Autoimmune Mice Research Articles

Liver kinase B1 depletion from astrocytes worsens disease in a mouse model of multiple sclerosis.

Liver kinase B1 (LKB1) is a ubiquitously expressed kinase involved in the regulation of cell metabolism, growth, and inflammatory activation. We previously reported that a single nucleotide polymorphism in the gene encoding LKB1 is a risk factor for multiple sclerosis (MS). Since astrocyte activation and metabolic function have important roles in regulating neuroinflammation and neuropathology, we examined the serine/threonine kinase LKB1 in astrocytes in a chronic experimental autoimmune encephalomyelitis mouse model of MS. To reduce LKB1, a heterozygous astrocyte-selective conditional knockout (het-cKO) model was used. While disease incidence was similar, disease severity was worsened in het-cKO mice. RNAseq analysis identified Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched in het-cKO mice relating to mitochondrial function, confirmed by alterations in mitochondrial complex proteins and reductions in mRNAs related to astrocyte metabolism. Enriched pathways included major histocompatibility class II genes, confirmed by increases in MHCII protein in spinal cord and cerebellum of het-cKO mice. We observed increased numbers of CD4+ Th17 cells and increased neuronal damage in spinal cords of het-cKO mice, associated with reduced expression of choline acetyltransferase, accumulation of immunoglobulin-γ, and reduced expression of factors involved in motor neuron survival. In vitro, LKB1-deficient astrocytes showed reduced metabolic function and increased inflammatory activation. These data suggest that metabolic dysfunction in astrocytes, in this case due to LKB1 deficiency, can exacerbate demyelinating disease by loss of metabolic support and increase in the inflammatory environment.

Synthetic PreImplantation Factor (sPIF) induces posttranslational protein modification and reverses paralysis in EAE mice

An autoimmune response against myelin protein is considered one of the key pathogenic processes that initiates multiple sclerosis (MS). The currently available MS disease modifying therapies have demonstrated to reduce the frequency of inflammatory attacks. However, they appear limited in preventing disease progression and neurodegeneration. Hence, novel therapeutic approaches targeting both inflammation and neuroregeneration are urgently needed. A new pregnancy derived synthetic peptide, synthetic PreImplantation Factor (sPIF), crosses the blood-brain barrier and prevents neuro-inflammation. We report that sPIF reduces paralysis and de-myelination of the brain in a clinically-relevant experimental autoimmune encephalomyelitis mice model. These effects, at least in part, are due to post-translational modifications, which involve cyclic AMP dependent protein kinase (PKA), calcium-dependent protein kinase (PKC), and immune regulation. In terms of potential MS treatment, sPIF was successfully tested in neurodegenerative animal models of perinatal brain injury and experimental autoimmune encephalitis. Importantly, sPIF received a FDA Fast Track Approval for first in human trial in autommuninty (completed).

Reduction of integrin alpha 4 activity through splice modulating antisense oligonucleotides

With recent approvals of antisense oligonucleotides as therapeutics, there is an increasing interest in expanding the application of these compounds to many other diseases. Our laboratory focuses on developing therapeutic splice modulating antisense oligonucleotides to treat diseases potentially amendable to intervention during pre-mRNA processing, and here we report the use of oligomers to down-regulate integrin alpha 4 protein levels. Over one hundred antisense oligonucleotides were designed to induce skipping of individual exons of the ITGA4 transcript and thereby reducing protein expression. Integrin alpha 4-mediated activities were evaluated in human dermal fibroblasts and Jurkat cells, an immortalised human T lymphocyte cell line. Peptide conjugated phosphorodiamidate morpholino antisense oligomers targeting ITGA4 were also assessed for their effect in delaying disease progression in the experimental autoimmune encephalomyelitis mouse model of multiple sclerosis. With the promising results in ameliorating disease progression, we are optimistic that the candidate oligomer may also be applicable to many other diseases associated with integrin alpha 4 mediated inflammation. This highly specific strategy to down-regulate protein expression through interfering with normal exon selection during pre-mRNA processing should be applicable to many other gene targets that undergo splicing during expression.

