Featured Research

from universities, journals, and other organizations

Gut immune cells keep beneficial microbes in their place

Date:
June 6, 2012
Source:
Perelman School of Medicine at the University of Pennsylvania
Summary:
Resident immune cells in intestinal tissues of healthy humans, mice, and non-human primates are critical in limiting the location of commensal bacteria. If the cells are depleted commensal bacteria move to peripheral tissues and promote inflammation. The bacteria were all members of a group called Alcaligenes, indicating a selective pathway to contain commensal bacteria.

This is a color-enhanced tissue section from a healthy mouse that displays the presence of commensal bacteria (Alcaligenes species, purple) on the interior of a Peyer's patch (gut-associated lymphoid tissue) and overlaying intestinal epithelial cells (green).
Credit: Gregory Sonnenberg, Ph.D.; David Artis, Ph.D., Perelman School of Medicine University of Pennsylvania; Science

The healthy human intestine is colonized with over 100 trillion beneficial, or commensal, bacteria of many different species. In healthy people, these bacteria are limited to the intestinal tissues and have a number of helpful properties, including aiding in the digestion of food and promoting a healthy immune system.

Related Articles


However, when it comes to commensal bacteria, location is key. While commensal bacteria in the intestine provide positive effects, several chronic human diseases, including HIV/AIDS, inflammatory bowel disease, viral hepatitis, and obesity are associated with the spread of these intestinal commensal bacteria to the blood stream and other peripheral tissues, which can cause chronic inflammation. 'Good bugs' that promote normal health can 'turn bad' if found in the wrong location.

In earlier work, researchers from the Perelman School of Medicine at the University of Pennsylvania found that barrier surfaces -- the skin, gut, and lung -- are guarded by immune cells and limit the inner body's exposure to viruses, bacteria, and parasites, as well as allergens and pollutants. But, how immune cells play a role in limiting the location of commensal bacteria to intestinal and other barrier sites remains unclear.

Now, David Artis, PhD, associate professor of Microbiology, and Gregory F. Sonnenberg, PhD, a postdoctoral researcher in the Artis lab, have identified that immune cells, called innate lymphoid cells, are resident in the intestinal tissues of healthy humans, mice, and non-human primates, and are critical in limiting the location of commensal bacteria. If the innate lymphoid cells are depleted in mice, commensal bacteria move to peripheral tissues and promote inflammation. The research appears this week in Science.

Remarkably, the commensal bacteria that were found in peripheral tissues were all members of a group called Alcaligenes, indicating that the immune system may have developed highly selective pathways to regulate containment of different groups of commensal bacteria.

"A fundamental question that has puzzled researchers for many years is how did the human body evolve to accommodate all these commensal bacteria and keep them in their correct locations?," asks Artis. "The indication from these studies is that the body may have many different pathways to limit the spread of commensal bacteria and these pathways may be tailored to specific types of bacteria."

Supporting experiments in animal models, Alcaligenes-specific immune responses were associated with patients with Crohn's disease or progressive hepatitis C virus infection, two debilitating human diseases linked to the spread of commensal bacteria to systemic tissues.

"The identification of systemic Alcaligenes-specific immune responses in these patient populations suggests that, coupled with other groups of bacteria, the spread of Alcaligenes to tissues outside the intestine may be contributing to chronic inflammation and disease progression," suggests Sonnenberg.

Innate immune cells may become impaired in chronic human diseases, resulting in the spread of Alcaligenes bacteria and pathologic inflammation, which may represent a novel pathway to target in human disease, say the investigators.

"Although it's still early days for this line of research, these findings suggest that targeting innate lymphoid cell responses or directly targeting specific groups of commensal bacteria may be useful in the treatment of some chronic inflammatory diseases," adds Artis.

