X-linked Foxp3 (Scurfy) mutation dominantly inhibits submandibular gland development and inflammation respectively through adaptive and innate immune mechanisms

Probiotic-Derived Ecto-5'-Nucleotidase Produces Anti-Inflammatory Adenosine Metabolites in Treg-Deficient Scurfy Mice

Probiotic Limosilactobacillus reuteri DSM 17938 (DSM 17938) prolongs the survival of Treg-deficient scurfy (SF) mice and reduces multiorgan inflammation by a process requiring adenosine receptor 2A (A2A) on T cells. We hypothesized that L. reuteri-derived ecto-5'-nucleotidase (ecto-5'NT) activity acts to generate adenosine, which may be a central mediator for L. reuteri protection in SF mice. We evaluated DSM 17938-5'NT activity and the associated adenosine and inosine levels in plasma, gut, and liver of SF mice. We examined orally fed DSM 17938, DSM 17938Δ5NT (with a deleted 5'NT gene), and DSM 32846 (BG-R46) (a naturally selected strain derived from DSM 17938). Results showed that DSM 17938 and BG-R46 produced adenosine while "exhausting" AMP, whereas DSM 17938∆5NT did not generate adenosine in culture. Plasma 5'NT activity was increased by DSM 17938 or BG-R46, but not by DSM 17938Δ5NT in SF mice. BG-R46 increased both adenosine and inosine levels in the cecum of SF mice. DSM 17938 increased adenosine levels, whereas BG-R46 increased inosine levels in the liver. DSM 17938Δ5NT did not significantly change the levels of adenosine or inosine in the GI tract or the liver of SF mice. Although regulatory CD73+CD8+ T cells were decreased in spleen and blood of SF mice, these regulatory T cells could be increased by orally feeding DSM 17938 or BG-R46, but not DSM 17938Δ5NT. In conclusion, probiotic-5'NT may be a central mediator of DSM 17938 protection against autoimmunity. Optimal 5'NT activity from various probiotic strains could be beneficial in treating Treg-associated immune disorders in humans.

Probiotic-derived ecto-5'-nucleotidase produces anti-inflammatory adenosine metabolites in Treg-deficient scurfy mice

Probiotic Limosilactobacillus reuteri DSM 17938 (DSM 17938) prolonges the survival of Treg-deficient scurfy (SF) mice and reduces multiorgan inflammation by a process requiring adenosine receptor 2A (A _2A ) on T cells. We hypothesized that L. reuteri -derived ecto-5'-nucleotidase (ecto-5'NT) activity acts to generate adenosine, which may be a central mediator for L. reuteri protection in SF mice. We evaluated DSM 17938-5'NT activity and the associated adenosine and inosine levels in plasma, gut and liver of SF mice. We examined orally fed DSM 17938, DSM 17938Δ5NT (with a deleted 5'NT gene), and DSM 32846 (BG-R46) (a naturally selected strain derived from DSM 17938). Results showed that DSM 17938 and BG-R46 produced adenosine while "exhausting" AMP, whereas DSM 17938∆5NT did not generate adenosine in culture. Plasma 5'NT activity was increased by DSM 17938 or BG-R46, but not by DSM 17938Δ5NT in SF mice. BG-R46 increased both adenosine and inosine levels in the cecum of SF mice. DSM 17938 increased adenosine levels, whereas BG-R46 increased inosine levels in the liver. DSM 17938Δ5NT did not significantly change the levels of adenosine or inosine in the GI tract or the liver of SF mice. Although regulatory CD73 ⁺ CD8 ⁺ T cells were decreased in spleen and blood of SF mice, these regulatory T cells could be increased by orally feeding DSM 17938 or BG-R46, but not DSM 17938Δ5NT. In conclusion, probiotic-5'NT may be a central mediator of DSM 17938 protection against autoimmunity. Optimal 5'NT activity from various probiotic strains could be beneficial in treating Treg-associated immune disorders in humans.

