Protective Efficacy of a DNA Influenza Virus Vaccine Is Markedly Increased by the Coadministration of a Schiff Base-Forming Drug

Abstract

Effective vaccination against heterologous influenza virus infection remains elusive. Immunization with plasmid DNA (pDNA) expressing conserved genes from influenza virus is a promising approach to achieve cross-variant protection. However, despite having been described for more than a decade, pDNA vaccination still requires further optimization to be applied clinically as a standard vaccination approach. We have recently described a simple and efficient approach to enhance pDNA immunization, based on the use of tucaresol, a Schiff base-forming drug. In this report we have tested the ability of this drug to increase the protection conferred by pDNA vaccination against influenza virus infection. Our results demonstrate that a significant protection was achieved in two strains of mice by using the combination of pDNA and tucaresol. This protection was associated with an elevated humoral and cellular response and a switch in the type of the T helper cell (Th) immune response from type 2 to type 1. This vaccine combination represents a promising strategy for designing a clinical study for the protection from influenza and similar infections.

Imidazole Schiff base ligands: Synthesis, coordination complexes and biological activities

“…The lack of activity found for uncoordinated ligand 2 and its Cu(II) and Zn(II) complexes is similar to that previously reported [8] 2 ] against the same organisms (except MRSA, which was not tested). In contrast to the relative inactivity of 2, a related Schiff base, formed from Apim and 2-formylphenox yacetic acid, was found to be quite active in its uncoordinated form against strains of S. aureus and E. Coli (MIC 100 value of 6.25 lg/ml in each case), indicating the importance of functionalization of the salicylate phenyl ring [14].…”

“…In recent years, metal complexes comprising Schiff base ligands have been shown to exhibit significant anticancer, antiviral and antimicrobial activity [1][2][3][4]. Commercially available 1-(3-aminopropyl)imidazole (Apim) (Fig.…”

Nitric Oxide, Immunity and Cancer: From Pathogenesis to Therapy

“…With regards to humoral immunity, co-administration of oxidized carbohydrates with antigen increases the secretion of antigen-specific immunoglobulins. Parallel studies of T cell-dependent immune responses demonstrate similar increases in responsiveness when using the Schiff base-forming agent tucaresol during immunization [69]. Furthermore, endogenous NO generation by cytokine induction in immune-related cells and exogenous NO (provided locally by NO-releasing compounds) have been demonstrated to be essential for the priming of the immune response (T cell priming) against specific antigens and some tumor associated antigens (TAAs) [57,70].…”

Synthesis, Characterization and Antimicrobial Activities of Copper, Nickel, Cobalt, Chromium Complexes Derived from (Z)-4-Fluoro-N-(2,7-dimethylhept-6-enylidene) benzenamine

“…[4][5][6][7] In this context, with the aim of developing new antifungal and antibacterial compounds, we report the synthesis, characterization of a novel Schiff base and its metal complexes and their antifungal, antibacterial properties. While the antibacterial studies exhibit moderate activity against the species studied, antifungal studies revealed an interesting result.…”