Suppression of IL-17F, but not of IL-17A, provides protection against colitis by inducing Treg cells through modification of the intestinal microbiota.

The cytokines IL-17A and IL-17F have 50% amino-acid identity and bind the same receptor; however, their functional differences have remained obscure. Here we found that Il17f-/- mice resisted chemically induced colitis, but Il17a-/- mice did not, and that Il17f-/- CD45RBhiCD4+ T cells induced milder colitis in lymphocyte-deficient Rag2-/- mice, accompanied by an increase in intestinal regulatory T cells (Treg cells). Clostridium cluster XIVa in colonic microbiota capable of inducing Treg cells was increased in both Il17f-/- mice and mice given transfer Il17f-/- T cells, due to decreased expression of a group of antimicrobial proteins. There was substantial production of IL-17F, but not of IL-17A, not only by naive T cells but also by various colon-resident cells under physiological conditions. Furthermore, antibody to IL-17F suppressed the development of colitis, but antibody to IL-17A did not. These observations suggest that IL-17F is an effective target for the treatment of colitis.

Differences in male climacteric symptoms with aging among rotating night shift workers.

OBJECTIVE: The aim of this study was to clarify the actual status of male climacteric symptoms in rotating night shift workers and how to cope with the symptoms. METHODS: We planned a self-administered questionnaire survey in male rotating night shift workers. Male climacteric symptoms were evaluated by using the Aging Males' Symptoms (AMS) scale. RESULTS: Of 1891 questionnaires that were sent, 1561 were collected. There were significant differences in total AMS scores among the age groups. In all age groups, there were high proportions of men with increased need for sleep and often feeling tired (64.9%) and decrease in muscular strength (60.7%). There were significant differences in AMS scores for somatic symptoms between men in their 20 s and those in their 40 s or 50 s and between men in their 30 s and those in their 50 s and in AMS scores for sexual symptoms between men in their 20 s and those in their 30 s, 40 s, 50 s or 60 s, between men in their 30 s and those in their 40 s, 50 s or 60 s and between men in their 40 s and those in their 50 s or 60 s. CONCLUSION: Significant age-dependent differences are found in somatic symptoms and sexual symptoms in rotating night shift workers.

IL-36α from Skin-Resident Cells Plays an Important Role in the Pathogenesis of Imiquimod-Induced Psoriasiform Dermatitis by Forming a Local Autoamplification Loop.

IL-36α (gene symbol Il1f6), a member of the IL-36 family, is closely associated with inflammatory diseases, including colitis and psoriasis. In this study, we found that Il1f6-/- mice developed milder psoriasiform dermatitis upon treatment with imiquimod, a ligand for TLR ligand 7 (TLR7) and TLR8, whereas Il1f6-/- mice showed similar susceptibility to dextran sodium sulfate-induced colitis to wild-type mice. These effects were observed in both cohoused and separately housed conditions, and antibiotic treatment did not cancel the resistance of Il1f6-/- mice to imiquimod-induced dermatitis. Bone marrow (BM) cell transfer revealed that IL-36α expression in skin-resident cells is important for the pathogenesis of dermatitis in these mice. Following stimulation with IL-36α, the expression of Il1f6 and Il1f9 (IL-36γ), but not Il1f8 (IL-36ß), was enhanced in murine BM-derived Langerhans cells (BMLCs) and murine primary keratinocytes but not in fibroblasts from mice. Upon stimulation with agonistic ligands of TLRs and C-type lectin receptors (CLRs), Il1f6 expression was induced in BMLCs and BM-derived dendritic cells. Furthermore, IL-36α stimulation resulted in significantly increased gene expression of psoriasis-associated Th17-related cytokines and chemokines such as IL-1α, IL-1ß, IL-23, CXCL1, and CXCL2 in BMLCs and fibroblasts, and IL-1α, IL-1ß, IL-17C, and CXCL2 in keratinocytes. Collectively, these results suggest that TLR/CLR signaling-induced IL-36α plays an important role for the development of psoriasiform dermatitis by enhancing Th17-related cytokine/chemokine production in skin-resident cells via a local autoamplification loop.

Dectin-2 recognition of alpha-mannans and induction of Th17 cell differentiation is essential for host defense against Candida albicans.

