Quantitative analysis of cytokine mRNA induction in micro-dissected epithelium in cattle during foot-and-mouth disease virus infection

Introduction: There is a need to understand the factors which regulate the pathogenesis and persistence of foot-and-mouth disease virus (FMDV). In this paper, the cytokine mRNA levels in micro-dissected epithelium during the acute stage of FMDV infection in cattle were quantified. Materials and Methods: Epithelia from tongue, coronary band on feet and dorsal soft palate were collected from cattle acutely infected with FMDV O UKG34/2001 at different days after infection. Laser Micro-Dissection (LMD) was carried out on frozen sections from selected tissues of infected cattle. After RNA extraction the cytokine mRNA and 28S rRNA (used as a RNA marker) from these samples were quantified by RT-PCR. Results: Quantitative RT-PCR assays in combination with LMD were successfully developed to quantify mRNA levels of the inflammatory cytokines IL-1 α and TNF-α and the antiviral cytokines IFN-α, IFN-β and IFN-γ in micro-dissected epithelium. Induction kinetics of these cytokine mRNA were then analyzed during the acute stage of FMDV infection. Discussion: Cytokine mRNA response in micro-dissected epithelium from various sites examined during the acute stage of FMDV infection in cattle was different, suggesting that epithelial cells in different epithelia may mount a different defence following infection.