Limosilactobacillus reuteri and Lacticaseibacillus rhamnosus GG differentially affect gut microbes and metabolites in mice with Treg deficiency

Treg deficiency causes a lethal, CD4+ T cell-driven autoimmune disease called IPEX syndrome (immunodysregulation, polyendocrinopathy, and enteropathy, with X-linked inheritance) in humans and in the scurfy (SF) mouse, a mouse model of the disease. Feeding Limosilactobacillus reuteri DSM 17938 (LR 17938, LR) to SF mice reprograms the gut microbiota, reduces disease progression, and prolongs lifespan. However, the efficacy and mechanism of LR, compared with other probiotics, in producing these effects is unknown. We compared LR with Lacticaseibacillus rhamnosus GG (LGG), an extensively investigated probiotic. LR was more effective than LGG in prolonging survival. Both probiotics restored the fecal microbial alpha diversity, but they produced distinct fecal bacterial clusters and differentially modulated microbial relative abundance (RA). LR increased the RA of phylum_Firmicutes, genus_Oscillospira whereas LR reduced phylum_Bacteroidetes, genus_Bacteroides and genus_Parabacteroides, reversing changes attributed to the SF phenotype. LGG primarily reduced the RA of genus_Bacteroides. Both LR and LGG reduced the potentially pathogenic taxon class_γ-proteobacteria. Plasma metabolomics revealed substantial differences among 696 metabolites. We observed similar changes of many clusters of metabolites in SF mice associated with treatment with either LR or LGG. However, a unique effect of LR was to increase the abundance of plasma adenosine metabolites such as inosine, which we previously showed had immune modulatory effects. In conclusion: 1) different probiotics produce distinct signatures in the fecal microbial community in mice with Treg deficiency; and 2) when comparing different probiotics, there are strain-specific microbial products with different anti-inflammatory properties, reinforcing the concept that "one size does not fit all" in the treatment of autoimmune disease.NEW & NOTEWORTHY In the treatment of Treg-deficiency-induced autoimmunity, Limosilactobacillus reuteri DSM 17938 (LR) showed greater efficacy than Lacticaseibacillus rhamnosus GG (LGG). The study demonstrated that two different probiotics produce distinct signatures in the fecal microbial community in mice with Treg deficiency, but with many similarities in global plasma metabolites in general. However, there are strain-specific microbial products with different anti-inflammatory properties, reinforcing the concept that "one size does not fit all" in the treatment of autoimmune disease.

Association of Sjögren's Syndrome With Reduced Lifetime Sex Hormone Exposure: A Case-Control Study

OBJECTIVE

To test whether cumulative estrogen exposure, as determined by age at menarche, age at menopause, female hormone use, hysterectomy, and parity, have an effect on the development of primary Sjögren's syndrome (SS).

METHODS

We performed a case-control study of 2,680 women from the Sjögren's International Collaborative Clinical Alliance registry, including 1,320 registrants with primary SS and 1,360 with sicca symptoms but no key features of primary SS (sicca controls). The composite estrogen score (CES) was calculated by point assignment for early menarche (age ≤10 years), high parity (>3 pregnancies), hysterectomy, female hormone use, and late menopause (age ≥53 years). Cumulative menstrual cycling (CMC) was calculated as years menstruating minus time pregnant.

RESULTS

Using a regression model that adjusted for age, recruitment site, ethnicity, education, employment status, and smoking, we observed a progressive inverse trend between primary SS and CES. The odds ratio (OR) and 95% confidence interval (95% CI) were as follows for the sicca control group: CES 1, OR 0.81 (95% CI 0.67-0.99); CES 2, OR 0.74 (95% CI 0.57-0.97); CES 3, OR 0.50 (95% CI 0.30-0.86). This trend was corroborated by analysis of CMC. At the highest level of CMC within the postmenopausal group there was a 24% reduction in cumulative sex hormone exposure among primary SS participants relative to controls.

CONCLUSION

Women with primary SS have lower estrogen exposure and CMC compared to sicca controls. Increasing estrogen exposure was negatively associated with development of primary SS. Further longitudinal studies of sex hormone exposure in primary SS are needed to confirm these findings.

Adenosine A2A Receptor Deletion Blocks the Beneficial Effects of Lactobacillus reuteri in Regulatory T-Deficient Scurfy Mice

