IDM PhD & MS Journal Club

Matthew Good, MS Student / Mailliard Lab

Wednesday 3/1 12:00PM - 1:00PM
A719 Public Health
Remzi Onur Eren, Marta Reverte, Matteo Rossi.  Mammalian Innate Immune Response to a Leishmania-Resident RNA Virus Increases Macrophage Survival to Promote Parasite Persistence.  Cell Host & Microbe 20:318–328,2016.

Some strains of the protozoan parasite Leishmania guyanensis (L.g) harbor a viral endosymbiont called
Leishmania RNA virus 1 (LRV1). LRV1 recognition by TLR-3 increases parasite burden and lesion swelling in vivo. However, the mechanisms by which anti-viral innate immune responses affect parasitic infection are largely unknown. Upon investigating the mammalian host’s response to LRV1, we found that miR-155 was singularly and strongly upregulated in macrophages infected with LRV1+ L.g when compared to LRV1 L.g. LRV1-driven miR-155 expression was dependent on TLR-3/TRIF signaling. Furthermore, LRV1-induced TLR-3 activation promoted parasite persistence by enhancing macrophage survival through Akt activation in a
manner partially dependent on miR-155. Pharmacological inhibition of Akt resulted in a decrease in LRV1- mediated macrophage survival and consequently decreased parasite persistence. Consistent with these data, miR-155-deficient mice showed a drastic decrease in LRV1-induced disease severity, and lesional macrophages from these mice displayed reduced levels of Akt phosphorylation.

Last Updated On Tuesday, February 28, 2017 by Malenka, Judith Ann
Created On Tuesday, January 3, 2017