Maternal microchimeric cells are linked to early life immunity in children

Introduction Upon formation of the hemochorial placenta during mammalian pregnancies, maternal immune cells are transferred from mother to fetus (maternal microchimeric (MMc) cells). Pilot data arising from small observational studies point toward advantageous effects such as replacement of diseased cell subsets like ß-islet cells in diabetes type 1, but also suggest disadvantageous consequences, such as graft-versus-host reactions. We here sought to disentangle the function of MMc cells on early life immunity.

Methods We assessed MMc cells at birth upon screening for deletion-insertion-polymorphisms (DIP) specific for the mother among the neonatal cells in cord blood samples (n=122), MMc-specific sequences were then amplified by DIP-specific duplex digital PCR. We then linked the number of MMc cells to the incidence of early life infections of the neonate, which have been reported by the parents during the first year of life.

Results When evaluating the association between MMc cells at birth and subsequent parent-reported infections during the first year of life, we could identify a significant association in boys, revealing a higher number of infections during early life when MMc cells were low at birth. No such association was present in females. This sex-specific risk for infections in boys was not due to lower MMc cell numbers or higher numbers of infections in boys in general, as the number of infections was similar in boys and girls.

Conclusion Taken together, our data strongly support that MMc cells mitigate offspring’s immunity, which reduces the risk for early life infections, at least in male infants.

Publikationsverlauf

Artikel online veröffentlicht:
07. Oktober 2020