Objective: To compare the proteome of Mycobacterium tuberculosis (MTB) H(37)Rv strain with Bovine mycobacterium (Bacillus Calmette-Guerin, BCG) strain at the sub-cellular level.
Methods: Proteins of the cell wall, membrane and cytolymph of H(37)Rv and BCG were extracted by density gradient centrifugation. Sub-cellular proteome of H(37)Rv and BCG were analyzed using 2-dimensional liquid chromatography. The immunity reactions of H(37)Rv fractions with sera from patients (n = 5) and healthy controls (n = 5), as well as BCG fractions with sera from healthy controls (n = 5) were analyzed by ELISA. Data was analyzed by t test.
Results: Twenty-six fractions of H(37)Rv were found to elicit specific antibody response. Fraction M3Fr18 of H(37)Rv reacted with sera from patients. The A(450) [(721 ± 3) × 10(-3)] was higher than that with sera from healthy controls [(356 ± 6) × 10(-3)], as well as the A(450) of the corresponding fractions of BCG with sera from healthy controls [(414 ± 7) × 10(-3)]. The differences between the patient group and the 2 healthy control groups were significant (t = 1.852 and 1.037, all P < 0.01). Moreover, fraction M10Fr21 of H(37)Rv reacted with sera from the patients. The A(450) [(954 ± 6) × 10(-3)] was higher than that with sera from the healthy controls [(415 ± 6) × 10(-3)], as well as the A(450) of the corresponding fractions of BCG with sera from the healthy controls [(315 ± 4) × 10(-3)]. The differences between the patient group and the 2 healthy control groups were significant (t = 2.113 and 2.550, all P < 0.01).
Conclusions: The combination of 2-dimensional liquid chromatography and immunology technology is useful in finding antigens associated with MTB infection. Fractions M3Fr18 and M10Fr21 can elicit specific immune reaction among MTB patients, suggesting that they may be specific antigens of MTB infection.