Levamisole : old drug in new clothes
Frane Božić, Jelena Šuran, Ivica Valpotić, Maja Popović, Gordana Lacković · 2008
Levamisole 2, 3, 5, 6-tetrahydro-6-phenylimidazole (2, 1-b) thiazole, a levo-isomer of tetramisole and member of thioimidazoles, was originally described as a highly effective anthelminthic compound. Soon following that Renoux & Renoux (1971) observed an increased response to Brucella vaccination in mice treated with levamisole, accusing the drug for its immunomodulatory property. Since then, many reports have confirmed its immunomodulatory activity and the issue has been well reviewed. In this context, levamisole was the first chemically defined agent shown to have an immunomodulatory effect. This agent possesses antianergic properties and it enhances or restores to normal depressed immune responses acting primarily on cells that participate in cell-mediated immunity such as macrophages and T lymphocytes. It has been used in several human clinical trials as an anticancer drug, and may be used as an adjuvant for preventive vaccines. Although the drug traditionally appeared to act primarily on cellular immune responses, enhancing immune activity specifically in immunocytes whose function is impaired, it was recently shown that levamisole, when administered in combination with some experimental viral, parasitic or bacterial vaccines, enhanced both cellular and antibody response. The potential mechanisms by which levamisole co-administered with these vaccines may affect an immune response are enhanced translocations of specific antigens to the lymph nodes, upregulation of antigen presentation, co-stimulation and cytokine production.