First, Collect Antigens

Science's STKE  09 May 2006:
Vol. 2006, Issue 334, pp. tw159
DOI: 10.1126/stke.3342006tw159

Antibodies are produced by B cells after antigens stimulate receptors on their surface and other appropriate signals have been received. If antigens are bound to the surface of another cell, activation signals can be particularly strong and allow B cells to discriminate among a wide range of antigen affinities. Fleire et al. (see the Perspective by Harnett) show that B cells can actually focus antigen into aggregates that resemble the well-characterized immune synapses of T cells. After initial contact, B cells spread themselves over the other cell and then contract, gathering up antigens in the process. This response depended on both antigen affinity and ligand occupancy, suggesting how both parameters might be used to optimize an evolving antibody response.

S. J. Fleire, J. P. Goldman, Y. R. Carrasco, M. Weber, D. Bray, F. D. Batista, B cell ligand discrimination through a spreading and contraction response. Science 312, 738-741 (2006). [Abstract] [Full Text]

M. M. Harnett, B cells spread and gather. Science 312, 709-710 (2006). [Summary] [Full Text]