Depletion of invariant NKT cells reduces inflammation-induced preterm delivery in mice

This study sought to determine whether invariant NKT (iNKT) cells play an essential role in inflammation-induced preterm delivery. Preterm delivery and fetal death rates were determined in wild-type (WT) C57BL/6 mice and iNKT cell-deficient Jα18(-/-) mice injected i.p. with LPS. The percentages of decidual immune cells, including activated subsets, and costimulatory molecule expression were analyzed by flow cytometry. Th1 and Th2 cytokine production in the culture supernatants of decidual mononuclear cells was measured by ELISA. To some extent, Jα18(-/-) mice were resistant to LPS-induced preterm delivery. The proportions of decidual CD3(+) and CD49b(+) cells were slightly lower in Jα18(-/-) mice than in WT Jα18(+/+) mice, whereas almost no CD3(+)CD49b(+) cells could be found in Jα18-null mice. The percentages of activated decidual DCs, T cells, and NK cells were significantly lower in LPS-treated Jα18(-/-) mice than in WT mice. The CD40, CD80, and CD86 expression levels on decidual CD11c(+) cells from Jα18(-/-) mice were also significantly lower than in WT mice. Mean concentrations of Th1 cytokines IFN-γ and IL-12p70 in the culture supernatants of decidual mononuclear cells from LPS-treated Jα18(-/-) mice were apparently lower than those of LPS-induced WT mice. Additionally, the proportions of activated CD11c(+) cells, CD3(+) cells, and CD49b(+) cells in LPS-induced preterm delivery mice were strikingly higher in both WT and null mice when compared with the control PBS group and LPS-injected but normally delivered mice. Our results suggest that iNKT cells may play an essential role in inflammation-induced preterm birth.     

Isolation and Sugar Composition of Blood Group H-Like Substance from Seeds of Euonymus Sieboldiana

Blood group H-like polysaccharides were isolated from seeds of Euonymus Sieboldiana by a procedure that included fractionation with (NH₄)SO₄, heat treatment, chromatography on DEAE-cellulose and gel filtration on Bio-Gel P-150. One of the highly purified polysaccharide fractions was composed of arabinose, mannose, glucose, rhamnose, galactose and fucose. Arabinose and mannose were the main components, and their molar ratio was calculated as about 3: 1 by gas chromatographic analysis. An analytical ultracentrifugal experiment revealed that the finally purified H-like substance was close to an homogeneous preparation with a small disperse fraction. This heteropolysaccharide inhibited the haemagglutination of human group O red blood cells and eel anti-H serum minimally at 0.004 mg/ml, reacted also with the eel anti-H serum on an immunodiffusion plate to form sharp precipitin line(s).     

Impact of Histone H1 on the Progression of Allergic Rhinitis and Its Suppression by Neutralizing Antibody in Mice

Nuclear antigens are known to trigger off innate and adaptive immune responses. Recent studies have found that the complex of nucleic acids and core histones that are derived from damaged cells may regulate allergic responses. However, no fundamental study has been performed concerning the role of linker histone H1 in mast cell-mediated type I hyperreactivity. In this study, we explored the impact of histone H1 on mast cell-mediated allergic responses both in vitro and in vivo. In the course of a bona-fide experimental allergen sensitization model upon co-injection with alum adjuvant, ovalbumin (OVA), but not PBS, induced elevated levels of circulating histone H1. Intranasal challenge with histone H1 to OVA/alum- (but not PBS/alum)-sensitized mice induced significantly severer symptoms of allergic rhinitis than those in mice sensitized and challenged with OVA. A monoclonal antibody against histone H1 not only suppressed mast cell degranulation, but also ameliorated OVA-induced nasal hyperreactivity and IgE-mediated passive cutaneous anaphylaxis. Our present data suggest that nuclear histone H1 represents an alarmin-like endogenous mediator acting on mast cells, and that its blockage has a therapeutic potential for mast cell-mediated type I hyperreactivity.     

