Type 2 immunity and wound healing: evolutionary refinement of adaptive immunity by helminths

Abstract

In this Opinion, the authors provide their perspective on how the type 2 immune response may have evolved and how it functions to mediate both resistance and tolerance to tissue-destructive helminths. They propose that the damage induced during helminth migration and the subsequent need for tissue repair have been major factors in driving the evolution of the type 2 response. Helminth-induced type 2 immune responses, which are characterized by the T helper 2 cell-associated cytokines interleukin-4 (IL-4) and IL-13, mediate host protection through enhanced tissue repair, the control of inflammation and worm expulsion. In this Opinion article, we consider type 2 immunity in the context of helminth-mediated tissue damage. We examine the relationship between the control of helminth infection and the mechanisms of wound repair, and we provide a new understanding of the adaptive type 2 immune response and its contribution to both host tolerance and resistance.