Human milk is a remarkable interface between maternal and infant immunity, providing antibodies and immune cells that can directly influence the developing mucosal immune system of the newborn. Yet, despite its central role in early life, the cellular and molecular mechanisms through which maternal immunity is transferred through milk and shapes infant immune development remain poorly understood.
Our research focuses on human milk as a unique window into maternal mucosal immunity. We characterize the B cells and antibody repertoires present in human milk and investigate how maternal immune responses are reflected in this compartment. Using deep sequencing, single cell approaches, and proteomic analyses, we examine antibody diversity, germline gene usage, somatic hypermutation, and clonal relationships between blood and milk B cells. These studies allow us to define how systemic and mucosal immunity are connected and how maternal immune responses are selectively represented in human milk.
We further investigate how milk antibodies interact with the infant's developing mucosal environment. In particular, we study the coating of infant oral bacteria by different antibody isotypes and how this antibody–microbe interface changes with age and breastfeeding. By integrating antibody profiling with microbial and molecular analyses, we aim to understand how maternal antibodies influence microbial colonization and immune education during the critical first months of life. This work may reveal mechanisms through which breastfeeding actively shapes, rather than simply protects, the developing infant immune system.
A complementary component of our research examines maternal immunity during pregnancy and the transfer of antibodies across the placenta. Many vaccine preventable infections, including influenza, pertussis, and tetanus, pose serious risks to pregnant women and young infants. Although maternal vaccination can protect infants through placental antibody transfer, the mechanisms governing the maternal antibody response and selective transport to the fetus remain incompletely understood. By comparing antibody repertoires in pregnant and non pregnant vaccine recipients and analyzing maternal and cord blood, we investigate how pregnancy shapes humoral immunity and how the placenta selects antibodies for transfer.
Together, these studies establish a continuum of maternal–infant immunity spanning pregnancy, human milk, and the developing infant mucosa. Rather than viewing maternal antibodies solely as passive protection, we seek to understand them as active determinants of early immune development and the infant's microbial and mucosal environment. These insights could inform improved maternal vaccination strategies and reveal new ways to harness maternal antibodies and antibody–microbe interactions to promote healthy immune development early in life.
