Li Xiangmin, Liu Ruifeng, Tang Huanju, Jin Meilin, Chen Huanchun, Qian Ping
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, Hubei, PR China.
Vaccine. 2008 May 23;26(22):2714-22. doi: 10.1016/j.vaccine.2008.03.020. Epub 2008 Apr 1.
Foot-and-mouth disease (FMD) causes morbidity to livestock and serious economic consequences to its associated industry and therefore it is necessary to develop a safe and efficient vaccine to prevent or control this disease. A recombinant live attenuated virus vaccine, designated PRV-P1, was generated by insertion of an expression cassette containing CMV promoter, FMDV P1 gene and SV 40 poly-A into the gG gene region of a live attenuated pseudorabies virus vaccine strain (TK-/gG-/LacZ+). To determine the induction of protective immunity, 16 FMDV and PRV seronegative white swine were randomly divided into four groups and immunized intramuscularly. The parental virus (TK-/gG-/LacZ+) was injected into three pigs, the recombinant virus PRV-P1 into five pigs and commercial FMD-inactivated vaccine into five pigs, with PBS (negative control) into three pigs. All animals were immunized again 4 weeks later to boost the immune response and challenged with virulent type O FMDV O/ES/2001 strain 4 weeks after the second immunization. Results showed PRV-P1 vaccinated pigs induced high-level neutralizing antibody response to both FMDV and PRV, and strong CTL response against FMD antigen activation. Three of five pigs were completely protected against challenge with FMDV, one pig minimally protected and the other one had increased protection but not complete. However, one pig vaccinated with commercial FMD vaccine developed constant pyrexia. Average levels of antibodies against non-structural 3ABC proteins were significantly lower and efficacy on inhibition of FMDV replication was much increased in swine vaccinated with PRV-P1 than those immunized with commercial FMD vaccine after FMDV challenge. Our results showed that the recombinant PRV-P1 can induce not only humoral and cell-mediated immune responses but also partial protection against FMDV challenge, making it a good candidate for future development of the FMD vaccine.
口蹄疫（FMD）会导致家畜发病，并给相关产业带来严重的经济后果，因此有必要研发一种安全有效的疫苗来来来你那或控制这种疾病。一种重组减毒活病毒疫苗，命名为PRV-P1，是通过将包含巨细胞病毒（CMV）启动子、口蹄疫病毒（FMDV）P1基因和SV40多聚腺苷酸的表达盒插入减毒伪狂犬病病毒疫苗株（TK-/gG-/LacZ+）的gG基因区域而产生的。为了确定保护性免疫的诱导情况，将16头FMDV和PRV血清阴性的白色猪随机分为四组并进行肌肉注射免疫。将亲本病毒（TK-/gG-/LacZ+）注射到3头猪体内，重组病毒PRV-P1注射到5头猪体内，商业FMD灭活疫苗注射到5头猪体内，3头猪注射磷酸盐缓冲盐水（PBS，阴性对照）。4周后所有动物再次免疫以增强免疫反应，并在第二次免疫后4周用强毒O型FMDV O/ES/2001株进行攻毒。结果显示，接种PRV-P1的猪对FMDV和PRV均诱导出高水平的中和抗体反应，以及针对FMD抗原激活的强烈细胞毒性T淋巴细胞（CTL）反应。5头接种PRV-P1的猪中有3头完全抵抗了FMDV攻毒，1头有轻微保护作用，另一头的保护作用有所增强但不完全。然而，1头接种商业FMD疫苗的猪出现持续发热。FMDV攻毒后，接种PRV-P1的猪中针对非结构3ABC蛋白的抗体平均水平显著更低，且对FMDV复制的抑制效果比接种商业FMD疫苗的猪有大幅提高。我们的结果表明，重组PRV-P1不仅能诱导体液免疫和细胞介导的免疫反应，还能对FMDV攻毒提供部分保护，使其成为未来FMD疫苗开发的良好候选者。
