Targeting CD33 in Chemoresistant AML Patient-Derived Xenografts by CAR-CIK Cells Modified with an Improved SB
Maria Caterina Rotiroti1, Chiara Buracchi1, Silvia Arcangeli1
1Tettamanti Research Center, Department of Pediatrics, University of Milano-Bicocca/Fondazione MBBM, 20900 Monza, Italy.
Abstract:
The successful implementation of chimeric antigen receptor (CAR)-T cell therapy in the clinical context of B cell malignancies has paved the way for further development in the more critical setting of acute myeloid leukemia (AML). Among the potentially targetable AML antigens, CD33 is insofar one of the main validated molecules. Here, we describe the feasibility of engineering cytokine-induced killer (CIK) cells with a CD33.CAR by using the latest optimized version of the non-viral Sleeping Beauty (SB) transposon system "SB100X-pT4." This offers the advantage of improving CAR expression on CIK cells, while reducing the amount of DNA transposase as compared to the previously employed "SB11-pT" version. SB-modified CD33.CAR-CIK cells exhibited significant antileukemic activity in vitro and in vivo in patient-derived AML xenograft models, reducing AML development when administered as an "early treatment" and delaying AML progression in mice with established disease. Notably, by exploiting an already optimized xenograft chemotherapy model that mimics human induction therapy in mice, we demonstrated for the first time that CD33.CAR-CIK cells are also effective toward chemotherapy resistant/residual AML cells, further supporting its future clinical development and implementation within the current standard regimens.
Insights
Engineered CD33.CAR-CIK cells show promise for treating acute myeloid leukemia (AML). These cells effectively target AML in preclinical models, including chemotherapy-resistant disease, supporting clinical development.
Area of Science:
- Immunotherapy
- Hematologic Malignancies
- Gene Engineering
Background:
- Chimeric antigen receptor (CAR)-T cell therapy is successful for B cell malignancies.
- Acute myeloid leukemia (AML) remains a critical challenge.
- CD33 is a validated target antigen in AML.
Purpose of the Study:
- To assess the feasibility of engineering cytokine-induced killer (CIK) cells with a CD33.CAR using the Sleeping Beauty (SB) transposon system.
- To evaluate the antileukemic activity of CD33.CAR-CIK cells in vitro and in vivo.
- To determine the efficacy of CD33.CAR-CIK cells against chemotherapy-resistant AML.
Main Methods:
- Engineering CIK cells with CD33.CAR using the optimized SB100X-pT4 non-viral transposon system.
- In vitro and in vivo evaluation of CD33.CAR-CIK cell antileukemic activity in patient-derived AML xenograft models.
- Utilizing a xenograft chemotherapy model mimicking human induction therapy.
Main Results:
- SB-modified CD33.CAR-CIK cells demonstrated significant antileukemic activity.
- Early administration of CD33.CAR-CIK cells reduced AML development.
- CD33.CAR-CIK cells delayed AML progression in established disease models.
- Efficacy against chemotherapy-resistant/residual AML cells was demonstrated.
Conclusions:
- CD33.CAR-CIK cell engineering using the SB system is feasible and enhances CAR expression.
- SB-modified CD33.CAR-CIK cells exhibit potent antileukemic effects in preclinical AML models.
- These findings support the clinical development of CD33.CAR-CIK cells as a potential therapy for AML, including resistant populations.
