Biology subjects

Silina, K.

Publications and source records attributed to Silina, K..

4 recordsLinked to original sources

bioRxiv2024

Melanoma Response to Immunotherapy is regulated by B Cell-Derived Extracellular Vesicles

The immune tumor microenvironment (TME) is increasingly recognized as a dynamic ecosystem where B cells play pivotal roles in modulating therapeutic responses, particularly in the context of immune checkpoint blockade (ICB) therapy. While B cells have traditionally been viewed as bystanders in tumor immunity, recent evidence suggests they may actively influence anti-tumor immunity, albeit with conflicting reports regarding their pro-tumor or anti-tumor roles. This study explores the crucial roles played by B cells and their secreted extracellular vesicles (EVs) in shaping melanoma responses to ICB therapy. We show a significant enrichment of B cells in ICB therapy responders compared to non-responders, pre-treatment, through retrospective analyses of melanoma patient tumors. Functional assays demonstrate that B cell depletion impairs T cell-mediated tumor cytotoxicity, underscoring the importance of B cells in anti-tumor responses. To investigate the clinical relevance, EVs were isolated from melanoma patient tumors, and fractioned into tumor and immune subpopulations. MiRNA profiling of CD19+ EVs identifies miR-99a-5p as a top candidate, among several others, upregulated in responders. Functional assays show that miR-99a-5p silencing in B cells diminishes T cell-mediated anti-tumor activity, suggesting its role in promoting B cell-mediated immune responses. Mechanistically, miR-99a-5p influences B cell maturation within the TME by mediating class-switch recombination. Our findings highlight the important role of B cells and their derived EVs in shaping the efficacy of melanoma immunotherapy, paving the way for novel therapeutic strategies targeting B cell-related pathways. Graphical abstract (created with Biorender) O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=177 SRC="FIGDIR/small/628150v1_ufig1.gif" ALT="Figure 1"> View larger version (60K): org.highwire.dtl.DTLVardef@144bbe6org.highwire.dtl.DTLVardef@18c1e9eorg.highwire.dtl.DTLVardef@2e37aaorg.highwire.dtl.DTLVardef@487e18_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

Sustained innate interferon is an essential inducer of tertiary lymphoid structures

Tertiary lymphoid structures (TLS) resemble follicles of secondary lymphoid organs and develop in non-lymphoid tissues during inflammation and cancer. Which cell types and signals drive the development of TLS is largely unknown. To investigate early events of TLS development in the lungs, we repeatedly instilled p(I:C) plus ovalbumin (Ova) intranasally. This induced TLS ranging from lymphocytic aggregates to organized and functional structures containing germinal centers. We found that TLS development is independent of FAP+ fibroblasts, alveolar macrophages or CCL19 but crucially depends on type I (IFN-I)-but not type III interferon (IFN-III)-signaling. Mechanistically, IFN-I initiates two synergistic pathways that culminate in the development of TLS. On the one hand, IFN-I induces lymphotoxin (LT) in lymphoid cells, which stimulate stromal cells to produce the B-cell-attracting chemokine CXCL13 through LT{beta}R-signaling. On the other hand, IFN-I is sensed by stromal cells that produce the T-cell-attracting chemokines CXCL9, CXCL10 as well as CCL19 and CCL21 independently of LT{beta}R. Consequently, B-cell aggregates develop within a week, whereas follicular dendritic cells and germinal centers appear after 3 weeks. Thus, sustained production of IFN-I together with an antigen is essential for the induction of functional TLS in the lungs. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=152 SRC="FIGDIR/small/591846v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@a2d940org.highwire.dtl.DTLVardef@165294aorg.highwire.dtl.DTLVardef@79c43forg.highwire.dtl.DTLVardef@4316ce_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2023

Multi-resolution deep learning characterizestertiary lymphoid structures in solid tumors

Tertiary lymphoid structures (TLSs) are dense accumulations of lym-phocytes in inflamed peripheral tissues, including cancer, and are associated with improved survival and response to immunotherapy in various solid tumors. Histological TLS quantification has been pro-posed as a novel predictive and prognostic biomarker, but lack of standardized methods of TLS characterization hampers assessment of TLS densities across different patients, diseases, and clinical centers. We introduce a novel approach based on HookNet-TLS, a multi-resolution deep learning model, for automated and unbiased TLS quantification and identification of germinal centers in routine hema-toxylin and eosin stained digital pathology slides. We developed a HookNet-TLS model using n=1019 manually annotated TCGA slides from clear cell renal cell carcinoma, muscle-invasive blad-der cancer, and lung squamous cell carcinoma. We show that HookNet-TLS automates TLS quantification with a human-level performance and demonstrates prognostic associations similar to visual assessment. We made HookNet-TLS publicly available to aid the adoption of objective TLS assessment in routine pathology.

pathology↗

bioRxiv2020

CD39+PD-1+CD8+ T cells mediate metastatic dormancy in breast cancer

Some breast tumors metastasize aggressively whereas others remain in a state of metastatic dormancy for months or even years. The mechanism governing such metastatic dormancy remains largely unknown. Through high-parametric single-cell mapping in mice, we identified a discrete population of CD39+PD-1+CD8+ T cells present both in primary tumors and in dormant metastasis, which was hardly found in aggressively metastasizing tumors. Using blocking antibodies, we found that dormancy depended on TNF and IFN{gamma}. Of note, immunotherapy reduced the number of dormant cancer cells in the lungs. Adoptive transfer of purified CD39+PD-1+CD8+ T cells prevented metastatic outgrowth. In human breast cancer, the frequency of CD39+PD-1+CD8+ but not of total CD8+ T cells correlated with delayed metastatic relapse after resection (disease-free survival), thus underlining the biological relevance of CD39+PD-1+CD8+ T cells for controlling experimental and human breast cancer. Furthermore, density of CD39+PD-1+CD8+ T cells may serve as a novel biomarker and may serve as a potential immunotherapy target. Thus, we discovered that a primary breast tumor primes a systemic, CD39+PD-1+CD8+ T cell response that is essential for metastatic dormancy in the lungs.

cancer biology↗