A defective proviral DNA with a 2.6-kb deletion of human immunodeficiency virus type 1 (HIV-1) in a persistently HIV-1 infected cell clone.

A cell line (H2-5) producing defective doughnut-shaped particles of human immunodeficiency virus type I (HIV-1) was found to contain proviral DNA with a large deletion of 2558 bases, corresponding to the 3' half of pol gene, the vif and vpr genes, and the 5' terminal of the tat gene.

Production of infectious particles from defective human immunodeficiency virus type 1 (HIV-1)-producing cell clones by superinfection with infectious HIV-1.

A total of 81 cell clones persistently infected with the LAV-1 or HTLV-IIIB strain of human immunodeficiency virus type 1 (HIV-1) was isolated from cells which were obtained by serial passage of some proliferating MT-4 cells after a drastic cytolysis of most cells by HIV-1-infection. These cell clones were classified into 8 types (I to VIII) in terms of the expression of HIV-1 antigens, syncytium formation capacity, and reverse transcriptase activity and infectivity of virus particles in the culture fluid. Type I cell clones were producers of infectious HIV-1 particles, while types II to VIII cell clones did not produce infectious HIV-1 or were producers of uninfectious defective HIV-1 particles.

Human immunodeficiency virus type 1 vif, vpr, and vpu mutants can produce persistently infected cells.

A series of human immunodeficiency virus type 1 (HIV-1) mutants in vif, vpr, vpu, and nef were constructed from an infectious plasmid (pNL 432) containing the full-length HIV-1 DNA by frameshift mutations. The capacities for replication and cell killing of these mutant viruses were examined in a clonal cell line (M 10) isolated from HTLV-I-transformed MT-4 cells. In all cases, the mutant viruses replicated, expressed HIV-1 antigens, and induced drastic cytopathic effects.