Real-world experience with weight gain among pregnant women living with HIV who are using integrase inhibitors.

OBJECTIVES: We assessed real-world weight change and pregnancy outcomes among pregnant women living with HIV who used integrase strand transferase inhibitor (INSTI)-based combined antiretroviral therapy (cART). METHODS: In a retrospective cohort study from 2014 to 2021 for prevention of perinatal HIV infection, we evaluated changes in weight from the first prenatal visit to near delivery for two groups. The categories of change were: low (< 0.18 kg/week), normal (0.18-0.59 kg/week), and high (> 0.59 kg/week). The backbones were lamivudine + tenofovir disoproxil or lamivudine + zidovudine. The comparison groups were women with body mass index (BMI) < 25 kg/m2 versus BMI ≥ 25 kg/m2 and INSTI-naïve versus INSTI-experienced. Continuous variables were analysed with a Kruskal-Wallis test and count or categorical data with χ2 tests. RESULTS: We enrolled 198 pregnant women. At study entry, 74 had BMI < 25 kg/m2 and 124 had BMI ≥ 25 kg/m2 . Excess gestational weight gain was more frequent among women who were INSTI-naïve among both BMI groups (< 25 and ≥ 25). However, the proportion of participants per weight change category was only significantly different between INSTI-naïve women with baseline BMI < 25 kg/m2 and INSTI-experienced women with BMI < 25 kg/m2 . In particular, INSTI-naïve women with BMI < 25 kg/m2 had significantly higher rates of excess gestational weight gain (31.6%) compared with participants with BMI < 25 kg/m2 who conceived while on INSTIs (11.8%, p = 0.004). Rates of unfavourable pregnancy outcomes were low and did not differ significantly between groups. CONCLUSIONS: INSTI-naïve participants with BMI < 25 kg/m2 gained more weight during pregnancy than participants with BMI ≥ 25 kg/m2 who conceived while using INSTIs. Rates of adverse pregnancy outcomes did not differ between the groups.

HIV-1 genetic diversity and transmitted drug resistance to integrase strand transfer inhibitors among recently diagnosed adults in Porto Alegre, South Brazil.

OBJECTIVES: The HIV-1 genetic diversity and the presence of transmitted drug resistance mutations (TDRMs) against integrase strand transfer inhibitors (INSTIs) were assessed sequencing samples of antiretroviral (ARV)-naive HIV-1-infected individuals from South Brazil. METHODS: Viral RNA from 42 ART-naive individuals was submitted to complete HIV-1 integrase gene amplification by RT-PCR and sequencing. RESULTS: Viral strains carrying TDRMs against INSTIs were not detected in the present study. However, the polymorphisms L74M and L74I were each observed in 4.8% of the individuals. These accessory mutations have been reported as putative causes of TDRMs in ART with raltegravir, but only when associated with additional major mutations. When submitted to HIV-1 subtyping, 50% were classified as subtype C, 21% as recombinant BC, 19% as subtype B, 4.8% as subtype F1 and 4.8% as recombinant CF1. CONCLUSIONS: All 42 ARV-naive individuals were apparently susceptible to INSTIs, included in the Brazilian therapeutic guideline since 2009. To the best of our knowledge, this is the first study to evaluate TDRMs against INSTIs in Brazil. The most prevalent HIV-1 subtypes were subtype C, followed by the recombinant BC and subtype B, which is in agreement with previous studies. However, the presence of subtype F1 and recombinant CF1 reported herein was not observed in previous studies.

HIV-1 subtype F integrase polymorphisms external to the catalytic core domain contribute to severe loss of replication capacity in context of the integrase inhibitor resistance mutation Q148H.

