Sergio Lo Caputo

Self-reported symptoms and medication side effects influence Adherence to highly active antiretroviral therapy in persons with HIV infection

Objectives: To identify variables predictive of nonadherence to highly active antiretroviral therapy (HAART) and to assess whether self‐reported symptoms or medication side effects are related to adherence. Design: Cross‐sectional multicenter study Adherence Italian Cohort Naive Antiretrovirals [AdICONA] within the Italian Cohort Naive Antiretrovirals (ICONA). Methods: Participants receiving HAART completed a 16‐item self‐administered questionnaire to assess nonadherence in the last 3 days as well as the type and intensity of 24 common HIV‐ and HAART‐related symptoms experienced during the last 4 weeks. Results: From May 1999 to March 2000, 358 persons were enrolled: 22% reported nonadherence and were less likely to have HIV RNA <500 copies/ml (odds ratio = 0.51; 95% confidence interval: 0.31‐0.85). Frequency of moderate/severe symptoms or medication side effects in nonadherent participants ranged from 3.6% to 30%. On univariate analysis, nausea, anxiety, confusion, vision problems, anorexia, insomnia, taste perversion, and abnormal fat distribution were significantly associated with nonadherence. Nonadherent persons had a higher mean overall symptom score (12.3 ± 9.2 versus 8.1 ± 6.6; p < .001) and mean medication side effect score (2.9 ± 2.7 versus 1.9 ± 1.9; p < .001) when compared with adherent participants. In the multivariate analysis, nausea (p = .003); anxiety (p = .006); younger age (p = .007); unemployment (p < .001); not recalling name, color, and timing of drugs (p = .009); running out of pills between visits (p = .002); and being too busy (p = .03) were independently associated with nonadherence in the last 3 days. Conclusions: In addition to patient characteristics, medication‐related variables, and reasons for nonadherence, patient‐reported symptoms and medication side effects were significantly associated with adherence to HAART.

Human Immunodeficiency Virus (HIV)-Specific IgA and HIV Neutralizing Activity in the Serum of Exposed Seronegative Partners of HIV-Seropositive Persons

The presence and activity of human immunodeficiency virus (HIV)-specific antibodies were analyzed in the sera of 15 sexually exposed seronegative persons who had systemic HIV-specific cell-mediated immunity and IgA-mediated mucosal immunity and in their HIV-infected partners. The HIV-positive subjects had HIV-specific serum IgG and IgA; the seronegative persons had HIV-specific serum IgA in the absence of IgG. Testing of the seronegative persons 1 year after the interruption of at-risk sex showed that no IgG seroconversion had occurred and that HIV-specific IgA serum concentrations had declined. Serum from the HIV-exposed seronegative persons was analyzed for the ability to neutralize primary HIV-1 isolates. Neutralizing activity was detected in 5 of 15 sera and in 2 cases was retained by serum-purified IgA. Thus, the immunologic picture for resistance to HIV infection should include HIV-specific cell-mediated immunity as well as HIV-specific IgA-mediated mucosal and systemic immunity.

IL-22 Participates in an Innate Anti-HIV-1 Host-Resistance Network through Acute-Phase Protein Induction

Certain individuals are resistant to HIV-1 infection, despite repeated exposure to the virus. Although protection against HIV-1 infection in a small proportion of Caucasian individuals is associated with mutant alleles of the CCR5 HIV-1 coreceptor, the molecular mechanism underlying resistance in repeatedly HIV-1-exposed, uninfected individuals (EU) is unclear. In this study, we performed complementary transcriptome and proteome analyses on peripheral blood T cells, and plasma or serum from EU, their HIV-1-infected sexual partners, and healthy controls, all expressing wild-type CCR5. We report that activated T cells from EU overproduce several proteins involved in the innate immunity response, principally those including high levels of peroxiredoxin II, a NK-enhancing factor possessing strong anti-HIV activity, and IL-22, a cytokine involved in the production of acute-phase proteins such as the acute-phase serum amyloid A (A-SAA). Cell supernatants and serum levels of these proteins were up-regulated in EU. Moreover, a specific biomarker for EU detected in plasma was identified as an 8.6-kDa A-SAA cleavage product. Incubation of in vitro-generated myeloid immature dendritic cells with A-SAA resulted in CCR5 phosphorylation, down-regulation of CCR5 expression, and strongly decreased susceptibility of these cells to in vitro infection with a primary HIV-1 isolate. Taken together, these results suggest new correlates of EU protection and identify a cascade involving IL-22 and the acute phase protein pathway that is associated with innate host resistance to HIV infection.

Mucosal and systemic HIV-1-specific immunity in HIV-1-exposed but uninfected heterosexual men.

