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Biology subjects

Taber, A.

Publications and source records attributed to Taber, A..

3 recordsLinked to original sources

Human lung γδ T cells maintain functionality during inflammatory lung disease

{gamma}{delta} T cells provide mucosal defense against infection while also contributing to tissue repair. However, data regarding the effect of the human lung environment on {gamma}{delta} T cell functionality remains limited. To address whether lung inflammation impacts {gamma}{delta} T cell functionality, we analyzed lung and matched hilar lymph node (LN) tissue from deceased donors and patients with interstitial lung disease (ILD). We performed high-parameter spectral flow cytometry to examine the expression pattern of phenotypic biomarkers and assess ex vivo function. We identified lung-specific enrichment of {gamma}{delta} T cells with an effector memory phenotype relative to matched regional LN. We then used an ex vivo stimulation approach to interrogate the capacity to protect against infection (granzyme B [GzmB], interferon-{gamma} [IFN{gamma}] and tumor necrosis factor [TNF]) and promote epithelial cell proliferation (amphiregulin [AREG]). We found that {gamma}{delta} T cells in lung and LN from deceased donors had similar functional properties. While {gamma}{delta} T cell populations from ILD lungs largely maintained cytokine production capacity, expression was diminished relative to LN counterparts. Importantly, lung {gamma}{delta} T cells maintained polyfunctional GzmB, IFN{gamma} and TNF expression across cohorts. Overall, we report human lung {gamma}{delta} T cells are regionally distinct with conserved functionality in a fibrotic environment.

immunology↗

TGF-β broadly modifies rather than specifically suppresses reactivated memory CD8 T cells in a dose-dependent manner

Transforming growth factor {beta} (TGF-{beta}) directly acts on naive, effector and memory T cells to control cell fate decisions, which was shown using genetic abrogation of TGF-{beta} signaling. TGF-{beta} availability is altered by infections and cancer, however the dose-dependent effects of TGF-{beta} on memory CD8 T cell (Tmem) reactivation are still poorly defined. We examined how activation and TGF-{beta} signals interact to shape the functional outcome of Tmem reactivation. We found that TGF-{beta} could suppress cytotoxicity in a manner that was inversely proportional to the strength of the activating TCR or pro-inflammatory signals. In contrast, even high doses of TGF-{beta} had a comparatively modest effect on IFN-{gamma} expression in the context of weak and strong reactivation signals. Since CD8 Tmem may not always receive TGF-{beta} signals concurrently with reactivation, we also explored whether the temporal order of reactivation versus TGF-{beta} signals is of importance. We found that exposure to TGF-{beta} prior to as well as after an activation event were both sufficient to reduce cytotoxic effector function. Concurrent ATAC-seq and RNA-seq analysis revealed that TGF-{beta} altered [~]10% of the regulatory elements induced by reactivation and also elicited transcriptional changes indicative of broadly modulated functional properties. We confirmed some changes on the protein level and found that TGF-{beta}-induced expression of CCR8 was inversely proportional to the strength of the reactivating TCR signal. Together, our data suggest that TGF-{beta} is not simply suppressing CD8 Tmem, but modifies functional and chemotactic properties in context of their reactivation signals and in a dose-dependent manner.

immunology↗

Expression and Manufacturing of Protein Therapeutics in Spirulina

Arthrospira platensis (commonly known as spirulina) is a photosynthetic cyanobacterium1. It is a highly nutritious food that has been consumed for decades in the US, and even longer by indigenous cultures2. Its widespread use as a safe food source and proven scalability have driven frequent attempts to convert it into a biomanufacturing platform. But these were repeatedly frustrated by spirulinas genetic intractability. We report here efficient and versatile genetic engineering methodology for spirulina that allows stable expression of bioactive protein therapeutics at high levels. We further describe large-scale, indoor cultivation and downstream processing methods appropriate for the manufacturing of biopharmaceuticals in spirulina. The potential of the platform is illustrated by pre-clinical development and human testing of an orally delivered antibody therapeutic against campylobacter, a major cause of infant mortality in the developing world and a growing antibiotic resistance threat3,4. This integrated development and manufacturing platform blends the safety of food-based biotechnology with the ease of genetic manipulation, rapid growth rates and high productivity characteristic of microbial platforms. These features combine for exceptionally low-cost production of biopharmaceuticals to address medical needs that are unfeasible with current biotechnology platforms.

molecular biology↗