1
|
Ishii Y, Mori S, Takeuchi T, Kukimoto I. Differential requirement of the transcription factor HOXC13 for the stable maintenance of human papillomavirus genome among high-risk genotypes. Virology 2024; 597:110151. [PMID: 38914027 DOI: 10.1016/j.virol.2024.110151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 05/20/2024] [Accepted: 06/20/2024] [Indexed: 06/26/2024]
Abstract
The viral genome of the high-risk human papillomavirus (HPV), the causative agent of cervical cancer, is stably maintained as extrachromosomal episomes that establish persistent infection. We previously identified homeobox-transcription factor HOXC13 as an important host protein mediating the short-term retention of the HPV16 and HPV18 genomes in normal human immortalized keratinocytes (NIKS). Here, we used CRISPR-Cas9 technology to construct HOXC13 knockout (KO) NIKS cells to determine whether HOXC13 is required for the long-term maintenance of high-risk HPV genomes. HPV16, HPV18, HPV52, and HPV58 whole genomes were transfected into HOXC13 KO cells, and the copy number of viral genomes per cell was monitored over cell passages. Copy numbers of HPV16, HPV52, and HPV58 genomes decreased continuously in HOXC13 KO cells, whereas HPV18 genomes remained stable throughout passages. Thus, HOXC13 is critical for the stable maintenance of the viral genomes of HPV16, HPV52, and HPV58, but not HPV18.
Collapse
Affiliation(s)
- Yoshiyuki Ishii
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan.
| | - Seiichiro Mori
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takamasa Takeuchi
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Iwao Kukimoto
- Pathogen Genomics Center, National Institute of Infectious Diseases, Tokyo, Japan
| |
Collapse
|
2
|
Coursey TL, McBride AA. Development of Keratinocyte Cell Lines Containing Extrachromosomal Human Papillomavirus Genomes. Curr Protoc 2021; 1:e235. [PMID: 34496149 DOI: 10.1002/cpz1.235] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Human papillomaviruses (HPVs) cause persistent infections in stratified cutaneous and mucosal epithelia. In these infections, the viral DNA replicates as low-copy-number, extrachromosomal, double-stranded-DNA circular plasmids in the nucleus of the dividing basal cells. When the infected cells begin the process of differentiation, the viral DNA amplifies to a high copy number and virions are assembled in the superficial cells. To study HPV DNA replication, our laboratory generates primary keratinocyte cell lines that contain replicating extrachromosomal HPV genomes. Here, we describe protocols to culture human keratinocytes, to transfect viral DNA into cells using electroporation, to determine the efficiency of genome establishment in cells with a colony-forming assay, and to measure the copy number and extrachromosomal status of viral genomes using Southern blotting. These methods can be used to study DNA replication of different oncogenic Alphapapillomavirus HPV types. Published 2021. This article is a U.S. Government work and is in the public domain in the USA. Basic Protocol 1: Electroporation to transfect keratinocytes with recircularized HPV genomes Alternate Protocol: Use of HPV replicon containing selection marker in keratinocyte transfection Support Protocol 1: Rheinwald-Green method of co-culture of irradiated J2 3T3 feeders and human keratinocytes Support Protocol 2: Recircularization of HPV genomes Basic Protocol 2: Quantitative colony formation assay to measure the efficiency of HPV genome establishment Basic Protocol 3: Southern blot analysis of extrachromosomal viral DNA Support Protocol 3: Hirt extraction of low-molecular-weight DNA Support Protocol 4: Qiagen DNeasy Blood & Tissue DNA extraction Support Protocol 5: Generation of a 32 P-labeled HPV DNA probe.
