Single-cell glycomics analysis by CyTOF-Lec reveals glycan features defining cells differentially susceptible to HIV

High-parameter single-cell phenotyping has enabled in-depth classification
and interrogation of immune cells, but to date has not allowed for glycan
characterization. Here, we develop CyTOF-Lec as an approach to
simultaneously characterize many protein and glycan features of human
immune cells at the single-cell level. We implemented CyTOF-Lec to compare
glycan features between different immune subsets from blood and multiple
tissue compartments, and to characterize HIV-infected cell cultures. Using
bioinformatics approaches to distinguish preferential infection of
cellular subsets from viral-induced remodeling, we demonstrate that HIV
upregulates the levels of cell surface fucose and sialic acid in a
cell-intrinsic manner, and that memory CD4+ T cells co-expressing high
levels of fucose and sialic acid are highly susceptible to HIV infection.
Sialic acid levels were found to distinguish memory CD4+ T cell subsets
expressing different amounts of viral entry receptors, pro-survival
factors, homing receptors, and activation markers. The ability of sialic
acid to distinguish memory CD4+ T cells with different susceptibilities to
HIV infection was experimentally validated through sorting experiments.
Together, these results suggest that HIV remodels not only cellular
proteins but also glycans, and that glycan expression can differentiate
memory CD4+ T cells with vastly different susceptibility to HV infection.