126 research outputs found
Virus-Free CRISPR CAR T cells induce solid tumor regression
Chimeric antigen receptor (CAR) T cell therapy has shown promising efficacy in treating hematologic malignancies and has led to the FDA-approval of three CAR T cell products. However, there has been little success in treating solid tumors, as clinical trials to date have yielded little to no responses and no improvement in survival. Current methods of CAR T cell production typically involve the use of viral vectors which can give rise to complications such as insertional mutagenesis, leading to gene silencing or oncogene activation. In addition, GMP-grade viral vector manufacturing can be expensive with lengthy wait times for new batches. Here we have developed a virus-free strategy in primary T cells that has eliminated the use of viral vectors through the use of CRISPR-Cas9 to precisely edit the chimeric antigen receptor into the TRAC gene1. Our method of virus free production begins through the generation of a double stranded DNA (dsDNA) template produced by polymerase chain reaction (PCR). This template is then combined with a SpCas9-single guide RNA to create a ribonucleoprotein (RNP) complex. Isolated human primary T cells from adult healthy donors are then nucleofected with the RNP and dsDNA template on day 2 of ex vivo expansion. Flow cytometry is then utilized to immunophenotype the cell product and analyze the percent of efficiency of CAR gene transfer. Within the cell product, the editing efficiencies are \u3e95% TCR knockout and 35% CAR+. Transcriptional profiling indicates that the virus-free CART cells have a favorable memory-like phenotype. In addition to our in vitro work, in vivo mice studies with anti-GD2 CART products demonstrate regression of GD2+ solid tumors upon virus-free CART treatment, showing similar potency and survival to viral-produced CAR T cells. The production of virus-free CAR T cells has high potential to enable the rapid and flexible manufacturing of highly defined and highly potent CAR T cell products for the treatment of solid tumors.
1 Mueller, K. et al. CRISPR-mediated insertion of a chimeric antigen receptor produces nonviral T cell products capable of inducing solid tumor regression. bioRxiv preprint doi: https://doi.org/10.1101/2021.08.06.455489 (2021)
Virus-Free CRISPR CAR T cells induce solid tumor regression
Chimeric antigen receptor (CAR) T cell therapy has shown promising efficacy in treating hematologic malignancies and has led to the FDA-approval of three CAR T cell products. However, there has been little success in treating solid tumors, as clinical trials to date have yielded little to no responses and no improvement in survival. Current methods of CAR T cell production typically involve the use of viral vectors which can give rise to complications such as insertional mutagenesis, leading to gene silencing or oncogene activation. In addition, GMP-grade viral vector manufacturing can be expensive with lengthy wait times for new batches. Here we have developed a virus-free strategy in primary T cells that has eliminated the use of viral vectors through the use of CRISPR-Cas9 to precisely edit the chimeric antigen receptor into the TRAC gene1. Our method of virus free production begins through the generation of a double stranded DNA (dsDNA) template produced by polymerase chain reaction (PCR). This template is then combined with a SpCas9-single guide RNA to create a ribonucleoprotein (RNP) complex. Isolated human primary T cells from adult healthy donors are then nucleofected with the RNP and dsDNA template on day 2 of ex vivo expansion. Flow cytometry is then utilized to immunophenotype the cell product and analyze the percent of efficiency of CAR gene transfer. Within the cell product, the editing efficiencies are \u3e95% TCR knockout and 35% CAR+. Transcriptional profiling indicates that the virus-free CART cells have a favorable memory-like phenotype. In addition to our in vitro work, in vivo mice studies with anti-GD2 CART products demonstrate regression of GD2+ solid tumors upon virus-free CART treatment, showing similar potency and survival to viral-produced CAR T cells. The production of virus-free CAR T cells has high potential to enable the rapid and flexible manufacturing of highly defined and highly potent CAR T cell products for the treatment of solid tumors. 1 Mueller, K. et al. CRISPR-mediated insertion of a chimeric antigen receptor produces nonviral T cell products capable of inducing solid tumor regression. bioRxiv preprint doi: https://doi.org/10.1101/2021.08.06.455489 (2021)
A supramolecular helix that disregards chirality
The functions of complex crystalline systems derived from supramolecular biological and non-biological assemblies typically emerge from homochiral programmed primary structures via first principles involving secondary, tertiary and quaternary structures. In contrast, heterochiral and racemic compounds yield disordered crystals, amorphous solids or liquids. Here, we report the self-assembly of perylene bisimide derivatives in a supramolecular helix that in turn self-organizes in columnar hexagonal crystalline domains regardless of the enantiomeric purity of the perylene bisimide. We show that both homochiral and racemic perylene bisimide compounds, including a mixture of 21 diastereomers that cannot be deracemized at the molecular level, self-organize to form single-handed helical assemblies with identical single-crystal-like order. We propose that this high crystalline order is generated via a cogwheel mechanism that disregards the chirality of the self-assembling building blocks. We anticipate that this mechanism will facilitate access to previously inaccessible complex crystalline systems from racemic and homochiral building blocks
The naked truth: a comprehensive clarification and classification of current 'myths' in naked mole-rat biology.
