Project description:VRC01-class broadly neutralizing antibodies (bnAbs) target the CD4-binding site (CD4BS) of the human immunodeficiency virus-1 (HIV-1) envelope glycoprotein (Env) and are of major interest for vaccine design. Unlike mature antibodies, corresponding VRC01-class germline precursors poorly bind to Env due to their weak ability to overcome the steric hindrance imparted by the glycans surrounding the CD4 BS. To date, immunogen design initiatives have largely relied on removal of these glycans and have met limited success in eliciting VRC01-class bnAbs. To understand elicitation of such bnAbs in humans, we structurally characterized the inferred germline precursor of VRC01 in complex with wild-type core gp120 by X-ray crystallography and modified trimeric 426c Env constructs by single-particle electron microscopy. We then validated glycan length and composition of germline VRC01-compatible Env constructs by EThcD LC-MS/MS. Our results reveal that engagement of the VRC01 germline antibody by a wild-type 426c gp120 is possible and can be enhanced by tailoring glycan length in the vicinity of the CD4BS.
Project description:This study is aimed to comprehensively and globally characterize seminal plasma glycoproteins in a site-specific manner with information of N-glycosites and corresponding glycan structures, as well as glycan isomers using mass spectrometry. Furthermore, the function of specific glycan structures is introduced during human reproduction. In addition, site-specific glycoproteins are compared precisely to explored the sub-glycan structure regulation of glycoprotein in human seminal plasma and spermatozoa.
Project description:Anti-carbohydrate antibodies (Abs) play crucial roles in pathogen control, but their generation remains poorly understood. By studying responses to Streptococcus pyogenes in humans, we reveal that the glycan-targeted response shifts from IgM towards IgG and IgA memory with age and antigen exposure across blood, spleen, and tonsils. Both natural colonization and controlled human infection with S. pyogenes increased class-switched B cells, with evidence of within-clone switching. Glycan-specific B cells readily participated in germinal center (GC) responses and showed robust somatic hypermutation despite a molecular signature consistent with receiving reduced T cell help. We conclude that mucosal pathogen encounters elicit glycan responses that class-switch, evolve and diversify through the GC. These findings reveal how age and infection history can influence the quality, quantity, and isotype use of glycan-specific B cells, with implications for the design and schedule of glycan-containing vaccines.