Non-immune functions of MHC class I glycoproteins in normal and malignant cells.
MHC class I glycoproteins play a pivotal role in the regulation of immune responses by presenting antigenic peptides to cytotoxic T lymphocytes and by regulating cytolytic activities of natural killer cells. Cells originating in malignant tumours are often characterized by a profound immune escape phenotype. This phenotype is frequently associated with alterations in MHC class I-related antigen processing and presentation that enable tumours to escape immune surveillance. However, it now becomes clear that MHC class I molecules do not only provide a mechanistic framework for the presentation of antigenic peptides but, rather, possess broader biological functions due to their ability to regulate cell-to-cell communication and receptor-mediated trans-membrane signal transduction. In the present review we made an attempt to reevaluate the significance of an altered MHC class I phenotype for tumour progression in view of the current state of knowledge concerning the aforementioned non-immune functions performed by these membrane glycoproteins.
Fishman
D
D
Department of Immunology and Microbiology, Faculty of Health Sciences, Ben-Gurion University Cancer Research Center, Ben-Gurion University of the Negev Beer-Sheva, Israel.
Elhyany
S
S
Segal
S
S
D000818:Animals; D017951:Antigen Presentation; D002450:Cell Communication; D006023:Glycoproteins / Q000276:immunology*; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007157:Immunologic Surveillance; D015398:Signal Transduction; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D006023:Glycoproteins; D015395:Histocompatibility Antigens Class I