Cell-mediated Autoimmunity Research Articles

1176-P: Synthetic Immunomodulatory Peptoids to Control Autoimmunity in Type 1 Diabetes

Type 1 diabetes is an autoimmune disease associated with hyperglycemia. Increased glucose flux enhances the hexosamine biosynthetic pathway and intracellular posttranslational modification of proteins by the sugar N-acetyl glucosamine (GlcNAc) in a process called O-GlcNAcylation. We discovered that hyperglycemia increases the O-GlcNAcylation of the transcription factor, nuclear factor kappaB (NF-κB) c-Rel at serine 350. O-GlcNAcylation of c-Rel activates c-Rel-dependent transcription of proautoimmune cytokines in T cells and inhibits the expression of T regulatory cell specific transcription factor FOXP3. These reciprocal effects caused by c-Rel O-GlcNAcylation may act as positive feedback accelerator of autoimmunity under hyperglycemia. Hence, blocking the function of O-GlcNAcylated c-Rel will have dual benefits in controlling autoimmune diabetes by diminishing the T cell-mediated autoimmunity and enhancing the T regulatory cell function to suppress autoimmunity. We developed a novel peptoid, called peptoid3 that specifically blocks the function of O-GlcNAcylated c-Rel. We found that peptoid3 treatment significantly decreased T cell receptor-induced, O-GlcNAcylation-dependent expression of proautoimmune cytokines and enhanced FOXP3 expression in T cells. Peptoid3 treatment selectively affected autoimmunity-associated genes and did not exhibit toxicity on survival or proliferation of T cells. Broad inhibition of hexosamine biosynthetic pathway or NF-κB will cause many side effects due to their ubiquitous importance in multiple biological functions. Therefore, inhibitors of O-GlcNAcylated NF-κB c-Rel function may prove long-sought-after specific molecular therapeutic to diminish autoimmunity in type 1 diabetes. Disclosure P. Ramakrishnan: None. J. Pokorski: None. T.J. de Jesus: None. J. Centore: None. Funding National Institute of Allergy and Infectious Diseases (R01AI116730-01A1)

Anti-inflammatory Trained Immunity Mediated by Helminth Products Attenuates the Induction of T Cell-Mediated Autoimmune Disease.

Recent studies have suggested that the innate immune system can display characteristics of immunological memory and this has been called “innate immune memory” or “trained immunity.” Certain fungal products have been shown to induce epigenetic imprinting on monocytes/macrophages that results in heightened inflammatory responses to subsequent stimuli. Here we report that innate immune cells can be trained to be more anti-inflammatory following exposure to products of a helminth pathogen. Macrophages trained in vitro with Fasciola hepatica total extract (FHTE) had enhanced IL-10 and IL-1RA, but reduced TNF production upon re-stimulation with FHTE or TLR ligands and this was reversed by inhibitors of DNA methylation. In contrast, macrophages trained with β-glucan or Bacillus Calmette–Guérin had enhanced TNF production upon re-stimulation with Pam3cys or LPS. Furthermore, FHTE-trained macrophages had enhanced expression of markers of alternative activated macrophages (AAM). Macrophages from mice treated with FHTE expressed markers of AAM and had heightened IL-10 and IL-1RA production in response to FHTE or TLR ligands and had suppressed TNF and IL-12p40 production. Macrophages from mice treated with FHTE had reduced APC function and inhibited IL-17 production and the encephalitogenic activity of T cells in the experimental autoimmune encephalomyelitis (EAE) model. In addition, mice pre-treated with FHTE were resistant to induction of EAE and this was associated with a significant reduction in IL-17-producing γδ and CD4 T cells infiltrating the CNS. Our findings reveal that cells of the innate immune system can be trained in vitro or in vivo to be more anti-inflammatory by exposure to helminth products and this protects mice against the induction of a T cell-mediated autoimmune disease.

