Portal de Periódicos da CAPES

B Cells Use Mechanical Energy to Discriminate Antigen Affinities

2013; American Association for the Advancement of Science; Volume: 340; Issue: 6140 Linguagem: Inglês

10.1126/science.1237572

1095-9203

Elizabeth Natkanski, Wing-Yiu Jason Lee, Bhakti Mistry, Antonio Casal, Justin E. Molloy, Pavel Tolar,

Monoclonal and Polyclonal Antibodies Research

The generation of high-affinity antibodies depends on the ability of B cells to extract antigens from the surfaces of antigen-presenting cells. B cells that express high-affinity B cell receptors (BCRs) acquire more antigen and obtain better T cell help. However, the mechanisms by which B cells extract antigen remain unclear. Using fluid and flexible membrane substrates to mimic antigen-presenting cells, we showed that B cells acquire antigen by dynamic myosin IIa-mediated contractions that pull out and invaginate the presenting membranes. The forces generated by myosin IIa contractions ruptured most individual BCR-antigen bonds and promoted internalization of only high-affinity, multivalent BCR microclusters. Thus, B cell contractility contributes to affinity discrimination by mechanically testing the strength of antigen binding.