Jorge Quarleri

MicroRNAs differentially present in the plasma of HIV elite controllers reduce HIV infection in vitro

Elite controllers maintain HIV-1 viral loads below the limit of detection. The mechanisms responsible for this phenomenon are poorly understood. As microRNAs (miRNAs) are regulators of gene expression and some of them modulate HIV infection, we have studied the miRNA profile in plasma from HIV elite controllers and chronically infected individuals and compared against healthy donors. Several miRNAs correlate with CD4+ T cell count or with the known time of infection. No significant differences were observed between elite controllers and healthy donors; however, 16 miRNAs were different in the plasma of chronic infected versus healthy donors. In addition, levels of hsa-miR-29b-3p, hsa-miR-33a-5p and hsa-miR-146a-5p were higher in plasma from elite controllers than chronic infected and hsa-miR-29b-3p and hsa-miR-33a-5p overexpression significantly reduced the viral production in MT2 and primary T CD4+ cells. Therefore, levels of circulating miRNAs might be of diagnostic and/or prognostic value for HIV infection, and hsa-miR-29b-3p and miR-33a-5p may contribute to the design of new anti-HIV drugs.

Drug resistance testing provides evidence of the globalization of HIV type 1: a new circulating recombinant form.

To monitor HIV-1 diversity in Argentina, a phylogenetic-based analysis of HIV-1 partial pol sequences obtained for resistance testing in 587 treatment failure patients was performed in Buenos Aires city between 2001 and 2003. HIV-1 RNA was isolated from plasma samples and partial pol fragments amplified by RT-PCR. Sequences were obtained by automated sequencing. Phylogenetic analysis was performed and recombination patterns characterized. A total of 299 sequences grouped into clade B (50.94%) and 284 were B/F recombinants (48.38%). Four sequences were grouped into clades A, C, and F (0.68%). The clade C sample, 96105, was found to be a BC recombinant and samples 103396 and 104575 showed the same mosaic pattern with Kisii5009 from Kenya and 97KR004 from Korea, previously described as A2D recombinants. With the presence of two full-length genomes, one from Kenya and one from Korea, and now two partial genomes from Argentina, this recombinant is designated CRF16_A2D. Its presence on three continents shows that CRF16_A2D has a global distribution.

HIV-1 Induces Telomerase Activity in Monocyte-Derived Macrophages, Possibly Safeguarding One of Its Reservoirs

ABSTRACT Monocyte-derived macrophages (MDM) are widely distributed in all tissues and organs, including the central nervous system, where they represent the main part of HIV-infected cells. In contrast to activated CD4+ T lymphocytes, MDM are resistant to cytopathic effects and survive HIV infection for a long period of time. The molecular mechanisms of how HIV is able to persist in macrophages are not fully elucidated yet. In this context, we have studied the effect of in vitro HIV-1 infection on telomerase activity (TA), telomere length, and DNA damage. Infection resulted in a significant induction of TA. This increase was directly proportional to the efficacy of HIV infection and was found in both nuclear and cytoplasmic extracts, while neither UV light-inactivated HIV nor exogenous addition of the viral protein Tat or gp120 affected TA. Furthermore, TA was not modified during monocyte-macrophage differentiation, MDM activation, or infection with vaccinia virus. HIV infection did not affect telomere length. However, HIV-infected MDM showed less DNA damage after oxidative stress than noninfected MDM, and this resistance was also increased by overexpressing telomerase alone. Taken together, our results suggest that HIV induces TA in MDM and that this induction might contribute to cellular protection against oxidative stress, which could be considered a viral strategy to make macrophages better suited as longer-lived, more resistant viral reservoirs. In the light of the clinical development of telomerase inhibitors as anticancer therapeutics, inhibition of TA in HIV-infected macrophages might also represent a novel therapeutic target against viral reservoirs.

