Biology subjects

Mehta, C.

Publications and source records attributed to Mehta, C..

4 recordsLinked to original sources

bioRxiv2025

Angiogenic CD8 T cells from PWH induce Granzymes-dependent PAR1 activation promoting endothelial inflammation

In people with HIV (PWH), T cell immune activation and endothelial inflammation are contributors of the increased cardiovascular risk, however the mechanisms remain poorly understood. PAR1 connects the coagulation cascade, endothelial cells and CD8 T cells at the site of endothelial inflammation and we hypothesized that HIV driven CD8 T cell immune activation alters endothelial repair mechanisms. Endothelial repair is partially mediated by angiogenic T (Tang) cells that facilitate proliferation of endothelial cells, and differentiation of endothelial progenitor cells at site of vascular injury. During LCMV infection, we identified a subset of CD31highCD8 T cells that exhibited a long-lived memory precursor phenotype (CD127+KLRG1-) and secreted the proangiogenic cytokine vascular endothelial growth factor (VEGF) after viral control. Furthermore, in PWH, the frequencies of CD8 Tang cells were reduced and showed an activated phenotype and expression of granzymes. GZMA+GZMB+CD8 Tang cells correlated with atherosclerotic cardiovascular disease (ASCVD) risk. In vitro, granzyme dependent PAR1 activation led to calcium mobilization and secretion of proinflammatory cytokines IL-6, IL-8 and angiopoietin-2 by primary human endothelial cells. Altogether, these findings suggest that CD8 T cells are involved in immunity against viruses and endothelial homeostasis and HIV driven immune activation alters these functions.

immunology↗

bioRxiv2024

Associations on the Fly, a new feature aiming to facilitate exploration of the Open Targets Platform evidence

MotivationThe Open Targets Platform (https://platform.opentargets.org) is a unique, comprehensive, open-source resource supporting systematic identification and prioritisation of targets for drug discovery. The Platform combines, harmonises and integrates data from >20 diverse sources to provide target-disease associations, covering evidence derived from genetic associations, somatic mutations, known drugs, differential expression, animal models, pathways and systems biology. An in-house target identification scoring framework weighs the evidence from each data source and type, contributing to an overall score for each of the 7.8M target-disease associations. However, the previous infrastructure did not allow user-led dynamic adjustments in the contribution of different evidence types for target prioritisation, a limitation frequently raised by our user community. Furthermore, the previous Platform user interface did not support navigation and exploration of the underlying target-disease evidence on the same page, occasionally making the user journey counterintuitive. ResultsHere, we describe "Associations on the Fly" (AOTF), a new Platform feature - developed as part of a wider product refactoring project - to enable formulation of more flexible and impactful therapeutic hypotheses through dynamic adjustment of the weight of contributing evidence from each source, altering the prioritisation of targets. Availability and implementationAll Open Targets code is available as open source: [https://github.com/opentargets]. This tool was implemented using React v18 and its code is accessible here: [https://github.com/opentargets/ot-ui-apps]. The tools described in the paper are accessible through the Open Targets Platform web interface [https://platform.opentargets.org/] and GraphQL API (https://platform-docs.opentargets.org/data-access/graphql-api). Data is available for download here: [https://platform.opentargets.org/downloads] and from the EMBL-EBI FTP: [https://ftp.ebi.ac.uk/pub/databases/opentargets/platform/]. Supplementary informationAdditional information on this tool can be found on the Platform documentation pages [https://platform-docs.opentargets.org/web-interface, https://platform-docs.opentargets.org/web-interface/associations-on-the-fly, https://platform-docs.opentargets.org/target-prioritisation] and training video [https://youtu.be/2A9bksboAag]. ContactAnnalisa Buniello, EMBL-EBI, buniello@ebi.ac.uk

bioinformatics↗

bioRxiv2023

Frizzled2 receives the WntA morphogen during butterfly wing pattern formation

Butterfly color patterns provide visible and biodiverse phenotypic readouts of the patterning processes that occur in a developing epithelium. While the secreted ligand WntA was shown to instruct the color pattern formation in butterflies, its modes of reception and signal transduction remain elusive. Butterfly genomes encode four homologues of the Frizzled-family of Wnt receptors. Here we show that CRISPR mosaic knock-outs of frizzled2 (fz2) phenocopy the color pattern effects of WntA loss-of-function in multiple nymphalids. While WntA mosaic clones result in intermediate patterns of reduced size, consistently with a morphogen function, fz2 clones are cell-autonomous. Shifts in pupal expression in WntA crispants show that WntA and fz2 are under positive and negative feedback, respectively. Fz1 is required for Wnt-independent planar cell polarity (PCP) in the wing epithelium. Fz3 and Fz4 show phenotypes consistent with Wnt competitive-antagonist functions in vein formation (Fz3 and Fz4), wing margin specification (Fz3), and color patterning in the Discalis and Marginal Band Systems (Fz4). Overall, these data show that the WntA/Frizzled2 morphogen-receptor pair forms a signaling axis that instructs butterfly color patterning, and shed light on the functional diversity of insect Frizzled receptors.

developmental biology↗

bioRxiv2018

Dual language experience enhances neural activation variability during an fMRI reading and language task

Previous work has shown that experience speaking more than one language in childhood is associated with decreased intra-individual neural variability in electrophysiological responses during a low-level speech perception task. However, no study has yet evaluated the impact of dual language experience on variability in fMRI responses during a higher-level spoken and written language processing task. In the current study, we calculated trial-by-trial variability in neural activation during an fMRI task that involved deciding whether spoken or printed English words matched pictures of items. We compared trial-by-trial neural activation variability between two groups of 8-15 year-old children: a group of dual language learners (N = 24; 11 female) who were Spanish-dominant and acquiring English, and a group of monolingual learners who were English-dominant (N = 17; 9 female). We found that when controlling for a variety of language, general cognitive, and demographic measures, neural activation variability for printed words was greater in the dual language learners compared to the monolingual learners in the right middle frontal gyrus, a brain region previously associated with attentional control. This finding highlights how neural variability offers a window of opportunity to examine experience-dependent mechanisms during human development, and motivates future research on bilingual language processing.

neuroscience↗