The transcriptional repressor Blimp-1 promotes Th2 development and lung inflammatory disease in a house dust mite induced model of allergic asthma

Abstract Asthma is a T cell-mediated chronic inflammatory lung disease that is thought of as a type 2/Th2 disease, yet precisely how Th2 cell development in the lung is initiated is unknown. Blimp-1 is a transcriptional repressor that regulates effector T cell responses to constrain T cell-mediated autoimmunity. We describe Blimp-1 as an unexpected regulator of allergen-induced airway inflammation that is critical to promote Th2 cell development in the lung and subsequent airway inflammation. Using a house dust mite (HDM) antigen model to drive allergic lung disease, we show that the T cell specific absence of Blimp-1 leads to reduced lung inflammation, a significant decrease in eosinophil recruitment to the lung tissue, and a near absence of Th2 cells in the lung. Intriguingly, Th1 and Th17 responses are intact, suggesting Blimp-1 is specifically required for Th2 differentiation in this model. Furthermore, despite a lack of Th2 cells in the lung, IgE responses are intact, dissociating IL-4-mediated antibody driven responses from Th2 cells in the lung. Bcl6 expression is increased in both the draining lymph node and lung and using T cell specific Bcl6 and Blimp-1 double deficient mice, we find that Th2 cells are restored when Bcl6 is deleted in addition to Blimp-1. Bcl6 is a potent repressor of GATA3, suggesting Blimp-1 acts to indirectly promote GATA3 expression by suppression of Bcl6. Furthermore, we show that STAT3 signaling in T cells is responsible to upregulate Blimp-1 and subsequent Th2 development, implicating this pathway as a possible therapeutic target. Taken together, our data suggests Blimp-1 plays an unexpected and context-dependent role in allergic lung inflammation to promote Th2 cell differentiation and subsequent lung disease.

Regulation of T cell activation and pathogenicity by dimeric pyruvate kinase M2 (PKM2)

Abstract Pyruvate kinase (PK) catalyses the conversion of phosphorenolpyruvate to pyruvate during glycolysis. Previous studies suggested that the PK isoform PKM2 also plays moonlighting activities different from its enzymatic one, such are regulation of gene transcription and protein phosphorylation. PKM2 was previously shown to control macrophage metabolic remodelling and pro-inflammatory potential, but its role in CD4+ T cell biology is poorly understood. In the present work, we report that PKM2 is upregulated in both murine and human CD4+ T cells following activation in vitro. In particular, PKM2 is present in equilibrium between a monomeric, dimeric and tetrameric isoform in T cells, with the dimeric one appearing exclusively upon activation. Treatment of T cells with TEPP-46, an allosteric activator that induces PKM2 tetramerisation and blocks dimer formation, strongly reduces their activation, proliferation and cytokine production through alteration of intracellular metabolism. TEPP-46 inhibits the generation of both T helper 17 (Th17) and Th1 cells, while inducing regulatory T cell development in vitro. Finally, in vivo treatment with TEPP-46 ameliorates experimental autoimmune encephalomyelitis (EAE), the mouse model of multiple sclerosis. Overall, our results suggest that PKM2 induction and dimerisation are essential steps for T cell activation and pathogenicity, and targeting PKM2 dynamics may have therapeutic utility in T cell-mediated inflammation and autoimmunity.

MAdCAM-1-Mediated Intestinal Lymphocyte Homing Is Critical for the Development of Active Experimental Autoimmune Encephalomyelitis.

Lymphocyte homing into the intestine is mediated by binding of leukocytes to mucosal addressin cell adhesion molecule 1 (MAdCAM-1), expressed on endothelial cells. Currently, the immune system of the gut is considered a major modulator not only of inflammatory bowel disease, but also of extra-intestinal autoimmune disorders, including multiple sclerosis (MS). Despite intense research in this field, the exact role of the intestine in the pathogenesis of (neuro-)inflammatory disease conditions remains to be clarified. This prompted us to investigate the role of MAdCAM-1 in immunological processes in the intestine during T cell-mediated autoimmunity of the central nervous system (CNS). Using the experimental autoimmune encephalomyelitis model of MS, we show that MAdCAM-1-deficient (MAdCAM-1-KO) mice are less susceptible to actively MOG35−55-induced disease. Protection from disease was accompanied by decreased numbers of immune cells in the lamina propria and Peyer's patches as well as reduced immune cell infiltration into the spinal cord. MOG35−55-recall responses were intact in other secondary lymphoid organs of MAdCAM-1-KO mice. The composition of specific bacterial groups within the microbiome did not differ between MAdCAM-1-KO mice and controls, while MAdCAM-1-deficiency severely impaired migration of MOG35−55-activated lymphocytes to the gut. Our data indicate a critical role of MAdCAM-1 in the development of CNS inflammation by regulating lymphocyte homing to the intestine, and may suggest a role for the intestinal tract in educating lymphocytes to become encephalitogenic.

