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Agmo Hernandez, Victor
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Publications (10 of 30) Show all publications
Norling, K., Bernasconi, V., Agmo Hernandez, V., Parveen, N., Edwards, K., Lycke, N. Y., . . . Bally, M. (2019). Gel Phase 1,2-Distearoyl-sn-glycero-3-phosphocholine-Based Liposomes Are Superior to Fluid Phase Liposomes at Augmenting Both Antigen Presentation on Major Histocompatibility Complex Class II and Costimulatory Molecule Display by Dendritic Cells in Vitro. ACS infectious diseases, 5(11), 1867-1878
Open this publication in new window or tab >>Gel Phase 1,2-Distearoyl-sn-glycero-3-phosphocholine-Based Liposomes Are Superior to Fluid Phase Liposomes at Augmenting Both Antigen Presentation on Major Histocompatibility Complex Class II and Costimulatory Molecule Display by Dendritic Cells in Vitro
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2019 (English)In: ACS infectious diseases, ISSN 2373-8227, Vol. 5, no 11, p. 1867-1878Article in journal (Refereed) Published
Abstract [en]

Lipid-based nanoparticles have in recent years attracted increasing attention as pharmaceutical carriers. In particular, reports of them having inherent adjuvant properties combined with their ability to protect antigen from degradation make them suitable as vaccine vectors. However, the physicochemical profile of an ideal nanoparticle for vaccine delivery is still poorly defined. Here, we used an in vitro dendritic cell assay to assess the immunogenicity of a variety of liposome formulations as vaccine carriers and adjuvants. Using flow cytometry, we investigated liposome-assisted antigen presentation as well as the expression of relevant costimulatory molecules on the cell surface. Cytokine secretion was further evaluated with an enzyme-linked immunosorbent assay (ELISA). We show that liposomes can successfully enhance antigen presentation and maturation of dendritic cells, as compared to vaccine fusion protein (CTA1-3Eα-DD) administered alone. In particular, the lipid phase state of the membrane was found to greatly influence the vaccine antigen processing by dendritic cells. As compared to their fluid phase counterparts, gel phase liposomes were more efficient at improving antigen presentation. They were also superior at upregulating the costimulatory molecules CD80 and CD86 as well as increasing the release of the cytokines IL-6 and IL-1β. Taken together, we demonstrate that gel phase liposomes, while nonimmunogenic on their own, significantly enhance the antigen-presenting ability of dendritic cells and appear to be a promising way forward to improve vaccine immunogenicity.

Keywords
adjuvant effect, antigen delivery, dendritic cell activation, immunogenicity, lipid nanoparticle, mucosal vaccination
National Category
Infectious Medicine Pharmacology and Toxicology Analytical Chemistry
Identifiers
urn:nbn:se:uu:diva-396978 (URN)10.1021/acsinfecdis.9b00189 (DOI)000496041000006 ()31498993 (PubMedID)
Funder
Swedish Foundation for Strategic Research , SB12-0088Swedish Research Council, 2018-04900Knut and Alice Wallenberg Foundation
Available from: 2019-11-12 Created: 2019-11-12 Last updated: 2019-12-04Bibliographically approved
Eriksson, E. K., Edwards, K., Grad, P., Gedda, L. & Agmo Hernandez, V. (2019). Osmoprotective effect of ubiquinone in lipid vesicles modelling the E. coli plasma membrane. Biochimica et Biophysica Acta - Biomembranes (7), 1388-1396
Open this publication in new window or tab >>Osmoprotective effect of ubiquinone in lipid vesicles modelling the E. coli plasma membrane
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2019 (English)In: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, no 7, p. 1388-1396Article in journal (Refereed) Published
National Category
Natural Sciences
Identifiers
urn:nbn:se:uu:diva-396977 (URN)10.1016/j.bbamem.2019.04.008 (DOI)
Available from: 2019-11-12 Created: 2019-11-12 Last updated: 2019-11-12
Eriksson, E. K., Agmo Hernandez, V. & Edwards, K. (2018). Effect of ubiquinone-10 on the stability of biomimetic membranes of relevance for the inner mitochondrial membrane.. Biochimica et Biophysica Acta - Biomembranes, 1860(5), 1205-1215
Open this publication in new window or tab >>Effect of ubiquinone-10 on the stability of biomimetic membranes of relevance for the inner mitochondrial membrane.
2018 (English)In: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, Vol. 1860, no 5, p. 1205-1215Article in journal (Refereed) Published
Abstract [en]

