Dear All,

On Thursday 25.04 we will host Dr. Isaak Quast from Monash University (Melbourne, Australia). His lecture will be entitled: "Maintaining diversity while maximising affinity: The balancing act of B cell selection”

Abstract:
Antibodies (Abs) are an essential component for our immune system’s defense against invading pathogens and the basis of almost all vaccine success. To generate protective Abs, B cells are selected by CD4 T cells based on their ability to capture and present pathogen derived structures (antigens), a property determined by B cell receptor affinity. T:B cell interactions then result in B cell proliferation, diversification and differentiation into Ab-secreting plasma cells or memory B cells, the two forms of long-lived immunological memory. This process, known as the germinal center (GC) reaction, does not just select high affinity B cells but simultaneously maintains a diverse repertoire of B cell reactivities. The latter is key to ensure Abs to multiple antigens are generated, and to counteract antigenic escape mutation of pathogens like influenza virus or SARS-CoV-2. We have shown that one of the mechanisms by which the immune system achieves this is via IL-21, a T cell derived cytokine that promiscuously promotes B cell proliferation during affinity-based selection. In addition, the primary output of the GC response, antigen-specific Abs, has itself potent regulatory potential. As such, our recent unpublished data reveal how Ab dose-, affinity-, and specificity can direct B cell activation and differentiation. I will discuss these findings, their contribution to our understanding how the balancing act of Ab diversity and affinity is achieved, and their implications for vaccine design and schedule.

The lecture will take place at 3 p.m. in the CN lecture hall and it will be followed by a get together.

Hope to see you all there,

Tomasz Wypych