Biology subjects

Cerosaletti, K.

Publications and source records attributed to Cerosaletti, K..

6 recordsLinked to original sources

bioRxiv2025

Integrated histopathology of the human pancreas throughout stages of type 1 diabetes progression

Type 1 diabetes (T1D) is a progressive autoimmune condition that culminates in the loss of insulin-producing beta cells. Pancreatic histopathology provides essential insights into disease initiation and progression yet an integrated perspective of in situ pathogenic processes is lacking due to limited sample availability, the dispersed nature of anatomical lesions, and often restricted analytical dimensionality. Here, we combined multiplexed immunostaining, high-magnification whole-slide imaging, digital pathology, and semi-automated image analysis strategies to interrogate pancreatic tail and head regions obtained from organ donors across T1D stages including at-risk and at-onset cases. Deconvolution of architectural features, endocrine cell composition, immune cell burden, and spatial relations of [~]25,000 islets revealed a series of novel histopathological correlates especially in the prodromal disease stage preceding clinical T1D. Altogether, our comprehensive "single-islet" analyses permit the reconstruction of a revised natural T1D history with implications for further histopathological investigations, considerations of pathogenetic modalities, and therapeutic interventions.

immunology↗

bioRxiv2024

Companion to: A molecular basis for milk allergen immune recognition in eosinophilic esophagitis

BackgroundEosinophilic esophagitis (EoE) is a chronic, type 2 inflammatory disease that is increasing in incidence and has substantial morbidity. Despite being clinically defined as a food allergy, the molecular details of food antigen presentation and recognition by the immune system are unknown. ObjectiveThe objective of this study was to identify and characterize the molecular basis of milk antigen presentation and T cell recognition in a patient with EoE milk allergy. MethodsMilk-expanded TCR clonotypes were identified using ex vivo stimulation followed by single cell RNA with linked, paired TRA and TRB sequencing. HLA restriction and antigen specificity of TCRs were identified using a combination of lentiviral expression, HLA sequencing, antibody blockade, and a peptide library screen. ResultsWe isolated a {beta}-casein specific TCR clonotype (eoeTCR-4) and determined its HLA restriction (HLA-DRB1*07:01) and cognate antigen ({beta}-casein AA 59-78). EoeTCR-4 was not detected among a larger group of subjects and is likely private to EoE Subject 1. ConclusionIn conjunction with the parent manuscript, this companion article provides the first molecular identity of food antigen presentation and immune recognition in EoE. SUMMARYThis manuscript is a companion to the parent manuscript "A molecular basis for milk allergen immune recognition in eosinophilic esophagitis". It provides additional data and detailed methods not provided in the parent manuscript. It is designed to supplement and support the findings and conclusions of the parent manuscript.

immunology↗

bioRxiv2024

Unsupervised generative AI discovers pan-leukocyte dysregulated pathways in single-cell lupus data

Comparisons of single-cell RNA-sequencing (scRNA-seq) data from healthy and diseased tissues are widely used to identify cell-type-specific dysregulated genes, pathways, and processes. Accordingly, many sophisticated methods have been developed for this purpose. However, such tools generally require considerable user expertise for optimal performance. Here, we show that unsupervised application of a linearly-decoded Variational Auto Encoder (a generative AI model) to scRNA-seq data recapitulates and extends findings from a seminal recent lupus study and leads to new insights. Thanks to existing software libraries, our approach is straightforward to implement, computationally efficient, methodologically robust, and produces consistent and reproducible results.

bioinformatics↗

bioRxiv2022

Shifts in isoform usage underlie transcriptional differences in regulatory T cells in type 1 diabetes

Genome-wide association studies have identified numerous loci with allelic associations to Type 1 Diabetes (T1D) risk. Most disease-associated variants are enriched in regulatory sequences active in lymphoid cell types, suggesting that lymphocyte gene expression is altered in T1D. We assayed gene expression between T1D cases and healthy controls in two autoimmunity-relevant lymphocyte cell types, memory CD4+/CD25+ T-regulatory cells (Treg) and memory CD4+/CD25- T-cells, using a splicing event-based approach to characterize tissue-specific transcriptomes. Limited differences in isoform usage between T1D cases and controls were observed in memory CD4+/CD25- T-cells. In Tregs, 553 genes demonstrated differences in isoform usage between cases and controls, particularly RNA recognition and splicing factor genes. Many of these genes are regulated by the variable inclusion of exons that can trigger nonsense mediated decay. Our results suggest that dysregulation of gene expression, through shifts in alternative splicing in Tregs, contributes to T1D etiology.

genetics↗

bioRxiv2022

PTPN22 R620W gene editing in T cells enhances low avidity TCR responses

A genetic variant in the gene PTPN22 (R620W, rs2476601) is strongly associated with increased risk for multiple autoimmune diseases and has been linked to altered TCR regulation. Here, we utilize Crispr/Cas9 gene editing with donor DNA repair templates in human cord blood-derived, naive T cells to generate PTPN22 risk edited, non-risk edited (silent modification), or knock out T cells from the same donor. PTPN22 risk edited cells exhibited increased activation marker expression following non-specific TCR engagement, findings that mimicked PTPN22 KO cells. Next, using lentiviral delivery of T1D patient-derived islet-antigen specific TCRs, we demonstrate that loss of PTPN22 function led to enhanced signaling in T cells expressing a lower avidity self-reactive TCR. In this setting, loss of PTPN22 mediated enhanced proliferation and Th1 skewing. Importantly, expression of the risk variant in association with a lower avidity TCR also increased proliferation relative to PTPN22 non-risk T cells. Together, these findings suggest that, in primary human T cells, PTPN22 rs2476601 contributes to autoimmunity risk by permitting increased TCR signaling in mildly self-reactive T cells, thereby potentially expanding the self-reactive T cell pool and skewing this population toward an inflammatory phenotype.

immunology↗

bioRxiv2021

Endomembrane targeting of human OAS1 p46 augments antiviral activity

Many host RNA sensors are positioned in the cytosol to detect viral RNA during infection. However, most positive-strand RNA viruses replicate within a modified organelle co-opted from intracellular membranes of the endomembrane system, which shields viral products from host cell innate immune sensors. Targeting innate RNA sensors to the endomembrane system may enhance their ability to sense viral RNA generated by viruses that use these compartments for replication. Here, we reveal that an isoform of oligoadenylate synthetase 1, OAS1 p46, is prenylated and targeted to the endomembrane system. Membrane localization of OAS1 p46 confers enhanced access to viral replication sites and results in increased antiviral activity against a subset of RNA viruses including flavivirus, picornavirus, and SARS-CoV-2. Finally, our human genetic analysis shows that the OAS1 splice-site SNP responsible for production of the OAS1 p46 isoform strongly associates with COVID-19 severity. This study highlights the importance of endomembrane targeting for the antiviral specificity of OAS1 and suggests early control of SARS-CoV-2 replication through OAS1-p46 is an important determinant of COVID-19 severity.

immunology↗