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For its cell surface expression, radioprotective 105 (RP105) - an orphan Toll-like receptor - must form a complex with a soluble glycoprotein called myeloid differentiation 1 (MD-1). The number of RP105-negative cells is significantly increased in patients with systemic lupus erythematosus (SLE); however, to elucidate the mechanism underlying this increase, how RP105 is expressed on the cell surface depending on MD-1 should be investigated. We demonstrated that RP105 exhibits two forms depending on MD-1 and its two N-glycosylation sites, N96 and N156. Cell surface expression of RP105 decreased in the presence of mutant MD-1 (N96Q/N156Q). Nonglycosylated MD-1 decreased the de novo cell surface expression of RP105 but not pre-expressed RP105. Thus, the N-glycans of MD-1 may represent targets for SLE therapy.

The dynamic structure factor

The extracellular matrix (ECM) is the basis for virtually all cellular processes and is also related to tumor metastasis. Fibronectin (FN), a major ECM macromolecule expressed by different cell types and also present in plasma, consists of multiple functional modules that bind to ECM-associated, plasma, and cell-surface proteins such as integrins and FN itself, thus ensuring its cell-adhesive and modulatory role. Here we show that FN constitutes an immune checkpoint. Thus, FN was identified as a physiological ligand for a tumor/leukemia/lymphoma- as well as autoimmune-associated checkpoint, ILT3/LILRB4 (B4, CD85k). Human B4 and the murine ortholog, gp49B, bound FN with sub-micromolar affinities as assessed by bio-layer interferometry. The major B4-binding site in FN was located at the N-terminal 30-kDa module (FN30), which is apart from the major integrin-binding site present at the middle of the molecule. Blockade of B4–FN binding such as with B4 antibodies or a recombinant FN30-Fc fusion protein paradoxically ameliorated autoimmune disease in lupus-prone BXSB/Yaa mice. The unexpected nature of the B4–FN checkpoint in autoimmunity is discussed, referring to its potential role in tumor immunity.

X-ray diffraction (XRD) and small angle X-ray scattering (SAXS) measurements for fluid Hg and fluid Se up to the supercritical region have been carried out using synchrotron radiation at SPring-8. We obtained the structure factor, S ( Q ) $S\left(Q\right)$ , including a small angle region, and the pair distribution function, g ( r ) $g\left(r\right)$ , for both fluids from the liquid to the dense vapor region. Change of the local structure and medium-range correlations at the metal-insulator transition in fluid Hg were revealed. On the other, the average coordination number of two was preserved at the semiconductor-metal transition in fluid Se. From a SAXS experiment of fluid Se in 2012, SAXS spectra near the semiconductor-metal transition region show the Ornstein–Zernike profile and the SAXS intensity is reduced with increasing pressure. These results indicate difficulties of separating fluctuations intrinsic to the semiconductor-metal transition from those arising from the liquid-vapor critical point in fluid Se, although fluctuations intrinsic to the electronic transitions are largely expected in both fluids.

The dynamic structure factor S ( Q , E ) , where Q and E are momentum and energy transfer, respectively, has been measured for liquid Eu8Ga16Ge30 (EGG), using inelastic x-ray scattering. The excitation energy of the longitudinal acoustic mode in the liquid was scaled to that in liquid Ba8Ga16Sn30 (BGS) with the effective mass. This result means that the local structure in both liquids are similar. The longitudinal acoustic excitation energy of type-I clathrate compound EGG disperses faster than that in the liquid, suggesting that the interatomic force is weakened on melting. The lower energy excitation was observed in both liquid EGG and liquid BGS. In comparison with the longitudinal phonon dispersion in crystalline clathrate compound EGG obtained by density functional theory-based calculations, the lower energy in the liquid was found to be near the optical mode energy. The result indicates that the lower energy mode arises from the relative motion between Eu and (Ga, Ge) atoms.

The dynamic structure factor $S(Q,E)$ of liquid ${\mathrm{Ge}}_{2}{\mathrm{Sb}}_{2}{\mathrm{Te}}_{5}$ has been obtained by inelastic x-ray scattering, where $Q$ and $E$ are momentum and energy transfer, respectively. The dispersion curve of the longitudinal acoustic excitation energy exhibits flat-topped $Q$ dependence similarly to that in liquid GeTe and liquid Bi, where the local structure is modulated by Peierls distortion. The flat-topped energy in liquid ${\mathrm{Ge}}_{2}{\mathrm{Sb}}_{2}{\mathrm{Te}}_{5}$ is split into low and high energy parts arising from Sb-Te and Ge-Te correlations, respectively. Furthermore, the high energy part depends on $Q$ like an optical mode with decreasing $Q$ to zero, and it approaches the vibrational energy of fourfold coordinated Ge atoms with octahedral configurations. The result indicates that a majority of Ge in the liquid stays in octahedral order as predicted by first-principles molecular dynamics simulations.

