Biology subjects

McMahon-Skates, T.

Publications and source records attributed to McMahon-Skates, T..

3 recordsLinked to original sources

bioRxiv2025

Conserved Landscape of Chemokine Receptor Co-expression Defines the Functional States of CD8+ T Cells in Melanoma

Cancer immunotherapies, from checkpoint blockade to adoptive cell therapies like tumor-infiltrating lymphocytes (TILs), have revolutionized cancer treatment but are limited by variable efficacy and significant toxicities. A central challenge is identifying ideal T-cell populations that effectively eliminate tumors without causing off-target damage, a distinction not captured by existing biomarkers. We show that co-expression patterns of chemokine receptors (CRs) CXCR3, CCR5, and CXCR6 on CD8+ T cells provide a functional "code" defining subsets with divergent roles in on-target immunity versus off-target inflammation. In mouse and human melanoma, a triple-positive (CXCR3+CCR5+CXCR6+) T-cell subset is essential for tumor control, and its genetic signature correlates with positive clinical response, while a distinct CCR5+CXCR6+ subset drives liver immune-related adverse events (IRAEs). Crucially, this CR code reveals that immunotherapy actively reshapes T-cell trafficking patterns, uncovering profound heterogeneity within conventional populations and distinguishing potent anti-tumor progenitors from cells predisposed to exhaustion or off-target migration. This work establishes CR co-expression as a practical tool, providing a surface marker-based strategy to identify and enrich optimized T cells for adoptive therapies, thereby offering a framework to uncouple efficacy from toxicity. One Sentence SummaryCo-expression of CCR5, CXCR6, and CXCR3 provides a functional code that separates T-cell-mediated anti-tumor efficacy from off-target toxicity, enabling the selection of superior cells for safer and more effective cancer immunotherapies. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=120 SRC="FIGDIR/small/693486v2_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@19b0f44org.highwire.dtl.DTLVardef@1076129org.highwire.dtl.DTLVardef@17c0be6org.highwire.dtl.DTLVardef@f14893_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LI{middle dot} CXCR6, CXCR3 and CCR5 co-expression signature stratifies patient survival in human melanoma C_LIO_LI{middle dot} CD8+ T cells co-expressing CXCR6, CXCR3 and CCR5 are critical effectors with high proliferative, cytotoxic, and activation profile in human and mice melanoma C_LIO_LI{middle dot} CD8+ T cells co-expressing CXCR6, CXCR3 and CCR5 drive anti-tumoral responses during checkpoint blockade in both human and mice C_LI

immunology↗

bioRxiv2024

Harmonizing terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) with multiplexed iterative immunofluorescence enriches spatial contextualization of cell death

Terminal deoxynucleotidyl transferase dUTP Nick End Labeling (TUNEL) is an essential tool for the detection of cell death in tissues. Although TUNEL is not known to be compatible with multiplexed spatial proteomic methods, harmonizing TUNEL with such methods offers the opportunity to delineate cell-type specific cell death labeling and precise spatial contextualization of cell death in complex tissues. Here we evaluated variations of the TUNEL assay for their compatibility with a multiplexed immunofluorescence method, multiple iterative labeling by antibody neodeposition (MILAN), in two different tissues and injury models for cell death, acetaminophen-induced hepatocyte necrosis and dexamethasone-induced adrenocortical apoptosis. Using a commercial Click-iT-based assay as a standard, TUNEL signal could be reliably produced independent of antigen-retrieval method, with tissue-specific minor differences in signal-to-noise. In contrast, proteinase K treatment consistently reduced or even abrogated protein antigenicity, while pressure cooker treatment consistently enhanced protein antigenicity for the targets tested. Antibody-based TUNEL protocols using pressure-cooker antigen retrieval were MILAN erasure-compatible thus enabling harmonization of TUNEL with MILAN. As many as four staining cycles could be performed without loss of subsequent TUNEL signal, while first-round TUNEL did not influence protein antigenicity in subsequent rounds. We conclude this harmonized assay performs comparably to an established commercial assay, but preserves protein antigenicity, thus enabling versatile integration with multiplexed immunofluorescence using MILAN. We anticipate this harmonized protocol will enable broad and flexible integration of TUNEL into multiplexed spatial proteomic assays, thus vastly enhancing the spatial contextualization of cell death in complex tissues.

pathology↗

bioRxiv2023

Chronic metabolic stress drives developmental programs and loss of tissue functions in non-transformed liver that mirror tumor states and stratify survival

Under chronic stress, cells must balance competing demands between cellular survival and tissue function. In metabolic dysfunction-associated steatotic liver disease (MASLD, formerly NAFLD/NASH), hepatocytes cooperate with structural and immune cells to perform crucial metabolic, synthetic, and detoxification functions despite nutrient imbalances. While prior work has emphasized stress-induced drivers of cell death, the dynamic adaptations of surviving cells and their functional repercussions remain unclear. Namely, we do not know which pathways and programs define cellular responses, what regulatory factors mediate (mal)adaptations, and how this aberrant activity connects to tissue-scale dysfunction and long-term disease outcomes. Here, by applying longitudinal single-cell multi-omics to a mouse model of chronic metabolic stress and extending to human cohorts, we show that stress drives survival-linked tradeoffs and metabolic rewiring, manifesting as shifts towards development-associated states in non-transformed hepatocytes with accompanying decreases in their professional functionality. Diet-induced adaptations occur significantly prior to tumorigenesis but parallel tumorigenesis-induced phenotypes and predict worsened human cancer survival. Through the development of a multi-omic computational gene regulatory inference framework and human in vitro and mouse in vivo genetic perturbations, we validate transcriptional (RELB, SOX4) and metabolic (HMGCS2) mediators that co-regulate and couple the balance between developmental state and hepatocyte functional identity programming. Our work defines cellular features of liver adaptation to chronic stress as well as their links to long-term disease outcomes and cancer hallmarks, unifying diverse axes of cellular dysfunction around core causal mechanisms.

systems biology↗