Metabolic reprogramming orchestrates CD4+ T-cell immunological status and restores cardiac dysfunction in autoimmune induced-dilated cardiomyopathy mice

Cellular autoimmune responses, especially those mediated by T-cells, play vital roles in the immunopathogenesis of dilated cardiomyopathy (DCM). Metabolic reprogramming directly controls T-cell function, imprinting distinct functional fates. However, its contribution to T-cell dysfunction and the immunopathogenesis of DCM is unknown. Here, we found that in DCM patients, CD4+ T-cells exhibited immune dysfunction and glycolytic metabolic reprogramming based on extracellular acidification and oxygen consumption rates. Similar results were observed in splenic and cardiac CD4+ T-cells from autoimmune-induced DCM mice. In vitro, the glycolysis inhibitor 2-deoxy-d-glucose (2-DG) reversed T-cell dysfunction; thus, heightened metabolic activity directly controls CD4+ T-cell immunological status. Adoptive transfer of CD4+ T-cells from DCM mice to normal recipients induced cardiac remodeling and cardiac T-cell dysfunction. Strikingly, these effects were abolished by preconditioning cells with 2-DG, indicating that CD4+ T-cell dysfunction partially induced by metabolic reprogramming contributes to cardiac remodeling. Moreover, the microRNA let-7i modulated the metabolism and function of T-cells from DCM mice by directly targeting Myc. Collectively, our results show that metabolic reprogramming occurs in T-cells of autoimmune-induced DCM mice and patients. Further, our findings highlight that glycolytic metabolism is a critical contributor to T-cell dysfunction and DCM immunopathogenesis. Our data position the modulation of the metabolism as a central integrator for T-cell function, representing a promising strategy against autoimmune-mediated DCM progression.

PAHSAs attenuate immune responses and promote β cell survival in autoimmune diabetic mice.

Palmitic acid esters of hydroxy stearic acids (PAHSAs) are endogenous antidiabetic and antiinflammatory lipids. Here, we show that PAHSAs protect against type 1 diabetes (T1D) and promote β cell survival and function. Daily oral PAHSA administration to nonobese diabetic (NOD) mice delayed the onset of T1D and markedly reduced the incidence of T1D, whether PAHSAs were started before or after insulitis was established. PAHSAs reduced T and B cell infiltration and CD4+ and CD8+ T cell activation, while increasing Treg activation in pancreata of NOD mice. PAHSAs promoted β cell proliferation in both NOD mice and MIN6 cells and increased the number of β cells in NOD mice. PAHSAs attenuated cytokine-induced apoptotic and necrotic β cell death and increased β cell viability. The mechanism appears to involve a reduction of ER stress and MAPK signaling, since PAHSAs lowered ER stress in NOD mice, suppressed thapsigargin-induced PARP cleavage in human islets, and attenuated ERK1/2 and JNK1/2 activation in MIN6 cells. This appeared to be mediated in part by glucagon-like peptide 1 receptor (GLP-1R) and not the G protein-coupled receptor GPR40. PAHSAs also prevented impairment of glucose-stimulated insulin secretion and improved glucose tolerance in NOD mice. Thus, PAHSAs delayed the onset of T1D and reduced its incidence by attenuating immune responses and exerting direct protective effects on β cell survival and function.

AhR-ROR-γt complex is a therapeutic target for MAP4K3/GLKhighIL-17Ahigh subpopulation of systemic lupus erythematosus.

The cytokine IL-17A plays critical roles in the pathogenesis of autoimmune diseases. The frequencies of MAP kinase kinase kinase kinase 3 [also named germinal center kinase–like kinase (GLK)]-overexpressing T cells are correlated with disease severity of systemic lupus erythematosus (SLE). T-cell–specific GLK-transgenic mice develop spontaneous autoimmune responses through IL-17A. GLK signaling selectively stimulates IL-17A production in murine T cells through inducing aryl hydrocarbon receptor (AhR)–retinoic acid receptor–related orphan nuclear receptor-γt (ROR-γt) complex formation. Here, we investigated whether GLK-induced AhR–ROR-γt complex in T cells is a therapeutic target for human SLE. The population of GLK+IL-17A+ T cells was enhanced in the peripheral blood from patients with SLE compared with that of healthy controls using flow cytometry. The receiver operating characteristic curve analysis showed that increased GLK+IL-17A+ T-cell population in peripheral blood reflected an active stage of SLE. In addition, peripheral blood T cells from patients with SLE displayed induction of ROR-γt phosphorylation and the AhR–ROR-γt (and AhR–phosphorylated ROR-γt) complex. Moreover, we identified a small-molecule inhibitor, verteporfin, that inhibited GLK kinase activity and AhR–ROR-γt interaction. The small-molecule inhibitor verteporfin suppressed the disease severity in autoimmune mouse models and IL-17A production in T cells from patients with SLE. Collectively, the GLK-induced AhR–ROR-γt (and AhR–phosphorylated ROR-γt) complex is a therapeutic target for the GLKhighIL-17Ahigh subpopulation of human patients with SLE.—Chuang, H.-C., Chen, Y.-M., Chen, M.-H., Hung, W.-T., Yang, H.-Y., Tseng, Y.-H., Tan, T.-H. AhR–ROR-γt complex is a therapeutic target for MAP4K3/GLKhighIL-17Ahigh subpopulation of systemic lupus erythematosus.

