Inhibitory effect of endophytic fungi from Dysosma versipellis on HIV-1 IN-LEDGF/p75 interaction / 中国中药杂志

To determine the inhibitory effect of endophytic fungi from Dysosma versipellis on HIV-1 IN-LEDGF/p75 interaction,the protein-protein interaction between human immunodeficiency virus type 1( HIV-1) integrase and lens epithelial growth factor p75 protein( LEDGF/p75) was used as a target. The homogeneous time-resolved fluorescence( HTRF) technique was used in the inhibitory activity assay. The results showed that eight endophytic fungi with anti-IN-LEDGF/p75 interaction activity were screened out from fifty-three strains with different morphological characteristic. Among them,106 strain showed strong inhibitory activity against HIV-1 IN-LEDGF/p75 interaction with IC50 value of 5. 23 mg·L-1,and was identified as a potential novel species of Magnaporthaceae family by the analyses of ITS-rDNA,LSU and RPB2 sequences data. This study demonstrated that potential natural active ingredients against the HIV-1 IN-LEDGF/p75 interaction exist in the endophytic fungi of D. versipellis. These results may provide available candidate strain resources for the research and development of new anti-acquired immunodeficiency syndrome drugs.

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 / 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)...

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...

¿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...

Wikstroelide M potently inhibits HIV replication by targeting reverse transcriptase and integrase nuclear translocation / 中国天然药物

AIM@#To evaluate the anti-HIV activity and mechanism of action of wikstroelide M, a daphnane diterpene from Daphne acutiloba Rehder (Thymelaeaceae).@*METHODS@#The anti-HIV activities of wikstroelide M against different HIV strains were evaluated by cytopathic effect assay and p24 quantification assay with ELISA. The inhibitory effect of wikstroelide M on HIV reverse transcription was analyzed by real-time PCR and ELISA. The effect of wikstroelide M on HIV-1 integrase nuclear translocation was observed with a cell-based imaging assay. The effect of wikstroelide M on LEDGF/p75-IN interaction was assayed by molecular docking.@*RESULTS@#Wikstroelide M potently inhibited different HIV-1 strains, including HIV-1IIIB, HIV-1A17, and HIV-19495, induced a cytopathic effect, with EC50 values ranging from 3.81 to 15.65 ng·mL⁻¹. Wikstroelide M also had high inhibitory activities against HIV-2ROD and HIV-2CBL-20-induced cytopathic effects with EC50 values of 18.88 and 31.90 ng·mL⁻¹. The inhibitory activities of wikstroelide M on the three HIV-1 strains were further confirmed by p24 quantification assay, with EC50 values ranging from 15.16 to 35.57 ng·mL⁻¹. Wikstroelide M also potently inhibited HIV-1IIIB induced cytolysis in MT-4 cells, with an EC50 value of 9.60 ng·mL⁻¹. The mechanistic assay showed that wikstroelide M targeted HIV-1 reverse transcriptase and nuclear translocation of integrase through disrupting the interaction between integrase and LEDGF/p75.@*CONCLUSION@#Wikstroelide M may be a potent HIV-1 and HIV-2 inhibitor, the mechanisms of action may include inhibition of reverse trascriptase activity and inhibition of integrase nuclear translocation through disrupting the interaction between integrase and LEDGF/p75.

Prokaryotic soluble expression, purification and function study of LEDGF/p75 protein / 药学学报

HIV-1 integrase (IN) is a key enzyme for the viral replication. The protein-protein interaction (PPI) between HIV-1 IN and a cellular cofactor lens epithelium-derived growth factor (LEDGF/p75) is a validated target for anti-HIV drug discovery. In order to build the platform for screening inhibitor against PPI between IN and LEDGF/p75, the vector containing the LEDGF/p75 protein cDNA was constructed and expressed in Escherichia coli and the function of the LEDGF/p75 protein was assayed. The LGDGF/p75 encoding gene optimized according to the preference codon usage of E. coli, was synthesized and cloned into the expression vector pGEX-4T-1 to form a recombined plasmid, then transformed into host cell E. coli BL21 (DE3). The recombined clones were identified and confirmed by BamH I/Sal I digestion and sequencing, the successfully recombined plasmid in the host cell was induced by IPTG and the condition of the expression was optimized. The expressed protein was purified by the Ni2+ affinity chromatography column and SDS-PAGE was used to analyze the molecular weight and specificity. In addition, ELISA assay was used to analyze the function of the recombinant protein. The recombinant LGDGF/p75 was soluble, and expressed highly and stably in E. coli. The protein was proved to enhance HIV-1 IN strand transfer activity in vitro by ELISA. It will be helpful to build the platform of screening inhibitors against PPI between IN and LEDGF/p75.

