Structure of the gene of tum- transplantation antigen P35B: presence of a point mutation in the antigenic allele.

摘要: Mutagen treatment of P815 tumour cells produces tum- variants that are rejected by syngeneic mice because they express new transplantation antigens. These 'tum-' antigens elicit a cytolytic T lymphocyte (CTL) response but no detectable antibody response. The DNA variant P35 was transfected into cell line P1.HTR. Transfectants expressing antigen P35B were identified on the basis their ability to stimulate anti-P35B CTL. This repeated with cosmid library and carrying sequence encoding recovered from transfectant antigen. Gene is 6 kb long contains 11 exons. shows homology previously gene P91A nor any presently recorded in data banks. antigenic allele differs normal point mutation located exon 5. mutation, which replaces Ser an Asn residue, shown site-directed mutagenesis be responsible for expression A synthetic decapeptide covering surrounding rendered sensitive lysis Surprisingly, homologous peptide corresponding had same effect, indicating this does not exert its effect generating aggretope or epitope peptide. As observed P91A, we found fragments containing only exons 4 5, cloned non-expression vectors, transferred efficiently