Studies on binding of HIV-1 p24gag peptide to HLA-Cw3+ cells.
Human major histocompatibility complex class I antigens, HLA-C, are expressed on the cell surface at approximately a tenfold lower level than HLA-A and -B. We hypothesized that the expression of HLA-C is limited by the quantity of high affinity peptides which bind to these molecules, thus allowing only a small fraction of HLA-C molecules to be transported and/or to remain stable on the cell surface. If this assumption is correct, then the addition of exogenous peptide should increase cell surface HLA-C expression. To verify the hypothesis, we pulsed lymphoblastoid cell line PAJ (HLA-Cw3+) with synthetic HIV-1 p24gag 145-152 peptide, known to be presented to T-lymphocytes by HLA-Cw3 molecule. PAJ (HLA-Cw3+) cells bound approximately two times more of the peptide than HAJ (HLA-Cw3-), and four times more than 500/C9 (HLA-Cw3-) cells. Accordingly, overnight pulsing of PAJ cells with the p24gag 145-152 peptide caused an increase in class I HLA expression detected on the cell surface by flow cytofluorimetric analysis with anti-HLA-B,C monoclonal antibodies but not by anti-HLA-A antibody. In contrast, HLA-Cw3- cells treated in the same manner did not show any increase of HLA class I expression. Our data suggest that low concentration of high affinity peptides within the cell may be one of the factors limiting cell surface expression of HLA-C molecules.
Kość
A
A
Laboratory of Immunogenetics, Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw.
Dubis
J
J
Wojciechowska
I
I
Maćkiewicz
Z
Z
Gorczyca
W
W
Myc
A
A
Kupryszewski
G
G
Mańczak
M
M
Myc
P
P
Kuśnierczyk
P
P
D000911:Antibodies, Monoclonal / Q000276:immunology; D002460:Cell Line; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D016655:HIV Core Protein p24 / Q000378:metabolism*; D015234:HLA-A Antigens / Q000378:metabolism; D015235:HLA-B Antigens / Q000378:metabolism; D015236:HLA-C Antigens / Q000096:biosynthesis*; D006801:Humans; D008214:Lymphocytes; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000378:metabolism
D000911:Antibodies, Monoclonal; D016655:HIV Core Protein p24; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D015236:HLA-C Antigens; D010446:Peptide Fragments