Mobilization of plasmacytoid and myeloid dendritic cells to mucosal sites in children with respiratory syncytial virus and other viral respiratory infections.
BACKGROUND
Respiratory syncytial virus (RSV) is the principal etiologic agent of bronchiolitis and viral pneumonia in infants and young children. Yet, many aspects of its immunopathogenesis are not well understood.


METHODS
We analyzed the immune cells that are mobilized by RSV and other respiratory viruses, by studying nasal wash samples from children hospitalized with acute viral respiratory infections.


RESULTS
RSV mobilizes virtually all blood immune cells, including myeloid dendritic cells (DCs) and plasmacytoid DCs (pDCs), to the nasal mucosa. DCs were also mobilized to the nasal mucosa of children with other viral respiratory infections. The increased number of pDCs in the nasal compartment significantly correlates with RSV load (P=.022), and it is associated with a significant decrease in the number of pDCs in the blood (P=.007). The influx of DCs in the nasal mucosa is not transient, as even higher numbers of both DC subsets were found in respiratory secretions weeks after the acute symptoms of RSV infection had resolved. Immunochemistry analysis of respiratory samples has demonstrated the presence of the RSV fusion protein within HLA-DR-positive cells.


CONCLUSIONS
Infection with RSV and other respiratory viruses mobilizes DCs to the site of viral entry.
Gill
Michelle A
MA
Baylor Institute for Immunology Research, and Division of Pediatric Infectious Diseases, Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas and Children's Medical Center Dallas, Dallas, Texas 75204, USA.
Palucka
A Karolina
AK
Barton
Theresa
T
Ghaffar
Faryal
F
Jafri
Hasan
H
Banchereau
Jacques
J
Ramilo
Octavio
O
D001988:Bronchiolitis / Q000276:immunology / Q000821:virology; D003713:Dendritic Cells / Q000276:immunology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D017817:Nasal Lavage Fluid / Q000166:cytology / Q000276:immunology; D011024:Pneumonia, Viral / Q000276:immunology / Q000821:virology; D020545:Respiratory Mucosa / Q000166:cytology / Q000276:immunology*; D018357:Respiratory Syncytial Virus Infections / Q000276:immunology*; D012141:Respiratory Tract Infections / Q000276:immunology* / Q000821:virology*; D014764:Viral Proteins / Q000032:analysis; D014777:Virus Diseases / Q000276:immunology* / Q000821:virology
D014764:Viral Proteins