Anti-Virus Activity Induced By BCG-PSN In Vitro

Polysaccharide nucleic acid fraction of Bacillus Calmette Guerin (BCG-PSN) has function of immunocyte activity. Previous study demonstrated that BCG-PSN could stimulate immune cells, such as macrophages, lymphocytes and natural killer cells, to produce a number of cytokines. In human clinical medicine, BCG-PSN was used to prevent and treat some diseases, such as asthma, chronic bronchitis, tuberculosis, allergic rhinitis, allergic dermatosis, vitiligo and some neoplastic disease. But little study has been reported in veterinary clinical medicine. In addition, the exact functions of polysaccharide (PSA) and nucleic acid (NA) in BCG-PSN are still unknown. The study firstly extract BCG-PSN, PSA and NA from Bacillus Calmette-Guerin (BCG) by improving breaking method of BCG membrance under low temperature, and then investigate the anti-virus activity of BCG-PSN. vestigate the anti-virus activity of BCG-PSN.Extraction and separation of BCG-PSN, PSA and NA from BCG At low temperature, ultrasonic wave was used to break cells wall of BCG and BCG-PSN was extracted form BCG through hot phenol method. The content of BCG-PSA and BCG-NA were determined by phenol-sulfuric acid method and ultraviolet spectrophotometer respectively. The result showed that6.515g of BCG-PSN were extracted from616.0g of BCG. in which BCG-PSA and BCG-NA was about72.6%and23.5%respectively. The yield of BCG-PSN was1.06%. BCG-PSA and BCG-NA were isolated from BCG-PSN by DEAE-cellulose column chromatography. The yield and purity of BCG-PSN was84.7%and91.5%respectively. The yield and purity of BCG-NA was68.1%and31.5%respectively.The effects of BCG-PSN on IFN in chick embryo fibroblast cells in vitro To investigate the anti-viral activity of Bacillus Calmette Guerin (BCG-PSN), vesicular stomatits virus (VSV), MTT methods and CPE method were used to observe the cell viability and to detect the protection of CEF cells from VSV infection in vitro. The optimal incubation time and concentration were also determined according to MTT method. The result showed that BCG-PSN has toxicity to CEF cells after treated with more than800μg/mL BCG-PSN. BCG-PSN can inhibit VSV growth in CEF cells, however the anti-viral activity was not changed with concentration induction of BCG-PSN and incubation time accordingly. The anti-VSV activity was maximal for144.0μg/mL of BCG-PSN treatment at24h. The result also showed that the anti-viral activities induced by BCG-PSN in CEF cells are related to the levels of IFN-a and IFN-p.