Biology subjects

Spencer, T.

Publications and source records attributed to Spencer, T..

5 recordsLinked to original sources

bioRxiv2026

Serum free expansion and transduction of human Vγ9δ2 T cells for adoptive immunotherapy

Background and AimGamma delta T cells are multivalent immune cells with innate and adaptive features that sense a broad spectrum of tumor-associated stress patterns to lyse them without prior potentiation. They are therefore a good option for developing an off-the-shelf therapeutic immune cell product with antitumor functions. Therefore, we aimed to develop an optimized cGMP compatible protocol for expanding V gamma 9-V delta 2 T cells in a serum-free media for adoptive immunotherapy applications. Methods and ResultsPeripheral blood mononuclear cells (PBMC) from healthy donors were activated with Zoledronic Acid (ZOL) and IL-2 for 14 days. Cell proliferation, fold expansion, and phenotype were monitored. Among the regular donors, the baseline levels (day 0) of CD3+Vgamma9+delta2+ T cells were (05.10+/-0.74%). There was a robust expansion of V gamma 9-V delta 2 T cells in the serum-free media (110+/-29.89-fold). During processing, an abrupt reduction of {beta} T cells was observed as early as day +07. After two weeks, 87.82+/-5.11% (n=8) of T cells were CD3+Vgamma9+ in Optimizer with 97.15+/-0.7% of the CD3+Vgamma9+ T cells positive for delta2. The CD3+Vgamma9+ NKG2D+ increased during expansion, reaching 93.76+/-1.55% expression on day +14. V gamma 9-V delta 2 T cells expanded in the serum-free (Optimizer) media had relatively reduced variance and reduced over all yield and fold expansion but comparable percentage of Vgamma9+ and {beta} TCR+ T cells on day 14. A flow cytometry-based tumor-toxicity assay gauged the antitumor functions against K562 cell lines. Pretreatment of K562 cells with ZOL differentially enhanced (2.48+/-0.76 fold) the cytotoxic capacity of V gamma 9-V delta 2 T cells in a donor-dependent manner. The conditions for lentiviral transduction and transgene expressions of V gamma 9-V delta 2 T cells were improvised as gauged by GFP expression driven by CMV promoter (39.09+/- 8.94%) without compromising the viability. ConclusionWe have optimized a cGMP compatible protocol for expansion of human V gamma 9-V delta 2 T cells in a serum-free media with high purity and viability in as early as 07 days. Pretreatment of target tumor cells with ZOL enhanced the cytotoxicity, revealing the impact of V gamma 9-V delta 2 T cell intrinsic factors in tumor lysis. This protocol, may be scaled up for clinical translation for adoptive immunotherapy.

bioengineering↗

bioRxiv2024

Transcriptomic signature and pro-osteoclastic secreted factors of abnormal bone marrow stromal cells in fibrous dysplasia

Fibrous dysplasia (FD) is a mosaic skeletal disorder caused by somatic activating variants in GNAS, encoding for Gs, which leads to excessive cAMP signaling in bone marrow stromal cells (BMSCs). Despite advancements in our understanding of FD pathophysiology, the effect of Gs activation in the BMSC transcriptome remains unclear, as well as how this translates into their local influence in the lesional microenvironment. In this study, we analyzed changes induced by Gs activation in BMSC transcriptome and performed a comprehensive analysis of their production of cytokines and other secreted factors. We performed RNAseq of cultured BMSCs from patients with FD and healthy volunteers, and from an inducible mouse model of FD, and combined their transcriptomic profiles to build a robust FD BMSC genetic signature. Pathways related to Gs activation, cytokine signaling, and extracellular matrix deposition were identified. In addition, a comprehensive profile of their secreted cytokines and other factors was performed to identify modulation of several key factors we hypothesized to be involved in FD pathogenesis. We also screened circulating cytokines in a collection of plasma samples from patients with FD, finding positive correlations of several cytokines to their disease burden score, as well as to one another and bone turnover markers. Overall, these data support a pro-inflammatory, pro-osteoclastic behavior of BMSCs bearing hyperactive Gs variants, and point to several cytokines and other secreted factors as possible therapeutic targets and/or circulating biomarkers for FD.

