BACKGROUND:Our previous study demonstrated that laundry detergents induce group 2 innate lymphoid cell-driven eosinophilic airway inflammation by disrupting airway epithelial barriers and promoting IL-33 release, and that detergent residues are present in nearly all household dust. However, their impact on allergen-induced airway inflammation remains unclear. METHODS:C57BL/6 background mice were intranasally primed four times with ovalbumin (OVA) or house dust mite (HDM) allergens in the presence or absence of a commercial laundry detergent. Following priming, mice were challenged with the same antigen for 3 consecutive days and sacrificed the day after the final challenge. Bronchoalveolar lavage fluid (BALF) and sera were analyzed by ELISA. Lungs were evaluated histologically and analyzed by qPCR. RESULTS:Mice intranasally primed with antigen in the presence of detergent exhibited eosinophilic airway inflammation upon antigen challenge, accompanied by increased IL-5 and IL-13 levels in the BALF. Intranasal administration of detergent and antigen also stimulated antigen-specific IgE production. These detergent- and allergen-induced type 2 responses were significantly suppressed in Il33-/- and Il13-/- mice. Administration of an anti-IL-4 receptor α chain antibody during the challenge phase reduced eosinophil counts in the BALF and antigen-specific IgE levels in the serum. By contrast, anti-IL-33 antibody treatment during the challenge phase did not affect eosinophilic airway inflammation or antigen-specific IgE production. CONCLUSIONS:Laundry detergents promote sensitization to co-inhaled allergens and exacerbate eosinophilic airway inflammation and antigen-specific IgE responses via IL-33 and IL-13. These findings suggest that detergents can act as adjuvants that facilitate airway sensitization.

Background Eosinophilic gastrointestinal disorders (EGIDs), excluding eosinophilic esophagitis (EoE), are increasingly recognized conditions with poorly understood pathogenesis. Current animal models inadequately represent the complexity of human non-EoE EGIDs, thereby limiting therapeutic development. We aim to establish a new mouse model of eosinophilic enteritis (EoN) using continuous succinate administration and elucidate the underlying immunological mechanisms. Methods Four-week-old wild-type C57BL/6J mice received succinate (150 mM) in drinking water for 21 days. We analyzed eosinophil infiltration, tuft cell populations, body weight changes, and cytokine expression. Knockout mice deficient in Pou2f3 (Skn-1a), Il25, Il5, Il13, and Rag2 were used to investigate mechanistic pathways. Transcriptomic analysis compared gene expression patterns between our model and human EGID datasets. Results Continuous succinate administration induced significant eosinophilic infiltration in the ileum (p < 0.05), accompanied by tuft cell proliferation and failure to thrive (p < 0.001). These changes occurred without neutrophil infiltration, elevated IgE levels, or diarrhea. Pou2f3 knockout mice, lacking the transcription factor required for tuft cell differentiation, showed complete abrogation of both eosinophilic inflammation and failure to thrive, demonstrating tuft cell dependency. IL-25 and IL-5 deficiency prevented eosinophilic infiltration and failure to thrive, whereas IL-13 knockout specifically blocked tuft cell proliferation. Transcriptomic analysis revealed overlap with human eosinophilic colitis gene expression patterns, particularly in IL-13 and serotonin receptor pathways. Conclusions We established a new mouse model of eosinophilic enteritis recapitulating key features of human non-EoE EGIDs through the tuft cell-IL-25-ILC2 axis. This model provides new insights into EGID pathogenesis and offers a valuable platform for therapeutic development.

