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torsdag 20 december 2018

Nanokosmokseen saavuttu ja uutta rokotekehittelyä mahdollistuu exosomitasolta

https://www.ncbi.nlm.nih.gov/pubmed/29274250

2018 Apr;13(4):e1700443. doi: 10.1002/biot.201700443. Epub 2018 Mar 24.

An Exosome-Based Vaccine Platform Imparts Cytotoxic T Lymphocyte Immunity Against Viral Antigens.Anticoli S1, Manfredi F1, Chiozzini C1, Arenaccio C1, Olivetta E1, Ferrantelli F1, Capocefalo A2, Falcone E2, Ruggieri A2, Federico M1. Abstract

Exosomes are 50-150 nm sized nanovesicles released by all eukaryotic cells. The authors very recently described a method to engineer exosomes in vivo with the E7 protein of Human Papilloma Virus (HPV). This technique consists in the intramuscular injection of a DNA vector expressing HPV-E7 fused at the C-terminus of an exosome-anchoring protein, that is, Nefmut , the authors previously characterized for its high levels of incorporation in exosomes. In this configuration, the ≈11 kDa E7 protein elicited a both strong and effective antigen-specific cytotoxic T lymphocyte (CTL) immunity. Attempting to establish whether this method could have general applicability, the authors expanded the immunogenicity studies toward an array of viral products of various origin and size including Ebola Virus VP24, VP40 and NP, Influenza Virus NP, Crimean-Congo Hemorrhagic Fever NP, West Nile Virus NS3, and Hepatitis C Virus NS3. All antigens appeared stable upon fusion with Nefmut , and are uploaded in exosomes at levels comparable to Nefmut . When injected in mice, DNA vectors expressing the diverse fusion products elicited a well detectable antigen-specific CD8+ T cell response associating with a cytotoxic activity potent enough to kill peptide-loaded and/or antigen-expressing syngeneic cells. These data definitely proven both effectiveness and flexibility of this innovative CTL vaccine platform. KEYWORDS:
CTL immunity; DNA immunization; Ebola virus; HIV-1 Nef; exosomes


(2) 
https://www.ncbi.nlm.nih.gov/pubmed/30167966 

2018 Nov;60(11):773-782. doi: 10.1007/s12033-018-0114-3.

DNA Vectors Generating Engineered Exosomes Potential CTL Vaccine Candidates Against AIDS, Hepatitis B, and Tumors. Ferrantelli F1, Manfredi F1, Chiozzini C1, Anticoli S1, Olivetta E1, Arenaccio C1, Federico M2. Abstract

Eukaryotic cells constitutively produce nanovesicles of 50-150 nm of diameter, referred to as exosomes, upon release of the contents of multivesicular bodies (MVBs). We recently characterized a novel, exosome-based way to induce cytotoxic T lymphocyte (CTL) immunization against full-length antigens. It is based on DNA vectors expressing products of fusion between the exosome-anchoring protein Nef mutant (Nefmut) with the antigen of interest. The strong efficiency of Nefmut to accumulate in MVBs results in the production of exosomes incorporating huge amounts of the desired antigen. When translated in animals, the injection of Nefmut-based DNA vectors generates engineered exosomes whose internalization in antigen-presenting cells induces cross-priming and antigen-specific CTL immunity. Here, we describe the molecular strategies we followed to produce DNA vectors aimed at generating immunogenic exosomes potentially useful to elicit a CTL immune response against antigens expressed by the etiologic agents of major chronic viral infections, i.e., HIV-1, HBV, and the novel tumor-associated antigen HOXB7. Unique methods intended to counteract intrinsic RNA instability and nuclear localization of the antigens have been developed. The success we met with the production of these engineered exosomes opens the way towards pre-clinic experimentations devoted to the optimization of new vaccine candidates against major infectious and tumor pathologies. KEYWORDS:
Constitutive transport elements; Exosomes; HBV; HIV-1; HOXB7; Nef
PMID:
30167966
DOI:
10.1007/s12033-018-0114-3
[Indexed for MEDLINE]


Exosomit apuna fulevaisuuden rokotteissa viruksia vastaan

2018 Nov;60(11):773-782. doi: 10.1007/s12033-018-0114-3.

DNA Vectors Generating Engineered Exosomes Potential CTL Vaccine Candidates Against AIDS, Hepatitis B, and Tumors.Ferrantelli F1, Manfredi F1, Chiozzini C1, Anticoli S1, Olivetta E1, Arenaccio C1, Federico M2.  Abstract

Eukaryotic cells constitutively produce nanovesicles of 50-150 nm of diameter, referred to as exosomes, upon release of the contents of multivesicular bodies (MVBs).

