Maekawa Daniel, Whang Patrick, Riblet Sylva M, Hurley David J, Guy James S, García Maricarmen
Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
Food Animal Health and Management Program, Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
Avian Pathol. 2021 Dec;50(6):540-556. doi: 10.1080/03079457.2021.1989379. Epub 2021 Nov 9.
The types of immune cells that populate the trachea after ILTV vaccination and infection have not been assessed. The objective of this study was to quantify CD4, CD8α, CD8β, TCRγδ, and MRC1LB cells that infiltrate the trachea after vaccination with chicken embryo origin (CEO), tissue culture origin (TCO), and recombinant herpesvirus of turkey-laryngotracheitis (rHVT-LT) vaccines, and after challenge of vaccinated and non-vaccinated chickens with a virulent ILTV strain. Eye-drop vaccination with CEO, or TCO, or vaccination with rHVT-LT did not alter the number of CD4, CD8α, CD8β, TCRγδ, and MRC1LB cells in the trachea. After challenge, the CEO vaccinated group of chickens showed swift clearance of the challenge virus, the mucosa epithelium of the trachea remained intact, and a limited number of CD4, CD8α, and CD8β cells were detected in the upper trachea mucosa. The TCO and rHVT-LT vaccinated groups of chickens showed narrow viral clearance with moderate disruption of the trachea epithelial integrity, and a significant increase in CD4, CD8α, CD8β, and TCRγδ cells infiltrated the upper trachea mucosa. Non-vaccinated challenged chickens showed high levels of viral replication, the epithelial organization of the upper trachea mucosa was heavily disrupted, and the predominant infiltrates were CD4, TCRγδ, and MRC1LB cells. Hence, the very robust protection provided by CEO vaccination was characterized by minimal immune cell infiltration to the trachea mucosa. In contrast, partial protection induced by the TCO and rHVT-LT vaccines requires a prolonged period of T cell expansion to overcome the established infection in the trachea mucosa.
传染性喉气管炎病毒（ILTV）疫苗接种和感染后气管中存在的免疫细胞类型尚未得到评估。本研究的目的是量化接种鸡胚源（CEO）、组织培养源（TCO）和重组火鸡疱疹病毒-喉气管炎（rHVT-LT）疫苗后以及用强毒ILTV毒株攻击接种和未接种疫苗的鸡后浸润气管的CD4、CD8α、CD8β、TCRγδ和MRC1LB细胞数量。用CEO或TCO滴眼接种，或用rHVT-LT接种，均未改变气管中CD4、CD8α、CD8β、TCRγδ和MRC1LB细胞的数量。攻击后，接种CEO疫苗的鸡群迅速清除攻击病毒，气管黏膜上皮保持完整，在上段气管黏膜中检测到数量有限的CD4、CD8α和CD8β细胞。接种TCO和rHVT-LT疫苗的鸡群病毒清除缓慢，气管上皮完整性受到中度破坏，CD4、CD8α、CD8β和TCRγδ细胞浸润上段气管黏膜显著增加。未接种疫苗而受到攻击的鸡显示出高水平的病毒复制，上段气管黏膜的上皮组织严重破坏，主要浸润细胞为CD4、TCRγδ和MRC1LB细胞。因此，CEO疫苗提供的非常强大的保护表现为气管黏膜免疫细胞浸润极少。相比之下，TCO和rHVT-LT疫苗诱导的部分保护需要延长T细胞扩增期以克服气管黏膜中已建立的感染。