Isolation, idetification and anti-HIV-1 integrase activity of culturable endophytic fungi from Tibetan medicinal plant Phlomis younghusbandii Mukerjee / 药学学报

A total of 52 endophytic fungi were isolated from roots and stems of Tibetan medicinal plant Phlomis younghusbandii Mukerjee. These fungal isolates were molecularly identified based on ITS sequnces and 28S sequences distributed to 12 genera, including Phoma, Chaetosphaeronema, Fusarium and Leptosphaeria, etc. Among them, the dominant genus was Phoma. Extracts of all strains were evaluated for anti-HIV-1 integrase activity by using soluable integrase expressed in E. coli BL21 (DE3). The results showed that seven samples from five fungal endophytes PHY-24, PHY-38, PHY-40, PHY-51, PHY-53, which belonged to genus Chaetosphaeronema, inhibited strand transfer reaction catalyzed by HIV-1 integrase with IC50 values, of 6.60, 5.20, 2.86, 7.86, 4.47, 4.56 and 3.23 microg x mL(-1) respectively. In conclusion, the endophytic fungi of Phlomis younghusbandii Mukerjee are valuable for further screening anti-HIV-1 integrase agents.

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.

Resistance to inhibitors of the human immunodeficiency virus type 1 integration

This review will summarize the role of integrase in HIV-1 infection, the mechanism of integrase inhibitors and resistance with an emphasis on raltegravir (RAL), the first integrase inhibitor licensed to treat HIV-1 infection.

Advances in the study of HIV-1 integrase inhibitors of alpha, gamma-diketo compounds / 药学学报

HIV-1 integrase (IN) is an essential enzyme for retroviral replication. There is no analogue for this enzyme in human cells so that inhibition of IN will not bring strong effect on human body. Thus, HIV-1 IN has become a rational target for therapy of AIDS. This review provides a comprehensive report of alpha, gamma-diketo IN inhibitors discovered in recent years. Compilation of such data will prove to be beneficial in developing QSAR, pharmacophore hypothesis generation and validation, virtual screening and synthesis of compounds with higher activity.

Inhibition of the replication of HIV-1 by norcantharidin in vitro / 药学学报

For obtaining new structural compounds with unique resistance profiles or novel mechanisms of action on HIV-1 from natural products, anti-HIV-1 drug screening models were used in vitro. Norcantharidin (NCTD), a derivative from cantharidin, was found to have inhibitory activities on HIV-1(IIIB) p24 antigen in lymphocyte lines MT-4, CEM and H9. It inhibited HIV-1 strain 018a (sensitive to zidovudine) from replicating with EC50 (50% effective concentration) of 14.9 micromol L(-1) and also inhibited HIV-1 strain 018c (resistant to zidovudine) from replicating with EC50 of 20.2 micromol L(-1) in primary lymphocytes peripheral blood mononuclear cells (PBMC). Norcantharidin showed synergistic activity with zidovudine on HIV-1(IIIB) in MT-4 cells, the combination index was less than 0.3. But, it was not active on HIV-1 integrase, reverse transcriptase or protease in vitro. As the structure of norcantharidin is unique and different from that of all clinic drugs approved, it would be possible to obtain new and effective compounds against HIV-1 with low toxicities after modification of norcantharidin.

Effective components against HIV-1 replicative enzymes isolated from plants / 药学学报

Plant active components characterized of many different structures and activities on multiple targets, have made them to be the important sources of inhibitors on HIV-1. For finding leading compounds with new structure against HIV-1, three key HIV-1 replicative enzymes (reverse transcriptase, protease and integrase) were used as screening models. The in vitro activities of 45 plant derived components isolated from Schisandraceae, Rutaceae and Ranunculaceae were reported. Within twelve triterpene components isolated, eight compounds were found to inhibit HIV-1 protease, in these eight active compounds, kadsuranic acid A (7) and nigranoic acid (8), inhibited both HIV-1 protease and integrase; Among fifteen lignans, meso-dihydroguaiaretic acid (15) and kadsurarin (16) were active on HIV-1 reverse transcriptase, and 4, 4-di(4-hydroxy-3-methoxyphenly)-2, 3-dimethylbutanol (13) active on HIV-1 integrase. All of the six alkaloids, seven flavones, and five others compounds were not active or only with low activities against HIV-1 replicative enzymes. Further studies of the triterpene components showing strong inhibitory activities on HIV-1 were warranted.

