OX40+ plasmacytoid dendritic cells in the tumor microenvironment promote antitumor immunity

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Abstract

Plasmacytoid dendritic cells (pDC), the major producers of Type I interferon, are principally recognized as key mediators of antiviral immunity. However, their role in tumor immunity is less clear. Depending on the context, pDC can both promote or suppress antitumor immune responses. In this study, we identified a naturally occurring pDC subset expressing high levels of OX40 (OX40+ pDC) enriched in the tumor microenvironment (TME) of head and neck squamous cell carcinoma. OX40+ pDC were distinguished by a distinct immunostimulatory phenotype, cytolytic function and ability to synergize with conventional dendritic cells (cDC) in generating potent tumor antigen-specific CD8+ T cell responses. Transcriptomically, we found they selectively utilized EIF2 signaling and oxidative phosphorylation pathways. Moreover, depletion of pDC in the murine OX40+ pDC-rich tumor model accelerated tumor growth. Collectively, we present evidence of a pDC subset in the TME that favors antitumor immunity.

Authors

Kate O. Poropatich, Donye Dominguez, Wen-Ching Chan, Jorge Andrade, Yuanyuan Zha, Brian D. Wray, Jason Miska, Lei Qin, Lisa E. Cole, Sydney Coates, Urjeet A. Patel, Sandeep Samant, Bin Zhang

Norrin mediates tumor-promoting and -suppressive effects in glioblastoma via Notch and WNT

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Abstract

Glioblastoma (GBM) contains a subpopulation of cells, GBM stem cells (GSCs), that maintain the bulk tumor and represent a key therapeutic target. Norrin is a Wnt ligand that binds the Frizzled4 (FZD4) receptor to activate canonical Wnt signaling. While Norrin, encoded by NDP, has a well- described role in vascular development, its function in human tumorigenesis is largely unexplored. Here, we show that NDP expression is enriched in neurological cancers, including GBM, and its levels positively correlated with survival in a GBM subtype defined by low expression of ASCL1, a proneural factor. We investigated the function of Norrin and FZD4 in GSCs and found that it mediated opposing tumor-promoting and -suppressive effects on ASCL1lo and ASCL1hi GSCs. Consistent with a potential tumor suppressive effect of Norrin suggested by the tumour outcome data, we found that Norrin signaling through FZD4 inhibited growth in ASCL1lo GSCs. In contrast, in ASCL1hi GSCs Norrin promoted Notch signaling, independently of WNT, to promote tumor progression. Forced ASCL1 expression reversed the tumor suppressive effects of Norrin in ASCL1lo GSCs. Our results identify Norrin as a modulator of human brain cancer progression and reveal an unanticipated Notch mediated function of Norrin in regulating cancer stem cell biology.

Authors

Ahmed El-Sehemy, Hayden J. Selvadurai, Arturo Ortin-Martinez, Neno T. Pokrajac, Yasin Mamatjan, Nobuhiko Tachibana, Katherine J. Rowland, Lilian Lee, Nicole I. Park, Kenneth D. Aldape, Peter Dirks, Valerie A. Wallace

Neutralizing antibody VRC01 failed to select for HIV-1 mutations upon viral rebound

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Abstract

Infusion of the broadly neutralizing antibody VRC01 has been evaluated in HIV-1 chronically infected individuals. Here we studied how VRC01 infusions impacted viral rebound after cessation of antiretroviral therapy (ART) in 18 acutely-treated and durably-suppressed individuals. Viral rebound occurred in all individuals, yet VRC01 infusions modestly delayed rebound and participants who showed a faster decay of VRC01 in serum rebounded more rapidly (Rho=0.60, p=0.03). Participants with strains most sensitive to VRC01 or with VRC01 epitope motifs similar to known VRC01-susceptible strains rebounded later (Rho=-0.70, p<0.03). Upon rebound, HIV-1 sequences were indistinguishable from those sampled at diagnosis. Across the cohort, participant derived Env showed different sensitivity to VRC01 neutralization (including two resistant viruses), yet neutralization sensitivity was similar at diagnosis and post-rebound, indicating the lack of selection for VRC01-resistance during treatment interruption.Our results showed that viremia rebounded despite the absence of HIV-1 adaptation to VRC01 and an average VRC01 trough of 221µg/mL. While VRC01 levels were insufficient to prevent a resurgent infection, knowledge that they did not mediate Env mutations in acute-like viruses is relevant for antibody-based strategies in acute infection.

