TY - JOUR
T1 - Cell surface α1-protease inhibitor on human peripheral mononuclear cells in culture
AU - Boldt, D. H.
AU - Kai Chan, S.
AU - Keaton, K.
PY - 1982/1/1
Y1 - 1982/1/1
N2 - We have studied expression of α1-protease inhibitor (α1-PI) by human mononuclear cells. α1-PI was detected on 50% of freshly isolated peripheral mononuclear cells. Unless a proliferative stimulus was provided, α1-PI subsequently disappeared from the cell surfaces. Plant mitogens, periodate, neuraminidase-galactose oxidase, or allogeneic cells all were effective stimuli of α1-PI expression. Concanavalin A stimulated de novo synthesis of α1-PI in cell cultures containing both lymphocytes and mononuclear phagocytes, and α1-PI simultaneously appeared on surfaces of activated lymphocytes. Inhibition of protein synthesis by cycloheximide or monocyte depletion abolished de novo α1-PI synthesis, but only monocyte depletion inhibited α1-PI expression. Lymphocytes, but not monocytes, displayed saturable binding of radioiodinated α1-PI. The data are consistent with the interpretation that human mononuclear phagocytes synthesize and secrete α1-PI. When protein synthesis is inhibited, mitogenic stimuli may provoke release of previously synthesized α1-PI from mononuclear phagocytes. Secreted α1-PI then may bind to specific lymphocyte cell surface receptors. This pattern of α1-PI synthesis, secretion, binding, and expression on lymphoid cell surfaces appears to be a common characteristic of many immunologic reactions in vitro.
AB - We have studied expression of α1-protease inhibitor (α1-PI) by human mononuclear cells. α1-PI was detected on 50% of freshly isolated peripheral mononuclear cells. Unless a proliferative stimulus was provided, α1-PI subsequently disappeared from the cell surfaces. Plant mitogens, periodate, neuraminidase-galactose oxidase, or allogeneic cells all were effective stimuli of α1-PI expression. Concanavalin A stimulated de novo synthesis of α1-PI in cell cultures containing both lymphocytes and mononuclear phagocytes, and α1-PI simultaneously appeared on surfaces of activated lymphocytes. Inhibition of protein synthesis by cycloheximide or monocyte depletion abolished de novo α1-PI synthesis, but only monocyte depletion inhibited α1-PI expression. Lymphocytes, but not monocytes, displayed saturable binding of radioiodinated α1-PI. The data are consistent with the interpretation that human mononuclear phagocytes synthesize and secrete α1-PI. When protein synthesis is inhibited, mitogenic stimuli may provoke release of previously synthesized α1-PI from mononuclear phagocytes. Secreted α1-PI then may bind to specific lymphocyte cell surface receptors. This pattern of α1-PI synthesis, secretion, binding, and expression on lymphoid cell surfaces appears to be a common characteristic of many immunologic reactions in vitro.
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M3 - Article
C2 - 6181147
AN - SCOPUS:0019908101
VL - 129
SP - 1830
EP - 1836
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 5
ER -