Current HIV Research (v.13, #2)

Meet the Editorial Board Members by Leondios Kostrikis, Prasad Koka (89-89).

HIV Extracellular Tat: Myth or Reality? by Erwann Loret (90-97).
The human immunodeficiency virus type 1 (HIV) eradication will require elimination of HIV infected cells. No antiretroviral treatments (ART) or vaccine approaches have been able to reduce significantly the level of HIV infected cells in peripheral blood. This inefficacy is generally explained by the presence of a major reservoir of latent HIV infected cells in the central nervous system (CNS) that would be a sanctuary where Cytotoxic T Lymphocytes (CTL) have no access and would refresh peripheral blood with activated HIV infected cells. In this review, the presence of a major reservoir in the CNS appears to be inconsistent with recent clinical studies measuring HIV DNA. The major reservoirs are gut tissue, rectal tissue and the peripheral blood where HIV infected cells survive in an environment containing CTL. Extracellular Tat might protect HIV infected cells from CTL due to its capacity to cross CTL membranes and trigger apoptosis. Evidences of Tat secretion from HIV infected cells are shown with the detection of Tat antibodies in different clinical studies. Presence of neutralizing Tat antibodies in cohorts of patients who were exposed to HIV but who are now seronegative is described. The conclusion of this review is that a vaccine eliciting neutralizing antibodies against Tat might significantly reduce the level of HIV infected cells, what ART or other vaccine approaches have been unable to achieve now. It could be a first step towards HIV eradication.

Cardiac Morbidity in an HIV-1 Lipodystrophy Patient Cohort Expressing the TNF-α-238 G/A Single Nucleotide Gene Polymorphism by Supriya D. Mahajan, Asmita Gaekwad, Jyoti Pawar, Srikanth Tripathy, Manisha Ghate, Jayanta Bhattacharya, Hari Om Singh, Stanley A. Schwartz, Ramesh Paranjape, Raman Gangakhedkar (98-108).
In the current study we investigated the prevalence of the TNF-α 238G/A single nucleotide polymorphism (SNP) of the TNF-α gene in the development of lipodystrophy among HIV-1 infected individuals who had been receiving antiretroviral therapy (ART) in the immunodeficiency clinics of the National AIDS Research Institute (NARI) at Pune, India. We assessed the association of this SNP with the development of lipoatrophy/dyslipidemia and insulin resistance in these patients and measured carotid intima thickening which is a surrogate marker for chronic cardiac morbidity. Our results show that the incidence of the TNF-α 238G/A SNP is ~ two fold higher in patients with lipodystrophy as compared to those without lipodystrophy. Patients with lipodystrophy demonstrated a higher likelihood of the development of metabolic syndrome as evident by increased insulin sensitivity and increased percentage (%) β cell function. Further, a significant increase in left carotid intima thickness was observed in patients with lipodystrophy. Our study validates the association of the TNF-α 238G/A SNP allelic variant with the development of HIV- lipodystrophy via the modulation of TNF-α production, which contributes to dyslipidemia, increased lipolysis, increased insulin resistance, altered differentiation of adipocytes and increased carotid intima thickness. The contribution of genetic determinants such as the TNF-α 238G/A SNP to lipodystrophy, may provide insight into the mechanisms that underlie this disease condition and may be useful in the future for personalized therapy. Additionally, these findings will be useful in monitoring chronic cardiac morbidities among HIV infected individuals who express this SNP.

