Beta 2-microglobulin and HLA-DR expression in relation to the presence of Epstein-Barr virus in nasopharyngeal carcinomas.
We have investigated the immunohistochemical expression of beta 2-microglobulin and HLA-DR proteins in nasopharyngeal carcinoma (NPC) in relation to the expression of the Epstein-Barr virus (EBV)-encoded EBER 1-2 mRNAs and LMP-1 protein. beta 2-Microglobulin is expressed in association with MHC-I molecules on most nucleated cells and HLA-DR belongs to the MHC-II molecules which are expressed mostly on antigen-presenting cells. Formalin-fixed paraffin-embedded tissue from 37 NPC cases was stained with immunohistochemistry for beta 2-microglobulin, HLA-DR and LMP-1 proteins and by RNA in situ hybridization for EBER 1-2 mRNAs. beta 2-Microglobulin-positive staining was found in neoplastic cells in all cases. In 19/37 NPC cases the positive staining was found in most neoplastic cells. In the remaining 18 NPC cases more than 25% of the neoplastic cells showed significantly reduced or negative staining in comparison to the normal epithelium and infiltrating small lymphocytes. HLA-DR-positive staining was found in 27/37 NPC cases. EBER 1-2 transcripts were deteced in neoplastic cells in 13/37 NPC cases. LMP-1 expression in tumour cells was found in 4/13 EBER1-2-positive cases. No correlation was found between the presence of EBER1-2 transcripts or LMP-1 protein and the beta 2-microglobulin-reduced expression in NPC. Thus, EBV does not seem to use downregulation of MHC-I to avoid the T cell cytotoxic immune response in NPC. HLA-DR expression was observed in all 13 EBV-positive cases of NPC, suggesting that EBV may participate in the induction of HLA-DR expression in a proportion of NPC.
Kouvidou
C
C
Department of Pathology, University Hospital of Heraklion, Athens, Greece.
Rontogianni
D
D
Tzardi
M
M
Datseris
G
G
Panayiotides
I
I
Darivianaki
K
K
Karidi
E
E
Delides
G
G
Kanavaros
P
P
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000276:immunology / Q000821:virology; D002294:Carcinoma, Squamous Cell / Q000276:immunology* / Q000821:virology*; D005260:Female; D006684:HLA-DR Antigens / Q000378:metabolism*; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000276:immunology* / Q000821:virology*; D012367:RNA, Viral / Q000032:analysis / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D012269:Ribosomal Proteins; D014763:Viral Matrix Proteins / Q000378:metabolism; D001613:beta 2-Microglobulin / Q000378:metabolism*
C037662:EBV-associated membrane antigen, Epstein-Barr virus; C099537:Epstein-Barr virus encoded RNA 1; D006684:HLA-DR Antigens; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; D014763:Viral Matrix Proteins; D001613:beta 2-Microglobulin; C067169:RPL22 protein, human