Truncations of the simian immunodeficiency virus transmembrane protein confer expanded virus host range by removing a block to virus entry into cells.
AUTOR(ES)
Johnston, P B
RESUMO
We have investigated how truncation of the cytoplasmic domain of the transmembrane (TM) glycoprotein of simian immunodeficiency virus (SIV) modulates the host range of this virus. Termination codons were introduced into the env gene of SIVmac239 which resulted in the truncation of the transmembrane protein from a wild-type 354 amino acids (TM354) to 207 (TM207) and 193 (TM193) amino acids. Expression of the wild-type and mutant env genes from a simian virus 40-based vector resulted in normal biosynthesis and processing of the glycoproteins to gp130 and gp41 or the truncated TM proteins (gp28 and gp27). When expressed on the surface of COS-1 cells, all three glycoproteins mediated fusion of both CEMX174 and HUT78 cells. Virions containing the wild-type and mutant glycoproteins were capable of efficient replication in macaque peripheral blood lymphocytes and CEMX174 cells; in contrast, only virions that contained TM207 were capable of rapid infection of HUT78 cells. Both truncated glycoproteins were capable of efficiently mediating infection of both CEMX174 and HUT78 cells by an env-deficient human immunodeficiency virus. The wild-type SIV glycoprotein, however, was unable to mediate human immunodeficiency virus infection of HUT78 cells when assayed with this system. An analysis of the protein composition of SIV released from infected CEMX174 cells showed that the mutant virions contained significantly higher levels of glycoprotein compared with the wild type. These results demonstrate that truncation of the SIV cytoplasmic domain removes a block at the level of glycoprotein-mediated virus entry into HUT78 cells and points to a role for glycoprotein density in determining virus tropism.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=237644Documentos Relacionados
- Triterpene derivatives that block entry of human immunodeficiency virus type 1 into cells.
- Secreted phospholipases A2, a new class of HIV inhibitors that block virus entry into host cells
- Actin-Dependent Receptor Colocalization Required for Human Immunodeficiency Virus Entry into Host Cells
- Coexpression of the simian immunodeficiency virus Env and Rev proteins by a recombinant human adenovirus host range mutant.
- The cytoplasmic domain of simian immunodeficiency virus transmembrane protein modulates infectivity.