Neuroimmunology Research

Portland, VA, United States

Neuroimmunology Research

Portland, VA, United States
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Dotson A.L.,Neuroimmunology Research | Dotson A.L.,Oregon Health And Science University | Offner H.,Neuroimmunology Research | Offner H.,Oregon Health And Science University
Journal of Neuroscience Research | Year: 2017

Ischemic stroke is a leading cause of death and disability in the United States. It is known that males and females respond differently to stroke. Depending on age, the incidence, prevalence, mortality rate, and disability outcome of stroke differ between the sexes. Females generally have strokes at older ages than males and, therefore, have a worse stroke outcome. There are also major differences in how the sexes respond to stroke at the cellular level. Immune response is a critical factor in determining the progress of neurodegeneration after stroke and is fundamentally different for males and females. Additionally, females respond to stroke therapies differently from males, yet they are often left out of the basic research that is focused on developing those therapies. With a resounding failure to translate stroke therapies from the bench to the bedside, it is clearer than ever that inclusion of both sexes in stroke studies is essential for future clinical success. This Mini-Review examines sex differences in the immune response to experimental stroke and its implications for therapy development. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Chen Y.,Oregon Health And Science University | Zhu W.,Oregon Health And Science University | Zhang W.,Oregon Health And Science University | Libal N.,Oregon Health And Science University | And 4 more authors.
Journal of Neuroscience Methods | Year: 2015

Background: We previously demonstrated that tissue plasminogen activator (tPA) reduces infarct size after mechanical middle cerebral artery occlusion (MCAO) in wild-type (WT) mice and transgenic mice expressing human leukocyte antigen DR2 (DR2-Tg). Clinically, tPA limits ischemic damage by dissolving the clot blocking blood flow through a cerebral artery. To mimic the clinical situation, we developed a new mouse model of thromboembolic stroke, and tested the efficacy of tPA in WT and DR2-Tg mice. New Method Autologous blood is withdrawn into a PE-8 catheter filled with 2 IU α-thrombin. After exposing the catheter briefly to air, the catheter is reintroduced into the external (ECA) and advanced into the internal carotid artery (ICA) to allow for intravascular injection of thrombin at the MCA bifurcation. To validate the model, we tested the effect of tPA on laser-Doppler perfusion (LDP) over the MCA territory and infarct size in WT and DR2-Tg mice. Results: The procedure results in a consistent drop in LDP, and leads to a highly reproducible ischemic lesion. When administered at 15 min after thrombosis, tPA restored LDP and resulted in a significant reduction in infarct size at 24 h after thrombosis in both WT and DR2-Tg. Comparison with Existing Methods: Our model significantly reduces surgery time, requires a single anesthesia exposure, and produces a consistent and predictable infarction, with low variability and mortality. Conclusion: We validated the efficacy of tPA in restoring blood flow and reducing infarct in a new model of endovascular thromboembolic stroke in the mouse. © 2015 Elsevier B.V.

Zhu W.,Oregon Health And Science University | Dotson A.L.,Oregon Health And Science University | Dotson A.L.,Neuroimmunology Research | Libal N.L.,Oregon Health And Science University | And 7 more authors.
Neuroscience | Year: 2015

We have previously demonstrated that recombinant T-cell receptor ligand 1000 (RTL1000) reduces infarct size and improves long-term functional recovery after experimental stroke in young transgenic mice expressing human leukocyte antigen DR2 (DR2-Tg). In this study, we determined the effect of RTL1000 on infarct size in 12-month-old middle-aged DR2-Tg mice, and investigated its mechanism of action. Twelve-month-old male DR2-Tg mice underwent 60min of intraluminal reversible middle cerebral artery occlusion (MCAO). Vehicle or RTL1000 was injected 4, 24, 48 and 72h after MCAO. Cortical, striatal and total hemispheric infarcts were measured 96h after stroke. Spleen and brain tissues were collected 96h after stroke for immunological analysis. Our data showed that RTL1000 significantly reduced infarct size 96h after MCAO in middle-aged male DR2-Tg mice. RTL1000 decreased the number of activated monocytes/microglia cells (CD11b+CD45hi) and CD3+ T cells in the ischemic hemisphere. RTL1000 also reduced the percentage of total T cells and inflammatory neutrophils in the spleen. These findings suggest that RTL1000 protects against ischemic stroke in middle-aged male mice by limiting post-ischemic inflammation. © 2014 IBRO.

Dotson A.L.,Neuroimmunology Research | Dotson A.L.,Oregon Health And Science University | Zhu W.,Oregon Health And Science University | Libal N.,Oregon Health And Science University | And 3 more authors.
Frontiers in Cellular Neuroscience | Year: 2014

Stroke is a leading cause of death and disability in the United States. The lack of clinical success in stroke therapies can be attributed, in part, to inadequate basic research on aging rodents. The current study demonstrates that recombinant TCR ligand therapy uses different immunological mechanisms to protect young and older mice from experimental stroke. In young mice, RTL1000 therapy inhibited splenocyte efflux while reducing frequency of T cells and macrophages in the spleen. Older mice treated with RTL1000 exhibited a significant reduction in inflammatory cells in the brain and inhibition of splenic atrophy. Our data suggest age specific differences in immune response to stroke that allow unique targeting of stroke immunotherapies. © 2014, Frontiers Research Foundation, All rights reserved.

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.

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.

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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