Design, synthesis of quinolinone acid-containing compounds with anti-HIV integrase activity / 药学学报

A series of novel quinolinone acid-containing compounds were designed and synthesized. Their structures were confirmed with 1H NMR and MS. The target compounds were tested for anti-HIV-1 integrase activities in vitro with enzyme linked immunosorbent assay (ELISA). The result showed that D-2, D-4 and D-7 have anti-integrase activity with IC50 < 100 micromol L(-1).

LEDGF/p75: a novel target for anti-HIV therapy and advances in the study of its related inhibitors / 药学学报

LEDGF/p75 is a newly found cell cofactor, which plays an essential role in the integration of HIV-1 cDNA into host chromosomes. LEDGF/p75 tethers HIV integrase to chromatin, protects it from degradation, and strongly influences the genome-wide pattern of HIV integration. Depleting the protein from cells or over-expressing the integrase-binding domain of LEDGF/p75 blocks viral replication. The essential role of LEDGF/p75 in HIV-1 replication makes it a new target for anti-HIV-1 drug development. This article reviews the function of LEDGF/p75, LEDGF/p75-integrase interaction and LEDGF/p75 inhibitors.

Anti-HIV activities of Achyranthes bidentata polysaccharide sulfate in vitro and in vivo / 药学学报

Achyranthes bidentata polysaccharide sulfate (ABPS) was a sulfated derivate derived from Achyranthes bidentata polysaccharide (ABP) which was isolated and identified from Chinese herb Achyranthes bidentata. The anti human immunodeficiency virus type 1 (HIV-1) activities were studied in vitro and in vivo. ABPS was found to inhibit HIV-1 reverse transcriptase and integrase with the 50% inhibiting concentration (IC60) of (2.948 +/- 0.556) micromol x L(-1) and (0.155 +/- 0.030) micromol x L(-1), respectively, but the parent compound ABP was not effective. ABPS inhibited HIV-1 P24 antigen with IC50 of (0.082 +/- 0.044) micromol x L(-1) and selective index (SI) of > (358 +/- 148) in MT-4 cell cultures acutely infected with HIV-1 IIIB virus, and with IC50 of (11.80 +/- 5.90) micromol x L(-1) and SI of > (24.2 +/- 12.1) in PBMC cell cultures acutely infected with clinical isolated zidovudine resistant HIV-1 virus, but there was no activity even at its concentration of 500 micromol x L(-1) in latent infection of H9/HIV-1 IIIB cell cultures. 5% sera taken from rats after intraperitoneal injection from rats with ABPS 125 mg x kg(-1) once or mice with 3 mg x kg(-1) qd for 20 days effectively inhibited HIV-1 P24 in MT-4 cell cultures, but those had no inhibitory effect when given orally. The results suggested that ABPS is a promising HIV-1 inhibitor, active on HIV-1 reverse transcriptase, integrase in vitro and HIV-1 P24 antigens in cell cultures, it was well absorbed by intraperitoneal injection but poor in oral bioavailability. It warrants further study.

Caracterização molecular da região da integrase do gene pol de subtipos de HIV-1 prevalentes no Brasil: avaliação de marcadores de resistência e antigenicidade / Molecular characterization of the region of integrase of the gene pol of subtypes of HIV-1 in Brazil: evaluation of resistance markers and antigenicity

