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Proc Natl Acad Sci U S A. 2016 Jan 26;113(4):E450-8. doi: 10.1073/pnas.1524193113. Epub 2016 Jan 12.

Versatile strategy for controlling the specificity and activity of engineered T cells.

Author information

1
Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92037;
2
Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037;
3
Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA 92037; SCIEX Separations, Brea, CA 92821;
4
Experimental Transplantation and Immunology Branch, National Institutes of Health, National Cancer Institute, Bethesda, MD 20892.
5
Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92037; Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037; schultz@scripps.edu tyoung@calibr.org chkim@calibr.org.
6
Department of Biology, California Institute for Biomedical Research, La Jolla, CA 92037; schultz@scripps.edu tyoung@calibr.org chkim@calibr.org.

Abstract

The adoptive transfer of autologous T cells engineered to express a chimeric antigen receptor (CAR) has emerged as a promising cancer therapy. Despite impressive clinical efficacy, the general application of current CAR-T--cell therapy is limited by serious treatment-related toxicities. One approach to improve the safety of CAR-T cells involves making their activation and proliferation dependent upon adaptor molecules that mediate formation of the immunological synapse between the target cancer cell and T-cell. Here, we describe the design and synthesis of structurally defined semisynthetic adaptors we refer to as "switch" molecules, in which anti-CD19 and anti-CD22 antibody fragments are site-specifically modified with FITC using genetically encoded noncanonical amino acids. This approach allows the precise control over the geometry and stoichiometry of complex formation between CD19- or CD22-expressing cancer cells and a "universal" anti-FITC-directed CAR-T cell. Optimization of this CAR-switch combination results in potent, dose-dependent in vivo antitumor activity in xenograft models. The advantage of being able to titrate CAR-T-cell in vivo activity was further evidenced by reduced in vivo toxicity and the elimination of persistent B-cell aplasia in immune-competent mice. The ability to control CAR-T cell and cancer cell interactions using intermediate switch molecules may expand the scope of engineered T-cell therapy to solid tumors, as well as indications beyond cancer therapy.

KEYWORDS:

B-cell aplasia; cancer immunotherapy; chimeric antigen receptor T cell; cytokine release syndrome; noncanonical amino acids

PMID:
26759368
PMCID:
PMC4743826
DOI:
10.1073/pnas.1524193113
[Indexed for MEDLINE]
Free PMC Article

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