title: HLA-DRB alleles are differentially expressed by tumor cells in breast carcinoma.
abstract: The biologic and prognostic significance of HLA-DR expression and T-cell infiltration in breast carcinoma are presently controversial. To test the hypothesis that these factors are influenced by particular HLA-DRB alleles, 52 breast tumor samples, composed of 26 DRB1*04 and 26 non-DRB1*04 tumors, were assessed using immunohistochemistry for expression of DR and its associated invariant chain (Ii) and for infiltrating CD3+ T cells. While DR expression by tumor cells was significantly associated with T-cell infiltration, DRB1*04 tumors were more frequently DR+ Ii+ and contained smaller CD3+ infiltrates than non-DRB1*04 tumors. This difference was largely attributable to DRB1*07 tumors, which were typically DR- Ii-, although they contained similar numbers of T cells to DR+ Ii+ tumors. Further analysis of DR+ tumors using allotype discriminating antibodies revealed that DRB1*04 alleles were always expressed, while non-DRB1*04 alleles were inconsistently expressed. The results of this study provide the first reported evidence that DRB alleles influence DR expression and T-cell infiltration in breast carcinoma and suggest that multiple factors contribute to DR expression. Ongoing studies aimed at elucidating the molecular and immunologic mechanisms controlling differential DR expression and implications for prognosis and outcome should further our understanding of the antitumor immune response and evasion strategies employed by tumor cells.
authors.affiliation: Division of Basic Medical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.
authors.forename: Sharon A
authors.initials: SA
authors.lastname: Oldford
authors.forename: J Desmond
authors.initials: JD
authors.lastname: Robb
authors.forename: Peter H
authors.initials: PH
authors.lastname: Watson
authors.forename: Sheila
authors.initials: S
authors.lastname: Drover
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D000944:Antigens, Differentiation, B-Lymphocyte / Q000276:immunology / Q000378:metabolism*; D000951:Antigens, Neoplasm; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology; D017252:CD3 Complex / Q000378:metabolism; D044584:Carcinoma, Ductal / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D005805:Genes, MHC Class I / Q000276:immunology / Q000502:physiology; D006684:HLA-DR Antigens / Q000276:immunology / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D011379:Prognosis; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000944:Antigens, Differentiation, B-Lymphocyte; D000951:Antigens, Neoplasm; D017252:CD3 Complex; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; C045084:invariant chain