兔抗犬细小病毒2a型多克隆抗体交叉保护研究

Study on Preparation of Rabbit Anti-canine Parvovirus Type 2a Polyclonal Antibody

为探究犬细小病毒(canine parvovirus,CPV)血清型只有一种的条件下,常用疫苗CPV-2型和CPV-2a病毒免疫血清抗体对国内流行CPV-2a病毒的中和率,试验将藏獒源CPV-2a毒株(105 TCID50/100μL)和CPV-2(104.5 TCID50/100μL)疫苗接于F81细胞增殖,PEG6000法浓缩制成免疫原,各免疫新西兰长白兔3只,间隔2周1次,共免疫4次。收集血清纯化制备多克隆抗体,通过血凝抑制试验(HI)和血清中和试验(SN)分别用2种抗体中和CPV-2、CPV-2a病毒,对两者保护率进行初步评价,并对本地感染CPV-2a的4只犬,每组2只进行治疗,每日跟踪白细胞消长规律。结果显示,CPV-2a多抗中和国内流行病毒CPV-2a的HI抗体、中和抗体水平都极显著高于CPV-2多抗(P<0.01),而中和CPV-2病毒的HI抗体、中和抗体水平两者差异不显著(P>0.05),CPV-2a多抗组治疗能较快恢复正常值,2组白细胞数有显著差异(P<0.05)。结果表明,CPV-2a多抗与常用CPV-2型疫苗免疫抗体相比能高滴度的中和CPV-2a,更适用于中国犬细小病毒的防制,对研发新型生物制品有一定意义。

To study the antigenic relationship among the original canine parvovirus type （CPV） 2 （CPV-2） and the variants CPV-2a,the strain of 10STCIDs0/100 μL from infected Tibetan mastiff which turns out the gene was CPV 2a and CPV2 strain from vaccine was picked out to be generally amplified in the F81 cells. After analyzing the strains with HA and protein concen- tration with PEG6000, the viral suspension was emulsified with the adjuvant to immune two groups of each three New Zealand rabbits in every two weeks and four times. Serum antibody titer was detected in each preimmune. After four times immunity, serum of each group was collected to make separated gene polyclonal antibody. Then the antibody titer was tested by SN and HI with CPV-2 and CPV2a virus and protection data was analyzed by SPSS 17.0. And two polyclonal antibodies were separa- ted treated 2 dogs which was inoculation CPV-2a and infected. Blood samples were collected every day during treatment, then WBC was analyzed by SPSS 17.0. The results showed that the CPV-2a polyclonal antibody was more significant to CPV-2a vi- rus than the other one by HI and SN （P〈0.01）. But counteract CPV-2 strain was not significant （P〈0.05）. CPV-2a poly- clonal antibody was given more protection against CPV-2a and WBC was faster recovery to normal level than the other in exper- imental treatment （P〈0.05）. It showed that CPV-2a polyclonal antibody have higher homologous protection than the antibody induced by CPV-2 vaccine in Chinese canine parvovirus control.