Adult Patients: A Validation Cohort Analyses

BackgroundAn association between early CD4+ recovery and survival after T-replete allogeneic Hematopoietic Cell Transplantation (HCT) in pediatric and young adult patients was previously reported (Admiraal et al, JACI 2017). However, validation in a separate cohort and in patients undergoing ex vivo T cell depleted (TCD) HCT is lacking. Therefore, we studied the relation between CD4+ T cell immune reconstitution (IR) and clinical outcomes, in a setting where a majority of patients received a TCD HCT.MethodsWe performed a retrospective analysis of data on children and young adults receiving their 1st allo-HCT for any indication between Jan-2008 and Dec-2017. The main goal was to relate CD4 IR (measured every 2-4 wks), within 100 days after HCT to the outcomes of interest. The main outcome of interest was overall survival (OS). Other outcomes of interest were non-relapse mortality (NRM), event-free survival (EFS), relapse and acute graft-versus-host-disease (aGvHD) grade 2-4. CD4 IR was defined according to previous studies, as having more than 50 CD4+ T cells/uL at 2 consecutive measurements within 100 days. Cox-proportional hazard and Fine and Gray competing risk models were used (R version 1.2.1335)Findings315 patients (220 Malignant, 95 non-malignant indications) were included, with a median age of 10.4 years (IQR 5.0–16.5yr). 66.0% (208/315) of the patients received a TCD graft, 12.7% (40/315) received cord blood, and 21.2% (67/315) T-replete bone marrow. The CI of CD4+ IR at 100 days was 66.7%. Incidence of achieving CD4 IR after TCD was lower compared to other cell sources, 54.7% vs 90.0% after cord blood and 89.6% after T-replete bone marrow (HR 0.47, P<0.001). The other multivariate predictors for CD4+ IR were age (continuous; 0.97, p=0.002) and mismatch MUD (HR 0.5, p=0.005). No impact of CD4+ IR on relapse or aGvHD grade 2-4 was found. Absence of CD4 IR was found to be a predictor for inferior OS (HR: 2.35, 95% CI 1.46-3.79, P<0.001; Fig 1A), and EFS (HR: 1.80, 95% CI 1.20–2.69, P=0.004) and increased NRM (HR: 6.58, 95% CI 2.82–15.38, P < 0.001; Fig 1B).InterpretationWe confirmed, in a separate HCT cohort, that early CD4 IR is a strong predictor for outcomes. Early CD4+ IR is an excellent biomarker for outcomes after HCT and should therefore be considered as a standard outcome measure. Finding strategies to better predict CD4+ T cell recovery after HCT may influence outcomes/survival in the future. An association between early CD4+ recovery and survival after T-replete allogeneic Hematopoietic Cell Transplantation (HCT) in pediatric and young adult patients was previously reported (Admiraal et al, JACI 2017). However, validation in a separate cohort and in patients undergoing ex vivo T cell depleted (TCD) HCT is lacking. Therefore, we studied the relation between CD4+ T cell immune reconstitution (IR) and clinical outcomes, in a setting where a majority of patients received a TCD HCT. We performed a retrospective analysis of data on children and young adults receiving their 1st allo-HCT for any indication between Jan-2008 and Dec-2017. The main goal was to relate CD4 IR (measured every 2-4 wks), within 100 days after HCT to the outcomes of interest. The main outcome of interest was overall survival (OS). Other outcomes of interest were non-relapse mortality (NRM), event-free survival (EFS), relapse and acute graft-versus-host-disease (aGvHD) grade 2-4. CD4 IR was defined according to previous studies, as having more than 50 CD4+ T cells/uL at 2 consecutive measurements within 100 days. Cox-proportional hazard and Fine and Gray competing risk models were used (R version 1.2.1335) 315 patients (220 Malignant, 95 non-malignant indications) were included, with a median age of 10.4 years (IQR 5.0–16.5yr). 66.0% (208/315) of the patients received a TCD graft, 12.7% (40/315) received cord blood, and 21.2% (67/315) T-replete bone marrow. The CI of CD4+ IR at 100 days was 66.7%. Incidence of achieving CD4 IR after TCD was lower compared to other cell sources, 54.7% vs 90.0% after cord blood and 89.6% after T-replete bone marrow (HR 0.47, P<0.001). The other multivariate predictors for CD4+ IR were age (continuous; 0.97, p=0.002) and mismatch MUD (HR 0.5, p=0.005). No impact of CD4+ IR on relapse or aGvHD grade 2-4 was found. Absence of CD4 IR was found to be a predictor for inferior OS (HR: 2.35, 95% CI 1.46-3.79, P<0.001; Fig 1A), and EFS (HR: 1.80, 95% CI 1.20–2.69, P=0.004) and increased NRM (HR: 6.58, 95% CI 2.82–15.38, P < 0.001; Fig 1B). We confirmed, in a separate HCT cohort, that early CD4 IR is a strong predictor for outcomes. Early CD4+ IR is an excellent biomarker for outcomes after HCT and should therefore be considered as a standard outcome measure. Finding strategies to better predict CD4+ T cell recovery after HCT may influence outcomes/survival in the future. Figure 1.Figure 1 View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Abstract LB-019: Anti-CD4 monoclonal antibody immunotherapy exerts an antitumor effect by replacing the T cell receptor repertoire in patients with gastrointestinal cancer

