Autoimmune Phenotype Research Articles

Detection of serum IgG autoantibodies to FcεRIα by ELISA in patients with chronic spontaneous urticaria.

Mast cells are a key effector cell in the pathogenesis of chronic spontaneous urticaria (CSU) and activated by circulating FcεRI-specific IgG as well as IgE. This study evaluated the prevalence of circulating autoantibodies to FcεRIα in the sera of CSU patients. Eighty-eight patients with CSU and 76 healthy controls (HCs) were enrolled. To detect circulating autoantibodies (IgG/IgA/IgM) to FcεRIα, ELISA was done using YH35324 (as a solid phase antigen), and its binding specificity was confirmed by the ELISA inhibition test. The antibody levels were presented by the ratio of YH35324-preincubated to mock-preincubated absorbance values. Clinical and autoimmune parameters, including atopy, urticaria activity score (UAS), serum total/free IgE levels, serum antinuclear antibody (ANA) and autologous serum skin test (ASST) results, were assessed. The autoimmune group was defined if CSU patients had positive results to ASST and/or ANA. The ratio of serum IgG to FcεRIα was significantly lower in CSU patients than in HCs (P<0.05), while no differences were noted in serum levels of IgG to recombinant FcεRIα or IgA/IgM autoantibodies. The autoimmune CSU group had significantly lower ratios of IgG/IgA (not IgM) autoantibodies to FcεRIα than the nonautoimmune CSU group (P<0.05 for each). No significant associations were found between sex, age, atopy, urticaria duration, UAS, or serum total/free IgE levels according to the presence of IgG/IgA/IgM antibodies. This study confirmed the presence of IgG to FcεRIα in the sera of CSU patients, especially those with the autoimmune phenotype.

Transcription-independent regulation of STING activation and innate immune responses by IRF8 in monocytes

Sensing of cytosolic DNA of microbial or cellular/mitochondrial origin by cGAS initiates innate immune responses via the adaptor protein STING. It remains unresolved how the activity of STING is balanced between a productive innate immune response and induction of autoimmunity. Here we show that interferon regulatory factor 8 (IRF8) is essential for efficient activation of STING-mediated innate immune responses in monocytes. This function of IRF8 is independent of its transcriptional role in monocyte differentiation. In uninfected cells, IRF8 remains inactive via sequestration of its IRF-associated domain by its N- and C-terminal tails, which reduces its association with STING. Upon triggering the DNA sensing pathway, IRF8 is phosphorylated at Serine 151 to allow its association with STING via the IRF-associated domain. This is essential for STING polymerization and TBK1-mediated STING and IRF3 phosphorylation. Consistently, IRF8-deficiency impairs host defense against the DNA virus HSV-1, and blocks DNA damage-induced cellular senescence. Bone marrow-derived mononuclear cells which have an autoimmune phenotype due to deficiency of Trex1, respond to IRF-8 deletion with reduced pro-inflammatory cytokine production. Peripheral blood mononuclear cells from systemic lupus erythematosus patients are characterized by elevated phosphorylation of IRF8 at the same Serine residue we find to be important in STING activation, and in these cells STING is hyper-active. Taken together, the transcription-independent function of IRF8 we describe here appears to mediate STING activation and represents an important regulatory step in the cGAS/STING innate immune pathway in monocytes.

Increased maternofoetal transfer of antibodies in a murine model of systemic lupus erythematosus, but no immune activation and neuroimmune sequelae in offspring

Maternally transferred autoantibodies can negatively impact the development and health of offspring, increasing the risk of neurodevelopmental disorders. We used embryo transfers to examine maternofoetal immune imprinting in the autoimmune BXSB/MpJ mouse model. Anti-double-stranded DNA antibodies and total immunoglobulins were measured, using allotypes of the IgG subclass to distinguish maternally transferred antibodies from those produced endogenously. Frequencies of germinal center and plasma cells were analysed by flow cytometry. Microglial morphology in offspring CNS was assessed using immunohistochemistry. In contrast to prior findings, our results indicate that BXSB/MpJ mothers display a mild autoimmune phenotype, which does not significantly impact the offspring.

Silencing GmBIR1 in Soybean Results in Activated Defense Responses.