Ubiquinone-10 (Q10) plays a pivotal role as electron-carrier in the mitochondrial respiratory chain, and is also well known for its powerful antioxidant properties. Recent findings suggest moreover that Q10 could have an important membrane stabilizing function. In line with this, we showed in a previous study that Q10 decreases the permeability to carboxyfluorescein (CF) and increases the mechanical strength of 1-palmitoyl-2-oleyl-sn-glycero-phosphocholine (POPC) membranes. In the current study we report on the effects exerted by Q10 in membranes having a more complex lipid composition designed to mimic that of the inner mitochondrial membrane (IMM). Results from DPH fluorescence anisotropy and permeability measurements, as well as investigations probing the interaction of liposomes with silica surfaces, corroborate a membrane stabilizing effect of Q10 also in the IMM-mimicking membranes. Comparative investigations examining the effect of Q10 and the polyisoprenoid alcohol solanesol on the IMM model and on membranes composed of individual IMM components suggest, moreover, that Q10 improves the membrane barrier properties via different mechanisms depending on the lipid composition of the membrane. Thus, whereas Q10's inhibitory effect on CF release from pure POPC membranes appears to be directly and solely related to Q10's lipid ordering and condensing effect, a mechanism linked to Q10's ability to amplify intrinsic curvature elastic stress dominates in case of membranes containing high proportions of palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (POPE).

Keywords
Biomimetic membranes, Coenzyme Q10, Liposomes, Membrane stability, Solanesol
National Category
Biophysics
Identifiers
urn:nbn:se:uu:diva-353473 (URN)10.1016/j.bbamem.2018.02.015 (DOI)000435057700029 ()29470946 (PubMedID)
Funder
Swedish Research Council, 2016-03464Swedish Cancer Society, 17 0566
Available from: 2018-06-13 Created: 2018-06-13 Last updated: 2018-09-23Bibliographically approved
Lundsten, S., Spiegelberg, D., Agmo Hernandez, V., Brown, C., Edwards, K., Lane, D. & Nestor, M. (2017). Radioiodination Of Small Stapled Peptides For p53 Therapy. In: : . Paper presented at EANM´17, Annual Congress of the European Association of Nuclear Medicine, October 21 – 25, 2017, Vienna, Austria (pp. 769). SPRINGER, 44(2)
Open this publication in new window or tab >>Radioiodination Of Small Stapled Peptides For p53 Therapy
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2017 (English)Conference paper, Poster (with or without abstract) (Refereed)
Place, publisher, year, edition, pages
SPRINGER, 2017
National Category
Analytical Chemistry Organic Chemistry
Identifiers
urn:nbn:se:uu:diva-396979 (URN)
Conference
EANM´17, Annual Congress of the European Association of Nuclear Medicine, October 21 – 25, 2017, Vienna, Austria
Note

Proceedings https://doi.org/10.1007/s00259-017-3822-1

Available from: 2019-11-12 Created: 2019-11-12 Last updated: 2020-01-16Bibliographically approved
Reijmar, K., Edwards, K., Andersson, K. & Agmo Hernández, V. (2016). Characterizing and controlling the loading and release of cationic amphiphilic peptides onto and from PEG-stabilized lipodisks. Langmuir, 32(46), 12091-12099
Open this publication in new window or tab >>Characterizing and controlling the loading and release of cationic amphiphilic peptides onto and from PEG-stabilized lipodisks
2016 (English)In: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 32, no 46, p. 12091-12099Article in journal (Refereed) Published
Abstract [en]

