Biology subjects

Boudreau, J. E.

Publications and source records attributed to Boudreau, J. E..

2 recordsLinked to original sources

bioRxiv2025

An atlas of natural killer cell receptor expression on healthy donor T and NK lymphocytes

Human T cells and natural killer (NK) cells exhibit variegated co-expression of germlineencoded receptors, which diversifies their effector functions. CD8+ T cell expression of receptors more typically associated with NK cells has been noted, but a systematic analysis of their distribution has not been described. Here, we comprehensively measured human NK cells and T cells expression of NK cell-associated receptors to define their co-expression and patterns associated with donor sex, maturation, and activation. To assess the activating and inhibitory receptor repertoire of human T cells and NK cells, we developed a 25-colour flow cytometry panel that included channels based on receptor functions. Since NK cell function is known to be driven by interactions with HLA supergroups (KIR ligands), we stratified donors based on KIR-HLA allelic combinations. NK and CD8+ T cell phenotypes and responsiveness were assessed at rest, and in response to the missing self target cell line, K562. We find that NK cells universally express CD45RA, CD161, and the inhibitory receptors TIGIT/TIM3/LAG3. On CD56dimCD16high NK cells (those most aligned with missing self reactivity, CD161, CD45RA, natural cytotoxicity receptors (NCRs), and TIGIT/TIM3/LAG3 were most frequently expressed. Not all educated NK cells respond to missing self-targets; those that did exhibited high expression of NCRs, NKG2C, IL-7R/IL-18Ra, and TIGIT/TIM3/LAG3, and lower expression of DNAM-1 and CCR7, in addition to the KIR molecules that defined their status as educated. We note that up to 50% of NK cells express CD8, and this population co-expressed CD16, NCRs, and KIR, and exhibited greater cytotoxicity than the CD8-NK cell population. Among CD8+ T cells, acquisition of NK cell-associated receptors was increased as they progressed through differentiation states: effector memory and terminally-differentiated CD8+ T cells exhibiting higher expression of NKG2A, KIR, and CD16. Taken together, the variability of receptor expression patterns highlights the diversity of lymphocyte populations and suggests shared features among the cytotoxic lymphocytes.

immunology↗

bioRxiv2022

Tumor Spheroids Layered in an Imageable Cancer Environment (T-SLICE): a novel in vitro platform to study tumor biology

Cancer treatment is shifting towards precise medicine informed by tumor genetics and structural features. In recent years, it has become increasingly recognized that patient tumors--even those of the same tissue origin--can differ substantially between patients and respond differently to treatment. Given this, it is necessary to design therapies that target the heterogeneity of tumors. When investigating novel therapeutics in the laboratory, conventional cell culture models do not adequately recapitulate this heterogeneity and therefore may not accurately represent drug responses. Recent advances in miniaturized organ-on-a-chip models have been able to generate more complex microenvironments for in vitro studies. However, many of these models do not resemble the scale of clinically relevant tumors and pose a high barrier to use because they are technically complex. To facilitate mechanistic studies of the tumor microenvironment (TME), we designed T-SLICE, a chip made using commercially available elastomers and designed to fit in a standard 6-well plate. This simple 3-D tumor model incorporates microfluidic principles into a fully customizable TME, wherein cells drive the formation of biochemical gradients akin to those observed within a real tumor. In T-SLICE, spheroids are seeded atop a monolayer of fibroblasts situated between two closely spaced coverslips (300-700 {micro}m). The restrictive gap height limits the permeation of oxygen (O2) and hinders the removal of carbon dioxide (CO2) and metabolic waste, which leads to the generation of tumor-like hypoxic gradients. We demonstrate that T-SLICE establishes cell-driven oxygen gradients leading to the formation of a hypoxic core, with further impacts on cellular viability, mitochondrial membrane potential (MMP), and proliferation. T-SLICE cultures can be imaged live or fixed and stained for immunohistochemistry (IHC). These features of T-SLICE make it an accessible and faithful model of a tumors heterogeneity and open the possibility for more faithful testing of novel therapeutics in the context of a realistic TME.

bioengineering↗