The NOD Mouse Beyond Autoimmune Diabetes

Characterization and effective expansion of CD4-CD8- TCRαβ+ T cells from individuals living with type 1 diabetes

CD4-CD8- TCRαβ+ (double-negative [DN]) T cells represent a rare T cell population that promotes immunological tolerance through various cytotoxic mechanisms. In mice, autologous transfer of DN T cells has shown protective effects against autoimmune diabetes and graft-versus-host disease. Here, we characterized human DN T cells from people living with type 1 diabetes (PWT1D) and healthy controls. We found that while DN T cells and CD8+ T cells share many similarities, DN T cells are a unique T cell population, both at the transcriptomic and protein levels. We also show that by using various cytokine combinations, human DN T cells can be expanded in vitro up to 1,000-fold (mean >250-fold) and remain functional post-expansion. In addition, we report that DN T cells from PWT1D display a phenotype comparable to that of healthy controls, efficiently expand, and are highly functional. As DN T cells are immunoregulatory and can prevent T1D in various mouse models, these observations suggest that autologous DN T cells may be amenable to therapy for the prevention or treatment of T1D.

The IsletTester Mouse: An Immunodeficient Model With Stable Hyperglycemia for the Study of Human Islets

The gold standard for assessing the function of human islets or β-like cells derived from stem cells involves their engraftment under the kidney capsule of hyperglycemic, immunodeficient mice. Current models, such as streptozotocin treatment of severely immunodeficient mice or the NRG-Akita strain, are limited due to unstable and variable hyperglycemia and/or high morbidity. To address these limitations, we developed the IsletTester mouse via CRISPR/Cas9-mediated gene editing of glucokinase (Gck), the glucose sensor of the β-cells, directly in NSG zygotes. IsletTester mice are heterozygous for an Arg345→stop mutation in Gck and present with stable random hyperglycemia (∼250 mg/dL [14 mmol/L]), normal lifespan, and fertility. We demonstrate the utility of this model through functional engraftment of both human islets and human embryonic stem cell-derived β-like cells. The IsletTester mouse will enable the study of human islet biology over time and under different physiological conditions and can provide a useful preclinical platform to determine the functionality of stem cell-derived islet products.

ARTICLE HIGHLIGHTS

Current mouse models for assessing islet function in vivo are limited due to unstable and variable hyperglycemia and/or high morbidity. We derived the IsletTester mouse to address these limitations. Leveraging a previously characterized glucokinase mutation and CRISPR/Cas9 technology, we successfully developed a moderately hyperglycemic and immunodeficient mouse model for the in vivo assessment of islet function. Our IsletTester mouse has stable, moderate hyperglycemia that can be corrected with primary human islets or stem cell-derived insulin-producing cells. The IsletTester mouse provides a reliable, easy-to-use platform for the preclinical assessment of stem cell-derived islet products or islet-targeted drugs.

Supplementation with active vitamin D3 ameliorates experimental autoimmune thyroiditis in mice by modulating the differentiation and functionality of intrathyroidal T-cell subsets

Objective

People with Hashimoto's thyroiditis (HT) often have low vitamin D3 concentrations. Some research has suggested that vitamin D3 supplementation reduces thyroid inflammation, but this remains controversial.

Methods

EAT was induced in female NOD/ShiLtJ mice by giving them water containing 0.05% sodium iodide, and 1μg/kg of 1α,25-(OH)2D3 was injected intraperitoneally every other day. After 8 weeks, the morphological architecture of the mouse thyroid follicles was examined by histological sections, thyroid autoantibodies and thyroid hormone concentrations were determined by enzyme-linked immunosorbent assays (ELISAs), and the major functions and subsets of B- and T-lymphocytes in the mouse thyroid were determined by tissue multiple immunofluorescence technology and ELISA.

Results

EAT caused thyroiditis follicle destruction and interfollicular lymphocyte infiltration in mice, increased concentrations of circulating thyroid autoimmune antibodies TG-Ab and TPO-Ab, and abnormal thyroid hormone levels. EAT also increased the number and functionality of CD4+ Tfh, Th17,Th1 and Th2 cells in the thyroid, while decreasing the number and functionality of CD4+ Treg cells and CD19+B10 cells. Treatment with VD3 reversed these changes.

Conclusion

Vitamin D3 supplementation can effectively treat autoimmune thyroiditis in mice. VD3 reduces autoimmune thyroid damage and decreases serum thyroid antibody levels in mice by inhibiting the differentiation and functionality of pro-inflammatory Tfh, Th17, Th1 and Th2 cells and by facilitating the differentiation and functionality of anti-inflammatory B10 cells and Treg.

Serum and tear autoantibodies from NOD and NOR mice as potential diagnostic indicators of local and systemic inflammation in Sjögren's disease

Background

Sjögren's Disease (SjD) is an autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands (LG). The LG produces the protein-rich aqueous component of tears, and SjD-associated autoimmune dacryoadenitis (AD) may thus alter tear autoantibody composition.

