Altered donor P2X7 activity in human leukocytes correlates with P2RX7 genotype but does not affect the development of graft-versus-host disease in humanised mice

S R Adhikary; N J Geraghty; P Cuthbertson; R Sluyter; D Watson

doi:10.1007/s11302-019-09651-8

Altered donor P2X7 activity in human leukocytes correlates with P2RX7 genotype but does not affect the development of graft-versus-host disease in humanised mice

Purinergic Signal. 2019 Jun;15(2):177-192. doi: 10.1007/s11302-019-09651-8. Epub 2019 Apr 18.

Authors

S R Adhikary^{1

2

3}, N J Geraghty^{1

2

3}, P Cuthbertson^{1

2

3}, R Sluyter^{4

5

6}, D Watson^{7

8

9}

Affiliations

¹ School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia.
² Molecular Horizons, University of Wollongong, Wollongong, NSW, 2522, Australia.
³ Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia.
⁴ School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia. rsluyter@uow.edu.au.
⁵ Molecular Horizons, University of Wollongong, Wollongong, NSW, 2522, Australia. rsluyter@uow.edu.au.
⁶ Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia. rsluyter@uow.edu.au.
⁷ School of Chemistry and Molecular Bioscience, University of Wollongong, Wollongong, NSW, 2522, Australia. dwatson@uow.edu.au.
⁸ Molecular Horizons, University of Wollongong, Wollongong, NSW, 2522, Australia. dwatson@uow.edu.au.
⁹ Illawarra Health and Medical Research Institute, Wollongong, NSW, 2522, Australia. dwatson@uow.edu.au.

Abstract

Graft-versus-host disease (GVHD) is a life-threatening consequence of allogeneic haematopoietic stem cell transplantation, a curative therapy for haematological malignancies. The ATP-gated P2X7 receptor channel is implicated in the development of GVHD. P2X7 activity on human leukocytes can be influenced by gain-of-function (GOF) and loss-of-function (LOF) single nucleotide polymorphisms (SNPs) in the P2RX7 gene. In this study, the P2RX7 gene was sequenced in 25 human donors and the P2X7 activity on subsets of peripheral blood T cells, natural killer (NK) cells and monocytes was measured using an ATP-induced dye uptake assay. GOF and LOF SNPs representing 10 of the 17 known P2RX7 haplotypes were identified, and correlated with P2X7 activity on all leukocyte subsets investigated. Notably, invariant (i) NK T cells displayed the highest P2X7 activity amongst all cell types studied. To determine if donor P2X7 activity influenced the development of GVHD, immunodeficient NOD-SCID-IL2Rγ^null (NSG) mice were injected with human peripheral blood mononuclear cells isolated from donors of either GOF (hP2X7^GOF mice) or LOF (hP2X7^LOF mice) P2RX7 genotype. Both hP2X7^GOF and hP2X7^LOF mice demonstrated similar human leukocyte engraftment, and showed comparable weight loss, GVHD clinical score and overall survival. Donor P2X7 activity did not affect human leukocyte infiltration or GVHD-mediated tissue damage, or the relative expression of human P2X7 or human interferon-γ (hIFNγ) in tissues. Finally, hP2X7^GOF and hP2X7^LOF mice demonstrated similar concentrations of serum hIFNγ. This study demonstrates that P2X7 activity correlates with donor P2RX7 genotype on human leukocyte subsets important in GVHD development, but does not affect GVHD development in a humanised mouse model of this disease.

Keywords: Bone marrow transplantation; Humanised mice; Leukocyte; P2RX7 gene single nucleotide polymorphism; P2X7 receptor; Purinergic receptor; Xenogeneic graft-versus-host disease.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Genotype
Graft vs Host Disease / genetics*
Humans
Leukocytes, Mononuclear / metabolism
Mice
Mice, Inbred NOD
Mice, Knockout
Mice, SCID
Polymorphism, Single Nucleotide
Receptors, Purinergic P2X7 / genetics*
Receptors, Purinergic P2X7 / metabolism*

Substances

P2RX7 protein, human
Receptors, Purinergic P2X7