Inclusion of an IgG1-Fc spacer abrogates efficacy of CD19 CAR T cells in a xenograft mouse model
| Autor: | Jan Terje Andersen, Jon Amund Kyte, Gunnar Kvalheim, E. Walseng, Mengyu Wang, Ludvig A. Munthe, Alexandr Kristian, M R Myhre, Gustav Gaudernack, E M Suso, H Almåsbak |
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| Rok vydání: | 2015 |
| Předmět: |
T-Lymphocytes
Genetic enhancement Antigens CD19 Receptors Antigen T-Cell Biology Gene delivery Immunotherapy Adoptive CD19 Mice CD28 Antigens Mice Inbred NOD In vivo Cell Line Tumor Genetics Animals Humans Molecular Biology Cells Cultured Leukemia Macrophages Electroporation Receptors IgG CD28 Genetic Therapy Macrophage Activation Receptors OX40 Xenograft Model Antitumor Assays Molecular biology Recombinant Proteins Chimeric antigen receptor In vitro HEK293 Cells Cancer research biology.protein Molecular Medicine |
| Zdroj: | Gene Therapy. 22:391-403 |
| ISSN: | 1476-5462 0969-7128 |
| DOI: | 10.1038/gt.2015.4 |
| Popis: | Cancer therapy with T cells expressing chimeric antigen receptors (CARs) has produced remarkable clinical responses in recent trials, but also severe side effects. Whereas most protocols use permanently reprogrammed T cells, we have developed a platform for transient CAR expression by mRNA electroporation. This approach may be useful for safe clinical testing of novel receptors, or when a temporary treatment period is desirable. Herein, we investigated therapy with transiently redirected T cells in vitro and in a xenograft mouse model. We constructed a series of CD19-specific CARs with different spacers and co-stimulatory domains (CD28, OX40 or CD28-OX40). The CAR constructs all conferred T cells with potent CD19-specific activity in vitro. Unexpectedly, the constructs incorporating a commonly used IgG1-CH2CH3 spacer showed lack of anti-leukemia activity in vivo and induced severe, partly CD19-independent toxicity. By contrast, identical CAR constructs without the CH2-domain eradicated leukemia in vivo, without notable toxicity. Follow-up studies demonstrated that the CH2CH3-spacer bound soluble mouse Fcγ-receptor I and mediated off-target T-cell activation towards murine macrophages. Our findings highlight the importance of non-signalling CAR elements and of in vivo studies. Finally, the results show that transiently redirected T cells control leukemia in mice and support the rationale for developing an mRNA-CAR platform. |
| Databáze: | OpenAIRE |
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