Collapse
Affiliation(s)
- Tami L Coursey
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| | - Alison A McBride
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
3
|
McBride AA, Warburton A, Khurana S. Multiple Roles of Brd4 in the Infectious Cycle of Human Papillomaviruses. Front Mol Biosci 2021; 8:725794. [PMID: 34386523 PMCID: PMC8353396 DOI: 10.3389/fmolb.2021.725794] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/14/2021] [Indexed: 12/17/2022] Open
Abstract
Human Papillomaviruses (HPV) reproduce in stratified epithelia by establishing a reservoir of low- level infection in the dividing basal cells and restricting the production of viral particles to terminally differentiated cells. These small DNA viruses hijack pivotal cellular processes and pathways to support the persistent infectious cycle. One cellular factor that is key to multiple stages of viral replication and transcription is the BET (bromodomain and extra-terminal domain) protein, Brd4 (Bromodomain containing protein 4). Here we provide an overview of the multiple interactions of Brd4 that occur throughout the HPV infectious cycle.
Collapse
Affiliation(s)
- Alison A. McBride
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | | | | |
Collapse
|
4
|
Regulation of HPV18 Genome Replication, Establishment and Persistence by Sequences in the Viral Upstream Regulatory Region. J Virol 2021; 95:e0068621. [PMID: 34232709 DOI: 10.1128/jvi.00686-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During persistent human papillomavirus infection, the viral genome replicates as an extrachromosomal plasmid that is efficiently partitioned to daughter cells during cell division. We have previously shown that an element which overlaps the HPV18 transcriptional enhancer promotes stable DNA replication of replicons containing the viral replication origin. Here we perform comprehensive analyses to elucidate the function of this maintenance element. We conclude that no unique element or binding site in this region is absolutely required for persistent replication and partitioning, and instead propose that the overall chromatin architecture of this region is important to promote efficient use of the replication origin. These results have important implications on the genome partitioning mechanism of papillomaviruses. Importance Persistent infection with oncogenic HPVs is responsible for ∼5% human cancers. The viral DNA replicates as an extrachromosomal plasmid and is partitioned to daughter cells in dividing keratinocytes. Using a complementation assay that allows us to separate viral transcription and replication, we provide insight into viral sequences that are required for long term replication and persistence in keratinocytes. Understanding how viral genomes replicate persistently for such long periods of time will guide the development of anti-viral therapies.
Collapse
|
5
|
Della Fera AN, Warburton A, Coursey TL, Khurana S, McBride AA. Persistent Human Papillomavirus Infection. Viruses 2021; 13:v13020321. [PMID: 33672465 PMCID: PMC7923415 DOI: 10.3390/v13020321] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2021] [Revised: 02/16/2021] [Accepted: 02/17/2021] [Indexed: 12/16/2022] Open
Abstract
Simple Summary The success of HPV as an infectious agent lies not within its ability to cause disease, but rather in the adeptness of the virus to establish long-term persistent infection. The ability of HPV to replicate and maintain its genome in a stratified epithelium is contingent on the manipulation of many host pathways. HPVs must abrogate host anti-viral defense programs, perturb the balance of cellular proliferation and differentiation, and hijack DNA damage signaling and repair pathways to replicate viral DNA in a stratified epithelium. Together, these characteristics contribute to the ability of HPV to achieve long-term and persistent infection and to its evolutionary success as an infectious agent. Abstract Persistent infection with oncogenic human papillomavirus (HPV) types is responsible for ~5% of human cancers. The HPV infectious cycle can sustain long-term infection in stratified epithelia because viral DNA is maintained as low copy number extrachromosomal plasmids in the dividing basal cells of a lesion, while progeny viral genomes are amplified to large numbers in differentiated superficial cells. The viral E1 and E2 proteins initiate viral DNA replication and maintain and partition viral genomes, in concert with the cellular replication machinery. Additionally, the E5, E6, and E7 proteins are required to evade host immune responses and to produce a cellular environment that supports viral DNA replication. An unfortunate consequence of the manipulation of cellular proliferation and differentiation is that cells become at high risk for carcinogenesis.
