Coevolutionary immune system dynamics driving pathogen speciation

Area of Science:

• Immunology
• Evolutionary Biology
• Mathematical Biology

Background:

• Adaptive immune responses typically clear pathogens.
• Chronic infections can arise from complex host-pathogen interactions.
• Pathogen mutation rates significantly influence infection dynamics.

Purpose of the Study:

• To model the within-host coevolution of pathogens and the adaptive immune system.
• To investigate the roles of pathogen mutation and lymphocyte homeostasis in chronic infection.
• To understand the emergent structures and long-term consequences of this coevolutionary dynamic.

Main Methods:

• Development of a within-host dynamical model.
• Analysis of pathogen mutation and lymphocyte homeostasis.
• Simulation of coevolutionary interactions over time.

Main Results:

• Pathogen mutation and lymphocyte constraints permit chronic infections.
• Emergent branching patterns indicate asexual pathogen speciation.
• Coevolutionary dynamics lead to immune system fragility and loss of control.

Conclusions:

• The interplay between pathogen evolution and immune response can lead to chronic disease.
• Pathogen speciation is a consequence of within-host coevolution.
• Prolonged immune system pressure results in eventual immune failure.