[show abstract][hide abstract] ABSTRACT: Late-stage CCR5 tropic human immunodeficiency virus type 1 (HIV-1) isolates (R5 HIV-1) can deplete nearly all CD4+ thymocytes from human thymus/liver grafts, despite the fact that fewer than 5% of these cells express CCR5. To resolve this paradox, we studied the replication and cytopathic effects (CPE) of late-stage R5 HIV-1 biological clones from two progressors and two long-term nonprogressors (LTNP) in fetal thymic organ culture (FTOC) with and without added cytokines. We found that R5 HIV-1 clones from progressors but not LTNP were cytopathic in untreated FTOC. Moreover, R5 HIV-1 clones from progressors replicated to higher levels than LTNP-derived R5 HIV-1 clones in this system. In contrast, when FTOC was maintained in the presence of interleukin 2 (IL-2), IL-4, and IL-7, both progressor and LTNP clones exhibited similar replication and CPE, which were equal to or greater than the levels achieved by progressor-derived R5 HIV-1 clones in untreated FTOC. This finding was likely due to IL-2-induced CCR5 expression on CD4+ thymocytes in FTOC. R5 HIV-1 clones showed greater pathogenesis for CCR5+ cells but also showed evidence of CPE on CCR5- cells. Furthermore, infection of FTOC by R5 HIV-1 induced IL-10 and transforming growth factor beta (TGF-beta) expression. Both IL-10 and TGF-beta in turn induced CCR5 expression in FTOC. Induction of CCR5 expression via cytokine induction by R5 HIV-1 infection of CCR5+ thymocytes likely permitted further viral replication in newly CCR5+ thymocytes. CCR5 expression, therefore, is a key determinant of pathogenesis of R5 HIV-1 in FTOC.
Journal of Virology 02/2005; 79(1):458-71. · 5.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: Control of viremia in natural human immunodeficiency virus type 1 (HIV-1) infection in humans is associated with a virus-specific T-cell response. However, still much is unknown with regard to the extent of CD8(+) cytotoxic T-lymphocyte (CTL) responses required to successfully control HIV-1 infection and to what extent CTL epitope escape can account for rises in viral load and ultimate progression to disease. In this study, we chose to monitor through full-length genome sequence of replication-competent biological clones the modifications that occurred within predicted CTL epitopes and to identify whether the alterations resulted in epitope escape from CTL recognition. From an extensive analysis of 59 biological HIV-1 clones generated over a period of 4 years from a single individual in whom the viral load was observed to rise, we identified the locations in the genome of five CD8(+) CTL epitopes. Fixed mutations were identified within the p17, gp120, gp41, Nef, and reverse transcriptase genes. Using a gamma interferon ELIspot assay, we identified for four of the five epitopes with fixed mutations a complete loss of T-cell reactivity against the wild-type epitope and a partial loss of reactivity against the mutant epitope. These results demonstrate the sequential accumulation of CTL escape in a patient during disease progression, indicating that multiple combinations of T-cell epitopes are required to control viremia.
Journal of Virology 01/2004; 77(23):12430-40. · 5.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: In approximately half of human immunodeficiency virus (HIV) type 1-infected individuals, the development of CXC chemokine receptor 4-using, syncytium-inducing (SI) virus variants precedes a rapid progression to acquired immunodeficiency syndrome (AIDS). In other individuals, only CC chemokine receptor 5-using (R5), non-SI (NSI) virus variants are present throughout infection. These individuals may be either long-term survivors (LTSs) or rapid progressors. The basis for this variable disease progression in individuals with only R5 virus variants is not yet fully understood. In this study, the beta-chemokine sensitivity of biological HIV-1 clones isolated from 13 individuals who harbored only R5, NSI virus variants (7 LTSs and 6 progressors) was investigated. We found a statistically significant decrease in sensitivity of virus variants to RANTES (regulated on activation, normally T cell-expressed and -secreted) neutralization during the course of progressive infection, but not during follow-up of LTSs. Our data suggest that a role exists for RANTES neutralization sensitivity of HIV-1 in AIDS pathogenesis.
