Involvement of GANP in B Cell Activation in T Cell-dependent Antigen Response

Adaptive immunity is dependent on proliferation of antigen-driven B cells for clonal expansion in germinal centers (GCs) against T cell-dependent antigens (TD-Ag), accompanied with somatic hypermutation of variable-region gene and class switching of B cell antigen receptors. To study molecular mechanisms for B cell differentiation in GCs, we have identified and studied a 210 kDa GANP protein expressed in GC-B cells. GANP has domains for MCM3-binding and RNA-primase activities and is selectively up-regulated in centrocytes surrounded with follicular dendritic cells (FDCs) upon immunization with TD-Ag in vivo and in B cells stimulated with anti-CD40 monoclonal antibody in vitro, which suggested that GANP plays a certain important role in the maturation of immunoglobulin or selection of B cells in GC during the immune response to TD-Ag. Since this up-regulation has not been detected in T cells in GCs and in Concanavalin A-stimulated T cells in vitro, selective function of GANP molecule on B cell proliferation and differentiation might exist

Protein phosphatase subunit G5PR is needed for inhibition of B cell receptor–induced apoptosis

B cell receptor (BCR) cross-linking induces B cell proliferation and sustains survival through the phosphorylation-dependent signals. We report that a loss of the protein phosphatase component G5PR increased the activation-induced cell death (AICD) and thus impaired B cell survival. G5PR associates with GANP, whose expression is up-regulated in mature B cells of the peripheral lymphoid organs. To study G5PR function, the G5pr gene was conditionally targeted with the CD19-Cre combination (G5pr−/− mice). The G5pr−/− mice had a decreased number of splenic B cells (60% of the controls). G5pr−/− B cells showed a normal proliferative response to lipopolysaccharide or anti-CD40 antibody stimulation but not to BCR cross-linking with or without IL-4 in vitro. G5pr−/− B cells did not show abnormalities in the BCR-mediated activation of Erks and NF-κB, cyclin D2 induction, or Akt activation. However, G5pr−/− B cells were sensitive to AICD caused by BCR cross-linking. This was associated with an increased depolarization of the mitochondrial membrane and the enhanced activation of c-Jun NH2-terminal protein kinase and Bim. These results suggest that G5PR is required for the BCR-mediated proliferation associated with the prevention of AICD in mature B cells

LL55: Selective Early Lymphoid Expression of a Murine cDNA Clone Which Encodes a Putative RNA-Binding Protein

Specific expression of various RNA-binding protein (RNP) molecules is one of the critical factors that determine the development in Drosophila melanogaster and Caenorhabditis elegans. In the present study, we found a complementary DNA clone, LL55 encoding a putative RNP. Structural comparison of nucleotide and amino acid sequences demonstrate that LL55 encoding a nuclear protein with two RNA-binding consensus motifs and the common arginine-serine repeats, is similar to the sex-determining transformer-2 (tra-2) gene of Drosophila melanogaster. The expression of 2.3 kilobase (kb) and 1.5 kb LL55 messenger RNA (mRNA) is ubiquitous in murine organs and tissues, but it is selective in the early development of fetal life. It appears as early as day 10.5 and increases until day 15 of gestation in accordance with the expression of λ5 mRNA which is involved in murine pre-B cell generation. Taking account of the selective expression and the specific regulation of RNP molecules, the finding of LL55 RNP provides a new outlook for the generation and function of the immune system

Plasmacytoid Dendritic Cells Activate Lymphoid-Specific Genetic Programs Irrespective of Their Cellular Origin

AbstractThe developmental origin of type I interferon (IFN)-producing plasmacytoid dendritic cells (PDCs) is controversial. In particular, the rearrangement of immunoglobulin heavy chain (IgH) genes in murine PDCs and the expression of pre-T cell receptor α (pTα) gene by human PDCs were proposed as evidence for their “lymphoid” origin. Here we demonstrate that PDCs capable of IFN production develop efficiently from both myeloid- and lymphoid-committed progenitors. Rearranged IgH genes as well as RAG transcripts were found in both myeloid- and lymphoid-derived PDCs. The human pTα transgenic reporter was activated in both myeloid- and lymphoid-derived PDCs at a level comparable to pre-T cells. PDCs were the only cell population that activated murine RAG1 knockin and human pTα transgenic reporters outside the lymphoid lineage. These results highlight a unique developmental program of PDCs that distinguishes them from other cell types including conventional dendritic cells

The expression of the mouse VpreB/λ5 locus in transformed cell lines and tumors of the B lineage differentiation pathway

The expression of RNA transcripts from two pre B lymphocyte related genes, VpreB and λ5, has been studied in a series of transformed cell lines which appear frozen at different states of B lineage differentiation, from early progenitors to surface Ig positive B cells. In the HAFTL-1 cell line, which arose from fetal liver by transformation with a retrovlrus containing the Hras oncogene, Northern analysis of poly A+ mRNA as well as in situ hybridization of RNA In single cells revealed that λ5 and VpreB are already expressed at the progenitor stage and increase in expression as the progenitors differentiate to precursor (preB) cells, or are turned off as the progenitors differentiate to myeloid cells. Continued rearrangements of Ig genes in pre B cell lines leading to Ig expression on the surface of NFS-5 pre B cells do not influence the continued expression of VpreB and λ5. Surface Ig-positive B lineage cell lines also express the pre B-related genes. Both Ly1+ as well as Ly1− pre B cells are VpreB and λ5positlve. Lipopolysaccharide (LPS) stimulation of 70Z/3 pre B cells does not turn off λ5 expression. It therefore appears that, at least In transformed cell lines, the expression of VpreB and λ5, is not directly regulated by the expression of μH, κL, or λL chains, LPS reactivity, or the Ly1 surface antigen. Fusion of plasmacytoma cells with normal pre B cells to generate pre B hybridomas leads to down-regulation of VpreB/λ5 expression. These results suggest that different trans-acting factors in more mature cells might down-regulate the expression of VpreB/λ

