Human breastmilk memory T cells throughout lactation manifest an activated and tissue-oriented profile with prominent regulation

ABSTRACT: Breastfeeding provides important immunological benefits to the neonate, but how different immunoactive components in breastmilk contribute to immunity remains poorly understood. Here, we characterized human breastmilk T cells using single cell RNA sequencing and flow cytometry. Breastmilk contained predominantly memory T cells with immune response signaling, proliferation and an effector Th1/cytotoxic profile with high cytokine production capacities. High activation markers were balanced by an enriched Treg population and immune regulatory markers in conventional memory T cells. Gene and surface expression of tissue-residency markers indicated that breastmilk T cells represent tissue-adapted rather than circulatory T cells. In addition, breastmilk T cells had a broad homing profile and higher activation markers in these migratory subsets. The partly overlapping transcriptome profile between breastmilk and breast tissue T cells, particularly cytotoxic T cells, might support a role in local immune defense in the mammary gland. However, unique features of breastmilk, such as regulatory T cells, might imply an additional role in neonatal immune defense. We found some correlations between the breastmilk T-cell profile and clinical parameters, most notably with maternal and household factors. . Together, our data suggest that breastmilk contains an adapted T cell population that exerts their function in specific tissue-sites.

ORGANISM(S): Homo sapiens

PROVIDER: GSE273105 | GEO | 2024/07/26

REPOSITORIES: GEO