Receptor-like kinases (RLKs) are a large group of pattern recognition receptors (PRRs) and play a critical role in recognizing pathogens, transducing defense signals, and mediating the activation of immune defense responses. Although extensively studied in the model plant Arabidopsis, studies of RLKs in crops, including soybean, are limited. When a BAK1-interacting receptor-like kinase (BIR1) homolog (referred to as GmBIR1 hereafter) was silenced by the BPMV (Bean pod mottle virus)-induced gene silencing (BPMV-VIGS), it resulted in phenotypes that were reminiscent of constitutively activated defense responses, including a significantly stunted stature with observable cell death on the leaves of the silenced plants. In addition, both SA and H2O2 were over-accumulated in the leaves of the GmBIR1-silenced plants. Consistent with this autoimmune phenotype, GmBIR1-silenced plants exhibited significantly enhanced resistance to both Pseudomonas syringae pv. glycinea (Psg) and Soybean mosaic virus (SMV), two different types of pathogens, compared to the vector control plants. Together, our results indicated that GmBIR1 is a negative regulator of immunity in soybean and the function of BIR1 homologs is conserved in different plant species.

Endometriosis and inflammatory immune responses: Indian experience.

Endometriosis is a public health disorder affecting ∼ 247 million women globally and ∼ 42 million women in India. Women with endometriosis suffer from dysmenorrhea, chronic pelvic pain, dyspareunia, dyschezia, fatigue, depression, and infertility leading to significant socioeconomic impact and morbidity. The etiology of endometriosis is not understood well even after 100 years of research. Currently, there is no permanent cure for endometriosis. The inflammatory immune response is one of the important features of etiopathogenesis of endometriosis and therefore understanding the inflammatory immune response would lead to a better understanding of this enigmatic disorder and may also lead to biomarker discovery for diagnosis of endometriosis. We investigated the autoimmune etiology of endometriosis in the Indian population. Using the proteomics approach, anti-endometrial antibodies (AEAs) were detected in Indian women with endometriosis [anti-endometrial antibodies - tropomyosin 3 (TPM3), stomatin-like protein2 (SLP-2), and tropomodulin 3 (TMOD3)]. The studies on AEAs provided a better understanding of autoimmune mechanisms in endometriosis. All three subtypes of endometriosis; superficial peritoneal, ovarian endometrioma, and deep infiltrating endometriosis were reported in Indian women. In this review, we discuss our experiences of the inflammatory immune response, autoimmunity, comorbidities, and clinical phenotypes in women with endometriosis in India.

Clinical characteristics of idiopathic interstitial pneumonias with anti-Ro52/tripartite motif-containing 21 antibodies

Antibodies to Ro52/tripartite motif-containing 21 (TRIM21), referred to as anti-Ro52, are found in patients diagnosed with diverse systemic autoimmune rheumatic disease and associated with interstitial lung diseases. However, little is known about the clinical characteristics of anti-Ro52 in patients with idiopathic interstitial pneumonias (IIPs). We aimed to analyze the prevalence, co-existent autoantibodies, and clinical characteristics of anti-Ro52 in patients with IIP. The study enrolled 288 patients diagnosed with IIP. Clinical, laboratory and radiographic findings of IIP patients were compared between anti-Ro52 positives and negatives. Anti-Ro52 (20/288; 6.9%), anti-ARS (18/288; 6.3%), and anti-Ro60/SS-A (16/288; 5.6%) were the most common autoantibodies detected in IIP patients. Among 20 IIP patients who had anti-Ro52, anti-ARS was present in 8 (40%) patients. The criteria for interstitial pneumonia with autoimmune features (IPAF) were significantly better fulfilled by patients with anti-Ro52 than those without (P = 0.001). Meeting serological domain (P < 0.001) and Raynaud’s phenomenon (P = 0.009) were significantly more common in the anti-Ro52-positive patients. Anti-Ro52-positive IIP patients have clinical features consistent with IPAF. Anti-Ro52 may have an important role in detecting the autoimmune phenotype in IIP patients.

