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Differential Role of “Signal 3” Inflammatory Cytokines in Regulating CD8 T Cell Expansion and Differentiation in vivo
Following an infection, naïve CD8 T cells are stimulated by dendritic cells (DC) displaying pathogen-derived peptides on MHC class I molecules (signal 1) and costimulatory molecules (signal 2). Additionally, pathogen-induced inflammatory cytokines also act directly on the responding CD8 T cells to r...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Research Foundation
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3342074/ https://www.ncbi.nlm.nih.gov/pubmed/22566795 http://dx.doi.org/10.3389/fimmu.2011.00004 |
Sumario: | Following an infection, naïve CD8 T cells are stimulated by dendritic cells (DC) displaying pathogen-derived peptides on MHC class I molecules (signal 1) and costimulatory molecules (signal 2). Additionally, pathogen-induced inflammatory cytokines also act directly on the responding CD8 T cells to regulate their expansion and differentiation. In particular, both type I interferons (IFNs) and IL-12 have been described as critical survival signals (signal 3) for optimal CD8 T cell accumulation during the expansion phase. Furthermore, expansion in numbers of antigen-specific CD8 T cells is coupled with their acquisition of effector functions to combat the infection. However, it still remains unclear whether these same cytokines also regulate the effector/memory differentiation program of the CD8 T cell response in vivo. Here, we demonstrate that defective signaling by either type I IFNs or IL-12 to the responding CD8 T cells impairs maximal expansion in response to DC immunization + CpG ODN, but neither of these cytokines is essential to regulate the effector/memory differentiation program. In addition, lack of direct IL-12 signaling to CD8 T cells accelerates the development of central memory phenotype in both primary and secondary antigen-specific memory CD8 T cells. |
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