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Zhang B.,Oregon Health And Science University | Subramanian S.,Neuroimmunology Research | Dziennis S.,Oregon Health And Science University | Jia J.,Oregon Health And Science University | And 10 more authors.
Journal of Immunology | Year: 2010

Reduced risk and severity of stroke in adult females is thought to depend on normal endogenous levels of estrogen, a well-known neuroprotectant and immunomodulator. In male mice, experimental stroke induces immunosuppression of the peripheral immune system, characterized by a reduction in spleen size and cell numbers and decreased cytokine and chemokine expression. However, stroke-induced immunosuppression has not been evaluated in female mice. To test the hypothesis that estradiol (E2) deficiency exacerbates immunosuppression after focal stroke in females, we evaluated the effect of middle cerebral artery occlusion on infarct size and peripheral and CNS immune responses in ovariectomized mice with or without sustained, controlled levels of 17-β-E2 administered by s.c. implant or the putative membrane estrogen receptor agonist, G1. Both E2- and G1-replacement decreased infarct volume and partially restored splenocyte numbers. Moreover, E2-replacement increased splenocyte proliferation in response to stimulation with anti-CD3/CD28 Abs and normalized aberrant mRNA expression for cytokines, chemokines, and chemokine receptors and percentage of CD4+CD25+FoxP3+ T regulatory cells observed in E2-deficient animals. These beneficial changes in peripheral immunity after E2 replacement were accompanied by a profound reduction in expression of the chemokine, MIP-2, and a 40-fold increased expression of CCR7 in the lesioned brain hemisphere. These results demonstrate for the first time that E2 replacement in ovariectomized female mice improves stroke-induced peripheral immunosuppression. Copyright © 2010 by The American Association of Immunologists, Inc.


Adamus G.,Casey Eye Institute | Brown L.,Casey Eye Institute | Andrew S.,Neuroimmunology Research | Meza-Romero R.,Neuroimmunology Research | And 3 more authors.
Investigative Ophthalmology and Visual Science | Year: 2012

PURPOSE. Optic neuritis (ON) is a condition involving primary inflammation, demyelination, and axonal injury in the optic nerve and leads to apoptotic retinal ganglion cell (RGC) death, which contributes to the persistence of visual loss. Currently, ON has no effective treatment. The goal was to determine the effectiveness of immunotherapy with recombinant T-cell receptor ligand (RTL) in preventing ON in humanized HLA-DR2 transgenic mice. METHODS. Experimental autoimmune encephalomyelitis (EAE) was induced with myelin oligodendrocyte glycoprotein in humanized HLA-DR2 (DRβ*1501) transgenic mice. Five consecutive doses of RTL342M were administrated at the onset of ON. The development of autoimmune ON was assessed by histopathology at different time points. The levels of myelin loss, axonal loss, and RGC damage were examined by immunofluorescence. RESULTS. HLA-DR2 mice developed chronic ON 2 days before EAE characterized by progressive neurodegeneration in both organs. RTL342M significantly suppressed inflammation in the optic nerve and spinal cord and provided protection for at least 30 days. Examination of myelin loss showed a marked suppression of demyelination and an increase in myelin recovery in the optic nerve. Moreover, RTL342M treatment revealed a neuroprotective effect on optic nerve axons and RGCs in retinas at postimmunization (PI) day 62. CONCLUSIONS. RTL342M suppressed clinical and histologic signs of EAE/ON by preventing the recruitment of inflammatory cells into the optic nerve and showed neuroprotective effects against ON. However, to achieve full therapeutic benefit, more doses may be needed. These findings suggest a possible clinical application of this novel class of T-cell-tolerizing drugs for patients with optic neuritis. © 2012 The Association for Research in Vision and Ophthalmology, Inc.


Huan J.,Oregon Health And Science University | Meza-Romero R.,Oregon Health And Science University | Mooney J.L.,Oregon Health And Science University | Vandenbark A.A.,Oregon Health And Science University | And 4 more authors.
Mucosal Immunology | Year: 2011

Celiac disease (CD) is a disorder of the small intestine caused by intolerance to wheat gluten and related proteins in barley and rye. CD4 T cells have a central role in CD, recognizing and binding complexes of HLA-DQ2.5 bearing gluten peptides that have survived digestion and that are deamidated by tissue transglutaminase (TG2), propagating a cascade of inflammatory processes that damage and eventually destroy the villous tissue structures of the small intestine. In this study, we present data showing that recombinant DQ2.5-derived molecules bearing covalently tethered α2-gliadin-61-71 peptide have a remarkable ability to block antigen-specific T-cell proliferation and inhibited proinflammatory cytokine secretion in human DQ2.5-restricted α2-gliadin-specific T-cell clones obtained from patients with CD. The results from our in vitro studies suggest that HLA-DQ2.5-derived molecules could significantly inhibit and perhaps reverse the intestinal pathology caused by T-cell-mediated inflammation and the associated production of proinflammatory cytokines. © 2011 Society for Mucosal Immunology.


