Circulating T-cell Subsets Research Articles

Immune Disorder in Atherosclerotic Cardiovascular Disease - Clinical Implications of Using Circulating T-Cell Subsets as Biomarkers.

Atherosclerotic cardiovascular disease (ACVD) is an inflammatory phenomenon that leads to structural abnormality in the vascular lumen due to the formation of atheroma by the deposition of lipid particles and inflammatory cytokines. There is a close interaction between innate immune cells (neutrophils, monocyte, macrophages, dendritic cells) and adaptive immune cells (T and B lymphocytes) in the initiation and progression of atherosclerosis. According to novel insights into the role of adaptive immunity in atherosclerosis, the activation of CD4+T cells in response to oxidized low-density lipoprotein-antigen initiates the formation and facilitates the propagation of atheroma, whereas CD8+T cells cause the rupture of a developed atheroma by their cytotoxic nature. Peripheral CD4+and CD8+T-cell counts were altered in patients with other cardiovascular risk factors. Furthermore, on evaluation of the feasibility of immune cells as a diagnostic tool, the blood CD4+(helper), CD8+(cytotoxic), and CD4+CD25+Foxp3+(regulatory) T cells and the ratio of CD4 to CD8 cells hold promise as biomarkers of coronary artery disease and their subtypes. T cells also could be a therapeutic target for cardiovascular diseases. The goal of this review was therefore to summarize the available information regarding immune disorders in ACVD with a special focus on the clinical implications of circulating T-cell subsets as biomarkers.

Postoperative cellular stress in the kidney is associated with an early systemic \u03b3\u03b4 T-cell immune cell response

BackgroundBasic science data suggest that acute kidney injury (AKI) induced by ischemia-reperfusion injury (IRI) is an inflammatory process involving the adaptive immune response. Little is known about the T-cell contribution in the very early phase, so we investigated if tubular cellular stress expressed by elevated cell cycle biomarkers is associated with early changes in circulating T-cell subsets, applying a bedside-to-bench approach.MethodsOur observational pilot study included 20 consecutive patients undergoing endovascular aortic repair for aortic aneurysms affecting the renal arteries, thereby requiring brief kidney hypoperfusion and reperfusion. Clinical-grade flow cytometry-based immune monitoring of peripheral immune cell populations was conducted perioperatively and linked to tubular cell stress biomarkers ([TIMP-2]•[IGFBP7]) immediately after surgery. To confirm clinical results and prove T-cell infiltration in the kidney, we simulated tubular cellular injury in an established mouse model of mild renal IRI.ResultsA significant correlation between tubular cell injury and a peripheral decline of γδ T cells, but no other T-cell subpopulation, was discovered within the first 24 hours (r = 0.53; p = 0.022). Turning to a mouse model of kidney warm IRI, a similar decrease in circulating γδ T cells was found and concomitantly was associated with a 6.65-fold increase in γδ T cells (p = 0.002) in the kidney tissue without alterations in other T-cell subsets, consistent with our human data. In search of a mechanistic driver of IRI, we found that the damage-associated molecule high-mobility group box 1 protein HMGB1 was significantly elevated in the peripheral blood of clinical study subjects after tubular cell injury (p = 0.019). Correspondingly, HMGB1 RNA content was significantly elevated in the murine kidney.ConclusionsOur investigation supports a hypothesis that γδ T cells are important in the very early phase of human AKI and should be considered when designing clinical trials aimed at preventing kidney damage.Trial registrationClinicalTrials.gov, NCT01915446. Registered on 5 Aug 2013.

Dynamic changes of T-cell subsets and their relation with tumor recurrence after microwave ablation in patients with hepatocellular carcinoma.

