In-Press Preview

Stromal Notch ligands foster lymphopenia-driven functional plasticity and homeostatic proliferation of naïve B cells

• Text
• PDF

Abstract

In lymphopenic environments, secondary lymphoid organs regulate the size of B and T-cell compartments by supporting homeostatic proliferation of mature lymphocytes. The molecular mechanisms underlying these responses and their functional consequences remain incompletely understood. To evaluate homeostasis of the mature B-cell pool during lymphopenia, we turned to an adoptive transfer model of purified follicular B-cells into Rag2-/- mouse recipients. Highly purified follicular B-cells transdifferentiated into marginal zone-like B-cells when transferred into Rag2-/- lymphopenic hosts, but not into wild-type hosts. In lymphopenic spleens, transferred B-cells gradually lost their follicular phenotype and acquired characteristics of marginal zone B-cells, as judged by cell surface phenotype, expression of integrins and chemokine receptors, positioning close to the marginal sinus, and an ability to rapidly generate functional plasma cells. Initiation of follicular to marginal zone B-cell transdifferentiation preceded proliferation. Furthermore, the transdifferentiation process was dependent on Notch2 receptors in B-cells and expression of Delta-like1 Notch ligands by splenic Ccl19-Cre+ fibroblastic stromal cells. Gene expression analysis showed rapid induction of Notch-regulated transcripts followed by upregulated Myc expression and acquisition of broad transcriptional features of marginal zone B-cells. Thus, naïve mature B-cells are endowed with plastic transdifferentiation potential in response to increased stromal Notch ligand availability during lymphopenia.

Authors

Daniela Gómez Atria, Brian T. Gaudette, Jennifer Londregan, Samantha Kelly, Eric Perkey, Anneka Allman, Bhaskar Srivastava, Ute Koch, Freddy Radtke, Burkhard Ludewig, Christian W. Siebel, Russell J.H. Ryan, Tanner F. Robertson, Janis K. Burkhardt, Warren S. Pear, David Allman, Ivan Maillard

A translatable RNAi-driven gene therapy silences PMP22/Pmp22 genes and improves neuropathy in CMT1A mice

• Text
• PDF

Abstract

Charcot-Marie-Tooth disease type 1A (CMT1A), the most common inherited demyelinating peripheral neuropathy, is caused by PMP22 gene duplication. Over-expression of wild-type PMP22 in Schwann cells destabilizes the myelin sheath, leading to demyelination and ultimately to secondary axonal loss and disability. No treatments currently exist that modify the disease course. The most direct route to CMT1A therapy will involve reducing PMP22 to normal levels. To accomplish this, we developed a gene therapy strategy to reduce PMP22 using novel artificial microRNAs targeting human and mouse PMP22/Pmp22 mRNAs. Our lead therapeutic microRNA, miR871, was packaged into an AAV9 vector and delivered by lumbar intrathecal injection into C61-het mice, a model of CMT1A. AAV9-miR871 efficiently transduced Schwann cells in C61-het peripheral nerves and reduced human and mouse PMP22/Pmp22 mRNA and protein levels. Treatment at early and late stages of the disease significantly improved multiple functional outcome measures and nerve conduction velocities. Furthermore, myelin pathology in lumbar roots and femoral motor nerves was ameliorated. Treated mice also showed reductions in circulating biomarkers of CMT1A. Taken together, our data demonstrate that AAV9-miR871-driven silencing of PMP22 rescues a CMT1A model and provides proof of principle for treating CMT1A using a translatable gene therapy approach.

Authors

Marina Stavrou, Alexia Kagiava, Sarah G. Choudury, Matthew J. Jennings, Lindsay M. Wallace, Allison M. Fowler, Amanda Heslegrave, Jan Richter, Christina Tryfonos, Christina Christodoulou, Henrik Zetterberg, Rita Horvath, Scott Q. Harper, Kleopas A. Kleopa

Deficiency of the splicing factor RBM10 limits EGFR inhibitor response in EGFR mutant lung cancer

• Text
• PDF

Abstract

Molecularly targeted cancer therapy has improved outcomes for cancer patients with targetable oncoproteins, such as mutant epidermal growth factor receptor (EGFR) in lung cancer. Yet, long-term patient survival remains limited because treatment responses are typically incomplete. One potential explanation for the lack of complete and durable responses is that oncogene-driven cancers with activating mutations in the EGFR often harbor additional co-occurring genetic alterations. This hypothesis remains untested for most genetic alterations that co-occur with mutant EGFR. Here, we report the functional impact of inactivating genetic alteration of the mRNA splicing factor RBM10 that co-occur with mutant EGFR. RBM10 deficiency decreased EGFR inhibitor efficacy in patient-derived EGFR mutant tumor models. RBM10 modulated mRNA alternative splicing of the mitochondrial apoptotic regulator Bcl-x to regulate tumor cell apoptosis during treatment. Genetic inactivation of RBM10 diminished EGFR inhibitor-mediated apoptosis by decreasing the ratio of Bcl-xS-(pro-apoptotic)-to-Bcl-xL(anti-apoptotic) Bcl-x isoforms. RBM10 deficiency was a biomarker of poor response to EGFR inhibitor treatment in clinical samples. Co-inhibition of Bcl-xL and mutant EGFR overcame resistance induced by RBM10 deficiency. This study sheds light on the role of co-occurring genetic alterations, and on the impact of splicing factor deficiency in the modulation of sensitivity to targeted kinase inhibitor cancer therapy.