HIV, HBV, and HCV molecular epidemiology among trans (transvestites, transsexuals, and transgender) sex workers in Argentina

Commercial sex work is frequent among male‐to‐female transvestites, transsexuals and transgenders in Argentina, leading to high susceptibility to HIV, HBV, and HCV among other sexually transmitted infections. In a global context of scarce data on the trans sex workers population, this study was aimed to study the genomic characterization of these viruses. Plasma presence of HIV, HBV, and HCV genomic material was evaluated in samples from 273 trans sex workers. Genomic sequences of HIV‐gag, pol, and vif‐vpu genes, HBV‐S gene, and HCV‐5′UT and NS5B genes were obtained. Molecular characterization involved phylogenetic analysis and several in silico tools. Resistance‐associated mutations in HIV and HBV pol genes were also analyzed. The HIV genomic characterization in 62 trans sex workers samples showed that 54.8% of the isolates corresponded to BF intersubtype recombinants, and 38.7% to subtype B. The remaining were classified as subtypes C (4.8%) and A (1.6%). HBV and HCV co‐infection prevalence among HIV positive trans sex workers yielded rates of 3.2% and 6.5% respectively. Drug resistance‐associated mutations were found in 12/62 (19%) HIV pol sequences, but none among HBV. Based on phylogenetic relationships, HIV isolates characterized as subtypes BF and B appeared intermingled with those from other high‐risk groups. Despite trans sex workers declared not to have received antiviral treatment, complex drug resistance‐associated mutation patterns were found in several HIV isolates. Planned prevention, screening, and treatment are needed to reduce further transmission and morbidity. J. Med. Virol. 86:64–70, 2014.

Hepatitis B precore/core promoter mutations in isolates from HBV-monoinfected and HBV-HIV coinfected patients: a 3-yr prospective study.

BACKGROUND The course of chronic HBV infection is modified by HIV-coexistence. OBJECTIVE To analyze the role of HBV genomic heterogeneity in basal core promoter (BCP) and precore (Pc) genomic regions. STUDY DESIGN In a 3-yr prospective study, 39 HBV infected patients (20 monoinfected and 19 HIV-coinfected) were included. Eighty-two HBV isolates were studied at quasispecies level in the BCP/Pc genomic region. Clinical records obtained include data on lamivudine therapy and resistance mutations, HBV and HIV-viral load. RESULTS HBV isolates were predominantly ascribed to genotype (Gt) A2 among HBV-monoinfected and HIV-coinfected patients. BCP mutations in isolates from monoinfected patients were significantly more frequent than in those from coinfected ones, irrespective of the HBe expression pattern (p<0.0001). Regardless of the HIV-coexistence, the Pc mutation at G1896A only barely appeared among clone-derived sequences of GtF1 isolates, mainly from HBe(-) HBV-monoinfected patients. CONCLUSIONS HBV isolates characterized from HIV-coinfected patients seem to be more prone to exhibit a wild type genomic pattern at BCP regulatory region with respect to those from HBV-monoinfected ones. Besides, mutations at Pc region might be genotype-dependent in their frequency but not on HIV co-presence related.

Molecular characterization of hepatitis A virus in children with fulminant hepatic failure in Argentina

Background: Hepatitis A infection, a vaccine‐preventable disease, is an important cause of fulminant hepatic failure (FHF) in children in Argentina. Universal vaccination in 1‐year‐old children was implemented in June 2005. The limited studies about the correlation between the characteristics of the hepatitis A virus (HAV) and FHF have been carried out in adults.

Hepatitis B virus, hepatitis C virus and HIV coinfection among people living with HIV/AIDS in Buenos Aires, Argentina.