Clinical and Immunological Phenotype of Patients With Primary Immunodeficiency Due to Damaging Mutations in NFKB2.

Non-canonical NF-κB-pathway signaling is integral in immunoregulation. Heterozygous mutations in NFKB2 have recently been established as a molecular cause of common variable immunodeficiency (CVID) and DAVID-syndrome, a rare condition combining deficiency of anterior pituitary hormone with CVID. Here, we investigate 15 previously unreported patients with primary immunodeficiency (PID) from eleven unrelated families with heterozygous NFKB2-mutations including eight patients with the common p.Arg853* nonsense mutation and five patients harboring unique novel C-terminal truncating mutations. In addition, we describe the clinical phenotype of two patients with proximal truncating mutations. Cohort analysis extended to all 35 previously published NFKB2-cases revealed occurrence of early-onset PID in 46/50 patients (mean age of onset 5.9 years, median 4.0 years). ACTH-deficiency occurred in 44%. Three mutation carriers have deceased, four developed malignancies. Only two mutation carriers were clinically asymptomatic. In contrast to typical CVID, most patients suffered from early-onset and severe disease manifestations, including clinical signs of T cell dysfunction e.g., chronic-viral or opportunistic infections. In addition, 80% of patients suffered from (predominately T cell mediated) autoimmune (AI) phenomena (alopecia > various lymphocytic organ-infiltration > diarrhea > arthritis > AI-cytopenia). Unlike in other forms of CVID, auto-antibodies or lymphoproliferation were not common hallmarks of disease. Immunophenotyping showed largely normal or even increased quantities of naïve and memory CD4+ or CD8+ T-cells and normal T-cell proliferation. NK-cell number and function were also normal. In contrast, impaired B-cell differentiation and hypogammaglobinemia were consistent features of NFKB2-associated disease. In addition, an array of lymphocyte subpopulations, such as regulatory T cell, Th17-, cTFH-, NKT-, and MAIT-cell numbers were decreased. We conclude that heterozygous damaging mutations in NFKB2 represent a distinct PID entity exceeding the usual clinical spectrum of CVID. Impairment of the non-canonical NF-κB pathways affects function and differentiation of numerous lymphocyte-subpopulations and thus causes a heterogeneous, more severe form of PID phenotype with early-onset. Further characteristic features are multifaceted, primarily T cell-mediated autoimmunity, such as alopecia, lymphocytic organ infiltration, and in addition frequently ACTH-deficiency.

Defective Autophagy in T Cells Impairs the Development of Diet-Induced Hepatic Steatosis and Atherosclerosis.

Macroautophagy (or autophagy) is a conserved cellular process in which cytoplasmic cargo is targeted for lysosomal degradation. Autophagy is crucial for the functional integrity of different subsets of T cells in various developmental stages. Since atherosclerosis is an inflammatory disease of the vessel wall which is partly characterized by T cell mediated autoimmunity, we investigated how advanced atherosclerotic lesions develop in mice with T cells that lack autophagy-related protein 7 (Atg7), a protein required for functional autophagy. Mice with a T cell-specific knock-out of Atg7 (Lck-Cre Atg7f/f) had a diminished naïve CD4+ and CD8+ T cell compartment in the spleen and mediastinal lymph node as compared to littermate controls (Atg7f/f). Lck-Cre Atg7f/f and Atg7f/f mice were injected intravenously with rAAV2/8-D377Y-mPCSK9 and fed a Western-type diet to induce atherosclerosis. While Lck-Cre Atg7f/f mice had equal serum Proprotein Convertase Subtilisin/Kexin type 9 levels as compared to Atg7f/f mice, serum cholesterol levels were significantly diminished in Lck-Cre Atg7f/f mice. Histological analysis of the liver revealed less steatosis, and liver gene expression profiling showed decreased expression of genes associated with hepatic steatosis in Lck-Cre Atg7f/f mice as compared to Atg7f/f mice. The level of hepatic CD4+ and CD8+ T cells was greatly diminished but both CD4+ and CD8+ T cells showed a relative increase in their IFNγ and IL-17 production upon Atg7 deficiency. Atg7 deficiency furthermore reduced the hepatic NKT cell population which was decreased to < 0.1% of the lymphocyte population. Interestingly, T cell-specific knock-out of Atg7 decreased the mean atherosclerotic lesion size in the tri-valve area by over 50%. Taken together, T cell-specific deficiency of Atg7 resulted in a decrease in hepatic steatosis and limited inflammatory potency in the (naïve) T cell compartment in peripheral lymphoid tissues, which was associated with a strong reduction in experimental atherosclerosis.

