Costimulation through OX40 is crucial for induction of an alloreactive human T-cell response

The alloreactive immune response is a series of events initiated by the interaction of T cells with allogeneic dendritic cells (DCs), involving alloantigen recognition and costimulatory signals. In this study, we investigated the role of OX40 in alloreactivity in vitro. We first demonstrated that anti-OX40 ligand (anti-OX40L) monoclonal antibody (mAb) could markedly suppress the mixed leucocyte reaction (MLR) of peripheral blood mononuclear cells (PBMC). To further define the contribution of the OX40/OX40L system to the MLR, we set up a co-culture system of CD4+ T cells and allogeneic monocyte-derived dendritic cells (DCs). After 2 days, OX40 expression was induced on CD4+ T cells and this induction was strongly inhibited by the addition of cytotoxic T lymphocyte-associated antigen-4 (CTLA-4)-Fc fusion protein, suggesting that the expression of OX40 during alloreaction is dependent on CD28 signalling. Next we examined the effects of anti-OX40L mAb, CTLA-4-Fc fusion protein and anti-human leucocyte antigen (HLA)-DR mAb on the proliferative response of CD4+ T cells to allogeneic DCs. The proliferation of T cells was almost completely suppressed by anti-OX40L mAb, which was comparable with that of CTLA-4-Fc. Measurement of interleukin-2 (IL-2) production in the culture supernatants showed that suppression of a proliferative response was at least in part ascribed to reduced IL-2 production. Furthermore, purified OX40L- allogeneic DCs could induce considerable proliferation of CD4+ T cells, which was suppressed by anti-OX40L mAb. These results suggest that the OX40/OX40L system is crucial for induction of the allogeneic T-cell response and the OX40/OX40L system is subsequent to and dependent on CD28 signalling, but is crucial for the end outcome of the human alloreactive T-cell response.     

Protective effect of S-allyl-L-cysteine,a garlic compound,on amyloid beta-protein-induced cell death in nerve growth factor-differentiated PC12 cells

Aged garlic extract (AGE) contains several neuroactive compounds, including S-allyl-L-cysteine (SAC) and allixin. We characterized cell death induced by amyloid beta-protein (Abeta), 4-hydroxynonenal (HNE), tunicamycin, an endoplasmic reticulum (ER) stressor, or trophic factor deprivation, and investigated whether and how SAC could prevent this in nerve growth factor (NGF)-differentiated PC12 cells, a model of neuronal cells. Exposure of the cells to amyloid beta-protein(1-40) (Abeta(1-40)) decreased the extent of [3-(4,5)-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium (MTT) reduction activity and loss of neuronal integrity, but these effects were not prevented by Ac-DEVD-CHO, a caspase-3 inhibitor. Simultaneously applied SAC protected the cells against Abeta-induced cell death in a concentration-dependent manner. It also protected them against tunicamycin-induced neuronal death. In contrast, it afforded no protection against cell death induced by HNE and trophic factor deprivation, which is mediated by a caspase-3-dependent pathway. These results suggest that SAC may selectively protect cell death induced by Abeta and tunicamycin, which may be triggered by ER dysfunction in NGF-differentiated PC12 cells.     

IL‐2 is positively involved in the development of colitogenic CD4+ IL‐7Rαhigh memory T cells in chronic colitis

IL‐2 and IL‐7 share a common γ‐chain receptor and are critical for T‐cell homeostasis. We aimed to clarify the reciprocal roles of IL‐2 and IL‐7 in the development and persistence of chronic colitis. We performed a series of adoptive transfers of IL‐2^?/? CD4⁺CD45RB^high T cells into RAG‐2^?/? mice and assessed the role of IL‐2 in the induction of IL‐7Rα on colitogenic CD4⁺ T cells and the development of chronic colitis. RAG‐2^?/? mice transferred with WT but not with IL‐2^?/? CD4⁺CD45RB^high T cells developed Th1/Th17‐mediated colitis. Consistently, re‐expression of IL‐7Rα was severely impaired on IL‐2^?/? but not on WT CD4⁺ T cells from the transferred mice. To exclude a contribution of the preclinical autoimmunity of IL‐2^?/?mice, WT Ly5.1⁺ or IL‐2^?/? Ly5.2⁺ CD4⁺CD45RB^high T cells from GFP mice previously transplanted with the same number of WT and IL‐2^?/? BM cells were transferred into RAG‐2^?/? mice. RAG‐2^?/? mice transferred with IL‐2^?/?‐derived CD4⁺CD45RB^high T cells did not develop colitis, but their splenic CD4⁺ T cells changed from effector‐memory to central‐memory type. These results show that IL‐2 is critically involved in the establishment and maintenance of IL‐7‐dependent colitogenic memory CD4⁺IL‐7Rα^high T cells.     

