Mouse Models Of Autoimmune Diseases Research Articles

The therapeutic potential of tuftsin-phosphorylcholine in giant cell arteritis

Tuftsin-PhosphorylCholine (TPC) is a novel bi-specific molecule which links tuftsin and phosphorylcholine. TPC has shown immunomodulatory activities in experimental mouse models of autoimmune diseases. We studied herein the effects of TPC ex vivo on both peripheral blood mononuclear cells (PBMCs) and temporal artery biopsies (TABs) obtained from patients with giant cell arteritis (GCA) and age-matched disease controls. GCA is an immune-mediated disease affecting large vessels. Levels of 18 cytokines in supernatants, PBMC viability, T helper (Th) cell differentiation of PBMCs and gene expression in TABs were analyzed. Treatment ex vivo with TPC decreased the production of IL-1β, IL-2, IL-5, IL-6, IL-9, IL-12(p70), IL-13, IL-17A, IL-18, IL-21, IL-22, IL-23, IFNγ, TNFα, GM-CSF by CD3/CD28 activated PBMCs whereas it negligibly affected cell viability. It reduced Th1 and Th17 differentiation while did not impact Th22 differentiation in PBMCs stimulated by phorbol 12-myristate 13-acetate plus ionomycin. In inflamed TABs, treatment with TPC down-regulated the production of IL-1β, IL-6, IL-13, IL-17A and CD68 gene expression. The effects of TPC were comparable to the effects of dexamethasone, included as the standard of care, with the exception of a greater reduction of IL-2, IL-18, IFNγ in CD3/CD28 activated PBMCs and CD68 gene in inflamed TABs. In conclusion our results warrant further investigations regarding TPC as an immunotherapeutic agent in GCA and potentially other autoimmune and inflammatory diseases.

Intravenous immunoglobulin induces IL-4 in human basophils by signaling through surface-bound IgE

Therapeutic normal IgG or intravenous immunoglobulin (IVIG) exerts anti-inflammatory effects through several mutually nonexclusive mechanisms. Recent data in mouse models of autoimmune disease suggest that IVIG induces IL-4 in basophils by enhancing IL-33 in SIGN-related 1-positive innate cells. However, translational insight on these data is lacking. We sought to investigate the effect of IVIG on human basophil functions. Isolated circulating basophils from healthy donors were cultured in the presence of IL-3, IL-33, GM-CSF, thymic stromal lymphopoietin, or IL-25. The effect of IVIG and F(ab')2 and Fc IVIG fragments was examined based on expression of various surface molecules, phosphorylation of spleen tyrosine kinase, induction of cytokines, and histamine release. Basophil phenotypes were also analyzed from IVIG-treated patients with myopathy. Approaches, such as depletion of anti-IgE reactivity from IVIG, blocking antibodies, or inhibitors, were used to investigate the mechanisms. We report that IVIG directly induces activation of IL-3-primed human basophils, but IL-33 and other cytokines were dispensable for this effect. Activation of basophils by IVIG led to enhanced expression of CD69 and secretion of IL-4, IL-6, and IL-8. IVIG-treated patients with myopathy displayed enhanced expression of CD69 on basophils. The spleen tyrosine kinase pathway is implicated in these functions of IVIG and were mediated by F(ab')2 fragments. Mechanistically, IVIG induced IL-4 in human basophils by interacting with basophil surface-bound IgE but independent of FcγRII, type II Fc receptors, C-type lectin receptors, and sialic acid-binding immunoglobulin-like lectins. These results uncovered a pathway of promoting the TH2 response by IVIG through direct interaction of IgG with human basophils.

