T cell control of staphylococcal enterotoxin B (SEB) lethal sensitivity in mice: CD4+ CD45RB(bright)/CD4+ CD45RB(dim) balance defines susceptibility to SEB toxicity.
Radiation chimeras, generated by transplantation of SCID bone marrow into C3H/HeJ mice, show lethal susceptibility to staphylococcal enterotoxin B (SEB), thus constituting a valid murine model for SEB shock. This SEB sensitivity is due to the ability of the irradiated host to restore residual T cell populations, since the SCID donor bone marrow is unable to generate T cells. SCID bone marrow transplanted into irradiated nude mice does not generate SEB-sensitive chimeras, as a consequence of the inability of the recipient nude mice to develop mature T cells. Thymectomy of normal recipient mice prior to bone marrow transplantation does not affect the development of susceptibility to SEB, suggesting that postthymic, residual T cells of the host probably mediate this SEB sensitivity. In vivo depletion experiments show that CD4+ T cells are required for the SEB-triggered shock, while CD8+ cells suppress it. A further examination of the T helper subpopulations in the SEB-sensitive mice reveals a prevalence of CD4+ CD45RB(dim) cells over CD4+ CD45RB(bright) cells. This T helper balance was statistically significant when correlated with SEB-induced mortality. Our model provides a possible explanation for the SEB resistance of normal mice: they have a prevalence of CD4+ CD45RB(dim) over CD4+ CD45RB(bright) cells.
Canaan
A
A
Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel.
Marcus
H
H
Burakova
T
T
David
M
M
Dekel
B
B
Segall
H
H
Reisner
Y
Y
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004768:Enterotoxins / Q000633:toxicity*; D005260:Female; D017493:Leukocyte Common Antigens / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D016513:Mice, SCID; D011828:Radiation Chimera; D013211:Staphylococcus aureus / Q000472:pathogenicity*
D004768:Enterotoxins; C031818:enterotoxin B, staphylococcal; D017493:Leukocyte Common Antigens