Marilen Benner

CHAPTER 7 192 when combining 4 features: frequency of Th17 cells and CD5 + B cells of the spleen, fold-change of ROR γ T assessed in placental tissue, and frequencies of CD4 + T cells of MLN (normalized expression values, Figure 2B). Principal component analysis illustrated separation of maternal immunity after antimicrobial intervention from healthy control (Figure 2C). The area under the curve (AUC) of 0.99 of the receiver operating characteristic (ROC) analysis confirmed robust classification based on the 4 identified features (Figure 2D). F PC1 PC2 A B C D Figure 2. Multivariate analysis of immunologic assessment across samples of spleen, mesenteric lymph node, inguinal lymph node, peritoneal cavity lavage fluid, amniotic fluid, and placenta. (A) Recursive feature reduction used in an ensemble machine-learning strategy to determine the number of top features needed to achieve robust (>90% accuracy) cohort classification. (B) Top 4 immune features that allow for distinction between cohorts. Normalized expression levels are depicted. (C) Principal component analysis based on the top 4 features that allowed for optimal cohort classification. (D) Individual classification algorithms were run with the top 4 features of the ensemble ranking. The receiver operating curve of Ridge regression is shown. The same results were observed using Passive-Aggressive or Logistic regression. Additional receiver operating curves are depicted in Supplementary Figure 2. AB: Cohort treated with antibiotics, MLN: mesenteric lymph nodes. Systemic and placental T cell adaptations mediated by gestational antibiotics Immune features of adaptive immunity contributed to cohort stratification as shown by machine- learning. Additionally, by univariate analysis, extra attention was payed to the different T cell subsets, whose differentiation is known to be influenced by symbiotic microbiota (35-37). While frequencies of Th1 (CD4 + CXCR3 + ) and Th2 (CD4 + T1/ST2 + ) in spleen, ILN, MLN and PCLF were not affected by treatment (Supplementary Figure S3A and B), a significant increase in placental Th2 cell frequencies was observed (29.0% ± 2.8% compared to 20.8% ± 4.4% in the control