Abstract Background: Depletion of CD4+ immunosuppressive cells using an anti-CD4 monoclonal antibody (mAb) results in a strong antitumor effect by expanding a broad variety of tumor-reactive CD8+ T cells in mice. However, the impact of CD4+ cell depletion on the immune response in cancer patients is not known. Here, we analyzed changes in the T cell receptor (TCR) repertoire of blood and tumor biopsy samples following depletion of CD4+ cells by IT1208, a defucosylated humanized anti-CD4 mAb, in a first-in-human clinical trial. Methods: Patients with advanced gastrointestinal tumors were treated with 0.1 or 1.0 mg/kg IT1208. The count and immunophenotype of peripheral blood T cells were analyzed by flow cytometry. Libraries for TCR sequencing were prepared from purified blood CD4+ and CD8+ T cells, and unfractionated tumor biopsies, collected before and after IT1208 treatment. TCR sequencing was performed using Ion Proton and Ion S5 sequencers, then changes in the repertoire, and temporal and inter-organ overlap after IT1208 treatment, were analyzed. Results: Among 11 patients enrolled in the trial, one achieved a durable partial response and two achieved stable disease lasting at least 3 months. The blood CD4+ T cell count decreased rapidly after IT1208 treatment and remained low during the observation period. In contrast, the blood CD8+ T cell count increased from day 29 after treatment compared to baseline in most patients, resulting in a remarkably decreased CD4/8 ratio. Immunohistological analysis showed a decrease of CD4+ T cells in the tumor after IT1208 treatment. In the TCR repertoire analysis, a decrease in similarity and increase in clonality were observed in blood CD4+ and CD8+ T cells after IT1208 treatment, particularly in patients receiving 1.0 mg/kg IT1208. These changes persisted to at least day 60 after treatment in some cases. Temporal tracking of the blood TCR repertoire revealed that the number of expanded CD4+ T cell clones increased in a dose-dependent manner. In addition, the number of contracted CD8+ T cell clones showed a strong correlation with the increased CD8+ T cell count and CD45RAhi CCR7- effector population among CD8+ T cells in the blood. We also analyzed blood-tumor overlapping CD8+ T cell clones to investigate changes in potential tumor-associated clones. The frequency of overlapping CD8+ T cell clones in the blood tended to increase after treatment. Interestingly, an increased frequency of these overlapping clones in the blood was associated with maximum shrinkage in the tumor diameter. Conclusion: IT1208 treatment depleted CD4+ T cells from the blood and tumor. This depletion promoted the replacement of CD4+ and CD8+ T cell repertoire systemically. The IT1208 treatment-induced increase of tumor-associated CD8+ T cell clones may be associated with its anti-tumor effect in cancer patients. Citation Format: Hiroyasu Aoki, SATOSHI UEHA, Shigeyuki Shichino, Haru Ogiwara, Kohei Shitara, Tetsuya Nakatsura, Toshihiro Suzuki, Manami Shimomura, Toshiaki Yoshikawa, Kayoko Shoda, Shigehisa Kitano, Makiko Yamashita, Takayuki Nakayama, Akihiro Sato, Sakiko Kuroda, Masashi Wakabayashi, Shogo Nomura, Shoji Yokochi, Satoru Ito, Toshihiko Doi, Kouji Matsushima. Anti-CD4 monoclonal antibody immunotherapy exerts an antitumor effect by replacing the T cell receptor repertoire in patients with gastrointestinal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-019.

