RESUMO
Pregnant women and their fetuses are often excluded from clinical trials due to missing drug-related pre-clinical trial information at the human feto-maternal interface (FMi). The two interfaces-placenta/decidua and fetal membranes/decidua are gatekeepers of drug transport; however, testing their functions is impractical during pregnancy. Limitations of current in-vivo/in-vitro models have hampered drug development and testing during pregnancy. Hence, major complications like preterm births and maternal and neonatal mortalities remain high. Advancements in organ-on-chip (OOC) platforms to test drug kinetics and efficacy and novel extracellular vesicle-based fetal drug delivery are expected to accelerate preclinical trials related to pregnancy complications. Here we report the development and testing of a humanized multi-organ fetal membrane/placenta (fetal)-decidua (maternal) interface OOC (FMi-PLA-OOC) that contains seven cell types interconnected through microchannels to maintain intercellular interactions as seen in-utero. Cytotoxicity, propagation, mechanism of action, and efficacy of engineered extracellular vesicles containing anti-inflammatory interleukin (IL)-10 (eIL-10) were evaluated to reduce FMi inflammation associated with preterm birth. A healthy and disease model (lipopolysaccharide-infectious inflammation) of the FMi-PLA-OOC was created and co-treated with eIL-10. eIL-10 propagated from the maternal to fetal side within 72-hours, localized in all cell types, showed no cytotoxicity, activated IL-10 signaling pathways, and reduced lipopolysaccharide-induced inflammation (minimized NF-kB activation and proinflammatory cytokine production). These data recapitulated eIL-10s' ability to reduce inflammation and delay infection-associated preterm birth in mouse models, suggesting FMi-PLA-OOC as an alternative approach to using animal models. Additionally, we report the utility of eIL-10 that can traverse through FMis to reduce inflammation-associated pregnancy complications.
RESUMO
Immune cells at the feto-maternal interface play an important role in pregnancy; starting at implantation, maintenance of pregnancy, and parturition. The role of decidual immune cells in induction of labor still needs to be understood. Published reports on this topic show heterogeneity in methods of cell isolation, assay, analysis and cellular characterization making it difficult to collate available information in order to understand the contribution of immune cells at term leading to parturition. In the present study, available literature was reviewed to study the differences in immune cells between the decidua basalis and decidua parietalis, as well as between immune cells in term and preterm labor. Additionally, immune cells at the decidua parietalis were isolated from term not in labor (TNL) or term in labor (TL) samples and characterized via flow cytometry using a comprehensive, high-dimensional antibody panel. This allowed a full view of immune cell differences without combining multiple studies, which must include variation in isolation and analysis methods, for more conclusive data. The ratio of cells found in decidua parietalis in this study generally matched those reported in the literature, although we report a lower percentage of natural killer (NK) cells at term. We report that CD4 expression on CD8- NK cells decreased in term labor compared to not in labor samples, suggesting that natural killer cells may be migrating to other sites during labor. Also, we report a decrease in CD38 expression on CD8+ CD57+ T cells in labor, indicative of cytotoxic T cell senescence. Our study provides a comprehensive status of immune cells at the decidua-chorion interface at term.