Coordinate up-regulation of the beta-chemokine subfamily in autoimmune sialoadenitis of MRL/lpr mice.

Mononuclear cell (MNC) infiltration of the salivary and lacrimal glands is a major feature in Sjogren's syndrome (SS) and its animal model, murine autoimmune sialoadenitis (MAS). To investigate factors that influence selective infiltration by MNC of submandibular glands in young and adult MRL/lpr mice with MAS, expression of mRNA encoding the beta-chemokines monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and regulated upon activation, normal T-cell expressed and secreted (RANTES) was investigated by in situ hybridization. MCP-1 protein production was also evaluated by immunohistochemistry. Young mice with MAS showed an early up-regulation of mRNA expression for MCP-1, MIP-1beta and RANTES, while MIP-1alpha mRNA expression was not affected. Adult mice with MAS showed a further up-regulation of mRNA expression for MCP-1, MIP-1beta and RANTES, and a remarkably strong up-regulation for MIP-1alpha. Immunohistochemistry revealed that MCP-1 protein production paralleled MCP-1 mRNA expression in both young and adult mice. These observations implicate MCP-1, MIP-1beta and RANTES as potential chemokines in induction of MAS, and MCP-1, MIP-1beta, RANTES and prominently MIP-1alpha in progression and perturbation of MAS.