ダイ5ジ ナンキョク チイキ カンソクタイ エットウタイ キショウ ブモン ガイホウ

Meteorological observations at Syowa Base in 5th expedition were maintained in the year 1960-1962. Among scientific disciplines importance was attached to the meteorological section consisting of 4 members, to take various types of observation. General and characteristic features in meteorological observations are summarized in the following. A. Surface observation: 3-hourly observations were made throughout the wintering period, 4 observations were transmitted to Mother Station (Mawson), twice daily. In addition to the specified observations, radiation, sunshine and ground temperature were also observed by continuous selfrecording instrument respectively. The special features of this year is that, compared with the appearance of the annual minimum temperature normally in September in the Antarctic, the minimum occurred in July and it is shown that the average temperature in September was 5.5℃ higher than the normal value. B. Upper air observation: One time (12Z) daily rawinsonde observations were made throughout the year except a few cases of only radiosonde observation. Twice daily (00 and 12Z) rawinsonde observations were made during World Meteorological Interval of Post-IGY (July 16-July 25). All observations were transmitted to Mother Station every day. Equipments used : D-55A type Automatic Direction Finder (Similar type with GMD-1A) JMA-RSII Rawinsonde, 1680 Mc JMA-SIII Radiosonde, 27 Mc 800g Balloon (Latex) CaH_2 Cans for Hydrogen gas to fill balloons. Monthly average temperatures and heights were shown in respective figures. In September, combined with the surface temperature, the strong warm-air inflow throughout the troposphere below 300mb could be seen. A rapid warming in the stratosphere in spring was also clearly observed. Wind rose at some selected pressure levels were shown in Figs. 7-10. In general, the wind is strong in winter, especially in the stratosphere and NE-ly and SW-ly winds are predominant in the troposphere, SW-ly or W-ly in the stratosphere. The E-ly winds were also observed above 30 mb in summer. C. Ozone observation: i) Total ozone observation Dobson ozone spectrophotometer was used for this observation. Table 3 shows the results of only direct sunlight observation with reliable AD wave length setting. Comparison is made in Figs. 11 and 12 between Syowa Base, Little America and Halley Bay. Total ozone amount can be said to increase in spring from November to December over the Antarctic and the maximum seems to appear in summer. The 10-days average values of Syowa Base and Halley Bay show to be in good similarity in spite of different year. It may also be noted that a good correlation exists between rapid increase of ozone amount and temperature of 50mb in late November. ii) Surface ozone observation The density of surface ozone was measured on days without drifting snow from the end of February 1961. Based on Ehmert method, the equipment developed by Mr. KAWAMURA, Meteorological Research Institute, was used. It may be seen that the density increase in autumn and reaches its maximum value about 40 μg/m^3 in early June in polar night season, then decreases rapidly until the sun comes back and indicates minimum in early summer. It should be noted that there is 6 months\u27 phase difference between the surface ozone amount and the total ozone amount. D. Special observation: Snow accumulation Toward ENE-ly direction from the base, 6 snow stakes were erected and snow accumulation was observed several times every month. The result is shown in Table 4 in which the annual accumulation was 121 cm. Average density of snow was 0.474 and the equivalent amount of water was 574 m/m

発症早期ALS患者に対する超高用量メチルコバラミンの有効性・安全性について : ランダム化比較試験

Importance: Post hoc analysis in a phase 2/3 trial indicated ultra-high dose methylcobalamin slowed decline of the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R) total score at week 16 as well as at week 182, without increase of adverse events, in patients with amyotrophic lateral sclerosis (ALS) who were enrolled within 1 year from onset. Objective: To validate the efficacy and safety of ultra-high dose methylcobalamin for patients with ALS enrolled within 1 year of onset. Design: A multicenter, placebo-controlled, double-blind, randomized phase 3 trial with 12-week observation and 16-week randomized period, conducted from October 2017 to September 2019. Setting: Twenty-five neurology centers in Japan. Participants: Patients with ALS diagnosed within 1 year of onset by the updated Awaji criteria were initially enrolled. Of those, patients fulfilling the following criteria after 12-week observation were eligible for randomization: 1- or 2-point decrease in ALSFRS-R total score, a percent forced vital capacity over 60%, no history of noninvasive respiratory support and tracheostomy, and being ambulant. The target number was 64 in both methylcobalamin and placebo groups. Of 203 patients enrolled in the observation, 130 patients (age, 61.0 ± 11.7 years; female, 56) met the criteria and were randomly assigned through an electronic web-response system to methylcobalamin or placebo (65 for each). Of these, 129 patients were eligible for the full analysis set, and 126 completed the double-blind stage. Interventions: Intramuscular injection of methylcobalamin 50 mg or placebo twice weekly for 16 weeks. Main outcomes and measures: The primary endpoint was change in ALSFRS-R total score from baseline to week 16 in the full analysis set. Results: The least-squares mean difference in ALSFRS-R total score at week 16 of the randomized period was 1.97 points greater with methylcobalamin than placebo (−2.66 versus −4.63; 95% CI, 0.44–3.50; P = 0.012). The incidence of adverse events was similar between the two groups. Conclusions and relevance: Ultra-high dose methylcobalamin was efficacious in slowing functional decline and safe in the 16-week treatment period in ALS patients in the early stage and with moderate progression rate. Trial registration: UMIN-CTR Identifier: UMIN000029588 (umin.ac.jp/ctr); ClinicalTrials.gov Identifier: NCT03548311 (clinicaltrials.gov