The lack of a functional Foxp3 transcription factor and regulatory T (Treg) cells causes lethal, CD4+ T cell-driven autoimmune diseases in scurfy (SF) mice and humans. Recent studies have shown that adenosine A2A receptor activation limits inflammation and tissue damage, thereby playing an anti-inflammatory role. However, the role of the adenosine A2A receptor in the development of disease in SF mice remains unclear. Using a genetic approach, we found that adenosine A2A receptor deletion in SF mice (SF[Formula: see text]) does not affect early life events, the development of a lymphoproliferative disorder, or hyper-production of pro-inflammatory cytokines seen in the Treg-deficiency state. As shown previously, Lactobacillus reuteri DSM 17938 treatment prolonged survival and reduced multiorgan inflammation in SF mice. In marked contrast, A2A receptor deletion completely blocked these beneficial effects of L. reuteri in SF mice. Altogether, these results suggest that although absence of the adenosine A2A receptor does not affect the development of disease in SF mice, it plays a critical role in the immunomodulation by L. reuteri in Treg-deficiency disease. The adenosine A2A receptor and its activation may have a role in treating other Treg dysfunction-mediated autoimmune diseases.

The contribution of epigenetics in Sjögren's Syndrome

Sjögren’s syndrome (SS) is a chronic autoimmune epithelitis that combines exocrine gland dysfunctions and lymphocytic infiltrations. While the pathogenesis of SS remains unclear, its etiology is multifunctional and includes a combination of genetic predispositions, environmental factors, and epigenetic factors. Recently, interest has grown in the involvement of epigenetics in autoimmune diseases. Epigenetics is defined as changes in gene expression, that are inheritable and that do not entail changes in the DNA sequence. In SS, several epigenetic mechanisms are defective including DNA demethylation that predominates in epithelial cells, an abnormal expression of microRNAs, and abnormal chromatin positioning-associated with autoantibody production. Last but not least, epigenetic modifications are reversible as observed in minor salivary glands from SS patients after B cell depletion using rituximab. Thus epigenetic findings in SS open new perspectives for therapeutic approaches as well as the possible identification of new biomarkers.

The value of animal models to study immunopathology of primary human Sjögren's syndrome symptoms

Sjögren's syndrome (SjS) is a complex chronic autoimmune disease of multifactorial etiology that results in eventual loss of secretory function in the exocrine glands. The challenges towards finding a therapeutic prevention or treatment for SjS are due primarily to a lack of understanding in the pathophysiological and clinical progression of the disease. In order to circumnavigate this problem, there is a need for appropriate animal models that resemble the major phenotypes of human SjS and deliver a clear underlying biological or molecular mechanism capable of defining various aspects for the disease. Here, we present an overview of SjS mouse models that are providing insight into the autoimmune process of SjS and advance our focus on potential diagnostic and therapeutic targets.

Innate immune signaling induces interleukin-7 production from salivary gland cells and accelerates the development of primary Sjögren's syndrome in a mouse model

Elevated IL-7 in the target tissues is closely associated with multiple autoimmune disorders, including Sjögren’s syndrome (SS). We recently found that IL-7 plays an essential role in the development and onset of primary SS (pSS) in C57BL/6.NOD-Aec1Aec2 mice, a well-defined mouse model of primary SS. However, environmental signals that cause excessive IL-7 production are not well-characterized. Innate immune signaling plays a critical role in shaping the adaptive immune responses including autoimmune responses. We and others have previously shown that innate immune signaling can induce IL-7 expression in lungs and intestines of C57BL/6 mice. In this study, we characterized the effects of poly I:C, a double-stranded RNA analog and toll-like receptor 3 agonist, on the induction of IL-7 expression in salivary glands and on pSS development. We showed that poly I:C administration to C57BL/6 mice rapidly induced IL-7 expression in the salivary glands in a type 1 IFN- and IFN-γ-dependent manner. Moreover, poly I:C-induced IL-7 contributed to the optimal up-regulation of CXCL9 in the salivary glands, which may subsequently promote recruitment of more IFN-γ-producing T cells. Repeated administration of poly I:C to C57BL/6.NOD-Aec1Aec2 mice accelerated the development of SS-like exocrinopathy, and this effect was abolished by the blockade of IL-7 receptor signaling with a neutralizing antibody. Finally, poly I:C or a combination of IFN-α and IFN-γ induced IL-7 gene expression and protein production in a human salivary gland epithelial cell line. Hence, we demonstrate that IL-7 expression in the salivary gland cells can be induced by poly I:C and delineate a crucial mechanism by which innate immune signals facilitate the development of pSS, which is through induction of IL-7 in the target tissues.

