In Vitro Th17-Polarized Human CD4 + T Cells Exacerbate Xenogeneic Graft-versus-Host Disease.

Acute graft-versus-host disease (aGVHD) is a severe complication of allogeneic hematopoietic stem cell transplantation. The role of Th17 cells in its pathophysiology remains a matter of debate. In this study, we assessed whether enrichment of human peripheral blood mononuclear cells (PBMCs) with in vitro Th17-polarized CD4 ⁺ T cells would exacerbate xenogeneic GVHD (xGVHD) into NOD-scid IL-2Rγ null (NSG) mice. Naive human CD4 ⁺ T cells were stimulated under Th17-skewing conditions for 8 to 10 days and then coinjected in NSG mice with fresh PBMCs from the same donor. We observed that Th17-polarized cells engrafted and migrated toward xGVHD target organs. They also acquired a double-expressing IL-17A ⁺ IFNγ ⁺ profile in vivo. Importantly, cotransfer of Th17-polarized cells (1 × 10 ⁶ ) with PBMCs (1 × 10 ⁶ ) exacerbated xGVHD compared with transplantation of PBMCs alone (2 × 10 ⁶ ). Furthermore, PBMC cotransfer with Th17-polarized cells was more potent for xGVHD induction than cotransfer with naive CD4 ⁺ T cells stimulated in nonpolarizing conditions (Th0 cells, 1 × 10 ⁶  + 1 × 10 ⁶ PBMCs) or with Th1-polarized cells (1 × 10 ⁶  + 1 × 10 ⁶ PBMCs). In summary, our results suggest that human Th17-polarized cells can cooperate with PBMCs and be pathogenic in the NSG xGVHD model.
(Copyright © 2018. Published by Elsevier Inc.)