Unlocking T-Cell Activation: The Ultimate Switch from Dormancy to Action

T Cell Activation Protocol

T cells, as the core component of adaptive immunity, require precise regulation by specific signals to transition from a resting state to a functionally active state. This activation process is fundamental for cellular immunology research and the development of immunotherapies.

Part 1: The Biological Essence of T Cell Activation

T cell activation is a process of signal transduction between T cells and antigen-presenting cells via the immunological synapse structure. This process involves the reception and integration of multiple signals, ultimately leading the T cell from a quiescent state into an activated state characterized by proliferation, differentiation, and the acquisition of effector functions.

Technical Value of In Vitro Activation

• Mechanism Studies: To dissect the regulatory roles of drugs, genes, or signaling pathways on T cell fate decisions.

• Therapeutic Applications: To provide high-quality functional T cells for adoptive cell therapies such as CAR-T and TCR-T.

• Immune Assessment: To evaluate vaccine efficacy or T cell function in pathological states by reconstructing immune responses in vitro.
  

Part 2: Core Elements – Key Signals for T Cell Activation

Complete activation of T cells requires the synergistic action of three key signals.

First Signal – Antigen-Specific Recognition

• Molecular Mechanism: T cell receptor recognizes the MHC-peptide complex on the surface of antigen-presenting cells.

• Technical Implementation: Anti-CD3 antibodies can specifically activate the TCR signaling pathway, mimicking the antigen recognition process.
  
  

Second Signal – Co-stimulatory Signal

• Biological Function: Ensures the specificity of the immune response, prevents T cell anergy or apoptosis, and promotes cell proliferation and survival.

• Technical Implementation: Anti-CD28 antibodies used in combination with anti-CD3 antibodies mimic the B7-CD28 interaction under physiological conditions.
  
  

Third Signal – Differentiation-Regulating Signal

• Biological Function: The cytokine microenvironment determines the direction of T cell differentiation into different functional subsets.

• Technical Implementation: IL-2, as a key growth factor, supports the clonal expansion of T cells in most culture systems.
  
  

These three signals act in a cascading and amplifying manner to collectively accomplish the complete activation and functional differentiation of T cells, providing fundamental technical support for immunological research and clinical applications.

Part 3: Mouse and Human T Cell Activation/Polarization Protocols

A. Human T Cell Activation Protocol

Protocol 1: Anti-Human CD3 Monoclonal Antibody Immobilization Method

1. Dilute the NA/LE Mouse Anti-Human CD3 monoclonal antibody in PBS to a final concentration of 5 µg/mL.
   
   

2. Add the diluted NA/LE Mouse Anti-Human CD3 monoclonal antibody to a 24-well plate at 1 mL per well for immobilization.
   
   

3. Incubate for 2 hours at 37°C with 5% CO₂, or overnight at 4°C.
   
   

4. Remove the NA/LE Mouse Anti-Human CD3 monoclonal antibody solution from the 24-well plate.
   

5. Prepare a single-cell suspension of human peripheral blood mononuclear cells (PBMCs). For T cell activation, cells should be resuspended in complete medium at a concentration of (1-3) × 10⁶ cells/mL. For a 24-well plate, a concentration of 1 × 10⁶ cells/mL is recommended.
   
   

6. In a V-bottom tube, prepare fully supplemented T cell medium and add the following cytokines and antibodies to the cell suspension from step 5:
   
   

   • 5 µg/mL NA/LE Mouse Anti-Human CD28 monoclonal antibody

   • 10 ng/mL Human Interleukin-2 (IL-2) protein
     
     

7. Transfer the required volume of cells to an appropriate cell culture plate, achieving a final density of (1-1.5) × 10⁶ cells/mL/cm².
   
   

8. Incubate for 2 days at 37°C with 5% CO₂.
   
   

9. After 2 days of culture, check cell health and record images.
   
   

10. Centrifuge the cell suspension at 400 × g for 5 minutes and discard the supernatant. Wash the cell pellet with PBS.
    
    

11. Centrifuge the cell suspension at 400 × g for 5 minutes and discard the supernatant. Resuspend the cells in 0.5 mL of 1% Bovine Serum Albumin (BSA) and count the cells. Assess cell viability, which should be >95%.
    
    

12. Block 1 × 10⁶ cells with 10 µg of human IgG antibody. Incubate on ice for 30 minutes.
    
    

13. Add Brilliant Violet 421™ anti-human CD25 antibody (302630) and Alexa Fluor® 488 anti-human CD69 antibody (310916) according to the manufacturer's instructions. Incubate at 4°C for 30 minutes.
    
    

14. Centrifuge the cell suspension at 400 × g for 5 minutes and wash the cell pellet twice with PBS containing 1% BSA.
    
    

15. Resuspend the cell pellet in 200 µL of PBS for flow cytometry analysis (require >10,000 cells).
    
    

Protocol 2: Anti-Human CD3 Monoclonal Antibody Soluble Method

1. Prepare a single-cell suspension of human peripheral blood mononuclear cells (PBMCs). For T cell activation, cells should be resuspended in complete medium at a concentration of (1-3) × 10⁶ cells/mL. For a 24-well plate, a concentration of 1 × 10⁶ cells/mL is recommended.
   