A diversidade genética do HIV-1 tem sido bem estudada tendo-se como alvo as proteínas estruturais. Porém, na região da integrase essa diversidade ainda não foi bem caracterizada. A integrase é uma enzima essencial para o ciclo de replicação do HIV-1 e é um alvo promissor para a terapia anti-retroviral. Atualmente, a terapia inclui inibidores de protease (PR), transcriptase reversa (TR) e de entrada viral. Entretanto, não está claro por quanto tempo os benefícios clínicos serão mantidos devido à emergência de variantes com resistência a múltiplas drogas. Neste contexto, o objetivo foi caracterizar a diversidade genética da integrase do HIV-1 em amostras dos subtipos B(B), C e F, obtidas de pacientes virgens de tratamento, e identificar a presença de mutações naturais relacionadas aos inibidores de integrase em amostras de indivíduos apresentando falha terapêutica, a fim de verificar se esta região ainda permaneceria como um alvo íntegro para o tratamento. O DNA proviral foi extraído de 111 amostras de sangue de indivíduos virgens de tratamento, infectados com os subtipos prevalentes no Brasil, previamente determinados com base na região C2-V3 do envelope. O RNA viral foi extraído de amostras de plasma de 30 indivíduos apresentando falha terapêutica às drogas correntes, infectados pelo subtipo B do HIV-1, previamente determinado com base no gene pol (PR/RT). As amostras foram amplificadas pela metodologia de nested PCR e seqüenciadas por sequenciamento automatizado. O pacote de programas DNASTAR, ClustalX e MEGA foram usados para edição, alinhamento, tradução, análise filogenética (neighbor-joining) e definição das seqüências consenso. Não verificamos a ocorrência de recombinação inter-gênica entre a região da integrase e os genes env e pr/rt, tipados previamente. Entretanto, identificamos genomas apresentando recombinação intra-gênica na região da integrase (3B/F, 3B/C) em amostras de indivíduos virgens de tratamento. Todos os recombinantes B/C apresentaram um...

Analysis on bioactivity of HIV-1 integrase by ELISA method / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To develop an ELISA-based method for analyzing biologic activities of HIV-1 integrase and for high throughput screening of integrase inhibitors.</p><p><b>METHODS</b>After expression, renaturation and purification of integrase, the bioactivity of integrase and the inhibition of luffin-a were evaluated with an in vitro assay based on biotin-avidin EILSA and chemiluminescent substrates.</p><p><b>RESULT</b>(1) The specific activity of the purified integrase was 54.92 units/mg of protein. (2)IC(50) (concentration causing 50% inhibition of integrase) of luffin-a was (0.63 +/- 0.026) micromol/L.</p><p><b>CONCLUSION</b>The non-radioactive assay can be used for analysis of bioactivities and high throughput screening of inhibitors of HIV-1 integrase.</p>

Cloning and expression of pokeweed antiviral protein-II gene from the summer leaves of Phytolacca amercana / 生物工程学报

The cDNA sequence encoding pokeweed antiviral protein-II was cloned from the fresh summer leaves of phytolacca amercana by RT-PCR. The recombinant PAP-II was subcloned into the expression vector pET-28a(+) and expressed in E. coli BL21 after IPTG induction. SDS-PAGE analysis showed that the expressed PAP-II existed in the form of inclusion bodies. The purified fusion protein was obtained after a series of steps including cell break, inclusion body solubilization, protein refolding and purification through BBST NTA resin column. The non-radioactive ELISA-based HIV-1 integrase assay showed that the recombinant pokeweed antiviral protein-II and RTA were able to inhibit HIV-1 integrase to some extent (IC50 = 303 microg/mL, 220 microg/mL respectively). MTT assay showed that cytotoxicity of pokeweed antiviral protein II for HEP-G2 cells and Hela cells was in a dose-dependent manner with IC50 s of 93 microg/mL and 102 microg/mL, respectively. The results suggested that pokeweed antiviral protein-II is a potent anti-tumor candidate. The finding of integrase inhibitory activity and the discovery of cytotoxicity provide more insights into the anti-HIV and the anti-tumor activities of PAP-II.

Obstacles to successful antiretroviral treatment of HIV-1 infection: problems & perspectives.

Mutations in human immunodeficiency virus type 1 (HIV-1) are a major impediment to successful highly active antiretroviral therapy (HAART) and the design of anti-HIV vaccines. Although HAART has made long-term suppression of HIV a reality, drug resistance, drug toxicity, drug penetration, adherence to therapy, low levels of continued viral replication in cellular reservoirs and augmentation of host immune responses are some of the most important challenges that remain to be sorted out. Continuing viral replication in the face of HAART leads to the accumulation of drug resistance mutations, increase in viral loads and eventual disease progression. Patients who fail therapy have minimal options for their clinical management. Therefore, a clear understanding of the pathogenesis of drug-resistant HIV-1, and all of the issues that influence the success of HAART is urgently needed. In the present article, we discuss various obstacles to HIV therapy, and provide perspectives relating to these issues that are critical in determining the success or failure of HAART.