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NK-, NKT- and CD8-Derived IFN? Drives Myeloid Cell Activation and Erythrophagocytosis, Resulting in Trypanosomosis-Associated Acute Anemia.

ABSTRACT: African trypanosomes are the causative agents of Human African Trypanosomosis (HAT/Sleeping Sickness) and Animal African Trypanosomosis (AAT/Nagana). A common hallmark of African trypanosome infections is inflammation. In murine trypanosomosis, the onset of inflammation occurs rapidly after infection and is manifested by an influx of myeloid cells in both liver and spleen, accompanied by a burst of serum pro-inflammatory cytokines. Within 48 hours after reaching peak parasitemia, acute anemia develops and the percentage of red blood cells drops by 50%. Using a newly developed in vivo erythrophagocytosis assay, we recently demonstrated that activated cells of the myeloid phagocytic system display enhanced erythrophagocytosis causing acute anemia. Here, we aimed to elucidate the mechanism and immune pathway behind this phenomenon in a murine model for trypanosomosis. Results indicate that IFN? plays a crucial role in the recruitment and activation of erythrophagocytic myeloid cells, as mice lacking the IFN? receptor were partially protected against trypanosomosis-associated inflammation and acute anemia. NK and NKT cells were the earliest source of IFN? during T. b. brucei infection. Later in infection, CD8+ and to a lesser extent CD4+ T cells become the main IFN? producers. Cell depletion and transfer experiments indicated that during infection the absence of NK, NKT and CD8+ T cells, but not CD4+ T cells, resulted in a reduced anemic phenotype similar to trypanosome infected IFN?R-/- mice. Collectively, this study shows that NK, NKT and CD8+ T cell-derived IFN? is a critical mediator in trypanosomosis-associated pathology, driving enhanced erythrophagocytosis by myeloid phagocytic cells and the induction of acute inflammation-associated anemia.

SUBMITTER: Cnops J

PROVIDER: S-EPMC4466398 | biostudies-literature | 2015 Jun

REPOSITORIES: biostudies-literature

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NK-, NKT- and CD8-Derived IFNγ Drives Myeloid Cell Activation and Erythrophagocytosis, Resulting in Trypanosomosis-Associated Acute Anemia.

Cnops Jennifer J De Trez Carl C Stijlemans Benoit B Keirsse Jiri J Kauffmann Florence F Barkhuizen Mark M Keeton Roanne R Boon Louis L Brombacher Frank F Magez Stefan S

PLoS pathogens 20150612 6

African trypanosomes are the causative agents of Human African Trypanosomosis (HAT/Sleeping Sickness) and Animal African Trypanosomosis (AAT/Nagana). A common hallmark of African trypanosome infections is inflammation. In murine trypanosomosis, the onset of inflammation occurs rapidly after infection and is manifested by an influx of myeloid cells in both liver and spleen, accompanied by a burst of serum pro-inflammatory cytokines. Within 48 hours after reaching peak parasitemia, acute anemia de ...[more]

PMID: 26070118

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Dataset Information

NK-, NKT- and CD8-Derived IFN? Drives Myeloid Cell Activation and Erythrophagocytosis, Resulting in Trypanosomosis-Associated Acute Anemia.

Publications

NK-, NKT- and CD8-Derived IFNγ Drives Myeloid Cell Activation and Erythrophagocytosis, Resulting in Trypanosomosis-Associated Acute Anemia.

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