Frontotemporal dementia (FTD) is an early onset form of dementia characterized by frontotemporal lobar atrophy accompanied by behavioral, personality, language, and motor deficits. Heterozygous mutations in GRN gene encoding progranulin (PGRN) are the genetic causes of FTD. Since PGRN is a neurotrophic and anti-inflammatory factor, most FTD-related PGRN mutations are thought to cause FTD due to haploinsufficiency. Therefore, therapies that increase PGRN levels by the administration of recombinant PGRN or viral vectors are attracting attention as an approach to the treatment of FTD. However, the mechanisms underlying the neuroprotective effects of PGRN remain unclear. To investigate the neuroprotective mechanisms of PGRN in vivo, we generated human PGRN transgenic (Tg) mice using the CAG promoter. Unexpectedly, mice overexpressing wild-type human PGRN showed a shortened lifespan and cerebellar dysfunction, including the loss of Purkinje cells. Furthermore, PGRN Tg mice developed cognitive impairment, gliosis, and lysosomal abnormalities. FTD-causative R432C-PGRN mutant Tg mice also showed FTD-like phenotypes, such as neuronal loss, gliosis, and behavioral deficits. In cultured cells, overexpression of PGRN induced endoplasmic reticulum (ER) stress and apoptotic cell death, suggesting that continuous increases in PGRN expression through viral vectors or genetic manipulation are neurotoxic and that PGRN-replacement therapy may be required to maintain optimal PGRN levels for each neuron type and brain region.

We previously reported that Plasmodium yoelii 17XNL (Py), a non-lethal rodent malarial parasite, could suppress collagen-induced arthritis (CIA) and increase the production of T cell-derived interleukin (IL)-10. However, it remained unclear whether IL-10 is essential for the Py-induced suppression of CIA. Male IL-10 knockout (KO) DBA/1 J mice were immunized with bovine type II collagen (CII) and subsequently infected with Py at one week post-immunization. The development of arthritis was evaluated by an arthritis score up to 6 weeks post-immunization. At 3 weeks post-immunization, cytokine production from splenocytes and serum anti-CII IgG/IgG1/IgG2a levels were compared between non-infected control mice and Py-infected mice. Py infection inhibited the development of CIA in IL-10KO mice until 4 weeks post-immunization, after which the arthritis score reached levels comparable with the control mice. Both pro-arthritic (IL-17 and TNF-α) and anti-arthritic (IFN-γ and IL-4) cytokines were down-regulated during the periods of parasitemia, while no significant differences were observed in levels of anti-CII IgG antibodies. Our findings indicate that Py alleviates CIA via IL-10-independent mechanisms.

Forkhead box protein P2 (Foxp2) regulates the expression of genes related to organ morphogenesis. Homozygous Foxp2(R552H) knock-in (Foxp2R552H/R552H) mice exhibit abnormal brain development, and die around the weaning period. Here we demonstrate that Foxp2R552H/R552H mice exhibit abnormal development of gastrointestinal (GI) system, followed by atrophy of stomach, abnormal rotation of intestine, and decreased expression of genes related to GI system development such as bar-like home box 1 (BARX1) and secreted frizzled-related protein 1 (Sfrp1), antagonist for Wnt/β-catenin signaling, and decreased expression of E-cadherin and Zonula occludens-1 (ZO-1) in epithelium, followed with increase of Zonulin in the serum, marker of leaky gut, and decrease of alpha-smooth muscle actin (SMA) in smooth muscle, resulting in their atrophy. Foxp2+/+ and Foxp2R552H/R552H transgenic mice expressing Foxp2 promoter-mediated mCherry exhibit that Foxp2 autoregulates its expression in the developing stomach. Foxp2 may control Wnt/β-catenin signaling via its autoregulation system, but Foxp2(R552H) may not. Our results suggest that Foxp2 is necessary for the development of the GI system.

