Discerning the kinetics of autoimmune manifestations in a model of Sjögren's syndrome

TNF is a critical cytokine in age-related dry eye disease

Aging is a complex biological process that is characterized by low-grade inflammation, called inflammaging. Aging affects multiple organs including eye and lacrimal gland. Tumor necrosis factor (TNF) is a pleiotropic cytokine that participates in inflammation, activation of proteases such as cathepsin S, and formation of ectopic lymphoid organs. Using genetic and pharmacological approaches, we investigated the role of TNF in age-related dry eye disease, emphasizing the ocular surface and lacrimal gland inflammation. Our results show the increased protein and mRNA levels of TNF in aged lacrimal glands, accompanied by increased TNF, IL1β, IL-18, CCL5, CXCL1, IL-2, IL-2 receptor alpha (CD25), IFN-γ, IL-12p40, IL-17, and IL-10 proteins in tears of aged mice. Moreover, genetic loss of the Tnf-/- in mice decreased goblet cell loss and the development of ectopic lymphoid structures in the lacrimal gland compared to wild-type mice. This was accompanied by a decrease in cytokine production. Treatment of mice at an early stage of aging (12-14-month-old) with TNF inhibitor tanfanercept eye drops for eight consecutive weeks decreased cytokine levels in tears, improved goblet cell density, and decreased the marginal zone B cell frequency in the lacrimal gland compared to vehicle-treated animals. Our studies indicate that modulation of TNF during aging could be a novel strategy for age-related dry eye disease.

The NOD Mouse Beyond Autoimmune Diabetes

Autoimmune diabetes arises spontaneously in Non-Obese Diabetic (NOD) mice, and the pathophysiology of this disease shares many similarities with human type 1 diabetes. Since its generation in 1980, the NOD mouse, derived from the Cataract Shinogi strain, has represented the gold standard of spontaneous disease models, allowing to investigate autoimmune diabetes disease progression and susceptibility traits, as well as to test a wide array of potential treatments and therapies. Beyond autoimmune diabetes, NOD mice also exhibit polyautoimmunity, presenting with a low incidence of autoimmune thyroiditis and Sjögren’s syndrome. Genetic manipulation of the NOD strain has led to the generation of new mouse models facilitating the study of these and other autoimmune pathologies. For instance, following deletion of specific genes or via insertion of resistance alleles at genetic loci, NOD mice can become fully resistant to autoimmune diabetes; yet the newly generated diabetes-resistant NOD strains often show a high incidence of other autoimmune diseases. This suggests that the NOD genetic background is highly autoimmune-prone and that genetic manipulations can shift the autoimmune response from the pancreas to other organs. Overall, multiple NOD variant strains have become invaluable tools for understanding the pathophysiology of and for dissecting the genetic susceptibility of organ-specific autoimmune diseases. An interesting commonality to all autoimmune diseases developing in variant strains of the NOD mice is the presence of autoantibodies. This review will present the NOD mouse as a model for studying autoimmune diseases beyond autoimmune diabetes.

Candida Infection as an Early Sign of Subsequent Sjögren's Syndrome: A Population-Based Matched Cohort Study

Background

Candida infection is prevalent in patients with Sjögren's syndrome (SjS), which usually takes years to reach diagnosis. Is the link a two-way street? The role of Candida infection before SjS has not been examined clearly. This study was conducted to provide epidemiological evidence regarding the relationship between the first acquisition of Candida infection and subsequent SjS.

Methods

Totally, 23,494 individuals newly diagnosed with Candida infection were enrolled from 2000, to 2012. Controls (N = 93,976) were selected at a 1:4 ratio through propensity score matched (PSM) using the greedy algorithm. Exposure was defined according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes.

Main Outcomes and Measures

SjS was recorded in the Registry for Catastrophic Illness Patients Database (RCIPD). Cox proportional hazard model was used to analyze the association and sensitivity analyses for cross-validation.

