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en: CD4 T-cell-dependent differentiation of CD23 follicular B cells contributes to the pulmonary pathology in a primary Sjögren's syndrome mouse model.

en: Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease that affects the function of exocrine glands, such as the lacrimal and the salivary glands. Extraglandular lesions and malignant lymphoma also occur during the progressive stage of pSS. We have, herein, focused on the pulmonary lesions of pSS and have aimed clarifying their pathophysiological mechanism by comparing the glandular with the extraglandular lesions observed in a mouse model of pSS. The histopathological analysis of lung tissues obtained from NFS/ mice that have undergone neonatal thymectomy was performed. Moreover, and experiments were conducted along with immunological analyses in order to characterize the unique phenotypes of the pulmonary lesions identified in these pSS model mice. Inflammatory lesions with a bronchus-associated lymphoid tissue-like structure were identified in the lungs of pSS model mice. In addition, relative to salivary gland lesions, pulmonary lesions showed increased CD23 follicular B (FB) cells. and pulmonary B cells were more readily driven to CD23 FB cell phenotype than salivary gland B cells in pSS model mice. Furthermore, the CD23 FB cell differentiation was found to be enhanced in a CD4 T-cell-dependent manner under a Th2-type condition in the lungs of herein examined pSS model mice. A Th2-type response in the pSS lung may promote the progression of autoimmune lesions through an enhanced abnormal differentiation of B cells.

en: Frontiers in Immunology

ja: Frontiers in Immunology


en: Disturbed natural killer cell homeostasis in the salivary gland enhances autoimmune pathology via IFN-γ in a mouse model of primary Sjogren's syndrome.

en: Innate lymphoid cells (ILCs), including natural killer (NK) cells, ILC1, ILC2, lymphoid tissue-inducer (LTi) cells, and ILC3 cell, play a key role in various immune responses. Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by chronic inflammation of exocrine glands, such as the lacrimal and salivary glands (SGs). The role of NK cells among ILCs in the pathogenesis of pSS is still unclear. In this study, the characteristics and subsets of NK cells in the salivary gland (SG) tissue were analyzed using a murine model of pSS. Multiple phenotypes and cytotoxic signature of the SG NK cells in control and pSS model mice were evaluated by flow cytometric analysis. Intracellular expression of interferon-γ (IFN-γ) among T cells and NK cells from the SG tissues was compared by experiments. In addition, pathological analysis was performed using anti-asialo-GM1 (ASGM1) antibody (Ab)-injected pSS model mice. The number of conventional NK (cNK) cells in the SG of pSS model mice significantly increased compared with that in control mice at 6 weeks of age. The production level of IFN-γ was significantly higher in SG NK cells than in SG T cells. The depletion of NK cells by ASGM1 Ab altered the ratio of tissue resident NK (rNK) cells to cNK cells, which inhibited the injury to SG cells with the recovery of saliva secretion in pSS model mice. The results indicate that SG cNK cells may enhance the autoreactive response in the target organ by upregulating of IFN-γ, whereas SG rNK cells protect target cells against T cell cytotoxicity. Therefore, the activation process and multiple functions of NK cells in the target organ could be helpful to develop potential markers for determining autoimmune disease activity and target molecules for incurable immune disorders.

en: Frontiers in Medicine

ja: Frontiers in Medicine


en: Exposure to Multiwall Carbon Nanotubes Promotes Fibrous Proliferation by Production of Matrix Metalloproteinase-12 via NF-κB Activation in Chronic Peritonitis.

en: The toxicologic effects of nanomaterials, such as carbon nanotubes (CNTs), on the immune system are considerably understood. However, the precise relationship between long-term exposure to CNTs and chronic inflammation remains unclear. In this study, a mouse model of chronic peritonitis was established using i.p. injection of multiwalled CNTs treated by the Taquann method with high dispersion efficiency. Chronic peritonitis with fibrosis was observed in Taquann-treated multiwalled CNT (T-CNT)-injected mice, but not in Taquann-treated titanium dioxide-injected mice. In vivo and in vitro experiments showed that matrix metalloproteinase-12 (MMP-12) of macrophages was up-regulated by T-CNT to enhance fibroblast activation and profibrotic molecule expression in fibroblasts. In addition, T-CNT-induced peritonitis reduced MMP-12 expression in Nfκb1 mice, suggesting that MMP-12-producing macrophages play a key role in chronic inflammation due to T-CNT exposure through NF-κB activation. The results of this study could be helpful in understanding the molecular toxicity of nanomaterial and chronic inflammation.

