High-dimensional CyTOF profiling reveals distinct maternal and fetal immune landscapes in gestational diabetes mellitus

AimsGestational diabetes mellitus (GDM) is the most common pregnancy-related medical complication. GDM is linked to aberrant immune responses in both mothers and offsprings, specifically, the subsequent development of inflammatory diseases. Whereas prior research has focused on specific immune cell subsets, a comprehensive overview of the impacts of GDM on maternal and fetal immune landscape is lacking. Here, we aim to comprehensively decipher how GDM modulates various immune cell populations in mothers and offsprings. MethodsA prospective, longitudinal case-control study was carried out. Maternal blood from GDM-affected (GDM, n=18) and non-GDM-affected (Ctrl, n=21) mothers were collected at ante-(36-38 weeks of gestation) and post-partum (6-8 weeks post-partum) timepoints. Cord blood from GDM (n=7) and Ctrl (n=11) pregnancies were collected upon C-section. They were analyzed with the state-of-the-art cytometry by time of flight (CyTOF) with a 40-marker panel. Additionally, a publicly available RNA-seq dataset for cord blood mononuclear cells was re-analyzed to confirm results from CyTOF experiments. ResultsCompared to Ctrl, GDM was associated with more activated maternal T cell subsets ante-partum, including increased CD45RO+ and Ki67+ CD4+ T cell populations, which reverted post-partum. GDM-affected maternal innate lymphoid cell (ILC) also exhibited increased granzyme B production ante-partum. On the other hand, in GDM-impacted cord blood, fetal T and B cells were more activated, displaying less naive and more effector phenotypes, further supported by RNA-seq analyses. ConclusionsOur comprehensive analyses revealed that GDM is linked to profound changes in the immune landscapes of the mothers (ante-/post-partum) and foetuses (at birth), casting novel insights towards GDM pathophysiology. Longitudinal immune profiling might be warranted for early detection and stratification of risk, and development of targeted interventions to prevent inflammatory disorders in GDM mothers and their offspring. Research in contextO_LIWhat is already known about this subject? O_LIThe maternal and intrauterine environments are important contributors to long-term health outcomes of mothers and offsprings. C_LIO_LISome maternal and fetal immunity changes have been observed in gestational diabetes mellitus (GDM)-affected pregnancies. C_LIO_LIGDM is associated with increased risk of later-life metabolic and inflammatory diseases in mothers as well as offsprings. C_LI C_LIO_LIWhat is the key question? O_LIWhat are the longitudinal alterations in maternal and fetal immune landscapes in GDM-affected pregnancies? C_LI C_LIO_LIWhat are the new findings? O_LIHigh-dimensional immune profiling provided the most comprehensive overview of alterations in maternal and fetal immune landscapes associated with GDM. C_LIO_LIGDM is associated with skewing of maternal CD4+ T cell and ILC towards activated phenotypes ante-partum. C_LIO_LIGDM is linked to more activated fetal T and B cell profiles. C_LI C_LIO_LIHow might this impact on clinical practice in the foreseeable future? O_LIUnderstanding the complex alterations in the maternal and fetal immune landscape in GDM-affected pregnancy provides insights into the long-term impacts of GDM on the mother and offspring. C_LI C_LI