Interleukin-7 enhances the Th1 response to promote the development of Sjögren's syndrome-like autoimmune exocrinopathy in mice

OBJECTIVE

Although elevated interleukin-7 (IL-7) levels have been reported in patients with primary Sjögren's syndrome (SS), the role of IL-7 in this disease remains unclear. We undertook this study to characterize the previously unexplored role of IL-7 in the development and onset of primary SS using the C57BL/6.NOD-Aec1Aec2 (B6.NOD-Aec) mouse model, which recapitulates human primary SS.

METHODS

For gain-of-function studies, recombinant IL-7 or control phosphate buffered saline was injected intraperitoneally (IP) into 12-week-old B6.NOD-Aec mice for 8 weeks. For loss-of-function studies, anti-IL-7 receptor α-chain (anti-IL-7Rα) antibody or its isotype control IgG was administered IP into 16-week-old B6.NOD-Aec mice. Salivary flow measurement, histologic and flow cytometric analysis of salivary glands, and serum antinuclear antibody assay were performed to assess various disease parameters.

RESULTS

Administration of exogenous IL-7 accelerated the development of primary SS, whereas blockade of IL-7Rα signaling almost completely abolished the development of primary SS, based on salivary gland inflammation and apoptosis, autoantibody production, and secretory dysfunction. IL-7 positively regulated interferon-γ (IFNγ)-producing Th1 and CD8+ T cells in the salivary glands without affecting IL-17. Moreover, IL-7 enhanced the expression of CXCR3 ligands in a T cell- and IFNγ-dependent manner. Accordingly, IFNγ induced a human salivary gland epithelial cell line to produce CXCR3 ligands. IL-7 also increased the level of tumor necrosis factor α, another Th1-associated cytokine that can facilitate tissue destruction and inflammation.

CONCLUSION

IL-7 plays a pivotal pathogenic role in SS, which is underpinned by an enhanced Th1 response and IFNγ/CXCR3 ligand-mediated lymphocyte infiltration of target organs. These results suggest that targeting the IL-7 pathway may be a potential future strategy for preventing and treating SS.

STIM1 and STIM2 protein deficiency in T lymphocytes underlies development of the exocrine gland autoimmune disease, Sjogren's syndrome

Primary Sjögren's Syndrome (pSS) is an autoimmune disease involving salivary and other exocrine glands that leads to progressive lymphocytic infiltration into the gland, tissue damage, and secretory defects. The mechanism underlying this disease remains poorly understood. Here we report that mice with T-cell-targeted deletion of Stromal Interaction Molecule (STIM) 1 and STIM2 [double-knockout (DKO)] mice develop spontaneous and severe pSS-like autoimmune disease, displaying major hallmarks of the disease. In DKO mice, diffuse lymphocytic infiltration was seen in submandibular glands, a major target of pSS, by age 6 wk, progressing to severe inflammation by age 12 wk. Sjögren's syndrome-specific autoantibodies (SSA/Ro and SSB/La) were detected in the serum, and progressive salivary gland destruction and loss of fluid secretion were also seen. Importantly, we report that peripheral blood mononuclear cells as well as lymphocytic infiltrates in submandibular glands from patients with pSS demonstrated significant reductions in STIM1 and STIM2 proteins. Store-operated calcium entry was also reduced in peripheral blood mononuclear cells from pSS patients compared with those from healthy controls. Thus, deficiency of STIM1 and STIM2 proteins in T cells, and consequent defects in Ca(2+) signaling, are associated with salivary gland autoimmunopathy in DKO mice and pSS patients. These data reveal a previously unreported link between STIM1 and STIM2 proteins and pSS.

The forkhead transcription factor, FOXP3, is required for normal pituitary gonadotropin expression in mice