An ab initio molecular-dynamics simulation has been carried out to investigate structure of fluid sulfur at 1323 K, a supercritical region. The simulated structure factor agrees well with that experimentally obtained. We found that various kinds of sulfur molecules are formed and a bond at the end of a chain molecule is shorter than that at the inside of the chain. In particular, a S4 chain molecule exhibits approximately 0.3 A difference between them. This result explains the results obtained by x-ray diffraction [Inui et al., J. Phys.: Conf. Ser. 98,012,008 (2008)], why the average bond length is almost constant although the coordination number decreases to 1.0, corresponding to a S2 molecule with a double bond, at low densities.

AbstractImmune homeostasis is critically regulated by the balance between activating and inhibitory receptors expressed on various immune cells such as T and B lymphocytes, and myeloid cells. The inhibitory receptors play a fundamental role in the immune checkpoint pathway, thus maintaining peripheral tolerance. We recently found that expression of leukocyte immunoglobulin-like receptor (LILR)B4, an inhibitory member of the human LILR family, is augmented in auto-antibody-producing plasmablasts/plasma cells of systemic lupus erythematosus (SLE) patients. However, the mechanism behind the ‘paradoxical’ up-regulation of this inhibitory receptor upon pathogenic antibody-secreting cells is yet to be known. To this end, in this study, we examined if glycoprotein 49B (gp49B), the murine counterpart of human LILRB4, is also elevated in auto-antibody-producing cells in several SLE mouse models, and tried to clarify the underlying mechanism. We found that gp49B is expressed on plasma cells of lupus-prone models but not of healthy C57BL/6 mice, and the level was positively correlated to the anti-double-stranded DNA IgG titer in serum. Gp49B genetic deletion, however, did not abolish the serum auto-antibodies or fully ameliorate the lethal glomerulonephritis, indicating that gp49B is not the sole regulator of lupus but a pathogenic element in the disease. We conclude that the elevated expression of this inhibitory receptor on pathogenic plasma cells was also relevant upon the murine SLE model. The mechanism of gp49B underlying the disease progression in lupus-prone mice has been discussed.

We report a new experimental approach for observing mesoscopic fluctuations underlying the thermodynamic anomalies of ambient liquid water. In this approach, two sound velocity measurements with different frequencies, namely inelastic X-ray scattering (IXS) in THz band and ultrasonic (US) in MHz band, are required to investigate the relaxation phenomenon with the characteristic frequency between the two aforementioned frequencies. We performed IXS measurements to obtain the IXS sound velocity of liquid water from the ambient conditions to the supercritical region of liquid-gas phase transition (LGT) and compared the results with the US sound velocity in the literature. We found that the ratio of the two sound velocities, Sf, which corresponds to the relaxation intensity, exhibits a simple but significant change. Two distinct rises were observed in the high-temperature and low-temperature regions, implying that two relaxation phenomena exist: in the high-temperature region, a peak was observed near the LGT critical ridge line, which was linked with changes in the density fluctuation and isochoric and isobaric specific heat capacities; in the low-temperature region, Sf increased toward the low-temperature region, which was linked with the change in the isochoric heat capacity. We concluded that these two relaxation phenomena are originated from critical fluctuations of liquid-gas phase transition (LGT) and liquid-liquid phase transition, respectively. The linkage between Sf and isochoric heat capacity in the low-temperature region proves that the relaxation is the cause of the well-known heat capacity anomaly of ambient liquid water. In this study, both LGT and LLT critical fluctuations were observed, and the relationship between thermodynamics and the critical fluctuations was comprehensively discussed.

The dynamic structure factor $S(Q,E)$, where $Q$ and $E$ are momentum and energy transfer, respectively, has been measured for liquid Sb, using inelastic x-ray scattering. A modified damped harmonic oscillator model function was applied to analyse $S(Q,E)$ of liquid Sb and also to that of liquid Bi [M. Inui et al. {\it Phys. Rev.} B {\bf 92}, 054206]. The obtained excitation energy was in fairly good agreement with that predicted by ab initio molecular dynamics simulations on these liquid semi-metals. The excitation energy of the longitudinal acoustic mode in liquid Sb and liquid Bi exhibits flat-topped $Q$ dependence whereas the lower excitation energy below the longitudinal acoustic excitation shows $Q$-gap behaviour. From the viscosity estimated from the $Q$-gap experimentally obtained, it is inferred that the lower energy excitation arises from the transverse acoustic excitation in the liquids.

