Agglutination of Normal Cells by Plant Lectins following Infection with Nononcogenic Viruses

Abstract

MAMMALIAN cells transformed by oncogenic viruses and chemical carcinogens undergo characteristic changes in their surface properties, some of which affect the control of cell multiplication. Certain plant lectins agglutinate transformed cells but not normal cells^1–6, which, although possessing binding sites, can only be agglutinated following treatment with proteolytic enzymes^3–5. Furthermore, both normal and transformed cells bind equal amounts of lectins, indicating that the increased susceptibility of transformed and trypsinized cells to agglutination is not caused by simple “unmasking” of hidden receptor sites. Nevertheless, the increased susceptibility of normal cells to agglutination following trypsinization may well result from changes occurring in the cell coat material. Since lytic infections with certain nononcogenic viruses¹⁰ and various drug treatments¹¹ are known to cause modification of the coat material in normal cells, we were interested to see whether these treatments increased the susceptibility of cells to agglutination by lectins.