Shin A-Rum, Lee Kil-Soo, Lee Ji-Sook, Kim Su-Young, Song Chang-Hwa, Jung Saet-Byel, Yang Chul-Su, Jo Eun-Kyeong, Park Jeong-Kyu, Paik Tae-Hyun, Kim Hwa-Jung
Department of Microbiology, College of Medicine, Chungnam National University, 6 Muwha-Dong, Jung-Ku, Daejeon 301-747, Korea.
Clin Vaccine Immunol. 2006 Aug;13(8):869-75. doi: 10.1128/CVI.00103-06.
Identification and characterization of serologically active mycobacterial antigens are prerequisites for the development of diagnostic reagents. We examined the humoral immune responses of active tuberculosis (TB) patients against Triton-soluble proteins extracted from Mycobacterium tuberculosis by immunoblotting. A 29-kDa protein reacted with immunoglobulin M (IgM) in the pooled sera of the patients, and its N-terminal amino acid sequence matched that of the heparin-binding hemagglutinin (HBHA). Recombinant full-length HBHA was expressed in Escherichia coli (rEC-HBHA) and M. smegmatis (rMS-HBHA). In immunoblot analysis, the IgM antibodies of the TB patients reacted strongly with rMS-HBHA but not with rEC-HBHA, whereas the IgG antibodies of these patients reacted weakly with both recombinant HBHA proteins. In enzyme-linked immunosorbent assay analysis using rMS-HBHA and 85B as antigens, the mean levels and sensitivities of the anti-HBHA IgM antibodies of the TB patients were significantly higher than those of the anti-antigen 85B IgM antibodies, while the IgG antibodies showed the opposite results. Of interest in this respect, the pooled sera from the TB patients that contained anti-HBHA IgM antibodies neutralized the entry of M. tuberculosis into epithelial cells. These findings suggest that IgM antibody to HBHA may play a role in protection against extrapulmonary dissemination.
鉴定和表征具有血清学活性的分枝杆菌抗原是开发诊断试剂的先决条件。我们通过免疫印迹法检测了活动性肺结核（TB）患者对从结核分枝杆菌中提取的 Triton 可溶性蛋白的体液免疫反应。一种 29 kDa 的蛋白与患者混合血清中的免疫球蛋白 M（IgM）发生反应，其 N 端氨基酸序列与肝素结合血凝素（HBHA）的序列匹配。重组全长 HBHA 在大肠杆菌（rEC-HBHA）和耻垢分枝杆菌（rMS-HBHA）中表达。在免疫印迹分析中，TB 患者的 IgM 抗体与 rMS-HBHA 强烈反应，但与 rEC-HBHA 不反应，而这些患者的 IgG 抗体与两种重组 HBHA 蛋白均反应较弱。在以 rMS-HBHA 和 85B 作为抗原的酶联免疫吸附测定分析中，TB 患者抗 HBHA IgM 抗体的平均水平和敏感性显著高于抗抗原 85B IgM 抗体，而 IgG 抗体则呈现相反结果。在这方面有趣的是，含有抗 HBHA IgM 抗体的 TB 患者混合血清可中和结核分枝杆菌进入上皮细胞。这些发现表明，针对 HBHA 的 IgM 抗体可能在防止肺外播散中发挥作用。
