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1.
PLoS Pathog ; 18(6): e1010507, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35714165

RESUMO

The HIV/SIV envelope glycoprotein (Env) cytoplasmic domain contains a highly conserved Tyr-based trafficking signal that mediates both clathrin-dependent endocytosis and polarized sorting. Despite extensive analysis, the role of these functions in viral infection and pathogenesis is unclear. An SIV molecular clone (SIVmac239) in which this signal is inactivated by deletion of Gly-720 and Tyr-721 (SIVmac239ΔGY), replicates acutely to high levels in pigtail macaques (PTM) but is rapidly controlled. However, we previously reported that rhesus macaques and PTM can progress to AIDS following SIVmac239ΔGY infection in association with novel amino acid changes in the Env cytoplasmic domain. These included an R722G flanking the ΔGY deletion and a nine nucleotide deletion encoding amino acids 734-736 (ΔQTH) that overlaps the rev and tat open reading frames. We show that molecular clones containing these mutations reconstitute signals for both endocytosis and polarized sorting. In one PTM, a novel genotype was selected that generated a new signal for polarized sorting but not endocytosis. This genotype, together with the ΔGY mutation, was conserved in association with high viral loads for several months when introduced into naïve PTMs. For the first time, our findings reveal strong selection pressure for Env endocytosis and particularly for polarized sorting during pathogenic SIV infection in vivo.


Assuntos
Síndrome de Imunodeficiência Adquirida dos Símios , Vírus da Imunodeficiência Símia , Animais , Endocitose , Produtos do Gene env/genética , Macaca mulatta/metabolismo , Macaca nemestrina , Síndrome de Imunodeficiência Adquirida dos Símios/genética , Síndrome de Imunodeficiência Adquirida dos Símios/patologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/metabolismo
2.
J Immunol ; 209(5): 864-873, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-36130133

RESUMO

HIV-1-specific CD4+ T cells (TCD4+s) play a critical role in controlling HIV-1 infection. Canonically, TCD4+s are activated by peptides derived from extracellular ("exogenous") Ags displayed in complex with MHC class II (MHC II) molecules on the surfaces of "professional" APCs such as dendritic cells (DCs). In contrast, activated human TCD4+s, which express MHC II, are not typically considered for their APC potential because of their low endocytic capacity and the exogenous Ag systems historically used for assessment. Using primary TCD4+s and monocyte-derived DCs from healthy donors, we show that activated human TCD4+s are highly effective at MHC II-restricted presentation of an immunodominant HIV-1-derived epitope postinfection and subsequent noncanonical processing and presentation of endogenously produced Ag. Our results indicate that, in addition to marshalling HIV-1-specific immune responses during infection, TCD4+s also act as APCs, leading to the activation of HIV-1-specific TCD4+s.


Assuntos
Soropositividade para HIV , HIV-1 , Apresentação de Antígeno , Linfócitos T CD4-Positivos , Células Dendríticas , Epitopos , Antígenos de Histocompatibilidade Classe II , Humanos , Peptídeos , Linfócitos T
3.
PLoS Pathog ; 12(11): e1005983, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27855210

RESUMO

HIV-1 entry can be inhibited by soluble peptides from the gp41 heptad repeat-2 (HR2) domain that interfere with formation of the 6-helix bundle during fusion. Inhibition has also been seen when these peptides are conjugated to anchoring molecules and over-expressed on the cell surface. We hypothesized that potent anti-HIV activity could be achieved if a 34 amino acid peptide from HR2 (C34) were brought to the site of virus-cell interactions by conjugation to the amino termini of HIV-1 coreceptors CCR5 or CXCR4. C34-conjugated coreceptors were expressed on the surface of T cell lines and primary CD4 T cells, retained the ability to mediate chemotaxis in response to cognate chemokines, and were highly resistant to HIV-1 utilization for entry. Notably, C34-conjugated CCR5 and CXCR4 each exhibited potent and broad inhibition of HIV-1 isolates from diverse clades irrespective of tropism (i.e., each could inhibit R5, X4 and dual-tropic isolates). This inhibition was highly specific and dependent on positioning of the peptide, as HIV-1 infection was poorly inhibited when C34 was conjugated to the amino terminus of CD4. C34-conjugated coreceptors could also inhibit HIV-1 isolates that were resistant to the soluble HR2 peptide inhibitor, enfuvirtide. When introduced into primary cells, CD4 T cells expressing C34-conjugated coreceptors exhibited physiologic responses to T cell activation while inhibiting diverse HIV-1 isolates, and cells containing C34-conjugated CXCR4 expanded during HIV-1 infection in vitro and in a humanized mouse model. Notably, the C34-conjugated peptide exerted greater HIV-1 inhibition when conjugated to CXCR4 than to CCR5. Thus, antiviral effects of HR2 peptides can be specifically directed to the site of viral entry where they provide potent and broad inhibition of HIV-1. This approach to engineer HIV-1 resistance in functional CD4 T cells may provide a novel cell-based therapeutic for controlling HIV infection in humans.


