Smad 2/3 and CD8+ distribution pattern in liver of mice vaccinated with gamma radiation-attenuated Schistosoma mansoni larvae

Background: gamma radiation-attenuated vaccine has a very promising value in controlling schistosomiasis. the objective of this study is to investigate the effects of vaccination with gamma radiation-attenuated schistosomules regarding histopathological and immunohistochemical changes in mice model of human schistosoma mansoni infection. materials and methods: the study is conducted upon 40 mice, divided into four groups of 10 each: uninfected control group a (normal control), schistosoma mansoni infected group b (infected control), group c subcutaneously injected with 200 gy gamma radiation–attenuated schistosomules (vaccine control) and group d injected with the same dose of gamma radiation-attenuated schistosomules then challenged after 4 weeks by s. mansoni cercariae (vaccinated-challenged). parts of liver tissues stained with masson's trichrome (mt) stain for classifying the granulomas into cellular, fibrocellular or fibrous according to the amount of collagens; stained bluish green. immunohistochemistry assay was then done on the other portion through expression of smad2/3 protein and cd8+ in the extracellular matrix (ecm). results: compared to control infected group, mild histopathological changes with decrease of egg granulomas mainly cellular is detected in vaccinated-challenged group. this is accompanied with moderate immunohistochemical expression of smad2/3 and cd8+ proteins in vaccine-control group and mild expression in vaccinated -challenged group. conclusion: the the results indicate that vaccination with 200 gy gamma-irradiated schistosomules could reduce histopathological and immunohistochemical changes induced due to infection which represents an effective strategy in disease control.