In blue light exposed retinas, microglia were activated and migrated toward the outer retina, whereas a T-lymphocyte response was minimal. The innate immune system was markedly activated, with substantial complement deposition in the outer retina after light exposure. This complement deposition was prevented by AL-8309A. This model may be useful in the evaluation of complement inhibitors and other neuroprotectants intended for ocular use. AL-8309 is under evaluation in the clinic and may be useful in the treatment of AMD.

We have previously shown that cd T cells traffic to the CNS during EAE with concurrently increased expression of b 2 -integrins and production of IFN-c and TNF-a. To extend these studies, we transferred bioluminescent cd T cells to WT mice and followed their movement through the acute stages of disease. We found that cd T cells rapidly migrated to the site of myelin oligodendrocyte glycoprotein peptide injection and underwent massive expansion. Within 6 days after EAE induction, bioluminescent cd T cells were found in the spinal cord and brain, peaking in number between days 10 and 12 and then rapidly declining by day 15. Reconstitution of cd T cell À/À mice with cd T cells derived from b 2 -integrin-deficient mice (CD11a, -b or -c) demonstrated that cd T-cell trafficking to the CNS during EAE is independent of this family of adhesion molecules. We also examined the role of cd T-cellproduced IFN-c and TNF-a in EAE and found that production of both cytokines by cd T cells was required for full development of EAE. These results indicate that cd T cells are critical for the development of EAE and suggest a therapeutic target in demyelinating disease.Key words: EAE/MS . Neuroimmunology . T cells . Transgenic/knockout mice Introduction gd T cells are one of several T-cell subsets that contribute to the development of EAE, a T-cell-mediated autoimmune disease of the CNS that mimics many aspects of the human disease MS [1][2][3]. Cellular infiltration of the brain and spinal cord by several leukocyte subsets, including gd T cells [4][5][6][7][8], is a characteristic feature of both EAE and MS [1,3]. Although it has been appreciated for some time that gd T cells produce cytokines that contribute to the pro-inflammatory milieu [9][10][11][12][13][14][15] and express adhesion molecules that may be critical for initial priming, trafficking to, and infiltration of the CNS [15][16][17], the significance of their contribution to demyelinating disease remains controversial.gd T cells are considered innate immune T cells by virtue of their limited T-cell receptor repertoire, tissue-specific homing patterns and recognition of non-traditional T-cell antigens [18][19][20][21]. Activation of gd T cells occurs on presentation of phosphoantigens, WC1 molecules or self-antigens by non-classical MHC molecules with cytokines and TLR providing co-stimulation [22][23][24][25][26][27][28][29][30]. Regardless of the priming event(s), trafficking mechanisms employed by gd T cells in demyelinating disease remain ill-defined. Studies have implicated VLA-4 as a participant in gd T-cell adhesion to endothelium, epithelium or fibroblasts, and in transmigration [16,17,31,32], but none have implicated VLA-4 in migration of gd T cells to the CNS. In contrast, gd T cells express all four members of the b 2 -integrin family of adhesion molecules and expression increases through the course of myelin oligodendrocyte glycoprotein (MOG)-induced EAE [15]. Importantly, deletion of three of the four b 2 -integrins (CD11a-c) results in significantly attenuate...

The induction of an inflammatory response and release of cytokines such as TNF may be involved in the age-related etiology of Alzheimer disease (AD). In the brain, microglia have been shown to produce a wide variety of immune mediators, including the pro-inflammatory cytokine tumor necrosis factor (TNF). We hypothesize that with age there is increased ability of microglia to produce TNF or that age decreases the neuroprotective effect of TNF against beta-amyloid (Abeta) toxicity in neurons. We investigated the effects of Abeta(1-40) on TNF secretion from forebrain cultures of microglia from embryonic, middle-age (9-month) and old (36-month) rats. Over the first 12 hr of exposure to 10 microM Abeta (1-40), microglia from embryonic and old rats increase TNF secretion, although microglia from middle-age rats did not produce detectable levels of TNF. When low concentrations of TNF are added to neurons together with Abeta (1-40) in the absence of exogenous antioxidants, neuroprotection for old neurons is significantly less than neuroprotection for middle-age neurons. In neurons from old rats, high levels of TNF together with Abeta are more toxic than in neurons from middle-age or embryonic rats. These results are discussed in relation to neuroprotection and toxicity of the age-related pathology of AD.

The expression of beta 2-integrins on gammadelta T cells in naïve mice or those with experimental autoimmune encephalomyelitis (EAE) remains poorly characterized. We compared beta 2-integrin expression and cytokine production between gammadelta and alphabeta T cells over the acute course of EAE. We observed that unlike in alphabeta T cells, beta 2-integrin expression on gammadelta T cells increased significantly from baseline, peaked at Day 10, and remained unchanged in the draining lymph nodes or declined in the spleen and CNS by Day 15. In addition, IFN-gamma- and TNF-alpha-producing gammadelta T cells infiltrated the CNS rapidly and produced significantly more of these cytokines than alphabeta T cells throughout the course of EAE. These results suggest unique roles for beta 2-integrins in the trafficking of gammadelta versus alphabeta T cells during EAE and that gammadelta T cells infiltrate the CNS rapidly, producing cytokines, which modulate acute disease.

Multiple sclerosis (MS) is an autoimmune disease characterized by central nervous system (CNS) inflammation and leukocyte infiltration, demyelination of neurons, and blood-brain barrier breakdown. The development of experimental autoimmune encephalomyelitis (EAE), the animal model for MS is dependent on a number of components of the immune system including complement and adhesion molecules. Previous studies in our lab have examined the role of C3, the central complement component, and intercellular adhesion molecule-1 (ICAM-1) a key cell adhesion molecule involved in leukocyte trafficking to sites of inflammation including the CNS. In these studies we demonstrated that myelin oligodendrocyte glycoprotein (MOG)-induced EAE is markedly attenuated in both ICAM-1 −/− and C3 −/− mice. Given the pivotal role that these proteins play in EAE, we hypothesized that EAE in ICAM-1 −/− and C3 −/− double mutant mice would likely fail to develop. Unexpectedly, EAE in ICAM-1 −/− × C3 −/− mice was only modestly attenuated compared to wild type mice and significantly worse than C3 −/− mice. Leukocyte infiltration was commensurate with disease severity between the three groups of mice. Spinal cord T cells from ICAM-1 −/− × C3 −/− mice produced the highest levels of IFN-γ and TNF-α, despite reduced disease severity compared to wild type mice. The mechanisms behind the elevated EAE severity in ICAM-1 −/− × C3 −/− mice may relate to altered homing of leukocytes or processing of self-antigens in the double mutant background. Keywordsexperimental autoimmune encephalomyelitis; adhesion molecules; complement; neuroimmunology The role of complement and adhesion molecules in the development of experimental autoimmune encephalomyelitis (EAE), the animal model for multiple sclerosis has been extensively studied [1,2,11]. In the course of these studies it has become clear that two ligands for members of the β 2 -integrin family of adhesion molecules, C3 and ICAM-1, play a critical Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. role in the onset and progression of EAE. Null mutations in either gene significantly delay the onset of, and reduce the severity of EAE [6,14]. Likewise, the deletion of the β 2 -integrin receptors that bind C3 and ICAM-1, namely Mac-1 and p150,95, also significantly attenuates EAE [4,5]. These studies indicate important and nonredundant functions for these proteins in the pathogenesis of demyelinating disease. Based on the significant, but incomplete protection from EAE observed when using mice deficient in either protein, we reasoned that a double mutant would develop...