Evaluation of an In-House HIV-1 Drug Resistance Genotypic Testing for Using Dried Blood Spot Specimens in China by Hai Zhao, Lingjie Liao, Hui Xing, Zhe Wang, Bin Su, Jia Liu, JianJun Wu, Yi Feng, Cui He, Yuhua Ruan, Yiming Shao (109-116).
Objectives: We evaluated an In-house assay for HIV-1 drug resistance genotyping by using DBS samples in China.
Methods: The amplification sensitivity was assessed using 79 DBS specimens with plasma viral load ranging from 1,000 to 6,000 copies/ml. Precision was assessed using 5 DBS specimens with 5 replicates tested in one test run. Reproducibility was evaluated using other 5 DBS specimens with 5 replicates genotyped in 5 test runs. Nucleotide sequence identity and the degree of concordance in detecting drug resistance mutations were assessed within and between test runs. In addition, nucleotide sequence and drug resistance mutations were compared between 64 matched plasma and DBS specimens.
Results: The amplification rate of DBS specimens with plasma viral load of 1,000-6,000 copies/ml was 96.2% (76/79). The nucleotide sequence identity was 99.7A±0.34% and 99.6A±0.25% within and between test runs, respectively. Moreover, there was a near perfect agreement of detecting drug resistance mutations intra- and inter- test runs with kappa value of 0.972 and 0.963, respectively. Between 64 pairs of plasma and DBS specimens, the nucleotide identity was excellent with 99.5A±0.34%. As compared to the results of plasma specimens, the sensitivity and specificity for detecting drug resistance mutations in DBS specimens were 99.4 % (95% CI, 97.4-99.8%) and 99.8% (95% CI, 99.7-99.9%), respectively. Totally 15 discordant drug resistance mutations were found. Among them, 53.3 % (8/15) were caused by mixture base.
Conclusion: The In-house HIVDR genotyping assay could be used for testing DBS samples with viral load above 1,000 copies/ml in China and had a low intra- and inter- assay variability. DBS is an excellent alternative to plasma for HIV-1 drug resistance genotyping at population levels in China.

Reviving an Old HIV-1 Gene: The HIV-1 Antisense Protein by Cynthia Torresilla, Jean-Michel Mesnard, Benoit Barbeau (117-124).
The existence of an HIV-1 protein translated from an antisense transcript was suggested over 25 years ago. However, this Antisense Protein (ASP) gene has still not been completely accepted by the HIV-1 research community. The aim of this review is to discuss recent findings, which suggest that ASP needs to be considered as a viral gene, playing an important role in HIV-1 replication and persistence. In past years, several studies have highlighted the existence of HIV-1 antisense transcripts. More recently, we and others have convincingly demonstrated that this transcript produces a protein with a unique distribution and a rapid turnover, when expressed in mammalian cells. Furthermore, a role in autophagy and HIV-1 replication has been associated with this protein. In light of these recent reports, we believe that ASP needs to be added to the schematic representation of the HIV-1 proviral DNA and requires further investigation, as it could represent a new potential target for anti-retroviral therapies and vaccine strategies.

Meta-Analysis and Time Series Modeling Allow a Systematic Review of Primary HIV-1 Drug-Resistant Prevalence in Latin America and Caribbean by Antonio Victor Campos Coelho, Ronald Rodrigues De Moura, Ronaldo Celerino Da Silva, Anselmo Jiro Kamada, Rafael Lima Guimaraes, Lucas Andre Cavalcanti Brandao, Hemilio Fernandes Campos Coelho, Sergio Crovella (125-142).
Here we review the prevalence of HIV-1 primary drug resistance in Latin America and Caribbean using meta-analysis as well as time-series modeling. We also discuss whether there could be a drawback to HIV/AIDS programs due to drug resistance in Latin America and Caribbean in the next years. We observed that, although some studies report low or moderate primary drug resistance prevalence in Caribbean countries, this evidence needs to be updated. In other countries, such as Brazil and Argentina, the prevalence of drug resistance appears to be rising. Mutations conferring resistance against reverse transcriptase inhibitors were the most frequent in the analyzed populations (70% of all mutational events). HIV-1 subtype B was the most prevalent in Latin America and the Caribbean, although subtype C and B/F recombinants have significant contributions in Argentina and Brazil. Thus, we suggest that primary drug resistance in Latin America and the Caribbean could have been underestimated. Clinical monitoring should be improved to offer better therapy, reducing the risk for HIV-1 resistance emergence and spread, principally in vulnerable populations, such as men who have sex with men transmission group, sex workers and intravenous drug users.

