TY - JOUR
T1 - Antigen footprint governs activation of the B cell receptor
AU - Ferapontov, Alexey
AU - Omer, Marjan
AU - Baudrexel, Isabelle
AU - Nielsen, Jesper Sejrup
AU - Dupont, Daniel Miotto
AU - Juul-Madsen, Kristian
AU - Steen, Philipp
AU - Eklund, Alexandra S.
AU - Thiel, Steffen
AU - Vorup-Jensen, Thomas
AU - Jungmann, Ralf
AU - Kjems, Jørgen
AU - Degn, Søren Egedal
N1 - Publisher Copyright:
© 2023, The Author(s).
PY - 2023/12
Y1 - 2023/12
N2 - Antigen binding by B cell receptors (BCR) on cognate B cells elicits a response that eventually leads to production of antibodies. However, it is unclear what the distribution of BCRs is on the naïve B cell and how antigen binding triggers the first step in BCR signaling. Using DNA-PAINT super-resolution microscopy, we find that most BCRs are present as monomers, dimers, or loosely associated clusters on resting B cells, with a nearest-neighbor inter-Fab distance of 20–30 nm. We leverage a Holliday junction nanoscaffold to engineer monodisperse model antigens with precision-controlled affinity and valency, and find that the antigen exerts agonistic effects on the BCR as a function of increasing affinity and avidity. Monovalent macromolecular antigens can activate the BCR at high concentrations, whereas micromolecular antigens cannot, demonstrating that antigen binding does not directly drive activation. Based on this, we propose a BCR activation model determined by the antigen footprint.
AB - Antigen binding by B cell receptors (BCR) on cognate B cells elicits a response that eventually leads to production of antibodies. However, it is unclear what the distribution of BCRs is on the naïve B cell and how antigen binding triggers the first step in BCR signaling. Using DNA-PAINT super-resolution microscopy, we find that most BCRs are present as monomers, dimers, or loosely associated clusters on resting B cells, with a nearest-neighbor inter-Fab distance of 20–30 nm. We leverage a Holliday junction nanoscaffold to engineer monodisperse model antigens with precision-controlled affinity and valency, and find that the antigen exerts agonistic effects on the BCR as a function of increasing affinity and avidity. Monovalent macromolecular antigens can activate the BCR at high concentrations, whereas micromolecular antigens cannot, demonstrating that antigen binding does not directly drive activation. Based on this, we propose a BCR activation model determined by the antigen footprint.
UR - http://www.scopus.com/inward/record.url?scp=85148719985&partnerID=8YFLogxK
U2 - 10.1038/s41467-023-36672-0
DO - 10.1038/s41467-023-36672-0
M3 - Journal article
C2 - 36813795
AN - SCOPUS:85148719985
SN - 2041-1723
VL - 14
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 976
ER -