Studies on the immunological biomarkers of bovine tuberculosis in naturally infected cattle

Background Bovine tuberculosis (bTB) is a chronic infectious disease caused primarily by infection with M. bovis, which belongs to the Mycobacterium tuberculosis complex. There are different diagnostic tests for the diagnosis of bovine tuberculosis, among which, determination of biomarkers plays a significant role. However, the biomarkers for the diagnosis of bTB in naturally infected cattle are limited. Methods In the present study, the gene expression profile of host immune-related genes (MCP-1, MMP-9, CCR5, iNOS, IFNγ, TNFα, and IL-23A) was studied. The aim of the study was to evaluate this set of immune-related genes for their potential use as diagnostic biomarkers of bTB infection in cattle. A total of 40 HF cross-breed cattle were grouped into two groups uninfected, and bTB infected, on the basis of results obtained by CITT, IS6100 PCR. The PBMCs from both groups were cultured and stimulated in vitro with bovine tuberculin PPD. Results In the results, the mRNAs (MCP-1, MMP-9, CCR5, iNOS, IFNγ, TNFα and IL-23A) were upregulated in bTB-positive animals relative to negative controls. The transcripts can discriminate between bTB-positives and uninfected controls, with AUC ranging from 0.8 to 1. The targeted genes showed promising results and further studies are needed to explore the potential of these highly expressed transcripts as the potential biomarker of bTB in naturally infected cattle.