Results

Of 117,470 individuals (106,077 [89%] women), 23,494 individuals (20.0%) had Candida infection and 104 individuals (0.1%) developed SjS. The incidence of SjS was higher in the exposed group compared with the controls (1.92 vs. 0. 98 per 10,000 person-years) with adjusted hazard ratio (aHR) 1.90 (95% CI, 1.25–2.87). The aHRs in subgroups of aged 18–30 years, oral candidiasis and depression were 4.30 (95% CI, 1.60–11.55), 4.70 (4.70–13.93) and 6.34 (2.16–18.66). Sensitivity analyses yield consistent results.

Conclusions

Residents in Taiwan with Candida infection have higher risk of SjS. For early diagnosis of SjS, clinicians are advised to take Candida infection into account in some situation.

Transcriptomic and Single-Cell Analysis Reveals Regulatory Networks and Cellular Heterogeneity in Mouse Primary Sjögren's Syndrome Salivary Glands

Sjögren’s Syndrome (SS) is a chronic autoimmune disease of unknown etiology which primarily affects the salivary and lacrimal glands resulting in the loss of secretory function. Treatment options for SS have been hampered due to the lack of a better understanding of the underlying gene regulatory circuitry and the interplay between the myriad pathological cellular states that contribute to salivary gland dysfunction. To better elucidate the molecular nature of SS, we have performed RNA-sequencing analysis of the submandibular glands (SMG) of a well-established primary Sjögren’s Syndrome (pSS) mouse model. Our comprehensive examination of global gene expression and comparative analyses with additional SS mouse models and human datasets, have identified a number of important pathways and regulatory networks that are relevant in SS pathobiology. To complement these studies, we have performed single-cell RNA sequencing to examine and identify the molecular and cellular heterogeneity of the diseased cell populations of the mouse SMG. Interrogation of the single-cell transcriptomes has shed light on the diversity of immune cells that are dysregulated in SS and importantly, revealed an activated state of the salivary gland epithelial cells that contribute to the global immune mediated responses. Overall, our broad studies have not only revealed key pathways, mediators and new biomarkers, but have also uncovered the complex nature of the cellular populations in the SMG that are likely to drive the progression of SS. These newly discovered insights into the underlying molecular mechanisms and cellular states of SS will better inform targeted therapeutic discoveries.

Autoimmune B Cell Repertoire in a Mouse Model of Sjögren's Syndrome

In genetically prone individuals, chronic immune activation may lead to expansion of autoreactive lymphocyte clones that can induce organ damage developing autoimmune disorders. Sjögren’s Syndrome (SjS) is a systemic chronic autoimmune disease that primarily affects exocrine glands. Despite the accumulated evidences of profound B-cell alterations of humoral immunity, the repertoire and development of B-cell autoreactivity in SjS remains to be determined. We hypothesize that SjS mice will have an increased frequency of self-reactive B cells with a progressive evolution to antigen-driven oligoclonality. Here, we study the B cell repertoire of NOD.H-2^h4 mice, a mouse model of spontaneous autoimmunity mimicking SjS without developing diabetes. A library of 168 hybridomas from NOD.H-2^h4 mice and 186 C57BL/6J splenocytes at different ages was created. The presence of mono or polyreactive autoantibodies to several antigens was evaluated by ELISA, and their staining patterns and cellular reactivity were tested by IFA and FACS. We observed a higher frequency of autoreactivity among B-cell clones from NOD.H-2^h4 mice as compared to wild-type mice. The presence of polyreactive and autoreactive IgG clones increased with mice age. Strikingly, all anti-Ro52 autoantibodies were polyreactive. No loss of polyreactivity was observed upon antibody class switching to IgG. There was a progression to oligoclonality in IgG B cells with mice aging. Our results indicate that in the NOD.H-2^h4 mouse model of SjS, IgG+ B cells are mainly polyreactive and might expand following an unknown antigen-driven positive selection process.

