Lectins as Promising Therapeutics for the Prevention and Treatment of HIV and Other Potential Coinfections

Mazalovska, Milena; Kouokam, J. Calvin

Influenza causes high morbidity in HIV positive individuals [83] . Several reports have demonstrated the anti-inhibitory activities of lectins against influenza viruses. For example, a lectin from the red alga Kappaphycus alvarezii (KAA-2) inhibits infection by multiple influenza strains with EC50 values in the low nanomolar range, by interfering with virus entry into host cells upon direct binding of hemagglutinin (HA) on the viral envelope [59] . Similarly, a lectin derived from the green alga Boodlea coacta (BCA) exerts potent anti-influenza effects by directly binding HA of multiple strains, including the pandemic H1N1-2009 virus [59] . In addition, three other lectins, including ConA, Lens culinaris agglutinin (LCA), and peanut agglutinin (PNA), were shown to suppress cell fusion and hemadsorption associated with human parainfluenza virus type 2 (hPIV-2) in vitro, mainly by preventing virus adsorption to the cells [84] . In a screen of 12 lectins, the red alga Eucheuma serra derived high-mannose binding anti-HIV lectin ESA-2 was very effective in inhibiting influenza virus infection with an EC50 of 12.4 nM [57] . Finally, the mannose-specific Narcissus tazetta lectin (NTL) strongly inhibits influenza A (H1N1, H3N2, and H5N1) and influenza B viruses with IC50 values between 0.20 g/ml and 1.33 g/ml and markedly reduces plaque formation by the human respiratory syncytial virus (RSV) with an IC50 of 2.30 g/ml [60] .