Interactions between host immune response and antigenic variation that control Borrelia burgdorferi population...

Area of Science:

• Microbiology and Immunology
• Mathematical Biology
• Infectious Disease Dynamics

Background:

• Pathogen population dynamics within hosts arise from host immunity and pathogen evasion strategies.
• Chronic infections are medically significant, yet the interplay between variable antigens and adaptive immunity driving pathogen dynamics remains unclear.

Purpose of the Study:

• To investigate the interaction between antigenic variation and adaptive immunity in explaining within-host pathogen population dynamics.
• To model the population dynamics of Borrelia burgdorferi using its vls antigenic variation system.

Main Methods:

• Mathematical modeling was employed to simulate pathogen population dynamics.
• Models incorporated variable and constant immune removal rates of antibody-bound pathogens.
• Model parameters were fitted using empirical data.

Main Results:

• A variable immune removal rate model successfully explained the characteristic pathogen population dynamics, including long-term persistence.
• A constant immune removal rate model could not replicate long-term persistence, despite fitting rapid population decline.
• Model predictions offer testable hypotheses for experimental validation.

Conclusions:

• Variable immune removal rates are crucial for explaining the persistence of Borrelia burgdorferi during chronic infections.
• Understanding these dynamics is essential for developing strategies against chronic infections.
• Experimental validation of model assumptions is needed to confirm mechanisms affecting pathogen population dynamics.