Inflammatory Mediators in Uveitis: Differential Induction of Cytokines and Chemokines in Th1- Versus Th2-Mediated Ocular Inflammation

Abstract

Ocular inflammation leads to vision loss through the destruction and scarring of delicate tissues along the visual axis. To identify inflammatory mediators involved in this process, we used real time RT-PCR to quantify the expression of mRNA transcripts of 34 cytokines, 26 chemokines, and 14 chemokine receptors at certain time points during T cell-mediated ocular inflammation. We induced disease by adoptive transfer of Ag-specific Th1 or Th2 cells into recipients expressing the target Ag in their eyes. We also compared the mediator expression patterns seen in adoptive transfer-induced inflammation with that seen in mouse eyes developing experimental autoimmune uveoretinitis. In addition, we used laser capture microdissection to examine chemokine mRNA production by both retinal pigment epithelium cells and infiltrating leukocytes in inflamed eyes. Major findings included the following: 1) Three patterns of expression of the inflammation-related molecules were seen in recipients of adoptively transferred Th cells: preferential expression in Th1 recipients, or in Th2 recipients, or similar expression in both recipient groups. 2) In experimental autoimmune uveoretinitis, the inflammatory mediator expression pattern largely paralleled that seen in Th1-induced disease. 3) Both retinal pigment epithelium and infiltrating leukocytes expressed chemokine transcripts in distinct, but overlapping patterns in inflamed eyes. 4) Interestingly, trancripts of multiple cytokines, chemokines, and chemokine receptors were constitutively expressed in high levels in mouse eyes. Seven of these molecules have not been previously associated with the eye. These data underscore the multiplicity of mediators that participate in the pathogenesis of eye inflammation and point to upstream cytokines as potential therapeutic targets.

Pertussis Toxin Is Superior to TLR Ligands in Enhancing Pathogenic Autoimmunity, Targeted at a Neo-Self Antigen, by Triggering Robust Expansion of Th1 Cells and Their Cytokine Production

“…The ligands' activities were assessed by an experimental system we developed, in which naive CD4 cells, specific against HEL, are adoptively transferred into recipient mice that express HEL in their eyes (28,29). The transferred naive cells do not induce disease in untreated recipients, but do so in mice treated with agents capable of stimulating the naive CD4 cells to become effector cells (6,28).…”

“…Naive CD4 cells were isolated from spleens and lymph nodes of 3A9 mice using T cell columns and MACS beads as described in detail elsewhere (28,29). Isolated CD4 cells (5 ϫ 10 6 ) were injected via the tail vein into naive HEL-Tg mice.…”

“…In the system we used, transgenic (Tg) mice expressing hen egg lysozyme (HEL) in their eyes are injected with naive CD4 cells that transgenically express a TCR specific against HEL (6,28,29). No pathological changes were detected in eyes of the recipient mice, even following injection with HEL.…”

Active Participation of Antigen-Nonspecific Lymphoid Cells in Immune-Mediated Inflammation

“…Th1 cells were prepared as described in detail elsewhere (15,16). Briefly, purified CD4 cells (Ͼ95%) from 3A9 mice were incubated for 3 days with HEL (at 2 g/ml) and irradiated (30 Gy) syngeneic wild-type naive spleen cells, serving as APC, in Th1 polarizing conditions (IL-12 and anti-IL-4 Ab (15,16)).…”

“…We have investigated the cells and molecules that participate in immune-mediated inflammation by using an experimental model in which transgenic (Tg) mice expressing hen egg lysozyme (HEL) in their eyes develop ocular inflammation following adoptive transfer of TCR Tg HEL-specific Th1 cells (15,16). In a previous study (8), we characterized the features of the donor Th1 cells and the remarkable changes in their surface markers during the various stages of their activation in vitro, early migration to lymphoid tissues, and invasion of the target eye.…”