CTL cross-reactivities reveal shared immunodominant determinants created by structurally homologous regions of MHC class i antigens
Hunt, P.; Sears, D.W.
Journal of Immunology 130(3): 1439-1446
1983
ISSN/ISBN: 0022-1767 PMID: 6185588 Document Number: 212521
The CTL revealed that Ld has an identical Tyr155-Tyr156 dipeptide, which suggests that Ld alone would be cross-reactive with Kbm1. This was confirmed by cold target inhibition studies. In another analysis of b anti-a CTL, it was shown that Kbm11 as a target antigen is cross-reactive with Kk and Ld but not Dd. Sequence comparisons at position 77, the site of the Kbm11 mutation, revealed that Kb of the effector haplotype and Dd have Asp77 in common, whereas Ld has Asn77. From the cross-reactivity data it is predicted that the unknown amino acids at position 77 of both Kk and Kbm11 are likely to be Asn by homology to Ld. In examining the genetic control of CTL reactions to these determinants, it was found that mice of the k haplotype do not recognize the determinant(s) that distinguishes Kbm11 from Kb but do recognize the immunodominant determinant(s) created by Tyr155-Tyr156 of both Kbm1 and Ld. Mice of the dm2 haplotype, although capable of generating anti-Ld-specific CTL, do not recognize the Tyr155-Tyr156-related determinants of Ld even though sequence analysis of the appropriate class I antigens indicates this should be possible. Further study of the genetic control of CTL reactivity to define determinants will be aided by using genetically engineered cells such as the Ld-transformed cell line, T1.1.1, which was found in the present study to be an effective target and inhibitor of anti-Ld-specific CTL.