Figure 3. Immunohistochemical detection of perforin⁺CD56⁺ and perforin⁺CD3⁺ IH cells from HCV-infected patients and flow cytometric analysis.

Representative pictures from immunohistochemical staining of HCV-infected liver (n = 4) with double perforin/CD56 labeling (A) showing perforin⁺CD56⁺ cells characterized by brown CD56⁺ staining and red cytoplasmic perforin⁺ staining in HCV-infected liver with septal fibrosis and low A1 Metavir activity (magnification ×20). Many double positive CD56⁺perforin⁺ cells (asterisk) were detected, mainly localized in lobules (L), far away from piecemeal necrosis (PN). B) Detection of brown CD3⁺ cells and red perforin⁺ cells in HCV-infected liver with septal fibrosis. Rare double positive CD3⁺perforin⁺ cells were detected in lobules. C) High magnification (x40) showing that perforin granules were polarized at the apical pole of IH-CD56⁺ cells. D) Flow cytometric analysis depicting perforin⁺cells gated on CD56⁺CD3⁻ cells and CD107a⁺ gated on perforin⁺NK cells.