DIFFERENT EFFECTS OF SUBSTITUTIONS AT RESIDUES 224 AND 228 OF MHC CLASS-I ON THE RECOGNITION OF CD8

作者：SEKIMATA M; TANABE M; SARAI A; YAMAMOTO J; KARIYONE A; NAKAUCHI H; EGAWA K; TAKIGUCHI M

来源：The Journal of Immunology, 1993, 150(10): 4416-4426.

DOI：10.4049/jimmunol.150.10.4416

Previous studies indicated that weak xenoresponse to HLA class I by mouse T cells is due to the inefficient interaction of mouse CD8 with the alpha3 domain of HLA class I. The present study using chimeric H-2K(b) molecules with recombinant alpha3 domain between H-2K(b) and HLA-B7 as well as single amino acid mutants of H-2K(b) demonstrated that each substitution at residues 224 and 228 affects recognition of CD8-dependent mouse CTL clones. On the other hand, reactivity of IL-2-producing H-2K(b)-specific T cell hybridoma transfected with mouse CD8alpha was abrogated by substitution at residue 224 but not by that at residue 228. This indicates that the substitution at residue 228 affects recognition of CD8-dependent CTL but does not critically affect binding of CD8 to MHC class I molecules, although residue 224 abrogates binding of CD8. The model structure of the alpha3 domain of H-2K(b) suggests that the substitution at residue 224 induces conformational change of CD8 binding loop, whereas minimum structure change by the substitution at residue 228 is expected. It is therefore speculated that minimum structure change of CD8 binding loop by substitution at residue 228 may influence binding affinity of CD8, which abrogates recognition of CD8-dependent CTL but not IL-2 production of the CD8-dependent T cell hybridoma.

• 出版日期1993-5-15
• 单位河北医科大学