Conditioning for Hematopoietic Stem Cell Transplantation Using Antibody-Drug Conjugate Targeting CD45 Permits Engraftment across Immunologic Barriers

INTRODUCTION: Hematopoietic stem cell transplantation (HSCT) is a potentially curative therapy for benign and malignant hematologic diseases. It also holds great promise as treatment for infectious and autoimmune disease and for autologous gene therapy. However, due to the toxicity of conditioning regimens for HSCT, it is generally reserved for the most life-threatening diagnoses, such as acute leukemia. Targeted approaches to conditioning may improve the safety of HSCT and extend its applicability to other diseases. Recently, conditioning regimens were described consisting of treatment with anti-CD45.2 or anti-cKit antibodies conjugated to the ribosome-inhibiting protein saporin (CD45-SAP and cKit-SAP, respectively) (Palchaudhuri et al (2016), Nat Biotechnol, Czechowicz et al (2016), ASH Abstract). These were reported to deplete murine hematopoietic stem cells (HSCs) and permit engraftment of syngeneic HSCs with minimal toxicity. However, the ability of CD45-SAP and cKit-SAP to permit HSCT across immunologic barriers without chemotherapy or radiation, or to target malignant cells expressing these receptors, are potential applications that were not explored.METHODS: We compared CD45-SAP and cKit-SAP conditioning in syngeneic (B6 to B6) and allogeneic (CB6F1 to B6) murine transplantation models. Donor chimerism in peripheral blood (PB) and complete blood counts (CBCs) were assessed monthly during these experiments. Successful HSC engraftment was confirmed by serial transplantation experiments. Human CD45-SAP and cKit-SAP conjugates were also tested for their ability to target MOLM13 AML cells using XTT viability assays, and in targeting cord-blood derived HSCs using colony forming cell assays.RESULTS: We confirmed that CD45-SAP dosed at 75 µg per mouse could effectively deplete B6 mice of HSCs and condition them for syngeneic HSCT as reported (Palchaudhuri et al (2016), Nat Biotechnol), with normal-range CBCs and stable donor PB chimerism of approximately 80% at 6 months post-transplant. Donor-derived HSC in CD45-SAP treated mice successfully engrafted upon transplantation to secondary B6 recipients. cKit-SAP dosed at 10 µg per mouse was sufficient for HSC depletion, but robust syngeneic engraftment required dosing at 50 µg per mouse. Notably, CD45-SAP treatment combined with CD4+and CD8+ T cell depletion permitted haploidentical transplantation from CB6F1 donors to B6 recipients, with normal-range CBCs and stable donor PB chimerism of approximately 70% at 3 months post-transplant. Finally, human CD45-SAP conjugates could successfully target MOLM13 leukemia cells and cord-blood derived HSCs in vitro.CONCLUSIONS: Transplantation in mice across immunological barriers is achievable using CD45-SAP conditioning, with high-level donor chimerism without chemotherapy or radiation. Furthermore, human CD45-SAP conjugates can successfully target human leukemia cell lines and primary HSCs in vitro. Further studies are underway in three areas. First, by combining T and NK cell depletion with CD45-SAP conditioning, we are attempting full-mismatch HSCT in mice. Second, using humanized mouse models, we will assess the ability of CD45-SAP to target human leukemia cells and HSCs in vivo. Finally, we are exploring using HSCT with CD45-SAP conditioning as a treatment in mouse models of autoimmune disease. DisclosuresRettig:Amphivena Therapeutics: Research Funding; Novimmune: Research Funding.

Immunoglobulin Light Chain Gene Rearrangements, Receptor Editing and the Development of a Self-Tolerant Antibody Repertoire.

Discussion of the antibody repertoire usually emphasizes diversity, but a conspicuous feature of the light chain repertoire is its lack of diversity. The diversity of reported allelic variants of germline light chain genes is also limited, even in well-studied species. In this review, the implications of this lack of diversity are considered. We explore germline and rearranged light chain genes in a variety of species, with a particular focus on human and mouse genes. The importance of the number, organization and orientation of the genes for the control of repertoire development is discussed, and we consider how primary rearrangements and receptor editing together shape the expressed light chain repertoire. The resulting repertoire is dominated by just a handful of IGKV and IGLV genes. It has been hypothesized that an important function of the light chain is to guard against self-reactivity, and the role of secondary rearrangements in this process could explain the genomic organization of the light chain genes. It could also explain why the light chain repertoire is so limited. Heavy and light chain genes may have co-evolved to ensure that suitable light chain partners are usually available for each heavy chain that forms early in B cell development. We suggest that the co-evolved loci of the house mouse often became separated during the inbreeding of laboratory mice, resulting in new pairings of loci that are derived from different sub-species of the house mouse. A resulting vulnerability to self-reactivity could explain at least some mouse models of autoimmune disease.

