95 research outputs found
Mannosylated-serum albumin nanoparticle imaging to monitor tumor-associated macrophages under anti-PD1 treatment
Background
Immune checkpoint inhibitors such as anti-programmed cell death protein 1 (PD1) block tumor growth
by reinvigorating the immune system; however, determining their efcacy only by the changes in tumor size may
prove inaccurate. As the immune cells including macrophages in the tumor microenvironment (TME) are associ‑
ated with the response to anti-PD1 therapy, tumor-associated macrophages (TAMs) imaging using nanoparticles can
noninvasively provide the immune enrichment status of TME. Herein, the mannosylated-serum albumin (MSA) nano‑
particle was labeled with radioactive isotope 68Ga to target the mannose receptors on macrophages for noninvasive
monitoring of the TME according to anti-PD1 therapy.
Results
B16F10-Luc and MC38-Luc tumor-bearing mice were treated with anti-PD1, and the response to anti-PD1
was determined by the tumor volume. According to the fow cytometry, the responders to anti-PD1 showed an
increased proportion of TAMs, as well as lymphocytes, and the most enriched immune cell population in the TME
was also TAMs. For noninvasive imaging of TAMs as a surrogate of immune cell augmentation in the TME via anti-PD1,
we acquired [
68Ga] Ga-MSA positron emission tomography. According to the imaging study, an increased number of
TAMs in responders at the early phase of anti-PD1 treatment was observed in both B16F10-Luc and MC38-Luc tumorbearing mice models.
Conclusion
As representative immune cells in the TME, non-invasive imaging of TAMs using MSA nanoparticles can
refect the immune cell enrichment status in the TME closely associated with the response to anti-PD1. As non-inva‑
sive imaging using MSA nanoparticles, this approach shows a potential to monitor and evaluate anti-tumor response
to immune checkpoint inhibitors.This research was supported by the Basic Science Research Program through
the National Research Foundation of Korea (NRF), funded by the Ministry of
Education (NRF-2020R1A6A3A13069409), the Korean government the Ministry
of Science, ICT and Future Planning (2020R1A2C2010202, 2020R1A4A2002903,
2020M3A9B6038086, 2021M2E7A2079570, 2021R1A2C3009427,
2022M3E5F2018261), and the Ministry of Health and Welfare (HI19C0339,
HN22C0644). This study also was carried out by the research fund supported
by the fund project of Park Yang Sook - Chung Yung Ho in Seoul National
University
IS6110-Restriction Fragment Length Polymorphism and Spoligotyping Analysis of Mycobacterium tuberculosis Clinical Isolates for Investigating Epidemiologic Distribution in Korea
The Beijing family of Mycobacterium tuberculosis has been emerging in the world. However, there are few nationwide data of genotypic distribution in Korea. This study aimed to identify the genotypic diversity of clinical isolates of M. tuberculosis and to demonstrate the population of Beijing family in Korea. We collected 96 clinical M. tuberculosis isolates from 11 university hospitals nationwide in Korea from 2008 to 2009. We observed 24 clusters in IS6110-RFLP analysis and 19 patterns in spoligotyping. Seventy-five isolates were confirmed to be Beijing family. Two isolates of the K strain and 12 isolates of the K family strain were also found. We found that drug resistance phenotypes were more strongly associated with Beijing family than non-Beijing family (P=0.003). This study gives an overview of the distribution of genotypes of M. tuberculosis in Korea. These findings indicate that we have to pay more attention to control of M. tuberculosis strains associated with the Beijing family
The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-filament Structure, Monoceros R2
We present and analyze observations of polarized dust emission at 850 μm toward the central 1
7 1 pc hub-filament structure of Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the B-fields in Star-forming Region Observations survey. The orientations of the magnetic field follow the spiral structure of Mon R2, which are well described by an axisymmetric magnetic field model. We estimate the turbulent component of the magnetic field using the angle difference between our observations and the best-fit model of the underlying large-scale mean magnetic field. This estimate is used to calculate the magnetic field strength using the Davis–Chandrasekhar–Fermi method, for which we also obtain the distribution of volume density and velocity dispersion using a column density map derived from Herschel data and the C18O (J = 3 - 2) data taken with HARP on the JCMT, respectively. We make maps of magnetic field strengths and mass-to-flux ratios, finding that magnetic field strengths vary from 0.02 to 3.64 mG with a mean value of 1.0 \ub1 0.06 mG, and the mean critical mass-to-flux ratio is 0.47 \ub1 0.02. Additionally, the mean Alfv\ue9n Mach number is 0.35 \ub1 0.01. This suggests that, in Mon R2, the magnetic fields provide resistance against large-scale gravitational collapse, and the magnetic pressure exceeds the turbulent pressure. We also investigate the properties of each filament in Mon R2. Most of the filaments are aligned along the magnetic field direction and are magnetically subcritical