Radioprotective 105 (RP105) (also termed CD180) is an orphan and unconventional Toll-like receptor (TLR) that lacks an intracellular signaling domain. The agonistic anti-RP105 monoclonal antibody (mAb) can cross-link RP105 on B cells, resulting in the proliferation and activation of B cells. Anti-RP105 mAb also has a potent adjuvant effect, providing higher levels of antigen-specific antibodies compared to alum. However, adjuvanticity is required for the covalent link between anti-RP105 mAb and the antigen. This is a possible obstacle to immunization due to the link between anti-RP105 mAb and some antigens, especially multi-transmembrane proteins. We have previously succeeded in inducing rapid and potent recombinant mAbs in mice using antibody gene-based delivery. To simplify the covalent link between anti-RP105 mAb and antigens, we generated genetic constructs of recombinant anti-RP105 mAb (αRP105) bound to the transmembrane domain of the IgG-B cell receptor (TM) (αRP105-TM), which could enable the anti-RP105 mAb to link the antigenviathe cell membrane. We confirmed the expression of αRP105-TM and the antigen hemagglutinin, which is a membrane protein of the influenza virus, on the same cell. We also found that αRP105-TM could activate splenic B cells, including both mature and immature cells, depending on the cell surface RP105in vitro. To evaluate the adjuvanticity of αRP105-TM, we conducted DNA immunization in mice with the plasmids encoding αRP105-TM and hemagglutinin, followed by challenge with an infection of a lethal dose of an influenza virus. We then obtained partially but significantly hemagglutinin-specific antibodies and observed protective effects against a lethal dose of influenza virus infection. The current αRP105-TM might provide adjuvanticity for a vaccineviaa simple preparation of the expression plasmids encoding αRP105-TM and of that encoding the target antigen.

Inelastic X-ray scattering (IXS) experiments were performed on polycrystalline Mg97Zn1Y2 and Mg85Zn6Y9 alloys with synchronized long-period stacking ordered (LPSO) phase of about 24% and 100%, respectively, together with the reference pure Mg at room temperature for investigating the impurity effects in the microscopic elastic properties of the LPSO alloys. Inelastic neutron scattering (INS) measurements were also carried out on a polycrystalline Mg97Zn1Y2 alloy. The IXS measurements were carried out for the momentum transfers Q between 1.6 and 15.9 nm−1 including the whole first- and partially second Brillouin zones, and for the energy transfers ω below 40 meV. Peaks arising from longitudinal acoustic (LA) modes were clearly observed in the IXS spectra of both the LPSO alloys and pure Mg, while transverse acoustic (TA) modes can mainly be detected in the second Brillouin zone. The dispersion relations in pure polycrystalline Mg are in good agreement with those of previous INS data on single crystal Mg. Broader inelastic signals and larger quasielastic peaks are characteristic for the LPSO alloys due to the phonon scattering by the Zn/Y impurities. Only the TA excitation energies increase by adding the impurities, which indicate a harder stiffness of the bond angles relating to the existence of the L12-type clusters in the LPSO alloys. Besides, new impurity-derived dispersion-less excitation modes are observed at about 10 meV by adding the Zn/Y impurities. By comparing with the INS data on the polycrystalline LPSO alloy, the contributions of the impurities to these excitation modes are discussed using the differences in the scattering cross-sections between neutrons and X-rays.

Kawasaki disease (KD) is an acute, systemic vasculitis syndrome that occurs in children. The clinical symptoms and epidemiologic features of KD strongly suggest that KD is triggered by unidentified infectious agents in genetically predisposed patients. In addition, a number of studies have described the role of B cells in the development of KD. To obtain a mechanistic insight into the humoral immune response of B-lineage cells in KD patients, we examined peripheral blood antibody secreting cells (ASCs) and inhibitory immunoreceptors, immunoglobulin-like transcript (ILT)/leukocyte immunoglobulin-like receptor (LILR), on each B cell subpopulation.Eighteen Japanese KD patients and thirteen healthy control subjects were recruited for this study. Their peripheral blood mononuclear cells were examined by flow cytometry for the number of CD19 B cells, the size of each B cell subset and the expression of the inhibitory isoforms of ILT/LILR on the B cell subset.The frequency of CD19CD27 ASCs was significantly increased in the acute phase of KD and reduced after high-dose intravenous immunoglobulin (IVIG) treatment. Interestingly, while ILT2/LILRB1 expression was ubiquitously observed on every B cell/ASCs subset and the level was not significantly different after IVIG, ILT3/LILRB4 (B4) was uniquely expressed on only ASCs, and its expression was significantly decreased after IVIG.In the acute phase of KD, the frequency of ASCs is high with augmented B4 expression, whereas it is lower with decreased B4 expression after IVIG. Further studies of B4 expression on ASCs in autoimmune and infectious diseases will be needed to confirm the significance of our findings.