PSGL-1 regulates the extent of TCR-dependent activation in T cells and prevents their suppression by Tregs

Abstract We recently demonstrated that PSGL-1 (P-selectin glycoprotein-1) could act as a T cell-intrinsic checkpoint inhibitor during chronic viral infection. As such, PSGL-1 may be a viable target to control T cell responses in the setting of autoimmune disease. In this study, we investigated the role of PSGL-1 on the activation of T cells and in mouse models of autoimmune disease. Here we find that the lack of PSGL-1 on T cells results in clinically worse disease in both EAE and adoptive transfer colitis, which supports its function as a negative regulator of T cell activation. However, in vivo treatment with an anti-PSGL-1 antibody known to block binding of the ligand, P-selectin, from the time of disease initiation had little effect on disease severity in the transfer colitis model and led to exacerbated disease in the EAE model. Crosslinking PSGL-1 on naïve T cells in vitro in the presence of TCR signals results in up-regulation of PD-1 but also up-regulation of other activation markers, suggesting that PSGL-1 exerts regulatory effects during the early activation program in T cells. Surprisingly, however, in an in vitro assay, crosslinking PSGL-1 on effector T cells resulted in resistance to regulatory T cell suppression. Therefore, anti-PSGL-1 treatment results in enhanced T cell activation and resistance to Treg suppression, thereby leading to more severe autoimmune disease by altering/blocking PSGL-1 signaling to phenocopy PSGL-1-deficiency.

RTA 1701 is an orally-bioavailable, potent, and selective RORγt inhibitor that suppresses Th17 differentiation in vitro and is efficacious in mouse models of autoimmune disease.

Abstract Retinoic acid-related orphan receptor γt (RORγt) is a transcription factor that directs the differentiation of Th17 cells, a subset of CD4+ helper T cells involved in autoimmune disorders. Once differentiated, Th17 cells secrete interleukin-17A (IL-17A) and other key cytokines implicated in autoimmune and inflammatory disease. Antibodies that target Th17 cells are approved for several autoimmune disorders, validating the important role of Th17 cells in disease. RTA 1701 is a potent and selective RORγt inhibitor in preclinical development for autoimmune disorders. It inhibits the activity of RORγt, as assessed using ligand binding domain and full-length RORγt reporters. Moreover, RTA 1701 is selective for RORγt and does not inhibit the activity of two closely-related receptors, RORα and RORβ. By inhibiting RORγt, RTA 1701 blocks Th17 differentiation of naïve CD4+ T cells and IL-17A production by both Th17 polarized CD4+ T cells and activated peripheral blood mononuclear cells (PBMCs). The expression of other RORγt target genes and Th17 signature genes (eg, IL-17F, IL-21, CCL20) is also reduced following RTA 1701 treatment of Th17-polarized naïve CD4+ T cells, as assessed by qPCR. RTA 1701 is orally bioavailable with excellent pharmacokinetic properties in rodents and monkey. Furthermore, this compound is efficacious in animal models of autoimmune disease, including the collagen-induced arthritis (CIA) mouse model of rheumatoid arthritis and the experimental autoimmune encephalomyelitis (EAE) mouse model of multiple sclerosis. Together, these results suggest that RORγt inhibition by RTA 1701 may have therapeutic potential in Th17-associated autoimmune disorders.

