The Three Levels of Immunity in the Animal: A Case of a Good Defense Preventing Too Much Offense (and Damage)

摘要

Mucosal immune responses involve the immune modulation of the mucosa epithelial cells. These cells respond to microbial produced ligands and metabolites and modulate the immune response. They regulate anti-inflammatory response and regulatory environment to prevent overreaction of the pro-inflammatory response. Macrophages in the lamina propria are particularly sensitive to signals from gut bacteria including endotoxin from gram-negative bacteria to induce pro-inflammatory responses. With changes diet that occur at weaning or at parturition, the microflora population changes are considerable. This is where immune homeostasis is important-maintaining a balance between anti-inflammatory response of the mucosa and the pro-inflammatory response needed for the innate immune system to respond. This combination of adipose remodeling, macrophage activation and microflora can result in a cytokine storm. A cytokine storm (hypercytokinemia) is the systemic expression of a healthy and vigorous immune system resulting in the release of more than 150 known inflammatory mediators (cytokines, oxygen free radicals, and coagulation factors). It is an overreaction of the immune system. Both pro-inflammatory cytokines [such as tumor necrosis factor-alpha (TNF-alpha),interleukin-1, and Interleukin-6] and anti-inflammatory cytokines (such as interleukin 10 and interleukin 1 receptor antagonist) are elevated in the serum of people or animals experiencing a cytokine storm. In this case, a healthy immune system may be aliability rather than an asset. An experimental approach in cattle to study these interactions will be discussed along with the proof of concept immunological measurements. Studying specific localized responses will require novel approaches.