IgE plays a key role in allergies by binding to allergens and then sensitizing mast cells through the Fc receptor, resulting in the secretion of proinflammatory mediators. Therefore, IgE is a major target for managing allergies. Previous studies have reported that oligomannose on IgE can be a potential target to inhibit allergic responses. However, enzymes that can modulate IgE activity are not yet known. Here, we found that the commercial receptor-destroying enzyme (RDE) (II) from Vibrio cholerae culture fluid specifically modulates IgE, but not IgG, and prevents the initiation of anaphylaxis. RDE (II)-treated IgE cannot access its binding site on bone marrow-derived mast cells, resulting in reduced release of histamine and cytokines. We also noted that RDE (II)-treated IgE could not induce passive cutaneous anaphylaxis in mouse ears. Taken together, we concluded that RDE (II) modulates the IgE structure and renders it unable to mediate allergic responses. To reveal the mechanism by which RDE (II) interferes with IgE activity, we performed lectin microarray analysis to unravel the relationship between IgE modulation and glycosylation. We observed that RDE (II) treatment significantly reduced the binding of IgE to Lycopersicon esculentum lectin, which recognizes poly-N-acetylglucosamine and poly-N-acetyllactosamine. These results suggest that RDE (II) specifically modulates branched glycans on IgE, thereby interfering with its ability to induce allergic responses. Our findings may provide a basis for the development of drugs to inhibit IgE activity in allergies.

Inelastic x-ray scattering measurements using high-pressure apparatus were carried out for liquid Te up to 1673 K above the boiling point at the normal pressure. We could obtain the dynamic structure factor S(Q,E) of good quality at 1.8 ≤ Q ≤ 22 nm−1. Although the excitation energies of the acoustic mode are fluctuating more at lower temperatures, we found that the dynamical sound speed at 1.8 and 2.1 nm−1 becomes fast with increasing temperature from 773 to 923 K, similarly to the temperature dependence of ultrasonic sound speed in liquid Te. Despite this unusual temperature dependence at the lowest Q, the sound speed at higher Q is consistent with those obtained by the previous inelastic neutron and x-ray scattering studies, in which the dynamical sound just slows down with increasing temperature. The present results may be correlated with the temperature-driven semiconductor-metal transition in liquid Te, and if so, it is inferred that a domain size of inhomogeneity induced with the transition is comparable to the wave length corresponding to the lowest Q. Keywords: Inelastic x-ray scattering, Atomic dynamics, Collective mode, Semiconductor-metal transition, Liquid chalcogen

Extracellular matrix (ECM) not only provides a supporting framework for each tissue, but also elicits cellular responses by providing an inductive substrate. Fibronectin (FN), a major ECM macromolecule, is composed of multiple modules that interact with ECM-associated proteins, plasma proteins, and cell-surface proteins to ensure its modulatory roles. Here we revealed that FN is identified as a physiological ligand of the immunoglobulin (Ig)-like transcript 3/leukocyte Ig-like receptor B4 (ILT3/LILRB4) which serves as an immune checkpoint for autoimmune and cancer diseases. Human LILRB4 and the murine ortholog, gp49B, bound FN with sub-micromolar affinities as assessed by bio-layer interferometry. The major LILRB4-binding site in FN was located at the N-terminal 30-kDa module (FN30). Blockade of B4–FN binding with gp49 antibody or a recombinant FN30-Fc fusion protein reduced the secretion of pathogenic IgG autoantibodies, thereby reducing PAS-positive glomerular deposition in lupus-prone BXSB/Yaa mice. Compared with the control group, activation-induced cytidine deaminase (AID) expression in splenic activated B cells of FN30-Fc-treated BXSB/Yaa mice was decreased, indicating gp49B-FN30 signaling contributes in the class switch recombination (CSR) of Ig genes. These results suggested that gp49B–FN interplay is critical for pathogenic autoantibodies-mediated glomerulonephritis in the BXSB/Yaa lupus mouse model.

To clarify microscopic elastic properties of a Pd40Ni40P20 bulk metallic glass, inelastic X-ray scattering (IXS) experiments were carried out using high-resolution IXS spectrometer installed at BL35XU/SPring-8. Clear longitudinal acoustic (LA) excitation modes are observed in the whole momentum transfer Q range up to ~22 nm-1. The microscopic sound velocity of the LA modes obtained from the Q → 0 limit of the dispersion relation is about 12% faster than the macroscopic value, suggesting the microscopic heterogeneity in the elastic properties of this BMG. In addition, transverse acoustic (TA) modes can be deduced from a detailed analysis of the IXS spectra. The microscopic Poisson’s ratio obtained from the ratio of the excitation energies of the TA and LA modes is 0.47 ± 0.04, larger than the macroscopic value of 0.40. Thus, the fragile nature of this BMG already found in the macroscopic sense is much enhanced in the microscopic view.

