Prof. Dr. Hans-Martin Jäck

Abteilung für Molekulare Immunologie
Medizinische Klinik III
Nikolaus-Fiebiger-Zentrum
Friedrich-Alexander-Universität Erlangen-Nürnberg
Glückstr. 6
91054 Erlangen                

Tel. +49 (0) 9131 85 35913
hans-martin.jaeck@fau.de

Dr. rer. nat. Wolfgang Schuh

Abteilung für Molekulare Immunologie
Medizinische Klinik III
Nikolaus-Fiebiger-Zentrum
Friedrich-Alexander-Universität Erlangen-Nürnberg
Glückstr. 6
91054 Erlangen

Tel. +49 (0) 9131 85 39339
wolfgang.schuh@uk-erlangen.de

microRNA-controlled generation and maintenance of humoral memory

The generation of immunological memory after successful vaccination is essential for long-lasting protection against future infections. Our long-term goal is to identify the molecular circuits that control antibody-mediated memory with the aim of developing new treatments to either maintain physiologic or remove pathologic memory B cells and antibody-secreting plasma cells. In this funding period, we will elucidate how one class of small interfering non-coding RNAs, the so-called microRNAs (miRNAs), regulates and fine-tunes the differentiation and survival of memory B cells and long-lived plasma cells. In the first section, we will address the importance of miRNAs in generating memory B cells and plasma cells. For this purpose, we have already established a transgenic knock-in mouse line with a floxed DGCR8 allele encoding an essential subunit of the nuclear miRNA processing complex. miRNA synthesis can now be conditionally ablated in vivo at various stages of B cell development by breeding our floxed DGCR8 knock-in mouse to mouse strains that produce B cell-restricted Cre recombinase either before or after the establishment of plasma cells and memory B cells. In the second section, we will identify miRNAs that control the development of plasma cells via the in vitro reconstitution of DGCR8-deficient mature B cells with miRNAs that are upregulated during B cell activation. In the last section, we will elucidate the mechanisms by which miR-148a, a plasma cell signature miRNA, orchestrates the differentiation of B cells into plasma cells through B cell-specific Cre-mediated ablation and determining mRNA target profiles. These studies will provide new molecular insights into the regulatory circuits that control the production of antibodies. Our findings could potentially lead to new avenues for diagnosing or treating diseases associated with aberrant plasma cell development, e.g., primary antibody deficiencies, plasma cell malignancies, and autoimmune disorders.