China unveils booster to amplify immune responses against cancer, viruses

China has introduced a major breakthrough in immunotherapy with the development of the world’s most powerful vaccine booster, according to a report by the South China Morning Post. This technology is capable of amplifying immune responses against tumours and infections up to 150-fold and comes with the potential to significantly enhance cancer treatments and improve vaccine effectiveness against rapidly mutating viruses such as Covid-19.

 

The research, conducted jointly by Sun Yat-sen University, Fudan University, and Liaoning University, was published in the journal Nature on March 27.

 

How does the new vaccine booster work?

Central to this system is a delivery system known as SABER, short for 'STING Agonist-Based ER-Targeting Molecules'. Traditional vaccines work by stimulating the immune system, but their effectiveness is often limited by how well they can deliver antigens (the substances that trigger an immune response) to the right parts of immune cells.

 

For a vaccine to be effective, it must successfully deliver antigens to CD8+ T cells, a type of immune cell crucial for attacking cancer cells and infections. This process involves three key steps:

1. Getting the antigen inside antigen-presenting cells (APCs), which help the immune system recognise threats.
2. Activating the APCs to alert other immune cells.
3. Transporting the antigen to the endoplasmic reticulum (ER), an essential structure inside the cell where immune responses are fine-tuned.

 

The ER functions as a communication hub within cells, connecting the nucleus and cytoplasm. In traditional vaccine delivery, antigens struggle to reach this critical area, limiting their effectiveness. SABER acts as a molecular "elevator," bypassing cellular barriers and ensuring precise delivery of antigens to the ER. This approach enhances the immune response significantly, resolving what scientists call the “last-mile” delivery problem.

 

What did the experiments show?

In animal studies, SABER demonstrated improvements in immune response. When tested in mice with tumours, the technology completely halted disease progression in cases of melanoma. While the control group only experienced a slight slowing of tumour growth, with 90 per cent of the mice dying within five weeks, the SABER-treated group showed full survival.

 

For infectious diseases, the technology also proved highly effective. In trials using a Covid-19 peptide vaccine, the T-cell response in SABER-treated groups was 150 times stronger than in control groups. Additionally, in viral-infection studies, mice treated with SABER had 99 per cent lower viral loads in their lungs and brains compared to untreated mice.

 

Why is this breakthrough important?

The innovation behind SABER is not only in its ability to enhance T-cell responses, but also in its impact on the humoral immune response - the body’s antibody-producing defence mechanism. SABER was able to convert 30 per cent of circulating CD8+ T cells into antigen-specific cells, a significant improvement over existing catalysts, which rarely exceed 5 per cent.

 

This dual benefit makes SABER a potential game-changer in both cancer immunotherapy and vaccine development. By increasing the body’s ability to generate targeted immune responses, it could pave the way for more effective cancer treatments and next-generation vaccines.

 

Following this breakthrough, researchers are now focusing on applying SABER to cancers with well-defined antigens, such as liver cancer. The next phase of development will also explore its use in chronic viral infections and preventive vaccines. While the full clinical application may take time, the successful development of SABER marks a crucial step forward in the fight against cancer and infectious diseases.