We recently characterized a novel, exosome-based way to induce cytotoxic T lymphocyte (CTL) immunization against full-length antigens. It is based on DNA vectors expressing products of fusion between the exosome-anchoring protein Nef mutant (Nefmut) with the antigen of interest. The strong efficiency of Nefmut to accumulate in MVBs results in the production of exosomes incorporating huge amounts of the desired antigen. When translated in animals, the injection of Nefmut-based DNA vectors generates engineered exosomes whose internalization in antigen-presenting cells induces cross-priming and antigen-specific CTL immunity.

Here, we describe the molecular strategies we followed to produce DNA vectors aimed at generating immunogenic exosomes potentially useful to elicit a CTL immune response against antigens expressed by the etiologic agents of major chronic viral infections, i.e., HIV-1, HBV, and the novel tumor-associated antigen HOXB7.
 Unique methods intended to counteract intrinsic RNA instability and nuclear localization of the antigens have been developed. The success we met with the production of these engineered exosomes opens the way towards pre-clinic experimentations devoted to the optimization of new vaccine candidates against major infectious and tumor pathologies.

HIV-1 infektioituneen solun exosomi edistää syöpiä NADC

https://www.ncbi.nlm.nih.gov/pubmed/30389917

2018 Nov 2;9(1):4585. doi: 10.1038/s41467-018-07006-2.
Exosomes derived from HIV-1-infected cells promote growth and progression of cancer via HIV TAR RNA. Chen L1, Feng Z1, Yue H1,2, Bazdar D3, Mbonye U4, Zender C5,6, Harding CV6,7,8, Bruggeman L8,9, Karn J4,6,8, Sieg SF3,8, Wang B6,10, Jin G11,12,13. Abstract

Suomennosta abstraktista 20.12. 2018.
Antiretrovirusterapiaa saavilla HIV/AIDS -potilailla  on lisääntynyttä riskiä NADC- tyyppisistä syövistä  (Non- AIDS-defining cancer). Kuitenkin on ollut epäselvää, mikä on  taustamekanismi tiettyjen NADS- syöpien  kehittymiselle ja progredioitumsielle.   Tässä artikkelissa  osoitetaan, että HIV-infektoituneista T-soluissa  vapautuneet  exosomit  sekä   HIV-positiivisten  potilaiden verestä puhdistetut exosomit stimuloivat  oro/orofaryngeaalisten syöpäsolujen  ja keuhkosyöpäsolujen  proliferaatiota, migraatiota ja invaasiota. HIV-infektoituneitten T-solujen  syöpäsoluproliferaatiota  edistävä tekijä on  HIV:n  TAR (transaktivaatiovaste-elementti)-RNA ja se indusoi proto-onkogeenien ilmenemistä  sekä  Tollin-reseptorien kaltaisilla   reseptoreilla indusoituvien geenien ilmenemistä.  Nämä vaikutukset riippuvat  molekyylin  rakenteellisista seikoista ( loop/bulge region , silmukka/esiintyöntymäkohta ). HIV-infektoituneitten T-solujen exosomit  menevät  nopeasti vastaanottavaan soluun epidermaalisen kasvutekijän reseptorin (EGFR)  kautta  ja stimuloivat ERK1/2 fosforylaatiota ja EGFR/TLR3-akselia  Täten tutkijoiden löydöt viittaavat siihen, että  TAR- RNA-pitoiset eksosomit HIV-infektoituneista T-soluista edistävät  tiettyjen NADC- syöpien kasvua ja progredioitumista  aktivoimalla  ERK- ketjureaktion EGFR/TLR3:sta riippuvalla tavalla.
  • People living with HIV/AIDS on antiretroviral therapy have increased risk of non-AIDS-defining cancers (NADCs). However, the underlying mechanism for development and progression of certain NADCs remains obscure. Here we show that exosomes released from HIV-infected T cells and those purified from blood of HIV-positive patients stimulate proliferation, migration and invasion of oral/oropharyngeal and lung cancer cells. The HIV transactivation response (TAR) element RNA in HIV-infected T-cell exosomes is responsible for promoting cancer cell proliferation and inducing expression of proto-oncogenes and Toll-like receptor 3 (TLR3)-inducible genes. These effects depend on the loop/bulge region of the molecule. HIV-infected T-cell exosomes rapidly enter recipient cells through epidermal growth factor receptor (EGFR) and stimulate ERK1/2 phosphorylation via the EGFR/TLR3 axis. Thus, our findings indicate that TAR RNA-containing exosomes from HIV-infected T cells promote growth and progression of particular NADCs through activation of the ERK cascade in an EGFR/TLR3-dependent manner.
PMID:
30389917
PMCID:
PMC6214989
DOI:
10.1038/s41467-018-07006-2
Muistiinpanoja  Mef  Nilbert- kirjasta: 
MÅLSTRUKTUR  EGFR;   
Ca tyyppi:  huvud, hals cancer   skivepitel  Preparat: Cetuximab
Ca tyyppi: Lung cancer:  erlotinib 
Ca tyyppi CRC: panitumumab.


