Limits...
Persistent resistance to HIV-1 infection in CD4 T cells from exposed uninfected Vietnamese individuals is mediated by entry and post-entry blocks.

Sáez-Cirión A, Versmisse P, Truong LX, Chakrabarti LA, Carpentier W, Barré-Sinoussi F, Scott-Algara D, Pancino G - Retrovirology (2006)

Bottom Line: In two cases this resistance was associated with low CCR5 surface expression, which was itself associated with heterozygous CCR5 mutations.The restriction was not overcome by a high viral inoculum, suggesting that it was not mediated by a saturable inhibitory factor.Various constitutive mechanisms of CD4 T cell resistance to HIV-1 infection, affecting entry or post-entry steps of viral replication, are associated with resistance to HIV-1 in subjects who remain uninfected despite long-term high-risk behavior.

View Article: PubMed Central - HTML - PubMed

Affiliation: Unité de Régulation des Infections Rétrovirales, Institut Pasteur, Paris, France. asiersc@pasteur.fr

ABSTRACT

Background: We have previously reported that CD4 T cells from some exposed uninfected (EU) Vietnamese intravenous drug users are relatively resistant to HIV infection in vitro. Here, we further characterized the restriction of viral replication in CD4 T cells from five EUs and assessed its persistence in serial samples.

Results: CD4 T cells and/or PBMC sampled during a period of between 2 and 6 years were challenged with replication-competent HIV-1 and other retroviral particles pseudotyped with envelope proteins of various tropisms. CCR5 expression and function in resistant CD4 T cells was evaluated. The step at which HIV-1 replication is restricted was investigated by real-time PCR quantification of HIV-1 reverse transcripts. We identified three patterns of durable HIV-1 restriction in EU CD4 T cells. CD4 T cells from four of the five EU subjects were resistant to HIV-1 R5 infection. In two cases this resistance was associated with low CCR5 surface expression, which was itself associated with heterozygous CCR5 mutations. In the other two cases, CD4 T cells were resistant to HIV-1 R5 infection despite normal CCR5 expression and signaling function, and normal beta-chemokine secretion upon CD4 T cell activation. Instead, restriction appeared to be due to enhanced CD4 T cell sensitivity to beta-chemokines in these two subjects. In the fifth EU subject the restriction involved post-entry steps of viral replication and affected not only HIV-1 but also other lentiviruses. The restriction was not overcome by a high viral inoculum, suggesting that it was not mediated by a saturable inhibitory factor.

Conclusion: Various constitutive mechanisms of CD4 T cell resistance to HIV-1 infection, affecting entry or post-entry steps of viral replication, are associated with resistance to HIV-1 in subjects who remain uninfected despite long-term high-risk behavior.

Show MeSH

Related in: MedlinePlus

R5 tropic HIV-1 restriction in CD4 T cells from four EUs. A. Relative infection by the HIV-BaL pseudotype (white bars; n = 3, mean ± SD) of CD4 T cells from the EUs B184, W336, B195 and W278, and percentage of cells with detectable surface expression of the CCR5 co-receptor (black bars, one experiment shown, representative of two different experiments). B. CCR5-mediated actin polymerisation in CD4 T cells from W278 (◆) B195 (▼) (top left and right panels respectively) and four different CCR5-wt controls. Cells from a control donor (bottom right panel) were also treated with TAK-779 (2 μM) for 60 minutes before RANTES stimulation (open circles). Results show the kinetics of actin polymerization triggered by RANTES stimulation, as measured by the incorporation of the FITC-phalloidin probe. The percentage of actin polymerization is expressed as follows: [(MFI after ligand addition)/(MFI before ligand addition)] × 100. 100% corresponds to the baseline level of unstimulated cells. C. Relative infection of CD4 T cells from subjects W278 (white bars) and B195 (black bars) by R5 (HIV-BaL; HIV-JRFL; HIV-YU2), X4 (HIV-HxB2) and pantropic (HIV-VSVG) pseudotypes (n = 3, mean ± SD). The luciferase activity in cell lysates from one representative control was attributed a value of 100%.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1636660&req=5

