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Updated: Jan 25, 2026

Analysis of Human Natural Killer Cell Metabolism
Published on: June 22, 2020
[Antitumor effect of natural killer cells in vitro by blocking transforming growth factor-β signaling]
Bo Yang1, Hui Liu, Li-ya Zhang
1Department of Medical Oncology, PLA General Hospital, Beijing 100853, China.
Objective:
To investigate the antitumor effect of natural killer (NK) cells on human colorectal cancer cells HT-29 in vitro by blocking transforming growth factor-β (TGF-β) signaling in NK cells transfected with vector containing dominant negative TGF-β type 2 receptor (DNTβR2).
Methods:
TGF-β1 was added at the final concentration of 10 ng/ml for HT-29 cells. Primary NK cells were transfected with recombinant plasmid pIRES2-AcGFP-DNTβR2 and control plasmid pIRES2-AcGFP using Amaxa Nucleofector technology respectively. The cytotoxicity of these two types of NK cells to HT-29 cells was detected and analyzed by cell counting kit-8.
Results:
The transfection efficiency of primary NK cells was 18.85% for the plasmid pIRES2-AcGFP-DNTβR2 and 35.28% for the control plasmid pIRES2-AcGFP. The expression of DNTβR2 in NK cells was confirmed by Western blotting and RT-PCR. Primary NK cells displayed significantly lower cytotoxicity against HT-29 cells incubated with TGF-β1 than that without TGF-β1 (effect-target cell ratio 10:1,14.40%∓ 2.00% vs. 26.14% ∓ 2.50%, P > 0.05; effect-target cell ratio 20:1, 19.18% ∓ 2.49% vs. 40.81% ∓ 3.50%, P > 0.05). The cytotoxicity of NK cells transfected with DNTβR2 vector was significantly higher than that with control vector against HT-29 cells cultured with 10 ng/ml TGF-β1 (effect-target cell ratio 10:1, 21.17% ∓ 2.49% vs. 11.48% ∓ 1.11% ,P > 0.05; and effect-target cell ratio 20:1, 35.30% ∓ 3.78% vs. 17.19% ∓ 2.29%, P > 0.05).
Conclusion:
NK cells transfected with DNTβR2 vector show better antitumor effect, which may provide new method for NK-based adoptive immunotherapy for cancer.
Insights
Blocking transforming growth factor-β (TGF-β) signaling in natural killer (NK) cells enhances their antitumor activity against colorectal cancer. This approach using dominant negative TGF-β type 2 receptor (DNTβR2) shows promise for NK-based adoptive immunotherapy.
Area of Science:
- Immunology
- Cancer Biology
- Cell Therapy
Context:
- Colorectal cancer (HT-29 cells) is often associated with an immunosuppressive tumor microenvironment.
- Transforming growth factor-β (TGF-β) signaling plays a crucial role in suppressing natural killer (NK) cell function.
- Targeting TGF-β signaling in NK cells is a potential strategy to overcome immune evasion in cancer.
Purpose:
- To evaluate the in vitro antitumor effect of NK cells engineered to block TGF-β signaling.
- To assess the efficacy of NK cells transfected with a dominant negative TGF-β type 2 receptor (DNTβR2) vector against HT-29 cells.
- To investigate the impact of TGF-β1 on NK cell cytotoxicity and the rescue effect of DNTβR2 expression.
Summary:
- Primary NK cells were transfected with either a DNTβR2 or control vector.
- NK cell cytotoxicity against HT-29 cells was measured in the presence of TGF-β1.
- DNTβR2-transfected NK cells exhibited significantly enhanced cytotoxicity compared to control NK cells when cultured with TGF-β1.
Impact:
- Blocking TGF-β signaling in NK cells via DNTβR2 transfection improves their ability to kill colorectal cancer cells.
- This strategy offers a potential new avenue for developing effective NK-based adoptive immunotherapies for cancer treatment.
- The findings support further research into genetically modified NK cells for cancer immunotherapy.
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