Collapse
|
6
|
Uhlorn BL, Jackson R, Li S, Bratton SM, Van Doorslaer K, Campos SK. Vesicular trafficking permits evasion of cGAS/STING surveillance during initial human papillomavirus infection. PLoS Pathog 2020; 16:e1009028. [PMID: 33253291 PMCID: PMC7728285 DOI: 10.1371/journal.ppat.1009028] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 12/10/2020] [Accepted: 10/02/2020] [Indexed: 12/26/2022] Open
Abstract
Oncogenic human papillomaviruses (HPVs) replicate in differentiating epithelium, causing 5% of cancers worldwide. Like most other DNA viruses, HPV infection initiates after trafficking viral genome (vDNA) to host cell nuclei. Cells possess innate surveillance pathways to detect microbial components or physiological stresses often associated with microbial infections. One of these pathways, cGAS/STING, induces IRF3-dependent antiviral interferon (IFN) responses upon detection of cytosolic DNA. Virion-associated vDNA can activate cGAS/STING during initial viral entry and uncoating/trafficking, and thus cGAS/STING is an obstacle to many DNA viruses. HPV has a unique vesicular trafficking pathway compared to many other DNA viruses. As the capsid uncoats within acidic endosomal compartments, minor capsid protein L2 protrudes across vesicular membranes to facilitate transport of vDNA to the Golgi. L2/vDNA resides within the Golgi lumen until G2/M, whereupon vesicular L2/vDNA traffics along spindle microtubules, tethering to chromosomes to access daughter cell nuclei. L2/vDNA-containing vesicles likely remain intact until G1, following nuclear envelope reformation. We hypothesize that this unique vesicular trafficking protects HPV from cGAS/STING surveillance. Here, we investigate cGAS/STING responses to HPV infection. DNA transfection resulted in acute cGAS/STING activation and downstream IFN responses. In contrast, HPV infection elicited minimal cGAS/STING and IFN responses. To determine the role of vesicular trafficking in cGAS/STING evasion, we forced premature viral penetration of vesicular membranes with membrane-perturbing cationic lipids. Such treatment renders a non-infectious trafficking-defective mutant HPV infectious, yet susceptible to cGAS/STING detection. Overall, HPV evades cGAS/STING by its unique subcellular trafficking, a property that may contribute to establishment of infection.
Collapse
Affiliation(s)
- Brittany L. Uhlorn
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Robert Jackson
- School of Animal & Comparative Biomedical Sciences, The University of Arizona, Tucson, Arizona, United States of America
| | - Shuaizhi Li
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
| | - Shauna M. Bratton
- Department of Physiology, The University of Arizona, Tucson, Arizona, United States of America
| | - Koenraad Van Doorslaer
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
- School of Animal & Comparative Biomedical Sciences, The University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, The University of Arizona, Tucson, Arizona, United States of America
- Genetics Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Samuel K. Campos
- Cancer Biology Graduate Interdisciplinary Program, The University of Arizona, Tucson, Arizona, United States of America
- Department of Immunobiology, The University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, The University of Arizona, Tucson, Arizona, United States of America
- Department of Molecular & Cellular Biology, The University of Arizona, Tucson, Arizona, United States of America
| |
Collapse
|
7
|
Liu X, Mondal AM. Conditional cell reprogramming for modeling host-virus interactions and human viral diseases. J Med Virol 2020; 92:2440-2452. [PMID: 32478897 PMCID: PMC7586785 DOI: 10.1002/jmv.26093] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/26/2020] [Accepted: 05/28/2020] [Indexed: 01/08/2023]
Abstract
Conventional cancer and transformed cell lines are widely used in cancer biology and other fields within biology. These cells usually have abnormalities from the original tumor itself, but may also develop abnormalities due to genetic manipulation, or genetic and epigenetic changes during long‐term passages. Primary cultures may maintain lineage functions as the original tissue types, yet they have a very limited life span or population doubling time because of the nature of cellular senescence. Primary cultures usually have very low yields, and the high variability from any original tissue specimens, largely limiting their applications in research. Animal models are often used for studies of virus infections, disease modeling, development of antiviral drugs, and vaccines. Human viruses often need a series of passages in vivo to adapt to the host environment because of variable receptors on the cell surface and may have intracellular restrictions from the cell types or host species. Here, we describe a long‐term cell culture system, conditionally reprogrammed cells (CRCs), and its applications in modeling human viral diseases and drug discovery. Using feeder layer coculture in presence of Y‐27632 (conditional reprogramming, CR), CRCs can be obtained and rapidly propagated from surgical specimens, core or needle biopsies, and other minimally invasive or noninvasive specimens, for example, nasal cavity brushing. CRCs preserve their lineage functions and provide biologically relevant and physiological conditions, which are suitable for studies of viral entry and replication, innate immune responses of host cells, and discovery of antiviral drugs. In this review, we summarize the applications of CR technology in modeling host‐virus interactions and human viral diseases including severe acute respiratory syndrome coronavirus‐2 and coronavirus disease‐2019, and antiviral discovery.
