During intrathymic T cell development, a huge repertoire of T cells with different antigen specificities are generated through somatic recombination at the T cell receptor (TCR) loci, which equips T cells with the capacity to recognize diverse microbial and environmental antigens. Within such a repertoire of T cells, self-reactive T cells exist and, if not properly controlled, can cause self-in...

Cyclosporin A (CsA) is a well-known immunosuppressive agent that modulates immune tolerance in many ways. CsA can give rise to a state of long-term nonimmunosuppressed transplantation tolerance, but it can also aggravate autoimmune diseases, and provoke specific forms of autoimmunity. These effects, which are often paradoxical, remain largely unexplained. In this study, we investigated the effe...

in this article, a study is made to demonstrate the possible utilization of hydrological anergy resources, contained in small water streams and water falls. the total energy, which could be recovered without extensive investments, has been estimated. it is shown that, the energy produced shall meet the total energy requirements of the rural areas of the country. a hystorical background of the u...

Acute graft-versus-host disease (GVHD) after allogeneic stem cell transplantation is associated with impaired deletion and anergy of host-reactive T cells. To elucidate the immunoregulatory events that may contribute to such dysregulated T-cell responses in GVHD, we studied superantigen (SAg) responses after adoptive T-cell transfer into severe combined immunodeficient (SCID) mice. SAg response...

Monomorphic MHC class II determinants are attractive targets for immunomodulation. HLA-DR ligation on antigen-presenting cells (APCs) can dramatically alter their function or induce cell death. In monocytes, HLA-DR triggering diminishes their capacity to stimulate T cell proliferation. To further investigate this monocyte-dependent T cell inhibition, we activated human T cells +/- HLA-DR trigge...

Chronic autoimmune thrombocytopenic purpura (AITP) is characterized by platelet-specific autoantibody production that is influenced by enhanced antiplatelet T-helper cell reactivity. Costimulatory signals are absolutely required for T-cell activation and play key roles in the decision between tolerance and immunity. In this study we cultured T cells isolated from patients with chronic AITP to i...

Infectious pathogens can selectively stimulate activation or suppression of T cells to facilitate their survival within humans. In this study we demonstrate that the trematode parasite Schistosoma mansoni has evolved with two distinct mechanisms to suppress T cell activation. During the initial 4- to 12-wk acute stages of a worm infection both CD4(+) and CD8(+) T cells are anergized. In contras...

We previously demonstrated that altered peptide ligands (APL) can partially activate T cells, resulting in multiple distinct functional phenotypes, including the induction of anergy. Such APL stimulate a unique pattern of T cell receptor (TCR) phospho-zeta species, and lack associated ZAP-70 kinase activity. While these data suggested that selective signaling pathways downstream of the TCR/CD3 ...