Biology subjects

Patten, D. A.

Publications and source records attributed to Patten, D. A..

4 recordsLinked to original sources

bioRxiv2024

Secreted Clever-1 Modulates T Cell Responses and Impacts Cancer Immunotherapy Efficacy

Clever-1 functions as a scavenger and adhesion receptor, promoting tolerogenic activities in macrophages and subsets of endothelial cells, thereby contributing to cancer progression. High Clever-1 expression associates with resistance to immune checkpoint inhibitors and combined targeting of Clever-1 with anti-PD-1 enhances response in refractory mouse tumor models. A Clever-1-targeting humanized IgG4 antibody, bexmarilimab, is investigated in clinical trials as a macrophage-reprogramming therapy to treat solid tumors (NCT03733990) and hematological malignancies (NCT05428969). Here we describe a secreted form of (s)Clever-1 enriched in plasma of cancer patients, that was decreased upon bexmarilimab treatment. With the production of a recombinant sClever-1, mimicking the one found in human plasma, we show that sClever-1 can selectively bind activated T cells and disrupt T cell receptor signalling leading to impaired Th1 expansion. We demonstrate that sClever-1 binds to insulin growth factor 2 receptor (IGF2R) on T cells via its mannose-6-phosphate modification and further show that sClever-1 contributes to the immunosuppressive properties of macrophage-secreted extracellular vesicles, driving T cell tolerance and impairing anti-PD-1 efficacy. These findings suggest that Clever-1 exerts a systemic immunosuppressive effect independently of the cells it is expressed on, highlighting its potential as a target in cancer immunotherapy and a valuable biomarker for disease detection.

immunology↗

bioRxiv2023

Comprehensive interrogation of human skeletal muscle reveals a dissociation between insulin resistance and mitochondrial capacity

Aims/HypothesisInsulin resistance and blunted mitochondrial capacity in skeletal muscle are often synonymous; however, this association remains controversial. The aim of this study was to perform an in-depth multi-factorial comparison of skeletal muscle mitochondrial capacity between individuals who were lean and active (Active), individuals with obesity (Obese) and individuals with Obesity, insulin resistance and type 2 diabetes (T2D). MethodsSkeletal muscle biopsies were obtained from the Vastus Lateralis of individuals who were lean and active (Active- n = 9), individuals with obesity (Obese- n = 9) and individuals with obesity insulin resistance and T2D (T2D- n =22) in this cross-sectional design. Mitochondrial capacity was assessed by ex vivo mitochondrial respiration with fatty-acid and glycolytic supported protocols adjusted for mitochondrial content (mtDNA and citrate synthase activity). Supercomplex assembly was measured by BN-PAGE and immunoblot. TCA cycle intermediates were assessed with targeted metabolomics. Exploratory transcriptomics and DNA methylation analyses were performed to uncover molecular differences affecting mitochondrial function among the three groups. ResultsActive had greater mitochondrial capacity compared to both Obese and T2D for ex vivo mitochondrial respiration with fatty-acid and glycolytic supported protocols adjusted for mitochondrial content (P < 0.05). Complex IV supercomplex assembley was greater in Active compared to Obese and T2D (P < 0.05) whereas Complex I and III supercomplex assembly was greater in Active compared to T2D only (P < 0.05). TCA cycle intermediates; citrate, succinate, fumarate and malate were all significantly greater in Active compared to Obese and T2D (P < 0.05). Strikingly, Obese and T2D do not differ in any of the skeletal muscle mitochondrial measurements. Active had an upregulation of genes related to respiration/mitochondrial capacity compared to both Obese and T2D. Transcriptional differences between Obese and T2D were not driven by mitochondrial related process. Active had reduced methylation correlated with increased gene expression for important mitochondrial-related genes, including ATP5PD and MFN2. Conclusions/InterpretationsWe reveal no discernable differences in skeletal muscle mitochondrial content, mitochondrial capacity and mitochondrial molecular profiles between obese individuals with and without T2D that had comparable levels of confounding factors (BMI, age, aerobic capacity) that affect mitochondrial capacity. We highlight that lean, active individuals have enhanced skeletal muscle mitochondrial capacity that is also reflected at the level of DNA methylation and gene transcription. The collective observation of comparable muscle mitochondrial capacity in individuals with obesity and T2D (vs. individuals without T2D) underscores a dissociation from skeletal muscle insulin resistance. Clinical trial numberNCT0191110

molecular biology↗

bioRxiv2021

Exploring the prognostic value of SCARF1 in non-small cell lung cancers

Scavenger receptor class F member 1 (SCARF1) has previously been shown to be highly expressed within the human liver, hold prognostic value in hepatocellular carcinoma and mediate the specific recruitment of leukocytes to liver sinusoidal endothelial cells; however, to date, the liver remains the only major organ in which SCARF1 has been explored in any detail. Here, we utilised publically-available RNA-sequencing data from The Cancer Genome Atlas (TGCA) to identify the lungs as a site of significant SCARF1 expression and attribute the majority of its expression to endothelial cell populations. Next, we show that SCARF1 expression is significantly reduced in two histologically distinct types of non-small cell lung carcinoma cancers (NSCLCs), lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC), compared to non-tumoural tissues. Interestingly, loss of SCARF1 expression was associated with aggressive tumour biology in LUAD tissues, but not in LUSC. Furthermore, increased SCARF1 expression was highly prognostic of better overall survival in LUAD tumour tissues, but this was again in contrast to LUSC tumours, in which SCARF1 held no prognostic value. Finally, we showed that SCARF1 is widely expressed in tumour endothelial cells of non-small cell lung cancers and that its total expression in LUAD tumour tissues correlated with immune score and CD4+ T cell infiltration. This study represents the first detailed exploration of SCARF1 expression in normal and diseased human lung tissues and further highlights the prognostic value and therapeutic potential of SCARF1 in immunologically active cancers.

cancer biology↗

bioRxiv2019

TSC2-deficiency potentiates a catabolic signaling switch that differentiates neural and neural crest lineage development and progressive disease manifestations

Lymphangioleiomyomatosis (LAM) is a rare lung disease marked by cystic destruction caused by invasive LAM cells harboring loss-of-function mutations in TSC2 that exhibit dysregulated mTORC1 signaling. Rapamycin, the only approved treatment, is not curative. Therapeutic discovery has been limited by inadequate cell and animal models due to the unknown LAM cell of origin. We report a novel TSC2--/-- human pluripotent stem cell (hPSC)-derived neural crest cell (NCC) model, which replicates key LAM features. Leveraging this model, temporal RNA sequencing and genome-wide CRISPR knockout screens identified synthetic lethal genes including TWIST1 and SUN4. Antisense oligonucleotides (ASOs) targeting TWIST1 and SUN4 demonstrated selective TSC2 mutant NCC cytotoxicity and inhibited invasion. Using a "test-withdraw-monitor" clinical trial paradigm, TWIST1 and SUN4 ASOs profoundly suppressed tumor viability in a Tsc2--/-- mouse allograft model and eradicated 40% of tumors, outperforming standard of care rapamycin and highlighting their promise as novel cytoablative LAM therapeutics.

cancer biology↗