Characterization of CD127 -  CD25 ++ Treg from human colostrum.

Problem: Breastfeeding's influence on the tolerance to environmental antigens is essential for short- and long-term homeostasis for children. Colostrum is rich in leucocytes, but it is unknown whether regulatory T cells (Treg) account for part of this cell population.
Method of Study: Frequencies of CD127 ^-  CD25 ⁺⁺ Treg and levels of immunoregulatory-associated cell markers were determined in colostrum and were compared with autologous blood cells. In addition, we evaluated whether the birth conditions can affect these features.
Results: Higher frequencies of CD127  ^- CD25 ⁺⁺ Treg cells expressing Foxp3 and CD45RO were observed in the colostrum. The cells' CD25, CD152, CD279, and TGF-β expression levels were greater than those in autologous blood cells. In addition, the CD279 and TGF-β expressions of colostrum CD127 ^-  CD25 ⁺⁺ Treg cells were influenced by gestational age and delivery mode.
Conclusion: The higher proportion of these cells with a function-associated phenotype may reflect certain tolerogenic effects of breastmilk on newborns and infants, contributing to immune system homeostasis.
(© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)