Intracoronary artery transplantation of cardiomyoblast-like cells from human adipose tissue-derived multi-lineage progenitor cells improve left ventricular dysfunction and survival in a swine model of chronic myocardial infarction

Transplantation of human cardiomyoblast-like cells (hCLCs) from human adipose tissue-derived multi-lineage progenitor cells improved left ventricular function and survival of rats with myocardial infarction. Here we examined the effect of intracoronary artery transplantation of human CLCs in a swine model of chronic heart failure. Twenty-four pigs underwent balloon-occlusion of the first diagonal branch followed by reperfusion, with a second balloon-occlusion of the left ascending coronary artery 1week later followed by reperfusion. Four weeks after the second occlusion/reperfusion, 17 of the 18 surviving animals with severe chronic MI (ejection fraction <35% by echocardiography) were immunosuppressed then randomly assigned to receive either intracoronary artery transplantation of hCLCs hADMPCs or placebo lactic Ringer's solution with heparin. Intracoronary artery transplantation was followed by the distribution of DiI-stained hCLCs into the scarred myocardial milieu. Echocardiography at post-transplant days 4 and 8weeks showed rescue and maintenance of cardiac function in the hCLCs transplanted group, but not in the control animals, indicating myocardial functional recovery by hCLCs intracoronary transplantation. At 8week post-transplantation, 7 of 8 hCLCs transplanted animals were still alive compared with only 1 of the 5 control (p=0.0147). Histological studies at week 12 post-transplantation demonstrated engraftment of the pre DiI-stained hCLCs into the scarred myocardium and their expression of human specific alpha-cardiac actin. Human alpha cardiac actin-positive cells also expressed cardiac nuclear factors; nkx2.5 and GATA-4. Our results suggest that intracoronary artery transplantation of hCLCs is a potentially effective therapeutic strategy for future cardiac tissue regeneration.     

Overexpression of an ADP-ribose pyrophosphatase, AtNUDX2, confers enhanced tolerance to oxidative stress in Arabidopsis plants

Mutant pqr-216 from an Arabidopsis activation-tagged line showed a phenotype of increased tolerance to oxidative stress after treatment with 3 μ m paraquat (PQ). Based on the phenotype of transgenic plants overexpressing the genes flanking the T-DNA insert, it was clear that enhanced expression of a Nudix (nucleoside diphosphates linked to some moiety X) hydrolase gene, AtNUDX2 (At5g47650), was responsible for the tolerance. It has been reported that the AtNUDX2 protein has pyrophosphatase activities towards both ADP-ribose and NADH ( Ogawa et al ., 2005 ). Interestingly, the pyrophosphatase activity toward ADP-ribose, but not NADH, was increased in pqr-216 and Pro _35S :AtNUDX2 plants compared with control plants. The amount of free ADP-ribose was lower in the Pro _35S :AtNUDX2 plants, while the level of NADH was similar to those in control plants under both normal conditions and oxidative stress. Depletion of NAD⁺ and ATP resulting from activation of poly(ADP-ribosyl)ation under oxidative stress was observed in the control Arabidopsis plants. Such alterations in the levels of these molecules were significantly suppressed in the Pro _35S :AtNUDX2 plants. The results indicate that overexpression of AtNUDX2 , encoding ADP-ribose pyrophosphatase, confers enhanced tolerance of oxidative stress on Arabidopsis plants, resulting from maintenance of NAD⁺ and ATP levels by nucleotide recycling from free ADP-ribose molecules under stress conditions.     

Pulmonary surfactant protein D binds MD-2 through the carbohydrate recognition domain

Pulmonary surfactant protein D (SP-D) is a member of the collectin family and plays crucial roles in the innate immunity of the lung. We have previously shown that surfactant protein A (SP-A), a homologous collectin, interacts with MD-2 and alters lipopolysaccharide signaling. In this study, we examined and characterized the binding of SP-D to MD-2 using a soluble form of recombinant MD-2 (sMD-2). SP-D bound in a concentration- and Ca(2+)-dependent manner to sMD-2 coated onto microtiter wells. Excess mannose abolished the binding of SP-D to sMD-2. In solution, SP-D cosedimented with sMD-2 in the presence of Ca(2+). The direct binding of SP-D to sMD-2 was confirmed by BIAcore analysis. Anti-SP-D monoclonal antibody that recognizes the carbohydrate recognition domain (CRD) of SP-D significantly inhibited the binding of SP-D to sMD-2, indicating the involvement of the CRD for the binding to sMD-2. Ligand blot analysis revealed that SP-D bound to N-glycopeptidase F-treated sMD-2. In addition, the biotinylated SP-D pulled down the mutant sMD-2 with Asn(26) --> Ala and Asn(114) --> Ala substitutions, which lacks the consensus for N-glycosylation. Furthermore, the sMD-2 mutant cosedimented SP-D. These results demonstrate that SP-D directly interacts with MD-2 through the CRD.     