BACKGROUND: In prior studies, HIV-1 BF recombinants with subtype F integrases failed to develop resistance to raltegravir through the Q148H mutational pathway. We aimed to determine the role of subtype-specific polymorphisms in integrase on drug susceptibility, viral replication and integration. METHODS: Integrase sequences were retrieved from the Los Alamos Database or obtained from the Garrahan HIV cohort. HIV-1 infectious molecular clones with or without Q148H (+ G140S) resistance mutations were constructed using integrases of subtype B (NL4-3) or F1(BF) ARMA159 and URTR23. Integrase chimeras were generated by reciprocal exchanges of a 200 bp fragment spanning amino acids 85-150 of the catalytic core domain (CCD) of NL4-3-Q148H and either ARMA159-Q148H or URTR23-Q148H. Viral infections were quantified by p24 ELISA and Alu-gag integration PCR assay. RESULTS: At least 18 different polymorphisms distinguish subtype B from F1(BF) recombinant integrases. In phenotypic experiments, p24 at Day 15 post-infection was high (105-106 pg/mL) for WT and NL4-3-Q148H; by contrast, it was low (102-104 pg/mL) for both F1(BF)-Q148H + G140S viruses, and undetectable for the Q148H mutants. Compared with WT viruses, integrated DNA was reduced by 5-fold for NL4-3-Q148H (P = 0.05), 9-fold for URTR23-Q148H (P = 0.01) and 16000-fold for ARMA159-Q148H (P = 0.01). Reciprocal exchange between B and F1(BF) of an integrase CCD region failed to rescue the replicative defect of F1(BF) integrase mutants. CONCLUSIONS: The functional impairment of Q148H in the context of subtype F integrases from BF recombinants explains the lack of selection of this pathway in vivo. Non-B polymorphisms external to the integrase CCD may influence the pathway to integrase strand transfer inhibitor resistance.

Analysis of HIV-1 integrase genotypes and polymorphisms among integrase inhibitors-based antiretroviral treatment naïve patients in South Sudan.

HIV-1 genetic diversity and drug resistance mutations remain public health challenges especially in regions where treatment is limited. The aim of this study was to characterize the HIV-1 integrase (IN) subtype and the possible occurrence of drug-resistance mutations or polymorphisms in resource-poor settings in South Sudan. Dried blood spots from integrase inhibitor treatment (Integrase strand transfer inhibitor [INSTI]) naïve HIV-1 infected patients were subjected to DNA amplification and direct sequencing of integrase genes. The sequences were interpreted for drug resistance according to the Stanford algorithm and the International AIDS Society-USA guidelines. Phylogenetic analysis revealed that HIV-1 subtype D, C, G, A1, and recombinant forms accounted for 40%, 10%, 13.3%, 23.4%, and 13.3%, respectively. Furthermore, inter-subtype recombinants were interspersed within viral strains sampled in other African countries, highlighting complex transmission dynamics within a mobile host population. A total of 78 of 288 (27%) amino acid IN positions presented at least one polymorphism each. Major INSTI resistance mutations were absent, however, polymorphic accessory mutations at positions M50ILR (26.6%) and L74I (3.3%) were detected. Despite the limited size of the study population, our findings underscore the need for monitoring minor and natural polymorphisms that may influence the outcome of treatment regimens.

Impact of genotypic diversity on selection of subtype-specific drug resistance profiles during raltegravir-based therapy in individuals infected with B and BF recombinant HIV-1 strains.

BACKGROUND: Current knowledge on HIV-1 resistance to integrase inhibitors (INIs) is based mostly on subtype B strains. This contrasts with the increasing use of INIs in low- and middle-income countries, where non-B subtypes predominate. MATERIALS AND METHODS: HIV-1 drug resistance genotyping was performed in 30 HIV-1-infected individuals undergoing virological failure to raltegravir. Drug resistance mutations (DRMs) and HIV-1 subtype were characterized using Stanford HIVdb and phylogenetic analyses. RESULTS: Of the 30 integrase (IN) sequences, 14 were characterized as subtype F (47%), 8 as subtype B (27%), 7 as BF recombinants (23%) and 1 as a putative CRF05_DF (3%). In 25 cases (83%), protease and reverse transcriptase (PR-RT) sequences from the same individuals confirmed the presence of different BF recombinants. Stanford HIVdb genotyping was concordant with phylogenetic inference in 70% of IN and 60% of PR-RT sequences. INI DRMs differed between B and F IN subtypes, with Q148K/R/H, G140S and E138K/A being more prevalent in subtype B (63% versus 0%, P = 0.0021; 50% versus 0%, P = 0.0096; and 50% versus 0%, P = 0.0096, respectively). These differences were independent of the time on raltegravir therapy or viral load at the time of genotyping. INI DRMs in subtype F IN genomes predicted a lower level of resistance to raltegravir and no cross-resistance to second-generation INIs. CONCLUSIONS: Alternative resistance pathways to raltegravir develop in subtypes B and F IN genomes, with implications for clinical practice. Evaluating the role of HIV-1 subtype in development and persistence of mutations that confer resistance to INIs will be important to improve algorithms for resistance testing and optimize the use of INIs.

