M. Wojewodzka et al., ANTI-CD38 PREVENTS THE DEVELOPMENT OF THE ADAPTIVE RESPONSE INDUCED BY X-RAYS IN HUMAN-LYMPHOCYTES, Mutagenesis, 11(6), 1996, pp. 593-596
Irradiation of human lymphocytes (1 cGy X-rays, 37 degrees C) evoked a
n similar to 30% decrease in the frequency of micronuclei upon subsequ
ent X-irradiation (1.5 Gy), The response was reflected in a lower micr
onucleus frequency but not in the DNA repair rate measured by the come
t assay directly after the challenge dose. Treatment of lymphocytes wi
th anti-CD38 antibody 1 h before irradiation with the adaptive dose pr
evented the development of the adaptive response measured as micronucl
ei frequency, but adaptation was not reflected in a lower rate of DNA
repair, measured by the alkaline version of the 'comet' assay. In lymp
hocytes that were anti-CD38-treated and irradiated and or irradiated w
ith the adaptive dose the rate of DNA repair was not changed. However,
the mean DNA damage level in adapted anti-CD38-treated lymphocytes wa
s significantly lower than that in the control lymphocytes at all time
points, We conclude that ligation of CD38 by antibody initiates signa
lling that prevents the development of the adaptive response induced b
y X-rays, Lower chromosome damage revealed by the cytokinesis block-mi
cronucleus test in the adapted lymphocytes is unrelated to DNA repair
rate.