Slow growing behavior in African trypanosomes during adipose tissue colonization.

Area of Science:

• Parasitology
• Molecular Biology
• Disease Ecology

Background:

• Trypanosoma brucei causes sleeping sickness.
• Parasite adaptation to host tissues impacts disease progression.
• The behavior of T. brucei in adipose tissue was previously unknown.

Purpose of the Study:

• To investigate the proliferation and drug response of Trypanosoma brucei in adipose tissue.
• To understand how adipose tissue colonization affects parasite population dynamics.
• To determine the implications for sleeping sickness chronicity and treatment failure.

Main Methods:

• Mathematical modeling of parasite populations.
• Proteomic analysis of adipose tissue forms (ATFs).
• Measurement of protein synthesis and proliferation rates.
• Intravital imaging for drug response assessment.

Main Results:

• Adipose tissue forms (ATFs) of T. brucei proliferate slower (12h doubling time) than blood forms (6h).
• ATFs exhibit heterogeneous doubling times (5h–35h), with slow-growing parasites retaining the ability to revert to faster growth.
• Intravital imaging revealed that ATFs are refractory to drug treatment.

Conclusions:

• A subpopulation of T. brucei in adipose tissue adopts a slow-growing phenotype.
• This slow growth contributes to the chronicity of sleeping sickness.
• Parasite adaptation in adipose tissue leads to treatment failure.