Assuntos
Linfócitos T CD4-Positivos/virologia , Proteína gp41 do Envelope de HIV/metabolismo , Infecções por HIV/metabolismo , HIV-1/metabolismo , Fragmentos de Peptídeos/metabolismo , Receptores CXCR4/metabolismo , Internalização do Vírus , Animais , Linfócitos T CD4-Positivos/metabolismo , Citometria de Fluxo , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos NOD
4.
J Virol ; 90(10): 4966-4980, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26937037

RESUMO

UNLABELLED: CD4 tropism is conserved among all primate lentiviruses and likely contributes to viral pathogenesis by targeting cells that are critical for adaptive antiviral immune responses. Although CD4-independent variants of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) have been described that can utilize the coreceptor CCR5 or CXCR4 in the absence of CD4, these viruses typically retain their CD4 binding sites and still can interact with CD4. We describe the derivation of a novel CD4-independent variant of pathogenic SIVmac239, termed iMac239, that was used to derive an infectious R5-tropic SIV lacking a CD4 binding site. Of the seven mutations that differentiate iMac239 from wild-type SIVmac239, a single change (D178G) in the V1/V2 region was sufficient to confer CD4 independence in cell-cell fusion assays, although other mutations were required for replication competence. Like other CD4-independent viruses, iMac239 was highly neutralization sensitive, although mutations were identified that could confer CD4-independent infection without increasing its neutralization sensitivity. Strikingly, iMac239 retained the ability to replicate in cell lines and primary cells even when its CD4 binding site had been ablated by deletion of a highly conserved aspartic acid at position 385, which, for HIV-1, plays a critical role in CD4 binding. iMac239, with and without the D385 deletion, exhibited an expanded host range in primary rhesus peripheral blood mononuclear cells that included CCR5(+) CD8(+) T cells. As the first non-CD4-tropic SIV, iMac239-ΔD385 will afford the opportunity to directly assess the in vivo role of CD4 targeting on pathogenesis and host immune responses. IMPORTANCE: CD4 tropism is an invariant feature of primate lentiviruses and likely plays a key role in pathogenesis by focusing viral infection onto cells that mediate adaptive immune responses and in protecting virions attached to cells from neutralizing antibodies. Although CD4-independent viruses are well described for HIV and SIV, these viruses characteristically retain their CD4 binding site and can engage CD4 if available. We derived a novel CD4-independent, CCR5-tropic variant of the pathogenic molecular clone SIVmac239, termed iMac239. The genetic determinants of iMac239's CD4 independence provide new insights into mechanisms that underlie this phenotype. This virus remained replication competent even after its CD4 binding site had been ablated by mutagenesis. As the first truly non-CD4-tropic SIV, lacking the capacity to interact with CD4, iMac239 will provide the unique opportunity to evaluate SIV pathogenesis and host immune responses in the absence of the immunomodulatory effects of CD4(+) T cell targeting and infection.