Anti-p80 coilin autoantibodies react with a conserved epitope and are associated with anti-DFS70/LEDGF autoantibodies

p80 coilin is a nuclear autoantigen that strongly accumulates in Cajal bodies (CB) and is considered a marker for CBs. No clear clinical features have been associated with anti-p80 autoantibodies, and the epitopes recognized by these antibodies are entirely unknown. We determined the epitope specificity for 34 anti-p80 coilin-positive sera from Japanese patients to better understand its clinical significance. Western blotting and immunoprecipitation analysis revealed that the autoepitope of p80 coilin was restricted to a single region encompassing amino acid residues 421-576 from the C-terminus of p80 coilin. Additionally, sera from 30 of 34 (88%) patients with anti-p80 coilin antibody titers were also positive for anti-DFS70/LEDGF antibody. This autoantibody is sometimes found in patients with some allergic diseases but rarely in patients with connective tissue disease (CTD). Other similar characteristics between these two autoantibodies were also noted. In contrast, few anti-p80 coilin positive patients were positive for CTD-marker antibodies, such as anti-Sm, anti-dsDNA, and anti-SS-A. We conclude that the presence of anti-p80 coilin autoantibodies is not associated with any particular clinical syndromes nor is it diagnostic of any conditions.     

Hepatitis C virus NS5B delays cell cycle progression by inducing interferon-beta via Toll-like receptor 3 signaling pathway without replicating viral genomes

To clarify the pathogenesis of hepatitis C virus (HCV), we have studied the effects of HCV proteins using human hepatocytes. Here, we found that HCV NS5B, an RNA-dependent RNA polymerase, delayed cell cycle progression through the S phase in PH5CH8 immortalized human hepatocyte cells. Since treatment with anti-interferon (IFN)-beta neutralizing antibody restored the cell cycle delay, IFN-beta was deemed responsible for the cell cycle delay in NS5B-expressing PH5CH8 cells. The induction of IFN-beta and the cell cycle delay were overridden by the down-regulation of Toll-like receptor 3 (TLR3) through RNA interference in NS5B-expressing PH5CH8 cells. Moreover, the NS5B full form was required for the cell cycle delay, the induction of IFN-beta, and the activation of the IFN-beta signaling pathway. Our findings revealed that NS5B induced IFN-beta through the TLR3 signaling pathway in immortalized human hepatocytes even without replicating viral genomes.     

Distinctive features of female-to-male transsexualism and prevalence of gender identity disorder in Japan

IntroductionThe prevalence of transsexualism is thought to differ among socio-geographic backgrounds, and little is known about its prevalence in Japan. Polycystic ovary syndrome (PCOS), which is known to be associated with insulin resistance and metabolic syndrome, is often seen in female-to-male (FTM) transsexual patients. Consequently, detection of PCOS is an important part of health care for these individuals.AimThe purpose of this study was to assess the prevalence of transsexuality in Japan, as well as the incidences of PCOS and insulin resistance among Japanese FTM transsexual patients.MethodsOne hundred four male-to-female (MTF) and 238 FTM Japanese transsexual patients were studied. Medical histories, including histories of menstrual cycling and hormone treatment, were taken. To exclude other diseases, such as congenital adrenal hyperplasia and hormone-secreting tumors, thorough medical assessments, including transvaginal or transrectal ultrasonography and measurement of serum hormone levels and insulin resistance indexes, were performed.Main Outcome MeasuresThe diagnosis of PCOS was based on the Rotterdam 2003 criteria.ResultsBased on demographic statistics, the prevalences of MTF and FTM transsexuality are about 3.97 and 8.20 per 100,000 people, respectively, making the MTF-to-FTM ratio about 1:2. Of the FTM transsexual patients studied, 128 had not taken hormones before their initial assessment (untreated group); the remaining 50 self-administered androgen. Among the untreated group, 32.0% were diagnosed with PCOS, 30.1% were insulin-resistant, and 31.1% showed hypoadiponectinemia.ConclusionsThe sex ratio among Japanese transsexuals is different than among Caucasians. PCOS and insulin resistance are common findings in FTM transsexual patients at initial presentation. Baba T, Endo T, Ikeda K, Shimizu A, Honnma H, Ikeda H, Masumori N, Ohmura T, Kiya T, Fujimoto T, Koizumi M, and Saito T. Distinctive features of female-to-male transsexualism and prevalence of gender identity disorder in Japan.     

