Polychlorinated biphenyl-induced suppression of cytotoxic T lymphocyte activity: role of prostaglandin-E2.

Prostaglandin-E2 (PGE2) was investigated for its role in suppression of splenic cytotoxic T lymphocyte (CTL) activity following exposure to 3,3',4,4',5,5'-hexachlorobiphenyl (HxCB) in mice. Following i.p. alloantigen injection, PGE2 levels significantly increased in peritoneal fluid and in spleen cell culture supernatants. HxCB exposure (1) significantly elevated PGE2 levels above control in peritoneal fluid, (2) significantly reduced production of PGE2 by spleen cells, and (3) did not alter PGE2 production by peritoneal cells. The levels of PGE2 observed were below (> 100-fold) those shown by others to cause immune suppression, and splenic CTL activity was unaltered by indomethacine treatment sufficient to reduce peritoneal PGE2 to undetectable levels. We conclude that altered PGE2 production is not involved in suppression of CTL activity by HxCB.