Navigation Links
Interfering RNA silences genes in 'slippery' immune cells

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 t o 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.


'"/>

Source:Children's Hospital of Philadelphia


Related biology news :

1. Used in a new way, RNA interference permanently silences key breast cancer gene
2. Researchers find protein that silences genes
3. MIT: Pulsing light silences overactive neurons
4. Newly-discovered class of genes determines ?and restricts ?stem cell fate
5. Inexpensive, mass-produced genes core of synthetic biology advances at UH
6. First atlas of key brain genes could speed research on cancer, neurological diseases
7. U-M scientists find genes that control growth of common skin cancer
8. Researchers find missing genes of ancient organism
9. Scientists document complex genomic events leading to the birth of new genes
10. Genrate: a generative model that finds and scores new genes and exons in genomic microarray data
11. Advances in the characterisation of the oyster mushroom genes
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/11/2017)... N.Y. , April 11, 2017 ... fingerprints, but researchers at the New York University ... College of Engineering have found that partial similarities ... security systems used in mobile phones and other ... thought. The vulnerability lies in the ...
(Date:4/6/2017)... , April 6, 2017 ... RFID, ANPR, Document Readers, by End-Use (Transportation & Logistics, ... Facility, Oil, Gas & Fossil Generation Facility, Nuclear Power), ... Educational, Other) Are you looking for a ... sector? ...
(Date:4/5/2017)... April 5, 2017 Today HYPR Corp. ... the server component of the HYPR platform is officially ... the end-to-end security architecture that empowers biometric authentication across ... has already secured over 15 million users across the ... of connected home product suites and physical access represent ...
Breaking Biology News(10 mins):
(Date:6/22/2017)... ... June 22, 2017 , ... ... RegMedNet has produced a Spotlight series on “Cell Therapy Regulation” ... perspectives by leading experts on the unique regulatory challenges of stem cell medical ...
(Date:6/22/2017)... (PRWEB) , ... June 22, 2017 , ... The first ... took 20 years until the first data on cross-contamination of human cell lines with ... been an increasing issue in cell culture labs and is associated with dramatic consequences ...
(Date:6/22/2017)... ... June 22, 2017 , ... Charm Sciences, Inc. is pleased to ... was determined to be appropriate as a screening test at dairies and farms for ... EZ system, and the Charm EZ Lite system. These systems are a combination incubator ...
(Date:6/20/2017)... ... 2017 , ... Biologist Dawn Maslar MS has found a biomarker that she ... Women Choose: The Neuroscience of Meeting, Dating, Losing Your Mind, and Finding True Love, ... logical next step, in my estimation, was to scientifically track the evidence of commitment ...
Breaking Biology Technology: