Memory B cells from human tonsils colonize mucosal epithelium and directly present antigen to T cells by rapid up-regulation of B7-1 and B7-2

Immunity. 1995 Mar;2(3):239-48. doi: 10.1016/1074-7613(95)90048-9.


Human memory B cells that carry mutated IgV region genes were isolated from tonsils by negative selection of IgD+ naive B cells and CD38+ germinal center B cells and plasma cells. They were mainly found within the intraepithelial areas, but not in the B cell follicles of human tonsils. Memory B cells but not naive B cells have the capacity to present antigen directly to T cells, owing to the constitutive expression of the accessory molecules B7-1/CD80 and B7-2/CD86. Signals through antigen receptors and CD40 antigen result in these two molecules being further up-regulated more rapidly and strongly on memory B cells than on naive B cells. The unique anatomical localization of memory B cells beneath the surface of mucosa, together with their strong APC capacity, may explain the well-known prompt and robust secondary antibody responses.

MeSH terms

  • Antigen-Presenting Cells / immunology*
  • Antigens, CD*
  • Antigens, Surface / immunology
  • B-Lymphocyte Subsets / immunology*
  • B7-1 Antigen / biosynthesis
  • B7-1 Antigen / immunology*
  • B7-2 Antigen
  • CD40 Ligand
  • Cells, Cultured
  • Fluorescent Antibody Technique
  • Humans
  • Immunologic Memory / immunology*
  • Membrane Glycoproteins / biosynthesis
  • Membrane Glycoproteins / immunology*
  • Mucous Membrane / immunology
  • Palatine Tonsil / cytology
  • Up-Regulation / immunology


  • Antigens, CD
  • Antigens, Surface
  • B7-1 Antigen
  • B7-2 Antigen
  • CD86 protein, human
  • Membrane Glycoproteins
  • CD40 Ligand