We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us
GLOBE SCIENTIFIC, LLC

Download Mobile App




Peptides That Mimic a T-Cell Receptor May Prevent Toxic Shock Syndrome

By LabMedica International staff writers
Posted on 28 Sep 2011
Blocking the binding of bacterial superantigens to specific T-cell surface receptors may be a way to prevent potentially fatal toxic shock syndrome.

Superantigens (SAgs) are a class of antigens, which cause nonspecific activation of T-cells resulting in polyclonal T cell activation and massive cytokine release. More...
SAgs can be produced by pathogenic microbes (including viruses, mycoplasma, and bacteria) as a defense mechanism against the immune system. Compared to a normal antigen-induced T-cell response where 0.001% to 0.0001% of the body’s T-cells are activated, these SAgs are capable of activating up to 20% of the body’s T-cells. The large number of activated T-cells secretes massive amounts of cytokines (the most important of which is TNF-alpha (tumor necrotic factor-alpha)). TNF-alpha is particularly important as a part of the body's inflammatory response and in normal circumstances (where it is released locally in low levels) helps the immune system defeat pathogens. However, when it is systemically released in the blood and in high levels, it can cause severe and life-threatening symptoms, including shock and multiple organ failure.

Investigators at the Hebrew University of Jerusalem (Israel) have been studying how superantigen toxins engage the immune system. Their work was based on the understanding that in order to act, a superantigen must first bind to the CD28 protein receptor on the surface of the human immune cell. CD28 (Cluster of Differentiation 28) is one of the molecules expressed on T cells that provide co-stimulatory signals, which are required for T cell activation.

The investigators reported in the September 13, 2011, online edition of the journal PLoS Biology that to elicit inflammatory cytokine gene expression and toxicity, superantigens must bind directly into the dimer interface of CD28. Preventing access of the superantigen to CD28 was sufficient to block its lethality. Mice were protected from lethal superantigen challenge by short peptides that mimicked the structure of the CD28 dimer interface and by peptides selected to compete with the superantigen for its binding site in CD28.

These findings provide a novel therapeutic approach against toxic shock. Since the blocking peptides mimic a human cellular structure, resistance cannot arise in the infecting bacteria or in the toxins because the peptides mimic a human immune receptor that is constant and will not change.

Related Links:

Hebrew University of Jerusalem


Gold Member
Antipsychotic TDM Assays
Saladax Antipsychotic Assays
Serological Pipet Controller
PIPETBOY GENIUS
New
Automated Biochemical Analyzer
iBC 900
New
Silver Member
Fibrinolysis Assay
HemosIL Fibrinolysis Assay Panel
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








Channels

Hematology

view channel
Image: CitoCBC is the world first cartridge-based CBC to be granted CLIA Waived status by FDA (Photo courtesy of CytoChip)

Disposable Cartridge-Based Test Delivers Rapid and Accurate CBC Results

Complete Blood Count (CBC) is one of the most commonly ordered lab tests, crucial for diagnosing diseases, monitoring therapies, and conducting routine health screenings. However, more than 90% of physician... Read more

Immunology

view channel
Image: A simple blood test could replace surgical biopsies for early detecion of heart transplant rejection (Photo courtesy of Shutterstock)

Blood Test Detects Organ Rejection in Heart Transplant Patients

Following a heart transplant, patients are required to undergo surgical biopsies so that physicians can assess the possibility of organ rejection. Rejection happens when the recipient’s immune system identifies... Read more

Pathology

view channel
These images illustrate how precision oncology Organ Chips recapitulate individual patients’ responses to chemotherapy (Photo courtesy of Wyss Institute at Harvard University)

Cancer Chip Accurately Predicts Patient-Specific Chemotherapy Response

Esophageal adenocarcinoma (EAC), one of the two primary types of esophageal cancer, ranks as the sixth leading cause of cancer-related deaths worldwide and currently lacks effective targeted therapies.... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.