The N-terminal region of Jaw1 has a role to inhibit the formation of organized smooth endoplasmic reticulum as an intrinsically disordered region

Jaw1/LRMP is a type II integral membrane protein that is localized at the endoplasmic reticulum (ER) and outer nuclear membrane. We previously reported that a function of Jaw1 is to maintain the nuclear shape as a KASH protein via its carboxyl terminal region, a component of linker of nucleoskeleton and cytoskeleton complex in the oligomeric state. Although the oligomerization of some KASH proteins via the cytosolic regions serves to stabilize protein-protein interactions, the issue of how the oligomerization of Jaw1 is regulated is not completely understood. Therefore, we focused on three distinct regions on the cytosolic face of Jaw1: the N-terminal region, the coiled-coil domain and the stem region, in terms of oligomerization. A co-immunoprecipitation assay showed that its coiled-coil domain is a candidate for the oligomerization site. Furthermore, our data indicated that the N-terminal region prevents the aberrant oligomerization of Jaw1 as an intrinsically disordered region (IDR). Importantly, the ectopic expression of an N-terminal region deleted mutant caused the formation of organized smooth ER (OSER), structures such as nuclear karmellae and whorls, in B16F10 cells. Furthermore, this OSER interfered with the localization of the oligomer and interactors such as the type III inositol 1,4,5-triphosphate receptor (IP3R3) and SUN2. In summary, the N-terminal region of Jaw1 inhibits the formation of OSER as an IDR to maintain the homeostatic localization of interactors on the ER membrane

Generation of three induced pluripotent stem cell lines from postmortem tissue derived following sudden death of a young patient with STXBP1 mutation

We established three iPSC lines from postmortem-cultured fibroblasts derived following the sudden unexpected death of an 8-year-old girl with Lennox-Gastaut syndrome, who turned out to have the R551H-mutant STXBP1 gene. These iPSC clones showed pluripotent characteristics while retaining the genotype and demonstrated trilineage differentiation capability, indicating their utility in disease-modeling studies, i.e., STXBP1-encephalopathy. This is the first report on the establishment of iPSCs from a sudden death child, suggesting the possible use of postmortem-iPSC technologies as an epoch-making approach for precise identification of the cause of sudden death

Absolute Energy Measurements with Superconducting Transition-Edge Sensors for Muonic X-ray Spectroscopy at 44 keV

Superconducting transition-edge sensor (TES) microcalorimeters have great utility in x-ray applications owing to their high energy resolution, good collecting efficiency and the feasibility of being multiplexed into large arrays. In this work, we develop hard x-ray TESs to measure the absolute energies of muonic-argon ($\mu$-Ar) transition lines around 44 keV and 20 keV. TESs with sidecar absorbers of different heat capacities were fabricated and characterized for their energy resolution and calibration uncertainty. We achieved ~ 1 eV absolute energy measurement accuracy at 44 keV, and < 12 eV energy resolution at 17.5 keV

A circulating subset of iNKT cells mediates antitumor and antiviral immunity

新規の循環型iNKT細胞を発見 --抗腫瘍・抗ウイルス感染効果の高い免疫細胞療法の開発への貢献に期待--. 京都大学プレスリリース. 2022-10-24.Invariant natural killer T (iNKT) cells are a group of innate-like T lymphocytes that recognize lipid antigens. They are supposed to be tissue resident and important for systemic and local immune regulation. To investigate the heterogeneity of iNKT cells, we recharacterized iNKT cells in the thymus and peripheral tissues. iNKT cells in the thymus were divided into three subpopulations by the expression of the natural killer cell receptor CD244 and the chemokine receptor CXCR6 and designated as C0 (CD244⁻CXCR6⁻), C1 (CD244⁻CXCR6⁺), or C2 (CD244⁺CXCR6⁺) iNKT cells. The development and maturation of C2 iNKT cells from C0 iNKT cells strictly depended on IL-15 produced by thymic epithelial cells. C2 iNKT cells expressed high levels of IFN-γ and granzymes and exhibited more NK cell–like features, whereas C1 iNKT cells showed more T cell–like characteristics. C2 iNKT cells were influenced by the microbiome and aging and suppressed the expression of the autoimmune regulator AIRE in the thymus. In peripheral tissues, C2 iNKT cells were circulating that were distinct from conventional tissue-resident C1 iNKT cells. Functionally, C2 iNKT cells protected mice from the tumor metastasis of melanoma cells by enhancing antitumor immunity and promoted antiviral immune responses against influenza virus infection. Furthermore, we identified human CD244⁺CXCR6⁺ iNKT cells with high cytotoxic properties as a counterpart of mouse C2 iNKT cells. Thus, this study reveals a circulating subset of iNKT cells with NK cell–like properties distinct from conventional tissue-resident iNKT cells

Production of Recombinant Monoclonal Antibodies in the Egg White of Gene-Targeted Transgenic Chickens

Increased commercial demand for monoclonal antibodies (mAbs) has resulted in the urgent need to establish efficient production systems. We previously developed a transgenic chicken bioreactor system that effectively produced human cytokines in egg whites using genome-edited transgenic chickens. Here, we describe the application of this system to mAb production. The genes encoding the heavy and light chains of humanized anti-HER2 mAb, linked by a 2A peptide sequence, were integrated into the chicken ovalbumin gene locus using a CRISPR/Cas9 protocol. The knock-in hens produced a fully assembled humanized mAb in their eggs. The mAb expression level in the egg white was 1.4&ndash;1.9 mg/mL, as determined by ELISA. Furthermore, the antigen binding affinity of the anti-HER2 mAb obtained was estimated to be equal to that of the therapeutic anti-HER2 mAb (trastuzumab). In addition, antigen-specific binding by the egg white mAb was demonstrated by immunofluorescence against HER2-positive and -negative cells. These results indicate that the chicken bioreactor system can efficiently produce mAbs with antigen binding capacity and can serve as an alternative production system for commercial mAbs