Complete Genome Sequence of Turicibacter sp. Strain H121, Isolated from the Feces of a Contaminated Germ-Free Mouse.

Turicibacterbacteria are commonly detected in the gastrointestinal tracts and feces of humans and animals, but their phylogeny, ecological role, and pathogenic potential remain unclear. We present here the first complete genome sequence ofTuricibactersp. strain H121, which was isolated from the feces of a mouse line contaminated following germ-free derivation.

Mouse Models of Experimental Autoimmune Uveitis: Comparative Analysis of Adjuvant-Induced vs Spontaneous Models of Uveitis.

Mouse models of experimental autoimmune uveitis (EAU) mimic unique features of human uveitis, and serve as a template for preclinical study. The "classical" EAU model is induced by active immunization of mice with the retinal protein IRBP in adjuvant, and has proved to be a useful tool to study basic mechanisms and novel therapy in human uveitis. Several spontaneous models of uveitis induced by autoreactive T cells targeting on IRBP have been recently developed in IRBP specific TCR transgenic mice (R161H) and in AIRE(-/-) mice. The "classical" immunization-induced EAU exhibits acute ocular inflammation with two distinct patterns: (i) severe monophasic form with extensive destruction of the retina and rapid loss of visual function, and (ii) lower grade form with an acute onset followed by a prolonged chronic phase of disease. The spontaneous models of uveitis in R161H and AIRE(-/-) mice have a gradual onset and develop chronic ocular inflammation that ultimately leads to retinal degeneration, along with a progressive decline of visual signal. The adjuvant-dependent model and adjuvant-free spontaneous models represent distinct aspects and/or various forms of human uveitis. This review will discuss and compare clinical manifestations, pathology as well as visual function of the retina in the different models of uveitis, as measured by fundus imaging and histology, optical coherence tomography (OCT) and electroretinography (ERG).

Spontaneous Ocular Autoimmunity in Mice Expressing a Transgenic T Cell Receptor Specific to Retina: A Tool to Dissect Mechanisms of Uveitis.

The "classical" EAU model induced by immunization of mice with the retinal protein IRBP or its peptides has been very useful to study basic mechanisms of ocular inflammation, but is inadequate for some types of studies due to the need for active immunization in the context of strong bacterial adjuvants. We generated transgenic (Tg) mice on the B10.RIII background that express a T cell receptor (TCR) specific for IRBP161-180. Three strains of TCR Tg mice were established. Spontaneous uveitis developed in two of the three strains by 2-3 months of age. Susceptibility correlated with a higher copy number of the transgenic TCR and a higher proportion of TCR Tg T cells in the peripheral repertoire. Even in mice with uveitis, peripheral IRBP-specific CD4(+) T cells displayed mostly a naïve phenotype. In contrast, T cells infiltrating uveitic eyes mostly showed an effector/memory phenotype, and included Th1, Th17 as well as T regulatory cells. These mice thus provide a new and distinct model of uveitis from the "classical" EAU, and may represent some types of uveitis more faithfully. Importantly, this new transgenic model of uveitis can serve as a template for therapeutic manipulations, and as a source of naïve retina-specific T cells for a variety of basic and pre-clinical studies. Several examples of such studies will be discussed.

The role of TNFalpha and IL-17 in the development of excess IL-1 signaling-induced inflammatory diseases in IL-1 receptor antagonist-deficient mice.

IL-1 receptor antagonist (IL-1Ra)-deficient mice spontaneously develop several inflammatory diseases, resembling rheumatoid arthritis, aortitis, and psoriasis in humans. As adoptive T cell transplantation could induce arthritis and aortitis in recipient mice, it was suggested that an autoimmune process is involved in the development of diseases. In contrast, as dermatitis developed in scid/scid-IL-IRa-deficient mice and could not be induced by T cell transfer, a T cell-independent mechanism was suggested. The expression of proinflammatory cytokines was augmented at the inflammatory sites. The development of arthritis and aortitis was significantly suppressed by the deficiency of TNFalpha or IL-17. The development of dermatitis was also inhibited by the deficiency of TNFalpha. These observations suggest that TNFalpha and IL-17 play a crucial role in the development of autoimmunity downstream of IL-1 signaling, and excess IL-1 signaling-induced TNFalpha also induces skin inflammation in a T cell-independent manner.

Suppression of oxidative stress after transient focal ischemia in interleukin-1 knock out mice.

