B cells' promising therapeutic potential

B cells are essential to the adaptive immune system with their role in antibody secretion. Research often targets the capabilities of T cells, but B cells also hold therapeutic potential.  

What are B cells?

B cells are adaptive immune cells that mediate humoral immunity. They are different from other immune cells with their unique expression of the B cell receptor (BCR), better known as antibody when produced in its soluble form. Each antibody is meticulously tailored to recognise and bind to native antigens, forming a frontline defence against infectious agents.

Learn more in our introduction to B cells.

B cells can defend against other threats, including cancer. Their antibodies can identify neoantigens present on cancerous cells, and compelling evidence links their presence to improved outcomes in specific cancer types.

However, B cells can also cause harm and are implicated in conditions like autoimmunity and cancer. B cells can mistakenly recognise and produce antibodies against self-antigens, attacking the body’s own tissues. Dysfunctional B cells can also promote tumour growth and evade the immune system’s surveillance. Understanding this duality in B cell biology is crucial to developing therapeutics.

B cells as therapeutic targets

B cells are promising therapeutic targets for treating various medical conditions. B cell therapies include:

• B cell depletion therapies

Drugs that selectively deplete B cells have been successful in treating certain autoimmune diseases. Notably the drug rituximab, designed to target CD20-expressing B cells, has shown efficacy in treating conditions like rheumatoid arthritis and lupus. Selectively depleting CD20-expressing B cells effectively interrupts the autoimmune process. 

Despite this success, it is important to note that general B cell depletion therapies like rituximab are associated with limited vaccine responses and can elevate the risk of infections. 

• Precision therapies 

Advances in molecular profiling have identified specific B cell subsets associated with autoimmune disorders and tumour progression. Precision therapies targeting these subsets offer a more nuanced approach, enhancing treatment efficacy while minimising potential side effects. This contrasts with general B cell depleting therapies. As well as depleting these specific subsets, harnessing the immunomodulatory potential of B cell subsets could suppress abnormal immune responses and thus treat autoimmune diseases. 

• Genetically engineered B cells 

This is a rapidly evolving area in B cell therapeutics, comparable to the groundbreaking field of CAR-T therapy. The original BCR on isolated B cells are replaced with a BCR with a known specificity. 

This innovation could be applied to infectious diseases. For example, B cells could be engineered to encode antibodies that neutralise challenging viruses like HIV-1. Additionally, researchers are investigating the use of genetically engineered B cells to enhance anti-tumour responses, an exciting update in innovative therapeutic strategies. 

Targeting B cells is a promising path towards enhanced clinical outcomes in cancer and autoimmune diseases. As our knowledge of B cell biology expands, we can uncover more effective, personalised treatments and improve patient outcomes. 

Monoclonal antibodies

Monoclonal antibody production is another encouraging B cell-derived therapeutic. As previously discussed, B cells are essential to the production of antibodies. This innate capability has been used strategically to create monoclonal antibodies with therapeutic applications. 

Each B cell serves as a unique source, generating a specific antibody tailored to its target. This has led to the development of monoclonal antibodies with specific target antigens. B cells can essentially be used as therapeutic factories, producing monoclonal antibodies targeting antigens associated with cancer cells, autoimmune triggers, and infectious diseases.

Monoclonal antibodies can also be engineered to have heightened specificity towards their targets. As well as more precise targeting, other improvements include extending their half-life and preventing Fc receptor binding.  

Monoclonal antibodies are adaptable and show promise across various clinical applications. From trastuzumab, a monoclonal antibody used in breast cancer therapy, to adalimumab, for the treatment of rheumatoid arthritis. As exemplified by monoclonal antibodies, B cell-derived therapies show immense potential in revolutionising treatments across medicine.