Authors

Shigeki Nanjo, Wei Wu, Niki Karachaliou, Collin M. Blakely, Junji Suzuki, Yu-Ting Chou, Siraj M. Ali, D. Lucas Kerr, Victor R. Olivas, Jonathan Shue, Julia Rotow, Manasi K. Mayekar, Franziska Haderk, Nilanjana Chatterjee, Anatoly Urisman, Jia Chi Yeo, Anders J. Skanderup, Aaron C. Tan, Wai Leong Tam, Oscar Arrieta, Kazuyoshi Hosomichi, Akihiro Nishiyama, Seiji Yano, Yuriy Kirichok, Daniel S.W. Tan, Rafael Rosell, Ross A. Okimoto, Trever G. Bivona

mTORC2 mediates structural plasticity in distal nociceptive endings that contributes to pain hypersensitivity following inflammation

• Text
• PDF

Abstract

The encoding of noxious stimuli into action potential firing is largely mediated by nociceptive free nerve endings. Tissue inflammation, by changing the intrinsic properties of the nociceptive endings, leads to nociceptive hyperexcitability, and thus to the development of inflammatory pain. Here, we showed that tissue inflammation-induced activation of the mammalian target of rapamycin complex 2 (mTORC2) triggers changes in the architecture of nociceptive terminals and leads to inflammatory pain. Pharmacological activation of mTORC2 induced elongation and branching of nociceptor peripheral endings and caused long-lasting pain hypersensitivity. Conversely, nociceptor-specific deletion of the mTORC2 regulatory protein, Rictor, prevented inflammation-induced elongation and branching of cutaneous nociceptive fibers and attenuated inflammatory pain hypersensitivity. Computational modelling demonstrated that mTORC2-mediated structural changes in the nociceptive terminal tree are sufficient to increase the excitability of nociceptors. Targeting mTORC2 using a single injection of antisense oligonucleotide against Rictor provided long-lasting alleviation of inflammatory pain hypersensitivity. Collectively, we showed that tissue inflammation-induced activation of mTORC2 causes structural plasticity of nociceptive free nerve endings in the epidermis and inflammatory hyperalgesia, representing a therapeutic target for inflammatory pain.

Authors

Calvin Wong, Omer Barkai, Feng Wang, Carolina Thörn Pérez, Shaya Lev, Weihua Cai, Shannon Tansley, Noosha Yousefpour, Mehdi Hooshmandi, Kevin C. Lister, Mariam Latif, A. Claudio Cuello, Masha Prager-Khoutorsky, Jeffrey S. Mogil, Philippe Séguéla, Yves De Koninck, Alfredo Ribeiro-da-Silva, Alexander M. Binshtok, Arkady Khoutorsky

KRAS mutant-driven SUMOylation controls extracellular vesicle transmission to trigger lymphangiogenesis in pancreatic cancer

• Text
• PDF

Abstract

Lymph node (LN) metastasis occurs frequently in pancreatic ductal adenocarcinoma (PDAC) and predicts poor prognosis for patients. The KRASG12D mutation confers an aggressive PDAC phenotype that is susceptible to lymphatic dissemination. However, the regulatory mechanism underlying KRASG12D mutation-driven LN metastasis in PDAC remains unclear. Herein, we identified that PDAC with KRASG12D mutation (KRASG12D PDAC) sustained extracellular vesicle (EV)-mediated transmission of hnRNPA1 in a SUMOylation-dependent manner and promoted lymphangiogenesis and LN metastasis in vitro and in vivo. Mechanistically, hnRNPA1 bound with SUMO2 at the lysine 113 residue via KRASG12D-induced hyperactivation of SUMOylation, which enabled its interaction with TSG101 to enhance hnRNPA1 packaging and transmission via EVs. Subsequently, SUMOylation induced EV-packaged hnRNPA1 anchoring to the adenylate and uridylate-rich elements of PROX1 in lymphatic endothelial cells, thus stabilizing PROX1 mRNA. Importantly, impeding SUMOylation of EV-packaged hnRNPA1 dramatically inhibited LN metastasis of KRASG12D PDAC in a genetically engineered KrasG12D/+; Trp53R172H/+; Pdx-1-Cre (KPC) mice model. Our findings highlight the mechanism by which KRAS mutant-driven SUMOylation triggers EV-packaged hnRNPA1 transmission to promote lymphangiogenesis and LN metastasis, shedding light on the potential application of hnRNPA1 as a therapeutic target in patients with KRASG12D PDAC.