Authors

Evan M. Cale, Hongjun Bai, Meera Bose, Michael A. Messina, Donn Colby, Eric Sanders-Buell, Bethany L. Dearlove, Yifan Li, Emily Engeman, Daniel Silas, Anne Marie O’Sullivan, Brendan Mann, Suteeraporn Pinyakorn, Jintana Intasan, Khunthalee Benjapornpong, Carlo Sacdalan, Eugene Kroon, Nittaya Phanuphak, Robert Gramzinski, Sandhya Vasan, Merlin L. Robb, Nelson L. Michael, Rebecca M. Lynch, Robert Bailer, Amélie Pagliuzza, Nicolas Chomont, Amarendra Pegu, Nicole A. Doria-Rose, Lydie Trautmann, Trevor A. Crowell, John Mascola, Jintanat Ananworanich, Sodsai Tovanabutra, Morgane Rolland

Diminished hepatic IFN response following HCV clearance triggers HBV reactivation in coinfection

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Abstract

In patients with HBV and HCV coinfection, HBV reactivation leading to severe hepatitis has been reported with the use of direct-acting antivirals (DAAs) to treat HCV infection. Here we study the molecular mechanisms behind this viral interaction. In coinfected cell culture and humanized mice, HBV replication was suppressed by HCV coinfection. In vitro, HBV suppression was attenuated when interferon signaling was blocked. In vivo, HBV viremia, after initial suppression by HCV super-infection, rebounded following HCV clearance by DAA treatment that was accompanied by a reduced hepatic interferon response. Using blood samples of coinfected patients, interferon-stimulated gene products including C-X-C motif chemokine 10 (CXCL10) and C-C motif chemokine ligand 5 (CCL5), and alanine aminotransferase (ALT) were identified to have predictive value for HBV reactivation after HCV clearance. Taken together, our data suggest that HBV reactivation is a result of diminished hepatic interferon response following HCV clearance and identifies serologic markers that can predict HBV reactivation in DAA-treated HBV-HCV coinfected persons.

Authors

Xiaoming Cheng, Takuro Uchida, Yuchen Xia, Regina Umarova, Chun-Jen Liu, Pei-Jer Chen, Anuj Gaggar, Vithika Suri, Marcus Maximilian Mücke, Johannes Vermehren, Stefan Zeuzem, Yuji Teraoka, Mitsutaka Osawa, Hiroshi Aikata, Keiji Tsuji, Nami Mori, Shuhei Hige, Yoshiyasu Karino, Michio Imamura, Kazuaki Chayama, T. Jake Liang

PIK3Cδ expression by fibroblasts promotes triple-negative breast cancer progression

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Abstract

As there is growing evidence for the tumor microenvironment’s (TME) role in tumorigenesis, we investigated the role of fibroblast-expressed kinases in triple negative breast cancer (TNBC). Using a high-throughput kinome screen combined with 3D invasion assays, we identified fibroblast-expressed PIK3Cδ (f-PIK3Cδ) as a key regulator of progression. Although PIK3Cδ was expressed in primary fibroblasts derived from TNBC patients, it was undetectable in breast cancer cell lines. Genetic and pharmacologic gain- and loss-of functions experiments verified the contribution of f-PIK3Cδ in TNBC cell invasion. Integrated secretomics and transcriptomics analyses revealed a paracrine mechanism via which f-PIK3Cδ confers its pro-tumorigenic effects. Inhibition of f-PIK3Cδ promoted the secretion of factors, including PLGF and BDNF, which led to upregulation of NR4A1 in TNBC cells where it acts as a tumor suppressor. Inhibition of PIK3Cδ in an orthotopic BC mouse model reduced tumor growth only after inoculation with fibroblasts, indicating a role of f-PIK3Cδ in cancer progression. Similar results were observed in the MMTV-PyMT transgenic BC mouse model, along with a decrease on tumor metastasis emphasizing the potential immune-independent effects of PIK3Cδ inhibition. Finally, analysis of BC patient cohorts and TCGA datasets identified f-PIK3Cδ (protein and mRNA levels) as an independent prognostic factor for overall and disease free survival, highlighting it as a therapeutic target for TNBC.

