Immune response and alteration of pulmonary function after primary human metapneumovirus (hMPV) infection of BALB/c mice

Human metapnemovirus (hMPV), a recently identified virus, causes upper and lower respiratory tract diseases. In this study, we show that BALB/c mice inoculated with hMPV exhibited significant morbidity on 1-2 days post-infection, when airway obstruction was found. Increased airway hyper-responsiveness to metacholine was found on day 4 concurrent with lung viral replication. Both IgGI and IgG2a hMPV-specific antibodies were found in sera, while interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) were found in bronchoalveolar lavage. Lung histology showed parenchymal pneumonia and increased lymphocytic infiltration. We present here an animal model that may be helpful in studying hMPV pathogenesis and evaluating the effects of vaccines. (c) 2005 Elsevier Ltd. All rights reserved.