Authors

Yuming Luo, Zhihua Li, Yao Kong, Wang He, Hanhao Zheng, Mingjie An, Yan Lin, Dingwen Zhang, Jiabin Yang, Yue Zhao, Changhao Chen, Rufu Chen

LFA-1 activation enriches tumor-specific T cells in a cold tumor model and synergizes with CTLA-4 blockade

• Text
• PDF

Abstract

The inability of CD8+ T effectors (Teff) to reach tumor cells is an important mechanism of tumor resistance to cancer immunotherapy. The recruitment of these cells to the tumor microenvironment (TME) is regulated by integrins, a family of adhesion molecules that is expressed on T cells. Here we show that 7HP349, a small molecule activator of Lymphocyte function–associated antigen-1 (LFA-1) and very late activation antigen-4 (VLA-4) integrin-cell-adhesion receptors, facilitated the preferential localization of tumor-specific T cells to the tumor and improve antitumor response. 7HP349 monotherapy had modest effects on anti- programmed death 1 (PD-1)–resistant tumors, whereas combinatorial treatment with anti- T-lymphocyte-associated protein 4 (CTLA-4) therapy increased CD8+ Teff intratumoral sequestration and synergized in inducing cancer regression, in cooperation with neutrophils. 7HP349 intratumoral CD8+ Teff enrichment activity depended on CXCL12. We analyzed gene expression profiles using RNA from baseline and on treatment tumor samples of 14 melanoma patients. We identified baseline CXCL12 gene expression may improve response likelihood to anti-CTLA-4 therapies. Our results provided a proof-of-principle demonstration that LFA-1 activation could convert a T cell-exclusionary TME to a T-cell enriched TME through mechanisms involving cooperation with innate immune cells.

Authors

Amber Hickman, Joost Koetsier, Trevin Kurtanich, Michael C. Nielsen, Glenn Winn, Yunfei Wang, Salah-Eddine Bentebibel, Leilei Shi, Simone Punt, Leila Williams, Cara Haymaker, Charles B. Chesson, Faisal Fa'ak, Ana Dominguez, Richard Jones, Isere Kuiatse, Amy R. Caivano, Sayadeth Khounlo, Navin D. Warier, Upendra Marathi, Robert V. Market, Ronald J. Biediger, John W. Craft Jr, Patrick Hwu, Michael A. Davies, Darren G. Woodside, Peter Vanderslice, Adi Diab, Willem W. Overwijk, Yared Hailemichael

Factors influencing maternal microchimerism throughout infancy and its impact on infant T cell immunity

• Text
• PDF

Abstract

Determinants of the acquisition and maintenance of maternal microchimerism (MMc) during infancy and the impact of MMc on infant immune responses are unknown. We examined factors which influence MMc detection and level across infancy and the effect of MMc on T cell responses to BCG vaccination in a cohort of HIV exposed, uninfected and HIV unexposed infants in South Africa. MMc was measured in whole blood from 58 infants using a panel of quantitative PCR assays at day one and 7, 15, and 36 weeks of life. Infants received BCG at birth, and selected whole blood samples from infancy were stimulated in vitro with BCG and assessed for polyfunctional CD4+ T cell responses. MMc was present in most infants across infancy with levels ranging from 0-1,193/100,000 genomic equivalents and was positively impacted by absence of maternal HIV, maternal-infant HLA compatibility, infant female sex, and exclusive breastfeeding. Initiation of maternal antiretroviral therapy prior to pregnancy partially restored MMc levels in HIV exposed, uninfected infants. Birth MMc was associated with an improved polyfunctional CD4+ T cell response to BCG. These data emphasize that both maternal and infant factors influence MMc, which may subsequently impact infant T cell responses.

Authors

Christina Balle, Blair Armistead, Agano Kiravu, Xiaochang Song, Anna-Ursula Happel, Angela A. Hoffmann, Sami B. Kanaan, J. Lee Nelson, Clive M. Gray, Heather B. Jaspan, Whitney E. Harrington

Favorable vaccine-induced SARS-CoV-2 specific T cell response profile in patients undergoing immune-modifying therapies

