RNA splicing factor SF3B1 is one of the most recurrently mutated genes in chronic lymphocytic leukemia (CLL) and frequently co-occurs with chromosome 13q deletion (del(13q)). This combination is associated with poor prognosis in CLL, suggesting these lesions increase CLL aggressiveness. While del(13q) in murine B cells (Mdr mice), but not expression of Sf3b1-K700E, drives the initiation of CLL, we hypothesize that SF3B1 mutation accelerates CLL progression. In this study, we crossed mice with a B-cell-specific Sf3b1-K700E allele with Mdr mice to determine the impact of Sf3b1 mutation on CLL progression. We found that the co-occurrence of these two lesions in murine B cells caused acceleration of CLL. We showed that Sf3b1-K700E impacted alternative RNA splicing of Nfatc1 and activated mTOR signaling and the MYC pathway, contributing to CLL acceleration. Moreover, concurrent inhibition of RNA splicing and mTOR pathways led to cell death in vitro and in vivo in murine CLL cells with SF3B1 mutation and del(13q). Our results thus suggest that SF3B1 mutation contributes to the aggressiveness of CLL by activating the mTOR pathway through alternative splicing of Nfatc1, providing a rationale for targeting mTOR and RNA splicing in the subset of CLL patients with both SF3B1 mutations and del(13q).
Bo Zhang, Prajish Iyer, Meiling Jin, Elisa ten Hacken, Zachary Cartun, Kevyn L. Hart, Mike Fernandez, Kristen Stevenson, Laura Rassenti, Emanuela M. Ghia, Thomas J. Kipps, Donna Neuberg, Ruben Carrasco, Wing Chan, Joo Y. Song, Yu Hu, Catherine Wu, Lili Wang
Psoriasis is a chronic autoimmune skin disease characterized by abnormal keratinocyte proliferation and immune dysregulation. Altered lipid metabolism has been implicated in its pathogenesis, but the underlying mechanisms remain unclear. In this study, we generated an keratinocyte-specific Sprouty RTK signaling antagonist 1 (SPRY1) knockout (Spry1ΔEpi) mouse model, which exhibits psoriasis-like symptoms. Using both psoriasis patient samples and Spry1ΔEpi mice, we investigated the role of diacylglycerol acyltransferase 2 (DGAT2) in psoriasis. Our results show that DGAT2 expression is reduced, and glycerides metabolism is disrupted in psoriatic lesions in both psoriasis patients and Spry1ΔEpi mice. Lipidomic analysis reveals significant alterations in glycerides, glycerophospholipids, sphingolipids, and fatty acids in Spry1ΔEpi mice. At the cellular level, DGAT2 downregulation and lipid dysregulation enhance Toll-like receptor 3 (TLR3)-mediated inflammatory signaling in keratinocytes. Furthermore, increased DGAT2 secretion from keratinocytes promotes CD8⁺ T cell activation, proliferation and survival, amplifying psoriatic inflammation. These findings highlight the role of DGAT2 and lipid metabolism in the pathogenesis of psoriasis and reveal their interaction with immune responses in psoriasis.
Ying-Ying Li, Li-Ran Ye, Ying-Zhe Cui, Fan Xu, Xi-Bei Chen, Feng-Fei Zhang, Yi Lu, Yu-Xin Zheng, Xiao-Yong Man
Hematopoietic stem cell transplantation (HCT) is a potentially life-saving therapy but can lead to lung injury due to chemoradiation toxicity, infection, and immune dysregulation. We previously showed that bronchoalveolar lavage (BAL) transcriptomes representing pulmonary inflammation and cellular injury can phenotype post-HCT lung injury and predict mortality. To test whether peripheral blood might be a suitable surrogate for BAL, we compared 210 paired BAL and blood transcriptomes obtained from 166 pediatric HCT patients at 27 hospitals. BAL and blood RNA abundance showed minimal correlation at the level of individual genes, gene set enrichment scores, imputed cell fractions, and T- and B-cell receptor clonotypes. Instead, we identified significant site-specific transcriptional programs. In BAL, pathways related to immunity, hypoxia, and epithelial mesenchymal transition were tightly co-expressed and linked to mortality. In contrast, in blood, expression of endothelial injury, DNA repair, and cellular metabolism pathways was associated with mortality. Integration of paired BAL and blood transcriptomes dichotomized patients into two groups with significantly different rates of hypoxia and clinical outcomes within 1 week of BAL. These findings reveal a compartmentalized injury response, where BAL and blood transcriptomes provide distinct but complementary insights into local and systemic mechanisms of post-HCT lung injury.
