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The coalescence of intrahost HIV lineages under symmetric CTL attack

Sivan Leviyang1

  • 1Department of Mathematics, Georgetown University, Washington, DC, USA. sr286@georgetown.edu

Bulletin of Mathematical Biology
|May 31, 2012
PubMed

Insights

Cytotoxic T lymphocytes (CTLs) control HIV infection. Our new model links CTL attack to HIV lineage coalescence using Poisson-Dirichlet distributions, improving understanding of viral evolution.

Area of Science:

  • Immunology
  • Mathematical Biology
  • Virology

Background:

  • Cytotoxic T lymphocytes (CTLs) are crucial for controlling Human Immunodeficiency Virus (HIV) infection.
  • Existing deterministic models of HIV-CTL interaction lack stochasticity, limiting their ability to capture population dynamics.
  • Understanding intrahost HIV evolution under immune pressure is vital for treatment strategies.

Purpose of the Study:

  • To develop a novel stochastic ordinary differential equation (ODE) model for HIV-CTL interactions.
  • To investigate the impact of CTL attack on intrahost HIV lineages.
  • To establish a connection between CTL-mediated immune pressure and HIV lineage coalescence patterns.

Main Methods:

  • Development of a stochastic ODE model extending deterministic approaches.
  • Analysis of CTL attack on multiple HIV epitopes with uniform strength.
  • Derivation of a limiting version of the stochastic ODE model.
  • Application of Poisson-Dirichlet distributions to describe HIV lineage coalescence.

Main Results:

  • The stochastic ODE model accurately reflects HIV lineages under CTL attack, particularly at lower HIV population sizes.
  • The coalescence of HIV lineages under CTL attack can be described by Poisson-Dirichlet distributions.
  • An explicit link between CTL attack dynamics and HIV lineage coalescence was established.

Conclusions:

  • The developed stochastic ODE model provides a more realistic framework for studying HIV-CTL interactions.
  • The findings offer a new perspective on HIV evolution by connecting immune responses to lineage dynamics.
  • This work bridges the gap between current lineage construction techniques (Kingman coalescent) and the influence of immune pressure.

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