Autoimmune cerebellar ataxia associated with anti-leucine-rich glioma-inactivated protein 1 antibodies: Two pediatric cases

ObjectivesTo report two pediatric cases of autoimmune cerebellar ataxia associated with the anti-Leucine-rich glioma-inactivated protein 1 (LGI1)antibodies. MethodsThe clinical features of the two patients were described retrospectively. The indirect immunofluorescence using transfected cells (cell-based assay, CBA) and the rat cerebellum (tissue-based assay, TBA) with the multi-antigen co-plate biochip mosaic techniques were used to detect the antibodies. Clinical and laboratory characteristics were described. ResultsTwo males were included. The onset ages were 2.7y and 4y, respectively. Patient 1 manifested as isolated acute cerebellar ataxia. Patient 2 had extra-cerebellar symptoms, including seizures, encephalopathy, faciobrachial dystonic seizures(FBDs), and significant cerebellar ataxia. The hyponatremia and tumors were not found. Both of them responded well to the immunotherapy. ConclusionsThe autoimmune cerebellar ataxia might be a new phenotype of LGI1-Abs autoimmunity in children.

S138: MICROENVIRONMENT-REGULATED TRANSCRIPTIONS FACTORS AHR AND HIF-1Α EXPRESSION IN TREGS PROMOTE CLL PROGRESSION BY IMPAIRING CD8+ T-CELL MEDIATED ANTI-TUMOR IMMUNITY

Background: Chronic Lymphocytic Leukemia (CLL) progression is highly dependent on complex interactions between tumor cells and the tumor microenvironment (TME). Indeed, CLL cells can modify stromal cells and immune cells to promote the survival of the leukemic clone and to escape from the immune system surveillance. Within the TME, regulatory T cells (Tregs) represent a subtype of CD4+ T cells with immunosuppressive abilities, causing the evasion of cancer cells from the immune system. We previously characterized extensively the immune microenvironment of pre-clinical CLL mouse models using mass cytometry, and we described a significant increase in the Tregs subsets with an enhanced immunosuppressive and activated phenotype compared to non-leukemic animals (Wierz et al., Blood, 2018). Interestingly, TIGIT+ Tregs are more immunosuppressive than their TIGIT- Treg counterparts and express higher levels of several transcription factors, including Ahr and Hif1α (Joller et al., Immunity, 2014), both involved in the cellular response to microenvironment-mediated stimuli. Aims: The aim of the present study is to investigate the role of AHR and HIF-1α in the suppressive ability of Tregs during CLL development. Methods: We generated conditional knock out mice (cKO) lacking Ahr or Hif1a genes exclusively in Tregs (Foxp3YFP-CreAhrfx/fx and Foxp3YFP-CreHif1afx/fx mice). We then performed adoptive transfer (AT) of CLL cells obtained from diseased Eµ-TCL1 mice into cKO and control mice. In order to decipher the mechanism by which AHR and HIF-1α pathways in Tregs affect CLL progression, we analyzed the splenic TME of recipient mice and evaluated immune checkpoint expression and cytokine production. Finally, we evaluated the suppression ability of the regulatory T cells with ex vivo suppression assays. Results: Generated cKO mice showed no sign of abnormalities or autoimmune phenotypes, and immune cells phenotyping revealed no major differences. However, we showed that CLL growth in cKO mice was drastically delayed compared to the control mice (A). Interestingly, this decrease was mitigated when CD8+ T cells were depleted. The analysis of the splenic TME in recipient cKO mice revealed an increase in IL-17 and TNF-α production, two major T-cell cytokines, in CD4+ T cells as compared to their WT counterparts. We also measured the expression of immune checkpoints and activation markers in the different T cell subpopulations and observed that Tregs lacking AHR or HIF-1α show decreased levels of the immune checkpoints CTLA-4 and TIGIT, two key proteins for the suppressive functions of Tregs. Ex vivo suppression assays demonstrated an increased proliferation of CD8+ T cells in the presence cKO Tregs (B-C). This result confirmed the decreased suppressive ability of Tregs in absence of the two transcription factors, explaining the observed delay in CLL progression in cKO mice. Image:Summary/Conclusion: Altogether, these results indicate that the TME-regulated transcription factors AHR and HIF-1α in Tregs are crucial for CLL development by promoting escape to anti-tumor immune response, and therefore represent potential therapeutic targets during CLL progression.

Autoimmune Cytopenias in Common Variable Immunodeficiency Are a Diagnostic and Therapeutic Conundrum: An Update.