Emma M. Pearce, Erica Evans, Madeline Y. Mayday, Gustavo Reyes, Miriam R. Simon, Jacob Blum, Hanna Kim, Jessica Mu, Peter J. Shaw, Courtney M. Rowan, Jeffery J. Auletta, Paul L. Martin, Caitlin Hurley, Erin M. Kreml, Muna Qayed, Hisham Abdel-Azim, Amy K. Keating, Geoffrey D.E. Cuvelier, Janet R. Hume, James S. Killinger, Kamar Godder, Rabi Hanna, Christine N. Duncan, Troy C. Quigg, Paul Castillo, Nahal R. Lalefar, Julie C. Fitzgerald, Kris M. Mahadeo, Prakash Satwani, Theodore B. Moore, Benjamin Hanisch, Aly Abdel-Mageed, Dereck B. Davis, Michelle P. Hudspeth, Greg A. Yanik, Michael A. Pulsipher, Christopher C. Dvorak, Joseph L. DeRisi, Matt S. Zinter
Maladaptive integrated stress response (ISR) activation is observed in human diseases of the brain. Genetic mutations of eIF2B, a critical mediator of protein synthesis, cause chronic pathway activation resulting in a leukodystrophy but the precise mechanism is unknown. We generated N208Y eIF2Bα mice and found that this metabolite binding mutation leads to destabilization of eIF2Bα, a systemic ISR, and neonatal lethality. 2BAct, an eIF2B activator, rescued lethality and significantly extended the lifespan of this severe model, underscoring its therapeutic potential in pediatric disease. Continuous treatment was required for survival, as withdrawal led to ISR induction in all tissues and rapid deterioration, thereby providing a model to assess the impact of the ISR in vivo by tuning drug availability. Single nuclei RNA-sequencing of the CNS identified astrocytes, oligodendrocytes, and ependymal cells as the cell types most susceptible to eIF2B dysfunction and revealed dysfunctional maturation of oligodendrocytes. Moreover, ISR activation decreased cholesterol biosynthesis, a process critical for myelin formation and maintenance. As such, persistent ISR engagement may contribute to pathology in other demyelinating diseases.
Karin Lin, Nina Ly, Rejani B. Kunjamma, Ngoc Vu, Bryan King, Holly M. Robb, Eric G. Mohler, Janani Sridar, Qi Hao, José Zavala-Solorio, Chunlian Zhang, Varahram Shahryari, Nick van Bruggen, Caitlin F. Connelly, Bryson D. Bennett, James J. Lee, Carmela Sidrauski
X-linked Lymphoproliferative Syndromes (XLP), arising from mutations in SH2D1A or XIAP genes, are characterized by fulminant Epstein-Barr Virus (EBV) infection. Lymphomas occur frequently in XLP-1 and in other congenital conditions with heightened EBV susceptibility, but not in XLP-2. Why XLP-2 patients are apparently protected from EBV-driven lymphomagenesis remains a key open question. To gain insights, newly EBV-infected versus receptor-stimulated primary B-cells from XLP-2 patients or with XIAP CRISPR editing were compared to healthy controls. XIAP perturbation impeded outgrowth of newly EBV-infected B-cells, but not that of CD40 ligand and interleukin-21 stimulated B-cells. XLP-2 deficient B-cells showed significantly lower EBV transformation efficiency than healthy controls. Interestingly, EBV-immortalized lymphoblastoid cell proliferation was not impaired by XIAP knockout, implicating an XIAP role in early EBV B-cell transformation. Mechanistically, nascent EBV infection activated p53-mediated apoptosis signaling, which was counteracted by XIAP in control cells. With XIAP deficiency, EBV markedly elevated apoptosis rates over the first two weeks of infection. Interferon-gamma, whose levels are increased with severe XLP2 EBV infection, markedly increased newly EBV-infected B-cell apoptosis. These findings underscored XIAP's crucial role in support of the earliest stages of EBV-mediated B-cell immortalization and provide insights into the curious absence of EBV+ lymphoma in XLP-2 patients.
