Constitutive expression of IL-7 receptor alpha does not support increased expansion or prevent contraction of antigen-specific CD4 or CD8 T cells following Listeria monocytogenes infection.

Abstract

Expression of IL-7Ralpha (CD127) has been suggested as a major determinant in the survival of memory T cell precursors. We investigated whether constitutive expression of IL-7Ralpha on T cells increased expansion and/or decreased contraction of endogenous Ag-specific CD4 and CD8 T cells following infection with Listeria monocytogenes. The results indicate that constitutive expression of IL-7Ralpha alone was not enough to impart an expansion or survival advantage to CD8 T cells responding to infection, and did not increase memory CD8 T cell numbers over those observed in wild-type controls. Constitutive expression of IL-7Ralpha did allow for slightly prolonged expansion of Ag-specific CD4 T cells; however, it did not alter the contraction phase or protect against the waning of memory T cell numbers at later times after infection. Memory CD4 and CD8 T cells generated in IL-7Ralpha transgenic mice expanded similarly to wild-type T cells after secondary infection, and immunized IL-7Ralpha transgenic mice were fully protected against lethal bacterial challenge demonstrating that constitutive expression of IL-7Ralpha does not impair, or markedly improve memory/secondary effector T cell function. These results indicate that expression of IL-7Ralpha alone does not support increased survival of effector Ag-specific CD4 or CD8 T cells into the memory phase following bacterial infection.

• Authors: Jodie S Haring, Xuefang Jing, Julie Bollenbacher-Reilley, Hai-Hui Xue, Warren J Leonard, John T Harty
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 180 Issue 5 Pg. 2855-62 (Mar 01 2008) ISSN: 0022-1767 [Print] United States
• PMID: 18292507 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Epitopes, T-Lymphocyte
• Growth Inhibitors
• Receptors, Interleukin-7
• interleukin-7 receptor, alpha chain

Topics

• Animals
• CD4-Positive T-Lymphocytes (cytology, immunology, metabolism)
• CD8-Positive T-Lymphocytes (cytology, immunology, metabolism)
• Cell Death (genetics, immunology)
• Cell Proliferation
• Cell Survival (genetics, immunology)
• Epitopes, T-Lymphocyte (genetics, immunology)
• Growth Inhibitors (biosynthesis, genetics, physiology)
• Immunologic Memory (genetics)
• Listeria monocytogenes (immunology)
• Listeriosis (genetics, immunology, pathology)
• Lymphocyte Activation (genetics)
• Lymphocyte Count
• Mice
• Mice, Inbred C57BL
• Mice, Transgenic
• Receptors, Interleukin-7 (biosynthesis, genetics, physiology)