Related Experiment Video
Updated: Mar 14, 2026
14:23
A Restriction Enzyme Based Cloning Method to Assess the In vitro Replication Capacity of HIV-1 Subtype C Gag-MJ4 Chimeric Viruses
Published on: August 31, 2014
16.3K
Large Variations in HIV-1 Viral Load Explained by Shifting-Mosaic Metapopulation Dynamics
Katrina A Lythgoe1,2, François Blanquart2, Lorenzo Pellis3
1Department of Zoology, Tinbergen Building, University of Oxford, Oxford, United Kingdom.
Plos Biology
|October 6, 2016
Summary
This study introduces a new mathematical model for HIV-1 infection, revealing that spatial structure significantly impacts viral load. The model explains patient variability by showing a dynamic balance between local infection and clearance.
Area of Science:
- Mathematical Biology
- Immunology
- Virology
Background:
- Mathematical models often simplify host environments, treating them as homogeneous.
- Previous models did not account for the spatial structure of viral populations within the body.
- Understanding HIV-1 dynamics requires considering immune cell trafficking and viral distribution.
Purpose of the Study:
- To develop and analyze a mathematical model incorporating spatial structure for HIV-1 infection dynamics.
- To investigate how spatial organization of viral populations and immune cells affects infection outcomes.
- To explain observed variations in set-point viral load (SPVL) between patients.
Main Methods:
- Developed a metapopulation model of virus replication and cytotoxic T lymphocyte (CTL) dynamics.
- Studied spatially segregated patches representing T cell areas connected by blood and lymph.
- Employed mathematical, analytical, and computational approaches to analyze model predictions.
Main Results:
- Spatial structure radically alters predictions compared to homogeneous models.
- Introduced the 'shifting-mosaic steady state' where overall viral load is stable but locally dynamic.
- The model explains inter-patient variability in SPVL and the low proportion of infected cells.
Conclusions:
- Spatial heterogeneity is crucial for accurately modeling HIV-1 infection dynamics.
- The shifting-mosaic steady state provides a novel framework for understanding viral load stability and variation.
- This model offers new insights into the determinants of viral load and immune responses in HIV-1 infection.
More Related Videos
Related Concept Videos
00:36Viral Mutations
40.6K
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...
40.6K
01:09Mutation, Gene Flow, and Genetic Drift
65.5K
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
65.5K
02:39Gene Flow
38.7K
Gene flow is the transfer of genes among populations, resulting from either the dispersal of gametes or from the migration of individuals.
38.7K
01:10Retrovirus Life Cycles
50.2K
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...
50.2K
01:26Size and Structure of Viral Genomes
987
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...
987
03:33Genetic Drift
44.8K
Natural selection—probably the most well-known evolutionary mechanism—increases the prevalence of traits that enhance survival and reproduction. However, evolution does not merely propagate favorable traits, nor does it always benefit populations.
44.8K