Inflammation
Abstract
The pericardium plays an important homeostatic function for the neighbouring heart providing both lubricating and structural support. In vivo models have further identified a protective role for the pericardium in modulating cardiac remodelling following myocardial infarction possibly through the actions of tissue-resident pericardial macrophages. Using patient derived pericardial samples, we establish that human pericardial immune cells directly inhibit cardiac fibroblast fibrotic activity and this action is dampened following myocardial infarction. Performing single-cell RNA sequencing of patient pericardial fluid cells, we identify two pericardial macrophage subsets that are uniquely altered in response to myocardial infarction, which contributes to a shift in their effector molecule expression profiles. We confirm that fibronectin-expressing human pericardial macrophages are the primary driver of the pericardial anti-fibrotic actions through the release of cystatin C. Finally, we establish cystatin C as a macrophage-derived cardioprotective effector molecule in an in vivo model of myocardial infarction. Collectively, we uncover a new molecular mechanism of the local immune environment that regulates cardiac remodelling post myocardial infarction.
Authors
Ali Fatehi Hassanabad, Sarthak Sinha, Arzina Jaffer, Darrell Belke, Nicole L. Rosin, Elodie Labit, Daniel Young, Friederike I. Schoettler, Keerthana Chockalingam, Benjamin Haeyul Lee, Jameson A. Dundas, Emilie de Chantal, Carmina A. Isidoro, Alexander Tam, Hanjoo B. Shim, Anna N. Zarzycki, Afshin Derakhshani, Elisabeth Gorgiogianni, Jeannine D. Turnbull, Antoine Dufour, Shalina S. Ousman, Jeff A. Biernaskie, Paul W.M. Fedak, Justin F. Deniset
Abstract
Authors
Sarah W. Robison, Jindong Li, Kristopher R. Genschmer, Liliana Viera, Jeremy B. Foote, Landon Wilson, W. Edward Swords, J. Edwin Blalock, Amit Gaggar, Xin Xu
Abstract
Chronic Graft-Versus-Host disease (cGVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic transplantation. CGVHD pathophysiology involves cooperation between Tfollicular helper cells (TFH) and germinal center B-cells (GCB), allo- and auto-antibody depositions in cGVHD tissues, and fibrosis. We evaluated human CD19-directed chimeric antigen receptor (CAR19) T-cell therapy in a clinically relevant murine cGVHD model with bronchiolitis obliterans syndrome (BOS). Although CD8 CAR19 T-cells effectively reduced peripheral B-cell and GCB frequencies, pulmonary function was unimproved. In contrast, a single CAR19 CD4 regulatory T-cells (Treg) infusion mitigated ongoing pulmonary disease and modulated germinal centers (GC) associated with reduced TFH frequencies compared to control Tregs but without measurable B-cell depletion. Compared to EGFR Treg infusion, mice receiving CAR19 Tregs exhibited enhanced suppression of B-cell activation, preserved splenic architecture, and provided greater opportunities for interaction with CD19+ B-cells at the B-cell follicle boundary zones. Taken together with the absence of detectable B-cell cytolysis, these findings are most consistent with GC suppression rather than B-cell depletion as the dominant mechanism. Overall, our findings suggest that CAR19 Tregs represent a promising and safe cGVHD/BOS therapeutic strategy, offering immunosuppressive benefits and improved disease outcomes that may be more limited with CD8 CAR19 T-cell treatment.
