background: cd8+ cytotoxic t lymphocytes have been recently divided based on their cytokine expression profile. objective: to evaluate the percentages of cd8+ lymphocytes and their effector subsets including tc1, tc2 and tc17 in the tumor draining lymph nodes (tdlns) of patients with breast cancer. methods: single cell suspensions were obtained from tdlns of 42 patients with breast cancer. stai...

Recently, a novel subset of TCRαβ(+) CD4(-) CD8(-) double-negative (DN) T cells was described to suppress immune responses in both mice and humans. Moreover, in murine models, infusion and/or activation of DN T cells specifically suppressed alloreactive T cells and prevented the development of graft-versus-host disease after allogeneic hematopoietic stem cell transplantation. We demonstrated th...

To study the cellular immunology of platelet-induced alloimmunization, a murine transfusion model was developed. BALB/c (H-2d) recipient mice were transfused weekly with 2 x 10(8) platelets or 10(3) leukocytes from C57BL/6 (H-2b) donor mice. Recipient antidonor major histocompatibility complex (MHC) class I alloantibodies could be detected in flow cytometric assays by the fifth platelet transfu...

Bacterial superantigens induce peripheral unresponsiveness in CD4+ T cell populations that express appropriate Vbeta chains. We have used Vbeta3/Valpha11 T cell receptor transgenic (Tg) mice and the Vbeta3-specific superantigen staphylococcal enterotoxin A (SEA) to further investigate the mechanisms that contribute to such unresponsiveness. As in other models, in vivo exposure to SEA rendered t...

Anergic T cells display a marked decrease in their ability to produce IL-2 and to proliferate in the presence of an appropriate antigenic signal. Two nonmutually exclusive classes of models have been proposed to explain the persistence of T cell anergy in vivo. While some reports indicate that anergic T cells have intrinsic defects in signaling pathways or transcriptional activities, other stud...

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...

Resistance to intracellular bacterial pathogens such as Brucella spp. relies on cell-mediated immunity, which involves activation of the bactericidal mechanisms of antigen-presenting cells (macrophages and dendritic cells) and the subsequent expansion of antigen-specific CD4+ and CD8+ T-cell clones. Brucella antigens induce the production of T helper type 1 (Th1) cytokines, and an adequate Th1 ...

TRAF6, TNFR-associated factor 6, is a key adaptor downstream from the TNF receptor and TLR superfamily members. T cell-specific deletion of TRAF6 (TRAF6-DeltaT) was recently shown to result in the development of multiorgan inflammatory disease and the resistance of responder T cells to suppression by CD4+CD25+ regulatory T cells. In this study we examined the role of TRAF6 in an additional mech...

Staphylococcus aureus enterotoxins have immunomodulatory properties. In this study, we show that Staphylococcal enterotoxin A (SEA) induces a strong proliferative response in a murine T cell clone independent of MHC class II bearing cells. SEA stimulation also induces a state of hypo-responsiveness (anergy). We characterized the components of the T cell receptor (TCR) during induction of anergy...