Fig. 3: CD5/_βLNP-FAPCAR 2.2 therapy rescued pulmonary fibrosis via FAP-fibroblast clearance.

A Schematic diagram of fibrosis model establishment and treatment strategy in young or aged mice. B, C Young mouse BW changes (B) and survival curve (C) of control and BLM groups treated with IgG/_βLNP-FAPCAR 2.2, CD5/_βLNP-FAPCAR 2.2 (10 μg) and saline (n = 10). The survival rate was analyzed using the log-rank (Mantel-Cox) test. D Lung coefficients (lung weight (mg)/BW (g)) (n = 5,5,10,10,10,7). E tdTomato reporter gene expressed in T cells of spleen and lung at 24 h after the second CD5/_βLNP-FAPCAR 2.2 injection (Scar bar: 10 μm). F Flow cytometry plots for FAPCAR expression in CD3⁺ pulmonary T cells of BLM+Saline and CD5/_βLNP-FAPCAR 2.2 treatment groups and the ratio of FAPCAR expression to CD3⁺ pulmonary T cells (n = 4). G Flow cytometry analysis of FAP⁺Pdgfra⁺ fibroblasts in BLM+Saline and CD5/_βLNP-FAPCAR 2.2 treatment groups, ratio of FAP⁺Pdgfra⁺ fibroblasts to all lung cells, and ratio of Pdgfra⁺ fibroblasts (both FAP⁺ and FAP^—) to all lung cells (n = 4). H, I Representative micro-CT images and mean HU density (H), and lung air volume (mm³) (I) computed according to CT results at postoperative 28 days (n = 4,4,7,7,7,7). J Digital photos of lung tissue. ‘n’ means independent biological replications. The values are the means ± SDs. *P < 0.05. P-value determined by one-way ANOVA followed by Tukey’s multiple comparisons test (D, F, H, I) and two tailed unpaired Student’s t-test (G). (BW: body weight; HU: Hounsfield unit). Source data are provided as a Source Data file. Created in BioRender (A, B)⁶⁵.