Medium modification of jet fragmentation in Au+Au collisions at √[s(NN)]=200 GeV measured in direct photon-hadron correlations

The jet fragmentation function is measured with direct photon-hadron correlations in p+p and Au+Au collisions at √[s(NN)]=200 GeV. The p(T) of the photon is an excellent approximation to the initial p(T) of the jet and the ratio z(T)=p(T)(h)/p(T)(γ) is used as a proxy for the jet fragmentation function. A statistical subtraction is used to extract the direct photon-hadron yields in Au+Au collisions while a photon isolation cut is applied in p+p. I(AA), the ratio of hadron yield opposite the photon in Au+Au to that in p+p, indicates modification of the jet fragmentation function. Suppression, most likely due to energy loss in the medium, is seen at high z(T). The associated hadron yield at low z(T) is enhanced at large angles. Such a trend is expected from redistribution of the lost energy into increased production of low-momentum particles.

Migratory properties of pulmonary dendritic cells are determined by their developmental lineage

The chemokine receptor, CCR7, directs the migration of dendritic cells (DCs) from peripheral tissue to draining lymph nodes (LNs). However, it is unknown whether all pulmonary DCs possess migratory potential. Using novel Ccr7(gfp) reporter mice, we found that Ccr7 is expressed in CD103⁺ and a CD14(med/lo) subset of CD11b(hi) classical (c)DCs but not in monocyte-derived (mo)DCs, including Ly-6C(hi)CD11b(hi) inflammatory DCs and CD14(hi)CD11b(hi) DCs. Consequently, cDCs migrated to lung-draining LNs but moDCs did not. Mice lacking the chemokine receptor, CCR2, also lacked inflammatory DCs in the lung after lipopolysaccharide inhalation but retained normal levels of migratory DCs. Conversely, the lungs of fms-like tyrosine kinase 3 ligand (Flt3L)-deficient mice lacked cDCs but retained moDCs, which were functionally mature but did not express Ccr7 and were uniformly non-migratory. Thus, the migratory properties of pulmonary DCs are determined by their developmental lineage.

Aggravation of inflammatory bowel diseases by oral streptococci

OBJECTIVES

Streptococcus mutans can aggravate colitis in mice. We evaluated the virulence of colitis using type strains as well as blood isolates of several oral streptococcal species.

MATERIALS AND METHODS

We investigated the susceptibility of blood isolates of several oral streptococci to phagocytosis, adhesion to and invasion of hepatic cells and interferon-γ secretion. A mouse model of dextran sodium sulphate-induced colitis was used to evaluate bacterial aggravation of colitis. In addition, interferon-γ antibody was administered to mice with prominent aggravation of colitis.

RESULTS

In vitro analyses showed that Streptococcus sanguinis ATCC 10556 was a possible virulent strain among type strains of several oral streptococci, and that analysis of blood isolates of S. sanguinis TW289 revealed a potential virulent strain. Intravenous administration of ATCC 10556 and TW289 caused prominent aggravation of dextran sodium sulphate-induced colitis, and histopathological examinations showed that interferon-γ secretion due to infection of hepatic cells caused colitis aggravation. Administration of interferon-γ antibody suppressed TW289-induced colitis.

CONCLUSION

These results suggest that some virulent oral streptococcal strains are associated with the aggravation of colitis induced by enhanced secretion of interferon-γ when they invade the bloodstream.

Advancing pig cloning technologies towards application in regenerative medicine

Regenerative medicine is expected to make a significant contribution by development of novel therapeutic treatments for intractable diseases and for improving the quality of life of patients. Many advances in regenerative medicine, including basic and translational research, have been developed and tested in experimental animals; pigs have played an important role in various aspects of this work. The value of pigs as a model species is being enhanced by the generation of specially designed animals through cloning and genetic modifications, enabling more sophisticated research to be performed and thus accelerating the clinical application of regenerative medicine. This article reviews the significant aspects of the creation and application of cloned and genetically modified pigs in regenerative medicine research and considers the possible future directions of the technology. We also discuss the importance of reproductive biology as an interface between basic science and clinical medicine.

