Tertiary lymphoid structures as local perpetuators of organ-specific immune injury: implication for lupus nephritis.

In response to inflammatory stimuli in conditions such as autoimmune disorders, infections and cancers, immune cells organize in nonlymphoid tissues, which resemble secondary lymphoid organs. Such immune cell clusters are called tertiary lymphoid structures (TLS). Here, we describe the potential role of TLS in the pathogenesis of autoimmune disease, focusing on lupus nephritis, a condition that incurs major morbidity and mortality. In the kidneys of patients and animals with lupus nephritis, the presence of immune cell aggregates with similar cell composition, structure, and gene signature as lymph nodes and of lymphoid tissue-inducer and -organizer cells, along with evidence of communication between stromal and immune cells are indicative of the formation of TLS. TLS formation in kidneys affected by lupus may be instigated by local increases in lymphorganogenic chemokines such as CXCL13, and in molecules associated with leukocyte migration and vascularization. Importantly, the presence of TLS in kidneys is associated with severe tubulointerstitial inflammation, higher disease activity and chronicity indices, and poor response to treatment in patients with lupus nephritis. TLS may contribute to the pathogenesis of lupus nephritis by increasing local IFN-I production, facilitating the recruitment and supporting survival of autoreactive B cells, maintaining local production of systemic autoantibodies such as anti-dsDNA and anti-Sm/RNP autoantibodies, and initiating epitope spreading to local autoantigens. Resolution of TLS, along with improvement in lupus, by treating animals with soluble BAFF receptor, docosahexaenoic acid, complement inhibitor C4BP(ß-), S1P1 receptor modulator Cenerimod, dexamethasone, and anti-CXCL13 further emphasizes a role of TLS in the pathogenesis of lupus. However, the mechanisms underlying TLS formation and their roles in the pathogenesis of lupus nephritis are not fully comprehended. Furthermore, the lack of non-invasive methods to visualize/quantify TLS in kidneys is also a major hurdle; however, recent success in visualizing TLS in lupus-prone mice by photon emission computed tomography provides hope for early detection and manipulation of TLS.

Diverse Roles of NETosis in the Pathogenesis of Lupus.

NETosis is a form of neutrophil cell death during which extracellular fibrillary structures composed of cytosolic and granule proteins assembled on scaffolds of decondensed chromatin, called neutrophil extracellular traps (NETs), are released. NETs normally contribute to host immune defense. Accumulating evidence implicates aberrant NET production and/or reduced NET clearance, along with alterations of molecules involved in NETosis pathway, in humans and animals with lupus. The extruded nuclear antigens released by NET are a source of autoantigens, which can contribute to the breakdown of self-tolerance in lupus. Excessive NET can also promote the production of pro-inflammatory cytokine interferon-α, elicit direct cytotoxic effect on various renal cells, and cause capillary necrosis and podocyte loss. Additionally, NET can induce endothelial-to-mesenchymal transdifferentiation, which can promote activated myofibroblasts leading to extracellular matrix production. Thus, aberrant NETosis can play diverse roles, including autoantibody production, inflammation, and tissue damage, at different stages of lupus pathogenesis. Evidence suggests that treatments currently used in lupus may reduce NETosis, suggesting a potential utility of targeting NETosis to treat lupus. In fact, several approaches are being experimented to therapeutically target pathways of NETosis. Future studies should precisely delineate distinct roles of NETosis at different stages of lupus pathogenesis in humans, which would offer a rational basis for NETosis-targeting treatments in the clinic.

Kidney transplant candidacy evaluation and waitlisting practices in the United States and their association with access to transplantation.

There are limited data on the degree of variability in practices surrounding prioritization of referrals for transplant evaluation and criteria for transplant candidacy and their association with transplantation rates. We surveyed transplant programs across the United States between January 2020 and May 2020 to determine current pre-transplantation practices. We examined the relation between these reported practices and the outcomes of waitlisted patients at responding programs between January 2015 and March 2021 using Scientific Registry of Transplant Recipients data. We used adjusted Cox models with random effects to accommodate clustering by program. Primary outcomes included living or deceased donor transplantation. Of 172 surveyed programs, 90 participated. Substantial variations were noted in when the candidacy evaluation began (13% reported when eGFR was <30 mL/min/1.73 m2 and 17% reported no set policy) and the approach to pre-transplantation cardiac workup (multi-modality [58%], stress echocardiogram [20%]). Using adjusted models, a program policy of using other measures of body habitus to determine transplant candidacy rather than requiring patients to meet a body mass index (BMI) threshold of ≤35 kg/m2 (reference group) for candidacy was associated with a higher hazard of living donor transplantation (HR 1.83 [95% CI 1.10-3.03]). Pre-transplant practices vary substantially across the United States, and select practices were associated with transplantation rates.

