title: Fetal and adult progenitors give rise to unique populations of CD8+ T cells.
abstract: During the ontogeny of the mammalian immune system, distinct lineages of cells arise from fetal and adult hematopoietic stem cells (HSCs) during specific stages of development. However, in some cases, the same immune cell type is produced by both HSC populations, resulting in the generation of phenotypically similar cells with distinct origins and divergent functional properties. In this report, we demonstrate that neonatal CD8+T cells preferentially become short-lived effectors and adult CD8+T cells selectively form long-lived memory cells after infection because they are derived from distinct progenitor cells. Notably, we find that naïve neonatal CD8+T cells originate from a progenitor cell that is distinguished by expression of Lin28b. Remarkably, ectopic expression of Lin28b enables adult progenitors to give rise to CD8+T cells that are phenotypically and functionally analogous to those found in neonates. These findings suggest that neonatal and adult CD8+T cells belong to separate lineages of CD8+T cells, and potentially explain why it is challenging to elicit memory CD8+T cells in early life.
authors.affiliation: Department of Microbiology and Immunology and.
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Wissink
authors.affiliation: Department of Microbiology and Immunology and.
authors.forename: Neva B
authors.initials: NB
authors.lastname: Watson
authors.affiliation: Department of Microbiology and Immunology and.
authors.forename: Norah L
authors.initials: NL
authors.lastname: Smith
authors.affiliation: Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY.
authors.forename: Andrew
authors.initials: A
authors.lastname: Grimson
authors.affiliation: Department of Microbiology and Immunology and.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Rudd
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology* / Q000378:metabolism; D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology*; D004268:DNA-Binding Proteins / Q000378:metabolism; D053686:Fetal Stem Cells / Q000166:cytology* / Q000378:metabolism; D005333:Fetus / Q000166:cytology*; D020869:Gene Expression Profiling; D007156:Immunologic Memory; D008810:Mice, Inbred C57BL; D010641:Phenotype; D016601:RNA-Binding Proteins; D013950:Thymus Gland / Q000166:cytology
chemical_list: D015415:Biomarkers; D004268:DNA-Binding Proteins; C570876:Lin28b protein, mouse; D016601:RNA-Binding Proteins