HLA-F is a surface marker on activated lymphocytes.

Publication Type:

Journal Article

Source:

European journal of immunology, Volume 40, Issue 8, p.2308-18 (2010)

Keywords:

2010, Antigens, CD4, ATP-Binding Cassette Transporters, Cell Membrane, Cells, Cultured, Center-Authored Paper, Clinical Research Division, Cytoplasm, Histocompatibility Antigens Class I, Humans, Immunologic Memory, Interleukin-2 Receptor alpha Subunit, Lymphocyte Activation, Lymphocyte Subsets, Membrane Transport Proteins, Protein Transport, T-Lymphocytes, Regulatory

Abstract:

Of the three nonclassical class I antigens expressed in humans, HLA-F has been least characterized with regard to expression or function. In this study, we examined HLA-F expression focusing on lymphoid cells, where our previous work with homologous cell lines had demonstrated surface HLA-F expression. HLA-F protein expression was observed by Western blot analysis in all resting lymphocytes, including B cells, T cells, NK cells, and monocytes, all of which lacked surface expression in the resting state. Upon activation, using a variety of methods to activate different lymphocyte subpopulations, all cell types that expressed HLA-F intracellularly showed an induction of surface HLA-F protein. An examination of peripheral blood from individuals genetically deficient for TAP and tapasin expression demonstrated the same activation expression profiles for HLA-F,but with altered kinetics post-activation. Further analysis of CD41+CD25+1 Treg showed that HLA-F was not upregulated on the major fraction of these cells when they were activated,whereas CD41+CD25- T cells showed strong expression of surface HLA-F when activated under identical conditions. These findings are discussed with regard to possible functions for HLA-F and its potential clinical use as a marker of an activated immune response.