Metabolic abnormalities exacerbate Sjögren's syndrome by and is associated with increased the population of interleukin-17-producing cells in NOD/ShiLtJ mice

Background

Sjögren’s syndrome (SS) is an autoimmune disease mediated by lymphocytic infiltration into exocrine glands, resulting in progressive lacrimal and salivary destruction and dysfunctional glandular secretion. Metabolic syndrome influences the immune system. To investigate its relationship with metabolic abnormalities, we evaluated the pathogenesis of SS and the immune cell populations in non-obese diabetic NOD/ShiLtJ mice with type 1 diabetes (T1D).

Methods

To induce metabolic abnormalities, streptozotocin (STZ)—a glucosamine–nitrosourea compound that destroys pancreatic β cells, resulting in T1D—was injected into NOD/ShiLtJ mice. The blood glucose level was measured to evaluate induction of T1D. The severity of SS was assessed by determining the body weight, salivary flow rate, and histologic parameters. The expression levels of proinflammatory factors in the salivary glands, lacrimal gland, and spleen were quantified by real–time PCR. The populations of various T– and B–cell subtypes in the peripheral blood, spleen, and salivary glands were assessed by flow cytometry.

Results

Induction of T1D in NOD/ShiLtJ mice increased both the severity of SS and the levels of proinflammatory cytokines in the salivary glands compared to the controls. Furthermore, the number of interleukin-17–producing immune cells in the peripheral blood, spleen, and salivary glands was increased in STZ- compared to vehicle-treated NOD/ShiLtJ mice.

Conclusions

Metabolic abnormalities play an important role in the development of SS.

Ly9 (CD229) Antibody Targeting Depletes Marginal Zone and Germinal Center B Cells in Lymphoid Tissues and Reduces Salivary Gland Inflammation in a Mouse Model of Sjögren's Syndrome

Sjögren's Syndrome (SjS) is a common chronic autoimmune disease characterized by the B cell hyperactivation, lymphocyte infiltration, and tissue damage of exocrine glands. It can also present life-threatening extraglandular manifestations, such as pulmonary and hepatic involvement, renal inflammation and marginal zone (MZ) B cell lymphoma. Several biologic agents have been tested in SjS but none has shown significant efficacy. Here, we report the effects of Ly9 (CD229) antibody targeting, a cell surface molecule that belongs to the SLAM family of immunomodulatory receptors, using NOD.H-2^h4 mice as a model of SjS-like disease. Female mice were treated with anti-Ly9 antibody or isotype control at week 24, when all mice present SjS related autoantibodies, salivary gland infiltrates, and marginal zone (MZ) B cell pool enlargement. Antibody injection depleted key lymphocyte subsets involved in SjS pathology such as MZ, B1, and germinal center B cells in spleen and draining lymph nodes without inducing a general immunosuppression. Importantly, mice receiving anti-Ly9 mAb showed a reduced lymphocyte infiltrate within salivary glands. This reduction may be, in part, explained by the down-regulation of L-selectin and alfa4/beta7 integrin induced by the anti-Ly9 antibody. Furthermore, levels of anti-nuclear autoantibodies were reduced after anti-Ly9 treatment. These data indicate that Ly9 is a potential therapeutic target for the treatment of SjS.

Requirement for CD40/CD40L Interactions for Development of Autoimmunity Differs Depending on Specific Checkpoint and Costimulatory Pathways

