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Updated: Dec 14, 2025
Advances in Human Induced Pluripotent Stem Cell-Derived Chimeric Antigen Receptor-Expressing Natural Killer Cells
Published on: February 14, 2025
Development and characterisation of NKp44-based chimeric antigen receptors that confer T cells with NK cell-like
Yasushi Kasahara1, Chansu Shin1, Nobuhiro Kubo1
1Department of Pediatrics Niigata University Graduate School of Medical and Dental Sciences Niigata Japan.
Objectives:
One of the reasons as to why chimeric antigen receptors (CAR)-T cell therapy for malignancies other than CD19- or BCMA-positive tumors has yet to produce remarkable progress is the paucity of targetable antigens. NKp44 is only expressed by activated natural killer cells and detects a variety of transformed cells, while it reportedly does not react with normal tissues. The aim of this study is to develop CAR-T cell that can target multiple types of tumor cells.
Methods:
We created a series of novel CAR constructs in first-generation (1G) and second-generation (2G) CAR format with the extracellular immunoglobulin-like domain of NKp44 (NKp44-CAR).
Results:
Transduction of the best 1G construct into human primary T cells led to specific cytotoxic effects and cytokine secretion upon encountering multiple types of neoplastic cells including AML, T-ALL and childhood solid tumors. Replacement of the extracellular hinge domain of NKp44 with that of CD8α resulted in diminished CAR function. The 1G NKp44-CAR-T cells exhibited significantly better tumor control in long-term co-culture assays compared with activated NK cells, as well as with NK cells transduced with identical NKp44-CAR. T cells transduced with the best 2G-CAR construct with 4-1BB co-stimulatory domain proliferated at significantly higher levels upon single antigen exposure and showed significantly better tumor control compared with the 1G-CAR and 2G-CAR with CD28 co-stimulatory domain.
Conclusions:
NKp44-based CAR endows T cells with NK cell-like anti-tumor specificity. The CAR gene created in this study will be useful for the development of novel gene-modified T-cell immunotherapy.
Insights
Researchers developed novel chimeric antigen receptor (CAR)-T cells targeting NKp44 for broader cancer immunotherapy. These NKp44-CAR-T cells demonstrated potent anti-tumor activity against various malignancies, offering a promising new avenue for gene-modified T-cell therapy.
Area of Science:
- Immunology
- Oncology
- Gene Therapy
Background:
- Chimeric antigen receptor (CAR)-T cell therapy faces limitations due to a scarcity of targetable antigens beyond CD19 and BCMA.
- Natural Killer group 2, member D (NKp44) is expressed on activated natural killer cells and targets various transformed cells without affecting normal tissues.
Purpose of the Study:
- To engineer novel CAR-T cells targeting NKp44 to broaden the applicability of CAR-T cell therapy.
- To evaluate the anti-tumor efficacy of NKp44-based CAR constructs.
Main Methods:
- Development of first-generation (1G) and second-generation (2G) CAR constructs utilizing the NKp44 extracellular domain.
- Transduction of CAR constructs into human primary T cells.
Main Results:
- NKp44-CAR-T cells exhibited specific cytotoxic effects and cytokine secretion against multiple cancer types, including AML, T-ALL, and childhood solid tumors.
- Second-generation NKp44-CAR-T cells with a 4-1BB co-stimulatory domain showed superior proliferation and tumor control compared to 1G-CAR and CD28-based 2G-CAR constructs.
- NKp44-CAR-T cells demonstrated enhanced tumor control in long-term assays compared to activated NK cells.
Conclusions:
- NKp44-based CAR effectively confers NK cell-like anti-tumor specificity to T cells.
- The developed NKp44-CAR gene holds potential for advancing novel gene-modified T-cell immunotherapies.
