Talin1 is required for integrin-dependent B lymphocyte homing to lymph nodes and the bone marrow but not for follicular B-cell maturation in the spleen

Blood. 2010 Dec 23;116(26):5907-18. doi: 10.1182/blood-2010-06-293506. Epub 2010 Oct 5.

Abstract

Talin1 is a key integrin coactivator. We investigated the roles of this cytoskeletal adaptor and its target integrins in B-cell lymphogenesis, differentiation, migration, and function. Using CD19 Cre-mediated depletion of talin1 selectively in B cells, we found that talin1 was not required for B-cell generation in the bone marrow or for the entry of immature B cells to the white pulp of the spleen. Loss of talin1 also did not affect B-cell maturation into follicular B cells but compromised differentiation of marginal zone B cells. Nevertheless, serum IgM and IgG levels remained normal. Ex vivo analysis of talin1-deficient spleen B cells indicated a necessary role for talin1 in LFA-1 and VLA-4 activation stimulated by canonical agonists, but not in B-cell chemotaxis. Consequently, talin1 null B splenocytes could not enter lymph nodes nor return to the bone marrow. Talin1 deficiency in B cells was also impaired in the humoral response to a T cell-dependent antigen. Collectively, these results indicate that talin1 is not required for follicular B-cell maturation in the spleen or homeostatic humoral immunity but is critical for integrin-dependent B lymphocyte emigration to lymph nodes and optimal immunity against T-dependent antigens.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / cytology*
  • B-Lymphocytes / immunology*
  • Bone Marrow / growth & development*
  • Bone Marrow / immunology
  • Cell Adhesion
  • Cell Differentiation
  • Cell Proliferation
  • Cells, Cultured
  • Chemotaxis, Leukocyte
  • Female
  • Flow Cytometry
  • Immunization
  • Integrin alpha4beta1 / metabolism
  • Integrins / metabolism*
  • Lymph Nodes / cytology*
  • Lymph Nodes / immunology
  • Lymphocyte Function-Associated Antigen-1 / metabolism
  • Male
  • Mice
  • Mice, Knockout
  • Spleen / cytology*
  • Spleen / immunology
  • Talin / physiology*

Substances

  • Integrin alpha4beta1
  • Integrins
  • Lymphocyte Function-Associated Antigen-1
  • Talin
  • Tln1 protein, mouse