CD40/CD40L interactions play a critical role in immunity and autoimmunity. In this study, we sought to understand the requirement for CD40 signaling in the programmed cell death-1 (PD-1) checkpoint and CD28 costimulatory pathways important for maintenance of peripheral tolerance. Blocking either pathway can result in loss of self-tolerance and development of autoimmunity. We found that primary Sjögren's syndrome (pSS) and autoimmune thyroid diseases (ATDs) that develop spontaneously in CD28-deficient IFN-γ-/- NOD.H-2h4 (CD28-/-) mice required CD40 signaling. Specifically, blockade of CD40L with the anti-CD40L mAb, MR1, inhibited autoantibody production and inflammation in thyroid and salivary gland target tissues. Unexpectedly, however, ATD and pSS in PD-1-deficient IFN-γ-/- NOD.H-2h4 (PD-1-/-) mice developed independently of CD40/CD40L interactions. Treatment with MR1 had no effect and even exacerbated disease development in pSS and ATD, respectively. Most interesting, anti-thyroglobulin and pSS-associated autoantibodies were increased following anti-CD40L treatment, even though MR1 effectively inhibited the spontaneous splenic germinal centers that form in PD-1-deficient mice. Importantly, blockade of the PD-1 pathway by administration of anti-PD-1 mAb in CD28-/- mice recapitulated the PD-1-/- phenotype, significantly impacting the ability of MR1 to suppress ATD and pSS in these mice. These results indicate that there can be different pathways and requirements to autoimmune pathogenesis depending on the availability of specific checkpoint and costimulatory receptors, and an intact PD-1 pathway is apparently required for inhibition of autoimmunity by anti-CD40L.

Spontaneous germinal centers and autoimmunity

Germinal centers (GCs) are dynamic microenvironments that form in the secondary lymphoid organs and generate somatically mutated high-affinity antibodies necessary to establish an effective humoral immune response. Tight regulation of GC responses is critical for maintaining self-tolerance. GCs can arise in the absence of purposeful immunization or overt infection (called spontaneous GCs, Spt-GCs). In autoimmune-prone mice and patients with autoimmune disease, aberrant regulation of Spt-GCs is thought to promote the development of somatically mutated pathogenic autoantibodies and the subsequent development of autoimmunity. The mechanisms that control the formation of Spt-GCs and promote systemic autoimmune diseases remain an open question and the focus of ongoing studies. Here, we discuss the most current studies on the role of Spt-GCs in autoimmunity.

Autoimmune manifestations in aged mice arise from early-life immune dysregulation

Autoantibodies can be present years to decades before the onset of disease manifestations in autoimmunity. This finding suggests that the initial autoimmune trigger involves a peripheral lymphoid component, which ultimately drives disease pathology in local tissues later in life. We show that Sjögren's syndrome manifestations that develop in aged NOD.H-2h4 mice were driven by and dependent on peripheral dysregulation that arose in early life. Specifically, elimination of spontaneous germinal centers in spleens of young NOD.H-2h4 mice by transient blockade of CD40 ligand (CD40L) or splenectomy abolished Sjögren's pathology of aged mice. Strikingly, a single injection of anti-CD40L at 4 weeks of age prevented tertiary follicle neogenesis and greatly blunted the formation of key autoantibodies implicated in glandular pathology, including anti-muscarinic receptor antibodies. Microarray profiling of the salivary gland characterized the expression pattern of genes that increased with disease progression and showed that early anti-CD40L greatly repressed B cell function while having a broader effect on multiple biological pathways, including interleukin-12 and interferon signaling. A single prophylactic treatment with anti-CD40L also inhibited the development of autoimmune thyroiditis and diabetes in NOD.H-2h4 and nonobese diabetic mice, respectively, supporting a key role for CD40L in the pathophysiology of several autoimmune models. These results strongly suggest that early peripheral immune dysregulation gives rise to autoimmune manifestations later in life, and for diseases predated by autoantibodies, early prophylactic intervention with biologics may prove efficacious.

