Modulation of in vivo granuloma formation related to regulation of in vitro IFN-gamma and IL-4 expressions in experimental Schistosomiasis japonica

Objective To find out relationship between the in vitro schistosome egg ant igen (SEA) stimulated IFN-gamma and IL-4 mRNA expressions and the in vivo S EA elicited granulomatous responses, the transcriptions of IFN-gamma and IL -4 gene were investigated in the spleen of BALB/c mice infected with Schist osoma japonicum (S. japonicum). Methods Spleens were removed at 0, 3, 5, 8, and 10 and 12 weeks after infec tion and the spleen cells were incubated in the presence of SEA. The extrac ted RNA was analyzed for IFN-gamma and IL-4 mRNA by reverse transcription P CR (RT-PCR). Newly-formed liver granulomas were measured. Results The study revealed that no detectable IFN-gamma and IL-4 mRNA RT-PC R products were found in SEA treated spleen cells from uninfected, or 3-wee k infected mice, whereas IL-4 mRNA was found to be expressed in 5- and 8-we ek infected mice, and an appreciable enhanced expression of IL-4 mRNA was o bserved in SEA stimulated spleen cells at 8-week infection than at 5-week i nfections. However, SEA could not induce IFN-gamma and IL-4 mRNA transcript ion in 10- and 12-week infected mice, indicating the modulated expression o f IFN-gamma and IL-4 mRNA. Conclusion The significant changes of IL-4 mRNA expression in SEA stimulate d spleen cells during S. japonicum infection were coincident with SEA elici ted granuloma formation and modulation in vivo.