Science Current Events | Science News | Brightsurf.com
 

Texas A&M researcher explains how embryo fights retroviral infection

June 25, 2010

Some viruses insert themselves into the host's DNA during infection in a process called retroviral integration, causing several diseases, including AIDS and cancer, notes a Texas A&M researcher who specializes in fetal diseases. However, stem cells that give rise to the early embryo and yolk sac fight back, inhibiting further infection by aggressively silencing the invading viral DNA, says Michael Golding of the Department of Veterinary Physiology and Pharmacology.

The work of the researcher was recently published in Cell Stem Cell.

Early mammalian embryos actually possess three stem cell lineages: ES (embryonic stem), TS (trophectoderm stem), and XEN (extraembryonic endoderm), which give rise to the fetus, placenta and yolk sac respectively, the Texas A&M researcher explains. Using the mouse as a model organism, Golding and his colleagues demonstrate that the mechanisms silencing gene expression are different between each of the three stem cell types.

"Much like a closed book cannot be read while an open book can, the DNA encoding genes can either be tightly wound up and silent or in a relaxed, open, active state," Golding explains. "The mechanisms that control this gene packaging are called epigenetic as they represent a level of regulation that is above or 'epi' to genetics."

The study shows "retroviral silencing in XEN cells is epigenetic in origin" and that "the three cell lineages of early mammalian embryo have vastly different viral silencing strategies as well as different capacities to suppress retroviral activity."

To examine the validity of a common assumption that these stem cells use similar mechanisms to silence retroviruses, Golding infected the mouse embryo stem cells with mouse leukemia virus (MLV) and monitored the virus' activity.

ES cells showed a progressive decline in virus activity, while TS cells had a constant level of virus activity. XEN cells, however, exhibited extremely aggressive and rapid silencing of virus activity, according to the study.

"Epigenetics is an exciting new field of research which is altering the way we think about fetal nutrition and exposure to environmental chemicals," Golding adds. "This discovery that all three stem cell types of the early embryo utilize slightly different mechanisms to control gene expression has profound implications for how we diagnose and treat fetal diseases."

Texas A&M University


Related Retroviral Current Events and Retroviral News Articles


Retroviral RNA may play a part in liver cancer
An international group led by RIKEN in Japan and INSERM in France have found that retroviral long-terminal-repeat (LTR) promoters--a type of repetitive element that are widely distributed in the human genome--are highly activated in hepatocellular carcinomas, the most common type of liver cancer.

Dormant viral genes may awaken to cause ALS
Scientists at the National Institutes of Health discovered that reactivation of ancient viral genes embedded in the human genome may cause the destruction of neurons in some forms of amyotrophic lateral sclerosis (ALS).

HIV patients should be included in early clinical trials of anti-TB drugs
Tuberculosis is the number one cause of death in HIV-infected patients in Africa and a leading cause of death in this population worldwide, yet the majority of these patients are excluded from the early stages in the development of new, anti-tuberculosis drugs.

First-ever observation of the native capside of a retrovirus
Bovine leukemia virus (BLV) is an infectious disease that affects the immune system of cattle, causing immunodeficiency and in some cases triggering the development of leukemia or solid tumors in the form of lymphomas.

Study shows role of disease-fighting cells in HIV-related neurological damage
Despite symptom-stifling anti-retroviral drugs, as many as half of all patients living with HIV experience neurological damage tied to chronic inflammation in the brain fueled by the body's own immune defenses.

Researchers 'un-can' the HIV virus
If the human immunodeficiency virus (HIV) is a bit like a hermetically sealed tin can no one has yet been able to break open, the good news is that researchers at the CHUM Research Centre, affiliated with the University of Montreal, have identified a way to use a "can opener" to force the virus to open up and to expose its vulnerable parts, allowing the immune system cells to then kill the infected cells.

Viruses: You've heard the bad -- here's the good
In sharp contrast to the gastrointestinal distress it causes in humans, the murine (mouse infecting) norovirus plays a role in development of the mouse intestine and its immune system, and can actually replace the beneficial effects of certain gut bacteria when these have been decimated by antibiotics.

