Studies On Enhancing Immune Effects Of Different Adjuvants To Specific Humoral Immunity And Nonspecific Cellular Immunity Of BCG

Polyporus umbellatus polysaccharide(PUP),eukaryotic express plasmid of Murine IL-2(pCDNA3IL-2) and eukaryotic express plasmid of Murine IL-3(pCDNA3IL-3) were used as adjuvants in the study. The experiments were conducted to compare the immune modulation effects and histological lesions of the three adjuvants to Mycobacterium bovis BCG vaccine according to the levels of cellular immunity, humoral immunity and histopathology in immune organs. The tested animals were guinea pigs. The results were as follows:All guinea pigs received a subcutaneous injection of 0.1 ml of M. Bovis BCG in the up cervix region except the controll group. The experimental groups were injected with three adjuvants and BCG respectively. The controll group included BCG and sham injection group. The BCG group were injected BCG only. The results were as follows:⑴The results of humoral immune assay (ELISA):Fifty days after first BCG vaccination, serum samples obtained via cardiac puncture were detected by indirect ELISA. The result showed that the OD value of guinea pigs of PUP group was significantly higher than that of BCG and sham injection group (p<0.01). The OD values of IL-2 and IL-3 group were also higher than those of BCG and sham injection group (p<0.05 or p<0.01). It suggests that PUP,pCDNA3IL-2 and pCDNA3IL-3 can both effectively enhance humoral immunity of guinea pig induced by BCG. ⑵The results of cellular immune assay (MTT):Fifty days after second vaccination, peripheral blood lymphocytes isolated by density gradient centrifugation in lymphocyte separation medium were tested by MTT (T lymphocyte proliferative responses). The result showed that the OD value of guinea pigs of PUP group was significantly higher than those of BCG and sham injection group (p<0.01). The OD values of IL-2 and IL-3 group were also higher than those of BCG and sham injection group (p<0.05 or p<0.01). Compared with IL-2 and IL-3 group, T lymphocyte proliferative responses of PUP group were more significant. The results suggest that PUP,pCDNA3IL-2 and pCDNA3IL-3 can both effectively enhance the cellular immunity of guinea pig induced by BCG.⑶ Results of histopathological lesions of immune organsThe lymphofollicular proliferation in T lymphocyte regions of spleens and lymphnodes of PUP,IL-2 and IL-3 groups were significantly higher than that of BCG and sham injection groups after two vaccination. Compared with IL-2 and IL-3 groups the lymphofollicular proliferation of PUP were more significant. These results further indicate that PUP,pCDNA3IL-2 and pCDNA3IL-3 can both effectively enhance the cellular immunity of guinea pig induced by BCG, and effects of PUP are more evident.