HIV-1 acquired drug resistance to integrase inhibitors in a cohort of antiretroviral therapy multi-experienced Mexican patients failing to raltegravir: a cross-sectional study.

BACKGROUND: In resource-limited settings, multi-experienced HIV infected patients are often prescribed raltegravir for salvage therapy. Patients failing raltegravir-containing regimens require other drugs including other integrase inhibitors. In this context, real-life data about the resistance and cross-resistance pathways between integrase inhibitors is limited. The aim of this study was to investigate integrase resistance pathways in a cohort of Mexican multi-experienced patients failing of a raltegravir-containing salvage regimen. METHODS: Twenty-five plasma samples from subjects failing antiretroviral regimens which included raltegravir were obtained from various healthcare centres from 2009 to 2017 in Mexico. Antiretroviral history and demographics were collected. Samples were processed for integrase resistance genotyping testing by sequencing. The viral sequences were analysed with the Stanford HIV drug resistance database algorithm. Data was analysed with SPSS Statistics software. RESULTS: We found a mean viral load of 4.17 log10 c/mL (SD 1.11) at the time of virologic failure. Forty-eight percent of the samples were raltegravir resistant. The Y143R/H/C substitutions were the most prevalent, followed by the N155H, and both Q148H/K and G140S/A in the same proportion. The Q148 + G140 combination was found in (12%) of the samples. Cross-resistance to elvitegravir was found in 83.3% and in 18.2% for both dolutegravir and bictegravir. Thirteen samples (52%) were susceptible to the four integrase strand-transfer inhibitors. CONCLUSIONS: Our findings suggest a high occurrence of resistance and cross-resistance to other integrase inhibitors among multi-experienced subjects failing raltegravir. We found a modestly lower proportion of cross-resistance to dolutegravir than data from clinical trials. Likely this drug could be used for salvage therapy. Explanations for the absence of mutations in half of the samples, other than reduced adherence, should be further investigated. Close surveillance is needed.

Prevalence of Drug Resistance Mutations in Protease, Reverse Transcriptase, and Integrase Genes of North Central Mexico HIV Isolates.

This study set out to determine the frequency of antiretroviral drug resistance mutations in treatment-naive subjects of the north central Mexican state of San Luis Potosí. Mexican studies of antiretroviral drug resistance mutations have focused mainly on large metropolitan areas and border towns subjected to intense international migrations. This study set forth to describe the frequency of these mutations in a Mexican region less subjected to such migratory influences and more representative of smaller Mexican cities. Thirty-eight full-length pol sequences spanning the protease, reverse-transcriptase, and integrase-encoding regions were obtained from 42 treatment-naive human immunodeficiency virus (HIV)-infected subjects. Most exhibited subtype B homology, but CRF02_AG was also detected. Evidence of APOBEC3 hypermutation was seen in two samples. Calibrated population analysis revealed a surveillance drug resistance mutation prevalence of 4.9% for protease inhibitors, of 2.7% for nucleoside reverse transcriptase inhibitors, of 8.1% for non-nucleoside reverse transcriptase inhibitors, and an overall prevalence of 9.5%. This corresponds to an intermediate level of transmitted drug resistance according to the World Health Organization. The identification of integrase mutations suggests that transmitted drug mutations are being imported, as inhibitors targeting integrase have not been widely used in Mexico. Our results provide a greater understanding of HIV diversity in Mexico and highlight the way internal migrations allow HIV mutations and genetic features to permeate regions less subjected to international migrations. The implications of these findings will become more evident as Mexico hosts increased repatriations of migrants in the coming years.

Impact of antiretroviral resistance and virological failure on HIV-1 informational entropy.