Thermal ablation can evoke an immune response, which may have effects on the prognosis of patients with hepatocellular carcinoma (HCC). Our aim is to investigate the changes of circulating T-cell subsets after microwave ablation (MWA) and to explore the risk factors of tumor recurrence in patients with hepatitis B virus (HBV)-related HCC. Thirty patients with HBV-related HCC were enrolled in this study. The blood samples were collected both before and after MWA (24 h, 72 h, and 1 month after MWA). The distributions of Th17 cells, regulatory Treg-cells, CD4+ T-cells, CD8+ T-cells, and CD3+ T-cells were determined by flow cytometer. The potential-related factors of tumor recurrence were analyzed by logistic regression. The levels of circulating T-cell subsets, except for Th17 cells, were relatively stable after MWA. The frequency of Th17 cells increased from 3.98% ± 2.40% before treatment to 5.53% ±3.27% 24 h after treatment. Eight of 30 patients had a tumor recurrence. The results of logistic regression suggested that among 11 candidates, only the level of Th17 cells was the risk factor of tumor recurrence. To remove the interference from other factors, seven patients with tumor(s) >3 cm or alpha-fetoprotein >400 ng/mL were excluded in another parallel logistic regression. The results of such regression clearly demonstrated that circulating Th17 cells is indeed a related factor of tumor recurrence. Thermal ablation may evoke a transitional immune response by increasing the frequency of Th17 cells. Patients with high levels of baseline circulating Th17 cells, instead of the transient elevation of Th17 cells induced by MWA, are at the risk of tumor recurrence.

Circulating T-Cell Subsets, Monocytes, and Natural Killer Cells in Peripartum Cardiomyopathy: Results From the Multicenter IPAC Study

ObjectiveThe aim of this work was to evaluate the hypothesis that the distribution of circulating immune cell subsets, or their activation state, is significantly different between peripartum cardiomyopathy (PPCM) and healthy postpartum (HP) women. BackgroundPPCM is a major cause of maternal morbidity and mortality, and an immune-mediated etiology has been hypothesized. Cellular immunity, altered in pregnancy and the peripartum period, has been proposed to play a role in PPCM pathogenesis. MethodsThe Investigation of Pregnancy-Associated Cardiomyopathy (IPAC) study enrolled 100 women presenting with a left ventricular ejection fraction of <0.45 within 2 months of delivery. Peripheral T-cell subsets, natural killer (NK) cells, and cellular activation markers were assessed by flow cytometry in PPCM women early (<6 wk), 2 months, and 6 months postpartum and compared with those of HP women and women with non–pregnancy-associated recent-onset cardiomyopathy (ROCM). ResultsEntry NK cell levels (CD3–CD56+CD16+; reported as % of CD3– cells) were significantly (P < .0003) reduced in PPCM (6.6 ± 4.9% of CD3– cells) compared to HP (11.9 ± 5%). Of T-cell subtypes, CD3+CD4–CD8–CD38+ cells differed significantly (P < .004) between PPCM (24.5 ± 12.5% of CD3+CD4–CD8– cells) and HP (12.5 ± 6.4%). PPCM patients demonstrated a rapid recovery of NK and CD3+CD4–CD8–CD38+ cell levels. However, black women had a delayed recovery of NK cells. A similar reduction of NK cells was observed in women with ROCM. ConclusionsCompared with HP control women, early postpartum PPCM women show significantly reduced NK cells, and higher CD3+CD4–CD8–CD38+ cells, which both normalize over time postpartum. The mechanistic role of NK cells and “double negative” (CD4–CD8–) T regulatory cells in PPCM requires further investigation.

Expression of CXCR4 on T-cell subsets and Plasma IL-17 Concentrations in Patients with Aplastic Anaemia

Acquired aplastic anaemia (AA) is caused by T-cells migrating to and attacking bone marrow (BM) in response to chemokines (e.g., CXCR4). We investigated CXCR4 expressions on circulating T-cell subsets, plasma IL-17A concentrations, and their correlations with AA manifestations. We enrolled 71 patients with acquired AA (36 severe AA cases [SAA] and 35 non-severe AA cases [NSAA]) and 42 healthy volunteers. We used flow cytometry and ELISA to measure circulating CD4+ and CD8+ T-cells, their CXCR4 expressions, and plasma IL-17A concentrations. Compared to the healthy controls, SAA patients had fewer peripheral CD4+ T-cells, more CD8+ T-cells, and a significantly decreased CD4+/CD8+ ratio which was positively correlated with AA manifestations. Patients with SAA or NSAA had higher proportions of CD4+CXCR4+ and CD8+CXCR4+ T-cells, which were negatively correlated with haemoglobin concentrations and absolute neutrophil counts. Patients with SAA or NSAA had higher plasma IL-17A concentrations, which were negatively correlated with AA manifestations and the CD4+/CD8+ ratio. IL-17A concentrations showed a very week correlation with CD4+CXCR4+ T-cells frequencies, and no correlation with CD8+CXCR4+ T-cells frequencies. Aberrant CXCR4 expression may allow circulating T-cells, especially CD8+ T-cells, to infiltrate BM during AA progression. Elevated IL-17A concentrations may contribute to AA progression outside of the CXCR4-SDF-1α axis.

