Abstract

Dr Nitschke is a professor of Genetics from Erlangen University, currently on Sabbatical in Cambridge. His lab in Erlangen is interested in B cell immunology. They are working on the process of B cell maturation and are trying to understand how B cell activation and the induction of the humoral immune response is regulated.

In the last years they have been concentrating on a family of inhibitory receptors on B cells, the Siglec family. These inhibitory receptors regulate B cell receptor signalling by recruitment of tyrosine phosphatases to their intracellular inhibitory ITIM motifs. They also bind with their extracellular domains to sialic acids on cell surface proteins, which further modulates B cell signalling.

B lymphocytes express CD22 and Siglec-G. Mouse models showed that CD22 is a general inhibitory receptor on most B lymphocytes, while Siglec-G regulates a subpopulation of B cells, so-called B1 cells, which have specific functions in the immune system.