• UCLA Health
  • myUCLAhealth
  • School of Medicine
UCLA Health

UCLA Health
  • About Us
    • What is UCLA Health?
    • Contact Us
    • Your Feedback
    • Accountable Care Organization
    • Awards & Achievements
    • Careers
    • Careers for Physicians
    • Departments - Administrative
    • Departments - Clinical
    • Giving to UCLA Health
    • Health Equity, Diversity & Inclusion
    • In the Community
    • Industry Relations
    • Innovation
    • Leadership
    • News Releases
    • Price Transparency
    • Social Media
    • #TeamLA
    • 340B Program
    Vital SignsLinked Graphic: Subscribe to Health Newsletters
    • Contact
    • Your Feedback
    • Accountable Care Organization
    • Awards and Achievements
    • Careers
    • Careers for Physicians
    • Departments - Administrative
    • Departments - Clinical
    • Giving to UCLA Health
    • Health Equity, Diversity and Inclusion
    • Industry Relations
    • Innovation
    • In the Community
    • 340B Program
    • Leadership
    • News Releases
    • Price Transparency
    • Social Media
    • TeamLA
    • Subscribe to UCLA Health Newsletters
  • Conditions & Treatment
    • Health Library
    • Tests & Procedures
    • Drug Interaction Checker
    • Brain & Nervous System
    • Cancer
    • Children's Health
    • Heart Disease
    • Nutrition & Wellness
    • Pregnancy & Newborns
    • Orthopedics
    • Women's Health
    • Video Library
    • Cancer
    • Cardiovascular
    • Chiropractic
    • Cosmetic Surgery
    • Ear, Nose and Throat
    • Gastrointestinal
    • General Healthcare
    • Neurological
    • Obstetrics/Gynecology
    • See all videos...
    Symptom Checker
    • Video Library
  • Locations

    Hospitals

    • Ronald Reagan UCLA Medical Center
    • UCLA Santa Monica Medical Center
    • UCLA Mattel Children's Hospital
    • Resnick Neuropsychiatric Hospital
    • Institutes and Centers
    • Take a Virtual Tour

    Medical Offices/Clinics

    • Primary Care
    • Specialty Care
    • Immediate Care
    • Emergency Care
    • Outpatient Surgery Centers
    • Community Cancer Care
    • Pediatric Locations
    • Imaging/Radiology
    • Clinical Labs
    • Pharmacies

    Interactive Map

    interactive map

    • Interactive Map
    • UCLA Medical Plazas
    • Locations Coming Soon
    • UCLA Hospitals
    • Take a Virtual Tour
    • Primary Care Practices
    • Specialty Care Practices
    • Immediate Care
    • Emergency Care
    • Pediatric Locations
    • Outpatient Surgery Centers
    • Clinical Labs
    • Pharmacies
    • Other Locations
    • Interactive Map
    • Coming Soon!
  • Medical Services
  • For Patients & Visitors
    • Directions & Parking
    • Appointments
    • Video Visits
    • Medical Chaperones
    • Admissions
    • Preparing For Surgery
    • Patient Services
    • Security & Parking Services
    • Office of the Patient Experience
    • For International Patients
    • Lodging & Nearby Services
    • Around Westwood
    • Gift Shops & Flowers
    • Patient Greeting Cards
    • Coronavirus Resources
    • Log in to myUCLAhealth
    • Billing and Insurance
    • Medical Records
    • Price Transparency
    • Health Encyclopedia
    • Interactive Patient Education Videos (Emmi)
    • FAQs
    • Calendar of Events
    • Secure Email Messages
    • Health Resources
    • Multimedia
    • Download our Apps
    • Doctor on video visit
    • Open Enrollment
    • Visit our Connect Blog
    • Send a Care Compliment
    • Read Health Publications
    • Vital Signs Newsletters
    • Join a Patient and Family Advisory Council
    • Share your Feedback
    • Contact Us
    • Appointments: Call, Click, Come in
    • Video Visits - Telemedicine
    • Medical Chaperones
    • Admissions Information
    • Advance Directive
    • Directions & Parking
    • Patient Services
    • Medical Records
    • myUCLAhealth
    • Smoke-Free
    • Publications
    • Multimedia
    • Health Resources
    • Around Westwood
    • Lodging
    • Preparing For Surgery
    • Patient-focused Technology Council
    • Health Forms
    • End of Life Option Act: Resources & Materials
    • Frequently Asked Questions
    • Secure Email Messages
    • Gift Shops
    • Patient Greeting Cards
  • For Healthcare Professionals
    • Referring a Patient
    • Continuing Medical Education
    • Ethics Center
    • UCLA HealthLink
    • Physician to Physician Access Line (P2P)
    • David Geffen School of Medicine at UCLA
    • Clinical Informatics Fellowship
    • Academic Positions
    • Physician Careers
    • UCLA School of Dentistry
    • UCLA School of Nursing
    • Department of Nursing

    Physician Publications

    • Physicians Update
    • Clinical Updates
    • U Magazine
    • Physician to Physician Access Line (P2P)
    • Physician Careers
    • Clinical Informatics Fellowship
    • Flu Resources for Healthcare Professionals
    • Publications
  • Clinical Research
    • All Clinical Trials
    • COVID-19 Clinical Research
  • Find a Provider
  • UCLA Health
  • myUCLAhealth
  • School of Medicine

News Releases

  1. Home
  2. About Us
  3. News Releases

News Releases

Health and Behavior

Study reveals new details about how bacterial toxins cause life-threatening colitis

UCLA RESEARCH BRIEF

01/07/2021
Clostridioides difficile bacteria

Medical illustration of Clostridioides difficile bacteria.