Authors
Sujeong Jin, Michael C. Zaiken, Cameron McDonald-Hyman, Christina R. Hartigan, Sara Bolivar-Wagers, Jemma H. Larson, Yiyun Peng, Sophia Hani, Megan Riddle, Asim Saha, Angela Panoskaltsis-Mortari, Eun Ko, Yujie Zhao, Rocio Amaro Marquez, Pooja Shree Marri Baskar, Cindy R. Eide, William J. Murphy, Keli L. Hippen, Geoffrey R. Hill, Jakub Tolar, Peter T. Sage, Christopher A. Pennell, Leslie S. Kean, Bruce R. Blazar
Abstract
Plasma membrane repair is critical for tissue integrity, especially for elongated contractile muscle cells. Genetically-mediated defects in plasma membrane resealing produce persistent leak, leading to a disordered extracellular matrix. Loss of the membrane repair protein dysferlin slows sarcolemmal resealing and promotes excess leak. Annexin A6 is also implicated in sarcolemmal repair, forming repair caps at the site of membrane disruption. On its own, deletion of the gene for annexin A6, Anxa6, had little effect on muscle health. In contrast, combined loss of dysferlin and annexin A6 (DysfA6) generated muscle fibers with profoundly defective membrane leak. Strikingly, Anxa6 deletion in the context of loss of dystrophin (mdxA6) did not exacerbate muscle defects. The persistent membrane leak in DysfA6 muscle resulted in marked macrophage infiltration with disordered macrophage polarization. Injured muscle fibers were targets of macrophage efferocytosis. Loss of Anxa6 was associated with increased expression of annexins A1 and A2, both of which were heavily deposited into the extracellular matrix. In vitro, macrophages exposed to annexins A1 and A2 increased Csf1 expression, consistent with a model where excess leak results in annexins A1 and A2 in the extracellular matrix, where this protein composition influences macrophage proliferation and efferocytosis.
Authors
GaHyun Lee, Alexander J. Fitt, Ashlee M. Long, Lauren A. Vaught, Dorothy DeBiasse, Alexander R. Keeble, Jason M. Kwon, Patrick G.T. Page, Marie-Therese Daher, Michele Hadhazy, Alexander B. Willis, David Ceja Galindo, Maxwell C. McCabe, Connor Lantz, Kirk C. Hansen, Rachelle H. Crosbie, Edward B. Thorp, Alexis R. Demonbreun, Elizabeth M. McNally
Abstract
Vaccine development for tuberculosis is a global priority. Our studies using Collaborative Cross (CC) mice show that genetic diversity influences the efficacy of BCG, the most widely used TB vaccine. BCG vaccination of CC042 mice reduced their lung bacillary burden and increased their survival following low-dose aerosol Mycobacterium tuberculosis infection (MTBI), despite impaired T cell trafficking due to a defective Itgal gene. BCG vaccination conferred early bacillary control which appeared to be independent of B cell or T cell recall responses following MTBI. In contrast, long term survival of BCG-vaccinated CC042 mice after MTBI required T cells. Thus, CC042 mice reveal two phases of immunity induced by BCG: an early phase mediated by innate immunity or innate-like T cells and a later phase mediated by conventional memory CD4 and/or CD8 T cells. Although measurement of vaccine-induced protection 30 days after MTBI is a standard measure of vaccine efficacy in the TB model, this time point might be independent of memory T cells in CC042 mice. Our results suggest that vaccine-elicited innate/innate-like responses could have a larger role in protection than previously considered. The concordance between lung CFU, pathology, and survival make CC042 mice useful for mechanistic studies on vaccine-induced immunity.
Authors
Abiola F. Ogunsola, Rocky Lai, Kelly Cavallo, Anthony V. Tran, Gillian L. Beamer, Samuel M. Behar
Abstract
Polymorphonuclear neutrophils (PMNs) serve as frontline defenders against injury and infection, eliminating pathogens and initiating mucosal tissue repair. However, excessive PMN transepithelial migration (TEpM) contributes to chronic mucosal inflammatory disorders, including inflammatory bowel disease. PMN pro-inflammatory and pro-repair functions are regulated by incompletely defined signaling cascades involving kinases and phosphatases. Here, we determined how the protein tyrosine phosphatase CD45/PTPRC regulates PMN trafficking and effector functions in the gut. Pharmacologic inhibition of CD45 significantly reduced PMN colonic TEpM in vitro and in vivo and decreased intestinal PMN trafficking was observed in transgenic mice with PMN-specific deletion of CD45 (MRP8-Cre;Cd45fl/fl). Beyond limiting TEpM, CD45 depletion impaired key antimicrobial functions, including degranulation and phagocytosis, indicating broader effects on PMN effector activity. Importantly, recovery from dextran sodium sulfate (DSS)–induced colitis and biopsy-induced colonic wounding was delayed in MRP8-Cre;Cd45fl/fl mice, linking altered PMN function to defective mucosal healing. Mechanistically, CD45 depletion reduced surface expression of the β2 integrin CD11b/CD18 and inactivated the Src family kinase member Lyn. Together, data highlight an important CD45–CD11b–Lyn signaling axis that regulates PMN trafficking and effector functions in the intestine and identify CD45 as a promising target for modulating PMN function to promote mucosal tissue repair.
