Effects of Allitridin on TGF-β_1 in Murine Cytomegalovirus Infection

Objective To study the effects of allitridin on the transcription and expression of TGF-β1 gene in the mice model with disseminative infection of murine cytomegalovirus(MCMV). Methods Sixty BALB/c mice were inoculated with MCMV Smith strains for establishing the model of disseminative infection,and randomly allocated into two groups: placebo-treated group and allitridin-treated group with a dose of 25 mg·kg-1·d-1.Another 60 mock-infected mice served as controls and were randomly allocated into allitridin-treated controls and mock-infected controls.The mice were sacrificed for extraction of serum and splenocytes at 1 d,3 d,7 d,14 d and 28 d after treatment,respectively.Inactive MCMV antigens were used as the stimulants for spleen cell culture in vitro.TGF-β1 levels in the serum and culture supernatant of splenocytes were measured by double-antibody sandwich ELISA and TGF-β1 mRNA levels in the splenocytes were detected by RT-PCR assay. Results In placebo-treated group,the TGF-β1 level in serum reached the peak at the 3 d,then went down gradually and was significantly higher than that of mock-infected controls at 28 d.The changes in TGF-β1 mRNA and protein expression in the splenocytes showed similar change,with significant increase at 3 d,going to peak at 7 d,returning to the level a bit higher than that of mock-infected group at 28 d.Comparing with placebo-treated group,TGF-β1 levels both in serum and splenocytes' supernatant were reduced after 3 days of treatment in allitridin-treated group,showing most significant difference from 3 d to 7 d,meanwhile,TGF-β1 mRNA levels were nearly similar to the those of placebo-treated group. Conclusion MCMV induce a higher transcription and expression of TGF-β1 gene in the acute phase of infection.However,allitridin can completely inhibit the transcription of TGF-β1 gene and significantly reduce TGF-β1 expressing levels in the serum and splenocytes' supernatant induced by MCMV.