Exosomit ja HIV-1 virus

https://www.ncbi.nlm.nih.gov/pubmed/29687643

2018 Sep;12(5):e1700142. doi: 10.1002/prca.201700142. Epub 2018 May 21.

Proteomic Analysis of Exosomes and Its Application in HIV-1 Infection. Cheruiyot C1, Pataki Z1, Ramratnam B1,2,3, Li M1. Abstract

 Suomennosta abstraktista  20.12. 2018 :
EXOSOMIT, extrasellulaariset eriterakkulat,  ovat 30 -100 nanometriä  läpimitaltaan ja niitä muodostuu myöhäisistä endosomeista erityyppisistä soluista. Lukuisat exosomeja käsittelevät tutkimukset viitatavat siihen, että HIV-1 viruksen biogeneesissä on exosomeilla merkitsevää osaa. Proteomitutkimukset kombinoituna  exosomien fraktiointiin ovat olleet menestyksekäs  menetelmä erilaisten exosomaalisten proteiinien tunnistamiseksi  ja auttaneet  myös  paljastamaan exosomien ja HIV-1:n välisiä interaktioita.
Tässä katsauksessa valaistaan nykyistä kehitystä erilaisissa  exosomieristys- ja  puhdistamismetodeissa ja   niiden sovelluksissa HIV-1-tutkimuksiin. 
Punnitaan erilaisten proteomitekniikoiden osuutta exosomien sisällön määrittelyssä.
Pohditaan  proteomien ja exosomien tutkimuksellisia ja kliinisiä sovellutuksia  HIV-1 viruksen  biologiaan.

( Koko artikkeli on hankittavissa  linkistä) 
  • Exosomes are 30-100 nm extracellular vesicles secreted from late endosomes by various types of cells. Numerous studies have suggested that exosomes play significant roles in human immunodeficiency virus 1 (HIV-1) biogenesis. Proteomics coupled with exosome fractionation has been successfully used to identify various exosomal proteins and helped to uncover the interactions between exosomes and HIV-1. 
  • To inform the current progress in the intersection of exosome, proteomics, and HIV-1, this review is focused on: i) analyzing different exosome isolation, purification methods, and their implications in HIV-1 studies; ii) evaluating the roles of various proteomic techniques in defining exosomal contents; iii) discussing the research and clinical applications of proteomics and exosome in HIV-1 biology.
PMID:
29687643
DOI:
10.1002/prca.201700142

onsdag 5 december 2018

Retrovirologian moderneimpien lääkkeiden (INSTI) ongelmia on resisitenssin muodosotus .

Ihmiskehon  geenivarastoss on mahdollisia antiretroviraaleja proeiineja. niiden esiinherättäminen on yksimahdollinen tie, muat se vaatii ahkeran genomitutkimustieteen, että tämä valtava arsenaali saadaan muovauspöydälle.
(Yksi tällainen tekijä TRIM28 (KAP1, TIFB) on  integraasin estäjä funktioltaan. tästä erikseen edellä).
HIV-1 integraasin(IN) esto  tarkoitaa käytännössä sitä, että estetään virusta saamasta oma provirusmateriaalinsa integroiduksi ihmisen genomiin.
On kehitelty  viruksen  intrgoitumisen estämiseksi lääkkeitä,  INSTI- ryhmä. ( Integration strand trnasfer inhibitors). niistä täässä alla artikkeli vuodelta 2017. otaten huomioon että HIV-1 virus menee hyvin varhain neurologiseen kudokseen  ja aivoon ja suoritaa integraatiota,  integraasin eston tulisi tapahtua varhain.

