IL-6 Protein, Equine

IL-6, a multifunctional cytokine, exerts diverse biological effects in immunity, tissue regeneration, and metabolism. Upon binding to its receptor, IL6R, the complex associates with the signaling subunit IL6ST/gp130, initiating the intracellular IL6-signaling pathway. This interaction can elicit 'classic signaling' when IL6 binds to membrane-bound IL6R, or 'trans-signaling' when IL6 and soluble IL6R engage IL6ST. Additionally, 'cluster signaling' occurs when IL6:IL6R complexes on transmitter cells activate IL6ST receptors on neighboring receiver cells. IL-6 is a crucial inducer of the acute phase response, rapidly produced during infection and tissue injury for host defense. However, excessive IL-6 synthesis is implicated in various disease pathologies. In the innate immune response, myeloid cells, including macrophages and dendritic cells, synthesize IL-6 upon recognizing pathogens through toll-like receptors (TLRs) at infection sites or tissue injuries. In the adaptive immune response, IL-6 is essential for B cell differentiation into immunoglobulin-secreting cells, T follicular helper (Tfh) cell development, and driving naive CD4(+) T cells toward the Th17 lineage. Furthermore, IL-6 plays a significant role in myeloma cell proliferation and the survival of plasmablast cells.