Related Experiment Video
Updated: Jul 22, 2025
09:08
Generation and Assembly of Virus-Specific Nucleocapsids of the Respiratory Syncytial Virus
Published on: July 27, 2021
3.8K
Within-Host Rhinovirus Evolution in Upper and Lower Respiratory Tract Highlights Capsid Variability and
Negar Makhsous1, Stephanie Goya1, Carlos C Avendaño1
1Department of Laboratory Medicine and Pathology, University of Washington, Seattle, USA.
The Journal of Infectious Diseases
|July 24, 2023
Summary
Rhinovirus (RV) can spread from the upper to lower respiratory tract in immunocompromised patients without evolving. Mutations in RV capsid proteins are common and can appear in future viral sequences.
Area of Science:
- Virology
- Immunocompromised Host Research
- Respiratory Tract Infections
Background:
- Rhinovirus (RV) infections can transition from the upper (URT) to lower (LRT) respiratory tract in immunocompromised individuals, leading to severe pneumonia.
- The evolutionary dynamics of RV within hosts during infection remain largely uncharacterized.
Purpose of the Study:
- To investigate the intrahost evolution of RV in immunocompromised patients.
- To determine if genetic adaptation is necessary for RV to spread from the URT to the LRT.
Main Methods:
- Complete RV genomes were sequenced from 12 hematopoietic cell transplant patients.
- Metagenomic and amplicon next-generation sequencing were employed to track intrahost single nucleotide variants (iSNVs).
- Samples were collected from both URT (nasal wash) and LRT (bronchoalveolar lavage) over 190 days.
Main Results:
- Identical RV populations were found in matched URT and LRT samples, indicating no adaptation is required for URT to LRT progression.
- Coding iSNVs were more prevalent in capsid genes (2.3-fold) compared to nonstructural genes.
- iSNVs were frequently located on capsid surface residues but not in known neutralizing antibody epitopes.
- Newly emerged RV haplotypes from immunocompromised hosts were detected in community sequences years later.
Conclusions:
- RV progression from URT to LRT in immunocompromised hosts occurs without specific evolutionary adaptation.
- RV capsid proteins exhibit the highest variability, and emergent mutations can be found in subsequent viral populations.
Related Concept Videos
00:36Viral Mutations
32.4K
A mutation is a change in the sequence of bases of DNA or RNA in a genome. Some mutations occur during replication of the genome due to errors made by the polymerase enzymes that replicate DNA or RNA. Unlike DNA polymerase, RNA polymerase is prone to errors because it is not capable of “proofreading” its work. Viruses with RNA-based genomes, like HIV, therefore accrue mutations faster than viruses with DNA-based genomes. Because mutation and recombination provide the raw material...
32.4K
01:29Viruses with RNA Genomes
57
RNA viruses are categorized into positive-strand, negative-strand, or double-stranded groups based on their genomic structure and replication mechanisms. This classification dictates how they exploit host cellular machinery for protein synthesis and replication. Some RNA viruses also utilize reverse transcription as part of their life cycle, further diversifying their replication strategies.Positive-Strand RNA VirusesPositive-strand RNA viruses have genomes that function directly as messenger...
57
01:26Size and Structure of Viral Genomes
61
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
61
00:57Viral Recombination
23.5K
Cells are sometimes infected by more than one virus at once. When two viruses disassemble to expose their genomes for replication in the same cell, similar regions of their genomes can pair together and exchange sequences in a process called recombination. Alternatively, viruses with segmented genomes can swap segments in a process called reassortment.
23.5K
00:56Viral Structure
62.5K
Viruses are extraordinarily diverse in shape and size, but they all have several structural features in common. All viruses have a core that contains a DNA- or RNA-based genome. The core is surrounded by a protective coat of proteins called the capsid. The capsid is composed of subunits called capsomeres. The capsid and genome-containing core are together known as the nucleocapsid.
62.5K
02:33Retroviruses
12.4K
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
12.4K