Dai Z, Mu W, Zhao Y, Jia X, Liu J, Wei Q, Tan T, Zhou J. The rational development of CD5-targeting biepitopic CARs with fully human heavy-chain-only antigen recognition domains.
Mol Ther 2021;
29:2707-2722. [PMID:
34274536 PMCID:
PMC8417515 DOI:
10.1016/j.ymthe.2021.07.001]
[Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/09/2021] [Accepted: 07/06/2021] [Indexed: 12/01/2022] Open
Abstract
T cell malignancies are a group of hematologic cancers with high recurrence and mortality rates. CD5 is highly expressed in ∼85% of T cell malignancies, although normal expression of CD5 is restricted to thymocytes, T cells, and B1 cells. However, CD5 expression on chimeric antigen receptor (CAR)-T cells leads to CAR-T cell fratricide. Once this limitation is overcome, CD5-targeting CAR-T therapy could be an attractive strategy to treat T cell malignancies. Here, we report the selection of novel CD5-targeting fully human heavy-chain variable (FHVH) domains for the development of a biepitopic CAR, termed FHVH3/VH1, containing FHVH1 and FHVH3, which were validated to bind different epitopes of the CD5 antigen. To prevent fratricide in CD5 CAR-T cells, we optimized the manufacturing procedures of a CRISPR-Cas9-based CD5 knockout (CD5KO) and lentiviral transduction of anti-CD5 CAR. In vitro and in vivo functional comparisons demonstrated that biepitopic CD5KO FHVH3/VH1 CAR-T cells exhibited enhanced and longer lasting efficacy; produced moderate levels of cytokine secretion; showed similar specificity profiles as either FHVH1, FHVH3, or the clinically tested H65; and is therefore suitable for further development.
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