| 1. |
- Edfors, Fredrik, et al.
(författare)
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Enhanced validation of antibodies for research applications
- 2018
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Ingår i: Nature Communications. - : Nature Publishing Group. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- There is a need for standardized validation methods for antibody specificity and selectivity. Recently, five alternative validation pillars were proposed to explore the specificity of research antibodies using methods with no need for prior knowledge about the protein target. Here, we show that these principles can be used in a streamlined manner for enhanced validation of research antibodies in Western blot applications. More than 6,000 antibodies were validated with at least one of these strategies involving orthogonal methods, genetic knockdown, recombinant expression, independent antibodies, and capture mass spectrometry analysis. The results show a path forward for efforts to validate antibodies in an application-specific manner suitable for both providers and users.
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| 2. |
- Uhlén, Mathias, et al.
(författare)
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The human secretome
- 2019
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Ingår i: Science Signaling. - : American Association for the Advancement of Science (AAAS). - 1945-0877 .- 1937-9145. ; 12:609
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Tidskriftsartikel (refereegranskat)abstract
- The proteins secreted by human cells (collectively referred to as the secretome) are important not only for the basic understanding of human biology but also for the identification of potential targets for future diagnostics and therapies. Here, we present a comprehensive analysis of proteins predicted to be secreted in human cells, which provides information about their final localization in the human body, including the proteins actively secreted to peripheral blood. The analysis suggests that a large number of the proteins of the secretome are not secreted out of the cell, but instead are retained intracellularly, whereas another large group of proteins were identified that are predicted to be retained locally at the tissue of expression and not secreted into the blood. Proteins detected in the human blood by mass spectrometry-based proteomics and antibody-based immuno-assays are also presented with estimates of their concentrations in the blood. The results are presented in an updated version 19 of the Human Protein Atlas in which each gene encoding a secretome protein is annotated to provide an open-access knowledge resource of the human secretome, including body-wide expression data, spatial localization data down to the single-cell and subcellular levels, and data about the presence of proteins that are detectable in the blood.
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| 3. |
- Boström, Tove, et al.
(författare)
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Antibodies as means for selective mass spectrometry
- 2016
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Ingår i: Journal of chromatography. B. - : Elsevier. - 1570-0232 .- 1873-376X. ; 1021, s. 3-13
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Tidskriftsartikel (refereegranskat)abstract
- For protein analysis of biological samples, two major strategies are used today; mass spectrometry (MS) and antibody-based methods. Each strategy offers advantages and drawbacks. However, combining the two using an immunoenrichment step with MS analysis brings together the benefits of each method resulting in increased sensitivity, faster analysis and possibility of higher degrees of multiplexing. The immunoenrichment can be performed either on protein or peptide level and quantification standards can be added in order to enable determination of the absolute protein concentration in the sample. The combination of immunoenrichment and MS holds great promise for the future in both proteomics and clinical diagnostics. This review describes different setups of immunoenrichment coupled to mass spectrometry and how these can be utilized in various applications.
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| 4. |
- Garousi, Javad, et al.
(författare)
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ADAPT, a Novel Scaffold Protein-Based Probe for Radionuclide Imaging of Molecular Targets That Are Expressed in Disseminated Cancers
- 2015
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Ingår i: Cancer Research. - : American Association for Cancer Research Inc.. - 0008-5472 .- 1538-7445. ; 75:20, s. 4364-4371
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Tidskriftsartikel (refereegranskat)abstract
- Small engineered scaffold proteins have attracted attention as probes for radionuclide-based molecular imaging. One class of these imaging probes, termed ABD-Derived Affinity Proteins (ADAPT), has been created using the albumin-binding domain (ABD) of streptococcal protein G as a stable protein scaffold. In this study, we report the development of a clinical lead probe termed ADAPT6 that binds HER2, an oncoprotein overexpressed in many breast cancers that serves as a theranostic biomarker for several approved targeting therapies. Surface-exposed amino acids of ABD were randomized to create a combinatorial library enabling selection of high-affinity binders to various proteins. Furthermore, ABD was engineered to enable rapid purification, to eradicate its binding to albumin, and to enable rapid blood clearance. Incorporation of a unique cysteine allowed site-specific conjugation to a maleimido derivative of a DOTA chelator, enabling radionuclide labeling, In-111 for SPECT imaging and Ga-68 for PET imaging. Pharmacologic studies in mice demonstrated that the fully engineered molecule In-111/Ga-68-DOTA(HE) 3-ADAPT6 was specifically bound and taken up by HER2-expressing tumors, with a high tumor-to-normal tissue ratio in xenograft models of human cancer. Unbound tracer underwent rapid renal clearance followed by high renal reabsorption. HER2-expressing xenografts were visualized by gamma-camera or PET at 1 hour after infusion. PET experiments demonstrated feasibility for discrimination of xenografts with high or low HER2 expression. Our results offer a preclinical proof of concept for the use of ADAPT probes for noninvasive in vivo imaging.
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| 5. |
- Garousi, Javad, et al.
