Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Viral protein influences key cell-signaling pathway

27.04.2005


New research shows that a protein produced by a cancer-causing virus influences a key signaling pathway in the immune cells that the virus infects. This stimulates the cells to divide, helping the virus spread through the body.



The study, led by researchers at Ohio State University, examined the human T lymphotropic virus type 1 (HTLV-1) and a protein that it produces called p12. The research is published in the April issue of the journal AIDS Research and Human Retroviruses.

The study found that p12 increases the activity of an important gene in host cells. That gene controls production of a cell protein called p300. The p300 protein, in turn, controls a variety of other genes in many types of cells, including T lymphocytes, the cells that HTLV-1 infects.


The findings might help scientists better understand how HTLV-1 maintains its lifelong infection and how the normal immune cells that “remember” a vaccination or an infection can survive for years or even decades.

“The p300 protein is an important central regulator of gene activity in lymphocytes and many other kinds of cells,” says Michael Lairmore, professor and chair of veterinary biosciences and a member of the OSU Comprehensive Cancer Center – Arthur G. James Cancer Hospital and Richard J. Solove Research Institute. “We were surprised to see p300 show-up among the many genes affected by this viral protein.”

HTLV-1 infects an estimated 15 to 20 million people worldwide. In about five percent of them, the infection will lead to adult T cell leukemia or lymphoma (ATLL). ATLL is an aggressive disease characterized by a long latent period and the proliferation of T lymphocytes. The virus is spread by sexual activity, by contact with infected blood and by infected women to children through breast milk.

HTLV-1, like its cousin HIV, inserts its genetic information permanently into the DNA of a T lymphocyte and remains there for the life of the cell. HTLV-1 infection is also lifelong. A hallmark of HTLV-1 infection is the proliferation of T lymphocytes.

This sets HTLV-1 apart from HIV, Lairmore says. “Unlike HIV, which kills cells and destroys the immune system, HTLV-1 enhances the survival of T cells.”

But scientists don’t understand how it prolongs T-cell survival and causes their proliferation.

This study’s findings offer some clues. It is the latest in a series of studies led by Lairmore that examine how HTLV-1 affects T lymphocytes and causes cancer.

The p12 gene is called an “accessory gene” because the protein encoded by the gene seemed unnecessary since the virus could still reproduce, or replicate, in cells grown in the laboratory even when p12 was missing.

“But viruses do not keep genes unless they have a purpose,” Lairmore says. In an earlier study, Lairmore and his colleagues tried to infect an animal model with an HTLV-1 that lacked the p12 gene, and it stopped the virus from replicating almost entirely.

“That told us this gene was important,” he says.

Subsequent research led by Lairmore showed that the p12 protein travels to the network of membranes within the cell known as the rough endoplasmic reticulum (RER). Among other things, the RER helps regulate the amount of calcium in the cell. The investigators found that the p12 protein allows calcium to leak out of the RER, thereby causing calcium levels to rise elsewhere in the cell.

“Calcium is exquisitely regulated in cells,” Lairmore says. “When p12 affects that balance, it affects the activity of a variety of genes.”

The current study used a non-infectious form of HIV to transplant the HTLV-1 p12 gene into laboratory-grown T cells. The infected cells then produced a constant level of p12 protein. The researchers then used gene microarray technology to identify which cellular genes out of 33,000 become either more or less active due to the p12 protein.

The researchers found that p12 altered the activity of a variety of genes linked to chemical pathways that control cell signaling, proliferation and death. The p300 gene stood out as one showing increased activity.

Taken overall, the findings suggest that HTLV-1 p12 protein influences the genetic activity of infected T cells to stimulate their proliferation and promote efficient viral infection.

Funding from National Cancer Institute supported this research.

Darrell E. Ward | EurekAlert!
Further information:
http://www.osu.edu

More articles from Life Sciences:

nachricht Molecular evolution: How the building blocks of life may form in space
26.04.2018 | American Institute of Physics

nachricht Multifunctional bacterial microswimmer able to deliver cargo and destroy itself
26.04.2018 | Max-Planck-Institut für Intelligente Systeme

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Why we need erasable MRI scans

New technology could allow an MRI contrast agent to 'blink off,' helping doctors diagnose disease

Magnetic resonance imaging, or MRI, is a widely used medical tool for taking pictures of the insides of our body. One way to make MRI scans easier to read is...

Im Focus: BAM@Hannover Messe: innovative 3D printing method for space flight

At the Hannover Messe 2018, the Bundesanstalt für Materialforschung und-prüfung (BAM) will show how, in the future, astronauts could produce their own tools or spare parts in zero gravity using 3D printing. This will reduce, weight and transport costs for space missions. Visitors can experience the innovative additive manufacturing process live at the fair.

Powder-based additive manufacturing in zero gravity is the name of the project in which a component is produced by applying metallic powder layers and then...

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

World's smallest optical implantable biodevice

26.04.2018 | Power and Electrical Engineering

Molecular evolution: How the building blocks of life may form in space

26.04.2018 | Life Sciences

First Li-Fi-product with technology from Fraunhofer HHI launched in Japan

26.04.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>