IL-27 Receptor Signaling on T cells Augments GVHD Severity through Enhancing Th1 Responses

Area of Science:

• Immunology
• Hematology
• Transplantation immunology

Background:

• Interleukin-27 (IL-27) is an IL-12 family cytokine with complex roles in immune responses.
• Its function in allogeneic hematopoietic stem cell transplantation (allo-HCT) and graft-versus-host disease (GVHD) remains unclear.
• Previous studies suggest IL-27 may have both pro-inflammatory and suppressive effects.

Purpose of the Study:

• To investigate the role of IL-27 receptor alpha (IL-27Rα) expressed on T cells in GVHD following allo-HCT.
• To determine the impact of IL-27Rα signaling on T cell effector functions in the context of allo-HCT.

Main Methods:

• Utilized three different MHC-mismatched murine models of allo-HCT.
• Assessed the effect of IL-27Rα expression on T cells in GVHD development and severity.
• Analyzed the impact of IL-27 administration on mortality post-allo-HCT.

Main Results:

• IL-27Rα expression on T cells exacerbated GVHD across all tested murine models.
• IL-27Rα signaling on T cells was essential for robust Th1 effector function.
• IL-27Rα promoted Th1 responses while inhibiting Th2 and T regulatory cell differentiation.
• IL-27 administration significantly increased mortality in the allo-HCT setting.

Conclusions:

• IL-27Rα signaling on T cells plays a critical role in promoting GVHD pathogenesis.
• Targeting IL-27Rα on T cells represents a potential therapeutic strategy to mitigate GVHD.
• The pro-GVHD effects of IL-27Rα signaling outweigh its suppressive functions in this model.