T-lymphocyte interaction with stromal, bone and hematopoietic cells in the bone marrow

Immunol Cell Biol. 2009 Jan;87(1):20-9. doi: 10.1038/icb.2008.84. Epub 2008 Nov 25.

Abstract

Mature T cells in the bone marrow (BM) are in constant exchange with the blood pool. Within the BM, T-cell recognition of antigen presented by dendritic cell (DC) can occur, nevertheless it is thought that BM T cells mostly receive non-antigenic signals by either stimulatory, for example, interleukin (IL)-7, IL-15, tumor necrosis factor family members, or inhibitory molecules, for example, transforming growth factor-beta. The net balance is in favor of T-cell proliferation. Indeed, the percentage of proliferating T cells is higher in the BM than in spleen and lymph nodes, both within CD4 and CD8 T cells. High numbers of memory T cells proliferate in the BM, as they preferentially home to the BM and have an increased turnover as compared with naive T cells. I propose here that the BM plays an essential role in maintaining normal peripheral T-lymphocyte numbers and antigen-specific memory for both CD4 and CD8 T cells. I also discuss BM T-cell contribution to the homeostasis of bone metabolism as well as of hematopoiesis. It emerges that BM T cells play unexpected roles in several diseases, for example AIDS and osteoporosis. A better knowledge on BM T cells has implications for currently used clinical interventions, for example, vaccination, BM transplantation, mesenchymal stem cell-based therapies.

Publication types

  • Review

MeSH terms

  • Animals
  • Bone Marrow / immunology*
  • Bone and Bones / immunology*
  • Bone and Bones / metabolism
  • Cell Communication / immunology*
  • Cell Movement / immunology
  • Cytokines / immunology
  • Hematopoiesis / immunology
  • Hematopoietic Stem Cell Transplantation
  • Hematopoietic Stem Cells / immunology*
  • Humans
  • Stromal Cells / immunology
  • T-Lymphocyte Subsets / immunology*

Substances

  • Cytokines