pathology↗

bioRxiv2023

Identifying the core genome of the nucleus-forming bacteriophage family and characterization of Erwinia phage RAY

We recently discovered that some bacteriophages establish a nucleus-like replication compartment (phage nucleus), but the core genes that define nucleus-based phage replication and their phylogenetic distribution were unknown. By studying phages that encode the major phage nucleus protein chimallin, including previously sequenced yet uncharacterized phages, we discovered that chimallin-encoding phages share a set of 72 highly conserved genes encoded within seven distinct gene blocks. Of these, 21 core genes are unique to this group, and all but one of these unique genes encode proteins of unknown function. We propose that phages with this core genome comprise a novel viral family we term Chimalliviridae. Fluorescence microscopy and cryo-electron tomography studies of Erwinia phage vB_EamM_RAY confirm that many of the key steps of nucleus-based replication encoded in the core genome are conserved among diverse chimalliviruses, and reveal that non-core components can confer intriguing variations on this replication mechanism. For instance, unlike previously studied nucleus-forming phages, RAY doesnt degrade the host genome, and its PhuZ homolog appears to form a five-stranded filament with a lumen. This work expands our understanding of phage nucleus and PhuZ spindle diversity and function, providing a roadmap for identifying key mechanisms underlying nucleus-based phage replication.

microbiology↗

bioRxiv2019

Precision-weighting of superior frontal cortex unsigned prediction error signals benefits learning, is mediated by dopamine, and is impaired in psychosis.

Recent theories of cortical function construe the brain as performing hierarchical Bayesian inference. According to these theories, the precision of cortical unsigned prediction error (i.e., surprise) signals plays a key role in learning and decision-making, to be controlled by dopamine, and to contribute to the pathogenesis of psychosis. To test these hypotheses, we studied learning with variable outcome-precision in healthy individuals after dopaminergic modulation and in patients with early psychosis. Behavioural computational modelling indicated that precision-weighting of unsigned prediction errors benefits learning in health, and is impaired in psychosis. FMRI revealed coding of unsigned prediction errors relative to their precision in bilateral superior frontal gyri and dorsal anterior cingulate, which was perturbed by dopaminergic modulation, impaired in psychosis, and associated with task performance and schizotypy. We conclude that precision-weighting of cortical prediction error signals is a key mechanism through which dopamine modulates inference and contributes to the pathogenesis of psychosis.

neuroscience↗

bioRxiv2019

The Evolution of Placental Invasion and Cancer Metastasis are Causally Linked

Among mammals, the extent of placental invasion is correlated with vulnerability to malignancy. Animals with more invasive placentation (e.g. humans) are more vulnerable to malignancy, whereas animals with a non-invasive placenta (e.g. ruminants) are less likely to develop malignant cancer. To explain this correlation, we propose the hypothesis of Evolved Levels of Invasibility (ELI) positing that the permissiveness of stromal tissue to invasion is a unitary character affecting both placental and cancer invasion. We provide evidence for this hypothesis by contrasting invasion of human and bovine cancer and placental cells into a lawn of stromal cells from different species. We find that both bovine endometrial and skin fibroblasts are more resistant to invasion of placental and cancer cells than their human counterparts. Gene expression profiling identified genes with high expression in human but not bovine fibroblasts. Knocking down of a subset of them in human fibroblasts leads to significantly stronger resistance to cancer cell invasion. Comparative analysis of gene expression among mammals suggests that humans evolved higher vulnerability to malignancy than the eutherian ancestor, possibly as a correlate of more invasive placentation, and boroeutherians evolved to decrease stromal invasibility. Identifying the evolutionary determinants of stromal invasibility can provide significant insights to develop rational anti-metastatic therapeutics.

cancer biology↗