 https://retrovirology.biomedcentral.com/articles/10.1186/s12977-017-0360-7

HIV drug resistance against strand transfer integrase inhibitors

,
,
Email authorView ORCID ID profile and
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^Deceased
Retrovirology201714:36
Received: 15 May 2017
Accepted: 30 May 2017
Published:
SUOMENNOSTA:

Integrase strand transfer inhibitors (INSTIs) are the newest class of antiretroviral drugs to be approved for treatment and act by inhibiting the essential HIV protein integrase from inserting the viral DNA genome into the host cell’s chromatin. Three drugs of this class are currently approved for use in HIV-positive individuals: raltegravir (RAL), elvitegravir (EVG), and dolutegravir (DTG), while cabotegravir (CAB) and bictegravir (BIC) are currently in clinical trials. RAL and EVG have been successful in clinical settings but have relatively low genetic barriers to resistance. Furthermore, they share a high degree of cross-resistance, which necessitated the development of so-called second-generation drugs of this class (DTG, CAB, and BIC) that could retain activity against these resistant variants. In vitro selection experiments have been instrumental to the clinical development of INSTIs, however they cannot completely recapitulate the situation in an HIV-positive individual. This review summarizes and compares all the currently available information as it pertains to both in vitro and in vivo selections with all five INSTIs, and the measured fold-changes in resistance of resistant variants in in vitro assays. While the selection of resistance substitutions in response to RAL and EVG bears high similarity in patients as compared to laboratory studies, there is less concurrence regarding the “second-generation” drugs of this class. This highlights the unpredictability of HIV resistance to these inhibitors, which is of concern as CAB and BIC proceed in their clinical development.

Background

Since the beginning of the pandemic, HIV/AIDS has claimed the lives of over 35 million people, and approximately 35 million individuals are currently infected [1]. Highly active antiretroviral therapy (HAART) has transformed a positive HIV diagnosis from a former death sentence into a chronic, manageable disease. However, no cure yet exists for HIV and patients must remain on therapy for the entirety of their lives which makes the development of drug resistance in the virus a real concern. In fact, drug resistance has been documented for every currently available drug class in patients [2]. This makes the continued study of the mechanisms of HIV drug resistance and novel therapeutics a top priority for HIV scientists worldwide.

The reverse transcriptase (RT) enzyme of HIV is highly error-prone, introducing mutations into the genome at a rate of 1.4 × 10−5 mutation per base pair, per replication cycle [3]. This high mutation rate allows for the generation of multiple different viruses within an infected individual, sometimes referred to as “quasi-species.” If one of these quasi-species has a mutation that provides a selective advantage for replication in the presence of antiretrovirals (ARVs), it will out-compete other viral forms to become the dominant species [4].

 The integrase (IN) enzyme catalyses the insertion of the viral DNA (vDNA) into the host’s genome through two catalytic actions: 3′ processing and strand transfer. In the cytoplasm, IN self-associates into tetramers on the newly reverse transcribed vDNA, where it catalyzes the removal of the last two nucleotides from the 3′ ends of both strands [5]. In addition, IN can spontaneously form larger multimers that are stabilized by the addition of allosteric integrase inhibitors, and reciprocally destabilized in the presence of DNA [6, 7, 8, 9, 10]. After nuclear translocation, IN associates with lens epithelium-derived growth factor (LEDGF)/p75 and is directed to sites of open chromatin, where it will initiate strand transfer, i.e. the nucleophilic attack of the 3′ hydroxyl groups on the viral DNA on the nucleotide backbone of the host DNA. The integration process is completed by host gap-repair machinery, resulting in a 5 base-pair repeat that flanks each end of the viral DNA [11].