Methods

The presence of tertiary lymphoid structures (TLS) in LG from two murine models of SjD-associated AD, male non-obese diabetic (NOD) and male non-obese insulitis resistant (NOR) mice, were evaluated using immunofluorescence. IgG and IgA reactivity in serum and tears from these models were probed in three studies against a panel of 80-120 autoantigens using autoantibody microarrays relative to serum and tears from healthy male BALB/c mice. Sources of Ig in tears were investigated using scRNA-Seq of the LG (GSE132420). Data were analyzed by R package Limma and Seurat.

Results

Analysis of immunofluorescence in LG sections from both SjD models showed TLS. Only one autoantibody was significantly elevated in tears and serum in both SjD models across all studies. Three autoantibodies were significantly elevated in serum but not in tears in both SjD models across all studies. Conversely, six IgG and thirteen IgA autoantibodies (6 sharing the same autoantigen) were significantly elevated in tears but not serum in both SjD models. Igha and Ighg2b expressing cells were identified in the plasma cell cluster of NOD.H2b LG.

Conclusion

NOD and NOR mice with SjD-associated AD have distinct autoantibody profiles in tears and serum. Tear IgA isotype autoantibodies showed a greater diversity than tear IgG autoantibodies. TLS observed in LG are a likely source of the tear autoantibodies.

Diabetes Mellitus Impairs Blood-Brain Barrier Integrality and Microglial Reactivity

Diabetes mellitus (DM), a chronic metabolic disorder that adversely affects the blood-brain barrier (BBB) and microglial function in the central nervous system (CNS), contributing to neuronal damage and neurodegenerative diseases. However, the underlying molecular mechanisms linking diabetes to BBB dysfunction and microglial dysregulation remain poorly understood. Here, we assessed the impacts of diabetes on BBB and microglial reactivity and investigated its mechanisms. We found diabetes severely disrupted the BBB integrity and microglial response to vascular injury. We also revealed a potential relationship between BBB disruption and impaired microglial function, whereby increasing BBB permeability led to a downregulation of microglial P2RY12 expression, thereby impairing microglial protection against cerebrovascular injury. Understanding these mechanisms may contribute to the developing of therapeutic strategies for diabetes-related neurological complications.

A human oral commensal-mediated protection against Sjögren's syndrome with maintenance of T cell immune homeostasis and improved oral microbiota

Sjögren's syndrome (SS) is a prevalent systemic autoimmune disease with substantial impacts on women's health worldwide. Although oral Haemophilus parainfluenzae is reduced in SS, its significance remains unclear. This study aimed to elucidate the pathophysiological role of H. parainfluenzae in SS. Reduced salivary H. parainfluenzae levels in SS patients were confirmed through quantitative PCR. Oral H. parainfluenzae inoculation in NOD mice alleviated focal sialadenitis, improved salivary function, and reduced IFN-γ+CD3+ and IFN-γ+CD8+ T cells in salivary gland-draining lymph nodes, maintaining immune homeostasis against a biased type 1 response. Inoculation also enhanced salivary microbiota diversity, balanced the Firmicutes-to-Proteobacteria ratio, and reduced the overwhelming presence of Pseudomonas mendocina. In vitro, H. parainfluenzae-preconditioned A253 cells limited CD8 T cell expansion with reduced IFN-γ production. These findings suggest that H. parainfluenzae improves oral microbial diversity, promotes homeostatic T-cell immunity, and protects against SS, supporting its potential as a next-generation probiotic.

Serum and Tear Autoantibodies from NOD and NOR Mice as Potential Diagnostic Indicators of Local and Systemic Inflammation in Sjögren's Disease

Background

Sjögren's Disease (SjD) is an autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands (LG). The LG produces the protein-rich aqueous component of tears, and SjD-associated autoimmune dacryoadenitis (AD) may thus alter tear autoantibody composition.

Methods

The presence of tertiary lymphoid structures (TLS) in LG from two murine models of SjD-associated AD, male NOD and male NOR mice, were evaluated using immunofluorescence. IgG and IgA reactivity in serum and tears from these models were probed in three studies against a panel of 80-120 autoantigens using autoantibody microarrays relative to serum and tears from healthy male BALB/c mice. Data were analyzed by R package Limma.

Results

Analysis of immunofluorescence in LG sections from both SjD models showed TLS. Only one autoantibody was significantly elevated in tears and serum in both SjD models across all studies. Three autoantibodies were significantly elevated in serum but not in tears in both SjD models across all studies. Conversely, six IgG and thirteen IgA autoantibodies (6 sharing the same autoantigen) were significantly elevated in tears but not serum in both SjD models.

Conclusion

NOD and NOR mice with SjD-associated AD have distinct autoantibody profiles in tears and serum. Tear IgA isotype autoantibodies showed a greater diversity than tear IgG autoantibodies. TLS observed in LG are a likely source of the tear autoantibodies.

