Demonstration and partial characterization of the interferon-gamma receptor on human B lymphocytes.
The expression of interferon-gamma (IFN-gamma) receptors on normal human B cells and four B cell lines was studied. Recombinant human IFN-gamma was labeled with [gamma-32P]ATP using the catalytic subunit of a cAMP-dependent protein kinase. All four B cell lines, although differing in their responsiveness to IFN-gamma, were found to express high-affinity receptors (1,000-11,000 receptors/cell). Normal unactivated B lymphocytes were also found to express constitutively high-affinity receptors, approximately 1,400 receptors per cell with an estimated affinity of 295 pM. Activation of the normal B cells in vitro with the polyclonal B cell activator, Staphylococcus aureus Cowan strain I (SAC), resulted in a slight decline in receptor number and a more pronounced fall in receptor density. One of the B cell lines and unactivated normal B cells were shown to internalize labeled IFN-gamma rapidly. Chemical cross-linking of 32P-IFN-gamma to the CB B cell line and to freshly isolated B lymphocytes revealed one major cross-linked receptor-ligand complex which had an estimated molecular weight of approximately 110 kilodaltons. This complex corresponded to a 93 kD receptor cross-linked to recombinant IFN-gamma. Our data indicate that normal B lymphocytes constitutively express an approximately 93 kD IFN-gamma receptor which is similar to the receptor present on Epstein-Barr virus-transformed B cell lines.
Nakagawa
T
T
Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
Nakagawa
N
N
Delsing
G A
GA
Volkman
D
D
Kehrl
J H
JH
D001402:B-Lymphocytes / Q000032:analysis / Q000378:metabolism*; D002460:Cell Line; D003432:Cross-Linking Reagents; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism*; D011971:Receptors, Immunologic / Q000032:analysis / Q000378:metabolism*; D017471:Receptors, Interferon; D011994:Recombinant Proteins
D003432:Cross-Linking Reagents; D011971:Receptors, Immunologic; D017471:Receptors, Interferon; D011994:Recombinant Proteins; D007371:Interferon-gamma