Dectin-1-Mediated Production of Pro-Inflammatory Cytokines Induced by Yeast β-Glucans in Bovine Monocytes

• Published in: Frontiers in immunology Vol. 12; p. 689879
• Main Authors: Pedro, Ana R. V., Lima, Tânia, Fróis-Martins, Ricardo, Leal, Bárbara, Ramos, Isabel C., Martins, Elisabete G., Cabrita, Ana R. J., Fonseca, António J. M., Maia, Margarida R. G., Vilanova, Manuel, Correia, Alexandra
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 28-05-2021
• Subjects: bovine; cytokines; dectin-1; Immunology; monocytes; siRNA; β-glucans
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2021.689879

Yeast-derived products containing β-glucans have long been used as feed supplements in domesticated animals in an attempt to increase immunity. β-glucans are mainly recognized by the cell surface receptor CLEC7A, also designated Dectin-1. Although the immune mechanisms elicited through Dectin-1 activation have been studied in detail in mice and humans, they are poorly understood in other species. Here, we evaluated the response of bovine monocytes to soluble and particulate purified β-glucans, and also to Zymosan. Our results show that particulate, but not soluble β-glucans, can upregulate the surface expression of costimulatory molecules CD80 and CD86 on bovine monocytes. In addition, stimulated cells increased production of IL-8 and of
TNF, IL1B
, and
IL6
mRNA expression, in a dose-dependent manner, which correlated positively with
CLEC7A
gene expression. Production of IL-8 and
TNF
expression decreased significantly after
CLEC7A
knockdown using two different pairs of siRNAs. Overall, we demonstrated here that bovine monocytes respond to particulate β-glucans, through Dectin-1, by increasing the expression of pro-inflammatory cytokines. Our data support further studies in cattle on the induction of trained immunity using dietary β-glucans.