Host cell membrane proteins on human immunodeficiency virus type 1 after in vitro infection of H9 cells and blood mononuclear cells. An immuno-electron microscopic study

Abstract

Human immunodeficiency virus type 1 (HIV-1)-infected H9 and blood mononuclear cells (MNCs) were studied by immunogold electron microscopy for the presence of HIV-1 gag p24 protein, env gp41 and gpl20 proteins, and host cell molecules CD4, CDlla, CD25, CD54, CD63, HLA class I and HLA-DR. Uninfected H9 cells and MNC membranes labelled for CD4, HLA class I and class II, and, at low density, CDlla and CD54; lysosomal structures in the cytoplasm labelled for CD63. The infected cell surface showed immunolabelling for HIV-1 proteins, as did budding particle-like structures.Immunogold labelling of the cell membrane for CD4 was almost non-existent. The level of immunolabelling for CD1 la and CD54 on infected cells was greater than that on uninfected cells; this is presumably related to a state of activation during virus synthesis. Budding particle-like structures and free virions in the intercellular space were immunogold-labelled for all host cell markers investigated. This was confirmed by double immunogold labelling using combinations of HIV-1 gag p24 labelling and labelling for the respective host cell molecule. We conclude that virions generated in HIV-1-infected cells concentrate host-derived molecules on their envelope. Also molecules with a prime function in cellular adhesion concentrate on the virion.Infection of cells by human immunodeficiency virus type 1 (HIV-1) is followed by the disappearance of the virus receptor molecule CD4 from the cell membrane (Geleziunas et al., 1991 ;Gielen et al., 1989; Hoxie et al., 1986). This phenomenon has also been observed for other surface molecules including HLA antigens (Eales et al., 1988; Gelderblom et al., 1987b;Henderson et al., 1987;Kerkau et al., 1989;Schols et al., 1992) and the CD3, CD8 and CDll antigens (Stevenson et al., 1987). By using immuno-electron microscopy we have previously demonstrated the complete absence of CD4 antigen and the partial absence of HLA-DR and CD5 antigen on H9 cells 2 days after HIV-1 infection (Meerloo et al., 1992). The CD3 and CD25 antigens remained detectable on the cell surface at similar density, and the CD63 antigen, a t Present address:

Recombinant Extracellular Domains of Tetraspanin Proteins Are Potent Inhibitors of the Infection of Macrophages by Human Immunodeficiency Virus Type 1

“…Consistent with a role in viral release, vesicle fractions in infected H9 T cells contain increased levels of CD63 compared with uninfected cells (15,16). More recently, it has been shown that HIV-1 infection is inhibited by anti-CD63 antibodies, but not antibodies to tetraspanin CD9 or CD81.…”

“…CD63-positive multivesicular bodies accumulate Gag (18) and are sites of virion assembly in macrophages (20,25); multivesicular bodies also contain tetraspanins CD81 and CD82. CD63 is highly enriched in the envelopes of newly budded virus particles (16,19); in fact, anti-CD63 antibodies could immunoprecipitate nearly 100% of virus, whereas other anti-tetraspanin antibodies (CD81, CD82, CD53, and CD151) were much less efficient (20). Treatment of macrophages with anti-CD63 antibody has also been shown to inhibit CCR5 (R5)-but not CXCR4 (X4)-tropic virus infection in a cell type-specific-manner; macrophage, but not peripheral blood mononuclear cell (PBMC), infection was shown to be sensitive (28).…”

Nanoparticle-based flow virometry for the analysis of individual virions

“…The same is true for HIV-1 SF162 and HIV-1 LAI.04 virions produced in Jurkat cells (P > 0.21). Thus, at least for the two cellular antigens evaluated here, the antigenic gens on viral particles (35), but few virions can be analyzed with this laborious technique.…”

Human retroviruses and AIDS 1997

“…Constituents of the viral envelope The lipids of the viral envelope are derived from the plasma membrane of the virus-producing cell during budding (Aloia et al, 1993). Besides SU and TM, a number of cellular proteins have been demonstrated to be present on HIV and SIV by immuno EM and other immunological techniques (Gelderblom et al, 1987b;Henderson et al, 1987;Hoxie et al, 1987;Meerloo et al, 1993). For example, HLA class I or HLA DR (class IT) proteins are tightly inserted during budding into the viral envelope (Fig.…”