Interferon gamma and IP 10 mRNA quantitative real time PCR in whole blood culture of guinea pig and cattle to multi-antigen recombinant protein cocktail and PPD of Mycobacterium bovis (3/86Rv)

Abstract

In vivo tuberculin skin test and in vitro IFNγ assays are the most explored diagnostics for Mycobacterium bovis infection (Bovine Tuberculosis) in animals. However, there are other potential biomarkers like IP10 which may allow diagnosis of tuberculosis. In this study, IFNγ and IP10 mRNA responses in guinea pig and cattle were determined by quantitative RT-PCR in whole blood samples stimulated PPDs and recombinant protein cocktail containing eight purified rCFP2, rESAT6, rCFP10, rMTC28, rMPB53, rMPB63, rMPB64 and rMPB83 proteins. Blood samples were obtained from M. bovis sensitised guinea pigs and tuberculin test positive cattle. Both guinea pigs and cattle blood cultures produced a significant increase in mRNA level of IFNγ and IP10 when stimulated with protein cocktail as compared to that of bovine PPD. Upon different antigenic stimulations, IP10 mRNA responses were followed the similar kinetics to those of IFNγ with high correlation (r = 0.97 for guinea pig and 0.96 for cattle).