Distribution of invariant natural killer T cells and dendritic cells in late pre-term birth without acute chorioamnionitis

Problem: Acute chorioamnionitis (aCAM) is an important cause of pre-term birth. However, little is known about the pathogenesis of late pre-term birth without aCAM that was the most common category of pre-term birth. Here we analyze the kinetics of immune cells obtained from the decidua of women with late pre-term births with and without aCAM. Method of study: Deciduas were obtained from women who underwent labor with late pre-term birth without aCAM (PB-n/aCAM) or with aCAM (PB-w/aCAM). The population of DEC-205(+) dendritic cells (DCs), macrophages, invariant natural killer T (iNKT) cells, NK cells, CD8(+) T cells, and CD4(+) T cells were analyzed by flow cytometry. Results: The number of iNKT cells was higher in the decidua obtained from women with PB-n/aCAM than PB-w/aCAM. DEC-205(+) DCs obtained from women with PB-n/aCAM preferentially induced iNKT cell proliferation. Conclusion: iNKT cell accumulation with DEC-205(+) DCs in PB-n/aCAM suggests that iNKT cells contribute to the onset of PB-n/aCAM.