Amedeo Capetti

Hydroxychloroquine drastically reduces immune activation in HIV-infected, antiretroviral therapy-treated immunologic nonresponders.

Despite optimal suppression of HIV replication, restoration of CD4(+) T cells is not always achieved in antiretroviral therapy-treated individuals. Defective CD4 recovery in immunologic nonresponders is possibly associated with TLR-mediated immune activation driven by alterations of gut permeability. Hydroxychloroquine (HCQ) reduces endosomal TLR signaling; thus, we verified whether HCQ could dampen immune activation and be associated with an increase in CD4(+) T cells. To this end, we enrolled in a prospective study 20 HIV-infected immunologic nonresponders (CD4 count < 200 cells/mL or CD4 increase < 5% in the last 12 months) who received 400 mg/day HCQ for 6 months. HCQ had a notable impact on immune activation as shown by significant modifications of the following parameters: (1) reduced plasma lipopolysaccharide; (2) decreased TLR4-expressing CD14(+) cells, TLR4-mediated signal transduction, and mRNA synthesis; (3) reduced percentages of activated CD4(+) (CD4(+)/Ki67(+)) and CD14(+) (CD14(+)/CD69(+)) cells; (4) increased T-regulatory cells (Tregs), naive Tregs, and TLR4-expressing Tregs; (5) augmented plasmacytoid dendritic cells and reduced IFNα-secreting plasmacytoid dendritic cells; and (6) reduced IL-6 and TNFα production. HCQ-induced immune modulation was associated with increased percentages of circulating CD4(+) T cells and was mostly retained 2 months after therapy interruption. HCQ reduces lipopolysaccharide/TLR-mediated immune activation; this compound could be a useful immunomodulant in HIV-infected patients. This study is registered at EutraCT as 2009-012499-28 with study number HLS01/2009-1-16-03-2009.

Evaluation of the immune benefits of two probiotic strains Bifidobacterium animalis ssp. lactis, BB-12® and Lactobacillus paracasei ssp. paracasei, L. casei 431® in an influenza vaccination model: a randomised, double-blind, placebo-controlled study

The present study investigated the ability of Bifidobacterium animalis ssp. lactis (BB-12®) and Lactobacillus paracasei ssp. paracasei (L. casei 431®) to modulate the immune system using a vaccination model in healthy subjects. A randomised, double-blind, placebo-controlled, parallel-group study was conducted in 211 subjects (56 % females, mean age 33·2 (sd 13·1) years). Subjects consumed a minimum of 10⁹ colony-forming units of BB-12® (capsule) or L. casei 431® (dairy drink) or a matching placebo once daily for 6 weeks. After 2 weeks, a seasonal influenza vaccination was given. Plasma and saliva samples were collected at baseline and after 6 weeks for the analysis of antibodies, cytokines and innate immune parameters. Changes from baseline in vaccine-specific plasma IgG, IgG1 and IgG3 were significantly greater in both probiotic groups v. the corresponding placebo group (L. casei 431®, P = 0·01 for IgG; P < 0·001 for remaining comparisons). The number of subjects obtaining a substantial increase in specific IgG (defined as ≥ 2-fold above baseline) was significantly greater in both probiotic groups v. placebo (BB-12®, P < 0·001 for IgG, IgG1 and IgG3; L. casei 431®, P < 0·001 for IgG1 and IgG3). Significantly greater mean fold increases for vaccine-specific secretory IgA in saliva were observed in both probiotic groups v. placebo (BB-12®, P = 0·017; L. casei 431®, P = 0·035). Similar results were observed for total antibody concentrations. No differences were found for plasma cytokines or innate immune parameters. Data herein show that supplementation with BB-12® or L. casei 431® may be an effective means to improve immune function by augmenting systemic and mucosal immune responses to challenge.

Immune activation, apoptosis, and Treg activity are associated with persistently reduced CD4+ T-cell counts during antiretroviral therapy.

