Fig. 2.

Mice with selective deletion of Abcg1 in T2 cells have abnormal surfactant and lamellar body homeostasis. A: The fresh weight of the lungs was increased in Abcg1^T2-KO mice. B: Representative electron micrographs from Abcg1^flox/flox and Abcg1^T2-KO mice (original magnification: 17,400×). Increased T2 cell number (C) and relative area of lamellar bodies within each T2 cell (D). E: Flow cytometry gating strategy to identify T2 cells (defined as EpCAM^hiT1α⁻ cells). Single-cell suspensions of negatively selected CD45⁻ cells were stained with fluorophore-conjugated antibodies and analyzed by flow cytometry. Among single cells, the live cells were selected for further analysis to identify T2 cells (EpCAM^hiT1α⁻). F: Abcg1 expression is significantly reduced in EpCAM^hiT1α⁻ T2 cells. G: ABCG1 protein is absent from EpCAM^hiT1α⁻ T2 cells. H: Abcg1 expression is unchanged in CD45⁺ cells isolated from Abcg1^T2-KO mice. I: Increased Abca3 and Abca1 expression in EpCAM^hiT1α⁻ T2 cells. J: Decreased Srebp-2, Fdps, and Ldlr expression in EpCAM^hiT1α⁻ T2 cells. K: Increased Il1β, Il6, and Tnfα expression in EpCAM^hiT1α⁻ T2 cells. Significance was measured by Student’s t-test. Data are expressed as mean ± SEM. *P < 0.05, **P < 0.01, ***P < 0.001.