Wyatt C R, Brackett E J, Barrett W J
Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164-7040, USA.
J Parasitol. 1999 Aug;85(4):765-8.
We had previously shown that ileal intraepithelial lymphocytes isolated from calves with cryptosporidiosis include significantly increased numbers of CD8+ T lymphocytes and activated CD4+ cells. These increases could result from redistribution of resident mucosal lymphocytes or from homing of peripheral T cells to ileal mucosa. To determine whether resident mucosal lymphocytes can redistribute to Cryptosporidium parvum-infected epithelium, oocysts were inoculated in vitro onto ileum explants taken from 1-2-wk-old noninfected calves. After 24 hr of incubation, the explants were collected and frozen in liquid nitrogen. Immunohistochemical analysis of T-lymphocyte subpopulations was performed on sections, and labeled lymphocytes adjacent to villous epithelial cells were counted. Compared with uninoculated explants, there was a statistically significant increase in the number of CD8+ T lymphocytes per 100 epithelial cells in oocyst-inoculated tissue. In addition, there were increased numbers of CD4+ T cells and activated (CD25+) lymphocytes adjacent to C. parvum-infected epithelium. These results show that resident mucosal T lymphocytes can accumulate at the epithelium during C. parvum infection.
我们之前已经表明，从患有隐孢子虫病的小牛中分离出的回肠上皮内淋巴细胞包含数量显著增加的CD8 + T淋巴细胞和活化的CD4 +细胞。这些增加可能是由于常驻黏膜淋巴细胞的重新分布，或者是外周T细胞归巢至回肠黏膜所致。为了确定常驻黏膜淋巴细胞是否能够重新分布到感染微小隐孢子虫的上皮细胞，将卵囊体外接种到取自1 - 2周龄未感染小牛的回肠外植体上。孵育24小时后，收集外植体并在液氮中冷冻。对切片进行T淋巴细胞亚群的免疫组织化学分析，并对绒毛上皮细胞相邻的标记淋巴细胞进行计数。与未接种的外植体相比，卵囊接种组织中每100个上皮细胞中CD8 + T淋巴细胞的数量有统计学上的显著增加。此外，在感染微小隐孢子虫的上皮细胞相邻处，CD4 + T细胞和活化（CD25 +）淋巴细胞的数量增加。这些结果表明，在微小隐孢子虫感染期间，常驻黏膜T淋巴细胞可在上皮细胞处积聚。