Background:Persistently reduced CD4+ T-lymphocyte counts in the face of undetectable HIV viremia are seen in a sizable percentage of HIV-infected patients undergoing antiretroviral therapy (ART). We analyzed the immune correlates of this phenomenon. Materials and methods:Sixty-seven HIV-infected patients with undetectable viremia (<50 copies/μl) after more than 7 years of ART were enrolled in the study and divided into two groups (CD4 cell counts >500 cells/μl or <500 cells/μl). Duration of HIV infection (>16 years) was comparable. Peripheral blood mononuclear cell were stimulated with gag+env or with cytomegalovirus peptides. Activated T cells (Ki67+), Treg lymphocytes (CD4+/CD25high/Foxp3+), divided into naive and activated cells based on PD1 expression, interleukin (IL)-10 and transforming growth factor (TGF)-β production, annexin V, activation of caspases 8 and 9, Toll-like receptor (TLR)2 and TLR4 expression on immune cells, and plasma lipopolysaccharide (LPS) concentration were analyzed. Results:CD4+/Ki67+ T cells; plasma LPS; total, naive, and activated Treg; TLR2-expressing and TLR4-expressing Treg; IL-10 production; and early and late apoptotic CD4 T cells, were significantly increased in patients with undetectable viremia and CD4 cell counts less than 500 cells/μl after more than 7 years of ART. As previously shown, CD4 nadir were also lower in these individuals. Immune activation, LPS concentration, Treg, and degree of apoptosis were negatively correlated with CD4 cell counts. Conclusion:Lack of CD4 recovery in individuals in whom ART suppresses HIV replication is associated with complex immune alterations. Immune activation, likely driven by altered gut permeability and resulting in augmented Treg activity could play a pivotal role in this process.

A novel methodology for large-scale phylogeny partition

Phylogenetic analysis is used to identify transmission chains, but no software is available for the automated partition of large phylogenies. Prosperiet al. apply a new search algorithm to identify transmission clusters within the phylogeny of HIV-1gene sequences linking molecular and epidemiological data. Supplementary information The online version of this article (doi:10.1038/ncomms1325) contains supplementary material, which is available to authorized users.

Plasma Concentration of Cytokine Antagonists in Patients with HIV Infection

There is increasing evidence that cytokines contribute to the immunopathogenesis of human immunodeficiency virus (HIV) infection. It may be, therefore, that compensatory rises in circulating cytokine antagonists also occur in HIV infection and that such changes mark disease progression. To test this idea, plasma concentrations of the cytokine antagonists alpha-melanocyte-stimulating hormone (alpha-MSH), interleukin-1 receptor antagonist (IL-1ra), and soluble tumor necrosis factor receptor (sTNFr) were measured in patients of different Centers for Disease Control (CDC) categories of HIV infection and in seronegative controls. Plasma levels of all these cytokine antagonists were higher in HIV-infected patients. IL-1ra and sTNFr concentrations were correlated with indicators of disease activity: positively with plasma neopterin and negatively with CD4+ T lymphocyte counts. alpha-MSH and sTNF r were greater in CDC groups III and IV, whereas IL-1ra was elevated only in the latter group. Because cytokines activate the hypothalamic-pituitary-adrenal axis and adrenal steroids inhibit cytokine production, we measured circulating adrenocorticotropic hormone (ACTH) and cortisol in HIV-infected patients and investigated relations among these hormones, cytokine antagonists, and markers of disease progression. It appears that these physiological modulators of cytokine activity are not closely linked to sTNFr, IL-1ra and alpha-MSH: there were no significant correlations between plasma concentrations of ACTH or cortisol and those of cytokine antagonists, nor were there correlations between hormones and markers of disease progression such as neopterin or CD4+ T cell counts. It is notable that severe adrenal insufficiency was extremely rare (3%) in HIV-infected patients; it was confined to the AIDS group and was consistently secondary to ACTH deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Intractable pruritus in HIV infection: immunologic characterization.

Background: Severe, intractable pruritus, often associated with erythematopapular skin lesions and hypereosinophilia, is a condition observed in some nonatopic, HIV‐infected patients. We performed immunovirologic analyses of this condition.