• Text
• PDF

Abstract

BACKGROUND. Patients undergoing immune-modifying therapies demonstrate a reduced humoral response after COVID-19 vaccination, but we lack a proper evaluation of the impact of such therapies on vaccine-induced T cell responses. METHODS. We longitudinally characterized humoral and Spike-specific T cell responses in inflammatory bowel disease (IBD) patients who are on antimetabolite therapy (azathioprine or methotrexate), TNF inhibitors and/or other biologic treatment (anti-integrin or anti-p40) for up to 6 months after completing two-dose COVID-19 mRNA vaccination. RESULTS. We demonstrated that a Spike-specific T cell response is not only induced in treated IBD patients at levels similar to healthy individuals, but also sustained at higher magnitude for up to 6 months after vaccination, particularly in those treated with TNF inhibitor therapy. Furthermore, the Spike-specific T cell response in these patients is mainly preserved against mutations present in SARS-CoV-2 B.1.1.529 (Omicron) and characterized by a Th1/IL-10 cytokine profile. CONCLUSION. Despite the humoral response defects, patients under immune-modifying therapies demonstrated a favorable profile of vaccine-induced T cell responses that might still provide a layer of COVID-19 protection. FUNDING. This study was funded by the National Centre for Infectious Diseases NCID Catalyst Grant (FY2021ES) and the National Research Fund Competitive Research Programme (NRF-CRP25-2020-0003). The funders played no role in the design, conduct, or reporting of this study.

Authors

Martin Qui, Nina Le Bert, Webber Pak Wo Chan, Malcolm Tan, Shou Kit Hang, Smrithi Hariharaputran, Jean Xiang Ying Sim, Jenny Guek Hong Low, Weiling Ng, Wei Yee Wan, Tiing Leong Ang, Antonio Bertoletti, Ennaliza Salazar

Caffeine intake exerts dual genome-wide effects on hippocampal metabolism and learning-dependent transcription

• Text
• PDF

Abstract

Caffeine is the most consumed psychoactive substance worldwide. Strikingly, molecular pathways engaged by its regular consumption remain unclear. We herein addressed the mechanisms associated with habitual (chronic) caffeine consumption in the mouse hippocampus using untargeted orthogonal-omics techniques. Our results revealed that chronic caffeine exerts concerted pleiotropic effects in the hippocampus, at the epigenomic, proteomic and metabolomic levels. Caffeine lowers metabolic-related processes in the bulk tissue, while it induces neuronal-specific epigenetic changes at synaptic transmission/plasticity-related genes and increased experience-driven transcriptional activity. Altogether, these findings suggest that regular caffeine intake improves the signal-to-noise ratio during information encoding, in part through a fine-tuning of metabolic genes while boosting the salience of information processing during learning in neuronal circuits.

Authors

Isabel Paiva, Lucrezia Cellai, Céline Meriaux, Lauranne Poncelet, Ouada Nebie, Jean-Michel Saliou, Anne-Sophie Lacoste, Anthony Papegaey, Hervé Drobecq, Stéphanie Le Gras, Marion Schneider, Enas M. Malik, Christa E. Müller, Emilie Faivre, Kevin Carvalho, Victoria Gomez-Murcia, Didier Vieau, Bryan Thiroux, Sabiha Eddarkaoui, Thibaud Lebouvier, Estelle Schueller, Laura Tzeplaeff, Iris Grgurina, Jonathan Seguin, Jonathan Stauber, Luisa V. Lopes, Luc Buee, Valerie Buée-Scherrer, Rodrigo A. Cunha, Rima Ait-Belkacem, Nicolas Sergeant, Jean-Sébastien Annicotte, Anne-Laurence Boutillier, David Blum

A p300/GATA6 axis determines differentiation and Wnt dependency in pancreatic cancer models

• Text
• PDF

Abstract

Wnt signaling regulates the balance between stemness and differentiation in multiple tissues and in cancer. RNF43-mutant pancreatic cancers are dependent on Wnt production, and pharmacologic blockade of the pathway, e.g., by PORCN inhibitors, leads to tumor differentiation. However, primary resistance to these inhibitors has been observed. To elucidate potential mechanisms, we performed in vivo CRISPR screens in PORCN inhibitor-sensitive RNF43-mutant pancreatic cancer xenografts. As expected, genes in the Wnt pathway whose loss conferred drug resistance were identified, including APC, AXIN1, and CTNNBIP1. Unexpectedly, the screen also identified the histone acetyltransferase EP300 (p300), but not its paralog CREBBP (CBP). We found that EP300 is silenced due to genetic alterations in all the existing RNF43-mutant pancreatic cancer cell lines that are resistant to PORCN inhibitors. Mechanistically, loss of EP300 directly down-regulated GATA6 expression, thereby silencing the GATA6-regulated differentiation program and leading to a phenotypic transition from the classical subtype to the dedifferentiated basal-like/squamous subtype of pancreatic cancer. EP300 mutation and loss of GATA6 function bypassed the anti-differentiation activity of Wnt signaling, rendering these cancer cells resistant to Wnt inhibition.