Objectives: The present study investigated the relationship between genomic variability and resistance of HIV-1 sequences in protease (PR) and reverse transcriptase (RT) regions of the pol gene. In addition, we analysed the resistance among 651 individuals presenting antiretroviral virological failure, from 2009 to 2011, in the state of São Paulo, Brazil. Methods: The genomic variability was quantified by using informational entropy methods and the relationship between resistance and replicative fitness, as inferred by the residual viral load and CD4+ T cell count. Results: The number of antiretroviral schemes is related to the number of resistance mutations in the HIV-1 PR (α = 0.2511, P = 0.0003, R2 = 0.8672) and the RT (α = 0.7892, P = 0.0001, R2 = 0.9141). Increased informational entropy rate is related to lower levels of HIV-1 viral loads (α = -0.0121, P = 0.0471, R2 = 0.7923), lower levels of CD4+ T cell counts (α = -0.0120, P = 0.0335, R2 = 0.8221) and a higher number of antiretroviral resistance-related mutations. Conclusions: Less organized HIV genomes as inferred by higher levels of informational entropy relate to less competent host immune systems, lower levels of HIV replication and HIV genetic evolution as a consequence of antiretroviral resistance.

Structural basis for the potent inhibition of the HIV integrase-LEDGF/p75 protein-protein interaction.

Integrase (IN) constitutes one of the key enzymes involved in the lifecycle of the Human Immunodeficiency Virus (HIV), the etiological agent of AIDS. The biological role of IN strongly depends on the recognition and binding of cellular cofactors belonging to the infected host cell. Thus, the inhibition of the protein-protein interaction (PPI) between IN and cellular cofactors has been envisioned as a promising therapeutic target. In the present work we explore a structure-activity relationship for a set of 14 compounds reported as inhibitors of the PPI between IN and the lens epithelium-derived growth factor (LEDGF/p75). Our results demonstrate that the possibility to adopt the bioactive conformation capable of interacting with the hotspots IN-LEDGF/p75 hotspots residues constitutes a critical feature to obtain a potent inhibition. A ligand efficiency (|Lig-Eff|) quantitative descriptor combining both interaction energetics and conformational requirements was developed and correlated with the reported biological activity. Our results contribute to the rational development of IN-LEDGF/p75 interaction inhibitors providing a solid quantitative structure-activity relationship aimed for the screening of new IN-LEDGF/p75 interaction inhibitors.

Ampliação de uso dos medicamentos antirretrovirais dolutegravir (DTG) e darunavir (DRV), já disponibilizados pelo Ministério da Saúde para o tratamento da infecção pelo HIV / Expansion of use of anti-retroviral drugs dolutegravir (DTG) and darunavir (DRV), already available by the Ministry of Health for the treatment of HIV infection

Contexto: A infecção pelo HIV atualmente é considerada uma doença de caráter crônico. Quando diagnosticada e tratada precocemente, observa-se impacto significativo na redução da morbimortalidade. Apesar dos inúmeros avanços na terapia antirretroviral (TARV), ainda se observam elevadas taxas de falha virológica. Destacam-se, dentre suas principais causas, a má adesão à TARV e a resistência virológica. Entre os principais motivos que comprometem a adesão, destacam-se fatores relacionados à tolerabilidade, posologia, interações medicamentosas e eventos adversos relacionados às medicações. Outra causa importante de falha virológica é o surgimento de cepas resistentes aos antirretrovirais (ARV). A resistência aos ARV pode ser causada pela seleção de mutantes durante o uso irregular da TARV (resistência secundária), ou por cepas resistentes transmitidas diretamente de um indivíduo para outro (resistência transmitida) potencialmente comprometendo a resposta ao tratamento. Estudo elaborado em 2015 para a Organização Mundial de Saúde (OMS) comparou a efetividade de esquemas antirretrovirais mais modernos com os tradicionalmente usados por pessoas vivendo com HIV e AIDS virgens de tratamento. As conclusões do estudo foram que a eficácia e segurança dos antirretrovirais melhoraram substancialmente com a introdução de novas classes de ARV, como a dos inibidores de integrase. Evidências científicas: Demonstrou-se por meio de estudo recente conduzido pelo Ministério da Saúde um aumento expressivo na taxa global de resistência no Brasil aos tratamentos de primeira linha quando comparado a estudos realizados anteriormente. A mutação mais encontrada nesse estudo foi a K103N/S, que confere resistência a efavirenz. Isso demonstra que o uso maciço desse ARV em 1ª linha de tratamento antirretroviral resulta em importante impacto na seleção desta mutação e aponta para uma menor efetividade de esquemas que utilizam efavirenz em 1ª linha. Por meio de metanálise elaborada em 2015 compararam-se a efetividade de esquemas antirretrovirais mais modernos com os tradicionalmente usados por pessoas vivendo com HIV/AIDS (PVHA) virgens de tratamento. As conclusões do estudo foram que a eficácia e segurança dos antirretrovirais melhoraram substancialmente com a introdução de novas classes de ARV, como a dos inibidores de integrase. Demonstrou-se na revisão sistemática que o uso do dolutegravir (DTG) ou raltegravir para pacientes virgens de tratamento melhorou a eficácia e tolerabilidade em comparação aos regimes com efavirenz, e sugeriu-se que ambos devam ser considerados como 1ª linha de tratamento. Além disso, já se preconiza em importantes guidelines internacionais o uso de medicamentos da classe dos inibidores de integrase para compor esquemas de 1ª linha há alguns anos. O uso de darunavir vem demonstrando que o medicamento dispõe de alta afinidade pela HIV-1 protease, alta eficácia e alta barreira genética. Apresenta-se, dessa maneira, como uma ótima opção para 2ª linha de tratamento, como já se preconizam em importantes guidelines internacionais. Decisão: A CONITEC deliberou, por unanimidade, recomendar a incorporação do dolutegravir e darunavir para o tratamento da infecção pelo HIV, no âmbito do Sistema Único de Saúde ­ SUS, dada pela Portaria nº 35, republicada no DOU nº 193, página 40, no dia 06 de outubro de 2016.

Resistência genotípica para inibidores da integrase do HIV-1

A Integrase participa de uma das etapas fundamentais para a replicação do HIV, a inserção do DNA retrotranscrito no genoma humano.Atualmente já foram licenciados três inibidores da integrase (INIs) para o usode pacientes naïve à terapia antirretroviral ou multi-experimentados, raltegravir (RAL), elvitgeravir (EVG) e dolutegravir (DTG). Embora esses medicamentos sejam eficientes e bem tolerados, a falha terapêutica pode estar associada a seleção de mutações em pelo menos quatro vias distintas(E92Q, Q148H/R/K, N155H e menos frequente a Y143R/H/C) associadas ou não à mutações secundárias. Este estudo teve por objetivo avaliar o gene da integra-se em pacientes vivendo com HIV/AIDS. Foram incluídas 265amostras de pacientes com perfis diferentes de exposições à terapia antirretroviral (TARV): naïve de TARV (n=34), naïve para INIs (n=59), em terapia com TARV+RAL com carga viral suprimida (n=35) e em terapia com TARV+RAL com falha virológica (n=137). As amostras dos pacientes com exposição a INIs foram coletadas no período entre julho de 2009 e maio de2015...

The integrase part of one of the key steps for HIV replication, insertionof DNA retrotranscribed in the human genome. Currently they were alreadylicensed three integrase inhibitors (INIs) for the use of antiretroviral therapy naïve patients or multi-experienced, raltegravir, elvitegravir and dolutegravir. Although these drugs are effective and well tolerated, therapy failure may beassociated with selection of mutations in at least four distinct pathways(E92Q, Q148H/R/K N155H and less frequent Y143R/ F/C) or not associatedwith secondary mutations. This study aims to evaluate the integrase gene inpatients living with HIV/Aids. We included 265 samples from patients withdifferent profiles of exposure to antiretroviral therapy (ART): naïve to antiretroviral therapy (n=34), naïve to INIS (n=59), in therapy with TARV+RAL with suppressed viral load (n=35) and therapy with TARV+RAL withvirologic failure (n=137). Samples from patients exposed to INIs were collected between July 2009 and May 2015...