297 PRODUCTION OF CHIMERIC PORCINE FETUSES BY AGGREGATION METHOD USING PARTHENOGENETIC EMBRYOS

Porcine induced pluripotent stem (iPS) cells are considered to be an invaluable research tool in translational research with pigs as a large animal model. Pluripotency of the iPS cells needs to be verified by their competence to contribute to chimera formation. The aim of the present study is to establish feasible system to create chimeric pig fetuses using parthenogenetic embryos. In Experiment 1, inner cell mass (ICM) was isolated by immunosurgery from Day 6 blastocysts obtained by parthenogenetic activation of in vitro matured (IVM) oocytes. Isolated ICM were used as the donor cells after staining with fluorescent carbocyanine dye (DiI). Using parthenogenetic morulae or 4- to 8-cell embryos as the host embryos, chimeric embryos were prepared by injection or aggregation method. Injection of ICM was performed by micromanipulation: a single ICM was directly injected into the centre portion of the host morulae. In the aggregation method, a single ICM was aggregated with blastomeres isolated from 2 host embryos at the morula or 4- to 8-cell stage in a micro-well (400 µm diameter, 300 µm deep). The chimeric embryos were cultured in PZM-5 (Yoshioka et al. 2008) for 2 to 3 days to examine development to blastocysts and incorporation of donor ICM cells into the resultant blastocysts ICM (ICM chimerism). In Experiment 2, donor blastomeres isolated from a parthenogenetic morula or 4- to 8-cell embryo were stained by DiI and aggregated with a parthenogenetic host embryo at the morula or 4- to 8-cell stage, and the in vitro development to the blastocyst stage and the ICM chimerism were examined. In Experiment 3, ICM isolated from IVF blastocysts harboring humanized Kusabira-Orange (huKO) gene were used as donor cells. Donor ICM were aggregated with the host embryos at the morula or 4- to 8-cell stage, and the resultant blastocysts were transferred to 4 recipient gilts to collect fetuses on Day 18. Results of Experiments 1 and 2 are summarised in Table 1. Combination of the donor ICM and host morulae yielded high rates of blastocyst formation (~95%) and ICM chimerism (~85%), regardless of the method used (injection or aggregation). Transfer of 73 blastocysts developed from host morulae to 2 recipients (Experiment 3) gave rise to 25 (34.2%) fetuses, of which 6 (24.0%) were confirmed to be chimeric by their clear orange fluorescence and immunostaining by anti-huKO antibody. Of 22 (40.7%) fetuses obtained after transfer of 54 blastocysts derived from 4- to 8-cell host embryos to 2 recipients, 3 (13.6%) were chimeric. Contribution of the donor cells in the tissues of the chimeric fetuses measured by image analysis software (ImageJ, NIH, Bethesda, MD, USA) ranged between 16.1 and 65.2%. These results demonstrate that the aggregation method using parthenogenetic host embryos is an efficient means to produce chimeric pig fetuses, and thereby feasible for verification of pluripotent cells such as iPS cells. Table 1.In vitro development of injected or aggregated porcine embryos

324 PRODUCTION OF GENETICALLY MODIFIED PIGS BY ARTIFICIAL REPRODUCTIVE TECHNOLOGIES USING FROZEN EPIDIDYMAL SPERM

Genetically modified (GM) pigs are useful tools for many types of biomedical research. The objective of this study was to develop a reliable protocol for the reproduction of GM pigs using frozen epididymal sperm. Epididymal sperm were collected from 3 GM boars: (1) humanized Kusabira-Orange (huKO) transgenic, (2) mutant human hepatocyte nuclear factor 1α (HNF-1α) transgenic, and (3) α1,3-galactosyltransferase gene knockout (GalT-KO). Additionally, a wild type (WT) boar was also used for sperm collection. After collection, the sperm were frozen in Niwa and Sasaki freezing medium (Niwa et al. 1989 Manual for Cryopreservation of Pig Spermatozoa 19–23; 1.0 × 109 sperm mL–1) using 0.5-mL straws. The sperm were cooled utilising the 2-step method, from 25 to 15°C at a rate of 0.17°C min–1, and then from 15 to 5°C at 0.08°C min–1. After cooling to 5°C, the straws were frozen in liquid nitrogen with 3% glycerol for storage. After storage for 0.5 to 21 months, the straws were thawed by immersion into a 37°C water bath. The recovered sperm were washed by centrifugation in PBS + 1 mg mL–1 BSA and were resuspended in either Beltsville thawing solution (Pursel and Johnson. 1975 J. Anim. Sci. 40, 99–102) for intra-fallopian AI or in porcine fertilization medium (PFM, Research Institute for the Functional Peptides, Yamagata, Japan) for IVF. Prepubertal gilts (6.5 months), in which oestrus was induced by 1000 IU eCG and 1500 IU hCG given 66 or 72 h apart, were surgically inseminated with 0.9–7.9 × 106 progressive motile sperm 41 to 51 h after receiving an hCG injection. Oocytes, which matured in vitro either in modified porcine oocyte medium (IFP) or modified NCSU23 medium, were inseminated in PFM for 8 h with either 0.5 (huKO, GalT-KO) or 1.6 (HNF-1α) × 106 progressive motile sperm mL–1. The in vitro fertilized oocytes were cultured in porcine zygote medium-5 (Research Institute for the Functional Peptides) for 5 to 6 days until they were transferred. Some of these oocytes were examined for their fertilization rates. Blastocysts were transferred into the uterus of the recipient 150 h after hCG treatment. The fertilization rates for huKO, HNF-1α and GalT-KO sperm were 63.5% (61/96), 62.5% (70/112) and 92.4% (61/66), respectively; 50.8% (31/61), 82.9% (58/70) and 60.7% (37/61) of these were monospermic. The rate at which the IVF embryos developed into blastocysts was 47.8–52.4%. This study demonstrates that IVF using frozen epididymal sperm is more efficient method for reproducing genetically modified pigs than AI (87.5 v. 33.3%). Table 1.Pig production efficiencies of frozen epididymal sperm from genetically modified pigs utilising AI and IVF This study was supported by JST, ERATO, NAKAUCHI Stem Cell and Organ Regeneration Project, Tokyo.

326 GENERATION OF A DOUBLE-TRANSGENIC PIG WITH PANCREAS-SPECIFIC GREEN AND LIVER-SPECIFIC RED FLUORESCENCE

Transgenic (Tg) pigs with organ/tissue-specific fluorescence expression provide invaluable research tools for many types of studies, such as organogenesis analysis, in vitro tissue generation from pluripotent cells, and progenitor/stem cell transplantation therapy. We aimed to develop a Tg pig characterised by pancreas- and liver-specific fluorescence expression. A 8.4 kb transgene construct expressing Venus (green fluorescence) under the control of the mouse Pdx1 (pancreatic duodenal homeobox-1) promoter and a BAC-derived construct (170 kb) consisting of the whole-length porcine albumin (Alb) promoter and humanized Kusabira-Orange (huKO, red fluorescence) was introduced into porcine in vitro-matured oocytes using the intracytoplasmic sperm injection (ICSI)-mediated gene transfer method. Injected embryos were transferred to the oviducts of oestrus-synchronized recipients after culture for 1 to 3 days. The transfer of 370 Pdx1-Venus embryos into 4 recipients produce 22 (5.9%) fetuses/piglets, and 9 (40.9%) Tg pigs exhibited pancreas-specific Venus expression. Two (1 male and 1 female) founder Pdx1-Venus-Tg pigs were mated with wild-type (WT) pigs and produced 32 offspring in 3 litters, of which 16 (50.0%) were transgenic. Pancreas-specific Venus expression was inherited in these Tg offspring. The transfer of 523 Alb-huKO embryos into 4 recipients resulted in 19 (3.6%) piglets including a Tg female, which showed liver-specific huKO fluorescent expression. Expression of huKO was detected by RT-PCR exclusively in liver, but not in 7 other organs/tissues examined, including heart, lung, stomach, small intestine, spleen, kidney and skin. This founder Tg female produced a total of 12 non-Tg and 5 Tg offspring (in 2 litters) after mating with a WT boar. Liver-specific huKO expression was inherited in these Tg offspring. Furthermore, the mating of a female Pdx1-Venus pig with an Alb-huKO boar yielded 7 non-Tg and 10 Tg pigs. Four of these Tg pigs carrying both of the transgenes exhibited both pancreas-specific Venus and liver-specific huKO expression in single individuals. Double-Tg pigs with pancreas-specific green fluorescence and liver-specific red fluorescence grew normally, and tests of their reproduction ability are currently underway. These data demonstrate that transgene introduction by ICSI-mediated gene transfer into in vitro-matured oocytes is a feasible option for generating pigs expressing fluorescent proteins in a tissue-specific manner.

