Human bone marrow hosts polyfunctional memory CD4+ and CD8+ T cells with close contact to IL-15-producing cells

J Immunol. 2011 Jun 15;186(12):6965-71. doi: 10.4049/jimmunol.1100243. Epub 2011 May 11.

Abstract

Recently, a key role in memory T cell homing and survival has been attributed to the bone marrow (BM) in mice. In the human BM, the repertoire, function, and survival niches of CD4(+) and CD8(+) T cells have not yet been elucidated. In this study, we demonstrate that CD4(+) and CD8(+) effector memory T cells accumulate in the human BM and are in a heightened activation state as revealed by CD69 expression. BM-resident memory T cells produce more IFN-γ and are frequently polyfunctional. Immunofluorescence analysis revealed that CD4(+) and CD8(+) T cells are in the immediate vicinity of IL-15-producing BM cells, suggesting a close interaction between these two cell types and a regulatory role of IL-15 on T cells. Accordingly, IL-15 induced an identical pattern of CD69 expression in peripheral blood CD4(+) and CD8(+) T cell subsets. Moreover, the IL-15-inducible molecules Bcl-x(L), MIP-1α, MIP-1β, and CCR5 were upregulated in the human BM. In summary, our results indicate that the human BM microenvironment, in particular IL-15-producing cells, is important for the maintenance of a polyfunctional memory CD4(+) and CD8(+) T cell pool.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens, CD / analysis
  • Antigens, Differentiation, T-Lymphocyte / analysis
  • Bone Marrow / immunology*
  • Bone Marrow Cells / immunology
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Cell Communication / immunology
  • Humans
  • Immunologic Memory / immunology*
  • Interleukin-15 / immunology*
  • Lectins, C-Type / analysis
  • T-Lymphocyte Subsets / immunology
  • T-Lymphocytes / immunology*

Substances

  • Antigens, CD
  • Antigens, Differentiation, T-Lymphocyte
  • CD69 antigen
  • Interleukin-15
  • Lectins, C-Type