Common variable immunodeficiency (CVID) is the most common symptomatic primary immunodeficiency (PID). CVID is a heterogenous condition and clinical manifestations may vary from increased susceptibility to infections to autoimmune manifestations, granulomatous disease, polyclonal lymphoproliferation, and increased risk of malignancy. Autoimmune manifestations may, at times, be the first and only clinical presentation of CVID, resulting in diagnostic dilemma for the treating physician.Autoimmune cytopenias (autoimmune haemolytic anaemia and/or thrombocytopenia) are the most common autoimmune complications seen in patients with CVID. Laboratory investigations such as antinuclear antibodies, direct Coomb’s test and anti-platelet antibodies may not be useful in patients with CVID because of lack of specific antibody response. Moreover, presence of autoimmune cytopenias may pose a significant therapeutic challenge as use of immunosuppressive agents can be contentious in these circumstances. It has been suggested that serum immunoglobulins must be checked in all patients presenting with autoimmune cytopenia such as immune thrombocytopenia or autoimmune haemolytic anaemia.It has been observed that patients with CVID and autoimmune cytopenias have a different clinical and immunological profile as compared to patients with CVID who do not have an autoimmune footprint. Monogenic defects have been identified in 10-50% of all patients with CVID depending upon the population studied. Monogenic defects are more likely to be identified in patients with CVID with autoimmune complications. Common genetic defects that may lead to CVID with an autoimmune phenotype include nuclear factor kappa B subunit 1 (NF-kB1), Lipopolysaccharide (LPS)-responsive beige-like anchor protein (LRBA), cytotoxic T lymphocyte antigen 4 (CTLA4), Phosphoinositide 3-kinase (PI3K), inducible T-cell costimulatory (ICOS), IKAROS and interferon regulatory factor-2 binding protein 2 (IRF2BP2). In this review, we update on recent advances in pathophysiology and management of CVID with autoimmune cytopenias.

Steroid nuclear receptor coactivator 2 controls immune tolerance by promoting induced Treg differentiation via up-regulating Nr4a2.

Steroid nuclear receptor coactivator 2 (SRC2) is a member of a family of transcription coactivators. While SRC1 inhibits the differentiation of regulatory T cells (Tregs) critical for establishing immune tolerance, we show here that SRC2 stimulates Treg differentiation. SRC2 is dispensable for the development of thymic Tregs, whereas naive CD4+ T cells from mice deficient of SRC2 specific in Tregs (SRC2fl/fl/Foxp3YFP-Cre) display defective Treg differentiation. Furthermore, the aged SRC2fl/fl/Foxp3YFP-Cre mice spontaneously develop autoimmune phenotypes including enlarged spleen and lung inflammation infiltrated with IFNγ-producing CD4+ T cells. SRC2fl/fl/Foxp3YFP-Cre mice also develop severer experimental autoimmune encephalomyelitis (EAE) due to reduced Tregs. Mechanically, SRC2 recruited by NFAT1 binds to the promoter and activates the expression of Nr4a2, which then stimulates Foxp3 expression to promote Treg differentiation. Members of SRC family coactivators thus play distinct roles in Treg differentiation and are potential drug targets for controlling immune tolerance.

A Human MSH6 Germline Variant Associated With Systemic Lupus Erythematosus Induces Lupus-like Disease in Mice.

ObjectiveTo determine if single‐nucleotide polymorphisms (SNPs) in DNA repair genes are enriched in individuals with systemic lupus erythematosus (SLE) and if they are sufficient to confer a disease phenotype in a mouse model.MethodsHuman exome chip data of 2499 patients with SLE and 1230 healthy controls were analyzed to determine if variants in 10 different mismatch repair genes (MSH4, EXO1, MSH2, MSH6, MLH1, MSH3, POLH, PMS2, ML3, and APEX2) were enriched in individuals with SLE. A mouse model of the MSH6 SNP, which was found to be enriched in individuals with SLE, was created using CRISPR/Cas9 gene targeting. Wildtype mice and mice heterozygous and homozygous for the MSH6 variant were then monitored for 2 years for the development of autoimmune phenotypes, including the presence of high levels of antinuclear antibodies (ANA). Additionally, somatic hypermutation frequencies and spectra of the intronic region downstream of the VHJ558‐rearranged JH4 immunoglobulin gene was characterized from Peyer's patches.ResultsBased on the human exome chip data, the MSH6 variant (rs63750897, p.Ser503Cys) is enriched among patients with SLE versus controls after we corrected for ancestry (odds ratio = 8.39, P = 0.0398). Mice homozygous for the MSH6 variant (Msh6 S502C/S502C ) harbor significantly increased levels of ANA. Additionally, the Msh6 S502C/S502C mice display a significant increase in the infiltration of CD68+ cells (a marker for monocytes and macrophages) into the lung alveolar space as well as apoptotic cells. Furthermore, characterization of somatic hypermutation in these mice reveals an increase in the DNA polymerase η mutational signature.ConclusionAn MSH6 mutation that is enriched in humans diagnosed with lupus was identified. Mice harboring this Msh6 mutation develop increased autoantibodies and an inflammatory lung disease. These results suggest that the human MSH6 variant is linked to the development of SLE.

