Fig. 6: Antibody-mediated blocking of CD44 increases heCIC formation and immune killing.
From: Cell-in-cell structure mediates in-cell killing suppressed by CD44
a Representative cytospin images for heCIC formation (arrows) in F6ft (green)—CCRF-CEM (red) co-culture treated with control IgG or Hermes-1, a CD44 blocking antibody. Scale bar, 50 µm. b, c Quantification of heCIC formation between F6ft and CCRF-CEM (b), or NK92MI (c). F6ft cells were pretreated with Hermes-1 for 1 h followed by co-culture for 8 h with either CCRF-CEM cells or NK92MI cells. Data are means ± SD of six images of 20× objective. n > 800 cells analyzed for each cell. **P < 0.01, ***P < 0.001, ****P < 0.0001. d Representative images for tumor cell killing by NK92MI cells in the presence of different amounts of Hermes-1 antibody. Scale bar, 50 µm. e Tumor cell killing by NK92MI cells was promoted by Hermes-1 (Her) treatment. Cells were co-cultured for 8 h (E/T = 4:1) before measured by Cell Counting Kit-8. *P < 0.05; ****P < 0.0001. Data are means ± SD of triplicate assays. f, g Hermes-1 (Her) treatment had little influence on the autonomous cell growth of either NK92MI (f) or F6ft cells (g). h Representative images of heCIC structures formed between F6ft cells and NK92MI cells in xenograft tumor tissues stained with antibodies against E-cadherin (green) and NKp46 (red). Scale bar, 15 µm. i Increased heCIC formation in xenograft tumor tissue treated with Hermes-1. Data are means ± SD of six images of 20× objective. ****P < 0.0001. j Four groups of tumors xenografts collected from the SCID Beige mice. Her: Hermes-1. k Quantification of xenografted tumors 21 days post the inoculation of F6ft cells together with the indicated antibodies and NK92MI (NK92) cells. Her: Hermes-1. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. F test was employed.
