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Discover how PEPperPRINT Peptide Microarray products have been used in different fields of research.

Anti-allodynic effect of intrathecal antibodies against macrophage-inducible C-type lectin in spinal nerve ligation model in rat

Kang, Dong Ho; Kim, Woong Mo; Bae, Hong Beom; Yang, Jihoon; Choi, Jeong Il
Heliyon.
Nov 2024
*Introduction* Macrophage-inducible C-type lectin (Mincle) has emerged as a potential contributor to neuropathic pain induction and neuroinflammatory responses within the spinal cord. Moreover, evidence suggests a close association between toll-like receptor (TLR) and Mincle expression in myeloid cells. This study evaluated the effectiveness of Mincle antibodies in neuropathic pain and identified the epitope of these antibodies. In addition, the mode of interaction between Mincle and TLR inhibition was explored using isobolographic analysis. *Methods* Three different Mincle antibodies and a specific TLR4 inhibitor (TAK-242) were intrathecally administered, and mechanical allodynia was evaluated using the von Frey test in a rat model of spinal nerve ligation (SNL). Isobolographic analysis was conducted on the effect of combination of TAK-242 and Mincle Ab. Microarray analysis examined the specific region of Mincle targeted by the antibodies. *Results* All Mincle antibodies and TAK-242 significantly alleviated mechanical allodynia in a dose-dependent manner. However, the maximal possible effects (MPE) produced by the antibodies ranged widely from 37.1% to 91.8%, comparable to that of TAK-242 (88.7%). The combination of TAK-242 and the antibody with the highest MPE resulted in an additive interaction for their anti-allodynic effects. Epitope mapping revealed that each antibody targeted the extracellular domain, with epitope lengths ranging from 5 to 15 amino acids. *Conclusions* The current study demonstrates the anti-allodynic effect of Mincle antibodies and additive interaction with TLR4 inhibition in spinal nerve ligation model, suggesting the potential of blocking of Mincle signaling with its antibodies as a novel treatment strategy for neuropathic pain.

Discovery of a novel highly specific, fully human PSCA antibody and its application as an antibody-drug conjugate in prostate cancer

Chu, Xiaojie; Shin, Seungmin; Baek, Du-San; Zhang, Liyong; Conard, Alex; Shi, Megan; Kim, Ye-Jin; Adams, Cynthia; Hines, Maggie; Liu, Xianglei; Chen, Chuan; Sun, Zehua; Jelev, Dontcho V.; Mellors, John W.; Dimitrov, Dimiter S.; Li, Wei
Prostate stem cell antigen (PSCA) is expressed in all stages of prostate cancer, including in advanced androgen-independent tumors and bone metastasis. PSCA may associate with prostate carcinogenesis and lineage plasticity in prostate cancer. PSCA is also a promising theranostic marker for a variety of other solid tumors, including pancreatic adenocarcinoma and renal cell carcinoma. Here, we identified a novel fully human PSCA antibody using phage display methodology. The structure-based affinity maturation yielded a high-affinity binder, F12, which is highly specific and does not bind to 6,000 human membrane proteins based on a membrane proteome array assay. F12 targets PSCA amino acids 63–69 as tested by the peptide scanning microarray, and it cross-reacts with the murine PSCA. IgG1 F12 efficiently internalizes into PSCA-expressing tumor cells. The antimitotic reagent monomethyl auristatin E (MMAE)-conjugated IgG1 F12 (ADC, F12-MMAE) exhibits dose-dependent efficacy and specificity in a human prostate cancer PC-3-PSCA xenograft NSG mouse model. This is a first reported ADC based on a fully human PSCA antibody and MMAE that is characterized in a xenograft murine model, which warrants further optimizations and investigations in additional preclinical tumor models, including prostate and other solid tumors.

Antigen-Heterologous Vaccination Regimen Triggers Alternate Antibody Targeting in SARS-CoV-2-DNA-Vaccinated Mice

Frische, Anders; Krogfelt, Karen Angeliki; Fomsgaard, Anders; Lassaunière, Ria
Vaccines.
Feb 2024
An in-depth analysis of antibody epitopes following vaccination with different regimens provides important insight for developing future vaccine strategies. B-cell epitopes conserved across virus variants may be ideal targets for vaccine-induced antibodies and therapeutic drugs. However, challenges lie in identifying these key antigenic regions, and directing the immune system to target them. We previously evaluated the immunogenicity of two candidate DNA vaccines encoding the unmodified spike protein of either the SARS-CoV-2 Index strain or the Beta variant of concern (VOC). As a follow-on study, we characterized here the antibody binding profiles of three groups of mice immunized with either the DNA vaccine encoding the SARS-CoV-2 Index strain spike protein only, the Beta VOC spike protein only, or a combination of both as an antigen-heterologous prime-boost regimen. The latter induced an antibody response targeting overlapping regions that were observed for the individual vaccines but with additional high levels of antibody directed against epitopes in the SD2 region and the HR2 region. These heterologous-vaccinated animals displayed improved neutralization breadth. We believe that a broad-focused vaccine regimen increases neutralization breadth, and that the in-depth analysis of B-cell epitope targeting used in this study can be applied in future vaccine research.

