针对HBV S基因mRNA反义锁核酸设计及其在2.2.15细胞内的抗病毒作用

Antiviral effect of hepatitis B virus S gene-specific anti-gene locked nucleic acid in hepatitis B virus transgenic mice

AIM

To investigate the antiviral effect of hepatitis B virus (HBV) S gene-specific anti-gene locked nucleic acid (LNA) in transgenic mice.

METHODS

Thirty HBV transgenic mice were randomly divided into 5 groups (n = 6 each): blank control group, negative control group (unrelated sequence), lamivudine group, antisense-LNA treatment group, and anti-gene LNA treatment group. LNA was injected into transgenic mice via the tail vein, and lamivudine was given by gavage. Serum HBV DNA was tested by real-time PCR; serum hepatitis B surface antigen (HBsAg) was determined by ELISA; the mRNA level of HBV S gene was detected by RT-PCR; and the positive rate of HBsAg in liver cells was detected by immunohistochemistry.

RESULTS

On 3, 5, and 7 d after anti-gene LNA treatment, HBV DNA was reduced by 37.18%, 50.27%, and 61.46%, respectively, and HBsAg was reduced by 30.17%, 44%, and 57.76%, respectively; there was a significant difference in HBV DNA and HBsAg compared with those before administration (P < 0.05) or compared with control groups (blank control, negative control, lamivudine, and antisense-LNA) (P < 0.05). The mRNA level of HBV S gene (0.33) and the HBsAg positive rate of liver cells (31%) were significantly reduced compared with control groups (P < 0.05). The function of liver and kidney tests and tissue HE staining showed no abnormal changes.

CONCLUSION

Anti-gene LNA targeting the S gene has a strong inhibitory effect on HBV replication and expression in HBV transgenic mice, and this provides experimental basis for gene therapy of HBV.

Antiviral effects of locked nucleic acid antisense oligonucleotides targeting the HBV preS1 gene in HepG2 2.2.15 cells

AIM: To investigate the inhibitory effects of locked nucleic acid (LNA) antisense oligonucleotides targeting the purine region of the hepatitis B virus (HBV) preS1 gene in HepG2 2.2.15 cells, and to screen effective LNA anti-gene oligonucleotides.

METHODS: LNA anti-gene oligonucleotides of different lengths that were complementary to the purine-abundant regions (2 941-2 962 nt, 3 015-3 036 nt and 3 089-3 110 nt) of the HBV preS1 gene were designed, synthesized, and introduced into HepG2 2.2.15 cells by cationic liposome-mediated transfection. Hepatitis B surface antigen (HBsAg) and HBV DNA levels in cell supernatants were tested by time-resolved fluorescence immune assay (TRFIA) and fluorescent quantitative polymerase chain reaction (FQ-PCR) 1, 3, 5 and 7 d after transfection. The cell toxicity of LNA anti-gene oligonucleotides was detected by methyl thiazolyl tetrazolium (MTT) assay.

RESULTS: LNA anti-gene oligonucleotides targeting the HBV preS1 gene showed strong inhibitory effects on HBV DNA replication and HBsAg expression in vitro, and the effects were time-dependent. Seven days after transfection, the reduced rates of HBV DNA and HBsAg levels were 64.32% and 67.51%, respectively. The inhibitory effects were significantly different between each experimental group and control group (all P < 0.05). The inhibitory effect of the LNA anti-gene oligonucleotide targeting the region 2 941-2 962 nt was most strong. The optimal length of LNA anti-gene oligonucleotides ranges from 20 to 30 bases. No obvious cell toxicity was observed with LNA anti-gene oligonucleotides.

CONCLUSION: LNA anti-gene oligonucleotides targeting the HBV preS1 gene showed strong inhibitory effects on HBV replication in vitro. The inhibitory effect of the LNA anti-gene oligonucleotide targeting the region 2 941-2 962 nt was most strong, and the optimal length of LNA anti-gene oligonucleotides ranges from 20 to 30 bases.

Inhibitory effect of locked nucleic acid antisense oligonucleotides versus lamivudine on HBV replication in HepG2.2.15 cells

AIM: To compare the inhibitory effect of locked nucleic acid antisense oligonucleotides (antisense-LNA) and lamivudine on HBV replication in HepG2.2.15 cells.

METHODS: Antisense-LNA was introduced into HepG2.2.15 cells by cationic liposome-mediated transfection. Supernatants were collected 2, 4, 6, 8, 10 days after medication. The concentrations of HBsAg and HBeAg in cell supernatants were tested by ELISA. HBV DNA levels in cell supernatants were determined by FQ-PCR. Cell toxicity of antisense-LNA and lamivudine was detected by MTT assay.

RESULTS: Lamivudine only inhibited viral DNA synthesis. Antisense-LNA effectively inhibited the expression of HBsAg and HBeAg and the replication of HBV DNA (67.69%, 59.71%, 62.96%, P < 0.05) in a time-dependent manner. Both antisense-LNA and lamivudine showed no obvious cell toxicity.

CONCLUSION: The anti-HBV effect of antisense-LNA is more effective than that of lamivudine in HepG2.2.15 cells.