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Interferon-mediated innate immune responses against malaria parasite liver stages

Interferon-mediated innate immune responses against malaria parasite liver stages
Published: 
Apr 2014
Publisher: 
Cell Rep. 2014 Apr 24;7(2):436-47
Author: 
Stefan H. Kappe, Ph.D.

Miller JL1, Sack BK1, Baldwin M1, Vaughan AM1, Kappe SH2.

Author information

  • 1Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA.
  • 2Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA; Department of Global Health, University of Washington, Seattle, WA 98195, USA. Electronic address: stefan.kappe@seattlebiomed.org.

Abstract

Mosquito-transmitted malaria parasites infect hepatocytes and asymptomatically replicate as liver stages. Using RNA sequencing, we show that a rodent malaria liver-stage infection stimulates a robust innate immune response including type I interferon (IFN) and IFNγ pathways. Liver-stage infection is suppressed by these infection-engendered innate responses. This suppression was abrogated in mice deficient in IFNγ, the type I IFN α/β receptor (IFNAR), and interferon regulatory factor 3. Natural killer and CD49b(+)CD3(+) natural killer T (NKT) cells increased in the liver after a primary infection, and CD1d-restricted NKT cells, which secrete IFNγ, were critical in reducing liver-stage burden of a secondary infection. Lack of IFNAR signaling abrogated the increase in NKT cell numbers in the liver, showing a link between type I IFN signaling, cell recruitment, and subsequent parasite elimination. Our findings demonstrate innate immune sensing of malaria parasite liver-stage infection and that the ensuing innate responses can eliminate the parasite.

Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.