Regulatory T cells (Tregs) play an integral role in the adaptive immune system through suppression of selfreactive immune responses in order to prevent autoimmunity and maintain homeostasis. However, they are deleterious in cancer through suppression of the antitumor immune response. In fact, we show that deletion of 50% of Tregs results in normal tumor growth. Therefore, it is advantageous to ...

OBJECTIVES A sizeable percentage of individuals infected by HIV and on antiretroviral therapy (ART) fail to increase their CD4 T-cells to satisfactory levels. The percentage of regulatory T-cells (Tregs) has been suggested to contribute to this impairment. This study aimed to address this question and to expand the analysis of Tregs subpopulations during ART. DESIGN Longitudinal follow-up of ...

PURPOSE Tumor-infiltrating lymphocytes represent the host immune response to cancer. CD4+CD25+FOXP3+ regulatory T cells (Tregs) suppress the immune reaction. The aim of the present study was to investigate the clinicopathologic significance and roles of Tregs and CD8+ T cells during hepatocarcinogenesis. EXPERIMENTAL DESIGN We examined the infiltration of FOXP3+ Tregs and CD8+ T cells in the ...

PURPOSE Acute myeloid leukemia (AML) provides an environment that enables immune suppression, resulting in functionally defective effector T cells; regulatory T cells (Treg) are significant contributors to the impaired antitumor immune response. As TNF is present at high levels in AML and TNF receptor-2 (TNFR2)-expressing Tregs identify highly functional Tregs, we examine the hypothesis that TN...

CD4+CD25+Foxp3+ regulatory T cells (Tregs) play a key role in the induction and maintenance of peripheral tolerance. Rapid and transient production of IFN-gamma by Tregs from mice tolerized to alloantigen in vivo has been shown to be critical for their regulatory function. This IFN-gamma has the potential to affect the function of cells present in the same local microenvironment as the Tregs, i...

CD4+FOXP3+ regulatory T cells (Tregs) are a subset of CD4 T cells that play an essential role in maintaining peripheral immune tolerance, controlling acute and chronic inflammation, allergy, autoimmune diseases, and anti-cancer immune responses. Over the past 20 years, significant progress has been made since Tregs were first characterized in 1995. Many concepts and principles regarding Tregs g...

A significant enrichment of CD4þFoxp3þ T cells (regulatory T cells, Treg) is frequently observed in murine and human carcinomas. As Tregs can limit effective antitumor immune responses, thereby promoting tumor progression, it is important that the mechanisms underpinning intratumoral accumulation of Tregs are identified. Because of evidence gathered mostly in vitro, the conversion of convention...

Increased CD4+CD25+Foxp3+ regulatory T cells (Tregs) predict poor prognosis in renal cell carcinoma (RCC). The aim of this study was to investigate the underlying causes of the aberrant accumulation of Tregs in RCC. pcDNA3.1-hCOX-2 and control pcDNA3.1 were transfected into the RCC cell line OS-RC-2. Under stimulation of anti-CD3/CD28 antibody and APC cells, isolated CD4+Foxp3- T cells were co-...

Mechanisms by which donor-specific blood transfusion (DSBT) promotes organ allograft acceptance are unclear. In a rat fully mismatched cardiac allograft model, we found that DSBT alone (without immunotherapy) induces the development of regulatory T cells (DSBT-Tregs) posttransplant, thereby shedding new light in the mechanisms of the transfusion effect. Compartments and timing of expansion, req...

Regulatory T cells (Tregs) have a reduced capacity to activate the PI3K/Akt pathway downstream of the TCR, and the resulting low activity of Akt is necessary for their development and function. The molecular basis for the failure of Tregs to activate Akt efficiently, however, remains unknown. We show that PH-domain leucine-rich-repeat protein phosphatase (PHLPP), which dephosphorylates Akt, is ...