Anti-phospholipase C antibodies inhibit the lectin-induced proliferation of human lymphocytes.
A novel approach was used to assess the role of phosphoinositide hydrolysis in the mitogenic action of phytohemagglutinin (PHA) or concanavalin A (ConA). The treatment of human peripheral blood leukocytes (PBL) with monospecific antibodies against phospholipase C (PLC) produced a dose-dependent inhibition (up to 100%) of PHA (10 micrograms/ml) or ConA (25 micrograms/ml) proliferative effects. Thus, the activation of membrane-bound PLC is a sine-qua-non condition for lectin-induced proliferation of T lymphocytes. The key-role of PLC versus protein kinase C (PKC) is stressed by the fact that the inhibition of PKC with Hidaka's compound H-7 (40 microM) produced only a partial blockade (about 25%) of lectin mitogenic effect.
Division of Cell Biology, Faculty of Medicine, Bucharest, Romania.
I I
II
Moraru
M
M
Manciulea
A
A
Călugăru
G
G
Ghyka
L M
LM
Popescu
D000906:Antibodies / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007128:Immunoglobulin Fragments / Q000276:immunology; D037102:Lectins / Q000494:pharmacology; D008213:Lymphocyte Activation; D010738:Type C Phospholipases / Q000276:immunology / Q000378:metabolism*
D000906:Antibodies; D007128:Immunoglobulin Fragments; D037102:Lectins; D010738:Type C Phospholipases