The Natural Expression of Genes Encoding Major Antigens of Rd1 and Rd9 in M. Tuberculosis and other Mycobacteria
Shumaila N. M. Hanif*, Rajaa Al-Attiyah and Abu Salim Mustafa
Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait
- Corresponding Author:
- Shumaila Nida Muhammad Hanif
Department of Microbiology, Faculty of Medicine
Kuwait University, P.O.BOX 24923 13110, Safat, Kuwait
E-mail: [email protected]
Received Date: November 28, 2011; Accepted Date: December 13, 2011; Published Date: december 15, 2011
Citation: Hanif SNM, Al-Attiyah R, Mustafa AS (2011) The Natural Expression of Genes Encoding Major Antigens of Rd1 and Rd9 in M. www.omicsonline.org/2168-958X/2168-958X-1-102.phpTuberculosis and other Mycobacteria. Mycobact Diseases 1:105. doi:10.4172/2161-1068.1000105
Copyright: © 2011 Hanif SNM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The natural expression of genes of five major antigenic proteins present in the genomic region of difference (RD)1, i.e. pe35, ppeE68, esxA and esxB , and RD9, i.e. esxV , was determined, at mRNA and protein levels, in M. tuberculosis, M. bovis BCG, and environmental mycobacterial species of M.avium and M.vaccae . The expression of mRNA was determined using total mycobacterial RNA and gene-specific forward and reverse primers in reverse transcription-polymerase chain reaction (RT-PCR), and the expression of proteins was determined by Western immunoblot analysis of mycobacterial sonicates with anti-sera containing protein-specific antibodies raised in rabbits. Furthermore, the expression of each protein in various sub-cellular fractions of M.tuberculosis was studied by Western immunoblot analysis of cell walls, culture filtrates and sonicates of M.tuberculosis using the rabbit anti-sera. The results showed mRNA and protein expressions for PE35, PPE68, ESXA, and ESXB only in M. tuberculosis , whereas ESXV was expressed in M.tuberculosis and M.bovis BCG, but none of them were expressed in M.avium and M.vaccae . Furthermore, all of the proteins were detected in various sub-cellular fractions of M. tuberculosis. In conclusion, our study demonstrates that the five major antigenic proteins encoded by genes present in RD1 and RD9 regions are naturally expressed in M.tuberculosis , whereas only ESXV is expressed in M. bovis BCG and none of these proteins are expressed in the environmental mycobacterial species of M. avium and M. vaccae . As these proteins are major antigens recognized by Th1 cells of protective phenotype, they could be useful in specific diagnosis and/or development of new vaccines against tuberculosis.