Review of autoantigens in Sjögren's syndrome: an update

Primary Sjögren’s syndrome (pSS) is an autoimmune disease characterized by inflammation in exocrine glands, resulting in reduced secretion of tears and saliva, manifesting as xerophthalmia and xerostomia, respectively. It is commonly associated with Sjögren’s syndrome type A (Ro) and Sjögren’s syndrome type B (La) antigens. However, in most patients, the identity of the triggering antigen is not known. Factors such as genetics of histocompatibility, dysregulation of T-cells, B-cells and viral infections have been implicated. Several important studies on autoantigens in pSS have been published since a review in 2012, and the aim of this review is to provide an update on further peer-reviewed original articles in this field. Oxidative damage of Ro60 antigen may explain the epitope spreading during the immune activation in pSS. Immune-mediated destruction of the muscarinic receptor-3-expressing cells has been associated with a reduction in parasympathetic function, which could cause reduced secretory function of exocrine glands. Such a process also activates reactive oxidative species and antioxidants, which are linked to the triggering of inflammatory responses. Elevated levels of kallikrein, yet another antigen present in the lacrimal gland and other tissues, are similarly involved in triggering an autoimmune T-cell response against target glands. Studying additional antigens, the platelet-selectin and vasoactive intestinal peptides, in patients with pSS can help to elucidate the origin and process of autoimmunity, or even lead to potential biomarkers. In conclusion, the understanding of autoantigens has led to exciting major advances in the biology of pSS and may influence diagnosis and management of pSS in future.

Mechanisms by Which B Cells and Regulatory T Cells Influence Development of Murine Organ-Specific Autoimmune Diseases

Experiments with B cell-deficient (B−/−) mice indicate that a number of autoimmune diseases require B cells in addition to T cells for their development. Using B−/− Non-obese diabetic (NOD) and NOD.H-2h4 mice, we demonstrated that development of spontaneous autoimmune thyroiditis (SAT), Sjogren’s syndrome and diabetes do not develop in B−/− mice, whereas all three diseases develop in B cell-positive wild-type (WT) mice. B cells are required early in life, since reconstitution of adult mice with B cells or autoantibodies did not restore their ability to develop disease. B cells function as important antigen presenting cells (APC) to initiate activation of autoreactive CD4+ effector T cells. If B cells are absent or greatly reduced in number, other APC will present the antigen, such that Treg are preferentially activated and effector T cells are not activated. In these situations, B−/− or B cell-depleted mice develop the autoimmune disease when T regulatory cells (Treg) are transiently depleted. This review focuses on how B cells influence Treg activation and function, and briefly considers factors that influence the effectiveness of B cell depletion for treatment of autoimmune diseases.

New Murine Model of Early Onset Autoimmune Thyroid Disease/Hypothyroidism and Autoimmune Exocrinopathy of the Salivary Gland

Sixty to seventy percent of IFN-γ(-/-) NOD.H-2h4 mice given sodium iodide (NaI)-supplemented water develop a slow onset autoimmune thyroid disease, characterized by thyrocyte epithelial cell (TEC) hyperplasia and proliferation (H/P). TEC H/P develops much earlier in CD28(-/-) mice and nearly 100% (both sexes) have severe TEC H/P at 4 mo of age. Without NaI supplementation, 50% of 5- to 6-mo-old CD28(-/-)IFN-γ(-/-) mice develop severe TEC H/P, and 2-3 wk of NaI is sufficient for optimal development of severe TEC H/P. Mice with severe TEC H/P are hypothyroid, and normalization of serum thyroxine levels does not reduce TEC H/P. Activated CD4(+) T cells are sufficient to transfer TEC H/P to SCID recipients. Thyroids of mice with TEC H/P have infiltrating T cells and expanded numbers of proliferating thyrocytes that highly express CD40. CD40 facilitates, but is not required for, development of severe TEC H/P, as CD40(-/-)IFN-γ(-/-)CD28(-/-) mice develop severe TEC H/P. Accelerated development of TEC H/P in IFN-γ(-/-)CD28(-/-) mice is a result of reduced regulatory T cell (Treg) numbers, as CD28(-/-) mice have significantly fewer Tregs, and transfer of CD28(+) Tregs inhibits TEC H/P. Essentially all female IFN-γ(-/-)CD28(-/-) NOD.H-2h4 mice have substantial lymphocytic infiltration of salivary glands and reduced salivary flow by 6 mo of age, thereby providing an excellent new model of autoimmune exocrinopathy of the salivary gland. This is one of very few models where autoimmune thyroid disease and hypothyroidism develop in most mice by 4 mo of age. This model will be useful for studying the effects of hypothyroidism on multiple organ systems.

