Featured Research

from universities, journals, and other organizations

Penn Study Finds A New Role For RNA In Human Immune Response

Date:
August 24, 2005
Source:
University of Pennsylvania School of Medicine
Summary:
Researchers at the University of Pennsylvania School of Medicine have published the first study to test the role of RNA chemical modifications on immunity. They have demonstrated that RNA from bacteria stimulates immune cells to orchestrate destruction of invading pathogens. The authors concluded that the potential of RNA to activate immunity seems to be inversely correlated with the extent of its chemical modification.

Philadelphia, PA - Researchers at the University of Pennsylvania Schoolof Medicine have published the first study to test the role of RNAchemical modifications on immunity. They have demonstrated that RNAfrom bacteria stimulates immune cells to orchestrate destruction ofinvading pathogens. Most RNA from human cells is recognized as beingself and does not stimulate an immune response to the same extent asinvading bacteria or viruses. The researchers hypothesize that if thisself-recognition fails, then autoimmune diseases such as systemic lupuserythematosus could result.

Related Articles


The research was a collaborative work led by Drew Weissman, MD, PhD, of the Division of Infectious Diseases and Katalin Karikσ,PhD, of the Department of Neurosurgery. The investigators publishedtheir findings in the August issue of Immunity. "We think this studywill open a new area of research in understanding how our immunesystems protect us," says Weissman.

"One application of our findings is that scientists will beable to design better therapeutic RNAs, including anti-sense orsmall-interfering RNAs, for treating diseases such as cancer andsingle-gene genetic diseases," saysKarikσ.

RNA is the genetic material that programs cells to makeproteins from DNA's blueprint and specifies which proteins should bemade. There are many types of RNA in the cells of mammals, such astransfer RNA, ribosomal RNA, messenger RNA, and all of them havespecific types of chemical tags, or modifications. In contrast, RNAsfrom bacteria have fewer or no modifications.

Another type of RNA in mammalian cells is found inmitochondria, the powerhouses of cells. Mitochondrial RNA is thought tohave originated from bacteria millions of years ago. Similar to RNAfrom bacteria, mitochondrial RNA has fewer chemical tags. It is theabsence of modifications that causes RNA from bacteria and mitochondriato activate the immune response. The researchers suggest that thesemodifications have evolved in animals as one of the ways for the innateimmune system to discriminate self from non-self.

When a tissue is damaged by injury, infection, or inflammation,cells release their mitochondrial RNA. This RNA acts as a signal to theimmune system to recognize the damage and help defend and repair thetissue.

Conversely, the presence of the modifications on the othertypes of RNA does not activate an immune response and thus allows theinnate immune system to discriminate self from non-self. "We showedthat special proteins on the surface of immune cells, called Toll-likereceptors, are instrumental in recognizing bacterial and mitochondrialRNA," explains Weissman. The amount of modification on the RNA isimportant because as little as one or two tags per RNA molecule couldprevent or suppress the immune reaction.

The authors concluded that the potential of RNA to activateimmunity seems to be inversely correlated with the extent of itschemical modification and may explain why some viral RNA that is overlymodified evades immune surveillance. The authors plan to investigatewhether longer RNAs with specific tags will be useful for deliveringtherapeutic molecules to diseased cells.

###

This study was funded by the National Institutes of Health. Co-authors are Michael Buckstein and Houping Ni, both from Penn.



Story Source:

The above story is based on materials provided by University of Pennsylvania School of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

University of Pennsylvania School of Medicine. "Penn Study Finds A New Role For RNA In Human Immune Response." ScienceDaily. ScienceDaily, 24 August 2005. <www.sciencedaily.com/releases/2005/08/050824082351.htm>.
University of Pennsylvania School of Medicine. (2005, August 24). Penn Study Finds A New Role For RNA In Human Immune Response. ScienceDaily. Retrieved March 27, 2015 from www.sciencedaily.com/releases/2005/08/050824082351.htm
University of Pennsylvania School of Medicine. "Penn Study Finds A New Role For RNA In Human Immune Response." ScienceDaily. www.sciencedaily.com/releases/2005/08/050824082351.htm (accessed March 27, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, March 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

House Ready to Pass Medicare Doc Bill

House Ready to Pass Medicare Doc Bill

AP (Mar. 26, 2015) — In rare bipartisan harmony, congressional leaders pushed a $214 billion bill permanently blocking physician Medicare cuts toward House passage Thursday, moving lawmakers closer to resolving a problem that has plagued them for years. (March 26) Video provided by AP
Powered by NewsLook.com
HIV Outbreak Prompts Public Health Emergency In Indiana

HIV Outbreak Prompts Public Health Emergency In Indiana

Newsy (Mar. 26, 2015) — Indiana Gov. Mike Pence says he will bring additional state resources to help stop the epidemic. Video provided by Newsy
Powered by NewsLook.com
Indiana Permits Needle Exchange as HIV Cases Skyrocket

Indiana Permits Needle Exchange as HIV Cases Skyrocket

Reuters - US Online Video (Mar. 26, 2015) — Governor Mike Pence declares the recent HIV outbreak in rural Indiana a "public health emergency" and authorizes a short-term needle-exchange program. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
AAA: Distracted Driving a Serious Teen Problem

AAA: Distracted Driving a Serious Teen Problem

AP (Mar. 25, 2015) — While distracted driving is not a new problem for teens, new research from the AAA Foundation for Traffic Safety says it&apos;s much more serious than previously thought. (March 25) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins