Figure 3.

Signaling pathway for yeast β-glucans in teleost fish organisms. Proposed scheme of the β-glucan activation pathway in fish. (1) Intestinal epithelial enterocytes synthesize metabolic proteins activated by yeast β-glucan that secretes them into the systemic circulation. (2) Recognition of β-glucan by pathogen-associated molecular pattern receptors (PAMPs) that generate innate cellular immune responses and gene expression through translocation of the nuclear factor kappa beta (NF-κB) by phosphorylation, ubiquitination, and protein degradation. (3) Production of pro- and anti-inflammatory cytokines, receptors, and other proteins that activate the communication and activity of the adaptive immune system. (4) Production of immunoglobulins by B cells activated by the recognition of β-glucan.