Development of a Cynomolgus Macaque Model for Human Adenovirus 55 Respiratory Disease

Overview

This study establishes a cynomolgus macaque model that replicates key clinical, immunological, and pathological features of human adenovirus type 55 (HAdV-55) respiratory infection. Infected macaques exhibited respiratory symptoms, characteristic lung imaging findings, and immune responses similar to those observed in human cases, providing a valuable platform for preclinical vaccine and therapeutic evaluation.

Background

Human adenovirus type 55 (HAdV-55) is an emerging respiratory pathogen causing severe pneumonia outbreaks, especially in crowded settings like military camps. It causes a spectrum of respiratory illnesses from mild symptoms to severe pneumonia and acute respiratory distress syndrome, with significant morbidity and mortality. Existing small animal models inadequately mimic human disease, limiting pathogenesis and therapeutic studies. Cynomolgus macaques, due to their physiological and immunological similarity to humans, offer a promising model to study HAdV-55 infection and immune responses.

Data Highlights

Key Findings

• Cynomolgus macaques infected with HAdV-55 develop respiratory symptoms mirroring human disease, including nasal discharge and cough.
• Lung imaging reveals peri-bronchial consolidation and ground-glass opacities consistent with pneumonia.
• Histopathological analysis shows granulomatous inflammation and macrophage infiltration similar to human pathology.
• Hematologic changes include early neutrophilia and basophilia, followed by eosinophilia and increased large unstained cells.
• Cytokine responses demonstrate early induction of IFN-γ, IFN-β, and IL-6, with delayed IL-8 elevation and suppression of IL-4.
• The model recapitulates key immunological and clinical features of HAdV-55 infection, supporting its utility for vaccine and therapeutic testing.

Clinical Implications

The cynomolgus macaque model provides a clinically relevant platform to study HAdV-55 pathogenesis and immune responses, facilitating the evaluation of candidate vaccines and antiviral therapies. Its ability to mimic human respiratory disease and immune kinetics enhances translational research potential for managing HAdV-55 outbreaks.

Conclusion

This study successfully establishes a nonhuman primate model that reproduces the clinical, pathological, and immunological features of HAdV-55 respiratory infection, addressing a critical gap in preclinical research. The cynomolgus macaque model is a valuable tool for advancing understanding and intervention strategies against this emerging respiratory pathogen.

References

1. Original Study -- Development of a Cynomolgus Macaque Model for Investigating Respiratory Illness Induced by Human Adenovirus Type 55