Stabilin-1 plays a protective role against Listeria monocytogenes infection through the regulation of cytokine and chemokine production and immune cell recruitment

Abstract

Scavenger receptors are part of a complex surveillance system expressed by host cells to efficiently orchestrate innate immune response against bacterial infections. Stabilin-1 (STAB-1) is a scavenger receptor involved in cell trafficking, inflammation, and cancer; however, its role in infection remains to be elucidated. <i>Listeria monocytogenes</i> (<i>Lm</i>) is a major intracellular human food-borne pathogen causing severe infections in susceptible hosts. Using a mouse model of infection, we demonstrate here that STAB-1 controls <i>Lm</i>-induced cytokine and chemokine production and immune cell accumulation in <i>Lm</i>-infected organs. We show that STAB-1 also regulates the recruitment of myeloid cells in response to <i>Lm</i> infection and contributes to clear circulating bacteria. In addition, whereas STAB-1 appears to promote bacterial uptake by macrophages, infection by pathogenic <i>Listeria</i> induces the down regulation of STAB-1 expression and its delocalization from the host cell membrane.We propose STAB-1 as a new SR involved in the control of <i>Lm</i> infection through the regulation of host defense mechanisms, a process that would be targeted by bacterial virulence factors to promote infection.