Hydrogen-Deuterium Exchange Effects on β-Endorphin Release from AtT20 Murine Pituitary Tumor Cells

Abundant evidences demonstrate that deuterium oxide (D₂O) modulates various secretory activities, but specific mechanisms remain unclear. Using AtT20 cells, we examined effects of D₂O on physiological processes underlying β-endorphin release. Immunofluorescent confocal microscopy demonstrated that 90% D₂O buffer increased the amount of actin filament in cell somas and decreased it in cell processes, whereas β-tubulin was not affected. Ca²⁺ imaging demonstrated that high-K⁺-induced Ca²⁺ influx was not affected during D₂O treatment, but was completely inhibited upon D₂O washout. The H₂O/D₂O replacement in internal solutions of patch electrodes reduced Ca²⁺ currents evoked by depolarizing voltage steps, whereas additional extracellular H₂O/D₂O replacement recovered the currents, suggesting that D₂O gradient across plasma membrane is critical for Ca²⁺ channel kinetics. Radioimmunoassay of high-K⁺-induced β-endorphin release demonstrated an increase during D₂O treatment and a decrease upon D₂O washout. These results demonstrate that the H₂O-to-D₂O-induced increase in β-endorphin release corresponded with the redistribution of actin, and the D₂O-to-H₂O-induced decrease in β-endorphin release corresponded with the inhibition of voltage-sensitive Ca²⁺ channels. The computer modeling suggests that the differences in the zero-point vibrational energy between protonated and deuterated amino acids produce an asymmetric distribution of these amino acids upon D₂O washout and this causes the dysfunction of Ca²⁺ channels.     

Differential gene expression profiling between wild-type and ALAS2-null erythroblasts: identification of novel heme-regulated genes

To identify erythroid-specific heme-regulated genes, we performed differential expression analysis between wild-type and heme-deficient erythroblasts, which had been prepared from wild-type and erythroid-specific delta-aminolevulinate synthase-null mouse ES cells, respectively. Among 8737 clones on cDNA array, 40 cDNA clones, including 34 unknown ESTs, were first selected by their high expression profiles in wild-type erythroblasts, and evaluated further for their erythroid-lineage specificity, expression in hematopoietic tissues in vivo, and heme-dependent expression, which yielded 11, 4, and 4 genes, respectively. Because of the selection strategy employed, the final 4 were considered as the newly identified erythroid-specific heme-regulated genes. These 4 genes were uncoupling protein 2, nucleolar spindle-associated protein, cellular nucleic acid-binding protein, and a novel acetyltransferase-like protein. These findings thus suggest that heme may regulate a wide variety of hitherto unrecognized genes, and further analysis of these genes may clarify their role in erythroid cell differentiation.     

Comparison of cell lines for stable production of fucose-negative antibodies with enhanced ADCC

Several methods have been described to enhance antibody-dependent cellular cytotoxicity (ADCC) using different host cells that produce antibody with reduced levels of fucose on their carbohydrates. We compared the suitability of these methods for the serum-free fed-batch production of antibody for clinical trials and commercial uses. Recombinant anti-human CD20 chimeric IgG1-producing clones were established from host-cells that have been shown to produce more than 90% fucose-negative antibody. The cell lines were a FUT8 (alpha-1,6-fucosyltransferase) knockout Chinese hamster ovary (CHO) cell line, Ms704, and two Lens culinaris agglutinin (LCA)-resistant cell lines, one derived from a variant CHO line, Lec13 and the other from a rat hybridoma cell line, YB2/0. The amount of fucose-negative antibody produced by Lec13 and YB2/0 significantly decreased with the culture. The increase in fucosylation was due to remaining synthesis of GDP-fucose via de novo pathway for the CHO line and the elevation of FUT8 expression by the YB2/0 cells. In contrast, Ms704 cells stably produced fucose-negative antibody with a consistent carbohydrate structure until the end of the culture. The productivity of the Ms704 cells reached 1.76 g/L with a specific production rate (SPR) of 29 pg/cell/day for 17 days in serum-free fed-batch culture using a 1 L spinner bioreactor. Our results demonstrate that FUT8 knockout has the essential characteristics of host cells for robust manufacture of fucose-negative therapeutic antibodies with enhanced ADCC.