Generation and Functional Verification of Hypoxia-Sensitive Chimeric Antigen Receptor-T Cells

Summary

Here we present a protocol for the generation and functional verification of hypoxia-sensitive chimeric antigen receptor (CAR)-T cells. This protocol presents the lentivirus-based generation of hypoxia-sensitive CAR-T cells and their characterization, including the validation of hypoxia-dependent CAR expression and selective cytotoxicity.

Abstract

Extensive studies have proven the promise of chimeric antigen receptor T (CAR-T) cell therapy in treating hematological malignancies. However, treating solid tumors remains challenging, as exemplified by the safety concerns that arise when CAR-T cells attack normal cells expressing the target antigens. Researchers have explored various approaches to enhance the tumor selectivity of CAR-T cell therapy. One representative strategy along this line is the construction of hypoxia-sensitive CAR-T cells, which are designed by fusing an oxygen-dependent degradation domain to the CAR moiety and are strategized to attain high CAR expression only in a hypoxic environment-the tumor microenvironment (TME). This paper presents a protocol for the generation of such CAR-T cells and their functional characterization, including methods to analyze the changes in CAR expression and killing capacity in response to different oxygen levels established by a mobile incubator chamber. The constructed CAR-T cells are anticipated to demonstrate CAR expression and cytotoxicity in an oxygen-sensitive manner, thus supporting their capability to distinguish between hypoxic TME and normoxic normal tissues for selective activation.

Introduction

Chimeric antigen receptor T cell (CAR-T) therapy has represented a significant breakthrough in cancer treatment. Since the Food and Drug Administration (FDA) approved the first CAR-T therapy for treating advanced/resistant lymphoma and acute lymphoblastic leukemia in 2017^1,2,3, 10 CAR-T therapies targeting CD19 or B-cell maturation antigen (BCMA) have received approval globally⁴. However, despite extensive research, replicating the remarkable efficacy of CAR-T therapy in treating hematological malignancies remains challenging for ....

Protocol

In this study, HER2-BBz-ODD, a hypoxia-sensitive CAR targeting HER2 (Gene ID: 2064) was compared with its regular counterpart, HER2-BBz. The schematics of the two CARs are illustrated in Figure 1A, which shows that HER2-BBz-ODD is derived from HER2-BBz by adding the ODD sequence to the C-terminal of CD3ξ. The construction of lentiviral vectors expressing the two CARs and the generation of the corresponding lentivirus by 293T cell transfection has been previously described

Discussion

Safety concerns are significant issues that must be addressed for any CAR-T cell therapy to advance to clinical use. Utilizing the unique properties of tumor cells or the TME has become a primary research direction focusing on the development of CAR-T cells that target tumor tissues selectively. Designing a hypoxia-sensitive CAR-T is an attractive strategy in this direction, with several approaches being explored, including the one presented in this study-fusing the CAR moiety with the naturally occurring hypoxia-sensing.......