Authors

Teresa Gagliano, Kalpit Shah, Sofia Gargani, Liyan Lao, Mansour Alsaleem, Jianing Chen, Vasileios Ntafis, Penghan Huang, Angeliki Ditsiou, Viviana Vella, Kritika Yadav, Kamila Bienkowska, Giulia Bresciani, Kai Kang, Leping Li, Philip Carter, Graeme Benstead-Hume, Timothy O’Hanlon, Michael Dean, Frances M.G. Pearl, Soo Chin Lee, Emad A. Rakha, Andrew R Green, Dimitris L. Kontoyiannis, Erwei Song, Justin Stebbing, Georgios Giamas

Post-sepsis immunosuppression depends on NKT cell regulation of mTOR/IFNγ in NK cells

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Abstract

As treatment of the early, inflammatory phase of sepsis improves, post-sepsis immunosuppression and secondary infection have increased in importance. How early inflammation drives immunosuppression remains unclear. Although IFNγ typically helps microbial clearance, we found that increased plasma IFNγ in early clinical sepsis was associated with the later development of secondary Candida infection. Consistent with this observation, we found that exogenous IFNγ suppressed macrophage phagocytosis of zymosan in vivo, and antibody blockade of IFNγ after endotoxemia improved survival of secondary candidemia. Transcriptomic analysis of innate lymphocytes during endotoxemia suggested that NKT cells drove IFNγ production by NK cells via mTORC1. Activation of iNKT cells with glycolipid antigen drove immunosuppression. Deletion of iNKT cells in Cd1d-/- mice or inhibition of mTOR by rapamycin reduced immunosuppression and susceptibility to secondary Candida infection. Thus, although rapamycin is typically an immunosuppressive medication, in the context of sepsis, rapamycin has the opposite effect. These results implicated a NKT cell-mTOR-IFNγ axis in immunosuppression following endotoxemia or sepsis. In summary, in vivo iNKT cells activated mTORC1 in NK cells to produce IFNγ , which worsened macrophage phagocytosis, clearance of secondary Candida infection and mortality.

Authors

Edy Y. Kim, Hadas Ner-Gaon, Jack Varon, Aidan M. Cullen, Jingyu Guo, Jiyoung Choi, Diana Barragan-Bradford, Angelica Higuera, Mayra Pinilla-Vera, Samuel A.P. Short, Antonio J. Arciniegas-Rubio, Tomoyoshi Tamura, David E. Leaf, Rebecca M. Baron, Tal Shay, Michael B. Brenner

KLK6 expression in skin induces PAR1-mediated psoriasiform dermatitis and inflammatory joint disease

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Abstract

Kallikrein-related peptidase 6 (KLK6) is a secreted serine protease hypothesized to promote inflammation via cleavage of protease-activated receptors (PAR)1 and PAR2. KLK6 levels are elevated in multiple inflammatory and autoimmune conditions, but no definitive role in pathogenesis has been established. Here, we show that skin-targeted overexpression of KLK6 causes generalized, severe psoriasiform dermatitis with spontaneous development of debilitating psoriatic arthritis-like joint disease. The psoriatic skin and joint phenotypes are reversed by normalization of skin KLK6 levels and attenuated following genetic elimination of PAR1 but not PAR2. Conservation of this regulatory pathway was confirmed in human psoriasis using vorapaxar, an FDA-approved PAR1 antagonist, on explanted lesional skin from psoriasis patients. Beyond defining a critical role for KLK6-PAR1 signaling in promoting psoriasis, our results demonstrate that KLK6-PAR1-mediated inflammation in the skin alone is sufficient to drive inflammatory joint disease. Further, we identify PAR1 as a promising cytokine-independent target in therapy of psoriasis and psoriatic arthritis.

Authors

Allison C. Billi, Jessica E. Ludwig, Yi Fritz, Richard Rozic, William R. Swindell, Lam C. Tsoi, Dennis Gruszka, Shahla Abdollahi-Roodsaz, Xianying Xing, Doina Diaconu, Ranjitha Uppala, Maya I. Camhi, Philip A. Klenotic, Mrinal K. Sarkar, M. Elaine Husni, Jose U. Scher, Christine McDonald, J. Michelle Kahlenberg, Ronald J. Midura, Johann E. Gudjonsson, Nicole L. Ward

Ventromedial hypothalamic nucleus neuronal subset regulates blood glucose independently of insulin

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Abstract

To identify neurons that specifically increase blood glucose from among the diversely-functioning cell types in the ventromedial hypothalamic nucleus (VMN), we studied the cholecystokinin (CCK) receptor-B (CCKBR)-expressing VMN targets of glucose-elevating parabrachial nucleus neurons. Activating these VMNCCKBR neurons increased blood glucose. Furthermore, while silencing the broader VMN decreased energy expenditure and promoted weight gain without altering blood glucose, silencing VMNCCKBR neurons decreased hepatic glucose production (HGP), insulin-independently decreasing blood glucose without altering energy balance. Silencing VMNCCKBR neurons also impaired the counter-regulatory response (CRR) to insulin-induced hypoglycemia and glucoprivation and replicated hypoglycemia-associated autonomic failure (HAAF). Hence, VMNCCKBR cells represent a specialized subset of VMN cells that function to elevate glucose. These cells not only mediate the allostatic response to hypoglycemia, but also insulin-independently modulate the homeostatic setpoint for blood glucose, consistent with a role for the brain in the insulin-independent control of glucose homeostasis.

