Stereotypic Immune System Development in Newborn Children

TLDR

Early life exposures shape immune‑mediated disease risk, yet most studies rely on mouse models or cord blood and fail to capture the environmental influences on newborns after birth. The study longitudinally profiled 100 newborns over their first three months to investigate immune system development. Using 100 µL of blood, the authors profiled 58 immune cell subsets by mass cytometry and 267 plasma proteins by immunoassays, revealing dramatic, stereotypic developmental changes. The analyses showed that preterm and term infants differ at birth but converge onto a shared, stereotypic trajectory driven by microbial interactions, though early gut bacterial dysbiosis impairs this process.

Abstract

Epidemiological data suggest that early life exposures are key determinants of immune-mediated disease later in life. Young children are also particularly susceptible to infections, warranting more analyses of immune system development early in life. Such analyses mostly have been performed in mouse models or human cord blood samples, but these cannot account for the complex environmental exposures influencing human newborns after birth. Here, we performed longitudinal analyses in 100 newborn children, sampled up to 4 times during their first 3 months of life. From 100 μL of blood, we analyze the development of 58 immune cell populations by mass cytometry and 267 plasma proteins by immunoassays, uncovering drastic changes not predictable from cord blood measurements but following a stereotypic pattern. Preterm and term children differ at birth but converge onto a shared trajectory, seemingly driven by microbial interactions and hampered by early gut bacterial dysbiosis.