Poly-LacNAc as an Age-Specific Ligand for Rotavirus P[11] in Neonates and Infants

Abstract

Rotavirus (RV) P[11] is an unique genotype that infects neonates. The mechanism of such age-specific host restriction remains unknown. In this study, we explored host mucosal glycans as a potential age-specific factor for attachment of P[11] RVs. Using in vitro binding assays, we demonstrated that VP8* of a P[11] RV (N155) could bind saliva of infants (60.3%, N = 151) but not of adults (0%, N = 48), with a significantly negative correlation between binding of VP8* and ages of infants (P<0.01). Recognition to the infant saliva did not correlate with the ABO, secretor and Lewis histo-blood group antigens (HBGAs) but with the binding of the lectin Lycopersicon esculentum (LEA) that is known to recognize the oligomers of N-acetyllactosamine (LacNAc), a precursor of human HBGAs. Direct evidence of LacNAc involvement in P[11] binding was obtained from specific binding of VP8* with homopolymers of LacNAc in variable lengths through a glycan array analysis of 611 glycans. These results were confirmed by strong binding of VP8* to the Lec2 cell line that expresses LacNAc oligomers but not to the Lec8 cell line lacking the LacNAc. In addition, N155 VP8* and authentic P[11] RVs (human 116E and bovine B223) hemagglutinated human red blood cells that are known to express poly-LacNAc. The potential role of poly-LacNAc in host attachment and infection of RVs has been obtained by abrogation of 116E replication by the PAA-conjugated poly-LacNAc, human milk, and LEA positive infant saliva. Overall, our results suggested that the poly-LacNAc could serve as an age-specific receptor for P[11] RVs and well explained the epidemiology that P[11] RVs mainly infect neonates and young children.

The sweet spot: defining virus–sialic acid interactions

“…HBGAs are oligosaccharides that are expressed on erythrocytes and epithelial cells and are also present in mucosal secretions. In addition, human P[11] rotavirus strains, which cause diarrhoea in neonates, bind to HBGA precursors 12,29 .…”

“…Various cell surface carbohydrates, including sialylated glycans 1–6 , glycosaminoglycans 7–10 and human blood group antigens (HBGAs) 11,12 , function as host cell receptors for viral attachment and entry.…”

Histo-blood group antigens: a common niche for norovirus and rotavirus

“…These binding specificities have been confirmed by haemagglutination of red blood cells, blocking by monoclonal antibodies (mAbs), and binding of the authentic virions. In addition, P [9], P [14] and P [25] genotypes of the P[III] genogroup that infect humans bound specifically to the type A antigens (Refs 28, 30), whereas P [11] of the P[IV] genogroup that infects infants interacted with single and repeated LacNAc, the type 2 precursor glycan ( Refs 52,82). Direct evidence of RV-HBGA interaction has been shown by Xray crystallography of a P [14] VP8* in complex with the type A oligosaccharide (Ref.…”

Functional and Structural Characterization of P[19] Rotavirus VP8* Interaction with Histo-blood Group Antigens

“…Furthermore, the electrostatic potential surface comparison revealed the similarities and differences among different P genotypes, which may explain to some extent the various binding patterns observed in the functional assays (11,12,(16)(17)(18)36). However, for the potential binding site of P [19], the surface presentation of P [3] and Sia, P [14] and A, P [11] and LNnT, and P [19] showed that there was indeed a cavity in the potential binding site in P [19] VP8* (Fig.…”

“…P [11] showed obvious binding to type 1/type 2 precursors (16,17). In addition, P [9], P [14], and P [25] all bound to A type HBGA (A-HBGA) (18).…”