OBJECTIVESTo investigate the internal links between immune responses and Tregs and cytokine by the expression of T regulatory cells (Tregs), Foxp3 mRNA of different response groups and the detection of cytokine secretion after hepatitis B vaccination.

METHODSBlood samples were collected in different response groups. Real-time fluorescence quantitative PCR was used to detect the expression of Foxp3 mRNA of peripheral blood mononuclear cells; The surface markers CD4 and CD25 in peripheral-blood mononuclear cells were determined by flow cytometry; ELISA tests were used to detect the production level of phytohemagglutinin (PHA) in peripheral blood mononuclear cells, IL -4, IL-12, IL-18 stimulated by HBsAg and (IFN) gamma.

RESULTS(1) Foxp3 expressions in response group and non-response group were higher before or after PHA and HBsAg were stimulated. Differences were statistically significant (P value less than 0.05) ; (2) In peripheral blood, the percentage of CD4+CD25+ Treg of CD4+ T cells in response group (0.59%+/-0.46%) was obviously lower than those in control group (1.30%+/-1.44%) ; (3) Peripheral blood mononuclear cells stimulated by PHA and HbsAg in each group, the concentration of IFNgamma in non-response group [(11.00+/-9.03) IU/ml] was markedly lower than those in response group [(38.88+/-28.16) IU/ml],and differences were statistically significant (P value less than 0.01); (4) In PHA- or HBsAg-stimulated peripheral-blood mononuclear cells, the concentrations of IL-18, IL-4 and IL-12 had no significant difference.

CONCLUSIONSTo some extent, CD4+CD25+Foxp3+ Treg cells may be involved in negative regulation of the immune responses to HBV vaccination. Immune non-response to HBV vaccination may be connected to insufficient secretion of IFNgamma; There was no correlation between the titer of anti-HBs and the expressions of IFNgamma and CD4+CD25+ Foxp3.