Selective control of SNARE recycling by Golgi retention

AbstractTwo distinct sets of soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) catalyze membrane fusion in the cis-Golgi and trans-Golgi. The mechanism that controls Golgi localization of SNAREs remains largely unknown. Here we tested three potential mechanisms, including vesicle recycling between the Golgi and the endoplasmic reticulum, partitioning in Golgi lipid microdomains, and selective intra-Golgi retention. Recycling rates showed a linear relationship with intra-Golgi mobility of SNAREs. The cis-Golgi SNAREs had higher mobility than intra-Golgi SNAREs, whereas vesicle SNAREs had higher mobility than target membrane SNAREs. The differences in SNARE mobility were not due to preferential partitioning into detergent-resistant membrane microdomains. We propose that intra-Golgi retention precludes entropy-driven redistribution of SNAREs to the endoplasmic reticulum and endocytic compartments

Expression and function of inducible co-stimulator in patients with systemic lupus erythematosus: possible involvement in excessive interferon-γ and anti-double-stranded DNA antibody production

Inducible co-stimulator (ICOS) is the third member of the CD28/cytotoxic T-lymphocyte associated antigen-4 family and is involved in the proliferation and activation of T cells. A detailed functional analysis of ICOS on peripheral blood T cells from patients with systemic lupus erythematosus (SLE) has not yet been reported. In the present study we developed a fully human anti-human ICOS mAb (JTA009) with high avidity and investigated the immunopathological roles of ICOS in SLE. JTA009 exhibited higher avidity for ICOS than a previously reported mAb, namely SA12. Using JTA009, ICOS was detected in a substantial proportion of unstimulated peripheral blood T cells from both normal control individuals and patients with SLE. In CD4(+)CD45RO(+ )T cells from peripheral blood, the percentage of ICOS(+ )cells and mean fluorescence intensity with JTA009 were significantly higher in active SLE than in inactive SLE or in normal control individuals. JTA009 co-stimulated peripheral blood T cells in the presence of suboptimal concentrations of anti-CD3 mAb. Median values of [(3)H]thymidine incorporation were higher in SLE T cells with ICOS co-stimulation than in normal T cells, and the difference between inactive SLE patients and normal control individuals achieved statistical significance. ICOS co-stimulation significantly increased the production of IFN-γ, IL-4 and IL-10 in both SLE and normal T cells. IFN-γ in the culture supernatants of both active and inactive SLE T cells with ICOS co-stimulation was significantly higher than in normal control T cells. Finally, SLE T cells with ICOS co-stimulation selectively and significantly enhanced the production of IgG anti-double-stranded DNA antibodies by autologous B cells. These findings suggest that ICOS is involved in abnormal T cell activation in SLE, and that blockade of the interaction between ICOS and its receptor may have therapeutic value in the treatment of this intractable disease

Diagnostic reliability of magnetic resonance imaging for central nervous system syndromes in systemic lupus erythematosus: a prospective cohort study

<p>Abstract</p> <p>Background</p> <p>Previous studies of magnetic resonance imaging (MRI) as a diagnostic tool for central nervous system (CNS) syndromes in systemic lupus erythematosus (SLE) contained several limitations such as study design, number of enrolled patients, and definition of CNS syndromes. We overcame these problems and statistically evaluated the diagnostic values of abnormal MRI signals and their chronological changes in CNS syndromes of SLE.</p> <p>Methods</p> <p>We prospectively studied 191 patients with SLE, comparing those with (n = 57) and without (n = 134) CNS syndrome. CNS syndromes were characterized using the American College of Rheumatology case definitions.</p> <p>Results</p> <p>Any abnormal MRI signals were more frequently observed in subjects in the CNS group (n = 25) than in the non-CNS group (n = 32) [relative risk (RR), 1.7; 95% confidence interval (CI), 1.1-2.7; <it>p </it>= 0.016] and the positive and negative predictive values for the diagnosis of CNS syndrome were 42% and 76%, respectively. Large abnormal MRI signals (ø ≥ 10 mm) were seen only in the CNS group (n = 7; RR, 3.7; CI, 2.9-4.7; <it>p </it>= 0.0002), whereas small abnormal MRI signals (ø < 10 mm) were seen in both groups with no statistical difference. Large signals always paralleled clinical outcome (<it>p </it>= 0.029), whereas small signals did not (<it>p </it>= 1.000).</p> <p>Conclusions</p> <p>Abnormal MRI signals, which showed statistical associations with CNS syndrome, had insufficient diagnostic values. A large MRI signal was, however, useful as a diagnostic and surrogate marker for CNS syndrome of SLE, although it was less common.</p

