Seeing strangers or announcing "danger": galectin-3 in two models of innate immunity.

Recent investigations on the molecular mechanisms by which our immune system recognizes infections and initiates defense against those infections have led to the proposition of two models explaining the way our innate immunity system functions; the self-nonself model and the Danger model. In this review, the roles of galectin-3 in innate immunity against infections--host-pathogen interactions--will be discussed. We will shed light on the potential contribution of a beta-galactoside binding mammalian lectin, galectin-3 as a molecule implicated in innate immunity from the angle of both the self-nonself model and the Danger model.