MHC class II-dependent activation of CD4+ T cell hybridomas by human mast cells through superantigen presentation.
J Leukoc Biol
; 66(1): 105-12, 1999 Jul.
Article
em En
| MEDLINE
| ID: mdl-10410997
ABSTRACT
Human mast cells (MC) were examined for expression of MHC class II antigens and for their ability to activate CD4+ T cell hybridomas through presentation of superantigen (SAg). HMC-1, a leukemic immature MC line expressing class II Ags, was shown to efficiently present the staphylococcal enterotoxin B (SEB) SAg to responding T cell hybridoma on treatment with interferon-gamma (IFN-gamma), which up-regulated class II molecules. The study was then extended to human normal MC. Almost pure (>99%) cord blood-derived MC (CBMC) were shown to express class II Ags (HLA-DR and HLA-DQ) and CD80, which were up-regulated by IFN-gamma treatment and, to a lesser extent, by interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GM-CSF). CBMC directly activated CD4+ T cell hybridomas through presentation of SEB and TSST1 SAgs. The production of IL-2 required a cell-to-cell contact between T cells and CBMC and it was inhibited by anti-class II antibodies. Furthermore, an additional pretreatment of CBMC by IFN-gamma or GM-CSF or IL-4 had no effect on their presenting efficiency. This previously unknown function of human MC, i.e., MHC class II-dependent activation of CD4+ T cells, may be critical in subsequent cellular activation events because colocalization of mast and T cells is frequently observed at sites of antigen entry.
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Base de dados:
MEDLINE
Assunto principal:
Toxinas Bacterianas
/
Ativação Linfocitária
/
Linfócitos T CD4-Positivos
/
Antígenos de Histocompatibilidade Classe II
/
Superantígenos
/
Apresentação de Antígeno
/
Mastócitos
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Leukoc Biol
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
França