BACKGROUND AND PURPOSE Cerebral ischemia is ensued by a cellular immune depression syndrome. The postischemic functional capacity of T lymphocytes is controversial, and interactions between leukocyte subsets are largely unknown. Understanding the immunologic interplay between antigen-presenting cells and lymphocytes as well as between distinct lymphocyte subsets after stroke might be of clinica...

Toll-like receptors (TLRs) play a crucial role in the initiation of innate responses following microbial infection and also in adaptive immune responses by orchestrating the activation of different cell populations. TLRs are expressed at high levels in antigen-presenting cells and recent studies have demonstrated the expression and biological role of TLRs in mouse and human CD4(+) T cells. In t...

The expression of CD25 antigen, the a-chain of the interleukin-2 receptor (IL-2Ra), has been repeatedly shown to be associated with poor outcome in adults with either acute myelogenous (AML) or lymphoblastic leukemia. To explain this finding mechanistically, it has been hypothesized that CD25þ AML blasts are enriched in chemoresistant leukemia stem cells (LSCs), as they bear an LSC-like molecul...

Therapeutic efficacy of a tumor cell-based vaccine against experimental B16 melanoma requires the disruption of either of two immunoregulatory mechanisms that control autoreactive T cell responses: the cytotoxic T lymphocyte-associated antigen (CTLA)-4 pathway or the CD25(+) regulatory T (Treg) cells. Combination of CTLA-4 blockade and depletion of CD25(+) Treg cells results in maximal tumor re...

Melanoma patients were injected with various vaccines containing a MAGE-A3 peptide presented by HLA-DP4. Anti-MAGE-A3.DP4 T cells were not detectable in the blood before vaccination, but their frequencies after vaccination ranged from 2 x 10(-6) to 2 x 10(-3) among the CD4(+) blood T lymphocytes of the patients. The CD4(+) blood T lymphocytes that stained ex vivo with HLA-DP4 tetramers folded w...

We have previously demonstrated that interleukin (IL)-10-deficient (IL-10 knockout [KO]) but not wild-type (WT) mice develop colitis after infection with Helicobacter hepaticus. Here, we show that infected recombination activating gene (RAG) KO mice develop intestinal inflammation after reconstitution with CD4(+) T cells from IL-10 KO animals and that the cotransfer of CD4(+) T cells from H. he...

DNA vaccination is a promising strategy to induce effector T cells but also regulatory Foxp3(+) CD25(+) CD4(+) Treg cells and inhibit autoimmune disorders such as type 1 diabetes. Little is known about the antigen requirements that facilitate priming of Treg cells but not autoreactive effector CD8(+) T cells. We have shown that the injection of preproinsulin (ppins)-expressing pCI/ppins vector ...

BACKGROUND Recently, a study from the Consortium of Food Allergy Research (CoFAR) showed that allergen-induced IL-4 expression in CD25(+) mononuclear cells was increased in allergic patients. However, they did not find the expected increase in GATA-3 expression, suggesting that allergen-induced IL-4 might not be of T-cell origin. We sought to determine whether other cell types were responsible ...

PURPOSE To determine whether supernatants of human retinal pigment epithelium (RPE) cells can convert CD4⁺ T cells into regulatory T cells (Tregs) under Treg-induction conditions in vitro and in vivo. METHODS Peripheral blood mononuclear cells were cocultured with supernatants from TGFβ2-pretreated human RPE lines on anti-CD3-coated plates. Cells were then separated with a CD4⁺CD25⁺ Treg isol...