B Cell-Specific Deletion of CR6-Interacting Factor 1 Drives Lupus-like Autoimmunity by Activation of Interleukin-17, Interleukin-6, and Pathogenic Follicular Helper T Cells in a Mouse Model.

CR6-interacting factor 1 (CRIF1) is a nuclear transcriptional regulator and a mitochondrial inner membrane protein; however, its functions in B lymphocytes have been poorly defined. This study was undertaken to investigate the effects of CRIF1 on B cell metabolic regulation, cell function, and autoimmune diseases. Using mice with B cell-specific deletion of CRIF1 (Crif1ΔCD19 mice), we assessed the relevance of CRIF1 function for lupus disease parameters, including anti-double-stranded DNA (anti-dsDNA), cytokines, and kidney pathology. RNA sequencing was performed on B cells from Crif1ΔCD19 mice. The phenotypic and metabolic changes in immune cells were evaluated in Crif1ΔCD19 mice. Roquinsan/+ mice crossed with Crif1ΔCD19 mice were monitored to assess the functionality of CRIF1-deficient B cells in lupus development. Crif1ΔCD19 mice showed an autoimmune lupus-like phenotype, including high levels of autoantibodies to dsDNA and severe lupus nephritis with increased mesangial hypercellularity. While loss of CRIF1 in B cells showed impaired mitochondrial oxidative function, CRIF1-deficient B cells promoted the production of interleukin-17 (IL-17) and IL-6 and was more potent in helping T cells develop into follicular helper T cells. In a mouse model of autoimmune lupus, depletion of CRIF1 in B cells exacerbated lupus severity, and CRIF1 overexpression prevented lupus development in roquinsan/san mice. These results demonstrated that CRIF1 negatively correlates with disease severity and that overexpression of CRIF1 ameliorates disease development. Our findings suggest that CRIF1 is essential for preventing lupus development by maintaining B cell self tolerance.

Functional IKK/NF-κB signaling in pancreatic stellate cells is essential to prevent autoimmune pancreatitis

Pancreatic stellate cells (PSCs) are resident cells in the exocrine pancreas which contribute to pancreatic fibrogenesis and inflammation. Studies on NF-κB in pancreatitis so far focused mainly on the parenchymal and myeloid compartments. Here we show a protective immunomodulatory function of NF-κB in PSCs. Conditional deletion of NEMO (IKKγ) in PSCs leads to spontaneous pancreatitis with elevated circulating IgM, IgG and antinuclear autoantibodies (ANA) within 18 weeks. When further challenged with caerulein, NEMOΔCol1a2 mice show an exacerbated autoimmune phenotype characterized by increased infiltration of eosinophils, B and T lymphocytes with reduced latency period. Transcriptomic profiling shows that NEMOΔCol1a2 mice display molecular signatures resembling autoimmune pancreatitis patients. Mechanistically, we show that PSCΔNEMO cells produce high levels of CCL24 ex vivo which contributes to eosinophil recruitment, as neutralization with a CCL24 antibody abolishes the transwell migration of eosinophils. Our findings uncover an unexpected immunomodulatory role specifically of NF-κB in PSCs during pancreatitis.

Activation of NLR-Mediated Autoimmunity in Arabidopsis Early in Short Days 4 Mutant

