T helper 3 cell

Th3 cell

T helper 3 (Th3) cells are a subset of CD4+ T cells that play a crucial role in the immune system's regulation, particularly in the context of autoimmune diseases and mucosal immunity. Unlike their more well-known counterparts, T helper 1 (Th1) cells and T helper 2 (Th2) cells, which are involved in cell-mediated and humoral immunity, respectively, Th3 cells are primarily recognized for their regulatory functions and their secretion of transforming growth factor-beta (TGF-β) and interleukin-10 (IL-10).

Function

Th3 cells are essential in maintaining immune tolerance and preventing autoimmune responses. They achieve this by producing anti-inflammatory cytokines such as TGF-β and IL-10, which can suppress the activity of Th1 and Th2 cells, thereby reducing inflammation and tissue damage. TGF-β, in particular, plays a critical role in the induction of regulatory T cells (Tregs), which further contribute to immune tolerance.

In the context of mucosal immunity, Th3 cells are involved in the regulation of immune responses at mucosal surfaces, such as the gastrointestinal tract. This is crucial for preventing excessive immune reactions to dietary antigens and commensal bacteria, which could lead to chronic inflammation and diseases such as inflammatory bowel disease (IBD).

Development

The development of Th3 cells is influenced by the local environment and the presence of specific cytokines. TGF-β is a key factor in the differentiation of naive CD4+ T cells into Th3 cells. The process is also modulated by other factors, including the nature of the antigen and the presence of other immune cells.

Clinical Significance

Th3 cells have been a focus of research for their potential therapeutic applications in autoimmune diseases and allergies. By enhancing the function of Th3 cells or their production of TGF-β and IL-10, it may be possible to suppress pathological immune responses that underlie these conditions. Additionally, understanding the mechanisms that regulate Th3 cell differentiation and function could lead to new strategies for promoting immune tolerance in transplantation and treating autoimmune diseases.

See Also

• T cell
• Regulatory T cell
• Autoimmune disease
• Mucosal immunity
• Cytokine