B cells still front and centre in immunology

Despite the maturity of the field of B cell biology, or possibly because of it, discoveries continue to be made that provide fundamental insights into cell biology and into the immune system itself. Here, I describe some of my personal highlights of the past year, encompassing B cell behaviour in response to antigen and in germinal centres, as well as the behaviour of plasma cells.

Key advances

• Metabolism is part of an integrated system to ensure that B cells receive all appropriate signals before activation is launched.

• Mitochondria function as a ‘time bomb’ in B cells, being triggered by antigen engagement of the B cell receptor but defused by the receipt of a second signal.

• Quantification of the immune response, in terms of inputs and outputs and with time as a variable, will reveal the ‘rules’ that regulate immunity.

• Cell frequency, antigen affinity and antigen avidity are variables that can be manipulated to target specific immune outcomes.

• Plasma cell heterogeneity extends beyond immunoglobulin isotype and into cytokine secretion.

• Plasma cells may modify their environment by secreting other regulatory molecules.