Lowering an ER stress-regulated long noncoding RNA protects mice from diabetes and isolated pancreatic islets from cell death

We investigated the role of the endoplasmic reticulum (ER) stress-regulated long noncoding RNA (lncRNA) lncMGC in pancreatic islets and the pathology of type 1 diabetes (T1D), as well as the potential of lncMGC-based therapeutics. In vivo, blood glucose levels (BGLs) and HbA1c were significantly lower in lncMGC-knockout (KO)-streptozotocin (STZ)-treated diabetic mice compared to wild-type STZ. Antisense oligonucleotides (GapmeR) targeting lncMGC significantly attenuated insulitis and BGLs in T1D NOD mice compared to GapmeR-negative control (NC). GapmeR-injected T1D Akita mice showed significantly lower BGLs compared to Akita-NC mice. hlncMGC-GapmeR lowered BGLs in partially humanized lncMGC (hlncMGC)-STZ mice compared to NC-injected mice. CHOP (ER stress regulating transcription factor) and lncMGC were upregulated in islets from diabetic mice but not in lncMGC-KO and GapmeR-injected diabetic mice, suggesting ER stress involvement. In vitro, hlncMGC-GapmeR increased the viability of isolated islets from human donors and hlncMGC mice and protected them from cytokine-induced apoptosis. Anti-ER stress and anti-apoptotic genes were upregulated, but pro-apoptotic genes were down-regulated in lncMGC KO mice islets and GapmeR-treated human islets. Taken together, these results show that a GapmeR-targeting lncMGC is effective in ameliorating diabetes in mice and also preserves human and mouse islet viability, implicating clinical translation potential.

Prevalence of latent and overt polyautoimmunity in type 1 diabetes: A systematic review and meta-analysis

BACKGROUND

Patients afflicted by type 1 diabetes (T1D) exhibit polyautoimmunity (PolyA). However, the frequency and distribution of PolyA in T1D is still unknown.

OBJECTIVE

We conducted a systematic review and meta-analysis to define the prevalence of latent and overt PolyA in individuals with T1D.

METHODS

Following PRISMA guidelines, a comprehensive search across medical databases identified studies on latent and overt PolyA in T1D. Two researchers independently screened, extracted data, and assessed study quality. A random effects model was utilized to calculate the pooled prevalence, along with its corresponding 95 % confidence interval (CI), for latent PolyA and overt PolyA. Meta-regression analysis was conducted to study the effect of study designs, age, sex, and duration of disease on pooled prevalence.

RESULTS

A total of 158 articles, encompassing a diverse composition of study designs were scrutinized. The analysis included 270,890 individuals with a confirmed diagnosis of T1D. The gender was evenly distributed (50.30 % male). Notably, our analysis unveiled an overt PolyA prevalence rate of 8.50 % (95 % CI, 6.77 to 10.62), with North America having the highest rates (14.50 %, 95 % CI, 7.58 to 24.89). This PolyA profile was further characterized by a substantial incidence of concurrent autoimmune thyroid disease (7.44 %, 95 % CI, 5.65 to 9.74). Moreover, we identified a notable prevalence of latent PolyA in the T1D population, quantified at 14.45 % (95 % CI, 11.17 to 18.49) being most frequent in Asia (23.29 %, 95 % CI, 16.29 to 32.15) and Oceania (21.53 %, 95 % CI, 16.48 to 27.62). Remarkably, this latent PolyA phenomenon primarily featured an array of autoantibodies, including rheumatoid factor, followed by Ro52, thyroid peroxidase antibodies, and thyroglobulin antibodies. Duration of the disease was associated with a highest frequency of latent (β: 0.0456, P-value: 0.0140) and overt PolyA (β: 0.0373, P-value: 0.0152). No difference in the pooled prevalence by study design was observed.

CONCLUSION

This meta-analysis constitutes a substantial advancement in the realm of early detection of PolyA in the context of T1D. Individuals with T1D should regularly undergo assessments to identify potential concurrent autoimmune diseases, especially as they age.

Soluble antigen arrays provide increased efficacy and safety over free peptides for tolerogenic immunotherapy

Autoantigen-specific immunotherapy using peptides offers a more targeted approach to treat autoimmune diseases, but clinical implementation has been challenging. We previously showed that multivalent delivery of peptides as soluble antigen arrays (SAgAs) efficiently protects against spontaneous autoimmune diabetes in the non-obese diabetic (NOD) mouse model. Here, we compared the efficacy, safety, and mechanisms of action of SAgAs versus free peptides. SAgAs, but not their corresponding free peptides at equivalent doses, efficiently prevented the development of diabetes. SAgAs increased the frequency of regulatory T cells among peptide-specific T cells or induce their anergy/exhaustion or deletion, depending on the type of SAgA used (hydrolysable (hSAgA) and non-hydrolysable 'click' SAgA (cSAgA)) and duration of treatment, whereas their corresponding free peptides induced a more effector phenotype following delayed clonal expansion. Over time, the peptides induced an IgE-independent anaphylactic reaction, the incidence of which was significantly delayed when peptides were in SAgA form rather than in free form. Moreover, the N-terminal modification of peptides with aminooxy or alkyne linkers, which was needed for grafting onto hyaluronic acid to make hSAgA or cSAgA variants, respectively, influenced their stimulatory potency and safety, with alkyne-functionalized peptides being more potent and less anaphylactogenic than aminooxy-functionalized peptides. Immunologic anaphylaxis occurred in NOD mice in a dose-dependent manner but not in C57BL/6 or BALB/c mice; however, its incidence did not correlate with the level of anti-peptide antibodies. We provide evidence that SAgAs significantly improve the efficacy of peptides to induce tolerance and prevent autoimmune diabetes while at the same time reducing their anaphylactogenic potential.

