Camille Lécuroux

Acute Plasma Biomarkers of T Cell Activation Set-Point Levels and of Disease Progression in HIV-1 Infection

T cell activation levels, viral load and CD4+ T cell counts at early stages of HIV-1 infection are predictive of the rate of progression towards AIDS. We evaluated whether the inflammatory profile during primary HIV-1 infection is predictive of the virological and immunological set-points and of disease progression. We quantified 28 plasma proteins during acute and post-acute HIV-1 infection in individuals with known disease progression profiles. Forty-six untreated patients, enrolled during primary HIV-1 infection, were categorized into rapid progressors, progressors and slow progressors according to their spontaneous progression profile over 42 months of follow-up. Already during primary infection, rapid progressors showed a higher number of increased plasma proteins than progressors or slow progressors. The plasma levels of TGF-β1 and IL-18 in primary HIV-1 infection were both positively associated with T cell activation level at set-point (6 months after acute infection) and together able to predict 74% of the T cell activation variation at set-point. Plasma IP-10 was positively and negatively associated with, respectively, T cell activation and CD4+ T cell counts at set-point and capable to predict 30% of the CD4+ T cell count variation at set-point. Moreover, plasma IP-10 levels during primary infection were predictive of rapid progression. In primary infection, IP-10 was an even better predictor of rapid disease progression than viremia or CD4+ T cell levels at this time point. The superior predictive capacity of IP-10 was confirmed in an independent group of 88 HIV-1 infected individuals. Altogether, this study shows that the inflammatory profile in primary HIV-1 infection is associated with T cell activation levels and CD4+ T cell counts at set-point. Plasma IP-10 levels were of strong predictive value for rapid disease progression. The data suggest IP-10 being an earlier marker of disease progression than CD4+ T cell counts or viremia levels.

Early and Long-Lasting Alteration of Effector CD45RA−Foxp3high Regulatory T-Cell Homeostasis During HIV Infection

Regulatory T-cell (Treg) quantification in human immunodeficiency virus (HIV) infection remains ill defined because of the lack of reliable specific markers to identify human Tregs and the diversity of clinical stages of HIV infection. Using a recently described Treg identification strategy based on CD45RA and Foxp3 expression, we performed an extensive quantification of total, naive (CD45RA(+)Foxp3(low)), and effector (CD45RA(-)Foxp3(high)) Tregs in different contexts of HIV infection: primary HIV infection, long-term viremic patients, aviremic patients treated with highly active antiretroviral therapy, and HIV controllers. We showed that although total Treg percentages were mildly affected by HIV infection, Treg absolute numbers were significantly reduced in all groups studied. We demonstrated that although naive Treg numbers were essentially preserved, effector Tregs were consistently affected during HIV infection. Finally, we demonstrated that effector but not total or naive Treg numbers were negatively correlated with the magnitude of HIV-specific CD8 T-cell responses.

Potential role for HIV-specific CD38-/HLA-DR+ CD8+ T cells in viral suppression and cytotoxicity in HIV controllers

Background HIV controllers (HIC) are rare HIV-1-infected patients who exhibit spontaneous viral control. HIC have high frequency of CD38−/HLA-DR+ HIV-specific CD8+ T cells. Here we examined the role of this subset in HIC status. Materials and Methods We compared CD38−/HLA-DR+ CD8+ T cells with the classical CD38+/HLA-DR+ activated phenotype in terms of 1) their activation status, reflected by CD69, CD25, CD71, CD40 and Ki67 expression, 2) functional parameters: Bcl-2 expression, proliferative capacity, and IFN-γ and IL-2 production, and 3) cytotoxic activity. We also investigated how this particular profile is generated. Results Compared to CD38+/HLA-DR+ cells, CD38−/HLA-DR+ cells exhibited lower expression of several activation markers, better survival capacity (Bcl-2 MFI, 367 [134–462] vs 638 [307–747], Pu200a=u200a0.001), higher frequency of polyfunctional cells (15% [7%–33%] vs 21% [16%–43%], Pu200a=u200a0.0003), greater proliferative capacity (0-fold [0–2] vs 3-fold [2]–[11], Pu200a=u200a0.007), and higher cytotoxicity in vitro (7% [3%–11%] vs 13% [6%–22%], Pu200a=u200a0.02). The CD38−/HLA-DR+ profile was preferentially generated in response to low viral antigen concentrations. Conclusions These data highlight the role of CD38−/HLA-DR+ HIV-specific CD8+ T cell cytotoxicity in HIC status and provide insights into the mechanism by which they are generated. Induction of this protective CD8+ subset may be important for vaccine strategies.