Authors

Zheng Zhong, Nathan Harmston, Kris C. Wood, Babita Madan, David M. Virshup

Peripheral monocyte-derived cells counter amyloid plaque pathogenesis in a mouse model of Alzheimer’s disease

• Text
• PDF

Abstract

Microglia, the parenchymal tissue macrophages in the brain, surround amyloid plaques in Alzheimer’s disease (AD) but are ineffective at clearing amyloid to mitigate disease progression. Recent studies in mice indicate that microglia are exclusively derived from primitive yolk-sac hematopoiesis and self-renew without contribution from ontogenically-distinct monocytes/macrophages of definitive ‘adult’ hematopoietic origin. Using genetic fate-mapping to label cells of definitive hematopoietic-origin throughout the life-span, we discovered that circulating monocytes contribute 6% of plaque-associated macrophages in aged AD mice. Moreover, peripheral monocytes contributed to a higher fraction of macrophages in the choroid plexus, meninges and perivascular spaces of aged AD mice versus wild-type controls, indicating enrichment at potential sites for entry into the brain parenchyma. Splenectomy, which markedly reduced circulating Ly6Chi monocytes, also reduced abundance of plaque-associated macrophages of definitive-hematopoietic origin, resulting in increased amyloid plaque load. Together, these results indicate that peripherally-derived monocytes invade the brain parenchyma, targeting amyloid plaques to reduce plaque load.

Authors

Ping Yan, Ki-Wook Kim, Qingli Xiao, Xiucui Ma, Leah R. Czerniewski, Haiyan Liu, David R. Rawnsley, Yan Yan, Gwendalyn J. Randolph, Slava Epelman, Jin-Moo Lee, Abhinav Diwan

ACVR1 antibodies exacerbate heterotopic ossification in fibrodysplasia ossificans progressiva (FOP) by activating FOP-mutant ACVR1

• Text
• PDF

Abstract

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder whose most debilitating pathology is progressive and cumulative heterotopic ossification (HO) of skeletal muscles, ligaments, tendons, and fascia. FOP is caused by mutations in the type I BMP receptor gene ACVR1, which enable ACVR1 to utilize its natural antagonist, Activin A, as an agonistic ligand. The physiological relevance of this property is underscored by the fact that HO in FOP is exquisitely dependent on activation of FOP-mutant ACVR1 by Activin A, an effect countered by inhibition of Activin A via monoclonal antibody treatment. Hence, we surmised that ACVR1 antibodies that block activation of ACVR1 by ligand should also inhibit HO in FOP and provide an additional therapeutic option for this condition. Therefore, we generated ACVR1 monoclonal antibodies that block ACVR1’s activation by its ligands. Surprisingly, in vivo, these ACVR1 antibodies stimulate HO and activate signaling of FOP-mutant ACVR1. This property is restricted to FOP-mutant ACVR1 and results from ACVR1 antibody-mediated dimerization of ACVR1. Conversely, wild type ACVR1 is inhibited by ACVR1 antibodies. These results uncover an additional novel property of FOP-mutant ACVR1 and indicate that ACVR1 antibodies should not be considered as therapeutics for FOP.

Authors

Senem Aykul, Lily Huang, Lili Wang, Nanditha M. Das, Sandra Reisman, Yonaton Ray, Qian Zhang, Nyanza J. Rothman, Kalyan C. Nannuru, Vishal Kamat, Susannah Brydges, Luca Troncone, Laura Johnsen, Paul B. Yu, Sergio Fazio, John Lees-Shepard, Kevin Schutz, Andrew J. Murphy, Aris N. Economides, Vincent Idone, Sarah J. Hatsell

IL-33 acts as a costimulatory signal to generate alloreactive Th1 cells in graft-versus-host disease

• Text
• PDF

Abstract

Antigen-presenting cells (APC) integrate signals emanating from local pathology and program appropriate T cell responses. In allogeneic hematopoietic stem cell transplantation (alloHCT), recipient conditioning releases Damage-Associated Molecular Patterns (DAMPs) that generate pro-inflammatory APC that secrete IL-12, which is a driver of donor Type 1 T helper (Th1) responses causing graft vs. host disease (GVHD). Nevertheless, other mechanisms exist to initiate alloreactive T cells responses, as recipients with disrupted DAMP signaling or lacking IL-12 develop GVHD. We established that tissue damage signals are perceived directly by donor CD4+ T cells and promoted T cell expansion and differentiation. Specifically, the fibroblastic reticular cell-derived DAMP, IL-33, is increased by recipient conditioning and is critical for the initial activation, proliferation, and differentiation of alloreactive Th1 cells. IL-33-stimulation of CD4+ T cell was not required for lymphopenia-induced expansion, however. IL-33 promoted IL-12-independent expression of Tbet and generation of Th1 cells that infiltrated GVHD target tissues. Mechanistically, IL-33 augmented CD4+ T cell TCR-associated signaling pathways in response to alloantigen. This enhanced T cell expansion and Th1 polarization, but inhibited the expression of regulatory molecules like IL-10 and Foxp3. These data established an unappreciated role for IL-33 as a costimulatory signal for donor Th1 generation after alloHCT.