The HIV epidemic in Argentina has changed since the first case was reported in 1982. Since the beginning of the 1990s, a decrease in the number parenterally acquired infections has been observed, with a marked increase in transmission through unprotected sexual contact (heterosexual and homosexual), and in the number of women living with HIV/AIDS [1]. Few prevalence studies have addressed the hepatitis B and C virus coinfection in Argentina. We performed this study in a large single clinic in Buenos Aires, taking care of more than 3,000 HIV patients. During a seven-month period (9/2004 to 3/2005), all HIV-positive patients ≥ 18 years old, who were followed up at our unit and who had their scheduled controls for HIV viral load (VL) at the Argentinean National Reference Centre for AIDS (CNRS), were invited to participate in the study. The study was approved by the Fernandez Hospital Ethics Committee. Patients gave their informed consent to be included in the study. Six hundred subjects were asked to enter the study, and 593 accepted. Studied population: 65.6% males, 64% young adults between 20 and 40 years old. The main route of HIV infection was through sexual contact (70%). Of the 593 samples, 52% (n=308) showed positive results for serological markers (HBcAb/HBsAg/anti-HCV) for hepatitis B or C coinfection. Coinfection rates and subjects characteristics are described in Table 1. Table 1 Demographics, rates of HCV/HBV coinfection, main routes of infection, median levels of CD4 cell count, HIV viral load, HAART, frequency of ALT level among HIV-positive patients studied HBV genotype A was identified in 85% of the samples with detectable HBV DNA, instead of genotype F, the most prevalent in our country among blood donors [2]. Among the 22 HBsAg-positive samples, four showed mutations in the rt domain of the pol gene. These samples belonged to patients who had a prolonged history of exposure to lamivudine (median: 25 months) and none of them had received tenofovir. This data reinforces the importance of adequate management of drugs with HBV/HIV dual activity when selecting antiretroviral therapies in coinfected patients, as stated in the last update of the European and North American guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents [3,4]. The main isolated HCV genotype was 1 (65%), followed by genotype 3 (16.5%). Our study shows a change in the prevalence of HCV and HBV coinfection comparing with a previous report of the same geographical area [5], among people living with HIV/AIDS in Buenos Aires, the city with the highest prevalence of HIV in Argentina. A reduction in prevalence rates of dual HIV/HCV (from 58.5% in 1999 to 21%, p 0.000) and HIV/HBV coinfection (from 14.5% in 1999 to 3.7%, p 0.000) was observed. This could be related to the decreasing number of injecting drug users in our country because of the introduction of non-injecting recreational drugs and the increasing transmission through unprotected sex [1]. Despite the decrease in the rates of HCV/HIV and HBV/HIV coinfections the prevalence of those coinfections continues to be high and it could lead to the increase in the morbidity and mortality associated with liver disease, especially in the context of expanded antirretroviral therapy in Argentina. The epidemiological data presented in this study provides information for the development of prevention campaigns for hepatitis C through harm reduction policies and for hepatitis B vaccination programs among people living with HIV/AIDS.

Mother-to-Child Transmission of Hepatitis C Virus (HCV) Among HIV/HCV-Coinfected Women.

BACKGROUND Maternal human immunodeficiency virus (HIV) coinfection has been associated with increased hepatitis C virus (HCV) mother-to-child transmission (MTCT). We hypothesized that HCV/HIV-coinfected women with well-controlled HIV disease would not have increased HCV MTCT. METHODS The NISDI Perinatal and LILAC cohorts enrolled HIV-infected pregnant women and their infants in Latin America and the Caribbean. This substudy evaluated the HCV infection status of mothers at participating sites and their live born, singleton infants who had a 6-month postnatal visit by December 31, 2008. Mothers who were anti-HCV-positive, or who had CD4 counts (cells/mm(3)) <200 with detectable HCV RNA, were considered HCV-infected. All HCV-infected women were tested for HCV RNA. Infants with HCV RNA were considered HCV-infected. RESULTS Of 1042 enrolled women, 739 (71%) mother-infant pairs met the inclusion criteria. Of the 739 women, 67 (9%) were anti-HCV-positive and 672 anti-HCV-negative [68 (10%) with CD4 counts <200; of these, 3 (4.4%) were HCV RNA-positive]. Therefore, our study population comprised 70 HCV-infected (47 with HCV RNA) and 669 HCV-uninfected women (and their infants). Factors associated with maternal HCV infection included unemployment (odds ratio [OR] = 2.58); tobacco (OR = 1.73) or marijuana (OR = 3.88) use during pregnancy; enrollment HIV viral load ([VL] copies/mL) ≥10 000 (OR = 2.27); HIV clinical disease stage C (OR = 2.12); and abnormal alanine aminotransferase (OR = 4.24) or aspartate aminotransferase (OR = 11.98). Four of 47 infants (8.5%) born to HCV-viremic women were HCV-infected, and all 4 mothers had HIV VL <1000 at hospital discharge after delivery. CONCLUSIONS HCV MTCT among HIV/HCV-coinfected women with well-controlled HIV disease may be lower than reported in other coinfected populations. Studies with longer infant follow-up are needed.

