IL-22 dampens the T cell response in experimental malaria

Sci Rep. 2016 Jun 17:6:28058. doi: 10.1038/srep28058.

Abstract

A tight regulation between the pro- and anti-inflammatory immune responses during plasmodial infection is of crucial importance, since a disruption leads to severe malaria pathology. IL-22 is a member of the IL-10 cytokine family, which is known to be highly important in immune regulation. We could detect high plasma levels of IL-22 in Plasmodium falciparum malaria as well as in Plasmodium berghei ANKA (PbA)-infected C57BL/6J mice. The deficiency of IL-22 in mice during PbA infection led to an earlier occurrence of cerebral malaria but is associated with a lower parasitemia compared to wt mice. Furthermore, at an early time point of infection T cells from PbA-infected Il22(-/-) mice showed an enhanced IFNγ but a diminished IL-17 production. Moreover, dendritic cells from Il22(-/-) mice expressed a higher amount of the costimulatory ligand CD86 upon infection. This finding can be corroborated in vitro since bone marrow-derived dendritic cells from Il22(-/-) mice are better inducers of an antigen-specific IFNγ response by CD8(+) T cells. Even though there is no IL-22 receptor complex known on hematopoietic cells, our data suggest a link between IL-22 and the adaptive immune system which is currently not identified.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B7-2 Antigen / metabolism
  • Bone Marrow Cells / cytology
  • CD8-Positive T-Lymphocytes / cytology
  • CD8-Positive T-Lymphocytes / drug effects
  • CD8-Positive T-Lymphocytes / immunology*
  • Cells, Cultured
  • Dendritic Cells / cytology
  • Dendritic Cells / drug effects
  • Dendritic Cells / metabolism
  • Erythrocytes / cytology
  • Erythrocytes / metabolism
  • Interferon-gamma / metabolism
  • Interleukin-17 / metabolism
  • Interleukin-22
  • Interleukins / blood
  • Interleukins / deficiency
  • Interleukins / genetics*
  • Lipopolysaccharides / toxicity
  • Malaria / immunology
  • Malaria / mortality
  • Malaria / pathology*
  • Malaria / veterinary
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Parasitemia / parasitology
  • Parasitemia / pathology
  • Plasmodium berghei / immunology
  • Plasmodium berghei / physiology*
  • RNA, Protozoan / isolation & purification
  • RNA, Protozoan / metabolism
  • Spleen / cytology
  • Spleen / metabolism
  • Spleen / pathology
  • Survival Rate

Substances

  • B7-2 Antigen
  • Interleukin-17
  • Interleukins
  • Lipopolysaccharides
  • RNA, Protozoan
  • Interferon-gamma