Authors

Gaelen K. Dwyer, Lisa R. Mathews, Jose A. Villegas, Anna Lucas, Anne Gonzalez de Peredo, Bruce R. Blazar, Jean-Philippe Girard, Amanda C. Poholek, Sanjiv A. Luther, Warren Shlomchik, Hēth R. Turnquist

CAR T-cell manufacturing from naive/stem memory T-lymphocytes enhances antitumor responses while curtailing cytokine release syndrome

• Text
• PDF

Abstract

Chimeric antigen receptor (CAR) T-cell expansion and persistence represent key factors to achieve complete responses and prevent relapses. These features are typical of early memory T cells, which can be highly enriched through optimized manufacturing protocols. Here, we investigated the efficacy and safety profiles of CAR T-cell products generated from pre-selected naive/stem memory T cells (TN/SCM), as compared to unselected T cells (TBULK). Notwithstanding their reduced effector signature in vitro, limiting CAR TN/SCM doses showed superior antitumor activity and the unique ability to counteract leukemia re-challenge in hematopoietic stem/precursor cell-humanized mice, featuring increased expansion rates and persistence, together with an ameliorated exhaustion and memory phenotype. Most relevantly, CAR TN/SCM proved to be intrinsically less prone to induce severe cytokine release syndrome, independently of the costimulatory endodomain employed. This safer profile was associated with milder T-cell activation, which translated in reduced monocyte activation and cytokine release. These data suggest that CAR TN/SCM are endowed with a wider therapeutic index compared to CAR TBULK.

Authors

Silvia Arcangeli, Camilla Bove, Claudia Mezzanotte, Barbara Camisa, Laura Falcone, Francesco Manfredi, Eugenia Bezzecchi, Rita El Khoury, Rossana Norata, Francesca Sanvito, Maurilio Ponzoni, Beatrice Greco, Marta Angiola Moresco, Matteo G. Carrabba, Fabio Ciceri, Chiara Bonini, Attilio Bondanza, Monica Casucci

High-affinity autoreactive plasma cells disseminate through multiple organs in patients with immune thrombocytopenic purpura

• Text
• PDF

Abstract

The major therapeutic goal for immune thrombocytopenia (ITP) is to restore normal platelet counts using drugs to promote platelet production or by interfering with mechanisms responsible for platelet destruction. 80% of patients possess anti-integrin αIIbβ3 (GPIIbIIIa) IgG autoantibodies causing platelet opsonization and phagocytosis. The spleen is considered the primary site of autoantibody production by autoreactive B cells and platelet destruction. The immediate failure in ~50% of patients to recover a normal platelet count after anti-CD20 Rituximab-mediated B cell depletion and splenectomy suggest that autoreactive, rituximab-resistant, IgG-secreting B cells (IgG-SC) reside in other anatomical compartments. We analyzed >3,300 single IgG-SC from spleen, bone marrow and/or blood of 27 patients with ITP revealing high inter-individual variability in affinity for GPIIbIIIa with variations over 3 logs. IgG-SC dissemination and range of affinities were however similar per patient. Longitudinal analysis of autoreactive IgG-SC upon treatment with anti-CD38 mAb daratumumab demonstrated variable outcomes, from complete remission to failure with persistence of high-affinity anti-GPIIbIIIa IgG-SC in the bone marrow. This study demonstrates the existence and dissemination of high-affinity autoreactive plasma cells in multiple anatomical compartments of patients with ITP that may cause the failure of current therapies.

Authors

Pablo Canales-Herrerias, Etienne Crickx, Matteo Broketa, Aurélien Sokal, Guilhem Chenon, Imane Azzaoui, Alexis Vandenberghe, Angga Perima, Bruno Iannascoli, Odile Richard-Le Goff, Carlos Castrillon, Guillaume Mottet, Delphine Sterlin, Ailsa Robbins, Marc Michel, Patrick England, Gael A. Millot, Klaus Eyer, Jean Baudry, Matthieu Mahevas, Pierre Bruhns

The microbiome restrains melanoma bone growth by promoting intestinal NK and Th1 cells homing to bone

• Text
• PDF

Abstract

Bone metastases are frequent complications of malignant melanoma leading to reduced quality of life and significant morbidity. Regulation of immune cells by the gut microbiome influences cancer progression, but the role of the microbiome in tumor growth in bone is unknown. Using intracardiac or intratibial injections of B16-F10 melanoma cells in mice we showed that gut microbiome depletion by broad-spectrum antibiotics accelerated intraosseous tumor growth and osteolysis. Microbiome depletion blunted melanoma-induced expansion of intestinal natural killer (NK) cells and T helper 1 (Th1) cells and their migration from the gut to tumor bearing bones. Demonstrating the functional relevance of immune cell trafficking from the gut to the bone marrow (BM) in bone metastasis, blockade of S1P-mediated NK and Th1 cells intestinal egress, or inhibition of their CXCR3/CXCL9-mediated influx into the BM prevented expansion of BM NK and Th1 cells and accelerated tumor growth and osteolysis. Using a mouse model, this study revealed mechanisms of microbiota-mediated gut-bone crosstalk that are relevant to the immunological restraint of melanoma metastasis and tumor growth in bone. Microbiome modifications induced by antibiotics might have negative clinical consequences in melanoma patients.