Figure 2: R5 tropic HIV-1 restriction in CD4 T cells from four EUs. A. Relative infection by the HIV-BaL pseudotype (white bars; n = 3, mean ± SD) of CD4 T cells from the EUs B184, W336, B195 and W278, and percentage of cells with detectable surface expression of the CCR5 co-receptor (black bars, one experiment shown, representative of two different experiments). B. CCR5-mediated actin polymerisation in CD4 T cells from W278 (◆) B195 (▼) (top left and right panels respectively) and four different CCR5-wt controls. Cells from a control donor (bottom right panel) were also treated with TAK-779 (2 μM) for 60 minutes before RANTES stimulation (open circles). Results show the kinetics of actin polymerization triggered by RANTES stimulation, as measured by the incorporation of the FITC-phalloidin probe. The percentage of actin polymerization is expressed as follows: [(MFI after ligand addition)/(MFI before ligand addition)] × 100. 100% corresponds to the baseline level of unstimulated cells. C. Relative infection of CD4 T cells from subjects W278 (white bars) and B195 (black bars) by R5 (HIV-BaL; HIV-JRFL; HIV-YU2), X4 (HIV-HxB2) and pantropic (HIV-VSVG) pseudotypes (n = 3, mean ± SD). The luciferase activity in cell lysates from one representative control was attributed a value of 100%.

Mentions: Flow cytometry of R5-restricted CD4 T cells revealed that the percentage of CD4 T cells expressing detectable surface CCR5 was far lower in the two EUs carrying heterozygous CCR5 mutations (B184 and W336) than in controls expressing the wild-type (wt) CCR5 molecule (fig. 2A). In contrast, no such difference was found, in either the percentage (fig. 2A) or the mean fluorescence intensity (MFI), in the other two EUs (W278 and B195) who both had wt CCR5 (the CCR5 MFI was 1.38 and 1.21 in subjects W278 and B195, respectively, and 1.39 ± 0.24, mean ± SD, in five CCR5-wt controls).


Persistent resistance to HIV-1 infection in CD4 T cells from exposed uninfected Vietnamese individuals is mediated by entry and post-entry blocks.

Sáez-Cirión A, Versmisse P, Truong LX, Chakrabarti LA, Carpentier W, Barré-Sinoussi F, Scott-Algara D, Pancino G - Retrovirology (2006)

R5 tropic HIV-1 restriction in CD4 T cells from four EUs. A. Relative infection by the HIV-BaL pseudotype (white bars; n = 3, mean ± SD) of CD4 T cells from the EUs B184, W336, B195 and W278, and percentage of cells with detectable surface expression of the CCR5 co-receptor (black bars, one experiment shown, representative of two different experiments). B. CCR5-mediated actin polymerisation in CD4 T cells from W278 (◆) B195 (▼) (top left and right panels respectively) and four different CCR5-wt controls. Cells from a control donor (bottom right panel) were also treated with TAK-779 (2 μM) for 60 minutes before RANTES stimulation (open circles). Results show the kinetics of actin polymerization triggered by RANTES stimulation, as measured by the incorporation of the FITC-phalloidin probe. The percentage of actin polymerization is expressed as follows: [(MFI after ligand addition)/(MFI before ligand addition)] × 100. 100% corresponds to the baseline level of unstimulated cells. C. Relative infection of CD4 T cells from subjects W278 (white bars) and B195 (black bars) by R5 (HIV-BaL; HIV-JRFL; HIV-YU2), X4 (HIV-HxB2) and pantropic (HIV-VSVG) pseudotypes (n = 3, mean ± SD). The luciferase activity in cell lysates from one representative control was attributed a value of 100%.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1636660&req=5