Dectin-2 (gene symbol Clec4n) is a C-type lectin expressed by dendritic cells (DCs) and macrophages. However, its functional roles and signaling mechanisms remain to be elucidated. Here, we generated Clec4n(-/-) mice and showed that this molecule is important for host defense against Candida albicans (C. albicans). Clec4n(-/-) DCs had virtually no fungal alpha-mannan-induced cytokine production. Dectin-2 signaling induced cytokines through an FcRgamma chain and Syk-CARD9-NF-kappaB-dependent signaling pathway without involvement of MAP kinases. The yeast form of C. albicans induced interleukin-1beta (IL-1beta) and IL-23 secretion in a Dectin-2-dependent manner. In contrast, cytokine production induced by the hyphal form was only partially dependent on this lectin. Both yeast and hyphae induced Th17 cell differentiation, in which Dectin-2, but not Dectin-1, was mainly involved. Because IL-17A-deficient mice were highly susceptible to systemic candida infection, this study suggests that Dectin-2 is important in host defense against C. albicans by inducing Th17 cell differentiation.

CCR8 regulates contact hypersensitivity by restricting cutaneous dendritic cell migration to the draining lymph nodes.

Allergic contact dermatitis (ACD) is a typical occupational disease in industrialized countries. Although various cytokines and chemokines are suggested to be involved in the pathogenesis of ACD, the roles of these molecules remain to be elucidated. CC chemokine receptor 8 (CCR8) is one such molecule, of which expression is up-regulated in inflammatory sites of ACD patients. In this study, we found that Ccr8(-/-) mice developed severer contact hypersensitivity (CHS) responses to 2,4-dinitrofluorobenzene, a murine model of ACD, compared with wild-type mice. T cells from Ccr8(-/-) mice showed enhanced proliferative recall responses and Th1 and Th17 cell populations were expanded in these mice. However, CHS responses were similar between SCID mice adoptively transferred with Ccr8(-/-) and wild-type T cells, suggesting that CCR8 in T cells is not responsible for the exacerbation of CHS. Notably, skin-resident dendritic cells (DCs), such as Langerhans cells and dermal DCs, and inflammatory DCs were highly accumulated in lymph nodes (LNs) of Ccr8(-/-) mice after sensitization. Consistent with this, Ccr8(-/-) antigen-presenting cells readily migrated from the skin to the draining LNs after sensitization. These observations suggest that CCR8 negatively regulates migration of cutaneous DCs from the skin to the draining LNs in CHS by keeping these cells in the skin.

CTRP3 plays an important role in the development of collagen-induced arthritis in mice.

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease exhibited most commonly in joints. We found that the expression of C1qtnf3, which encodes C1q/TNF-related protein 3 (CTRP3), was highly increased in two mouse RA models with different etiology. To elucidate the pathogenic roles of CTRP3 in the development of arthritis, we generated C1qtnf3(-/-) mice and examined the development of collagen-induced arthritis in these mice. We found that the incidence and severity score was higher in C1qtnf3(-/-) mice compared with wild-type (WT) mice. Histopathology of the joints was also more severe in C1qtnf3(-/-) mice. The levels of antibodies against type II collagen and pro-inflammatory cytokine mRNAs in C1qtnf3(-/-) mice were higher than WT mice. These observations indicate that CTRP3 plays an important role in the development of autoimmune arthritis, suggesting CTRP3 as a possible medicine to treat RA.

Negative-High Titer of Helicobacter pylori Antibody and Lipid Profiles.

Background: Helicobacter pylori (HP) is a causative factor for several gastrointestinal diseases. A HP seropositive antibody titer (i.e., ≥10 U/mL), a threshold indicating an HP infection, is known to be associated with changes in lipid metabolism. There is evidence that HP infection can be found in some individuals with HP antibody titer of between 3 and 9.9 U/mL (termed as "negative-high titer"). However, it is unknown about the relationship between HP negative-high titer and lipid metabolism. The present study aimed to quantify the association between HP negative-high antibody titer and lipid profiles. Materials and Methods: We surveyed 2,478 people who underwent a Ningen Dock examination and had serological HP antibody data, from May 2016 to December 2020 at National Center for Global Health and Medicine, Tokyo, Japan. Multiple regression models were used to quantify the association between HP antibody titer and serum lipid levels. Results: The adjusted odds ratio (95% confidence interval [CI]) for dyslipidemia in HP negative-high and positive titer was 1.24 (0.96, 1.79) and 1.36 (1.10, 1.68), respectively, compared with HP negative-low titer; p trend =0.005. The adjusted mean (95% CI) of high-density lipoprotein cholesterol (HDL-C) in HP negative-low, negative-high, and positive titer was 58.78 (57.86-59.71), 55.30 (53.70-56.91), and 53.76 (52.90-54.63) mg/dL, respectively; p trend <0.001. Higher HP antibody titers were also associated with higher ratio of low-density lipoprotein cholesterol (LDL-C) to HDL-C, but not triglycerides, or total cholesterols. Conclusion: The present cross-sectional study suggests that a HP negative-high antibody titer may be associated with dyslipidemia, HDL-C, and LDL-C to HDL-C ratio among Japanese Ningen Dock's participants.

