Human receptor for calicivirus binding detected using Retrogenix cell microarray technology

Background

Following the accidental infection of a laboratory worker with San Miguel sea lion virus (SMSLV) in 1998, a related virus was isolated in cell culture and has shown the ability to replicate in human cells. Now, a study published in the journal mBio describes the characterisation of this strain, Hom-1, and the identification of the specific cell surface receptor involved in its infection of human cells. These findings add to the knowledge on a group of viruses that infect a broad range of animal hosts and are associated with various chronic and acute illnesses.

 

Receptor identification using cell microarray technology

The investigation into the mechanism by which human cells could be infected with Hom-1 was led by scientists at the National Insititutes for Health (NIH) and Oregon State University in the US in collaboration with Retrogenix.

The Retrogenix cell microarray technology was used to identify the specific human cell surface receptor for Hom-1. Over 3,500 expression vectors, each encoding an individual full-length human plasma membrane protein as well as ZsGreen1 protein, were arrayed in duplicate on microarray slides. The vectors were reverse transfected into human HEK293 cells – with ZsGreen1 serving as a control to ensure efficient transfection. Cells were fixed and Hom-1 virus-like particles (VLPs) were added to the slides. Hom-1 VLP binding was detected using fluorescent antibodies. A single interacting protein was identified: human junctional adhesion molecule-1 (hJAM1).

Validation of hJAM1 as the functional receptor

The interaction was confirmed by inducing susceptibility to Hom-1 infection via expression of hJAM1 in nonpermissive cells. In addition, susceptibility to infection was also reversed in permissive cell lines following knockout of hJAM1. Permissive cells that were pre-treated with anti-hJAM1 monoclonal antibodies showed markedly decreased levels of viral infection further indicating the role of hJAM1 as the functional receptor.

Impact

Hom-1 is the first calicivirus that has been shown to replicate efficiently in cultured human cells. Identification of its specific human receptor using cell microarray technology presents a new avenue for studying the members of this virus family – which includes norovirus – and their species specificity.

This project highlights the versatility of the Retrogenix technology in identifying specific cell surface receptors for a wide variety of ligands, from viruses and whole cells (such as CAR T cells) through to isolated functional ligands such as antibodies, proteins, peptides and small molecules.

The paper by Stanislav Sosnovtsev et al. is entitled: “Identification of human junctional adhesion molecule-1 as a functional receptor for the Hom-1 calicivirus on humans cells.” Please click here to view the open-access full text.

Download case study