IL-36γ drives skin toxicity induced by EGFR/MEK inhibition and commensal Cutibacterium acnes

• Text
• PDF

Abstract

Epidermal growth factor receptor (EGFR) and MEK inhibitors (EGFR/MEKi) are beneficial for the treatment of solid cancers but are frequently associated with severe therapy-limiting acneiform skin toxicities. The underlying molecular mechanisms are poorly understood. Using gene expression profiling we identified IL-36γ and IL-8 as candidate drivers of EGFR/MEKi skin toxicity. We provide molecular and translational evidence that EGFR/MEKi in concert with the skin commensal bacterium Cutibacterium acnes act synergistically to induce IL-36γ in keratinocytes and subsequently IL-8, leading to cutaneous neutrophilia. IL-36γ expression was the combined result of C. acnes-induced NF-κB activation and EGFR/MEKi-mediated expression of the transcription factor Krüppel-like factor 4 (KLF4), due to the presence of both NF-κB- and KLF4-binding sites in the human IL-36γ gene promoter. EGFR/MEKi increased KLF4 expression by blockade of the EGFR-MEK-ERK pathway. These results provide an insight into understanding the pathological mechanism of the acneiform skin toxicities induced by EGFR/MEKi and identify IL-36γ and the transcription factor KLF4 as potential therapeutic targets.

Authors

Takashi K. Satoh, Mark Mellett, Barbara Meier-Schiesser, Gabriele Fenini, Atsushi Otsuka, Hans-Dietmar Beer, Tamara Rordorf, Julia-Tatjana Maul, Jürg Hafner, Alexander A. Navarini, Emmanuel Contassot, Lars E. French

Chikungunya virus replication in skeletal muscle cells is required for disease development

• Text
• PDF

Abstract

Chikungunya virus (CHIKV) is an arbovirus capable of causing a severe and often debilitating rheumatic syndrome in humans. CHIKV replicates in a wide variety of cell types in mammals, which has made attributing pathologic outcomes to replication at specific sites difficult. To assess the contribution of CHIKV replication in skeletal muscle cells to pathogenesis, we engineered a CHIKV strain exhibiting restricted replication in these cells via incorporation of target sequences for skeletal muscle cell-specific miR-206. This virus, which we term SKE, displayed diminished replication in skeletal muscle cells in a mouse model of CHIKV disease. Mice infected with SKE developed less severe disease signs, including diminished swelling in the inoculated foot and less necrosis and inflammation in the interosseous muscles. SKE infection was associated with diminished infiltration of T cells into the interosseous muscle as well as decreased production of IL-1b, IL-6, IP-10, and TNFa. Importantly, blockade of the IL-6 receptor led to diminished swelling of a control CHIKV strain capable of replication in skeletal muscle, reducing swelling to levels observed in mice infected with SKE. These data implicate replication in skeletal muscle cells and release of IL-6 as important mediators of CHIKV disease.

Authors

Anthony J. Lentscher, Mary K. McCarthy, Nicholas A. May, Bennett J. Davenport, Stephanie A. Montgomery, Krishnan Raghunathan, Nicole McAllister, Laurie A. Silva, Thomas E. Morrison, Terence S. Dermody

Lysine acetyltransferase 8 is involved in cerebral development and syndromic intellectual disability

• Text
• PDF

Abstract

Epigenetic integrity is critical for many eukaryotic cellular processes. An important question is how different epigenetic regulators control development and impact disease. Lysine acetyltransferase 8 (KAT8) is critical for acetylation of histone H4 at lysine 16 (H4K16), an evolutionarily conserved epigenetic mark. It is unclear what roles KAT8 plays in cerebral development and human disease. Here, we report that cerebrum-specific knockout mice displayed cerebral hypoplasia in the neocortex and hippocampus, along with improper neural stem and progenitor cell (NSPC) development. Mutant cerebrocortical neuroepithelia exhibited faulty proliferation, aberrant neurogenesis, massive apoptosis and scant H4K16 propionylation. Mutant NSPCs formed poor neurospheres, and pharmacological KAT8 inhibition abolished neurosphere formation. Moreover, we describe KAT8 variants in nine patients with intellectual disability, seizures, autism, dysmorphisms and other anomalies. The variants altered chromobarrel and catalytic domains of KAT8, thereby impairing nucleosomal H4K16 acetylation. Valproate was effective for treating epilepsy in at least two of the individuals. This study uncovers a critical role of KAT8 in cerebral and NSPC development, identifies nine individuals with KAT8 variants, and links deficient H4K16 acylation directly to intellectual disability, epilepsy and other developmental anomalies.

