牛源乳铁蛋白体外抗HBsAg分泌的研究

目的探讨牛源乳铁蛋白(BLF)体外抑制HbsAg分泌作用。方法以天然HBV感染HepG2细胞为模型,应用ELISA法测定细胞上清中的HBsAg水平,并用MTT法对BLF对HepG2细胞的毒性进行研究。结果BLF对细胞的最大无毒剂量(TD0)为3.0g/L,半数中毒剂量(TD50)为11.08g/L;先用HBV对HepG2细胞进行感染,再加入BLF,各浓度组BLF均对HBsAg分泌有一定抑制作用,BLF浓度3.0g/L时对HBsAg的抑制率达58.34%;将BLF与HBV阳性血清作用后再接种于细胞,各实验组均不能抑制HBsAg分泌,将BLF先与细胞作用后洗去BLF,在接种病毒后,BLF浓度0.5g/L以上各组均能显著抑制HBsAg分泌,但BLF0.1g/L组不能抑制HBsAg分泌。乳铁蛋白水解物不能抑制HBsAg分泌。结论牛源乳铁蛋白不能通过与HBV结合来阻断对HepG2细胞的感染,但可以通过对HepG2细胞的保护来阻断感染;当HepG2细胞感染HBV后,牛源乳铁蛋白仍可抑制HBsAg分泌,将乳铁蛋白水解后无抑制作用,说明是乳铁蛋特有结构起作用。

Study of inhibition effect of bovine lactoferrin in vitro on hepatitis B surface antigen

OBJECTIVE: To probe inhibition effect of bovine lactoferrin (BLF) in vitro on hepatitis B surface antigen (HBsAg). METHODS: Nature hepatitis B virus (HBV) was used to infect HepG2 cell, HBsAg in the culture supernatant was measured by ELISA, and MTT test was used to examine cytotoxic effect of BLF. RESULTS: The maximum nontoxic dose (TD0) in HepG2 cell of BLF was 3.0 g/L,50% of toxic dose (TD50) was 11.08 g/L. After HepG2 cell were infected with HBV, every BLF test group had effect on inhibiting HBsAg to some extent. At the highest concentration of 3.0 g/L BLF was most effective, exhibiting 58.34% of inhibition. Mixing BLF with HBV, then HepG2 cell were infected with them, every BLF all test concentrations were not shown to inhibit HBsAg. Adding BLF to HepG2 cell, then HepG2 cell were infected with HBV after washing BLF, test groups were shown to significantly inhibite HBsAg as concentration of over 0.5 g/L BLF, but at the concentration 0.1 g/L of BLF inhibitious of HBsAg were not observed. HBsAg wasn't inhibited by lactoferrin hydrolysate. CONCLUSION: BLF was shown to inhibit HBV infection into HepG2 cell by protecting corresponding cell sites rather than binding to HBV. After HepG2 cell was infected, HBsAg also could be inhibited by BLF and lactoferrin hydrolysate didn't have this function. It was seemed that BLF could have structure's work, but the possible mechanism need to be lucubrated.