CD8 T-cells from most HIV-infected patients lack ex vivo HIV-suppressive capacity during acute and early infection.

The strong CD8+ T-cell-mediated HIV-1-suppressive capacity found in a minority of HIV-infected patients in chronic infection is associated with spontaneous control of viremia. However, it is still unclear whether such capacities were also present earlier in the CD8+ T cells from non controller patients and then lost as a consequence of uncontrolled viral replication. We studied 50 patients with primary HIV-1-infection to determine whether strong CD8+ T-cell-mediated HIV suppression is more often observed at that time. Despite high frequencies of polyfunctional HIV-specific CD8+ T-cells and a strong CD4+ T-helper response, CD8+ T-cells from 48 patients lacked strong HIV-suppressive capacities ex vivo. This indicates that the superior HIV-suppressive capacity of CD8+ T-cells from HIV controllers is not a general characteristic of the HIV-specific CD8+ T cell response in primary HIV infection.

Pressure from TRIM5α Contributes to Control of HIV-1 Replication by Individuals Expressing Protective HLA-B Alleles

ABSTRACT The expression of certain HLA class I alleles, including HLA-B*27 and HLA-B*57, is associated with better control of human immunodeficiency virus type 1 (HIV-1) infection, but the mechanisms responsible are not fully understood. We sought evidence that pressure from the human restriction factor TRIM5α (hTRIM5α) could contribute to viral control. The hTRIM5α sensitivity of viruses from both HLA-B*57-positive (HLA-B*57+) and HLA-B*27+ patients who spontaneously controlled viral replication, but not viruses from viremic patients expressing these alleles, was significantly greater than that of viruses from patients not expressing these protective HLA-B alleles. Overall, a significant negative correlation between hTRIM5α sensitivity and viral load was observed. In HLA-B*57+ patients, the T242N mutation in the HLA-B*57-restricted TW10 CD8+ T lymphocyte (CTL) epitope was strongly associated with hTRIM5α sensitivity. In HLA-B*27+ controllers, hTRIM5α sensitivity was associated with a significant reduction in emergence of key CTL mutations. In several patients, viral evolution to avoid hTRIM5α sensitivity was observed but could be associated with reduced viral replicative capacity. Thus, in individuals expressing protective HLA-B alleles, the combined pressures exerted by CTL, hTRIM5α, and capsid structural constraints can prevent viral escape both by impeding the selection of necessary resistance/compensatory mutations and forcing the selection of escape mutations that increase hTRIM5α sensitivity or impair viral replicative capacity.

High Soluble CD14 Levels at Primary HIV-1 Infection Predict More Rapid Disease Progression

The soluble CD14 (sCD14) level was found associated with mortality during the chronic phase of human immunodeficiency virus (HIV) infection. Here we assessed its prognostic value in 138 patients with primary HIV infection. Higher sCD14 levels were associated with death, from myocardial infarction, but this was based on 3 deaths only. Among 68 untreated patients, those with higher sCD14 levels had more rapid spontaneous CD4 cell decline during the first 18 months following primary infection. This association persisted after adjustment for age, the CD4 cell count, and HIV viral load at diagnosis.

A Mature NK Profile at the Time of HIV Primary Infection Is Associated with an Early Response to cART

Natural killer (NK) cells are major effectors of the innate immune response. Despite an overall defect in their function associated with chronic human immunodeficiency virus (HIV) infection, their role in primary HIV infection is poorly understood. We investigated the modifications of the NK cell compartment in patients from the ANRS-147-Optiprim trial, a study designed to examine the benefits of intensive combination antiretroviral therapy (cART) in patients with acute or early primary HIV infection. Multiparametric flow cytometry combined with bioinformatics analyses identified the NK phenotypes in blood samples from 30 primary HIV-infected patients collected at inclusion and after 3u2009months of cART. NK phenotypes were revealed by co-expression of CD56/CD16/NKG2A/NKG2C and CD57, five markers known to delineate stages of NK maturation. Three groups of patients were formed according to their distributions of the 12 NK cell phenotypes identified. Their virological and immunological characteristics were compared along with the early outcome of cART. At inclusion, HIV-infected individuals could be grouped into those with predominantly immature/early differentiated NK cells and those with predominantly mature NK cells. Several virological and immunological markers were improved in patients with mature NK profiles, including lower HIV viral loads, lower immune activation markers on NK and dendritic cell (DC), lower levels of plasma IL-6 and IP-10, and a trend to normal DC counts. Whereas all patients showed a decrease of viremia higher than 3 log10u2009copies/ml after 3u2009months of treatment, patients with a mature NK profile at inclusion reached this threshold more rapidly than patients with an immature NK profile (70 vs. 38%). In conclusion, a better early response to cART is observed in patients whose NK profile is skewed to maturation at inclusion. Whether the mature NK cells contributed directly or indirectly to HIV control through a better immune environment under cART is unknown. The NK maturation status of primary infected patients should be considered as a relevant marker of an immune process contributing to the early outcome of cART that could help in the management of HIV-infected patients.

