Biology subjects

McGraw, T. E.

Publications and source records attributed to McGraw, T. E..

11 recordsLinked to original sources

bioRxiv2025

Tumor-draining lymph node derived CD8⁺ T cells sustain durable systemic immunity after neoadjuvant IL-15 and PD-1 blockade.

The tumor-draining lymph node (tdLN) serves as a critical reservoir of tumor-reactive T cells, yet its contribution to preventing metastatic recurrence remains poorly understood. In this study, we investigate CD8 T cell clonal dynamics and memory responses induced by neoadjuvant anti-PD-1 therapy. We demonstrate that PD-1 blockade promotes the emergence of protective CD8 T cell memory, enriched with tumor-relevant clones that persist in the lymph nodes of long-term survivors. Furthermore, we show that combination of a neoadjuvant IL-15 superagonist with PD-1 blockade significantly increases clonal diversity, cytotoxicity, and clonal persistence in non-draining lymph nodes. These changes result in enhanced systemic antitumor immunity and durable memory that prevents tumor relapse. Our findings establish the tdLN as a critical immunologic hub that can be therapeutically targeted by IL-15 to augment PD-1 blockade efficacy and support a rationale for a phase II neoadjuvant combination immunotherapy trial in early-stage NSCLC. One sentence summaryNeoadjuvant IL-15 with PD-1 blockade expands lymph node clonal diversity and preserves stem-like CD8 T cell features, yielding superior antitumor efficacy, durable memory, and reduced metastatic recurrence.

immunology↗

bioRxiv2025

Simultaneous immunomodulation and epithelial-to-mesenchymal transition drives lung adenocarcinoma progression

Lung cancer remains the deadliest cancer in the United States, with lung adenocarcinoma (LUAD) as its most prevalent subtype. While computed tomography (CT)-based screening has improved early detection and enabled curative surgeries, the molecular and cellular dynamics driving early-stage LUAD progression remain poorly understood, limiting non-surgical treatment options. To address this gap, we profiled 2.24 million cells from 122 early-stage LUAD patients using multiplexed imaging mass cytometry (IMC). This analysis revealed the molecular, spatial, and temporal dynamics of LUAD development. Our findings uncover a binary progression model. LUAD advances through either inflammation, driven by a balance of cytotoxic and regulatory immune activity, or fibrosis, characterized by stromal activation. Surprisingly, tumor cell populations did not increase significantly. Instead, they displayed a mixed phenotypic profile consistent with epithelial-to-mesenchymal transition (EMT), effectively masking the expansion of malignant cells. Furthermore, we addressed discrepancies between CT-based and histology-based subtyping. CT scans, while non-invasive, often mischaracterize invasive fibrotic tumors--which account for 20.5% of LUAD cases--as mild, non-solid ground glass opacities (GGOs). Using high-content IMC imaging, we demonstrate that these tumors harbor significant risks and advocate for improved diagnostic strategies. These strategies should integrate molecular profiling to refine patient stratification and therapeutic decision-making. Altogether, our study provides a high-resolution, systems-level view of the tumor microenvironment in early-stage LUAD. We characterize key transitions in oncogenesis and propose a precision-driven framework to enhance the detection and management of aggressive disease subtypes.

cancer biology↗

bioRxiv2025

Acquisition of discrete immune suppressive barriers contributes to the initiation and progression of preinvasive to invasive human lung cancer.

Computerized chest tomography (CT)-guided screening in populations at risk for lung cancer has increased the detection of preinvasive subsolid nodules, which progress to solid invasive adenocarcinoma. Despite the clinical significance, there is a lack of effective therapies for intercepting the progression of preinvasive to invasive adenocarcinoma. To uncover determinants of early disease emergence and progression, we used integrated single-cell approaches, including scRNA-seq, multiplexed imaging mass cytometry and spatial transcriptomics, to construct the first high-resolution map of the composition, lineage/functional states, developmental trajectories and multicellular crosstalk networks from microdissected non-solid (preinvasive) and solid compartments (invasive) of individual part-solid nodules. We found that early disease initiation and subsequent progression are associated with the evolution of immune-suppressive cellular phenotypes characterized by decreased cytotoxic CD8 T and NK cells, increased T cell exhaustion and accumulation of immunosuppressive regulatory T cells (Tregs) and M2-like macrophages expressing TREM2. Within Tregs, we identified a unique population of 4-1BB+ Treg subset enriched for the IL2-STAT5 suppressive pathway with transcription profiles supporting discrete metabolic alterations. Spatial analysis showed increased density of suppressive immune cells around tumor cells, increased exhaustion phenotype of both CD4 and CD8 T cells expressing chemokine CXCL13, and spatial micro-complex of endothelial and lymphocyte interactions within tertiary lymphoid structures. The single-cell architecture identifies determinants of early disease emergence and progression, which may be developed not only as diagnostic/prognostic biomarkers but also as targets for disease interception. Additionally, our dataset constitutes a valuable resource for the preinvasive lung cancer research community.

