B cells acquire particulate antigen in a macrophage-rich area at the boundary between the follicle and the subcapsular sinus of the lymph node.
Adaptive B cell responses are initiated by B cell receptor-antigen engagement. Despite its importance, the early stages of B cell interaction with antigen in vivo remain elusive. Using fluorescent particulate antigen in combination with multiphoton microscopy and immune staining, we identified the follicle-subcapsular sinus (SCS) boundary of the lymph node as a site for B cell-antigen acquisition. In this macrophage-rich region, antigen accumulated shortly after administration, where specific follicular B cells were retained for long periods of time. These B cells acquired antigen cumulatively and became the main antigen carriers inside the follicle before polarizing to the B cell-T cell border. These observations not only provide evidence of a B cell role as antigen transporters into the follicle, but also highlight the boundary between the follicle and the SCS as a site for initiation of B cell responses.
Lymphocyte Interaction Laboratory, Cancer Research United Kingdom London Research Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London WC2A 3PX, United Kingdom. ycarrasco@cnb.uam.es
Yolanda R
YR
Carrasco
Facundo D
FD
Batista
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D002478:Cells, Cultured; D018985:Epitopes, B-Lymphocyte / Q000276:immunology / Q000378:metabolism*; D007700:Kinetics; D008198:Lymph Nodes / Q000033:anatomy & histology* / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D036641:Microscopy, Fluorescence, Multiphoton; D010316:Particle Size; D021381:Protein Transport / Q000276:immunology
D018985:Epitopes, B-Lymphocyte