The naked mole-rat (Heterocephalus glaber) has fascinated zoologists for at least half a century. It has also generated considerable biomedical interest not only because of its extraordinary longevity, but also because of unusual protective features (e.g. its tolerance of variable oxygen availability), which may be pertinent to several human disease states, including ischemia/reperfusion injury and neurodegeneration. A recent article entitled 'Surprisingly long survival of premature conclusions about naked mole-rat biology' described 28 'myths' which, those authors claimed, are a 'perpetuation of beautiful, but falsified, hypotheses' and impede our understanding of this enigmatic mammal. Here, we re-examine each of these 'myths' based on evidence published in the scientific literature. Following Braude et al., we argue that these 'myths' fall into four main categories: (i) 'myths' that would be better described as oversimplifications, some of which persist solely in the popular press; (ii) 'myths' that are based on incomplete understanding, where more evidence is clearly needed; (iii) 'myths' where the accumulation of evidence over the years has led to a revision in interpretation, but where there is no significant disagreement among scientists currently working in the field; (iv) 'myths' where there is a genuine difference in opinion among active researchers, based on alternative interpretations of the available evidence. The term 'myth' is particularly inappropriate when applied to competing, evidence-based hypotheses, which form part of the normal evolution of scientific knowledge. Here, we provide a comprehensive critical review of naked mole-rat biology and attempt to clarify some of these misconceptions
Innervation patterns of sea otter (Enhydra lutris) mystacial follicle-sinus complexes
Sea otters (Enhydra lutris) are the most recent group of mammals to return to the sea, and may exemplify divergent somatosensory tactile systems among mammals. Therefore, we quantified the mystacial vibrissal array of sea otters and histologically processed follicle-sinus complexes (F - SCs) to test the hypotheses that the number of myelinated axons per F - SC is greater than that found for terrestrial mammalian vibrissae and that their organization and microstructure converge with those of pinniped vibrissae. A mean of 120.5 vibrissae were arranged rostrally on a broad, blunt muzzle in 7–8 rows and 9–13 columns. The F-SCs of sea otters are tripartite in their organization and similar in microstructure to pinnipeds rather than terrestrial species. Each F-SC was innervated by a mean 1339 ± 408.3 axons. Innervation to the entire mystacial vibrissal array was estimated at 161,313 axons. Our data support the hypothesis that the disproportionate expansion of the coronal gyrus in somatosensory cortex of sea otters is related to the high innervation investment of the mystacial vibrissal array, and that quantifying innervation investment is a good proxy for tactile sensitivity. We predict that the tactile performance of sea otter mystacial vibrissae is comparable to that of harbor seals, sea lions and walruses
Iterative Evolution of Sympatric Seacow (Dugongidae, Sirenia) Assemblages during the Past ∼26 Million Years
Extant sirenians show allopatric distributions throughout most of their range. However, their fossil record shows evidence of multispecies communities throughout most of the past ∼26 million years, in different oceanic basins. Morphological differences among co-occurring sirenian taxa suggest that resource partitioning played a role in structuring these communities. We examined body size and ecomorphological differences (e.g., rostral deflection and tusk morphology) among sirenian assemblages from the late Oligocene of Florida, early Miocene of India and early Pliocene of Mexico; each with three species of the family Dugongidae. Although overlapping in several ecomorphological traits, each assemblage showed at least one dominant trait in which coexisting species differed. Fossil sirenian occurrences occasionally are monotypic, but the assemblages analyzed herein show iterative evolution of multispecies communities, a phenomenon unparalleled in extant sirenian ecology. As primary consumers of seagrasses, these communities likely had a strong impact on past seagrass ecology and diversity, although the sparse fossil record of seagrasses limits direct comparisons. Nonetheless, our results provide robust support for previous suggestions that some sirenians in these extinct assemblages served as keystone species, controlling the dominance of climax seagrass species, permitting more taxonomically diverse seagrass beds (and sirenian communities) than many of those observed today
Discovery and Preclinical Pharmacology of INE963, a Potent and Fast-Acting Blood-Stage Antimalarial with a High Barrier to Resistance and Potential for Single-Dose Cures in Uncomplicated Malaria.
A series of 5-aryl-2-amino-imidazothiadiazole (ITD) derivatives were identified by a phenotype-based high-throughput screening using a blood stage Plasmodium falciparum (Pf) growth inhibition assay. A lead optimization program focused on improving antiplasmodium potency, selectivity against human kinases, and absorption, distribution, metabolism, excretion, and toxicity properties and extended pharmacological profiles culminated in the identification of INE963 (1), which demonstrates potent cellular activity against Pf 3D7 (EC50 = 0.006 μM) and achieves artemisinin-like kill kinetics in vitro with a parasite clearance time of \u3c24 h. A single dose of 30 mg/kg is fully curative in the Pf-humanized severe combined immunodeficient mouse model. INE963 (1) also exhibits a high barrier to resistance in drug selection studies and a long half-life (T1/2) across species. These properties suggest the significant potential for INE963 (1) to provide a curative therapy for uncomplicated malaria with short dosing regimens. For these reasons, INE963 (1) was progressed through GLP toxicology studies and is now undergoing Ph1 clinical trials
- …