Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Staph infection process leading to B cell suicide described by UCSD researchers


The method that Staphylococcus aureus (staph) infection uses to inactivate the body’s immune response and cause previously healthy B cells to commit suicide, is described for the first time by researchers at the University of California, San Diego (UCSD) School of Medicine in the May 5, 2003 issue of the Journal of Experimental Medicine. The paper was selected for early online publication on April 28.

Normally, B cells mount an early defense against invading bacteria. From this immunologic experience, memory B cells are developed with the ability to quickly recognize these antigens and destroy the bacteria if they return in the future. When staph infections occur, however, this important process for immune defense can be corrupted.

In studies with mice, the researchers found that a staph protein, called SpA, acts like a B cell toxin because it mounts a pre-emptive attack to target a specific region on the antigen receptors of B cells, which ultimately causes their death. Although the B cells begin to respond, they are quickly shut down, as the SpA de-activates these B cell antigen receptors, and there is also loss of other surface molecules such as CD19 and CD21, which are important for amplifying immune responses. Then, within a few hours, the SpA toxin induces B cells to turn on themselves in a programmed suicide process called apoptosis. As a direct consequence, the B cells never get a chance to develop the memory cells necessary to recognize and fight future staph infections.

"This mechanism may explain why staph infections are so common and why many people get them recurrently," said Gregg Silverman, M.D., UCSD professor of medicine and senior author of the paper.

He noted that apoptosis usually takes place on a regular basis in a small proportion of cells to control the size of lymphocyte populations and maintain homeostasis, to keep a balance in the internal equilibrium of body. However, SpA co-opts the normal apoptosis process, in effect killing the B cells too early, before they’ve had a chance to do their job.

"Inappropriate mechanisms of induced apoptosis are not unique to many infections," Silverman said. "However, we should be able to use the same process induced by SpA, to treat the disease-causing B cells in autoimmune diseases and cancers like leukemia and lymphoma. These studies may also help us to make protective vaccines against staph."

In follow up studies, the Silverman team will examine people with staph infections to verify that the same process takes place and that it prevents individuals from defending against staph infections. In addition, the investigators are planning a clinical trial in one to two years to treat patients that have autoimmune diseases such as lupus, that occur due to faulty B cells.

Sue Pondrom | EurekAlert!
Further information:

More articles from Health and Medicine:

nachricht Inflammation Triggers Unsustainable Immune Response to Chronic Viral Infection
24.10.2016 | Universität Basel

nachricht Resolving the mystery of preeclampsia
21.10.2016 | Universitätsklinikum Magdeburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>