Discovery of putative breast cancer antigens using an integrative platform of genomics-driven immunoproteomics

Qendro, Veneta; Lundgren, Deborah H.; Palczewski, Samuel; Hegde, Poornima; Stevenson, Christina; Perpetua, Laurie; Latifi, Ardian; Merriman, Jesse; Bugos, Grace; Han, David K.
Proteomics.
Aug 2018
Recent advances in cancer immuno-therapeutics such as checkpoint inhibitors, chimeric antigen-receptor T cells, and tumor infiltrating T cells (TIL) are now significantly impacting cancer patients in a positive manner. Although very promising, reports indicate no more than 25% of cases result in complete remission. One of the limitations of these treatments is the identity of putative cancer antigens in each patient, as it is technically challenging to identify cancer antigens in a rapid fashion. Thus, identification of cancer antigens followed by targeted treatment will increase the efficacy of cancer immunotherapies. To achieve this goal, a combined technologies platform of deep genomic sequencing and personalized immune assessment was devised, termed Genomics Driven Immunoproteomics (GDI). Using this technological platform, we report the discovery of 149 tumor antigens from human breast cancer patients. Significant number of these putative cancer antigens arise from single nucleotide variants (SNVs), as well as insertions and deletions that results into frame-shift mutations. We propose a general model of anti-cancer immunity and suggest that the GDI platform may help identify patient-specific tumor antigens in a timely fashion for precision immunotherapies.

Circulating GRP78 antibodies from ovarian cancer patients: a promising tool for cancer cell targeting drug delivery system?

Van Hoesen, Kylie; Meynier, Sonia; Ribaux, Pascale; Petignat, Patrick; Delie, Florence; Cohen, Marie
Oncotarget.
Dec 2017
Glucose-regulated protein 78 (GRP78) is a chaperone protein that has a high frequency in tumor cells. Normally it is found in the endoplasmic reticulum to assist in protein folding, but under cellular stress, GRP78 influences proliferative signaling pathways at the cell surface. The increased expression elicits autoantibody production, providing a biomarker of ovarian cancer, as well as other types of cancer. This study aims to determine the epitope recognition of GRP78 autoantibodies isolated from serum of ovarian cancer patients and use the identified antibodies to design new drug delivery systems to specifically target cancer cells. We first confirmed that the membrane GRP78 levels are increased in ovarian cancer cells and positively correlate with proliferation. However, the level of circulating GRP78 autoantibodies did not correlate with membrane GRP78 expression in ovarian cancer cells and was lower, although not significantly, compared to control patients. We then determined the epitope recognition of GRP78 autoantibodies and showed that treatment with paclitaxel-loaded nanoparticles coated with anti-GRP78 antibodies significantly decreased tumor development in chick embryo culture of ovarian cancer cell tumors compared to paclitaxel treatment alone. This evidence suggests that nanoparticle drug delivery systems coupled with antibodies against GRP78 has potential as a powerful therapy against ovarian cancer.

A novel neutralizing human monoclonal antibody broadly abrogates hepatitis C virus infection in vitro and in vivo

Desombere, Isabelle; Mesalam, Ahmed Atef; Urbanowicz, Richard A.; Van Houtte, Freya; Verhoye, Lieven; Keck, Zhen-Yong; Farhoudi, Ali; Vercauteren, Koen; Weening, Karin E.; Baumert, Thomas F.; Patel, Arvind H.; Foung, Steven K.H.; Ball, Jonathan; Leroux-Roels, Geert; Meuleman, Philip
Antiviral Research.
Dec 2017
Infections with hepatitis C virus (HCV) represent a worldwide health burden and a prophylactic vaccine is still not available. Liver transplantation (LT) is often the only option for patients with HCV-induced end-stage liver disease. However, immediately after transplantation, the liver graft becomes infected by circulating virus, resulting in accelerated progression of liver disease. Although the efficacy of HCV treatment using direct-acting antivirals has improved significantly, immune compromised LT-patients and patients with advanced liver disease remain difficult to treat. As an alternative approach, interfering with viral entry could prevent infection of the donor liver. We generated a human monoclonal antibody (mAb), designated 2A5, which targets the HCV envelope. The neutralizing activity of mAb 2A5 was assessed using multiple prototype and patient-derived HCV pseudoparticles (HCVpp), cell culture produced HCV (HCVcc), and a human-liver chimeric mouse model. Neutralization levels observed for mAb 2A5 were generally high and mostly superior to those obtained with AP33, a well-characterized HCV-neutralizing monoclonal antibody. Using humanized mice, complete protection was observed after genotype 1a and 4a HCV challenge, while only partial protection was achieved using gt1b and 6a isolates. Epitope mapping revealed that mAb 2A5 binding is conformation-dependent and identified the E2-region spanning amino acids 434 to 446 (epitope II) as the predominant contact domain. Conclusion: mAb 2A5 shows potent anti-HCV neutralizing activity both in vitro and in vivo and could hence represent a valuable candidate to prevent HCV recurrence in LT-patients. In addition, the detailed identification of the neutralizing epitope can be applied for the design of prophylactic HCV vaccines.