The research was funded by the National Institute of Allergy and Infectious Disease (AI061570, AI087990, AI074878, AI083480, AI095466, AI095608, T32-AI007532, T32-RR007063, K08-DK093784, AI47619); the NIH-funded Penn Center for AIDS Research (P30 AI 045008); the Burroughs Wellcome Fund Investigator in Pathogenesis of Infectious Disease Award; the Philadelphia VA Medical Research and Merit Review; and the American Gastroenterological Association.

Co-authors in addition to Artis and Sonnenberg are Laurel A. Monticelli, Theresa Alenghat, Thomas C. Fung, Natalie A. Hutnick, Stephanie Grunberg, Rohini Sinha, Adam M. Zahm, Ronald G. Collman, Abraham Shaked, David B. Weiner, Joshua R. Friedman, Frederic D. Bushman, and Kyong-Mi Chang, all from Penn, as well as Jun Kunisawa, Naoko Shibata, and Hiroshi Kiyono from the University of Tokyo; Mιlanie R. Tardif, and Philippe A. Tessier from Laval University; Lynette A Fouser from Pfizer Worldwide R&D; and Taheri Sathaliyawala, Masaru Kubota, and Donna L. Farber from Columbia University.


Story Source:

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


Journal Reference:

  1. Gregory F. Sonnenberg, Laurel A. Monticelli, Theresa Alenghat, Thomas C. Fung, Natalie A. Hutnick, Jun Kunisawa, Naoko Shibata, Stephanie Grunberg, Rohini Sinha, Adam M. Zahm, Mιlanie R. Tardif, Taheri Sathaliyawala, Masaru Kubota, Donna L. Farber, Ronald G. Collman, Abraham Shaked, Lynette A. Fouser, David B. Weiner, Philippe A. Tessier, Joshua R. Friedman, Hiroshi Kiyono, Frederic D. Bushman, Kyong-Mi Chang, and David Artis. Innate Lymphoid Cells Promote Anatomical Containment of Lymphoid-Resident Commensal Bacteria. Science, 6 June 2012 DOI: 10.1126/science.1222551

Cite This Page:

Perelman School of Medicine at the University of Pennsylvania. "Gut immune cells keep beneficial microbes in their place." ScienceDaily. ScienceDaily, 6 June 2012. <www.sciencedaily.com/releases/2012/06/120606142658.htm>.
Perelman School of Medicine at the University of Pennsylvania. (2012, June 6). Gut immune cells keep beneficial microbes in their place. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2012/06/120606142658.htm
Perelman School of Medicine at the University of Pennsylvania. "Gut immune cells keep beneficial microbes in their place." ScienceDaily. www.sciencedaily.com/releases/2012/06/120606142658.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Touch-Free Smart Phone Empowers Mobility-Impaired

Touch-Free Smart Phone Empowers Mobility-Impaired

Reuters - Innovations Video Online (Dec. 21, 2014) — A touch-free phone developed in Israel enables the mobility-impaired to operate smart phones with just a movement of the head. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Earthworms Provide Cancer-Fighting Bacteria

Earthworms Provide Cancer-Fighting Bacteria

Reuters - Innovations Video Online (Dec. 21, 2014) — Polish scientists isolate bacteria from earthworm intestines which they say may be used in antibiotics and cancer treatments. Suzannah Butcher reports. Video provided by Reuters
Powered by NewsLook.com
Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Existing Chemical Compounds Could Revive Failing Antibiotics, Says Danish Scientist

Reuters - Innovations Video Online (Dec. 21, 2014) — A team of scientists led by Danish chemist Jorn Christensen says they have isolated two chemical compounds within an existing antipsychotic medication that could be used to help a range of failing antibiotics work against killer bacterial infections, such as Tuberculosis. Jim Drury went to meet him. Video provided by Reuters
Powered by NewsLook.com
Hugging It Out Could Help You Ward Off A Cold

Hugging It Out Could Help You Ward Off A Cold

Newsy (Dec. 21, 2014) — Carnegie Mellon researchers found frequent hugs can help people avoid stress-related illnesses. Video provided by Newsy
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