Deciphering the Mechanism Underlying Short- and Long-term Airway Hyperresponsiveness Following Early-life RSV Infection
Respiratory
Synthetical Virus (RSV) is the most common respiratory virus that causes young
children sickness with cough, wheezing, and respiratory distress. In severe
cases, sick babies need care in hospitals, even in intensive care units, with a
breathing tube and ventilator to help them breathe. In addition, severe RSV
infection at a young age increases the asthma risk in later childhood.
Nevertheless, the only FDA-approved medication to prevent severe RSV infection
is the monoclonal RSV antibody, such as Palivizumab or Nirsevimab. Their
protective effect is promising but incomplete. Therefore, effective treatment
of RSV infection remains a significant unmet need. Early-life RSV infection is
known to induce airway inflammation and obstruction. Our research on
RSV-induced airway obstruction focuses on airway smooth muscle cell (ASMC)
dysfunction, as ASMCs are essential in regulating airway resistance. Our
research objective is to explore how RSV infection modifies the ASMC function
in early life, thus provoking abnormal airway constriction in the short and
long term. To achieve the research goal, we established three models to
replicate the airway epithelial RSV infection using infant and adult human
epithelial culture, precision-cut lung slices (PCLSs), and BALB/c mouse pups
and adults. These models reproduced worse RSV epithelial inflammation in early
life than in adulthood. They also demonstrated that RSV did not infect ASMCs.
Still, the inflammatory agents from RSV-infected epithelial cells could induce
airway hyperresponsiveness (AHR) in neonates but not adults. In addition, RSV
epithelial inflammation changed the gene expression profile in infant ASMCs, in
particular, increasing the Bruton Tyrosine Kinase (BTK) gene expression.
Building upon these findings, we propose an in-depth investigation to disclose
the short and long-term ASM dysfunction induced by early-life RSV epithelial
inflammation and the underlying mechanism through the abnormal BTK pathway in
ASMCs. This research will inform how RSV epithelial infection causes airway
obstruction in early life and its connection to asthma risk in later childhood.
It will also lay the foundation for novel therapy to improve respiratory
distress in acute RSV bronchiolitis and reduce the risk of childhood asthma.