The effects of human umbilical cord-derived mesenchymal stem cell transplantation on endometrial receptivity are associated with Th1/Th2 balance change and uNK cell expression of uterine in autoimmune premature ovarian failure mice

BackgroundTo explore the mechanism of human umbilical cord-derived mesenchymal stem cell (hUMSC) transplantation to improve ovarian function and the endometrial receptivity in autoimmune premature ovarian failure (POF) mice.MethodsThe POF model was established in mice treated with zona pellucida 3 polypeptide fragment (zona pellucida 3, ZP3). The hUMSCs were transplanted into the POF mice through tail vein injection. Following the transplantation, the serum hormone levels of follicle stimulating hormone (FSH), estrogen (E2), progesterone (P), γ-interferon (IFN-γ), interleukin-2 (IL-2), and interleukin-4 (IL-4) were evaluated by ELISA analysis. Morphological changes of ovarian and uterus tissues were examined by HE staining and immunohistochemistry. The expression of Th1/Th2 cytokines of T cells in spleen and CD56+CD16− cells (uterine natural killer cells, uNK cells) in uterine was measured by flow cytometry (FCM) and immunohistochemistry. The expression of HOXA10 in uterine endometrium was examined by immunohistochemistry and RT-PCR analysis. The pinopodes of epithelial cells in uterine endometrium were examined by scanning electron microscopy.ResultsFollowing hUMSC transplantation, the serum levels of E2, P, and IL-4 were increased but FSH, IFN-γ, and IL-2 levels were decreased in POF mice. Also, the transplantation of hUMSCs caused an increase in total number of healthy follicles and decrease of atresia follicles. The expression of HOXA10 gene was significantly increased but the CD56+CD16− uNK cells decreased in the endometrium of uterine. The ratio of Th1/Th2 cytokines was also significantly decreased.ConclusionThe data suggest that the recovery of ovarian function and endometrial receptivity in POF mice was regulated by the balance of Th1/Th2 cytokines and expression of uNK cells in the endometrium following hUMSC transplantation.

Autoimmune receptor encephalitis in mice induced by active immunization with conformationally stabilized holoreceptors.

Autoimmunity to membrane proteins in the central nervous system has been increasingly recognized as a cause of neuropsychiatric disease. A key recent development was the discovery of autoantibodies to N-methyl-d-aspartate (NMDA) receptors in some cases of encephalitis, characterized by cognitive changes, memory loss, and seizures that could lead to long-term morbidity or mortality. Treatment approaches and experimental studies have largely focused on the pathogenic role of these autoantibodies. Passive antibody transfer to mice has provided useful insights but does not produce the full spectrum of the human disease. Here, we describe a de novo autoimmune mouse model of anti-NMDA receptor encephalitis. Active immunization of immunocompetent mice with conformationally stabilized, native-like NMDA receptors induced a fulminant encephalitis, consistent with the behavioral and pathologic characteristics of human cases. Our results provide evidence for neuroinflammation and immune cell infiltration as components of the autoimmune response in mice. Use of transgenic mice indicated that mature T cells and antibody-producing cells were required for disease induction. This active immunization model may provide insights into disease induction and a platform for testing therapeutic approaches.

