A POTENTIAL IMMUNOSUPPRESSIVE ROLE FOR VASOACTIVE-INTESTINAL-PEPTIDE (VIP) IN LEISHMANIASIS - EVIDENCE FROM THE USE OF A SELECTIVE VIP ANTAGONIST

The immunological relevance of vasoactive intestinal peptide (VIP) in the pathology of leishmaniasis has been tested. Leishmania-primed mous e-derived splenic cells were examined and found to exhibit suppressed and up-regulated mitogenic responses in the absence and the presence o f VIP respectively. Furthermore, plasma derived from Leishmania-primed hamsters induced a suppressive effect on the mitogenic response of no rmal hamster splenic cells; this was significantly blocked by a select ive VIP antagonist. The results showed the functional presence of VIP at the level of immunological disorder within a Leishmania-primed mili eu.