Figures and data

Peripheral cNK cells extravasate into the pregnant uterus and acquire a uterine trNK cells phenotype.
(A) Representative flow plots depicting the presence of non-vascular CD49b+ Eomes+ cNK cells within the gravid uterus of wildtype mice intravascularly labeled with anti-CD45.2 antibody in vivo at gds 6.5 and 14.5 (gd 6.5: C57BL/6 dams, n=3, implantation sites n=9; gd 14.5: C57BL/6 dams, n=3, implantation sites n=9). Previously gated on Live, Single Cells; CD3- CD19- CD45.1- CD45.2–PE-Cy7- CD45.2–Pacific Blue+ NK1.1+ NKp46+ cells. (B) Absolute cell counts of non-vascular CD49b+ Eomes+ cNK cells within the gravid uterus of wildtype mice at gds 6.5 and 14.5. (C) Concatenated flow plots of implantation sites showing that adoptively transferred cNK cells in pregnant uterus of wildtype dams upregulate CD49a and down regulate CD49b by gd 10.5, acquiring a CD49a+ CD49b- Eomes+ phenotype characteristic of uterine trNK cells (C57BL/6 dams n=4). Here, 2.5x106 CD45.2+ CD3- CD19- NK1.1+ NKp46+ CD49b+ splenic cNK cells were adoptively transferred into pregnant C57BL/6-CD45.1 dams at gd 0.5, and the receptor profile of these cells was subsequently assessed at gd 10.5. Previously gated on Live, Single Cells; CD3- CD19- CD45.1- CD45.2–PE-Cy7- CD45.2–PE+ NK1.1+ NKp46+ cells. (D) Proportion of uterine ILC subsets derived from adoptively transferred splenic cNK cells in the pregnant uterus of wildtype dams. Error bars indicate SEM.

Loss of TGF-β Signaling in Ncr1-expressing cells impairs uterine trNK cell differentiation in pregnant mice.
(A) Representative histograms depicting TGF-β Receptor II expression on splenic NK cells from virgin wildtype mice as well as splenic and uterine NK cell subsets from pregnant wildtype mice at gd 10.5 (virgin mice: C57BL/6, n=5; gd 10.5: C57BL/6 dams, n=8, implantation sites n=8). MFI, median fluorescent intensity. Previously gated on Live, Single Cells; CD3- CD19- CD45.1- CD45.2+ NK1.1+ NKp46+ cells. (B) Representative flow plots showing the expression of CD49a, CD49b, and Eomes across ILC subsets in the pregnant spleens of littermate control and TGF-βRIINcr1Δ dams at gd 6.5 (Littermates, n=6; TGF-βRIINcr1Δ, n=5). Previously gated on Live, Single Cells; CD3- CD19- CD45.1- CD45.2+ NK1.1+ NKp46+ cells. (C) Absolute cell counts of CD49a+ Eomes+ trNK cells, CD49a+ Eomes- ILC1s, and CD49b+ Eomes+ cNK cells in the spleens of pregnant littermate control and TGF-βRIINcr1Δ dams at gd 6.5. (D) Representative flow plots showing the expression of CD49a, CD49b, and Eomes across ILC subsets in the gravid uterus of littermate control and TGF-βRIINcr1Δ dams at gd 6.5 (Littermates, n=6, implantation sites n=54; TGF-βRIINcr1Δ, n=5, implantation sites n=15). (E) Absolute cell counts of CD49a+ Eomes+ trNK cells, CD49a+ Eomes- ILC1s, and CD49b+ Eomes+ cNK cells in the gravid uterus of littermate control and TGF-βRIINcr1Δ dams at gd 6.5. Statistics were calculated using unpaired t tests with the Mann-Whitney correction. Error bars indicate SEM; *** p < 0.001; and **** p < 0.0001.

Impaired TGF-β–dependent uterine trNK cells differentiation leads to adverse pregnancy outcomes characterized by reduced litter sizes.
(A) Number of live pups at first parturition from littermate control and TGF-βRIINcr1Δ dams (Littermates, n=7; TGF-βRIINcr1Δ, n=7). (B) Pup birth weight in grams (g) from pups birthed by littermate control and TGF-βRIINcr1Δ dams (Littermates, n=68; TGF-βRIINcr1Δ, n=31). (C) Gestational period in days for littermate control and TGF-βRIINcr1Δ dams (Littermates, n=7; TGF-βRIINcr1Δ, n=7). Statistics were calculated using unpaired t tests with the Mann-Whitney correction. Error bars indicate SEM; *** p < 0.001.

TGF-β–dependent uterine trNK cell differentiation required for proper spiral artery remodeling and fetal survival.
(A) At gd 10.5, TGF-βRIINcr1Δ dams had fewer implantation sites than littermate control dams (Littermates, n=7; TGF-βRIINcr1Δ, n=7). (B) Fetal resorption rates in littermate control and TGF-βRIINcr1Δ dams at gd 10.5, showing increased resorptions in conditional knockout dams (Littermates, n=7; TGF-βRIINcr1Δ, n=7). Resorption rates (RR) were calculated as: RR(%) = (number of resorbed implantation sites/number of total implantation sites) X 100. (C) Representative images of gd 10.5 decidual spiral arteries from three littermate control and three TGF-βRIINcr1Δ dams stained with Masson’s Trichrome (Littermates, n=7; TGF-βRIINcr1Δ, n=7; Scale bar, 100μm). (D) Spiral artery wall-to-lumen ratio at gd 10.5 implantation sites from littermate control and TGF-βRIINcr1Δ dams. Increased wall-to-lumen ratio in TGF-βRIINcr1Δ dams indicative of impaired spiral artery remolding. (Littermates, n=7, decidual spiral arteries n=257; TGF-βRIINcr1Δ, n=7 decidual spiral arteries n=305). Statistics were calculated unpaired t tests with the Mann-Whitney correction. Error bars indicate SEM; ** p < 0.01; and **** p < 0.0001.