cancer biology↗

bioRxiv2023

Multiple beta cell-independent mechanisms drive hypoglycemia in Timothy syndrome

The canonical G406R gain of function mutation that reduces inactivation and increases Ca2+ influx through the CACNA1C-encoded CaV1.2 voltage gated Ca2+ channel underlies the multisystem disorder Timothy syndrome (TS), characterized by invariant Long QT syndrome and consequent life-threatening arrhythmias. Severe episodic hypoglycemia, which exacerbates arrhythmia risk, is among the myriad non-cardiac TS pathologies that are poorly characterized. While hypoglycemia is thought to result from increased Ca2+ influx through CaV1.2 channels in pancreatic beta cells and consequent hyperinsulinism, this mechanism has never been demonstrated due to a lack of informative animal models, thus hampering development of preventive strategies. We generated a CaV1.2 G406R knockin mouse model that recapitulates key TS features including hypoglycemia. Unexpectedly, these mice did not show hyperactive beta cells or hyperinsulinism in the setting of normal intrinsic beta cell function, suggesting dysregulated glucose homeostasis. We discovered multiple alternative contributors to hypoglycemia, including perturbed counterregulatory hormone responses with defects in glucagon secretion and abnormal hypothalamic glucose sensing. Together, these data provide new insights into physiological contributions of the broadly expressed CaV1.2 channel and reveal integrated consequences of the mutant channel that underlie the life-threatening events in TS. Brief SummaryGain of function mutant CaV1.2 channels drive hypoglycemia through adverse effects on counterregulatory hormones and central nervous system glucose sensing

physiology↗

bioRxiv2023

GLUT4 dynamic subcellular localization is controlled by AMP kinase activation as revealed by proximal proteome mapping in human muscle cells

Regulation of glucose transport into muscle and adipocytes, central for control of whole-body metabolism, is determined by the amount of GLUT4 glucose transporter in the plasma membrane (PM). Physiologic signals (activated insulin receptor or AMP kinase [AMPK]), acutely increase PM GLUT4 to enhance glucose uptake. Here we show in kinetic studies that intracellular GLUT4 is in equilibrium with the PM in unstimulated cultured human skeletal muscle cells, and that AMPK promotes GLUT4 redistribution to the PM by regulating both exocytosis and endocytosis. AMPK-stimulation of exocytosis requires Rab10 and Rab GTPase activating protein TBC1D4, requirements shared with insulin control of GLUT4 in adipocytes. Using APEX2 proximity mapping, we identify, at high-density and high-resolution, the GLUT4 proximal proteome, revealing GLUT4 traverses both PM proximal and distal compartments in unstimulated muscle cells. These data support intracellular retention of GLUT4 in unstimulated muscle cells by a dynamic mechanism dependent on the rates of internalization and recycling. AMPK promoted GLUT4 translocation to the PM involves redistribution of GLUT4 among the same compartments traversed in unstimulated cells, with a significant redistribution of GLUT4 from the PM distal Trans Golgi Network Golgi compartments. The comprehensive proximal protein mapping provides an integrated, whole cell accounting of GLUT4s localization at a resolution of [~]20 nm, a structural framework for understanding the molecular mechanisms regulating GLUT4 trafficking downstream of different signaling inputs in physiologically relevant cell type and as such, sheds new light on novel key pathways and molecular components as potential therapeutic approaches to modulate muscle glucose uptake.

cell biology↗

bioRxiv2022

Disinhibition of Rab10 gates AMPAR insertion and spine enlargement during long-term potentiation