Authors

Subhashis Pal, Daniel S. Perrien, Tetsuya Yumoto, Roberta Faccio, Andreea Stoica, Jonathan Adams, Craig M. Coopersmith, Rheinallt M. Jones, M. Neale Weitzmann, Roberto Pacifici

BCG therapy downregulates HLA-I on malignant cells to subvert antitumor immune responses in bladder cancer

• Text
• PDF

Abstract

Patients with high-risk non muscle-invasive bladder cancer (NMIBC) frequently relapse after standard intravesical BCG therapy and may have a dismal outcome. Resistance mechanisms to such immunotherapy remain misunderstood. Here, using cancer cell lines, freshly resected human bladder tumors and cohorts of bladder cancer patients pre- and post-BCG therapy, we demonstrate two distinct patterns of immune subversion upon BCG relapse. In the first pattern, intracellular BCG infection of cancer cells induced a post-transcriptional downregulation of HLA-I membrane expression via an inhibition of the autophagy flux. Patients with HLA-I deficient cancer cells post-BCG therapy displayed a myeloid immunosuppressive tumor microenvironment with epithelial-to-mesenchymal transition (EMT) characteristics and dismal outcomes. Conversely, patients with HLA-I proficient cancer cells post-BCG therapy presented with CD8+ T cell tumor infiltrates, upregulation of inflammatory cytokines and inhibitory immune checkpoint molecules. Those patients had a very favorable outcome. We surmise that HLA-I expression in bladder cancers at relapse post-BCG does not result from immunoediting but rather from an immune subversion process directly induced by BCG on cancer cells, which predicts dismal prognosis. Cancer cells HLA-I scoring by immunohistochemistry (IHC) staining can be easily implemented by pathologists in routine practice in order to stratify future urothelial cancer patient treatment strategies.

Authors

Mathieu Rouanne, Julien Adam, Camélia Radulescu, Diane Letourneur, Delphine Bredel, Severine Mouraud, Anne-Gaelle Goubet, Marion Leduc, Noah Chen, Tuan Zea Tan, Nicolas Signolle, Amélie E. Bigorgne, Michael Dussiot, Lambros Tselikas, Sandrine Susini, François-Xavier Danlos, Anna K. Schneider, Roman M. Chabanon, Sophie Vacher, Ivan Bièche, Thierry Lebret, Yves Allory, Jean-Charles Soria, Nicholas Arpaia, Guido Kroemer, Oliver Kepp, Jean Paul Thiery, Laurence Zitvogel, Aurélien Marabelle

Bitter taste signaling in tracheal epithelial brush cells elicits innate immune responses to bacterial infection

• Text
• PDF

Abstract

Constant exposure of the airways to inhaled pathogens requires efficient early immune responses protecting against infections. How bacteria on the epithelial surface are detected and first-line protective mechanisms are initiated are not well understood. We have recently shown that tracheal brush cells (BC) express functional taste receptors. Here we report that bitter taste signaling in murine BC induces neurogenic inflammation. We demonstrate that BC signaling stimulates adjacent sensory nerve endings in the trachea to release the neuropeptides CGRP and Substance P that mediate plasma extravasation, neutrophil recruitment and diapedesis. Moreover, we show that bitter tasting quorum-sensing molecules from Pseudomonas aeruginosa activate tracheal BC. BC signaling depends on the key taste transduction gene Trpm5, triggers secretion of immune mediators, among the most abundant members of the complement system, and is needed to combat Pseudomonas aeruginosa infections. Our data provide functional insight into first-line defense mechanisms against bacterial infections of the lung.

