A mutation in the alpha 3 domain of Db that abrogates CD8 binding does not affect presentation of an immunodominant H-Y peptide.
The peptidic nature of the male (H-Y) antigen, a model minor histocompatibility antigen in H-2b mice, has recently been demonstrated. In this study we show that the H-Y peptide, which is recognized by PM-1, a Db-restricted cytotoxic T-lymphocyte (CTL) clone, is absent in male H-2d spleen cells but present in male H-2d spleen cells that also express a transgenic Db molecule under its endogenous promoter. This result indicates that both the H-Y and the Db gene products are essential and sufficient for production of the Db-restricted H-Y peptide. By comparing the ability of the PM-1 clone and bulk CTL generated in a secondary mixed lymphocyte culture to recognize H-Y peptidic material eluted from affinity-purified Db molecules and separated by reversed-phase high-performance liquid chromatography (HPLC), we provide evidence that there is an immunodominant H-Y epitope that is presented by the Db molecule. Furthermore, the presentation of this epitope is not affected by a mutation in the alpha 3 domain of Db (asp227 to lys227), which abrogates CD8 binding, since similar amounts of H-Y peptide were eluted from affinity-purified wild-type or mutant Db molecules. However, the generation of the H-Y epitope is dependent on the presence of beta 2-microglobulin, since it is absent in male H-2b mice that lack a functional beta 2-microglobulin gene. The implications of these findings on T-cell development are discussed.
Dutz
J P
JP
Department of Microbiology and Immunology, University of British Columbia, Vancouver, Canada.
Teh
S J
SJ
Killeen
N
N
Teh
H S
HS
D000818:Animals; D017951:Antigen Presentation; D016827:CD8 Antigens / Q000378:metabolism*; D002460:Cell Line; D046508:Culture Techniques; D000939:Epitopes / Q000276:immunology; D005260:Female; D006182:H-Y Antigen / Q000276:immunology*; D016056:Immunodominant Epitopes / Q000276:immunology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008822:Mice, Transgenic; D009154:Mutation; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D001613:beta 2-Microglobulin / Q000276:immunology
D016827:CD8 Antigens; D000939:Epitopes; D006182:H-Y Antigen; D016056:Immunodominant Epitopes; D001613:beta 2-Microglobulin