Oncology
Abstract
Lymphocyte activation gene-3 (LAG-3) is a cell-surface molecule with diverse biologic effects on T cell function. We recently showed that LAG-3 signaling is important in CD4+ regulatory T cell suppression of autoimmune responses. Here, we demonstrate that LAG-3 maintains tolerance to self and tumor antigens via direct effects on CD8+ T cells using 2 murine systems. Naive CD8+ T cells express low levels of LAG-3, and expression increases upon antigen stimulation. Our data show increased levels of LAG-3 protein on antigen-specific CD8+ T cells within antigen-expressing organs or tumors. In vivo antibody blockade of LAG-3 or genetic ablation of the Lag-3 gene resulted in increased accumulation and effector function of antigen-specific CD8+ T cells within organs and tumors that express their cognate antigen. Most notably, combining LAG-3 blockade with specific antitumor vaccination resulted in a significant increase in activated CD8+ T cells in the tumor and disruption of the tumor parenchyma. A major component of this effect was CD4 independent and required LAG-3 expression by CD8+ T cells. Taken together, these data demonstrate a direct role for LAG-3 on CD8+ T cells and suggest that LAG-3 blockade may be a potential cancer treatment.
Authors
Joseph F. Grosso, Cristin C. Kelleher, Timothy J. Harris, Charles H. Maris, Edward L. Hipkiss, Angelo De Marzo, Robert Anders, George Netto, Derese Getnet, Tullia C. Bruno, Monica V. Goldberg, Drew M. Pardoll, Charles G. Drake
Abstract
The exploitation of the physiologic processing and presenting machinery of DCs by in vivo loading of tumor-associated antigens may improve the immunogenic potential and clinical efficacy of DC-based cancer vaccines. Here we show that lymphocytes genetically modified to express self/tumor antigens, acting as antigen carriers, efficiently target DCs in vivo in tumor-bearing mice. The infusion of tyrosinase-related protein 2–transduced (TRP-2–transduced) lymphocytes induced the establishment of protective immunity and long-term memory in tumor-bearing mice. Analysis of the mechanism responsible for the induction of such an immune response allowed us to demonstrate that cross-presentation of the antigen mediated by the CD11c+CD8α+ DC subset had occurred. Furthermore, we demonstrated in vivo and in vitro that DCs had undergone activation upon phagocytosis of genetically modified lymphocytes, a process mediated by a cell-to-cell contact mechanism independent of CD40 triggering. Targeting and activation of secondary lymphoid organ–resident DCs endowed antigen-specific T cells with full effector functions, which ultimately increased tumor growth control and animal survival in a therapeutic tumor setting. We conclude that the use of transduced lymphocytes represents an efficient method for the in vivo loading of tumor-associated antigens on DCs.
Authors
Vincenzo Russo, Arcadi Cipponi, Laura Raccosta, Cristina Rainelli, Raffaella Fontana, Daniela Maggioni, Francesca Lunghi, Sylvain Mukenge, Fabio Ciceri, Marco Bregni, Claudio Bordignon, Catia Traversari
Abstract
The actin filament–associated protein AFAP-110 is an actin cross-linking protein first identified as a substrate of the viral oncogene v-Src. AFAP-110 regulates actin cytoskeleton integrity but also functions as an adaptor protein that affects crosstalk between Src and PKC. Here we investigated the roles of AFAP-110 in the tumorigenic process of prostate carcinoma. Using immunohistochemistry of human tissue arrays, we found that AFAP-110 was absent or expressed at very low levels in normal prostatic epithelium and benign prostatic hyperplasia but significantly increased in prostate carcinomas. The level of AFAP-110 in carcinomas correlated with the Gleason scores. Downregulation of AFAP-110 in PC3 prostate cancer cells inhibited cell proliferation in vitro and tumorigenicity and growth in orthotopic nude mouse models. Furthermore, downmodulation of AFAP-110 resulted in decreased cell-matrix adhesion and cell migration, defective focal adhesions, and reduced integrin β1 expression. Reintroduction of avian AFAP-110 or a mutant disabling its interaction with Src restored these properties. However, expression of an AFAP-110 lacking the PKC-interacting domain failed to restore properties of parental cells. Thus, increased expression of AFAP-110 is associated with progressive stages of prostate cancer and is critical for tumorigenic growth, in part by regulating focal contacts in a PKC-dependent mechanism.