Mast cells (MCs) are tissue-resident cells of hematopoietic origin that play an important role in host’s defense mechanism against nematodes. However, excessive activation of these cells contributes to the development of certain allergic diseases. Immunoglobin E (IgE) is one of the well-known molecules that activate MCs. Even in the absence of specific antigens, the binding of highly cytokinergic IgE to FcεRI on MCs prolongs their survival and induces cytokine production without enhancing their degranulation. In the present study, we examined the effects of the members of the interleukin-10 (IL-10) family of cytokines on IgE-mediated MCs functions. The receptors including Il10r1, Il10r2, and Il20r2, but not Il20r1, Il22r1 or Il28r1, were constitutively expressed in mouse bone marrow cell-derived cultured MCs (BMCMCs), suggesting that IL-10 may influence MCs function. Indeed, we found that only IL-10 could influence upon BMCMCs function; IL-10 enhanced prolongation of survival, promoted IL-6 and/or IL-13 production dependently of STAT1 and STAT3, and suppressed tumor necrosis factor production independently of STAT1 and STAT3 on IgE-stimulated BMCMCs. Moreover, the IL-10-mediated enhancement of IL-6 production by IgE-stimulated BMCMCs promotes Th17 cell expansion. These results suggest that IL-10 has a dual role as an anti-inflammatory and pro-inflammatory cytokine in MCs functions.

A pleiotropic immunoregulatory cytokine, TGF-β, signals via the receptor-regulated SMADs: SMAD2 and SMAD3, which are constitutively expressed in normal cells. Here, we show that selective repression of SMAD3 induces cDC differentiation from the CD115+ common DC progenitor (CDP). SMAD3 was expressed in haematopoietic cells including the macrophage DC progenitor. However, SMAD3 was specifically down-regulated in CD115+ CDPs, SiglecH- pre-DCs, and cDCs, whereas SMAD2 remained constitutive. SMAD3-deficient mice showed a significant increase in cDCs, SiglecH- pre-DCs, and CD115+ CDPs compared with the littermate control. SMAD3 repressed the mRNA expression of FLT3 and the cDC-related genes: IRF4 and ID2. We found that one of the SMAD transcriptional corepressors, c-SKI, cooperated with phosphorylated STAT3 at Y705 and S727 to repress the transcription of SMAD3 to induce cDC differentiation. These data indicate that STAT3 and c-Ski induce cDC differentiation by repressing SMAD3: the repressor of the cDC-related genes during the developmental stage between the macrophage DC progenitor and CD115+ CDP.

DICER1 syndrome is a tumor predisposition syndrome caused by familial genetic mutations in DICER1. Pathogenic variants of DICER1 have been discovered in many rare cancers, including cystic liver tumors. However, the molecular mechanisms underlying liver lesions induced by these variants remain unclear. In the present study, we sought to gain a better understanding of the pathogenesis of these variants by generating a mouse model of liver-specific DICER1 syndrome. The mouse model developed bile duct hyperplasia with fibrosis, similar to congenital hepatic fibrosis, as well as cystic liver tumors resembling those in Caroli's syndrome, intrahepatic cholangiocarcinoma, and hepatocellular carcinoma. Interestingly, the mouse model of DICER1 syndrome showed abnormal formation of primary cilia in the bile duct epithelium, which is a known cause of bile duct hyperplasia and cyst formation. These results indicated that DICER1 mutations contribute to cystic liver tumors by inducing defective primary cilia. The mouse model generated in this study will be useful for elucidating the potential mechanisms of tumorigenesis induced by DICER1 variants and for obtaining a comprehensive understanding of DICER1 syndrome. © 2024 The Pathological Society of Great Britain and Ireland.

The bone marrow (BM) stromal cell antigen-2 (BST-2), also known as tetherin, CD317, PDCA-1, or HM1.24, is a membrane protein overexpressed in several types of tumors and may act as a promising target for cancer treatment via antibody-dependent cellular cytotoxicity. BST-2 is also expressed in human BM stromal cells (BMSC), which support B cell development. While the activity of BST-2 as an antiviral factor has been demonstrated, the expression patterns and the role of BST-2 on B-cell development and activation have not been investigated, especially in vivo. In this study, Bst2 knockout (Bst2-/- ) mice were generated to assess the role of BST-2 on B cell development and activation. It was observed that BST-2 was not expressed in BMSC or all B cell progenitors even in wild-type mice and does not play a significant role in B cell development. In addition, the loss of BST-2 had no effect on B cell activation. Furthermore and in contrast to the well-known antiviral role of BST-2, infection of vesicular stomatitis Indiana virus to the BM cells collected from the Bst2-/- mice produced less infectious virus compared with that from the WT mice. These results suggest that murine BST-2 is different from human BST-2 in the expression pattern, physiological function, in vivo, and might possess positive role on VSV replication.

