Faster Adaptation in Smaller Populations: Counterintuitive Evolution of HIV during Childhood Infection.

Analysis of HIV-1 gene sequences sampled longitudinally from infected individuals can reveal the evolutionary dynamics that underlie associations between disease outcome and viral genetic diversity and divergence. Here we extend a statistical framework to estimate rates of viral molecular adaptation...

Full description

Saved in:
Bibliographic Details
Main Authors: Jayna Raghwani, Samir Bhatt, Oliver G Pybus
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2016-01-01
Series:PLoS Computational Biology
Online Access:https://doi.org/10.1371/journal.pcbi.1004694
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850125517881081856
author Jayna Raghwani
Samir Bhatt
Oliver G Pybus
author_facet Jayna Raghwani
Samir Bhatt
Oliver G Pybus
author_sort Jayna Raghwani
collection DOAJ
description Analysis of HIV-1 gene sequences sampled longitudinally from infected individuals can reveal the evolutionary dynamics that underlie associations between disease outcome and viral genetic diversity and divergence. Here we extend a statistical framework to estimate rates of viral molecular adaptation by considering sampling error when computing nucleotide site-frequencies. This is particularly beneficial when analyzing viral sequences from within-host viral infections if the number of sequences per time point is limited. To demonstrate the utility of this approach, we apply our method to a cohort of 24 patients infected with HIV-1 at birth. Our approach finds that viral adaptation arising from recurrent positive natural selection is associated with the rate of HIV-1 disease progression, in contrast to previous analyses of these data that found no significant association. Most surprisingly, we discover a strong negative correlation between viral population size and the rate of viral adaptation, the opposite of that predicted by standard molecular evolutionary theory. We argue that this observation is most likely due to the existence of a confounding third variable, namely variation in selective pressure among hosts. A conceptual non-linear model of virus adaptation that incorporates the two opposing effects of host immunity on the virus population can explain this counterintuitive result.
format Article
id doaj-art-3becd65af8d141a0bdad3d806d88ed6e
institution OA Journals
issn 1553-734X
1553-7358
language English
publishDate 2016-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS Computational Biology
spelling doaj-art-3becd65af8d141a0bdad3d806d88ed6e2025-08-20T02:34:06ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582016-01-01121e100469410.1371/journal.pcbi.1004694Faster Adaptation in Smaller Populations: Counterintuitive Evolution of HIV during Childhood Infection.Jayna RaghwaniSamir BhattOliver G PybusAnalysis of HIV-1 gene sequences sampled longitudinally from infected individuals can reveal the evolutionary dynamics that underlie associations between disease outcome and viral genetic diversity and divergence. Here we extend a statistical framework to estimate rates of viral molecular adaptation by considering sampling error when computing nucleotide site-frequencies. This is particularly beneficial when analyzing viral sequences from within-host viral infections if the number of sequences per time point is limited. To demonstrate the utility of this approach, we apply our method to a cohort of 24 patients infected with HIV-1 at birth. Our approach finds that viral adaptation arising from recurrent positive natural selection is associated with the rate of HIV-1 disease progression, in contrast to previous analyses of these data that found no significant association. Most surprisingly, we discover a strong negative correlation between viral population size and the rate of viral adaptation, the opposite of that predicted by standard molecular evolutionary theory. We argue that this observation is most likely due to the existence of a confounding third variable, namely variation in selective pressure among hosts. A conceptual non-linear model of virus adaptation that incorporates the two opposing effects of host immunity on the virus population can explain this counterintuitive result.https://doi.org/10.1371/journal.pcbi.1004694
spellingShingle Jayna Raghwani
Samir Bhatt
Oliver G Pybus
Faster Adaptation in Smaller Populations: Counterintuitive Evolution of HIV during Childhood Infection.
PLoS Computational Biology
title Faster Adaptation in Smaller Populations: Counterintuitive Evolution of HIV during Childhood Infection.
title_full Faster Adaptation in Smaller Populations: Counterintuitive Evolution of HIV during Childhood Infection.
title_fullStr Faster Adaptation in Smaller Populations: Counterintuitive Evolution of HIV during Childhood Infection.
title_full_unstemmed Faster Adaptation in Smaller Populations: Counterintuitive Evolution of HIV during Childhood Infection.
title_short Faster Adaptation in Smaller Populations: Counterintuitive Evolution of HIV during Childhood Infection.
title_sort faster adaptation in smaller populations counterintuitive evolution of hiv during childhood infection
url https://doi.org/10.1371/journal.pcbi.1004694
work_keys_str_mv AT jaynaraghwani fasteradaptationinsmallerpopulationscounterintuitiveevolutionofhivduringchildhoodinfection
AT samirbhatt fasteradaptationinsmallerpopulationscounterintuitiveevolutionofhivduringchildhoodinfection
AT olivergpybus fasteradaptationinsmallerpopulationscounterintuitiveevolutionofhivduringchildhoodinfection