About Bone Marrow Stromal Cell Antigen 1:
Defined as a stromal cell line-derived glycosylphosphatidylinositol-anchored molecule, Bone Marrow Stromal Cell Antigen 1 is a facilitator of pre-B-cell growth. Part of the CD38 family, it is an ectoenzyme which exhibits both cyclic ADP ribose hydrolase activities and DP-ribosyl cyclase.
Also concerned with the growth of B-cells, Bone Marrow Stromal Cell Antigen 2 has been known to inhibit certain viruses, including the Marburg and Lassa virions, as well as inhibiting HIV-1 infection in the absence of Vpu.
BST1 Mechanism
As Bone Marrow Stromal Cell Antigen 1 (BST1) is still being researched and studied, it’s exact mechanism of action is currently unknown. However, following studies in relation to various medical conditions, including rheumatoid arthritis, Parkinson’s disease, and kidney injuries, it appears that BST1-expression on hematopoietic cells may impact the development and treatment of certain conditions, whilst it is thought to be regulated, at least in part, by Sphingosine kinase 2 (SphK2KO).
Furthermore, studies have suggested the Bone Marrow Stromal Cell Antigen 1 stimulates neutrophil migration to sites of inflammation and supports B lymphocyte survival in cases of rheumatoid arthritis, although the exact mechanism of this remains unknown.
BST1 Structure
Confirmed as a single, glycosylated polypeptide chain, BST1 contains 267 amino acids (33-293a.a.) and has a molecular mass of 30.5kDa. Studies have shown that Bone Marrow Stromal Cell Antigen 1 is produced in Sf9 Baculovirus cells, is purified by proprietary chromatographic techniques and is expressed by a 6 amino acid His tag at C-Terminus.
BST1 Functions
Bone Marrow Stromal Cell Antigen 1 is thought to be a mediator of neutrophil migration and adhesion. Having a pleiotropic function, BST1 acts as a receptor and as an ectoenzyme. Usually expressed by myeloid lineage, Bone Marrow Stromal Cell Antigen 1 can be observed in bone marrow stromal cells, endothelial cells, synovial cells and other types of cells.
Studies using agonistic monoclonal antibodies (mAbs) have suggested that BST1 could function by acting as a receptor with signal transduction capacity. However, as BST1 is not thought to have a cytoplasmic domain, it would need to associate with other receptors in order to achieve this. While further investigation is on-going, it is believed that Bone Marrow Stromal Cell Antigen 1 is necessary for neutrophil migration and adhesion. Whilst BST1 may make up for its structural limitations by effectively acting as a parasite and relying on other receptors, this does not necessarily minimize its function in respect to the migration and adhesion of neutrophils.
Bone Marrow Stromal Cell Antigen 1 Interactions
It has been proposed that Bone Marrow Stromal Cell Antigen 1 uses functional interactions in order to impact the adhesion and migration of neutrophils. As such, studies have shown that BST1 interacts with CD11b/CD18 complex and that, via this interaction, signal transduction can be achieved.
Although research is on-going, existing studies have highlighted various interactions could lead to Bone Marrow Stromal Cell Antigen 1 becoming functional. Already associated with the immune response and various medical conditions, further understanding of Bone Marrow Stromal Cell Antigen 1 is required before it can be successfully manipulated to aid in the treatment and prevention of such conditions.