International experts call for an end to preventable deaths from acute kidney injury by 2025
Preventable deaths caused by acute kidney injury (AKI) could be nearly eliminated in just 10 years, according to leading medical experts.

New protein booster may lead to better DNA vaccines and gene therapy
Scientists have discovered a new way to manipulate how cells function, a finding that might help advance an experimental approach to improving public health: DNA vaccines, which could be more efficient, less expensive and easier to store than traditional vaccines.

Fewer viral relics may be due to a less bloody evolutionary history
A researcher from Plymouth University School of Biomedical and Healthcare Sciences had led an international team investigating viruses that entered the DNA of our ancestors millions of years ago.
More Retroviral Current Events and Retroviral News Articles

  Retroviral Transfer of Human Mutated Thymidylate Synthase Gene into Hematopoietic Stem Cells for Protection from High-Dose Fluoropyrimidine Toxicity
by Naoko Takebe (Author)




Mortal Combat: AIDS Denialism and the Struggle for Antiretrovirals in South Africa

Mortal Combat: AIDS Denialism and the Struggle for Antiretrovirals in South Africa
by Nicoli Nattrass (Author)


Mortal Combat is a history of AIDS policy in South Africa. The book exposes the strategy and tactics of AIDS denialists and focuses on the struggle for antiretrovirals to prevent mother-to-child transmission of HIV and to extend the lives of people living with AIDS. *** "AIDS denialism has resulted in the deaths of at least hundreds of thousands of people. Nattrass's book provides an important service to the world and will save lives." - Mark Wainberg, Director of the McGill U. AIDS Centre, past President of the International AIDS Society, and co-chair of the Toronto 2006 AIDS Conference

Retroviral: Webster's Timeline History, 1939 - 2007

Retroviral: Webster's Timeline History, 1939 - 2007
by Icon Group International (Author)


Webster's bibliographic and event-based timelines are comprehensive in scope, covering virtually all topics, geographic locations and people. They do so from a linguistic point of view, and in the case of this book, the focus is on "Retroviral," including when used in literature (e.g. all authors that might have Retroviral in their name). As such, this book represents the largest compilation of timeline events associated with Retroviral when it is used in proper noun form. Webster's timelines cover bibliographic citations, patented inventions, as well as non-conventional and alternative meanings which capture ambiguities in usage. These furthermore cover all parts of speech (possessive, institutional usage, geographic usage) and contexts, including pop culture, the arts, social sciences...

  Cytotoxic T Cells in HIV and Other Retroviral Infections
by P. Racz (Editor), N.L. Letvin (Editor), J.-C. Gluckman (Editor)


Cytotoxic T lymphocytes play a central role in containing the spread of the AIDS virus (HIV) as well as other retroviruses. This publication provides a broad overview of our current understanding of this immune response in the HIV-infected patient. With contributions from major laboratories throughout the world, the effector T lymphocyte response is described in virus-infected humans and also in non-human primates infected with monkey AIDS viruses. The precise molecular events which govern cytotoxic T cell recognition of HIV, the role of these cells in protecting against the progression of AIDS and the contributions of cytotoxic T lymphocytes to clinical manifestations of disease are thoroughly discussed. The functional characterization of these cells as well as their definition in...

Hematopoietic Stem Cell Protocols (Methods in Molecular Biology)

Hematopoietic Stem Cell Protocols (Methods in Molecular Biology)
by Kevin D. Bunting (Editor)


This revised edition provides up-to-date protocols developed in the HSC field. A team of leading researchers supply this volume with in-depth, readily reproducible methods for effective characterization of HSC and their developmental potential. The book provides detailed flow cytometry protocols for thorough analysis of enriched HSC populations, and offers a variety of transplantation approaches to measure HSC function in vivo. This is a much needed technical resource in the critically important field of stem cell investigation.