INTRODUCTION:Epidemiological studies demonstrated that cleaning work and frequent use of cleaning products are risk factors for asthma. Laundry detergents have been reported to have epithelial barrier-opening effects. However, whether laundry detergents directly induce airway inflammation and its mechanisms in vivo remain to be elucidated.METHODS:Two commercial laundry detergents and two commonly used surfactants for cleaning and cosmetics (sodium lauryl sulfate and sodium dodecyl benzene sulfonate) were intranasally administered to mice. Lungs were analyzed using flow cytometry, histology, ELISA, and quantitative PCR. Human bronchial epithelial cells were stimulated with laundry detergents and analyzed using quantitative PCR and western blotting. Involvement of oxidative stress was assessed using an antioxidant. Dust samples from homes were analyzed to determine their detergent content by measuring their critical micelle concentration (CMC).RESULTS:The administered laundry detergents and surfactants-induced eosinophilic airway inflammation accompanied by increased IL-33 expression and activation of group 2 innate lymphoid cells (ILC2s). Detergent-induced eosinophilic airway inflammation was significantly attenuated in Rag2-/- Il2rg-/- , Il33-/- mice, and also in wild-type mice treated with NAC. Detergent-induced IL-33 expression in airways was attenuated by NAC treatment, both in vivo and in vitro. CMCs were found in all of the tested dust extracts, and they differed significantly among the homes.CONCLUSION:The laundry detergents and surfactants-induced eosinophilic airway inflammation in vivo through epithelial cell and ILC2 activation. They induced IL-33 expression in airway epithelial cells through oxidative stress. Furthermore, detergent residues were present in house dust and are presumably inhaled into the airway in daily life.

Severely immunodeficient mice are useful for understanding the pathogenesis of certain tumors and for developing therapeutic agents for such tumors. In addition, engraftment of these mice with human hematopoietic cells can yield information that helps us understand the in vivo molecular mechanisms underlying actual human viral infections. In our present research, we discovered a novel, severely immunodeficient strain of mice having a mutation in exon 57 of the Prkdc gene (PrkdcΔex57/Δex57) in an inbred colony of B10.S/SgSlc mice. Those PrkdcΔex57/Δex57 mice showed thymic hypoplasia and lack of mature T cells and B cells in peripheral lymphoid tissues, resulting in very low levels of production of serum immunoglobulins. In addition, those mice were highly susceptible to influenza viruses due to the lack of acquired immune cells. On the other hand, since they had sufficient numbers of NK cells, they rejected tumor transplants, similarly to Prkdc+/+ mice. Next, we generated Foxn1nu/nu PrkdcΔex57/Δex57 Il2rg−/− (NPG) mice on the BALB/cSlc background, which lack all lymphocytes such as T cells, B cells and innate lymphoid cells, including NK cells. As expected, these mice were able to undergo engraftment of human tumor cell lines. These findings suggest that PrkdcΔex57/Δex57 mice will be useful as a novel model of immunodeficiency, while NPG mice will be useful for xenografting of various malignancies.

