17Beta-estradiol increases Leishmania mexicana killing in macrophages from DBA/2 mice by enhancing production of nitric oxide but not pro-inflammatory cytokines.

We have previously shown that female DBA/2 mice are significantly more resistant to Leishmania mexicana compared with males. Here, we have analyzed the effect of 17beta-estradiol (E(2)) on function and cytokine production in male and female DBA/2 macrophages in vitro. We show that E(2) increases NO production and parasite killing in L. mexicana-infected male and female DBA/2 macrophages without increasing production of pro-inflammatory cytokines. These data indicate that E(2) may enhance leishmanicidal activity in macrophages by directly regulating production of NO.