Abstract A067: Cognate interaction with CD4+ T-cells instructs M2-like macrophages to acquire M1-like phenotype

Abstract Current tumor immunotherapy approaches are based on application of checkpoint inhibitors, such as monoclonal antibodies against PD-1/PD-L1 and CTLA-4 or adoptive T-cell therapy using ex vivo expanded TILs or genetically modified autologous T-cells expressing recombinant T-cell receptors (TCRs) or chimeric antigen receptors (CARs). However, the success of these therapeutic strategies is often limited by various inhibitory immune cell types accumulating in the tumor. In particular, tumor-associated macrophages (TAMs) contribute to the immune suppressive tumor micro-milieu, since so-called M2-like macrophages suppress the function of T effector cells and promote the differentiation of regulatory T-cells (Treg) through secretion of inhibitory cytokines such as TGF-β and IL10. Tumor antigen-specific CD4+ T effector cells, on the other hand, can essentially sustain antitumoral immune responses as shown for various tumor entities. In fact, using peritoneal exudate cells (PECs) as source for macrophages we demonstrate that MHC II restricted interaction between ovalbumin (OVA) specific CD4+ T-cells and M2-like macrophages drives M1 polarization. This was confirmed by detailed gene and protein expression analyses as well as functional assays testing phagocytic and pinocytic activities of repolarized macrophages. Moreover, in a set of preclinical experiments, adoptive transfer of CD4+, OVA-specific OT-II cells into C57BL/6 mice bearing OVA expressing IAb-/- tumors resulted in increased intratumoral number of M1-like TAMs as determined by gene expression analysis and flow cytometry. Furthermore, we observed a significant survival benefit of mice treated with a combination of OVA-specific CD4+ (OT-II) and CD8+ (OT-I) cells after transplantation of B16F10-Ova tumors and a complete response in some mice that rejected the tumor cells also upon a later re-challenge. While the antitumoral effect of this adoptive transfer experiment has been already described, we now offer a possible explanation for the supportive effect of specific CD4+ cells on co-transferred CD8+ cells. Taken together, the instructive impact of CD4+ T-cells on M2-like macrophages described in this presentation points towards a so far underestimated function of the CD4+ T-cell / TAM axis in reconditioning the immunosuppressive tumor micro-milieu. Citation Format: David Eisel, Wolfram Osen, Krishna Das, Franziska Marie-Claire Hoerhold, Rainer König, Stefan B. Eichmüller. Cognate interaction with CD4+ T-cells instructs M2-like macrophages to acquire M1-like phenotype [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A067.

Impact of CD4+ blood cell count and HIV viral load on treatment response with direct acting antivirals in HIV and HCV coinfected patients: insights from the German Hepatitis C-Registry

Background: Direct-acting antivirals (DAAs) lead to high cure rates of Hepatitis C Virus (HCV) infections in HIV/HCV coinfected patients. Recent data suggest that treatment failures occur more often in HIV/HCV coinfected persons.Objective: We aimed to identify risk factors for treatment failure in coinfected patients.Methods: We analyzed data collected from the German Hepatitis C-Registry (DHC-R, Trials Registration number DRKS00009717). 437 HIV/HCV coinfected patients were included. Sustained virological response (SVR) rates and the impact of CD4+ count, HIV viral load, liver cirrhosis and splenomegaly were evaluated.Results: 83.5% (365/437) of the patients were male (average age: 46.6 ± 9.2 y). Most patients received antiretroviral therapy (ART) (88.1%; 385/437), had a HIV RNA ≤40 copies/ml (88.5%; 285/322) and were infected with HCV genotype (GT) 1 (77.6%; 339/437). Overall SVR12 rate was 92% (402/437). In patients with HIV RNA ≤40 copies/ml and >40 copies/ml SVR12 rates were 93.2% (272/292) and 85.3%, respectively (29/34; p = .11). SVR12 rates were 91.8% (45/49) and 92.7% (253/273; p = .84) in patients with a CD4+ <350/µl and ≥350/µl. We observed no difference in either of the subgroups in patients with cirrhosis or splenomegaly. In the univariate logistic regression analysis none of the analyzed HIV or HCV specific parameters, liver cirrhosis or splenomegaly were associated with treatment outcome.Conclusion: We found high SVR12 rates in HIV/HCV coinfected patients and no significant difference was observed due to the patients CD4+ cell count, HIV viral load, portal hypertension or liver cirrhosis.