Authors

Lin Li, Mohammad Ghorbani, Monika Weisz-Hubshman, Justine Rousseau, Isabelle Thiffault, Rhonda E. Schnur, Catherine Breen, Renske Oegema, Marjan M.M. Weiss, Quinten Waisfisz, Sara Welner, Helen Kingston, Jordan A. Hills, Elles M.J. Boon, Lina Basel-Salmon, Osnat Konen, Hadassa Goldberg-Stern, Lily Bazak, Shay Tzur, Jianliang Jin, Xiuli Bi, Michael Bruccoleri, Kirsty McWalter, Megan T. Cho, Maria Scarano, G. Bradley Schaefer, Susan S. Brooks, Susan Starling Hughes, K.L.I. van Gassen, Johanna M. van Hagen, Tej K. Pandita, Pankaj B. Agrawal, Philippe M. Campeau, Xiang-Jiao Yang

CD73 Immune Checkpoint Defines Regulatory NK-cells within the Tumor Microenvironment

• Text
• PDF

Abstract

High levels of ecto-5'-nucleotidase (CD73) have been implicated in immune suppression and tumor progression, and have also been observed in cancer patients who progress on anti-PD-1 immunotherapy. While regulatory T cells can express CD73 and inhibit T cell responses via the production of adenosine, less is known about CD73 expression in other immune cell populations. We found that tumor-infiltrating NK cells upregulate CD73 expression and the frequency of these CD73+ NK cells correlated with larger tumor size in breast cancer patients. In addition, the expression of multiple alternative immune checkpoint receptors including LAG-3, VISTA, PD-1, and PD-L1 was significantly higher in CD73 positive NK cells than in CD73 negative NK cells. Mechanistically, NK cells transport CD73 in intracellular vesicles to the cell surface and the extracellular space via actin polymerization-dependent exocytosis upon engagement of 4-1BBL on tumor cells. These CD73 positive NK cells undergo transcriptional reprogramming and upregulate IL10 production via STAT3 transcriptional activity, suppressing CD4 T cell proliferation and IFN-ɣ production. Taken together, our results support that tumors can hijack NK cells as a means to escape immunity and that CD73 expression defines an inducible population of NK cells with immune regulatory properties within the tumor microenvironment.

Authors

Shi Yong Neo, Ying Yang, Record Julien, Ran Ma, Xinsong Chen, Ziqing Chen, Nicholas P. Tobin, Emily Blake, Christina Seitz, Ron Thomas, Arnika Kathleen Wagner, John Andersson, Jana de Boniface, Jonas Bergh, Shannon Murray, Evren Alici, Richard Childs, Martin Johansson, Lisa S. Westerberg, Felix Haglund, Johan Hartman, Andreas Lundqvist

A stress-responsive enhancer induces dynamic drug resistance in acute myeloid leukemia

• Text
• PDF

Abstract

The drug efflux pump ABCB1 is a key driver of chemoresistance, and high expression predicts for treatment failure in acute myeloid leukemia (AML). In this study, we identified and functionally validated the network of enhancers that controls expression of ABCB1. We show that exposure of leukemia cells to daunorubicin activated an integrated stress response-like transcriptional program to induce ABCB1 through remodeling and activation of an ATF4-bound, stress-responsive enhancer. Protracted stress primed enhancers for rapid increases in activity following re-exposure of cells to daunorubicin, providing an epigenetic memory of prior drug treatment. In primary human AML, exposure of fresh blast cells to daunorubicin activated the stress-responsive enhancer and led to dose-dependent induction of ABCB1. Dynamic induction of ABCB1 by diverse stressors, including chemotherapy, facilitated escape of leukemia cells from targeted third-generation ABCB1 inhibition, providing an explanation for the failure of ABCB1 inhibitors in clinical trials. Stress-induced up regulation of ABCB1 was mitigated by combined use of pharmacologic inhibitors U0126 and ISRIB, which inhibit stress signalling and have potential for use as adjuvants to enhance the activity of ABCB1 inhibitors.