Association of Th1/Th2-related chemokine receptors in peripheral T cells with disease activity in patients with multiple sclerosis and neuromyelitis optica.

We evaluated 30 patients with clinically definite multiple sclerosis (MS) and 8 patients with neuromyelitis optica (NMO) to investigate correlations between Th1/Th2 balance, disease activity, effects of interferon (IFN)-ß treatment, and expressions of chemokine receptors CXCR3 and CCR4 on CD4+ and CD8+ T cells in peripheral blood. MS and NMO patients in the relapsing phase showed a significantly increased CD4+CXCR3+/CD4+CCR4+ ratio and CD8+CXCR3+/CD8+CCR4+ ratio compared with respective patients in the remission phase. After IFN-ß treatment, the CD4+CXCR3+/CD4+CCR4+ ratio and CD8+CXCR3+/CD8+CCR4+ ratio were significantly decreased compared with the relapsing phase and slightly lower than in the remission phase. The CD8+CXCR3+/CD8+CCR4+ ratio showed a more marked change associated with disease activity than CD4+ T cells in MS and NMO patients. Moreover, in patients in the relapsing phase of NMO, the CD4+CXCR3+/CD4+CCR4+ ratio and CD8+CXCR3+/CD8+CCR4+ ratio were significantly higher than in MS patients in the relapsing phase. We confirmed marked changes in the CD8+CXCR3+/CD8+CCR4+ ratio according to disease activity and treatment of MS and NMO. Furthermore, this ratio was more strongly linked to immune and inflammatory activity in NMO patients than in MS patients, and may represent an important factor in differentiating the pathogenesis of MS and NMO.

Therapeutic efficacy of interferon ß-1b in Japanese patients with optic-spinal multiple sclerosis.

Optic neuritis and myelitis are manifestations in both multiple sclerosis (MS) and neuromyelitis optica (NMO). But unlike MS, NMO is characterized by severe optic neuritis, longitudinally extensive and transverse myelitis, and the presence of aquaporin-4 antibody. Since patients with optic neuritis and myelitis have often been diagnosed with "optic-spinal MS (OSMS)" in Asia, it was obscure whether "OSMS" is synonymous with NMO or includes both NMO and MS. Interferon ß (IFNß)-1a and -1b are used as the first-line disease-modifying therapy for MS. However, some neurologists have been reluctant to use IFNß to treat patients with optic-spinal symptoms, because IFNß therapy is not efficacious in NMO. To evaluate the therapeutic effect of IFNß in patients with "genuine" OSMS, we retrospectively evaluated Japanese MS patients who fulfilled the following six criteria: 1) Relapsing-remitting MS with optic-spinal presentation alone (no brain symptoms), 2) With or without asymptomatic brain MRI lesions, 3) Oligoclonal IgG band-positive, 4) aquaporin-4 antibody seronegativity, 5) No myelitis extending longitudinally over ≥ 3 vertebral segments, and 6) Duration of IFNß-1b therapy ≥ 2 years. Among 157 patients with MS, six (four women and two men, age 43.8 ± 8.5 years old) met all the criteria. Their Expanded Disability Status Scale scores were lowered (4.1 ± 2.4 → 3.1 ± 2.8) (P = 0.033) and annualized relapse rate was decreased (0.59 ± 0.34 → 0.13 ± 0.15) (P = 0.027) after IFNß-1b therapy. These results suggest that IFNß is therapeutically effective in inhibiting functional worsening and reducing relapse rate in "genuine" OSMS.