Abstract 3228: Immune checkpoint blockade and autoimmune diseases: Development of a mouse model of colitis induced by anti-CTLA-4

Abstract Immunotherapies prime or activate patient’s immune system to fight disease and has recently been a source of registered and promising new cancer treatments with major beneficial clinical outcomes in several cancers. However, by increasing the activity of the immune system, therapies as such targeting the immune checkpoint blockade can have profound inflammatory side effects, termed immune-related adverse events, with particular organs affected such as gastrointestinal tract, endocrine glands, skin and liver. In patients treated with the anti-CTLA-4 antibody, Ipilimumab, the overall incidence of diarrhea and colitis has been reported as 32.8%. This side effect is also observed in patients treated with anti-PD-1 therapy. The reproduction of such aspects of immune checkpoint inhibitors side effects in preclinical animal models would serve to dig into deciphering mechanisms involved, but also to evaluate combination therapies and modalities to reduce and manage such incidence with potential beneficial translation in clinical practice. We thus first ought to establish a checkpoint blockade-related autoimmune mouse model of colitis, using female C57BL/6 mice which were tested to determine their response to orally administered dextran sulfate sodium (DSS) combined to multiple injections of anti-CTLA-4 antibody or an isotype control antibody. After administration of DSS in drinking water for 7 days, mice that received an anti-CTLA-4 antibody showed no difference in body weight loss and Disease Activity Index (composite of body weight loss, stool consistency and presence of blood in stools), when compared to mice that received DSS plus the isotype control antibody. Histological sections analysis from the colons of mice culled at Day 10 confirmed that the combined treatment did not change the colitis score.However, when looking at later time points corresponding to the usual recovery phase of colitis, the effect of anti-CTLA4 treatment was clearly revealed by a sustained body weight loss and the persistence of a high Disease Activity Index, while the isotype control-treated animals slowly returned to baseline values similar to untreated animals. At sacrifice on Day 19, these in life findings were confirmed by a decrease in colon length (- 0.94 cm), an increase in colon weight (+ 231 mg) and a high mucus colon production in the anti-CTLA4-treated group versus the isotype control-treated group. Histological analysis of colons, and a more in depth characterization of the immune infiltrates will be presented. Citation Format: Edwige Nicodeme, Florence Blandel, Valerie Boullay, Yannick Saintillan, Gael Krysa, Anne-Benedicte Boullay, Jean-Jacques Tousaint, Robin Artus, Laure Levenez, Jeremy Odillard, Ingrid Jacquet, Olivier Duchamp, Fabrice Viviani. Immune checkpoint blockade and autoimmune diseases: Development of a mouse model of colitis induced by anti-CTLA-4 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3228.

Human placenta-derived mesenchymal stem cells inhibit apoptosis of granulosa cells induced by IRE1α pathway in autoimmune POF mice.

Previous studies have shown that the ovarian failure in autoimmune-induced premature ovarian failure (POF) mice could be improved by the transplantation of human placenta-derived mesenchymal stem cells (hPMSCs); however, the protective mechanism of hPMSCs transplantation on ovarian dysfunction remains unclear. Ovarian dysfunction is closely related to the apoptosis of granulosa cells (GCs). To determine the effects of hPMSCs transplantation on GCs apoptosis, an autoimmune POF mice model was established with zona pellucida glycoprotein 3 (ZP3) peptide. It is reported that the inositol-requiring enzyme 1α (IRE1α) and its downstream molecules play a central role in the endoplasmic reticulum (ER) stress-induced apoptosis pathway. So the aim of this study is to investigate whether hPMSCs transplantation attenuated GCs apoptosis via inhibiting ER stress IRE1α signaling pathway. The ovarian dysfunction, follicular dysplasia, and GCs apoptosis were observed in the POF mice. And the IRE1α pathway was activated in ovaries of POF mice, as demonstrated by, increased X-box binding protein 1 (XBP1), up-regulated 78 kDa glucose-regulated protein (GRP78) and caspase-12. Following transplantation of hPMSCs, the ovarian structure and function were significantly improved in POF mice. In addition, the GCs apoptosis was obviously attenuated and IRE1α pathway was significantly inhibited. Transplantation of hPMSCs suppressed GCs apoptosis-induced by ER stress IRE1α signaling pathway in POF mice, which might contribute to the hPMSCs transplantation-mediating ovarian function recovery.