Assuntos
Antígenos CD4/metabolismo , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/fisiologia , Tropismo Viral , Ligação Viral , Animais , Anticorpos Neutralizantes/imunologia , Sítios de Ligação , Antígenos CD4/imunologia , Linfócitos T CD8-Positivos/virologia , Linhagem Celular , Humanos , Leucócitos Mononucleares/virologia , Macaca mulatta , Mutagênese , Receptores CCR5/imunologia , Receptores CCR5/metabolismo , Receptores CXCR4/imunologia , Receptores CXCR4/metabolismo , Vírus da Imunodeficiência Símia/imunologia , Vírus da Imunodeficiência Símia/patogenicidade , Proteínas do Envelope Viral/genética , Replicação Viral/genética
5.
EFSA J ; 22(7): e8894, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38993591

RESUMO

EFSA was asked by the European Parliament to provide a scientific opinion on the analysis by the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) of Annex I of the European Commission proposal for a regulation 'on plants obtained by certain new genomic techniques (NGTs) and their food and feed, and amending regulation (EU) 2017/625'. The Panel on genetically modified organisms (GMO) assessed the opinion published by ANSES, which focuses on (i) the need to clarify the definitions and scope, (ii) the scientific basis for the equivalence criteria and (iii) the need to take potential risks from category 1 NGT plants into account. The EFSA GMO Panel considered the ANSES analysis and comments on various terms used in the criteria in Annex I of the European Commission proposal and discussed definitions based on previous EFSA GMO Panel opinions. The EFSA GMO Panel concluded that the available scientific literature shows that plants containing the types and numbers of genetic modifications used as criteria to identify category 1 NGT plants in the European Commission proposal do exist as the result of spontaneous mutations or random mutagenesis. Therefore, it is scientifically justified to consider category 1 NGT plants as equivalent to conventionally bred plants with respect to the similarity of genetic modifications and the similarity of potential risks. The EFSA GMO Panel did not identify any additional hazards and risks associated with the use of NGTs compared to conventional breeding techniques in its previous Opinions.

6.
EFSA J ; 22(4): e8716, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38681739

RESUMO

Following the submission of dossier GMFF-2022-3670 under Regulation (EC) No 1829/2003 from Corteva Agriscience Belgium BV and Bayer Agriculture BV, the Panel on genetically modified organisms of the European Food Safety Authority was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the herbicide-tolerant and insect-resistant genetically modified maize MON 89034 × 1507 × NK603, for food and feed uses, excluding cultivation within the European Union. The data received in the context of this renewal application contained post-market environmental monitoring reports, a systematic search and evaluation of literature, updated bioinformatic analyses and a search for additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequences of the events in maize MON 89034 × 1507 × NK603 considered for renewal are identical to the sequences of the originally assessed events, the GMO Panel concludes that there is no evidence in renewal dossier GMFF-2022-3670 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on maize MON 89034 × 1507 × NK603.

7.
EFSA J ; 22(4): e8715, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38686342

RESUMO

Following the joint submission of dossier GMFF-2022-9170 under Regulation (EC) No 1829/2003 from Bayer Agriculture B.V. and Corteva Agriscience Belgium B.V., the Panel on genetically modified organisms of the European Food Safety Authority was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the herbicide tolerant and insect resistant genetically modified maize MON 89034 × 1507 × MON 88017 × 59122 and 8 out of 10 of its subcombinations, for food and feed uses, excluding cultivation within the European Union. The data received in the context of this renewal application contained post-market environmental monitoring reports, an evaluation of the literature retrieved by a scoping review, a search for additional studies performed by or on behalf of the applicant and updated bioinformatics analyses. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequences of the events in maize MON 89034 × 1507 × MON 88017 × 59122 and 8 out of 10 of its subcombinations considered for renewal are identical to the sequences of the originally assessed events, the GMO Panel concludes that there is no evidence in renewal dossier GMFF-2022-9170 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on maize MON 89034 × 1507 × MON 88017 × 59122 and 8 out of 10 of its subcombinations.

8.
EFSA J ; 22(1): e8489, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38250501

RESUMO

Following the submission of dossier GMFF-2022-9450 under Regulation (EC) No 1829/2003 from Bayer Agriculture BV, the Panel on Genetically Modified Organisms of the European Food Safety Authority was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the insect protected genetically modified maize MON 810, for food and feed uses (including pollen), excluding cultivation within the European Union. The data received in the context of this renewal application contained post-market environmental monitoring reports, an evaluation of the literature retrieved by a scoping review, additional studies performed by or on behalf of the applicant and updated bioinformatics analyses. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequence of the event in maize MON 810 considered for renewal is identical to the sequence of the originally assessed event, the GMO Panel concludes that there is no evidence in dossier GMFF-2022-9450 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on maize MON 810.