Serum Levels of Total IgE, IL-12, IL-13 and IL-18 in Children Patients with Asthma

T-cell activation and alteration of cytokine levels are involved in the pathogenesis of asthma. However, the profile of circulating T-lymphocyte subsets and related cytokines during asthmatic attacks is still unclear. We compared the serum concentrations of proinflammatory cytokines Interleukine-18( IL-18) and Interleukine-12(IL-12), T-helper 2 (Th2) cytokine Interleukine-13(IL-13 ) and Immunoglobuline-E ( IgE) in 27 asthmatic children and 21 sex and age matched healthy control subjects. Serum cytokines and IgE concentrations were measured by enzyme-linked immunosorbent assay. Serum IL-13 , IL-18 and IgE concentrations were significantly higher in asthmatic patients than normal control subjects ( IL-13: median 9.73 versus 4.43 pg/ml, P&lt;0.05 ; IL-18: 76.81 versus 35.41 pg/ml, P&lt;0.05 ; IgE: 225.44 versus 37.94 IU/ml, P&lt;0.05 . Asthmatic patients showed a decreased serum IL-12 concentration 93.57 versus 122.83 pg/ml, P&lt;0.05 . In conclusion, it was suggested that IL-13 and IL-18 might have a potential role in controling lymphocyte responses in asthmatic patients specially in children through an IgE-mediated pathway.&#x0D; Key words: Asthma, Interleukine-12, -13, -18, Immunoglobuline-E.

Blood chemokine profile in untreated early rheumatoid arthritis: CXCL10 as a disease activity marker

BackgroundWe have recently analyzed the profile of T-cell subtypes based on chemokine receptor expression in blood from untreated early rheumatoid arthritis (ueRA) patients compared to healthy controls (HC). Here, we compared the levels of the respective chemokines in blood plasma of ueRA patients with those of HC. We also studied the association of chemokine levels with the proportions of circulating T-cell subsets and the clinical disease activity.MethodsPeripheral blood was obtained from 43 patients with ueRA satisfying the ACR 2010 criteria and who had not received any disease-modifying anti-rheumatic drugs (DMARD) or prednisolone, and from 14 sex- and age-matched HC. Proportions of T helper cells in blood, including Th0, Th1, Th2, Th17, Th1Th17, TFh, and regulatory T cells, were defined by flow cytometry. Fifteen chemokines, including several CXCL and CCL chemokines related to the T-cell subtypes as well as to other major immune cells, were measured in blood plasma using flow cytometry bead-based immunoassay or ELISA. Clinical disease activity in patients was evaluated by assessing the following parameters: Disease Activity Score in 28 joints (DAS28), Clinical Disease Activity Index (CDAI), swollen joint counts (SJC), tender joint counts (TJC), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). The data were analyzed using multivariate factor analyses followed by univariate analyses.ResultsMultivariate discriminant analysis showed that patients with ueRA were separated from HC based on the blood plasma chemokine profile. The best discriminators were CXCL9, CXCL10, CXCL13, CCL4, and CCL22, which were significantly higher in ueRA compared to HC in univariate analyses. Among the chemokines analyzed, only CXCL10 correlated with multiple disease activity measures, including DAS28-CRP, DAS28-ESR, CDAI, SJC in 66 joints, CRP, and ESR.ConclusionsHigh circulating levels of CXCL10 in the plasma of ueRA patients and the association with the clinical disease activity suggests that CXCL10 may serve as a disease activity marker in early rheumatoid arthritis.