Dotson A.L.,Neuroimmunology Research | Dotson A.L.,Oregon Health And Science University | Wang J.,Oregon Health And Science University | Saugstad J.,Oregon Health And Science University | And 3 more authors.
Journal of Neuroimmunology | Year: 2015

The peripheral immune response contributes to neurodegeneration after stroke yet little is known about how this process differs between males and females. The current study demonstrates that splenectomy prior to experimental stroke eliminates sex differences in infarct volume and activated brain monocytes/microglia. In the periphery of both sexes, activated T cells correlate directly with stroke outcome while monocytes are reduced by splenectomy only in males. This study provides new information about the sex specific mechanisms of the peripheral immune response in neurodegeneration after stroke and demonstrates the need for representation of both sexes in basic and clinical stroke research. © 2014 Elsevier B.V.


Bodhankar S.,Neuroimmunology Research | Bodhankar S.,Oregon Health And Science University | Chen Y.,Oregon Health And Science University | Vandenbark A.A.,Neuroimmunology Research | And 5 more authors.
Metabolic Brain Disease | Year: 2014

Clinical stroke induces inflammatory processes leading to cerebral and splenic injury and profound peripheral immunosuppression. IL-10 expression is elevated during major CNS diseases and limits inflammation in the brain. Recent evidence demonstrated that absence of B-cells led to larger infarct volumes and CNS damage after middle cerebral artery occlusion (MCAO) that could be prevented by transfer of IL-10+ B-cells. The purpose of this study was to determine if the beneficial immunoregulatory effects on MCAO of the IL-10 + B-cell subpopulation also extends to B-cell-sufficient mice that would better represent stroke subjects. CNS inflammation and infarct volumes were evaluated in male C57BL/6J (WT) mice that received either RPMI or IL-10+ B-cells and underwent 60 min of middle cerebral artery occlusion (MCAO) followed by 96 h of reperfusion. Transfer of IL-10+ B-cells markedly reduced infarct volume in WT recipient mice when given 24 h prior to or 4 h after MCAO. B-cell protected (24 h pre-MCAO) mice had increased regulatory subpopulations in the periphery, reduced numbers of activated, inflammatory T-cells, decreased infiltration of T-cells and a less inflammatory milieu in the ischemic hemispheres of the IL-10+ B-cell-treated group. Moreover, transfer of IL-10+ B-cells 24 h before MCAO led to a significant preservation of regulatory immune subsets in the IL-10+ B-cell protected group presumably indicating their role in immunomodulatory mechanisms, post-stroke. Our studies are the first to demonstrate a major immunoregulatory role for IL-10+ regulatory B-cells in preventing and treating MCAO in WT mice and also implicating their potential role in attenuating complications due to post-stroke immunosuppression. © 2013 Springer Science+Business Media.


Zhu W.,Oregon Health And Science University | Libal N.L.,Oregon Health And Science University | Casper A.,Oregon Health And Science University | Bodhankar S.,Oregon Health And Science University | And 4 more authors.
Translational Stroke Research | Year: 2014

RTL1000 is a partial human MHC molecule coupled to a human myelin peptide. We previously demonstrated that RTL1000 was protective against experimental ischemic stroke in HLA-DR2 transgenic (DR2-Tg) mice. Since thrombolysis with recombinant tissue plasminogen activator (t-PA) is a standard therapy for stroke, we determined if RTL1000 efficacy is altered when combined with t-PA in experimental stroke. Male DR2-Tg mice underwent 60 min of intraluminal middle cerebral artery occlusion (MCAO). t-PA or vehicle was infused intravenously followed by either a single or four daily subcutaneous injections of RTL1000 or vehicle. Infarct size was measured by 2, 3, 5-triphenyltetrazolium chloride staining at 24 or 96 h of reperfusion. Our data showed that t-PA alone reduced infarct size when measured at 24 h but not at 96 h after MCAO. RTL1000 alone reduced infarct size both at 24 and 96 h after MCAO. Combining RTL1000 with t-PA did not alter its ability to reduce infarct size at either 24 or 96 h after MCAO and provides additional protection in t-PA treated mice at 24 h after ischemic stroke. Taken together, RTL1000 treatment alone improves outcome and provides additional protection in t-PA-treated mice in experimental ischemic stroke. © 2014 Springer Science+Business Media New York.


Subramanian S.,Neuroimmunology Research | Yates M.,Neuroimmunology Research | Yates M.,Oregon Health And Science University | Vandenbark A.A.,Neuroimmunology Research | And 3 more authors.
Immunology | Year: 2011

