Endocytosis and recycling of immune complexes by follicular dendritic cells enhances B cell antigen binding and activation

Immunity. 2013 Jun 27;38(6):1164-75. doi: 10.1016/j.immuni.2013.02.023. Epub 2013 Jun 13.


Stromal-derived follicular dendritic cells (FDCs) are a major reservoir for antigen that are essential for formation of germinal centers, the site where memory and effector B cells differentiate. A long-standing question is how FDCs retain antigen in its native form for extended periods and how they display it to specific B cells. Here we found that FDCs acquired complement-coated immune complexes (ICs) from noncognate B cells via complement receptors 1 and 2 (CD35 and CD21, respectively) and rapidly internalized them by an actin-dependent pathway. ICs were retained intact within a nondegradative cycling compartment and were displayed periodically on the cell surface where they were accessible to antigen-specific B cells. This would explain how antigens are protected from damage and retained over long periods of time, while remaining accessible for B cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Animals
  • Antigen Presentation
  • Antigen-Antibody Complex / immunology
  • Antigen-Antibody Complex / metabolism*
  • Antigens / immunology
  • Antigens / metabolism*
  • B-Lymphocytes / immunology*
  • Cells, Cultured
  • Dendritic Cells, Follicular / immunology*
  • Endocytosis / immunology
  • Lymphocyte Activation
  • Mice
  • Mice, Inbred C57BL
  • Protein Binding
  • Receptors, Complement 3b / metabolism
  • Receptors, Complement 3d / metabolism


  • Actins
  • Antigen-Antibody Complex
  • Antigens
  • Receptors, Complement 3b
  • Receptors, Complement 3d