Rose M E, Hesketh P, Grencis R K, Bancroft A J
Division of Immunology and Pathology, Institute for Animal Health, Compton, Newbury, Berkshire RG20 7NN, UK.
Parasite Immunol. 2000 Apr;22(4):161-72. doi: 10.1046/j.1365-3024.2000.00287.x.
BALB/c mice are normally more resistant than C57BL/6 (B6) mice to infection with Eimeria vermiformis, but these phenotypes can be reversed by oral or parenteral vaccination with a crude antigen prepared from the parasite. Treatment of mice with antibodies specific for CD4+ or CD8+ T cells showed that the increased susceptibility of vaccinated BALB/c mice was associated with the presence of CD4+ T cells. This finding was confirmed when the recipients of CD4+ T cells selected from the mesenteric lymph nodes (MLN) of vaccinated BALB/c mice produced more oocysts after challenge than the recipients of a similar population of cells from sham-vaccinated mice. The residual population of cells (presumably enriched for CD8+ T cells, 'CD8+'), on the other hand, conferred some protection and, in B6 mice, the findings were reversed. Thus, vaccination induced suppressive or protective CD4+ cells and protective or suppressive 'CD8+' cells, depending upon the normal resistance/susceptibility phenotype of the host. Examinations of the isotypes (IgG1, IgG2a) of specific serum antibodies, and of the levels of IFN-gamma and IL-5 cytokines released by MLN cells stimulated ex vivo, did not allow any further characterization of the mechanisms involved.
BALB/c小鼠通常比C57BL/6（B6）小鼠对蠕虫艾美耳球虫感染更具抵抗力，但通过用从该寄生虫制备的粗抗原进行口服或肠胃外疫苗接种，这些表型可以逆转。用针对CD4 +或CD8 + T细胞的特异性抗体处理小鼠表明，接种疫苗的BALB/c小鼠易感性增加与CD4 + T细胞的存在有关。当从接种疫苗的BALB/c小鼠的肠系膜淋巴结（MLN）中选择的CD4 + T细胞受体在受到攻击后比假接种小鼠的类似细胞群体受体产生更多卵囊时，这一发现得到了证实。另一方面，细胞的剩余群体（可能富含CD8 + T细胞，“CD8 +”）提供了一些保护，并且在B6小鼠中，结果相反。因此，根据宿主的正常抗性/易感性表型，疫苗接种诱导抑制性或保护性CD4 +细胞以及保护性或抑制性“CD8 +”细胞。对特异性血清抗体的同种型（IgG1、IgG2a）以及体外刺激的MLN细胞释放的IFN-γ和IL-5细胞因子水平的检测，无法对所涉及的机制进行进一步表征。