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by type 2 immune responses. Interleukin-25 (IL-25) is produced predominantly by epithelial cells. It can activate Th2 cells to produce type 2 cytokines such as IL-4, IL-5 and IL-13, contributing to host defense against nematodes. However, excessive/inappropriate production of IL-25 is considered to be involved in development of type 2 cytokine-associated allergic disorders such as asthma. On the other hand, the contribution of IL-25 to the pathogenesis of AD remains poorly understood. In the present study, we found that expression of Il25 mRNA was significantly increased in the skin of mice during oxazolone-induced chronic contact hypersensitivity (CHS), which is a mouse model of human AD. In addition, development of oxazoloneinduced chronic CHS was significantly reduced in IL-25-deficient (Il25-/-) mice compared with wildtype mice on the C57BL/6, but not BALB/c, background, although IL-25 was not essential for IL-4 production by hapten-specific T cells. Therefore, IL-25 is crucial for development of chronic CHS, although that is partly dependent on the genetic background of the mice.(c) 2022 Elsevier Inc. All rights reserved.

Exposure to various antigens derived from house dust mites (HDM) is considered to be a risk factor for development of certain allergic diseases such as atopic asthma, atopic dermatitis, rhinitis and conjunctivitis. Chitin is an insoluble polysaccharide (β-(1–4)-poly-N-acetyl-d-glucosamine) and a major component in the outer shell of HDMs. Mice exposed to chitin develop asthma-like airway eosinophilia. On the other hand, several lines of evidence show that the effects of chitin on immune responses are highly dependent on the size of chitin particles. In the present study, we show that chitin induced production of IL-33 and TSLP by alveolar and bronchial epithelial cells, respectively, in mice. IL-25, IL-33 and TSLP were reported to be important for group 2 innate lymphoid cell (ILC2)-, but not Th2 cell-, dependent airway eosinophilia in a certain model using chitin beads. Here, we show that—in our murine models—epithelial cell-derived IL-33 and TSLP, but not IL-25, were crucial for activation of resident lung Th2 cells as well as group 2 innate lymphoid cells (ILC2s) to produce IL-5, resulting in development of chitin-induced airway eosinophilia. Our findings provide further insight into the underlying mechanisms of development of HDM-mediated allergic disorders.

Extracellular vesicles derived from mammalian cells could be useful carriers for drug delivery systems (DDSs); however, with regard to clinical application, there are several issues to be overcome. Acerola (Malpighia emarginata DC.) is a popular health food. In this study, the feasibility of orally administered nucleic acid drug delivery by acerola exosome-like nanoparticles (AELNs) was examined. AELNs were recovered from acerola juice using an affinity column instead of ultracentrifugation. MicroRNA (miRNA) was sufficiently encapsulated in AELNs by 30-min incubation on ice and was protected against RNase, strong acid, and base treatments. The administration of an AELN/miRNA mixture in cells achieved downregulation of the miRNA's target gene, and this mixture showed cytoplasmic localization. AELNs orally delivered small RNA to the digestive system in vivo. The target gene-suppressing effect in the small intestine and liver peaked 1 day after administration, indicating potential for use as an oral DDS for nucleic acid in the digestive system.

BACKGROUND:Platelets are thought to be involved in the pathophysiology of asthma, presumably through direct adhesion to inflammatory cells, including group 2 innate lymphoid cells (ILC2s). Here, we tried to elucidate the effects of platelet adhesion to ILC2s in vitro and in vivo, as well as the mechanisms involved.METHODS:Alternaria-induced ILC2-dependent airway inflammation models using wild-type and c-mpl-/- mice were evaluated. Both purified CD41+ and CD41- ILC2s were cultured with IL-2 and IL-33 to determine in vitro Type 2 (T2) cytokine production and cell proliferation. RNA-seq data of flow-cytometry-sorted CD41+ and CD41- ILC2s were used to isolate ILC2-specific genes. Flow cytometry was performed to determine the expression of CD41 and adhesion-related molecules on ILC2s in both mouse and human tissues.RESULTS:T2 inflammation and T2 cytokine production from ILC2s were significantly reduced in the c-mpl-/- mice compared to wild-type mice. Platelet-adherent ILC2s underwent significant proliferation and showed enhanced T2 cytokine production when exposed to IL-2 and IL-33. The functions of ILC2-specific genes were related to cell development and function. Upstream regulator analysis identified 15 molecules, that are thought to be involved in ILC2 activation. CD41 expression levels were higher in ILC2s from human PBMCs and mouse lung than in those from secondary lymphoid tissues, but they did not correlate with the P-selectin glycoprotein ligand-1 or CD24 expression level.CONCLUSION:Platelets spontaneously adhere to ILC2s, probably in the peripheral blood and airways, thereby potentiating ILC2s to enhance their responses to IL-33.