The integrase strand transfer inhibitor (INSTI) class of antiretroviral drugs is the latest to be approved for treatment of HIV-positive individuals. As their name suggest, INSTIs inhibit the second step catalyzed by IN, i.e. strand transfer, through competitive binding to the enzyme’s active site. INSTIs not only displace the 3′ end of the vDNA from the active site, but also chelate the divalent cation (Mg2+ or Mn2+) that is required for IN enzymatic activity [12]. There are currently three INSTIs approved for the treatment of HIV infection: raltegravir (RAL), elvitegravir (EVG), and dolutegravir (DTG) [13]. Cabotegravir (CAB) and bictegravir (BIC) are newer INSTIs currently in clinical trials [14,15)

Although highly efficacious in the management of HIV, both RAL and EVG are susceptible to virological failure through the development of resistance mutations. What is more, most of the changes that cause resistance to RAL also cause resistance to EVG, and vice versa [16]. This is, however, not the case with DTG. Not only does DTG appear to have a higher genetic barrier to resistance than either of the other two drugs, it has not yet been shown to definitively select for any resistance-associated changes in treatment-naïve patients [17]. Although two reports of potential emergence of resistance in individuals treated with DTG in first line therapy recently appeared, baseline IN was not sequenced in one of these cases, nor did the supposed-emergent mutation lead to persistent virological failure while DTG was still being used together with an optimized background regimen containing rilpivirine (RPV), an NNRTI with a modest genetic barrier to resistance [18]. Specifically, initial TDF/FTC/DTG treatment was supplemented with ritonavir-boosted darunavir following failure; the latter drug was subsequently substituted with RPV for reason of diffuse erythoderma. The second case reported transient emergence of a T97A substitution that did not confer any resistance on its own against DTG in vitro and was not observed at subsequent time points [19]. Although it cannot be excluded that unambiguously documented cases of emergent resistance mutations against first-line DTG will eventually be reported, it is expected that this will be rare. This is supported by the fact that despite dolutegravir being used by tens of thousands treatment-naïve individuals in Europe and the USA, the abovementioned two cases are the only known reports of potential primary de novo resistance against this drug. There have also been rare cases of treatment failure with resistance mutations in treatment-experienced but INSTI-naïve patients, and, in this setting, DTG has most often selected for the novel resistance substitution R263K [20]. Other substitutions at residues E92, Q148 and N155, have been reported when DTG monotherapy was used in treatment-experienced patients.
Primary resistance substitutions arise first in response to INSTI drug pressure and cause a decrease in susceptibility at the expense of viral fitness, most often through alterations to the enzyme’s active site where the inhibitors bind [16, 21]. Secondary resistance substitutions arise after continued drug pressure and usually act to alleviate the negative effects of primary mutations, and may also increase levels of INSTI resistance [22, 23]. Some of these secondary changes are specific to a certain primary resistance pathway, but many may be selected after several different primary mutations.

 Pre-clinical and in vitro studies have been instrumental in the evaluation of novel therapeutic agents for the treatment of HIV infection, however they do not always accurately predict clinical outcomes for patients. Laboratory viral strains and cell lines, although excellent scientific tools, can never recapitulate in vivo human infections with 100% accuracy. In this review, we compare both the in vitro selection and antiviral activity reported for drugs of the INSTI class with the analogous data available from treated patients to assess the predictive power of in vitro studies for INSTI clinical outcomes.

Raltegravir

In 2004 a group of researchers at Merck & Co. reported on the efficacy of the diketo acid (DKA)-based lead compound L-870812 against simian immunodeficiency virus (SIV) in infected rhesus macaques [24]. This led to the approval of the first INSTI, raltegravir, in 2007 for treatment-experienced AIDS patients with multidrug resistance, and two years later for treatment-naïve individuals as well [25, 26]. In the 10 years since its first approval, RAL has been shown to be well tolerated in the vast majority of patients, although it is does require twice daily dosing. It displays a modest genetic barrier to resistance, with the most common mutational pathways consisting of changes at positions Y143, Q148, and N155 [27].......( more  information in the link) 

Elvitegravir

EVG is a monoketo acid derivative that also demonstrated high specificity for inhibition of HIV IN strand transfer reactions [77]. EVG was developed by Gilead Sciences and approved for use in HIV infected individuals in 2012 [26]. Because EVG is processed by the cytochrome p450 enzyme CYP3A4/5, it needs to be co-formulated with cobicistat to boost plasma concentrations. This permits once daily dosing of EVG [78].
It is evident from both Tables 3.........( More information  in the link) 


Second-generation INSTIs

The relatively low genetic barrier and high degree of cross-resistance among the so called “first-generation” INSTIs RAL and EVG spurred research into the chase for “second-generation” drugs of this class, aimed at retaining efficacy against RAL/EVG resistant variants. There have been four candidate second-generation INSTIs to date. DTG, manufactured by ViiV-Healthcare and GlaxoSmithKline, was approved in 2013 for both treatment-naïve and—experienced patients and is the only second-generation INSTI to be approved to date [79]. MK-2048 showed potent activity against most RAL/EVG resistant variants and did not select for the same substitutions in tissue culture studies but its clinical development was halted due to poor pharmacokinetics. Both CAB and BIC are promising and both are currently in advanced clinical trials [15, 19, 50, 80].
( More info in the link...) 