Abstract 4365: A phase II trial of high-dose Interleukin-2 (HDIL-2) with recombinant MAGE-A3 protein combined with adjuvant system AS15 in patients with unresectable or metastatic melanoma

Abstract Background: As shown in a phase III study, active immunization against gp100 tumor antigen can significantly potentiate the antitumor activity of HDIL-2 as well as improve the disease-specific survival of patients (pts) with metastatic melanoma (MM) (Schwartzentruber NEJM 2011). In addition, a phase II study of MAGE-A3 immunotherapy demonstrated modest clinical benefit in pts with MM, and identified a gene signature (GS) associated with response (Kruit JCO 2013). Hypothesis: We hypothesized that the combination of HDIL-2 and MAGE-A3 immunotherapy would improve the clinical efficacy with reduced toxicity in pts with MM. We also wanted to evaluate whether pretreatment GS is predictive of response to the combination. Methods: We conducted a phase II trial of MAGE-A3 immunotherapy and HDIL-2 in pts with MAGE-A3 positive MM (NCT01266603). Pts’ archived or fresh tumor tissue was screened for MAGE-A3 expression using RT-PCR. Mandatory baseline biopsy was performed for gene expression profiling for the previously described GS by RT-PCR. Optional tumor biopsies were performed at wk 8 and at end of treatment (EOT). Serum and PBMC were collected on d 1 of each cycle, following cycle 1 of HDIL-2, and at EOT for circulating T-cell subsets, interferon and interferon-induced factors. In the induction phase, 300 μg of recMAGE-A3 and AS-15 immunostimulant were given every 2 wk x 6, and then every 3 wk x 6. HDIL-2 was initiated on the day following MAGE-A3 immunotherapy on wk 1,3,9,11,18,21,27 and 30 at 720,000 IU/kg every (q) 8 hr for up to 14 doses/cycle. Following completion of HDIL-2, pts who remained on study were continued on maintenance phase with MAGE-A3 immunotherapy alone, q 6 wk x 4, then q 12 wk x 4, and then q 24 wk x4. Response was assessed by RECIST v1.1 every 8 wk. Results: The combination of MAGE-A3 immunotherapy and HDIL-2 was well tolerated, with expected toxicities from HDIL-2. Sixteen pts were evaluable for response. Four pts had partial response (PR) as the best response during induction phase: 1 pt was rendered free of disease after resection, and remaining 3 pts achieved complete response (CR) during maintenance phase. The overall response rate was 25%, and an additional 6 patients had durable stable disease for a disease control rate of 63%. GS was not predictive of response. Conclusions: The combination of HDIL-2 and MAGE-A3 immunotherapy shows robust antitumor activity compared to historical HDIL-2 monotherapy and a comparable safety profile. MAGE-A3 immunotherapy maintenance was able to convert some PRs to durable CRs and thus may be a strategy to limit exposure to the toxicities of HDIL-2. GS is not predictive of response to the combination therapy. Ongoing exploration of the tumor microenvironment and circulating immune biomarkers as predictors of response will be presented. Funding source: GlaxoSmithKline Biologicals SA Citation Format: Jennifer Leigh McQuade, Carlos Antonio Torres-Cabala, Rashmi Murthy, Marihella L. James, Jade Homsi, Luis M. Vence, Wen-Jen Hwu. A phase II trial of high-dose Interleukin-2 (HDIL-2) with recombinant MAGE-A3 protein combined with adjuvant system AS15 in patients with unresectable or metastatic melanoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4365.

Inflammation-Induced Changes in Circulating T-Cell Subsets and Cytokine Production During Human Endotoxemia.

Observational clinical studies suggest the initial phase of sepsis may involve impaired cellular immunity. In the present study, we investigated temporal changes in T-cell subsets and T-cell cytokine production during human endotoxemia. Endotoxin (Escherichia coli lipopolysaccharide 4 ng/kg) was administered intravenously in 15 healthy volunteers. Peripheral blood and bronchoalveolar lavage fluid (BALF) were collected at baseline and after 2, 4, 6, 8, and 24 hours for flow cytometry. CD4+CD25+CD127lowFoxp3+ regulatory T cells (Tregs), CD4+CD161+ cells, and activated Human leukocyte antigen, HLA-DR+CD38+ T cells were determined. Ex vivo whole-blood cytokine production and Toll-like receptor (TLR)-4 expression on Tregs were measured. Absolute number of CD3+CD4+ (P = .026), CD3+CD8+ (P = .046), Tregs (P = .023), and CD4+CD161+ cells (P = .042) decreased after endotoxin administration. The frequency of anti-inflammatory Tregs increased (P = .033), whereas the frequency of proinflammatory CD4+CD161+ cells decreased (P = .034). Endotoxemia was associated with impaired whole-blood production of tumor necrosis factor-α, interleukin-10, IL-6, IL-17, IL-2, and interferon-γ in response to phytohaemagglutinin but did not affect TLR4 expression on Tregs. No changes in the absolute count or frequency of BALF T cells were observed. Systemic inflammation is associated with lymphopenia, a relative increase in the frequency of anti-inflammatory Tregs, and a functional impairment of T-cell cytokine production.