Since cervical cancer still afflicts women around the world, it is necessary to understand the underlying mechanism of cervical cancer development. Infection with HPV is essential for the development of cervical intraepithelial neoplasia (CIN). In addition, estrogen receptor signaling is implicated in the development of cervical cancer. Previously, we have isolated human wings apart-like (WAPL), which is expected to cause chromosomal instability in the process of HPV-infected precancerous lesions to cervical cancer. However, the role of WAPL in the development of CIN is still unknown. In this study, in order to elucidate the role of WAPL in the early lesion, we established WAPL overexpressing mice (WAPL Tg mice) and HPV E6/E7 knock-in (KI) mice. WAPL Tg mice developed CIN lesion without HPV E6/E7. Interestingly, in WAPL Tg mice estrogen receptor 1 (ESR1) showed reduction as compared with the wild type, but cell growth factors MYC and Cyclin D1 controlled by ESR1 expressed at high levels. These results suggested that WAPL facilitates sensitivity of ESR1 mediated by some kind of molecule, and as a result, affects the expression of MYC and Cyclin D1 in cervical cancer cells. To detect such molecules, we performed microarray analysis of the uterine cervix in WAPL Tg mice, and focused MACROD1, a co-activator of ESR1. MACROD1 expression was increased in WAPL Tg mice compared with the wild type. In addition, knockdown of WAPL induced the downregulation of MACROD1, MYC, and Cyclin D1 but not ESR1 expression. Furthermore, ESR1 sensitivity assay showed lower activity in WAPL or MACROD1 downregulated cells than control cells. These data suggested that WAPL increases ESR1 sensitivity by activating MACROD1, and induces the expression of MYC and Cyclin D1. Therefore, we concluded that WAPL not only induces chromosomal instability in cervical cancer tumorigenesis, but also plays a key role in activating estrogen receptor signaling in early tumorigenesis.

AIMS:Many parasitic helminths are known to alter host immune responses and consequently affect the progression of autoimmune and allergic diseases. The parasitic nematode Trichinella sp has been reported to suppress several experimental diseases in rodents, including experimental autoimmune encephalomyelitis, type 1 diabetes, colitis, airway inflammation and autoimmune arthritis. We tried to clarify requirement of Th2 cytokines in the anti-arthritic effects of Trichinella spiralis (Ts) against collagen-induced arthritis (CIA).METHODS AND RESULTS:We infected Ts and then induced CIA in STAT6KO DBA/1 mice, comparing the disease progression with that in wild-type (WT) DBA/1 mice, Ts significantly mitigated arthritis in WT mice, in addition to the impairment of anti-type II collagen (IIC) IgG production in a subclass-independent manner. The genetic absence of STAT6 in the mice did not abrogate the anti-arthritic effects of Ts. Alteration of splenic cytokines was not related to the anti-arthritic effects of the parasite. Moreover, lack of IL-10 did not abrogate the anti-arthritic effects of Ts.CONCLUSION:Our results suggest that the anti-arthritic effects of Ts do not require host Th2 signals.