67 A HOLLOW FIBER VITRIFICATION METHOD ENABLES CRYOBANKING OF IN VITRO-MATURATION/IN VITRO-FERTILIZATION-DERIVED TRANSGENIC PIG EMBRYOS

We have recently developed a novel high-performance embryo cryopreservation method: the hollow fiber vitrification (HFV) method (Matsunari et al. 2012 J. Reprod. Dev., in press). In this study, we aimed to demonstrate the utility of the HFV method for the cryopreservation of transgenic pig embryos produced by in vitro oocyte maturation/fertilization (IVM/IVF). In vitro-matured oocytes were inseminated with cryopreserved epididymal sperm (Kikuchi et al. 1998 Theriogenology 50, 615–623) from a transgenic pig carrying the humanized Kusabira-Orange gene (Matsunari et al. 2008 Cloning Stem Cell 10, 313–323) and then cultured for 96 h. Morulae with normal morphology were divided into the vitrification and nonvitrification groups. The vitrification of embryos was performed by the HFV method using 20-mM HEPES-buffered TCM199 containing 20% calf serum as a base medium. Cellulose acetate hollow fibers (25 mm), each containing 10 to 20 embryos, were placed in an equilibration solution containing 7.5% ethylene glycol and 7.5% dimethyl sulfoxide for 5 to 7 min and were then placed for 1 min in the vitrification solution containing 15% ethylene glycol, 15% dimethyl sulfoxide, and 0.5 M sucrose. The embryos were then vitrified by immersion in liquid nitrogen and held there for 5 to 10 min. The embryos were warmed by immersing the hollow fiber in a 1-M sucrose solution at 38.5°C, followed by a stepwise dilution of the cryoprotectants using 0.5-M sucrose solution (3 min) and the base medium (10 min). Vitrified and nonvitrified embryos were cultured for 40 h, and their development into blastocysts was evaluated. The in vitro development of vitrified embryos to the blastocyst stage was compared with that of the nonvitrified controls on Day 6. In the embryo-transfer experiments, blastocysts at either Day 5 or Day 6 from both the vitrification and nonvitrification groups were transferred to 3 recipient gilts per group (25–32 blastocysts/gilt), and their development through farrowing was compared. To test long-term preservation, some of the vitrified morulae were kept in liquid nitrogen for 43 days, and their development to Day 30 fetuses was evaluated after transfer to an additional recipient. The differences in proportional data between the 2 groups were analyzed with the χ2-test. Of the 393 putative zygotes obtained by IVM/IVF, 169 (43.0%) developed into morulae. In vitro development of the vitrified morulae to blastocysts (66/85, 77.6%) was comparable with that of the nonvitrified morulae (67/84, 79.8%, not significant: NS). The embryo-transfer experiments resulted in pregnancy in all 6 of the recipients. The production efficiency of piglets (piglets/embryos transferred) was 17/88 (19.3%) for the vitrification group and 27/88 (27.7%, NS) for the nonvitrification group. Approximately 50% of the offspring in both groups were transgenic. Long-term cryopreservation using the HFV method resulted in similar piglet production efficiency (7 piglets produced out of 32 embryos transferred). This study demonstrated for the first time that the HFV method effectively cryopreserves IVM/IVF-derived transgenic pig embryos. Supported by the JST CREST program.

The key role of IL-6-arginase cascade for inducing dendritic cell-dependent CD4(+) T cell dysfunction in tumor-bearing mice

Evaluation of immune dysfunction during the tumor-bearing state is a critical issue in combating cancer. In this study, we initially found that IL-6, one of the cachectic factors, suppressed CD4(+) T cell-mediated immunity through downregulation of MHC class II by enhanced arginase activity of dendritic cells (DC) in tumor-bearing mice. We demonstrated that administration of Ab against IL-6R (anti-IL-6R mAb) greatly enhanced T cell responses and inhibited the growth of tumor in vivo. We also found that IL-6 upregulated the expression of arginase-1 and arginase activity of DC in vitro. Tumor-infiltrating CD11c(+) DC exhibited upregulated mRNA expression of arginase-1 but reduced expression of MHC class II in parallel with the increase in serum IL-6 levels at the late stage in tumor-bearing hosts. However, the administration of anti-IL-6R mAb into tumor-bearing mice inhibited both the downmodulation of MHC class II and the upregulation of arginase-1 mRNA levels in DC. Furthermore, we noted that N(ω)-hydroxy-L-arginine or L-arginine, an arginase-1 inhibitor, blocked the reduction in MHC class II levels on CD11c(+) DC during the tumor-bearing state. Finally, we demonstrated that the administration of N(ω)-hydroxy-L-arginine at the peritumor site significantly enhanced CD4(+) T cell responses and inhibited tumor growth. Thus, IL-6-mediated arginase activation and the subsequent reduction in MHC class II expression on DC appeared to be critical mechanisms for inducing dysfunction of the immune system in the tumor-bearing state. Blockade of the IL-6-arginase cascade is a promising tool to overcome the dysfunction of antitumor immunity in tumor-bearing hosts.