T-Helper Cell-Mediated Islet Inflammation Contributes to β-Cell Dysfunction in Chronic Pancreatitis.

Beta-cell dysfunction and endocrine insufficiency in chronic pancreatitis (CP) is considered as a late manifestation emanating from fibrosis. To ascertain the role of T-helper cells in β-cell dysfunction, we enumerated circulating T-cell subsets, examined their infiltration into pancreatic islets, and assessed islet functions. Pancreatic tissues and peripheral blood were obtained from CP patients with/without diabetes. T cells were enumerated on flow cytometry and by immunostaining. Islets were assessed for glucose-stimulated insulin release (GSIR) and apoptosis (Annexin V/caspase-3). Islet proteins were probed for insulin gene transcription factor. Circulating T-helper type 1 (Th1) cells were higher (P < 0.003) in CP patients with diabetes in comparison with control and CP patients without diabetes. Intra-islet colocalization of Th1 and Th17 cells was evident. In comparison with the controls, 2% ± 0.87% β cells from CP patients without diabetes were apoptotic whereas GSIR was decreased by 60% ± 12%, and 40% ± 9% from CP patients with diabetes were apoptotic, with minimal GSIR (1.42% ± 0.9%) in the remaining 60% viable cells. Western blots of islet proteins revealed an increase in STAT1 (signal transducer and activator of transcription 1) and a decrease in phosphorylated pancreatic duodenal homeobox (Pdx-1). T cell-mediated inflammation is associated with β-cell dysfunction during progression of CP.

Immunologic Monitoring of T-Lymphocyte Subsets and Hla-Dr-Positive Monocytes in Kidney Transplant Recipients: A Prospective, Observational Cohort Study.

The clinical significance of circulating T-lymphocyte subsets and human leukocyte antigen (HLA)-DR-positive monocytes in the peripheral blood of kidney transplant recipients (KTRs) remains unclear. We examined the efficacy of enumerating these cells for the immunologic monitoring of KTRs.Blood samples were obtained before transplantation, 2 weeks after transplantation and at diagnosis, and 2 weeks after treating biopsy-proven acute cellular rejection and cytomegalovirus (CMV) infection. Serial flow cytometric analysis was performed using peripheral blood obtained from 123 patients to identify the frequencies of HLA-DR+, CD3+, CD4+, CD8+, and CD25+ T-lymphocytes and HLA-DR-positive monocytes.Frequencies of CD4+CD25+/CD4+ T cells, CD8+CD25+/CD8+ T cells, and HLA-DR-positive monocytes were significantly lower at 2 weeks after transplantation than before transplantation (all P < 0.001). This decrease was not correlated with clinical parameters. The frequency of CD4+CD25+/CD4+ T cells was significantly higher in KTRs with acute rejection than in KTRs at 2 weeks after transplantation (9.10% [range 4.30–25.6%] vs 5.10% [range 0.10–33.3%]; P = 0.024). However, no significant differences were observed between stable KTRs and KTRs with CMV infection. Analysis of the receiver operating characteristic curve adjusted by covariates showed that acute rejection could be predicted with 75.0% sensitivity and 68.4% specificity by setting the cutoff value of CD4+CD25+/CD4+ T cell frequency as 5.8%.Circulating T-lymphocyte and monocyte subsets showed significant and consistent changes in their frequencies after immunosuppression. Of the various immune cells examined, circulating levels of CD4+CD25+ T cells might be a useful noninvasive immunologic indicator for detecting acute rejection.

