Department of Gynecology and Obstetrics, University Medicine Greifswald, Greifswald, Germany.
Front Immunol. 2024 Aug 8;15:1447190. doi: 10.3389/fimmu.2024.1447190. eCollection 2024.
, 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 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 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.
参与结肠癌发生的类杆菌，已被描述为女性上生殖道共生菌群的一部分。虽然其对破坏性炎症过程的贡献已得到充分描述，但作为共生子宫细菌的作用尚未得到彻底研究。由于癌变与早期妊娠发育（包括增殖、侵袭、血液供应和诱导耐受）具有相似的机制，这些机制可能在早期妊娠中发挥作用。此外，着床和胎盘形成需要平衡的免疫激活，而适量的细菌或细菌残留可能会起到这种作用。我们评估了灭活类杆菌对巨噬细胞-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极化成为 M1、M2a 或 M2c 巨噬细胞，然后用灭活的梭杆菌（细菌：巨噬细胞比例为 0.1 和 1）处理。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 Western（HIF 和 P-NF-κB）和 ELISA（VEGF 分泌）评估对巨噬细胞的直接影响。通过划痕实验评估早期妊娠绒毛外滋养层细胞（HTR-8/SVneo）对巨噬细胞条件培养基的反应的功能，通过侵袭（发芽实验）和管形成实验评估功能。通过 ELISA（VEGF 分泌）和 qPCR（基质降解因子和调节剂）研究潜在的分子变化。炎症激活的巨噬细胞（M1）和大量细菌增加了促炎 NF-κB 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 激活和随后的 VEGF-A 分泌增加。因此，滋养层管形成增加。我们的结果表明，低质量的子宫内膜/蜕膜微生物群可以被耐受，同时支持着床和进一步的妊娠过程。
