Schrijver R S
ID-DLO, Afdeling Zoogdiervirologie, Lelystad.
Tijdschr Diergeneeskd. 1998 Nov 15;123(22):658-62.
This paper describes recent findings on the immunobiology of bovine respiratory syncytial virus (BRSV) infections. The pathobiology of alveolar macrophages and BRSV, and the immunological reaction of cattle to the virus after natural or experimental infection, or vaccination, were studied. Because in severe cases BRSV infection leads to lower respiratory tract disease, replication of BRSV in alveolar macrophages was studied. Alveolar macrophages, which are important aspecific defense cells in the lower respiratory tract, exhibited a high intrinsic resistance to BRSV. Furthermore, BRSV-infected alveolar macrophages produced significantly less nitric oxide (which has a bacteriocidal effect) than uninfected macrophages. The kinetics of antibody titres against the envelope protein G were different from those of antibody titres against the envelope protein F. For example, many animals that are reinfected do not possess antibodies against the G protein. After vaccination or after natural infection, antibody titres against the F and G protein, and against epitopes on the F protein, differed markedly, and also in animals with different MHC haplotypes. These findings may be related to differences in protection. The strains of BRSV that circulate in the Netherlands belong to the subgroups A and AB. There was no evidence for differences in virulence between these subgroups. BRSV could be detected in 30% of lungs obtained from calves suffering from severe lower respiratory tract disease. Based on cross-protection studies, calves that were infected with a virus from a particular BRSV subgroup were protected against reinfection with a virus from a different subgroup. A recombinant gE-protein negative bovine herpesvirus 1 vaccine carrying a gene encoding the G protein of BRSV, and a DNA vaccine encoding the same protein afforded protection after experimental challenge of calves. This offers the possibility to develop effective multivalent (gE-negative BHV1) marker vaccines in the future.
本文描述了关于牛呼吸道合胞病毒（BRSV）感染免疫生物学的最新研究结果。研究了肺泡巨噬细胞与BRSV的病理生物学，以及牛在自然感染、实验感染或接种疫苗后对该病毒的免疫反应。由于在严重病例中BRSV感染会导致下呼吸道疾病，因此对BRSV在肺泡巨噬细胞中的复制进行了研究。肺泡巨噬细胞是下呼吸道重要的非特异性防御细胞，对BRSV表现出高度的内在抗性。此外，感染BRSV的肺泡巨噬细胞产生的一氧化氮（具有杀菌作用）明显少于未感染的巨噬细胞。针对包膜蛋白G的抗体滴度动力学与针对包膜蛋白F的抗体滴度动力学不同。例如，许多再次感染的动物不具有针对G蛋白的抗体。接种疫苗后或自然感染后，针对F和G蛋白以及F蛋白表位的抗体滴度存在显著差异，不同MHC单倍型的动物也是如此。这些发现可能与保护作用的差异有关。在荷兰传播的BRSV毒株属于A和AB亚组。没有证据表明这些亚组之间的毒力存在差异。在患有严重下呼吸道疾病的犊牛的30%的肺中可检测到BRSV。基于交叉保护研究，感染特定BRSV亚组病毒的犊牛可免受不同亚组病毒的再次感染。携带编码BRSV G蛋白基因的重组gE蛋白阴性牛疱疹病毒1疫苗，以及编码相同蛋白的DNA疫苗，在对犊牛进行实验性攻毒后提供了保护。这为未来开发有效的多价（gE阴性BHV1）标记疫苗提供了可能性。
