Biology subjects

Rosenstein, A.

Publications and source records attributed to Rosenstein, A..

3 recordsLinked to original sources

bioRxiv2024

FAST-STEM: A human pluripotent stem cell engineering toolkit for rapid design-build-test-learn development of human cell-based therapeutic devices

Very recent clinical advances in stem cell derived tissue replacement and gene therapy, in addition to the rise of artificial intelligence-aided scientific discovery, have placed the possibility of sophisticated human cell-based therapies firmly within reach. However, development of such cells and testing of their engineered gene circuit components, has proven highly challenging, due to the need for generating stable cell lines for each design-build-test-learn engineering cycle. Current approaches to generating stable human induced pluripotent stem cell (hiPSC) lines are highly time-consuming and suffer from lack of control, poor integration efficiency, and limited functionality. Validation in clinically relevant stem cell derived tissues is also broadly lacking. Such drawbacks are prohibitive to repeatably conducting cutting-edge stem cell engineering with broad application within a realistic timeframe and will not scale with the future of regenerative medicine. We have developed FAST-STEM (Facile Accelerated Stem-cell Transgene integration with SynBio Tunable Engineering Modes), a hPSC engineering platform that drastically reduces the time to generate differentiation ready stem cell lines from several weeks to 5 days, exhibiting a ~612-fold improvement in transgene integration rate over previous methodologies. Additional FAST-STEM innovations include: (i) rapid and highly efficient transgene integration; (ii) copy number control; (iii) simultaneous or consecutive integration of multiple gene cassettes; (iv) library screen capability. In addition to this unique functional versatility, platform transportability and broad use case for stem cell-engineering was confirmed by differentiation into eight different cell types across nine different laboratories. This platform dramatically lowers the bar for integration of synthetic biology with regenerative medicine, enabling experiments which were previously deemed logistically impossible, thus paving the way for sophisticated human cell device development.

bioengineering↗

bioRxiv2023

Gut-associated lymphoid tissue attrition associates with response to anti-α4β7 therapy in ulcerative colitis

Targeting the 4{beta}7-MAdCAM-1 axis with vedolizumab (VDZ) is a front-line therapeutic paradigm in ulcerative colitis (UC). However, mechanism(s) of action (MOA) of VDZ remain relatively undefined. Here, we examined three distinct cohorts of patients with UC (n=83, n=60, and n=21), to determine the effect of VDZ on the mucosal and peripheral immune system. Transcriptomic studies with protein level validation were used to study drug MOA using conventional and transgenic murine models. We found a significant decrease in colonic and ileal naive B and T cells and circulating gut-homing plasmablasts ({beta}7+) in VDZ-treated patients, pointing to gut-associated lymphoid tissue (GALT) targeting by VDZ. Murine Peyers patches (PP) demonstrated a significant loss cellularity associated with reduction in follicular B cells, including a unique population of epithelium-associated B cells, following anti-4{beta}7 antibody (mAb) administration. Photoconvertible (KikGR) mice unequivocally demonstrated impaired cellular entry into PPs in anti-4{beta}7 mAb treated mice. In VDZ-treated, but not anti-tumor necrosis factor-treated UC patients, lymphoid aggregate size was significantly reduced in treatment responders compared to non-responders, with an independent validation cohort further confirming these data. GALT targeting represents a novel MOA of 4{beta}7-targeted therapies, with major implications for this therapeutic paradigm in UC, and for the development of new therapeutic strategies.

immunology↗

bioRxiv2019

Predictability in the evolution of Orthopteran cardenolide insensitivity

The repeated evolutionary specialisation of distantly related insects to cardenolide-containing host plants provides a stunning example of parallel adaptation. Hundreds of herbivorous insect species have independently evolved insensitivity to cardenolides, which are potent inhibitors of the alpha-subunit of Na+, K+-ATPase (ATP). Previous studies investigating ATP-mediated cardenolide insensitivity in five insect orders have revealed remarkably high levels of parallelism in the evolution of this trait, including the frequent occurrence of parallel amino acid substitutions at two sites and recurrent episodes of duplication followed by neo-functionalisation. Here we add data for a sixth insect order, Orthoptera, which includes an ancient group of highly aposematic cardenolide-sequestering grasshoppers in the family Pyrgomorphidae. We find that Orthopterans exhibit largely predictable patterns of evolution of insensitivity established by sampling other insect orders. Taken together the data lend further support to the proposal that negative pleiotropic constraints are a key determinant in the evolution of cardenolide insensitivity in insects. Furthermore, analysis of our expanded taxonomic survey implicates positive selection acting on site 111 of cardenolide-sequestering species with a single-copy of ATP, and sites 115, 118 and 122 in lineages with neo-functionalised duplicate copies, all of which are sites of frequent parallel amino acid substitution.

evolutionary biology↗