M-LoCUS: A Scalable Intervention Enhances Growth Mindset and Internal Locus of Control in Undergraduate Students in STEM.

Student self-beliefs regarding intelligence and ability have been shown to correspond to achievement and persistence in an academic domain. Specifically, previous research has suggested that a growth mindset-or the belief that intelligence is malleable and can increase with effort-is associated with student success. Locus of control is a related but distinct self-belief regarding personal agency over various academic and nonacademic outcomes and has also been associated with study skills and academic persistence. However, academic interventions targeting student mindsets and loci of control have remained relatively underexplored, specifically in the context of undergraduate STEM education. Here, we describe the development and assessment of an intervention encouraging students to adopt a growth mindset and internal locus of control. This five-part intervention is administered entirely online and is therefore independent of individual instructor variability. We administered the intervention in five introductory biology courses and show that the intervention was successful in impacting student mindsets and loci of control across various demographics.

Potential utility of anti-TNF drugs in synovial chondromatosis associated with ankylosing spondylitis.

We describe a previously unreported association of ankylosing spondylitis with synovial chondromatosis, and briefly review previously reported cases and treatment of synovial chondromatosis in patients with other immune-mediated inflammatory arthritides. A 20-year-old man with ankylosing spondylitis whose axial disease was in remission with nonsteroidal anti-inflammatory drugs and oral disease-modifying anti-rheumatic drugs developed recurrent right knee pain and swelling. Magnetic resonance imaging of his right knee revealed calcified loose bodies, suggestive of synovial chondromatosis. While waiting for the surgical intervention and other invasive therapy previously reported in patients with synovial chondromatosis, a trial of etanercept eliminated the pain and swelling of the knee; however, the loose bodies have persisted during the 2-year follow-up. Thus, synovial chondromatosis should be considered in the differential diagnoses of a refractory monoarticular pain and swelling in patients with otherwise controlled inflammatory arthritis. Our report advocates a trial of anti-tumor necrosis factor drugs, which might delay the need for invasive therapy in patients with synovial chondromatosis.

Heparin and aspirin combination therapy restores T-cell phenotype in pregnant patients with antiphospholipid syndrome-related recurrent pregnancy loss.

Recurrent pregnancy loss (RPL) is the most common manifestation of anti-phospholipid syndrome (APS), and activated CD4+ T cells are involved in its pathogenesis. Treatment with low-molecular weight heparin (LMWH) and aspirin combination improves pregnancy outcome, however, its mechanism of action is unclear. We investigated the effect of this therapy on Th1/Th2 cells in 89 patients with APS-RPL. The results showed that serum cytokine levels, T cell phenotypes, and transcription factors' gene expression levels representing Th1 responses were higher, whereas those representing Th2 responses were lower in patients with APS-RPL at the time of early pregnancy. This Th1-bias was reversed in patients who had live birth after receiving the combination therapy at the time of delivery. Patients with miscarriages continued to exhibit Th1-bias. In conclusion, these data support a role of Th1-bias in the pathogenesis of APS-RPL and suggest restoring T-cell phenotype as a new immunomodulatory mechanism of LMWH/aspirin combination.

Self-glycerophospholipids activate murine phospholipid-reactive T cells and inhibit iNKT cell activation by competing with ligands for CD1d loading.

Glycosphingolipids and glycerophospholipids bind CD1d. Glycosphingolipid-reactive invariant NKT-cells (iNKT) exhibit myriad immune effects, however, little is known about the functions of phospholipid-reactive T cells (PLT). We report that the normal mouse immune repertoire contains αß T cells, which recognize self-glycerophospholipids such as phosphatidic acid (PA) in a CD1d-restricted manner and don't cross-react with iNKT-cell ligands. PA bound to CD1d in the absence of lipid transfer proteins. Upon in vivo priming, PA induced an expansion and activation of T cells in Ag-specific manner. Crystal structure of the CD1d:PA complex revealed that the ligand is centrally located in the CD1d-binding groove opening for TCR recognition. Moreover, the increased flexibility of the two acyl chains in diacylglycerol ligands and a less stringent-binding orientation for glycerophospholipids as compared with the bindings of glycosphingolipids may allow glycerophospholipids to readily occupy CD1d. Indeed, PA competed with α-galactosylceramide to load onto CD1d, leading to reduced expression of CD1d:α-galactosylceramide complexes on the surface of dendritic cells. Consistently, glycerophospholipids reduced iNKT-cell proliferation, expansion, and cytokine production in vitro and in vivo. Such superior ability of self-glycerophospholipids to compete with iNKT-cell ligands to occupy CD1d may help maintain homeostasis between the diverse subsets of lipid-reactive T cells, with important pathogenetic and therapeutic implications.