CCR2 mediates transendothelial migration of human pathogenic Th17 cells

Abstract Leukocyte extravasation is a multistep process characterized by rolling and arrest on the endothelium followed by transendothelial migration (TEM). Arrest and TEM by T cells typically requires the activities of chemokines and their receptors. Previously, we showed that CCR2 identifies highly differentiated, readily activated CD4+ memory T cells in human blood with diverse effector capabilities, and we showed that CCR6 is the signature chemokine receptor for Th17 cells. Here we describe studies of the migratory capabilities and effector profiles of CD4+ CCR6+ CCR2+ as compared with CD4+ CCR6+ CCR2− and CD4+ CCR6− CCR2− T cells from human blood. Using flow chamber assays with TNFa-activated human umbilical vein endothelial cells, we found that among the CCR6+ cells, only the CCR2+ subset was able to cross the endothelial monolayer efficiently. Using antibodies against the CCR6 ligand, CCL20, and a specific inhibitor of CCR2, we found that CCR6 was important for arrest and that CCR2 was critical for subsequent TEM. Using intracellular staining of cells activated ex vivo, we found that although IL-17-expressing cells were found within all CCR6+ subsets, the CCR6+CCR2+ cells were distinguished by their production of IFNg, GM-CSF, and TNFa, thereby demonstrating the cytokine profile of pathogenic Th17 cells as identified in mouse models of autoimmune disease. Taken together, our studies suggest that chemokine receptors on memory Th cells play non-redundant roles in the egress from blood, that providing T cells with CCR6 and CCR2 could enhance their trafficking into tissue, and that, on the other hand, blocking CCR2 alone could prevent the extravasation of pathogenic Th17 cells and ameliorate tissue damage in Th17-cell driven disease.

Angiotensin II-C-C chemokine receptor2/5 axis-dependent monocyte/macrophage recruitment contributes to progression of experimental autoimmune myocarditis.

Angiotensin II (ANG II) plays critical roles in modulation of circulatory homeostasis and activation of innate and adaptive immunity and has also been implicated in several mouse models of autoimmune disease. However, how ANG II regulates macrophages and is involved in development of experimental autoimmune myocarditis (EAM) remains unclear. Therefore, the present study aimed to address the above question and explore possible mechanisms. EAM was induced in BALB/c mice. ANG II was quantitated by ELISA and hematoxylin and eosin staining was employed to analyze pathological changes and macrophage infiltration. The chemotactic ability of ANG II was assessed by using a Transwell system. It was found that ANG II is up-regulated in serum and heart tissues of mice with EAM and that ANG II significantly drives monocyte/macrophage infiltration through the C-C chemokine receptor 2/5 (CCR2/5) axis. CCR2/5 antagonists and ANG II receptor inhibitor could all abrogate monocyte/macrophage infiltration and ameliorate development of EAM. Our results have firstly identified a novel function of ANG II: that it is a critical chemokine for monocyte/macrophage recruitment. Furthermore, our results indicate that ANG II is a potential candidate for treatment of inflammatory diseases.

Autoimmune disease mouse model exhibits pulmonary arterial hypertension.

BackgroundPulmonary arterial hypertension is often associated with connective tissue disease. Although there are some animal models of pulmonary hypertension, an autoimmune disease-based model has not yet been reported. MRL/lpr mice, which have hypergammaglobulinemia, produce various autoimmune antibodies, and develop vasculitis and nephritis spontaneously. However, little is known about pulmonary circulation in these mice. In the present study, we examined the pulmonary arterial pressure in MRL/lpr mice.Methods and resultsWe used female MRL/lpr mice aged between 12 and 14 weeks. Fluorescent immunostaining showed that there was no deposition of immunoglobulin or C3 in the lung tissue of the MRL/lpr mice. Elevation of interferon-γ and interleukin-6 was recognized in the lung tissue of the MRL/lpr mice. Right ventricular systolic pressure, Fulton index and the ratio of right ventricular weight to body weight in the MRL/lpr mice were significantly higher than those in wild type mice with same background (C57BL/6). The medial smooth muscle area and the proportion of muscularized vessels in the lung tissue of the MRL/lpr mice were larger than those of the C57BL/6 mice. Western blot analysis demonstrated markedly elevated levels of prepro-endothelin-1 and survivin as well as decreased endothelial nitric oxide synthase phosphorylation in the lung tissue of the MRL/lpr mice. Terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling assay showed the resistance against apoptosis of pulmonary arterial smooth muscle cells in the MRL/lpr mice.ConclusionWe showed that MRL/lpr mice were complicated with pulmonary hypertension. MRL/lpr mice appeared to be a useful model for studying the mechanism of pulmonary hypertension associated with connective tissue diseases.