Abstract Autoimmune uveitis is a T cell driven, intraocular inflammation that affects the neuroretina and can lead to blindness. In a mouse model of spontaneous autoimmune uveitis (R161H), retina-specific T cells are primed in the gut through their TCR and trigger disease (PMID: 26287682). To support the relevance to human disease, we examined development of uveitis and its association with bacterial taxa in gnotobiotic R161H mice harboring human flora. Specifically, fecal samples from three healthy human donors were inoculated into germ-free R161H mice and their wild type (WT) littermates in separate isolators. Fecal pellets from reconstituted mice and their offspring were collected periodically and subjected to 16S amplicon sequencing. Uveitis scores were determined in R161H offspring by histology at termination of the experiment. Our results show that healthy human gut commensals can support uveitis in R161H mice, but to a lesser extent than native mouse flora from the NIH facility. Diversity analyses indicate that human flora-reconstituted mice retained a distinct but simplified gut microbial community compared to the original sample, and R161H mice tended to have a more complex microbiome profile than WT littermates. Among R161H offspring, mice with high disease scores appeared to harbor more diverse gut flora than those with low scores. Differentially abundant bacterial taxa were identified between mice with different disease scores, which may associate with intensity of autoreactive T cell activation and development of autoimmunity. R161H associated with human gut flora could provide a more translatable platform than mouse flora to explore microbial candidates and products that may modulate autoreactive T cells in uveitis.

Silica crystals (silica), which are a major mineral component of volcanic ash and desert dust, contribute to the pathogenesis of pulmonary disorders such as asthma and fibrosis. Although administration of silica or sand dust to rodents exacerbates development of ovalbumin-induced or house dust mite-induced asthma-like airway inflammation, the detailed mechanisms remain unclear. Here, using murine models, we found that silica can induce IL-33 expression in pulmonary epithelial cells. IL-33, but not IL-25 or TSLP, and type 2 cytokines such as IL-5 and IL-13 were critically involved in silica's exacerbation of OVA-induced airway eosinophilia in mice. Innate lymphoid cells (ILCs), but not T, B or NKT cells, were also involved in the setting. Moreover, a scavenger receptor that recognized silica was important for silica's exacerbating effect. These observations suggest that IL-33 induced in epithelial cells by silica activates ILCs to produce IL-5 and/or IL-13, contributing to silica's exacerbation of OVA-induced airway eosinophilia in mice. Our findings provide new insight into the underlying mechanisms of exacerbation of pulmonary disorders such as asthma following inhalation of silica-containing materials such as volcanic ash and desert dust.

Introduction: Mesenchymal stem cells (MSCs) are promising therapeutic tools in regenerative medicine. In particularly adipose tissue derived MSC (AMSC) has powerful potential for the therapeutics of rheumatoid arthritis (RA) because these cells can control immune balance. RA systemically occurs autoimmune disease. Interestingly, IL-1 receptor antagonist deficient (IL-1ra−/−) mice induce inflammation in joints like RA. In RA therapy, although AMSC improves the inflammation activity, it is little known to play roles of extracellular microvesicles (EV) for improvement of RA. To clarify the MSC-derived EVs are involved amelioration mechanisms for RA by themselves, we examined the functional effects of development for RA by AMSC-EVs. Methods: We isolated AMSCs derived mice adipose tissue and purified EVs from the culture supernatant of AMSCs. To examine whether EVs can improve RA, we administrated EVs or AMSCs to IL-1ra knockout mice as RA model mice. We analyzed EVs-included factor by western blot methods and RA improvement effect by ELISA. Results: In this study, we showed that the swellings of joints on mice in wild type AMSC and that in AMSC-EVs decreased than that in IL-1ra−/− mice-AMSC-EVs and in none-treated. We detected IL-1ra expression in AMSC-EVs in wild type mice but not that in IL-1ra−/− mice. Proinflammatory cytokine expression changes in mice showed in AMSCs and AMSC-EVs, but no apparent differences cytokine expressions were detected in IL-1ra−/− mice. Conclusions: In this study, we concluded that MSCs might improve RA by the transferring of factors such as IL-1ra, which are included their MSC derived- EVs.