Childhood blastic NK cell leukemia successfully treated with L-asparagenase and allogeneic bone marrow transplantation

Blastic NK cell lymphoma/leukemia is a rare and highly malignant neoplasia in both adults and children. It is characterized by lymphoblastoid morphology without cytoplasmic granules and immature NK cell immunophenotypes (CD56+, CD57-, CD16-). It has predilection for extranodal organ involvement, and the prognosis of affected patients is extremely poor under the current chemotherapy. We present a 14-year-old girl who was diagnosed as having blastic NK cell leukemia with mediastinal, pleural, and pericardial involvement. Immunophenotyping of her leukemic cells showed positive for CD2, CD5, CD7, CD34, CD56, HLA-DR, and cytoplasmic CD3. T cell receptor (TCR) and Immunoglobulin heavy chain genes were not rearranged. She received chemotherapy for acute lymphoblastic leukemia incorporating L-asparaginase (L-asp) which successfully induced complete remission. Bone marrow transplantation (BMT) from her HLA-identical sibling was conducted after two courses of consolidation therapy. Expression of aspargine synthetase (AS) protein in the leukemic cells at diagnosis was examined by an immunocytochemical method. She remains in hematological remission for over 36 months after BMT. The expression of AS protein was negative, suggesting that the leukemic cells were sensitive to L-asp. Induction and consolidation therapy incorporating L-asp followed by allo-BMT might be a promising treatment for child hood blastic NK cell leukemia, but more samples of the rare leukemia need to be studied before any definitive conclusions can be drawn.     

A Case of Lipiduria After Arterial Embolization for Renal Angiomyolipomas

We report the case of a 31-year-old woman who suffered lipiduria after selective transcatheter arterial embolization for renal angiomyolipoma (AML). Computed tomography confirmed cystic liquefactive necrosis with fat-fluid level in AML. Although the process by which AML fat tissue excretion occurs is not clear, we speculated that the infarcted AML was connected to the urinary collection duct system and subsequently its adipose component was excreted into the urine.     

Angiopoietins and angiopoietin-like proteins in angiogenesis.

Vascular network formation requires several endothelial cell growth factors. These factors have a potent angiogenic effect, and their precise coordination is essential for vascular development. Among them, angiopoietins function through the Tie2 receptor, whose signaling is critical to regulate vascular stabilization and remodeling. It has been reported that the angiopoietin/Tie2 signal is involved in survival and migration of endothelial cells and regulates vascular remodeling and maintenance of vascular integrity. More recent studies demonstrate that angiopoietin/Tie2 signaling is also required for lymphangiogenesis. The authors and several other groups have identified six angiopoietin-like proteins (Angptls) containing a coiled-coil domain and a fibrinogen-like domain, both of which are characteristic of angiopoietins. Interestingly, Angptls also function in angiogenesis through regulating survival and migration of endothelial cells, although Angptls do not bind the angiopoietin receptor Tie2. Currently, Angptls are orphan ligands, but they have been reported to have pleiotropic effects not only on vascular cells but also on metabolism and tumor biology. Here, the authors review current findings relating to the roles of angiopoietins and Angptls in vascular biology and discuss molecular mechanisms relevant to these factors and angiogenesis.     

DICER and DROSHA gene expression and polymorphisms in autoimmune thyroid diseases

Dicer and Drosha are RNase III enzymes that are necessary for the biogenesis of most miRNAs. However, there are no reports on the association of Dicer and Drosha with the pathogenesis of autoimmune thyroid disease (AITD). We genotyped DICER rs3742330A/G and rs1057035T/C as well as DROSHA rs644236C/T and rs10719C/T polymorphisms in 255?Hashimoto's disease (HD) patients, in 255 Graves' disease (GD) patients and in 128 healthy controls by the polymerase chain reaction (PCR)- restriction fragment length polymorphism (RFLP) method. We also examined the expression of DICER and DROSHA gene in peripheral blood mononuclear cells (PBMCs) by quantitative RT-PCR (qRT-PCR) methods. The TT genotype of the DICER rs1057035 polymorphism was less frequent in GD patients (p?=?0.0098) than in healthy subjects. The CC genotype of DROSHA rs644236 polymorphism were more frequent in GD patients than in HD patients (p?=?0.0171). The gene expression of DICER was lower in patients with AITD compared with that in control subjects (p?=?0.0064) and was lower in patients with GD in remission than in patients with intractable GD (p?=?0.0213). In addition, the expression of DROSHA was lower in patients with AITD than that in control subjects (p?p?=?0.0440). In conclusion, the DICER rs1057035 TT genotype and DROSHA rs644236?CC genotype were associated with the development of GD and the differentiation between GD and HD, respectively. The expression levels of DICER and DROSHA genes were low in AITD and differed depending on the intractability of GD and the severity of HD, respectively.