Recent studies have identified PEG-stabilized lipid nanodisks (lipodisks) as promising carriers for cationic amphiphilic peptides with antimicrobial and anticancer activity. Using fluorimetric and nanogravimetric methods, we have in this work characterized the parameters describing and controlling the binding of three selected peptides (melittin, LL37, and magainin 2) onto lipodisks. It was found that the affinity of melittin for lipodisks is independent of the disk size and rim charge. On the other hand, the number of binding sites is strongly dependent on both parameters, with the highest loading being obtained for small disks with a negatively charged rim. An optimized composition of the lipodisks was utilized to study the loading of antimicrobial peptides magainin 2 and human LL37. It was observed that although magainin 2 can be loaded in large amounts, it is released very fast upon dilution, which limits future therapeutic applications. In contrast, LL37 can be loaded at relevant concentrations and the formulation is stable. This opens up for applications of LL37-loaded lipodisks as antibiotics and in anticancer treatments.

National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-305377 (URN)10.1021/acs.langmuir.6b03012 (DOI)000388914400012 ()
Funder
Swedish Cancer Society
Available from: 2016-10-17 Created: 2016-10-17 Last updated: 2017-11-29Bibliographically approved
Duong-Thi, M.-D., Bergström, M., Edwards, K., Eriksson, J., Ohlson, S., To Yiu Ying, J., . . . Agmo Hernández, V. (2016). Lipodisks integrated with weak affinity chromatography enable fragment screening of integral membrane proteins. The Analyst, 141(3), 981-988
Open this publication in new window or tab >>Lipodisks integrated with weak affinity chromatography enable fragment screening of integral membrane proteins
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2016 (English)In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 141, no 3, p. 981-988Article in journal (Refereed) Published
Abstract [en]

Membrane proteins constitute the largest class of drug targets but they present many challenges in drug discovery. Importantly, the discovery of potential drug candidates is hampered by the limited availability of efficient methods for screening drug-protein interactions. In this work we present a novel strategy for rapid identification of molecules capable of binding to a selected membrane protein. An integral membrane protein (human aquaporin-1) was incorporated into planar lipid bilayer disks (lipodisks), which were subsequently covalently coupled to porous derivatized silica and packed into HPLC columns. The obtained affinity columns were used in a typical protocol for fragment screening by weak affinity chromatography (WAC), in which one hit was identified out of a 200 compound collection. The lipodisk-based strategy, which ensures a stable and native-like lipid environment for the protein, is expected to work also with other membrane proteins and screening procedures.

National Category
Analytical Chemistry
Identifiers
urn:nbn:se:uu:diva-269874 (URN)10.1039/C5AN02105G (DOI)000368942600028 ()26673836 (PubMedID)
Funder
Swedish Research Council
Available from: 2015-12-18 Created: 2015-12-18 Last updated: 2017-12-01Bibliographically approved
Eriksson, A., Edwards, K. & Agmo Hernández, V. (2015). Cooperative adsorption behavior of phosphopeptides on TiO2 leads to biased enrichment, detection and quantification. The Analyst, 140(1), 303-312
Open this publication in new window or tab >>Cooperative adsorption behavior of phosphopeptides on TiO2 leads to biased enrichment, detection and quantification
2015 (English)In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 140, no 1, p. 303-312Article in journal (Refereed) Published
Abstract [en]

The adsorption behavior of phosphopeptides onto TiO2 surfaces was studied using the quartz crystal microbalance with dissipation monitoring (QCM-D) as the main experimental technique. The main focus is the characterization of the emergence of positive cooperativity under conditions where the peptides have a positively charged C-term. It is shown that when carrying no net charge, small water-soluble peptides as a rule develop positive cooperativity. The impact of the adsorption mechanism on the outcome of TiO2 based enrichment methods was investigated with the help of matrix assisted laser desorption-ionization mass spectrometry (MALDI-MS). The data presented illustrate how the phosphopeptide profile in the enriched material may deviate from that in the native sample, as cooperative phosphopeptides are overrepresented in the former. Furthermore, commonly employed washing and elution solutions may facilitate preferential release of certain peptides, leading to further bias in the recovered sample. Taken together, the results of the present study demonstrate that thorough understanding of the mechanisms behind the adsorption of phosphopeptides on the enrichment material is necessary in order to develop reliable qualitative and quantitative methods for phosphoproteomics.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2015
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-234196 (URN)10.1039/C4AN01580K (DOI)000345824700036 ()
Available from: 2014-10-15 Created: 2014-10-15 Last updated: 2017-12-05Bibliographically approved
Agmo Hernández, V., Eriksson, E. K. & Edwards, K. (2015). Ubiquinone-10 alters mechanical properties and increases stability of phospholipid membranes. Biochimica et Biophysica Acta - Biomembranes, 1848(10), 2233-2243
Open this publication in new window or tab >>Ubiquinone-10 alters mechanical properties and increases stability of phospholipid membranes
2015 (English)In: Biochimica et Biophysica Acta - Biomembranes, ISSN 0005-2736, E-ISSN 1879-2642, Vol. 1848, no 10, p. 2233-2243Article in journal (Refereed) Published
Abstract [en]

