The virus attaches to the host cell by the attachment protein binding to a CD4 receptor of a T-helper cell.The viral envelope fuses with the host cell plasma membrane and the capsid enters the host cell.Once inside the cytoplasm of the T helper cell, the capsid is digested by host cell enzymes and the two RNA strands and the enzymes reverse transcriptase, integrase and protease are released into the cytoplasm.Reverse transcriptase then uses the RNA as a template to synthesise double stranded DNA.The newly synthesised DNA is taken into the nucleus through a nuclear pore by the enzyme integrase. Integrase makes a cut in the host cell DNA and inserts the viral DNA into the host cell DNAViral DNA is transcribed to mRNA by the host cell's RNA polymerase and the mRNA passes out of the nucleus through the nuclear pore.The mRNA is used to make new viral capsid proteins and enzymes.Hundreds of virions are assembled from the viral mRNA and the newly synthesised viral proteins.The virions move to the cell surface and bud out of the cell covered in some of the host cell's lipid membrane as their lipid outer envelope