Materials

Name	Company	Catalog Number	Comments
1.5 mL Centrifuge tube	QSP	509-GRD-Q	Supernatants and cells cellection Protocol Step 2,3,4
10% ExpressCast PAGE	NCM biotech	P2012	Immunoblotting Protocol Step 3
10x PBS	NCM biotech	20220812	Cell culture Protocol Step 4
10 mL pipette	Yueyibio	YB-25H	Pipetting Protocol Step 1
10xTRIS-Glycine-SDS electrophoresis buffer	Epizyme	3673020	Immunoblotting Protocol Step 3
15 mL Centrifuge tube	Thermo Scientific	339650	Supernatants and cells cellection Protocol Step 1
25 cm2 EasYFlask	Thermo Scientific	156367	Cell culture Protocol Step 3,4
4x Protein SDS PAGE Loading Buffer	Takara	9173	Immunoblotting Protocol Step 3
6-well flat-bottom tissue culture plates	Thermo Scientific	140675	T Cells culture Protocol Step 1
96-well black flat-bottom tissue culture plates	Greiner	655090	Cytotoxicity assay Protocol Step 4
96-well ELISA plates	Corning	3590	ELISA Protocol Step 5
96-well plate shaker	QILINBEIER	MH-2	Shake Protocol Step 4
96-well U-bottom tissue culture plates	Thermo Scientific	268200	Supernatants cellection Protocol Step 4,5
anti-FLAG antibody	Sigma	F1804-50UG	Immunoblotting Protocol Step 3
Carbinol	Sinopharm	10010061	Immunoblotting Protocol Step 3
Carbon dioxide incubator	Thermo Scientific	360	Cell culture Protocol Step 1,2,3,4
Cell counting plate	Hausser scientific	1492	Cell counting Protocol Step 1,3,4
CELLection Pan Mouse IgG Kit	Thermo Scientific	11531D	Mouse IgG magnetic beads Protocol Step 1
Centrifuge	Thermo Scientific	75002432	Cell culture Protocol Step 1,3,4
Chemiluminescence gel imaging system	BIO-RAD	12003154	Immunoblotting Protocol Step 3
Cobalt chloride solution (0.5 M)	bioleaper	BR4000203	Hypoxic condition Protocol Step 2,3,4
DMEM	Corning	10-103-CV	Cell culture Protocol Step 4
Electronic balance	Sartorius	PRACTUM612-1CN	weigh Protocol Step 5
FBS	BI	04-001-1ACS	Cell culture Protocol Step 3,4
GAPDH Mouse mAb	ABclonal	AC002	Immunoblotting Protocol Step 3
Gel electrophoresis apparatus	BIO-RAD	1645070	Immunoblotting Protocol Step 3
GloMax Microplate Readers	Promega	GM3000	luciferase activity measurement Protocol Step 4
Goat anti-Mouse IgG (H+L)	Yeasen	P1126151	Immunoblotting Protocol Step 3
High speed microfreezing centrifuge	eppendorf	5810 R	Cell culture Protocol Step 1
Human IFN-γ ELISA Set	BD	555142	ELISA Protocol Step 5 Items: Recombinant Human IFN-γ Lyophilized Standard, Detection Antibody Biotin Anti-Human IFN-γ , Capture Antibody Purified Anti-Human IFN-γ, Enzyme Reagent Streptavidin-horseradish peroxidase conjugate (SAv-HRP)
Human IL-2 ELISA Set	BD	555190	ELISA Protocol Step 5 Items: Recombinant Human IL-2 Lyophilized Standard, Detection Antibody Biotin Anti-Human IL-2 , Capture Antibody Purified Anti-Human IL-2, Enzyme Reagent Streptavidin-horseradish peroxidase conjugate (SAv-HRP)
IL-15	R&D systems	P40933	T Cells culture Protocol Step 1
IL-21	Novoprotein	GMP-CC45	T Cells culture Protocol Step 1
IL-7	R&D systems	P13232	T Cells culture Protocol Step 1
Inverted microscope	Olympus	CKX41	Cell culture Protocol Step 1,3,4
Jurkat	ATCC	TIB-152	CAR-Jurkat construction Protocol Step 3
LSRFortessa	BD	LSRFortessa	Flow cytometry Protocol Step 2
Luciferase Assay System	Promega	E1501	luciferase reporter assay Protocol Step 4 Items: Passive lysis buffer, firefly luciferase substrate
Microplate reader	BioTek	HTX	ELISA Protocol Step 5
mobile CO2/O2/N2 Incubator Chamber	China Innovation Instrument Co., Ltd.	Smartor118	Hypoxic condition Protocol Step 2, 3, 4
Mouse Anti-Hexa Histidine tag	Sigma	SAB2702218	Immunoblotting Protocol Step 3
NcmBlot Rapid Transfer Buffer	NCM biotech	WB4600	Immunoblotting
NcmECL Ultra	NCM biotech	P10300	Immunoblotting Protocol Step 3 Items: NcmECL Ultra Luminol/Enhancer Reagent (A) ,NcmECL Ultra Stabilized Peroxide Reagent (B)
NovoNectin -coated 48-well flat plates	Novoprotein	GMP-CH38	CAR-T cells construction Protocol Step 1
OPD (o-phenylenediamine dihydrochloride) tablet set	Sigma	P9187	Substrate Reagent Protocol Step 5 Items: OPD tablet (silver foil),urea hydrogen peroxide tablet (gold foil)
PE-conjugated anti-DYKDDDDK	Biolegend	637310	Flow cytometry Protocol Step 2
Protamine sulfate	Sigma	P3369-1OG	Lentivirus infection Protocol Step 1
Protein Marker 10 Kda-250 KDa	Epizyme	WJ102	Immunoblotting Protocol Step 3
Purifed NA/LE Mouse Anti-Human CD3	BD	566685	T Cells culture Protocol Step 1
Purified NA/LE Mouse Anti-Human CD28	BD	555725	T Cells culture Protocol Step 1
PVDF membrane	Millipore	168627	Immunoblotting Protocol Step 3
RPMI 1640	Corning	10-040-CVRC	Cell culture Protocol Step 3
Skim milk powder	Yeasen	S9129060	Immunoblotting Protocol Step 3
SKOV3-Luc	ATCC	HTB-77	Cytotoxicity assay Protocol Step 4
Trypsin-EDTA	NCM biotech	C125C1	Cell culture Protocol Step 4
Tween 20	Sinopharm	30189328	Immunoblotting Protocol Step 3
Water bath	keelrein	NB014467	Heating Protocol Step 1
X-VIVO 15	LONZA	04-418Q	Serum-free lymphocyte culture medium Protocol Step 1