Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Newly Identified B-Cell Selection Process Adds to Our Understanding of Antibody Diversity

11.06.2014

Using high-throughput sequencing, investigators make a surprising discovery about the immune system.

As elite soldiers of the body’s immune response, B cells serve as a vast standing army ready to recognize and destroy invading antigens, including infections and cancer cells. To do so, each new B cell comes equipped with its own highly specialized weapon, a unique antibody protein that selectively binds to specific parts of the antigen. The key to this specialization is the antigen-binding region that tailors each B cell to a particular antigen, determining whether B cells survive boot camp and are selected for maturation and survival, or wash out and die.

Now, using high-throughput sequencing technology and computational and systems biology, investigators from Beth Israel Deaconess Medical Center (BIDMC) have discovered that B cells can be selected for survival independent of their antigen binding regions. Described online this week in the journal Proceedings of the National Academy of Sciences (PNAS), the findings add a surprising new dimension to the understanding of antibody repertoires – each individual’s complement of millions of B cells -- and the potential for shaping these repertoires to better fight disease.

“B cells play essential roles in vaccination, infection, autoimmunity, aging and cancer,” explains senior author Ramy Arnaout, MD, DPhil, an investigator in the Department of Pathology at BIDMC and Assistant Professor of Pathology at Harvard Medical School whose work focuses on the emerging field of high-throughput multimodality immunology, also known as immunomics. “We were surprised and excited to find that B cell survival could be influenced by a non-antigen-binding region of the antibody, specifically the ‘elbow’ region that connects the antigen-binding regions to the signaling domain.”

... more about:
»Antibody »B-cell »BIDMC »CDR3 »elbow »genes

Each new B cell makes its own unique antibody by mixing and matching from a set of a few hundred genes, taking one each from subsets called V, D and J. The most diverse part of an antibody is the region where the three genes come together, a stretch called the third complementarity-determining region, or CDR3.

“CDR3 is thought to be the single most important determinant of antigen binding,” explains Arnaout. As a result, in understanding how the body fights infections and in developing new vaccines, immunologists have primarily focused their attention on CDR3, while considering other parts of the antibody, including the elbow region, to play secondary roles.

In their new study, Arnaout and colleagues sequenced 2.8 million VDJ-recombined heavy-chain genes from immature and mature B-cell subsets in mice. “We initially wanted to ask how selection on CDR3 changed antibody repertoires during B-cell maturation,” says Arnaout. But, unexpectedly, during the course of the investigation, they found they were instead focused on the antibody’s ‘elbow’ region.”

They found that B cells for which antibodies use V genes that encode ‘looser’ elbows were more likely to mature, regardless of their CDR3 sequence. This effect was both distinct from, and larger than previously described maturation-associated changes in CDR3 in the mice. Furthermore, it had a unique source: Differences in the V genes were hard-coded into the genome, as opposed to the mixed-and-matched combination of V, D and J genes that typically differs from B cell to B cell.

“This discovery was a little like going to watch a concert pianist perform and being mesmerized by her fingers only to realize that music was also coming from her elbows,” says Arnaout. “It was something of a shock.”

One explanation for how this “loose elbow” promotes survival relates to the bending process of the antibody. “B-cell selection and maturation depend on signaling,” he explains. “Antigen binding is the signal, but for it to get to the cell it has to go through the elbow. It, therefore, makes sense that previous experiments have found that disrupting the elbow abolishes signaling without affecting antigen binding. We think a loose elbow might affect how the cell perceives binding, which then determines whether the B-cell soldiers are able to divide and form an elite antigen-fighting platoon, or turn in their weapons and retreat.”

Ultimately, the authors write, “This discovery adds a surprising new dimension to the understanding of antibody repertoires and might one day help us shape them ourselves.”

Coauthors include BIDMC investigators Joseph Kaplinsky (first author) and Anthony Li and New York University Medical Center investigators Amy Sun, Maryaline Coffre and Sergei B. Koralov (co-senior author.) Coffre and Koralov were supported by a grant from the Beckman Foundation.

Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School, and currently ranks third in National Institutes of Health funding among independent hospitals nationwide.

The BIDMC health care team includes Beth Israel Deaconess Hospital-Milton, Beth Israel Deaconess Hospital-Needham, Beth Israel Deaconess Hospital-Plymouth, Anna Jaques Hospital, Cambridge Health Alliance, Lawrence General Hospital, Signature Health Care, Commonwealth Hematology-Oncology, Beth Israel Deaconess HealthCare, Community Care Alliance, and Atrius Health. BIDMC is also clinically affiliated with the Joslin Diabetes Center and Hebrew Senior Life and is a research partner of Dana-Farber/Harvard Cancer Center. BIDMC is the official hospital of the Boston Red Sox. For more information, visit www.bidmc.org.

Bonnie Prescott | newswise

Further reports about: Antibody B-cell BIDMC CDR3 elbow genes

More articles from Life Sciences:

nachricht New Model of T Cell Activation
27.05.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Fungi – a promising source of chemical diversity
27.05.2016 | Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie - Hans-Knöll-Institut (HKI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Worldwide Success of Tyrolean Wastewater Treatment Technology

A biological and energy-efficient process, developed and patented by the University of Innsbruck, converts nitrogen compounds in wastewater treatment facilities into harmless atmospheric nitrogen gas. This innovative technology is now being refined and marketed jointly with the United States’ DC Water and Sewer Authority (DC Water). The largest DEMON®-system in a wastewater treatment plant is currently being built in Washington, DC.

The DEMON®-system was developed and patented by the University of Innsbruck 11 years ago. Today this successful technology has been implemented in about 70...

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Atomic precision: technologies for the next-but-one generation of microchips

In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.

In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...

Im Focus: Researchers demonstrate size quantization of Dirac fermions in graphene

Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices

Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.

Im Focus: Graphene: A quantum of current

When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene

In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

International expert meeting “Health Business Connect” in France

19.05.2016 | Event News

 
Latest News

11 million Euros for research into magnetic field sensors for medical diagnostics

27.05.2016 | Awards Funding

Fungi – a promising source of chemical diversity

27.05.2016 | Life Sciences

New Model of T Cell Activation

27.05.2016 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>