Yizhe Sun, Janet Chou, Kevin D. Dong, Steven P. Gygi, Benjamin E. Gewurz
Autophagy is a catabolic quality control pathway that has been linked to neurodegenerative disease, atherosclerosis and ageing, and can be modified by nutrient availability in preclinical models. Consequently, there is immense public interest in stimulating autophagy in people. However, progress has been hampered by the lack of techniques to measure human autophagy. As a result, several key concepts in the field, including nutritional modulation of autophagy, have yet to be validated in humans. We conducted a single arm pre-post study in 42 healthy individuals, to assess whether an acute nutritional intervention could modify autophagy in humans. Two blood samples were collected per participant: after a 12 h overnight fast and 1 h post-consumption of a high protein meal. Autophagy turnover was assessed using a physiologically relevant measure of autophagic flux in peripheral blood mononuclear cells. A lysosomal inhibitor was added directly to whole blood, with the resulting build-up of autophagy marker LC3B-II designated as flux, and measured quantitatively via ELISA. Notably, consumption of a high protein meal had no impact on autophagy, with no differences between overnight fasting and postprandial autophagic flux. We observed sexual dimorphism in autophagy, with females having higher autophagic flux compared to males (p = 0.0031). Exploratory analyses revealed sex-specific correlations between autophagy, insulin and glucose signalling. Importantly, our findings show that an acute nutritional intervention (overnight fasting followed by consumption of a protein-rich meal) does not change autophagic flux in humans, highlighting the need to conduct further autophagy studies in humans.
Sanjna Singh, Célia Fourrier, Kathryn J. Hattersley, Leanne K. Hein, Jemima Gore, Alexis Martin, Linh V.P. Dang, Barbara King, Rachael A. Protzman, Paul J. Trim, Leonie K. Heilbronn, Julien Bensalem, Timothy J. Sargeant
Acute kidney injury (AKI) is characterized by a rapid decline in renal function. In severe or recurrent cases, AKI can progress to chronic kidney disease (CKD), marked by renal inflammation and fibrosis. Despite the severity of these outcomes, early-stage diagnostic tools and pharmacological interventions for AKI-to-CKD progression remain limited. In this study, we examined circular RNA (circRNA) expression profiles in mouse renal cortex tissues 14 days post-ischemia/reperfusion (I/R) injury using circRNA sequencing. The renal biopsy samples of patients after AKI exhibited reduced CircNSD1 expression, which was inversely associated with inflammation and fibrosis. Overexpression of CircNSD1 attenuated ferroptosis in vivo and in vitro, while slowing AKI-to-CKD progression. Mechanistically, CircNSD1 downregulated ACSL4 and SlC39A14 expression through histone H3 lysine 36 (H3K36) methylation, a critical pathway regulating ferroptosis after AKI or hypoxia/reoxygenation (H/R) injury. Furthermore, we identified that CircNSD1 encoded a NSD1-916aa peptide, which may functionally contribute to its observed effect. Collectively, these findings demonstrated that CircNSD1 may serve as a diagnostic and therapeutic target for early detection of AKI-to-CKD transition.
Li Gao, Junsheng Zhang, Chaoyi Chen, Sai Zhu, Xianglong Wei, Guiqin Tang, Sheng Wang, Yukai Wang, Xinran Liu, Ling Jiang, Yonggui Wu
Metabolic health is influenced by adipose tissue, and obesity and lipodystrophy are characterized by inflammation and metabolic dysfunction. Whereas obesity and lipodystrophy treatments involve pharmacological approaches and lifestyle changes, these therapies require long-term, repeated dosing, and are not successful for all patients. Gene therapy with targets such as FGF21 and sTGFBR2 provides an alternative approach, specifically in lipodystrophy. Preclinical experiments in mice housed at 22°C are confounded by a mild cold stress not generally experienced by humans, which can negatively affect translation of metabolic therapeutics. In this study, we investigated effects of FGF21/sTGFBR2 combination gene therapy on obese and lipodystrophic mice, and how housing temperature influences therapeutic efficacy. In obese mice, FGF21/sTGFBR2 improved insulin resistance and hyperlipidemia more dramatically at warmer temperatures. In lipodystrophic mice on a high fat diet, combination therapy required adipose tissue to improve insulin resistance at 30°C, whereas FGF21 alone improved insulin resistance at 22°C. Transcriptomic analyses revealed that lipodystrophic mice had upregulated hepatic cell proliferation and fibrosis pathways, and that FGF21 promoted hepatic metabolism. Thus, metabolic dysfunction caused by lipodystrophy is improved by targeting FGF21 and TGFB signaling, but effectiveness in preclinical models may be dependent upon environmental temperature and presence of adipose tissue.
Jessica N. Maung, Yang Chen, Keegan S. Hoose, Rose E. Adler, Hadla Hariri, Mia J. Dickson, Taryn A. Hetrick, Gabriel A. Ferguson, Rebecca L. Schill, Hiroyuki Mori, Romina M. Uranga, Kenneth T. Lewis, Isabel D. K. Hermsmeyer, Donatella Gilio, Christopher de Solis, Amber Toliver, Noah Davidsohn, Elif A. Oral, Ormond A. MacDougald
Uracil DNA glycosylase (UNG) excises uracil and 5-fluorouracil bases from DNA and is implicated in fluorodeoxyuridine (FdU) resistance. Here we explore the effects of inhibiting UNG activity, or depleting the UNG protein, in two mouse syngeneic models for colorectal cancer. Overexpressing the uracil DNA glycosylase inhibitor protein in mismatch repair (MMR)-deficient MC38 cells injected into C57/B6 mice delayed tumor growth and prolonged survival when combined with FdU. Combining UNG inhibition with FdU numerically increased CD4+ T lymphocytes and B cells compared to FdU or UNG inhibition alone, suggesting an immune component to the effects. In contrast, shRNA depletion of UNG in the absence of FdU treatment resulted in 70% of mice clearing their tumors, and a 3-fold increase in overall survival compared to FdU. Analysis of MC38 tumor-infiltrating immune cells showed UNG depletion increased monocyte and dendritic cell populations, with CD8+ T cells also numerically increased. shRNA depletion of UNG in MMR-proficient CT-26 cells injected into Balb/C mice produced minimal benefit; the addition of anti-PD-1 antibody synergized with UNG-depletion to increase survival. Cytotoxic T cell depletion abolished the benefits of UNG depletion in both models. These findings suggest UNG inhibition and/or depletion could enhance antitumor immune response in humans.
Eric S. Christenson, Brandon E. Smith, Thanh J. Nguyen, Alens Valentin, Soren Charmsaz, Nicole E Gross, Sarah M. Shin, Alexei Hernandez, Won Jin Ho, Srinivasan Yegnasubramanian, James T. Stivers
Yellow Fever virus (YFV) infection is fatal in 5–10% of the 200,000 yearly cases. There is currently no available antiviral treatment. We showed previously that administration of 50 mg/kg of a YFV-specific neutralizing monoclonal antibody (nmAb) at 2 days post-infection (dpi), prior to the onset of severe disease, protected YFV-infected rhesus macaques from death. To further explore the clinical applicability of our nmAb MBL-YFV-01, we treated rhesus macaques with a lower dose (10 mg/kg) of this nmAb prophylactically or therapeutically at 3.5 dpi. We show that a single prophylactic or therapeutic intravenous dose of our nmAb protects rhesus macaques from death following challenge. A comprehensive analysis of 167 inflammatory cytokine and chemokines revealed that protection was associated with significantly reduced expression of 125 of these markers, including type I interferons, IL6, and CCL2. This study further expands the potential clinical use of our YFV-specific nmAb, which could be used during an outbreak for immediate prophylactic immunity or for patients with measurable serum viremia.
