The immune response modifier resiquimod mimics CD40-induced B cell activation

Members of the imidazoquinoline molecule family, including imiquimod and re siquimod (R-848), have potent antiviral and antitumor activities. Imiquimod cream (5%) (Aldara) is currently indicated for treatment of external genit al and perianal warts. Previous characterization of these compounds has foc used upon their ability to activate monocytes and dendritic cells, but rece nt studies have shown that resiquimod also stimulates B lymphocytes to prol iferate and express an activated phenotype. This suggests that resiquimod c ould potentially serve as an effective vaccine adjuvant in stimulating a hu moral immune response. This study shows that resiquimod mimics effects of t he T-dependent CD40 signal in both mouse and human B cell lines. Resiquimod , like CD40, stimulates antibody secretion, cytokine production, protection from apoptosis, and CD80 upregulation. In addition, it shows synergy with signals delivered by the B cell antigen receptor and heightens CD40-mediate d B cell activation, demonstrating that resiquimod can enhance antigen-spec ific responses in B lymphocytes. (C) 2001 Academic Press.