[The enhancing effect of "Xuebijing injection" on lipopolysaccharide-induced apoptosis of regulatory T cells and mediation of polarization of helper T cells].

OBJECTIVE: To investigate the enhancing effect of Chinese medicine-Xuebijing injection on lipopolysaccharide (LPS) -induced apoptosis of CD4+ CD25+ regulatory T cells (Tregs) and polarization of helper T cells (Th). METHODS: CD4+ CD25+ Tregs collected from rat spleen in vitro by immunomagnetic beads assay were divided into the control group, anti-CD3/CD28 group, anti-CD3/CD28 + LPS group, anti-CD3/CD28 + "Xuebijing injection" group and anti-CD3/CD28 + LPS + "Xuebijing injection" group. Tregs apoptosis rate and expression of winged helix transcription factor (Foxp3) in Tregs were detected by flow cytometry on 3rd post culture day. CD4+ CD25- T cells were co-cultured with CD4+ CD25- Tregs (1:1) for 68 hours with canavalin A stimulation. Interferon gamma (gamma-IFN), interleukin (IL)-4 and IL-17 in supernatants, which respectively was secreted by Th1, Th2 and Th17, were measured by ELISA. RESULTS: Tregs apoptosis rate of anti-CD3/CD28 + LPS + "Xuebijing injection" group (45.1 +/- 2.7%) was significantly higher than that of anti-CD3/CD28 + LPS group (29.4 +/- 1.6%, P < 0.01). Meanwhile, Foxp3 expressions in Tregs in above 2 groups were 95 +/- 9 and 140 +/- 18 respectively, showing statistically significant difference between them (P < 0.01). Gamma-IFN levels secreted in anti-CD3/CD28 + LPS + "Xuebijing injection" group were significantly higher than those in anti-CD3/CD28 + LPS group (P < 0.01), while IL-4 levels had an opposite tendency compared with gamma-IFN (P < 0.05), resulting in a marked increase in the ra- tio of gamma-IFN/IL-4 in anti-CD3/CD28 + LPS + "Xuebijing injection" group (P < 0.01). In anti-CD3/ CD28 + "Xuebijing injection" group, IL-17 secretion levels were significantly decreased compared with anti-CD3/CD28 group (P < 0.05). CONCLUSIONS: Activation of CD4+ CD25+ Tregs induced by LPS may mediate Th1 shift to Th2 response. "Xuebijing injection" can effectively regulate immune function of T cells, increase the LPS-induced apoptosis of CD4+ CD25+ Tregs as well as enhance the polarization of Th2 to Th1, thereby abating the suppressive state of cell-mediated immunity.

[Effect of apoptosis of CD4+ CD25+ regulatory T cells on proliferation as well as secretion of effector T cells and interventional activity of Xuebijing injection in septic rats].

OBJECTIVE: To investigate the effect of apoptosis of CD4+ CD25+ regulatory T cells (Tregs) on proliferation as well as secretory function of effector T cells (Teff) and potential influence of Xuebijing injection on them in septic rats. METHODS: A sepsis model was reproduced by cecal ligation puncture (CLP), and Wistar rats were randomly divided into the control group (n = 8), sham-operated group (n = 8), CLP group (n = 8), and Xuebijing injection treatment group (n = 8). CD4+ CD25+ Tregs in each group were separated by immunomagnetic beads isolate system on day 3, the apoptosis rate, expression of forkhead/winged helix transcription factor p3 (Foxp3) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) on Tregs were analyzed by flow cytometry, and secretion levels of interleukin (IL)-10 from Tregs were measured by ELISA. Following co-culture of CD4+ CD25+ Treg with CD4+ CD25- T cells (1:1) for 68 hours, proliferative activity of Teff was determined by MTT, and IL-2/sIL-2R alpha levels were measured by ELISA. RESULTS: The apoptosis rate of Tregs in control group was 12.03% +/- 0.89%, which was not significantly different from sham-operated group 9.48% +/- 2.17%. The apoptosis rate of Tregs in CLP group 5.87% +/- 0.44% was lower than that in control group (P < 0.01), and treatment with Xuebijing injection markedly enhanced the apoptosis of Tregs 27.29% +/- 2.48%. Compared to CLP group, expression of Foxp3, CTLA-4, and the secretion of IL-10 of Treg were significantly lowered in Xuebijing injection group (all P < 0.01). The Teff proliferative activity in response to ConA, and IL-2 levels of Teff in CLP group were significantly suppressed compared with control group (P < 0.01), and secretion of sIL-2R alpha in the supernatants was much higher than that of the control group. In comparison to the CLP group, inhibitory rate of Teff proliferative activity and the sIL-2R alpha levels were significantly decreased, while the secretion of IL-2 was increased in Xuebijing injection group (P <0.01). CONCLUSION: CD4+ CD25+ Tregs could markedly upregulate the suppressive function on Teff in sepsis, and treatment with Xuebijing injection effectively enhanced apoptosis of Tregs, thereby down-regulating the suppression on Teff.

