Targeting Th9 cells in autoimmune diseases: a narrative review

Area of Science:

• Immunology
• Molecular Biology

Background:

• T helper 9 (Th9) cells are a distinct effector T cell subset defined by Interleukin-9 (IL-9) production.
• Key transcription factors, PU.1 and IRF4, regulate the expression of the IL9 gene, influencing Th9 cell biology.

Purpose of the Study:

• To comprehensively review the intricate relationship between Th9 cells, their associated cytokines (IL-9), transcription factors (PU.1, IRF4), and 14 autoimmune diseases.
• To explore the regulatory mechanisms of intracellular and extracellular signaling pathways governing Th9 cell functions in autoimmunity.

Main Methods:

• Literature review synthesizing evidence from both in vivo and in vitro studies.
• Analysis of reported aberrant expression of IL-9, PU.1, and IRF4 in various inflammatory and autoimmune conditions.

Main Results:

• Th9 cells and their related molecules (IL-9, PU.1, IRF4) show aberrant expression in numerous autoimmune diseases.
• Functional analyses confirm significant roles of these factors in the pathogenesis of autoimmune conditions.

Conclusions:

• Th9 cell-related factors are critically involved in the development and progression of autoimmune diseases.
• Understanding these pathways may pave the way for novel therapeutic strategies targeting Th9 cells in clinical settings.