The humoral immune response is initiated in lymph nodes by B cells that acquire soluble antigen directly in the follicles

Immunity. 2007 Apr;26(4):491-502. doi: 10.1016/j.immuni.2007.02.011. Epub 2007 Mar 22.


The initial step in a humoral immune response involves the acquisition of antigens by B cells via surface immunoglobulin. Surprisingly, anatomic studies indicate that lymph-borne proteins do not have access to the follicles where naive B cells reside. Thus, it is unclear how B cells acquire antigens that drain to lymph nodes. By tracking a fluorescent antigen and a peptide:MHC II complex derived from it, we show that antigen-specific B cells residing in the follicles acquire antigen within minutes of injection, first in the region closest to the subcapsular sinus where lymph enters the lymph node. Antigen acquisition, presentation, and subsequent T cell-dependent activation did not require B cell migration through the T cell area or exposure to dendritic cells. These results indicate that the humoral response is initiated as soluble antigens diffuse directly from lymph in the subcapsular sinus to be acquired by antigen-specific B cells in the underlying follicles.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Antibodies / immunology
  • Antibody Formation*
  • Antigen Presentation*
  • B-Lymphocytes / immunology*
  • Cell Movement
  • Dendritic Cells / immunology
  • Genes, T-Cell Receptor alpha / genetics
  • Histocompatibility Antigens Class II / immunology
  • Lymph Nodes / cytology
  • Lymph Nodes / immunology*
  • Male
  • Mice
  • Mice, Knockout
  • Peptides / immunology
  • T-Lymphocytes / immunology


  • Antibodies
  • Histocompatibility Antigens Class II
  • Peptides