Adaptive immune responses of patients with asthma to the attachment (G) glycoprotein of respiratory syncytial virus

A history of acute bronchiolitis in infancy caused by respiratory syncytial virus is a risk factor for recurrent wheezing in early childhood. Because the attachment (G) protein sensitizes mice for pulmonary eosinophilia and b ecause Th2 cells are central in the pathogenesis of asthma, plasma and peri pheral blood mononuclear cells (PBMC) from donors with asthma and from heal thy donors were evaluated for anti-G protein responses. A significant trend connecting severity of asthma with anti-G protein IgG1 and IgG2 titers was observed. The correlation between anti-F protein IgG3 titers and asthma se verity approached significance. Peptide mapping studies revealed that more positive recall responses (interferon-gamma and interleukin-10 secretion) o ccurred after PBMC from donors with asthma were stimulated with peptides re presenting the nonglycosylated domain of G protein. The same peptides elici ted more positive recall responses (proliferation and interferon-gamma secr etion) in the PBMC of healthy donors. These data suggest that a mechanism m ay exist whereby adaptive immune responses against G protein contribute to wheezing.