Colorectal cancer (CRC) remains the third most common form of cancer and, despite its reduced mortality, results in over 50,000 deaths annually, highlighting the need for novel therapeutic ...approaches. VAX014 is a novel clinical-stage, oncolytic bacterial minicell-based therapy shown to elicit protective antitumor immune responses in cancer, but it has not been fully evaluated in CRC. Here, VAX014 was demonstrated to induce oncolysis in CRC cell lines in vitro and was evaluated in vivo, both as a prophylactic (before spontaneous development of adenomatous polyps) and as a neoadjuvant treatment using the Fabp-CreXApc
preclinical animal model of colon cancer. As a prophylactic, VAX014 significantly reduced the size and number of adenomas without inducing long term changes in the gene expression of inflammatory, T helper 1 antitumor, and immunosuppression markers. In the presence of adenomas, a neoadjuvant VAX014 treatment reduced the number of tumors, induced the gene expression of antitumor T
1 immune markers in adenomas, and promoted the expansion of the probiotic bacterium
. The neoadjuvant VAX014 treatment was associated with decreased Ki67 proliferation in vivo, suggesting that VAX014 inhibits adenoma development through both oncolytic and immunotherapeutic effects. Combined, these data support the potential of VAX014 treatment in CRC and "at risk" polyp-bearing or early adenocarcinoma populations.
Age-related macular degeneration (AMD) is a common cause of blindness worldwide. While recent studies have revealed that the loss of choroidal endothelial cells (ChECs) is critical to the disease ...pathogenesis of dry AMD, in vitro studies are needed to fully elucidate the disease mechanism. However, these studies remain hindered due to the lack of publically available human ChEC lines. To address this need, ChECs were harvested form donor tissue and enriched for by using magnetic cell separation using anti-CD31 conjugated microbeads. Next, lenti-viral vectors with endothelial-specific promoters driving genes necessary for immortalization, CDH5p-hTERT and CDH5p TAg, were generated. Stable integration of both gene cassettes allowed cells to maintain their proliferative state and yielded an immortalized cell line (iChEC-1). Immunocytochemical analysis of iChEC-1 confirmed the expression of important ChEC markers such as CA4, a marker of choriocapillaris endothelial cells, CDH5, and CD34, pan-endothelial cell markers. qRT-PCR analysis of expanded clones from iChEC-1 further showed that the line maintained expression of other important endothelial markers, vWF, PECAM1, and PLVAP, similar to primary cells. Functional responses were characterized by tube-forming assays and repopulation of decellularized choroid with the immortalized cell line. In conclusion, the iChEC-1 line presents a suitable immortalized human ChEC line for future in vitro studies of AMD.
•Choroidal endothelial cells (ChECs) were isolated from a human donor eye.•Transduction with CDH5p-hTERT/CDH5p-TAg yielded an immortalized cell line (iChEC-1).•iChEC-1 retains phenotypic and functional properties of choroidal endothelial cells.•iChEC-1 is a suitable immortalized human ChEC line for future studies.
Abstract
The Kepler and TESS missions have demonstrated that planets are ubiquitous. However, the success of these missions heavily depends on ground-based radial velocity (RV) surveys, which ...combined with transit photometry can yield bulk densities and orbital properties. While most Kepler host stars are too faint for detailed follow-up observations, TESS is detecting planets orbiting nearby bright stars that are more amenable to RV characterization. Here, we introduce the TESS-Keck Survey (TKS), an RV program using ∼100 nights on Keck/HIRES to study exoplanets identified by TESS. The primary survey aims are investigating the link between stellar properties and the compositions of small planets; studying how the diversity of system architectures depends on dynamical configurations or planet multiplicity; identifying prime candidates for atmospheric studies with JWST; and understanding the role of stellar evolution in shaping planetary systems. We present a fully automated target selection algorithm, which yielded 103 planets in 86 systems for the final TKS sample. Most TKS hosts are inactive, solar-like, main-sequence stars (4500 K ≤
T
eff
<6000 K) at a wide range of metallicities. The selected TKS sample contains 71 small planets (
R
p
≤ 4
R
⊕
), 11 systems with multiple transiting candidates, six sub-day-period planets and three planets that are in or near the habitable zone (
S
inc
≤ 10
S
⊕
) of their host star. The target selection described here will facilitate the comparison of measured planet masses, densities, and eccentricities to predictions from planet population models. Our target selection software is publicly available and can be adapted for any survey that requires a balance of multiple science interests within a given telescope allocation.
