CD28抗体—艾普蒂

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     Confocal Immunofluorescence analysis of NIH3T3 cells using CD28 mouse mAb (green). Red: Actin filaments have been labeled with Alexa Fluor-555 phalloidin. Blue: DRAQ5 fluorescent DNA dye.    

  
  

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     Flow cytometric analysis of Hela cells using CD28 mouse mAb (green) and negative control (red).    

  
  

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     Flow cytometric analysis of HL-60 cells using CD28 mouse mAb (green) and negative control (red).    

  
  

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     Flow cytometric analysis of Jurkat cells using CD28 mouse mAb (green) and negative control (red).    

  
  

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     Flow cytometric analysis of SK-BR-3 cells using CD28 mouse mAb (green) and negative control (red).    

  
  

CD28 is a critical co-stimulatory receptor expressed on T cells, playing a central role in adaptive immunity. Upon binding to its ligands CD80/CD86 on antigen-presenting cells, CD28 delivers a secondary activation signal alongside T-cell receptor (TCR) engagement, amplifying T-cell proliferation, survival, and cytokine production. This co-stimulation is essential for effective immune responses, making CD28 a key therapeutic target.

CD28 antibodies are broadly categorized into **agonistic** or **antagonistic** types. **Agonistic antibodies** (e.g., super-agonists like TGN1412) aim to hyperactivate T cells, potentially enhancing anti-tumor immunity. However, early clinical trials revealed severe cytokine storm risks due to systemic T-cell overactivation, underscoring safety challenges. **Antagonistic antibodies** (e.g., abatacept derivatives) block CD28-CD80/86 interactions to suppress T-cell activation, offering promise in autoimmune diseases or transplantation by inducing immune tolerance.

Therapeutic development has evolved to improve specificity. Newer agents, such as **CD28 domain antibodies** (dAbs) or bispecific constructs, focus on localized activity or conditional activation to minimize off-target effects. Preclinical studies also explore CD28-targeting CAR-T cells to augment persistence and efficacy. Despite setbacks, CD28 remains a cornerstone in immunomodulation, balancing its dual role as a catalyst for immunity and a gatekeeper for tolerance. Current research prioritizes fine-tuning CD28 signaling to harness its therapeutic potential safely.