McDonald V, Robinson H A, Kelly J P, Bancroft G J
Department of Clinical Sciences, London School of Hygiene and Tropical Medicine, London, United Kingdom.
Infect Immun. 1996 Jul;64(7):2556-62. doi: 10.1128/iai.64.7.2556-2562.1996.
The role of gut intraepithelial lymphocytes (IEL) in immunity to cryptosporidial infection was investigated with a murine infection model involving Cryptosporidium muris. Oocyst shedding was monitored in severe combined immunodeficiency (SCID) mice infected with C. muris following intravenous injection of mesenteric lymph node (MLN) cells or intestinal IEL from BALB/c donor mice which were naive or previously infected with C. muris. SCID mice receiving no lymphoid cells developed chronic infections and excreted large numbers of oocysts until the end of the experiment. SCID mice injected with IEL from immune animals, however, were able to overcome the infection, and furthermore, these animals produced fewer oocysts and recovered sooner than ones which received IEL or MLN cells from naive BALB/c donors. Similar levels of protection were obtained in SCID mice injected with either 2 X 10(6) IEL or MLN cells from immune donor mice. Depletion of CD4+ cells from immune IEL, however, abrogated the ability to transfer immunity to SCID mice, while depletion of CD8+ cells only marginally reduced the protective capacity of immune IEL. Finally, control SCID mice which received no lymphocytes had < or = 1% CD4+ cells in the IEL from the small intestine, whereas the IEL from SCID mice recovered from infection, as a result of injection with immune IEL, contained 15% CD4+ cells. Thus, the ability to control C. muris infection correlated with the presence of the protective CD4+ cells in the gut epithelium.
利用涉及微小隐孢子虫的小鼠感染模型，研究了肠道上皮内淋巴细胞（IEL）在抵抗隐孢子虫感染免疫中的作用。在静脉注射来自未感染或先前感染过微小隐孢子虫的BALB/c供体小鼠的肠系膜淋巴结（MLN）细胞或肠道IEL后，监测严重联合免疫缺陷（SCID）小鼠感染微小隐孢子虫后的卵囊排出情况。未接受淋巴细胞的SCID小鼠发生慢性感染，并排出大量卵囊直至实验结束。然而，注射来自免疫动物的IEL的SCID小鼠能够克服感染，此外，这些动物产生的卵囊较少，且比接受来自未感染BALB/c供体的IEL或MLN细胞的小鼠恢复得更快。给SCID小鼠注射来自免疫供体小鼠的2×10⁶个IEL或MLN细胞可获得相似水平的保护。然而，从免疫IEL中去除CD4⁺细胞消除了将免疫力转移给SCID小鼠的能力，而去除CD8⁺细胞仅略微降低了免疫IEL的保护能力。最后，未接受淋巴细胞的对照SCID小鼠小肠IEL中的CD4⁺细胞≤1%，而由于注射免疫IEL从感染中恢复的SCID小鼠的IEL含有15%的CD4⁺细胞。因此，控制微小隐孢子虫感染的能力与肠道上皮中保护性CD4⁺细胞的存在相关。