262-OR: INAD 012-776 Pilot Study: Allogeneic “Neo-Islets,” Composed of Mesenchymal Stem and Islet Cells, Are Immune Protected and Dose-Dependently and Durably Control Autoimmune T1DM in Pet Dogs

We demonstrated that allogeneic, ip administered “Neo-Islets” (NIs), aggregates of cultured islet cells (ICs) and immune- and cyto-protective Adipose Derived Stem Cells (ASCs), reestablished durable normoglycemia through omental engraftment and splenic and omental upregulation of Tregs, in autoimmune T1DM NOD mice without immunosuppressive agents (SCTM 2017;6:1631). Comparable euglycemia was achieved with dog- or human-derived NIs in STZ-diabetic NOD/SCID mice. Here we update our report on an FDA supervised study using NI therapy in diabetic pet dogs. Insulin dependent, diabetic pet dogs, ≤12 kg, were included; 7 enrolled; 5 treated; and 4 followed for ≥6 mos. Pre-treatment serum samples were tested for islet autoantibodies. Comorbidities and blood glucose levels were treated. NIs were given once ip in a dose escalation protocol (2.5x10e5 to 5x10e5/kg bw). Blood glucose levels, insulin need and antibody responses were monitored. Prior to treatment 3 dogs had islet autoantibodies indicating autoimmunity, and 1 dog had no islet autoantibodies, potentially indicating insulin resistance. NIs appear to engraft, redifferentiate and physiologically produce insulin, and are neither rejected by auto- or allo-immune attacks, as evidenced by (a) an absent IgG response to the administered NIs, and (b) progressively, durably (≥ 12 mos) and dose-dependently improved glycemic control, achieved with a 50% reduction in daily insulin need paralleled by a fall in HbA1c in one dog from 12.1 to 6.8%. One dog was not compliant with keeping blood glucose levels controlled in the first few weeks post treatment and failed to respond. We conclude that this novel therapy may have significant translational relevance to human T1DM. We thank site PIs Drs. R. Sellon, WSU, Pullman, WA, N. Loy Son and J. Fisher, Veterinary Specialty Hospital, San Diego, CA, for their excellent collaboration. Disclosure C. Westenfelder: Consultant; Self; SymbioCellTech. S.S. Chowdhury: Employee; Self; SymbioCellTech. A. Gooch: Board Member; Self; SymbioCellTech.

Sjogren's Syndrome and TAM Receptors: A Possible Contribution to Disease Onset.

Sjogren's syndrome (SS) is a chronic, progressive autoimmune disease featuring both organ-specific and systemic manifestations, the most frequent being dry mouth and dry eyes resulting from lymphocytic infiltration into the salivary and lacrimal glands. Like the related autoimmune disease systemic lupus erythematosus (SLE), SS patients and mouse models display accumulation of apoptotic cells and a Type I interferon (IFN) signature. Receptor tyrosine kinases (RTKs) of the Tyro3, Axl, and Mer (TAM) family are present on the surface of macrophages and dendritic cells and participate in phagocytosis of apoptotic cells (efferocytosis) and inhibition of Type I IFN signaling. This review examines the relationship between TAM receptor dysfunction and SS and explores the potential contributions of TAM defects on macrophages to SS development.

Extracellular vesicle fibrinogen induces encephalitogenic CD8+ T cells in a mouse model of multiple sclerosis

Extracellular vesicles (EVs) are emerging as potent mediators of intercellular communication with roles in inflammation and disease. In this study, we examined the role of EVs from blood plasma (pEVs) in an experimental autoimmune encephalomyelitis mouse model of central nervous system demyelination. We determined that pEVs induced a spontaneous relapsing-remitting disease phenotype in MOG35-55-immunized C57BL/6 mice. This modified disease phenotype was found to be driven by CD8+ T cells and required fibrinogen in pEVs. Analysis of pEVs from relapsing-remitting multiple sclerosis patients also identified fibrinogen as a significant portion of pEV cargo. Together, these data suggest that fibrinogen in pEVs contributes to the perpetuation of neuroinflammation and relapses in disease.

Innovative drug discovery for autoimmune diseases aiming at BAFF signaling pathway