Authors

Monika I. Hollenhorst, Rajender Nandigama, Saskia B. Evers, Igor Gamayun, Noran Abdel Wadood, Alaa Salah, Mario Pieper, Amanda Wyatt, Alexey Stukalov, Anna Gebhardt, Wiebke Nadolni, Wera Burow, Christian Herr, Christoph Beisswenger, Soumya Kusumakshi, Fabien Ectors, Tatjana I. Kichko, Lisa Hübner, Peter Reeh, Antje Munder, Sandra-Maria Wienhold, Martin Witzenrath, Robert Bals, Veit Flockerzi, Thomas Gudermann, Markus Bischoff, Peter Lipp, Susanna Zierler, Vladimir Chubanov, Andreas Pichlmair, Peter König, Ulrich Boehm, Gabriela Krasteva-Christ

An anti-ACVR1 antibody exacerbates heterotopic ossification by fibro-adipogenic progenitors in fibrodysplasia ossificans progressiva mice

• Text
• PDF

Abstract

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disease characterized by progressive and catastrophic heterotopic ossification (HO) of skeletal muscle and associated soft tissues. FOP is caused by dominantly acting mutations in the gene encoding the bone morphogenetic protein (BMP) type I receptor, ACVR1 (ALK2), the most prevalent of which results in an arginine to histidine substitution at position 206[ACVR1(R206H)]. The fundamental pathological consequence of FOP-causing ACVR1 receptor mutations is to enable activin A to initiate canonical BMP signaling in fibro-adipogenic progenitors (FAPs), which drives HO. We developed a monoclonal blocking antibody (JAB0505) to the extracellular domain of ACVR1 and tested its effect on HO in two independent FOP mouse models. Although JAB0505 inhibited BMP-dependent gene expression in wild-type and ACVR1(R206H)-overexpressing cell lines, JAB0505 treatment profoundly exacerbated injury-induced HO. JAB0505-treated mice exhibited multiple, distinct foci of heterotopic lesions, suggesting an atypically broad anatomical domain of FAP recruitment to endochondral ossification. This was accompanied by dysregulated FAP population growth and an abnormally sustained immunological reaction following muscle injury. JAB0505 drove injury-induced HO in the absence of activin A, indicating that JAB0505 has receptor agonist activity. These data raise serious safety and efficacy concerns for the use of bivalent anti-ACVR1 antibodies to treat patients with FOP.

Authors

John B. Lees-Shepard, Sean J. Stoessel, Julian T. Chandler, Keith Bouchard, Patricia Bento, Lorraine N. Apuzzo, Parvathi Madhavi Devarakonda, Jeffrey W. Hunter, David J. Goldhamer

Antibodies from convalescent plasma promote SARS-CoV-2 clearance in individuals with and without endogenous antibody response

• Text
• PDF

Abstract

BACKGROUND. Neutralizing antibodies are considered a key correlate of protection by current SARS-CoV-2 vaccines. The manner in which human infections respond to therapeutic SARS-CoV-2 antibodies, including convalescent plasma therapy (CPT), remains to be fully elucidated. METHODS. Here, we conducted a proof-of-principle study of CPT based on a phase I trial in thirty hospitalized COVID-19 patients with a median interval between the onset of symptoms and the first transfusion of 9 days (IQR, 7-11.8 days). A comprehensive longitudinal monitoring of the virologic, serologic, and disease status of recipients allowed deciphering of parameters on which plasma therapy efficacy depends. RESULTS. In the context of this trial CPT was safe as evidenced by the absence of transfusion related adverse events and a low mortality (3.3%). Treatment with highly neutralizing plasma was significantly associated with faster virus clearance, as demonstrated by Kaplan-Meier analysis (p= 0.034) and confirmed in a parametric survival model including viral load and comorbidity (adjusted hazard ratio (HR)= 3.0 [95% confidence interval (CI) 1.1;8.1], p= 0.026). The onset of endogenous neutralization had a noticeable effect on viral clearance but, importantly, even after adjusting for their pre-transfusion endogenous neutralization status recipients benefitted from plasma therapy with high neutralizing antibodies (HR= 3.5 [95% CI 1.1;11], p= 0.034). CONCLUSION. In summary, our data demonstrate a clear impact of exogenous antibody therapy on the rapid clearance of viremia before and after onset of the endogenous neutralizing response and more broadly point beyond antibody-based interventions to critical laboratory parameters for improved evaluation of current and future SARS-CoV-2 therapies. TRIAL REGISTRATION. ClinicalTrials.gov NCT04869072 FUNDING. This study was funded via an “Innovation-Pool” project by the University Hospital Zurich, the “Swiss Red Cross “Glückskette” Corona Funding”, Pandemiefonds of the UZH Foundation and the Clinical Research Priority Program ‘Comprehensive Genomic Pathogen Detection’ of the University of Zurich.

Authors

Maddalena Marconato, Irene A. Abela, Anthony Hauser, Magdalena Schwarzmüller, Rheliana Katzensteiner, Dominique L. Braun, Selina Epp, Annette Audigé, Jacqueline Weber, Peter Rusert, Emèry Schindler, Chloé Pasin, Emily West, Jürg Böni, Verena Kufner, Michael Huber, Maryam Zaheri, Stefan Schmutz, Beat M. Frey, Roger D. Kouyos, Huldrych F. Günthard, Markus G. Manz, Alexandra Trkola