New insights into B cell biology in systemic lupus erythematosus and Sjögren's syndrome

PURPOSE OF REVIEW

Our understanding of the physiological and pathogenic functions of B cells in systemic lupus erythematosus (SLE) and Primary Sjögren's syndrome (pSS) continues to expand. In this review, we discuss novel insights published in the last 18 months into the roles of B cells in systemic autoimmunity.

RECENT FINDINGS

Data have continued to expand regarding the diverse mechanisms by which innate immune signals including Toll-like receptors (TLRs) regulate the B cell compartment. Localized B cells and long-lived plasma cells have been identified as playing an important role in target tissue including the development of ectopic lymphoid structures in kidney and salivary gland. In addition to pathogenic roles for B cells, there is mounting evidence for regulatory B cell subsets that play a protective role and new insights into the signals that regulate their development.

SUMMARY

The past few years have provided insights into the multiple paths by which innate immune signals can lead to B cell activation in SLE and pSS and the increasingly diverse ways in which B cells contribute to disease expression. Further understanding the imbalance between protective and pathogenic functions for B cells in disease including in understudied target tissue should yield new treatment approaches.

Mouse Models of Primary Sjogren's Syndrome

Sjogren's syndrome (SjS) is a chronic autoimmune disorder characterized by immune cell infiltration and progressive injury to the salivary and lacrimal glands. As a consequence, patients with SjS develop xerostomia (dry mouth) and keratoconjunctivitis sicca (dry eyes). SjS is the third most common rheumatic autoimmune disorder, affecting 4 million Americans with over 90% of patients being female. Current diagnostic criteria for SjS frequently utilize histological examinations of minor salivary glands for immune cell foci, serology for autoantibodies, and dry eye evaluation by corneal or conjunctival staining. SjS can be classified as primary or secondary SjS, depending on whether it occurs alone or in association with other systemic rheumatic conditions, respectively. Clinical manifestations typically become apparent when the disease is relatively advanced in SjS patients, which poses a challenge for early diagnosis and treatment of SjS. Therefore, SjS mouse models, because of their close resemblance to the human SjS, have been extremely valuable to identify early disease markers and to investigate underlying biological and immunological dysregulations. However, it is important to bear in mind that no single mouse model has duplicated all aspects of SjS pathogenesis and clinical features, mainly due to the multifactorial etiology of SjS that includes numerous susceptibility genes and environmental factors. As such, various mouse models have been developed in the field to try to recapitulate SjS. In this review, we focus on recent mouse models of primary SjS xerostomia and describe them under three categories of spontaneous, genetically engineered, and experimentally induced models. In addition, we discuss future perspectives highlighting pros and cons of utilizing mouse models and current demands for improved models.

Genes and environment as predisposing factors in autoimmunity: acceleration of spontaneous thyroiditis by dietary iodide in NOD.H2(h4) mice

In the field of autoimmune thyroiditis, NOD.H2(h4) mice have attracted significant and increasing attention since they not only develop spontaneous disease but they present thyroiditis with accelerated incidence and severity if they ingest iodide through their drinking water. This animal model highlights the interplay between genetic and dietary factors in the triggering of autoimmune disease and offers new opportunities to study immunoregulatory parameters influenced by both genes and environment. Here, we review experimental findings with this mouse model of thyroiditis.

Changes in the Submandibular Salivary Gland Epithelial Cell Subpopulations During Progression of Sjögren's Syndrome-Like Disease in the NOD/ShiLtJ Mouse Model