Experimental rat models for Hashimoto's thyroiditis

PURPOSE

Hashimoto's thyroiditis (HT) is an autoimmune thyroid disease characterized by T lymphocyte-mediated destruction of thyroid follicles. To study the pathogenesis of HT and the efficacy of new substances for its treatment, an easily obtained and adequate to the human disease experimental model is needed. The aim of our study was to find out whether it is possible to induce experimental autoimmune thyroiditis (EAT) similar to Hashimoto's thyroiditis by injecting with thyroglobulin (Tg) without using agents that enhance its thyroiditogenicity and without taking into account the genetic sensitivity of animals.

METHODS

Wistar rats were immunized with freshly isolated rat Tg or porcine Tg. In 8 weeks, histological studies of the thyroid and parathyroid glands were performed. Thyroid function and total serum calcium level were also evaluated.

RESULTS

Immunization with both rat and porcine freshly isolated Tg caused T lymphocytic infiltration of the thyroid gland, thyroid follicle atrophy and degradation in Wistar rats. EAT caused by porcine Tg was characterized by greater severity than EAT induced with rat Tg. In 55% of rats with porcine Tg-induced EAT, oxyphilic metaplasia was detected in the parathyroid glands. In addition, low total serum calcium was observed in these rats.

CONCLUSION

Two rat models of autoimmune thyroiditis were obtained. EAT caused in Wistar rats by immunization with rat Tg is similar to Hashimoto's thyroiditis. EAT induced with porcine Tg was accompanied by oxyphil cell metaplasia in the parathyroids and hypocalcemia.

Differential pulmonary toxicity and autoantibody formation in genetically distinct mouse strains following combined exposure to silica and diesel exhaust particles

BACKGROUND

Inhalation of airborne particulate matter, such as silica and diesel exhaust particles, poses serious long-term respiratory and systemic health risks. Silica exposure can lead to silicosis and systemic autoimmune diseases, while DEP exposure is linked to asthma and cancer. Combined exposure to silica and DEP, common in mining, may have more severe effects. This study investigates the separate and combined effects of occupational-level silica and ambient-level DEP on lung injury, inflammation, and autoantibody formation in two genetically distinct mouse strains, thereby aiming at understanding the interplay between genetic susceptibility, particulate exposure, and disease outcomes. Silica and diesel exhaust particles were administered to mice via oropharyngeal aspiration. Assessments of lung injury and host response included in vivo lung micro-computed tomography, lung function tests, bronchoalveolar lavage fluid analysis including inflammatory cytokines and antinuclear antibodies, and histopathology with particle colocalization.

RESULTS

The findings highlight the distinct effects of silica and diesel exhaust particles (DEP) on lung injury, inflammation, and autoantibody formation in C57BL/6J and NOD/ShiLtJ mice. Silica exposure elicited a well-established inflammatory response marked by inflammatory infiltrates, release of cytokines, and chemokines, alongside mild fibrosis, indicated by collagen deposition in the lungs of both C57BL/6J and NOD/ShilLtJ mice. Notably, these strains exhibited divergent responses in terms of respiratory function and lung volumes, as assessed through micro-computed tomography. Additionally, silica exposure induced airway hyperreactivity and elevated antinuclear antibody levels in bronchoalveolar lavage fluid, particularly prominent in NOD/ShiLtJ mice. Moreover, antinuclear antibodies correlated with extent of lung inflammation in NOD/ShiLTJ mice. Lung tissue analysis revealed DEP loaded macrophages and co-localization of silica and DEP particles. However, aside from contributing to airway hyperreactivity specifically in NOD/ShiLtJ mice, the ambient-level DEP did not significantly amplify the effects induced by silica. There was no evidence of synergistic or additive interaction between these specific doses of silica and DEP in inducing lung damage or inflammation in either of the mouse strains.

CONCLUSION

Mouse strain variations exerted a substantial influence on the development of silica induced lung alterations. Furthermore, the additional impact of ambient-level DEP on these silica-induced effects was minimal.