Lauren N. Rust, Michael J. Ricciardi, Savannah S. Lutz, Sofiya Yusova, Johan J. Louw, Aaron Yrizarry-Medina, Sreya Biswas, Miranda Fischer, Aaron Barber-Axthelm, Gavin Zilverberg, Lauren Bailey, Tonya Swanson, Rachael Tonelli, G.W. McElfresh, Brandon C. Rosen, Thomas B. Voigt, Christakis Panayiotou, Jack T. Mauter, Noor Ghosh, Jenna Meanor, Giovana Godoy, Michael Axthelm, Jeremy Smedley, Mark K. Slifka, Esper G. Kallas, Gabriela Webb, Robert Zweig, Caralyn S. Labriola, Benjamin N. Bimber, Jonah B. Sacha, David I. Watkins, Benjamin J. Burwitz
The aryl hydrocarbon receptor (AhR) is proposed to mediate the frailty-promoting effects of the tryptophan metabolite kynurenine (Kyn), which increases with age in mice and humans. The goal of the current study was to test whether administration of pharmacological AhR inhibitors, BAY2416964 and CH-223191, could abrogate musculoskeletal decline in aging mice. Female C57BL/6 mice (18 months old) were treated with vehicle (VEH) or BAY2416964 (30 mg/kg) via daily oral gavage 5 days/week for 8 weeks. A second AhR antagonist, CH-223191, was administered to 16-month-old male and female C57BL/6 mice via intraperitoneal injections (3.3 mg/kg) 3 days/week for 12 weeks. While grip strength declined over time in VEH-treated mice, BAY2416964 preserved grip strength in part by improving integrity of neuromuscular junctions, an effect replicated during in vitro studies with siRNA against AhR. Cortical bone mass was also greater in BAY2416964- than VEH-treated mice. Similarly, CH-223191 treatment improved cortical bone and showed beneficial effects in skeletal muscle, including reducing oxidative stress as compared to VEH-treated animals. Transcriptomic and proteomic data from BAY2416964-treated mice supported a positive impact of BAY2416964 on molecular targets that affect neuromuscular junction function. Taken together, these data support AhR as a therapeutic target for improving musculoskeletal health during aging.
Kanglun Yu, Sagar Vyavahare, Dima W. Alhamad, Husam Bensreti, Ling Ruan, Anik Tuladhar, Caihong Dai, Joseph C. Shaver, Alok Tripathi, Kehong Ding, Rafal Pacholczyk, Marion A. Cooley, Roger Zhong, Maribeth H. Johnson, Jie Chen, Wendy B. Bollag, Carlos M. Isales, William D. Hill, Mark W. Hamrick, Sadanand Fulzele, Meghan E. McGee-Lawrence
Tumor immunosuppression impacts survival and treatment efficacy. Tumor NOS2/COX2 coexpression strongly predicts poor outcome in ER– breast cancer by promoting metastasis, drug resistance, cancer stemness, and immune suppression. Herein, a spatially distinct NOS2/COX2 and CD3+CD8+PD1– T effector (TEff) cell landscape correlated with poor survival in ER– tumors. NOS2 was primarily expressed at the tumor margin, whereas COX2 together with B7H4 was associated with immune desert regions lacking TEff cells, where a higher ratio of tumor NOS2 or COX2 to TEff cells predicted poor survival. Also, PDL1/PD1, regulatory T cells (TReg) and IDO1 were primarily associated with stroma restricted TEff cells. Regardless of the survival outcome, CD4+ T cells and macrophages were primarily in stromal lymphoid aggregates. Finally, in a 4T1 model, COX2 inhibition led to increased CD8+ TEff/CD4+ TReg ratio and CD8+ TEff infiltration while Nos2 deficiency had no significant effect, thus reinforcing our observations that COX2 is an essential component of immunosuppression through CD8+ TEff cell exclusion from the tumor. Our study indicates that tumor NOS2/COX2 expression plays a central role in tumor immune evasion, suggesting that strategies combining clinically available NOS2/COX2 inhibitors with immune therapy could provide effective options for the treatment of aggressive and drug-resistant ER– breast tumors.
