猪繁殖与呼吸综合征病毒感染抑制猪瘟疫苗的免疫应答

对20日龄SPF猪和20日龄猪繁殖与呼吸综合征（PRRS）血清阳性猪，人工感染猪繁殖与呼吸综合征病毒（PRRSV）北京分离株（BJ－4）后48h接种猪瘟疫苗，利用ELISA方法检测仔猪针对PRRSV和猪瘟疫苗的体液免疫，利用MTS法检测仔猪外周血单核细胞对有丝分裂原ConA的刺激反应。结果表明，不论是SPF仔猪还是带有PRRSV抗体的仔猪，在鼻内接种PRRSV后48h接种猪瘟疫苗，其对猪瘟疫苗的抗体反应显著低于对照组，对有丝分裂原ConA的刺激反应也下降。由此说明，PRRSV感染使仔猪对猪瘟疫苗的免疫应答受到抑制。

Infection of Porcine Reproductive and Respiratory Syndrome Virus Inhibits Immune Response Against Hog Cholera Virus Vaccine

To evaluate the effect of PRRSV on humoral and cellular immune responses,threeweek old SPF piglets and conventional piglets with antibody to PRRSV were inoculated nasally with PRRSV BJ 4 strain,and immunized intramuscularly with hog cholera vaccine 48 hours postinoculation.Results of serum antibodies detected by ELISA indicated that the infected piglets had specific antibody against PRRSV BJ 4 strain in two weeks,and had significantly lower levels of the antibody against hog cholera vaccine than those of controls.Peripheral blood mononuclear cell(PBMC) from piglets infected with BJ 4 strain showed decreased proliferation responses to mitogen ConA.All results above indicated PRRS virus can suppress both the humoral and cellular immune responses of infected piglets.