The JCMT BISTRO Survey: Studying the Complex Magnetic Field of L43
We present observations of polarized dust emission at 850 μm from the L43 molecular cloud, which sits in the Ophiuchus cloud complex. The data were taken using SCUBA-2/POL-2 on the James Clerk Maxwell Telescope as a part of the BISTRO large program. L43 is a dense (NH 10
22 2 ~ –1023 cm−2) complex molecular cloud with a submillimeter-bright starless core and two protostellar sources. There appears to be an evolutionary gradient along the isolated filament that L43 is embedded within, with the most evolved source closest to the Sco OB2 association. One of the protostars drives a CO outflow that has created a cavity to the southeast. We see a magnetic field that appears to be aligned with the cavity walls of the outflow, suggesting interaction with the outflow. We also find a magnetic field strength of up to ∼160 ± 30 μG in the main starless core and up to ∼90 ± 40 μG in the more diffuse, extended region. These field strengths give magnetically super- and subcritical values, respectively, and both are found to be roughly trans-Alfvénic. We also present a new method of data reduction for these denser but fainter objects like starless cores
Filamentary Network and Magnetic Field Structures Revealed with BISTRO in the High-mass Star-forming Region NGC 2264: Global Properties and Local Magnetogravitational Configurations
We report 850 μm continuum polarization observations toward the filamentary high-mass star-forming region NGC 2264, taken as part of the B-fields In STar forming Regions Observations large program on the James Clerk Maxwell Telescope. These data reveal a well-structured nonuniform magnetic field in the NGC 2264C and 2264D regions with a prevailing orientation around 30° from north to east. Field strength estimates and a virial analysis of the major clumps indicate that NGC 2264C is globally dominated by gravity, while in 2264D, magnetic, gravitational, and kinetic energies are roughly balanced. We present an analysis scheme that utilizes the locally resolved magnetic field structures, together with the locally measured gravitational vector field and the extracted filamentary network. From this, we infer statistical trends showing that this network consists of two main groups of filaments oriented approximately perpendicular to one another. Additionally, gravity shows one dominating converging direction that is roughly perpendicular to one of the filament orientations, which is suggestive of mass accretion along this direction. Beyond these statistical trends, we identify two types of filaments. The type I filament is perpendicular to the magnetic field with local gravity transitioning from parallel to perpendicular to the magnetic field from the outside to the filament ridge. The type II filament is parallel to the magnetic field and local gravity. We interpret these two types of filaments as originating from the competition between radial collapsing, driven by filament self-gravity, and longitudinal collapsing, driven by the region's global gravity
Filamentary Network and Magnetic Field Structures Revealed with BISTRO in the High-Mass Star-Forming Region NGC2264 : Global Properties and Local Magnetogravitational Configurations
We report 850 m continuum polarization observations toward the
filamentary high-mass star-forming region NGC 2264, taken as part of the
B-fields In STar forming Regions Observations (BISTRO) large program on the
James Clerk Maxwell Telescope (JCMT). These data reveal a well-structured
non-uniform magnetic field in the NGC 2264C and 2264D regions with a prevailing
orientation around 30 deg from north to east. Field strengths estimates and a
virial analysis for the major clumps indicate that NGC 2264C is globally
dominated by gravity while in 2264D magnetic, gravitational, and kinetic
energies are roughly balanced. We present an analysis scheme that utilizes the
