Increased hepatic interleukin-1, arachidonic acid, and reactive oxygen species mediate the protective potential of peptides shared by gut cysteine peptidases against Schistosoma mansoni infection in mice.

Abstract

BackgroundMultiple antigen peptide (MAP) construct of peptide with high homology to Schistosoma mansoni cathepsin B1, MAP-1, and to cathepsins of the L family, MAP-2, consistently induced significant (P MethodologyOutbred mice were immunized with MAP-2 in combination with alum and/or MAP-1. Challenge infection was performed three weeks (wks) after the second injection. Blood and liver pieces were obtained on an individual mouse basis, 23 days post-infection (PI), a time of S. mansoni development and feeding in the liver before mating. Serum samples were examined for the levels of circulating antibodies and cytokines. Liver homogenates were used for assessment of liver cytokines, uric acid, arachidonic acid (ARA), and reactive oxygen species (ROS) content. Parasitological parameters were evaluated 7 wks PI.Principal findingsImmunization of outbred mice with MAP-2 in combination with alum and/or MAP-1 elicited highly significant (P Conclusion/significanceThe findings provided an explanation for the gut cysteine peptidases vaccine-mediated reduction in challenge worm burden and increase in egg counts.