en: The American Journal of Pathology

ja: The American Journal of Pathology


en: Virus Infections Play Crucial Roles in the Pathogenesis of Sjögren's Syndrome.

en: Sjögren's syndrome (SS) is an autoimmune disease especially targeting exocrine glands, such as the salivary and lacrimal glands. A radical therapy for SS based on its etiology has not been established because of the complex pathogenesis of the disease. Several studies have demonstrated a relationship between virus infection and SS pathogenesis. In particular, infection with the Epstein-Barr (EB) virus among others is a potent factor associated with the onset or development of SS. Specifically, virus infection in the target organs of SS triggers or promotes autoreactive responses involving the process of autoantigen formation, antigen-presenting function, or T-cell response. Our review of recent research highlights the crucial roles of virus infection in the pathogenesis of SS and discusses the critical association between virus infection and the etiology of autoimmunity in SS.

en: Viruses

ja: Viruses


en: Formation of Autoimmune Lesions Is Independent of Antibiotic Treatment in NOD Mice.

en: The relationship between autoimmunity and changes in intestinal microbiota is not yet fully understood. In this study, the role of intestinal microbiota in the onset and progression of autoimmune lesions in non-obese diabetic (NOD) mice was evaluated by administering antibiotics to alter their intestinal microenvironment. Flow cytometric analysis of spleen cells showed that antibiotic administration did not change the proportion or number of T and B cells in NOD mice, and pathological analysis demonstrated that autoimmune lesions in the salivary glands and in the pancreas were also not affected by antibiotic administration. These results suggest that the onset and progression of autoimmunity may be independent of enteral microbiota changes. Our findings may be useful for determining the appropriate use of antibiotics in patients with autoimmune diseases who are prescribed drugs to maintain systemic immune function.

en: International Journal of Molecular Sciences


en: Ascl2-Regulated Follicular Helper T Cells Promote Autoimmunity in a Murine Model for Sjögren's Syndrome.

en: mice that received neonatal thymectomy treatment demonstrated that Ascl2 contributes to the Tfh cell differentiation associated with autoimmunity during the early stages independent of Bcl6. In conclusion, our results indicate that abnormal Tfh cell differentiation via Ascl2 regulation might contribute to the pathogenesis of autoimmunity.


en: Novel effects of rooibos extract on tear and saliva secretion mediated by the muscarinic acetylcholine receptor 3 in mice

en: Sicca syndrome is characterized by dry mouth and eyes and results in a reduction of the patient's quality of life. Various natural plants, including certain herbs, have long been employed to alleviate such symptoms. Rooibos grown in South Africa is one of the potent herbal plants used for the treating dry mouth. However, the precise mechanism of action by which rooibos alleviates symptoms of dryness remains unclear. The in vivo effects of rooibos extract (RE), which comprises eriodictyol-6-C-glucoside, on the secretory function of saliva and tears were analyzed after intraoral RE administration using wild-type C57BL/6 (B6) mice. In addition, the mechanisms of RE were investigated after administration of a muscarinic acetylcholine receptor 3 (M3R) antagonist. Tear and saliva volumes in mice increased significantly and in a dose-dependent manner following intraoral RE administration compared to those in mice in the control group administered HO. An experiment performed using darifenacin administration revealed that the effects of RE on secretory function were exerted via M3R. These results suggest that RE administration is an effective treatment for symptoms of dryness and may be used in clinical settings against sicca syndrome.

en: Journal of Oral Biosciences

ja: Journal of Oral Biosciences