Immunotherapeutic targeting of LIGHT/LT beta R/HVEM pathway fully recapitulates the reduced cytotoxic phenotype of LIGHT-deficient T cells
MABS
Authors: del Rio, Maria-Luisa; Fernandez-Renedo, Carlos; Chaloin, Olivier; Scheu, Stefanie; Pfeffer, Klaus; Shintani, Yasushi; Perez-Simon, Jose-Antonio; Schneider, Pascal; Rodriguez-Barbosa, Jose-Ignacio
Abstract
Tumor necrosis factor (TNF)/TNF receptor (TNFR) superfamily members play essential roles in the development of the different phases of the immune response. Mouse LIGHT (TNFSF14) is a type II transmembrane protein with a C-terminus extracellular TNF homology domain (THD) that assembles in homotrimers and regulates the course of the immune responses by signaling through 2 receptors, the herpes virus entry mediator (HVEM, TNFSFR14) and the lymphotoxin beta receptor (LT beta R, TNFSFR3). LIGHT is a membrane-bound protein transiently expressed on activated T cells, natural killer (NK) cells and immature dendritic cells that can be proteolytically cleaved by a metalloprotease and released to the extracellular milieu. The immunotherapeutic potential of LIGHT blockade was evaluated in vivo. Administration of an antagonist of LIGHT interaction with its receptors attenuated the course of graft-versus-host reaction and recapitulated the reduced cytotoxic activity of LIGHT-deficient T cells adoptively transferred into non-irradiated semiallogeneic recipients. The lack of LIGHT expression on donor T cells or blockade of LIGHT interaction with its receptors slowed down the rate of T cell proliferation and decreased the frequency of precursor alloreactive T cells, retarding T cell differentiation toward effector T cells. The blockade of LIGHT/LT beta R/HVEM pathway was associated with delayed downregulation of interleukin-7R alpha and delayed upregulation of inducible costimulatory molecule expression on donor alloreactive CD8 T cells that are typical features of impaired T cell differentiation. These results expose the relevance of LIGHT/LT beta R/HVEM interaction for the potential therapeutic control of the allogeneic immune responses mediated by alloreactive CD8 T cells that can contribute to prolong allograft survival.
Amelioration of amyloid-beta-induced deficits by DcR3 in an Alzheimer's disease model
MOLECULAR NEURODEGENERATION
Authors: Liu, Yi-Ling; Chen, Wei-Ting; Lin, Yu-Yi; Lu, Po-Hung; Hsieh, Shie-Liang; Cheng, Irene Han-Juo
Abstract
Background: Microglia mediate amyloid-beta peptide (A beta)-induced neuroinflammation, which is one of the key events in the pathogenesis of Alzheimer's disease (AD). Decoy receptor 3 (DcR3)/TNFRSF6B is a pleiotropic immunomodulator that promotes macrophage differentiation toward the M2 anti-inflammatory phenotype. Based on its role as an immunosupressor, we examined whether DcR3 could alleviate neuroinflammation and AD-like deficits in the central nervous system. Method: We crossed human APP transgenic mice (line J20) with human DcR3 transgenic mice to generate wild-type, APP, DcR3, and APP/DcR3 mice for pathological analysis. The Morris water maze, fear conditioning test, open-field, and elevated-plus maze were used to access their cognitive behavioral changes. Furthermore, the pathological and immune profiles were examined by immunostaining, ELISA, Q-PCR, and IP. In vitro assays were designed to examine DcR3-mediated innate cytokine profile alteration and the potential protective mechanism. Results: We reported that DcR3 ameliorates hippocampus-dependent memory deficits and reduces amyloid plaque deposition in APP transgenic mouse. The protective mechanism of DcR3 mediates through interacting with heparan sulfate proteoglycans and activating IL-4(+) YM1(+) M2a-like microglia that reduces A beta-induced proinflammatory cytokines and promotes phagocytosis ability of microglia. Conclusion: The neuroprotective effect of DcR3 is mediated via modulating microglia activation into anti-inflammatory M2a phenotype, and upregulating DcR3 expression in the brain may be a potential therapeutic approach for AD.