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 aut oimmune sialoadenitis (MAS). To investigate factors that influence selectiv e infiltration by MNC of submandibular glands in young and adult MRL/lpr mi ce with MAS, expression of mRNA encoding the beta-chemokines monocyte chemo attractant protein (MCP)-1, macrophage inflammatory protein (MIP)-1 alpha, MIP-1 beta and regulated upon activation, normal T-cell expressed and secre ted (RANTES) was investigated by in situ hybridization. MCP-1 protein produ ction was also evaluated by immunohistochemistry. Young mice with MAS showe d an early up-regulation of mRNA expression for MCP-1, MIP-1 beta and RANTE S, while MIP-1 alpha mRNA expression was not affected. Adult mice with MAS showed a further up-regulation of mRNA expression for MCP-1, MLP-1 beta and RANTES, and a remarkably strong up-regulation for MIP-1 alpha. Immunohisto chemistry revealed that MCP-1 protein production paralleled MCP-1 mRNA expr ession in both young and adult mice. These observations implicate MCP-1, MI P-1 beta and RANTES as potential chemokines in induction of MAS, and MCP-1, MIP-1 beta, RANTES and prominently MIP-1 alpha in progression and perturba tion of MAS.