| Abstract |
*For correspondence. (S.J. Han) E-mail: hansjung@yuhs.ac / (S.N. Cho)
E-mail: raycho@yuhs.ac
Paul J. Park, Ah Reum Kim, Yangkyo P. Salch,
Taeksun Song, Sung Jae Shin, Seung Jung Han*,
and Sang-Nae Cho*
Department of Microbiology and Institute for Immunology and
Immunological Diseases, Brain Korea 21 Plus Project for the Medical
Sciences, Yonsei University College of Medicine, Seoul 120-752,
Republic of Korea
(Received Apr 16, 2014 / Revised Jul 14, 2014 / Accepted Jul 16, 2014)
Journal of Microbiology (2014) Vol. 52, No. 10, pp. 871–878
Copyright 2014, The Microbiological Society of Korea
DOI 10.1007/s12275-014-4235-5
Characterization of a Novel Antigen of Mycobacterium tuberculosis K
strain and Its Use in Immunodiagnosis of Tuberculosis
Mycobacterium tuberculosis-specific antigens would be of
great value in developing immunodiagnostic tests for tuberculosis
(TB), but regional differences in molecular types of
the organism may result in antigenic variation, which in turn
affects the outcome of the tests. For example, the Beijing
strains of M. tuberculosis are prevalent in East Asia, and in
particular, the K strain and related strains of the Beijing
family, are most frequently isolated during school outbreaks
of TB in South Korea. From comparison of genome sequences
between M. tuberculosis K strain and the H37Rv strain, a
non-Beijing type, we identified a K strain-specific gene, InsB,
which has substantial homology with the ESAT-6-like proteins.
This study was, therefore, initiated to characterize the
InsB protein for its immunogenicity in mice and to confirm
its expression in TB patients by detecting antibodies to the
protein. The InsB gene was cloned from M. tuberculosis K
strain and expressed in Escherichia coli. The recombinant
InsB protein was used for immunization of mice. All mice
showed strong antibody responses to the InsB protein, and
splenocytes stimulated with InsB showed strong IFN-γ and
IL-17 responses and a weak IL-2 response, all of which have
been implicated in disease expression and used for the immunodiagnosis
of TB. Serum samples from TB patients also
showed significant antibody responses to the InsB protein as
compared to healthy control samples. These results indicate
that the InsB protein is an M. tuberculosis K-strain-specific
antigen that could further improve the current immunodiagnostic
methods, especially for the South Korean population. |
