Genomic Sequencing and Analysis of a Novel Human Cowpox Virus With Mosaic Sequences From North America and Old World Orthopoxvirus

Orthopoxviruses (OPXVs) not only infect their natural hosts, but some OPXVs can also cause disease in humans. Previously, we partially characterized an OPXV isolated from an 18-year-old male living in Northern Norway. Restriction enzyme analysis and partial genome sequencing characterized this virus as an atypical cowpox virus (CPXV), which we named CPXV-No-H2. In this study, we determined the complete genome sequence of CPXV-No-H2 using Illumina and Nanopore sequencing. Our results showed that the whole CPXV-No-H2 genome is 220,276 base pairs (bp) in length, with inverted terminal repeat regions of approximately 7 kbp, containing 217 predicted genes. Seventeen predicted CPXV-No-H2 proteins were most similar to OPXV proteins from the Old World, including Ectromelia virus (ECTV) and Vaccinia virus, and North America, Alaskapox virus (AKPV). CPXV-No-H2 has a mosaic genome with genes most similar to other OPXV genes, and seven potential recombination events were identified. The phylogenetic analysis showed that CPXV-No-H2 formed a separate clade with the German CPXV isolates CPXV_GerMygEK938_17 and CPXV_Ger2010_MKY, sharing 96.4 and 96.3% nucleotide identity, respectively, and this clade clustered closely with the ECTV-OPXV Abatino clade. CPXV-No-H2 is a mosaic virus that may have arisen out of several recombination events between OPXVs, and its phylogenetic clustering suggests that ECTV-Abatino-like cowpox viruses form a distinct, new clade of cowpox viruses.

Abstract 3279: Expression of chemerin and chemerin receptors in neuroblastoma: implications in tumorigenesis

Chemerin is an adipokine and immunomodulating factor that promotes chemotaxis of immature dendritic cells, natural killer cells, macrophages and endothelial cells. Secreted as prochemerin with low activity, it can be C-terminally processed by different proteases expressed by a broad range of cell types and tissues. The resulting isoforms vary in receptor affinity and biological activity and are natural ligands for the G protein-coupled receptors (GPCRs) CMKLR1, GPR1 and CCLR2. To date, the activation of CMKLR1 (chemokine-like receptor 1) by chemerin and its role in metabolism and metabolic disorders as well as inflammation is best understood.

Neuroblastoma (NB) is a malignancy of the sympathetic nervous system and the most common extracranial solid pediatric tumor. Several chemoattractant GPCRs have been suggested to promote tumor progression, angiogenesis and metastasis in NB. Although for some cancers a potential function has been suggested, the role of chemerin and its receptors in the NB tumor microenvironment remains unknown.

In our study, the screening of microarray databases and analysis of neuroblastoma expression data showed a correlation between high CMKLR1, GPR1 and CCLR2 expression and a reduction in the overall survival probability. Expression of CMKLR1, GPR1, and chemerin was shown in nine neuroblastoma cell lines using RT-PCR, Western blot and immunocytochemistry. Furthermore, chemerin and CMKLR1 were also detected in neuroblastoma tumor tissue by immunohistochemistry. Stimulation of NB cell lines with active chemerin induced calcium mobilization and increased phosphorylation of MEK1/2 and ERK1/2 indicating an activation of the MAPK signaling pathway. Furthermore, chemerin stimulation led to increased NF-κB phosphorylation and translocation to the nucleus. The induction of NF-κB mediated signaling was observed by luciferase reporter assay. TNFα, IL-1β or serum stimulation increased chemerin protein expression and secretion in neuroblastoma cells.

To assess the functional significance of chemerin and its receptors in neuroblastoma tumorigenesis, cell clones overexpressing or silenced for CMKLR1/ Chemerin/ GPR1 are used in NB animal models.

Citation Format: Conny Tuemmler, Igor Snapkov, Ugo L. Moens, Per Kogner, John Inge Johnsen, Baldur Sveinbjørnsson. Expression of chemerin and chemerin receptors in neuroblastoma: implications in tumorigenesis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3279. doi:10.1158/1538-7445.AM2015-3279

Abstract 3990: Chemerin and chemerin receptors in neuroblastoma tumor microenvironment

Tumor promoting inflammatory cells as well as inflammatory mediators such as chemokines are important contributors to the tumor microenvironment as they can support tumor progression, angiogenesis and metastasis. Chemerin (also known as TIG-2 or RARRES2) is a chemoattractant factor for macrophages, immature DCs and NK-cells and a known adipokine involved in inflammation, metabolism and adipogenesis. Synthesized as a 163aa preproprotein, chemerin is N-terminally cleaved and secreted as inactive prochemerin. Following secretion, chemerin can be cleaved at the C-terminus by a variety of extracellular proteases resulting in several isoforms with varying length and biological activity. During inflammation initiation, maintenance and resolution the different chemerin isoforms may function pro- and/ or anti- inflammatory. Chemerin is a natural ligand for the G protein- coupled receptors CMKLR1 (Chem23) and GPR1. The role of chemerin and CMKLR1 in the tumor microenvironment has not been extensively studied.

The aim of this work is to study the function of chemerin and its receptors in neuroblastoma (NB). Screening of mRNA expression arrays showed a correlation between high expression of CMKLR1 and GPR1 and a worsened prognosis in NB. Chemerin, CMKLR1 and GPR1 expression was detected in different neuroblastoma cell lines by RT-PCR, immunocytochemistry and Western Blot. Stimulation with chemerin resulted in rapid and transient ERK1/2 and Akt phosphorylation.

TNF-α and IL-1β treatment increased chemerin and CMKLR1 protein levels. The functional significance of chemerin/ CMKLR1 in NB will be assessed by the use of NB animal models using cell clones silenced for chemerin/ CMKLR1.

Citation Format: Conny Tuemmler, Igor Snapkov, Ugo L. Moens, Baldur Sveinbjørnsson. Chemerin and chemerin receptors in neuroblastoma tumor microenvironment. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3990. doi:10.1158/1538-7445.AM2014-3990