Tagliabue A, Villa L, De Magistris M T, Romano M, Silvestri S, Boraschi D, Nencioni L
J Immunol. 1986 Sep 1;137(5):1504-10.
Cellular immunity against Salmonella typhi was observed by using a direct anti-bacterial in vitro assay in volunteers orally vaccinated with the live S. typhi mutant strain Ty 21a. With this experimental approach, it was demonstrated that Ty 21a vaccine also induces cellular immunity against S. paratyphi A and B. Interestingly, the mechanism involved in cellular immunity against bacteria seems to be of an antibody-dependent cellular cytotoxicity (ADCC) type, with IgA acting as the humoral arm and CD4+ T lymphocytes as the cellular one. In accordance with the increase in IgA-driven ADCC against S. typhi, a major rise in IgA against O and H antigens was observed in the serum of vaccinees in parallel to an increase in IgG of identical specificity. Furthermore, a Ty 21 vaccine induced cellular activity against flagellar antigens. These results indicate that IgA-ADCC by T lymphocytes against bacteria can originate from local stimulation of the gut mucosal immune system. This cellular defense mechanism might be at the origin of the protection induced by Ty 21a vaccine.
在口服接种活伤寒沙门氏菌突变株Ty 21a的志愿者中，通过直接体外抗菌试验观察到了针对伤寒沙门氏菌的细胞免疫。采用这种实验方法，证明Ty 21a疫苗也能诱导针对甲型和乙型副伤寒沙门氏菌的细胞免疫。有趣的是，针对细菌的细胞免疫所涉及的机制似乎是抗体依赖性细胞毒性（ADCC）类型，其中IgA作为体液部分，CD4 + T淋巴细胞作为细胞部分。与针对伤寒沙门氏菌的IgA驱动的ADCC增加一致，在疫苗接种者血清中观察到针对O和H抗原的IgA大幅上升，同时具有相同特异性的IgG也增加。此外，Ty 21疫苗诱导了针对鞭毛抗原的细胞活性。这些结果表明，T淋巴细胞针对细菌的IgA-ADCC可能源于肠道黏膜免疫系统的局部刺激。这种细胞防御机制可能是Ty 21a疫苗诱导保护作用的根源。
