VOLUME 12, NUMBER 15 • FEBRUARY 16, 2001

Immunologist to Discuss Antibody System Today

Klaus Rajewsky, a professor at the Institute of Genetics, University of Cologne, will present today’s Friday lecture (Feb. 16). His topic will be "Conditional Mutagenesis as a Physiological Process and an Experimental Approach in the Antibody System."

Rajewsky’s goal is to understand how lymphocytes develop and are controlled in vivo, how immunological memory is generated and maintained, and how self-aggression is avoided.

The main emphasis of his work is on B lymphocyte development from the stem cell in the bone marrow of the mouse to the memory cell, generated upon primary contact with antigen. B cell development is guided by immunoglobulin (Ig) gene re-arrangements, through expression of Ig heavy and light chains in receptor complexes on the cell surface.

The lab has identified, by gene targeting and molecular single cell analysis, "checkpoints" that the cells have to pass on the basis of receptor expression. The generation of memory B cells involves somatic hypermutation of antibody V region genes and selection of high-affinity mutants. His lab has shown that this process occurs in germinal centers, and they are now trying to understand the mechanism of hypermutation.

To understand gene function in vivo, his lab plans to further develop the approach of conditional gene targeting that they have initiated. Here the ultimate goal is to introduce mutations in genes in mice at will, in a celltype-specific and inducible manner. The mutations include gene inactivation, activation and replacement. Only in this way will it be possible to understand which role a given gene product plays at a given stage of development in a given cell in vivo. The main emphasis will be on developmental processes and control mechanisms in the immune system, in both health and disease.

Rajewsky has won a number of awards for his work, including the Avery Landsteiner Award; Behring-Kitasato Prize; Robert Pfleger Prize; Humboldt Research Award; Rabbi Shai Shacknai Memorial Prize, Hebrew University; Robert Koch Prize; Max-Planck-Research Award; Dr. Albert-Wander-Memorial Prize, Bern University; UCL Prize Lecture in Clinical Science; Körber Prize for European Science and the Behring-Heidelberger Award, American Association of Immunologists.

His talk begins in Caspary Auditorium at 3:45 p.m. and is preceded by a tea in Abby Aldrich Rockefeller Lounge at 3:15 p.m. All are welcome