Th1 and Th17 Immune Responses Act Complementarily to Optimally Control Superficial Dermatophytosis

Area of Science:

• Immunology
• Mycology
• Dermatology

Background:

• Dermatophytoses are common worldwide fungal infections.
• The immune response to dermatophytoses is not well understood.

Purpose of the Study:

• To investigate the role of T-cell receptor (TCR)-mediated immunity in controlling superficial dermatophytosis.
• To elucidate the specific contributions of Th1 and Th17 immune responses and their associated cytokines (IFN-γ and IL-17A) in fungal clearance and recovery.

Main Methods:

• Comparison of Trichophyton benhamiae infection in wild-type and Rag2^-/- mice.
• Analysis of CD4+ T cell differentiation (Th1 and Th17) in skin-draining lymph nodes.
• Assessment of fungal clearance and clinical recovery in IL-17A-deficient, IFN-γ-deficient, and double-deficient mice.

Main Results:

• TCR-mediated immunity is essential for fungal clearance and clinical recovery from dermatophytosis.
• Both Th1 and Th17 immune responses are activated during infection.
• IL-17A and IFN-γ are individually dispensable but cooperatively contribute to optimal dermatophytosis resolution.
• Double-deficient mice showed significantly impaired fungal clearance and recovery compared to single-deficient mice.

Conclusions:

• TCR-mediated adaptive immunity is critical for controlling superficial dermatophytosis.
• Immune responses are polarized towards both Th1 and Th17 pathways.
• The Th17 response is key for direct fungal clearance, while the Th1 response aids in clearance and modulates Th17-driven inflammation.