T-cell activation tool

Overview of T Cell Subsets

This article provides an overview of the major subsets of T cells, which are critical components of the adaptive immune system. T cells are broadly categorized by their surface markers and functions.

Major T Cell Subsets

The primary subsets are defined by the expression of CD4 or CD8 co-receptors.

CD4+ T Helper Cells

CD4+ T cells, often called helper T cells, orchestrate immune responses by activating other immune cells. They recognize antigens presented by MHC class II molecules.

• Th1 Cells: Primarily involved in cell-mediated immunity against intracellular pathogens.
• Th2 Cells: Important for humoral immunity and responses to parasites.
• Th17 Cells: Defend against extracellular bacteria and fungi and are involved in inflammation.
• Treg Cells (Regulatory T cells): Suppress immune responses to maintain tolerance.

CD8+ Cytotoxic T Cells

CD8+ T cells directly kill infected or cancerous cells. They recognize antigens presented by MHC class I molecules.

Other T Cell Types

Additional subsets have specialized roles.

Gamma Delta T Cells

These cells possess a distinct T cell receptor and bridge innate and adaptive immunity.

Memory T Cells

Memory T cells provide long-term immunity after an initial infection. They can be central memory or effector memory cells.

Summary Table of T Cell Subsets

Understanding these subsets is fundamental to immunology and has important implications for vaccine development and treating diseases.