Authors

Mark S. Williams, Fabio M.R. Amaral, Fabrizio Simeoni, Tim C.P. Somervaille

Oral immunotherapy tolerizes mice to enzyme replacement therapy for Morquio A syndrome

• Text
• PDF

Abstract

Immune response to therapeutic enzymes poses a detriment to patient safety and treatment outcome. Enzyme replacement therapy (ERT) is a standard therapeutic option for some types of Mucopolysaccharidoses including Morquio A syndrome caused by GALNS deficiency. Current protocols tolerize patients using cytotoxic immunosuppressives which can cause adverse effects. Here we show development of tolerance in Morquio A mice via oral delivery of peptide or GALNS during ten days prior to ERT. Our results show that using an immunodominant peptide (I10) or the complete enzyme (GALNS) to orally induce tolerance to GALNS prior to ERT, resulted in several improvements to ERT in mice: i) decreased splenocyte proliferation after in-vitro GALNS stimulation; ii) modulation of cytokine secretion profile; iii) decline in GALNS-specific IgG or IgE plasma; iv) decreased GAG storage in liver; and v) fewer circulating immune-complexes in plasma. This model could be extrapolated to other lysosomal storage disorders where immune response hinders ERT.

Authors

Angela C. Sosa, Barbara Kariuki, Qi Gan, Alan P. Knutsen, Clifford J. Bellone, Miguel A. Guzmán, Luis A. Barrera, Shunji Tomatsu, Anil K. Chauhan, Eric Armbrecht, Adriana M. Montaño

GABA interneurons are the cellular trigger for ketamine’s rapid antidepressant actions

• Text
• PDF

Abstract

A single sub-anesthetic dose of ketamine, an NMDA receptor (NMDAR) antagonist, produces rapid and sustained antidepressant actions in depressed patients, addressing a major unmet need for the treatment of mood disorders. Ketamine produces a rapid increase in extracellular glutamate and synaptic formation in the prefrontal cortex, but the initial cellular trigger that initiates these and its behavioral actions has not been identified. To address this question, we used a combination of viral shRNA and conditional mutation to produce cell specific knockdown or deletion of a key NMDAR subunit, GluN2B, implicated in the actions of ketamine. The results demonstrate that the antidepressant actions of ketamine were blocked by GluN2B-NMDAR knockdown on GABA (Gad1) interneurons, as well as subtypes expressing somatostatin (Sst), or parvalbumin (Pvalb), but not glutamate principle neurons in the mPFC. Further analysis of GABA subtypes showed that cell specific knockdown or deletion of GluN2B in Sst interneurons blocked or occluded the antidepressant actions of ketamine and revealed sex-specific differences that are associated with excitatory postsynaptic currents on mPFC principle neurons. These findings demonstrate that GluN2B-NMDARs on GABA interneurons are the initial cellular trigger for the rapid antidepressant actions of ketamine and show sex-specific adaptive mechanisms to GluN2B modulation.

Authors

Danielle M. Gerhard, Santosh Pothula, Rong-Jian Liu, Min Wu, Xiao-Yuan Li, Matthew J. Girgenti, Seth R. Taylor, Catharine H. Duman, Eric Delpire, Marina Picciotto, Eric S. Wohleb, Ronald S. Duman

C-type lectin receptors Mcl and Mincle control development of multiple sclerosis-like neuroinflammation

• Text
• PDF

Abstract

Pattern recognition receptors (PRRs) are crucial for responses to infections and tissue damage, however, their role in autoimmunity is less clear. Herein we demonstrate that two C-type lectin receptors (CLRs), Mcl and Mincle, play an important role in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of Multiple Sclerosis (MS). Congenic rats expressing lower levels of Mcl and Mincle on myeloid cells exhibited a drastic reduction in EAE incidence. In vivo silencing of Mcl and Mincle or blockade of their endogenous ligand SAP130 revealed that receptors expression in the central nervous system is crucial for the T cell recruitment and reactivation into a pathogenic Th17/GM-CSF phenotype. Consistent with this, we uncovered MCL/MINCLE-expressing cells in brain lesions of MS patients and we further found an upregulation of the MCL/MINCLE signaling pathway and an increased response following MCL/MINCLE stimulation in peripheral blood mononuclear cells from MS patients. Together these data support a role for CLRs in autoimmunity and implicate the MCL/MINCLE pathway as a potential therapeutic target in MS.