Polyoxometalates: From Platonic Solids to Anti-Retroviral Activity (Topics in Molecular Organization and Engineering)

Polyoxometalates: From Platonic Solids to Anti-Retroviral Activity (Topics in Molecular Organization and Engineering)
by Michael Pope (Editor), Achim Müller (Editor)


MICHAEL T. POPE AND ACHIM MULLER Department of Chemistry, Georgetown University, Washington, DC 20057-2222, U.S.A.; Department of Chemistry, University of Bielefeld, D-4BOO Bielefeld 1, F.R.G. Polyoxometalates, from their discovery and early development in the final decades of the 19th century to their current significance in disciplines as diverse as chemistry, mathematics, and medicine, continue to display surprisingly novel structures, unexpected reactivities and applications, and to attract increasing attention worldwide. Most of the contributors to the present volume participated in the workshop held at the Center for Interdisciplinary Research at the University of Bielefeld, July 15-17, 1992. The choice of topics illustrates some of the variety of directions and fields in which...

HIV and AIDS in South Asia: An Economic Development Risk (Directions in Development)

HIV and AIDS in South Asia: An Economic Development Risk (Directions in Development)
by Markus Haacker (Editor), Mariam Claeson (Editor)


'HIV and AIDS in South Asia: An Economic Development Risk' offers an original perspective on HIV and AIDS as major development issues for the region. Although the impact of HIV and AIDS on economic growth appears to be very small, three risks to development are associated with HIV and AIDS in South Asia: the risk of escalating concentrated epidemics, the economic welfare costs, and the fiscal costs of scaling up treatment. As the authors show, South Asian countries have relatively low estimated national HIV prevalence rates, but prevalence is growing rapidly among vulnerable groups at high risk, such as sex workers and their clients, men having sex with men, and injecting drug users and their partners.

The cost benefits of targeted prevention programs are high, and the...

HIV Interactions with Host Cell Proteins (Current Topics in Microbiology and Immunology)

HIV Interactions with Host Cell Proteins (Current Topics in Microbiology and Immunology)
by Paul Spearman (Editor), Eric O. Freed (Editor)


The study of viruses necessarily involves dissecting the intimate details of cellular pathways. Viruses have often been employed as tools in studying cellular pathways, as was done by early retrovirologists such as Peyton Rous in attempting to understand the mechanism of cellular transformation and oncogenesis. On the other side of the coin, virologists seek to de?ne those cellular elements interacting intimatelywiththeir virus ofinterestinorder to better understand viral replication itself, and in some cases to develop antiviral strategies. It is in the intersection of virology and cell biology that many of us ?nd the most rewarding aspects of our research. When a new discovery yields insights into basic cellular mechanisms and presents new targets for int- vention to ?ght a serious...

Pharmaceutical Autonomy and Public Health in Latin America: State, Society and Industry in Brazil's AIDS Program (Routledge Studies in Latin American Politics)

Pharmaceutical Autonomy and Public Health in Latin America: State, Society and Industry in Brazil's AIDS Program (Routledge Studies in Latin American Politics)
by Matthew B. Flynn (Author)


Brazil has occupied a central role in the access to medicines movement, especially with respect to drugs used to treat those with the human immunodeficiency virus (HIV) that causes the acquired immune deficiency syndrome (AIDS). How and why Brazil succeeded in overcoming powerful political and economic interests, both at home and abroad, to roll-out and sustain treatment represents an intellectual puzzle. In this book, Matthew Flynn traces the numerous challenges Brazil faced in its efforts to provide essential medicines to all of its citizens. Using dependency theory, state theory, and moral underpinnings of markets, Flynn delves deeper into the salient factors contributing to Brazil’s successes and weaknesses, including control over technology, creation of political alliances, and...

  Retroviral Testing and Quality Assurance - Essentials for Laboratory Diagnosis
by Niel T. Constantine (Author), Rebecca D. Saville (Author), Elizabeth M. Dax (Author), Constantine (Foreword)


Paperback published throught MedMira Laboratories educational grant. FR215

© 2016 BrightSurf.com