Locus-specific analysis of human leukocyte antigen class I expression in melanoma cell lines.
Surface expression of human leukocyte antigen (HLA) class I antigens on melanoma lines was evaluated by locus-specific monoclonal antibodies (mAbs) with three different techniques: Fluorescence-activated cell sorting (FACS), immunohistochemistry with cytospin preparation (ICP), and complement-mediated cytotoxicity (CMC). Eleven HLA class I-expressing cell lines developed from metastases were used. Specific expression of HLA loci was examined under routine culture conditions and after 48-h incubation in interferon-gamma (IFN-gamma; 500 U/ml). Loss of allelic expression was seen in one line (586-MEL): Products of genes coding for HLA-A29 and -B44, in strong linkage disequilibrium, were not detectable. HLA-A antigens were consistently detected by all methodologies and minimally affected by pretreatment with IFN-gamma. HLA-B antigens were detectable in 8 of 11 lines by ICP and 3 of 11 lines by CMC. By FACS the supratypic specificity HLA-Bw6 was expressed at low levels in most lines (mean fluorescence 47.2 +/- 13.4 and rose to 259.8 +/- 45.9 after incubation with IFN-gamma; p < 0.001). HLA-Cw antigen detection by CMC correlated with HLA-B (p < 0.01), suggesting that down-regulation and sensitivity to IFN-gamma are shared by the two loci. This low expression of the HLA-B antigens may play a role in the evasion of the host immune response and its up-regulation may be useful in allowing tumor antigen recognition.
Marincola
F M
FM
Surgery Branch, Clinical Oncology Program, Division of Cancer Treatment, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
Shamamian
P
P
Simonis
T B
TB
Abati
A
A
Hackett
J
J
O'Dea
T
T
Fetsch
P
P
Yannelli
J
J
Restifo
N P
NP
Mulé
J J
JJ
D003601:Cytotoxicity Tests, Immunologic; D005434:Flow Cytometry; D015234:HLA-A Antigens / Q000032:analysis* / Q000097:blood; D015235:HLA-B Antigens / Q000032:analysis* / Q000097:blood; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000494:pharmacology; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D008545:Melanoma / Q000276:immunology* / Q000378:metabolism; D009362:Neoplasm Metastasis; D014407:Tumor Cells, Cultured
D015234:HLA-A Antigens; D015235:HLA-B Antigens; D007371:Interferon-gamma