Sojka, D. | Search bioRxiv

bioRxiv2025

Serpins A1/A3 within tumor-derived extracellular vesicles support pro-tumoral bias of neutrophils in cancer

Neutrophils are known to play an important regulatory role during tumor progression in several types of cancer. However, the mechanisms responsible for their tumorigenic bias and extended lifespan in cancer are not clear to date. This study uncovers a previously unknown mechanism by which tumor-derived small extracellular vesicles (sEVs), via their serpin cargo, reprogram neutrophils to adopt a tumor-supporting phenotype. We demonstrated here an elevated content of plasma sEVs during head and neck cancer progression, and their significant cargo enrichment with inhibitors of neutrophil serine proteases: serpins A1 and A3. Mechanistically, neutrophils educated with serpin-rich tumor-derived sEVs displayed typical pro-tumoral characteristics, including prolonged lifespan and activated CD62Llow CD11bhigh PDL1high phenotype. Functionally, such neutrophils demonstrated a strong ability to promote the epithelial-to-mesenchymal transition of tumor cells. Moreover, such neutrophils induced remarkable suppression of cytotoxic CD8 T cells, significantly reducing their tumor cell-killing capacity. Importantly, serpin cargo was essential for this activity, as serpin-depleted sEVs failed to reprogram neutrophils. These findings again highlight the clinical significance of sEVs and suggest their serpin content as important mediators of pro-tumoral functionality. Targeting the biogenesis or uptake of such immunosuppressive sEVs, or modifying their cargo, could potentially serve as a potent adjuvant anti-cancer therapy.

cancer biology↗

bioRxiv2022

Integrative assessment of the transcriptome and virome of the poultry red mite Dermanyssus gallinae.

Dermanyssus gallinae is a blood-feeding mite that parasitises on wild birds and farmed poultry. The D. gallinae mite has a short life cycle of fewer than two weeks from the egg to an egg-laying female. The remarkably swift processing of blood, together with the capacity to blood-feed in most developmental stages, makes this mite a highly debilitating pest. We have constructed developmental stage-specific transcriptomes, through Illumina RNA-seq, to mine the repertoire of protein-encoding mRNA transcripts, products of which participate in key processes that ensure the success of blood digestion, rapid ontogeny, and immunity. As a result of high reproductive capacity, the prevalence of D. gallinae in egg-producing poultry farms globally causes significant economic losses. Acaricides that are used to limit the reproduction of D. gallinae mites target cys-loop ion channels, which are widely shared across the phylogeny of invertebrates. To catalogue a comprehensive list of potential invertebrate-specific ion channels, we have constructed and analysed an additional RNA-seq library of D. gallinae micro-dissected midguts, a tissue with direct exposure to host blood and potential anti-parasitics. We phylogenetically defined groups of cys-loop proteins and probed their sensitivity to selected acaricides. Ultimately, we have catalogued all assembled transcripts and their expression values in a hyper-linked excel sheet with available sequences of individual contigs. The transcriptomic data were complemented by mass-spectrometry (MS)-based metabolite identification and by viability assays using selected inhibitors applied either by microinjection or through artificial membrane feeding. Additionally, we have described the RNA-virome of D. gallinae and identified a novel virus dubbed Red Mite Quaranjavirus 1.

microbiology↗