B cells spread to affinity

B cells extend like fishnets to capture and then draw in antigens, according to new research by Sebastian Fleire, Facundo Batista (Cancer Research UK London Research Institute, London, UK), and colleagues. The mechanism allows B cells to discern the affinities of the different membrane-bound antigens they encounter.

The interaction of B cell receptors with antigens gives birth to the immunological synapse, spurring B cell activation and antigen presentation to T cells if the antigen is sufficiently well suited to the B cell receptor. Batista's group examined the cellular changes that accompany the first moments of synapse formation.

The authors exposed naive B cells to lysozyme antigens with varying affinities for a B cell receptor and watched as the cells first spread, and then contracted inward, drawing in their captured antigens. The...