Open AccessMolecular aberrations in the MHC class I‐restricted pathway for antigen presentation in methylcholanthrene sarcomas from nude mice: discrepancies between MHC mRNA and surface protein
Author(s) -
ENGEL A.M.,
SVANE I. M.,
MADSEN M. W.,
PEDERSEN M.,
WERDELIN O.
Publication year - 1997
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1046/j.1365-2249.1997.4361335.x
Subject(s) - methylcholanthrene , major histocompatibility complex , immunology , mhc class i , mhc restriction , messenger rna , biology , antigen , mhc class ii , antigen presentation , antigen processing , immune system , genetics , gene , t cell , carcinogen
In a previous study, we demonstrated that eight sarcomas induced by chemical carcinogenesis in nude mice were rejected by syngeneic immunocompetent recipients at a much higher rate than eight sarcomas induced with the same method in syngeneic immmunocompetent mice. In the present study, we investigated these 16 sarcomas for structural and quantitative aberrations in components of the MHC class I‐restricted antigen‐processing and ‐presentation pathway. Considerable discrepancies between mRNA levels and cell surface protein expression of MHC class I (K d , D d and L d ) molecules were observed almost exclusively in the tumours derived from nude mice. Several of the nude mouse‐derived tumours also displayed incongruent levels of heavy chain mRNA and β 2 ‐microglobulin mRNA. These findings are taken as indications of abnormal regulation of gene transcription in nude mouse tumours, and if this abnormal regulation extends to the entire genome, it may explain the pronounced immunogenicity of these tumours. Proteasome composition, heat shock protein expression, TAP‐molecule inducibility and intercellular adhesion molecule‐1 expression were investigated in the same tumours. We found no indications of structural defects or quantitative differences in these molecules between the two groups of tumours.