Authors
Jing Zhang, Serk In Park, Marlene C. Artime, Justin M. Summy, Ami N. Shah, Joshua A. Bomser, Andrea Dorfleutner, Daniel C. Flynn, Gary E. Gallick
Abstract
The effectiveness of IFN-α2b for human multiple myeloma has been variable. TRAIL has been proposed to mediate IFN-α2b apoptosis in myeloma. In this study we assessed the effects of IFN-α2b signaling on the apoptotic activity of TRAIL and human myeloma cell survival. While TRAIL was one of the most potently induced proapoptotic genes in myeloma cells following IFN-α2b treatment, less than 20% of myeloma cells underwent apoptosis. Thus, we hypothesized that an IFN-stimulated gene (ISG) with prosurvival activity might suppress TRAIL-mediated apoptosis. Consistent with this, IFN-α2b stabilized mitochondria and inhibited caspase-3 activation, which antagonized TRAIL-mediated apoptosis and cytotoxicity after 24 hours of cotreatment in cell lines and in fresh myeloma cells, an effect not evident after 72 hours. Induced expression of G1P3, an ISG with largely unknown function, was correlated with the antiapoptotic activity of IFN-α2b. Ectopically expressed G1P3 localized to mitochondria and antagonized TRAIL-mediated mitochondrial potential loss, cytochrome c release, and apoptosis, suggesting specificity of G1P3 for the intrinsic apoptosis pathway. Furthermore, RNAi-mediated downregulation of G1P3 restored IFN-α2b–induced apoptosis. Our data identify the direct role of a mitochondria-localized prosurvival ISG in antagonizing the effect of TRAIL. Curtailing G1P3-mediated antiapoptotic signals could improve therapies for myeloma or other malignancies.
Authors
Venugopalan Cheriyath, Keith B. Glaser, Jeffrey F. Waring, Rachid Baz, Mohamad A. Hussein, Ernest C. Borden
Abstract
PTEN is a tumor suppressor gene mutated in many human cancers. We generated a bronchioalveolar epithelium–specific null mutation of Pten in mice [SP-C-rtTA/(tetO)7-Cre/Ptenflox/flox (SOPtenflox/flox) mice] that was under the control of doxycycline. Ninety percent of SOPtenflox/flox mice that received doxycycline in utero [SOPtenflox/flox(E10–16) mice] died of hypoxia soon after birth. Surviving SOPtenflox/flox(E10–16) mice and mice that received doxycycline postnatally [SOPtenflox/flox(P21–27) mice] developed spontaneous lung adenocarcinomas. Urethane treatment accelerated number and size of lung tumors developing in SOPtenflox/flox mice of both ages. Histological and biochemical examinations of the lungs of SOPtenflox/flox(E10–16) mice revealed hyperplasia of bronchioalveolar epithelial cells and myofibroblast precursors, enlarged alveolar epithelial cells, and impaired production of surfactant proteins. Numbers of bronchioalveolar stem cells (BASCs), putative initiators of lung adenocarcinomas, were increased. Lungs of SOPtenflox/flox(E10–16) mice showed increased expression of Spry2, which inhibits the maturation of alveolar epithelial cells. Levels of Akt, c-Myc, Bcl-2, and Shh were also elevated in SOPtenflox/flox(E10–16) and SOPtenflox/flox(P21–27) lungs. Furthermore, K-ras was frequently mutated in adenocarcinomas observed in SOPtenflox/flox(P21–27) lungs. These results indicate that Pten is essential for both normal lung morphogenesis and the prevention of lung carcinogenesis, possibly because this tumor suppressor is required for BASC homeostasis.
Authors
Shigehisa Yanagi, Hiroyuki Kishimoto, Kohichi Kawahara, Takehiko Sasaki, Masato Sasaki, Miki Nishio, Nobuyuki Yajima, Koichi Hamada, Yasuo Horie, Hiroshi Kubo, Jeffrey A. Whitsett, Tak Wah Mak, Toru Nakano, Masamitsu Nakazato, Akira Suzuki
Abstract
The fact that adenoviral vectors activate innate immunity and induce type I IFNs has not been fully appreciated in the context of cancer gene therapy. Type I IFNs influence different aspects of human immune response and are believed to be crucial for efficient tumor rejection. We performed transcriptional profiling to characterize the response of cutaneous lymphomas to intralesional adenovirus-mediated IFN-γ (Ad-IFN-γ) gene transfer. Gene expression profiles of skin lesions obtained from 19 cutaneous lymphoma patients before and after treatment with Ad-IFN-γ revealed a distinct gene signature consisting of IFN-γ– and numerous IFN-α–inducible genes (type II– and type I–inducible genes, respectively). The type I IFN response appears to have been induced by the vector itself, and its complexity, in terms of immune activation, was potentiated by the IFN-γ gene insert. Intralesional IFN-γ expression together with the induction of a combined type I/II IFN response to Ad-IFN-γ gene transfer seem to underlie the objective (measurable) clinical response of the treated lesions. Biological effects of type I IFNs seem to enhance those set in motion by the transgene, in our case IFN-γ. This combination may prove to be of therapeutic importance in cytokine gene transfer using Ads.
