Oral Immunization with Attenuated<i>Salmonella</i>Choleraesuis Expressing the P42 and P97 Antigens Protects Mice against<i>Mycoplasma hyopneumoniae</i>Challenge
Guodong Zhou, Yichen Tian, Jiashuo Tian, Qifeng Ma, Shan Huang, Quan Li, Shifeng Wang, Huoying Shi
Abstract
Mhp is the main pathogen of porcine enzootic pneumonia, a highly infectious and economically significant respiratory disease that affects pigs of all ages. As the target tissue of Mhp infections are the mucosal sites of the respiratory tract, the induction of protective immunity at the mucosal tissues is the most efficient strategy by which to block disease transmission. Because the stimulation of mucosal immune responses is efficient, Salmonella-vector oral vaccines are expected to be especially useful against mucosal-invading pathogens. In this study, we expressed the immunogenic proteins of P42 and P97 with the attenuated Salmonella Choleraesuis vector rSC0016, thereby generating a low-cost and more effective vaccine candidate against Mhp by inducing significant mucosal, humoral and cellular immunity. Furthermore, rSC0016(pS-P42) effectively prevents Mhp-induced weight loss and the pulmonary inflammation of mice. Because of the effectiveness of rSC0016(pS-P42) against Mhp infection in mice, this novel vaccine candidate strain shows great potential for its use in the pig breeding industry.