Resistência genotípica para inibidores da integrase do HIV-1 / Genotypic resistance to HIV-1 integrase inhibitors

A Integrase participa de uma das etapas fundamentais para a replicação do HIV, a inserção do DNA retrotranscrito no genoma humano. Atualmente já foram licenciados três inibidores da integrase (INIs) para o uso de pacientes naïve à terapia antirretroviral ou multi-experimentados, raltegravir (RAL), elvitgeravir (EVG) e dolutegravir (DTG). Embora esses medicamentos sejam eficientes e bem tolerados, a falha terapêutica pode estar associada a seleção de mutações em pelo menos quatro vias distintas(E92Q, Q148H/R/K, N155H e menos frequente a Y143R/H/C) associadas ou não à mutações secundárias. Este estudo teve por objetivo avaliar o gene da integrase em pacientes vivendo com HIV/AIDS. Foram incluídas 265 amostras de pacientes com perfis diferentes de exposições à terapia antirretroviral (TARV): naïve de TARV (n=34), naïve para INIs (n=59), em terapia com TARV+RAL com carga viral suprimida (n=35) e em terapia com TARV+RAL com falha virológica (n=137). As amostras dos pacientes com exposição a INIs foram coletadas no período entre julho de 2009 e maio de 2015. Sequências genéticas foram submetidas à websites e ferramentas de bioinformática para a análise de resistência aos antirretrovirais e determinação de subtipos virais. Nenhuma mutação principal foi observada em amostras de pacientes naïve para INIs, porém alguns polimorfismos observados parecem estar associados a certos subtipos do HIV-1. Entre os pacientes expostos as TARV+RAL, a maioria tinham poucos antirretrovirais ativos compondo a terapia. A adesão e a viremia nas semanas 12-24 após aTARV+RAL (p<0,01) apresentaram associação à supressão viral. Mutações principais para o INIs foram observadas em 62% dos pacientes em uso de TARV+RAL. Em um paciente houve a seleção da mutação F121Y, com evolução subsequente para Y143R. Entre os pacientes com falha virológica ao TARV+RAL, 35% apresentaram resistência intermediaria ou alta ao DTG,com associação das mutações G140S/A e E138A/K (p<0,001)...

¿Es posible que se genere resistencia al dolutegravir cuando se utiliza este agente en el tratamiento de primera línea? / Is resistance to Dolutegravirpossible when this drug is used in first-line therapy?

Dolutegravir (DTG) es un inhibidor de la integrasa del VIH aprobado recientemente como tratamiento por la FDA (Food and Drug Administration) en los Estados Unidos. Utilizado como parte de un tratamiento de primera línea, DTG es el único tratamiento antirretroviral frente al cual no se ha seleccionado resistencia en la clínica. Nuestra teoría es que esto se debe al prolongado tiempo de unión del DTG a la enzima integrasa así como a una capacidad de replicación muy disminuida por parte de los virus que podrían volverse resistentes al DTG. Además, conjeturamos que DTG podría ser utilizado en estrategias que apunten a la erradicación del VIH...

Dolutegravir (DTG) is an HIV integrase inhibitor that was recently approved for therapy by the Food and Drug Administration in the United States. When used as part of First-line therapy, DTG is the only HIV drug that has not selected for resistance mutations in the clinic. We believe that this is due to the long binding time of DTG to the integrase enzyme as well as greatly diminished replication capacity on the parte of viruses that might become resistant to DTG. We further speculatethat DTG might be able to be used in strategies aimed at HIV eradication...

Monitoring the emergence of resistance mutations in patients infected with HIV-1 under salvage therapy with raltegravir in Rio de Janeiro, Brazil: a follow-up study.

