TY - JOUR
T1 - Gene expression in the tuberculous granuloma
T2 - Analysis by laser capture microdissection and real-time PCR
AU - Zhu, Guofeng
AU - Xiao, Huifang
AU - Mohan, Vellore P.
AU - Tanaka, Kathryn
AU - Tyagi, Sanjay
AU - Tsen, Fred
AU - Salgame, Padmini
AU - Chan, John
PY - 2003/7/1
Y1 - 2003/7/1
N2 - We have assessed the kinetics of host gene expression in granulomas of mice infected with virulent Mycobacterium tuberculosis, using an approach that incorporates the laser capture microdissection (LCM) and real-time PCR technology in conjunction with a newly derived mathematical equation. The results have provided evidence indicating that conventional use of whole infected lungs to study granuloma-specific gene expression can yield data that may not genuinely reflect intralesional events. Significantly, the expression of nine host genes known to regulate the inflammatory response to M. tuberculosis, as determined by real-time PCR analysis of microdissected granuloma-derived cDNAs, was downregulated (up to 27-fold) at around the time when the rapid growth phase of the bacilli in the lungs of infected mice ends. This downregulation was masked when whole infected lungs were used for the studies. The data suggest that the host immune system can adjust and respond to, or can be modulated by specific physiological states of the tubercle bacillus in vivo. The LCM/real-time PCR-based system described in this study can be applied to safely and accurately evaluate gene expression in any lesions that can be microscopically visualized, including those contained in biohazardous tissues.
AB - We have assessed the kinetics of host gene expression in granulomas of mice infected with virulent Mycobacterium tuberculosis, using an approach that incorporates the laser capture microdissection (LCM) and real-time PCR technology in conjunction with a newly derived mathematical equation. The results have provided evidence indicating that conventional use of whole infected lungs to study granuloma-specific gene expression can yield data that may not genuinely reflect intralesional events. Significantly, the expression of nine host genes known to regulate the inflammatory response to M. tuberculosis, as determined by real-time PCR analysis of microdissected granuloma-derived cDNAs, was downregulated (up to 27-fold) at around the time when the rapid growth phase of the bacilli in the lungs of infected mice ends. This downregulation was masked when whole infected lungs were used for the studies. The data suggest that the host immune system can adjust and respond to, or can be modulated by specific physiological states of the tubercle bacillus in vivo. The LCM/real-time PCR-based system described in this study can be applied to safely and accurately evaluate gene expression in any lesions that can be microscopically visualized, including those contained in biohazardous tissues.
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U2 - 10.1046/j.1462-5822.2003.00288.x
DO - 10.1046/j.1462-5822.2003.00288.x
M3 - Article
C2 - 12814435
AN - SCOPUS:0038049387
SN - 1462-5814
VL - 5
SP - 445
EP - 453
JO - Cellular Microbiology
JF - Cellular Microbiology
IS - 7
ER -