title: Mycobacterium tuberculosis HBHA protein reacts strongly with the serum immunoglobulin M of tuberculosis patients.
abstract: 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.
authors.affiliation: Department of Microbiology, College of Medicine, Chungnam National University, 6 Muwha-Dong, Jung-Ku, Daejeon 301-747, Korea.
authors.forename: A-Rum
authors.initials: AR
authors.lastname: Shin
authors.forename: Kil-Soo
authors.initials: KS
authors.lastname: Lee
authors.forename: Ji-Sook
authors.initials: JS
authors.lastname: Lee
authors.forename: Su-Young
authors.initials: SY
authors.lastname: Kim
authors.forename: Chang-Hwa
authors.initials: CH
authors.lastname: Song
authors.forename: Saet-Byel
authors.initials: SB
authors.lastname: Jung
authors.forename: Chul-Su
authors.initials: CS
authors.lastname: Yang
authors.forename: Eun-Kyeong
authors.initials: EK
authors.lastname: Jo
authors.forename: Jeong-Kyu
authors.initials: JK
authors.lastname: Park
authors.forename: Tae-Hyun
authors.initials: TH
authors.lastname: Paik
authors.forename: Hwa-Jung
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000818:Animals; D000937:Antigen-Antibody Reactions / Q000276:immunology*; D000942:Antigens, Bacterial / Q000276:immunology / Q000378:metabolism; D001426:Bacterial Proteins / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D002908:Chronic Disease; D006801:Humans; D015151:Immunoblotting; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D008565:Membrane Proteins / Q000097:blood / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011994:Recombinant Proteins / Q000097:blood / Q000276:immunology / Q000378:metabolism; D014376:Tuberculosis / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C440647:HbhA protein, Mycobacterium tuberculosis; D007075:Immunoglobulin M; D008565:Membrane Proteins; D011994:Recombinant Proteins