Development and analytical performance of a new ARCHITECT automated dipeptidyl peptidase-4 immunoassay

Hemken, Philip M.; Jeanblanc, Nicolette M.; Rae, Tracey; Brophy, Susan E.; Datwyler, Maria J.; Xu, Ying; Manetz, T. Scott; Vainshtein, Inna; Liang, Meina; Xiao, Xiaodong; Chowdhury, Partha S.; Chang, Chien-ying; Streicher, Katie; Greenlees, Lydia; Ranade, Koustubh; Davis, Gerard J.
Practical Laboratory Medicine.
Dec 2017
Background Dipeptidyl peptidase-4 (DPP-4) may be a suitable biomarker to identify people with severe asthma who have greater activation of the interleukin-13 (IL-13) pathway and may therefore benefit from IL-13-targeted treatments. We report the analytical performance of an Investigational Use Only immunoassay and provide data on the biological range of DPP-4 concentrations. Methods We assessed assay performance, utilising analyses of precision, linearity and sensitivity; interference from common endogenous assay interferents, and from asthma and anti-diabetic medications, were also assessed. The assay was used to measure the range of serum DPP-4 concentrations in healthy volunteers and subjects with diabetes and severe, uncontrolled asthma. Results The total precision of DPP-4 concentration measurement (determined using percentage coefficient of variation) was ≤5% over 20 days. Dilution analysis yielded linear results from 30 to 1305 ng/mL; the limit of quantitation was 19.2 ng/mL. No notable endogenous or drug interferences were observed at the expected therapeutic concentration. Median DPP-4 concentrations in healthy volunteers and subjects with asthma or Type 1 diabetes were assessed, with concentrations remaining similar in subjects with diabetes and asthma across different demographics. Conclusion These analyses indicate that the ARCHITECT DPP-4 Immunoassay is a reliable and robust method for measuring serum DPP-4 concentration.

Bayesian Analysis of MicroScale Thermophoresis Data to Quantify Affinity of Protein:Protein Interactions with Human Survivin

Garcia-Bonete, Maria-Jose; Jensen, Maja; Recktenwald, Christian V.; Rocha, Sandra; Stadler, Volker; Bokarewa, Maria; Katona, Gergely
Sci Rep.
Dec 2017
A biomolecular ensemble exhibits different responses to a temperature gradient depending on its diffusion properties. MicroScale Thermophoresis technique exploits this effect and is becoming a popular technique for analyzing interactions of biomolecules in solution. When comparing affinities of related compounds, the reliability of the determined thermodynamic parameters often comes into question. The thermophoresis binding curves can be assessed by Bayesian inference, which provides a probability distribution for the dissociation constant of the interacting partners. By applying Bayesian machine learning principles, binding curves can be autonomously analyzed without manual intervention and without introducing subjective bias by outlier rejection. We demonstrate the Bayesian inference protocol on the known survivin:borealin interaction and on the putative protein-protein interactions between human survivin and two members of the human Shugoshin-like family (hSgol1 and hSgol2). These interactions were identified in a protein microarray binding assay against survivin and confirmed by MicroScale Thermophoresis.

Identification of two conserved B-cell epitopes in the gp90 of reticuloendothelial virus using peptide microarray

Khairy, Wiaam O.A.; Qian, Kun; Shao, Hongxia; Ye, Jianqiang; Qin, Aijian
Veterinary Microbiology.
Nov 2017
Since the gp90 protein of Reticuloendotheliosis virus (REV) plays vital roles in virus neutralization, so detailed analysis of REV-gp90 epitopes is important for the development of epitope based marker vaccines and diagnostic tools for REV infections. In this study, two monoclonal antibodies (mAbs) namely 6C12 and 09980 were used to map the epitopes in REVgp90 using peptide microarray and ELISA. Peptide microarray revealed that mAbs 6C12 and 09980 recognized 216YHPLA220 and 230DPQTSDILEA239 motifs, respectively. This result was confirmed by ELISA using synthetic peptides. Moreover, homology analysis indicated that mAbs defined epitopes are highly conserved among REV strains used in this study. The mAbs and their epitopes identified in this study may have potential applications in development of diagnostic techniques and epitope-based marker vaccines for control of REV infections.