There are fewer reports on the resistance patterns of CAB, a novel INSTI under development at GlaxoSmithKline. CAB was developed concomitantly with DTG and shares most of its structure; it has the potential to be formulated as a long acting injectable for both pre-exposure prophylaxis and treatment of HIV infection [84]. In the LATTE clinical trial, one patient in the CAB arm did develop a mutation in the Q148 pathway, which suggests that this second-generation INSTI may select for the same mutations as RAL and EVG [15]. In in vitro selection studies, CAB has selected for changes at positions 146 and 153 that could also be selected in the presence of EVG and DTG, respectively (Table 4).

(More info in the link) 


TRIM28, joka rajoittaa HIV-1 integraasia : TRIM2((KAP1):n taistelusta HIV-1:täv astaan.

 https://www.cell.com/cell-host-microbe/fulltext/S1931-3128(11)00168-5?code=cell-site


The integration of viral cDNA into the host genome is a critical step in the life cycle of HIV-1. This step is catalyzed by integrase (IN), a viral enzyme that is positively regulated by acetylation via the cellular histone acetyl transferase (HAT) p300. To investigate the relevance of IN acetylation, we searched for cellular proteins that selectively bind acetylated IN and identified KAP1, a protein belonging to the TRIM family of antiviral proteins. KAP1 binds acetylated IN and induces its deacetylation through the formation of a protein complex which includes the deacetylase HDAC1. Modulation of intracellular KAP1 levels in different cell types including T cells, the primary HIV-1 target, revealed that KAP1 curtails viral infectivity by selectively affecting HIV-1 integration. This study identifies KAP1 as a cellular factor restricting HIV-1 infection and underscores the relevance of IN acetylation as a crucial step in the viral infectious cycle.

Protein interactions

Protein Gene Interaction Pubs
Envelope surface glycoprotein gp120 env Tandem affinity purification and mass spectrometry analysis identify tripartite motif containing 28 (TRIM28), HIV-1 Gag, Gag/Pol, gp120, and Nef incorporated into staufen1 RNP complexes isolated from HIV-1-expressing cells PubMed
Gag-Pol gag-pol Tandem affinity purification and mass spectrometry analysis identify tripartite motif containing 28 (TRIM28), HIV-1 Gag, Gag/Pol, gp120, and Nef incorporated into staufen1 RNP complexes isolated from HIV-1-expressing cells PubMed
Nef nef Tandem affinity purification and mass spectrometry analysis identify tripartite motif containing 28 (TRIM28), HIV-1 Gag, Gag/Pol, gp120, and Nef incorporated into staufen1 RNP complexes isolated from HIV-1-expressing cells PubMed
Pr55(Gag) gag Tandem affinity purification and mass spectrometry analysis identify tripartite motif containing 28 (TRIM28), HIV-1 Gag, Gag/Pol, gp120, and Nef incorporated into staufen1 RNP complexes isolated from HIV-1-expressing cells PubMed
integrase gag-pol KAP1 inhibits HIV-1 integration via HIV-1 IN acetylation-dependent mechanism through HDAC1 PubMed

gag-pol The interaction between HIV-1 IN and KAP1 is highly favored by HAT/p300-mediated IN acetylation PubMed
Go to the HIV-1, Human Interaction Database 


HIV_1 integraasin inhibiittoreita on kehitelty.
 

