Phenotypic heterogeneity in a panel of infectious molecular human immunodeficiency virus type 1 clones derived from a single individual

Abstract

Previously, we and others have demonstrated a relation between the clinical course of human immunodeficiency virus type 1 (HIV-1) infection and biological properties of HIV-1 variants such as replication rate, syncytium-inducing (SI) capacity, and cytotropism. For the molecular analysis of the biological variability in these properties, we generated a panel of phenotypically distinct yet genetically highly homologous infectious molecular clones. These clones were derived from HIV-1 isolates, mostly recovered by direct clonal isolation, from a single individual in whom a transition from non-SI to SI isolates had been identified over time. Of 17 molecular clones tested, 8 were infectious. The clones exhibited differences in SI capacity and T-cell line tropism. Their phenotypes corresponded to those of their parental isolates, formally demonstrating that biological variability of HIV-1 isolates can be attributed to single molecular clones. With these clones we demonstrated that SI capacity and tropism for the H9 T-cell line, almost invariably coupled in primary HIV-1 isolates, are discernible properties. Also different requirements appeared to exist for H9 and Sup Tl cell line tropism. We obtained evidence that T-cell line tropism is not caused by differences in level of HIV-1 expression but most probably is restricted at the level of virus entry. Restriction mapping of four clones with divergent phenotypes revealed a high degree of nucleotide sequence homology (over 96.3%), indicating the usefulness of these clones for the tracking of genetic variability critical for differences in biological phenotype.

Changing Virus‐Host Interactions in the Course of HIV‐1 Infection

“…In several independent studies, the envelope gene was identified as a major determinant responsible for differences in the biological properties of HIV-1 (WesterveU et al 1992, Shioda et al 1991, O'Brien et al 1990, Hwang et al 1991. Sequence analysis of NSI and SI molecular HIV-1 clones from the same individual has revealed that variation in Cl to V4 domain of gpl20 is associated with SI capacity in PBMC (Groenink et al , 1991. Although the envelope V\c,^^-V2 region as well as the V3-V4 region independently contribute to SI capacity, only exchange of the entire gpl 20 V1-V3 fragment completely confers the full SI phenotype (Groenink et al 1993), The V3 domain of SI isolates has a significantly higher positive charge than the V3 domain of NSI/monocytotropic isolates , due to positively charged amino acid residues located on either side of the V3 loop.…”

Pol gene quasispecies of human immunodeficiency virus: mutations associated with drug resistance in virus from patients undergoing no drug therapy

“…Retroviruses share with other RNA viruses the potential for rapid genetic and antigenic diversification (5, 7, 8, 11, 12-14, 23, 29, 49, 57, 61, 62). In particular, the human immunodeficiency virus type 1 (HIV-1) can reach dramatic levels of heterogeneity not only within infected individuals (1,27,28,39,60) but also within an organ of an infected individual (16). The amplitude and great complexity of HIV-1 quasispecies are probably influenced by the prolonged replication of the virus in diseased individuals, the tropism of the virus for a variety of cells involved in immune surveillance, and the expression of provirus triggered by T-cell activation, irrespective of the replicative fitness of the integrated viral genome (62).…”

Human immunodeficiency virus type 1 infection of the brain.

“…This restricted activity was not dependent on levels of CD4 as many of the macrophage cell lines expressed higher levels of CD4 than their T-cell counterparts. In fact, different isolates of HIV-1, often from the same patient, varied in their tropisms for different cell types (4,12,50,51,54,147,150,191,371). In general, HIV-1 isolated from AIDS patients early in disease replicated less efficiently and had a narrower host range in cell culture than HIV-1 isolated from the same patients at later stages of the disease (12,54,110).…”