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

Mazalovska, Milena; Kouokam, J. Calvin

Cyanovirin-N (CV-N) is a lectin that was firstly isolated from the cyanobacterium Nostoc ellipsosporum, in an attempt to discover anti-HIV agents from natural extracts [19] . The CV-N lectin consists of 101 amino acids with a molecular weight of 11 kDa and contains two carbohydrate-binding sites with specificity towards the terminal 1,2-mannose sugars on high-mannose glycans [34] . CV-N has broad neutralization activity in the low nanomolar range against primary isolates and laboratory-adapted strains of HIV-1 and HIV-2, simian immunodeficiency virus (SIV), and feline immunodeficiency virus [35] . This broad activity of CV-N is due to high affinity of binding to gp120, essential for its anti-HIV effects. The mechanism of action of CV-N is still not quite understood, but it is believed that the antiviral activity against HIV occurs after virus-cell attachment or at a post-CD4-binding step in the entry process [36] . Unfortunately, CV-N treatment results in cell activation, mitogenicity, and increased cytokine production in human PMBC [37] .