ISSN:
0730-2312
Keywords:
γ-interferon
;
receptors
;
B lymphocytes
;
internalization
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
The expression of interferon-γ (IFN-γ) receptors on normal human B cells and four B cell lines was studied. Recombinant human IFN-γ was labeled with [γ- 32P]ATP using the catalytic subunit of a cAMP-dependent protein kinase. All four B cell lines, although differing in their responsiveness to IFN-γ, 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-γ rapidly. Chemical cross-linking of 32P-IFN-γ 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-γ. Our data indicate that normal B lymphocytes constitutively express an approximately 93 kD IFN-γ receptor which is similar to the receptor present on Epstein-Barr virus-transformed B cell lines.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jcb.240400403
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