Ocular tropism of respiratory viruses

Abstract

Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism.

Fig 1

Distribution of sialic acids in human ocular and respiratory tract tissues. Major components of human ocular and respiratory tissues are depicted, with the predominant α2-6- and/or α2-3-linked glycans expressed on epithelial cells identified where known (see references and 3). While these sialic acids are predominantly employed by adenovirus and influenza virus, additional cellular receptors and the viruses which utilize them are discussed in the text.

Fig 2

Location of human ocular cell types permissive to respiratory virus infection. Cell types of the human eye previously shown to support viral replication of adenovirus (75, 92, 93, 95), influenza virus (55, 58, 122), and respiratory syncytial virus (56, 131) are depicted.