T Helper 17 Cell

**Semantic type:** Cell

**Definition:** A subset of helper T-lymphocytes which synthesize and secrete the interleukins (IL), IL-17A, -21 and -22. These cytokines mediate inflammation by increasing chemokine production, which leads to the recruitment of both monocytes and neutrophils to sites of infection or inflammation. Th17 cells modulate both host immunity against extracellular bacteria and fungi and inflammation. Overexpression of these cells is associated with tissue injury caused by autoimmune diseases.

**Synonyms:** - Th17 - Th17 Cell - Th17 cells