Rhinovirus structure, replication, and classification

Rhinovirus (RV) is a major cause of the common cold and more severe respiratory illnesses including asthma and chronic obstructive pulmonary disease exacerbations, pneumonia, and bronchiolitis. RV is a nonenveloped, single-stranded RNA virus belonging to the Enterovirus genus in the family Picornaviridae. Different RVs bind to one of three known cellular receptors (intercellular adhesion molecule-1, low density lipoprotein receptor, and cadherin-related family member 3) on airway epithelial cells to initiate their replication cycle. Strategies to categorize RVs have been shaped by increased understanding of virus biology and have passed through several iterations since virus discovery in the 1950s. The RVs are currently classified into over 160 types within three species (A, B, and C) based on phylogenetic sequence criteria and distinct genomic features. An understanding of RV structure, replication, and diversity is necessary to develop novel treatment strategies. This chapter will provide an overview of the structural and genetic features that distinguish RV species, as well as methods of RV classification.