Cold-nuclear-matter effects on heavy-quark production in d+Au collisions at sqrt[S(NN)]=200 GeV

The PHENIX experiment has measured electrons and positrons at midrapidity from the decays of hadrons containing charm and bottom quarks produced in d+Au and p+p collisions at sqrt[S(NN)]=200 GeV in the transverse-momentum range 0.85 ≤ p(T)(e) ≤ 8.5 GeV/c. In central d+Au collisions, the nuclear modification factor R(dA) at 1.5<p(T)<5 GeV/c displays evidence of enhancement of these electrons, relative to those produced in p+p collisions, and shows that the mass-dependent Cronin enhancement observed at the Relativistic Heavy Ion Collider extends to the heavy D meson family. A comparison with the neutral-pion data suggests that the difference in cold-nuclear-matter effects on light- and heavy-flavor mesons could contribute to the observed differences between the π(0) and heavy-flavor-electron nuclear modification factors R(AA).

Evolution of π(0) suppression in Au+Au collisions from √(s(NN))=39 to 200 GeV

Neutral-pion π(0) spectra were measured at midrapidity (|y|<0.35) in Au+Au collisions at √(s(NN))=39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1<p(T)<10 GeV/c. The high-p(T) tail is well described by a power law in all cases, and the powers decrease significantly with decreasing center-of-mass energy. The change of powers is very similar to that observed in the corresponding spectra for p+p collisions. The nuclear modification factors (R(AA)) show significant suppression, with a distinct energy, centrality, and p(T) dependence. Above p(T)=7 GeV/c, R(AA) is similar for √(s(NN))=62.4 and 200 GeV at all centralities. Perturbative-quantum-chromodynamics calculations that describe R(AA) well at 200 GeV fail to describe the 39 GeV data, raising the possibility that, for the same p(T) region, the relative importance of initial-state effects and soft processes increases at lower energies. The p(T) range where π(0) spectra in central Au+Au collisions have the same power as in p+p collisions is ≈5 and 7 GeV/c for √(s(NN))=200 and 62.4 GeV, respectively. For the √(s(NN))=39 GeV data, it is not clear whether such a region is reached, and the x(T) dependence of the x(T)-scaling power-law exponent is very different from that observed in the √(s(NN))=62 and 200 GeV data, providing further evidence that initial-state effects and soft processes mask the in-medium suppression of hard-scattered partons to higher p(T) as the collision energy decreases.

Potential involvement of collagen-binding proteins of Streptococcus mutans in infective endocarditis

OBJECTIVE

Streptococcus mutans, a major pathogen of dental caries, is considered to be one of the causative agents of infective endocarditis (IE). Two types of cell surface collagen-binding proteins, Cnm and Cbm, have been identified in the organism. The aim of the present study was to analyze these proteins as possible etiologic factors for IE.

MATERIALS AND METHODS

The binding activities of S. mutans strains to collagen types I, III, and IV were analyzed relative to the presence of Cnm and Cbm, as were their adhesion and invasion properties with human umbilical vein endothelial cells (HUVEC). In addition, distributions of the genes encoding Cnm and Cbm in S. mutans-positive heart valve specimens extirpated from IE and non-IE patients were analyzed by PCR.

RESULTS

Most of the Cbm-positive strains showed higher levels of binding to type I collagen as well as higher rates of adhesion and invasion with HUVEC as compared to the Cnm-positive strains. Furthermore, the gene encoding Cbm was detected significantly more frequently in heart valve specimens from IE patients than from non-IE patients.

CONCLUSIONS

These results suggest that the collagen-binding protein Cbm of S. mutans may be one of the potential important factor associated with the pathogenesis of IE.

Observation of direct-photon collective flow in Au + Au collisions at √s(NN)] = 200 GeV

The second Fourier component v(2) of the azimuthal anisotropy with respect to the reaction plane is measured for direct photons at midrapidity and transverse momentum (p(T)) of 1-12 GeV/c in Au + Au collisions at √s(NN)] = 200 GeV. Previous measurements of this quantity for hadrons with p(T) < 6 GeV/c indicate that the medium behaves like a nearly perfect fluid, while for p(T) > 6 GeV/c a reduced anisotropy is interpreted in terms of a path-length dependence for parton energy loss. In this measurement with the PHENIX detector at the Relativistic Heavy Ion Collider we find that for p(T) > 4 GeV/c the anisotropy for direct photons is consistent with zero, which is as expected if the dominant source of direct photons is initial hard scattering. However, in the p(T) < 4 GeV/c region dominated by thermal photons, we find a substantial direct-photon v(2) comparable to that of hadrons, whereas model calculations for thermal photons in this kinematic region underpredict the observed v(2).