(författare)
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Comparative evaluation of dimeric and monomeric forms of ADAPT scaffold protein for targeting of HER2-expressing tumours
- 2019
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Ingår i: European journal of pharmaceutics and biopharmaceutics. - : ELSEVIER SCIENCE BV. - 0939-6411 .- 1873-3441. ; 134, s. 37-48
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Tidskriftsartikel (refereegranskat)abstract
- ADAPTs are small engineered non-immunoglobulin scaffold proteins, which have demonstrated very promising features as vectors for radionuclide tumour targeting. Radionuclide imaging of human epidermal growth factor 2 (HER2) expression in vivo might be used for stratification of patients for HER2-targeting therapies. ADAPT6, which specifically binds to HER2, has earlier been shown to have very promising features for in vivo targeting of HER2 expressing tumours. In this study we tested the hypothesis that dimerization of ADAPT6 would increase the apparent affinity to HER2 and accordingly improve tumour targeting. To find an optimal molecular design of dimers, a series of ADAPT dimers with different linkers, -SSSG- (DiADAPT6L1), -(SSSG)(2)- (DiADAPT6L2), and -(SSSG)(3)- (DiADAPT6L3) was evaluated. Dimers in combination with optimal linker lengths demonstrated increased apparent affinity to HER2. The best variants, DiADAPT6L2 and DiADAPT6L3 were site-specifically labelled with In-111 and I-125, and compared with a monomeric ADAPT6 in mice bearing HER2-expressing tumours. Despite higher affinity, both dimers had lower tumour uptake and lower tumour-to-organ ratios compared to the monomer. We conclude that improved affinity of a dimeric form of ADAPT does not compensate the disadvantage of increased size. Therefore, increase of affinity should be obtained by affinity maturation and not by dimerization.
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| 6. |
- Garousi, Javad, et al.
(författare)
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Comparative evaluation of tumor targeting using the anti-HER2 ADAPT scaffold protein labeled at the C-terminus with indium-111 or technetium-99m
- 2017
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- ABD-Derived Affinity Proteins (ADAPTs) is a novel class of engineered scaffold proteins derived from an albumin-binding domain of protein G. The use of ADAPT6 derivatives as targeting moiety have provided excellent preclinical radionuclide imaging of human epidermal growth factor 2 (HER2) tumor xenografts. Previous studies have demonstrated that selection of nuclide and chelator for its conjugation has an appreciable effect on imaging properties of scaffold proteins. In this study we performed a comparative evaluation of the anti-HER2 ADAPT having an aspartate-glutamate-alanine-valine-aspartate-alanine-asparagine-serine (DEAVDANS) N-terminal sequence and labeled at C-terminus with (99)mTc using a cysteine-containing peptide based chelator, glycine-serine-serine-cysteine (GSSC), and a similar variant labeled with In-111 using a maleimido derivative of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) chelator. Both (99)mTc-DEAVDANS-ADAPT6-GSSC and In-111-DEAVDANS-ADAPT6-GSSC-DOTA accumulated specifically in HER2-expressing SKOV3 xenografts. The tumor uptake of both variants did not differ significantly and average values were in the range of 19-21% ID/g. However, there was an appreciable variation in uptake of conjugates in normal tissues that resulted in a notable difference in the tumor-to-organ ratios. The In-111-DOTA label provided 2-6 fold higher tumor-to-organ ratios than (99)mTc-GSSC and is therefore the preferable label for ADAPTs.
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| 7. |
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| 8. |
- Garousi, Javad, et al.
(författare)
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Influence of the N -Terminal Composition on Targeting Properties of Radiometal-Labeled Anti-HER2 Scaffold Protein ADAPT6
- 2016
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Ingår i: Bioconjugate chemistry. - : American Chemical Society (ACS). - 1043-1802 .- 1520-4812. ; 27:11, s. 2678-2688
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Tidskriftsartikel (refereegranskat)abstract
- Radionuclide-imaging-based stratification of patients to targeted therapies makes cancer treatment more personalized and therefore more efficient. Albumin-binding domain derived affinity proteins (ADAPTs) constitute a novel group of imaging probes based on the scaffold of an albumin binding domain (ABD). To evaluate how different compositions of the N-terminal sequence of ADAPTS influence their biodistribution, a series of human epidermal growth factor receptor type 2 (HER2)-binding ADAPT6 derivatives with different N-terminal sequences were created: GCH(6)DANS (2), GC(HE)(3)DANS (3), GCDEAVDANS (4), and GCVD.ANS(5). These were compared with the parental variant: GCSS(HE)(3)DEAVDANS (1). All variants were site-specifically conjugated with a maleimido-derivative of a DOTA chelator and labeled with In-III. Binding to HER2-expressing cells in vitro, in vivo biodistribution as well as targeting properties of the new variants were compared with properties of the In-III-labeled parental ADAPT variant 1 (In-III-DOTA-1). The composition of the N-terminal sequence had an apparent influence on biodistribution of ADAPT6 in mice. The use of a hexahistidine tag in (InD)-In-III-OTA-2 was associated with elevated hepatic uptake compared to the (HE)(3)-containing counterpart, In-III-DOTA-3. All new variants without a hexahistidine tag demonstrated lower uptake in blood, lung, spleen, and muscle compared to uptake in the parental variant. The best new variants, In-III-DOTA-3 and In-III-DOTA-5, provided tumor uptakes of 14.6 +/- 2.4 and 12.5 +/- 1.3% ID/g at 4 h after injection, respectively. The tumor uptake of In-III-DOTA-3 was significantly higher than the uptake of the parental In-III-DOTA-1 (9.1 +/- 2.0% ID/g). The tumor-to-blood ratios of 395 +/- 75 and 419 +/- 91 at 4 h after injection were obtained for In-III-DOTA-5 and (IIII)n-DOTA-3, respectively. In conclusion, the N-terminal sequence composition affects the biodistribution and targeting properties of ADAPT-based imaging probes, and its optimization may improve imaging contrast.
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