Plasmablasts and plasma cells (PBs and PCs) producing pathogenic auto-antibodies in patients with systemic autoimmune diseases could be a better target for specific therapies for the disease than general immunosuppression or pan- or activated B-cell targeting. Our previous study indicated that leukocyte immunoglobulin-like receptor (LILR) B4 (B4, also known as ILT3/LIR-5/CD85k), a tolerogenic receptor in antigen-presenting cells, is ectopically expressed on the PB/PC surface in healthy individuals. Here, we show that the enlarged population size of PBs/PCs with augmented B4 expression is characteristic in non-treated systemic lupus erythematosus (SLE). Paradoxically, the transcription frequency of the anti-double-strand DNA immunoglobulin-coding VH sequence in the B4+ population of non-treated SLE was significantly higher than that in B4− cells. B4+ and B4− PBs/PCs were suggested to be developmentally equivalent based on the simultaneous generation of these populations upon activation of memory B cells in vitro. B4 expression was found to be induced efficiently by IL-2, while IFN-α effectively induced B4+ PBs/PCs in vitro. Utilizing the elevated B4 will support opening a new avenue for identifying the mechanism for generation of, and additional molecular markers for, pathogenic cells.

The design and implementation of a furnace for inelastic x-ray scattering from liquids with sample temperatures up to ~1600C is described. Carbon composite heaters operating in vacuum provide robust heating elements: one pair of heaters has been used for >18 days of operational time above 1500C, including 8 cycles to room temperature. High quality data has been obtained to scattering angles as low as 7 mrad in two-theta (Q, 15 pages, 8 Figures, Proceeding of NCM 14

Inelastic x-ray scattering (IXS) measurements were carried out on liquid Se50Te50 at temperatures up to 1323 K to investigate how the atomic dynamics changes with temperature through the semiconductor-metal transition. The acoustic mode was clearly observed in the dynamic structure factor and its energy was determined using a damped harmonic oscillator model. The dynamical sound speed obtained by IXS for [Formula: see text] nm-1 was found to behave similarly to the temperature dependence of ultrasonic sound velocity with a minimum near the semiconductor metal transition. The results can be explained by taking liquid Se50Te50 to be an inhomogeneous liquid consisting of metallic and semiconducting domains whose size is approximately 3 nm. The relaxation time obtained from frequency dependence of the dynamical sound speed was on a picosecond time scale.

Bee venom (BV) induces skin inflammation, characterized by erythema, blisters, edemas, pain and itching. Although BV has been found to have an inhibitory effect on toll-like receptors (TLRs), we here show that BV enhances keratinocyte responses to polyinosinic-polycytidylic acid [poly(I:C)], a ligand for TLR3. Our results revealed that the enhanced TLR activity was primarily induced by secretory phospholipase A2 (sPLA2), a component of BV (BV-sPLA2). PLA2 mediates the hydrolysis of membrane phospholipids into lysophospholipids and free fatty acids. We demonstrated that BV-sPLA2 increased the intracellular uptake of poly(I:C), phosphorylation of the nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs), and poly(I:C)-mediated interleukin 8 production in human keratinocytes. We further showed that the enzymatic activity of BV-sPLA2 was essential for the increased uptake of poly(I:C). These findings suggest that BV-sPLA2 may induce a modification of the cell membrane structure, leading to enhanced poly(I:C) uptake in keratinocytes. BV-sPLA2 might be able to promote wound healing by enhancing TLR3 responses.

Collective dynamics in liquid GeTe was investigated by inelastic x-ray scattering at $2\ensuremath{\le}Q\ensuremath{\le}31\phantom{\rule{4pt}{0ex}}{\mathrm{nm}}^{\ensuremath{-}1}$. The dynamic structure factor shows clear inelastic excitations. The excitation energies at low $Q$ disperse with increasing $Q$, consistent with the behavior of a longitudinal-acoustic excitation. The dispersion curve has a flat-topped region around the pseudo-Brillouin-zone boundary, similar to what is observed in liquid Bi [Inui et al., Phys. Rev. B 92, 054206 (2015)]. The dynamic structure factor shows a low-frequency excitation, and its coupling with the longitudinal-acoustic mode plays an important role for a flat-topped dispersion. From these results, it is inferred that atomic dynamics in liquid GeTe is strongly affected by a Peierls distortion similar to liquid Bi. By comparing the momentum transfer dependence of the excitation energy and quasielastic linewidth to partial structure factors obtained by our own ab initio molecular dynamics simulation for liquid GeTe, the quasielastic and inelastic components were found to be correlated with Te-Te and Ge-(Ge,Te) partial structure factors, respectively.

Plasma cells (PCs) acquiring long lifespans in the bone marrow (BM) play a pivotal role in the humoral arm of immunological memory. The PCs reside in a special BM niche and produce antibodies against past-encountered pathogens or vaccine components for a long time. In BM, cysteine-X-cysteine (CXC) chemokine receptor type 4 (CXCR4)-expressing PCs and myeloid cells such as dendritic cells are attracted to and held by CXC chemokine ligand 12 (CXCR12)-secreting stromal cells, where survival of the PCs is supported by soluble factors such as IL-6 and APRIL (a proliferation-inducing ligand) produced by neighboring myeloid cells. Although these stromal cells are also supposed to be involved in the support of the survival and antibody production, the full molecular mechanism has not been clarified yet. Here, we show that BM PDGFRα+Sca-1+-enriched mesenchymal stem cells (MSCs), which can contribute as stromal cells for hematopoietic stem cells, also support in vitro survival of and antibody production by BM PCs. IL-6 produced by MSCs was found to be involved in the support. Immunohistochemistry of BM sections suggested a co-localization of a minor population of PCs with PDGFRα+Sca-1+ MSCs in the BM. We also found that the sort-purified MSC preparation was composed of multiple cell groups with different gene expression profiles, as found on single-cell RNA sequencing, to which multiple roles in the in vitro PC support could be attributed.