Authors
Jael Miranda, Dylan J. Fink, Zachary S. Wilson, Roland Hilgarth, Asma Nusrat, Charles A. Parkos, Jennifer C. Brazil
Abstract
Community-acquired pneumonia is a major cause of morbidity and mortality globally. Specific molecular endotypes are currently not well defined, and different viral or bacterial pathogens may trigger specific host responses and pathogenic mechanisms. We performed longitudinal proteomic profiling of bronchoalveolar lavage fluid and plasma from bacterial, influenza, and SARS-CoV-2–driven pneumonia. Our analysis revealed highly pneumonia type–specific proteomic signatures, including COVID-19–specific antibodies locally produced in the lung. These antibodies showed biased immunoglobulin V–domain usage, linked to a CD69/CD83 plasma cell state associated with disease severity and degree of autoimmunity. Using mass spectrometry–driven autoantibody profiling in 2 independent COVID-19 cohorts, we identified 177 putative autoantibodies targeting extracellular matrix, nuclear, and immune-related proteins. Of note, temporal changes in autoantibody profiles correlated with clinical markers of inflammation, organ dysfunction, and duration of hospitalization. These findings highlight the autoimmune aspects of COVID-19 and provide potential biomarkers and therapeutic targets to help improve patient outcomes.
Authors
Anna Semenova, Taylor A. Poor, Johannes B. Müller-Reif, Sai Rama Sridatta Prakki, Phillip Geyer, Martin Mück-Häusl, Rogan A. Grant, Luke Rasmussen, Lesca M. Holdt, Daniel Teupser, Matthias Mann, Ali Ö. Yildirim, Richard G. Wunderink, Alexander V. Misharin, Ben D. Singer, G.R. Scott Budinger, Theodore S. Kapellos, Herbert B. Schiller
Abstract
Fibroblasts in the lung mesenchyme produce growth factors and extracellular matrix components that guide formation of distal airspaces during the saccular stage of lung development. Inflammation in preterm infants disrupts this process, leading to bronchopulmonary dysplasia (BPD). To examine how mesenchymal inflammation contributes to BPD pathogenesis, we developed a transgenic mouse model (“IKKβTbx4”) in which expression of activated human IκB kinase beta (IKKβ), an upstream activator of NF-κB, was induced in Tbx4 lung enhancer-positive mesenchymal cells during the saccular stage of lung development (postnatal day 0 [PN0] - PN5). Saccular stage IKKβTbx4 mice exhibited a BPD-like phenotype with interstitial thickening and reduced distal airspaces at PN5, progressing to emphysematous enlargement of the distal lung at 2 mo of age. Mesenchymal NF-κB activity upregulated the chemokines CCL2 and CCL7, recruiting CCR2pos monocyte-derived macrophages to the lung. Recruited macrophages disrupted the elastin scaffold and impaired microvascular organization with reductions in CAP2 endothelial cells (aCaps) and pericytes. Blocking CCR2-dependent monocyte recruitment with a small molecule CCR2 antagonist rescued the abnormal lung phenotype. These findings identify mesenchyme-macrophage crosstalk as a mechanism by which inflammation disrupts saccular stage lung development, suggesting a role for this signaling axis in BPD pathogenesis.