Therapeutic Vaccine Against S100A9 (S100 Calcium-Binding Protein A9) Inhibits Thrombosis Without Increasing the Risk of Bleeding in Ischemic Stroke in Mice.

Decreased adherence to daily ingestion of antiplatelet drugs is a critical issue, increasing mortality and morbidity in poststroke patients. As vaccination could be a promising approach to solving this, we designed an antiplatelet vaccine that inhibited S100A9 (S100 calcium-binding protein A9)/CD36 (cluster of differentiation 36) signaling in platelets, which was reported to be a key signal in arterial thrombosis, but not hemostasis. Immunization with this vaccine induced a sustainable increase in the anti-S100A9 antibody titer for >2 months and an additional booster immunization enhanced the antibody production further. The middle cerebral artery occlusion time was successfully prolonged in the vaccinated mice, which was comparable to that in mice treated with clopidogrel. The antithrombotic effect lasted for 84 days after the last vaccination, as well as after the booster immunization. Importantly, the bleeding time was not affected in the immunized mice. The antithrombotic effect was also observed in the common carotid artery, which was similar to that found in CD36-/- mice. Vascular injury increased the expression of S100A9 in the serum and phosphorylation of JNK (c-Jun N-terminal kinase) and VAV1 in the platelets, but these increases were inhibited in the immunized mice. Moreover, the S100A9 vaccine did not induce cell-mediated autoimmunity, as demonstrated by the enzyme-linked immunosorbent spot assay. Thus, immunization with the S100A9 vaccine resulted in long-term inhibition of thrombus formation through inhibition of increased S100A9/CD36 signaling without risk of bleeding or adverse autoimmune responses. Vaccination against S100A9 might be a novel therapy to prevent recurrent ischemic stroke.

TGF\u03b21 signaling sustains aryl hydrocarbon receptor (AHR) expression and restrains the pathogenic potential of TH17 cells by an AHR-independent mechanism

The aryl hydrocarbon receptor (AHR) is a transcription factor activated by ligand highly expressed on TH17 cells, and AHR-deficient CD4+ T cells have impaired production of IL-17A and IL-22. Although AHR activation can exacerbate in vivo TH17 cell-mediated autoimmunity, accumulating data indicate that AHR is a nonpathogenic TH17 marker. Thus it remains unclear how AHR activation is regulated and impacts on the generation of TH17 subsets. Here we demonstrated that AHR pathway is activated during in vitro pathogenic TH17 polarization, but it is quickly downregulated. Under these conditions, additional AHR activation promoted IL-22 but not IL-17A. Interestingly, AHR high sustained expression and IL-17A promotion were only achieved when TGFβ1 was present in the culture. In addition to the effect on AHR regulation, TGFβ1 presented a dual role by simultaneously suppressing the TH17 pathogenic phenotype acquisition. This latter effect was independent of AHR stimulation, since its activation did not confer a TH17 anti-inflammatory profile and Ahr−/− cells did not upregulate any TH17 pathogenic marker. Through the use of EAE model, we demonstrated that AHR is still functional in encephalitogenic CD4+ T cells and the adoptive transfer of Ahr−/− TH17 cells to recipient mice resulted in milder EAE development when compared to their WT counterparts. Altogether, our data demonstrated that although AHR is highly expressed on in vitro-generated nonpathogenic TH17 cells, its ligation does not shift TH17 cells to an anti-inflammatory phenotype. Further studies investigating the role of AHR beyond TH17 differentiation may provide a useful understanding of the physiopathology of autoimmune diseases.

ADAR1-mediated RNA editing is required for thymic self-tolerance and inhibition of autoimmunity.

T cells play a crucial role in the adaptive immune system, and their maturation process is tightly regulated. Adenosine deaminase acting on RNA 1 (ADAR1) is the enzyme responsible for adenosine-to-inosine RNA editing in dsRNAs, and loss of ADAR1 activates the innate immune sensing response via melanoma differentiation-associated protein 5 (MDA5), which interprets unedited dsRNA as non-self. Although ADAR1 is highly expressed in the thymus, its role in the adaptive immune system, especially in T cells, remains elusive. Here, we demonstrate that T cell-specific deletion of Adar1 in mice causes abnormal thymic T cell maturation including impaired negative selection and autoimmunity such as spontaneous colitis. This is caused by excessive expression of interferon-stimulated genes, which reduces T cell receptor (TCR) signal transduction, due to a failure of RNA editing in ADAR1-deficient thymocytes. Intriguingly, concurrent deletion of MDA5 restores thymocyte maturation and prevents colitis. These findings suggest that prevention of MDA5 sensing of endogenous dsRNA by ADAR1-mediated RNA editing is required for preventing both innate immune responses and T cell-mediated autoimmunity.