Interleukin-1 (IL-1) contributes to ischemic neurodegeneration. However, the mechanisms regulating action of IL-1 are still poorly understood. In order to clarify this central issue, mice that were gene deficient both IL-1alpha and beta (IL-1 KO) and wild-type mice were subjected to 1 hour transient middle cerebral artery occlusion (tMCAO). The concentration of 8-hydroxy deoxyguanosine (8OHdG) which is considered to be a reliable oxidative DNA damage by superoxide anion, in brain and of total nitric oxide (NO) in plasma were determined by use of HPLC. Twenty-four hours after tMCAO, the ratio of 8OHdG to dG in the ipsilateral hemisphere of wild-type mice were 2.24 x 10(-3) and 4.41 x 10(-3) in the neocortex and striatum, respectively. The concentration of 8OHdG in the ipsilateral hemisphere of the wild-type mice was higher than that of the IL-1 KO mice. The concentration of total NO in the plasma of IL-1 KO mice was also lower than that of the wild-type 24 hours after tMCAO. These results strongly suggest that IL-1 is participated in generating reactive oxygen spices and it aggravates and induces the ischemic neuronal cell death.(183 words).

IL-1 alpha, but not IL-1 beta, is required for contact-allergen-specific T cell activation during the sensitization phase in contact hypersensitivity.

Contact hypersensitivity (CHS) is a T cell-mediated cellular immune response caused by epicutaneous exposure to contact allergens. In this reaction, after the first epicutaneous allergen sensitization, Langerhans cells (LC) catch allergens and migrate from the skin to draining lymph nodes (LN) and activate naive T cells. Although IL-1 is suggested to be involved in these processes, the mechanisms have not been elucidated completely. In this report, to elucidate roles of IL-1alpha and IL-1beta in CHS, we analyzed ear swelling in 2,4,6-trinitrochlorobenzene (TNCB)-induced CHS using gene-targeted mice. We found that ear swelling was suppressed in IL-1alpha-deficient (IL-1alpha(-/-)) mice but not in IL-1beta(-/-) mice. LC migration from the skin into LN was delayed in both IL-1alpha(-/-) and IL-1beta(-/-) mice, suggesting that this defect was not the direct cause for the reduced CHS in these mice. However, we found that the proliferative response of trinitrophenyl (TNP)-specific T cells after sensitization with TNCB was specifically reduced in IL-1alpha(-/-) mice. Furthermore, adoptive transfer of TNP-conjugated IL-1-deficient epidermal cells (EC) into wild-type mice indicated that only IL-1alpha, but not IL-1beta, produced by antigen-presenting cells in EC could prime allergen-specific T cells. These observations indicate that IL-1alpha, but not IL-1beta, plays a crucial role in TNCB-induced CHS by sensitizing TNP-specific T cells.

Caspase-2 deficiency prevents programmed germ cell death resulting from cytokine insufficiency but not meiotic defects caused by loss of ataxia telangiectasia-mutated (Atm) gene function.

It is well established that programmed cell death claims up to two-thirds of the oocytes produced during gametogenesis in the developing fetal ovaries. However, the mechanisms underlying prenatal germ cell loss in females remain poorly understood. Herein we report that caspase-11 null female mice are born with a reduced number of oocyte-containing primordial follicles. This phenotype is likely due to failed cytokine processing known to occur in caspase-11 mutants since neonatal female mice lacking both interleukin (IL)-1alpha and IL-1beta also exhibit a reduced endowment of primordial follicles. In addition, germ cell death in wild-type fetal ovaries cultured ex vivo is suppressed by either cytokine, likely via ligand activation of type 1 IL-1 receptors expressed in fetal germ cells. Normal oocyte endowment can be restored in caspase-11 null female mice by simultaneous inactivation of the gene encoding the cell death executioner enzyme, caspase-2. However, caspase-2 deficiency cannot overcome gametogenic failure resulting from meiotic recombination defects in ataxia telangiectasia-mutated (Atm) null female mice. Thus, genetically distinct mechanisms exist for developmental deletion of oocytes via programmed cell death, one of which probably functions as a meiotic quality-control checkpoint that cannot be overridden.

Role of IL-1alpha and IL-1beta in ischemic brain damage.