A Subset of Extreme Human Immunodeficiency Virus (HIV) Controllers Is Characterized by a Small HIV Blood Reservoir and a Weak T-Cell Activation Level

Abstract Background Human immunodeficiency virus controllers (HICs) form a heterogeneous group of patients with regard to formal definitions, immunologic characteristics, and changes over time in viral load. Patients and Methods The HICs with undetectable viral load ([uHICs] ie, for whom a viral load had never been detected with routine assays; n = 52) were compared with 178 HICs with blips during the follow up (bHICs). Clinical characteristics, ultrasensitive HIV-ribonucleic acid (RNA) and HIV-deoxyribonucleic acid (DNA) loads, HIV1-Western blot profiles, and immune parameters were analyzed. Results Relative to bHICs, uHICs had significantly lower ultrasensitive plasma HIV-RNA loads (P < .0001) and HIV-DNA levels in peripheral blood mononuclear cells (P = .0004), higher CD4+ T-cell count (P = .04) at enrollment, and lower T-cell activation levels. Between diagnosis and inclusion in the cohort, the CD4+ T-cell count had not changed in uHICs but had significantly decreased in bHICs. Twenty-one percent of the uHICs lacked specific anti-HIV immunoglobulin G antibodies, and these individuals also had very low levels of HIV-DNA. Half of the uHICs had a protective human leukocyte antigen (HLA) allele (-B57/58/B27), a weak CD8+ T-cell response, and very small HIV-DNA reservoir. Conclusions We suggest that an interesting HIC phenotype combines protective HLA alleles, low level of HIV blood reservoirs, and reduced immune activation. Prospective studies aimed at evaluating the benefit of combined antiretroviral therapy in HICs might take into account the identification of uHICs and bHICs.

Impact of early cART on HIV blood and semen compartments at the time of primary infection

Background HIV-infected cells in semen facilitate viral transmission. We studied the establishment of HIV reservoirs in semen and blood during PHI, along with systemic immune activation and the impact of early cART. Methods Patients in the ANRS-147-OPTIPRIM trial received two years of early cART. Nineteen patients of the trial were analyzed, out of which 8 had acute PHI (WB ≤1 Ab). We quantified total cell-associated (ca) HIV-DNA in blood and semen and HIV-RNA in blood and semen plasma samples, collected during PHI and at 24 months of treatment. Results At enrollment, HIV-RNA load was higher in blood than in semen (median 5.66 vs 4.22 log10 cp/mL, p<0.0001). Semen HIV-RNA load correlated strongly with blood HIV-RNA load (r = 0.81, p = 0.02, the CD4 cell count (r = -0.98, p<0.0001), and the CD4/CD8 ratio (r = -0.85, p<0.01) in acute infection but not in later stages of PHI. Median blood and seminal cellular HIV-DNA levels were 3.59 and 0.31 log10cp/106 cells, respectively. HIV-DNA load peaked in semen later than in blood and then correlated with blood IP10 level (r = 0.62, p = 0.04). HIV-RNA was undetectable in blood and semen after two years of effective cART. Semen HIV-DNA load declined similarly, except in one patient who had persistently high IP-10 and IL-6 levels and used recreational drugs. Conclusions HIV reservoir cells are found in semen during PHI, with gradual compartmentalization. Its size was linked to the plasma IP-10 level. Early treatment purges both the virus and infected cells, reducing the high risk of transmission during PHI. Clinical trials registration NCT01033760

The potential role of HIV-specific CD38-/HLA-DR+ CD8+ T cells in viral suppressive activity and cytotoxicity in HIV controllers

In HIV-1 infection, some rare patients called HIV controllers (HICs) are capable to spontaneously control viral replication in vivo. Interestingly, HICs exhibit higher frequency of a particular activated phenotype CD38-HLA-DR+ HIV-specific CD8+ T cells. The aim of this study was to characterize this profile and evaluate its role in HICs.