TLRs are distributed in their characteristic cellular or subcellular compartments to efficiently recognize specific ligands and to initiate intracellular signaling. Whereas TLRs recognizing pathogen-associated lipids or proteins are localized to the cell surface, nucleic acid–sensing TLRs are expressed in endosomes and lysosomes. Several endoplasmic reticulum (ER)–resident proteins are known to regulate the trafficking of TLRs to the specific cellular compartments, thus playing important roles in the initiation of innate immune responses. In this study, we show that an ER-resident protein, Nogo-B (or RTN4-B), is necessary for immune responses triggered by nucleic acid–sensing TLRs, and that a newly identified Nogo-B–binding protein (glucosyltransferases, Rab-like GTPase activators and myotubularins [GRAM] domain containing 4 [GRAMD4]) negatively regulates the responses. Production of inflammatory cytokines in vitro by macrophages stimulated with CpG-B oligonucleotides or polyinosinic:polycytidylic acid was attenuated in the absence of Nogo-B, which was also confirmed in serum samples from Nogo-deficient mice injected with polyinosinic:polycytidylic acid. Although a deficiency of Nogo-B did not change the incorporation or delivery of CpG to endosomes, the localization of TLR9 to endolysosomes was found to be impaired. We identified GRAMD4 as a downmodulator for TLR9 response with a Nogo-B binding ability in ER, because our knockdown and overexpression experiments indicated that GRAMD4 suppresses the TLR9 response and knockdown of Gramd4 strongly enhanced the response in the absence of Nogo-B. Our findings indicate a critical role of Nogo-B and GRAMD4 in trafficking of TLR9.

A pressure-induced structural change of a polymer isotactic poly(4-methyl-1-pentene) (P4MP1) in the melted state at 270 °C has been investigated by high-pressure in situ x-ray diffraction, where high pressures up to 1.8 kbar were applied using helium gas. The first sharp diffraction peak (FSDP) position of the melt shows a less pressure dependence than that of the normal compression using a solid pressure transmitting medium. The contraction using helium gas was about 10% at 2 kbar, smaller than about 20% at the same pressure using a solid medium. The result indicates that helium entered the interstitial space between the main chains. The helium/monomer molar ratio was estimated to be 0.3 at 2 kbar from the FSDP positions. These results suggest that the compressibility of the P4MP1 melt can be largely dependent on the pressure transmitting media. As the pore size is reversibly and continuously controllable by compression, we suggest that the P4MP1 melt can be an ideal porous liquid for investigating a novel mechanical response of the pores in a non-crystalline substance.

Fluid metals exhibit significant properties of thermodynamic-state dependence, since the inter-particle interaction among the constituents (electrons and ions) considerably changes depending on their thermodynamic conditions. The authors have thus far carried out X-ray scattering experiments of fluid metals in the expanded state, which have enabled them to gain insight into microscopic understanding of the structural and electronic properties of fluid metals. The purpose of this chapter is to provide intriguing aspects of fluid metals originated from the existence of conduction electrons, which distinguishes fluid metals from non-conducting fluids, through the results of fluid rubidium and mercury.

Inelastic x-ray scattering spectra of fluid S were measured from 403 K near the melting point to 1343 K in the supercritical region at 25 MPa. Although the dynamic structure factor in the supercritical region exhibits a single peak profile, the spectrum includes collective inelastic excitations besides the quasielastic component. The acoustic excitation energy in the supercritical region is close to the one predicted by the sound speed in the fluid consisting of S8 molecules and the observed excitation energies of the stretching modes in S molecules suggest that few fraction of S2 molecules in the supercritical region near the liquid-vapor critical point. This result indicates that the nearest neighbor coordination number in the supercritical fluid S obtained by x-ray diffraction [Inui et al., J. Phys. Conf. Ser. 98 (2008) 012008] was underestimated.

