Biology subjects

Dieterich, L.

Publications and source records attributed to Dieterich, L..

4 recordsLinked to original sources

bioRxiv2025

Comprehensive immune profiling of melanoma-draining lymph nodes identifies plasmacytoid dendritic cells as new biomarker for PD-L1 blockade

Immune checkpoint blockade (ICB) has become a powerful weapon in the treatment of melanoma and other cancer types. Still, only a minority of patients profits from this type of therapy. As ICB is associated with considerable adverse effects, predictive biomarkers to select patients for ICB treatment are urgently needed. Here, we comprehensively immunophenotyped primary tumors and tumor-draining lymph nodes (tdLNs) from a panel of ICB-resistant and -sensitive melanoma models in mice. Surprisingly, we found that whereas tumor-infiltrating CD8+ T cells showed strong responses to PD-L1 blockade in ICB-sensitive melanoma, CD8+ T cell profiles in tdLNs were very similar in ICB responder and non-responder models. In contrast, we identified distinct myeloid immune profiles in tdLNs correlating with ICB responsiveness, including a low frequency of activated dendritic cells and a high frequency of plasmacytoid dendritic cells (pDCs). Notably, pDC marker genes and frequencies in tdLNs of melanoma patients correlated with favorable outcome. Thus, the level of pDCs in tdLNs represents a potential new biomarker for ICB in melanoma patients.

immunology↗

bioRxiv2025

A deep, quantitative lipid atlas of extracellular vesicles across multiple cell lines

Extracellular vesicles (EVs) are subcellular particles surrounded by a lipid bilayer membrane and incorporating various additional biomolecules derived from their donor cell. In many disease contexts circulating EVs have received increasing scientific attention due to their potential diagnostic and prognostic value. Additionally, EVs have been ascribed multiple biological functions, ranging from cellular waste disposal to sophisticated, intercellular communication. Consequently, EVs involved in pathological processes may represent therapeutic targets, whereas EV-based therapeutics are being developed for targeted delivery of molecular cargoes in vivo. Detailed knowledge of the molecular content of natural EVs derived from diverse cellular origins is crucial to identify biomarkers, dissect EV functions, and optimize EV engineering for therapeutic purposes. Although the lipid composition of biological membranes has a significant impact on their biophysical and -chemical properties and may affect signaling and interactions at the molecular and cellular level, relatively little is known about the lipid composition of EV membranes. Here, we applied high resolution mass spectrometry to deeply and quantitatively characterize the lipidome of EVs isolated from a panel of malignant and non-malignant cell lines, providing a comprehensive data resource for biomarker research and EV engineering efforts. Furthermore, subset comparisons indicate striking differences between lipid profiles of EVs isolated from cells of different tissue origin, suggesting distinct membrane characteristics that could affect EV biodistribution and function in vivo.

cell biology↗

bioRxiv2020

Lymphatic PD-L1 expression restricts tumor-specific CD8+ T cell responses

Lymph node (LN)-resident lymphatic endothelial cells (LECs) mediate peripheral tolerance by self-antigen presentation on MHC-I and constitutive expression of T cell inhibitory molecules, including PD-L1. Tumor-associated LECs also upregulate PD-L1 but the specific role of lymphatic PD-L1 in tumor immunity is not well understood. We generated a mouse model lacking lymphatic PD-L1 expression and challenged these mice with two orthotopic tumor models, B16F10 melanoma and MC38 colorectal carcinoma. Lymphatic PD-L1 deficiency resulted in a consistent expansion of tumor-specific CD8+ T cells in tumor-draining LNs in both tumor models, reduced primary tumor growth in the MC38 model, and increased the efficacy of adoptive T cell therapy in the B16F10 model. Strikingly, lymphatic PD-L1 primarily acted via apoptosis induction in tumor-specific CD8+ central memory T cells. Our findings demonstrate that LECs restrain tumor-specific immunity via PD-L1 and may explain why some cancer patients without PD-L1 expression in the tumor microenvironment still respond to PD-L1 / PD-1 targeting immunotherapy.

immunology↗

bioRxiv2020

LESR2 is a lymphatic endothelial-specific lncRNA that governs cell proliferation and migration through KLF4 and SEMA3C

Recent studies have revealed the importance of long noncoding RNAs (lncRNAs) as tissue-specific regulators of gene expression. There is ample evidence that distinct types of vasculature undergo tight transcriptional control to preserve their structure, identity, and functions. We determined, for the first time, the global lineage-specific lncRNAome of human dermal blood and lymphatic endothelial cells (BECs and LECs), combining RNA-Seq and CAGE-Seq. A subsequent genome-wide antisense oligonucleotide-knockdown screen of a robust set of BEC- and LEC-specific lncRNAs identified LETR1 as a critical gatekeeper of the global LEC transcriptome. Deep RNA-DNA, RNA-protein, and phenotype rescue analyses revealed that LETR1 acts as a nuclear trans-acting lncRNA modulating, via key epigenetic factors, the expression of essential target genes, including KLF4 and SEMA3C, governing the growth and migratory ability of LECs. Together, our study provides new evidence supporting the intriguing concept that every cell type expresses precise lncRNA signatures to control lineage-specific regulatory programs.

genomics↗