Characterization of the Cytokine Network at a Single Cell Level in Mice with Collagen-Induced Arthritis Using a Dual Color ELISPOT Assay

Abstract

Collagen-induced arthritis (CIA) in mice has been classified as a Th1-mediated disease. However, most evidence for this has been obtained by indirect experiments; for example, the administration of neutralizing antiinterferon-gamma (IFN-gamma) antibody reduced the severity of arthritis. To obtain direct evidence about the cytokine balance in CIA mice, we analyzed the cytokine-secreting cell in CIA mice at the single cell level using a dual color enzyme-linked immunospot (ELISPOT) assay, which enabled us to analyze interleukin-2 (IL-2)-secreting cells or IL-4-secreting cells or both simultaneously. Furthermore, to characterize the cytokine network in the pathogenesis of CIA, the frequency of the cells secreting IL-12, which induced the development of naive Th cells into Th1 cells, was analyzed. The results show that in the prearthritic phase, the number of IL-12-secreting cells in spleen and peritoneal exuded cells is increased, and Th1 cells in lymph node and spleen are dominant. In contrast, after the onset of clinical arthritis, the number of IL-12-secreting cells in spleen, lymph node, and peritoneal exuded cells is decreased, and there is a shift from a Th1-dominant to a Th2-dominant state in lymph node and spleen. The results indicated that the pathogenesis of CIA is associated with a disruption in the normal ratio of Th1/Th2 at cell level.