The hypothalamic-pituitary-gonadal axis is central to normal reproductive function. This pathway begins with the release of gonadotropin-releasing hormone in systematic pulses by the hypothalamus. Gonadotropin-releasing hormone is bound by receptors on gonadotroph cells in the anterior pituitary gland and stimulates the synthesis and secretion of luteinizing hormone and, to some extent, follicle-stimulating hormone. Once stimulated by these glycoprotein hormones, the gonads begin gametogenesis and the synthesis of sex hormones. In humans, mutations of the forkhead transcription factor, FOXP3, lead to an autoimmune disorder known as immunodysregulation, polyendocrinopathy, and enteropathy, X-linked syndrome. Mice with a mutation in the Foxp3 gene have a similar autoimmune syndrome and are infertile. To understand why FOXP3 is required for reproductive function, we are investigating the reproductive phenotype of Foxp3 mutant mice (Foxp3(sf/Y)). Although the gonadotroph cells appear to be intact in Foxp3(sf/Y) mice, luteinizing hormone beta (Lhb) and follicle-stimulating hormone beta (Fshb) expression are significantly decreased, demonstrating that these mice exhibit a hypogonadotropic hypogonadism. Hypothalamic expression of gonadotropin-releasing hormone is not significantly decreased in Foxp3(sf/Y) males. Treatment of Foxp3(sf/Y) males with a gonadotropin-releasing hormone receptor agonist does not rescue expression of Lhb or Fshb. Interestingly, we do not detect Foxp3 expression in the pituitary or hypothalamus, suggesting that the infertility seen in Foxp3(sf/Y) males is a secondary effect, possibly due to loss of FOXP3 in immune cells. Pituitary expression of glycoprotein hormone alpha (Cga) and prolactin (Prl) are significantly reduced in Foxp3(sf/Y) males, whereas the precursor for adrenocorticotropic hormone, pro-opiomelanocortin (Pomc), is increased. Human patients diagnosed with IPEX often exhibit thyroiditis due to destruction of the thyroid gland by autoimmune cells. We find that Foxp3(sf/Y) mice have elevated expression of thyroid-stimulating hormone beta (Tshb), suggesting that they may suffer from thyroiditis as well. Expression of the pituitary transcription factors, Pitx1, Pitx2, Lhx3, and Egr1, is normal; however, expression of Foxl2 and Gata2 is elevated. These data are the first to demonstrate a defect at the pituitary level in the absence of FOXP3, which contributes to the infertility observed in mice with Foxp3 loss of function mutations.

The Biology of Autoimmune Response in the Scurfy Mice that Lack the CD4+Foxp3+ Regulatory T-Cells

Due to a mutation in the Foxp3 transcription factor, Scurfy mice lack regulatory T-cells that maintain self-tolerance of the immune system. They develop multi-organ inflammation (MOI) and die around four weeks old. The affected organs are skin, tail, lungs and liver. In humans, endocrine and gastrointestinal inflammation are also observed, hence the disease is termed IPEX (Immunodysregulation, Polyendocrinopathy, Enteropathy, X-linked) syndrome. The three week period of fatal MOI offers a useful autoimmune model in which the controls by genetics, T-cell subsets, cytokines, and effector mechanisms could be efficiently investigated. In this report, we will review published work, summarize our recent studies of Scurfy double mutants lacking specific autoimmune-related genes, discuss the cellular and cytokine controls by these genes on MOI, the organ-specificities of the MOI controlled by environments, and the effector mechanisms regulated by specific Th cytokines, including several newly identified control mechanisms for organ-specific autoimmune response.

Activation of innate immunity accelerates sialoadenitis in a mouse model for Sjögren's syndrome-like disease

OBJECTIVE

Sjögren's syndrome is a chronic autoimmune disorder characterized by progressive lymphocytic infiltration within the salivary and lacrimal glands. This study was undertaken to investigate the effects of innate immunity activation on sialoadenitis in a mouse strain genetically susceptible for development of SS-like disease.

METHODS

Female New Zealand Black X New Zealand White F1 mice were repeatedly treated with toll-like 3 receptor agonist poly(I:C). Submandibular glands were investigated at different time points for sialoadenitis by immunohistochemistry and for gene expression of different chemokines by quantitative PCR. Submandibular gland-infiltrating cells were characterized by flow cytometry.

RESULTS

Poly(I:C) treatment significantly upregulated the expression of multiple chemokines within the submandibular glands. The severity and incidence of sialoadenitis was considerably higher in poly(I:C)-treated mice. There was a preponderance of dendritic cells and NK cells in the initial inflammatory cell infiltrates, and these were followed by CD4+ T cells.

CONCLUSIONS

Our data clearly demonstrate that systemic activation of innate immunity accelerates sialoadenitis in a mouse model for SS-like disease. These findings suggest that chronic activation of innate immunity can influence certain features of SS.

Sjögren's syndrome: studying the disease in mice

Sjögren's syndrome (SS), a systemic autoimmune disease, is characterized by inflammation of exocrine tissues accompanied by a significant loss of their secretory function. Clinical symptoms develop late and there are no diagnostic tests enabling early diagnosis of SS. Thus, particularly to study these covert stages, researchers turn to studying animal models where mice provide great freedom for genetic manipulation and testing the effect of experimental intervention. The present review summarizes current literature pertaining to both spontaneous and extrinsic-factor induced SS-like diseases in mouse models, discussing advantages and disadvantages related to the use of murine models in SS research.

