Analysis of human lymphotropic T-cell virus type II-like particle production by recombinant baculovirus-infected insect cells

The molecular processes involved in retrovirus assembly and budding formati on remain poorly understood. The gag-propel genes of human lymphotropic T-c ell Virus type Il (HTLV-II) are translated into Gag, Gag-Pro, or Gag-Pro-Po l by frameshift events. In the present study, we investigated the roles of the gag, pro, and pol regions of HTLV-II in Viral particle formation using recombinant baculoviruses. in this study we could successfully produce matu re HTLV-II viral particles containing core structures using a construct exp ressing the entire gag-pro-pol region. We also investigated the role of the pol region in particle formation. Deletion of the pol region affects viral particle assembly or release Very little, indicating that the gag-pro regi on is sufficient for viral particle formation and maturation. Expression of the Gag proteins alone or Gag proteins with inactivated viral proteases (P ro) resulted in the formation of viral particles; however, these particles did not contain core structures. These results suggest the intracellular ex pression of Gag with Pro of HTLV-II is essential for the production of matu re virus particles, whereas that of Pol is not. (C) 1999 Academic Press.