The distinct role and regulatory mechanism of IL-17 and IFN-γ in the initiation and development of plaque vs guttate psoriasis

BackgroundFew studies have explored the differences of immunopathogenesis in plaque vs guttate psoriasis, especially on the inhibitory role of regulatory T cells (Tregs) on IL-17/ IFN-γ production and the impact of CD4+T cells on keratinocytes. ObjectiveTo investigate the percentage and inhibitory function of CD4+CD25highTreg and differential expressions of IL-17/ IFN-γ in plaque vs guttate psoriasis, and the effects of CD4+T cells on the proliferation of keratinocytes. MethodsPeripheral blood mononuclear cells (PBMCs) were prepared from patients with the plaque and guttate psoriasis. The percentage of CD4+CD25high Tregs, IL-17/IFN-γ- producing CD4+ or CD8+T cells, and apoptosis and cell cycle of Hacat cells were determined by flow cytometry. The level of IFN-γ in supernatants was analyzed by ELISA. ResultsThe percentage of CD4+CD25highTregs in plaque psoriasis was significantly increased, and they can inhibit IFN-γ production from CD4+CD25- effector T cells. The percentage of CD8+IFN-γ+cells was also significantly increased in plaque psoriasis, and these cells positively correlated with disease severity. The percentage of CD4+CD25highTregs was decreased and CD4+IFN-γ+/IFN-γ+IL-17+ cells were predominantly increased in guttate psoriasis. CD4+T cells from guttate psoriasis induce apoptosis of keratinocytes while they promote the proliferation of keratinocytes in plaque psoriasis by decreasing late apoptosis and increasing the percentage of G1 phase. ConclusionThere was considerable discrepancy of the phenotype and function of T cells between plaque vs guttate psoriasis. IFN-γ and IL-17 from CD4+T cells play a crucial role in guttate psoriasis, however, IFN-γ and IL-17 from CD8+T cells are more important in the immunopathogenesis of plaque psoriasis.

THU-344 - Impact of CD4+ T-cell count on sustained virologic response to direct-acting antivirals in HIV-negative cancer patients with chronic hepatitis C

THU-344 - Impact of CD4+ T-cell count on sustained virologic response to direct-acting antivirals in HIV-negative cancer patients with chronic hepatitis C

Impact of CD4 and CD8 dynamics and viral rebounds on loss of virological control in HIV controllers.

ObjectiveHIV controllers (HICs) spontaneously maintain HIV viral replication at low level without antiretroviral therapy (ART), a small number of whom will eventually lose this ability to control HIV viremia. The objective was to identify factors associated with loss of virological control.MethodsHICs were identified in COHERE on the basis of ≥5 consecutive viral loads (VL) ≤500 copies/mL over ≥1 year whilst ART-naive, with the last VL ≤500 copies/mL measured ≥5 years after HIV diagnosis. Loss of virological control was defined as 2 consecutive VL >2000 copies/mL. Duration of HIV control was described using cumulative incidence method, considering loss of virological control, ART initiation and death during virological control as competing outcomes. Factors associated with loss of virological control were identified using Cox models. CD4 and CD8 dynamics were described using mixed-effect linear models.ResultsWe identified 1067 HICs; 86 lost virological control, 293 initiated ART, and 13 died during virological control. Six years after confirmation of HIC status, the probability of losing virological control, initiating ART and dying were 13%, 37%, and 2%. Current lower CD4/CD8 ratio and a history of transient viral rebounds were associated with an increased risk of losing virological control. CD4 declined and CD8 increased before loss of virological control, and before viral rebounds.DiscussionExpansion of CD8 and decline of CD4 during HIV control may result from repeated low-level viremia. Our findings suggest that in addition to superinfection, other mechanisms, such as low grade viral replication, can lead to loss of virological control in HICs.

Impact of CD4 + lymphocyte count on left ventricular systolic function in newly diagnosed HAART naïve HIV/AIDS patients seen at University of Port Harcourt Teaching Hospital, Port Harcourt, Rivers State

Impact of CD4 + lymphocyte count on left ventricular systolic function in newly diagnosed HAART naïve HIV/AIDS patients seen at University of Port Harcourt Teaching Hospital, Port Harcourt, Rivers State

Impact of CD4+ T Cell Responses on Clinical Outcome following Oral Administration of Wild-Type Enterotoxigenic Escherichia coli in Humans.