From a reverse genetic screen using CRISPR/Cas9 gene editing tool, we unintentionally identified an autoimmune mutant. Map-based cloning and whole-genome sequencing revealed that it contains a deletion in SMALL UBIQUITIN-RELATED MODIFIER (SUMO) protease encoding gene EARLY IN SHORT DAYS 4 (ESD4). Previous studies reported that esd4 mutants accumulate elevated levels of plant defense hormone salicylic acid (SA). However, upregulated PATHOGENESIS-RELATED GENE 1 (PR1) expression in esd4 only partly relies on SA level. In this study, we show that plant metabolite N-hydroxypipecolic acid (NHP) biosynthetic genes are upregulated in esd4, and NHP biosynthesis mutant flavin-dependent-monooxygenase 1 (fmo1) partially suppresses the autoimmune phenotypes of esd4, suggestive of a requirement of NHP signaling for the autoimmunity in esd4. As activation of nucleotide-binding leucine-rich repeat immune receptors (NLRs) are associates with the biosynthesis of SA and NHP and lipase-like protein ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) is a key component downstream of many NLRs, we examined the relationship between EDS1 and ESD4 by analyzing the eds1 esd4 double mutant. We found that eds1 largely suppresses esd4 autoimmunity and blocks the elevated expressions of SA and NHP biosynthesis-related genes in esd4. Overall, our study provides evidence supporting the hypothesis that SUMO protease ESD4 likely targets a yet to be identified guardee of NLR by removing its SUMO modification to avoid recognition by the cognate NLR. Loss of ESD4 results in activation of NLR-mediated autoimmunity.

Novel loss-of-function mutations in TNFAIP3 gene in patients with lupus nephritis.

Heterozygous loss-of-function mutations in the tumour necrosis factor alpha induced protein 3 (TNFAIP3) gene cause an early-onset auto-inflammatory disease named haploinsufficiency of A20 (HA20). Here we describe three unrelated patients with autoimmune lupus nephritis (LN) phenotypes carrying three novel mutations in the TNFAIP3 gene. Whole-exome sequencing (WES) was used to identify the causative mutations in three biopsy-proven LN patients. Sanger sequencing and quantitative polymerase chain reaction (qPCR) were used to validate the mutations identified by WES. RNA sequencing, qPCR and cytometric bead array was used to detect inflammatory signatures in the patients. The patients predominantly presented with an autoimmune phenotype, including autoimmune haemolytic anaemia, multipositive autoantibodies and LN. Additionally, novel phenotypes of allergy and pericardial effusion were first reported. WES identified three novel heterozygous mutations in the TNFAIP3 gene, including a novel splicing mutation located in the canonical splicing site (c.634+2T>C)resulting in an intron 4 insertion containing a premature stop codon, a de novo novel copy number variation (exon 7-8 deletion) and a novel nonsense mutation c.1300_1301delinsTA causing a premature stop codon. We further identified hyperactivation signatures of nuclear factor- kappa B and type I IFN signalling and overproduction of pro-inflammatory cytokines in the blood. This report expanded the phenotype to a later age, as two girls were diagnosed at age 3 years and one man at age 29 years. Kidney involvement may be the main feature of the clinical spectrum of HA20, even in adults. Genetic screening should be considered for early-onset LN patients.

FC033: Genome-Wide Association Meta-Analysis Identifies Novel Loci for Kidney Failure

Abstract BACKGROUND AND AIMS The genetics of kidney function has been extensively studied, but since these analyses have been done mostly in populations with normal or mildly impaired kidney function, it is still unknown whether variants linked to kidney function also translate into genetic susceptibility for kidney failure. The primary aim of this study was to investigate the genetic background of kidney failure. METHOD We performed a meta-analysis of kidney failure genome-wide association studies, using kidney transplant recipients as cases (n = 6942) and donors as controls (n = 4788). Secondary disease-specific analyses were performed for kidney failure due to diabetes, IgA nephropathy, glomerulonephritis or polycystic kidney disease. Subsequently, we investigated genetic overlap with eGFR and urinary albumin-creatinine ratio (UACR) variability, based on publicly available CKDgen consortium meta-analysis data. RESULTS In the primary analysis, we found two suggestive hits for kidney failure: rs17046239 in GRM7 (P = 8.9 × 10−8), and rs9273431 in HLA-DQB1 (P = 5.3 × 10−8). In disease-specific analyses, we found three genome-wide (P &amp;lt; 5 × 10−8) significant hits for kidney failure due to diabetes: rs9273431 in HLA-DQB1 (P = 5.0 × 10−50), rs2476601 in PTPN22 (P = 2.9 × 10−13) and rs7110099 in INS-IGF2 (P = 4.4 × 10−9). Furthermore, we found suggestive hits for kidney failure due to glomerulonephritis (rs6531751, nearest gene: PDS5a, P = 9.3 × 10−8) or polycystic kidney disease (rs111857047 in PTPRD, P = 9.6 × 10−8). As follow-up analysis, we performed lookups for the identified SNPs in prior kidney function GWAS results of the CKDGen consortium. Our top hits for kidney failure due to diabetes were nominally significant (P &amp;lt; 0.05) in the creatinine-based estimated glomerular filtration rate (eGFRcrea) and/or the UACR results. The other hits were not significantly associated with either phenotype. Linkage disequilibrium score regression (LDSC) analysis did not reveal a significant genetic correlation (rG) between kidney failure and eGFRcrea or UACR. There was significant genetic overlap of type 2 diabetes with both kidney failure due to any cause (rG = 0.27; P = 0.0027) and kidney failure due to diabetes (rG = 0.57; P = 0.0002). In silico sequencing revealed that our diabetes-induced kidney failure hits had previously been associated with auto-immunity and type 1 diabetes; the other hits yielded no results. A UK Biobank phenome-wide association scan confirmed the associations of the three diabetes-specific kidney failure genetic hits with auto-immunity and diabetes phenotypes, and additionally linked them to thyroid function and blood cell counts. CONCLUSION We identified three genome-wide significant variants associated with kidney failure due to diabetes and four additional suggestive hits associated with cause-specific or overall kidney failure. The lack of strong genetic overlap with eGFR and UACR suggests that there is a separate genetic component that drives the risk of progression to kidney failure, independent of normal kidney function.

