马抗猫细小病毒特异性免疫球蛋白的研制

由猫细小病毒(feline parvovirus,FPV)引起的猫泛白细胞减少症目前仍呈上升势头,发病率和死亡率较高。迄今国内外尚未见到较理想的治疗药物。本试验选用马作为免疫动物,收集血清。通过对传统正辛酸—硫酸铵沉淀法进行优化,用Protein A亲和层析、胃蛋白酶消化,获得精制抗猫瘟免疫球蛋白(IgG)生物制剂。对该生物制剂进行物理性状、热原性、安全性、无菌检验、SDS-PAGE纯度鉴定、血凝抑制试验、双向琼脂扩散试验、细胞中和试验和动物治疗试验。结果表明,该生物制剂为略带乳光的澄明液体,溶液稳定无分层,无可见颗粒,无微生物污染,保存期长;对家兔、小白鼠、豚鼠等试验动物安全稳定、无毒副作用;其热原性符合规定,F(ab′)2分子质量约为110 ku,中和效价在128倍以上,对5只人工感染FPV猫进行治疗,治愈率达100%,证实该制品对猫泛白细胞减少症有很好的治疗效果。

Preparation of Specific Anti-FPV IgG from Horse

Feline panleukopenia is an infectious disease that infected more and more animals by FPV upward momentum. It has high pathogenicity and mortality. Treatment of the disease had not better and effective drug at home and abroad. The test selected horses as immune animals and extracted its serum. We optimized a new method of purification of IgG, by digesting the serum at 37 ℃ with pepsase, removing albumin in caprylic acid, and the twice ammonium sulfate precipitation. According to the character that Protein A and Fc of immunoglobulin can connect with IgG of most mammals, the F(ab′)2 was collected and purified by Protein A column filter.According to the relavant items of “People’s Republic of China States Pharmacopoeia”(2005 version). The physical properties, heat antigenicity, safety, aseptic, HA and HI test, agarose double diffusion, cells neutralization test and animal treatment test of this biological product of horse anti-FPV IgG were examined. The results showed that the product is a milk white solution that is non-layered, free of visible particles, bacteria, fungi, mycoplasma and other microbial contaminations. Rabbits, mice, and guinea pigs injected with the product were observed for 10 successive days. The results showed that the product is highly specific with the titer of 128-fold, good security and stability, non-toxic side effects. F(ab′)2 molecular weight of about 110 ku, agents accounted for 70.7% of total protein. The clinical symptoms of all the 5 cats disappeared 7 days later with the recovery rate of 100%, indicating the high effectiveness of the product in treatment of feline panleukopenia.