The cytokine interleukin-1 (IL-1) has been strongly implicated in the pathogenesis of ischemic brain damage. Evidence to date suggests that the major form of IL-1 contributing to ischemic injury is IL-1beta rather than IL-1alpha, but this has not been tested directly. The objective of the present study was to compare the effects of transient cerebral ischemia [30 min middle cerebral artery occlusion (MCAO)] on neuronal injury in wild-type (WT) mice and in IL-1alpha, IL-1beta, or both IL-1alpha and IL-1beta knock-out (KO) mice. Mice lacking both forms of IL-1 exhibited dramatically reduced ischemic infarct volumes compared with wild type (total volume, 70%; cortex, 87% reduction). Ischemic damage compared with WT mice was not significantly altered in mice lacking either IL-1alpha or IL-1beta alone. IL-1beta mRNA, but not IL-1alpha or the IL-1 type 1 receptor, was strongly induced by MCAO in WT and IL-1alpha KO mice. Administration (intracerebroventricularly) of recombinant IL-1 receptor antagonist significantly reduced infarct volume in WT (-32%) and IL-1alpha KO (-48%) mice, but had no effect on injury in IL-1beta or IL-1alpha/beta KO mice. These data confirm that IL-1 plays a major role in ischemic brain injury. They also show that chronic deletion of IL-1alpha or IL-1beta fails to influence brain damage, probably because of compensatory changes in the IL-1 system in IL-1alpha KO mice and changes in IL-1-independent mediators of neuronal death in IL-1beta KO mice.

IL-1 enhances T cell-dependent antibody production through induction of CD40 ligand and OX40 on T cells.

IL-1 is a proinflammatory cytokine that plays pleiotropic roles in host defense mechanisms. We investigated the role of IL-1 in the humoral immune response using gene-targeted mice. Ab production against SRBC was significantly reduced in IL-1alpha/beta-deficient (IL-1(-/-)) mice and enhanced in IL-1R antagonist(-/-) mice. The intrinsic functions of T, B, and APCs were normal in IL-1(-/-) mice. However, we showed that IL-1(-/-) APCs did not fully activate DO11.10 T cells, while IL-1R antagonist (-/-) APCs enhanced the reaction, indicating that IL-1 promotes T cell priming through T-APC interaction. The function of IL-1 was CD28-CD80/CD86 independent. We found that CD40 ligand and OX40 expression on T cells was affected by the mutation, and the reduced Ag-specific B cell response in IL-1(-/-) mice was recovered by the treatment with agonistic anti-CD40 mAb both in vitro and in vivo. These observations indicate that IL-1 enhances T cell-dependent Ab production by augmenting CD40 ligand and OX40 expression on T cells.

Interleukin-1 beta, but not interleukin-1 alpha, is required for T-cell-dependent antibody production.

Interleukin-1 (IL-1) consists of two molecules, IL-1 alpha and IL-1 beta, and IL-1 receptor antagonist (IL-1Ra) is a natural inhibitor of these molecules. Although the adjuvant effects of exogenously administered IL-1 in the humoral immune response are well known, the roles of endogenous IL-1 and the functional discrimination between IL-1 alpha and IL-1 beta have not been elucidated completely. In this report, we investigated the role of IL-1 in the humoral immune response using gene-targeted mice. Both primary and secondary antibody production against T-dependent antigen, sheep red blood cells (SRBC), was significantly reduced in IL-1 alpha/beta-/- mice, and was enhanced in IL-1Ra-/- mice. The intrinsic functions of B cells, such as antibody production against type 1 T-independent antigen, trinitrophenyl-lipopolysaccharide and proliferative responses against mitogenic stimuli, were normal in IL-1 alpha/beta-/- mice. The proliferative response of T cells and cytokine production upon stimulation with anti-CD3 monoclonal antibody were also normal, as was the phagocytotic ability of antigen-presenting cells (APCs). However, SRBC-specific proliferative response and cytokine production of T cells through the interaction with APCs were markedly impaired in IL-1 alpha/beta-/- mice, and enhanced in IL-1Ra-/- mice. Moreover, we show that SRBC-specific antibody production was reduced in IL-1 beta-/- mice, but not in IL-1 alpha-/- mice. These results show that endogenous IL-1 beta, but not IL-1 alpha, is involved in T-cell-dependent antibody production, and IL-1 promotes the antigen-specific T-cell helper function through the T-cell-APC interaction.