Epitope-based precision immunotherapy of Type 1 diabetes

Antigen-specific immunotherapies (ASITs) address important clinical needs in treating autoimmune diseases. However, Type 1 diabetes is a heterogeneous disease wherein patient characteristics influence responsiveness to ASITs. Targeting not only disease-relevant T cell populations, but also specific groups of patients using precision medicine is a new goal toward achieving effective treatment. HLA-restricted peptides provide advantages over protein as antigens, however, methods for profiling antigen-specific T cells need to improve in sensitivity, depth, and throughput to facilitate epitope selection. Delivery approaches are highly diverse, illustrating the many ways relevant antigen-presenting cell populations and anatomical locations can be targeted for tolerance induction. The role of persistence of antigen presentation in promoting durable antigen-specific tolerance requires further investigation. Based on the outcome of ASIT trials, the field is moving toward using patient-specific variations to improve efficacy, but challenges still lie on the path to delivering more effective and safer treatment to the T1D patient population.

Selective ablation of thymic and peripheral Foxp3+ regulatory T cell development

Foxp3+ regulatory T (Treg) cells of thymic (tTreg) and peripheral (pTreg) developmental origin are thought to synergistically act to ensure immune homeostasis, with self-reactive tTreg cells primarily constraining autoimmune responses. Here we exploited a Foxp3-dependent reporter with thymus-specific GFP/Cre activity to selectively ablate either tTreg (ΔtTreg) or pTreg (ΔpTreg) cell development, while sparing the respective sister populations. We found that, in contrast to the tTreg cell behavior in ΔpTreg mice, pTreg cells acquired a highly activated suppressor phenotype and replenished the Treg cell pool of ΔtTreg mice on a non-autoimmune C57BL/6 background. Despite the absence of tTreg cells, pTreg cells prevented early mortality and fatal autoimmunity commonly observed in Foxp3-deficient models of complete Treg cell deficiency, and largely maintained immune tolerance even as the ΔtTreg mice aged. However, only two generations of backcrossing to the autoimmune-prone non-obese diabetic (NOD) background were sufficient to cause severe disease lethality associated with different, partially overlapping patterns of organ-specific autoimmunity. This included a particularly severe form of autoimmune diabetes characterized by an early onset and abrogation of the sex bias usually observed in the NOD mouse model of human type 1 diabetes. Genetic association studies further allowed us to define a small set of autoimmune risk loci sufficient to promote β cell autoimmunity, including genes known to impinge on Treg cell biology. Overall, these studies show an unexpectedly high functional adaptability of pTreg cells, emphasizing their important role as mediators of bystander effects to ensure self-tolerance.

Validation of a murine proteome-wide phage display library for identification of autoantibody specificities

Autoimmunity is characterized by loss of tolerance to tissue-specific as well as systemic antigens, resulting in complex autoantibody landscapes. Here, we introduce and extensively validate the performance characteristics of a murine proteome-wide library for phage display immunoprecipitation and sequencing (PhIP-seq) in profiling mouse autoantibodies. This library was validated using 7 genetically distinct mouse lines across a spectrum of autoreactivity. Mice deficient in antibody production (Rag2-/- and μMT) were used to model nonspecific peptide enrichments, while cross-reactivity was evaluated using anti-ovalbumin B cell receptor-restricted OB1 mice as a proof of principle. The PhIP-seq approach was then utilized to interrogate 3 distinct autoimmune disease models. First, serum from Lyn-/- IgD+/- mice with lupus-like disease was used to identify nuclear and apoptotic bleb reactivities. Second, serum from nonobese diabetic (NOD) mice, a polygenic model of pancreas-specific autoimmunity, was enriched in peptides derived from both insulin and predicted pancreatic proteins. Lastly, Aire-/- mouse sera were used to identify numerous autoantigens, many of which were also observed in previous studies of humans with autoimmune polyendocrinopathy syndrome type 1 carrying recessive mutations in AIRE. These experiments support the use of murine proteome-wide PhIP-seq for antigenic profiling and autoantibody discovery, which may be employed to study a range of immune perturbations in mouse models of autoimmunity profiling.

Exploring the mechanisms of action of Zengye decoction (ZYD) against Sjogren's syndrome (SS) using network pharmacology and animal experiment

CONTEXT

Zengye decoction (ZYD) has been considered to have a curative effect on Sjogren's syndrome (SS). However, its therapeutic mechanisms remain obscure.

OBJECTIVES

This research explores the mechanisms of ZYD against SS.

MATERIALS AND METHODS

The active compounds and targets of ZYD were searched in the TCMSP and BATMAN-TCM databases. SS-related targets were obtained from the GeneCards database. The GO and KEGG enrichment analyses elucidated the molecular mechanisms. Animal experiments were performed using 8 C57BL/6 mice that served as the control group (physiological saline treatment) and 16 NOD mice randomly divided into the model group (physiological saline treatment) and the ZYD group (ZYD treatment) for 8 weeks to verify the therapeutic effects of ZYD on SS.

RESULTS

Twenty-nine active compounds with 313 targets of ZYD and 1038 SS-related targets were screened. Thirty-two common targets were identified. β-Sitosterol and stigmasterol might be important components. GO analysis suggested that the action of ZYD against SS mainly involved oxidative stress, apoptotic processes, and tumor necrosis factor receptor superfamily binding, etc. KEGG analysis indicated the most significant signaling pathway was apoptosis-multiple species. Animal experiments showed that ZYD improved lymphocytic infiltration of the submandibular glands (SMGs), reduced the serum levels of TNF-α, IL-1β, IL-6, and IL-17, upregulated the expression of Bcl-2, and downregulated the expression of Bax and Caspase-3 in the model mice.

