Recombinant CFP-10 as antigen for diagnosis and quantification of IFN-γ expression by real-time PCR in guinea pigs sensitized with<em> Mycobacterium bovis</em>

Abstract

Culture filtrate protein (CFP-10) is a low molecular weight protein and is an early secretory protein in <em>Mycobacterium tuberculosis </em>culture filtrate and plays key roles in tuberculosis pathogenesis and in the stimulation of immunity. Keeping in view the important role of CFP10, we investigated the CFP10 gene in Indian <em>Mycobacterium bovis</em> (<em>M</em>. <em>bovis</em>) (3/86Rv) and its expression in suitable prokaryotic host for its diagnostics potential by single intradermal test (SID). Real-time PCR was used to quantify mRNA interferon-γ expression levels. The study concluded that the expression of IFN-γ mRNA in blood was found up to 19.962, 20.795, 9.633, 34.511 and 1.688 times in rCFP10, bovine PPD (purified protein derivative), avian PPD, conA and PBS stimulated groups, respectively as compared to healthy control group. The mRNA expression level of bovine PPD and avian PPD stimulated group was found statistically significant (at <em>P</em> <0.05) and among conA and rCFP10 stimulated group, it was highly significant (at <em>P</em> <0.01) in comparison to ‘without antigen stimulated’ group.