Background: Despite multiple, repeated exposures to HIV-1, some individuals never seroconvert. Mucosal and systemic immune correlates of this condition have been analysed in HIV-1-exposed women but no data are available concerning mucosal immunity and HIV-1-specific immune responses in exposed but uninfected men. Design: We analysed cellular and humoral immune parameters in peripheral lymphocytes, seminal fluid and urethral swabs of 14 recently HIV-1-exposed seonegative (ESN) heterosexual men, seven HIV-seropositive patients and seven healthy controls. Results: HIV-1-specific IgA were detected in urethral swabs of 11 out of 14 ESN and of six out of seven HIV-seropositive patients; Env- and Gag-specific IFNγ-producing CD4 and CD8 peripheral lymphocytes were present in ESN and HIV-seropositive patients; seminal lymphocytes, but not peripheral blood lymphocytes, of ESN were enriched in activated populations (CD8CD38RO and CD4CD25). p24-specific cytotoxic T lymphocytes were correlated with the percentage of CD4 in the HIV-seropositive partners. High urethral concentrations of HIV-1-specific IgA were seen in those ESN with the most recent unprotected sexual episode. Conclusions: This is the first report of HIV-specific mucosal immunity in ESN men. These data add to the body of knowledge of the immune correlates present in exposed, uninfected individuals and might be important in vaccine design.

Apolipoprotein B mRNA—Editing Enzyme, Catalytic Polypeptide—Like 3G: A Possible Role in the Resistance to HIV of HIV-Exposed Seronegative Individuals

Apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G (APOBEC3G), a human cytidine deaminase, is a potent inhibitor of HIV replication. To explore a possible role of this protein in modulating in vivo susceptibility to HIV infection, we analyzed APOBEC3G expression in HIV-exposed seronegative individuals, HIV-seropositive patients, and healthy control subjects. The results showed that the expression of APOBEC3G is significantly increased in peripheral blood mononuclear cells (PBMCs)--mainly CD14(+) cells--and in cervical tissues of HIV-exposed seronegative individuals. Higher APOBEC3G expression correlated with a reduced susceptibility of PBMCs to in vitro infection with the HIV-1(Ba-L) R5 strain. APOBEC3G could be important in modulating in vivo susceptibility to sexually transmitted HIV infection.

A Common Polymorphism in TLR3 Confers Natural Resistance to HIV-1 Infection

TLR3 recognizes dsRNA and activates antiviral immune responses through the production of inflammatory cytokines and type I IFNs. Genetic association studies have provided evidence concerning the role of a polymorphism in TLR3 (rs3775291, Leu412Phe) in viral infection susceptibility. We genotyped rs3775291 in a population of Spanish HIV-1–exposed seronegative (HESN) individuals who remain HIV seronegative despite repeated exposure through i.v. injection drug use (IDU-HESN individuals) as witnessed by their hepatitis C virus seropositivity. The frequency of individuals carrying at least one 412Phe allele was significantly higher in IDU-HESN individuals compared with that of a matched control sample (odds ratio for a dominant model = 1.87; 95% confidence interval, 1.06–3.34; p = 0.023). To replicate this finding, we analyzed a cohort of Italian, sexually HESN individuals. Similar results were obtained: the frequency of individuals carrying at least one 412Phe allele was significantly higher compared with that of a matched control sample (odds ratio, 1.79; 95% confidence interval, 1.05–3.08; p = 0.029). In vitro infection assays showed that in PBMCs carrying the 412Phe allele, HIV-1Ba-L replication was significantly reduced (p = 0.025) compared with that of Leu/Leu homozygous samples and was associated with a higher expression of factors suggestive of a state of immune activation (IL-6, CCL3, CD69). Similarly, stimulation of PBMCs with a TLR3 agonist indicated that the presence of the 412Phe allele results in a significantly increased expression of CD69 and higher production of proinflammatory cytokines including IL-6 and CCL3. The data of this study indicate that a common TLR3 allele confers immunologically mediated protection from HIV-1 and suggest the potential use of TLR3 triggering in HIV-1 immunotherapy.

Mucosal and Systemic Immune Activation Is Present in Human Immunodeficiency Virus—Exposed Seronegative Women

Immune parameters were analyzed in peripheral blood mononuclear cells (PBMC) and cervical mucosa biopsy specimens of human immunodeficiency virus (HIV)-seronegative women sexually exposed to HIV (exposed seronegative [ESN]), HIV-infected women, and healthy women without HIV exposure. HIV was not detected in PBMC or cervical mucosa biopsy specimens of ESN women. However, interleukin (IL)-6, IL-10, IL-12, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha and -beta mRNA were elevated in PBMC and cervical mucosa biopsy specimens of ESN and HIV-infected women; CCR5 and CXCR4 mRNA were augmented in cervical mucosa biopsy specimens, but not in PBMC, of ESN and HIV-infected women; HIV-specific IFN-gamma-secreting cells were detected in vaginal washes of ESN and HIV-infected women; and phenotypic alterations were present in PBMC of ESN women. These results suggest that active HIV infection is not required for T cell activation; immune alterations occur in women in whom HIV infection cannot be detected virologically or clinically.

