具核梭菌参与结肠癌的癌变，被描述为女性上生殖道共生菌群的一部分。尽管它对破坏性炎症过程的贡献已得到充分描述，但其作为子宫共生细菌的作用尚未得到彻底研究。由于致癌作用与妊娠早期发育具有相似的机制（包括增殖、侵袭、供血和诱导耐受），具核梭菌诱导的这些机制可能在妊娠早期发挥作用。此外，植入和胎盘需要良好平衡的免疫激活，这可以通过存在有限量的细菌或细菌残留物来适当地管理。我们评估了灭活的具核梭菌对巨噬细胞-滋养层相互作用的影响。单核细胞 (THP-1) 分别通过 IFN-γ、IL-4 或 TGF-β 极化为 M1、M2a 或 M2c 巨噬细胞，随后用灭活的梭杆菌处理（细菌：巨噬细胞比率为 0.1 和 1）。通过活力测定、流式细胞术（抗原呈递分子和细胞因子）、qPCR（细胞因子表达）、细胞内蛋白质印迹（HIF 和 P-NF-κB）和 ELISA（VEGF 分泌）评估对巨噬细胞的直接影响。通过迁移（划痕测定）、侵袭（出芽测定）和管形成，在显微镜下评估妊娠早期绒毛外滋养层细胞（HTR-8/SVneo）对巨噬细胞条件培养基的反应功能。通过 ELISA（VEGF 分泌）和 qPCR（基质降解因子和调节剂）研究了潜在的分子变化。炎症引发的巨噬细胞 (M1) 以及大量细菌会增加促炎 NF-κB 的表达和炎症反应。随后，滋养层功能受损。相反，低细菌刺激导致 M2c 巨噬细胞中 HIF 激活增加，随后 VEGF-A 分泌增加。因此，滋养层管形成增加。我们的结果表明，低质量子宫内膜/蜕膜微生物群是可以耐受的，同时它支持植入和进一步的妊娠过程。版权所有 © 2024 Einenkel、Ehrhardt、Zygmunt 和 Muzzio。

F. nucleatum, involved in carcinogenesis of colon carcinomas, has been described as part of the commensal flora of the female upper reproductive tract. Although its contribution to destructive inflammatory processes is well described, its role as commensal uterine bacteria has not been thoroughly investigated. Since carcinogenesis shares similar mechanisms with early pregnancy development (including proliferation, invasion, blood supply and the induction of tolerance), these mechanisms induced by F. nucleatum could play a role in early pregnancy. Additionally, implantation and placentation require a well-balanced immune activation, which might be suitably managed by the presence of a limited amount of bacteria or bacterial residues. We assessed the effect of inactivated F. nucleatum on macrophage-trophoblast interactions. Monocytic cells (THP-1) were polarized into M1, M2a or M2c macrophages by IFN-γ, IL-4 or TGF-β, respectively, and subsequently treated with inactivated fusobacteria (bacteria:macrophage ratio of 0.1 and 1). Direct effects on macrophages were assessed by viability assay, flow cytometry (antigen presentation molecules and cytokines), qPCR (cytokine expression), in-cell Western (HIF and P-NF-κB) and ELISA (VEGF secretion). The function of first trimester extravillous trophoblast cells (HTR-8/SVneo) in response to macrophage-conditioned medium was microscopically assessed by migration (scratch assay), invasion (sprouting assay) and tube formation. Underlying molecular changes were investigated by ELISA (VEGF secretion) and qPCR (matrix-degrading factors and regulators). Inflammation-primed macrophages (M1) as well as high bacterial amounts increased pro-inflammatory NF-κB expression and inflammatory responses. Subsequently, trophoblast functions were impaired. In contrast, low bacterial stimulation caused an increased HIF activation and subsequent VEGF-A secretion in M2c macrophages. Accordingly, there was an increase of trophoblast tube formation. Our results suggest that a low-mass endometrial/decidual microbiome can be tolerated and while it supports implantation and further pregnancy processes.Copyright © 2024 Einenkel, Ehrhardt, Zygmunt and Muzzio.