USDA-ARS, National Animal Disease Center, Ames, IA 50010, United States.
USDA-ARS, National Animal Disease Center, Ames, IA 50010, United States.
Vet Immunol Immunopathol. 2021 Jul;237:110268. doi: 10.1016/j.vetimm.2021.110268. Epub 2021 May 19.
In the present study, calves were infected with Mycobacterium avium subsp. paratuberculosis (MAP), Mycobacterium avium subsp. avium (M. avium), Mycobacterium kansasii (M. kansasii), or Mycobacterium bovis (M. bovis) to determine differences in cellular immunity. Comparative cellular responses were assessed upon stimulation of cells with mycobacterial whole cell sonicates respective of each infection group. Antigen-specific whole blood interferon gamma (IFN-γ) responses were observed in all infection groups compared to noninfected control calves, however, responses were more robust for M. bovis calves. Upon antigen stimulation of PBMCs, secretion of IFN-γ and IL-10 was higher for M. bovis calves compared to other infection groups. In contrast, IL-12 secretion was lower for M. bovis calves compared to MAP infected calves. Within the total PBMC population, higher numbers of CD4+, CD8+, and γδ TCR + T cells were observed for MAP and M. avium calves compared to M. bovis calves. This aligned with higher expression of CD26 on these subpopulations for MAP and M. avium calves, as well. In contrast, greater expression of CD25 was observed on CD4+ and γδ TCR + T cells and natural killer cells for M. bovis calves. Overall, similarities in cellular immune responses were observed between the closely related MAP and M. avium during infection of calves. In contrast, significant differences were noted between calves infected with MAP and M. bovis. This suggests that host immune responses to different mycobacteria may impact interpretation of diagnostic tools based upon their cellular immunity.
在本研究中，用牛分枝杆菌亚种副结核分枝杆菌（MAP）、禽分枝杆菌亚种（M. avium）、堪萨斯分枝杆菌（M. kansasii）或牛分枝杆菌（M. bovis）感染犊牛，以确定细胞免疫的差异。用每种感染组相应的分枝杆菌全细胞超声提取物刺激细胞后，评估比较细胞反应。与未感染对照犊牛相比，所有感染组均观察到针对抗原的全血干扰素 γ（IFN-γ）反应，但 M. bovis 犊牛的反应更强烈。在 PBMC 经抗原刺激后，与其他感染组相比，M. bovis 犊牛 IFN-γ和 IL-10 的分泌量更高。相比之下，与 MAP 感染的犊牛相比，M. bovis 犊牛的 IL-12 分泌量较低。在总 PBMC 群体中，与 M. bovis 犊牛相比，MAP 和 M. avium 犊牛的 CD4+、CD8+和 γδTCR+T 细胞数量更多。这与 MAP 和 M. avium 犊牛这些亚群上 CD26 的更高表达一致。相比之下，M. bovis 犊牛的 CD4+和 γδTCR+T 细胞和自然杀伤细胞上观察到 CD25 的表达更高。总的来说，在犊牛感染期间，MAP 和 M. avium 之间观察到细胞免疫反应的相似性。相比之下，MAP 和 M. bovis 感染的犊牛之间存在显著差异。这表明宿主对不同分枝杆菌的免疫反应可能会影响基于其细胞免疫的诊断工具的解释。
