Interleukin‐4 Induces Coxiella burnetii Replication in Human Monocytes but not in Macrophages
2003; Wiley; Volume: 990; Issue: 1 Linguagem: Inglês
10.1111/j.1749-6632.2003.tb07410.x
ISSN1749-6632
AutoresÉric Ghigo, Guenièvre Imbert, Christian Capo, Didier Raoult, Jean‐Louis Mège,
Tópico(s)Yersinia bacterium, plague, ectoparasites research
ResumoA bstract : Coxiella burnetii , an obligate intracellular bacterium, is the agent of Q fever. The chronic disease is characterized by impaired cell‐mediated immune response and microbicidal activity of monocytes. We hypothesized that interleukin(IL)‐4, a Th2 cytokine, interferes with the fate of C. burnetii inside monocytes. C. burnetii survived without multiplication in resting monocytes, but replicated in IL‐4‐treated monocytes. The effect of IL‐4 is specific for monocytes since IL‐4 did not stimulate C. burnetii replication in monocyte‐derived macrophages. The effects of IL‐4 on bacterial replication and on tumor necrosis factor (TNF) production in monocytes were apparently not related. Although IL‐4 inhibited C. burnetii ‐stimulated release of TNF, the addition of recombinant TNF to IL‐4‐treated monocytes did not prevent the IL‐4 effect. These results suggest that IL‐4 enables monocytes to support C. burnetii replication and a Th2 polarization of immune response that may interfere with immune control of Q fever.
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