Naringenin Modifies the Development of Lineage-Specific Effector CD4+ T Cells.

Disrupted balance in the lineages of CD4+ T cell subsets, including pro-inflammatory T helper (Th) cells and anti-inflammatory regulatory T cells (Treg), is a primary pathogenic factor for developing autoimmunity. We have found that this immunomodulatory effect of naringenin on effector T cells and T-cell mediated experimental autoimmune encephalomyelitis (EAE). We therefore explored the effects of naringenin on the development of different effector CD4+ T cells. Naïve CD4+ T cells were differentiated under respective Th1, Th2, Th17, and Treg polarizing conditions with naringenin. Percent populations of each differentiated CD4+ T cell subsets were determined and the corresponding regulating pathways were investigated as underlying mechanisms. Naringenin mainly inhibited CD4+ T cell proliferation and differentiation to Th1 and Th17, but did not affect Th2 cells. Impeded Th1 polarization was associated with inhibition of its specific regulator proteins T-bet, p-STAT1, and p-STAT4 by naringenin. Likewise, Th17 regulator proteins RORγt, p-STAT3, and Ac-STAT3 were also inhibited by naringenin. In addition, naringenin promoted Treg polarization and also prevented IL-6-induced suppression of Treg development via down-regulation of p-Smad2/3 as well as inhibition of IL-6 signaling, and the latter was further supported by the in vivo results showing lower soluble IL-6R but higher soluble gp130 levels in plasma of naringenin-fed compared to the control EAE mice. Naringenin impacts CD4+ T cell differentiation in a manner that would explain its beneficial effect in preventing/mitigating T cell-mediated autoimmunity.

CRL4DCAF2 is required for mature T-cell expansion via Aurora B-regulated proteasome activity

The proliferation of T cells in peripheral lymphoid tissues requires T cell receptor (TCR)-mediated cell cycle entry. However, the underlying mechanism regulating cell cycle progression in mature T cells is incompletely understood. Here, we have identified an E3 ubiquitin ligase, CRL4DCAF2, as a critical mediator controlling M phase exit in activated T cells. DCAF2 expression is induced upon TCR stimulation and its deficiency attenuates T cell expansion. Additionally, DCAF2 T cell-specific knockout mice display impaired peripheral T cell maintenance and reduced severity of various autoimmune diseases. Continuous H4K20me1 modification caused by DCAF2 deficiency inhibits the induction of Aurkb expression, which regulates 26S proteasome activity during G2/M phase. CRL4DCAF2 deficiency causes M phase arrest through proteasome-dependent mechanisms in peripheral T cells. Our findings establish DCAF2 as a novel target for T cell-mediated autoimmunity or inflammatory diseases.

Paraneoplastic autoimmune multiorgan syndrome (PAMS): Beyond the single phenotype of paraneoplastic pemphigus.

Paraneoplastic autoimmune multiorgan syndrome (PAMS) is characterized by a heterogenous group of signs and symptoms including severe desquamative stomatitis, a polymorphous cutaneous eruption, humoral immunity against plakin proteins, contribution of cell-mediated autoimmunity and commonly a progressive respiratory failure. Autoantibodies in PAMS target a wide array of antigens including plakins, cadherins, alpha-2-macroglobulin like 1 (A2ML1), BP180, plakophilin-3, and several neuromuscular antigens. Originally described as paraneoplastic pemphigus in 1990 due to some of its clinical and immunologic similarities to classic pemphigus (pemphigus vulgaris and pemphigus foliaceus), PAMS is a multiorganopathy with several distinct features from these classic forms of pemphigus. Epidemiologically, PAMS is associated with underlying neoplasia and has a differing HLA-II allele predisposition compared to classic forms of pemphigus. Clinically, lesion morphology is polymorphous, and lesion distribution fundamentally differs from that seen in classic pemphigus. PAMS has a significantly higher mortality rate and a poorer response to treatments typically effective in pemphigus. Histologically, PAMS is characterized by the presence of interface dermatitis, vacuolar changes, and dyskeratotic keratinocytes which are not seen in classic pemphigus. PAMS demonstrates not only intercellular IgG as seen in classic pemphigus, but the presence of linear basement membrane zone deposition. Antibodies against desmoglein 3 (Dsg3) map to a broader array of epitopes than in pemphigus vulgaris and there is a higher prevalence of complement binding anti-Dsg3 IgG autoantibodies in PAMS. Autoantibodies can in rare cases be absent in the more cell-mediated form of PAMS. Considering these numerable differences, we review the entity of PAMS, and provide similarities and differences to classic forms of pemphigus.