Authors

Marie N'diaye, Susanna Brauner, Sevasti Flytzani, Lara Kular, Andreas Warnecke, Milena Z. Adzemovic, Eliane Piket, Jin-Hong Min, Will Edwards, Filia Mela, Hoi Ying Choi, Vera Magg, Tojo James, Magdalena Linden, Holger M. Reichardt, Michael R. Daws, Jack van Horssen, Ingrid Kockum, Robert A. Harris, Tomas Olsson, Andre O. Guerreiro-Cacais, Maja Jagodic

Shortened TDP43 isoforms upregulated by neuronal hyperactivity drive TDP43 pathology in ALS

• Text
• PDF

Abstract

Neuronal hyperexcitability and cytoplasmic mislocalization of the nuclear RNA binding proteinTDP43 are universal features in amyotrophic lateral sclerosis (ALS), but the relationship between these phenomena remains poorly defined. Here, we show that neuronal hyperexcitability drives TDP43 pathology by upregulating shortened (s)TDP43 splice variants missing the canonical C-terminus. sTDP43 isoforms preferentially accumulate in the cytoplasm,forming insoluble inclusions that sequester full-length TDP43 via preserved N-terminal interactions. Consistent with these findings, sTDP43 overexpression is highly toxic to mammalian neurons, suggesting that neurodegeneration results from complementary gain- and loss-of-function mechanisms. In humans and mice, sTDP43 transcripts are significantly enriched in vulnerable motor neurons, and we observed a striking accumulation of sTDP43 protein within neurons and glia of ALS patients. These studies uncover a hitherto unknown role of alternative TDP43 splice isoforms in ALS, and indicate that sTDP43 production may be a key contributor to the susceptibility of motor neurons in ALS.

Authors

Kaitlin Weskamp, Elizabeth M. Tank, Roberto Miguez, Jonathon P. McBride, Nicolás B. Gómez, Matthew White, Ziqiang Lin, Carmen Moreno Gonzalez, Andrea Serio, Jemeen Sreedharan, Sami J. Barmada

Linear ubiquitin assembly complex regulates lung epithelial driven responses during influenza infection

• Text
• PDF

Abstract

Influenza A virus (IAV) is among the most common causes of pneumonia related death worldwide. Pulmonary epithelial cells are the primary target for viral infection and replication and respond by releasing inflammatory mediators that recruit immune cells to mount the host response. Severe lung injury and death during IAV infection results from an exuberant host inflammatory response. The linear ubiquitin assembly complex (LUBAC), composed of SHARPIN, HOIL-1L and HOIP, is a critical regulator of NF-κB-dependent inflammation. Using mice with lung epithelial specific deletions of HOIL-1L or HOIP in a model of IAV infection, we provided evidence that, while a reduction in the inflammatory response was beneficial, ablation of the LUBAC-dependent lung epithelial-driven response worsened lung injury and increased mortality. Moreover, we described a mechanism for the upregulation of HOIL-1L in infected and non-infected cells triggered by the activation of type I interferon receptor and mediated by IRF1, which was maladaptive and contributed to hyper-inflammation. Thus, we propose that lung epithelial LUBAC acts as a molecular rheostat that could be selectively targeted to modulate the immune response in patients with severe IAV-induced pneumonia.

Authors

Patricia L. Brazee, Luisa Morales-Nebreda, Natalia D. Magnani, Joe G.N. Garcia, Alexander V. Misharin, Karen M. Ridge, G.R. Scott Budinger, Kazuhiro Iwai, Laura A. Dada, Jacob I. Sznajder