The seventh meeting in the “Emergence and Convergence” series jointly
organized by La Fondation IPSEN and Nature brings together
today in San Antonio (Texas, USA) leading experts to discuss concepts
emerging from gene regulation studies in immune cells that have led to
insights into the initiation and maintenance of epigenetic chromatin
marks necessary for proper differentiation and function of these cells
in the immune system. The meeting was arranged by Laurie Dempsey
(Nature Immunology, USA), Arianne Heinrichs (Nature Reviews
Molecular Cell Biology, UK), Yves Christen (La Fondation IPSEN,
France) and Jacqueline Mervaillie (La Fondation IPSEN, France).
Every individual possesses a unique genetic blueprint that is found in
every cell of the body. Despite this common set of genetic instructions,
developmental- and tissue-specific gene expression occurs, which allows
specialization in cellular function. Such specialization in gene
expression is regulated by epigenetic chromatin modifications and
remodeling events that influence the accessibility of genes to the
transcriptional machinery and other regulators that activate or silence
gene activity. Studies of hematopoietic cells, for example, have been
especially insightful in elucidating how a common ‘undifferentiated’
cell undergoes specific epigenetic chromatin changes as the cell
differentiates and acquires unique functional capacities.
The meeting starts with the identification of specific epigenetic
histone modifications found in chromatin and the enzymatic machinery
that introduces or maintains such marks and how exposure to microbes
activates temporal changes necessary to combat the invaders and then
return to a quiescent state necessary to avoid collateral tissue damage.
Another session focuses on lymphocytes, which undergo a precise program
of developmentally regulated genetic rearrangements in their antigen
receptor loci. This regulated process generates a diverse population of
cells capable of responding to a vast array of potential microbial
threats. Epigenetic modifications contribute to locus accessibility and
influence how lymphocytes specifically target the DNA recombination
machinery to the antigen receptor genes, they specifically rearrange and
express only one functional allele. This process dictates allelic
exclusion and ensures only one unique antigenic specificity is displayed
per cell.
Speakers at the meeting are leading international experts: Yehudit
Bergman (The Hebrew University, Israel), Anne Corcoran (The
Babraham Institute, UK), Katia Georgopoulos (Harvard Medical
School, USA), Michael Krangel (Duke University, USA),
Matthias Merkenschlager (MRC Clinical Sciences Centre, UK),
Cornelis Murre (University of California, San Diego, USA),
Stephen Smale (University of California, Los Angeles, USA),
Alexander Tarakhovsky (The Rockefeller University, USA), Keji
Zhao (National Heart, Lung and Blood Institute, NIH, USA).
“Emergence and Convergence” series
La Fondation IPSEN and Nature Publishing Group share the same
desire to help new scientific knowledge emerge and facilitate the
exchange of the most promising ideas from a variety of different
research areas. In 2007, the two organizations came together to create a
new series of scientific events – the Emergence & Convergence
mini-symposia - one-day meetings highlighting some of the most dynamic
sectors in biological and medical research. Each meeting brings together
a group of speakers to address a topic of strong current interest and
one which has elements both of new advances in the field – 'emergence' –
and a developing consensus on the importance and integration of the new
advances with existing understanding – 'convergence'. Where applicable,
meetings are cross-disciplinary in nature to facilitate and promote
collaboration. The first six mini-symposia in the series discussed: Small
RNAs in Development, Immunology and Cancer (New York, October 2007), Genome
Evolution and Structural Variation: Next Steps in Natural Human Genetic
Variation (Seattle, November 2007), Epigenetics and Behavior
(Houston, March 2008), Multiple Sclerosis: From Pathogenesis to
Therapy (Paris, June 2008), Cell Shape and Polarity: Lymphocytes
and Beyond (Chicago, September 2008), and Mitochondrial
Dysfunction in Neurological Disease (Durham, December 2008).