DISCUSSION AND CONCLUSION

ZYD has anti-inflammatory and anti-apoptotic effects on SS, which provides a theoretical basis for the treatment of SS with ZYD.

Differential Pulmonary Toxicity and Autoantibody Formation in Genetically Distinct Mouse Strains Following Combined Exposure to Silica and Diesel Exhaust Particles

Background

Inhalation of airborne particulate matter, such as silica and diesel exhaust particles, poses serious long-term respiratory health risks. Silica exposure can lead to silicosis and systemic autoimmune diseases, while DEP exposure is linked to asthma and cancer. Combined exposure to silica and DEP, common in mining, may have more severe effects. This study investigates the separate and combined effects of silica and DEP on lung injury, inflammation, and autoantibody formation in two genetically distinct mouse strains, thereby aiming at understanding the interplay between genetic susceptibility, particulate exposure, and disease outcomes. Silica and diesel exhaust particles were administered to mice via oropharyngeal aspiration. Assessments of lung injury and host response included in vivo lung micro-computed tomography, lung function tests, bronchoalveolar lavage fluid analysis including inflammatory cytokines and antinuclear antibodies, and histopathology with particle colocalization.

Results

Silica exposure elicited a well-established inflammatory response marked by inflammatory infiltrates, release of cytokines, and chemokines, alongside limited fibrosis, indicated by collagen deposition in the lungs of both C57BL/6J and NOD/ShilLtJ mice. Notably, these strains exhibited divergent responses in terms of respiratory function and lung volumes, as assessed through micro-computed tomography. Additionally, silica exposure induced airway hyperreactivity and elevated antinuclear antibody levels in bronchoalveolar lavage fluid, particularly prominent in NOD/ShiLtJ mice. Lung tissue analysis revealed DEP loaded macrophages and co-localization of silica and DEP particles.

Conclusion

Mouse strain variations exerted a substantial influence on the development of silica induced lung alterations. Furthermore, the additional impact of diesel exhaust particles on these silica-induced effects was minimal.

Uncoupling of Natural Killer cell functional maturation and cytolytic function in NOD mice

NK cells are innate immune cells that target infected and tumor cells. Mature NK (mNK) cells undergo functional maturation characterized by four distinct stages, during which they acquire their cytotoxic properties. mNK cells from non-obese diabetic (NOD) mice exhibit a defect in functional maturation and have impaired cytotoxic functions. Hence, we tested whether the impaired cytotoxic function observed in mNK cells from NOD mice can be explained by their defect in functional maturation. By comparing the function of mNK cells from B6, B6g7 and NOD mice, we show that the expression of granzyme B is severely impaired in mNK cells from NOD mice, agreeing with their inability to control tumor growth in vivo. The low level of granzyme B expression in mNK cells from NOD mice is found at all stages of functional maturation and is therefore independent of their functional maturation defect. Consequently, this study demonstrates that phenotypic functional maturation of mNK cells can be uncoupled from the acquisition of cytotoxic functions.

Impacts of an age-related hearing loss allele of cadherin 23 on severity of hearing loss in ICR and NOD/Shi mice

The age-related hearing loss allele (Cdh23ahl) of the cadherin 23 gene leads to a more severe hearing loss phenotype through additive effects with risk alleles for hearing loss. In this study, we genome edited the Cdh23ahl allele to the wild-type Cdh23+ allele in outbred ICR mice and inbred NOD/Shi mice established from ICR mice and investigated their effects on hearing phenotypes. Several hearing tests confirmed that ICR mice developed early onset high-frequency hearing loss and exhibited individual differences in hearing loss onset times. Severe loss of cochlear hair cells was also detected in the high-frequency areas in ICR mice. These phenotypes were rescued by genome editing the Cdh23ahl allele to Cdh23+, suggesting that abnormal hearing phenotypes develop because of the interaction of the Cdh23ahl and risk alleles in the genetic background of ICR mice. NOD/Shi mice developed more severe hearing loss and hair cell degeneration than ICR mice. Hearing loss was detected at 1 month old. Hair cell loss, including degeneration of cell bodies and stereocilia, was observed in all regions of the cochlea in NOD/Shi mice. Although these phenotypes were partially rescued by genome editing to the Cdh23+ allele, the phenotypes associated with high-frequency hearing were mostly unrecovered in NOD/Shi mice. These results strongly suggest that the genetic background of NOD/Shi mice contain a potential risk allele for the acceleration of early onset high-frequency hearing loss.