9.
EFSA J ; 22(7): e8895, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39040572

RESUMO

EFSA was requested by the European Commission (in accordance with Article 29 of Regulation (EC) No 178/2002) to provide a scientific opinion on the application of new developments in biotechnology (new genomic techniques, NGTs) to viable microorganisms and products of category 4 to be released into the environment or placed on the market as or in food and feed, and to non-viable products of category 3 to be placed on the market as or in food and feed. A horizon scanning exercise identified a variety of products containing microorganisms obtained with NGTs (NGT-Ms), falling within the remit of EFSA, that are expected to be placed on the (EU) market in the next 10 years. No novel potential hazards/risks from NGT-Ms were identified as compared to those obtained by established genomic techniques (EGTs), or by conventional mutagenesis. Due to the higher efficiency, specificity and predictability of NGTs, the hazards related to the changes in the genome are likely to be less frequent in NGT-Ms than those modified by EGTs and conventional mutagenesis. It is concluded that EFSA guidances are 'partially applicable', therefore on a case-by-case basis for specific NGT-Ms, fewer requirements may be needed. Some of the EFSA guidances are 'not sufficient' and updates are recommended. Because possible hazards relate to genotypic and phenotypic changes introduced and not to the method used for the modification, it is recommended that any new guidance should take a consistent risk assessment approach for strains/products derived from or produced with microorganisms obtained with conventional mutagenesis, EGTs or NGTs.

10.
EFSA J ; 22(8): e8886, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39099613

RESUMO

Genetically modified maize MON 95275 was developed to confer protection to certain coleopteran species. These properties were achieved by introducing the mpp75Aa1.1, vpb4Da2 and DvSnf7 expression cassettes. The molecular characterisation data and bioinformatic analyses reveal similarity to known toxins, which was further assessed. None of the identified differences in the agronomic/phenotypic and compositional characteristics tested between maize MON 95275 and its conventional counterpart needs further assessment. The GMO Panel does not identify safety concerns regarding the toxicity and allergenicity of the Mpp75Aa1.1 and Vpb4Da2 proteins and the DvSnf7 dsRNA and derived siRNAs as expressed in maize MON 95275 and finds no evidence that the genetic modification would change the overall allergenicity of maize MON 95275. In the context of this application, the consumption of food and feed from maize MON 95275 does not represent a nutritional concern in humans and animals. The GMO Panel concludes that maize MON 95275 is as safe as the conventional counterpart and non-GM maize varieties tested, and no post-market monitoring of food/feed is considered necessary. In the case of accidental release of maize MON 95275 material into the environment, this would not raise environmental safety concerns. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of maize MON 95275. The GMO Panel concludes that maize MON 95275 is as safe as its conventional counterpart and the tested non-GM maize varieties with respect to potential effects on human and animal health and the environment.

11.
EFSA J ; 22(8): e8887, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39099615

RESUMO

Genetically modified (GM) maize DP910521 was developed to confer resistance against certain lepidopteran insect pests as well as tolerance to glufosinate herbicide; these properties were achieved by introducing the mo-pat, pmi and cry1B.34 expression cassettes. The molecular characterisation data and bioinformatic analyses did not identify issues requiring food/feed safety assessment. None of the identified differences in the agronomic/phenotypic and compositional characteristics tested between maize DP910521 and its conventional counterpart needs further assessment except for the levels of iron in grain, which do not raise safety and nutritional concerns. The GMO Panel does not identify safety concerns regarding the toxicity and allergenicity of the Cry1B.34, PAT and PMI proteins as expressed in maize DP910521. The GMO panel finds no evidence that the genetic modification impacts the overall safety of maize DP910521. In the context of this application, the consumption of food and feed from maize DP910521 does not represent a nutritional concern in humans and animals. The GMO Panel concludes that maize DP910521 is as safe as its conventional counterpart and non-GM maize varieties tested, and no post-market monitoring of food/feed is considered necessary. In the case of accidental release of maize DP910521 material into the environment, this would not raise environmental safety concerns. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of maize DP910521. The GMO Panel concludes that maize DP910521 is as safe as its conventional counterpart and the tested non-GM maize varieties with respect to potential effects on human and animal health and the environment.