Sjögren's syndrome (SS), an autoimmune exocrinopathy, is associated with dysfunction of the secretory salivary gland epithelium, leading to xerostomia. The etiology of SS disease progression is poorly understood as it is typically not diagnosed until late stage. Since mouse models allow the study of disease progression, we investigated the NOD/ShiLtJ mouse to explore temporal changes to the salivary epithelium. In the NOD/ShiLtJ model, SS presents secondary to autoimmune diabetes, and SS disease is reportedly fully established by 20 weeks. We compared epithelial morphology in the submandibular salivary glands (SMG) of NOD/ShiLtJ mice with SMGs from the parental strain at 12, 18, and 22 weeks of age and used immunofluorescence to detect epithelial proteins, including the acinar marker, aquaporin 5, ductal cell marker, cytokeratin 7, myoepithelial cell marker, smooth muscle α-actin, and the basal cell marker, cytokeratin 5, while confirming immune infiltrates with CD45R. We also compared these proteins in the labial salivary glands of human SS patients with control tissues. In the NOD/ShiLtJ SMG, regions of lymphocytic infiltrates were not associated with widespread epithelial tissue degradation; however, there was a decrease in the area of the gland occupied by secretory epithelial cells in favor of ductal epithelial cells. We observed an expansion of cells expressing cytokeratin 5 within the ducts and within the smooth muscle α-actin(+) basal myoepithelial population. The altered acinar/ductal ratio within the NOD/ShiLtJ SMG likely contributes to salivary hypofunction, while the expansion of cytokeratin 5 positive-basal cells may reflect loss of function or indicate a regenerative response.

Galectin-3 in autoimmunity and autoimmune diseases

Galectin-3 (gal-3) is a β-galactoside-binding lectin, which regulates cell-cell and extracellular interactions during self/non-self-antigen recognition and cellular activation, proliferation, differentiation, migration and apoptosis. It plays a significant role in cellular and tissue pathophysiology by organizing niches that drive inflammation and immune responses. Gal-3 has some therapeutic potential in several diseases, including chronic inflammatory disorders, cancer and autoimmune diseases. Gal-3 exerts a broad spectrum of functions which differs according to its intra- or extracellular localization. Recombinant gal-3 strategy has been used to identify potential mode of action of gal-3; however, exogenous gal-3 may not reproduce the functions of the endogenous gal-3. Notably, gal-3 induces monocyte-macrophage differentiation, interferes with dendritic cell fate decision, regulates apoptosis on T lymphocytes and inhibits B-lymphocyte differentiation into immunoglobulin secreting plasma cells. Considering the influence of these cell populations in the pathogenesis of several autoimmune diseases, gal-3 seems to play a role in development of autoimmunity. Gal-3 has been suggested as a potential therapeutic agent in patients affected with some autoimmune disorders. However, the precise role of gal-3 in driving the inflammatory process in autoimmune or immune-mediated disorders remains elusive. Here, we reviewed the involvement of gal-3 in cellular and tissue events during autoimmune and immune-mediated inflammatory diseases.

NOD.H-2h4 mice: an important and underutilized animal model of autoimmune thyroiditis and Sjogren's syndrome

NOD.H-2h4 mice express the K haplotype on the NOD genetic background. They spontaneously develop thyroiditis and Sjogren's syndrome, but they do not develop diabetes. Although autoimmune thyroid diseases and Sjogren's syndrome are highly prevalent autoimmune diseases in humans, there has been relatively little emphasis on the use of animal models of these diseases for understanding basic mechanisms involved in development and therapy of chronic organ-specific autoimmune diseases. The goal of this review is to highlight some of the advantages of NOD.H-2h4 mice for studying basic mechanisms involved in development of autoimmunity. NOD.H-2h4 mice are one of relatively few animal models that develop organ-specific autoimmune diseases spontaneously, i.e., without a requirement for immunization with antigen and adjuvant, and in both sexes in a relatively short period of time. Thyroiditis and Sjogren's syndrome in NOD.H-2h4 mice are chronic autoimmune diseases that develop relatively early in life and persist for the life of the animal. Because the animals do not become clinically ill, the NOD.H-2h4 mouse provides an excellent model to test therapeutic protocols over a long period of time. The availability of several mutant mice on this background provides a means to address the impact of particular cells and molecules on the autoimmune diseases. Moreover, to our knowledge, this is the only animal model in which the presence or absence of a single cytokine, IFN-γ, is sufficient to completely inhibit one autoimmune thyroid disease, with a completely distinct autoimmune thyroid disease developing when it is absent.