Biology subjects

James, F.

Publications and source records attributed to James, F..

4 recordsLinked to original sources

bioRxiv2026

Conventional dendritic cells type I with an enhanced type-I-IFN signaling underpin anti-tumor immune responses in brain metastases

Brain metastases are associated with poor prognosis. A better understanding of anti-tumor immune responses in the context of immune specialized microenvironment of the brain is required to develop improved therapeutic strategies for this disease. We demonstrate that the conventional dendritic cells type 1 (cDC1) gene signature positively correlates with a prolonged BrM-dependent survival in melanoma and breast cancer patients. Furthermore, intracranial anti-tumor immune responses in preclinical BrM models consistently rely on cDC1s for tumor growth control, BrM-dependent survival and maintenance of the intra-tumoral CD8+ T cell pool, in contrast to variable, cancer type-dependent cDC1 roles in extracranial tumors. This is underpinned by tumor site-specific cDC1 molecular profiles with distinct Toll like receptor repertoires, upregulation of co-stimulatory molecules and IL-12, and enhanced type-I-IFN signaling in intracranial cDC1s, with the latter driving increased cDC1 activation. cDC1s also promote the conversion of progenitor exhausted CD8+ T cells to transient effectors, which is further enhanced by immune checkpoint blockade therapy. These findings pinpoint cDC1s as a major cell population of interest in the development of future immunotherapies for BrM. Significance statementCharacteristics of immune cells and tumor microenvironment in brain metastases (BrM) are distinct to extracranial tumor sites and characterized by special immunological barriers and suppressive stroma. Conventional dendritic cells type 1 (cDC1s), which are key regulators of anti-tumor immunity, remain largely unexplored in this context. This study deepens our understanding of how anti-tumor immune responses differ between BrM and extracranial tumors by revealing BrM-specific phenotype and function of cDC1s, with the latter being critical for anti-tumor immunity in BrM even in cancer models where extracranial cDC1s demonstrate pro-tumorigenic function, highlighting cDC1s as universal regulators of intracranial anti-tumor immunity. Our study suggests that tumor site-specific augmentation of cDC1s should be pursued to enhance the efficacy of immunotherapies in BrM.

cancer biology↗

bioRxiv2026

Defining influenza-specific B cells in vaccine responders, non-responders and influenza breakthrough infections

Although seasonal influenza vaccination programs are effective at a population level, our data from inactivated influenza vaccine (IIV) cohorts in years 2015-2022 reveal that 50-60% of individuals do not seroconvert following immunization. The underlying mechanisms of vaccine non-responsiveness are far from understood. In this study, we sought to define key determinants of optimal B cell immune responses elicited by seasonal influenza vaccination, and to explore why some individuals fail to elicit humoral immunity following immunization. Immune responses associated with seroconversion and vaccine failure from individuals immunized with IIVs were compared at cellular and molecular levels using single-cell transcriptomics. We analyzed HA-specific B cell immunity across vaccine-responders, breakthrough infections and patients hospitalized with acute influenza. Droplet-based single-cell RNA sequencing and VDJ-sequencing of influenza-specific B cells from stored PBMCs was performed using 10x Genomics. Our results show that atypical B cells are the major subset of B cell responses in vaccine non-responders on day 28 post-vaccination. Conversely, individuals who seroconvert had diverse B cell phenotypes. The use of recombinant influenza-specific HA probes allowed us to dissect expression patterns on influenza HA-specific B cells. We found that HA-specific B cells of vaccine non-responders for A/H1N1 and A/H3N2 components displayed elevated atypical-like markers (CD11c, FcRL-5) at baseline, compared to responders. Analysis of differentially expressed genes (DEGs) between responders and non-responders identified differential expression of HLA-DR, CD74, CD83, and CXCR3 genes. We subsequently demonstrated reduced frequencies of HLA-DR-, CD74- and CD83-expressing B cells in patients hospitalized with influenza, compared to healthy participants. Hospitalized influenza patients also had significantly higher proportions of atypical CD21-CD27- B cells. Overall, our data demonstrate an association between elevated frequencies of atypical-like B cells with both lack of seroconversion following immunization and severe influenza infection. These findings broaden our understanding of humoral immunity in influenza vaccination and infection, providing novel insights for vaccination strategies and design.

immunology↗

bioRxiv2025

textToKnowledgeGraph: Generation of Molecular Interaction Knowledge Graphs Using Large Language Models for Exploration in Cytoscape

MotivationKnowledge graphs (KGs) are powerful tools for structuring and analyzing biological information due to their ability to represent data and improve queries across heterogeneous datasets. However, constructing KGs from unstructured literature remains challenging due to the cost and expertise required for manual curation. Prior works have explored text-mining techniques to automate this process, but have limitations that impact their ability to capture complex relationships fully. Traditional text-mining methods struggle with understanding context across sentences. Additionally, these methods lack expert-level background knowledge, making it difficult to infer relationships that require awareness of concepts indirectly described in the text. Large Language Models (LLMs) present an opportunity to overcome these challenges. LLMs are trained on diverse literature, equipping them with contextual knowledge that enables more accurate extraction of information. ResultsWe present textToKnowledgeGraph, an artificial intelligence tool using LLMs to extract interactions from individual publications directly in Biological Expression Language (BEL). BEL was chosen for its compact and detailed representation of biological relationships, allowing for structured and computationally accessible encoding. This work makes several contributions. 1. Development of the open-source Python textToKnowledgeGraph package (pypi.org/project/texttoknowledgegraph) for BEL extraction from scientific articles, usable from the command line and within other projects, 2. An interactive application within Cytoscape Web to simplify extraction and exploration, 3. A dataset of extractions that have been both computationally and manually reviewed to support future fine-tuning efforts. Availabilityhttps://github.com/ndexbio/llm-text-to-knowledge-graph

bioinformatics↗

bioRxiv2019

Major surgery induces acute changes in DNA methylation associated with activation of the immune response.

BackgroundSurgery is an invasive procedure evoking acute inflammatory and immune responses that are believed to mediate risk for postoperative complications including cognitive dysfunction and delirium. Although the specific mechanisms driving these responses have not been well-characterized, they are hypothesized to involve the epigenetic regulation of gene expression. We quantified genome-wide levels of DNA methylation in purified peripheral blood mononuclear cells (PBMCs) longitudinally collected from 55 elderly patients undergoing three types of major surgery (elective colorectal and hip replacement surgery, and emergency hip fracture surgery), comparing samples collected at baseline to those collected immediately post-operatively and at discharge from hospital.\n\nResultsMajor surgery was associated with acute changes in DNA methylation at sites annotated to immune system genes, paralleling changes in serum-levels of markers including C-reactive protein (CRP) and Interleukin 6 (IL-6) measured in the same individuals. Although many of the observed changes in DNA methylation are consistent across the three types of surgery, there is notable heterogeneity between surgery types at certain loci. The acute changes in DNA methylation induced by surgery are relatively stable in the postoperative period, generally persisting until discharge from hospital.\n\nConclusionsOur results highlight the dramatic alterations in gene regulation induced by invasive surgery, primarily reflecting upregulation of the immune system in response to trauma, wound healing and anaesthesia.

genomics↗