Hemozoin-induced IFN-γ production mediates innate immune protection against sporozoite infection

Adriano Franco; Yevel Flores-Garcia; Jarrett Venezia; Abdel Daoud; Alan L Scott; Fidel Zavala; David J Sullivan

doi:10.1016/j.micinf.2024.105343

Hemozoin-induced IFN-γ production mediates innate immune protection against sporozoite infection

Microbes Infect. 2024 Apr 24:105343. doi: 10.1016/j.micinf.2024.105343. Online ahead of print.

Authors

Adriano Franco¹, Yevel Flores-Garcia¹, Jarrett Venezia¹, Abdel Daoud², Alan L Scott¹, Fidel Zavala¹, David J Sullivan³

Affiliations

¹ Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD, 21205, USA.
² Department of Pathology, Johns Hopkins School of Medicine, 720 Rutland Avenue, Baltimore, MD, 21205, USA.
³ Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD, 21205, USA. Electronic address: dsulliv7@jhmi.edu.

PMID: 38670216
DOI: 10.1016/j.micinf.2024.105343

Abstract

Hemozoin is a crystal synthesized by Plasmodium parasites during hemoglobin digestion in the erythrocytic stage. The hemozoin released when the parasites egress from the red blood cell, which is complexed with parasite DNA, is cleared from the circulation by circulating and tissue-resident monocytes and macrophages, respectively. Recently, we reported that intravenous administration of purified hemozoin complexed with Plasmodium berghei DNA (Hz^PbDNA) resulted in an innate immune response that blocked liver stage development of sporozoites that was dose-dependent and time-limited. Here, we further characterize the organismal, cellular, and molecular events associated with this protective innate response in the liver and report that a large proportion of the IV administered Hz^PbDNA localized to F4/80⁺ cells in the liver and that the rapid and strong protection against liver-stage development waned quickly such that by 1 week post-Hz^PbDNA treatment animals were fully susceptible to infection. RNAseq of the liver after IV administration of Hz^PbDNA demonstrated that the rapid and robust induction of genes associated with the acute phase response, innate immune activation, cellular recruitment, and IFN-γ signaling observed at day 1 was largely absent at day 7. RNAseq analysis implicated NK cells as the major cellular source of IFN-γ. In vivo cell depletion and IFN-γ neutralization experiments supported the hypothesis that tissue-resident macrophages and NK cells are major contributors to the protective response and the NK cell-derived IFN-γ is key to induction of the mechanisms that block sporozoite development in the liver. These findings advance our understanding of the innate immune responses that prevent liver stage malaria infection.

Keywords: Hemozoin; IFN-γ signaling; Liver stage protection; Macrophage; Malaria; NK cells.