Biology subjects

Douglass, J.

Publications and source records attributed to Douglass, J..

5 recordsLinked to original sources

bioRxiv2026

Potential of HLA-E-targeting diabodies to induce lysis of HIV-1-infected cells by CD8+ T cells

A long-lived reservoir of cells harboring intact HIV-1 provirus persists throughout decades of antiretroviral therapy and can give rise to rapid viral rebound after treatment interruption. Some cure strategies employ cytotoxic T lymphocytes (CTL) to target this reservoir; however, the applicability and efficacy of immunotherapeutic strategies involving MHC class I-restricted CTL is limited by the polymorphic nature of MHC class I molecules and their downregulation by HIV-1 Nef. The non-polymorphic non-classical class I molecule HLA-E is stably expressed on HIV-1-infected CD4+ T cells and presents a potential universal target. We generated a single-chain diabody RLP-13 that redirects CTLs to target cells presenting a well-characterized peptide derived from Mycobacterium tuberculosis in the context of HLA-E. We verified the affinity and specificity of RLP-13. Through co-culture experiments, we confirmed that RLP-13 mediates polyfunctional, HLA-agnostic CTL responses. Using an HIV-1 reporter construct encoding the target peptide, we demonstrated robust and specific elimination of the HIV-1-expressing cell population. This proof-of-concept study shows that HLA-E antigens are promising immunotherapeutic targets that can bypass the limitations of classical MHC class I antigens - allelic variation and downregulation - and that such bispecific antibodies recognizing HIV-1-derived HLA-E binding epitopes could induce elimination of productively infected cells. SummarySengupta, Bachmann et al. utilize a novel HLA-E-restricted CD3-engaging single-chain diabody to induce antigen-specific polyfunctional CTL-responses that are HLA-type-independent. They further show that such biologics have potential to eliminate HIV-1-infected cells by targeting HLA-E-binding epitopes encoded in the HIV-1 provirus.

microbiology↗

bioRxiv2026

Precise measurement of rodent drinking using CLiQR (Capacitive Lick Quantification in Rodents)

Accurate quantification of rodent licking behavior is essential for studies of fluid intake, including investigations of alcohol use disorder and obesity. Lickometry systems vary widely in sensing modality, cost, scalability, and data resolution. Also, many available systems require specialized housing or store only binary lick/no lick data based on thresholding. Here, we present CLiQR (Capacitive Lick Quantification in Rodents), an open-source capacitive lickometry system designed for high-throughput recording of licking behavior in home-cage environments while preserving the full capacitance time series. The system uses MPR121 capacitive sensors connected to custom metal-tipped serological pipette sippers and a centralized desktop computer to record data from up to 24 mice concurrently, with capacity for two-bottle choice experiments. Validation experiments demonstrated that the capacitive signals reliably distinguish licking from non-licking interactions. Total lick counts showed a positive correlation with measured fluid consumption (R2 = 0.849, p < 0.0001), confirming that detected events provide a meaningful proxy for intake. All information necessary to reproduce the system is shared openly in this manuscript and online. By combining scalability, full-trace data acquisition, and low cost, CLiQR provides a flexible and extensible platform for high-throughput behavioral neuroscience experiments and enables retrospective improvement of lick-detection algorithms.

animal behavior and cognition↗

bioRxiv2025

Engineering immunotoxin-equipped effector cells and evaluation in primary human immune cells

Lethal toxins could become potent therapies against cancer, but their clinical utility is limited by adverse events upon systemic administration. These could be reduced if the toxins were delivered by effector cells that specifically infiltrate cancers, thereby releasing toxins locally into the tumor microenvironment. One of the challenges underlying this strategy is that cells delivering toxins would have to be resistant to them. We address this obstacle by showing that effectors derived from transformed human cell lines genetically engineered for resistance to bacterial adenosine diphosphate ribosylating toxins (ADPRTs), including Pseudomonas aeruginosa exotoxin A (PE), can produce targeted immunotoxins that specifically kill cancer cells expressing cognate tumor-associated antigens. Resistance to immunotoxins was achieved by knockout of genes in the diphthamide biosynthesis pathway (DPH1-4) required for the posttranslational modification of eukaryotic elongation factor 2 (EEF2) that is the target of ADPRTs, or by mutation of EEF2 itself. We show that engineering resistance to ADPRTs, one of the most potent toxins acting on human cells, is essential to achieve robust function of armored effector cell lines. This work establishes a first step on the path to equip effector cells with the ability to deliver powerful toxins to cancer cells and introduces a platform to investigate extension to primary autologous or allogeneic therapeutic cell types.

molecular biology↗

bioRxiv2024

Temperature drives seagrass recovery across the Western North Atlantic

Climate-driven shifts in herbivores, temperature and nutrient runoff threaten coastal ecosystem resilience. However, our understanding of ecological resilience, particularly for foundation species, remains limited due to a rarity of field experiments that are conducted across appropriate spatial and temporal scales and that investigate multiple stressors. This study aimed to evaluate the resilience of a widespread tropical marine plant (turtlegrass) to disturbances across its geographic range and how this is impacted by environmental gradients in (a)biotic factors. We assessed the resilience (i.e. recovery) of turtlegrass to a simulated disturbance (complete above- and belowground biomass removal) over a year. Contrary to temperate studies, higher temperature generally enhanced seagrass recovery. While nutrients and light availability had minimal impact, combined high levels of nutrients and herbivore grazing (meso and megaherbivore) reduced aboveground recovery. Our results suggest that the resilience of some tropical species, especially in cooler subtropical waters, may initially increase with warming.

ecology↗

bioRxiv2021

Supercharged Cellulases Show Reduced Non-Productive Binding, But Enhanced Activity, on Pretreated Lignocellulosic Biomass

Non-productive adsorption of cellulolytic enzymes to various plant cell wall components, such as lignin and cellulose, necessitates high enzyme loadings to achieve efficient conversion of pretreated lignocellulosic biomass to fermentable sugars. Carbohydrate-binding modules (CBMs), appended to various catalytic domains (CDs), promote lignocellulose deconstruction by increasing targeted substrate-bound CD concentration but often at the cost of increased non-productive enzyme binding. Here, we demonstrate how a computational protein design strategy can be applied to a model endocellulase enzyme (Cel5A) from Thermobifida fusca to allow fine-tuning its CBM surface charge, which led to increased hydrolytic activity towards pretreated lignocellulosic biomass (e.g., corn stover) by up to [~]330% versus the wild-type Cel5A control. We established that the mechanistic basis for this improvement arises from reduced non-productive binding of supercharged Cel5A mutants to cell wall components such as crystalline cellulose (up to 1.7-fold) and lignin (up to 1.8-fold). Interestingly, supercharged Cel5A mutants that showed improved activity on various forms of pretreated corn stover showed increased reversible binding to lignin (up to 2.2-fold) while showing no change in overall thermal stability remarkably. In general, negative supercharging led to increased hydrolytic activity towards both pretreated lignocellulosic biomass and crystalline cellulose whereas positive supercharging led to a reduction of hydrolytic activity. Overall, selective supercharging of protein surfaces was shown to be an effective strategy for improving hydrolytic performance of cellulolytic enzymes for saccharification of real-world pretreated lignocellulosic biomass substrates. Future work should address the implications of supercharging cellulases from various families on inter-enzyme interactions and synergism.

bioengineering↗