AEGiS-07IAC: A cell line susceptible to a selectively macrophage-tropic HIV-1 strain (BaL0): lack of cytophaticity, CD4 downregulation and receptor interference.

7th International AIDS Conference


Florence, Italy — June 16-21, 1991

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A cell line susceptible to a selectively macrophage-tropic HIV-1 strain (BaL0): lack of cytophaticity, CD4 downregulation and receptor interference.

Int Conf AIDS 1991 Jun 16-21; 7:102 (abstract no. M.A.1042)
Balotta C, Veronese F, Lori F, Pal R, Gallo RC, Lusso P; Laboratory of Tumor Cell Biology, NCI, Bethesda, MD 20892

OBJECTIVE: To establish a unified model for the study of the biology of divergent HIV isolates.

METHODS: Syncytia assay, p24 Ag capture, flow cytometry, sCD4 competiton assay.

RESULTS: From the HIV-1BaL isolate, we obtained a biologically pure macrophage-tropic substrain, HIV-1BaL0, which is unable to penetrate PHA-activated PBL, as well as several CD4+ neoplastic T-cell or promonocytic cell lines. We identified a human CD4+ EBV-transformed B-cell clone, ET62, which is susceptible to infection by both HIV-1IIIB and HIV-1BaL0. However, while HIV-1BaL0 established a persistent infection in the complete absence of syncytia formation and cellular death, HIV-1IIIB infection was highly cytopathic. No receptor interference was observed between HIV-1BaL0 and HIV-1IIIB, since ET62BaL0 could be superinfected with HIV-1IIIB, resulting in a productive coinfection with rapid syncytia formation. In addition, the 50% inhibitory concentration (IC50) of recombinant soluble CD4 for HIV-1BaL0 was approximately 100-fold higher than for HIV-1IIIB, suggesting a lower CD4/gp120 binding affinity for HIV-1BaL0.

DISCUSSION: The ET62 cell line may represent an optimal unified model for the study of both macrophage-tropic and T-cell tropic HIV isolates. The lack of interference between non-cytopathic and syncytiogenic HIV-1 isolates suggests the possibility of a direct interaction in vivo between divergent HIV isolates.

Keywords: AEGIS, Antigens, CD4, HIV-1, Macrophages, Down-Regulation, HIV, Receptors, HIV, HIV Envelope Protein gp120, Giant Cells, HIV Core Protein p24, HIV Infections, T-Lymphocytes, B-Lymphocytes, SK&F 106528, Human, genetics, ICA7KWDaegis,antigens,cd4,hiv-1,macrophages,down-regulation,hiv,receptors,hiv,hivenvelopeproteingp120,giantcells,hivcoreproteinp24,hivinfections,t-lymphocytes,b-lymphocytes,sk&f106528,human,genetics,ica7
910616
MA1042

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