M. Fay et al., PROTECTIVE EFFECT OF LPS AND POLY A-U AGAINST IMMUNE OXIDATIVE INJURY- ROLE OF THIOLS RELEASED BY ACTIVATED MACROPHAGES, Free radical biology & medicine, 18(4), 1995, pp. 649-654
Oxidative injury of immune cells has been observed both at inflammator
y sites and in pathologic situations, such as human immunodeficiency v
irus infection. We used an ex vivo model of immune oxidative injury to
test the antioxidant effect of two immunomodulating agents administer
ed to C57B1/6 mice. Lipopolysaccharide (LPS) and the synthetic polyrib
onucleotide poly A:U preserved the ConA-induced proliferative response
of spleen T cells against oxidative injury ex vivo. The glutathione a
nd thiol contents of fresh spleen T cells from LPS- and poly A:U-treat
ed mice were significantly higher than control values. In addition, sp
leen T cells from LPS- and poly A:U-treated mice were protected agains
t the oxidative injury-induced decrease in glutathione content after 4
8 h of ConA stimulation. Because LPS and poly A:U both activate macrop
hages, we sought an antioxidant effect of macrophage-released compound
s. Neither rhIL-1 alpha nor rhTNF alpha protected against oxidative in
jury in vitro. In contrast, LPS and poly A:U induced macrophages to re
lease acid-soluble thiols, which have been reported to participate in
the regulation of glutathione levels in lymphocytes and could therefor
e protect against immune oxidative injury.