CD4+ T-cell subsets in inflammatory diseases: beyond the Th1/Th2 paradigm

Area of Science:

• Immunology
• Cellular Biology

Background:

• CD4(+) T cells are vital for immune responses and inflammatory disease pathogenesis.
• Beyond T-helper 1 (Th1) and T-helper 2 (Th2) cells, subsets like Th17, Th9, T follicular-helper (Tfh), and T-regulatory (Treg) cells are increasingly recognized.

Purpose of the Study:

• To review the contribution of diverse T-helper cell subsets to immune-mediated inflammatory diseases.
• To explore the roles of these subsets in multiple sclerosis, psoriasis, and asthma.
• To discuss the plasticity and heterogeneity of T-helper cell subsets.

Main Methods:

• Review of current literature on T-helper cell subsets.
• Analysis of T-helper cell classification based on transcription factor expression.
• Discussion of molecular mechanisms driving T-helper cell plasticity.

Main Results:

• T-helper cell subsets exhibit heterogeneity, classified by transcription factor expression.
• Memory-type Th2 cells contribute to chronic type-2 immune diseases.
• Multiple T-helper subsets are implicated in multiple sclerosis, psoriasis, and asthma.

Conclusions:

• The Th1/Th2 balance model is insufficient to explain immune-mediated inflammatory diseases.
• A pathogenic T-helper population disease-induction model is proposed for disease induction and persistence.
• Understanding T-helper cell heterogeneity is crucial for disease etiology.