The Journal of Infectious Diseases 10/2003; 188(6):864-72. · 5.85 Impact Factor
[show abstract][hide abstract] ABSTRACT: A polymorphism at position -589 in the interleukin 4 (IL-4) promoter region was recently described as being associated with the presence of syncytium-inducing CXCR4 using (X4) HIV-1 variants.
To study the IL-4 promoter polymorphism -589T in relation to HIV-1 disease progression and acquisition of X4 HIV-1 variants.
Retrospective longitudinal study among 342 HIV-1-infected homosexual men who participated in the Amsterdam Cohort study. Polymerase chain reaction was used in combination with restriction analysis to identify IL-4 promoter genotypes.
Carriers of the -589T allele (either -589 C/T heterozygotes or -589 T/T homozygotes), showed comparable progression to AIDS [relative hazard (RH), 0.94; P = 0.71], and survival (RH IL-4 -589 C/T or T/T, 0.94; P = 0.69) as carriers of the -589 C/C genotype (the reference group). In contrast to a previous study, we found that the -589T polymorphism was associated with a delayed acquisition of X4 HIV-1 variants (RH, 0.56; P = 0.02 for IL-4 -589 C/T or T/T) and a reduced number of CCR5 expressing memory CD4 T cells.
In the Amsterdam Cohort of homosexual men with HIV infection, the IL-4 -589T promoter polymorphism was associated with a delayed acquisition of X4 variants but did not affect overall disease progression.
[show abstract][hide abstract] ABSTRACT: The presence of only non-syncytium-inducing beta-chemokine receptor 5-restricted (R5/NSI) human immunodeficiency virus type 1 (HIV-1) in an infected individual has been associated with long-term asymptomatic survival. However, the majority of R5/NSI HIV-1-infected individuals do progress to AIDS. Here, we compared the replicative capacity and cytopathicity of R5/NSI HIV-1 variants that were isolated early and late in the clinical course from 7 long-term asymptomatic individuals and 7 individuals with progressive HIV-1 infection. R5/NSI HIV-1 cytopathicity in vitro directly correlated with in vitro replication. HIV-1 variants obtained early and late during long-term asymptomatic HIV infection from the same individual were equally cytopathic. In contrast, HIV-1 variants obtained during late-stage progressive HIV infection were more cytopathic than viruses obtained early in infection from the same individuals. Our data indicate that the cytopathicity of HIV-1 variants may increase with progression to disease.
The Journal of Infectious Diseases 06/2003; 187(9):1397-403. · 5.85 Impact Factor
[show abstract][hide abstract] ABSTRACT: In peripheral blood mononuclear cells, syncytium-inducing (SI) human immunodeficiency virus type 1 (HIV-1) infected and depleted all CD4(+) T cells, including naive T cells. Non-SI HIV-1 infected and depleted only the CCR5-expressing T-cell subset. This may explain the accelerated CD4 cell loss after SI conversion in vivo.
Journal of Virology 12/2001; 75(21):10455-9. · 5.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: It has been hypothesized that human immunodeficiency virus type 1 (HIV-1) evolves toward increased cytopathicity in conjunction with disease progression in infected patients. A viral property known to evolve in some but not all patients is coreceptor utilization, and it has been shown that a switch in coreceptor utilization is sufficient for the development of increased cytopathicity. To test the hypothesis that the evolution of other viral properties also contributes to accelerating cytopathicity in vivo, we used human lymphoid tissue explants to assay the cytopathicity of a panel of primary HIV-1 isolates derived from various stages of disease characterized by the presence or absence of changes in coreceptor preference. We found no evidence of coreceptor-independent increases in cytopathicity in isolates obtained either before coreceptor preference changes or from patients who progressed to AIDS despite an absence of coreceptor evolution. Instead, the cytopathicity of all HIV-1 isolates was determined solely by their coreceptor utilization. These results argue that HIV-1 does not evolve toward increased cytopathicity independently of changes in coreceptor utilization.
Journal of Virology 10/2001; 75(18):8842-7. · 5.08 Impact Factor