Loss of miR-142 affects the composition of lymphoid tissue–resident DCs in vivo. (A) Flow cytometric analysis of splenic DC composition in miR-142–deficient mice and control animals. (B) Quantification of FLT3L-dependent cDCs in miR-142^−/− mice and littermate controls per milligram of spleen tissue. (C) Data from panel B were calculated for total splenic weight to account for splenomegaly. Total cell numbers were: DN DCs: 3.1 × 10⁵ ± 5.4 × 10⁴ in WT versus 6.3 × 10⁵ ± 2 × 10⁵ in miR142^−/−, P = .003; CD8α⁺ DCs: 1.2 × 10⁵ ± 2.4 × 10⁴ in WT versus 6.9 × 10⁴ ± 1.9 × 10⁴ in miR142^−/−, P = .003; and CD4⁺ DCs: 7 × 10⁵ ± 2.4 × 10⁵ in WT versus 2.8 × 10⁵ ± 6.4 × 10⁴ in miR142^−/−, P = .002. Each dot represents an independent animal. Five to 6 animals at an age of 6 weeks were used in each group. *P < .05 was considered significant using a Student 2-tailed t test. (D) Analysis of apoptotic miR-142–deficient and miR-142–competent cDCs determined by annexin V and propidium iodide staining. Each dot represents an independent animal. (E) Flow cytometric analysis of mesenteric lymph node- and small intestine–resident DCs isolated from miR-142^+/+ and miR-142^−/− animals. Each dot represents an independent animal. *P < .05 was considered significant using a Student 2-tailed t test.