Human immunodeficiency virus type 1 (HIV-1) infects T lymphocytes, macrophages and dendritic cells. The viral attachment onto cell surface is driven by interaction of viral envelope N-glycans with host cell glycan-binding receptors.
L-selectin (CD62L) is a cell adhesion molecule found on central memory T cells. Kononchik et al. investigated the role of this carbohydrate-binding receptor in HIV infection of T cells in relation to gp120, a viral glycoprotein essential for HIV-1 entry in the host cell.
The study shows that gp120-linked N-glycans interact with L-selectin nonetheless this receptor generally prefers sialyl-Lewis x type O-linked glycans. The competition assay with carbohydrates from Carbosynth in L-selectin-gp120 binding was performed to confirm the specificity of the interaction. L-selectin ligands heparin, fucoidan, sialyl-Lewis x and sialyllactose competed with viral glycoprotein which resulted in reduced L-selectin-gp120 interaction. N-acetylglucosamine and lactose have no affinity for L-selectin and consistently, no inhibition of L-selectin-gp120 interaction was detected.
The study also revealed the role of L-selectin in the final stages of HIV-1 lifecycle. The release of newly produced virions from infected cells requires L-selectin shedding. The inhibition of the shedding has striking consequences on viral lifecycle since it supresses viral release.
For more details, read the original paper published in Nature Communications: Kononchik et al., 2018.