   

2. In a V-bottom tube, prepare fully supplemented T cell medium and add the following cytokines and antibodies to the cell suspension from step 1:

   • 5 µg/mL NA/LE Mouse Anti-Human CD3 monoclonal antibody

   • 5 µg/mL NA/LE Mouse Anti-Human CD28 monoclonal antibody

   • 10 ng/mL Human Interleukin-2 (IL-2) protein
     

3. Transfer the required volume of cells to an appropriate cell culture plate, achieving a final density of (1-1.5) × 10⁶ cells/mL/cm².
   

4. Incubate for 2 days at 37°C with 5% CO₂.
   
   

5. After 2 days of culture, check cell health and record images.
   
   

6. Centrifuge the cell suspension at 400 × g for 5 minutes and discard the supernatant. Wash the cell pellet with PBS.
   
   

7. Centrifuge the cell suspension at 400 × g for 5 minutes and discard the supernatant. Resuspend the cells in 0.5 mL of 1% Bovine Serum Albumin (BSA) and count the cells. Assess cell viability, which should be >95%.
   
   

8. Block 1 × 10⁶ cells with 10 µg of human IgG antibody. Incubate on ice for 30 minutes.
   
   

9. Add Brilliant Violet 421™ anti-human CD25 antibody (302630) and Alexa Fluor® 488 anti-human CD69 antibody (310916) according to the manufacturer's instructions. Incubate at 4°C for 30 minutes.
   
   

10. Centrifuge the cell suspension at 400 × g for 5 minutes and wash the cell pellet twice with PBS containing 1% BSA.
    
    

11. Resuspend the cell pellet in 200 µL of PBS for flow cytometry analysis (require >10,000 cells).
    
    人T细胞激活试剂盒/CellXViva Human T cell Activation Kit_UA090033_优爱(UA BIOSCIENCE)官网

B. Mouse T Cell Activation Protocol

Protocol 1: Anti-Mouse CD3 Monoclonal Antibody Immobilization Method

Mouse T Cell Growth Medium Nutrient System:

• RPMI 1640 Medium, ATCC Modification (with L-glutamine, sodium pyruvate, and HEPES)

• 12% Premium Fetal Bovine Serum

• 1% Antibiotic-Antimycotic

• Cell Freezing: Immunocyte Serum-Free Freezing Medium
  
  Note: The above medium system is for reference only.
  

1. Dilute the NA/LE Rat Anti-Mouse CD3 Recombinant mAb in PBS to a final concentration of 5 µg/mL.
   

2. Add the diluted NA/LE Rat Anti-Mouse CD3 Recombinant mAb to a 24-well plate at 1 mL per well for immobilization.
   
   

3. Incubate for 2 hours at 37°C with 5% CO₂, or overnight at 4°C.
   
   

4. Remove the NA/LE Rat Anti-Mouse CD3 Recombinant mAb solution from the 24-well plate.
   
   

5. Prepare a single-cell suspension from mouse spleen. For T cell activation, cells should be resuspended in complete medium at a concentration of (1-3) × 10⁶ cells/mL. For a 24-well plate, a concentration of 1 × 10⁶ cells/mL is recommended.
   
   

6. In a V-bottom tube, prepare fully supplemented T cell medium and add the following cytokines and antibodies to the cell suspension from step 5:

   • 5 µg/mL NA/LE Syrian Hamster Anti-Mouse CD28 mAb

   • 10 ng/mL IL-2 Protein, Mouse
     
     

7. Transfer the required volume of cells to an appropriate cell culture plate, achieving a final density of (1-1.5) × 10⁶ cells/mL/cm².
   
   

8. Incubate for 2 days at 37°C with 5% CO₂.
   
   

9. After 2 days of culture, check cell health and record images.
   
   

10. Centrifuge the cell suspension at 400 × g for 5 minutes and discard the supernatant. Wash the cell pellet with PBS.
    
    

11. Centrifuge the cell suspension at 400 × g for 5 minutes and discard the supernatant. Resuspend the cells in 0.5 mL of 1% Bovine Serum Albumin (BSA) and count the cells. Assess cell viability, which should be >95%.
    
    

12. Block 1 × 10⁶ cells with 10 µg of mouse IgG antibody. Incubate on ice for 30 minutes.
    
    

13. Add FITC Rat Anti-Mouse CD25 Antibody (S-R441) (S0B5215) according to the manufacturer's instructions. Incubate at 4°C for 30 minutes.
    
    

14. Centrifuge the cell suspension at 400 × g for 5 minutes and wash the cell pellet twice with PBS containing 1% BSA.
    
    

15. Resuspend the cell pellet in 200 µL of PBS for flow cytometry analysis (require >10,000 cells).
    
    
    小鼠T细胞激活试剂盒/CellXViva Mouse T cell Activation Kit_UA090032_优爱(UA BIOSCIENCE)官网
    

Mouse T Cell Activation Kit / CellXViva Mouse T cell Activation Kit_UA090032_ UA BIOSCIENCE Official Website