β1 INTEGRIN IS CRITICAL FOR THE MAINTENANCE OF ANTIGEN-SPECIFIC CD4 T CELLS IN THE BONE MARROW BUT NOT LONG-TERM IMMUNOLOGICAL MEMORY1

• Published in: The Journal of immunology (1950) Vol. 186; no. 7; pp. 4019 - 4026
• Main Authors: DeNucci, Christopher C., Shimizu, Yoji
• Format: Journal Article
• Language: English
• Published: 25.02.2011
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.1003566

The long-term maintenance of memory CD4 T cells promotes protective immunity against future pathogen re-infection. As a site rich in survival cytokines, the bone marrow is proposed to be a critical niche for the survival of memory CD4 T cells. We demonstrate that endogenous, polyclonal Ag-specific CD4 T cells rapidly enter and are recovered long-term from the bone marrow following intravenous infection with Listeria monocytogenes . β1 integrin-deficient CD4 T cells also populate the bone marrow early following an infection, but their numbers in this site rapidly decline. This decline was not caused by increased death of T cells lacking β1 integrin but rather by reduced retention in the bone marrow after the primary immune response. The loss of memory CD4 T cells from the bone marrow does not lead to a loss of the predominant source of memory CD4 T cells in the spleen or the ability to mount a memory response. Thus, β1 integrin-dependent maintenance of memory CD4 T cells in the bone marrow is not required for long-term CD4 T cell memory.