FINDINGS

Research led by scientists from UCLA and Harvard University has uncovered details about how the bacterium Clostridioides difficile causes excessive inflammation in the gut that can lead to potentially deadly colitis. Studying C. difficile toxin A, one of two toxins released by the bacterium, the researchers produced two key findings. //p>

They pinpointed which part of the toxic protein can permeate cell membranes to gain entry to cellular structures called endosomes, demonstrating that even fragments of the protein that contain that key segment are capable of accessing endosomes.

In addition, they revealed how the toxin molecule causes inflammation, which has been a long-standing mystery because such molecules are generally quickly digested in the gut. The scientists found that toxin A — and surprisingly even fragments of the toxin — can organize DNA into ordered crystalline particles that amplify an immune response by binding to multiple TLR9 receptors, which are normally part of the body's early detection system for microbial DNA. The findings demonstrate that this mechanism causes the body's natural defenses to produce excessive inflammation.

BACKGROUND

Infection from C. difficile in the gut can cause life-threatening colitis, with nearly 500,000 cases and 29,000 deaths in the U.S. alone each year, according to the Centers for Disease Control and Prevention.

Older patients who have been treated with antibiotics are at particular risk from C. difficile, which is resistant to a number of antibiotics. The bacterium is usually harmless when it is kept in check by symbiotic microbes normally found in the human gut. However, when the gut microbiome is suppressed by antibiotics, C. difficile can take over: Its toxins can spur a severe autoimmune response that causes symptoms such as diarrhea, cramping, fever and nausea.

METHOD

The research combined machine learning, experiments with a technique called small-angle X-ray scattering at the Stanford Synchrotron Radiation Lightsource (a Department of Energy laboratory), and experiments using human cell lines, mouse cell lines and mice.

IMPACT

Understanding the mechanisms by which C. difficile's toxins trigger intestinal inflammation is an important step toward developing methods for treating or preventing infection by the bacterium.

AUTHORS

Jaime de Anda, a graduate student in bioengineering at UCLA, is the study's co-first author, along with Xinhua Chen and Xiaotong Yang of Harvard Medical School. Corresponding authors are Gerard Wong, a UCLA professor of bioengineering and member of the California NanoSystems Institute at UCLA, and Chen. Other authors are Jun Huang, Dan Li, Hua Xu, Kelsey Shields, Joshua Hansen, Marianne Grant and Ciarán Kelly of Harvard; Mária Dzunková of the Lawrence Berkeley National Laboratory; Ishan Patel of Stony Brook University Hospital in New York; Eric Yee of the University of Arkansas; and Douglas Golenbock of the University of Massachusetts.

JOURNAL

The study is published online in the journal Gastroenterology.>

FUNDING

The study was funded by the National Institutes of Health, the National Science Foundation, the DOE, the Irving W. and Charlotte F. Rabb Award, and the Crohn's and Colitis Foundation of America.



Media Contact
Marc Roseboro
(310) 794-4612
marc@cnsi.ucla.edu



Latest News

Health and Behavior
UCLA shares COVID-19 vaccine information with faculty and staff
01/15/2021
Members of the COVID-19 Response and Recovery Task Force updated faculty and staff on the progress of UCLA Health's vaccination program and to take questions.

Health and Behavior
In lab study, nanoparticle shows promising results for treating severe allergies
01/14/2021
A UCLA research team developed a possible way to impart long-term relief by inducing an active state of immune tolerance.

Health and Behavior
Cancer researchers awarded grant to study genomic alterations in prostate cancer
01/12/2021
Paul Boutros, PhD, Robert Reiter, MD, and Huihui Ye, MD, MS, of the UCLA Jonsson Comprehensive Cancer Center have received the 2020 Prostate Cancer Foundation Special Challenge Award to help improve the understanding of prostate cancer biology and identify new ways to help prevent, diagnose, prognose and treat lethal prostate cancer.

Health and Behavior
UCLA scientists develop method to more efficiently isolate and identify rare T cells
01/11/2021
Scientists from the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA have developed a technique that will enable researchers to more efficiently isolate and identify rare T cells that are capable of targeting viruses, cancer and other diseases.

Health and Behavior
MRI frequently underestimates tumor size in prostate cancer
01/07/2021
Research brief: Improving imaging processes will lead to more successful treatments and help reduce morbidity in men with the disease.

Facebook Twitter Instagram Youtube LinkedInWeibo
UCLA Health hospitals ranked best hospitals by U.S. News & World Report
  • UCLA Health
  • Find a Doctor
  • School of Medicine
  • School of Nursing
  • UCLA Campus
  • Directory
  • Newsroom
  • Subscribe
  • Patient Stories
  • Giving
  • Careers
  • Volunteer
  • International Services
  • Privacy Practices
  • Nondiscrimination
  • Billing
  • Health Plans
  • Emergency
  • Report Broken Links
  • Terms of Use
  • 1-310-825-2631
  • Maps & Directions
  • Contact Us
  • Your Feedback
  • Report Misconduct
  • Get Social
  • Sitemap

Sign in to myUCLAhealth

Learn more about myUCLAhealth