Collapse
Affiliation(s)
- Xuefeng Liu
- Department of Pathology, Center for Cell Reprogramming, Georgetown University Medical Center, Washington, DC.,Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| | - Abdul M Mondal
- Department of Pathology, Center for Cell Reprogramming, Georgetown University Medical Center, Washington, DC.,Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC
| |
Collapse
|
8
|
Abstract
Persistent viral infections require a host cell reservoir that maintains functional copies of the viral genome. To this end, several DNA viruses maintain their genomes as extrachromosomal DNA minichromosomes in actively dividing cells. These viruses typically encode a viral protein that binds specifically to viral DNA genomes and tethers them to host mitotic chromosomes, thus enabling the viral genomes to hitchhike or piggyback into daughter cells. Viruses that use this tethering mechanism include papillomaviruses and the gammaherpesviruses Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus. This review describes the advantages and consequences of persistent extrachromosomal viral genome replication.
Collapse
Affiliation(s)
- Tami L Coursey
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA;
| | - Alison A McBride
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA;
| |
Collapse
|
9
|
The Myb-related protein MYPOP is a novel intrinsic host restriction factor of oncogenic human papillomaviruses. Oncogene 2018; 37:6275-6284. [PMID: 30018400 PMCID: PMC6265261 DOI: 10.1038/s41388-018-0398-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/08/2018] [Accepted: 06/08/2018] [Indexed: 11/08/2022]
Abstract
The skin represents a physical and chemical barrier against invading pathogens, which is additionally supported by restriction factors that provide intrinsic cellular immunity. These factors detect viruses to block their replication cycle. Here, we uncover the Myb-related transcription factor, partner of profilin (MYPOP) as a novel antiviral protein. It is highly expressed in the epithelium and binds to the minor capsid protein L2 and the DNA of human papillomaviruses (HPV), which are the primary causative agents of cervical cancer and other tumors. The early promoter activity and early gene expression of the oncogenic HPV types 16 and 18 is potently silenced by MYPOP. Cellular MYPOP-depletion relieves the restriction of HPV16 infection, demonstrating that MYPOP acts as a restriction factor. Interestingly, we found that MYPOP protein levels are significantly reduced in diverse HPV-transformed cell lines and in HPV-induced cervical cancer. Decades ago it became clear that the early oncoproteins E6 and E7 cooperate to immortalize keratinocytes by promoting degradation of tumor suppressor proteins. Our findings suggest that E7 stimulates MYPOP degradation. Moreover, overexpression of MYPOP blocks colony formation of HPV and non-virally transformed keratinocytes, suggesting that MYPOP exhibits tumor suppressor properties.
Collapse
|
10
|
Abstract
The human tumor viruses that replicate as plasmids (we use the term plasmid to avoid any confusion in the term episome, which was coined to mean DNA elements that occur both extrachromosomally and as integrated forms during their life cycles, as does phage lambda) share many features in their DNA synthesis. We know less about their mechanisms of maintenance in proliferating cells, but these mechanisms must underlie their partitioning to daughter cells. One amazing implication of how these viruses are thought to maintain themselves is that while host chromosomes commit themselves to partitioning in mitosis, these tumor viruses would commit themselves to partitioning before mitosis and probably in S phase shortly after their synthesis.
Collapse
|