Cutting edge: Primary and secondary effects of CD19 deficiency on cells of the marginal zone

J Immunol. 2009 Jun 15;182(12):7343-7. doi: 10.4049/jimmunol.0804295.

Abstract

Marginal zone (MZ) B cells are absent in CD19(-/-) mice. Possible causes include an intrinsic defect in B cells and/or a secondary defect in the extrinsic MZ microenvironment as a result of changes in B cell differentiation in mice lacking CD19. Cells in the MZ also include MZ macrophages (MZM) and MZ dendritic cells (DC). Although CD19 is only expressed on B cells, SIGN-R1(+) MZM are absent and CD11c(+) MZ DC distribution is abnormal in CD19(-/-) mice. Adoptively transferred B cells from normal mice are able to reconstitute MZ B cells in CD19(-/-) mice. In contrast, CD19(-/-) B cells could not enter the MZ of the normal mice. Furthermore, MZM distribution and MZ DC distribution are restored following MZ B cell reconstitution in CD19(-/-) mice. Thus, MZ B cells are required for MZM differentiation and MZ DC localization, but the deficiency of MZ B cells in CD19(-/-) mice is caused by a defect of intrinsic B cell signaling.

Publication types

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

MeSH terms

  • Animals
  • Antigens, CD19 / genetics
  • Antigens, CD19 / immunology*
  • Antigens, CD19 / metabolism*
  • B-Lymphocytes / cytology
  • B-Lymphocytes / immunology
  • Cell Differentiation / immunology
  • Mice
  • Mice, Knockout
  • Signal Transduction / immunology
  • Spleen / cytology*
  • Spleen / immunology*
  • Spleen / metabolism

Substances

  • Antigens, CD19