TARM1 contributes to development of arthritis by activating dendritic cells through recognition of collagens.

TARM1 is a member of the leukocyte immunoglobulin-like receptor family and stimulates macrophages and neutrophils in vitro by associating with FcRγ. However, the function of this molecule in the regulation of the immune system is unclear. Here, we show that Tarm1 expression is elevated in the joints of rheumatoid arthritis mouse models, and the development of collagen-induced arthritis (CIA) is suppressed in Tarm1-/- mice. T cell priming against type 2 collagen is suppressed in Tarm1-/- mice and antigen-presenting ability of GM-CSF-induced dendritic cells (GM-DCs) from Tarm1-/- mouse bone marrow cells is impaired. We show that type 2 collagen is a functional ligand for TARM1 on GM-DCs and promotes DC maturation. Furthermore, soluble TARM1-Fc and TARM1-Flag inhibit DC maturation and administration of TARM1-Fc blocks the progression of CIA in mice. These results indicate that TARM1 is an important stimulating factor of dendritic cell maturation and could be a good target for the treatment of autoimmune diseases.

Establishment and analysis of a novel mouse line carrying a conditional knockin allele of a cancer-specific FBXW7 mutation.

F-box and WD40 domain protein 7 (FBXW7) is a component of the SKP1-CUL1-F-box protein (SCF) complex that mediates the ubiquitination of diverse oncogenic target proteins. The exploration of FBXW7 mutations in human primary cancer has revealed three mutation hotspots at conserved arginine residues (Arg465, Arg479, and Arg505) in the WD40 domain, which are critical for substrate recognition. To study the function of human FBXW7 R465C , the most frequent mutation in human malignancies, we generated a novel conditional knockin mouse line of murine Fbxw7 R468C corresponding to human FBXW7 R465C . Systemic heterozygous knockin of the Fbxw7 R468C mutation resulted in perinatal lethality due to defects in lung development, and occasionally caused an eyes-open at birth phenotype and cleft palate. Furthermore, mice carrying liver-specific heterozygous and homozygous Fbxw7 R468C alleles cooperated with an oncogenic Kras mutation to exhibit bile duct hyperplasia within 8 months of birth and cholangiocarcinoma-like lesions within 8 weeks of birth, respectively. In addition, the substrates affected by the mutant Fbxw7 differed between the embryos, embryonic fibroblasts, and adult liver. This novel conditional knockin Fbxw7 R468C line should be useful to gain a more profound understanding of carcinogenesis associated with mutation of FBXW7.

IL-1 receptor antagonist-deficient mice develop autoimmune arthritis due to intrinsic activation of IL-17-producing CCR2(+)Vγ6(+)γδ T cells.

Interleukin-17 (IL-17)-producing γδ T (γδ17) cells have been implicated in inflammatory diseases, but the underlying pathogenic mechanisms remain unclear. Here, we show that both CD4(+) and γδ17 cells are required for the development of autoimmune arthritis in IL-1 receptor antagonist (IL-1Ra)-deficient mice. Specifically, activated CD4(+) T cells direct γδ T-cell infiltration by inducing CCL2 expression in joints. Furthermore, IL-17 reporter mice reveal that the Vγ6(+) subset of CCR2(+) γδ T cells preferentially produces IL-17 in inflamed joints. Importantly, because IL-1Ra normally suppresses IL-1R expression on γδ T cells, IL-1Ra-deficient mice exhibit elevated IL-1R expression on Vγ6(+) cells, which play a critical role in inducing them to produce IL-17. Our findings demonstrate a pathogenic mechanism in which adaptive and innate immunity induce an autoimmune disease in a coordinated manner.

CTRP6 is an endogenous complement regulator that can effectively treat induced arthritis.

The complement system is important for the host defence against infection as well as for the development of inflammatory diseases. Here we show that C1q/TNF-related protein 6 (CTRP6; gene symbol C1qtnf6) expression is elevated in mouse rheumatoid arthritis (RA) models. C1qtnf6(-/-) mice are highly susceptible to induced arthritis due to enhanced complement activation, whereas C1qtnf6-transgenic mice are refractory. The Arthus reaction and the development of experimental autoimmune encephalomyelitis are also enhanced in C1qtnf6(-/-) mice and C1qtnf6(-/-) embryos are semi-lethal. We find that CTRP6 specifically suppresses the alternative pathway of the complement system by competing with factor B for C3(H2O) binding. Furthermore, treatment of arthritis-induced mice with intra-articular injection of recombinant human CTRP6 cures the arthritis. CTRP6 is expressed in human synoviocytes, and CTRP6 levels are increased in RA patients. These results indicate that CTRP6 is an endogenous complement regulator and could be used for the treatment of complement-mediated diseases.

