227 research outputs found
Immunotherapeutic efficacy of retargeted ohsvs designed for propagation in an ad hoc cell line
Our laboratory has pursued the generation of cancerâspecific oncolytic herpes simplex viruses (oHSVs) which ensure high efficacy while maintaining a high safety profile. Their blueprint included retargeting to a TumorâAssociated Antigen, e.g., HER2, coupled to detargeting from natural receptors to avoid offâtarget and offâtumor infections and preservation of the full complement of unmodified viral genes. These oHSVs are âfully virulent in their target cancer cellsâ. The 3rd generation retargeted oHSVs carry two distinct retargeting moieties, which enable infection of a producer cell line and of the target cancer cells, respectively. They can be propagated in an ad hoc Vero cell derivative at about tenfold higher yields than 1st generation recombinants, and more effectively replicate in human cancer cell lines. The Râ335 and Râ337 prototypes were armed with murine ILâ12. Intratumorallyâadministered Râ337 conferred almost complete protection from LLCâ 1âHER2 primary tumors, unleashed the tumor microenvironment immunosuppression, synergized with the checkpoint blockade and conferred longâterm vaccination against distant challenge tumors. In summary, the problem intrinsic to the propagation of retargeted oHSVsâwhich strictly require cells positive for targeted receptorsâwas solved in 3rd generation viruses. They are effective as immunotherapeutic agents against primary tumors and as antigenâagnostic vaccines
Completing the puzzle of the 2004-2005 outburst in V0332+53: the brightening phase included
Analysis of the data obtained with the RXTE observatory during a powerful
outburst of the X-ray pulsar V0332+53 in 2004-2005 is presented. Observational
data covering the outburst brightening phase are analysed in detail for the
first time. A comparison of source parameters and their evolution during the
brightening and fading phases shows no evidence for any hysteresis behaviour.
It is found that the dependences of the energy of the cyclotron absorption line
on the luminosity during the brightening and fading phases are almost
identical. The complete data sequence including the outburst brightening and
fading phases makes it possible to impose the more stringent constraints on the
magnetic field in the source. The pulse profile and pulsed fraction are studied
as functions of the luminosity and photon energy.Comment: 9 pages, 10 figures, accepted for publication in MNRA
Genotype of Immunologically Hot or Cold Tumors Determines the Antitumor Immune Response and Efficacy by Fully Virulent Retargeted oHSV
We report on the efficacy of the non-attenuated HER2-retargeted oHSV named R-337 against the immunologically hot CT26-HER2 tumor, and an insight into the basis of the immune protection. Preliminarily, we conducted an RNA immune profiling and immune cell content characterization of CT26-HER2 tumor in comparison to the immunologically cold LLC1-HER2 tumor. CT26-HER2 tumor was implanted into HER2-transgenic BALB/c mice. Hallmarks of R-337 effects were the protection from primary tumor, long-term adaptive vaccination directed to both HER2 and CT26-wt cell neoantigens. The latter effect differentiated R-337 from OncoVEXGM-CSF. As to the basis of the immune protection, R-337 orchestrated several changes to the tumor immune profile, which cumulatively reversed the immunosuppression typical of this tumor (graphical abstract). Thus, Ido1 (inhibitor of T cell anticancer immunity) levels and T regulatory cell infiltration were decreased; Cd40 and Cd27 co-immunostimulatory markers were increased; the IFNÎł cascade was activated. Of note was the dampening of IFN-I response, which we attribute to the fact that R-337 is fully equipped with genes that contrast the host innate response. The IFN-I shut-down likely favored viral replication and the expression of the mIL-12 payload, which, in turn, boosted the antitumor response. The results call for a characterization of tumor immune markers to employ oncolytic herpesviruses more precisely
Hard X-ray emission from the galaxy cluster A3667
We report the results of a long BeppoSAX observation of Abell 3667, one of
the most spectacular galaxy cluster in the southern sky. A clear detection of
hard X-ray radiation up to ~ 35 keV is reported, while a hard excess above the
thermal gas emission is present at a marginal level that should be considered
as an upper limit to the presence of nonthermal radiation. The strong hard
