Feline aminopeptidase N is not a functional receptor for avian infectious bronchitis virus

Victor C Chu,Lisa J Mcelroy,Jed M Aronson,Gary R Whittaker,Beverley E Bauman,Carole E Harbison,Trisha J Oura

doi:10.1186/1743-422x-4-20

Abstract

BackgroundCoronaviruses are an important cause of infectious diseases in humans, including severe acute respiratory syndrome (SARS), and have the continued potential for emergence from animal species. A major factor in the host range of a coronavirus is its receptor utilization on host cells. In many cases, coronavirus-receptor interactions are well understood. However, a notable exception is the receptor utilization by group 3 coronaviruses, including avian infectious bronchitis virus (IBV). Feline aminopeptidase N (fAPN) serves as a functional receptor for most group 1 coronaviruses including feline infectious peritonitis virus (FIPV), canine coronavirus, transmissible gastroenteritis virus (TGEV), and human coronavirus 229E (HCoV-229E). A recent report has also suggested a role for fAPN during IBV entry (Miguel B, Pharr GT, Wang C: The role of feline aminopeptidase N as a receptor for infectious bronchitis virus. Brief review. Arch Virol 2002, 147:2047–2056.ResultsHere we show that, whereas both transient transfection and constitutive expression of fAPN on BHK-21 cells can rescue FIPV and TGEV infection in non-permissive BHK cells, fAPN expression does not rescue infection by the prototype IBV strain Mass41. To account for the previous suggestion that fAPN could serve as an IBV receptor, we show that feline cells can be infected with the prototype strain of IBV (Mass 41), but with low susceptibility compared to primary chick kidney cells. We also show that BHK-21 cells are slightly susceptible to certain IBV strains, including Ark99, Ark_DPI, CA99, and Iowa97 (<0.01% efficiency), but this level of infection is not increased by fAPN expression.ConclusionWe conclude that fAPN is not a functional receptor for IBV, the identity of which is currently under investigation.

Highlights

Coronaviruses are an important cause of infectious diseases in humans, including severe acute respiratory syndrome (SARS), and have the continued potential for emergence from animal species
Samples were subjected to immunofluorescence staining to detect feline APN (fAPN) protein expression (Fig. 1A)
We found that nearly 40% of the BHK-21 population were efficiently transfected and stained positive for fAPN expression

Summary

Introduction

Coronaviruses are an important cause of infectious diseases in humans, including severe acute respiratory syndrome (SARS), and have the continued potential for emergence from animal species. A notable exception is the receptor utilization by group 3 coronaviruses, including avian infectious bronchitis virus (IBV). Feline aminopeptidase N (fAPN) serves as a functional receptor for most group 1 coronaviruses including feline infectious peritonitis virus (FIPV), canine coronavirus, transmissible gastroenteritis virus (TGEV), and human coronavirus 229E (HCoV-229E). The family of Coronaviridae is composed of group 1–3 coronaviruses (CoVs) [1] These viruses are able to infect human, canine, feline, murine, bovine, porcine, rat, and avian species. The etiological importance and zoonotic characteristics of coronaviruses have received much attention since the discovery of the newly emerged severe acute respiratory syndrome associated coronavirus (SARS-CoV). Bovine coronavirus (BCV) is thought to have jumped to human hosts, possibly by recombining with influenza C virus, giving rise to human coronavirus-OC43 (HCoV-OC43) around 1890 [4,8]

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