Hepatitis C Virus Reveals a Novel Early Control in Acute Immune Response

Recognition of viral RNA structures by the intracytosolic RNA helicase RIG-I triggers induction of innate immunity. Efficient induction requires RIG-I ubiquitination by the E3 ligase TRIM25, its interaction with the mitochondria-bound MAVS protein, recruitment of TRAF3, IRF3- and NF-κB-kinases and transcription of Interferon (IFN). In addition, IRF3 alone induces some of the Interferon-Stimulated Genes (ISGs), referred to as early ISGs. Infection of hepatocytes with Hepatitis C virus (HCV) results in poor production of IFN despite recognition of the viral RNA by RIG-I but can lead to induction of early ISGs. HCV was shown to inhibit IFN production by cleaving MAVS through its NS3/4A protease and by controlling cellular translation through activation of PKR, an eIF2α-kinase containing dsRNA-binding domains (DRBD). Here, we have identified a third mode of control of IFN induction by HCV. Using HCVcc and the Huh7.25.CD81 cells, we found that HCV controls RIG-I ubiquitination through the di-ubiquitine-like protein ISG15, one of the early ISGs. A transcriptome analysis performed on Huh7.25.CD81 cells silenced or not for PKR and infected with JFH1 revealed that HCV infection leads to induction of 49 PKR-dependent genes, including ISG15 and several early ISGs. Silencing experiments revealed that this novel PKR-dependent pathway involves MAVS, TRAF3 and IRF3 but not RIG-I, and that it does not induce IFN. Use of PKR inhibitors showed that this pathway requires the DRBD but not the kinase activity of PKR. We then demonstrated that PKR interacts with HCV RNA and MAVS prior to RIG-I. In conclusion, HCV recruits PKR early in infection as a sensor to trigger induction of several IRF3-dependent genes. Among those, ISG15 acts to negatively control the RIG-I/MAVS pathway, at the level of RIG-I ubiquitination.These data give novel insights in the machinery involved in the early events of innate immune response

TT ウイルス ボシ カンセン ノ コウホウシテキ, ゼンホウシテキ ケンキュウ : トクニ ボシ カンセン ヨウシキ ト シュウサンキ ニオケル リンショウテキ イギ ニツイテ

