Immune Mediators in Labour – Macrophages lead the Way

Einleitung From the conception of the fetus to the beginning of labour and the tissue regeneration afterwards, immune cells, such as macrophages are considered to play a key role. However, the mediating mechanisms used by macrophages in these processes are not well known yet. Here, we investigate the abundance, distribution and expression of functional receptors in uterine macrophages as it could impact the spontaneous onset of delivery and peripartum wound healing.

Material und Methodik Human uterine tissues were collected from healthy women with term deliveries of singleton pregnancies at the Clinic St Hedwig, Regensburg. In particular, myometrium (n=30) and placental (n=26) samples, containing surrounding decidual tissue were embedded in paraffin, sectioned and then analyzed by means of immunohistochemistry for the surface markers CD45, CD68 and CD206.

Ergebnisse Compared to the myometrial tissues of women without labour, significantly higher densities of CD45+immune cells (p=0.038) could be found in the myometrium of women who experienced labour, more abundantly located in the connective tissue surrounding the muscle fibers (p=0.002). Furthermore, the myometrial connective tissue of women in labour showed a significantly increased number of CD68+macrophages (p=0.032). No changes were observed in CD206+expression in macrophages in the connective tissue, or in CD45+, CD68+or CD206+cell density in myometrial muscle tissue. Similarly, the analysis of the immune cell and macrophage counts in the decidual tissue was unaffected in tissues of women with and without labour ([Abb. 1]).

Fig. 1  IHC analysis of CD45, CD68 and their ratio in myometrium.

Zusammenfassung These findings confirm a link between CD45+immune cells and CD68+macrophages and the process of labour or contractions in healthy women, which correlates to our hypothesis that macrophages and immune cells in general can be expanded during this process. The tissue remodeling marker, CD206, was not affected at the times investigated, although it may play a role at later steps of uterine regeneration as seen in mouse models.

Publication History

Article published online:
14 June 2024