BackgroundImmunologically cold tumors with an ‘immune desert’ phenotype lack tumor-infiltrating lymphocytes (TILs) and are typically impervious to systemic immune checkpoint blockade (ICB). ...Intratumoral treatment of tumors with immunomodulatory agents can promote local tumor inflammation leading to improved T cell responses in injected tumors. Addition of systemic ICB increases response frequency and immune-mediated clearance of injected and distal non-injected lesions, and this promising approach is being widely investigated clinically. In this work, we evaluate and characterize the local and systemic antitumor immunotherapeutic activity of VAX014, a novel non-viral targeted oncolytic agent based on recombinant bacterial minicells, following intratumoral administration and in combination with systemic ICB.MethodsThe immunotherapeutic activity of VAX014 following weekly intratumoral administration was investigated in multiple preclinical tumor models with B16F10 murine melanoma serving as the primary model for evaluation of immune desert tumors. Mice bearing a single intradermal tumor were used to evaluate tumor response and overall survival (OS), assess changes in immune cell populations, and explore global changes to immunotranscriptomes of injected tumors. Mice bearing bilateral intradermal tumors were then used to evaluate non-injected tumors for changes in TIL populations and phenotypes, compare immunotranscriptomes across treatment groups, and assess distal non-injected tumor response in the context of monotherapy or in combination with ICB.ResultsVAX014 demonstrated strong immune-mediated tumor clearance of injected tumors coinciding with significantly elevated CD8+ TILs and upregulation of multiple immune pathways essential for antitumor immune responses. Modest activity against distal non-injected immune desert tumors was observed despite elevated levels of systemic antitumor lymphocytes. Combination with systemic CTLA-4 blockade improved survival and elevated TILs but did not improve clearance rates of non-injected tumors. Immunotranscriptomes of non-injected tumors from this treatment combination group exhibited upregulation of multiple immune pathways but also identified upregulation of PD-1. Further addition of systemic PD-1 blockade led to rapid clearance of non-injected tumors, enhanced OS, and provided durable protective immunological memory.ConclusionsIntratumoral administration of VAX014 stimulates local immune activation and robust systemic antitumor lymphocytic responses. Combination with systemic ICB deepens systemic antitumor responses to mediate clearance of injected and distal non-injected tumors.
The refinement of tightly regulated prokaryotic expression systems that permit functional expression of toxic recombinant proteins is a continually evolving process. Unfortunately, the current best ...promoter options are either tightly repressed and produce little protein, or produce substantial protein but lack the necessary repression to avoid mutations stimulated by leaky expression in the absence of inducer. In this report, we present three novel prokaryotic expression constructs that are tightly regulated by L-rhamnose and D-glucose. These expression vectors utilize the Escherichia coli rhaT promoter and corresponding regulatory genes to provide titratable, high-level protein yield without compromising clone integrity. Together, these components may enable the stable cloning and functional expression of otherwise toxic proteins.
Abstract
Discovering and characterizing exoplanets at the outer edge of the transit method’s sensitivity has proven challenging owing to geometric biases and the practical difficulties associated ...with acquiring long observational baselines. Nonetheless, a sample of giant exoplanets on orbits longer than 100 days has been identified by transit hunting missions. We present long-term Doppler spectroscopy for 11 such systems with observation baselines spanning a few years to a decade. We model these radial velocity observations jointly with transit photometry to provide initial characterizations of these objects and the systems in which they exist. Specifically, we make new precise mass measurements for four long-period giant exoplanets (Kepler-111 c, Kepler-553 c, Kepler-849 b, and PH-2 b), we place new upper limits on mass for four others (Kepler-421 b, KOI-1431.01, Kepler-1513 b, and Kepler-952 b), and we show that several
confirmed
planets are in fact not planetary at all. We present these findings to complement similar efforts focused on closer-in short-period giant planets, and with the hope of inspiring future dedicated studies of cool giant exoplanets.
