Figure 7.

CAR⁺-T cells persistence in mice is associated with the elimination of NCI-H929 multiple myeloma tumor. (A) 25 µL of blood were collected from the tail vein was lysed with IOTEST 3 Lysing Solution (Beckman Coulter) for 10 minutes and stained with a mixture of fluorescent recombinant human B-cell maturation antigen (BCMA) protein, anti-CD3, anti-CD8 and anti-CD4. The percent of H8BB CAR-T cells in NSG blood (% of CD3⁺BCMA.CAR⁺ cells) was assessed by flow cytometry. (B) Average weight of the tumors excised from NCI-H929 multiple myeloma (MM) xenografts at day 9 post T-cell infusion. H8BB CAR-T xenograft tumors are shown in the bottom panel; non-transduced (NT) xenograft control tumors are shown in the upper panel. (C) Infiltration of tumor tissue (depicted in B, upper panel) by CD3⁺ T cells was assessed by immunohistochemistry using anti-human CD3 antibody by day 9 post H8BB CAR or NT T-cell infusion. Marker bar represents 50 µm. Note: Figure 7A to C refer to experiments performed on different cohorts of mice.