 One mode of action of this drug is to protect and stimulate the innate immune system, also called the nonspecific immune system, and the first line of defense.According to a study published in the Journal of Immunology and reflected in a press release by Hemispherx, Rintatolimod protects and stimulates the innate immune system by binding to Toll-like receptors 3 (TLR-3), and activating the TLR-3 receptors for broad-spectrum immune response.TLR-3 receptors are located intracellular at the membranes of endosomes.