12.
EFSA J ; 22(4): e8714, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38681741

RESUMO

Genetically modified (GM) maize MON 94804 was developed to achieve a reduction in plant height by introducing the GA20ox_SUP suppression cassette. The molecular characterisation and bioinformatic analyses do not identify issues requiring food/feed safety assessment. None of the agronomic/phenotypic and compositional differences identified between maize MON 94804 and its conventional counterpart needs further assessment, except for ear height, plant height and levels of carbohydrates in forage, which do not raise safety or nutritional concerns. The Panel on Genetically Modified Organisms (GMO Panel) does not identify safety concerns regarding the toxicity and allergenicity of the GA20ox_SUP precursor-miRNA and derived mature miRNA as expressed in maize MON 94804 and finds no evidence that the genetic modification would change the overall allergenicity of maize MON 94804. In the context of this application, the consumption of food and feed from maize MON 94804 does not represent a nutritional concern in humans and animals. The GMO Panel concludes that maize MON 94804 is as safe as the conventional counterpart and non-GM maize varieties tested, and no post-market monitoring of food/feed is considered necessary. In the case of accidental release of viable maize MON 94804 grains into the environment, this would not raise environmental safety concerns. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of maize MON 94804. The GMO Panel concludes that maize MON 94804 is as safe as its conventional counterpart and the tested non-GM maize varieties with respect to potential effects on human and animal health and the environment.

13.
EFSA J ; 22(3): e8655, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38510324

RESUMO

Genetically modified maize DP202216 was developed to confer tolerance to glufosinate-ammonium-containing herbicides and to provide an opportunity for yield enhancement under field conditions. These properties were achieved by introducing the mo-pat and zmm28 expression cassettes. The molecular characterisation data and bioinformatic analyses do not identify issues requiring food/feed safety assessment. None of the identified differences in the agronomic/phenotypic and compositional characteristics tested between maize DP202216 and its comparator needs further assessment, except for the levels of stearic acid (C18:0), which do not raise nutritional and safety concerns. The GMO Panel does not identify safety concerns regarding the toxicity and allergenicity of the PAT and ZMM28 proteins as expressed in maize DP202216, and finds no evidence that the genetic modification would change the overall allergenicity of maize DP202216. In the context of this application, the consumption of food and feed from maize DP202216 does not represent a nutritional concern in humans and animals. The GMO Panel concludes that maize DP202216 is as safe as the comparator and non-GM reference varieties tested, and no post-market monitoring of food/feed is considered necessary. In the case of accidental release of viable maize DP202216 grains into the environment, this would not raise environmental safety concerns. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of maize DP202216. The GMO Panel concludes that maize DP202216 is as safe as its comparator and the tested non-GM reference varieties with respect to potential effects on human and animal health and the environment.

14.
EFSA J ; 22(1): e8490, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38235311

RESUMO

Genetically modified maize DP915635 was developed to confer tolerance to glufosinate herbicide and resistance to corn rootworm pests. These properties were achieved by introducing the ipd079Ea, mo-pat and pmi expression cassettes. The molecular characterisation data and bioinformatic analyses do not identify issues requiring food/feed safety assessment. None of the identified differences in the agronomic/phenotypic and compositional characteristics tested between maize DP915635 and its conventional counterpart needs further assessment, except for the levels of crude protein in forage, which does not raise nutritional and safety concerns. The GMO Panel does not identify safety concerns regarding the toxicity and allergenicity of the IPD079Ea, PAT and PMI proteins expressed in maize DP915635. The GMO Panel finds no evidence that the genetic modification impacts the overall safety of maize DP915635. In the context of this application, the consumption of food and feed from maize DP915635 does not represent a nutritional concern in humans and animals. The GMO Panel concludes that maize DP915635 is as safe as the conventional counterpart and non-GM maize varieties tested, and no post-market monitoring of food/feed is considered necessary. In the case of accidental release of viable maize DP915635 grains into the environment, this would not raise environmental safety concerns. The post market environmental monitoring plan and reporting intervals are in line with the intended uses of maize DP915635. The GMO Panel concludes that maize DP915635 is as safe as its conventional counterpart and the tested non-GM maize varieties with respect to potential effects on human and animal health and the environment.

