AUTHOR=Ologunagba Deborah , Idowu Modoluwamu , Taiwo Godstime , Sidney Taylor , Treon Emily , Eichie Francisca , Bebe Frederick , Ogunade Ibukun M. 

TITLE=Hepatic mRNA expression of innate and adaptive immune genes in beef steers with divergent residual body weight gain

JOURNAL=Frontiers in Animal Science

VOLUME=Volume 5 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/animal-science/articles/10.3389/fanim.2024.1349499

DOI=10.3389/fanim.2024.1349499

ISSN=2673-6225

ABSTRACT=We evaluated the hepatic mRNA expression of genes involved in innate and adaptive immunity in crossbred beef steers with positive or negative residual body weight gain (RADG). Positive-RADG beef steers (n = 8; RADG = 0.73 kg/d) and negative-RADG beef steers (n = 8; RADG = -0.69 kg/d) were identified from a group of 108 growing crossbred after a 56-d performance testing period. Liver tissue samples were collected for RNA extraction and cDNA synthesis. The mRNA expression of 84 genes involved in immunity was analyzed using pathway-focused PCR-based arrays. The mRNA expression of genes with false discovery rate-adjusted P-values ≤ 0.05 and absolute fold change (FC) ≥ 1.2 were determined to be differentially expressed. Four genes (IL-2, MYD88, CD-80, NFkB-1) were differentially expressed and were all upregulated in positive-RADG beef steers. IL-2 is a cytokine that plays a critical role in the immune response by activating and proliferating T-cells. MYD88 is an adaptor protein that is essential for signaling by toll-like receptors. CD80 is a protein that is expressed on the surface of antigen-presenting cells and plays a critical role in the initiation of an immune response. The activation of NF-κB leads to the production of cytokines and chemokines that help to recruit immune cells to the site of infection. The upregulation of the aforementioned genes in positive-RADG beef steers suggests that they had a better ability than negative-RADG beef steers to quickly recognize pathogens and initiate appropriate responses to effectively fight off infections without causing inflammatory reactions.