[Is macrophage polarization the Gordian knot of bacterial infections?].
Converging studies show that M1 and M2 macrophages are functionally polarized in response to host mediators. Gene expression profiling of macrophages reveals that various bacteria induce the transcriptional activity of a common host response that includes genes belonging to the M1 program. The microbicidal machinery of M1 macrophages allows them to participate to the clearing of acute infections. However, excessive or prolonged M1 polarization can lead to tissue injury and contribute to pathogenesis. The so-called M2 macrophages play a critical role in the resolution of inflammation by producing anti-inflammatory mediators. These M2 macrophages cover a continuum of cells with different phenotypic and functional properties. Different bacterial pathogens escape from clearing by manipulating functions of M1 macrophages. It has recently been demonstrated that specific M2 programs induced in macrophages by bacterial pathogens are associated with the chronic evolution of infectious diseases.
Unité de recherche sur les maladies infectieuses transmissibles et émergentes, CNRS-IRD UMR 6236, Université de la Méditerranée, 27, boulevard Jean Moulin, 13385 Marseille Cedex 5, France. jean-louis.mege@medecine.univ-mrs.fr
Jean-Louis
JL
Mege
Christian
C
Capo
D000208:Acute Disease; D000818:Animals; D001424:Bacterial Infections / Q000276:immunology*; D002908:Chronic Disease; D016207:Cytokines / Q000494:pharmacology / Q000502:physiology; D018450:Disease Progression; D004790:Enzyme Induction; D020869:Gene Expression Profiling; D006801:Humans; D007249:Inflammation / Q000276:immunology; D008262:Macrophage Activation / Q000187:drug effects / Q000235:genetics; D008264:Macrophages / Q000145:classification / Q000187:drug effects / Q000276:immunology*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D051193:Toll-Like Receptors / Q000819:agonists
D016207:Cytokines; D051193:Toll-Like Receptors; D052247:Nitric Oxide Synthase Type II