Project description:Systemic lupus erythematosus (SLE) affects 1 in 537 of African American (AA) women, which is >2-fold more than European American (EA) women. AA patients also develop the disease at a younger age, have more severe symptoms, and a greater chance of early mortality. We used a multi-omics approach to uncover ancestry-specific immune alterations in SLE patients and healthy controls that may contribute to disease disparities. Cell composition, signaling, and epigenetics were evaluated by mass cytometry; droplet-based single cell transcriptomics and paired proteogenomics (scRNA-Seq/scCITE-Seq). Soluble mediator levels were measured in plasma and stimulated whole blood. TLR3/4/7/8/9 gene expression pathways in B cells and monocytes were enhanced in AA SLE patients compared to EA patients. TLR7/8/9 and IFN phospho-signaling responses were also heightened in healthy AA versus EA controls. Exposure of AA and EA healthy control cells to TLR7/8/9 agonists or IFN resulted in altered immune cell compositions that recapitulated the ancestry-associated differences in SLE patients. These data support that ancestry-based differences in TLR7/8, TLR9, and IFN responses that can be detected in healthy individuals could influence lupus disease course and severity.
Project description:Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease that displays a significant gender difference in terms of incidence and severity. However, the underlying mechanisms accounting for sexual dimorphism remain unclear. To reveal the heterogeneity in the pathogenesis of SLE between male and female patients. PBMC were collected from 15 patients with SLE (7 males, 8 females) and 15 age-matched healthy controls (7 males, 8 females) for proteomic analysis. Enrichment analysis of proteomic data revealed that type I interferon signaling and neutrophil activation networks mapped to both male and female SLE, while male SLE has a higher level of neutrophil activation compared with female SLE. Our findings define gender heterogeneity in the pathogenesis of SLE and may facilitate the development of gender-specific treatments.
Project description:Complex blood transcriptomes can lead to the clinical heterogeneity of systemic lupus erythematosus (SLE). In the current study, we integrated transcriptomics, public data mining and clinical parameters to reveal whether SLE severity is affected by specific genes or pathways.
Project description:Systemic lupus erythematosus (SLE) patients are 90% women and over three times more likely to die of cardiovascular disease than women in the general population. Chest pain with no obstructive cardiac disease is associated with coronary microvascular disease (CMD), where narrowing of the small blood vessels can lead to ischemia, and frequently reported by SLE patients. Using whole blood RNA samples, we asked whether gene signatures discriminate SLE patients with coronary microvascular dysfunction (CMD) on cardiac MRI (n=4) from those without (n=7) and whether any signaling pathway is linked to the underlying pathobiology of SLE CMD. RNA-seq analysis revealed 143 differentially expressed (DE) genes between the SLE and healthy control (HC) groups, with virus defense and interferon (IFN) signaling being the key pathways identified as enriched in SLE as expected. We next conducted a comparative analysis of genes differentially expressed in SLE-CMD and SLE-non-CMD relative to HC samples. Our analysis highlighted differences in IFN signaling, RNA sensing and ADP-ribosylation pathways between SLE-CMD and SLE-non-CMD. This is the first study to investigate possible gene signatures associating with CMD in SLE, and our data strongly suggests that distinct molecular mechanisms underly vascular changes in CMD and non-CMD involvement in SLE.
Project description:9G4+ IgG antibodies expand in SLE in a disease specific fashion and react with different lupus antigens including B cell antigens and apoptotic cells. Their shared use of VH4-34 represents a unique system to understand the molecular basis of lupus autoreactivity. Understanding the participation of apoptotic cells, a rich source of self-antigens including chromatin, in the diversification and selection of autoreactive memory B cells is particularly important in SLE where these cells accumulate in the germinal centers and may activate pathogenic autoreactive B cells. Our findings indicate that the three mabs with strong apoptotic binding recognized chromatin and individual histones as documented by glomerular proteome microarrays. While the actual antigens mediating APCB remain to be formally elucidating, our initial studies indicate that binding to histone/chromatin may mediate such autoreactivity in at least a fraction of these antibodies Single VH4-34 B cells sorted from IgD-CD27+ memory B cells of SLE patient are sorted and single -RT-PCR is performed to generate monoclonal antibody. 3 monoclonals which were strong apoptotic binders tested for protein array against Chromatin, Histone1, Histone 2A, Histone 2B, Histone 3, Histone 4 and total histones