Defining Th-cell subsets in a classical and tissue-specific manner: Examples from the skin.

Area of Science:

• Immunology
• Cell Biology
• Dermatology

Background:

• T helper (Th) cells are crucial for adaptive immunity and implicated in numerous diseases.
• The Th cell family has expanded beyond Th1 and Th2 to include Th9, Th17, Th22, and regulatory T (Treg) cells.
• Current classification relies on signature cytokine expression, but novel Th cell subsets challenge this paradigm.

Purpose of the Study:

• To review diverse T helper cell classification approaches, detailing their strengths and weaknesses.
• To highlight the functional characteristics of distinct Th subsets and their associated cytokines.
• To focus on the role of Th cells and their cytokines in tissue and disease contexts, particularly inflammatory skin diseases.

Main Methods:

• Literature review of T helper cell classification strategies.
• Analysis of functional properties and cytokine profiles of different Th subsets.
• Examination of Th cell involvement in various disease settings, with emphasis on skin inflammation.

Main Results:

• Traditional cytokine-based classification faces limitations with the discovery of new Th cell populations.
• Distinct Th subsets possess unique functional capabilities and effector cytokines.
• Th cells play significant roles in the pathogenesis of inflammatory skin conditions.

Conclusions:

• The expanding landscape of T helper cells necessitates a re-evaluation of current classification systems.
• Understanding the nuanced functions of Th subsets is critical for comprehending immune responses in health and disease.
• Further research into Th cell subsets, particularly in inflammatory skin diseases, is warranted.