[Role of allitridin in the blocking of murine cytomegalovirus induced regulatory T cells amplification in vitro].

OBJECTIVE

To investigate the effect of allitridin on murine cytomegalovirus (MCMV) induced regulatory T cells (Treg) amplification in vitro.

METHODS

A co-culture system of T cells and MCMV infected mouse embryo fibroblasts (MEF) was established. A maximum tolerance concentration (MTC) of allitridin was added into the co-culture system. After 3 days, the change of Foxp3 mRNA was measured by real-time PCR. And the percentages of Tc1 (CD3(+)CD8(+)IFN-γ(+)), Tc2 (CD3(+)CD8(+)IL-4(+)), Th1 (CD3(+)CD8(-)IFN-γ(+)) and Th2 (CD3(+)CD8(-)IL-4(+)) were analyzed by flow cytometry. The production of IL-10 and TGF-β in supernatants was detected with double-antibody sandwich ELISA while the viral load of culture quantified by plaque assay. All results were compared with those of the placebo group.

RESULTS

The MTC of allitridin was 9.83 µg/ml in MEF. The treatment of 9.83 µg/ml allitridin could partly block the MCMV induction of Foxp3 mRNA expression [(87 ± 5) vs (114 ± 8), P < 0.01]. The percentages of Tc1, Tc2 and Th1 significantly increased to the levels of (12.42 ± 1.23)%, (4.28 ± 0.56)% and (13.25 ± 0.68)% respectively. They showed statistic differences with those of placebo controls [(6.85 ± 0.92)%, (2.34 ± 0.42)% and (9.32 ± 0.86)%; all P < 0.01]. Meanwhile, the levels of IL-10 and TGF-β1 in supernatants also significantly decreased to (29.98 ± 3.15) pg/ml and (3.48 ± 0.23) ng/ml by allitridin treatment as compared with placebo controls [(38.21 ± 4.02) pg/ml and (5.31 ± 0.59) ng/ml, all P < 0.05]. In addition, the MCMV plaque assays showed that allitridin significantly suppressed the viral loads by one order of magnitude.

CONCLUSION

Allitridin can partly retrieve MCMV-induced Treg expansion and Treg-mediated anti-MCMV immunosuppression so as to enhance the specific cellular immune responses against CMV.