Analyzing classical and alternative macrophage activation in macrophage/neutrophil-specific IL-4 receptor-alpha-deficient mice.

Macrophage activation can be divided into a classical and an alternative pathway. Interferon-gamma-induced, classically activated macrophages are indispensable for protective effector responses against intracellular pathogens. However, excessive inflammatory immune responses mediated by classical macrophage activation can also be detrimental to the host.