[HTML][HTML] Host-derived oxidized phospholipids and HDL regulate innate immunity in human leprosy

D Cruz, AD Watson, CS Miller… - The Journal of …, 2008 - Am Soc Clin Investig
D Cruz, AD Watson, CS Miller, D Montoya, MT Ochoa, PA Sieling, MA Gutierrez, M Navab
The Journal of clinical investigation, 2008Am Soc Clin Investig
Intracellular pathogens survive by evading the host immune system and accessing host
metabolic pathways to obtain nutrients for their growth. Mycobacterium leprae, the causative
agent of leprosy, is thought to be the mycobacterium most dependent on host metabolic
pathways, including host-derived lipids. Although fatty acids and phospholipids accumulate
in the lesions of individuals with the lepromatous (also known as disseminated) form of
human leprosy (L-lep), the origin and significance of these lipids remains unclear. Here we …
Intracellular pathogens survive by evading the host immune system and accessing host metabolic pathways to obtain nutrients for their growth. Mycobacterium leprae, the causative agent of leprosy, is thought to be the mycobacterium most dependent on host metabolic pathways, including host-derived lipids. Although fatty acids and phospholipids accumulate in the lesions of individuals with the lepromatous (also known as disseminated) form of human leprosy (L-lep), the origin and significance of these lipids remains unclear. Here we show that in human L-lep lesions, there was preferential expression of host lipid metabolism genes, including a group of phospholipases, and that these genes were virtually absent from the mycobacterial genome. Host-derived oxidized phospholipids were detected in macrophages within L-lep lesions, and 1 specific oxidized phospholipid, 1-palmitoyl-2-(5,6-epoxyisoprostane E2)-sn-glycero-3-phosphorylcholine (PEIPC), accumulated in macrophages infected with live mycobacteria. Mycobacterial infection and host-derived oxidized phospholipids both inhibited innate immune responses, and this inhibition was reversed by the addition of normal HDL, a scavenger of oxidized phospholipids, but not by HDL from patients with L-lep. The accumulation of host-derived oxidized phospholipids in L-lep lesions is strikingly similar to observations in atherosclerosis, which suggests that the link between host lipid metabolism and innate immunity contributes to the pathogenesis of both microbial infection and metabolic disease.
The Journal of Clinical Investigation