Plasma osteopontin levels are associated with disease activity in the patients with multiple sclerosis and neuromyelitis optica.

Osteopontin (OPN) up-regulates pro-inflammatory cytokines from both T helper type 1 and T helper type 17 cell pathways. We measured plasma OPN levels in Japanese multiple sclerosis (MS) and neuromyelitis optica (NMO) patients to investigate its value as a potential biomarker of disease activity. In NMO patients, plasma OPN levels were significantly higher than those in healthy individuals, being equivalent to those in MS patients. In both NMO and MS patients, OPN levels were significantly higher during relapse compared with remission. There was also a significant positive correlation between Expanded Disability Status Scale of Kurzke scores and plasma OPN levels in both NMO and MS patients, and plasma OPN levels were significantly higher in patients with secondary progressive MS compared with those with relapsing-remitting MS. Diagnostic sensitivity and specificity of plasma OPN for MS and NMO during the relapse phase were 100% and 50%, respectively (cut-off point: 31.3ng/ml). Thus, elevated plasma OPN levels could be a potential biomarker for not only MS but also NMO. These are the first results to suggest that plasma OPN in NMO patients may be a useful marker, playing an important role in inflammation, disease activity, and disease progression, as well as MS.

Generation of a mouse model with down-regulated U50 snoRNA (SNORD50) expression and its organ-specific phenotypic modulation.

Box C/D-type small nucleolar RNAs (snoRNAs) are functional RNAs responsible for mediating 2'-O-ribose methylation of ribosomal RNAs (rRNAs) within the nucleolus. In the past years, evidence for the involvement of human U50 snoRNA in tumorigenesis has been accumulating. We previously identified U50HG, a non-protein-coding gene that hosted a box C/D-type U50 snoRNA, in a chromosomal breakpoint in a human B-cell lymphoma. Mouse genome analysis revealed four mouse U50 (mU50) host-genes: three mU50HG-a gene variants that were clustered in the genome and an mU50HG-b gene that we supposed to be the U50HG ortholog. In this study, to investigate the physiological importance of mU50 snoRNA and its involvement in tumorigenesis, we eliminated mU50 snoRNA sequences from the mU50HG-b gene. The established mouse line (ΔmU50(HG-b)) showed a significant reduction of mU50 snoRNA expression without alteration of the host-gene length and exon-intron structure, and the corresponding target rRNA methylation in various organs was reduced. Lifelong phenotypic monitoring showed that the ΔmU50(HG-b) mice looked almost normal without accelerated tumorigenicity; however, a notable difference was the propensity for anomalies in the lymphoid organs. Transcriptome analysis showed that dozens of genes, including heat shock proteins, were differentially expressed in ΔmU50(HG-b) mouse lymphocytes. This unique model of a single snoRNA knockdown with intact host-gene expression revealed further new insights into the discrete transcriptional regulation of multiple mU50 host-genes and the complicated dynamics involved in organ-specific processing and maintenance of snoRNAs.

The muscle protein Dok-7 is essential for neuromuscular synaptogenesis.

The formation of the neuromuscular synapse requires muscle-specific receptor kinase (MuSK) to orchestrate postsynaptic differentiation, including the clustering of receptors for the neurotransmitter acetylcholine. Upon innervation, neural agrin activates MuSK to establish the postsynaptic apparatus, although agrin-independent formation of neuromuscular synapses can also occur experimentally in the absence of neurotransmission. Dok-7, a MuSK-interacting cytoplasmic protein, is essential for MuSK activation in cultured myotubes; in particular, the Dok-7 phosphotyrosine-binding domain and its target in MuSK are indispensable. Mice lacking Dok-7 formed neither acetylcholine receptor clusters nor neuromuscular synapses. Thus, Dok-7 is essential for neuromuscular synaptogenesis through its interaction with MuSK.