هاپتن

Also known as hapten

Haptens (derived from the Greek haptein, meaning “to fasten”) are small molecules that elicit an immune response only when attached to a large carrier such as a protein; the carrier may be one that also does not elicit an immune response by itself. The mechanisms of absence of immune response may vary and involve complex immunological interactions, but can include absent or insufficient co-stimulatory signals from antigen-presenting cells. thumb|445x445px|Attaching of haptens to a carrier molecule lead to a complete antigen.