Fig. 4

Evaluation of explanted valve tissue for cytotoxic T-cells- a. Positive control. Anti-CD8 staining of the explanted valve known to be infected with bacteria and thus would have an expected cytotoxic T-cell population (green). Cell nuclei are stained with DAPI (blue). b-c. Representative images of the other two valves explanted from sheep that had no evidence of endocarditis. Cell nuclei (blue) are likely from recellularization by the host. There is no evidence of cytotoxic T-cells (green). d-f.) Isotype staining controls of valves explanted from all three sheep. Cell nuclei are present (blue) showing recellularization again by host, but there is no evidence of secondary antibody binding (green)