Figure 1.

Neonatal PP MNPs exhibit diminished antimicrobial activity and reduced antigen processing and presentation capacity

(A) OTII cell numbers (PP, Peyer’s patch; MLN, mesenteric lymph node; SPL, spleen) of PND10 mice administered with OVA ± FTY720 on PND 6–8 (n = 9–13, mean, one-way ANOVA/Kruskall-Wallis test).

(B) Percentage of CD44^hi of PP CD4⁺ T cells (left y axis, black line) and GC B cells of B cells (right y axis, yellow green line) (n = 4–20, mean + SD, one-way ANOVA/Kruskal-Wallis test).

(C) Representative immunofluorescent images of PP stained for CD11c (red), phalloidin (white), DAPI (blue); scale bars, 200 μm.

(D) Percentage of PP MNP subsets (cDC1 = XCR1⁺SIRPα⁻MHCII⁺CD11c⁺, cDC2 = SIRPα^+/hiBST2⁻XCR1⁻MHCII⁺CD11c⁺, Rorγt⁺ APC = RORγt⁺SIRPα^loXCR1⁻MHCII⁺CD11c⁺, MC = BST2⁺SIRPα⁺XCR1⁻MHCII⁺CD11c⁺) quantified by FACS (n = 5–12, mean + SD; one-way ANOVA/Kruskall-Wallis test).

(E) scRNA-seq of PP MNP (n = 2; pooled from PP from 1 L or 3 adult animals per sample). Pie charts depict relative contribution of PND11 and adult cells within the indicated subset.

(F and G) Pseudobulk profile comparison of scRNA-seq clusters from (D) against (F) all ImmGen gene expression profiles and (G) scRNA-seq of RORγt⁺MHCII⁺ cells from Akagbosu et al.²⁴ using a cosine similarity metric.

(H) DE genes in CCR7⁻ qDC1, CCR7⁻ qDC2, MC, and RORγt⁺ APC between PND11 and adult mice.

(I) GO terms overrepresented in qDC2 of PND11 (upper panel, blue circles) or adult (lower panel, red circles). Top 5 GO terms are labeled. See also Figure S1.