Correction of Ductal CFTR Activity Rescues Acinar Cell and Pancreatic and Salivary Gland Functions in Mouse Models of Autoimmune Disease

Sjögren's syndrome and autoimmune pancreatitis are disorders with decreased function of salivary, lacrimal glands, and the exocrine pancreas. Nonobese diabetic/ShiLTJ mice and mice transduced with the cytokine BMP6develop Sjögren's syndrome and chronic pancreatitis and MRL/Mp mice are models of autoimmune pancreatitis. Cystic fibrosis transmembrane conductance regulator (CFTR) is a ductalCl-channel essential for ductal fluid and HCO3- secretion. We used these models to ask the following questions: is CFTR expression altered in these diseases, does correction of CFTR correct gland function, and most notably, does correcting ductal function correct acinar function? We treated the mice models with the CFTR corrector C18 and the potentiator VX770. Glandular, ductal, and acinar cells damage, infiltration, immune cells and function were measured invivo and in isolated duct/acini. In the disease models, CFTR expression is markedly reduced. The salivary glands and pancreas are inflamed with increased fibrosis and tissue damage. Treatment with VX770 and, in particular, C18 restored salivation, rescued CFTR expression and localization, and nearly eliminated the inflammation and tissue damage. Transgenic overexpression of CFTR exclusively in the duct had similar effects. Most notably, the markedly reduced acinar cell Ca2+ signaling, Orai1, inositol triphosphate receptors, Aquaporin 5 expression, and fluid secretion were restored by rescuing ductal CFTR. Our findings reveal that correcting ductal function is sufficient to rescue acinar cell function and suggests that CFTR correctors are strong candidates for the treatment of Sjögren's syndrome and pancreatitis.

Inactivation of the KSRP gene modifies collagen antibody induced arthritis

The KH type splicing regulatory protein (KSRP) is a nucleic acid binding protein, which negatively regulates the stability and/or translatability of many mRNA species encoding immune-relevant proteins. As KSRP is expressed in immune cells including T and B cells, neutrophils, macrophages and dendritic cells, we wanted to analyze its importance for the development of autoimmune diseases.We chose collagen antibody-induced arthritis (CAIA) as an appropriate autoimmune disease mouse model in which neutrophils and macrophages constitute the main effector cell populations. We compared arthritis induction in wild type (WT) and KSRP−/− mice and paws were taken for histological sections and qPCR analysis. Furthermore, we determined the frequencies of spleen immune cells by flow cytometry. Cytokine levels in spleen cell supernatants were determined by cytometric bead array analyses (CBA).After CAIA induction we unexpectedly observed in WT animals much stronger swelling of the paws than in KSRP−/− mice. In accordance, histological staining of paw sections of KSRP−/− animals revealed much lower frequencies of infiltrating immune cells in the joints compared to WT animals. Furthermore, CAIA-treatment resulted in reduced expression of several inflammatory factors (like CXCL-1, iNOS, TNF-α and S100A8) as well as immune cell marker genes (e.g. LFA-1, CD68, Ly6G) in the joints of KSRP−/− mice.Spleen cells of KSRP−/− mice showed lower frequencies of myeloid cells. On cytokine level IFN-γ production was increased in spleen cells of KSRP−/− mice compared to WT samples.These data surprisingly suggest that the absence of KSRP protects against the induction of inflammatory arthritis.

MEDI-551 Treatment Effectively Depletes B Cells and Reduces Serum Titers of Autoantibodies in Mice Transgenic for Sle1 and Human CD19.