The present study describes a follow-up of a prospective and observational cohort of patients infected with HIV-1 and treated with raltegravir for salvage therapy in Brazil. Two groups of patients were analyzed: switching from T20 to RAL (Group 1, n = 9) and salvage therapy containing RAL (Group 2, n = 10). Blood samples were drawn for CD4(+) T-cell counts and HIV-1 viral load determinations. Protease, reverse transcriptase, and integrase genotyping were performed at baseline and at the time of virologic failure. CD4(+) T-cells increased at 6 and 12 months in both groups; HIV-1 viral load was continuously suppressed for Group 1, and for Group 2 it significantly decreased after starting a RAL-containing regimen. Three out of 10 patients from Group 2 could not suppress HIV-1 viral load. The mutations Q148H + G140S were observed for two patients and for the third patient only mutations to PR/RT inhibitors were detected. The genotypic sensitivity score (GSS) was analyzed for all patients of Group 2 and both patients who developed resistance to raltegravir presented a GSS < 2.0 for the RAL-containing scheme, which could be associated to the lack of effectiveness of the proposed scheme. The present study describes, for the first time in Brazil, the close follow-up of a series of patients using a raltegravir-containing HAART, showing the safety of the enfuvirtide switch to RAL and the effectiveness of a therapeutic regimen with RAL in promoting immune reconstitution and suppressing HIV replication, as well as documenting the occurrence of resistance to integrase inhibitors in the country.

Four-dimensional structure-activity relationship model to predict HIV-1 integrase strand transfer inhibition using LQTA-QSAR methodology.

Despite highly active antiretroviral therapy (HAART) implementation, there is a continuous need to search for new anti-HIV agents. HIV-1 integrase (HIV-1 IN) is a recently validated biological target for AIDS therapy. In this work, a four-dimensional quantitative structure-activity relationship (4D-QSAR) study using the new methodology named LQTA-QSAR approach with a training set of 85 HIV-1 IN strand transfer inhibitors (INSTI), containing the ß-diketo acid (DKA) substructure, was carried out. The GROMACS molecular dynamic package was used to obtain a conformational ensemble profile (CEP) and LQTA-QSAR was employed to calculate Coulomb and Lennard-Jones potentials and to generate the field descriptors. The partial least-squares (PLS) regression model using 14 field descriptors and 8 latent variables (LV) yielded satisfactory statistics (R2= 0.897, SEC = 0.270, and F = 72.827), good performance in internal (QLOO2 = 0.842 and SEV = 0.314) and external prediction (Rpred2 = 0.839, SEP = 0.384, AREpred = 4.942%, k = 0.981, k' = 1.016, and |R02 ­ R0'2 = 0.0257). The QSAR model was shown to be robust (leave-N-out cross validation; average QLNO2 = 0.834) and was not built by chance (y-randomization test; R2 intercept = 0.109; Q2 intercept = -0.398). Fair chemical interpretation of the model could be traced, including descriptors related to interaction with the metallic cofactors and the hydrophobic loop. The model obtained has a good potential for aid in the design of new INSTI, and it is a successful example of application of LQTA-QSAR as an useful tool to be used in computer-aided drug design (CADD).

BF integrase genes of HIV-1 circulating in São Paulo, Brazil, with a recurrent recombination region.

Although some studies have shown diversity in HIV integrase (IN) genes, none has focused particularly on the gene evolving in epidemics in the context of recombination. The IN gene in 157 HIV-1 integrase inhibitor-naïve patients from the São Paulo State, Brazil, were sequenced tallying 128 of subtype B (23 of which were found in non-B genomes), 17 of subtype F (8 of which were found in recombinant genomes), 11 integrases were BF recombinants, and 1 from subtype C. Crucially, we found that 4 BF recombinant viruses shared a recurrent recombination breakpoint region between positions 4900 and 4924 (relative to the HXB2) that includes 2 gRNA loops, where the RT may stutter. Since these recombinants had independent phylogenetic origin, we argue that these results suggest a possible recombination hotspot not observed so far in BF CRF in particular, or in any other HIV-1 CRF in general. Additionally, 40% of the drug-naïve and 45% of the drug-treated patients had at least 1 raltegravir (RAL) or elvitegravir (EVG) resistance-associated amino acid change, but no major resistance mutations were found, in line with other studies. Importantly, V151I was the most common minor resistance mutation among B, F, and BF IN genes. Most codon sites of the IN genes had higher rates of synonymous substitutions (dS) indicative of a strong negative selection. Nevertheless, several codon sites mainly in the subtype B were found under positive selection. Consequently, we observed a higher genetic diversity in the B portions of the mosaics, possibly due to the more recent introduction of subtype F on top of an ongoing subtype B epidemics and a fast spread of subtype F alleles among the B population.

