基因枪轰击小鹅瘟病毒VP3基因疫苗诱导鹅体内体液免疫的机制

将小鹅瘟病毒VP3基因疫苗(pcDNA-GPV-VP3)分别以每只1μg、3μg和6μg的基因枪轰击免疫30日龄四川白鹅,用免疫组织化学法检测pcDNA-GPV-VP3在鹅体内各组织器官表达情况;用间接ELISA检测免疫鹅血清中GPV抗体滴度.结果:①各剂量免疫组1d时能在免疫部位皮肤,3d时能在心脏/十二指肠/空肠/盲肠/肝脏,7d时在回肠/直肠检测到pcDNA-GPV-VP3的表达;7d表达最多;表达可持续至35～63d;表达产物的数量和表达持续时间总体规律为6μg组＞3μg组＞1μg组.②免疫后第7d血清抗体开始升高,21d达到最大值,免疫后第14～217d极显著(P<0.01)高于PBS和空白质粒对照;体液免疫效果存在一定的剂量依赖.研究表明,pcDNA-GPV-VP3基因枪轰击免疫雏鹅后能在免疫部位皮肤、心肌、肝脏和各肠段中表达并能够诱导雏鹅产生良好的体液免疫.

Immune mechanisms induced by goose parvovirus VP3 gene vaccine in goslings vaccinated by gene gun bombardment

The goose parvovirus VP3 gene vaccine (pcDNA-GPV-VP3) was delivered into 30 day-old goslings by gene gun bombardment with different immunization doses of 1μg, 3μg and 6μg. Different tissue samples were collected at 1h, 12h, 1d, 3d, 7d, 21d, 35d, 63d, 105d, 217d post immunization(PI), and the dynamic expression of the vaccine in goslings was studied by indirect immunohistochemistry and the specific anti-GPV antibodies in the gosling sera were studied by the indirect enzyme linked immunosorbent assay (ELISA). The results showed that the expression could be detected in the immunized skin of all the experimental groups at 1d PI, in the heart, duodenum, jejunum, cecum and liver at 3d PI, in ileum and rectum at 7d PI. The expression reached the peak at 7d PI and was still detected from 35th to 63rd dayPI. In the different immunized groups, expression quantities and persistence showed that, the group with the dose of 6μg was superior to the other groups of 3μg and 1μg, and the group of 1μg was inferior. The antibodies measured by ELISA began to ascend at 7d PI and peaked at 21d PI, and the antibody titers were higher significantly (P<0.01) than the PBS and plasmid control from 14th to 217th days PI. The humoral immune effects showed some dose-dependent correlations. The results indicated that, gene gun bombardment with pcDNA-GPV-VP3 could induce expression of the plasmids and elicit humoral immune responses in the immunized skin, cardiac muscle, liver and each intestine segment, and the valuable information for the immune mechanisms of pcDNA-GPV-VP3 could be provided.