Chymotryptic-type protease inhibitors block the increase in Ca2+ and Il-2 production in activated Jurkat T cells.
Several chymotryptic-type protease inhibitors were found to inhibit both anti-CD3 mAb- and PHA-induced rise in Ca2+ and IL-2 production in Jurkat T cells. The magnitude of inhibition was a function of the effectors used to stimulate Ca2+ entry and depended on the concentration of the inhibitors. Neither tryptic-type protease inhibitors nor an elastase substrate prevented anti-CD3 mAb- or PHA-induced Ca2+ rise in Jurkat cells. The inhibitory effect of N-alpha-p-tosyl-L-phenylalanine chloromethyl-ketone on anti-CD3 mAb- and PHA-induced rise in Ca2+ resulted from a rapid increase in Ca2+ efflux. The inhibitors which were effective on Ca2+ mobilization also inhibited IL-2 production initiated by an anti-CD3 mAb in the presence of 12-O-tetradecanoylphorbol-13-acetate, and to a lesser extent by PHA or the calcium ionophore A23187. No inhibition of IL-2 production was observed when tryptic-type protease inhibitors or the elastase inhibitor were used. In addition, membrane preparations from Jurkat cells were found to hydrolyze the chymotryptic substrate Suc-Ala-Ala-Phe-paranitroaniline, an effect markedly inhibited by N-alpha-p-tosyl-L-phenylalanine chloromethylketone. Moreover, this inhibitor protected one potential endogenous substrate (Mr 38 kDa) from proteolysis. Taken together, these observations show that chymotryptic-type protease inhibitors block the responses generated by the binding of anti-CD3 mAb to Jurkat cells, and suggest that a chymotryptic-like membrane protease contributes to T cell activation.
Auberger
P
P
Institut National de la Santé et de la Recherche Médicale U210, Nice, France.
Mary
D
D
Breittmayer
J P
JP
Aussel
C
C
Fehlmann
M
M
D000911:Antibodies, Monoclonal / Q000502:physiology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D017252:CD3 Complex; D000001:Calcimycin; D002118:Calcium / Q000096:biosynthesis*; D002460:Cell Line; D002462:Cell Membrane / Q000201:enzymology; D002918:Chymotrypsin / Q000494:pharmacology*; D004306:Dose-Response Relationship, Immunologic; D004533:Egtazic Acid; D006801:Humans; D006868:Hydrolysis; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis*; D008213:Lymphocyte Activation / Q000187:drug effects*; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D010835:Phytohemagglutinins; D011480:Protease Inhibitors / Q000494:pharmacology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D014108:Tosylphenylalanyl Chloromethyl Ketone / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D008565:Membrane Proteins; D010835:Phytohemagglutinins; D011480:Protease Inhibitors; D011948:Receptors, Antigen, T-Cell; D000001:Calcimycin; D014108:Tosylphenylalanyl Chloromethyl Ketone; D004533:Egtazic Acid; D002918:Chymotrypsin; D002118:Calcium