Gene expression profiling and analysis of miRNA as a measure of immunocompetence in cattle

  • 9:00 am (PDT)
Speakers: Drs. Axel Heiser, Principal Scientist and Sandeep Gupta, Scientist - AgResearch Limited

Gene expression analysis is a valuable tool for studying the immune status and function of livestock because monoclonal antibodies for many proteins of interest are not as readily available as in other species. Gene expression analyses of messenger RNA can be performed directly from biopsied tissue for in vivo studies or from blood or tissue cells stimulated in vitro as a model system. Analysis of miRNA as a circulating biomarker allows for the correlation of individual miRNAs or more often multiple miRNA “signatures” with different metabolic or disease states.

Treatment of periparturient cows with granulocyte colony-stimulating factor has been reported to increase circulating neutrophil count and enhance neutrophil. Using a NanoString® nCounter® Custom CodeSet, we analyzed the expression of 21 genes in neutrophils from cows treated with and without pegbovigrastim. In another study designed to study the effects of far-off and close-up feeding on immune function, expression profiles for 17 immune markers were measured in whole blood preparations from dairy cows, starting from one week before calving up to four weeks after calving.  Cells were stimulated in vitro to initiate a cell-mediated immune response and stimulated, and unstimulated preparations were compared. We investigated the effect of weaning age on immune function in calves by analyzing the expression of 16 immune-related genes.

Finally, using the nCounter Human v3 miRNA expression assay kit and understanding the expected homology of human miRNA probes with that of cattle, we detected 26 miRNA from serum of cattle with Johne’s disease; 13 of these miRNAs were previously uncharacterized in cattle. Using a combination of four different miRNAs, we developed a signature to distinguish moderate and severely infected animals from non-infected animals.

FOR RESEARCH USE ONLY. Not for diagnostic procedures.