Lisa A. Ridnour, Robert Y.S. Cheng, William F. Heinz, Milind Pore, Ana L. Gonzalez, Elise L. Femino, Rebecca L. Moffat, Adelaide L. Wink, Fatima Imtiaz, Leandro L. Coutinho, Donna Butcher, Elijah F. Edmondson, M. Cristina Rangel, Stephen T.C. Wong, Stanley Lipkowitz, Sharon A. Glynn, Michael P. Vitek, Daniel W. McVicar, Xiaoxian Li, Stephen K. Anderson, Nazareno Paolocci, Stephen M. Hewitt, Stefan Ambs, Timothy R. Billiar, Jenny C. Chang, Stephen J. Lockett, David A. Wink
Extracellular DNA (ecDNA) released from injured and dying cells powerfully induces injurious inflammation. In this study we define the role of ecDNA in systemic vasculitis affecting the kidney, using human kidney biopsies and murine models of myeloperoxidase anti-neutrophil cytoplasmic antibody-associated glomerulonephritis (MPO-ANCA GN). Twice daily administration of intravenous DNase I (ivDNase I) in two models of anti-MPO GN reduced glomerular deposition of ecDNA, histological injury, leukocyte infiltration and NETosis. Comprehensive investigation into DNase I modes of action revealed that after exposure to MPO, DNase I reduced lymph node DC numbers and their activation status, resulting in decreased frequency of MPO-specific CD4 effector T cells (IFN-, and IL-17A producing), and reductions in dermal anti-MPO delayed type hypersensitivity responses. To overcome the translational obstacle of the short half-life of DNase I (<5 hours), we tested an adeno-associated viral vector encoding DNase I (vec-DNase I). The method of DNase I delivery was more effective, as in addition to the histological and anti-inflammatory changes described above, a single vector treatment also reduced circulating MPO-ANCA titers and albuminuria. These results indicate ecDNA is a potent driver of anti-MPO GN and that DNase I is a potential therapeutic that can be delivered using gene technology
Anne Cao Le, Virginie Oudin, Jonathan Dick, Maliha A. Alikhan, Timothy A. Gottschalk, Lu Lu, Kate E. Lawlor, Daniel Koo Yuk Cheong, Mawj Mandwie, Ian E. Alexander, A R. Kitching, Poh-Yi Gan, Grant J. Logan, Kim M. O'Sullivan
Mammalian skin is a vital barrier with the epidermis serving as its protective outer layer, continually undergoing renewal. Given that loss of the epidermis or its barrier function is lethal for mammals, multiple stem cell populations likely exist for the interfollicular epidermis (IFE), enhancing evolutionary survival. Here, we demonstrate that transcription factor KROX20 marks a heterogeneous stem cell population in the upper and middle mouse hair follicle (HF), partially overlapping with known HF stem cell markers in those regions. Lineage tracing in mice using different reporter lines shows that Krox20-lineage cells migrate from the HF to the IFE, contributing to both basal and suprabasal layers during adulthood. Spatial transcriptomics data corroborate our findings. Depletion of epithelial Krox20-expressing cells leads to epidermal hyperplasia and a disruption of stratification during morphogenesis and homeostasis. Our study highlights the contribution of hair follicle Krox20-lineage cells to the IFE and the regulation of epidermal homeostasis.
Elnaz Ghotbi, Edem Tchegnon, Ze Yu, Tracey Shipman, Zhiguo Chen, Yumeng Zhang, Renee M. McKay, Chao Xing, Chung-Ping Liao, Lu Q. Le
The tumor microenvironment (TME) is highly heterogeneous and can dictate the success of therapeutic interventions. Identifying TMEs that are susceptible to specific therapeutic interventions paves the way for more personalized and effective treatments. In this study, using a spontaneous murine model of breast cancer, we characterize a TME that is responsive to inhibitors of the heme degradation pathway mediated by heme oxygenase (HO), resulting in CD8+ T- and NK-cell-dependent tumor control. A hallmark of this TME is a chronic type-I interferon (IFN) signal that is directly involved in orchestrating the anti-tumor immune response. Importantly, we identify that similar TMEs exist in human breast cancer which are associated with patient prognosis. Leveraging these observations, we demonstrate that combining a STING agonist, which induces type-I IFN responses, with an HO inhibitor produces a synergistic effect leading to superior tumor control. This study highlights HO activity as a potential resistance mechanism for type-I IFN responses in cancer offering a novel avenue for overcoming immune evasion in cancer therapy.
Dominika Sosnowska, Tik Shing Cheung, Jit Sarkar, James W. Opzoomer, Karen T. Feehan, Joanne E. Anstee, Chloé Amelia Woodman, Mohamed Reda Keddar, Kalum Clayton, Samira Ali, William Macmorland, Dorothy D. Yang, James Rosekilly, Cheryl E. Gillett, Francesca D. Ciccarelli, Richard Buus, James Spicer, Anita Grigoriadis, James N. Arnold
Idiopathic pulmonary fibrosis (IPF) is a severe diffuse progressive fibrosing interstitial disease leading to respiratory failure and death in the absence of organ transplantation. Substantial evidence has confirmed the pivotal role of fibroblasts in the progression of IPF, yet effective therapeutic options are scarce. Single-cell transcriptomics profiling revealed that among the diverse fibroblast subsets, FAP1+ alveolar fibroblasts (AFs) are pivotal for the progression of IPF. On the basis of these findings, we developed FAP1-targeting chimeric antigen receptor cytotoxic effector regulatory T (CAR-cTregs) cells, which leverage the targeted killing advantage of the currently trending CAR-based immunotherapy for tumors and incorporate the immunosuppressive functions of Tregs to mitigate the inflammation caused by both the disease itself and CAR-T-cell infusion. Accordingly, CAR-cTregs were constructed to effectively eliminate FAP1+ fibroblasts in vitro. This cytotoxic effect can be abrogated by inhibitors of the granzyme-perforin pathway. In the bleomycin-induced PF model, CAR-cTregs were found to reverse fibrosis characterized by diminished recruitment of fibrocytes and improved remodeling of epithelial cells. Together, our results demonstrate that CAR-cTregs can serve as a promising therapeutic option for IPF and provide a novel strategy for treating multiple chronic inflammatory diseases by inducing both cytotoxicity and immunosuppression.