Oestrogen (17β-oestradiol, E2) is a highly effective treatment for experimental autoimmune encephalomyelitis (EAE) that may potentiate Foxp3+ regulatory T (Treg) cells, which in turn limit the expansion of encephalitogenic T-cell specificities. To determine if Treg cells constitute the major non-redundant protective pathway for E2, we evaluated E2 protection of EAE after targeted deletion of Foxp3 expression in Foxp3-DTR mice. Unexpectedly, E2-treated Foxp3-deficient mice were completely protected against clinical and histological myelin oligodendrocyte glycoprotein (MOG)-35-55 peptide-induced EAE before succumbing to diphtheria toxin-induced mortality. This finding indicated the presence of alternative E2-dependent EAE-protective pathways that could compensate for the lack of Treg cells. Further investigation revealed that E2 treatment inhibited proliferation and expression of CCL2 and CXCL2, but enhanced secretion of interleukin-10 (IL-10) and IL-13 by MOG-35-55-specific spleen cells. These changes occurred concomitantly with increased expression of several chemokines and receptors, including CXCL13 and CXCR5, and the negative co-activation molecules, PD-L1 and B7.2, by B cells and dendritic cells. Furthermore, E2 treatment resulted in higher percentages of spleen and lymph node T cells expressing IL-17, interferon-γ and tumour necrosis factor-α, but with lower expression of CCR6, suggesting sequestration of MOG-35-55 peptide-specific T cells in peripheral immune organs. Taken together, these data suggest that E2-induced mechanisms that provide protection against EAE in the absence of Foxp3+ Treg cells include induction of regulatory B cells and peripheral sequestration of encephalitogenic T cells. © 2010 The Authors. Immunology © 2010 Blackwell Publishing Ltd.


Yates M.A.,Neuroimmunology Research | Yates M.A.,Oregon Health And Science University | Li Y.,Neuroimmunology Research | Li Y.,Oregon Health And Science University | And 6 more authors.
Journal of Neuroimmunology | Year: 2010

Ovarian hormones, including progesterone, are known to have immunomodulatory and neuroprotective effects which may alter the disease course of experimental autoimmune encephalomyelitis (EAE). In the current study, we examined the treatment potential of progesterone beginning at the onset of EAE symptoms. Progesterone treated animals showed reduced peak disease scores and cumulative disease indices, and decreased inflammatory cytokine secretion (IL-2 and IL-17). In addition, increased production of IL-10 was accompanied by increased numbers of CD19+ cells and an increase in CD8+ cells. Decreased chemokine and chemokine receptor expression in the spinal cord also contributed to decreased lesions in the spinal cord. © 2010 Elsevier B.V.


Song P.,Oregon Health And Science University | Chou Y.K.,Oregon Health And Science University | Zhang X.,Oregon Health And Science University | Meza-Romero R.,Neuroimmunology Research | And 4 more authors.
Biochemical and Biophysical Research Communications | Year: 2014

Cell type specific delivery of RNAi to T cells has remained to be a challenge. Here we describe an aptamer mediated delivery of shRNA to CD4+ T cells targeting RORγt to suppress Th17 cells. A cDNA encoding CD4 aptamer and RORγt shRNA was constructed and the chimeric CD4 aptamer-RORγt shRNA (CD4-AshR-RORγt) was generated using in vitro T7 RNA transcription. 2′-F-dCTP and 2′-F-dUTP were incorporated into CD4-AshR-RORγt for RNase resistance. CD4-AshR-RORγt was specifically uptaken by CD4+ Karpas 299 cells and primary human CD4+ T cells. The RORγt shRNA moiety of CD4-AshR-RORγt chimera was cleaved and released by Dicer. Furthermore, CD4-AshR-RORγt suppressed RORγt gene expression in Karpas 299 cells and CD4+ T cells and consequently inhibited Th17 cell differentiation and IL-17 production. These results demonstrate that aptamer-facilitated cell specific delivery of shRNA represents a novel approach for efficient RNAi delivery and is potentially to be developed for therapeutics targeting specific T cells subtypes.


Bodhankar S.,Neuroimmunology Research | Vandenbark A.A.,Neuroimmunology Research | Vandenbark A.A.,Oregon Health And Science University | Vandenbark A.A.,Research Service | And 2 more authors.
Immunology | Year: 2012

It is now well accepted that sex hormones have immunoregulatory activity and may prevent exacerbations in multiple sclerosis during pregnancy. Our previous studies demonstrated that oestrogen (17β-oestradiol; E2) protection against experimental autoimmune encephalomyelitis (EAE) is mediated mainly through oestrogen receptor-α (ERα) and the membrane receptor G-protein-coupled receptor 30 (GPR30) and is abrogated in the absence of B cells and the co-inhibitory receptor, Programmed Death-1 (PD-1). To critically evaluate the cell source of the E2 and PD-1 co-inhibitory pathways in EAE regulation, we assessed the requirement for ERs on transferred B cells and downstream effects on expression of PD-1/PD-ligand on CD4+ Foxp3+ regulatory T (Treg) cells in B-cell-replenished, E2-treated B-cell-deficient (μMT-/-) mice with EAE. The results clearly demonstrated involvement of ERα and GPR30 on transferred B cells that mediated the protective E2 treatment effect on EAE and further showed an E2-mediated B-cell-dependent up-regulation of PD-1 on CD4+ Foxp3+ Treg cells. These findings identify regulatory B-cell populations as key players in potentiating Treg-cell activity during E2-mediated protection against EAE. © 2012 The Authors. Immunology © 2012 Blackwell Publishing Ltd.

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