Fig. 1: A murine anti-BCMA CAR can be immunogenic.
From: Anti-BCMA chimeric antigen receptors with fully human heavy-chain-only antigen recognition domains
a 11D5-3-NS, a truncated nonsignaling CAR containing only the murine 11D5-3 scFv, hinge, and transmembrane regions was designed. Irradiated, autologous 11D5-3-NS-transduced T cells were used to stimulate PBMC in culture. PBMC were from a patient who received 11D5-3-CD828Z CAR T cells on a clinical trial. Seven days later, the PBMC were stimulated again with 11D5-3-NS-transduced T cells. Seven days after the second stimulation, the PBMC were cultured overnight with autologous T cells that were either untransduced, transduced with the human NGFR gene, or transduced with theΒ 11D5-3-NS gene. Culture supernatants were assayed for IFNΞ³ by ELISA. 11D5-3-NS-specific release of IFNΞ³ was found. b PBMC collected after CAR T-cell infusion to a different patient than in a were stimulated with autologous 11D5-3-CD828Z CAR+ T cells as in a. Peptide reactivity was assessed by culturing the stimulated PBMC for 6βh with autologous dendritic cells pulsed with 15-mer peptides of a peptide library covering all possible 15 mers of the 11D5-3 scFv. Specific IFNΞ³ production by T cells was found in an ICCS assay against peptide pool 5 and peptide 59 from pool 5. c A diagram of the FHVH33-CD8BBZ CAR with the fully human heavy-chain binding domain FHVH33, hinge and transmembrane domains from human CD8Ξ±, a human 4-1BB domain, and a human CD3ΞΆ domain. d 11D5-3-CD8BBZ has a murine scFv binding domain. Otherwise, 11D5-3-CD8BBZ has an identical sequence as FHVH33-CD8BBZ. e Except for substitution of CD28 for 4-1BB, FHVH33-CD828Z is identical to FHVH33-CD8BBZ.
