两种常见非结核分枝杆菌与结核分枝杆菌基因同源抗原、B细胞抗原表位和抗体交叉反应研究

目的 探讨我国常见两种非结核分枝杆菌与结核分枝杆菌蛋白抗原的交叉免疫反应状况,为以非结核分枝杆菌研制新型结核疫苗提供参考依据。方法 平均核酸一致性计算器计算胞内分枝杆菌、脓肿分枝杆菌和结核分枝杆菌的基因组同源性,OrthorFinder软件分析3种菌的同源基因,与结核分枝杆菌B细胞抗原表位编码基因进行比对。分别制备3种菌的灭活菌体抗原和全菌蛋白抗原,对新西兰大白兔进行皮下注射免疫。采用间接酶联免疫吸附试验技术,分别检测3种免疫兔血清抗体Ig G水平及交叉免疫的血清抗体Ig G水平。结果 脓肿分枝杆菌、胞内分枝杆菌与结核分枝杆菌同源基因分别为2 350个和2 740个,其同源基因中分别有479个和521个富含B细胞抗原表位。结核分枝杆菌、胞内分枝杆菌和脓肿分枝杆菌的蛋白抗原均能刺激兔产生较高水平的抗体滴度,分别达到1∶320 000、1∶160 000和1∶80 000。胞内分枝杆菌和脓肿分枝杆菌免疫兔血清均可与结核分枝杆菌抗原产生高水平的交叉反应,抗体滴度分别达到1∶40 000和1∶80 000。结论 胞内分枝杆菌、脓肿分枝杆菌与结核分枝杆菌之间均存在高水平的抗体交叉免疫反应,提示上...

Study of gene homologous antigen,B cell antigen epitope and cross reaction with antibody IgG between two common non-tuberculous Mycobacteria and Mycobacterium tuberculosis

  Objective  To investigate the cross-immune reaction of the protein antigens between two kinds of common non-tuberculous mycobacterium (NTM) and Mycobacterium tuberculosis in China and provide reference for the development of new tuberculosis vaccines by using NTM.   Methods  The genomic homology between M. intracellular, M. abscess and M. tuberculosis was calculated with the mean nucleic acid consistency calculator, the homologous genes were analyzed with OrthorFinder and the comparison with the B cell epitope encoding gene of M. tuberculosis was made. The inactivated antigen and whole protein antigens of the three kinds of bacteria were prepared respectively, and the white rabbits from New Zealand were immunized by subcutaneous injection. After immunization, indirect enzyme-linked immunosorbent assay (ELISA) was used to detect the serum IgG levels and cross-immunization serum IgG levels of the immunized rabbits.   Results  There were 2350 and 2740 homologous genes with M. tuberculosis in M. abscess and M. intracellular, among which 479 and 521 homologous genes were rich in B-cell epitopes. The protein antigens of M. tuberculosis, M. intracellular and M. abscess all stimulated the white rabbits to produce high levels of antibody IgG titers, reaching 1∶320000, 1∶160000 and 1∶80000, respectively. Both M. intracellular and M. abscess immunized rabbits sera had cross-reaction with M. tuberculosis protein antigens at high levels, resulting in antibody titers up to 1∶40000 and 1∶80000 respectively.   Conclusion  There were high level cross-immune reactions between M. intracellular, M. abscess and M. tuberculosis, suggesting that the two kinds of NTM and M. tuberculosis have more common protein antigens, which has a good potential application value in developing new tuberculosis vaccines.