Abstract 2855: Immunomodulatory activity of nivolumab monotherapy in patients with advanced melanoma

Abstract Background: Nivolumab, a fully human anti-programmed death-1 (PD-1) immune checkpoint inhibitor antibody, has shown encouraging clinical activity in melanoma. We evaluated the pharmacodynamic effects of nivolumab on immune endpoints in patients (pts) with advanced melanoma in an exploratory phase 1 study (NCT01621490). Methods: 85 pts (41 and 44 anti-CTLA-4 therapy-naïve and refractory, respectively) received nivolumab 3 mg/kg IV Q2W in 56-day cycles. Tumor biopsies were obtained at baseline (B/L) and on treatment during Cycle 1, Week 4 (C1Wk4). Response was assessed during the last week of each cycle. The primary objective was to evaluate the pharmacodynamic activity of nivolumab on immune biomarkers, including circulating T-cell subsets (by multiparametric flow cytometry), serum interferon (IFN) and IFN-induced factors (by multiplex immunoassay), and T-cell infiltration in the tumor microenvironment (by immunohistochemistry for CD3, CD4, CD8, PD-1 and FOXP3). Secondary objectives included safety, efficacy, and the association between tumor PD ligand-1 (PD-L1) expression and clinical responses. Results: Across all 85 pts, the objective response rate was 25%, with 2 pts having a confirmed complete response. The safety profile was consistent with prior nivolumab monotherapy trials. Of 85 pts, 34 had evaluable biopsies at B/L and C1Wk4. Increases in tumor infiltrating lymphocytes (TILs) at C1Wk4 relative to B/L were seen in most pts; 65% of pts had an increase in CD3+ T cells. Expression of other TIL markers CD4, CD8, FOXP3 and PD-1, correlated well with one another and CD3 after treatment (C1Wk4; r = 0.69-0.93, P&amp;lt;0.0001). Increased TIL, in particular CD3+ and CD8+, was associated with response; 100%/88% of responders had elevated CD3+/CD8+ TILs compared with 54%/58% of non-responders. PD-L1 expression was not consistently modulated between B/L and C1Wk4 (30 matched samples); however, highest PD-L1 expression (C1Wk4) was accompanied by highest TIL levels (C1Wk4). No consistent change in the frequency of activated peripheral T-cell subsets (HLA-DR+ or ICOS+, CD4 and CD8 T cells) was seen with nivolumab treatment, but peripheral increases in serum IFN-γ-stimulated cytokines were observed. Mean concentrations of serum CXCL9 and CXCL10 increased 2.2- and 1.1-fold from B/L, respectively, 43 days after initial dose; no association was apparent between the increases and response. Conclusions: Nivolumab monotherapy is marked by increased TIL, inclusive of cytotoxic CD8 T cells, and FOXP3+ T regulatory cells and these increases are associated with response. Unlike ipilimumab, nivolumab treatment does not demonstrate consistent increases in circulating activated T cells. However, increases in peripheral IFN-γ-stimulated cytokines, CXCL9 and CXCL10 are observed, presumably derived from the tumor microenvironment. Further characterization of the effects of nivolumab on the tumor microenvironment is ongoing. Citation Format: Walter J. Urba, Salvador Martín-Algarra, Margaret Callahan, Jedd D. Wolchok, William H. Sharfman, Jeffrey A. Sosman, Shailender Bhatia, Wen-Jen Hwu, Thomas F. Gajewski, Craig L. Slingluff, Yun Shen, Christine E. Horak, F Stephen Hodi. Immunomodulatory activity of nivolumab monotherapy in patients with advanced melanoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2855. doi:10.1158/1538-7445.AM2015-2855

Impact of age, sex and CMV-infection on peripheral T cell phenotypes: results from the Berlin BASE-II Study.

Advancing age is characterized by functional and phenotypic alterations in the distribution of circulating T-cell subsets, some of which are exacerbated by a latent infection with the persistent herpesvirus, cytomegalovirus (CMV). The influence of age, sex and CMV-infection on T-cell subpopulations in the peripheral blood remains incompletely understood. Here, T cells from 157 participants of the Berlin Aging Study II (BASE-II) were characterized at 21-34 (n=59) and 62-85 (n=98) years of age. We found that the frequency of naïve CD8(+) T cells was significantly lower in the older group than in the young, and was different in men and women. Elderly men had a significantly lower proportion of naïve CD8(+) T cells than younger men, regardless of their CMV-status, but in older women, this was seen only in the CMV-seropositive group. Reciprocally, older men had a higher proportion of late-differentiated, potentially "senescent" CD57(+) T cells. Thus, T-cell senescence may be more pronounced in older men than women. Within the CD4(+) population, in the elderly of both sexes there was a significantly higher proportion of late-differentiated TEMRA cells (T effector memory cells re-expressing CD45RA), but these were present exclusively in CMV-positive subjects. Finally, for the first time, we examined the so-called TSCM cell (T-stem cell-like memory) subpopulations in both CD4(+) and CD8(+) subsets and found that neither CMV-seropositivity nor age or sex affected their frequencies. This study confirms significant cross-sectional age-associated differences of T-cell subset distribution in a representative German urban population and emphasizes the impact of both sex and CMV-infection on T-cell naïve and memory phenotypes, but unaffected frequencies of T-stem cell-like memory cells.