Lipopolysaccharide-induced HIV-1 expression in transgenic mice is mediated by tumor necrosis factor-alpha and interleukin-1, but not by interferon-gamma nor interleukin-6.

BACKGROUND: As serum HIV-1 load correlates well with the prognosis of the disease, it is suggested that the viral load is one of the major determinants of the disease progression of AIDS. Accordingly, HIV-1 activation mechanisms were extensively studied in vitro, and involvement of cytokines including tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, IL-6 and interferon (IFN)-gamma has been suggested in this process. However, so far the roles of these cytokines in the HIV-1 expression in vivo have not been well elucidated because of the lack of appropriate animal disease models. OBJECTIVE: To elucidate the roles of cytokines in HIV-1 activation in vivo. DESIGN AND METHODS: Transgenic mice carrying a defective HIV-1 genome were used as a model for HIV-1 carriers. In order to examine the possible involvement of cytokines in HIV-1 expression, TNF-alpha-, IL-1-, IL-6- and IFN-gamma-deficient HIV-1 transgenic mice, were produced and HIV-1 expression was analyzed after activation with bacterial lipopolysaccharides (LPS). RESULTS: HIV-1 expression in the transgenic mouse spleen was activated 10- to 20-fold by LPS, and the serum p24 Gag protein levels reached 400 pg/ml, which is nearly equal to the levels that occur in AIDS patients. However, this augmentation was suppressed by 60% in TNF-alpha-deficient mice and by 40% in IL-1alpha/beta-deficient mice. In contrast, no suppression was observed in either IL-6-, IFN-gamma-, IL-1alpha, or IL-1beta-deficient mice. CONCLUSIONS: Results suggest that TNF-alpha and IL-1 play important roles in HIV-1 gene activation and selective suppression of these cytokines could improve clinical prognosis and potentially slow progression of the disease.

Protective role of interleukin-1 in mycobacterial infection in IL-1 alpha/beta double-knockout mice.

To understand the role of the proinflammatory cytokine interleukin-1 (IL-1) in mycobacterial inflammation, IL-1 alpha/beta double-knockout (KO) mice were produced. These mice were infected with either Mycobacterium tuberculosis H37Rv by the airborne route using an airborne infection apparatus, and their capacities to control mycobacterial growth, granuloma formation, cytokine, and nitric oxide (NO) production were examined. The IL-1 alpha/beta mice developed significantly larger (p < 0.01) granulomatous, but not necrotic, lesions in their lungs than wild-type (WT) mice after infection with H37Rv. Inflammatory lesions, but not granulomas, were observed in spleen and liver tissues from both IL-1 alpha/beta KO and wild-type mice. Granulomatous lesion development in IL-1 alpha/beta KO mice was not significantly inhibited by treatment with exogenous recombinant IL-1 alpha/beta. Compared with wild-type mice, splenic IFN-gamma and IL-12 levels were within the normal range. NO production by cultured alveolar macrophages from IL-1 alpha/beta KO mice was lower than in wild-type mice but were increased by the addition of recombinant IL-1 alpha/beta. Our data clearly indicate that IL-1 is important for the generation of early-phase protective immunity against mycobacterial infection.

Development of chronic inflammatory arthropathy resembling rheumatoid arthritis in interleukin 1 receptor antagonist-deficient mice.

Interleukin (IL)-1 is a proinflammatory cytokine that plays important roles in inflammation, host defense, and the neuro-immuno-endocrine network. IL-1 receptor antagonist (ra) is an endogenous inhibitor of IL-1 and is supposed to regulate IL-1 activity. However, its pathophysiological roles in a body remain largely unknown. To elucidate the roles of IL-1ra, IL-1ra-deficient mice were produced by gene targeting, and pathology was analyzed on different genetic backgrounds. We found that all of the mice on a BALB/cA background, but not those on a C57BL/6J background, spontaneously developed chronic inflammatory polyarthropathy. Histopathology showed marked synovial and periarticular inflammation, with articular erosion caused by invasion of granulation tissues closely resembling that of rheumatoid arthritis in humans. Moreover, elevated levels of antibodies against immunoglobulins, type II collagen, and double-stranded DNA were detected in these mice, suggesting development of autoimmunity. Proinflammatory cytokines such as IL-1beta, IL-6, and tumor necrosis factor alpha were overexpressed in the joints, indicating regulatory roles of IL-1ra in the cytokine network. We thus show that IL-1ra gene deficiency causes autoimmunity and joint-specific inflammation and suggest that IL-1ra is important in maintaining homeostasis of the immune system. Possible involvement of IL-1ra gene deficiency in RA will be discussed.