[Effect of apoptosis of CD4+ CD25+ regulatory T lymphocytes on polarization of helper T lymphocytes and potential interventional influence of Xuebijing injection in septic rats].

OBJECTIVE: To evaluate the influence of apoptosis of CD4(+)CD25(+) regulatory T lymphocyte (Treg) on polarization of helper T lymphocyte (Th) and effect of Xuebijing injection in septic rats. METHODS: A sepsis model was reproduced by cecal ligation and puncture (CLP). Wistar rats were randomly divided into the normal group (n=8), sham operation group (n=8), model group (n=8) and Xuebijing injection treatment group (n=8). CD4(+)CD25(+)Tregs in each group were separated by immunomagnetic beads isolation system on day 3, the apoptotic rates, expression of forkhead/winged helix transcription factor p3 (Foxp3) as well as cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) of Treg were analyzed by flow cytometry, and the secretion level of interleukin-10 (IL-10) of Tregs was determined by enzyme linked immunosorbent assay (ELISA) after culturing Tregs for 12 hours. Interferon-gamma (IFN-gamma), IL-4, and IL-17 levels, which were respectively secreted by Th1, Th2 and Th17, were measured by ELISA in the supernatant after CD4(+)CD25(+)Tregs were co-cultured with CD4(+)CD25(-)T lymphocytes for 68 hours. RESULTS: The apoptosis rate of the normal group was (12.03+/-0.89)%, which was not significantly different compared with the sham operation group [(9.48+/-2.17)%]. The apoptosis rate of model group [(5.87+/-0.44)%] was much lower than that of the normal and sham operation groups, while the Xuebijing injection treatment group [(27.29+/-2.48)%] had the highest apoptosis rate compared to others (all P<0.01) . The expression of Foxp3, CTLA-4, and the secretion of IL-10 of Treg were negatively correlated with the apoptosis rates, correlation coefficients (r) respectively were -0.878 (P=0.042), -0.877 (P=0.042), and -0.743 (P=0.010). The secretion of IFN-gamma, IL-4 and ratio of IFN-gamma/IL-4 in model group were significantly elevated compared with the normal group [IFN-gamma: (254.70+/-44.88) ng/L vs. (0.68+/-0.78) ng/L , IL-4: (8.82+/-0.61) ng/L vs. (3.48+/-0.98) ng/L, ratio of IFN-gamma/IL-4: 30.28+/- 4.87 vs. 0.23+/-0.30, all P<0.01], and secretion of IFN-gamma as well as ratio of IFN-gamma/IL-4 were markedly higher in Xuebijing injection treatment group [(491.54+/-84.28) ng/L, 45.31+/-8.01, respectively] than in model group (P<0.01 and P<0.05). No marked change in IL-17 levels was noted in various groups (all P>0.05) . CONCLUSION: Due to the apoptosis of Treg, the suppression function of CD4(+)CD25(+)Tregs on CD4(+)T lymphocyte appears to be abated, and treatment with Xuebijing injection could effectively enhance the apoptosis of Tregs, mediating the response of shifting Th2 to Th1.