PCP can enhance dendritic cells to present the HBsAg peptide.

AIM: To investigate the influence of paraclorophenol (pCP) on dendritic cells loading and presenting HBsAg from peripheral blood monocytes of healthy volunteers identified as hepatitis B vaccine nonresponders. METHODS: The density gradient centrifugation was performed to isolate mononuclear cells from 10 hepatitis B vaccine nonresponders. The adherent monocytes were incubated with HBsAg adding rhGM-CSF and rhIL-4 in the presence of absence of pCP for 7 days. Then the supernatant was collected for ELISA assays. The culture medium system without pCP was used as negative control and without pCP or HBsAG was named blank control. the matured DCs were co-incubated with autologous T lymphocytes for 72h and the supernatant was also collected for ELISA assays. RESULTS: In the presence of pCP, the level of IL-12 in supernate (265.68± 16.21) ng/L was significantly higher than the negative control (168.76±10.01) ng/L (P<0.05) and blank control (87±5.79)ng/L (P<0.05); after co-incubated with autologous T lymphocytes for 3 days, the level of IFN-γ with pCP (773.04±32.73) mg/L was also significantly higher than the negative control (573.59±26.11) mg/L (P<0.05) ans blank control (362.81±24.27)mg/L (P<0.05). CONCLUSION: pCP can effectively enhance the dendritic cells loading and presenting HBsAg from peripheral blood monocytes of healthy volunteers identified as hepatitis B vaccine nonresponders, which also can dramatically increase te autologous T lymphocytes response.7

[Construction of eukaryotic expression vector of siRNA specific for MAD2 and its effect on the growth of gastric cell line SGC7901].

AIM: To construct the RNA interference eukaryotic expression vector specific for human MAD2 gene and to observe its effect on the growth of gastric cancer cell line SGC7901. METHODS: The expression vectors of pSilencer3.1/MAD2-siRNA1 and pSilencer3.1/MAD2-siRNA2 were constructed by gene recombination and then were stably transfected into the gastric carcinoma cell line SGC7901 by liposome mediation. The expression of MAD2 on the levels of protein and mRNA was detected by Western blot and RT-PCR, and the monoclone with the highest inhibition efficiency was selected. The growth of the transfected cells was assessed by MTT. And the cells treated with 1.0 mg/L vincristine (VCR) for 24 h were analyzed by FCM for cell cycle. RESULTS: Sequence-specific siRNAs targeting MAD2 significantly down regulated the expression of MAD2 in SGC7901 cells. In MAD2-siRNA transfected cells, the rate of cell growth increased markedly and cell cycle couldn't be arrested in M phase induced by VCR, while the cells transfected with the mock vector could. CONCLUSION: Down regulation of MAD2 expression of SGC7901 bv sequence-specific siRNA could accelerate the cell growth and impair the mitosis arrest of SGC7901 induced by VCR.