The role of T8 in the cytotoxic activity of cloned cytotoxic T lymphocyte lines specific for class II and class I major histocompatibility complex antigens.
It is reported here that most cytotoxic T lymphocytes (CTL), which recognize class I major histocompatibility complex (MHC) loci, express the T cell differentiation antigen T8. However, a minority of T8+ CTL clones was found to recognize class II MHC antigens. To test the hypothesis that T8 is involved only in T cell recognition of class I MHC antigens, we studied the role of T8 in the cytotoxic activity of class II MHC-specific CTL. Monoclonal antibodies specific for T8 blocked the activity of most class I MHC-specific CTL clones but did not affect the activity of class II MHC-specific CTL clones. Moreover, a mild trypsin treatment of the clones, which removed and T8 determinant, affected the activity of class I MHC but not that of class II MHC-specific CTL clones. These findings indicate that the class II-specific MHC CTL clones described here did not require T8 for their cytolytic activity. The activity of one T8+ class I MHC-specific (HLA-B27) CTL clone (HG-61) against the B cell line JY, which was used to raise this CTL clone, was not blocked by trypsin treatment of this clone. However, the activity of CTL clone HG-61 against target cells different from JY but carrying the appropriate HLA specificity was blocked by anti-T8 antibodies and trypsin treatment. The implications of these findings for the hypothesis that T8 is involved only in the activity of CTL with a relatively low avidity for class I MHC antigens are discussed.
Spits
H
H
Yssel
H
H
Voordouw
A
A
de Vries
J E
JE
D000911:Antibodies, Monoclonal / Q000502:physiology; D000915:Antibody Affinity; D001667:Binding, Competitive; D002460:Cell Line; D002999:Clone Cells / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D000939:Epitopes / Q000276:immunology*; D006680:HLA Antigens / Q000145:classification / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D010641:Phenotype; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification / Q000276:immunology*; D014357:Trypsin / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D000939:Epitopes; D006680:HLA Antigens; D014357:Trypsin