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 antigen (SEA) stimulated IFN-gamma and IL-4 mRNA expressions and the in vivo SEA elicited granulomatous responses, the transcriptions of IFN-gamma and IL-4 gene were investigated in the spleen of BALB/c mice infected with Schistosoma japonicum (S. japonicum).

METHODS

Spleens were removed at 0, 3, 5, 8, and 10 and 12 weeks after infection and the spleen cells were incubated in the presence of SEA. The extracted RNA was analyzed for IFN-gamma and IL-4 mRNA by reverse transcription PCR (RT-PCR). Newly-formed liver granulomas were measured.

RESULTS

The study revealed that no detectable IFN-gamma and IL-4 mRNA RT-PCR products were found in SEA treated spleen cells from uninfected, or 3-week infected mice, whereas IL-4 mRNA was found to be expressed in 5- and 8-week infected mice, and an appreciable enhanced expression of IL-4 mRNA was observed in SEA stimulated spleen cells at 8-week infection than at 5-week infections. However, SEA could not induce IFN-gamma and IL-4 mRNA transcription in 10- and 12-week infected mice, indicating the modulated expression of IFN-gamma and IL-4 mRNA.

CONCLUSION

The significant changes of IL-4 mRNA expression in SEA stimulated spleen cells during S. japonicum infection were coincident with SEA elicited granuloma formation and modulation in vivo.