Lymphokine mediated microbicidal activity of peritoneal macrophages from Leishmania donovani infected and drug treated BALB/c mice.

The resident peritoneal macrophages from untreated mice develop potent microbicidal activity against amastigotes of Leishmania major and Leishmania donovani after in vitro exposure to lymphokines (LK) from mitogen stimulated spleen cells. However, to the best of our knowledge, the response of L. donovani infected peritoneal macrophages from already infected/treated animals to LK has not been investigated. Therefore in the present study, the effect of LK on infected macrophages from BALB/c mice following specific infection and subsequent treatment with sodium stibogluconate has been investigated. As the infection progressed, a decrease in percent microbicidal activity was noticed. An attempt was also made to treat the animals on different post infection days and reinfect them in vitro. Infection could not be produced in vitro in late treatment groups when the treatment was given on 14 days and 21 days post infection. Whereas, macrophages obtained from animals treated on 7 days post infection (early treatment) could be infected in vitro. However, only 50% of the cells got infection. This infection was eliminated when the cells were exposed to LK for 72 hours.