Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Interfering RNA silences genes in ’slippery’ immune cells

09.05.2006
Novel lab technique expands researchers’ toolbox

A technical advance in laboratory techniques may provide biology researchers broader access to RNA interference, a process of blocking the activity of targeted genes. RNA interference has recently emerged as an important tool in studying how genes function in normal biological processes and in disease.

Writing in the Journal of Immunological Methods, published online on March 24, a research team from The Children’s Hospital of Philadelphia combined laboratory technologies in using RNA interference to manipulate human T cells. T cells are immune cells that circulate in the blood, with important roles in autoimmune diseases, infectious diseases and some cancers.

"T cells have previously been difficult to modify with interfering RNA, being more mobile than other cell types that typically remain stationary in cell cultures," said study leader Terri H. Finkel, M.D., Ph.D., chief of Rheumatology at The Children’s Hospital of Philadelphia. "Our approach achieves results comparable to the conventional technique, which uses synthetic small interfering RNA but is very expensive and in short supply. We expect our technique to expand the toolbox for scientists doing research in immunology."

RNA interference (RNAi), which naturally occurs in cells, is a process in which brief RNA sequences, called small interfering RNA (siRNA) block signals from a particular gene. This process, called gene silencing, inhibits the gene from carrying out its function of creating a protein or another gene product. The body often uses RNAi as a defense against the action of hostile viruses.

Over the past few years, biomedical researchers have been investigating how they might eventually harness RNAi in new medicines. Another line of research uses RNAi as a research tool, investigating the functions of specific genes by studying what happens when RNAi temporarily silences them--a process calling "knocking down" the gene.

The research by Dr. Finkel’s team aims to extend RNAi to a wider pool of researchers by making the technique less expensive and more widely available, as well as adapting it to T cells, a cell type previously intractable to such manipulation. Their technique combines three technologies already accessible to lab investigators: nucleofection, siRNA expression cassettes, and siRNA expression vectors. Nucleofection technology uses specialized solutions and electrical pulses to temporarily open a cell nucleus. Into the nucleus, researchers insert a payload of DNA.

The DNA holds a sequence of genetic code that produces a specific siRNA after it enters a nucleus. The researchers encased the DNA within an siRNA expression cassette (SEC), an inexpensive, quickly synthesized product that carries genetic sequences to regulate the gene activity that yields an siRNA. After the researchers tested a variety of SECs to determine which is the most effective, they inserted the desired SEC into a vector, a biological agent that inserts itself into a target cell’s nucleus more efficiently than an unaccompanied cassette.

The researchers first tested their approach by introducing a gene for green fluorescent protein into human T cells, and using siRNA to inhibit that gene’s expression, and dim its fluorescent glow.

They then applied their approach to HALP, a gene naturally active in T cells. Dr. Finkel previously discovered and named HALP, an acronym for "HIV-associated life preserver," showing that it had a role in prolonging HIV infection by helping HIV-infected T cells survive attack by the immune system.

Using siRNA and their laboratory techniques, the investigators succeeded in "knocking down," that is, decreasing gene expression by HALP. Because their previous research strongly suggests that HALP promotes latent HIV infection, the new technique has a potential application to HIV treatment. "The siRNA may represent a suicide vector: by knocking down HALP it may allow HIV-infected cells to self-destruct, thus eliminating a hiding place for the virus," said Dr. Finkel.

"More broadly," she added, "the technique could theoretically be directed against other immune-related diseases, by silencing harmful genes active in T cells."

Dr. Finkel’s co-authors, all from The Children’s Hospital of Philadelphia, were Jiyi Yin, Ph.D., Zhengyu Ma, Nithianandan Selliah, Ph.D., Debra K. Shivers and Randy Q. Cron, M.D., Ph.D. National Institutes of Health grants supported the research, along with support from the University of Pennsylvania Center for AIDS Research and the University’s Cancer Center, the Bender Foundation, the Joseph Lee Hollander Chair at The Children’s Hospital of Philadelphia, and the W. W. Smith Charitable Trust.

"Effective Gene Suppression Using Small Interfering RNA in Hard-to-Transfect Human T Cells." Journal of Immunological Methods. In press, published online March 24, 2006.

John Ascenzi | EurekAlert!
Further information:
http://www.chop.edu

More articles from Life Sciences:

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Chemists at FAU successfully demonstrate imine hydrogenation with inexpensive main group metal
22.05.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

Im Focus: Computer-Designed Customized Regenerative Heart Valves

Cardiovascular tissue engineering aims to treat heart disease with prostheses that grow and regenerate. Now, researchers from the University of Zurich, the Technical University Eindhoven and the Charité Berlin have successfully implanted regenerative heart valves, designed with the aid of computer simulations, into sheep for the first time.

Producing living tissue or organs based on human cells is one of the main research fields in regenerative medicine. Tissue engineering, which involves growing...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | 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

 
Latest News

Asian tiger mosquito on the move

22.05.2018 | Life Sciences

Self-illuminating pixels for a new display generation

22.05.2018 | Trade Fair News

Embryonic development: How do limbs develop from cells?

22.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>