To evaluate treatment with MEDI-551, a humanized anti-human CD19 monoclonal antibody, in a model of autoimmunity involving mice transgenic (Tg) for Sle1 and human CD19 (hCD19). Sle1.hCD19-Tg mice were given either a single intravenous dose of MEDI-551 or repeated doses of MEDI-551 biweekly for up to 12 weeks. The numbers of B cells in the blood, spleen, and bone marrow were determined by flow cytometry assay. In the spleen and bone marrow, the number of IgM- and IgG-specific antibody-secreting cells (ASCs) and the number of ASCs specific for anti-double-stranded DNA (anti-dsDNA) were determined by enzyme-linked immunospot assay. Serum autoantibody and total immunoglobulin levels were determined by enzyme-linked immunosorbent assay, and levels of inflammatory proteins were tested using a multianalyte profiling platform. MEDI-551 treatment of Sle1.hCD19-Tg mice resulted in effective and sustained B cell depletion throughout the duration of the experiment. The frequency of IgM and IgG ASCs in the spleen was reduced by ≥90%, whereas in the bone marrow, the total ASC frequency was not changed. Levels of autoantibodies specific for dsDNA as well as antihistone and antinuclear antibodies were each reduced by 40-80%, but total serum immunoglobulin levels were largely unchanged at the end of 12 weeks of treatment. These findings highlight the ability of MEDI-551 to deplete B cells and ASCs in autoimmune Sle1.hCD19-Tg mice. MEDI-551 treatment resulted in a robust reduction of autoantibodies but had minimal effect on total serum immunoglobulins. Thus, the novel ability of MEDI-551 to remove a broad range of B cells as well as to lower most disease-driving autoantibodies in an autoimmune disease mouse model warrants continued research. Several clinical studies to explore the safety and activity of MEDI-551 in autoantibody-associated autoimmune diseases are ongoing.

BIP induces mice CD19(hi) regulatory B cells producing IL-10 and highly expressing PD-L1, FasL.

Many studies have shown that B cells possess a regulatory function in mouse models of autoimmune diseases. Regulatory B cells can modulate immune response through many types of molecular mechanisms, including the production of IL-10 and the expression of PD-1 Ligand and Fas Ligand, but the microenvironmental factors and mechanisms that induce regulatory B cells have not been fully identified. BIP (binding immunoglobulin protein), a member of the heat shock protein 70 family, is a type of evolutionarily highly conserved protein. In this article, we have found that IL-10(+), PD-L1(hi) and FasL(hi) B cells are discrete cell populations, but enriched in CD19(hi) cells. BIP can induce IL-10-producing splenic B cells, IL-10 secretion and B cells highly expressing PD-L1 and FasL. CD40 signaling acts in synergy with BIP to induce regulatory B cells. BIP increased surface CD19 molecule expression intensity and IL-10(+), PD-L1(hi) and FasL(hi) B cells induced by BIP share the CD19(hi) phenotype. Furthermore, B cells treated with BIP and anti-CD40 can lead to suppression of T cell proliferation and the effect is partially IL-10-dependent and mainly BIP-induced. Taken together, our findings identify a novel function of BIP in the induction of regulatory B cells and add a new reason for the therapy of autoimmune disorders or other inflammatory conditions.

Regulatory B10 cell development and function.

B cells are known to instigate and promulgate immune responses by producing antibodies and presenting antigens to T cells. However, a rare but potent B-cell subset in both humans and mice is capable of inhibiting immune responses through the production of the anti-inflammatory cytokine IL-10. Regulatory B cells do not express any unique combination of surface markers but instead represent a small population of B cells that have acquired the unique ability to produce IL-10. This numerically rare B-cell subset is therefore functionally referred to as 'B10 cells' to reflect both their molecular program and the fact that their anti-inflammatory effects in models of autoimmunity, infection and cancer are solely attributable to IL-10 production. As with most B cells, B10 cell development and function appear to be predominantly, if not exclusively, driven by antigen-receptor signals. Once generated, B10 cells respond to both innate and adaptive immune signals, with a requirement for antigen-specific local interactions with T cells to induce IL-10 production and to provide optimal immune suppression in mouse models of autoimmune disease. B10 cells therefore provide an antigen-specific mechanism for delivering IL-10 locally to sites of immune activation and inflammation. The ability of B10 cells to regulate innate and adaptive immune responses makes them an ideal therapeutic target for the treatment of many immune-related disorders.