X-ray scattering experiments for liquid As 2 Se 3 were carried out at high temperatures up to 1673 K at 6 MPa, using synchrotron radiation at SPring-8 in Japan, and the structure factor with reasonably nice statistics is obtained. The first peak position in the pair distribution function slightly shifts to smaller distance and the first minimum at 2.7 A develops, as the metallic properties are enhanced with increasing temperatures. A first sharp diffraction peak at 1.2 A − 1 in the structure factor becomes broad with an increasing temperature. The partial structure factors in liquid As 2 Se 3 were deduced by Reverse Monte Carlo modeling constrained by partial coordination number fractions reported by the first principles molecular dynamics simulations. Chemical order correlated with the medium range order expected by the first sharp diffraction peak is discussed on the basis of results from the Reverse Monte Carlo modeling.

A therapeutic preparation of polyclonal human IgG, i.e., intravenous immunoglobulin (IVIg), has been employed to treat several inflammatory and autoimmune disorders. B cells are supposed to be a target of IVIg, but the molecular mechanism is elusive because of the lack of a suitable experimental system. To gain an insight into the beneficial effect of IVIg on B cells, we first established an experimental setting in which IVIg modulates a murine B cell function in vitro, and then aimed at identifying the mechanistic features at the molecular level. Here we show that IVIg down-regulates IL-10 production by CpG-activated B cells in vitro. The responsible component of IVIg was identified as the F(ab’)2 portion, whose polyclonality is mandatory for the suppressive effect. IVIg, bound to the surface of activated B cells, was found to be co-localized with intracellular SHP-1 on confocal laser microscopy, suggesting that B cell-surface immunoreceptor tyrosine-based inhibitory motif-harboring receptors that recruit SHP-1 are target molecules for IVIg in our experimental setting. Overall, we postulate a scenario in which IVIg attenuates B cells by suppressing IL-10 production, a B cell growth factor, and thus down-regulates the production of pathogenic antibodies.

Liquid As2Se3 undergoes the semiconductor-metal transition with increasing temperature when pressure is applied to avoid evaporation of the liquid. To investigate the atomic dynamics of liquid As2Se3, we have carried out inelastic x-ray scattering experiments of this system at 1073 K and 6 MPa and obtained the dynamic structure factor S(Q,E), from approximately 1.6 nm−1 to 11 nm−1, where Q and E are momentum and energy transfer, respectively. The excitation energy in the semiconducting state at 1073 K disperses as fast as the ultrasonic sound velocity at Q 2.9 nm−1 it disperses approximately 1.8 times faster. We analyzed S(Q,E) at 1073 K using a simple viscoelastic model and discussed Q dependence of the propagation of the acoustic mode.

We have carried out x-ray diffraction and small-angle x-ray scattering measurements of expanded fluid alkali metal rubidium (Rb) and observed that the nearest neighbor distance decreases despite the fact that the average interatomic distance increases with volume expansion, indicating that the attractive force among ions is enhanced. Such structural change emerges in the density range where the fluid is still metallic. The density range also corresponds with the region where the instability of the electron gas has been theoretically predicted, suggesting the modulation in the charge fluctuations of the electron gas plays an essential role for such enhanced attraction among ions. Motivated by these unusual structural features, we have moved on investigating the electronic state in expanded fluid Rb through synchrotron-based high-resolution Compton scattering experiments. We have succeeded in measuring the Compton profile of fluid Rb using newly developed a high-pressure vessel for the Compton scattering experiments.

The transverse acoustic excitation modes were detected by inelastic x-ray scattering in liquid Ga in the Q range above 9 nm−1 although liquid Ga is mostly described by a hard-sphere liquid. An ab initio molecular dynamics simulation clearly supports this finding. From the detailed analysis for the S(Q,ω) spectra with a good statistic quality, the lifetime of 0.5 ps and the propagating length of 0.4–0.5 nm can be estimated for the transverse acoustic phonon modes, which may correspond the lifetime and size of cages formed instantaneously in liquid Ga. The microscopic Poisson’s ratio estimated from the dynamic velocities of sound is 0.42, indicating a rubber-like soft elastic property of the cages.

The injection of Clostridium difficile toxin A into the ileal loops caused fluid accumulation with the destruction of intestinal epithelial structure and the recruitment of neutrophils and macrophages. Concomitantly, intraileal gene expression of CX3CL1/fractalkine (FKN) and its receptor, CX3CR1, was enhanced. When treated with toxin A in a similar manner, CX3CR1-deficient (CX3CR1−/−) mice exhibited exaggerated fluid accumulation, histopathological alterations, and neutrophil recruitment, but not macrophage infiltration. Mice reconstituted with CX3CR1−/− mouse-derived bone marrow cells exhibited exacerbated toxin A-induced enteritis, indicating that the lack of the CX3CR1 gene for hematopoietic cells aggravated toxin A-induced enteritis. A heme oxygenase-1 (HO-1) inhibitor, tin-protoporphyrin-IX, markedly increased fluid accumulation in toxin A-treated wild-type mice, indicating the protective roles of HO-1 in this situation. HO-1 expression was detected mainly in F4/80-positive cells expressing CX3CR1, and CX3CR1−/− mice failed to increase HO-1 expression after toxin A treatment. Moreover, CX3CL1/FKN induced HO-1 gene expression by isolated lamina propria-derived macrophages or a mouse macrophage cell line, RAW264.7, through the activation of the ERK signal pathway. Thus, CX3CL1/FKN could induce CX3CR1-expressing macrophages to express HO-1, thereby ameliorating toxin A-induced enteritis.