Abstract Ubiquinone-10 is mostly known for its role as an electron and proton carrier in aerobic cellular respiration and its function as a powerful antioxidant. Accumulating evidence suggest, however, that this well studied membrane component could have several other important functions in living cells. The current study reports on a previously undocumented ability of ubiquinone-10 to modulate the mechanical strength and permeability of lipid membranes. Investigations of DPH fluorescence anisotropy, spontaneous and surfactant induced leakage of carboxyfluorescein, and interactions with hydrophobic and hydrophilic surfaces were used to probe the effects caused by inclusion of ubiquinone-10 in the membrane of phospholipid liposomes. The results show that ubiquinone in concentrations as low as 2 mol.% increases the lipid packing order and condenses the membrane. The altered physicochemical properties result in a slower rate of release of hydrophilic components, and render the membrane more resistant towards rupture. As judged from comparative experiments using the polyisoprenoid alcohol solanesol, the quinone moiety is essential for the membrane stabilizing effects to occur. Our findings imply that the influence of ubiquinone-10 on the permeability and mechanical properties of phospholipid membranes is similar to that of cholesterol. The reported data indicate, however, that the molecular mechanisms are different in the two cases.

Keywords
Coenzyme Q10, Liposomes, Leakage, Membrane stability, Solanesol
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-253627 (URN)10.1016/j.bbamem.2015.05.002 (DOI)000362153400032 ()
Funder
Swedish Research Council, 621-2011-3524Swedish Cancer Society, CAN20111504
Available from: 2015-05-29 Created: 2015-05-29 Last updated: 2018-09-23Bibliographically approved
Agmo Hernández, V., Lendeckel, U. & Scholz, F. (2013). Electrochemistry of Adhesion and Spreading of Lipid Vesicles on Electrodes. In: Schlesinger, Mordechay (Ed.), Applications of Electrochemistry in Medicine (pp. 189-247). Springer US, 56
Open this publication in new window or tab >>Electrochemistry of Adhesion and Spreading of Lipid Vesicles on Electrodes
2013 (English)In: Applications of Electrochemistry in Medicine / [ed] Schlesinger, Mordechay, Springer US , 2013, Vol. 56, p. 189-247Chapter in book (Other academic)
Abstract [en]

