A K‐ras 13GLY → ASP mutation is recognized by HLA‐DQ7 restricted T cells in a patient with colorectal cancer. Modifying effect of DQ7 on established cancers harbouring this mutation?

TLDR: On the basis of analysis of 251 colonic carcinomas, the presence of HLA‐DQ7 did not seem to protect against the establishment of carcinomas carrying the 13Asp mutation, since the frequency of the DQ7 haplotype was not decreased among patients having this mutation.

Abstract: We have characterized and described in detail 2 CD4+ T-lymphocyte clones (TLC) from a colonic cancer patient. These TLC specifically recognize a K-ras-derived peptide carrying the 13Asp mutation commonly found in adenocarcinomas of the colon. The TLC were independently derived, as they carried 2 different T-cell receptors. The TLC recognized partly overlapping epitopes within the 13Asp peptide, presented by HLA-DQ7 molecules, suggesting that this molecule might confer some protective immunity against the mutation. On the basis of analysis of 251 colonic carcinomas, the presence of HLA-DQ7 did not seem to protect against the establishment of carcinomas carrying the 13Asp mutation, since the frequency of the DQ7 haplotype was not decreased among patients having this mutation. A modifying effect of DQ7 on the development of carcinomas with a 13Asp mutation was, however, observed, resulting in fewer tumours reaching advanced Dukes stages when DQ7 was present.