MicroRNAs and Their Targets Are Differentially Regulated in Adult and Neonatal Mouse CD8+ T Cells |
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Authors: | Erin M. Wissink Norah L. Smith Roman Spektor Brian D. Rudd Andrew Grimson |
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Affiliation: | *Graduate Field of Biochemistry, Molecular, and Cell Biology, Cornell University, Ithaca, New York 14853;†Department of Microbiology and Immunology, Cornell University, Ithaca, New York 14853;‡Graduate Field of Genetics, Genomics, and Development, Cornell University, Ithaca, New York 14853;§Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853 |
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Abstract: | Immunological memory, which protects organisms from re-infection, is a hallmark of the mammalian adaptive immune system and the underlying principle of vaccination. In early life, however, mice and other mammals are deficient at generating memory CD8+ T cells, which protect organisms from intracellular pathogens. The molecular basis that differentiates adult and neonatal CD8+ T cells is unknown. MicroRNAs (miRNAs) are both developmentally regulated and required for normal adult CD8+ T cell functions. We used next-generation sequencing to identify mouse miRNAs that are differentially regulated in adult and neonatal CD8+ T cells, which may contribute to the impaired development of neonatal memory cells. The miRNA profiles of adult and neonatal cells were surprisingly similar during infection; however, we observed large differences prior to infection. In particular, miR-29 and miR-130 have significant differential expression between adult and neonatal cells before infection. Importantly, using RNA-Seq, we detected reciprocal changes in expression of messenger RNA targets for both miR-29 and miR-130. Moreover, targets that we validated include Eomes and Tbx21, key genes that regulate the formation of memory CD8+ T cells. Notably, age-dependent changes in miR-29 and miR-130 are conserved in human CD8+ T cells, further suggesting that these developmental differences are biologically relevant. Together, these results demonstrate that miR-29 and miR-130 are likely important regulators of memory CD8+ T cell formation and suggest that neonatal cells are committed to a short-lived effector cell fate prior to infection. |
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Keywords: | microRNA regulation adaptive immunity development |
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