Immunostimulatory activity of schistosomula in mice

Abstract

Introduction ― Our previous study cleared that both immunization with Egyptian Schistosoma mansoni schistosomula and therapy with praziquantel were able to induce significant levels of protection against re-infection as compared with immunization or treatment only. Aim ― The current study aimed to evaluate the immunostimulatory activity of schistosomula in naïve mice post injection with schistosomula either alone or with praziquantel to answer the question: can schistosomula be used as immunoadjuvant? Material and Methods ― Ten naïve mice were administered 3 doses of phosphate buffered saline. Ten mice injected with 500 schistosomula at day 0 and at 14th day. Ten mice were administered praziquantel (PZQ) (250 mg/kg body weight).Ten mice injected with schistosomula at day 0 and at 14th day and received PZQ. The levels of IgM and IgG against soluble egg antigen (SEA) and soluble worm antigen preparation (SWAP) were detected by ELISA. Immunophenotyping of mesenteric lymph nodes (MLN) lymphocytes and thymocytes were carried out. Results ― IgM and IgG levels were significantly elevated in sera from mice injected with schistosomula alone or with PZQ or PZQ only. The mean percentage of MLN CD4+, CD8+ T and B lymphocytes were increased but considered not significant. The MLN CD4+/CD8+ T ratios were >1. The mean % of CD4+ and CD8+ thymocytes were increased and the CD4+/CD8+ thymocytes ratios were >1. Conclusion ― Immunostimulatory activity schistosomula was detected by enhancing Igs titers, stimulating the mean % of CD4+, CD8+ T, B-MLN cells and thymocytes CD4+, CD8+ T. CD4+/CD8+ T cells ratios were >1 in MLN and thymus gland.

Keywords

• immunostimulatory
• schistosomula
• mesenteric lymph nodes
• thymus
• CD4+/CD8+ T lymphocytes ratio
• B-lymphocytes