Navigation Links
Biological catch-22 prevents induction of antibodies that block HIV
Date:12/15/2009

DURHAM, N.C. Scientists seeking to understand how to make an AIDS vaccine have found the cause of a major roadblock. It turns out that the immune system can indeed produce cells with the potential to manufacture powerful HIV-blocking antibodies but at the same time, the immune system works equally hard to make sure these cells are eliminated before they have a chance to mature.

"These studies show that a potentially protective neutralizing antibody against a viral disease is under the control of immunological tolerance," said Barton Haynes, M.D., director of the Center for HIV/AIDS Vaccine Immunology (CHAVI) at Duke University Medical Center and senior author of the study appearing in the online early edition of the Proceedings of the National Academy of Sciences. "This represents a new insight into the way HIV effectively evades detection by the B cell arm of the immune system and may offer new directions for vaccine design."

Over the years, scientists have assumed that B cells one of the first lines of defense against infection are simply not able to "see" the HIV virus. HIV has the ability to hide its most vulnerable parts from immune system surveillance, and researchers generally assumed that helped explain why B cells often took weeks and even months to arise following infection.

But several years ago, Duke researchers hypothesized that the antibodies required to broadly neutralize HIV may not be produced in the first place because the immune system "sees" them as a potential threat due to their similarity to antibodies that promote autoimmune disease and destroys them.

To see if this is indeed what happens, Laurent Verkoczy, Ph.D., assistant professor of medicine at Duke and the lead author of the study, and Haynes genetically engineered a mouse that could only produce B cells containing a rare but potent broadly neutralizing human antibody that is able to block HIV infection.

Researchers found that the mouse's immune system produced plenty of early stage B cells bearing this human neutralizing antibody on their surface but eliminated most of them before they had a chance to fully evolve into more mature B cells capable of secreting the antibody.

"This work may mean that we need to think and act very differently in envisioning how a successful vaccine may work," said Verkoczy. "The good news is that while about 85 percent of the "right" kind of B cells are eliminated, about 15 percent survive and wind up in circulating blood, but are turned off. One goal in vaccine design may be to figure out how to wake them up so they can go to work."

"We have now unveiled a major reason why members of this class of neutralizing antibodies are not routinely made: Our own immune systems block their production because they are perceived as potentially harmful, when in reality, they are not," said Haynes. "This is a very unusual way the virus has developed to evade the immune system."

Haynes says researchers plan on using the new mouse model to test ways to teach the immune system to enable the production of powerful neutralizing antibodies capable of blocking HIV.


'/>"/>

Contact: Michelle Gailiun
michelle.gailiun@duke.edu
919-660-1306
Duke University Medical Center
Source:Eurekalert

Related medicine news :

1. Thomson Scientific Announces BONDplus for Biological Researchers
2. Neurobiological Technologies Reports Going Concern Qualification
3. Neurobiological Technologies, Inc. Announces Receipt of Determination Letter from NASDAQ
4. Study questions assumptions about human sensitivity to biological motion
5. Neurobiological Technologies Reports $2.1 Million Quarterly Payment for Sales of Memantine
6. Neurobiological Technologies Announces Compliance With Nasdaq Listing Standards
7. Dr. Warren Wasiewski Appointed Chief Medical Officer of Neurobiological Technologies, Inc.
8. Biological markers of prostate cancer shed light on cancer burden faced by African-American men
9. Sanofi Pasteur Enters Agreement With Crucell for Next-Generation Biologicals Against Rabies
10. Biological Link Between BRCA1 and Breast Cancer Detailed
11. Boston IVF is First in Northeast to Offer Pioneering Test of Womens Biological Clock
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... , ... Austin residents seeking Mohs surgery services, can now turn to Dr. ... Russell Peckham for medical and surgical dermatology. , Dr. Dorsey brings specialization to include ... in Mohs Micrographic Surgery completed by Dr. Dorsey was under the direction of Glenn ...
(Date:6/25/2016)... ... June 25, 2016 , ... As a lifelong Southern Californian, Dr. Omkar ... M.D from the David Geffen School of Medicine at UCLA. He trained in Internal ... complete his fellowship in hematology/oncology at the UCLA-Olive View-Cedars Sinai program where he had ...
(Date:6/24/2016)... ... 24, 2016 , ... A recent article published June 14 on ... article goes on to state that individuals are now more comfortable seeking to undergo ... such as calf and cheek reduction. The Los Angeles area medical group, Beverly Hills ...
(Date:6/24/2016)... Texas (PRWEB) , ... June 24, 2016 , ... ... International Conference and Scientific Sessions in Dallas that it will receive two significant ... of the grants came as PHA marked its 25th anniversary by recognizing patients, ...
(Date:6/24/2016)... ... 24, 2016 , ... Topical BioMedics, Inc, makers of Topricin and MyPainAway Pain Relief Products, join ... wage raise to $12 an hour by 2020 and then adjusting it yearly to increase ... of the minimum wage, assure the wage floor does not erode again, and make future ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... , June 26, 2016 ... care operating models within the health care industry is ... financial efficiency , Deloitte offers a suite of ... business issues impacting efficient cost optimization: labor resource analysis, ... These services facilitate better outcomes and better economics ...
(Date:6/24/2016)... , June 24, 2016 ... has announced the addition of the " Global ... This report ... provides an updated review, including its applications in various ... total market, which includes three main industries: pharmaceutical and ...
(Date:6/24/2016)... Research and Markets has announced the addition of the ... to their offering. ... World Market for Companion Diagnostics covers the world market for ... report includes the following: , World IVD ... (N. America, EU, ROW), 2015-2020 , World IVD Companion ...
Breaking Medicine Technology: