title: Age-Related Gene Expression Differences in Monocytes from Human Neonates, Young Adults, and Older Adults.
abstract: A variety of age-related differences in the innate and adaptive immune systems have been proposed to contribute to the increased susceptibility to infection of human neonates and older adults. The emergence of RNA sequencing (RNA-seq) provides an opportunity to obtain an unbiased, comprehensive, and quantitative view of gene expression differences in defined cell types from different age groups. An examination of ex vivo human monocyte responses to lipopolysaccharide stimulation or Listeria monocytogenes infection by RNA-seq revealed extensive similarities between neonates, young adults, and older adults, with an unexpectedly small number of genes exhibiting statistically significant age-dependent differences. By examining the differentially induced genes in the context of transcription factor binding motifs and RNA-seq data sets from mutant mouse strains, a previously described deficiency in interferon response factor-3 activity could be implicated in most of the differences between newborns and young adults. Contrary to these observations, older adults exhibited elevated expression of inflammatory genes at baseline, yet the responses following stimulation correlated more closely with those observed in younger adults. Notably, major differences in the expression of constitutively expressed genes were not observed, suggesting that the age-related differences are driven by environmental influences rather than cell-autonomous differences in monocyte development.
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America.
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Lissner
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Thomas
authors.affiliation: Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Kathleen
authors.initials: K
authors.lastname: Wee
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America.
authors.forename: Ann-Jay
authors.initials: AJ
authors.lastname: Tong
authors.affiliation: Division of Infectious and Immunological Diseases, Department of Pediatrics, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Tobias R
authors.initials: TR
authors.lastname: Kollmann
authors.affiliation: Department of Microbiology, Immunology, and Molecular Genetics, University of California Los Angeles, Los Angeles, California, United States of America.
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Smale
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007231:Infant, Newborn; D008070:Lipopolysaccharides / Q000494:pharmacology; D008089:Listeria monocytogenes / Q000276:immunology; D008088:Listeriosis / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology / Q000276:immunology*
chemical_list: D008070:Lipopolysaccharides