7678619

pubmed:Citation

3

Staphylococcal enterotoxins, also known as superantigens (SAg), bind class II MHC molecules on APC and upon direct cell-to-cell contact stimulate proliferation of T cells expressing appropriate V beta gene products. The T cell surface molecule CD28 binds its costimulatory counter-receptor, B7 expressed on APC, and augments IL-2 production and T cell growth. Although the role of B7 costimulation during Ag-specific responses of T cells is established, its involvement during the activation of T cells with SAg has not been examined. Using a soluble Ig C gamma 1 chimera of CTLA-4, a second receptor for B7 and a homologue of CD28, this study examines the role of B7 expressed on APC during the induction of proliferation of CD4+ T cells upon stimulation with SAg (SAg/staphylococcal enterotoxins). CTLA-4lg, which has a higher avidity for B7 than CD28, had no effect on the synthesis of IL-2 as well as proliferative responses of CD4+ T cells induced by SAg presented on allogeneic EBV-transformed B cells, and IFN-gamma-activated endothelial cells. In contrast, T cell proliferation induced by alloAg presentation by the same APC was significantly inhibited by CTLA-4lg. mAb directed at the CD11a/CD18 molecule inhibited both SAg-induced and alloAg-induced proliferation of T cells. AlloAg-primed CD4+ T cells, which expressed both class II MHC and intercellular adhesion molecule-1 but not B7, presented SAg to and induced proliferation of both resting and SAg-primed T cells. These responses were inhibited by mAb directed at CD11a/CD18 but not by CTLA-4 Rg. These results suggest that SAg-induced responses differ from those induced by alloAg in that they are not obligatorily dependent on the costimulation by B7. In contrast, adhesive interaction between CD11a/CD18 on T cells and its counter-receptor on SAg-presenting cells is necessary and probably sufficient to support SAg-induced proliferation of T cells.

http://linkedlifedata.com/resource/pubmed/journal/2985117R

http://linkedlifedata.com/resource/pubmed/chemical/Antibodies, Monoclonal, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, Bacterial, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD11, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD18, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD28, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, CD80, http://linkedlifedata.com/resource/pubmed/chemical/Antigens, Differentiation..., http://linkedlifedata.com/resource/pubmed/chemical/Antigens, Surface, http://linkedlifedata.com/resource/pubmed/chemical/Enterotoxins, http://linkedlifedata.com/resource/pubmed/chemical/Interferon-gamma, http://linkedlifedata.com/resource/pubmed/chemical/enterotoxin B, staphylococcal

Feb

pubmed-author:DamleN KNK, pubmed-author:KlussmanKK, pubmed-author:LeytzeGG, pubmed-author:LinsleyP SPS

1

NLM

726-35

pubmed-meshheading:7678619-Animals, pubmed-meshheading:7678619-Antibodies, Monoclonal, pubmed-meshheading:7678619-Antigens, Bacterial, pubmed-meshheading:7678619-Antigens, CD, pubmed-meshheading:7678619-Antigens, CD11, pubmed-meshheading:7678619-Antigens, CD18, pubmed-meshheading:7678619-Antigens, CD28, pubmed-meshheading:7678619-Antigens, CD80, pubmed-meshheading:7678619-Antigens, Differentiation, T-Lymphocyte, pubmed-meshheading:7678619-Antigens, Surface, pubmed-meshheading:7678619-CD4-Positive T-Lymphocytes, pubmed-meshheading:7678619-Cell Line, pubmed-meshheading:7678619-Enterotoxins, pubmed-meshheading:7678619-Humans, pubmed-meshheading:7678619-Interferon-gamma, pubmed-meshheading:7678619-Lymphocyte Activation, pubmed-meshheading:7678619-Mice, pubmed-meshheading:7678619-Mice, Inbred BALB C, pubmed-meshheading:7678619-Staphylococcus aureus, pubmed-meshheading:7678619-T-Lymphocytes

Proliferation of human T lymphocytes induced with superantigens is not dependent on costimulation by the CD28 counter-receptor B7.

Journal Article