Yeast-containing feed additive alters gene expression profiles associated with innate immunity in whole blood of a rodent model

Abstract

Feeding a yeast-containing additive (YCA; OmniGen-AF) improves immune responses in ruminant livestock and reduces subsequent production losses. The objective was to identify molecular pathways by which dietary YCA may modify immune responses using a rodent model. Thirty-seven healthy, unchallenged CD rats received a diet containing 0 (control; n = 5, only 28 d), 0.5% (n = 15) or 1% (n = 17) YCA for 7 (n = 4/group), 14 (n = 3 or 4/group), 21 (n = 3 or 4/group) or 28 (n = 5/group) d. At the end of the feeding periods, whole blood was collected and the isolated RNA was analyzed for the expression of 84 genes involved in innate and cell-mediated adaptive immune responses. Three bacterial pattern recognition receptors TLR1 (0.5%: + 2.01; 1%: + 2.38), TLR6 (0.5%: + 2.11; 1%: + 2.34) and NOD2 (0.5%: + 2.32; 1%: + 2.23), two APC surface receptors CD1D1 (0.5%: + 1.75; 1%: + 2.33) and CD80 (0.5%: +2.45; 1%: +3.00), and the cell signaling molecule MAPK8 (0.5%: +1.87; 1%: +2.35) were significantly up-regulated by YCA at both inclusion rates. In conclusion, feeding YCA may potentially increase recognition and responses to bacterial pathogens and T-cell activation and differentiation and thereby maintain health and prevent production losses.

Lymphocyte proliferative responses in dairy cows supplemented with an immunomodulatory feed additive and administered polyvalent vaccination

“…Our hypothesis is supported by some previous findings in murine models (Branson et al, 2016) and ruminants (Wang et al, 2009). For instance, this feed additive has the ability to modulate the production of interleukin (IL)-1β (Wang et al, 2009), a pro-inflammatory cytokine, which affords an important linkage between innate and adaptive immune responses by providing an activating signal for lymphocyte proliferation (Murphy and Weaver, 2008).…”

“…For instance, this feed additive has the ability to modulate the production of interleukin (IL)-1β (Wang et al, 2009), a pro-inflammatory cytokine, which affords an important linkage between innate and adaptive immune responses by providing an activating signal for lymphocyte proliferation (Murphy and Weaver, 2008). Indeed, our hypothesis was strengthened by the finding of increased expression of genes involved in cellmediated adaptive immune response, such as the induction of CD1D1 and CD80 antigen presenting receptors, and a trend toward up-regulation of CD86, which in turn may activate naïve T cells, resulting in the stimulation of responsive B cells to proliferate and differentiate into plasma cells (Branson et al, 2016). To further investigate this scenario, the present study aimed to evaluate the effect of dietary OmniGen-AF ® supplementation on lymphocyte proliferation in dairy cows under vaccination.…”

“…OmniGen-AF ® is a commercially available, patented, proprietary, branded feed additive that exerts immunomodulatory effects in nonruminant (Branson et al, 2016) and ruminant species (Wang et al, 2009;Nace et al, 2014;Brandão et al, 2016). Therefore, there are many gaps in the understanding of how this feed additive acts on the immune system.…”

A natural bioactive feed additive alters expression of genes involved in inflammation in whole blood of healthy Angus heifers

“…Previous work conducted with OG showed a diverse in vivo response, including a decrease of a variety of infectious and metabolic adverse health conditions. 40 The role of OG supporting innate immune pathways has also been identified in model animals; 13 however, the current study is our first to measure the effect of OG supplementation of signaling pathways involved in the innate immune response. It is possible that the regulation of general, highly conserved pathways regulated in this study during the feeding period could explain the general improvements in animal health of OG-supplemented cattle (i.e.…”

“…Cattle were allowed a 7-d acclimatization period and then were randomly divided into two treatment groups: control animals (no additive) and the proprietary IFA OG (56 g/hd/d top-dressed; OmniGen-AF® Phibro Animal Health Corporation, Teaneck, NJ), which comprised a blend of ingredients that include silicon dioxide, aluminosilicate, dehydrated Saccharomyces cerevisiae , fermentation product of the fungus Trichoderma longibrachiatum , B complex vitamins, choline, and vitamin K precursors. 13…”