B-cell maturation in chronic lymphocytic leukaemia. IV. T-cell-dependent activation of leukaemic B cells by staphylococcal enterotoxin 'superantigens'.
Staphylococcal enterotoxins (SE) are potent T-lymphocyte activators that stimulate T cells by directly cross-linking HLA-DR molecules on antigen-presenting cells with the V beta gene products of the T-cell receptor. The different SE activate all T cells expressing a given V beta, and, therefore, have been termed 'superantigens'. Here we show that SE are potent activators of leukaemic B cells from patients with chronic lymphocytic leukaemia (CLL). Purified B cells from seven of eight CLL patients with high WBC counts (greater than 80,000/microliters) responded to one or several of the tested SE (SEA, SEB, SEC1, SED, SEE) by proliferation ([3H]TdR incorporation) and/or Ig secretion. In several instances, the response of leukaemic B cells to SE was much stronger than was the response to other known B-cell activators including EBV, pokeweed mitogen (PWM), phorbolester (TPA), and Staphylococcus aureus Cowan I (SAC). The activation of leukaemic B cells by SE was strictly dependent on the addition of irradiated T cells isolated from healthy donors. FACS analysis of cultured cells ensured that the proliferating cells were indeed B cells. Taken together, these results demonstrate that SE are strong T-cell-dependent B-cell activators that, in some cases, can stimulate maturation of leukaemic B cells which are refractory to other activation signals.
Duan
X
X
Institut für Immunologie, Universität Heidelberg, Germany.
Nerl
C
C
Janssen
O
O
Kabelitz
D
D
D000942:Antigens, Bacterial / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D004768:Enterotoxins / Q000276:immunology*; D005260:Female; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D008211:Lymphocyte Cooperation / Q000276:immunology; D008297:Male; D013211:Staphylococcus aureus / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D014407:Tumor Cells, Cultured / Q000276:immunology
D000942:Antigens, Bacterial; D004768:Enterotoxins