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

Nanoformulation of antiretroviral drugs enhances their penetration across the blood brain barrier in mice

UNLABELLED Eradication of virus by sanctuary sites is a main goal in HIV management. The central nervous system (CNS) is a classic model of sanctuary where viral replication occurs despite a complete viral suppression in peripheral blood. In recent years, nanotechnologies have provided a great promise in the eradication of HIV from the CNS. We hereby demonstrate for the first time that the structurally complex antiretroviral drug enfuvirtide (Enf), which normally is unable to penetrate the cerebrospinal fluid, is allowed to cross the blood brain barrier (BBB) in mice by conjugation with a nanoconstruct. Iron oxide nanoparticles coated with an amphiphilic polymer increase Enf translocation across the BBB in both in vitro and in vivo models. The mechanism involves the uptake of nanoconjugated-Enf in the endothelial cells, the nanocomplex dissociation and the release of the peptide, which is eventually excreted by the cells in the brain parenchyma. FROM THE CLINICAL EDITOR Despite the success of cocktail therapy of antiretroviral drugs, the complete eradication of HIV remains elusive, due to existence of viral sanctuary sites. The authors showed in this study that an antiretroviral drug complexed with iron oxide nanoparticles and coated with PMA amphiphilic polymer crosses the blood brain barrier. Furthermore, there was significant anti-viral activity. The results would aid further drug designs to eradicate HIV.

Pentoxifylline Improves Cell-Mediated Immunity and Reduces Human Immunodeficiency Virus (HIV) Plasma Viremia in Asymptomatic HIV-Seropositive Persons

The effects of pentoxifylline on immunologic and virologic parameters were evaluated in 10 human immunodeficiency virus-infected patients not receiving antiretroviral treatment. Patients were asymptomatic, had 300-500 CD4 cells/microL, and received pentoxifylline (1200 mg/day orally) for 4 months. Peripheral blood mononuclear cells were tested before and at five time points during therapy. A transient increase in CD4 cells was observed in 8 of 9 patients, and CD8 cells increased in 7 of 9 patients. These increases were negatively correlated with susceptibility to in vitro mitogen-stimulated apoptotic cell death. Pentoxifylline had a temporary effect on mitogen-stimulated cytokine production; thus, interferon-gamma, interleukin (IL)-2, tumor necrosis factor-alpha, and lymphotoxin increased more than IL-10. Pentoxifylline also potentiated antigen-stimulated IL-2 production and proliferation in 8 of 9 patients and induced significant but transient decreases in plasma viremia in 7 of 9 patients. These preliminary findings suggest that pentoxifylline in vivo has an interesting but temporary influence on both immunologic and virologic parameters.

Transmitted HIV type 1 drug resistance and non-B subtypes prevalence among seroconverters and newly diagnosed patients from 1992 to 2005 in Italy.

The patterns of transmitted drug-resistant (TDR) HIV-1 variants, non-B subtype spread, and epidemiological trends were evaluated either in seroconverters or in newly diagnosed individuals in Italy over a 13-year period. We analyzed 119 seroconverters, enrolled from 1992 to 2003 for the CASCADE study, and 271 newly diagnosed individuals of the SPREAD study (2002-2005), of whom 42 had a known seroconversion date. Overall, TDR was 15.1% in the CASCADE and 12.2% in the SPREAD study. In the 1992-2003 period, men having sex with men (MSMs) and heterosexuals (HEs) were 48.7% and 36.8%, respectively; TDR was found to be higher in MSMs compared to HEs (78.9% vs. 21%, p = 0.006). The same groups were 39.1% and 53.3% in the SPREAD study; however, no association was detected between modality of infection and TDR. Overall, 9.2% and 22.1% of individuals harbored a non-B clade virus in the CASCADE and SPREAD study, respectively. As evidence of onward transmission, 40% (24/60) of non-B variants were carried by European individuals in the latter study; among these patients the F1 subtype was highly prevalent (p = 0.00001). One of every eight patients who received a diagnosis of HIV-1 in recent years harbored a resistant variant, reinforcing the arguments for baseline resistance testing to customize first-line therapy in newly infected individuals. The spread of non-B clades may act as a dilution factor of TDR concealing the proportion of TDR in seroconverters and MSMs.