15.
EFSA J ; 22(1): e8483, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38239495

RESUMO

Genetically modified maize DP23211 was developed to confer control of certain coleopteran pests and tolerance to glufosinate-containing herbicide. These properties were achieved by introducing the pmi, mo-pat, ipd072Aa and DvSSJ1 expression cassettes. The molecular characterisation data and bioinformatic analyses do not identify issues requiring food/feed safety assessment. None of the identified differences in the agronomic/phenotypic and compositional characteristics tested between maize DP23211 and its conventional counterpart needs further assessment, except for those in levels of histidine, phenylalanine, magnesium, phosphorus and folic acid in grain, which do not raise safety and nutritional concerns. The GMO Panel does not identify safety concerns regarding the toxicity and allergenicity of the IPD072Aa, PAT and PMI proteins and the DvSSJ1 dsRNA and derived siRNAs newly expressed in maize DP23211, and finds no evidence that the genetic modification impacts the overall safety of maize DP23211. In the context of this application, the consumption of food and feed from maize DP23211 does not represent a nutritional concern in humans and animals. Therefore, no post-market monitoring of food/feed is considered necessary. In the case of accidental release of viable maize DP23211 grains into the environment, this would not raise environmental safety concerns. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of maize DP23211. The GMO Panel concludes that maize DP23211 is as safe as its conventional counterpart and the tested non-GM reference varieties with respect to potential effects on human and animal health and the environment.

16.
Retrovirology ; 10: 153, 2013 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-24330857

RESUMO

BACKGROUND: We examined the underlying mechanism of action of the peptide triazole thiol, KR13 that has been shown previously to specifically bind gp120, block cell receptor site interactions and potently inhibit HIV-1 infectivity. RESULTS: KR13, the sulfhydryl blocked KR13b and its parent non-sulfhydryl peptide triazole, HNG156, induced gp120 shedding but only KR13 induced p24 capsid protein release. The resulting virion post virolysis had an altered morphology, contained no gp120, but retained gp41 that bound to neutralizing gp41 antibodies. Remarkably, HIV-1 p24 release by KR13 was inhibited by enfuvirtide, which blocks formation of the gp41 6-helix bundle during membrane fusion, while no inhibition of p24 release occurred for enfuvirtide-resistant virus. KR13 thus appears to induce structural changes in gp41 normally associated with membrane fusion and cell entry. The HIV-1 p24 release induced by KR13 was observed in several clades of HIV-1 as well as in fully infectious HIV-1 virions. CONCLUSIONS: The antiviral activity of KR13 and its ability to inactivate virions prior to target cell engagement suggest that peptide triazole thiols could be highly effective in inhibiting HIV transmission across mucosal barriers and provide a novel probe to understand biochemical signals within envelope that are involved in membrane fusion.


Assuntos
Proteína gp120 do Envelope de HIV/metabolismo , HIV-1/efeitos dos fármacos , Peptídeos/metabolismo , Compostos de Sulfidrila/metabolismo , Triazóis/metabolismo , Vírion/efeitos dos fármacos , Inativação de Vírus , Antivirais/metabolismo , Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/metabolismo , Humanos , Conformação Proteica
17.
EFSA J ; 21(1): e07732, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36698485

RESUMO

EFSA carries out the risk assessment of genetically modified plants for food and feed uses under Regulation (EU) No 503/2013. Exposure assessment - anticipated intake/extend of use shall be an essential element of the risk assessment of genetically modified feeds, as required by Regulation (EU) No 503/2013. Estimates of animal dietary exposure to newly expressed proteins should be determined to cover average consumption across all the different species, age, physiological and productive phases of farmed and companion animals, and identify and consider particular consumer groups with expected higher exposure. This statement is aimed at facilitating the reporting of the information that applicants need to provide on expected animal dietary exposure to newly expressed proteins and to increase harmonisation of the application dossiers to be assessed by the EFSA GMO Panel. Advice is provided on the selection of proper feed consumption and feed concentration data, and on the reporting of exposure's estimates. An overview of the different uncertainties that may be linked to the estimations is provided. This statement also explains how to access an Excel calculator which should be used in future applications as basis to provide a more consistent presentation of estimates of expected animal dietary exposure.