History and milestones of mouse models of autoimmune diseases.

Autoimmune diseases are a group of disorders mediated by self-reactive T cells and/or autoantibodies. Mice, as the most widely used animal for modeling autoimmune disorders, have been extensively used in the investigation of disease pathogenesis as well as in the search for novel therapeutics. Since the first mouse model of multiple sclerosis was established more than 60 years ago, hundreds of mouse models have been established for tens of autoimmune diseases. These mouse models can be divided into three categories based on the approaches used for disease induction. The first one represents the induced models in which autoimmunity is initiated in mice by immunization, adoptive transfer or environmental factors. The second group is formed by the spontaneous models where mice develop autoimmune disorders without further induction. The third group refers to the humanized models in which mice bearing humanized cells, tissues, or genes, develop autoimmune diseases either spontaneously or by induction. This article reviews the history and highlights the milestones of the mouse models of autoimmune diseases.

Early Apoptotic Cells (ApoCell) As Prophylaxis of Graft-Versus-Host Disease in Myeloablative HLA-Matched Allogeneic Bone Marrow Transplantation Is Safe and Effective: 1 Year Follow-up

Apoptotic cells infusion (ApoCell) is a novel cellular therapy that was found to be effective in a variety of mouse models of autoimmune diseases. ApoCell was tested in humans in addition to cyclosporine and methotrexate, as prophylaxis of graft-versus-host disease (GVHD) in HLA-matched myeloablative allogeneic bone marrow transplantation (alloBMT) from a related donor. We conducted a phase I//IIa clinical trial where we treated 13 patients (median age, 37 years; range, 20-59 years) with advanced hematologic malignancies that received conventional myeloablation with 35, or 70, or 140, or 210x106 cell/kg of donor ApoCell, on day -1 of transplantation (Mevorach et al. BBMT 2014).The non-relapse mortality at day 100 and 180 after transplantation was the same, 7.7%. The overall survival at 100 and 180 days after transplantation was 92% and 85%, respectively. We now report 1 year overall survival rate which was 62% with a non-relapse survival rate of 89% (100% for the two higher cohorts).These results are in agreement with additional safety observations that included: ten serious adverse effects with all being not related (7) or unlikely to be related (3) to ApoCell infusion, and only three out of hundreds adverse effects, that were reported as possibly related to ApoCell infusion (with no definite or probable adverse effects).The incidences of acute grades II through IV GVHD for all 13 patients and for the two higher doses were 23% and 0% (six patients), respectively. GvHD clinical grade was supported by biomarker ratio levels including tumor necrosis factor receptor I (TNFR1), hepatocyte growth factor (HGF), interleukin 2 receptor alpha (IL-2Ra), and interleukin 7 (IL-7).These results suggest that single-infusion high-dose donor early apoptotic cells in HLA-matched myeloablative alloBMT is a safe and effective prophylaxis for acute GVHD (clinicaltrials.gov no. NCT00524784). DisclosuresMevorach:Enlivex: Consultancy, Equity Ownership.

157: Versatility of major histocompatibility complex class II dextramers for detection, and functional characterization of antigen-specific, autoreactive CD4 T cells in the mouse models of autoimmune diseases