Authors

Jonathan N. Flak, Paulette Goforth, James Dell'Orco, Paul V. Sabatini, Chien Li, Nadejda Bozadjieva, Matthew J. Sorensen, Alec C. Valenta, Alan C. Rupp, Alison H. Affinati, Corentin Cras-Méneur, Ahsan Ansari, Jamie Sacksner, Nandan Kodur, Darleen A. Sandoval, Robert t. Kennedy, David Olson, Martin G. Myers Jr.

S100A8/A9 regulates CD11b expression and neutrophil recruitment during chronic tuberculosis

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Abstract

Neutrophil accumulation is associated with lung pathology during active tuberculosis (ATB). However, the molecular mechanism(s) by which neutrophils accumulate in the lung and contribute to TB immunopathology is not fully delineated. Using the well-established mouse model of TB, our new data provides evidence that the alarmin S100A8/A9 mediates neutrophil accumulation during progression to chronic TB. Depletion of neutrophils or S100A8/A9 deficiency resulted in improved Mycobacterium tuberculosis (Mtb) control during chronic but not acute TB. Mechanistically, we demonstrate that following Mtb infection, S100A8/A9 expression is required for upregulation of the integrin molecule CD11b specifically on neutrophils, mediating their accumulation during chronic TB disease. These findings are further substantiated by increased expression of S100A8 and S100A9 mRNA in whole blood in human TB progressors when compared to non-progressors, and rapidly decreased S100A8/A9 protein levels in the serum upon TB treatment. Furthermore, we demonstrate that S100A8/A9 serum levels along with chemokines are useful in distinguishing between ATB and asymptomatic Mtb-infected latent individuals. Thus, our results support targeting S100A8/A9 pathways as host-directed therapy for TB.

Authors

Ninecia R. Scott, Rosemary V. Swanson, Noor Al-Hammadi, Racquel Domingo-Gonzalez, Javier Rangel-Moreno, Belinda A. Kriel, Allison N. Bucsan, Shibali Das, Mushtaq Ahmed, Smriti Mehra, Puthayalai Treerat, Alfredo Cruz-Lagunas, Luis Jimenez-Alvarez, Marcela Muñoz-Torrico, Karen Bobadilla-Lozoya, Thomas Vogl, Gerhard Walzl, Nelita du Plessis, Deepak Kaushal, Thomas Scriba, Joaquin Zuñiga, Shabaana Khader

Minimal PD-1 expression in mouse and human NK cells under diverse conditions

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Abstract

PD-1 expression is a hallmark of both early antigen-specific T-cell activation and later chronic stimulation suggesting key roles in both naive T-cell priming and memory T-cell responses. Although important similarities exist between T cells and NK cells, there are critical differences reflecting their biology and functions. The putative role of PD-1 expression in NK cell immunoregulation has been controversial. Our objective was to comprehensively assess PD-1 expression on NK cells using multiple sources and readouts. Primary human tumor samples, ex vivo culturing, mouse tumors and viral models were all assessed using flow cytometry, qRT-PCR and RNA sequencing. We demonstrate that under multiple activating conditions, highly purified human and mouse NK cells consistently lack PD-1 expression despite the marked upregulation of other regulatory markers such as TIGIT. We further show that neither NK cells from T-cell deficient Rag2-/- mice nor from transgenic PD-1 reporter mice express PD-1 using tumor or viral infection models. Asialo-GM1 (ASGM1), a receptor commonly targeted for NK-specific depletion, was also expressed on activated T cells co-expressing PD-1 contributing to in vivo effects previously attributed to NK cells. These data have important implications when attempting to discern NK from T cell effects depending on the models used and whether PD-1 blockade will directly impact NK cell therapies.

Authors

Sean J. Judge, Cordelia Dunai, Ethan G. Aguilar, Sarah C. Vick, Ian R. Sturgill, Lam T. Khuat, Kevin M. Stoffel, Jonathan Van Dyke, Dan L. Longo, Morgan A. Darrow, Stephen K. Anderson, Bruce R. Blazar, Arta M. Monjazeb, Jonathan S. Serody, Robert J. Canter, William J. Murphy