Mesfin G M, Bellamy J E
Infect Immun. 1979 Jan;23(1):108-14. doi: 10.1128/iai.23.1.108-114.1979.
Mice immunized with infections of 500, 5,000, or 20,000 oocysts of E. falciformis var. pragensis were reinfected with 20,000 and 100,000 oocysts at 20 and 38 days, respectively, after the initial infection. After the first challenge infection, none of the immunized mice showed clinical signs of coccidiosis; a few mice passed very low numbers of oocysts, and oocyst discharge seemed to correlate negatively with immunizing dose. None of the mice immunized twice passed oocysts after challenge. Mice immunized with three infections were completely immune to challenge for 4 months. The effect of the immune response on the life cycle of the coccidium was determined by histological examination of the intestines of immune and nonimmune mice infected with the parasite. In both the immune and nonimmune groups, sporozoites penetrated absorptive epithelial cells and migrated to crypt epithelial cells during the first 6 to 24 h postinfection. At 48 to 72 h postinfection, the sporozoites developed into mature first-generation schizonts in the nonimmune mice, whereas the developing first-generation schizonts degenerated within the crypt epithelial cells of the immune mice. In nonimmune mice, third-generation merozoites, inoculated intracecally, developed into mature fourth-generation schizonts, whereas in immune mice the developing fourth-generation schizonts degenerated before maturing. The possibility that a cellmediated immune mechanism is responsible for the arrest in schizogony is discussed.
用500、5000或20000个法氏艾美耳球虫布拉格变种卵囊感染的小鼠，在初次感染后分别于第20天和第38天用20000和100000个卵囊再次感染。初次攻击感染后，没有一只免疫小鼠出现球虫病的临床症状；少数小鼠排出的卵囊数量极少，卵囊排出量似乎与免疫剂量呈负相关。没有一只接受两次免疫的小鼠在攻击后排出卵囊。接受三次感染免疫的小鼠在4个月内对攻击完全免疫。通过对感染该寄生虫的免疫和非免疫小鼠的肠道进行组织学检查，确定了免疫反应对球虫生命周期的影响。在免疫组和非免疫组中，子孢子在感染后最初的6至24小时内穿透吸收性上皮细胞并迁移至隐窝上皮细胞。感染后48至72小时，非免疫小鼠中的子孢子发育成成熟的第一代裂殖体，而免疫小鼠隐窝上皮细胞内发育中的第一代裂殖体退化。本文讨论了细胞介导的免疫机制导致裂体生殖停滞的可能性。
