TY - JOUR
T1 - Rapid loss of group 1 innate lymphoid cells during blood stage Plasmodium infection
AU - Ng, Susanna S.
AU - Souza-Fonseca-Guimaraes, Fernando
AU - Rivera, Fabian De Labastida
AU - Amante, Fiona H.
AU - Kumar, Rajiv
AU - Gao, Yulong
AU - Sheel, Meru
AU - Beattie, Lynette
AU - Montes De Oca, Marcela
AU - Guillerey, Camille
AU - Edwards, Chelsea L.
AU - Faleiro, Rebecca J.
AU - Frame, Teija
AU - Bunn, Patrick T.
AU - Vivier, Eric
AU - Godfrey, Dale I.
AU - Pellicci, Daniel G.
AU - Lopez, J. Alejandro
AU - Andrews, Katherine T.
AU - Huntington, Nicholas D.
AU - Smyth, Mark J.
AU - McCarthy, James
AU - Engwerda, Christian R.
N1 - Publisher Copyright:
© 2018 The Authors. Clinical & Translational Immunology published by John Wiley & Sons Australia, Ltd on behalf of Australasian Society for Immunology Inc.
PY - 2018
Y1 - 2018
N2 - Objectives: Innate lymphoid cells (ILCs) share many characteristics with CD4+ T cells, and group 1 ILCs share a requirement for T-bet and the ability to produce IFNγ with T helper 1 (Th1) cells. Given this similarity, and the importance of Th1 cells for protection against intracellular protozoan parasites, we aimed to characterise the role of group 1 ILCs during Plasmodium infection. Methods: We quantified group 1 ILCs in peripheral blood collected from subjects infected with with Plasmodium falciparum 3D7 as part of a controlled human malaria infection study, and in the liver and spleens of PcAS-infected mice. We used genetically-modified mouse models, as well as cell-depletion methods in mice to characterise the role of group 1 ILCs during PcAS infection. Results: In a controlled human malaria infection study, we found that the frequencies of circulating ILC1s and NK cells decreased as infection progressed but recovered after volunteers were treated with antiparasitic drug. A similar observation was made for liver and splenic ILC1s in P. chabaudi chabaudi AS (PcAS)-infected mice. The decrease in mouse liver ILC1 frequencies was associated with increased apoptosis. We also identified a population of cells within the liver and spleen that expressed both ILC1 and NK cell markers, indicative of plasticity between these two cell lineages. Studies using genetic and cell-depletion approaches indicated that group 1 ILCs have a limited role in antiparasitic immunity during PcAS infection in mice. Discussion: Our results are consistent with a previous study indicating a limited role for natural killer (NK) cells during Plasmodium chabaudi infection in mice. Additionally, a recent study reported the redundancy of ILCs in humans with competent B and T cells. Nonetheless, our results do not rule out a role for group 1 ILCs in human malaria in endemic settings given that blood stage infection was initiated intravenously in our experimental models, and thus bypassed the liver stage of infection, which may influence the immune response during the blood stage. Conclusion: Our results show that ILC1s are lost early during mouse and human malaria, and this observation may help to explain the limited role for these cells in controlling blood stage infection. In a controlled human malaria infection study, we found that the frequencies of circulating ILC1s and NK cells decreased as infection progressed, but recovered after volunteers were treated with antiparasitic drug. A similar observation was made for liver and splenic ILC1s in P. chabaudi chabaudi AS (PcAS)-infected mice. Studies using genetic and cell-depletion approaches indicated that group 1 ILCs have a limited role in antiparasitic immunity during PcAS infection in mice.
AB - Objectives: Innate lymphoid cells (ILCs) share many characteristics with CD4+ T cells, and group 1 ILCs share a requirement for T-bet and the ability to produce IFNγ with T helper 1 (Th1) cells. Given this similarity, and the importance of Th1 cells for protection against intracellular protozoan parasites, we aimed to characterise the role of group 1 ILCs during Plasmodium infection. Methods: We quantified group 1 ILCs in peripheral blood collected from subjects infected with with Plasmodium falciparum 3D7 as part of a controlled human malaria infection study, and in the liver and spleens of PcAS-infected mice. We used genetically-modified mouse models, as well as cell-depletion methods in mice to characterise the role of group 1 ILCs during PcAS infection. Results: In a controlled human malaria infection study, we found that the frequencies of circulating ILC1s and NK cells decreased as infection progressed but recovered after volunteers were treated with antiparasitic drug. A similar observation was made for liver and splenic ILC1s in P. chabaudi chabaudi AS (PcAS)-infected mice. The decrease in mouse liver ILC1 frequencies was associated with increased apoptosis. We also identified a population of cells within the liver and spleen that expressed both ILC1 and NK cell markers, indicative of plasticity between these two cell lineages. Studies using genetic and cell-depletion approaches indicated that group 1 ILCs have a limited role in antiparasitic immunity during PcAS infection in mice. Discussion: Our results are consistent with a previous study indicating a limited role for natural killer (NK) cells during Plasmodium chabaudi infection in mice. Additionally, a recent study reported the redundancy of ILCs in humans with competent B and T cells. Nonetheless, our results do not rule out a role for group 1 ILCs in human malaria in endemic settings given that blood stage infection was initiated intravenously in our experimental models, and thus bypassed the liver stage of infection, which may influence the immune response during the blood stage. Conclusion: Our results show that ILC1s are lost early during mouse and human malaria, and this observation may help to explain the limited role for these cells in controlling blood stage infection. In a controlled human malaria infection study, we found that the frequencies of circulating ILC1s and NK cells decreased as infection progressed, but recovered after volunteers were treated with antiparasitic drug. A similar observation was made for liver and splenic ILC1s in P. chabaudi chabaudi AS (PcAS)-infected mice. Studies using genetic and cell-depletion approaches indicated that group 1 ILCs have a limited role in antiparasitic immunity during PcAS infection in mice.
KW - inflammation
KW - natural killer cells
KW - parasitic-protozoan
UR - http://www.scopus.com/inward/record.url?scp=85045305569&partnerID=8YFLogxK
U2 - 10.1002/cti2.1003
DO - 10.1002/cti2.1003
M3 - Article
SN - 2050-0068
VL - 7
JO - Clinical and Translational Immunology
JF - Clinical and Translational Immunology
IS - 1
M1 - e1003
ER -