Biology subjects

Geraldino-Pardilla, L.

Publications and source records attributed to Geraldino-Pardilla, L..

3 recordsLinked to original sources

bioRxiv2024

An engineered human cardiac tissue model reveals contributions of systemic lupus erythematosus autoantibodies to myocardial injury

Systemic lupus erythematosus (SLE) is a highly heterogenous autoimmune disease that affects multiple organs, including the heart. The mechanisms by which myocardial injury develops in SLE, however, remain poorly understood. Here we engineered human cardiac tissues and cultured them with IgG fractions containing autoantibodies from SLE patients with and without myocardial involvement. We observed unique binding patterns of IgG from two patient subgroups: (i) patients with severe myocardial inflammation exhibited enhanced binding to apoptotic cells within cardiac tissues subjected to stress, and (ii) patients with systolic dysfunction exhibited enhanced binding to the surfaces of viable cardiomyocytes. Functional assays and RNA sequencing (RNA-seq) revealed that IgGs from patients with systolic dysfunction exerted direct effects on engineered tissues in the absence of immune cells, altering tissue cellular composition, respiration and calcium handling. Autoantibody target characterization by phage immunoprecipitation sequencing (PhIP-seq) confirmed distinctive IgG profiles between patient subgroups. By coupling IgG profiling with cell surface protein analyses, we identified four pathogenic autoantibody candidates that may directly alter the function of cells within the myocardium. Taken together, these observations provide insights into the cellular processes of myocardial injury in SLE that have the potential to improve patient risk stratification and inform the development of novel therapeutic strategies.

bioengineering↗

bioRxiv2023

SAP expressing T peripheral helper cells identify systemic lupus erythematosus patients with lupus nephritis

IntroductionT follicular (TFH) and peripheral helper (TPH) cells have been increasingly recognized as a pathogenic subset of CD4 T cells in systemic lupus erythematosus (SLE). The SLAM Associated Protein (SAP) regulates TFH and TPH function by binding to the co -stimulatory signaling lymphocyte activation molecule family (SLAMF) receptors that mediate T cell - B cell interactions. SAP and SLAMF are critical for TPH dependent B cell maturation into autoantibody-producing plasma cells that characterize SLE pathogenesis. MethodsPeripheral blood mononuclear cells (PBMCs) were isolated using density gradient separation from whole blood. Cells were stained for cell surface markers, followed by permeabilization and staining of intracellular SAP for spectral flow cytometry analysis. Additionally, we analyzed SAP expression from renal infiltrating lupus nephritis (LN) T cells using the publicly available single-cell RNA sequencing (sc-RNA seq) Accelerated Medicines Partnership (AMP) in SLE dataset. ResultsPBMCs from 30 patients with SLE (34{+/-}10 years old, 83% female), including 10 patients with LN, were analyzed. We found an increase in total SAP-positive CD4 and CD8 T cells in SLE compared with controls (55.5{+/-}2.6 vs. 41.3{+/-}3.4, p=0.007 and 52.5{+/-}3.0 vs. 39.2{+/-}2.8, p=0.007 respectively). In CD4 T cells, the highest SAP expression was in the TPH subset. The frequency of SAP+TPH in circulation correlated with disease activity, SLE patients with renal disease had higher levels of circulating SAP+TPH that remained significant after adjusting for age, sex, race, low complements, and elevated anti-dsDNA (p=0.014). scRNA-seq data of renal infiltrating T cells identified increased SAP from LN compared with control kidney biopsy samples (p=0.03), including an expansion of SAP-positive TFH-like subsets in the LN kidneys. Increased SAP expression in LN was associated with the differential expression of SLAMF3 and SLAMF7 as well as granzyme K and EOMES. The existence of two predominant SAP-expressing subsets, the TFH-like CD4 T cells and granzyme K positive effector CD8 T cells, was verified using scRNA-seq data from a human transcriptomic atlas of fifteen major organs. ConclusionThe expansion of SAP expressing T helper cells was associated with lupus nephritis in our cohort and verified using scRNA-seq data of renal infiltrating T cells. Improved understanding of SLAM/SAP signaling can identify new therapeutic targets in LN.

immunology↗

bioRxiv2022

Cellular deconstruction of inflamed synovium defines diverse inflammatory phenotypes in rheumatoid arthritis

Rheumatoid arthritis (RA) is a prototypical autoimmune disease that causes destructive tissue inflammation in joints and elsewhere. Clinical challenges in RA include the empirical selection of drugs to treat patients, inadequate responders with incomplete disease remission, and lack of a cure. We profiled the full spectrum of cells in inflamed synovium from patients with RA with the goal of deconstructing the cell states and pathways characterizing pathogenic heterogeneity in RA. Our multicenter consortium effort used multi-modal CITE-seq, RNA-seq, and histology of synovial tissue from 79 donors to build a >314,000 single-cell RA synovial cell atlas with 77 cell states from T, B/plasma, natural killer, myeloid, stromal, and endothelial cells. We stratified tissue samples into six distinct cell type abundance phenotypes (CTAPs) individually enriched for specific cell states. These CTAPs demonstrate the striking diversity of RA synovial inflammation, ranging from marked enrichment of T and B cells (CTAP-TB) to a congregation of specific myeloid, fibroblast, and endothelial cells largely lacking lymphocytes (CTAP-EFM). Disease-relevant cytokines, histology, and serology metrics are associated with certain CTAPs. This comprehensive RA synovial atlas and molecular, tissue-based CTAP stratification reveal new insights into RA pathology and heterogeneity, which could lead to novel targeted-treatment approaches in RA.

genomics↗