Redox-Driven Events in the Human Immunodeficiency Virus Type 1 (HIV-1) Infection and their Clinical Implications by Andrea Name Colado Simao, Vanessa Jacob Victorino, Helena K. Morimoto, Edna Maria Vissoci Reiche, Carolina Panis (143-150).
Oxidative stress is a condition characterized by the imbalance between the production of reactive species (RS) or free radicals and their neutralization by the antioxidant defenses, leading to the accumulation of RS and their derived metabolites, with changes in the redox status of the cell. These RS can act on biological components and induce the oxidative and nitrosative reactions on lipids, proteins, and DNA. In this context, a wide variety of chronic diseases present oxidative stress as a part of the pathogenesis, including the human immunodeficiency virus type 1 (HIV-1) infection. The relationship between oxidative stress and HIV-1 infection lies in the fact that the RS species are important components of the innate immune response, and their derived metabolites and reactions participate in several events of the adaptative immune response. On the other hand, studies have shown specific roles for oxidative-driven events in both the host immunity and the virus biology. Undoubtedly, the occurrence of oxidative stress in HIV-1-infected patients has been implicated in disease progression, as well as in developing other secondary disorders, such as cardiovascular diseases, insulin resistance, and metabolic syndrome. This review aims to characterize the redox-driven events in the HIV-1 infection and their clinical implications in the disease features.

Co-signaling molecules have been demonstrated to regulate regulatory T cells' (Tregs) function during human immunodeficiency virus (HIV) infection. A recently reported co-signaling molecule called herpes virus entry mediator (HVEM), a member of the tumor necrosis factor receptor family, can both enhance and inhibit the immune response. HVEM was also reported to enhance the suppressive function of regulatory T cells in mice. However, it remains unknown whether HVEM can regulate Treg function in HIV-infected patients or whether HVEM affects HIV disease progression. In this study, we found that the blockage of the HVEM could weaken Tregs' suppressive activity to effector T cells (Teffs). HVEM expression is reduced during the asymptomatic phase of HIV infection and fairly predictive of the recovery of CD4+T-cells in response to highly active anti-retroviral therapy (HAART), more so than nadir CD4+T-cell count or viral load. Taken together, these findings demonstrate the importance of HVEM in relation to Treg function and HIV disease progression, which would have therapeutic implications and provide insight into the pathogenesis of acquired immune deficiency syndrome (AIDS).

Prediction of Drug-Resistance Using Genotypic and Docking Analysis Among Anti-Retroviral Therapy Naïve and First-Line Treatment Failures in Salem, Tamil Nadu, India by Thirunavukkarasu Dharmalingam, V. Udhaya, T. Umaarasu, V. Elangovan, S.V. Rajesh, Gnanendra Shanmugam (160-172).
The emergence of drug resistance among HIV-positive patients undergoing Anti- Retroviral Therapy (ART) with poor adherence to the HAART is a major concern in India. As the HIV accumulates the key mutations, the drug resistance occurs, that pose challenges to the ART regimens currently being used. Thus, the present study was carried out among the ART- naïve patients attending ART Centre at Salem district, Tamil Nadu, India. The mutations that concern the drug resistance were discriminated by determining the viral load before and after 6 months. The drug resistance was analyzed by HIV genotyping from the patients possessing a viral load of >1000 copies/mL after 6 months of ART. The mutations pertaining to drug resistance were analyzed by the online Stanford HIV Database. The 3D structures of the RT were modeled and the drugs used in the first-line regimens were docked to explore the effect of mutations on the binding pattern of the drugs. Among the 250 patients, the viral load data were obtained for 213 patients. The study found 23 patients with both virological and immunological failures and HIV drug mutations were also revealed by genotyping. The mutations of I135R/T/V/X, L178 I/M, M184V/I, D67N, K70R, and K103N were the most common among these 23 patients. The present study revealed that the NACO recommended first-line ART regimen is efficient in most of the patients attending ART center. The emergence of drug resistance of HIV variant is common even under the best circumstance of ART. This study reveals that there is a necessity for the implementation of improved and economically systematic attempt that allows the clinicians to make a rational choice of therapy regimen to overcome the first- line therapy failures among the ART- naive.