Human α Defensin in HIV-Exposed but Uninfected Individuals

Abstract:Human &agr; defensins 1, 2, and 3 are produced by CD8+ T cells of HIV-infected long-term nonprogressors and have an antiviral activity. &agr; Defensins were examined in peripheral blood mononuclear cells (PBMCs), cervical-vaginal mononuclear cells (CVMCs), and cervical biopsies of 9 HIV-1-exposed but uninfected women (ESNs), 10 HIV-infected patients (HIV), and 13 low-risk healthy controls (HCs). Results showed that, whereas &agr; defensin production and &agr; defensin-expressing CD8 lymphocytes were comparable in ESNs and HIV patients, constitutive &agr; defensin production by peripheral CD8 and CVMCs was augmented in ESNs compared with HCs (P = 0.001 and P = 0.058, respectively); &agr; defensin mRNA was increased in PBMCs of ESNs; unstimulated, &agr; defensin-expressing peripheral and mucosal CD8 lymphocytes were 10-fold higher in ESNs compared with HCs (P = 0.003 and P = 0.01, respectively); and &agr; defensin mRNA and &agr; defensin-expressing cells were augmented in cervical biopsies of ESN compared with HCs (mRNA:P = 0.03). The differences were reduced upon in vitro mitogen stimulation. A robust constitutive production of &agr; defensin is seen in HIV-exposed uninfected individuals; these peptides could have a role in the potentially protective immune response that characterizes ESNs.

Genetic diversity at endoplasmic reticulum aminopeptidases is maintained by balancing selection and is associated with natural resistance to HIV-1 infection

Human ERAP1 and ERAP2 encode two endoplasmic reticulum aminopeptidases. These enzymes trim peptides to optimal size for loading onto major histocompatibility complex class I molecules and shape the antigenic repertoire presented to CD8(+) T cells. Therefore, ERAP1 and ERAP2 may be considered potential selection targets and modulators of infection susceptibility. We resequenced two genic regions in ERAP1 and ERAP2 in three HapMap populations. In both cases, we observed high levels of nucleotide variation, an excess of intermediate-frequency alleles, and reduced population genetic differentiation. The genealogy of ERAP1 and ERAP2 haplotypes was split into two major branches with deep coalescence times. These features suggest that long-standing balancing selection has acted on these genes. Analysis of the Lys528Arg (rs30187 in ERAP1) and Asn392Lys (rs2549782 in ERAP2) variants in an Italian population of HIV-1-exposed seronegative (ESN) individuals and a larger number of Italian controls indicated that rs2549782 significantly deviates from Hardy-Weinberg equilibrium (HWE) in ESN but not in controls. Technical errors were excluded and a goodness-of-fit test indicated that a recessive model with only genetic effects adequately explains HWE deviation. The genotype distribution of rs2549782 is significantly different in the two cohorts (P = 0.004), mainly as the result of an over-representation of Lys/Lys genotypes in the ESN sample (P-value for a recessive model: 0.00097). Our data suggest that genetic diversity in ERAP1 and ERAP2 has been maintained by balancing selection and that variants in ERAP2 confer resistance to HIV-1 infection possibly via the presentation of a distinctive peptide repertoire to CD8(+) T cells.

Study of Genotypic and Phenotypic HIV-1 Dynamics of Integrase Mutations During Raltegravir Treatment: A Refined Analysis by Ultra-Deep 454 Pyrosequencing

BACKGROUND The dynamics of raltegravir-resistant variants and their impact on virologic response in 23 HIV-1-infected patients, who started a salvage raltegravir-containing regimen, were investigated. METHODS Integrase population sequencing and Ultra-Deep-454 Pyrosequencing (UDPS) were performed on plasma samples at baseline and at raltegravir failure. All integrase mutations detected at a frequency ≥1% were considered to be reliable for the UDPS analyses. Phylogenetic and phenotypic resistance analyses were also performed. RESULTS At baseline, primary resistance mutations were not detected by both population and UDPS genotypic assays; few secondary mutations (T97A-V151I-G163R) were rarely detected and did not show any statistically association either with virologic response at 24-weeks or with the development of resistant variants at failure. At UDPS, not all resistant variants appearing early during treatment evolved as major populations during failure; only specific resistance pathways (Y143R-Q148H/R-N155H) associated with an increased rate of fitness and phenotypic resistance were selected. CONCLUSIONS Resistance to raltegravir in integrase strand transfer inhibitor-naive patients remains today a rare event, which might be changed by future extensive use of such drugs. In our study, pathways of resistance at failure were not predicted by baseline mutations, suggesting that evolution plus stochastic selection plays a major role in the appearance of integrase-resistance mutations, whereas fitness and resistance are dominant factors acting for the late selection of resistant quasispecies.