18.
EFSA J ; 21(4): e07935, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37077301

RESUMO

The European Commission requested the Panel on Genetically Modified Organisms of the European Food Safety Authority (EFSA GMO Panel) to assess new scientific information on maize MIR162, and to indicate whether the previous conclusions on the safety of maize MIR162 as a single event and as a part of stacked events remain valid. The new information is included in a European patent that reports a decrease in male fertility in some MIR162 inbred lines, pointing to a potential link between such decrease and the Vip3 protein expressed by maize MIR162. The EFSA GMO Panel evaluated the data provided by the patent owner and found scarce support for a causal link between Vip3 and decreased fertility. The general hypothesis of an association between event MIR162 and altered fertility could not be confirmed. The EFSA GMO Panel conducted the safety assessment based on the conservative assumption that such an association exists. The EFSA GMO Panel concluded that a decrease in male fertility would have no impact on the previous conclusions on maize MIR162 and stacked events containing MIR162.

19.
EFSA J ; 21(4): e07934, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37122285

RESUMO

Following the submission of application EFSA-GMO-RX-024 under Regulation (EC) No 1829/2003 from BASF Agricultural Solutions Seed US LLC, the Panel on Genetically Modified Organisms of EFSA was asked to deliver a scientific risk assessment on the data submitted in the context of the renewal of authorisation application for the herbicide tolerant genetically modified oilseed rape MS8, RF3 and MS8 × RF3, for food and feed uses, excluding cultivation within the European Union. The data received in the context of this renewal application contained post-market environmental monitoring reports, a systematic search and evaluation of literature, updated bioinformatic analyses, and additional documents or studies performed by or on behalf of the applicant. The GMO Panel assessed these data for possible new hazards, modified exposure or new scientific uncertainties identified during the authorisation period and not previously assessed in the context of the original application. Under the assumption that the DNA sequences of the events in oilseed rape MS8, RF3 and MS8 × RF3 considered for renewal are identical to the sequences of the originally assessed events, the GMO Panel concludes that there is no evidence in renewal application EFSA-GMO-RX-024 for new hazards, modified exposure or scientific uncertainties that would change the conclusions of the original risk assessment on oilseed rape MS8, RF3 and MS8 × RF3.

20.
EFSA J ; 21(6): e08011, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37284025

RESUMO

Genetically modified maize Bt11 × MIR162 × MIR604 × MON 89034 × 5307 × GA21 was developed by crossing to combine six single events: Bt11, MIR162, MIR604, MON 89034, 5307 and GA21, the GMO Panel previously assessed the 6 single maize events and 27 out of the 56 possible subcombinations and did not identify safety concerns. No new data on the single maize events or the assessed subcombinations were identified that could lead to modification of the original conclusions on their safety. The molecular characterisation, comparative analysis (agronomic, phenotypic and compositional characteristics) and the outcome of the toxicological, allergenicity and nutritional assessment indicate that the combination of the single maize events and of the newly expressed proteins in the six-event stack maize does not give rise to food and feed safety and nutritional concerns. The GMO Panel concludes that six-event stack maize, as described in this application, is as safe as the conventional counterpart and non-GM maize varieties tested, and no post-market monitoring of food/feed is considered necessary. In the case of accidental release of viable six-event stack maize grains into the environment, this would not raise environmental safety concerns. The GMO Panel assessed the likelihood of interactions among the single events in 29 of the maize subcombinations not previously assessed and covered by the scope of this application and concludes that these are expected to be as safe as the single events, the previously assessed subcombinations and the six-event stack maize. The post-market environmental monitoring plan and reporting intervals are in line with the intended uses of maize Bt11 × MIR162 × MIR604 × MON 89034 × 5307 × GA21. The GMO Panel concludes that six-event stack maize and the 30 subcombinations covered by the scope of the application are as safe as its conventional counterpart and the tested non-GM maize varieties with respect to potential effects on human and animal health and the environment.

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