HIV-1 tropism dynamics and phylogenetic analysis from longitudinal ultra-deep sequencing data of CCR5- and CXCR4-using variants.

Objective Coreceptor switch from CCR5 to CXCR4 is associated with HIV disease progression. The molecular and evolutionary mechanisms underlying the CCR5 to CXCR4 switch are the focus of intense recent research. We studied the HIV-1 tropism dynamics in relation to coreceptor usage, the nature of quasispecies from ultra deep sequencing (UDPS) data and their phylogenetic relationships. Methods Here, we characterized C2-V3-C3 sequences of HIV obtained from 19 patients followed up for 54 to 114 months using UDPS, with further genotyping and phylogenetic analysis for coreceptor usage. HIV quasispecies diversity and variability as well as HIV plasma viral load were measured longitudinally and their relationship with the HIV coreceptor usage was analyzed. The longitudinal UDPS data were submitted to phylogenetic analysis and sampling times and coreceptor usage were mapped onto the trees obtained. Results Although a temporal viral genetic structuring was evident, the persistence of several viral lineages evolving independently along the infection was statistically supported, indicating a complex scenario for the evolution of viral quasispecies. HIV X4-using variants were present in most of our patients, exhibiting a dissimilar inter- and intra-patient predominance as the component of quasispecies even on antiretroviral therapy. The viral populations from some of the patients studied displayed evidences of the evolution of X4 variants through fitness valleys, whereas for other patients the data favored a gradual mode of emergence. Conclusions CXCR4 usage can emerge independently, in multiple lineages, along the course of HIV infection. The mode of emergence, i.e. gradual or through fitness valleys seems to depend on both virus and patient factors. Furthermore, our analyses suggest that, besides becoming dominant after population-level switches, minor proportions of X4 viruses might exist along the infection, perhaps even at early stages of it. The fate of these minor variants might depend on both viral and host factors.

Increased in vitro glial fibrillary acidic protein expression, telomerase activity, and telomere length after productive human immunodeficiency virus-1 infection in murine astrocytes

Although HIV‐associated neurocognitive disorders (HAND) result from injury and loss of neurons, productive infection routinely takes place in cells of macrophage lineage. In such a complex context, astrocytosis induced by local chemokines/cytokines is one of the hallmarks of HIV neuropathology. Whether this sustained astrocyte activation is able to alter telomere‐aging process is unknown. We hypothesized that interaction of HIV with astrocytes may impact astrocyte telomerase activity (TA) and telomere length in a scenario of astrocytic activation measured by expression of glial fibrillary acidic protein (GFAP). To test this hypothesis, cultured murine astrocytes were challenged with pseudotyped HIV/vesicular stomatitis virus (HIV/VSV) to circumvent the absence of viral receptors; and GFAP, telomerase activity, and telomere length were quantified. As an early and transient event after HIV infection, both TA activity and telomere length were significantly augmented (P < 0.001). Later, a strong negative correlation (−0.8616, P < 0.0001) between virus production and telomerase activity was demonstrated. Once HIV production had reached a peak (7 dpi), the TA decreased, showing levels similar to those of noninfected cells. In contrast, the astrocyte became activated, exhibiting significantly increased levels of GFAP expression directly related to the level of HIV/VSV replication (P < 0.0001). Our results suggest that HIV‐infected astrocytes exhibit early disturbance in their cellular functions, such as telomerase activity and telomere length, that may attenuate cell proliferation and enhance the astrocyte dysregulation, contributing to HIV neuropathogenesis. Understanding the mechanisms involved in HIV‐mediated persistence by altering the telomere‐related aging processes could aid in the development of therapeutic modalities for neurological complications of HIV infection.