polyinosine-polycytidylic acid

Polyinosine-polycytidylic acid is a **synthetic double-stranded polyribonucleotide** comprised of one polymer strand of inosinic acid and one of cytidylic acid. It acts as a **synthetic analog of viral double-stranded RNA** and is a potent immunostimulant, widely used in immunological research and as an adjuvant. Poly(I:C) potently activates **Toll-like receptor 3 (TLR3)**, which is found mainly in endosomal membranes of immune cells such as dendritic cells, macrophages, and B cells. By mimicking viral infection, it induces **innate immune responses**, leading to production of **type I interferons (IFN-α, IFN-β)** and proinflammatory cytokines, and activates endothelial cells to express adhesion molecules and chemokines that promote leukocyte recruitment. It is investigated for use as a vaccine adjuvant, as an immunomodulator, and in cancer therapy, but systemic use is limited by toxicity. Variants such as polyICLC (Hiltonol) are used in clinical trials for improved stability and tolerability[1][2][5][8][9].

Brand names

Hiltonol

Other names

polyinosinic-polycytidylic acidpolyinosinic:polycytidylic acidpoly ICpolyriboinosinic-polyribocytidylic acidpolyinosinic-polycytidylic sodium salt