近年同定され,輸血後肝炎との関連が示唆されているTTV について,その母子感染の自然史と周産期における臨床的意義について後方視的,前方視的に検討した.HBV 及びHCV が検出されない妊婦(前方視的研究;NBCPW 群)におけるTTV DNA 陽性率は19.0%(37/195)であり,このうちsAST/sALT 値が110 U/L を超える例は皆無であった.HBV あるいはHCV キャリア妊婦(後方視的研究;BCCPW 群)ではTTV DNA 陽性率は25.0%(21/84)である.このうちsAST/sALT 値が110U/L を超える例は23.8%(5/21)に達し,この5 例はTTV 単独キャリアではなく,HBV 又はHCV との重複キャリアであった.NBCPW 群の出生児(14 名)におけるTTV DNA 陽転率は57.1%であり,このうちsAST/sALT 値が110 U/L を超えた例は無かった.BCCPW 群の出生児(21 名)におけるTTV DNA 陽転率は42.9%であり,このうちsAST/sALT 値が110 U/L を超えた児は2 名(22.2%)で,この2 名はHCV キャリアでもあった.TTV DNA 陽転化した総数17 名の出生児は全員生後18 ヶ月時点までTTV DNA 陽性が持続しており,脱キャリア化は認められていない.また,キャリア化児におけるTTV DNA 出現時期および哺育方法より経胎盤感染,経産道感染および経唾液感染は否定的であり,経母乳感染の可能性が強く示唆される結果であった.また,キャリア妊婦及びキャリア化児における肝機能異常は母子共々TTV 単独キャリアでは認められず,TTV 感染の周産期における臨床的インパクトは低いと思われる.The natural history of mother-to-child transmission(MTCT) of the TT virus (TTV) was investigated retroandprospectively.Serum TTV DNA was detected in 37 out of the 195( 19.0%) pregnant women without both HBV and HCV in theirsera (NBCPW) and 21 out of the 84 (25.0 %) pregnantwomen with HBV and/or HCV (BCCPW). In the lattergroup, 5 out of the 21( 23.8%) TTV carrier pregnant womenshowed repeatedly sAST and/or sALT levels over110U/L, but none of the former group did.With informed consent (IC), 14 (NBCPW) and 21 (BCCPW)infants were followed from birth up to 18 months ofage by receiving tests for serum TTV DNA and levels ofsAST and sALT. Eight out of the 14 infants (57.1 %, NBCPW)and 9 out of the 21 infants( 42.9%, BCCPW) developedTTV carrier-state, and all of these 17 carrier infantsmaintained serum TTV DNA-positive through the followupperiods. No infants (NBCPW) showed elevated serumlevels (>110 U/L) of AST or ALT during the follow-upperiods, but 2 out of the 9 infants( 22.2%, BCCPW) showedsAST or sALT levels higher than 110 U/L, and these 2 infantswere found to be in HCV carrier-state.None of the infants developed a TTV-positive resultwithin 1 month after birth, and thereafter 11.8 % (2/17)developed carrier-state in 3 months, 47.1 % in 6 months,82.4 % in 12 months. These findings may exclude the intrauterineor trans-vaginal infection as a mode of TTVMTCT. On the other hand, all carrier infants with one exceptionwere raised by breast feeding, which was rich inTTV. Both carrier pregnant women and children, who wereneither HBV nor HCV carriers, showed no abnormal liverfunction through the follow-up periods.Thus, we conclude that TTV MTCT occurs highly, but itis not so significant practically

シュウサンキ リョウイキ ニオケル Gガタ カンエン ウイルス ノ リンショウテキ イギ : オナジ フラビ ウイルス カ ニ ゾクスル Cガタ カンエン ウイルス ト ヒカク シテ

