The skin, a novel niche for recirculating B cells

J Immunol. 2012 Jun 15;188(12):6027-35. doi: 10.4049/jimmunol.1102639. Epub 2012 May 4.

Abstract

B cells infiltrate the skin in many chronic inflammatory diseases caused by autoimmunity or infection. Despite potential contribution to disease, skin-associated B cells remain poorly characterized. Using an ovine model of granulomatous skin inflammation, we demonstrate that B cells increase in the skin and skin-draining afferent lymph during inflammation. Surprisingly, skin B cells are a heterogeneous population that is distinct from lymph node B cells, with more large lymphocytes as well as B-1-like B cells that coexpress high levels of IgM and CD11b. Skin B cells have increased MHC class II, CD1, and CD80/86 expression compared with lymph node B cells, suggesting that they are well-suited for T cell activation at the site of inflammation. Furthermore, we show that skin accumulation of B cells and Ab-secreting cells during inflammation increases local Ab titers, which could augment host defense and autoimmunity. Although skin B cells express typical skin-homing receptors, such as E-selectin ligand and α-4 and β-1 integrins, they are unresponsive to ligands for chemokine receptors associated with T cell homing into skin. Instead, skin B cells migrate toward the cutaneously expressed CCR6 ligand CCL20. Our data support a model in which B cells use CCR6-CCL20 to recirculate through the skin, fulfilling a novel role in skin immunity and inflammation.

Publication types

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

MeSH terms

  • Animals
  • B-Lymphocyte Subsets / immunology*
  • B-Lymphocyte Subsets / metabolism
  • B-Lymphocytes / immunology*
  • B-Lymphocytes / metabolism
  • Chemotaxis, Leukocyte / immunology*
  • Disease Models, Animal
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Flow Cytometry
  • Inflammation / immunology
  • Receptors, Chemokine / immunology
  • Sheep
  • Skin / cytology*
  • Skin / immunology*

Substances

  • Receptors, Chemokine