Age-dependent changes in the regulatory program of CD8+ Regulatory T cells (CD8+ Tregs)

Abstract Regulatory T cells (Tregs) help maintain the immune homeostasis. Any defect in the Tregs causes dysregulated immune responses that leads to risk of infection, autoimmunity, and cancer. Increased morbidity in the elderly patients is due to age-related changes in the immune system called immune aging. Despite several age-related studies in immune cells, immune aging in CD8+ Tregs are poorly characterized. With the growing number of evidence for the presence of various CD8+ Treg subset, our group has recently discovered that mice with knock out of specific CD8+ Treg subset characterized as CD8+ CD122+ Helios+ developed lethal autoimmune phenotype. To our surprise, the autoimmune phenotype is CD4+ Treg independent which underscores the important role of CD8+ CD122+ Helios+ Tregs in autoimmunity. This study investigated the age-associated changes in the CD8+ CD122+ Helios+ Tregs. We measured the quantitative and phenotypic changes of CD8+ Tregs at homeostasis in young (2 months) and older (12–24 months) mice. Our results demonstrate that at homeostasis, frequency of CD8+ Tregs in total lymphocytes is higher in older mice. Of note, older CD8+ Tregs upregulated the expression of Natural Killer group 2-member protein like NKG2A and NKG2D. We used acute infection model to test the age-related effect of infection/inflammation in the CD8+ Treg. We found that Treg numbers further expanded in older mice during acute infection and functionally superior to young mice. In addition, older CD8+ Tregs exhibited altered metabolic profile which might contribute to the immune senescence. In summary our findings support that CD8+ Treg may contribute to the weakened immune response in the elders.

Homeodomain protein Pbx1 regulates regulatory T cell development, stability and suppressive function

Abstract Pre-B cell leukemia transcription factor 1 (Pbx1) regulates multiple processes in various cell types. The Pbx1 gene is located in the Sle1a1 lupus susceptibility locus in the NZM2410 lupus-prone mouse model. The Pbx1-d dominant negative isoform lacking the DNA binding domain is more frequent in the CD4+ T cells from NZM240 mice as well as lupus patients as compared to healthy controls. In addition, the transgenic expression of Pbx1-d in CD4+ T cells reproduced the phenotypes of Sle1a1 mice, with impaired Foxp3+ Treg cell homeostasis as well as increased inflammatory CD4+ T cells. To study the role of Pbx1 in Treg cells, we generated Foxp3-specific Pbx1 knock-out mice (Foxp3-Pbx1 KO), which were bred to CD4-Pbx1-d-Tg mice to generate Pbx1-d Tg-KO mice that have Treg cells solely expressing Pbx1-d. Foxp3-Pbx1 KO mice showed reduced numbers of Treg cells with impaired suppressive activity. The numbers of natural Treg (nTrg) cells are decreased in thymus but not in spleen of Foxp3-Pbx1 KO mice, while the number of induced Treg (iTreg) cells are increased in the thymus and decreased in the periphery, suggesting that Pbx1 regulates Treg cell development and stability. The results were enhanced in Pbx1-d Tg-KO mice compared with Foxp3-Pbx1 KO mice, leading to autoimmune phenotypes, suggesting that the expression of Pbx1 functional isoform is necessary for the maintenance and function of Treg cells. RNAseq analyses with Pbx1-KO Treg cells indicated that Pbx1 regulates cell cycle, apoptosis and migration. Overall, our results suggest that Pbx1 regulates Treg cell homeostasis, stability and their suppressive functions and that Pbx1-d promotes lupus development by decreasing Treg cell development and functions. Supported by a grant from the NIH (R01 AI045050)