Authors
Mirjana Urosevic, Kazuyasu Fujii, Bastien Calmels, Elisabeth Laine, Nikita Kobert, Bruce Acres, Reinhard Dummer
Abstract
Authors
Chrystal M. Paulos, Claudia Wrzesinski, Andrew Kaiser, Christian S. Hinrichs, Marcello Chieppa, Lydie Cassard, Douglas C. Palmer, Andrea Boni, Pawel Muranski, Zhiya Yu, Luca Gattinoni, Paul A. Antony, Steven A. Rosenberg, Nicholas P. Restifo
Abstract
Targeted disruption of a highly conserved distal enhancer reduces expression of the PU.1 transcription factor by 80% and leads to acute myeloid leukemia (AML) with frequent cytogenetic aberrations in mice. Here we identify a SNP within this element in humans that is more frequent in AML with a complex karyotype, leads to decreased enhancer activity, and reduces PU.1 expression in myeloid progenitors in a development-dependent manner. This SNP inhibits binding of the chromatin-remodeling transcriptional regulator special AT-rich sequence binding protein 1 (SATB1). Overexpression of SATB1 increased PU.1 expression, and siRNA inhibition of SATB1 downregulated PU.1 expression. Targeted disruption of the distal enhancer led to a loss of regulation of PU.1 by SATB1. Interestingly, disruption of SATB1 in mice led to a selective decrease of PU.1 RNA in specific progenitor types (granulocyte-macrophage and megakaryocyte-erythrocyte progenitors) and a similar effect was observed in AML samples harboring this SNP. Thus we have identified a SNP within a distal enhancer that is associated with a subtype of leukemia and exerts a deleterious effect through remote transcriptional dysregulation in specific progenitor subtypes.
Authors
Ulrich Steidl, Christian Steidl, Alexander Ebralidze, Björn Chapuy, Hye-Jung Han, Britta Will, Frank Rosenbauer, Annegret Becker, Katharina Wagner, Steffen Koschmieder, Susumu Kobayashi, Daniel B. Costa, Thomas Schulz, Karen B. O’Brien, Roel G.W. Verhaak, Ruud Delwel, Detlef Haase, Lorenz Trümper, Jürgen Krauter, Terumi Kohwi-Shigematsu, Frank Griesinger, Daniel G. Tenen
Abstract
Vα24-invariant natural killer T (NKT) cells are potentially important for antitumor immunity. We and others have previously demonstrated positive associations between NKT cell presence in primary tumors and long-term survival in distinct human cancers. However, the mechanism by which aggressive tumors avoid infiltration with NKT and other T cells remains poorly understood. Here, we report that the v-myc myelocytomatosis viral related oncogene, neuroblastoma derived (MYCN), the hallmark of aggressive neuroblastoma, repressed expression of monocyte chemoattractant protein–1/CC chemokine ligand 2 (MCP-1/CCL2), a chemokine required for NKT cell chemoattraction. MYCN knockdown in MYCN-amplified neuroblastoma cell lines restored CCL2 production and NKT cell chemoattraction. Unlike other oncogenes, MYCN repressed chemokine expression in a STAT3-independent manner, requiring an E-box element in the CCL2 promoter to mediate transcriptional repression. MYCN overexpression in neuroblastoma xenografts in NOD/SCID mice severely inhibited their ability to attract human NKT cells, T cells, and monocytes. Patients with MYCN-amplified neuroblastoma metastatic to bone marrow had 4-fold fewer NKT cells in their bone marrow than did their nonamplified counterparts, indicating that the MYCN-mediated immune escape mechanism, which we believe to be novel, is operative in metastatic cancer and should be considered in tumor immunobiology and for the development of new therapeutic strategies.
Authors
Liping Song, Tasnim Ara, Hong-Wei Wu, Chan-Wook Woo, C. Patrick Reynolds, Robert C. Seeger, Yves A. DeClerck, Carol J. Thiele, Richard Sposto, Leonid S. Metelitsa
Abstract
The presumed involvement of paired box gene 5 (PAX5) in B-lymphomagenesis is based largely on the discovery of Pax5-specific translocations and somatic hypermutations in non-Hodgkin lymphomas. Yet mechanistically, the contribution of Pax5 to neoplastic growth remains undeciphered. Here we used 2 Myc-induced mouse B lymphoma cell lines, Myc5-M5 and Myc5-M12, which spontaneously silence Pax5. Reconstitution of these cells with Pax5–tamoxifen receptor fusion protein (Pax5ERTAM) increased neoplastic growth in a hormone-dependent manner. Conversely, expression of dominant-negative Pax5 in murine lymphomas and Pax5 knockdown in human lymphomas negatively affected cell expansion. Expression profiling revealed that Pax5 was required to maintain mRNA levels of several crucial components of B cell receptor (BCR) signaling, including CD79a, a protein with the immunoreceptor tyrosine-based activation motif (ITAM). In contrast, expression of 2 known ITAM antagonists, CD22 and PIR-B, was suppressed. The key role of BCR/ITAM signaling in Pax5-dependent lymphomagenesis was corroborated in Syk, an ITAM-associated tyrosine kinase. Moreover, we observed consistent expression of phosphorylated BLNK, an activated BCR adaptor protein, in human B cell lymphomas. Thus, stimulation of neoplastic growth by Pax5 occurs through BCR and is sensitive to genetic and pharmacological inhibitors of this pathway.
Authors
Diana Cozma, Duonan Yu, Suchita Hodawadekar, Anna Azvolinsky, Shannon Grande, John W. Tobias, Michele H. Metzgar, Jennifer Paterson, Jan Erikson, Teresa Marafioti, John G. Monroe, Michael L. Atchison, Andrei Thomas-Tikhonenko
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)