Association of chronic hepatitis C infection with T-cell phenotypes in HIV-negative and HIV-positive women.

Hepatitis C virus (HCV) viremia is thought to have broad systemic effects on the cellular immune system that go beyond its impact on just those T cells that are HCV specific. However, previous studies of chronic HCV and circulating T-cell subsets (activation and differentiation phenotypes) in HIV negatives used general population controls, rather than a risk-appropriate comparison group. Studies in HIV positives did not address overall immune status (total CD4⁺ count). We used fresh blood from HIV-positive and at-risk HIV-negative women, with and without chronic HCV, to measure percentages of activated CD4⁺ and CD8⁺ T cells, Tregs, and T-cell differentiation phenotypes (naive, central memory, effector memory (EM), and terminally differentiated effector). This included 158 HIV negatives and 464 HIV positives, of whom 18 and 63, respectively, were HCV viremic. In multivariate models of HIV negatives, HCV viremia was associated with 25% fewer naive CD4⁺ (P = 0.03), 33% more EM CD4⁺ (P = 0.0002), and 37% fewer central memory CD8⁺ (P = 0.02) T cells. Among HIV positives, we observed only 1 of these 3 relationships: higher percentage of EM CD4⁺ among HCV viremic women. Furthermore, the association with EM CD4⁺ among HIV positives was limited to individuals with diminished immune status (total CD4⁺ count ≤500 cells/μL), as were associations of HCV viremia with higher percentages of activated CD4⁺ and Tregs. Among HIV positives with high CD4⁺ count, no significant associations were observed. These data suggest that HCV viremia in HIV negatives is associated with accelerated T-cell differentiation, but among HIV positives, the impact of HCV viremia is less straightforward and varies by total CD4v count.

LBSapSal-vaccinated dogs exhibit increased circulating T-lymphocyte subsets (CD4+ and CD8+) as well as a reduction of parasitism after challenge with Leishmania infantum plus salivary gland of Lutzomyia longipalpis

BackgroundThe development of a protective vaccine against canine visceral leishmaniasis (CVL) is an alternative approach for interrupting the domestic cycle of Leishmania infantum. Given the importance of sand fly salivary proteins as potent immunogens obligatorily co-deposited during transmission of Leishmania parasites, their inclusion in an anti-Leishmania vaccine has been investigated in the last few decades. In this context, we previously immunized dogs with a vaccine composed of L. braziliensis antigens plus saponin as the adjuvant and sand fly salivary gland extract (LBSapSal vaccine). This vaccine elicited an increase in both anti-saliva and anti-Leishmania IgG isotypes, higher counts of specific circulating CD8+ T cells, and high NO production.MethodsWe investigated the immunogenicity and protective effect of LBSapSal vaccination after intradermal challenge with 1 × 107 late-log-phase L. infantum promastigotes in the presence of sand fly saliva of Lutzomyia longipalpis. The dogs were followed for up to 885 days after challenge.ResultsThe LBSapSal vaccine presents extensive antigenic diversity with persistent humoral and cellular immune responses, indicating resistance against CVL is triggered by high levels of total IgG and its subtypes (IgG1 and IgG2); expansion of circulating CD5+, CD4+, and CD8+ T lymphocytes and is Leishmania-specific; and reduction of splenic parasite load.ConclusionsThese results encourage further study of vaccine strategies addressing Leishmania antigens in combination with proteins present in the saliva of the vector.

