The budding of defective human immunodeficiency virus type 1 (HIV-1) particles from cell clones persistently infected with HIV-1

Abstract

Three cell clones producing large numbers of infectious or noninfectious particles of human immunodeficiency virus type 1 (HIV-1), designated M 10/LAV-2, M 16/LAV-3, and MT/LAV-17, were isolated from persistently HIV-1-infected MT-4 cells. In M 10/LAV-2, the HIV-1 proteins were defective in the cleavage of gag precursor protein, and the particles were doughnut-shaped with a double-ring structure. These particles were produced by budding at the cell surface from crescentic structures followed by the formation of double-ring structures. The viral proteins in M 16/LAV-3 were defective in the cleavage of env precursor protein. The morphology of the virus particles was intact, and an electron dense bar-shaped core was seen inside a single-ring enveloped structure. The intact particles were released from the cell surface by a budding process in which crescent shape structures first appeared at the cell membrane, then subsequently just before release matured to a complete structure with an electron dense core. In MT/LAV-17, the synthesis of HIV-1 proteins was normal, and the particles were teardrop-shaped with an intact core structure. These particles were produced by budding with an electron dense core at the cell surface. Thus, it was suggested that the morphological maturation of HIV-1 particles was completed just before release from the cell surface in several cell clones producing HIV-1 particles of different morphology.

Monitoring lentiviral vector production kinetics using online permittivity measurements

“…In addition, for HIV-1, from which LV are derived, it is hypothesized that the release of virus by membrane budding and fission takes place very shortly after the formation of particles [66]. It is also known that the production of HIV-forming proteins is initiated as early as 5-6 h after transfection [67].…”

Complete Inhibition of Human Immunodeficiency Virus Gag Myristoylation Is Necessary for Inhibition of Particle Budding

“…Electron Microscopy-The procedure for electron microscopic examination was described previously (36). Cells were collected at 36 h postinfection before appreciable cell lysis and washed with 0.05 M cacodylate buffer (pH 7.2).…”

Biochemical and Structural Analysis of Isolated Mature Cores of Human Immunodeficiency Virus Type 1

“…Most of our current understanding of the molecular organization of HIV-1 is derived from immuno-EM studies of complete virions (8,14,18,34,54), from biochemical fractionation of subviral components (4,26,33), and by analogy with other members of the family (reviewed in reference 52). Because of the inherent instability of the HIV-1 core, detailed characterization of its morphology and molecular architecture has not been performed.…”