Tatalick L M, Perryman L E
Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman 99164-7040, USA.
Vet Parasitol. 1995 Jul;58(4):281-90. doi: 10.1016/0304-4017(94)00729-v.
Cryptosporidium parvum is a protozoal pathogen which infects the gastrointestinal epithelium of mammals causing diarrhoea, the duration and severity of which is determined by the immunocompetency of the host. Currently, there is no effective treatment or prevention. We evaluated the ability of surface antigen-1 (SA-1), defined as those antigens recognized by neutralizing mAb 17.41, to elicit a protective antibody response when used as an immunogen. A SA-1 enriched fraction was obtained by immunoaffinity chromatography and was used to immunize a naive Holstein calf. SA-1 immune serum from this calf detected C. parvum epitopes to a 1:10,000 dilution in a dot blot assay, and sporozoite surface epitopes at a 1:10,000 dilution in a live immunofluorescence assay. Western blot analysis showed that SA-1 immune bovine serum recognized a similar pattern of C. parvum antigens as the defining mAb 17.41. Oral passive transfer of SA-1 immune bovine serum did not protect severe combined immunodeficient (scid) mice or suckling BALB/c mice from initial infection with C. parvum, or terminate a persistent infection in scid mice.
微小隐孢子虫是一种原生动物病原体，可感染哺乳动物的胃肠道上皮细胞，引起腹泻，腹泻的持续时间和严重程度取决于宿主的免疫能力。目前，尚无有效的治疗或预防方法。我们评估了表面抗原-1（SA-1，定义为可被中和单克隆抗体17.41识别的那些抗原）作为免疫原时引发保护性抗体反应的能力。通过免疫亲和层析获得了富含SA-1的组分，并用于免疫一头未接触过病原体的荷斯坦犊牛。这头犊牛的SA-1免疫血清在斑点印迹试验中能在1:10,000稀释度下检测到微小隐孢子虫表位，在活细胞免疫荧光试验中能在1:10,000稀释度下检测到子孢子表面表位。蛋白质印迹分析表明，SA-1免疫牛血清识别的微小隐孢子虫抗原模式与定义性单克隆抗体17.41相似。口服SA-1免疫牛血清不能保护严重联合免疫缺陷（scid）小鼠或哺乳的BALB/c小鼠免受微小隐孢子虫的初次感染，也不能终止scid小鼠的持续感染。