Tetramers are useful tools to enumerate the frequencies of antigen-specific T cells. However, unlike CD8 T cells, CD4 T cells – especially self-reactive cells – are challenging to detect with major histocompatibility complex (MHC) class II tetramers because of their low frequencies, and low affinities of their T cell receptors to MHC-peptide complexes. In our efforts to improve the sensitivity of MHC class II tetramers, we recently created next-generation tetramers, designated ‘dextramers’. The dextramer reagents were helpful tools to detect and study the functionalities of autoreactive CD4 T cells in several murine autoimmune disease models. These include experimental autoimmune encephalomyelitis induced with proteolipid protein 139–151, and myelin oligodendrocyte glycoprotein 35–55; and myocarditis induced with cardiac myosin heavy chain (Myhc)-α 334–352 and coxsackievirus B3 (CVB). Here, we report five key findings. (i) dextramers and not tetramers, permitted us to enumerate the precursor frequencies of antigen-specific CD4 T cells ex vivo in the brain and heart by flow cytometry; (ii) direct staining with dextramers was sufficient to detect antigen-reactive T cells in situ by confocal microscopy; (iii) using Myhc-α 334–352 dextramers, for the first time, we showed that CVB infection leads to the generation of pathogenic cardiac myosin-specific CD4 T cells; (iv) dextramers were powerful tools to derive antigen-specific T cell hybridomas including evaluation of T cell markers, T cell receptors and their vβ usage in a single step by flow cytometry; and (v) characterization of pathogenic potential of dextramer+ cells based on cytokine-secretion and chemokine receptor expression led us to conclude that autoreactive T cells sensitized with antigens derived from different organ systems do not have common cytokine signatures. The implications of these observations will be discussed.

Water pollutant trichloroethylene epigenetically alters CD4+ T cells in mouse model of autoimmune disease

Water pollutant trichloroethylene epigenetically alters CD4+ T cells in mouse model of autoimmune disease

A CD40-targeted peptide controls and reverses type 1 diabetes in NOD mice.

The CD40-CD154 interaction directs autoimmune inflammation. Therefore, a long-standing goal in the treatment of autoimmune disease has been to control the formation of that interaction and thereby prevent destructive inflammation. Antibodies blocking CD154 are successful in mouse models of autoimmune disease but, while promising when used in humans, unfortunate thrombotic events have occurred, forcing the termination of those studies. To address the clinical problem of thrombotic events caused by anti-CD154 antibody treatment, we created a series of small peptides based on the CD154 domain that interacts with CD40 and tested the ability of these peptides to target CD40 and prevent type 1 diabetes in NOD mice. We identified a lead candidate, the 15-mer KGYY15 peptide, which specifically targets CD40-positive cells in a size- and sequence-dependent manner. It is highly efficient in preventing hyperglycaemia in NOD mice that spontaneously develop type 1 diabetes. Importantly, KGYY15 can also reverse new-onset hyperglycaemia. KGYY15 is well tolerated and functions to control the cytokine profile of culprit Th40 effector T cells. The KGYY15 peptide is 87% homologous to the human sequence, suggesting that it is an important candidate for translational studies. Peptide KGYY15 constitutes a viable therapeutic option to antibody therapy in targeting the CD40-CD154 interaction in type 1 diabetes. Given the involvement of CD40 in autoimmunity in general, it will also be important to evaluate KGYY15 in the treatment of other autoimmune diseases. This alternative therapeutic approach opens new avenues of exploration in targeting receptor-ligand interactions.

IL-10-producing NKT10 cells are a distinct regulatory invariant NKT cell subset.

Invariant natural killer T (iNKT) cells rapidly produce copious amounts of multiple cytokines after activation, thereby impacting a wide variety of different immune reactions. However, strong activation of iNKT cells with α-galactosylceramide (αGalCer) reportedly induces a hyporeactive state that resembles anergy. In contrast, we determined here that iNKT cells from mice pretreated with αGalCer retain cytotoxic activity and maintain the ability to respond to TCR-dependent as well as TCR-independent cytokine-mediated stimulation. Additionally, αGalCer-pretreated iNKT cells acquired characteristics of regulatory cells, including production and secretion of the immunomodulatory cytokine IL-10. Through the production of IL-10, αGalCer-pretreated iNKT cells impaired antitumor responses and reduced disease in experimental autoimmune encephalomyelitis, a mouse model of autoimmune disease. Furthermore, a subset of iNKT cells with a similar inhibitory phenotype and function were present in mice not exposed to αGalCer and were enriched in mouse adipose tissue and detectable in human PBMCs. These data demonstrate that IL-10-producing iNKT cells with regulatory potential (NKT10 cells) represent a distinct iNKT cell subset.