The human T cell leukemia virus type I-tax gene is responsible for the development of both inflammatory polyarthropathy resembling rheumatoid arthritis and noninflammatory ankylotic arthropathy in transgenic mice.

We previously reported that inflammatory arthropathy resembling rheumatoid arthritis (RA) develops among transgenic mice carrying the long terminal repeat (LTR)-env-pX-LTR region of human T cell leukemia virus type I (LTR-pX-Tg mice). Because four genes are encoded in this region, we produced transgenic mice that only express the tax gene to examine its role in the development of arthritis. Transgenic mice were produced by constructing DNAs that express the tax gene alone under the control of either its own LTR or CD4 enhancer/promoter and by microinjecting them into C3H/HeN-fertilized ova. We produced seven transgenic mice carrying the LTR-tax gene and nine mice carrying the CD4-tax and found that one of the LTR-tax-Tg mice and five of CD4-tax-Tg mice developed RA-like inflammatory arthropathy similar to LTR-pX-Tg mice, indicating that the tax gene is arthritogenic. On the other hand, the other two LTR-tax-Tg mice had ankylotic changes caused by new bone formation without inflammation. In these ankylotic mice, tax mRNA, inflammatory cytokine mRNA, and autoantibody levels except for TGF-beta1 level were lower than those in LTR-pX- or CD4-tax-Tg mice. These results show that Tax is responsible for the development of inflammatory arthropathy resembling RA and that this protein also causes ankylotic arthropathy.

Caspase 1-independent IL-1beta release and inflammation induced by the apoptosis inducer Fas ligand.

Fas ligand is a well-characterized apoptosis inducer. Here we demonstrate that Fas ligand induces the processing and secretion of interleukin-1beta (IL-1beta) in peritoneal exudate cells. This IL-1beta secretion is independent of IL-1beta converting enzyme (caspase 1), yet it is inhibited by caspase inhibitors, indicating that a caspase(s) in addition to IL-1beta converting enzyme can process IL-1beta. Inoculation of tumor cells expressing Fas ligand into wild-type mice induces a massive neutrophil infiltration that is, in contrast, suppressed in IL-1alpha/beta knockout mice. These results demonstrate a newly discovered role for Fas ligand in inflammation, and challenge the dogma that apoptosis does not induce inflammation.

Production of mice deficient in genes for interleukin (IL)-1alpha, IL-1beta, IL-1alpha/beta, and IL-1 receptor antagonist shows that IL-1beta is crucial in turpentine-induced fever development and glucocorticoid secretion.

Interleukin (IL)-1 is a major mediator of inflammation and exerts pleiotropic effects on the neuro-immuno-endocrine system. To elucidate pathophysiological roles of IL-1, we have first produced IL-1alpha/beta doubly deficient (KO) mice together with mice deficient in either the IL-1alpha, IL-1beta, or IL-1 receptor antagonist (IL-1ra) genes. These mice were born healthy, and their growth was normal except for IL-1ra KO mice, which showed growth retardation after weaning. Fever development upon injection with turpentine was suppressed in IL-1beta as well as IL-1alpha/beta KO mice, but not in IL-1alpha KO mice, whereas IL-1ra KO mice showed an elevated response. At this time, expression of IL-1beta mRNA in the diencephalon decreased 1.5-fold in IL-1alpha KO mice, whereas expression of IL-1alpha mRNA decreased >30-fold in IL-1beta KO mice, suggesting mutual induction between IL-1alpha and IL-1beta. This mutual induction was also suggested in peritoneal macrophages stimulated with lipopolysaccharide in vitro. In IL-1beta KO mice treated with turpentine, the induction of cyclooxygenase-2 (EC 1.14.99.1) in the diencephalon was suppressed, whereas it was enhanced in IL-1ra KO mice. We also found that glucocorticoid induction 8 h after turpentine treatment was suppressed in IL-1beta but not IL-1alpha KO mice. These observations suggest that IL-1beta but not IL-1alpha is crucial in febrile and neuro-immuno-endocrine responses, and that this is because IL-1alpha expression in the brain is dependent on IL-1beta. The importance of IL-1ra both in normal physiology and under stress is also suggested.