Lack of Activation Marker Induction and Chemokine Receptor Switch in Human Neonatal Myeloid Dendritic Cells in Response to Human Respiratory Syncytial Virus

Abstract

Respiratory syncytial virus (RSV) causes disease early in life and can reinfect symptomatically throughout life without undergoing significant antigenic change. In contrast, reinfection by influenza A virus (IAV) requires antigenic change. The adaptive immune response depends on antigen presentation by dendritic cells (DC). We used myeloid DC (mDC) from cord blood and adult blood donors to evaluate whether immunological immaturity contributes to the inability to mount a fully protective immune response to RSV. While IAV induced some activation and chemokine receptor switching in cord blood mDC, RSV did not. This appeared to be due to a lack of activation and a weak and mostly reversible inhibition of DC functions. Both viruses induced a stronger activation of mDC from adults than mDC from cord blood. Thus, inefficient stimulation of mDC by RSV and immunological immaturity may contribute to reduced immune responses and increased susceptibility to RSV disease and reinfection in young infants.