Anna Rita Buonomini

Maraviroc as intensification strategy in HIV-1 positive patients with deficient immunological response: an Italian randomized clinical trial.

Background Immunological non-responders (INRs) lacked CD4 increase despite HIV-viremia suppression on HAART and had an increased risk of disease progression. We assessed immune reconstitution profile upon intensification with maraviroc in INRs. Methods We designed a multi-centric, randomized, parallel, open label, phase 4 superiority trial. We enrolled 97 patients on HAART with CD4+<200/µL and/or CD4+ recovery ≤25% and HIV-RNA<50 cp/mL. Patients were randomized 1:1 to HAART+maraviroc or continued HAART. CD4+ and CD8+ CD45+RA/RO, Ki67 expression and plasma IL-7 were quantified at W0, W12 and W48. Results By W48 both groups displayed a CD4 increase without a significant inter-group difference. A statistically significant change in CD8 favored patients in arm HAART+maraviroc versus HAART at W12 (p=.009) and W48 (p=.025). The CD4>200/µL and CD4>200/µL + CD4 gain ≥25% end-points were not satisfied at W12 (p=.24 and p=.619) nor at W48 (p=.076 and p=.236). Patients continuing HAART displayed no major changes in parameters of T-cell homeostasis and activation. Maraviroc-receiving patients experienced a significant rise in circulating IL-7 by W48 (p=.01), and a trend in temporary reduction in activated HLA-DR+CD38+CD4+ by W12 (p=.06) that was not maintained at W48. Conclusions Maraviroc intensification in INRs did not have a significant advantage in reconstituting CD4 T-cell pool, but did substantially expand CD8. It resulted in a low rate of treatment discontinuations. Trial Registration ClinicalTrials.gov NCT00884858 http://clinicaltrials.gov/show/NCT00884858

HIV-1 dual/mixed tropic isolates show different genetic and phenotypic characteristics and response to maraviroc in vitro

Dual/mixed-tropic HIV-1 strains are predominant in a significative proportion of patients, though few information is available regarding the genetic characteristics, quasispecies composition, and susceptibility against CCR5-antagonists of the primary-isolates. For this reason, we investigated in deep details, both phenotypically and genotypically, the characteristics of 54 HIV-1 primary-isolates obtained from HIV-infected patients. Tropism was assessed by multiple-cycles phenotypic-assay on U87MG-CD4(+)-CCR5(+)-/CXCR4(+)-expressing cells. In vitro selection in PBMCs of X4-tropic viral strains following maraviroc-treatment was also performed. Phenotypic-assay reported pure R5-tropic viruses in 31 (57.4%) isolates, dual/mixed-tropic viruses in 22 (40.7%), and pure X4-tropic virus in only 1 (1.8%). Among dual/mixed-tropic isolates, 12 showed a remarkably higher replication-efficacy in CCR5-expressing cells (R5(+)/X4), and 2 in CXCR4-expressing cells (R5/X4(+)). Genotypic-tropism testing showed a correlation between PSSM-scores, geno2pheno false-positive-rate, and V3-net-charge with both CCR5-usage and syncytium-inducing ability. Moreover, specific gp120- and gp41-mutations were significantly associated with tropism and/or syncytium-inducing ability. Ultra-deep V3-pyrosequencing showed the presence of a swarm of genetically distinct species with a preference for CCR5-coreceptor not only in all pure R5-isolates, but also in 6/7 R5(+)/X4-tropic isolates. In both pure-X4 and R5/X4(+)-isolates, we observed extensive prevalence of X4-using species. In vitro selection-experiments with CCR5-inhibitor maraviroc (up to 2 months) showed no-emergence of X4-tropic variants for all R5- and R5(+)/X4-isolates tested (while X4-virus remained fully-resistant). In conclusion, our study shows that dual/mixed-tropic viruses are constituted by different species, whereby those with characteristics R5(+)/X4 are genotypically and phenotypically similar to the pure-R5 isolates; thus the use of CCR5-antagonists in patients with R5(+)/X4-tropic viruses may be a therapeutic-option that deserves further investigations.

Maraviroc intensification for HIV-1-positive immunological non-responders (INRs) despite virological suppression during HAART

7‐11 November 2010, Tenth International Congress on Drug Therapy in HIV Infection, Glasgow, UK

Expression and Function of NKG2D Is Impaired in CD8+ T Cells of Chronically HIV-1-Infected Patients Without ART.

Objectives:Increasing line of evidence indicates that the NKG2D-activating receptor plays a relevant role in the effector functions of cytotoxic lymphocytes. In this study, we investigated the expression and function of NKG2D in CD8+ T cells from chronically HIV-1–infected patients with or without antiretroviral therapy (ART). Methods:We measured by flow cytometry the expression of NKG2D on CD8+ T-cell subsets of ART-naive and ART patients as well as seronegative healthy subjects (HIV-neg). An intrapatient analysis before and after ART initiation was also performed. Results were correlated with viral load, CD4+ T-cell counts, markers of immune activation (CD38, sCD14), and soluble NKG2D ligands (sMICA and sULBP2). The function of NKG2D on CD8+ T cell cytotoxicity was tested by ex vivo degranulation assays. Results:We showed that NKG2D was downregulated on all CD8+ T-cell subsets of ART-naive patients. The expression of NKG2D on CD8+ T cells inversely correlated with viral load and CD38 expression but not with plasma levels of sMICA and sULBP2. Importantly, we found that NKG2D-mediated costimulation of CD8+ T-cell lytic activity was strongly reduced in ART-naive patients if compared with HIV-neg and ART subjects. Finally, intrapatient analysis demonstrated that effective anti-HIV-1 therapy restores NKG2D expression and NKG2D-induced cytotoxicity by CD8+ T cells. Conclusions:These data underscore that NKG2D downregulation contributes to impaired CD8+ T-cell responses in untreated HIV-1 infection and have implications for monitoring immune functions and response to treatments, and for the development of novel anti-HIV-1 strategies combining ART with drugs that stimulate NKG2D expression and function.

Brief Report: L-Selectin (CD62L) Is Downregulated on CD4+ and CD8+ T Lymphocytes of HIV-1-Infected Individuals Naive for ART.

Abstract:The expression of L-selectin (CD62L) in HIV-1 infection has not been extensively investigated. Here, we measured CD62L expression on T-cell subsets of HIV-1–infected individuals naive for antiretroviral therapy (ART-naive) or receiving therapy (ART), and seronegative control subjects (HIV-neg). We found reduced frequencies of CD62L+ cells among CD4+ and CD8+ T cells from ART-naive as compared with ART and HIV-neg groups, particularly within naive and central memory subsets. CD62L expression on T cells inversely correlated with viral load and rapidly increased after ART initiation. Plasma sCD62L levels did not correlate with CD62L expression, being higher in all HIV-1–infected individuals as compared with HIV-neg subjects. Finally, CD62L downregulation was found associated with the expression of the CD38 activation marker in CD8+ T cells, but not in CD4+ T cells. We suggest that CD62L downregulation due to unconstrained HIV-1 replication may have important consequences for T-cell circulation and function and for disease progression.