excesses reported by BeppoSAX in Coma and A2256 and the only marginal detection
of nonthermal emission in A3667 can be explained in the framework of the
inverse Compton model. We argue that the nonthermal X-ray detections in the PDS
energy range are related to the radio index structure of halos and relics
present in the observed clusters of galaxie.Comment: 15 pages, 1 figure, ApJL in pres
Insights into Thymus Development and Viral Thymic Infections
T-cell development in the thymus is a complex and highly regulated process, involving a wide variety of cells and molecules which orchestrate thymocyte maturation into either CD4+ or CD8+ single-positive (SP) T cells. Here, we briefly review the process regulating T-cell differentiation, which includes the latest advances in this field. In particular, we highlight how, starting from a pool of hematopoietic stem cells in the bone marrow, the sequential action of transcriptional factors and cytokines dictates the proliferation, restriction of lineage potential, T-cell antigen receptors (TCR) gene rearrangements, and selection events on the T-cell progenitors, ultimately leading to the generation of mature T cells. Moreover, this review discusses paradigmatic examples of viral infections affecting the thymus that, by inducing functional changes within this lymphoid gland, consequently influence the behavior of peripheral mature T-lymphocytes
BeppoSAX Detection and Follow-up of GRB980425
We present BeppoSAX GRBM and WFC light curves of GRB980425 and NFI follow-up
data taken in 1998 April, May, and November. The first NFI observation has
detected within the 8' radius error box of the GRB an X-ray source positionally
consistent with the supernova SN 1998bw, exploded within a day of GRB980425,
and a fainter X-ray source, not consistent with the position of the supernova.
The former source is detected in the following NFI pointings and exhibits a
decline of a factor of two in six months. If it is associated with SN 1998bw,
this is the first detection of hard X-ray emission from a Type I supernova. The
latter source exhibits only marginally significant variability. Based on these
data, it is not possible to select either source as a firm candidate for the
GRB counterpart.Comment: 2 pages, 1 PostScript figure, submitted to A&AS, Proc. of the
Conference "Gamma-Ray Bursts in the Afterglow Era", held in Rome, 1998
November 3-6. Results concerning 'Source 2' have been update
On-ground performance tests of the SAX/PDS detector
The Phoswich Detection System (PDS) is one of the four narrow field experiments on board the SAX satellite. The PDS will be dedicated to deep temporal and spectral studies of celestial X-ray sources in the 15â300 keV energy band. It
also includes a gamma-ray burst monitor. The PDS detector is composed of 4 actively shielded NaI(Tl)/CsI(Na) phoswich scintillators with a total geometric area of 795 cm2 and a field of view of 1:4 (FWHM). The performance of the detector, before its integration with its flight electronic, was tested using standard instrumentation. Here we present results of these tests. The measured energy resolution of the phoswich units is better than 15% at 60 keV, confirming the expectations. Also test results of the anticoincidence shield of CsI(Na) and collimator are discussed
The very red afterglow of GRB 000418 - further evidence for dust extinction in a GRB host galaxy
We report near-infrared and optical follow-up observations of the afterglow
of the Gamma-Ray Burst 000418 starting 2.5 days after the occurrence of the
burst and extending over nearly seven weeks. GRB 000418 represents the second
case for which the afterglow was initially identified by observations in the
near-infrared. During the first 10 days its R-band afterglow was well
characterized by a single power-law decay with a slope of 0.86. However, at
later times the temporal evolution of the afterglow flattens with respect to a
simple power-law decay. Attributing this to an underlying host galaxy we find
its magnitude to be R=23.9 and an intrinsic afterglow decay slope of 1.22. The
afterglow was very red with R-K=4 mag. The observations can be explained by an
adiabatic, spherical fireball solution and a heavy reddening due to dust
extinction in the host galaxy. This supports the picture that (long) bursts are
associated with events in star-forming regions.Comment: Accepted for publication in The Astrophysical Journal. 12 pages;
citations & references updated; minor textual change
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