Rab-dependent membrane trafficking is critical for changing the structure and function of dendritic spines during synaptic plasticity. Here, we developed highly sensitive sensors to monitor Rab protein activity in single dendritic spines undergoing structural long-term potentiation (sLTP) in rodent organotypic hippocampal slices. During sLTP, Rab10 was persistently inactivated (>30 min) in the stimulated spines, whereas Rab4 was transiently activated over [~]5 min. Inhibiting or deleting Rab10 enhanced sLTP, electrophysiological LTP and AMPA receptor (AMPAR) trafficking during sLTP. In contrast, disrupting Rab4 impaired sLTP only in the first few minutes, and decreased AMPAR trafficking during sLTP. Thus, our results suggest that Rab10 and Rab4 oppositely regulate AMPAR trafficking during sLTP, and inactivation of Rab10 signaling facilitates the induction of LTP and associated spine structural plasticity.

neuroscience↗

bioRxiv2021

Therapeutic anti-PD-L1 antibody affects ESCRT-mediated functions in cells expressing oncogenic EGFR.

PD-L1, a transmembrane ligand for immune checkpoint receptor PD1, has been successfully targeted to activate an anti-tumor immune response in a variety of solid tumors, including non-small cell lung cancer (NSCLC). Despite the success of targeting PD-L1, only about 20% of patients achieve a durable response. The reasons for the heterogeneity in response are not understood, although some molecular subtypes (e.g., mutant EGF receptor tumors) are generally poor responders. Although PD-L1 is best characterized as a transmembrane PD1 ligand, the emerging view is that PD-L1 has functions independent of activating PD1 signaling. It is not known whether these cell-intrinsic functions of PD-L1 are shared among non-transformed and transformed cells, if they vary among cancer molecular subtypes, or if they are impacted by anti-PD-L1 therapy. Here we use quantitative microscopy techniques and APEX2 proximity mapping to describe the behavior of PD-L1 and to identify PD-L1s proximal proteome in human lung epithelial cells. Our data reveal growth factor control of PD-L1 recycling as a mechanism for acute and reversible regulation of PD-L1 density on the plasma membrane. In addition, we describe novel PD-L1 biology restricted to mutant EGFR cells. Anti-PD-L1 antibody treatment of mutant EGFR cells perturbs cell intrinsic PD-L1 functions, leading to reduced cell migration, increased half-life of EGFR and increased extracellular vesicle biogenesis, whereas anti-PD-L1 antibody does not induce these changes in wild type EGFR cells. These specific effects in mutant EGFR cells might contribute to the poor anti-PD-L1 response of mutant EGFR tumors.

cell biology↗

bioRxiv2020

Blunting of insulin-stimulated glucose uptake in brown adipose tissue induces systemic metabolic dysregulation in female mice

The role of brown adipose tissue (BAT) in thermogenesis is widely appreciated, whereas its more recently described role in whole-body metabolism is not as well understood. Here we demonstrate that deletion of Rab10 from brown adipocytes reduces insulin-stimulated glucose transport by inhibiting translocation of the GLUT4 glucose transporter to the plasma membrane. This blunting of glucose uptake into brown adipocytes induces glucose intolerance and insulin-resistance in female but not male mice. The defect in glucose uptake does not affect the thermogenic function of BAT, and the dysregulation of whole-body metabolism is independent of the thermogenic function of BAT, thereby revealing a metabolism-specific role for BAT in female mice. The reduced glucose uptake induced by RAB10 deletion disrupts ChREBP regulation of the expression of de novo lipogenesis-related (DNL) genes, providing a link between DNL in BAT and whole-body metabolic regulation that is independent of thermogenesis.

physiology↗

bioRxiv2020

A common human variant of GIPR improves systemic glucose homeostasis in a sexual dimorphic manner

