CD38 expression by neonatal human naive CD4+ T cells shapes their distinct metabolic and tolerogenic properties.
Level 5 - mechanism / opinion, no new human data
Bench and in vitro human cell mechanistic study
PubMed 41746743 · doi:10.1172/JCI200062
What was done
The authors investigated the mechanisms governing peripheral immune tolerance in early life by comparing human cord blood naive CD4+ T cells to adult peripheral blood naive CD4+ T cells in vitro. They examined FOXP3 induction, suppressive function, metabolic profiles (specifically glycolysis), expression of the NADase CD38 across age groups, and downstream signaling involving the NAD-dependent deacetylase SIRT1.
What was found
Cord blood naive CD4+ T cells demonstrated higher FOXP3 induction and tolerogenic capability compared to adult cells. This was accompanied by a metabolic shift toward glycolysis and elevated CD38 expression, which followed an age-dependent downward gradient. Mechanistically, high CD38 expression supported the glycolytic phenotype and tolerogenic differentiation partly through SIRT1 modulation. The abstract reports qualitative comparative directions and mechanistic pathways but provides no specific quantitative metrics or sample sizes.
Why it matters
The findings identify a developmental, age-dependent metabolic state driven by CD38 and SIRT1 that facilitates Treg differentiation in neonates, providing insight into how early-life peripheral immune tolerance is established.
Limits
The abstract reports purely in vitro mechanistic findings without providing sample sizes (n), demographic details of adult or neonatal donors, or quantitative effect sizes and confidence intervals. Clinical applicability and in vivo relevance in human neonates remain to be validated.
Cited by
- context For the first six months of life, the human immune system is relatively poor at being trained on antigens.