Biology subjects

Levy-Barda, A.

Publications and source records attributed to Levy-Barda, A..

4 recordsLinked to original sources

bioRxiv2024

Discordant effects of ex-vivo JAK inhibition on inflammatory responses in colonic compared to ileal mucosa

Background & aimsJanus kinase (JAK) inhibitors modulating JAK-STAT (signal transducers and activators of transcription) signaling pathway, are used for the treatment of patients with inflammatory bowel diseases (IBD). We aimed to identify the molecular effects of JAK inhibition in the human intestinal mucosa, considering the IBD location and phenotype. MethodsColonic and ileal explants from patients with ulcerative colitis (UC), Crohns disease (CD), or non-IBD controls (NC) were treated ex-vivo with the JAK inhibitor, tofacitinib. Phosphorylated STAT (p-STAT) levels were assessed by Western blot and Immunofluorescence. Inflammatory genes expression was assessed with Nanostring nCounter system. Human intestinal organoids were used to assess JAK inhibitors effects on p-STATs and iNOS expression. ResultsExplants were collected from 68 patients (NC=28; UC=20; CD=20). JAK inhibition reduced p-STAT1/3/5 expression in all explants. While p-STAT inhibition rates varied among patients (10%-88%), higher inhibition rates were observed in colonic compared to ileal explants. Significant alterations in 120 of 255 inflammatory genes were observed in colonic explants, while only 30 were observed in ileal NC explants. In colonic explants from UC, significant alterations were observed in 5 genes, including STAT1 and NOS2. Various JAK inhibitors reduced IFN-{gamma}-induced increase in p-STAT1 and iNOS expression in organoids. ConclusionsA site-specific anti-inflammatory effect of JAK inhibition by tofacitinib was noticed, whereby the colon was more robustly affected than the ileum. Ex-vivo response to tofacitinib is individual. JAK inhibition may attenuate inflammation by decreasing iNOS expression. Ex-vivo mucosal platforms may be a valuable resource for studying drug impact and evaluating personalized treatment effects.

immunology↗

bioRxiv2024

Biological insights from plasma proteomics of non-small cell lung cancer patients treated with immunotherapy

IntroductionImmune checkpoint inhibitors have made a paradigm shift in the treatment of non-small cell lung cancer (NSCLC). However, clinical response varies widely and robust predictive biomarkers for patient stratification are lacking. Here, we characterize early on-treatment proteomic changes in blood plasma to gain a better understanding of treatment response and resistance. MethodsPre-treatment (T0) and on-treatment (T1) plasma samples were collected from 225 NSCLC patients receiving PD-1/PD-L1 inhibitor-based regimens. Plasma was profiled using aptamer-based technology to quantify approximately 7000 plasma proteins per sample. Proteins displaying significant fold changes (T1:T0) were analyzed further to identify associations with clinical outcomes. Bioinformatic analyses of upregulated proteins were performed to determine potential cell origins and enriched biological processes. ResultsThe levels of 142 proteins were significantly increased in the plasma of NSCLC patients following ICI-based treatments. Soluble PD-1 exhibited the highest increase, with a positive correlation to tumor PD-L1 status. Bioinformatic analysis of the ICI monotherapy dataset revealed a set of 30 upregulated proteins that formed a single, highly interconnected network with CD8A serving as a central hub, suggesting T cell activation during ICI treatment. Notably, the T cell-related network was detected regardless of clinical benefit. Lastly, circulating proteins of alveolar origin were identified as potential biomarkers of limited clinical benefit, possibly due to a link with cellular stress and lung damage. ConclusionsOur study provides insights into the biological processes activated during ICI-based therapy, highlighting the potential of plasma proteomics to identify mechanisms of therapy resistance and potential biomarkers for outcome.

bioinformatics↗

bioRxiv2022

Altered somatic hypermutation patterns in COVID-19 patients classifies disease severity

The success of the human body in fighting SARS-CoV-2 infection relies on lymphocytes and their antigen receptors. Identifying and characterizing clinically relevant receptors is of utmost importance. We report here the application of a machine learning approach, utilizing B cell receptor repertoire sequencing data from severely and mildly infected individuals with SARS-CoV-2 compared with uninfected controls. In contrast to previous studies, our approach successfully stratifies non-infected from infected individuals, as well as disease level of severity. The features that drive this classification are based on somatic hypermutation patterns, and point to alterations in the somatic hypermutation process in COVID-19 patients. These features may be used to build and adapt therapeutic strategies to COVID-19, in particular to quantitatively assess potential diagnostic and therapeutic antibodies. These results constitute a proof of concept for future epidemiological challenges.

immunology↗

bioRxiv2022

Human intestinal epithelial cells can internalize luminal fungi via LC3-associated phagocytosis

Intestinal epithelial cells (IECs) are the first to encounter luminal microorganisms and actively participate in intestinal immunity. We reported that IECs express the {beta}-glucan receptor Dectin-1, and respond to commensal fungi and {beta}-glucans. In phagocytes, Dectin-1 mediates LC3 associated phagocytosis (LAP) utilizing autophagy components to process extracellular cargo. Dectin-1 can mediate phagocytosis of {beta}-glucan-containing particles by non-phagocytic cells. We aimed to determine whether human IECs phagocytose {beta}-glucan-containing fungal particles via LAP. Zymosan ({beta}-glucan particle) and Heat-killed and UV inactivated C. albicans were phagocytosed by monolayers of human colonic (n=18) and ileal (n=4) organoids and IEC lines. LAP was identified by LC3 and Rubicon recruitment to phagosomes and lysosomal processing of internalized particles was demonstrated by co-localization with lysosomal dyes and LAMP2. Phagocytosis was significantly diminished by blockade of Dectin-1, actin polymerization and NAPDH oxidases. Our results show that human IECs sense luminal fungal particles and internalize them via LAP. This novel mechanism of luminal sampling suggests that IECs may contribute to the maintenance of mucosal tolerance towards commensal fungi.

immunology↗