Biology subjects

Giulino-Roth, L.

Publications and source records attributed to Giulino-Roth, L..

5 recordsLinked to original sources

bioRxiv2025

Transcriptome sequencing of Hodgkin lymphoma Hodgkin and Reed-Stenberg cells reveals escape from NK cell recognition and an unfolded protein response

The mutational profile of classic Hodgkin lymphoma (cHL) overlaps with that of related B cell lymphomas, including primary mediastinal B cell lymphoma (PMBL), and yet these are different histologically and clinically. To discover the molecular features that distinguish cHL, we deployed flow cytometric cell sorting and low-input RNA sequencing to generate full transcriptome data from viable, isolated Hodgkin and Red-Sternberg (HRS) cells from eighteen primary tumors, alongside matched intra-tumoral non-neoplastic B cells and four cell lines. Comparison of HRS cells to normal cellular subsets revealed evidence of abortive plasma cell differentiation, with an unfolded protein response signature, shared with plasma cell neoplasms, but not other B-cell lymphoma types. Comparison of cHL to PMBL revealed similarities but also key differences in B cell differentiation programs accompanied by upregulation of genes involved in microtubule cytoskeleton organization in cHL, which may be related to the unique multinucleated nature of HRS cells. In HRS cells, we also observed a downregulation of SLAM family receptors, which are crucial for NK cell activation, providing a potential mechanism for immune evasion from NK-mediated killing. STATEMENT OF SIGNIFICANCEThis study defines a unique transcriptional program in classic Hodgkin Lymphoma (cHL) marked by oncogenic signaling, chromatin integrity, DNA repair, and immune escape including loss of NK-activating receptors. HRS cells resemble plasma cells and have an unfolded protein response signature, which distinguishes them from diffuse large and primary mediastinal B cell lymphomas.

cancer biology↗

bioRxiv2024

A necroptotic-to-apoptotic signaling axis underlies inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic condition caused by altered cytokine signaling, maladaptive immunity, dysbiosis, and intestinal barrier dysfunction. Patients with IBD receive therapy to correct these imbalances and achieve remission. However, most patients relapse, suggesting that pathological mechanisms persist during remission. Here, we show that excess epithelial cell death is an underlying feature of IBD that arises in patients in remission and on advanced therapy. Mechanistically, nascent inflammation reprograms epithelial cells into a macrophage-like state that promotes RIPK1-independent necroptotic signaling, then triggers iNOS-mediated mitochondrial apoptosis of absorptive epithelial cells and PUMA-mediated intestinal stem cell death. These findings reveal aberrant epithelial cell death signaling as a hallmark of IBD that occurs early in mucosal lesion development and persists despite current therapeutic approaches. One-Sentence SummaryEpithelial cell death is dysregulated in patients with inflammatory bowel disease.

cell biology↗

bioRxiv2023

An immunohistochemical atlas of necroptotic pathway expression

Necroptosis is a lytic form of regulated cell death reported to contribute to inflammatory diseases of the gut, skin and lung, as well as ischemic-reperfusion injuries of the kidney, heart and brain. However, precise identification of the cells and tissues that undergo necroptotic cell death in vivo has proven challenging in the absence of robust protocols for immunohistochemical detection. Here, we provide automated immunohistochemistry protocols to detect core necroptosis regulators - Caspase-8, RIPK1, RIPK3 and MLKL - in formalin-fixed mouse and human tissues. We observed surprising heterogeneity in protein expression within tissues, whereby short-lived immune barrier cells were replete with necroptotic effectors, whereas long-lived cells lacked RIPK3 or MLKL expression. Local changes in the expression of necroptotic effectors occurred in response to insults such as inflammation, dysbiosis or immune challenge, consistent with necroptosis being dysregulated in disease contexts. These methods will facilitate the precise localisation and evaluation of necroptotic signaling in vivo. HighlightsO_LI13 automated immunohistochemistry protocols for detecting the necroptotic pathway C_LIO_LINecroptotic pathway expression is confined to fast-cycling immune barriers C_LIO_LINecroptotic pathway expression changes at sites of immunoinflammatory challenge C_LIO_LIImmunodetection of necrosomes in IBD patients is a putative new diagnostic tool C_LI

cell biology↗

bioRxiv2022

Methionine Metabolism Controls the B-cell EBV Epigenome and Viral Latency

Epstein-Barr virus (EBV) subverts host epigenetic pathways to switch between viral latency programs, colonize the B-cell compartment and reactivate. Within memory B-cells, the reservoir for lifelong infection, EBV genomic DNA and histone methylation marks restrict gene expression. But, this epigenetic strategy also enables EBV-infected tumors, including Burkitt lymphomas to evade immune detection. Little is known about host cell metabolic pathways that support EBV epigenome landscapes. We therefore used amino acid restriction, metabolomic and CRISPR approaches to identify that an abundant methionine supply, and interconnecting methionine and folate cycles, maintain Burkitt EBV gene silencing. Methionine restriction, or methionine cycle perturbation, hypomethylated EBV genomes, de-repressed latent membrane protein and lytic gene expression. Methionine metabolism also shaped EBV latency gene regulation required for B-cell immortalization. Dietary methionine restriction altered murine Burkitt xenograft metabolomes and de-repressed EBV immunogens in vivo. These results highlight epigenetic/immunometabolism crosstalk supporting the EBV B-cell lifecycle and suggest therapeutic approaches. HighlightsO_LIMethionine metabolism is critical for Epstein-Barr virus B-cell latency C_LIO_LIExtensive cross-talk enables methionine metabolism to control the EBV epigenome C_LIO_LIMethionine restriction also impairs EBV-driven human B-cell immortalization C_LIO_LIDietary methionine restriction unmasks EBV antigens in Burkitt xenografts in vivo C_LI

microbiology↗

bioRxiv2021

Molecular evolution of classic Hodgkin lymphoma revealed through whole genome sequencing of Hodgkin and Reed Sternberg cells

The rarity of malignant Hodgkin and Reed Sternberg (HRS) cells within a classic Hodgkin lymphoma (cHL) biopsy limits the ability to study the genomics of cHL. To circumvent this, our group has previously optimized fluorescence-activated cell sorting to purify HRS cells. Here we leveraged this method to report the first whole genome sequencing landscape of HRS cells and reconstruct the chronology and likely etiology of pathogenic events prior to the clinical diagnosis of cHL. We identified alterations in driver genes not previously described in cHL, a high activity of the APOBEC mutational signature, and the presence complex structural variants including chromothripsis. We found that the high ploidy observed in cHL is often acquired through multiple, independent large chromosomal gain events including whole genome duplication. The first of these likely occurs several years prior to the diagnosis of cHL, and the last gains typically occur very close to the time of diagnosis. Evolutionary timing analyses revealed that driver mutations in B2M, BCL7A, GNA13, and PTPN1, and the onset of AID driven mutagenesis usually preceded large chromosomal gains. The study provides the first temporal reconstruction of cHL pathogenesis and suggests a relatively long time course between the first pathogenic event and the clinical diagnosis.

cancer biology↗