Figure 2: R5 tropic HIV-1 restriction in CD4 T cells from four EUs. A. Relative infection by the HIV-BaL pseudotype (white bars; n = 3, mean ± SD) of CD4 T cells from the EUs B184, W336, B195 and W278, and percentage of cells with detectable surface expression of the CCR5 co-receptor (black bars, one experiment shown, representative of two different experiments). B. CCR5-mediated actin polymerisation in CD4 T cells from W278 (◆) B195 (▼) (top left and right panels respectively) and four different CCR5-wt controls. Cells from a control donor (bottom right panel) were also treated with TAK-779 (2 μM) for 60 minutes before RANTES stimulation (open circles). Results show the kinetics of actin polymerization triggered by RANTES stimulation, as measured by the incorporation of the FITC-phalloidin probe. The percentage of actin polymerization is expressed as follows: [(MFI after ligand addition)/(MFI before ligand addition)] × 100. 100% corresponds to the baseline level of unstimulated cells. C. Relative infection of CD4 T cells from subjects W278 (white bars) and B195 (black bars) by R5 (HIV-BaL; HIV-JRFL; HIV-YU2), X4 (HIV-HxB2) and pantropic (HIV-VSVG) pseudotypes (n = 3, mean ± SD). The luciferase activity in cell lysates from one representative control was attributed a value of 100%.
Mentions: Flow cytometry of R5-restricted CD4 T cells revealed that the percentage of CD4 T cells expressing detectable surface CCR5 was far lower in the two EUs carrying heterozygous CCR5 mutations (B184 and W336) than in controls expressing the wild-type (wt) CCR5 molecule (fig. 2A). In contrast, no such difference was found, in either the percentage (fig. 2A) or the mean fluorescence intensity (MFI), in the other two EUs (W278 and B195) who both had wt CCR5 (the CCR5 MFI was 1.38 and 1.21 in subjects W278 and B195, respectively, and 1.39 ± 0.24, mean ± SD, in five CCR5-wt controls).

Bottom Line: In two cases this resistance was associated with low CCR5 surface expression, which was itself associated with heterozygous CCR5 mutations.The restriction was not overcome by a high viral inoculum, suggesting that it was not mediated by a saturable inhibitory factor.Various constitutive mechanisms of CD4 T cell resistance to HIV-1 infection, affecting entry or post-entry steps of viral replication, are associated with resistance to HIV-1 in subjects who remain uninfected despite long-term high-risk behavior.

View Article: PubMed Central - HTML - PubMed

Affiliation: Unité de Régulation des Infections Rétrovirales, Institut Pasteur, Paris, France. asiersc@pasteur.fr

ABSTRACT

Background: We have previously reported that CD4 T cells from some exposed uninfected (EU) Vietnamese intravenous drug users are relatively resistant to HIV infection in vitro. Here, we further characterized the restriction of viral replication in CD4 T cells from five EUs and assessed its persistence in serial samples.

Results: CD4 T cells and/or PBMC sampled during a period of between 2 and 6 years were challenged with replication-competent HIV-1 and other retroviral particles pseudotyped with envelope proteins of various tropisms. CCR5 expression and function in resistant CD4 T cells was evaluated. The step at which HIV-1 replication is restricted was investigated by real-time PCR quantification of HIV-1 reverse transcripts. We identified three patterns of durable HIV-1 restriction in EU CD4 T cells. CD4 T cells from four of the five EU subjects were resistant to HIV-1 R5 infection. In two cases this resistance was associated with low CCR5 surface expression, which was itself associated with heterozygous CCR5 mutations. In the other two cases, CD4 T cells were resistant to HIV-1 R5 infection despite normal CCR5 expression and signaling function, and normal beta-chemokine secretion upon CD4 T cell activation. Instead, restriction appeared to be due to enhanced CD4 T cell sensitivity to beta-chemokines in these two subjects. In the fifth EU subject the restriction involved post-entry steps of viral replication and affected not only HIV-1 but also other lentiviruses. The restriction was not overcome by a high viral inoculum, suggesting that it was not mediated by a saturable inhibitory factor.

Conclusion: Various constitutive mechanisms of CD4 T cell resistance to HIV-1 infection, affecting entry or post-entry steps of viral replication, are associated with resistance to HIV-1 in subjects who remain uninfected despite long-term high-risk behavior.

Show MeSH
Related in: MedlinePlus