Atomic motions and, especially, correlations in atomic motion over angstrom length scales are a sensitive probe of material properties: phonons in single crystals respond to the detailed interactions between atoms, including both short- and long-range forces, and screening thereof, while the atomic dynamics of liquids is intimately connected with nearly all aspects of liquid behavior. Scientific questions associated with measuring dynamics include the detailed nature of phase transitions, correlations of atomic motions with electronic or magnetic properties (superconductivity, ferro-electric behavior, magnetoelastic coupling, etc.), and also very practical issues, such as investigating elasticity. Not surprisingly, both from the point of view of basic science and for applications such as geology, there is strong desire to extend studies of atomic dynamics throughout material phase diagrams, into extreme conditions.

X-ray diffraction and inelastic x-ray scattering measurements of liquid Ba8Ga16Sn30 have been carried out to investigate local structure and atomic dynamics in the liquid. The pair distribution function shows shorter and longer interatomic distances in the first coordination shell. The dynamic structure factor exhibits the inelastic excitations on both sides of the quasielastic central peak. The inelastic excitations disperse with increasing the momentum transfer, suggesting the longitudinal acoustic mode. We found a low energy excitation in addition to the longitudinal acoustic excitation in the dynamic structure factor and it reminds us a strong relationship with a rattling motion of a guest (Ba) atom in the solid state. The temperature dependence of the pair distribution function and the longitudinal acoustic excitation energy is very weak in a range from 600 to 900 °C. The result suggests that Ba and other atoms in the melt are located around minimum positions of the effective pair potential approximated as a harmonic one.

Inelastic X-ray scattering measurements have been carried out to investigate the energy and line width of plasmons in liquid Rb at elevated temperatures (300 and 500 °C). The plasmon energy decreas...

We investigate the dynamic structure factor of the melt of the well known glass former, As2Se3, using inelastic x-ray scattering for temperatures, T, [Formula: see text] K and momentum transfers Q from [Formula: see text] nm-1. An anomaly was observed at Q = 2.7 nm-1 ([Formula: see text] K) with, in the context of a simple model, both an abrupt change in frequency and an increased linewidth reminiscent of an anti-crossing in a solid. Comparison with structural information from reverse Monte Carlo modeling of x-ray diffraction data allows us to associate the disappearance of the anomaly at higher temperatures with a drop in the number of mechanical constraints per atom, n mc, to [Formula: see text] reminiscent of the threshold applicable for glass formation in rigidity theory. It is inferred that the surprising jump in the dispersion in the liquid may be correlated with a stiffness transition in a network glass.

X-ray Compton scattering measurements have been carried out on germanium (Ge) and tin (Sn) in the solid and liquid states. While the shape of the Compton profiles (CPs) of Ge reflects the semiconductor-to-metal transition upon melting, it was found that even for Sn, which remains metallic during the solid–liquid phase transition, the shape of the CP in the liquid state exhibits more metallic characteristics than that in the solid state. The experimentally derived Fermi momenta of liquid Ge and Sn have systematically higher values than those of the electron gas at corresponding electron densities, which indicates a non-simple metallic nature of the group IV elements in the liquid state.

Osteoclasts, cells of myeloid lineage, play a unique role in bone resorption, maintaining skeletal homeostasis in concert with bone-producing osteoblasts. Osteoclast development and maturation (osteoclastogenesis) is driven by receptor activator of NF-κB ligand and macrophage-colony stimulating factor and invariably requires a signal initiated by immunoreceptor tyrosine-based activation motif (ITAM)-harboring Fc receptor common γ chain or DNAX-activating protein (DAP)12 (also referred to as KARAP or TYROBP) that associates with the cognate immunoreceptors. Here, we show that a third adaptor, YINM costimulatory motif-harboring DAP10, triggers osteoclastogenesis and bone remodeling. DAP10-deficient (DAP10−/−) mice become osteopetrotic with age, concomitant with a reduction in osteoclasts. The DAP10-associating receptor was identified as myeloid DAP12-associating lectin-1 (MDL-1), whose physiologic function has not been found. MDL-1-mediated stimulation of osteoclast precursor cells resulted in augmented osteoclastogenesis in vitro. MDL-1 associates with both DAP12 and DAP10 in osteoclasts and bone marrow-derived macrophages, where DAP10 association depends almost entirely on DAP12, suggesting a formation of MDL-1–DAP12/DAP10 trimolecular complexes harboring ITAM/YINM stimulatory/costimulatory motifs within a complex that could be a novel therapeutic target for skeletal and inflammatory diseases.