The glycoprotein isolated from vesicular stomatitis virus is mitogenic for mouse B lymphocytes.

The glycoprotein (G protein) of VSV was purified from the intact virion by Triton X-100 extraction. The isolated G protein has been shown to be a T cell-independent, B lymphocyte mitogen and polyclonal activator. Neither G protein nor the intact virion are stimulatory for murine T lymphocytes. The greater the density of G protein in lipid vesicles or the degree of aggregation of isolated G protein, the more highly stimulatory it is for murine splenocytes. As G protein is spread out in artificial vesicles, it becomes less mitogenic. It is probable that other viral components are also stimulatory since the Triton-insoluble pellet and VSV from which the G protein has been enzymatically removed retain mitogenic activity. To out knowledge, this is the first time a purified viral component has been demonstrated to be lymphocyte mitogen.