ABSTRACT
To evaluate the immunological properties of Leishmania major excreted- secreted [E-S] products on the progress of leishmaniasis in susceptible BALB/c mice. Promastigotes of the Leishmania major were cultured and E-S products were collected during the culture preiod. Groups of BALB/c mice [n = 12] were immunized with E-S products or whole antigen. Animals were challenged with promastigotes of stationary phase culture, then mortality was followed up to 6 months. In another group of animals drainage lymph nods cells were removed and cultured for cytokines assay. Activity of acteylcholinesters [AChE] and acid phosphatase [ACP] incresed time dependently. Using SDS-PAGE two major protein bands of 110 and 75 kDa were seen on the gel. Wound diameter in group receiving 24 h E-S products was significantly lower than the other experimental groups [P< 0.05]. During the first 4 months of the follow up no mortality was seen in this group, but mortality was started in the second months of the challenge in other groups. The IL-4 and IL-10 level in whole Ag group were significantly higher than the other groups. In cells from animals receiving 24 h E-S products the IL-2 level was significantly higher than the other experimental groups [P< 0.05]. Also the IFN g level was significantly higher both in 24 h E-S and whole Ag groups [P< 0.01]. The 24 h E-S group corresponded with small wounds, dominant Th1 cytokines response and low level of mortality