Enterotoxigenic Escherichia coli (ETEC) is a non-invasive enteric pathogen of considerable public health importance, being one of the most common attributable causes of diarrheal illness in infants and young children in developing countries and the most common cause of traveler’s diarrhea. To enhance study-to-study consistency of our experimental challenge model of ETEC in volunteers, and to allow concomitant multi-site trials to evaluate anti-ETEC immunoprophylactic products, hundreds of vials, each containing a standardized inoculum of virulent wild-type (wt) ETEC strain H10407 (serotype O78:H11 expressing colonization factor antigen I and heat-labile and heat-stable enterotoxins), were prepared under current Good Manufacturing Practices (cGMP) and frozen. Following thawing, the contents of each vial can be used (diluted as necessary) to prepare consistent challenge inoculum, even at different study sites. A preliminary human experimental challenge study using this cGMP inoculum was conducted on a research isolation ward and the clinical and cell-mediated immune responses evaluated. Of the 6 healthy adult volunteers challenged 83% (5/6) developed diarrhea and 50% developed moderate-to-severe diarrhea (MSD). Moderate and severe diarrhea were defined as passage of ≥ 1 liter or ≥ 3 liters of diarrheal stool respectively. We compared the CD4+ T cell responses of volunteers who developed MSD against those who did not and identified significant differences in ETEC-specific cytokine production and gut homing potential. We furthermore demonstrated that increased expression of the gut-homing molecule integrin α4β7 by peripheral T follicular helper cells (pTfh) correlated with decreased stool volume and increased ETEC-specific IgA B memory cell (BM) development. Collectively, despite small numbers of volunteers, our results indicate a potential role for CD4+ T cells, in particular pTfh, in modulating disease outcome following exposure to wt ETEC in a volunteer experimental challenge model.

Diagnostic sensitivity and related impact factors of T cell spot test of tuberculosis in acquired immunodeficiency syndrome/tuberculosis patients

Objective To analyze the diagnostic sensitivity and related impact factors of T cell spot test of tuberculosis (T-SPOT.TB) test in acquired immunodeficiency syndrome (AIDS)/tuberculosis (TB) patients. Methods Ninety-two confirmed cases with AIDS/TB coinfection were tested by T-SPOT.TB, and the impact of CD4+ T cells counts on the diagnostic sensitivity was analyzed. Multivariate Logistic analysis was used for the analysis of impact factors of T-SPOT.TB sensitivity. Blood samples of 19 cases with advanced stage AIDS/TB from January 2015 to January 2016 were collected, and peripheral blood mononuclear cell (PBMC) were isolated by Ficoll method, and lymphocytes were isolated by Percoll method. McNemar test was used for the comparison of these two methods. Results Among the 92 patients with AIDS/TB, T-SPOT.TB tests were positive in 51 cases, with positive rate of 55.4%. The sensitivity was 26.3% (10/38) when CD4+ T cell count less than 20/μL, and that was 92.9% (13/14) when CD4+ T cell more than 200/μL. In Logistic analysis, the sensitivity of T-SPOT. TB test in patients with extra-pulmonary tuberculosis was better than that in pulmonary tuberculosis patients (OR=3.042, P=0.038). The sensitivity of T-SPOT.TB was positively correlated with CD4+ T cell count, and the sensitivity increased by 2.889 times when CD4+ T cells increasing 100/μL (OR=3.889, P=0.016). The percentage of lymphocytes in PBMC was also positively correlated with T-SPOT.TB positivity, and the sensitivity increased by 1.393 times when the percentage increasing 30% (OR=2.393, P=0.045). When Percoll was used for lymphocytes isolation, the T-SPOT.TB sensitivity was 52.6% (10/19), and when Ficoll was used for PBMC isolation, the sensitivity was 36.8%(7/19). The difference was not statistically significant (P=0.375). Conclusion The sensitivity of T-SPOT.TB test based on lymphocytes is higher than that based on PBMC. Key words: Acquired immunodeficiency syndrome; Tuberculosis; T-SPOT.TB

The clinical impact of CD4+CD49b+regulatory T cells addition to FOXp3+regulatory T cells in cancer patients’ immunity

RESULTS: Consistent tumor growth was observed with time [Volume (mm3, Mean SD); 4wks: 1101 347, 8wks: 1958 590]. At 8 weeks, 30% of mice had succumbed to tumor growth suggesting utility of this model to assess disease specific survival. Staining for stromal components (collagen and aSMA) and immune markers (CD45) showed intense desmoplasia and immune infiltration. Minnelide treatment resulted in significant decrease in tumor volumes, tumor weight, stromal collagen content and CD3 infiltration.

