Nambooppha Boondarika, Rittipornlertrak Amarin, Muenthaisong Anucha, Koonyosying Pongpisid, Chomjit Paweena, Sangkakam Kanokwan, Tangtrongsup Sahatchai, Tiwananthagorn Saruda, Sthitmatee Nattawooti
Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
Department of Veterinary Biosciences and Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai 50100, Thailand.
Vet Sci. 2022 Jul 27;9(8):386. doi: 10.3390/vetsci9080386.
The intracellular bacterium is the causative pathogen of canine monocytic ehrlichiosis (CME) in dogs. Despite its veterinary and medical importance, there is currently no available vaccine against this pathogen. In this study, the recombinant GP19 (rGP19) was produced and used as a recombinant vaccine prototype in a mouse model against experimental infection. The efficacy of the rGP19 vaccine prototype in the part of stimulating B and T cell responses and conferring protection in mice later challenged with pathogen were evaluated. The rGP19-specific antibody response was evaluated by ELISA after challenge exposure (on days 0, 7, and 14 post-challenge), and demonstrated significantly higher mean antibody levels in rGP19-immunized mice compared with adjuvant-immunized and naive mice. Significantly lower ehrlichial loads in blood, liver, and spleen DNA samples were detected in the immunized mice with rGP19 by qPCR. The up-regulation of and mRNA expression were observed in mice immunized with rGP19. In addition, this study detected IFN-γ-producing memory CD4+ T cells in the rGP19-immunized mice and later infected with on day 14 post-infection period using flow cytometry. The present study provided a piece of evidence that rGP19 may eliminate by manipulating Th1 and B cell roles and demonstrated a promising strategy in vaccine development against infection in the definitive host for further study.
细胞内细菌是犬单核细胞埃立克体病（CME）的致病病原体。尽管其在兽医和医学领域具有重要意义，但目前尚无针对该病原体的可用疫苗。在本研究中，制备了重组GP19（rGP19）并将其用作针对实验性感染的小鼠模型中的重组疫苗原型。评估了rGP19疫苗原型在刺激B细胞和T细胞反应以及在随后受到病原体攻击的小鼠中提供保护方面的功效。在攻击暴露后（攻击后第0、7和14天）通过ELISA评估rGP19特异性抗体反应，结果显示与佐剂免疫小鼠和未免疫小鼠相比，rGP19免疫小鼠的平均抗体水平显著更高。通过qPCR在rGP19免疫小鼠的血液、肝脏和脾脏DNA样本中检测到显著更低的埃立克体载量。在用rGP19免疫的小鼠中观察到 和 mRNA表达上调。此外，本研究在感染后第14天使用流式细胞术在rGP19免疫小鼠中检测到产生IFN-γ的记忆CD4 + T细胞，这些小鼠随后感染了 。本研究提供了一条证据，表明rGP19可能通过操纵Th1和B细胞的作用来消除 ，并展示了一种在针对终末宿主中 感染的疫苗开发方面有前景的策略，以供进一步研究。