PDCB does not promote CNS autoimmunity in the context of genetic susceptibility but worsens its outcome

BackgroundPara-dichlorobenzene (PDCB) is an aromatic hydrocarbon contained in mothballs that is potentially neurotoxic. A potential pathogenic role of PDCB in MS pathogenesis has been suggested. MethodsTo determine the ability of chronic PDCB ingestion to induce CNS autoimmunity in a genetically susceptible mammalian species, naive myelin oligodendrocyte glycoprotein peptide (MOGp)35–55 T cell receptor (TCR) transgenic mice (2D2) on the C57Bl/6 background were orally gavaged once daily with corn oil control, 125 mg/kg PDCB, or 250 mg/kg PDCB for 45 days. The incidence of spontaneous EAE is increased in this mouse strain. ResultsBoth PDCB treatment groups showed the same spontaneous incidence of EAE, an earlier disease onset, and a slight decrease in survival for 125 mg/kg PDCB mice compared to control mice. We were unable to detect any PDCB, or its metabolites 2,5-dichlorophenol, 2,5-dicholormethylsulfide, and 2,5-dichloromethylsulfone in the brain and spinal cord of control mice. In contrast, PDCB was readily detectable in both compartments in mice who received PDCB via oral gavage, with concentrations being significantly higher in the brain (p < 0.01). Levels of the metabolites 2,5-dichlorophenol and 2,5-dichloromethylsulfone were also significantly higher in brains compared to spinal cords. ConclusionOur study refutes the hypothesis that PDCB or its metabolites trigger spontaneous T cell-mediated CNS autoimmunity in the setting of genetic susceptibility. A slight increase in mortality with PDCB exposure may be due systemic toxicity of hydrocarbons.

Acute polyradiculopathy secondary to idelalisib in Relapsed Classical Hodgkin's lymphoma

Patients with relapsed or refractory Hodgkin's lymphoma are likely incurable with standard treatment. Idelalisib, a delta-isoform specific Phosphatidyl-inositol-3-kinase (PI3K) inhibitor has shown its efficacy in other hematopoietic B malignancies. We report the case of a 51-years old patient with relapsed and refractory Hodgkin's Lymphoma receiving idelalisib after several regimens of chemotherapy. He achieved a good partial response for several months, unfortunately, idelalisib had to be stopped because of the onset of a severe polyradiculoneuritis attributed to this treatment. We assume here that the polyradiculoneuritis could be caused by T cell mediated autoimmunity to myelin proteins. To our knowledge, this adverse event has never been described so far with idelalisib.

Poly IC pretreatment suppresses B cell-mediated lupus-like autoimmunity through induction of Peli1.

Noncanonical NF-κB pathway is essential for the B cell activation and antibody production, which centralize the critical role of B cells in regulating the pathogenesis of systemic lupus erythematosus (SLE). We have previously demonstrated that Pellino1 (Peli1) negatively regulates noncanonical NF-κB activation and lupus autoimmunity. Here, we showed that poly IC is a potent inducer of Peli1 protein in mouse splenic B cells in dose- and time-dependent manners, and poly IC-induced Peli1 protein dramatically suppressed the activation of noncanonical NF-κB pathway. In addition, poly IC-pretreated B cells failed to induce lupus-like disease in BM12 CD4+ T cell-immunized mice. Accordingly, the induction of antibody-producing plasma cells and germinal center B cells, as well as the production of autoantibodies were significantly impaired in immunized μMT mice that were transferred with poly IC-pretreated B cells. Our findings demonstrate that poly IC-induced Peli1 negatively regulates the noncanonical NF-κB pathway in the context of restraining the pathogenesis of lupus-like disease.

Multiple sclerosis pathogenesis: missing pieces of an old puzzle.

