Because of the cytotoxic potential of CD8(+) T cells, maintenance of CD8(+) peripheral tolerance is extremely important. A major peripheral tolerance mechanism is the induction of anergy, a refractory state in which proliferation and IL-2 production are inhibited. We used a TCR transgenic mouse model to investigate the signaling defects in CD8(+) T cells rendered anergic in vivo. In addition to...

Oral infection with Toxoplasma gondii leads to transient systemic hyporesponsiveness. In this report, we characterized the presence in the lungs of GR1(+) CD11b(+) myeloid cells that have potent nitric oxide-dependent immunoregulatory properties. We also demonstrated the interleukin 2-reversible anergy of both pulmonary CD8(+) and CD4(+) activated T lymphocytes with infection.

a case of chronic mucocutaneous candidiasis due to candida albicans in a 13 yr-old boy is reported. evaluation of cell mediated immunity revealed cutaneous anergy to ppd and low level of t-lymphocytes b-cell count and immunoglobulin g (igg) were increased and there was a low level of serum iron. the patient was put under treatment with oral administration of ketoconazole and ferrus sulfate, whi...

Background: CD4+ and CD8+ T cells are the main types of lymphocytes in cell-mediated immunity and play a central role in the induction of efficient immune responses against tumors. The frequencies of T cell subtypes in the peripheral blood and tumor tissues, and draining lymph nodes (dLN) can be considered as useful markers for evaluation of the immune system in cancers. Methods: In this study,...

Induction of tolerance in self-reactive memory T cells is an important process in the prevention of autoimmune responses against peripheral self-antigens in autoimmune diseases. Although naive T cells can readily be tolerized, memory T cells are less susceptible to tolerance induction. Recently, we demonstrated that low avidity engagement of T cell receptor (TCR) by low densities of agonist pep...

Incomplete T cell antigen receptor-mediated signaling induces an unresponsive state known as anergy. Previously, we had shown that anergy can be induced in antigen-primed but not naive T cells. In this report, we found that in vitro primed T cells from IL-2R alpha-deficient mice were resistant to anergy induction in contrast to comparably treated wild-type T cells. This resistance persisted eve...

The interaction between dendritic cells (DCs) and T cells is crucial on immunity or tolerance induction. In an immature or semi-mature state, DCs induce tolerance through T-cell deletion, generation of regulatory T cells, and/or induction of T-cell anergy. Anergy is defined as an unresponsive state that retains T cells in an "off" mode under conditions in which immune activation is undesirable....

Tumors can be broadly placed into two categories: those that are T cell-inflamed and those that are not, with T cell-inflamed tumors having specific chemokine and type I interferon gene expression signatures as well as CD8 tumor-infiltrating T cells (TIL). The fact that these T cell-inflamed tumors are not destroyed by the CD8 TIL argues that mechanisms in the tumor microenvironment must render...