Yun-Han Jiang, Meng Zhou, Meng-Di Cheng, Sai Chen, Ying-Qiang Guo
The Z variant (Glu342Lys) causes alpha1 antitrypsin (AAT) to self-assemble into polymer chains that accumulate within hepatocytes causing liver disease and exposing a cryptic epitope recognised by the 2C1 monoclonal antibody (mAb). They can be blocked by the small molecule ‘716 that stabilises an intermediate on the polymerisation pathway. We have characterised 23 mutants of AAT in a cellular model to establish: (i) their ability to form intracellular polymers; (ii) whether polymer formation could be prevented by ‘716; and (iii) whether the polymers expose the 2C1 cryptic epitope. Most of the variants, including Mprocida (Leu41Pro), Mherleen (Pro369Leu), Mduarte (Asp256Val), Lfrankfurt (Pro255Thr), Yorzinuovi (Pro391His), Mwurzburg (Pro369Ser) and p.289S accumulated as intracellular polymers. Eleven formed polymers that were resistant to ‘716, including Mprocida, Mmalton (ΔPhe51), Lfrankfurt, Mduarte, S (Glu264Val), Mherleen, and Yorzinuovi. The ‘716 resistant mutants localise to a region of the AAT molecule separate from the binding site of the small molecule and form polymers that are less well-recognised by the 2C1 mAb. They are fully recognised by a novel 8A7 mAb that we developed to have a broader specificity. Our data suggest that individuals with these mutations are unlikely to benefit from treatment with ‘716 or its derivatives.
Riccardo Ronzoni, Ibrahim F. Aldobyian, Elena Miranda, Narinder Heyer-Chauhan, Emma L.K. Elliston, Juan Pérez, Annamaria Fra, James A. Irving, David A. Lomas
Mutations in Cullin-3 (CUL3) cause hypertension (HTN). We examined the role of smooth muscle cell (SMC) CUL3 in the regulation of renin gene expression. Mice with SMC-specific CUL3 deletion (S-CUL3KO) developed severe HTN with paradoxically preserved levels of plasma angiotensin peptides and renal renin expression. Cre-recombinase was active in JG cells resulting in decreased CUL3 expression. We evaluated components of the renin cell baroreceptor and revealed preserved lamin A/C but decreased integrin β1 expression in S-CUL3KO. We hypothesized that Rab proteins are involved in integrin β1 downregulation. Silencing either Rab21 or Rab5 in CUL3-deficient HEK293 cells increased integrin β1 protein. Co-immunoprecipitation revealed a direct interaction between Rab5 and CUL3. CUL3-deficiency increased Rab5 suggesting it is regulated by a CUL3-mediated mechanism and that CUL3-deficiency results in loss of Rab protein turnover leading to enhanced integrin β1 internalization. We conclude that the loss of integrin β1 from juxtaglomerular cells impairs the mechanosensory function of the renin cell baroreceptor, which underlies the persistent renin expression observed in hypertensive S-CUL3KO mice. These findings provide insights into the molecular mechanisms of HTN, revealing that dysregulation of Rab proteins and integrin β1 in the kidney due to CUL3-deficiency contributes to the development of HTN.
