Evaluation of the effects of 17β-estradiol (17β-E2) on gene expression in experimental autoimmune encephalomyelitis using DNA microarray

The aim of this study was to identify immune-related genes affected by treatment with 17beta-estradiol (17beta-E2) that contribute to protection of T cell antigen receptor double transgenic mice from experimental autoimmune encephalomyelitis (EAE). The Affymetrix microarray system was used to screen more than 12,000 genes from E2-treated mice protected from EAE vs. control mice with severe EAR In general, E2 treatment affected about 10% of the genes tested, but only IS cytokine, chemokine/receptor, adhesion molecule, or activation genes were up- or down-regulated more than 2.4-fold by E2 treatment. Down-regulated genes included TNFalpha (an important proinflammatory cytokine in EAE); peptidoglycan recognition proteins (Pgrp); regulated on activation, normal T cell expressed and secreted (RANTES); and neural cell adhesion molecule (MCP-1). Up-regulated genes included cytotoxic T lymphocyte antigen-4 (CTLA-4; known to inhibit T cell activation), TGFbeta3, IL-18, and two interferon-gamma-induced genes, the chemokines: monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1beta (MIP-1beta), vascular cell adhesion molecule (VCAM), and disintegrin metalloprotease (thought to regulate TNFalpha production). These results implicate a limited set of known and previously unsuspected E2-sensitive genes that may be crucial for inhibition of EAE and potentially the human disease, multiple sclerosis.