Immune responses may make HIV-1 therapeutic interfering particles less effective.

Area of Science:

• Virology
• Mathematical Biology
• Immunology

Background:

• Antiretroviral therapy (ART) is the standard HIV-1 treatment, requiring lifelong adherence.
• Therapeutic interfering particles (TIPs) are modified viruses that suppress wild-type HIV-1 by competing for essential viral proteins, offering a potential alternative treatment.

Purpose of the Study:

• To develop a novel ordinary differential equation model to analyze TIP dynamics in HIV-1 infection.
• To investigate the impact of host factors, including immune response and concurrent ART, on TIP efficacy.

Main Methods:

• Derivation of a new mathematical model using ordinary differential equations to simulate TIP-HIV-1 interactions.
• Analysis of the basic reproduction number (R₀^T) for TIPs to predict persistence.
• Inclusion of immune response dynamics into the model to assess its influence on therapeutic outcomes.

Main Results:

• Model confirms TIPs can reduce viral load if doubly infected cells produce sufficient viral particles.
• The basic reproduction number (R₀^T) predicts that concurrent ART hinders TIP persistence.
• Even a moderate immune response significantly narrows the parameter range for successful TIP therapy.

Conclusions:

• TIP efficacy is contingent upon wild-type virus characteristics and, more critically, the host's immune response.
• Predicting the therapeutic success of TIPs is challenging due to the complex interplay of viral and host factors.
• The findings highlight the need to consider immune modulation alongside TIP development for effective HIV-1 treatment.