Daria Golosova, Gaurav Kumar, Ko-Ting Lu, Patricia C. Muskus Veitia, Ana Hantke Guixa, Kelsey K. Wackman, Eva M. Fekete, Daniel T. Brozoski, Justin L. Grobe, Maria Luisa S. Sequeira-Lopez, R. Ariel Gomez, Pablo Nakagawa, Curt D. Sigmund
Hematopoietic Protein-1 (Hem1) is a component of the WASP-family verprolin-homologous protein (WAVE) actin regulatory complex, which is activated downstream of multiple immune receptors. Mutations in the NCKAP1L gene encoding HEM1 have recently been found to result in severe Primary Immunodeficiency Disease (PID), characterized by recurrent respiratory infections, hyperinflammation, autoimmunity, and high mortality. However, how loss of Hem1 results in PID is unclear. To define the importance of Hem1 specifically in T cells, we generated constitutive and T cell specific Hem1 null mice. Hem1 deficient T cells exhibited an increased shift from naïve to memory T cells, and increased ratio of immunosuppressive regulatory to effector T cells. Loss of Hem1 resulted in hallmarks of T cell exhaustion including T cell lymphopenia, decreased activation and proliferation, increased expression of PD-1 and Tim3, and increased IL-10 production. In vitro TCR stimulation of CD4 T cells resulted in increased production of Th1 (IFN), Th2 (IL-5, IL-13), Th17 (IL-17, IL-22), and Treg (IL-10) cytokines. This correlated with reduced F-actin, increased expression of CD107a, and increased granzyme release indicative of increased granule membrane fusion and exocytosis. These results suggest that Hem-1 is critical for maintaining T cell activation, homeostasis and regulated cytokine production following antigen encounter.
Alexandra Christodoulou, Nutthakarn Suwankitwat, Jacob T. Tietsort, Ryan Z. Culbert, Julia Y. Tsai, Fatima A. Tarbal, Chengsong Zhu, Brian M. Iritani
MICB is a ligand for NKG2D. We have shown NK cells are central to lung transplant acute lung injury (ALI) via NKG2D activation, and increased MICB in bronchoalveolar lavage predicts ALI severity. Separately, we found a MICB polymorphism (MICBG406A) is associated with decreased ALI risk. We hypothesized this polymorphism would protect against severe SARS-CoV-2 respiratory disease. We analyzed 1,036 patients hospitalized with SARS-CoV-2 infection from the IMPACC cohort. Associations between MICBG406A and outcomes were determined by linear regression or Cox Proportional Hazards models. We also measured immune profiles of peripheral blood, upper and lower airway. We identified 560 major allele homozygous patients, and 426 and 50 with one or two copies of the variant allele. MICBG406A conferred reduced odds of severe COVID-19 (OR = 0.73, CI = 0.58–0.93, P = 0.04). MICBG406A homozygous participants demonstrated 34% reduced cumulative odds for mechanical ventilation or death (CI = 0.51–0.85, P = 0.005) and 43% reduced risk for mortality (CI = 0.35–0.77, P = 0.001). Patients with MICBG406A variant alleles had reduced soluble inflammatory mediators and differential regulation of multiple immune pathways. These findings demonstrate a novel association between increasing MICBG406A variant allele copies and reduced COVID-19 severity, independent of SARS-CoV-2 viral burden and humoral immunity, suggesting the NKG2D-ligand pathway as an intervention target.
Harry Pickering, Narges Alipanah-Lechner, Ernie Chen, Dylan Duchen, Holden T. Maecker, Seunghee Kim-Schulze, Ruth R. Montgomery, Chris Cotsapas, Hanno Steen, Florian Krammer, Charles R. Langelier, Ofer Levy, Lindsey R. Baden, Esther Melamed, Lauren I.R. Ehrlich, Grace A. McComsey, Rafick P. Sekaly, Charles B. Cairns, Elias K. Haddad, Albert C. Shaw, David A. Hafler, David B. Corry, Farrah Kheradmand, Mark A. Atkinson, Scott C. Brakenridge, Nelson I. Agudelo Higuita, Jordan P. Metcalf, Catherine L. Hough, William B. Messer, Bali Pulendran, Kari C. Nadeau, Mark M. Davis, Ana Fernandez-Sesma, Viviana Simon, Monica Kraft, Christian Bime, David J. Erle, Joanna Schaenman, Al Ozonoff, Bjoern Peters, Steven H. Kleinstein, Alison D. Augustine, Joann Diray-Arce, Patrice M. Becker, Nadine Rouphael, Matthew C. Altman, Steven E. Bosinger, Walter L. Eckalbar, IMPACC Network, Carolyn S. Calfee, Oscar A. Aguilar, Elaine F. Reed, John R. Greenland, Daniel R. Calabrese