This work demonstrates the presence of immune regulatory cells in the cervical lymph nodes draining Bacillus Calmette-Guérin (BCG) vaccinated site on the dorsum of the ear in guinea pigs. It is shown that whole cervical lymph node cells did not proliferate in vitro in the presence of soluble mycobacterial antigens (PPD or leprosin) despite being responsive to whole mycobacteria. Besides, T cells from these lymph nodes separated as a non-adherent fraction on a nylon wool column, proliferated to PPD in the presence of autologous antigen presenting cells. Interestingly, addition of as low as 20% nylon wool adherent cells to these, sharply decreased the proliferation by 83%. Looking into what cells in the adherent fraction suppressed the proliferation, it was found that neither the T cell nor the macrophage enriched cell fractions of this population individually showed suppressive effect, indicating that their co-presence was necessary for the suppression. Since BCG induced granulomas resolve much faster than granulomas induced by other mycobacteria such as Mycobacterium leprae the present experimental findings add to the existing evidence that intradermal BCG vaccination influences subsequent immune responses in the host and may further stress upon its beneficial role seen in Covid-19 patients.

这项工作证明了在豚鼠耳背上卡介苗 (BCG) 接种部位的颈部淋巴结中存在免疫调节细胞。结果表明，整个颈部淋巴结细胞在体外没有增殖尽管对整个分枝杆菌有反应，但存在可溶性分枝杆菌抗原（PPD 或 leprosin）。此外，来自这些淋巴结的 T 细胞在尼龙毛柱上作为非贴壁部分分离，在存在自体抗原呈递细胞的情况下增殖为 P​​PD。有趣的是，向其中添加低至 20% 的尼龙羊毛贴壁细胞后，增殖急剧减少了 83%。研究贴壁部分中的哪些细胞抑制了增殖，发现该群体的 T 细胞和巨噬细胞富集细胞部分均未单独显示出抑制作用，表明它们的共存对于抑制是必要的。由于 BCG 诱导的肉芽肿比其他分枝杆菌（如麻风分枝杆菌）诱导的肉芽肿消退得更快目前的实验结果增加了现有证据，表明皮内 BCG 疫苗接种会影响宿主随后的免疫反应，并可能进一步强调其在 Covid-19 患者中的有益作用。