Cytokine Response to Respiratory Syncytial Virus Stimulation of Human Peripheral Blood Mononuclear Cells

A key impediment to developing respiratory syncytial virus (RSV) vaccines is a lack of understanding of enhanced disease that occurred in children who received a formalin-inactivated RSV (FI-RSV) vaccine. Studies in mice have suggested that the FI-RSV vaccine induces a TH2 and live RSV induces a TH1 memory T cell response. In this study, the cytokine mRNA response of peripheral blood mononuclear cells (PBMC) from adults and children with and without previous RSV infection was characterized using a semiquantitative polymerase chain reaction (PCR). PBMC from 22 subjects previously infected with RSV usually had RSV-specific increases in TH1 cytokine-specific mRNA (interferon-γ [IFN-γ] mRNA, 20; interleukin [IL]-2 mRNA, 12; IL-5 mRNA, 6; and IL-4 mRNA, 0). PBMC from RSV antibody-negative children had no RSV-specific increases in IFN-γ, IL-2, or IL-4 mRNA; 1 of 7 had an increase in IL-5 mRNA. These data indicate that naturally acquired RSV induces a TH1 memory T cell response.