IL-2-controlled expression of multiple T cell trafficking genes and Th2 cytokines in the regulatory T cell-deficient scurfy mice: implication to multiorgan inflammation and control of skin and lung inflammation

Scurfy (Sf) mice bear a mutation in the Foxp3 transcription factor, lack regulatory T cells (Treg), develop multiorgan inflammation, and die prematurely. The major target organs affected are skin, lungs, and liver. “Sf mice lacking the Il2 gene (Sf.Il2–/–), despite being devoid of Treg, did not develop skin and lung inflammation, but the inflammation in liver remained [corrected]. Genome-wide microarray analysis revealed hundreds of genes that were differentially regulated among Sf, Sf.Il2(-/-), and B6 CD4(+) T cells, but the most significant changes were those encoding receptors for trafficking/chemotaxis/retention and cytokines. Our study suggests that IL-2 controls the skin and lung inflammation in Sf mice in an apparent "organ-specific" manner through two novel mechanisms: by regulating the expression of genes encoding a variety of receptors for T cell trafficking/chemotaxis/retention and by regulating Th2 cell expansion and cytokine production. Thus, IL-2 is potentially a master regulator for multiorgan inflammation and an underlying etiological factor for various diseases associated with skin and lung inflammation.

Distinct regulation by lipopolysaccharides of the expression of interleukin-1β by murine macrophages and salivary glands

The regulation of interleukin (IL)-1 expression and secretion by salivary glands and macrophages in response to lipopolysaccharides (LPS) was compared. In wild-type mice, injection of LPS significantly decreased the volume of saliva stimulated by pilocarpine and increased its protein and amylase concentration. It did not modify the salivary concentration of IL-1β. The cytokine was expressed by submandibular acini and ducts. Macrophages also expressed IL-1β but at lower concentration than salivary glands. The pre-incubation of macrophages with LPS increased the phosphorylation of IκB and the expression of IL-1β. Adenosine triphosphate also promoted the secretion of the cytokine by these cells. These responses were absent in submandibular gland cells. These glands expressed CD14, TLR4 and MyD88. P2X(7)-KO mice secreted a lower volume of saliva which contained less proteins and amylase. In conclusion, IL-1β is constitutively expressed by submandibular glands and its secretion is not regulated by a P2X(7) agonist. In these cells, LPS do not activate the nuclear factor-κB-pro-IL-1β axis in spite of the expression of the proteins involved in their recognition.

Genetic control of the inflammatory T-cell response in regulatory T-cell deficient scurfy mice

IPEX (Immunodysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome is a rare, recessive disorder in patients with mutations in the foxp3 gene, the normal expression of which is required for the generation of functional regulatory T-cells. Scurfy mice also bear a mutation in the foxp3, and like IPEX patients, spontaneously develop multi-organ inflammation. As reviewed herein, breeding immune response genes into Scurfy mice has provided useful insight into how the inflammatory T-cell response is regulated in the absence of regulatory T-cells and post regulatory T-cell checkpoint. Of particular interest are those that preferentially affect the inflammatory T-cell response in an "apparent" organ-specific manner, implying that specific mechanisms of control exist for individual organs during multi-organ inflammation.

Regulation of multi-organ inflammation in the regulatory T cell-deficient scurfy mice

Scurfy mice display the most severe form of multi-organ inflammation due to total lack of the CD4+Foxp3+ regulatory T cells (Treg) resulted from a mutation of the X-linked transcription factor Foxp3. A large repertoire of Treg-suppressible, inflammation-inducing T cells was demonstrated by adoptive transfer experiments using Rag1-/- mice as recipients and by prolongation of lifespan through breeding with Faslpr/lpr mutant. Inflammation in the ear, eyes, skin, tail, salivary glands, lungs, stomach, pancreas, liver, small intestine, colon, skeletal muscle, and accessory reproductive organs are identified. Genetic and cellular regulations of specific organ inflammation are described. Sf mice may be useful for the identification of organ-specific antigens and Treg capable of suppressing inflammation in an organ-specific manner. Sf mice are also useful to determine the important inflammation process at the checkpoint after Treg regulation using genetic analysis through breeding.