Novel decidual innate lymphoid cells display lineage plasticity

• Published in: The Journal of immunology (1950) 2020-05, Vol.204 (1_Supplement), p.84-84.11
• Main Authors: Vazquez, Jessica, Fisher, Rachel Catherine, Stanic, Aleksandar K
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.204.Supp.84.11

Immune cells at the maternal-fetal interface play a complex role in regulation of vascular remodeling, fetal tolerance and protection from infection. We have previously reported the identification of two novel CD56high innate lymphoid cells (ILCs) based on Eomes (lo/hi) expression in the decidua. Preliminary experiments suggest that cytokines can modify the expression of canonical transcription factors (TF) by decidual ILCs. Decidual specimens were dissected from term placentas and mononuclear cells (MCs) were isolated by mechanical/enzymatic disruption, then cultured in the presence of IL7/IL15, IL1β/IL23, or IL2/TGFβ for 7 days, with matched samples processed without culturing for ex vivo assessment. MCs were labeled with fluorochrome-conjugated antibodies against CD3, 14, 16, 19, 34, 45, 49a, 56, 94, 117, 127, GATA3, Eomes, RORγt, and Tbet. Data was acquired using the BD Fortessa flow cytometer and analyzed using FlowJo 10.2. Our assessment of TF expression revealed significant differences between cytokine-stimulated cultured cells and direct ex vivo samples. GATA3 expression was highest in EomesLo (C2) and EomesHi (C10) cells cultured with IL7/IL15, compared to ex vivo cells. Interestingly, Eomes expression did not change across treatments, while Tbet expression was highest in C2/C10 cells cultured with IL7/IL15. Contrary to our expectations, culturing with IL1β/IL23 did not lead to higher RORγt expression, which was instead upregulated by IL7/IL15. Preliminary results suggest that both C10 and C2 decidual ILCs demonstrate a level of lineage plasticity. Further analysis will reveal if these novel subsets have the capacity of transdifferentiating fully or if they maintain a limited phenotypic and functional capacity.