Abstract Background and Purpose It is well known that BAFF (B cell activating factor) signaling is involved in the pathogenesis of autoimmune diseases. To search for specific inhibitors against BAFF signaling, we have established our original high throughput screening system and discovered a pyrroloprymidine derivative, BIK-13, which inhibits BAFF binding to its receptor, BR3. In this study, we explored the possibility of BIK-13 as a drug to treat autoimmune diseases. Methods Human PBMC were stimulated in vitro with a mixture of BAFF, IL-21, and anti-IgM and anti-CD40 antibodies in the presence of BIK-13. Differentiation of B cells and the expression level of Activation-induced cytidine deaminase (AID) in the cells were analyzed by FACS and qPCR, respectively. The amounts of IL-6, IL-10 and IgG in the culture supernatants were measured by ELISA. Serum levels of an anti-dsDNA antibody, IL-6 and IL-10 in BIK-13-treated autoimmune model mice, MRL/lpr, were measured by ELISA. The proportion of B cells among splenocytes and infiltration of lymphocytes into organs of the mice were analyzed by FACS and immunohistochemistry, respectively. Results In vitro experiments revealed that BIK-13 suppressed 1) differentiation of B cells, 2) AID expression and 3) IL-6, IL-10 and IgG production in a dose dependent manner. BIK-13 decreased the serum levels of an anti-dsDNA antibody, IL-6 and IL-10 in MRL/lpr mice. Notably, infiltration of B cells into lacrimal glands and the proportion of B cells among splenocytes were remarkably suppressed in BIK-13-treated mice. Conclusion Our data collectively suggest that BIK-13, a low molecular weight BAFF-signaling inhibitor, is a promising drug candidate for autoimmune diseases by suppressing B cell activation.

MAP4K3/GLK-induced AhR-RORγt complex is a novel therapeutic target for GLKhighIL-17Ahigh subpopulation of SLE patients

Abstract The cytokine IL-17A plays critical roles in the pathogenesis of autoimmune diseases. The frequencies of MAP4K3 (also named GLK)-overexpressing T cells are correlated with disease severity of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and adult-onset Still’s disease. T-cell specific GLK transgenic mice develop spontaneous autoimmune responses. GLK signaling selectively stimulates IL-17A production in murine T cells through inducing AhR-RORγt complex formation. Here, we investigated whether GLK-induced AhR-RORγt complex in T cell is a therapeutic target for human SLE or RA. The population of GLK+IL-17A+ T cells was enhanced in the peripheral blood from SLE patients compared to that of healthy controls using flow cytometry. The ROC curve analyses showed that increased GLK+IL-17A+ T cell population in peripheral blood reflected an active stage of SLE. In addition, peripheral blood T cells from SLE or RA patients displayed induction of RORγt phosphorylation and the AhR-RORγt complex. Moreover, we identified a small-molecule GLK inhibitor that inhibited GLK kinase activity and AhR-RORγt interaction. The GLK inhibitor suppressed the disease severity in autoimmune mouse models and IL-17A production in T cells from SLE or RA patients. Collectively, GLK-induced AhR-RORγt complex is a therapeutic target for the GLKhighIL-17Ahigh subpopulation of SLE or RA patients.

Altered expression patterns of complement factor H and miR-146a genes in acute-chronic phases in experimental autoimmune encephalomyelitis mouse.

Considerable advances have been made in identification of the involvement of immune modulators in diseases. There is growing evidence on the role of complement pathway in pathogenesis and course of multiple sclerosis (MS). Moreover, it has been recognized that microRNAs (miRNAs) play an essential role in modulation and development of immune response in the central nervous system. We aimed to investigate the expression profile of complement factor H (CFH) and miR-146a genes in experimental autoimmune encephalomyelitis (EAE) mouse model of MS to detect the possible roles of CFH and miR-146a as biomarkers of MS disease stats. Expression of CFH and miR-146a genes in liver and brain tissues of EAE mice was measured in acute and chronic phases of disease compared to matched controls using real-time polymerase chain reaction. In the liver, increased expression of CFH gene was observed in the chronic phase compared to the acute phase. However, no significant difference was observed between acute and chronic phase mice with normal mice, while miR-146a expression was significantly decreased in livers of EAE mice in chronic group compared to acute and control groups. The expression of CFH gene in brain had a significant decrease in acute and chronic phases compared to healthy mice. Taken together, these observations indicate probable implication of complement system and miR-146a in course of immune-related diseases and reveal more facts about the pathogenesis of MS. However, further work is needed to determine protein levels of CFH and other possible targets of miR-146a in serum and cerebrospinal fluid of MS patients.