Biological membranes have developed to separate different compartments of organisms and cells. There is a large number of rather different functions which membranes have to fulfil: (1) they control the material and energy fluxes of metabolic processes, (2) they provide a wrapping protecting the compartments from chemical and physical attacks of the environment, (3) they provide interfaces at which specific biochemical machineries can operate (e.g., membrane bound enzymes), (4) they are equipped for signal transduction, (5) they possess the necessary stability and flexibility to allow cell division, and endo- and exocytosis as well as migration, (6) they present anchoring structures that enable cell-to-cell and cell-to-matrix physical interactions and intercellular communication. These are certainly not all functions of membranes as new functionalities are continuously reported. Since the biological membranes separate essentially aqueous solutions, such separating borders—if they should possess a reasonable stability and also flexibility combined with selective permeability—have to be built up of hydrophobic molecules exposing to both sides a similar interface. It was one of the most crucial and most lucky circumstances for the development and existence of life that certain amphiphilic molecules are able to assemble in bilayer structures (membranes), which—on one side—possess a rather high physical and chemical stability, and—on the other side—are able to incorporate foreign molecules for modifying both the physical properties as well as the permeability of the membranes for defined chemical species. The importance of the chemical function of membranes and all its constituents, e.g., ion channels, pore peptides, transport peptides, etc., is generally accepted. The fluid-mosaic model proposed by Singer and Nicolson [1] is still the basis to understand the biological, chemical, and physical properties of biological membranes. The importance of the purely mechanical properties of membranes came much later into the focus of research. The reasons are probably the dominance of biochemical thinking and biochemical models among biologists and medical researchers, as well as a certain lack of appropriate methods to probe mechanical properties of membranes. The last decades have changed that situation due to the development of techniques like the Atomic Force Microscopy, Fluorescence Microscopy, Micropipette Aspiration, Raman Microspectroscopy, advanced Calorimetry, etc. This chapter is aimed at elucidating how the properties of membranes can be investigated by studying the interaction of vesicles with a very hydrophobic surface, i.e., with the surface of a mercury electrode. This interaction is unique as it results in a complete disintegration of the bilayer membrane of the vesicles and the formation of an island of adsorbed lipid molecules, i.e., a monolayer island. This process can be followed by current-time measurements (chronoamperometry), which allow studying the complete disintegration process in all its details: the different steps of that disintegration can be resolved on the time scale and the activation parameters can be determined. Most interestingly, the kinetics of vesicle disintegration on mercury share important features with the process of vesicle fusion and, thus, sheds light also on mechanisms of endocytosis and exocytosis. Most importantly, not only artificial vesicles (liposomes) can be studied with this approach, but also reconstituted plasma membrane vesicles and even intact mitochondria. Hence, one can expect that the method may provide in future studies also information on the membrane properties of various other vesicles, including exosomes, and may allow investigating various aspects of drug action in relation to membrane properties (transmembrane transport, tissue targeting, bioavailability, etc.), and also the impact of pathophysiological conditions (e.g., oxidative modification) on membrane properties, on a hitherto not or only hardly accessible level.

Place, publisher, year, edition, pages
Springer US, 2013
Series
Modern Aspects of Electrochemistry ; Vol. 56
National Category
Medical and Health Sciences Natural Sciences
Identifiers
urn:nbn:se:uu:diva-197698 (URN)10.1007/978-1-4614-6148-7_6 (DOI)978-1-4614-6148-7 (ISBN)
Available from: 2013-04-02 Created: 2013-04-02 Last updated: 2013-04-02Bibliographically approved
Agmo Hernández, V., Samuelsson, J., Forssén, P. & Fornstedt, T. (2013). Enhanced interpretation of adsorption data generated by liquid chromatography and by modern biosensors. Journal of Chromatography A, 1317(SI), 22-31
Open this publication in new window or tab >>Enhanced interpretation of adsorption data generated by liquid chromatography and by modern biosensors
2013 (English)In: Journal of Chromatography A, ISSN 0021-9673, E-ISSN 1873-3778, Vol. 1317, no SI, p. 22-31Article in journal (Refereed) Published
Abstract [en]

In this study we demonstrate the importance of proper data processing in adsorption isotherm estimations. This was done by investigating and reprocessing data from five cases on two closely related platforms: liquid chromatography (LC) and biosensors. The previously acquired adsorption data were reevaluated and reprocessed using a three-step numerical procedure: (i) preprocessing of adsorption data, (ii) adsorption data analysis and (iii) final rival model fit. For each case, we will discuss what we really measure and what additional information can be obtained by numerical processing of the data. These cases clearly demonstrate that numerical processing of LC and biosensor data can be used to gain deeper understanding of molecular interactions with adsorption media. This is important because adsorption data, especially from biosensors, is often processed using old and simplified methods.

Keywords
Surface Plasmon Resonance, Quartz Crystal Microbalance, Data processing, Fluorescence, Adsorption isotherm, Adsorption energy distribution
National Category
Chemical Sciences
Identifiers
urn:nbn:se:uu:diva-205628 (URN)10.1016/j.chroma.2013.07.077 (DOI)000327229600004 ()
Available from: 2013-08-21 Created: 2013-08-21 Last updated: 2018-01-23Bibliographically approved
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