2016: Progress in HIV-1 Integrase Inhibitors: A Review of their Chemical Structure Diversity

Author information Article notes Copyright and License information Disclaimer

HIV-1 integrase (IN) enzyme, one of the three main enzymes of HIV-1, catalyzed the insertion of the viral DNA into the genome of host cells. Because of the lack of its homologue in human cells and its essential role in HIV-1 replication, IN inhibition represents an attractive therapeutic target for HIV-1 treatment. Since identification of IN as a promising therapeutic target, a major progress has been made, which has facilitated and led to the approval of three drugs. This review focused on the structural features of the most important IN inhibitors and categorized them structurally in 10 scaffolds. We also briefly discussed the structural and functional properties of HIV-1 IN and binding modes of IN inhibitors. The SAR analysis of the known IN inhibitors provides some useful clues to the possible future discovery of novel IN inhibitors.
Key Words: HIV-1, Integrase enzyme, SAR, Molecular diversity, IN Inhibitors
IN inhibitors are consisting of two main classes: integrase strand transfer inhibitors (INSTIs) and protein–protein interaction inhibitors (PPIIs). INSTIs target the enzyme active site, and the FDA-approved IN inhibitors are all INSTIs. IN catalyzes the incorporation of viral DNA into the host chromatin on interactions with various cellular proteins, such as lens epithelium-derived growth factor (LEDGF)/p75. LEDGINs which act as inhibitors of the LEDGF/p75–integrase interaction have been substantially developed in recent years (-).
In this review, we provided an insight to the structure and function of HIV-1 IN and its role in HIV-1 replication. We also highlighted progress medicinal chemistry efforts have made to date on IN inhibitors.
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IN inhibitors are consisting of two main classes: integrase strand transfer inhibitors (INSTIs) and protein–protein interaction inhibitors (PPIIs). INSTIs target the enzyme active site, and the FDA-approved IN inhibitors are all INSTIs. IN catalyzes the incorporation of viral DNA into the host chromatin on interactions with various cellular proteins, such as lens epithelium-derived growth factor (LEDGF)/p75. LEDGINs which act as inhibitors of the LEDGF/p75–integrase interaction have been substantially developed in recent years (-).
In this review, we provided an insight to the structure and function of HIV-1 IN and its role in HIV-1 replication. We also highlighted progress medicinal chemistry efforts have made to date on IN inhibitors.


HIV-1 retroviral replication cycle (derived from 22).
 PMC full text:
2015 Apr 23;10(4):e0123935. doi: 10.1371/journal.pone.0123935. eCollection 2015.

KAP1 Deacetylation by SIRT1 Promotes Non-Homologous End-Joining Repair.

Abstract

Homologous recombination and non-homologous end joining are two major DNA double-strand-break repair pathways. While HR-mediated repair requires a homologous sequence as the guiding template to restore the damage site precisely, NHEJ-mediated repair ligates the DNA lesion directly and increases the risk of losing nucleotides. Therefore, how a cell regulates the balance between HR and NHEJ has become an important issue for maintaining genomic integrity over time. Here we report that SIRT1-dependent KAP1 deacetylation positively regulates NHEJ. We show that up-regulation of KAP1 attenuates HR efficiency while promoting NHEJ repair. Moreover, SIRT1-mediated KAP1 deacetylation further enhances the effect of NHEJ by stabilizing its interaction with 53BP1, which leads to increased 53BP1 focus formation in response to DNA damage. Taken together, our study suggests a SIRT1-KAP1 regulatory mechanism for HR-NHEJ repair pathway choice. PMID: 25905708 PMCID:PMC4408008 DOI: 10.1371/journal.pone.0123935[Indexed for MEDLINE]Free PMC Article

2013 Jun 1;14(6):648-52.

Sirtuin-1 and HIV-1: an overview.

Abstract

Sirtuins are a family of NAD+-dependent protein deacetylases, which regulate cell survival and energy metabolism, inflammation and cancer. Recent studies have shown that sirtuin-1 (SIRT1) modulates Human Immunodeficiency Virus (HIV)-1 transcription. The HIV-1 Tat protein is a substrate for the deacetylase activity of SIRT1; SIRT1 recycles Tat to its unacetylated form, catalyzing a fundamental step to start new cycles of viral transcription. Moreover, Tat has been reported to promote T-cell hyperactivation by suppressing SIRT1 activity. In fact, Tat blocks the ability of SIRT1 to deacetylate lysine 310 in the p65 subunit of nuclear factor- κB (NF- κB) by interacting with the deacetylase domain of SIRT1. This mechanism leads therefore to the hyperactivation of NF- κB proinflammatory pathway and may likely contribute to the chronic immune activation state of HIV-infected individuals. In the present review we first briefly describe the biological functions of sirtuins, then we delineate the interplay between SIRT1 and HIV-1 and discuss the potential role of SIRT1 as a pharmacological target of HIV-1 replication.
PMID:
23547809
[Indexed for MEDLINE]