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 A novel socio-ecological approach helps identifying suitable wolf habitats
17.02.2017 | Universität Zürich

nachricht New, ultra-flexible probes form reliable, scar-free integration with the brain
16.02.2017 | University of Texas at Austin

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Switched-on DNA

20.02.2017 | Materials Sciences

Second cause of hidden hearing loss identified

20.02.2017 | Health and Medicine

Prospect for more effective treatment of nerve pain

20.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>