Peripheral Blood Mononuclear Cells from Infants Hospitalized Because of Respiratory Syncytial Virus Infection Express T Helper–1 and T Helper–2 Cytokines and CC Chemokine Messenger RNA
The cellular immune response to respiratory syncytial virus (RSV) infection was examined in infants aged 1–21 months who were hospitalized because of RSV infection or non-RSV-related illness. RSV- or control-stimulated peripheral blood mononuclear cells were examined to determine RSV-specific intracellular T helper-1 (Th1) and T helper- 2 (Th2) cytokine expression, chemokine messenger RNA (mRNA) expression, and cell surface markers. Patients hospitalized because of RSV infection had increased numbers of CD16+ and CD56bright cells and had RSV-specific increases in Th1 (interleukin [IL]-2 and interferon-γ) and Th2 (IL-4 and IL-6) cytokines and CC chemokines (macrophage inflammatory protein [MIP]-1α, MIP-1β, and RANTES [regulated on activation, normally T cell expressed and secreted]) mRNA expression. The results suggest that RSV infection induces both Th1 and Th2 cytokine expression and CC chemokine expression.