Increased Activation and Altered Ratio of Interferon-Gamma: Interleukin-4 Secreting Cells in MRL-lpr/lprMice

Abstract
Cytokine specific ELIspot assays were used to monitor the number of cells secreting IL-4 and IFNγ in MRL-lpr/lpr mice of different ages. The cytokine repertoire expressed by MRL-lpr/lpr mice was skewed towards the over-production of IFNγ (and away from IL-4) when compared to that of MRL-±/± and BALB/c mice. With increasing age and disease severity, the ratio of IFNγ: IL-4 secreting cells rose in MRL-lpr/lpr mice but decreased in normal animals. This changing ratio of IFNγ: IL-4 secreting cells correlated with changes in the ratio of IgG2a: IgG1 secreting cells in these mice. Our findings suggest that cytokine secreting CD4+ and CDS+ cells are hyperactivated in young MRL-lpr/lpr mice, and that disease progression is associated with a disruption in the normal ratio of Th1: Th2 production in vivo.