Reactivation of CTLA4-expressing T cells accelerates resolution of lung fibrosis in a humanized mouse model

We performed single-cell sequencing to characterize the cellular landscape in mice treated with IgG1 or ipilimumab. Overall design: Humanized CTLA4 mice were obtained from genOway and housed in the Tulane University Vivarium. Twelve-week-old male mice were used for all experiments. Pulmonary fibrosis was induced by oropharyngeal administration of bleomycin (1.25 U/kg body weight) delivered in two doses, 2 weeks apart, under isoflurane/oxygen anesthesia. On day 21, mice in the control group received intraperitoneal injections of IgG1 isotype control antibody ( Bio X Cell), while mice in the treatment group received ipilimumab (Bio X Cell) at 5 mg/kg body weight, administered twice weekly for 4.5 weeks. At study completion, mice were euthanized; the right lung was harvested for single-cell RNA sequencing.