Recent Advances and Perspectives in Relation to the Metabolomics-Based Study of Diabetic Retinopathy

Diabetic retinopathy (DR), a prevalent microvascular complication of diabetes, is a major cause of acquired blindness in adults. Currently, a clinical diagnosis of DR primarily relies on fundus fluorescein angiography, with a limited availability of effective biomarkers. Metabolomics, a discipline dedicated to scrutinizing the response of various metabolites within living organisms, has shown noteworthy advancements in uncovering metabolic disorders and identifying key metabolites associated with DR in recent years. Consequently, this review aims to present the latest advancements in metabolomics techniques and comprehensively discuss the principal metabolic outcomes derived from analyzing blood, vitreous humor, aqueous humor, urine, and fecal samples.

Soluble antigen arrays improve the efficacy and safety of peptide-based tolerogenic immunotherapy

Autoantigen-specific immunotherapy using peptides offers a more targeted approach to treat autoimmune diseases, but the limited in vivo stability and uptake of peptides impedes clinical implementation. We previously showed that multivalent delivery of peptides as soluble antigen arrays (SAgAs) efficiently protects against spontaneous autoimmune diabetes in the non-obese diabetic (NOD) mouse model. Here, we compared the efficacy, safety, and mechanisms of action of SAgAs versus free peptides. SAgAs, but not their corresponding free peptides at equivalent doses, efficiently prevented the development of diabetes. SAgAs increased the frequency of regulatory T cells among peptide-specific T cells or induce their anergy/exhaustion or deletion, depending on the type of SAgA (hydrolysable (hSAgA) and non-hydrolysable 'click' SAgA (cSAgA)) and duration of treatment, whereas their corresponding free peptides induced a more effector phenotype following delayed clonal expansion. Moreover, the N-terminal modification of peptides with aminooxy or alkyne linkers, which was needed for grafting onto hyaluronic acid to make hSAgA or cSAgA variants, respectively, influenced their stimulatory potency and safety, with alkyne-functionalized peptides being more potent and less anaphylactogenic than aminooxy-functionalized peptides. Both SAgA variants significantly delayed anaphylaxis compared to their respective free peptides. The anaphylaxis, which occurred in NOD mice but not in C57BL/6 mice, was dose-dependent but did not correlate with the production of IgG1 or IgE against the peptides. We provide evidence that SAgAs significantly improve the efficacy and safety of peptide-based immunotherapy.

Validation of a murine proteome-wide phage display library for the identification of autoantibody specificities

Autoimmunity is characterized by loss of tolerance to tissue-specific as well as systemic antigens, resulting in complex autoantibody landscapes. Here, we introduce and extensively validate the performance characteristics of a murine proteome-wide library for phage display immunoprecipitation and sequencing (PhIP-seq), to profile mouse autoantibodies. This system and library were validated using seven genetic mouse models across a spectrum of autoreactivity. Mice deficient in antibody production (Rag2-/- and μMT) were used to model non-specific peptide enrichments, while cross-reactivity was evaluated using anti-ovalbumin B cell receptor (BCR)-restricted OB1 mice as a proof of principle. The PhIP-seq approach was then utilized to interrogate three distinct autoimmune disease models. First, serum from Lyn-/- IgD+/- mice with lupus-like disease was used to identify nuclear and apoptotic bleb reactivities, lending support to the hypothesis that apoptosis is a shared origin of these antigens. Second, serum from non-obese diabetic (NOD) mice, a polygenic model of pancreas-specific autoimmunity, enriched peptides derived from both insulin and predicted pancreatic proteins. Lastly, Aire-/- mouse sera were used to identify numerous auto-antigens, many of which were also observed in previous studies of humans with autoimmune polyendocrinopathy syndrome type 1 (APS1) carrying recessive mutations in AIRE. Among these were peptides derived from Perilipin-1, a validated autoimmune biomarker of generalized acquired lipodystrophy in humans. Autoreactivity to Perilipin-1 correlated with lymphocyte infiltration in adipose tissue and underscores the approach in revealing previously unknown specificities. These experiments support the use of murine proteome-wide PhIP-seq for antigenic profiling and autoantibody discovery, which may be employed to study a range of immune perturbations in mouse models of autoimmunity.

Molecular Mechanisms in Autoimmune Thyroid Disease

The most common cause of acquired thyroid dysfunction is autoimmune thyroid disease, which is an organ-specific autoimmune disease with two presentation phenotypes: hyperthyroidism (Graves-Basedow disease) and hypothyroidism (Hashimoto's thyroiditis). Hashimoto's thyroiditis is distinguished by the presence of autoantibodies against thyroid peroxidase and thyroglobulin. Meanwhile, autoantibodies against the TSH receptor have been found in Graves-Basedow disease. Numerous susceptibility genes, as well as epigenetic and environmental factors, contribute to the pathogenesis of both diseases. This review summarizes the most common genetic, epigenetic, and environmental mechanisms involved in autoimmune thyroid disease.

