The HLA crossroad in tumor immunology.
It is generally accepted that human and experimental tumor cells can lose major histocompatibility complex (MHC) class I molecules. These human leukocyte antigen (HLA) losses are detected when the primary tumor breaks the basal membrane, invades the surrounding tissues, and starts to metastasize. These altered HLA class I phenotypes probably constitute the major tumor escape mechanism facing anti-tumor T-cell mediated responses. Thus, it is important to characterize these phenotypes in clinical tumor samples, analyze the mechanism(s) responsible for them, and counsel patients before and during peptide anti-cancer immunotherapy. The present paper summarizes the most relevant altered HLA class I phenotypes found in human tumor samples, indicates their frequency, and outlines the mechanisms implicated. This review also points out that the natural killer (NK) escape mechanism of HLA class I deficient cancer cells is yet to be defined. Knowledge accumulated to date reveals that HLA class I molecules are an important crossroad in tumor immunology.
Algarra
I
I
Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaen, Spain.
Cabrera
T
T
Garrido
F
F
D015395:Histocompatibility Antigens Class I / Q000378:metabolism*; D006801:Humans; D007167:Immunotherapy; D007694:Killer Cells, Natural / Q000276:immunology; D009369:Neoplasms / Q000276:immunology* / Q000628:therapy; D010641:Phenotype; D013601:T-Lymphocytes / Q000276:immunology; D019139:Tumor Escape
D015395:Histocompatibility Antigens Class I