Characterization of <scp>CD</scp>127⁻ <scp>CD</scp>25⁺⁺ Treg from human colostrum

Abstract

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 CD 127 − CD 25 ++ 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 CD 127 − CD 25 ++ Treg cells expressing Foxp3 and CD 45 RO were observed in the colostrum. The cells’ CD 25, CD 152, CD 279, and TGF ‐β expression levels were greater than those in autologous blood cells. In addition, the CD 279 and TGF ‐β expressions of colostrum CD 127 − CD 25 ++ 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.