VAX014 minicells (VAX014) have been previously characterized as an integrin-specific oncolytic biotherapeutic agent. The present study was designed to evaluate the potential of VAX014 as an immediate ...post-operative intravesical adjuvant therapy in the treatment of non-muscle invasive bladder cancer (NMIBC).
The ability of VAX014 to kill a panel of dissociated urothelial carcinoma cell lines was tested in vitro. In vivo experiments were conducted using a single intravesical dose of VAX014 in the anti-implantation variation of the MB49 syngeneic orthotopic bladder cancer model with tumor implantation and overall survival rates serving as study endpoints.
VAX014 rapidly killed dissociated urothelial carcinoma cells, while single dose in vivo pharmacology studies demonstrated the dose-dependent ability of VAX014 to prevent tumor implantation and development, ultimately resulting in a significant survival advantage compared to controls.
These results suggest that VAX014 holds potential as an immediate post-operative adjuvant therapy in NMIBC.
Abstract
We report the discovery in TESS data and validation of HD 56414 b (a.k.a. TOI-1228 b), a Neptune-size (
R
p
= 3.71 ± 0.20
R
⊕
) planet with a 29 day orbital period transiting a young (age = ...420 ± 140 Myr) A-type star in the TESS southern continuous-viewing zone. HD 56414 is one of the hottest stars (
T
eff
= 8500 ± 150 K) to host a known sub-Jovian planet. HD 56414 b lies on the boundary of the hot Neptune desert in the planet radius–bolometric insolation flux space, suggesting that the planet may be experiencing mass loss. To explore this, we apply a photoevaporation model that incorporates the high near-ultraviolet continuum emission of A-type stars. We find that the planet can retain most of its atmosphere over the typical 1 Gyr main-sequence lifetime of an A-type star if its mass is ≥8
M
⊕
. Our model also predicts that close-in Neptune-size planets with masses <14
M
⊕
are susceptible to total atmospheric stripping over 1 Gyr, hinting that the hot Neptune desert, which has been previously observed around FGKM-type stars, likely extends to A-type stars.
Context. The detection and characterization of exoplanets and brown dwarfs around massive AF-type stars is essential to investigate and constrain the impact of stellar mass on planet properties. ...However, such targets are still poorly explored in radial velocity (RV) surveys because they only feature a small number of stellar lines and those are usually broadened and blended by stellar rotation as well as stellar jitter. As a result, the available information about the formation and evolution of planets and brown dwarfs around hot stars is limited.
Aims. We aim to increase the sample and precisely measure the masses and eccentricities of giant planets and brown dwarfs transiting early-type stars detected by the Transiting Exoplanet Survey Satellite (TESS).
Methods. We followed bright (V < 12 mag) stars with Teff > 6200 K that host giant companions (R > 7 R⊕) using ground-based photometric observations as well as high precision radial velocity measurements from the CORALIE, CHIRON, TRES, FEROS, and MINERVA-Australis spectrographs.
Results. In the context of the search for exoplanets and brown dwarfs around early-type stars, we present the discovery of three brown dwarf companions, TOI-629b, TOI-1982b, and TOI-2543b, and one massive planet, TOI-1107b. From the joint analysis of TESS and ground-based photometry in combination with high precision radial velocity measurements, we find the brown dwarfs have masses between 66 and 68 MJup, periods between 7.54 and 17.17 days, and radii between 0.95 and 1.11 RJup. The hot Jupiter TOI-1107b has an orbital period of 4.08 days, a radius of 1.30 RJup, and a mass of 3.35 MJup. As a by-product of this program, we identified four low-mass eclipsing components (TOI-288b, TOI-446b, TOI-478b, and TOI-764b).
Conclusions. Both TOI-1107b and TOI-1982b present an anomalously inflated radius with respect to the age of these systems. TOI-629 is among the hottest stars with a known transiting brown dwarf. TOI-629b and TOI-1982b are among the most eccentric brown dwarfs. The massive planet and the three brown dwarfs add to the growing population of well-characterized giant planets and brown dwarfs transiting AF-type stars and they reduce the apparent paucity.
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