A6.2 Purified microbial capsular polysaccharide Galactoxylomannan (GalXM) inhibits the effector T lymphocyte arm and potentiates the regulatory counterpart in rheumatoid arthritis

Background and ObjectivesWe previously demonstrated that the purified microbial polysaccharide Galactoxylomannan (GalXM) from the opportunistic fungus Cryptococcus neoformans is able to impair T-cell proliferation and to induce T lymphocyte apoptosis...

SAT0187 Immunomodulatory effects of human umbilical cord wharton jelly-derived mesenchymal stem cells (HUCMS) on circulating T-cell subsets in patients with sjögren’s syndrome

BackgroundhUCMS are adult stem cells easy to retrieve in bulk. Their immunomodulatory and pro-differentiation properties has been demonstrated. Indeed they may suppress lymphocyte activation, thereby prolonging skin graft survival time....

THU0129 Selective elimination of pathogenic TH17 cells from peripheral blood of rheumatoid arthritis patients by a purified fungal polysaccharide

BackgroundIt has been shown that the microbial polysaccharide Galactoxylomannan (GalXM) from the opportunistic fungus Cryptococcus neoformans is able to impair T-cell proliferation and to induce apoptosis in T lymphocytes following...

Hepatitis C with and without dermatological manifestations

BackgroundThe host's interaction between T lymphocytes and human leukocyte antigen (HLA) could affect the progression of hepatitis C virus (HCV) infection and contribute to the factors affecting disease outcome. The relation of HLA types and circulating T-cell subsets to hepatitis severity in patien

Abstract 5620: Immunomodulatory activity of NOV-002 potentiates the anti-tumor efficacy of cyclophosphamide in the CT26 murine colon cancer model

Abstract Clinical trials in a number of solid tumor indications have shown that the addition of NOV-002 (a formulation of disodium glutathione disulfide) to a range of cytotoxic chemotherapeutic regimens potentiates their anti-tumor efficacy. However, the specific mechanisms involved remain unclear. Previous in vitro studies demonstrated that NOV-002 generates oxidative signals in human tumor cell lines resulting in apoptosis and decreased proliferation. In addition, NOV-002 has been reported to display in vivo immunomodulatory properties in oncology settings. Hence, NOV-002: (i) significantly increases circulating T-lymphocyte subsets [CD4+, CD8+, NK-T lymphocytes] in non-small lung cancer patients receiving chemotherapy plus NOV-002 vs. chemotherapy alone; (ii) reverses T-cell suppressive effect of myeloid suppressor cells in mice; (iii) potentiates anti-tumor effect of adoptive immunotherapy in a mouse melanoma model; (iv) increases intra-tumoral memory T-cells and anti-tumor immune responsiveness in a mouse model of ovarian cancer. Here, we sought to test the hypothesis that NOV-002 potentiates the anti-tumor effect of chemotherapy through immune-mediated mechanisms. To this end in the CT26 murine colon cancer model, tumor-bearing mice were treated with NOV-002 (25 mg/kg, i.p.) or saline (daily on days 1-14, then Monday-Friday, beginning 5 days post-tumor injection until tumor progression), followed by 200mg/kg cyclophosphamide (CTX) on days 6 and 9. In three independent experiments we found that while NOV-002 alone had only a modest effect on tumor growth rate, the addition of NOV-002 to CTX resulted in significantly slower tumor growth compared to CTX alone. Mean overall survival was significantly longer in CTX/NOV mice [90 vs 47 days; P=0.005]. Interestingly, all mice receiving CTX alone developed tumors, while approximately 40% of CTX/NOV-002 mice showed no tumor development. To further investigate whether failure of tumor development in these mice was due to an immune mechanism, they underwent tumor rechallenge. In two independent experiments only 1/7 mice (14%) developed tumors after rechallenge. To test the contribution of memory T-cells, which are known to home to the bone marrow, CTX/NOV-002 mice with tumor failure were sacrificed and marrows adoptively transferred to mice bearing 7 day old CT26 tumors. A significant delay in tumor progression was observed in mice receiving adoptively transferred marrow suggesting that the immunologic memory generated after CTX/NOV-002 treatment was sufficient to effectively prevent or regress tumor formation. Taken together, these data provide further support to the hypothesis that, when combined with chemotherapy, NOV-002's anti-tumor efficacy may be due at least in part to enhancement of anti-tumor cellular immune responsiveness. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5620.