Glucose-dependent insulinotropic polypeptide (GIP) has a role in controlling postprandial metabolic tone. In humans, a GIP receptor (GIPR) variant (Q354, rs1800437) is associated with a lower body mass index (BMI) and increased risk for Type 2 Diabetes. To isolate the contribution of GIPR in metabolic control, we generated a mouse model of the GIPR-Q354 variant (GIPR-Q350 mice). Female GIPR-Q350 mice are leaner than littermate controls, and male GIPR-Q350 mice are resistant to diet-induced obesity, in line with the association of the variant with reduced BMI in humans. GIPR-Q350 mice of both sexes are more glucose tolerant and exhibit an increased sensitivity to GIP. Postprandial GIP levels are reduced in GIPR-Q350 mice, revealing feedback regulation that balances the increased sensitivity of GIP target tissues to secretion of GIP from intestinal endocrine cells. The increased GIP sensitivity is recapitulated ex vivo during glucose stimulated insulin secretion assays in islets. Generation of cAMP in islets downstream of GIPR activation is not affected by the Q354 substitution. However, post-activation traffic of GIPR-Q354 variant in {beta}-cells is altered, characterized by enhanced intracellular dwell time and increased localization to the Trans-Golgi Network (TGN). Consequently, our data link altered intracellular traffic of the GIPR-Q354 variant with GIP control of metabolism. We propose that this change in spatiotemporal signaling underlies the physiologic effects of GIPR-Q350/4 and GIPR-E350/4 in mice and humans. These findings contribute to a more complete understanding of the impact of GIPR-Q354 variant on glucose homeostasis that could perhaps be leveraged to enhance pharmacologic targeting of GIPR for the treatment of metabolic disease.

physiology↗

bioRxiv2020

Evolution of immune escape mechanisms in the progression from preinvasive to invasive human lung adenocarcinoma.

The tumor microenvironment (TME) of lung adenocarcinoma (LUAD) precursor lesions has not been described. We interrogated by multiplex immunofluorescence the TME of preinvasive and invasive Stage 1A LUADs selected by computer tomography (CT) scan-density. Pure non-solid (p-NS) CT density nodules are preinvasive/minimally invasive, whereas solid CT density nodules are frankly invasive cancers. Our data reveal an intensely immune-suppressive immune TME in p-NS tumors characterized by an increase in Treg cells and a decrease in cytotoxic T cells relative to normal lung. The TME of the solid tumor group, more advanced lesions than the p-NS yet still early in disease development, were increasingly more immune-suppressive. Provocatively, there was a further increase in both Treg cells and cytotoxic T cells, establishing a nascent albeit ineffective anti-tumor immune response in transition from preinvasive p-NS to invasive solid tumors. Regulatory T cells play a dominant role throughout progression, while additional immune evasive mechanisms are employed at different stages of disease progression, including T cell exclusion from cancer cell nests early and activation of immune checkpoints later. Our study establishes that different immune-targeted strategies are required to intercept disease progression at these two distinct early points of lung cancer development. Statement of SignificanceUsing multiplexed IF, we compared the cellular composition and activation state of the tumor immune microenvironment between pre/minimally invasive and frankly invasive adenocarcinoma. We found a progressive increase in immunosuppressive mechanisms in association with disease progression suggesting that Interception strategies should be specifically tailored based on underlying immune escape mechanisms

cancer biology↗

bioRxiv2020

Insulin promoted mobilization of GLUT4 from a perinuclear storage site requires RAB10.

Insulin controls glucose uptake into muscle and fat cells by inducing a net redistribution of GLUT4 from intracellular storage to the plasma membrane (PM). The TBC1D4-RAB10 signaling module is required for insulin-stimulated GLUT4 translocation to the PM, although where it intersects GLUT4 traffic was unknown. Here we demonstrate that TBC1D4-RAB10 functions to control GLUT4 mobilization from a Trans Golgi Network (TGN) storage compartment, establishing that insulin, in addition to regulating the PM proximal effects of GLUT4-containing vesicles docking to and fusion with the PM, also directly regulates the behavior of GLUT4 deeper within the cell. We also show that GLUT4 is retained in an element/domain of the TGN from which newly synthesized lysosomal proteins are targeted to the late endosomes and the ATP7A copper transporter is translocated to the PM by elevated copper. Insulin does not mobilize ATP7A nor does copper mobilize GLUT4. Consequently, GLUT4 intracellular sequestration and mobilization by insulin is achieved, in part, through utilizing a region of the TGN devoted to specialized cargo transport in general rather than being specific for GLUT4. Our results define GLUT4-containing region of the TGN as a sorting and storage site from which different cargo are mobilized by distinct signals.

cell biology↗