Genetic diversity and naturally polymorphisms in HIV type 1 integrase isolates from Maputo, Mozambique: implications for integrase inhibitors.

HIV proviral DNA integration into the host chromosome is carried out by integrase becoming an important target antiretroviral therapy. Raltegravir was the first integrase inhibitor approved for use in HIV therapy and elvitegravir is in the late phase of clinical development; both show good results in monotherapy studies and may be used worldwide for rescue therapy. In this work we analyzed 57 integrase sequences obtained from samples from drug-naive and first line regime-failing patients from Maputo, Mozambique, to evaluate the presence of natural polymorphisms and resistance mutations associated with raltegravir and elvitegravir. No major mutations conferring resistance to integrase inhibitors were found and polymorphic accessory mutations were solely observed in low frequency among subtype C sequences-L74M (3.4%), T97A (1.8%), and E157Q (1.8%)-suggesting that this new antiretroviral drug class will be effective in Mozambique providing a good perspective to the introduction of this class of drugs in that country.

Analysis of transmitted resistance to raltegravir and selective pressure among HIV-1-infected patients on a failing HAART in Sao Paulo, Brazil.

We studied the presence of primary resistance to raltegravir (RAL), natural polymorphisms, and selection pressure on HIV-1 integrase. We found a high frequency of integrase polymorphisms related to the resistance to RAL and sequence stability. Further studies are needed to determine the importance of these polymorphisms to RAL resistance.

Estudos sobre aspectos virais e genéticos relacionados à integrase e ao processo de integração do HIV-1 / Studies on viral and genetic aspects related integrase and the process of integration of HIV-1

A integrase (IN) é uma enzima chave para o ciclo de replicação do HIV, sendo responsável por catalisar a integração do genoma do HIV no cromossomo hospedeiro. Devido ao papel essencial desta enzima para a patogênese da infecção pelo HIV, a recente introdução dos inibidores de IN (INI) na prática clínica e em vista da escassez de informação sobre a diversidade genética da IN do HIV no Brasil, o presente estudo tem como objetivos a) investigar a diversidade genética da IN e os níveis de resistência primária nos subtipos B, C e F do HIV que são prevalentes no Brasil; b) acompanhar pacientes sob terapia antirretroviral em esquemas contendo raltegravir (RAL) a fim de monitorar a emergência de mutações de resistência aos INI; c) desenvolver um método de genotipagem da IN do HIV para ser usado na pratica clínica no Brasil; e d) investigar o envolvimento do processo de integração no controle da replicação do HIV. Não foram detectadas mutações principais associadas aos INI entre os indivíduos virgens de tratamento infectados com diferentes subtipos de HIV-1. O nível de mutações acessórias observadas foi bem baixo, e algumas posições foram polimórficas nas amostras brasileiras dos subtipos B, C e F. Esses resultados encorajam o uso de INI no Brasil. Analisando as coortes de pacientes que trocaram a enfuvirtida por RAL ou sob terapia de resgate com RAL, nós observamos um aumento nas contagens de células T CD4+ e uma rápida diminuição da carga viral no grupo sob terapia de resgate. Três pacientes não atingiram supressão virológica e as mutações Q148H+G140S foram detectadas em dois deles. A fim de monitorar o crescente número de pacientes sob terapia com RAL no Brasil, nós desenvolvemos um método de genotipagem in-house que está atualmente em teste pela rede de Genotipagem do Ministério da Saúde do Brasil para futura incorporação no monitoramento de pacientes falhando INI. Sobre o papel da IN no controle da infecção pelo HIV, não observamos mutações nos resíduos importantes para a atividade catalítica nas sequências de IN obtidas de pacientes controladores da infecção pelo HIV, nem acúmulo de DNA 2-LTR, sugerindo que não há um mecanismo bloqueando a integração nestes pacientes. Juntos, os resultados apresentados trazem informações importantes sobre a diversidade genética da IN, resistência aos INI e sobre o papel da IN na patogênese da infecção pelo HIV.