Institute of Veterinary Bacteriology, Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Laenggass-Str. 122, 3001, Bern, Switzerland.
Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland.
Vet Res. 2018 Jan 9;49(1):2. doi: 10.1186/s13567-017-0499-1.
Several studies suggest that synergisms between Mycoplasma bovis and other microorganisms might exacerbate disease outcome of bovine mycoplasmosis. Screening several bovine cell types to assess their potential use as in vitro infection models for M. bovis, it was observed that a widely used cell line of bovine macrophages (Bomac cells) is in fact persistently infected with bovine viral diarrhea virus (BVDV). The cell line was first cured of this virus allowing comparative studies between both cell lines. Subsequently, uptake and co-culture of two M. bovis strains of different clonal complexes with Bomac cells contaminated with BVDV and in BVDV-free Bomac cells were assessed. Additionally, cell viability, cytotoxicity and induction of apoptosis after infection with M. bovis were evaluated. No differences in the levels of uptake and growth in co-culture were observed between the two Bomac cell types and both M. bovis strains. Cytotoxicity was increased after infection of BVDV-free cells with one of the two strains, while apoptotic cell death was slightly induced by this strain in both cell lines. Overall, the presence or absence of BVDV in Bomac cells did not grossly change the parameters tested upon infection with M. bovis. Nevertheless, this cell model is very useful when studying viral co-infections with bacteria and could also be used for multiple co-infections. Considering the broad contamination of cell cultures with BVDV, careful screening for this virus should routinely be performed as its presence might be relevant depending on the molecular mechanisms being investigated.
几项研究表明，牛支原体与其他微生物之间的协同作用可能会加剧牛支原体病的疾病结果。为了评估几种牛细胞类型作为牛支原体体外感染模型的潜在用途，我们观察到一种广泛使用的牛巨噬细胞（Bomac 细胞）细胞系实际上持续感染了牛病毒性腹泻病毒（BVDV）。该细胞系首先被该病毒治愈，从而允许对两种细胞系进行比较研究。随后，评估了两种不同克隆复合体的牛支原体菌株与受 BVDV 污染的 Bomac 细胞和 BVDV 阴性 Bomac 细胞的共培养物中的摄取和共培养情况。此外，还评估了感染牛支原体后细胞活力、细胞毒性和细胞凋亡的诱导情况。在两种 Bomac 细胞类型和两种牛支原体菌株之间，共培养物中的摄取和生长水平没有差异。在 BVDV 阴性细胞中感染其中一种菌株后，细胞毒性增加，而该菌株在两种细胞系中均轻微诱导了细胞凋亡。总体而言，Bomac 细胞中 BVDV 的存在与否并未显著改变感染牛支原体后测试的参数。然而，当研究细菌与病毒的共同感染时，这种细胞模型非常有用，也可以用于多种共同感染。考虑到细胞培养物广泛受到 BVDV 的污染，应常规对其进行筛查，因为根据正在研究的分子机制，其存在可能是相关的。
