Correlated expression profiling of dicer1 and tlr genes across bubaline tissues vis-à-vis in PBMCs challenged with tlr agonists

Dicer, a Ribonuclease III enzyme, plays key role in the biogenesis of microRNAs and small interfering RNAs and is essential for development, cell differentiation and immune regulation. On the other hand, Toll like receptors are non-catalytic, pattern recognition receptors, which play central role in innate immunity against wide range of pathogens. In the present study, differential expression of bubaline dicer1 enzyme and Toll like receptors (tlr3 and tlr4) genes in nine different tissue samples and peripheral blood mononuclear cells (PBMCs) were profiled using real time PCR (TaqMan chemistry). All the genes exhibited highly differential pattern across the tissues studied, with the highest expression in heart for all the genes and low expression was observed in reproductive tissues (ovary and testis). Moreover, the tissue expression profile of dicer1 enzyme has been reported for the first time in Bubalus bubalis. In order to find any correlation between the expression of tlrs and dicer in case of any bacterial or viral infection, their expression were studied in bubaline PBMCs challenged with tlr4- and tlr3- ligands viz. LPS (component of gram negative bacteria) and PolyI:C (synthetic analogue of dsRNA molecule), respectively; thus mimicking the infection in vitro. Upon ligand stimulation, dicer1 gene expression was found to increase hand-in-hand with the increased expression of respective tlr genes. The study revealed positive association between the expressions of dicer1 vis-à-vis tlr3 and 4 genes in bubaline PBMC, indicating that specific viral or gram negative bacterial infection co-regulates the expression of dicer1 in PBMC. Thus, this finding warrants extensive study on identification of miRNAs associated with disease tolerance or susceptibility, which could be modulated by tlr-ligands through increased Dicer I activity in livestock.