Mitogenic activity of Sindbis virus and its isolated glycoproteins

Purified preparations of Sindbis virus, a member of the togavirus family, are mitogenic for lymphocytes from a number of different mouse strains. Cell separation techniques, as well as studies using lymphocytes from the congenitally athymic BALB/c nu/nu mouse, showed that Sindbis virus is a T-cell-independent B-cell mitogen. Additionally, the envelope glycoproteins of Sindbis virus, isolated by Triton X-100 extraction and butanol precipitation, stimulated lymphocytes to incorporate five times as much [3H]thymidine into their DNA as did the Sindbis virion. These results are similar to those previously reported for vesicular stomatitis virus and herpes simplex virus types I and II and for the purified glycoproteins of vesicular stomatitis virus and influenza virus.