Rhesus Macaques Are More Susceptible to Progressive Tuberculosis than Cynomolgus Macaques: a Quantitative Comparison

Area of Science:

• Veterinary Medicine
• Infectious Diseases
• Primate Models

Background:

• Nonhuman primates, particularly macaques, are crucial models for studying human tuberculosis (TB).
• Variability in TB pathogenesis among macaque species complicates experimental design.
• Standardized quantitative assessments are needed to compare TB outcomes across macaque models.

Purpose of the Study:

• To quantitatively assess and compare the outcomes of low-dose Mycobacterium tuberculosis infection in Chinese cynomolgus macaques, Chinese rhesus macaques, and Mauritian cynomolgus macaques.
• To identify differences and similarities in TB disease progression and bacterial burden among these macaque species.
• To provide data to guide the selection of appropriate macaque models for TB research.

Main Methods:

• Low-dose Mycobacterium tuberculosis infection was administered to three macaque species.
• Serial positron emission tomography and computed tomography (PET-CT) imaging was used for in-vivo assessment.
• Precise quantitative determination of bacterial burdens was performed.

Main Results:

• Substantial variability in TB infection outcomes was observed within and among the studied macaque species.
• Chinese rhesus macaques exhibited higher disease progression rates, greater lung and lymph node involvement, and higher bacterial burdens compared to Chinese cynomolgus macaques.
• Mauritian cynomolgus macaques showed TB infection outcomes more similar to rhesus macaques than to Chinese cynomolgus macaques.

Conclusions:

• Significant inter-species differences exist in Mycobacterium tuberculosis infection outcomes among macaques.
• Chinese rhesus macaques and Mauritian cynomolgus macaques appear to be more susceptible to TB progression than Chinese cynomolgus macaques.
• These findings offer valuable insights for selecting optimal macaque models in tuberculosis research.