Cytokine production of RSV/PHA-stimulated tonsillar mononuclear cells: Influences of age and atopy

Abstract

Links between immune responses to respiratory syncytial virus (RSV), age and atopic sensitisation are poorly understood. This study investigated the induction of target organ type-1, type-2 and pro-inflammatory cytokine responses to RSV and/or phytohaemagglutinin (PHA) in tonsillar mononuclear cells from children, in relation to age and atopic status. In comparison with the' control medium, RSV induced production of the type-1 cytokines interferon (IFN)-γ and interleukin (IL)-18, the pro-inflammatory cytokines IL-6, -8 and RANTES (regulated on activation, normal T-cell expressed and secreted), but not any of the type-2 cytokines IL-4, -5, -10 and -13. Induction of IL-6, -8 and RANTES, but not IFN-γ or IL-18, were shown to be dependent on virus replication. PHA induced all except IL-12, -13, and -15. Induction of IFN-γ, IL-6, -8, and RANTES was significantly increased in atopic children. Induction of both IFN-γ and IL-4 increased in parallel in relation to age, with no change in the IFN-γ:IL-4 ratio. These data are compatible with the hypothesis that immature type-1 immunity during early childhood plays a role in both respiratory syncytial virus bronchiolitis and in its relationship with atopy.