Authors
Benjamin C. Crawford, Jessica Chauviere Lee, Bertha C. Elias, Shivangi Dave, Riet van der Meer, Wei Han, Alexandria L. Sharkey, David S. Nichols, Charles Shissias, Lauren Pate, Hayden Tan, Dawn C. Newcomb, Wei Shi, Lawrence S. Prince, Erin J. Plosa, Bradley W. Richmond, Timothy S. Blackwell, Susan H. Guttentag, John T. Benjamin
Abstract
Systemic lupus erythematosus (SLE) is a heterogeneous systemic autoimmune disease, yet the molecular basis underlying this variability remains incompletely understood. We profiled the plasma proteome in 260 SLE patients and 86 healthy volunteers (HVs) using the SomaScan v4.1 platform, quantifying 7,288 analytes corresponding to 6,595 unique proteins. We identified 215 proteins that were robustly differentially abundant between SLE patients and HVs in both discovery (n=207 SLE, n=45 HVs) and validation sets (n=53 SLE, n=41 HVs). Within-cases analyses identified 421 proteins associated with disease activity. Network-based clustering delineated correlated protein modules, including an interferon-associated module and a renal-associated module. Autoantibody-stratified analyses further uncovered distinct proteomic endotypes: positivity for antibodies targeting RNA-binding proteins (anti-Sm, anti-Ro-60, anti-RNP68, anti-RNP-A) was associated with increased interferon-stimulated protein levels (e.g., MX1, ISG15, CXCL10), independent of disease activity. Anti-Sm, anti-RNP-A and anti-Ro52 antibodies were associated with reduced plasma levels of their respective autoantigens. Anti-dsDNA antibodies were associated with elevated levels of CD40 ligand (CD40LG) and the neutrophil protease proteinase-3. Moreover, we identified an association between CD40LG and disease activity specific to the anti-dsDNA positive subgroup. Together, these data define plasma protein signatures of SLE and disease activity, highlight autoantibody-specific molecular phenotypes, and provide a basis for precision medicine.
Authors
Geoffrey H. D. Leung, Charlotte Bottomley, Norzawani Buang, Robert T. Maughan, Benjamin J. Whittle, Boroumand Zeidaabadi, Yun-Ju Huang, Tabitha Turner-Stokes, Marie Condon, Liz Lightstone, Tom Cairns, Marina Botto, Matthew C. Pickering, James E. Peters
Abstract
Virally suppressed people with HIV (PWH) remain at risk for developing comorbidities due to chronic inflammation with one potential contributor being the HIV reservoir. Associations between the CD4-reservoir and inflammation have been extensively characterized, while the role the monocyte-reservoir is poorly understood despite evidence that inflammatory monocytes play a role in HIV-associated comorbidities. Additionally, most studies focus on a single cellular reservoir, while it is highly likely that these reservoirs are interdependent. In a cohort of 164 PWH, we used the intact proviral DNA assay to quantify cell-specific reservoirs, applied unsupervised clustering to identify reservoir phenotypes, and then determined if reservoir phenotypes were associated with distinct immune signatures compared to people without HIV. Five unique reservoir clusters emerged driven primarily by variability in the monocyte reservoir, and each associated with a distinct immune landscape. These included profiles characterized by systemic inflammation, leukocyte–vascular activation, T cell activation with vascular and neuronal injury, enhanced CD8 activation and NK cell recovery, and altered monocyte survival, activation, and migration. This multidimensional approach provides a framework to identify reservoir-immune profiles that may explain heterogeneity in inflammation despite viral suppression and may inform strategies to mitigate HIV-associated comorbidities.
Authors
Ruoyu Wang, Aparna B. Bhattacharyya, Lily Pohlenz, Erin N. Shirk, Hayley S. Romero, Katherine Haas, Jennifer M. Coughlin, Raha M. Dastgheyb, Leah H. Rubin, Rebecca T. Veenhuis
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