bioRxiv Science⌕ Search

Biology subjects

Borcherding, N. C.

Publications and source records attributed to Borcherding, N. C..

3 recordsLinked to original sources

Single Cell Resolution Tracking of Cutaneous T-Cell Lymphoma Reveals Clonal Evolution in Disease Progression

Cutaneous T-cell lymphoma (CTCL) remains a challenging disease due to its significant heterogeneity, therapy resistance, and relentless progression. Multi-omics technologies offer the potential to provide uniquely precise views of disease progression and response to therapy. We present here a comprehensive multi-omics view of CTCL clonal evolution, incorporating exome, whole genome, epigenome, bulk-, single cell (sc) VDJ-, and scRNA-sequencing of 114 clinically annotated serial skin, peripheral blood, and lymph node samples from 35 CTCL patients. We leveraged this extensive dataset to define the molecular underpinnings of CTCL progression in individual patients at single cell resolution with the goal of identifying clinically useful biomarkers and therapeutic targets. Our studies identified a large number of recurrent progression-associated clonal genomic alterations; we highlight mutation of CCR4, PI3K signaling, and PD-1 checkpoint pathways as evasion tactics deployed by malignant T cells. We also identified a gain of function mutation in STAT3 (D661Y) and demonstrated by CUT&RUN-seq that it enhances binding to transcription start sites of genes in Rho GTPase pathways, which we previously reported to have activated chromatin and increased expression in HDACi-resistant CTCL. These data provide further support for a previously unrecognized role for Rho GTPase pathway dysregulation in CTCL progression. A striking number of progression-associated mutations occurred in chromatin methylation modifiers, including EZH2, suggesting that EZH1/2 inhibition may also benefit patients with CTCL. Knowledge of these molecular changes should be leveraged for improved disease monitoring, biomarker-informed clinical trial design, and new therapeutic strategies in this challenging and incurable cancer.

cancer biology↗

Context-dependent triggering of STING-interferon signaling by CD11b agonists supports anti-tumor immunity in mouse models and human cancer patients

Chronic activation of inflammatory pathways and suppressed interferon signaling are hallmarks of myeloid cells in immunosuppressive tumors that drive poor responsiveness to conventional and immune therapies. Previous studies have identified agonistic activation of the CD11b integrin as a potential strategy to enhance anti-tumor immunity. However, the mechanisms by which CD11b-agonism reprogram tumor immunity are poorly understood, and this may impair patient selection and identification of effective treatment combinations. Herein we used a combination of in vitro systems, animal models, and samples from first in human clinical trials of the CD11b-agonist GB1275 to identify the mechanism of action of this approach and identify combinations for further testing. We found that CD11b agonism altered tumor-associated macrophage (TAM) phenotypes by simultaneously repressing NF{kappa}B/IL1-signaling and activating interferon (IFN) gene expression. Repression of NF{kappa}B/IL-1 signaling was due to rapid degradation of p65 protein by the proteosome and was not context dependent. In contrast, CD11b agonism triggered mitochondrial dysfunction to stimulate STING-induced, STAT1-mediated interferon signaling. The magnitude of CD11b agonist induction of STING/IFN signaling was dependent on the tumor microenvironment and was significantly amplified by cytotoxic therapies. Using tissues from phase I clinical trials, we demonstrated that GB1275 treatment activated STING and STAT1 signaling in TAMs in human tumors. Together, these mechanisms allowed macrophages to augment anti-tumor T cell immunity. These studies identified potential mechanism-based therapeutic strategies for CD11b agonist use and identified potential patient populations more likely to benefit from them. Statement of significanceCD11b agonists are a novel approach to reprogram myeloid cells in solid tumors. We show that GB1275, a CD11b-agonist, amplified STING/IFN signaling in TAMs to support anti-tumor immunity and this signaling is amplified further by cytotoxic therapy. These studies support new treatment strategies for advanced solid tumors with myeloid immunosuppression.

cancer biology↗

Pancreas resident macrophage-induced fibrosis has divergent roles in pancreas inflammatory injury and PDAC

Tissue-resident macrophages (TRMs) are long-lived cells that maintain locally and can be phenotypically distinct from monocyte-derived macrophages (MDMs). However, whether TRMs and MDMs have functional distinction under differing pathologies is not understood. Here, we show a significant portion of macrophages that accumulated during pancreatitis and pancreatic cancer were expanded from TRMs. We further established that pancreas TRMs have a distinct extracellular matrix remodeling phenotype that was critical for maintaining tissue homeostasis during inflammation. Loss of TRMs led to exacerbation of severe pancreatitis and animal death, due to impaired acinar cell survival and recovery. In pancreatitis, TRMs elicited protective effects by triggering the accumulation and activation of fibroblasts, which was necessary for initiating fibrosis as a wound healing response. The same TRM-driven fibrosis, however, drove pancreas cancer pathogenesis and progression. Together, these findings indicate that TRMs play divergent roles in the pathogenesis of pancreatitis and cancer through regulation of stromagenesis.

immunology↗