title: Decreased expression of B7 costimulatory molecules and major histocompatibility complex class-I in human hepatocellular carcinoma.
abstract: OBJECTIVE
  We analyzed the expression of antigen-processing and antigen-presenting molecules in surgically resected fresh samples of human hepatocellular carcinoma (HCC) tissue to elucidate a mechanism of immune escape. We also examined the expression of interleukin (IL)-10 protein, which might act to downregulate expression of antigen-processing and antigen-presenting molecules.
  
  
  METHODS
  Twenty-eight HCC samples obtained by surgical resection were analyzed for the expression of beta2-microglobulin, heat-shock protein (HSP)-70, human leukocyte antigen (HLA) class-I, CD80 (B7-1), CD86 (B7-2) and IL-10 by immunostaining.
  
  
  RESULTS
  Beta2-microglobulin and HSP-70 were preserved in all samples. In contrast, the expression of HLA class-I molecules was significantly reduced according to lowering in the histological grading of tumor differentiation (P = 0.024). Furthermore, B7-1 and B7-2 expression was reduced in tumor cells compared with corresponding areas of liver tissue without malignant involvement irrespective of the histological grading of tumors (21% and 36%, respectively). Although IL-10 protein was expressed in 54% of HCC, no relationship between the expression of IL-10 and downregulation of B7-1, B7-2, and HLA class-I was evident.
  
  
  CONCLUSIONS
  These findings suggest the potential role of B7 co-stimulatory molecules and HLA class-I molecules in facilitating HCC escape from immune surveillance without the involvement of IL-10.
authors.affiliation: Department of Medicine and Medical Science, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan.
authors.forename: Keishi
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Higashi
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nouso
authors.forename: Harushige
authors.initials: H
authors.lastname: Nakatsukasa
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Uemura
authors.forename: Shin-Ichiro
authors.initials: S
authors.lastname: Nakamura
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Sato
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hanafusa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yumoto
authors.forename: Ichiro
authors.initials: I
authors.lastname: Naito
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shiratori
mesh_terms: D000368:Aged; D018122:B7-1 Antigen / Q000096:biosynthesis*; D006528:Carcinoma, Hepatocellular / Q000276:immunology*; D005260:Female; D005805:Genes, MHC Class I / Q000276:immunology*; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis / Q000276:immunology; D006801:Humans; D016753:Interleukin-10 / Q000096:biosynthesis / Q000276:immunology; D008113:Liver Neoplasms / Q000276:immunology*; D008297:Male; D001613:beta 2-Microglobulin / Q000096:biosynthesis / Q000276:immunology
chemical_list: D018122:B7-1 Antigen; D018840:HSP70 Heat-Shock Proteins; D001613:beta 2-Microglobulin; D016753:Interleukin-10