Hypochlorous acid (HOCl) plays a significant role in immune responses, particularly in its interaction with T cells and its broader impact on the immune system.
Role of HOCl in Immune Responses
HOCl is primarily produced by activated neutrophils through the enzyme myeloperoxidase during the innate immune response. It is well-known for its microbicidal properties, effectively killing a wide range of pathogens. Beyond its role as a disinfectant, HOCl has important functions in modulating the immune response.
Impact on T Cells
HOCl acts as a natural adjuvant, enhancing T cell responses. It facilitates the processing and presentation of antigens by antigen-presenting cells (APCs) through the modification of proteins, which enhances their uptake and degradation by APCs. This process is independent of Toll-like receptor (TLR) signaling and involves the modification of N-linked carbohydrate side chains on glycoproteins, enhancing their interaction with scavenger receptors on the APC surface[1].
Enhancement of Antigen Presentation
HOCl enhances the immunogenicity of antigens, making them more recognizable by the immune system. This is particularly relevant in cancer immunotherapy, where HOCl-treated tumor cell lysates have been shown to improve the immunogenicity of cancer cells. This enhanced presentation leads to a stronger adaptive immune response, potentially improving the efficacy of cancer vaccines[6].
Broader Immune Modulation
HOCl also influences other aspects of the immune response:
- Extracellular Trap Formation: Macrophages exposed to HOCl can release extracellular traps, which are structures that capture and kill pathogens. This process is independent of certain enzymatic activities, indicating a unique mechanism of action for HOCl in immune modulation[3].
- Induction of Danger Signals: HOCl can induce the expression of danger-associated molecular patterns (DAMPs) on cancer cells, promoting their recognition and destruction by the immune system. This includes the upregulation of molecules like calreticulin (CRT), which serves as an “eat-me” signal for phagocytes[2].
Therapeutic Implications
The ability of HOCl to modulate immune responses and enhance antigen presentation has significant therapeutic implications. It is being explored as an adjuvant in cancer therapies and as a potential treatment to enhance immune responses in various diseases. Its role in promoting antitumor immunity and preventing metastasis further highlights its potential as a therapeutic agent in oncology[2][4].
In summary, hypochlorous acid is a critical component of the immune response, with roles extending beyond pathogen killing to include modulation of antigen presentation and enhancement of T cell responses. Its unique properties make it a promising candidate for therapeutic applications in enhancing immune responses and treating diseases like cancer.
Citations:
[1] https://pubmed.ncbi.nlm.nih.gov/20018624/
[2] https://www.spandidos-publications.com/10.3892/or.2021.8022
[3] https://www.sciencedirect.com/science/article/abs/pii/S0891584918315223
[4] https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.887220/full
[5] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7873122/
[6] https://www.mdpi.com/2076-393X/8/2/271
[7] https://link.springer.com/article/10.1007/s00018-020-03591-y
[8] https://www.sciencedirect.com/topics/medicine-and-dentistry/hypochlorous-acid