locally resolved magnetic field structures, together with the locally measured
gravitational vector field and the extracted filamentary network. From this, we
infer statistical trends showing that this network consists of two main groups
of filaments oriented approximately perpendicular to one another. Additionally,
gravity shows one dominating converging direction that is roughly perpendicular
to one of the filament orientations, which is suggestive of mass accretion
along this direction. Beyond these statistical trends, we identify two types of
filaments. The type-I filament is perpendicular to the magnetic field with
local gravity transitioning from parallel to perpendicular to the magnetic
field from the outside to the filament ridge. The type-II filament is parallel
to the magnetic field and local gravity. We interpret these two types of
filaments as originating from the competition between radial collapsing, driven
by filament self-gravity, and the longitudinal collapsing, driven by the
region's global gravity.Comment: Accepted for publication in the Astrophysical Journal. 43 pages, 32
figures, and 4 tables (including Appendix
JCMT BISTRO Survey: Magnetic Fields within the Hub-filament Structure in IC 5146
We present the 850 μm polarization observations toward the IC 5146 filamentary cloud taken using the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and its associated polarimeter (POL-2), mounted on the James Clerk Maxwell Telescope, as part of the B-fields In STar forming Regions Observations. This work is aimed at revealing the magnetic field morphology within a core-scale (lesssim1.0 pc) hub-filament structure (HFS) located at the end of a parsec-scale filament. To investigate whether the observed polarization traces the magnetic field in the HFS, we analyze the dependence between the observed polarization fraction and total intensity using a Bayesian approach with the polarization fraction described by the Rice likelihood function, which can correctly describe the probability density function of the observed polarization fraction for low signal-to-noise ratio data. We find a power-law dependence between the polarization fraction and total intensity with an index of 0.56 in A V ~ 20–300 mag regions, suggesting that the dust grains in these dense regions can still be aligned with magnetic fields in the IC 5146 regions. Our polarization maps reveal a curved magnetic field, possibly dragged by the contraction along the parsec-scale filament. We further obtain a magnetic field strength of 0.5 ± 0.2 mG toward the central hub using the Davis–Chandrasekhar–Fermi method, corresponding to a mass-to-flux criticality of ~1.3 ± 0.4 and an Alfvénic Mach number of <0.6. These results suggest that gravity and magnetic field are currently of comparable importance in the HFS and that turbulence is less important
The JCMT BISTRO Survey: An 850/450 μ m Polarization Study of NGC 2071IR in Orion B
Abstract: We present the results of simultaneous 450 μm and 850 μm polarization observations toward the massive star-forming region NGC 2071IR, a target of the BISTRO (B-fields in STar-forming Region Observations) Survey, using the POL-2 polarimeter and SCUBA-2 camera mounted on the James Clerk Maxwell Telescope. We find a pinched magnetic field morphology in the central dense core region, which could be due to a rotating toroidal disklike structure and a bipolar outflow originating from the central young stellar object IRS 3. Using the modified Davis–Chandrasekhar–Fermi method, we obtain a plane-of-sky magnetic field strength of 563 ± 421 μG in the central ∼0.12 pc region from 850 μm polarization data. The corresponding magnetic energy density of 2.04 × 10−8 erg cm−3 is comparable to the turbulent and gravitational energy densities in the region. We find that the magnetic field direction is very well aligned with the whole of the IRS 3 bipolar outflow structure. We find that the median value of polarization fractions is 3.0% at 450 μm in the central 3′ region, which is larger than the median value of 1.2% at 850 μm. The trend could be due to the better alignment of warmer dust in the strong radiation environment. We also find that polarization fractions decrease with intensity at both wavelengths, with slopes, determined by fitting a Rician noise model of 0.59 ± 0.03 at 450 μm and 0.36 ± 0.04 at 850 μm, respectively. We think that the shallow slope at 850 μm is due to grain alignment at the center being assisted by strong radiation from the central young stellar objects
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