Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Antibodies critical for fighting West Nile Virus infection

30.01.2003


Researchers at Washington University School of Medicine in St. Louis have found that immune cells called B cells and the antibodies they produce play a critical early role in defending the body against West Nile Virus. The results are published in the February issue of the Journal of Virology.



Mice that lacked B cells and antibodies were completely unable to combat the virus. They developed serious brain and spinal-cord infection and ultimately died.

"These findings may help explain why the elderly and others with weakened immunity are most likely to develop serious disease when infected by the virus," says study leader Michael S. Diamond, M.D., Ph.D., assistant professor of medicine, of molecular microbiology and of pathology and immunology.


West Nile Virus first emerged in the eastern United States in 1999 and has spread steadily westward, reaching the West Coast last year. It is carried by mosquitoes and causes encephalitis, a brain inflammation. The virus affects mainly birds, especially crows and jays, but it also can cause disease in horses, humans and other mammals.

In humans, West Nile Virus causes serious illness in only a small proportion of infected people. Last year, doctors reported more than 3,500 cases of infection, with 5 to 10 percent of those resulting in serious illness or death.

Diamond and his colleagues infected a strain of immune-deficient mice that lacked two important components of the immune system -- T cells and B cells -- and compared the animals’ response to mice with normal immunity. T cells coordinate immune responses and kill infected cells; B cells produce antibodies that attack viruses before they infect cells.

The immune-deficient mice became sick and died even with low doses of the virus. However, they could resist infection if given a dose of B cells after being injected with the virus.

"We were surprised by how susceptible the mice were when antibodies were missing," says Diamond. "Just one viral particle -- an exceedingly low dose -- was enough to kill the mice."

To confirm the importance of B cells and antibodies in defending against West Nile Virus, the researchers then gave the virus to a group of immune-deficient mice that lacked only B cells and antibodies, again comparing their response to mice with normal immunity. At day two, both the B-cell deficient mice and normal mice had equal levels of the virus in the blood. The levels declined thereafter in the normal mice and were undetectable by day six. In the B-cell deficient mice, however, viral levels continued to increase, with 500-fold higher levels by day four.

From this, the investigators conclude that B cells and antibodies appear to be essential for controlling the infection.

"Our findings suggest – but this is just speculation – that humans who have weak antibody responses early during infection are more likely to develop serious disease," says Diamond. "Those are the people we’d want to target when a vaccine or treatment becomes available."

Diamond and his colleagues now are studying how antibodies control infection and what other parts of the immune system are involved.


Diamond MS, Shrestha B, Marri A, Mahan D, Engle M. B cells and antibody play critical roles in the immediate defense of disseminated infection by West Nile Encephalitis Virus. Journal of Virology, February. 2003.

Funding from the National Institute of Allergy and Infectious Diseases supported this research.

The full-time and volunteer faculty of Washington University School of Medicine are the physicians and surgeons of Barnes-Jewish and St. Louis Children’s hospitals. The School of Medicine is one of the leading medical research, teaching and patient-care institutions in the nation. Through its affiliations with Barnes-Jewish and St. Louis Children’s hospitals, the School of Medicine is linked to BJC HealthCare.

Darrell Ward | EurekAlert!
Further information:
http://medinfo.wustl.edu/

More articles from Health and Medicine:

nachricht A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital

nachricht Stem cell transplants: activating signal paths may protect from graft-versus-host disease
20.04.2017 | Technische Universität München

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: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

Im Focus: Quantum-physical Model System

Computer-assisted methods aid Heidelberg physicists in reproducing experiment with ultracold atoms

Two researchers at Heidelberg University have developed a model system that enables a better understanding of the processes in a quantum-physical experiment...

Im Focus: Glacier bacteria’s contribution to carbon cycling

Glaciers might seem rather inhospitable environments. However, they are home to a diverse and vibrant microbial community. It’s becoming increasingly clear that they play a bigger role in the carbon cycle than previously thought.

A new study, now published in the journal Nature Geoscience, shows how microbial communities in melting glaciers contribute to the Earth’s carbon cycle, a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

New quantum liquid crystals may play role in future of computers

21.04.2017 | Physics and Astronomy

A promising target for kidney fibrosis

21.04.2017 | Health and Medicine

Light rays from a supernova bent by the curvature of space-time around a galaxy

21.04.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>