Effects of exogenous melatonin on clinical and pathological features of a human thyroglobulin-induced experimental autoimmune thyroiditis mouse model

Melatonin (MLT) plays a significant role in both innate and adaptive immunity, and dysregulation of the MLT signature can modify autoimmune disease phenotypes. In this study, the influence of exogenous MLT administration on regulating autoimmune thyroiditis animal models was evaluated. An experimental autoimmune thyroiditis model was established in MLT-synthesizing (CBA) and MLT-deficient (C57BL/6) mice by immunization with human thyroidglobulin (TG), which features thyrotoxicosis, thyrocyte damage, and CD3+ T cell infiltration. In TG-immunized CBA mice, exogenous MLT administration in drinking water (6 μg/ml) enhanced thyroiditis and increased TG-specific splenocyte proliferation but not the anti-thyroglobulin antibody (ATA) titer, while MLT alone caused no significant alteration in thyroid function or histopathology. Meanwhile, MLT administration did not modify thyroid function, the ATA titer, or the thyroid histopathology, but results showed an increase in the splenocyte proliferative capacity in TG-immunized C57BL/6 mice. Collectively, our data showed that early exogenous MLT modified the progression of autoimmune thyroiditis through T cell-driven immunity, and excess MLT worsened the clinical and pathological features.

T-cell repertoire profiling by next-generation sequencing reveals tissue migration dynamics of TRBV13-family clonotypes in a common experimental autoimmune encephalomyelitis mouse model

The experimental autoimmune encephalomyelitis (EAE) model is indispensable for autoimmunity research, but model-specific T cell dynamics are sparsely studied. We used next-generation immunosequencing across lymphoid organs, blood and spinal cord in response to immunization with myelin basic protein (MBP) to study T cell repertoires and migration patterns. Surprisingly, most spinal cord T cells were unique to the individual animal despite the existence of shared MBP-specific clones, suggesting a previously underestimated T cell diversity. Almost complete emigration of pathogenic clones from blood to spinal cord indicates that blood is not a suitable compartment to study EAE-mediating T cells.

Dissecting Integrin Expression and Function on Memory B Cells in Mice and Humans in Autoimmunity.

Immunological memory ensures life-long protection against previously encountered pathogens, and in mice and humans the spleen is an important reservoir for long-lived memory B cells (MBCs). It is well-established that integrins play several crucial roles in lymphocyte survival and trafficking, but their involvement in the retention of MBCs in secondary lymphoid organs, and differences between B cell subsets in their adhesion capacity to ICAM-1 and/or VCAM-1 have not yet been confirmed. Here, we use an autoimmune mouse model, where MBCs are abundant, to show that the highest levels of LFA-1 and VLA-4 amongst B cells are found on MBCs. In vivo blockade of VLA-4 alone or in combination with LFA-1, but not LFA-1 alone, causes a release of MBCs from the spleen into the blood stream. In humans, we find that in peripheral blood, spleens, and tonsils from healthy donors the highest expression levels of the integrins LFA-1 and VLA-4 are also found on MBCs. Consistent with this, we found MBCs to have a higher capacity to adhere to ICAM-1 and VCAM-1 than naïve B cells. In patients with the autoimmune disease rheumatoid arthritis, it is the MBCs that have the highest levels of LFA-1 and VLA-4; moreover, compared with healthy donors, naïve B and MBCs of patients receiving anti-TNF medication have enhanced levels of the active form of LFA-1. Commensurate levels of the active αL subunit can be induced on B cells from healthy donors by exposure to the integrin ligands. Thus, our findings establish the selective use of the integrins LFA-1 and VLA-4 in the localization and adhesion of MBCs in both mice and humans.

Sustained B cell depletion by CD19-targeted CAR T cells is a highly effective treatment for murine lupus.

The failure of anti-CD20 antibody (Rituximab) as therapy for lupus may be attributed to the transient and incomplete B cell depletion achieved in clinical trials. Here, using an alternative approach, we report that complete and sustained CD19+ B cell depletion is a highly effective therapy in lupus models. CD8+ T cells expressing CD19-targeted chimeric antigen receptors (CARs) persistently depleted CD19+ B cells, eliminated autoantibody production, reversed disease manifestations in target organs, and extended life spans well beyond normal in the (NZB × NZW) F1 and MRL fas/fas mouse models of lupus. CAR T cells were active for 1 year in vivo and were enriched in the CD44+CD62L+ T cell subset. Adoptively transferred splenic T cells from CAR T cell-treated mice depleted CD19+ B cells and reduced disease in naive autoimmune mice, indicating that disease control was cell-mediated. Sustained B cell depletion with CD19-targeted CAR T cell immunotherapy is a stable and effective strategy to treat murine lupus, and its effectiveness should be explored in clinical trials for lupus.