HIV-1 Infection Impairs Regulatory T-Cell Suppressive Capacity on a Per-Cell Basis

The impact of CD4+ regulatory T cells (Tregs) on human immunodeficiency virus type 1 (HIV-1) pathogenesis remains incompletely understood. Although it has been shown that Tregs can be infected with HIV-1, the consequences of infection on a per-cell basis are still unknown. In vitro HIV-GFP infected and noninfected Tregs were isolated by flow-based cell-sorting to investigate Treg suppressive capacity and gene expression profiles. Our data show that HIV-1-infected Tregs were significantly less suppressive than noninfected Tregs and demonstrated down-regulation of genes critical to Treg function. This impaired function may have detrimental consequences for the control of generalized immune activation and accelerate HIV disease progression.

Impact of CCR2 and SDF1 Polymorphisms on Disease Progression in HIV‐Infected Subjects in Thailand

The genotypic polymorphisms of CCR5, CCR2, and SDF1 were analyzed to determine their impact as potential confounders with regard to disease progression because of the role that host genetic factors appear to be involved in determining rates of disease progression. Genomic DNA was extracted from Ethylenediaminetetraacetate whole blood using Qiagen DNA extraction kit. The amplification of CCR5, CCR2, and SDF1 genes was performed by PCR. Two hundred and twenty-one samples were genotyped for the CCR5, CCR2, and SDF1 mutation. Among these, all (100%) were identified as wild type for CCR5. All were then investigated considering the impact on CD4+ T-cell counts. Samples were divided into two groups based on the CD4+ T-cell numbers. It revealed that in the group of CD4+ T-cell counts ≥200 cells/μl, 15 were found for the homozygous for SDF1 gene (3'A/3'A) whereas one was found in the group of CD4+ T-cell counts <200 cells/μl. Homozygosity for the CCR2 polymorphisms (64I/64I) were five in the group of CD4+ T-cell counts ≥200 cells/μl and none were found in the group of CD4+ T-cell counts <200 cells/μl. These results demonstrated that there was a significant association between CD4+ T-cell numbers and CCR2 and SDF1 polymorphisms (P < 0.001). The mutation of CCR2 and SDF1 genes showed a significant difference in the distribution of CD4+ T-cell numbers (P < 0.001) whereas mutation of chemokine coreceptor CCR5 was not appeared to be associated with the impact of CD4+ T-cell counts.

Partial Regulatory T Cell Depletion Prior to Schistosomiasis Vaccination Does Not Enhance the Protection

CD4+CD25+ regulatory T cells (Tregs) do not only influence self-antigen specific immune responses, but also dampen the protective effect induced by a number of vaccines. The impact of CD4+CD25+ Tregs on vaccines against schistosomiasis, a neglected tropical disease that is a major public health concern, however, has not been examined. In this study, a DNA vaccine encoding a 26 kDa glutathione S-transferase of Schistosoma japonicum (pVAX1-Sj26GST) was constructed and its potential effects were evaluated by depleting CD25+ cells prior to pVAX1-Sj26GST immunization. This work shows that removal of CD25+ cells prior to immunization with the pVAX1-Sj26GST schistosomiasis DNA vaccine significantly increases the proliferation of splenocytes and IgG levels. However, CD25+ cell-depleted mice immunized with pVAX1-Sj26GST show no improved protection against S. japonicum. Furthermore, depletion of CD25+ cells causes an increase in both pro-inflammatory cytokines (e.g. IFN-γ, GM-CSF and IL-4) and an anti-inflammatory cytokine (e.g. IL-10), with CD4+CD25- T cells being one of the major sources of both IFN-γ and IL-10. These findings indicate that partial CD25+ cell depletion fails to enhance the effectiveness of the schistosome vaccine, possibly due to IL-10 production by CD4+CD25- T cells, or other cell types, after CD25+ cell depletion during vaccination.