effect of stem cells as an adjuvant on the immunogenicity of a potential anti-schistosomal vaccine in mice

ABSTRACT

Vaccination against schistosomes can be targeted towards the prevention of infection and/or to the reduction of parasite fecundity and pathology. However, as eggs are responsible mainly for schistosomiasis pathology, so crude soluble egg antigen [SEA] seems suitable to be used as a potential vaccine. Many studies have provided new insights establishing a role for mesenchymal stem cells [MSCs] in liver regeneration and improvement of schistosomiasis hepatic fibrosis, in addition to the need for standardized and effective adjuvant-vaccine formulations. So, the aim of this work is to evaluate the effect of stem cells when used as an adjuvant of a potential antischistosomal vaccine [crude SEA] in murine models. The current work was carried out on 100 mice [30 males for harvesting MSCs + 70 females for seven study groups, each of 10]. A schedule of vaccination and challenge infection was followed so, G1 [control healthy], G2 [control infected only] infected subcutaneously with S. mansoni cercaria [80-90 Schistosorna mansoni cercariae suspended in 0.2 ml distilled water], G3 [FCA then infected] received Freund's complete adjuvant [FCA] then infected, G4 [MSCs then infected] received MSCs then infected, 05 [SEA then infected] received SEA vaccine then infected, G6 [SEA+FCA then infected] received SEA vaccine and FCA then infected, 07 [SEA+MSCs then infected] received SEA vaccine and MSCs then infected. The current work was assessed by histopathological study and morphometric analysis [using H and E and Masson's Trichrome stains] to highlight number, size arid type of liver granulomas and percentage of liver fibrosis, immunological and molecular studies [RNA extraction, Reverse Transcriptase and PCR technique] for detection of interleukin-1 0 mRNA gene expression in liver tissue by reverse transcriptase and polymerase chain reaction [RT and PCR]. The results showed that a- SEA alone as a potential anti-schistosomal vaccine was more or less moderately protective, b- MSCs alone before the infection had mild prophylactic effects, c- MSCs as an adjuvant of the crude SEA increased its capabilities with highly significant results regarding the decrease in granuloma number, size, percentage and density of hepatic fibrosis, and d-There was significant increase in IL-10 mRNA gene expression on using [SEA+MSCs] [G7] if compared to other tested groups