Efficacy of an Adenoviral Vectored Multivalent Centralized Influenza Vaccine

Lingel, Amy; Bullard, Brianna L.; Weaver, Eric A.
Sci Rep.
Nov 2017
Mice were immunized with Adenovirus expressing the H1-con, H2-con, H3-con and H5-con HA consensus genes in combination (multivalent) and compared to mice immunized with the traditional 2010–2011 FluZone and FluMist seasonal vaccines. Immunized mice were challenged with 10–100 MLD50 of H1N1, H3N1, H3N2 and H5N1 influenza viruses. The traditional vaccines induced robust levels of HA inhibition (HI) titers, but failed to protect against five different heterologous lethal influenza challenges. Conversely, the multivalent consensus vaccine (1 × 1010 virus particles (vp)/mouse) induced protective HI titers of ≥40 against 8 of 10 influenza viruses that represent a wide degree of divergence within the HA subtypes and protected 100% of mice from 8 of 9 lethal heterologous influenza virus challenges. The vaccine protection was dose dependent, in general, and a dose as low as 5 × 107 vp/mouse still provided 100% survival against 7 of 9 lethal heterologous influenza challenges. These data indicate that very low doses of Adenovirus-vectored consensus vaccines induce superior levels of immunity against a wide divergence of influenza subtypes as compared to traditional vaccines. These doses are scalable and translatable to humans and may provide the foundation for complete and long-lasting anti-influenza immunity.

Replacing antibodies with modified DNA aptamers in vaccine potency assays

Trausch, Jeremiah J.; Shank-Retzlaff, Mary; Verch, Thorsten
Vaccine.
Oct 2017
Vaccine in vitro potency assays are vital regulatory tests that are used to confirm the presence and concentration of an antigen of interest in a form that directly or indirectly relates to protective activity in patients. Current assays come in many forms, but they almost exclusively use antibody reagents for selective detection of the target antigen. Antibodies provide specific recognition of vaccine antigens but also exhibit drawbacks such as stability limitations, cost, and lot-to-lot variation, which can make it challenging to maintain the reagent throughout the lifetime of the vaccine. We explored replacing antibodies with aptamers. Aptamers are macromolecules, such as nucleic acids, which can bind to their targets with high specificity and affinity, similar to that of antibodies. Some of the advantages of using aptamers over antibodies is that aptamers can be more stable, smaller, less expensive to produce, synthesized in vitro, and logistically easier to supply throughout the multi-decade lifespan of a commercial vaccine. We created modified DNA aptamers against the common vaccine carrier protein, CRM197. Several aptamers were discovered and one was chosen for further characterization. The binding kinetics of the aptamer revealed an off-rate 16-fold slower than anti-CRM197 antibodies used for comparison. The aptamers were more sensitive than available antibodies in some assay formats and comparable in others. The aptamer epitope was mapped to the receptor-binding domain of CRM197, a site adjacent to a known antibody binding site. These data address some key aspects for a path forward in replacing antibodies with aptamers for use as critical reagents in vaccine assays. We further highlight the possibility of using nucleic acid reagents to develop next generation potency assays.

Antibody fingerprints in lyme disease deciphered with high density peptide arrays

Weber, Laura K.; Isse, Awale; Rentschler, Simone; Kneusel, Richard E.; Palermo, Andrea; Hubbuch, Jürgen; Nesterov-Mueller, Alexander; Breitling, Frank; Loeffler, Felix F.
Eng. Life Sci..
Oct 2017
Lyme disease is the most common tick-borne infectious disease in Europe and North America. Previous studies discovered the immunogenic role of a surface-exposed lipoprotein (VlsE) of Borreliella burgdorferi. We employed high density peptide arrays to investigate the antibody response to the VlsE protein in VlsE-positive patients by mapping the protein as overlapping peptides and subsequent in-depth epitope substitution analyses. These investigations led to the identification of antibody fingerprints represented by a number of key residues that are indispensable for the binding of the respective antibody. This approach allows us to compare the antibody specificities of different patients to the resolution of single amino acids. Our study revealed that the sera of VlsE-positive patients recognize different epitopes on the protein. Remarkably, in those cases where the same epitope is targeted, the antibody fingerprint is almost identical. Furthermore, we could correlate two fingerprints with human autoantigens and an Epstein-Barr virus epitope; yet, the link to autoimmune disorders seems unlikely and must be investigated in further studies. The other three fingerprints are much more specific for B. burgdorferi. Since antibody fingerprints of longer sequences have proven to be highly disease specific, our findings suggest that the fingerprints could function as diagnostic markers that can reduce false positive test results.

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