Comment; Salp15 has remarkable properties; 1. binds specifically to CD4 molecules on the surface of T lymphocytes, 2. interferes with T-Cell Receptor-mediated signaling transduction, 3. inhibits CD4+ (helper) T cell activation and proliferation, 4. impedes the secretion of interleukin 2 (IL-2), 5. binds specifically to dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) to up-regulate the expression of CD73 in regulatory T cells, slowing immune over-activity. That’s a lot of bang for the buck, now we need to understand more about how it works at the molecular level & how to harness it pharmaceutically.
Aihua Liu2,3,5* and Fukai Bao1,2,3*
- 1Department of Microbiology and Immunology, Kunming Medical University, Kunming, China
- 2The Center of Tropical Diseases, The Institute for Tropical Medicine, Kunming Medical University, Kunming, China
- 3Yunnan Demonstration Base of International Science and Technology Cooperation for Tropical Diseases, Kunming, China
- 4The First People’s Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Technology, Kunming, China
- 5Department of Biochemistry and Molecular Biology, Kunming Medical University, Kunming, China
Ixodes ticks are the main vectors for a number of zoonotic diseases, including Lyme disease. Ticks secrete saliva directly into a mammalian host while feeding on the host’s blood. This action serves to modulate host immunity and coagulation, thus allowing ticks to attach and feed upon their host. One of the most extensively studied components of tick saliva is Salp15. Research has shown that this protein binds specifically to CD4 molecules on the surface of T lymphocytes, interferes with TCR-mediated signaling transduction, inhibits CD4+ T cell activation and proliferation, and impedes the secretion of interleukin 2 (IL-2). Salp15 also binds specifically to dendritic cell dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) to up-regulate the expression of CD73 in regulatory T cells. Collectively, these findings render this salivary protein a potential candidate for a range of therapeutic applications. Here, we discuss our current understanding of Salp15 and the mechanisms that might be used to treat disease.