Traditionally, multiple sclerosis (MS) was considered to be a CD4 T cell-mediated CNS autoimmunity, compatible with experimental autoimmune encephalitis model, which can be characterized by focal lesions in the white matter. However, studies of recent decades revealed several missing pieces of MS puzzle and showed that MS pathogenesis is more complex than the traditional view and may include the following: a primary degenerative process (e.g. oligodendroglial pathology), generalized abnormality of normal-appearing brain tissue, pronounced gray matter pathology, involvement of innate immunity, and CD8 T cells and B cells. Here, we review these findings and discuss their implications in MS pathogenesis.

Proteomic Analysis Reveals Distinctive Protein Profiles Involved in CD8 T Cell-Mediated Murine Autoimmune Cholangitis

Abstract Autoimmune cholangitis arises from abnormal innate and adaptive immune responses in liver and T cells are critical drivers in this process, but little is known about the regulation of their functional behavior during disease development. We previously reported that mice with a T cell-restricted expression of a dominant negative form of transforming growth factor beta receptor type II (dnTGFbRII) spontaneously develop autoimmune cholangitis that resembles human primary biliary cholangitis (PBC). Adoptive transfer of CD8+ but not CD4+ T cells into Rag1−/− mice reproduced the disease, demonstrating a critical role for CD8 T cells in pathogenesis. Herein, we took advantage of SOMA scan technology to perform proteomic analysis of serum samples from dnTGFbRII and B6 control mice at different ages. In addition, we analyzed CD8 protein profiles after adoptive transfer of splenic CD8+ cells into Rag1−/− recipients. The use of the unique aptamer technology of SOMA scans reveals critical distinct profiles of CD8 cells, which are key to biliary mediation. 254 proteins were significantly increased, while 216 proteins significantly decreased in recipient hepatic CD8+ cells compared to donor splenic CD8+ cells. In contrast to donor splenic CD8+ cells, recipient hepatic CD8+ cells express distinct protein profiles involved in chemokine signaling, focal adhesion, T cell receptor and natural killer cell mediated cytotoxicity pathways.

Two B-cell epitope vaccines based on uPA effectively inhibit fertility in male mice

uPA, a trypsin-like serine protease, was found to take active part in male reproduction. Our previous work had demonstrated the antifertility effects of its full length protein immunization, but with immune tolerance and other latent side effects. Here we discovered two effective B-cell epitopes of uPA for male contraception in growth factor-like domain and kringle domain respectively. Together with carrier protein, immunization of these two epitope peptides could induce high titers of specific antibodies in male mice. Significant reduction of fertility was observed in these two groups in mating trial without evident systemic illness or abnormal mating behavior. Epididymal sperms of immunized males exhibited impaired progressive motility and ability to fertilize eggs in vitro. The immunization of another predicted epitope in serine protease domain and the control groups showed no similar positive results. Importantly, T cells were not activated after the challenge of these B-cell epitopes itself, which suggests that these vaccines do not induce cell-mediated autoimmunity. Taken together, our study discovered two uPA B-cell epitopes as novel targets for male immunocontraception with minimum side effects. Considering their high identity with human uPA protein, these two epitope vaccines hold great promise to be developed for man use in the future.

Integrity of IKK/NF-κB Shields Thymic Stroma That Suppresses Susceptibility to Autoimmunity, Fungal Infection, and Carcinogenesis.

A pathogenic connection between autoreactive T cells, fungal infection, and carcinogenesis has been demonstrated in studies of human autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) as well as in a mouse model in which kinase-dead Ikkα knock-in mice develop impaired central tolerance, autoreactive T cell-mediated autoimmunity, chronic fungal infection, and esophageal squamous cell carcinoma, which recapitulates APECED. IκB kinase α (IKKα) is one subunit of the IKK complex required for NF-κB activation. IKK/NF-κB is essential for central tolerance establishment by regulating the development of medullary thymic epithelial cells (mTECs) that facilitate the deletion of autoreactive T cells in the thymus. In this review, we extensively discuss the pathogenic roles of inborn errors in the IKK/NF-κB loci in the phenotypically related diseases APECED, immune deficiency syndrome, and severe combined immunodeficiency; differentiate how IKK/NF-κB components, through mTEC (stroma), T cells/leukocytes, or epithelial cells, contribute to the pathogenesis of infectious diseases, autoimmunity, and cancer; and highlight the medical significance of IKK/NF-κB in these diseases.