Human Adenovirus 52 Uses Sialic Acid-containing Glycoproteins and the Coxsackie and Adenovirus Receptor for Binding to Target Cells

Abstract

Most adenoviruses attach to host cells by means of the protruding fiber protein that binds to host cells via the coxsackievirus and adenovirus receptor (CAR) protein. Human adenovirus type 52 (HAdV-52) is one of only three gastroenteritis-causing HAdVs that are equipped with two different fiber proteins, one long and one short. Here we show, by means of virion-cell binding and infection experiments, that HAdV-52 can also attach to host cells via CAR, but most of the binding depends on sialylated glycoproteins. Glycan microarray, flow cytometry, surface plasmon resonance and ELISA analyses reveal that the terminal knob domain of the long fiber (52LFK) binds to CAR, and the knob domain of the short fiber (52SFK) binds to sialylated glycoproteins. X-ray crystallographic analysis of 52SFK in complex with 2-O-methylated sialic acid combined with functional studies of knob mutants revealed a new sialic acid binding site compared to other, known adenovirus:glycan interactions. Our findings shed light on adenovirus biology and may help to improve targeting of adenovirus-based vectors for gene therapy.

Glycomics and Proteomics Approaches to Investigate Early Adenovirus–Host Cell Interactions

“…Specifically the SSF interacts with SA. Structure function analysis revealed that the SA interface is on the side of the trimeric short fiber knob rather than in the central cavity as is the case for HAdV-37 [36].…”

“…HAdV-52 is equipped with two different fibers, SSFs and LSFs. The SSF binds to polysialic acidcontaining glycans, but through a different pocket than that in the knob of HAdV-37 [36,37]. In addition, several non-human AdV types can also bind to SAcontaining glycans [38][39][40].…”

“…The receptor is expressed in many organs including the brain, heart, lung, intestine, pancreas, liver, and kidney, which indicates that CAR possesses an important physiological role in several organs in vivo [62,63]. CAR was first identified as a receptor for coxsackie B viruses and species C (serotypes 2 and 5) AdVs [59,61] and subsequently shown to play a role as an attachment protein for species A, D-G AdVs, but not for species B AdVs [36]. On the virus side, the knob domain of the viral fiber protein is mediating binding to CAR [64].…”

Sialoglycovirology of Lectins: Sialyl Glycan Binding of Enveloped and Non-enveloped Viruses

“…Removal of the host cell surface Sia by NA treatment abolished HAdV-G52 binding to and infection of Sia-expressing original Chinese hamster ovary (CHO) cells but did not abolish (only partly reduced) virus binding to CHO cells that also express CAR (CAR-expressing CHO cells). When compared to original CHO cells, HAdV-G52 showed a remarkable increase in binding to CAR-expressing CHO cells [140]. Thus, HAdV-G52 may use its long or short fiber knob or both knobs for attachment to host CAR and/or Sia as a primary receptor or co-primary receptors to initiate virus infection.…”

Orchestrated efforts on host network hijacking: Processes governing virus replication

“…The ionic interactions between the virion and cell surface glycosphingolipids aid a number of enveloped and non-enveloped viruses in their entry, as the adhesion of virions to cell membrane permits them to be recognized by the specific internalization receptors [115]. For instance, the infection of subgroup D viruses of adenoviruses occurs after binding to α (2-3)-linked sialic acid (SA), a common carbohydrate component of glycolipids [116], and uses a positive feedback loop between virus uncoating and lipid signaling for efficient membrane penetration [117]. Many RNA viruses and some DNA viruses use lipids such as low-density lipoprotein receptors (LDLR), phospholipids, and gangliosides for entry [118].…”