Human Neonate CD8-T cells are biased towards innate immunity defense mechanisms

ABSTRACT: To understand better the nature of the poor response of human neonates to intracellular pathogens, we evaluated the transcriptome of neonates as compared to adult naïve CD8-T cells. A specific transcription signature of the neonatal cells was found, characterized by a lower expression of signalling and CTL functional genes and a high expression of maturation, cell cycle and innate-immunity associated genes. Functional assays demonstrated that neonatal CD8-T cells undergo homeostatic proliferation, transcribe antimicrobial peptides and produce reactive oxygen species. Master transcription factors were found presumably responsible for this specific signature. Genome wide epigenetic studies showed a corresponding chromatin signature for a number of the differentially expressed genes. Altogether our results show that CD8 neonatal T cells have a particular genetic program with functions within the innate immune response, while still undergoing their maturation process. Neonates are highly susceptible to infections by intracellular pathogens, which are a major cause of infant morbidity and mortality. CD8-T cells control intracellular pathogens through cytotoxic mechanisms in an antigen-dependent manner. We found that human neonatal CD8-T cells, as compared to adult lymphocytes, had a distinctive pattern of gene transcription, characterized by the lower expression of genes involved in TCR signalling and cytotoxicity and a high expression of genes involved in cell cycle and innate immunity. Functional studies corroborated that neonatal CD8-T cells are less cytotoxic, transcribe antimicrobial peptides and produce reactive oxygen species. These properties could explain the high sensitivity of neonates to intracellular pathogen infections and outline novel functions of neonatal CD8-T cells. PBMC total RNAs from Adult and Neonate subjects were profiled after hybridization with Agilent SurePrint G3 Human GE 8x60K Microarray.

ORGANISM(S): Homo sapiens

PROVIDER: GSE61570 | GEO | 2016/07/25

SECONDARY ACCESSION(S): PRJNA261493

REPOSITORIES: GEO