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The Timing of Stimulation and IL-2 Signaling Regulate Secondary CD8 T Cell Responses
Journal article   Open access   Peer reviewed

The Timing of Stimulation and IL-2 Signaling Regulate Secondary CD8 T Cell Responses

Shaniya H Khan, Matthew D Martin, Gabriel R Starbeck-Miller, Hai-Hui Xue, John T Harty and Vladimir P Badovinac
PLoS pathogens, Vol.11(10), pp.e1005199-e1005199
10/2015
DOI: 10.1371/journal.ppat.1005199
PMCID: PMC4592272
PMID: 26431533
url
https://doi.org/10.1371/journal.ppat.1005199View
Published (Version of record) Open Access

Abstract

Memory CD8 T cells provide protection to immune hosts by eliminating pathogen-infected cells during re-infection. While parameters influencing the generation of primary (1°) CD8 T cells are well established, the factors controlling the development of secondary (2°) CD8 T cell responses remain largely unknown. Here, we address the mechanisms involved in the generation and development of 2° memory (M) CD8 T cells. We observed that the time at which 1° M CD8 T cells enter into immune response impacts their fate and differentiation into 2° M CD8 T cells. Late-entry of 1° M CD8 T cells into an immune response (relative to the onset of infection) not only facilitated the expression of transcription factors associated with memory formation in 2° effector CD8 T cells, but also influenced the ability of 2° M CD8 T cells to localize within the lymph nodes, produce IL-2, and undergo Ag-driven proliferation. The timing of stimulation of 1° M CD8 T cells also impacted the duration of expression of the high-affinity IL-2 receptor (CD25) on 2° effector CD8 T cells and their sensitivity to IL-2 signaling. Importantly, by blocking or enhancing IL-2 signaling in developing 2° CD8 T cells, we provide direct evidence for the role of IL-2 in controlling the differentiation of Ag-driven 2° CD8 T cell responses. Thus, our data suggest that the process of 1° M to 2° M CD8 T cell differentiation is not fixed and can be manipulated, a notion with relevance for the design of future prime-boost vaccination approaches.
CD8-Positive T-Lymphocytes - cytology Mice, Inbred C57BL Immunoblotting Adoptive Transfer Cell Differentiation - immunology Signal Transduction - immunology Lymphocyte Activation - immunology Animals Flow Cytometry Interleukin-2 - immunology Time Factors Polymerase Chain Reaction Mice CD8-Positive T-Lymphocytes - immunology Immunologic Memory - immunology

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