Control of the rat T cell response to retroviral and bacterial superantigens by class II MHC products and Tcrb-V8.2 alleles.
The in vitro response of unprimed rat T cells to retroviral and bacterial superantigens (SAg) was analyzed with TCR V beta 8.2-, 8.5-, 10-, and 16-specific mAbs. Specific stimulation of V beta 8.2 and 8.5 CD4 cells was observed in the response to Mls1a, the retroviral SAg encoded by integrated provirus Mtv-7 (Mtv-7 SAg), which was presented by mouse B cells or mouse fibroblasts transfected with DR1 genes and the Mtv-7 SAg. Additionally, a strong response of V beta 16 CD4 cells to an as yet unidentified mouse SAg was found. Only some of the bacterial SAg known to stimulate mouse and human T cells also activated rat lymph node cells. SEA, SEE, and TSST-1 stimulated rat T cells well; SEB, SEC1, and SED did not. This defect was apparently a result of weak binding to rat MHC class II molecules because presentation by human MHC class II molecules restored T cell activation. Under these conditions, SEB stimulated V beta 8.2+ and 8.5+ CD4 and CD8 cells from Lewis rats. A comparison of several rat strains revealed an unresponsiveness to SEB or Mtv-7 SAg for V beta 8.2 cells from F344 and DA rats. Determination of the nucleotide sequences of the Tcrb-V8.2 of these strains revealed differences between SAg-responsive and SAg-unresponsive Tcrb-V8.2 in seven amino acids, four of them located in the putative SAg contact site. The significance of these findings for the evolution of TCR-SAg interactions is discussed.
Herrmann
T
T
Institute of Virology and Immunobiology, University of Würzburg, Germany.
Hochgrebe
T
T
Torres-Nagel
N E
NE
Huber
B T
BT
Hünig
T
T
D000483:Alleles; D000818:Animals; D017951:Antigen Presentation; D000942:Antigens, Bacterial / Q000008:administration & dosage; D000956:Antigens, Viral / Q000008:administration & dosage; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004768:Enterotoxins / Q000276:immunology; D005260:Female; D000949:Histocompatibility Antigens Class II; D006801:Humans; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D051381:Rats; D011917:Rats, Inbred Lew; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics; D012190:Retroviridae / Q000276:immunology; D018089:Superantigens / Q000008:administration & dosage*; D013601:T-Lymphocytes / Q000276:immunology*
D000942:Antigens, Bacterial; D000956:Antigens, Viral; D017931:DNA Primers; D004768:Enterotoxins; D000949:Histocompatibility Antigens Class II; D016693:Receptors, Antigen, T-Cell, alpha-beta; D018089:Superantigens; C031818:enterotoxin B, staphylococcal