DHBV感染鸭特异免疫应答比较

Comparison or specific immune responses to duck hepatitis B virus in infected, immune, and uninfected ducks

目的研究嗜肝病毒感染病毒清除或向慢性化转变的免疫机理。方法通过接种不同龄鸭、不同感染方案建立ＤＨＢＶ急性、慢性感染组及免疫组模型，并检测各组病毒复制及特异体液和细胞介导免疫反应。结果成年鸭接种ＤＨＢＶ导致一过性病毒血症的形成，感染后抗－ＤＨＢｓ和抗－ＤＨＢｃ的水平比慢性感染组高（Ｐ＜０．０５），而免疫组抗－ＤＨＢＳ、抗－ ＤＨＢｃ的水平又比急性感染组高（ Ｐ＜ ０．０１）。特异细胞介导免疫反应（ＣＭＩ）的分析提示急性感染组感染后 １０ ｄ外周血单个核细胞（ＰＢＭＣ）对特异抗原的体外增殖反应强于慢性感染组，但在感染 ５周内快速下降。而免疫组ＣＭＩ与急性感染组相比差异无显著意义。结论感染宿主免疫应答特别是特异免疫反应是决定感染转归的重要因素。

Objective To explore the factor in determining whether hepadnavirus infection is cleared or becomes chronic. Methods Experimental groups were established by inoculation with duck hepatitis B virus (DHBV) at different age and schedule. The kinetics of virus replication and the humoral and cell mediated immune response (CMI) by ducks acutely and chronically infected .with, or immune to DHBV infection was measured. Results infection of the adolescent animals with DHBV led to a transient viremia. The levels of anti-DHBs and anti- DHBc were higher in acutely infected group than in chronically infected group (P<0.05), but lower than in immune group (P<0.01). CMI analysis showed the response to DHBsAg and DHBcAg by peripheral blood mononuclear cells from acutely infected ducks (10 day pi) was stronger than that from chronically infected ones (P<0.05); however, the level of the response reduced over a period of 5 weeks. There were no differences regarding CMI response in acutely infected or immune ducks. Conclusions The immune response especially antigen -specific immune response is the key factor in determining the outcome of the infection.