Cell Surface Protein Changes Associated with HSV-2 Transformation

Abstract

<p>In these studies the cell surface proteins of Herpes simplex virus type 2 (HSV-2) transformed hamster embryo fibroblasts (HaEF) were examined using a variety of radioactive isotope labeling techniques with subsequent analysis on sodium-dodecyl sulphate- polyacrylamide slab gels. As well, a number of biological parameters of these cells lines were investigated including cell morphology, doubling time, saturation density, and tumourigenecity.</p> <p>Cell surface iodination performed on the series of HSV-2 transformed HaEF revealed at least three cell surface alterations. One such protein was the major iodinated species of 220,000 daltons commonly called LETS. LETS was reduced in the transformed lines. All transformed lines contained less than 50% of the level of LETS found in normal secondary HaEF.</p> <p>A variation was found for the HSV-2 transformed cells in their ability to produce tumours. A relationship was observed between tumour-forming ability and the growth properties of cell doubling time and saturation density. The more tumourigenic lines grew to higher saturation densities and doubled their numbers in the shortest time. In the HSV-2 transformed lines a correlation was also found between the amounts of LETS protein on the surface of the cells and tumourigenecity. The amount of LETS present was considerably greater for the weakly tumourigenic lines than for the more tumourgenic lines.</p> <p>There were few protein changes detected when whole cells labeled with 35S-methionine were examined, however, numerous alterations were evident when isolated plasma membranes from normal, secondary HaEF and the various HSV-2 transformed lines labeled with 35 S-methionine or inorganic 32P-phosphate were analyzed. These latter studies indicated that several plasma membrane protein changes are associated with HSV-2 transformation.</p>