The IL-27R (WSX-1) is required to suppress T cell hyperactivity during infection

Area of Science:

• Immunology
• T cell biology
• Infectious disease

Background:

• Interleukin-27 (IL-27) and its receptor WSX-1 are known to promote Th1 differentiation in naive CD4+ T cells.
• Previous research suggested a role for IL-27/WSX-1 signaling in initiating T cell responses.

Purpose of the Study:

• To investigate the role of WSX-1 signaling in regulating the intensity and duration of T cell activity during parasitic infection.
• To determine if WSX-1 is essential for generating protective immunity against Toxoplasma gondii.

Main Methods:

• Infection of WSX-1 deficient (WSX-1-/-) mice and wild-type controls with the intracellular pathogen Toxoplasma gondii.
• Analysis of T cell responses, including cytokine production (e.g., IFN-gamma), T cell activation, and proliferation in vivo.
• Assessment of parasite replication and survival in infected mice.

Main Results:

• WSX-1-/- mice established protective T cell responses and controlled parasite replication initially.
• However, WSX-1-/- mice failed to downregulate these responses, leading to lethal T cell-mediated inflammatory disease.
• Pathology in WSX-1-/- mice was marked by excessive IFN-gamma production, persistent T cell activation, and enhanced T cell proliferation.

Conclusions:

• WSX-1 signaling is not required for the generation of IFN-gamma-mediated immunity against Toxoplasma gondii.
• WSX-1 acts as a crucial antagonist of T cell-mediated immune hyperactivity, limiting the intensity and duration of T cell responses.
• Dysregulation of WSX-1 signaling can lead to detrimental immune overactivity and severe inflammatory pathology.