PurUUpurU: An Oligonucleotide Virulence Factor in RNA Viruses

• Published in: Curēus (Palo Alto, CA) Vol. 14; no. 9; p. e29340
• Main Authors: Sohn, Won J, Sloop, Gregory D, Pop, Gheorghe, Weidman, Joseph J, St. Cyr, John A
• Format: Journal Article
• Language: English
• Published: Palo Alto Cureus Inc 19.09.2022; Cureus
• Subjects: Coronaviruses; Dengue fever; Healthcare Technology; Infectious Disease; Medical Education; Respiratory syncytial virus; Viruses; Sudan
• DOI: 10.7759/cureus.29340
• ISSN: 2168-8184

BackgroundThe copy number of the oligonucleotide 5’-purine-uridine-uridine-purine-uridine-3’ (purUUpurU) motif in a viral genome was previously shown to correlate with the severity of acute illness. This study aimed to determine whether purUUpurU content correlates with virulence in other single-strand RNA (ssRNA) viruses that vary in clinical severity.MethodologyWe determined the copy number of purUUpurU in the genomes of two subtypes of human respiratory syncytial virus (RSV), respiratory syncytial virus A (RSV-A), and respiratory syncytial virus B (RSV-B), which vary in clinical severity. In addition, we determined the purUUpurU content of the four ebolaviruses that cause human disease, dengue virus, rabies virus, human rhinovirus-A, poliovirus type 1, astrovirus, rubella, yellow fever virus, and measles virus. Viral nucleotide sequence files were downloaded from the National Center for Biotechnology Information (NCBI)/National Institutes of Health website. In addition, we determined the cumulative case fatality rate of 20 epidemics of the Ebola virus and compared it with that of the other human ebolaviruses.ResultsThe genomic purUUpurU content correlated with the severity of acute illness caused by both subtypes of RSV and human ebolaviruses. The lowest purUUpurU content was in the genome of the rubella virus, which causes mild disease.ConclusionsThe quantity of genomic purUUpurU is a virulence factor in ssRNA viruses. Blood hyperviscosity is one mechanism by which purUUpurU causes pathology. Comparative quantitative genomic analysis for purUUpurU will be helpful in estimating the risk posed by emergent ssRNA viruses.