Henipavirus pathogenesis in human respiratory epithelial cells

Area of Science:

• Virology
• Immunology
• Respiratory Medicine

Background:

• Hendra virus (HeV) and Nipah virus (NiV) are deadly zoonotic viruses causing severe respiratory illness and encephalitis.
• No licensed vaccines or therapeutics exist for human henipavirus infections.
• The precise transmission routes and target cells in the human respiratory tract remain unclear.

Purpose of the Study:

• To characterize henipavirus pathogenesis in primary human respiratory tract cells.
• To investigate the replication kinetics and host responses to HeV and NiV strains.
• To identify differences in inflammatory responses and immune evasion mechanisms.

Main Methods:

• Primary human bronchial/tracheal epithelial cells (NHBE) and small airway epithelial cells (SAEC) were used.
• Virus growth kinetics of NiV-Malaysia, NiV-Bangladesh, and HeV were determined.
• Host responses were assessed via gene expression analysis and immunoassays, focusing on cytokine profiles and interferon antagonism.

Main Results:

• HeV and NiV replicated efficiently in NHBE and SAEC, forming syncytia.
• Significant differences in inflammatory responses were observed between HeV and NiV strains, and between NHBE and SAEC.
• HeV infection in SAEC elicited the highest inflammatory response, with elevated levels of key cytokines.
• NiV-Malaysia demonstrated more efficient type I interferon antagonism than NiV-Bangladesh and HeV.

Conclusions:

• Henipaviruses efficiently infect and replicate in human respiratory epithelial cells.
• Distinct strain-specific and cell-type-specific host responses and immune evasion strategies were identified.
• These findings provide critical insights into early-stage henipavirus pathogenesis in the human respiratory tract.