The Morphology of Human Immunodeficiency Virus Particles by Negative Staining Electron Microscopy

SUMMARYTwo cell lines of human T lymphocytes (H9 and CEM) chronically infected with isolates of human or simian immunodeficiency viruses were examined by electron microscopy. Scanning electron microscopy of H9 cells showed characteristic morphological changes in the cells after infection with human T cell lymphotropic virus type III (HTLV-IIIB); these included loss of cell microvilli and their replacement by rounded surface protrusions. Virus particles were present over the whole cell surface, but were more numerous between, rather than on, surface protrusions. In contrast, CEM cells infected with three other isolates of the virus showed little change in morphology compared with uninfected cells; they typically had a single large aggregate of virus particles at the posterior end of the cell. Transmission electron microscopy of sections of infected cells showed budding virus in only a small proportion of cells although many had mature virus particles on their surface. The immature particles released by budding had a ring-like morphology in contrast to the mature virus with its characteristic elongated nucleoid. Surface spikes were rarely seen on sectioned virus particles, but were more obvious on the simian immunodeficiency virus than on human isolates. Negative staining of purified virus preparations showed that the peripheral dense material of immature particles had a striated structure. Surface spikes were not seen by negative staining on either immature or mature virus particles. A third type of smaller particle with surface spikes was found in all negatively stained preparations.

Section: Negative Staining Temmentioning

confidence: 84%

Section: Negative Staining Temmentioning

confidence: 99%

Section: Negative Staining Temmentioning

confidence: 99%

See 1 more Smart Citation

Electron Microscopy of Human Immunodeficiency Virus

Hockley¹,

Wood²,

Jacobs

et al. 1988

“…SIV is related to the human immunodeficiency virus (HIV) (Essex & Kanki, 1988); as it causes simian acquired immunodeficiency syndrome in certain primates (Kannagi et al, 1986) it provides a model for studying HIV diseases in humans. Although there have been some negative staining electron microscopy studies on HIV (Hockley et al, 1988;Chrystie & Almeida, 1988;Palmer et al, 1988;Gelderblom et al, 1988;Stannard et al, 1987) such studies have so far been lacking for the various strains of SIV. However, microscopic studies of ultrathin sections of SIVinfected cells show SIV to have the same general morphological features which are found in other lentiviruses (Daniel et al, 1988;Hockley et al, 1988), i.e.…”

Section: Discussionmentioning

confidence: 99%

The Morphology of Simian Immunodeficiency Virus as Shown by Negative Staining Electron Microscopy

Grief

Hockley

Fromholc

et al. 1989

SUMMARYNegative staining electron microscopy was used to study sucrose gradient-purified preparations of the simian immunodeficiency virus (SlVmac251). Both isolated and aggregated virus particles were observed together with some free-lying virus cores. The cores were 110 nm long and 25 to 50 nm wide and were mainly conical or wedge-like in shape. Surface projections were seen on the envelope membrane of many of the virus particles; the knobs were approximately 6 nm in length, 10 nm wide and from an endon view they had a Y or triangular-shaped morphology.The simian immunodeficiency virus (SIV) is a retrovirus which was first isolated from captive rhesus macaques at the New England Regional Primate Research Center (Daniel et al., 1985). SIV is related to the human immunodeficiency virus (HIV) (Essex & Kanki, 1988); as it causes simian acquired immunodeficiency syndrome in certain primates (Kannagi et al., 1986) it provides a model for studying HIV diseases in humans. Although there have been some negative staining electron microscopy studies on HIV (Hockley et al., 1988;Chrystie & Almeida, 1988;Palmer et al., 1988;Gelderblom et al., 1988;Stannard et al., 1987) such studies have so far been lacking for the various strains of SIV. However, microscopic studies of ultrathin sections of SIVinfected cells show SIV to have the same general morphological features which are found in other lentiviruses (Daniel et al., 1988;Hockley et al., 1988), i.e. an electron-dense cylindrical or conical-shaped core and a fringed envelope.The SIVmae251 strain was obtained from Dr R. C. Desrosiers (New England Primate Research Center, Southborough, Mass., U.S.A.) and propagated in the lymphoid cell line HUT-78 (Daniel et al., 1985). Culture fluid containing the virus was clarified first by using low speed centrifugation. The virus was then pelleted through a 20~o sucrose cushion at 38000 r.p.m, for 2 h at 4 °C in a Beckman Ti45 rotor. The resuspended virus was layered onto a 20 to 609/o (w/v) continuous sucrose gradient, centrifuged at 20000 r.p.m, for 16 h at 4 °C in a Beckman SW30 rotor and the resulting 1 ml fractions were assayed for virus using a reverse transcriptase assay (Hoffman et al., 1985). Fractions containing the virus were inactivated by adding 100111 of the preparation to 900 txl of 2 ~ glutaraldehyde which was then stored at 4 °C. For negative staining, inactivated samples were centrifuged onto glow-discharge-treated carbon films on 400-mesh copper grids using a Beckman Airfuge operated at 25 lbf/in 2 (approx. 100000 g) for 10 min. The grids were washed with distilled water, negatively stained with 2~ aqueous uranyl acetate and examined with a Philips CM12 electron microscope operated at 80 kV.Negative staining electron microscopy of the sucrose gradient-purified SIV revealed the presence of large numbers of enveloped virus particles. Those particles which had collapsed during the negative staining procedure were in the size range of 125 to 160 nm, whereas particles filled with the negative stain revealed internal struc...

“…Stannard et al (1987) recently described the morphology of HIV-1 stained with phosphotungstic acid. Virions were roughly hexagonal with small ring-shaped surface projections.…”

mentioning

confidence: 99%

Ultrastructure of Human Immunodeficiency Virus Type 2

Palmer

Martin

Goldsmith

et al. 1988

SUMMARYThe ultrastructure of human immunodeficiency virus type 2 (HIV-2) was determined by negative stain and thin section electron microscopy (EM). Some virus particles had surface projections about 10 nm in length which were evenly spaced. Nonidet P40-treated particles which were penetrated by stain revealed a distinctive off-centre coneshaped core and, in addition, free-lying cores were also seen in detergent-treated preparations. The surface of the cores was composed of a layer of small subunits. The structure of HIV-2 determined by thin section EM was the same as that deduced by negative stain EM.