Coming of Age: Human Genomics and the Cancer-Immune Set Point.

Cancer is largely a disease of the tumor cell genome. As a result, the majority of genetics research in oncology has concentrated on the role of tumor somatic mutations, as well as inherited risk variants, in disease susceptibility and response to targeted treatments. The advent and success of cancer immunotherapies, however, have opened new perspectives for the investigation of the role of inherited genetic variation in codetermining outcome and safety. It is increasingly likely that the entirety of germline genetic variation involved in regulating immune responses accounts for a significant fraction of the observed variability in responses to cancer immunotherapies. Although germline genetic data from patients treated with cancer immunotherapies are still scarce, this line of research benefits from a vast body of knowledge derived from studies into autoimmune and infectious disease phenotypes, thus not requiring a start from a blank slate. Here, we discuss how a thorough investigation of genomic variation relevant for individuals' variability in (auto)immune responses can contribute to the discovery of novel treatment approaches and drug targets, and yield predictive biomarkers to stratify cancer patient populations in precision and personalized medicine settings.

Mortality Risk From COVID-19 Among Unvaccinated Subjects With Autoimmune Phenotypes of Interstitial Lung Disease.

Background: The impact of the severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2) virus on patients with interstitial lung disease (ILD) remains poorly understood. As patients with ILD often have severe underlying lung parenchymal involvement, and immunosuppressive therapy is common in this population, they are presumed to be at high risk for severe coronavirus disease 2019 (COVID-19) pneumonitis. Our aim was to explore demographic and clinical differences between those with ILD who tested positive for the SARS-CoV-2 virus compared to those with ILD who did not.Methods: In this retrospective cohort study, we identified adult, unvaccinated patients evaluated at the University of Chicago in 2020 who were enrolled in the ILD registry, and stratified by SARS-CoV-2 seropositive status. We then compared baseline clinical characteristics between SARS-CoV-2 seropositive and SARS-CoV-2 seronegative patients and assessed immunosuppressive therapy that the patient may have been on since ILD diagnosis. C-reactive protein and leukocyte subsets were evaluated at COVID diagnosis compared to the time of baseline ILD evaluation as were pulmonary function testing. Variable comparisons were determined by two-sided t-tests or chi-square tests as appropriate, and logistic regression models were fitted to assess the odds of death from COVID-19 using generalized linear models with maximum-likelihood estimation.Results: Of the 309 individuals with ILD in our cohort, 6.8% (n=21) tested positive for SARS-CoV-2. Those who were SARS-CoV-2 positive were younger (57 years vs 66 years; P=0.002), had baseline higher total lung capacity (81% vs 73%, P=0.045), similar forced vital capacity (71% vs. 67%, P=0.37), and similar diffusion capacity of carbon monoxide (71% vs. 62%, P=0.10) at baseline. Among patients with ILD and COVID-19, 67% had received immunosuppressive therapies compared to 74% of those with ILD without COVID-19. Those with ILD and COVID-19 were also more likely to have had a diagnosis of autoimmune-related ILD (connective tissue disease-ILD or interstitial pneumonia with autoimmune features) (62% vs 38%, P=0.029). Overall, the mortality hazard was highest among unvaccinated subjects with autoimmune-related ILD who had COVID-19 (OR=9.6, 95% CI=1.7-54.0; P=0.01).Discussion: SARS-CoV-2 is prevalent in ILD, and may put unvaccinated adults who are younger, with autoimmune ILD, and on immunosuppressive therapy at higher risk. This suggests a need for COVID-19 vaccinations and therapy (inpatient and outpatient) for this group of patients at high risk for COVID-19. Larger studies are needed to fully explore the relationship between ILD and immunosuppressive therapy in COVID-19.