HBV, HCV 同様血清肝炎を惹起する可能性を示唆されているHGV の(1)妊婦における検出率,(2)母子感染の自然史,そのリスクファクター及びキャリア化児の予後,(3)キャリア妊婦及びキャリア化児における肝機能を前方視的に調査し,同ウイルスの周産期における臨床的意義を同じフラビウイルス科に属するHCV と比較検討した.対象は1996&#12316;2004 年に当科を受診した妊婦3,738 名(HGV),4,023 名(HCV)とキャリア妊婦の出生児14 名(HGV),24 名(HCV)である.HGV RNA は RT-PCR 法(定性)k,real-time PCR(定量)及びcycle-sequence 法(genome sequence)により,HGV-E2 抗体はELISA 法を用いて,またHCV RNA はnested RT-PCR(定性),real- time PCR(定量)により,またHCV-Ab は2nd 及び3rd generation EIA を用いて測定した.対象児の血清サンプルは臍帯血から最長119 ヶ月まで定期的に検査に供された.妊婦におけるHGV RNA, HCV RNA の検出率は各々0.64%(24/3,738),0.60%(24/4,023)であり両者に有意差を認めなかった(p=0.7984).HGV-E2 抗体の検出率は4.4%(82/1,858)であり,HGV RNA とHGV-E2 抗体は相互排他的であった.HGV RNA 単独陽性妊婦で肝機能異常は見られなかった.出生児におけるHGV RNA,HCV RNA 陽性はそれぞれ64.3%(10/16),12.5%(3/24)に認められ,両ウイルス陽性児とも経膣分娩症例であり,キャリア妊婦のviral loads はそれぞれ107 及び105 copies/ml 以上の症例であった.HGV 母子感染と推測された4 組の母子ペア血清を用いたHGV RNA シークエンス相同性の検討では各母子間で100%の一致率が得られ,HGV 母子感染の直接的証拠が得られた.キャリア化した9 名の児のうち1名が肝機能異常(sALT 値>110 U/L)を呈したが,これはHCV との重複感染例であった.フォローアップ中にHCV では約16.7%がキャリア化後3 年以内に脱キャリア化したが,HGV キャリア児ではRNA 陰性化は少なくとも最長約10 年間のフォローアップ期間中には皆無であった.妊婦のHGV 及びHCV 保有率(キャリア率)はほぼ同等であり,一方母子感染率は前者が後者の約5.1 倍に達し,母子感染がHGV キャリアの主たる供給源であることが示唆された.HGV およびHCV 母子感染では,キャリア妊婦の血中viral loads 及び経膣分娩がリスクファクターであることが示された.さらに,同じフラビウイルス科に属しながら,HGV はHCV とは異なり,肝傷害性が殆ど無いことが判明した.The epidemiology and natural history of mother-to-childtransmission( MTCT) of hepatitis G virus( HGV) were investigatedto evaluate potential clinical significance of HGVin perinatal periods. The data was discussed by comparisonwith those of a well-known flavivirus, hepatitis C virus(HCV).During the periods from 1996 to 2006, 3,738 pregnantwomen received screening tests for HGV RNA and 4,023pregnant women received screening tests for HCV Antibodies(Ab). HGV RNA-positive pregnant women weretested for HGV-E2 Ab and HCV Ab-positive pregnantwomen were tested for HCV RNA. HGV- and HCV RNApositivewomen underwent the measurement of viral loadswith use of real-time PCR. With informed consent, 14 infantsborn to HGV carrier mothers and 24 infants born toHCV carrier mothers were followed from birth to 19months of age by receiving the measurement of serumHGV- or HCV RNA and sAST/sALT levels.HGV RNA was detected in 0.64 % (24/3,738) of thewomen tested and HCV RNA was detected in 0.60 %(24/4,023) of the women tested. HGV-E2 Ab was detectedin 4.4 % and mutually exclusive with HGV RNA. Nine ofthe 14 infants born to HGV carrier mothers( 64.3%) and 3of 24 infants born to HCV carrier mothers (12.5 %) developedHGV and HCV carrier-states respectively. The homologyof HGV RNA sequences was perfectly identical betweenthe 4 paired sera of mother-child.Both of vaginal delivery mode and maternal viral loads atdelivery (HGV>107, HCV>105 copies/ml) were suggestedas one of risk factors for MTCT. The elevation of sAST/sALT levels (>110 U/L) in the HGV and HCV carrier infantswere 7.1%( 1/9) and 66.7%(2/3) respectively. However,one HGV carrier infant with elevated sAST/sALTlevels was found to be a HCV carrier.We conclude that HGV MTCT occurs very frequently,but HGV is not so significant in perinatal periods comparedwith another flavivirus, HCV

Ramucirumab plus docetaxel versus placebo plus docetaxel in patients with locally advanced or metastatic urothelial carcinoma after platinum-based therapy (RANGE): a randomised, double-blind, phase 3 trial

Few treatments with a distinct mechanism of action are available for patients with platinum-refractory advanced or metastatic urothelial carcinoma. We assessed the efficacy and safety of treatment with docetaxel plus either ramucirumab-a human IgG1 VEGFR-2 antagonist-or placebo in this patient population