Research Description:

A Study on the Anti-Inflammatory Properties of Thymosin Beta 4 Sulfoxide Secreted in Response to Apoptosis of Macrophage Cells

Thymosin Beta 4 (TB4) is a small 5 kDa protein that is covalently modified with sulfoxide prior to secretion. The secreted form of TB4 has potent immunomodulatory properties. Corticosteroids stimulate the secretion of thymosin beta 4 sulfoxide by monocytes and macrophages, and evidence has been reported that suggests that TB4 sulfoxide is the signaling molecule that mediates inhibition of the inflammatory response by corticosteroids. Dr. Bubb's laboratory has confirmed these results and using an ELISA assay, has shown that marine natural products that prevent binding of TB4 to actin augment the secretion of thymosin beta 4 sulfoxide. Since TB4 sulfoxide is an oxidation product of TB4, we hypothesize that TB4 sulfoxide is produced by activated macrophages producing hydrogen peroxide as a counter-regulatory response to limit the inflammatory response of these cells. Specifically, what will be tested will be the effect of Taxol on the secretion of TB4 sulfoxide in macrophages. We hypothesize that Taxol, in stimulating cell apoptosis, will cause the cell to lyse, allowing TB4 to be oxidized by several oxidizing agents in the cell, causing an increase of TB4 sulfoxide. We expect to find a dosage-response and be able to quantitatively show that Taxol induces cell apoptosis. However, first, before we can evaluate the effect and dose dependence of TB4 sulfoxide secretion in response to macrophage activation by Taxol, we will develop a high-throughput assay for the detection of thymosin beta 4 sulfoxide using mass spectroscopy, HPLC, and/or 2-dimensional electrophoresis.