| Research Abstract |
Thrombospodin-1 (TSP-1), a homotrimetric macromolecule with a molecular weight of 450,000, is released from activated platelets and also synthesized by many types of cells including endothelial cells, monocytes, macrophages, fibroblasts, and various tumor cells. Although several monoclonal antibodies (MAbs) to TSP-1 have been reported, only a few reports have described their detail specificity.
In this study, we prepared 13 new monoclonal antibodies to TSP-1. Six of them were of the IgM variety, four were IgG1 and there were IgG3. Histochemical and serological characterization demonstrated that some of these MAbs are useful for immunohistochemical study and/or for determination or serum levels of TSP-1 in various cancers.
On the other hand, TSP-1, a component of extracellular matrices (ECMs), is an adhesion molecule and capable of binding various free macromolecules and many types of cells. Although many reports described the effects of ECM proteins, there seem to be few publications describing the effects of TSP-1 on immune cells. In the present study, we also studied the influence of TSP-1 upon in vitro culture of T cells and antigen-presenting cells (APCs) in the presence of phytohemagglutinin and found that soluble T cell proliferation and proliferation and enhances IL-10 secretion by APCs.
Taken together, the results obtained here indicate that TSP-1 may serve as a potential useful tumor maker and an immunosuppressive modulator possibly in inflammatory sites.
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