Mutated Pkhd1 alone is sufficient to cause autoimmune biliary disease on the nonobese diabetic (NOD) genetic background

We previously reported that nonobese diabetic (NOD) congenic mice (NOD.c3c4 mice) developed an autoimmune biliary disease (ABD) with similarities to human primary biliary cholangitis (PBC), including anti-mitochondrial antibodies and organ-specific biliary lymphocytic infiltrates. We narrowed the possible contributory regions in a novel NOD.Abd3 congenic mouse to a B10 congenic region on chromosome 1 ("Abd3") and a mutated Pkhd1 gene (Pkhd1del36-67) upstream from Abd3, and we showed via backcrossing studies that the NOD genetic background was necessary for disease. Here, we show that NOD.Abd3 mice develop anti-PDC-E2 autoantibodies at high levels, and that placing the chromosome 1 interval onto a scid background eliminates disease, demonstrating the critical role of the adaptive immune system in pathogenesis. While the NOD genetic background is essential for disease, it was still unclear which of the two regions in the Abd3 locus were necessary and sufficient for disease. Here, using a classic recombinant breeding approach, we prove that the mutated Pkhd1del36-67 alone, on the NOD background, causes ABD. Further characterization of the mutant sequence demonstrated that the Pkhd1 gene is disrupted by an ETnII-beta retrotransposon inserted in intron 35 in an anti-sense orientation. Homozygous Pkhd1 mutations significantly affect viability, with the offspring skewed away from a Mendelian distribution towards NOD Pkhd1 homozygous or heterozygous genotypes. Cell-specific abnormalities, on a susceptible genetic background, can therefore induce an organ-specific autoimmunity directed to the affected cells. Future work will aim to characterize how mutant Pkhd1 can cause such an autoimmune response.

Activation-induced cytidine deaminase expression by thymic B cells promotes T-cell tolerance and limits autoimmunity

Elimination of self-reactive T cells in the thymus is critical to establish T-cell tolerance. A growing body of evidence suggests a role for thymic B cells in the elimination of self-reactive thymocytes. To specifically address the role of thymic B cells in central tolerance, we investigated the phenotype of thymic B cells in various mouse strains, including non-obese diabetic (NOD) mice, a model of autoimmune diabetes. We noted that isotype switching of NOD thymic B cells is reduced as compared to other, autoimmune-resistant, mouse strains. To determine the impact of B cell isotype switching on thymocyte selection and tolerance, we generated NOD.AID^-/- mice. Diabetes incidence was enhanced in these mice. Moreover, we observed reduced clonal deletion and a resulting increase in self-reactive CD4⁺ T cells in NOD.AID^-/- mice relative to NOD controls. Together, this study reveals that AID expression in thymic B cells contributes to T-cell tolerance.

The Immune Landscape of Papillary Thyroid Cancer in the Context of Autoimmune Thyroiditis

Simple Summary

The association between papillary thyroid cancer and Hashimoto’s thyroiditis went through a long-standing human debate recently elucidated by the establishment of a novel mouse model. Papillary thyroid carcinoma is an excellent model for studying the tumor immune microenvironment because it is naturally accompanied by immune cells, making it a good candidate for the treatment with immune checkpoint inhibitors.

Abstract

Papillary thyroid cancer (PTC) often co-occurs with Hashimoto’s thyroiditis, an association that has long been reported in clinical studies, remaining controversial. Experimental evidence has recently shown that pre-existing thyroiditis has a beneficial effect on PTC growth and progression by a distinctive expansion of effector memory CD8 T cells. Although the link between inflammation and PTC might involve different components of the immune system, a deep characterization of them which includes T cells, B cells and tertiary lymphoid structures, Mye-loid cells, Neutrophils, NK cells and dendritic cells will be desirable. The present review article considers the role of the adaptive and innate immune response surrounding PTC in the context of Hashimoto’s thyroiditis. This review will focus on the current knowledge by in vivo and in vitro studies specifically performed on animals’ models; thyroid cancer cells and human samples including (i) the dual role of tumor-infiltrating lymphocytes; (ii) the emerging role of B cells and tertiary lymphoid structures; (iii) the role of myeloid cells, dendritic cells, and natural killer cells; (iv) the current knowledge of the molecular biomarkers implicated in the complex link between thyroiditis and PTC and the potential implication of cancer immunotherapy in PTC patients in the context of thyroiditis.

Biomolecular Mechanisms of Autoimmune Diseases and Their Relationship with the Resident Microbiota: Friend or Foe?

The use of innovative approaches to elucidate the pathophysiological mechanisms of autoimmune diseases, as well as to further study of the factors which can have either a positive or negative effect on the course of the disease, is essential. In this line, the development of new molecular techniques and the creation of the Human Genome Program have allowed access to many more solutions to the difficulties that exist in the identification and characterization of the microbiome, as well as changes due to various factors. Such innovative technologies can rekindle older hypotheses, such as molecular mimicry, allowing us to move from hypothesis to theory and from correlation to causality, particularly regarding autoimmune diseases and dysbiosis of the microbiota. For example, Prevotella copri appears to have a strong association with rheumatoid arthritis; it is expected that this will be confirmed by several scientists, which, in turn, will make it possible to identify other mechanisms that may contribute to the pathophysiology of the disease. This article seeks to identify new clues regarding similar correlations between autoimmune activity and the human microbiota, particularly in relation to qualitative and quantitative microbial variations therein.