TY - JOUR
T1 - Phytohemagglutinin rapidly lyses S49 T-lymphoma cells and the cytotoxicity is not mediated by generation of cAMP or increase in cytosolic calcium
AU - Gupta, Ajay
AU - Hruska, Keith A.
AU - Wedner, H. James
N1 - Funding Information:
This work was supported by a grant from the National Institutes of Health. The authors would like to thank Ulises Alvarez for his technical help with tissue cell cultures and Steve Mills for help with measurement of cytosolic calcium.
PY - 1990/8/16
Y1 - 1990/8/16
N2 - Thymic-like lymphomas are very sensitive to killing by phytohemagglutinin. To investigate the mechanism of cytotoxicity, we studied the effect of PHA on cytosolic calcium ([Ca2+]i) and cAMP in the S49 mouse lymphoma cell line. PHA produced a slow continuing rise in [Ca2+]i. Estimation of cell number by Coulter counting showed that PHA induced rapid lysis of S49 cells in a dose-dependent manner. Nicardipine (10-5 M) did not prevent PHA induced cell lysis or [Ca2+]i increase. Also ionomycin (10-7 M) did not induce cell lysis. The data suggest that PHA induced increase in [Ca2+]i is the result rather than the cause of cell lysis. Elevated intracellular cAMP has an antiproliferative effect on S49 cells. PHA had no effect on cAMP levels in S49 cells. Also S49 cyc- clone which is deficient in Gs was susceptible to killing by PHA. These results suggest that the cytotoxic effect of PHA on S49 cells is rapid, but is not mediated by cAMP generation or an increase in [Ca2+]i, and other mechanisms should be investigated.
AB - Thymic-like lymphomas are very sensitive to killing by phytohemagglutinin. To investigate the mechanism of cytotoxicity, we studied the effect of PHA on cytosolic calcium ([Ca2+]i) and cAMP in the S49 mouse lymphoma cell line. PHA produced a slow continuing rise in [Ca2+]i. Estimation of cell number by Coulter counting showed that PHA induced rapid lysis of S49 cells in a dose-dependent manner. Nicardipine (10-5 M) did not prevent PHA induced cell lysis or [Ca2+]i increase. Also ionomycin (10-7 M) did not induce cell lysis. The data suggest that PHA induced increase in [Ca2+]i is the result rather than the cause of cell lysis. Elevated intracellular cAMP has an antiproliferative effect on S49 cells. PHA had no effect on cAMP levels in S49 cells. Also S49 cyc- clone which is deficient in Gs was susceptible to killing by PHA. These results suggest that the cytotoxic effect of PHA on S49 cells is rapid, but is not mediated by cAMP generation or an increase in [Ca2+]i, and other mechanisms should be investigated.
UR - http://www.scopus.com/inward/record.url?scp=0025076615&partnerID=8YFLogxK
U2 - 10.1016/0006-291X(90)90496-A
DO - 10.1016/0006-291X(90)90496-A
M3 - Article
C2 - 2167667
AN - SCOPUS:0025076615
SN - 0006-291X
VL - 170
SP - 1035
EP - 1043
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -