Antibody based plasma protein profiling

This thesis is about protein profiling in serum and plasma using antibody suspension bead arrays for the analysis of biobanked samples and in the context of prostate cancer biomarker discovery. The influence of sample preparation methods on antibody based protein profiles were investigated (Papers I-III) and a prostate cancer candidate biomarker identified and verified (Papers III-V). Furthermore, a perspective on the research area affinity proteomics and its’ employment in biomarker discovery, for improved understanding and potentially improved disease diagnosis, is provided. Paper I presents the results of a comparative plasma and serum protein profiling study, with a targeted biomarker discovery approach in the context of metabolic syndrome. The study yielded a higher number of significant findings and a low experimental variability in blood samples prepared as plasma. Paper II investigated the effects from post-centrifugation delays at different temperatures prior sample storage of serum and plasma samples. Minor effects were found on the detected levels of more than 300 predicted or known plasma proteins. In Paper III, the detectability of proteins in plasma was explored by exposing samples to different pre-analytical heat treatments, prior target capture. Heat induced epitope retrieval was observed for approximately half of the targeted proteins, and resulted in the discovery of different candidate markers for prostate cancer. Several antibodies towards the prostate cancer candidate biomarker CNDP1 were generated, epitope mapped and evaluated in a bead based sandwich immunoassay, as presented in Papers IV and V. Furthermore, the developed sandwich immunoassay targeting multiple distinct CNDP1 epitopes in more than 1000 samples, confirmed the association of CNDP1 levels to aggres- sive prostate cancer and more specifically to prostate cancer patients with regional lymph node metastasis (Paper V). As an outcome of the present investigations and in parallel to studies within the Biobank profiling research group, valuable lessons from study design and multiplex antibody analysis of plasma within biomarker discovery to experimental, technical and biological verifications have been collected.QC 20130821</p

Antibody based plasma protein profiling

This thesis is about protein profiling in serum and plasma using antibody suspension bead arrays for the analysis of biobanked samples and in the context of prostate cancer biomarker discovery. The influence of sample preparation methods on antibody based protein profiles were investigated (Papers I-III) and a prostate cancer candidate biomarker identified and verified (Papers III-V). Furthermore, a perspective on the research area affinity proteomics and its’ employment in biomarker discovery, for improved understanding and potentially improved disease diagnosis, is provided. Paper I presents the results of a comparative plasma and serum protein profiling study, with a targeted biomarker discovery approach in the context of metabolic syndrome. The study yielded a higher number of significant findings and a low experimental variability in blood samples prepared as plasma. Paper II investigated the effects from post-centrifugation delays at different temperatures prior sample storage of serum and plasma samples. Minor effects were found on the detected levels of more than 300 predicted or known plasma proteins. In Paper III, the detectability of proteins in plasma was explored by exposing samples to different pre-analytical heat treatments, prior target capture. Heat induced epitope retrieval was observed for approximately half of the targeted proteins, and resulted in the discovery of different candidate markers for prostate cancer. Several antibodies towards the prostate cancer candidate biomarker CNDP1 were generated, epitope mapped and evaluated in a bead based sandwich immunoassay, as presented in Papers IV and V. Furthermore, the developed sandwich immunoassay targeting multiple distinct CNDP1 epitopes in more than 1000 samples, confirmed the association of CNDP1 levels to aggres- sive prostate cancer and more specifically to prostate cancer patients with regional lymph node metastasis (Paper V). As an outcome of the present investigations and in parallel to studies within the Biobank profiling research group, valuable lessons from study design and multiplex antibody analysis of plasma within biomarker discovery to experimental, technical and biological verifications have been collected.QC 20130821</p

A Blow to the Eye—Post Traumatic Orbital Emphysema Associated With Blowout Fracture

A case of a blowout fracture with sever post traumatic emphysema is described in this study. The clinical presentation, diagnosis and management of orbital emphysema associated with blowout fractures are discussed, and the literature reviewed. This case highlights the importance of proper diagnostic measures and necessary treatment when dealing with orbital trauma patients. The clinical examination of motility, visual acuity and pupillary affect are primarily the most important factors of deciding suitable therapy. In an emergency, time is of the essence to reduce the risk of permanent vision loss

Analysis of plasma from prostate cancer patients links decreased carnosine dipeptidase 1 levels to lymph node metastasis

There is a need for a better differentiation of aggressive tumors in prostate cancer to design a tailored treatment for each patient, preferably by a minimally invasive analysis of blood samples. In a previous study, we discovered a decrease of plasma levels of carnosine dipeptidase 1 (CNDP1) in association with aggressive prostate cancer. Now this relation has been investigated and characterized further by generating several new antibodies for extended analysis of CNDP1 in plasma. Multi-antibody sandwich assays were developed and applied to 1214 samples from two Swedish cohorts that confirmed decreased levels of CNDP1 in plasma from patients with advanced disease. Therein, data from CNDP1 assays allowed a better differentiation between tumor N stages than clinical tPSA, but did not when classifying T or M stages. Further investigations can now elucidate mechanisms behind decreasing levels of CNDP1 in plasma and primary in regards to lymph node metastasis

Affinity proteomics discovers decreased levels of AMFR in plasma from Osteoporosis patients

PURPOSE:: Affinity proteomic approaches by antibody bead arrays enable multiplexed analysis of proteins in body fluids. In the presented study, we investigated blood plasma within osteoporosis to discovery differential protein profiles and to propose novel biomarkers candidates for subsequent studies. EXPERIMENTAL DESIGN:: Starting with 4608 antibodies and plasma samples from 22 women for an untargeted screening, a set of 72 proteins were suggested for further analysis. Complementing these with targets from literature and other studies, a targeted bead array of was built to profile for 92 proteins in plasma samples of 180 women from two independent population-based studies. RESULTS:: Differential profiles between osteoporosis patients and matched controls were discovered for 12 proteins in at least one of the two study sets. Among these targets, the levels of Autocrine Motility Factor Receptor (AMFR) were concordantly lower in plasma of female osteoporosis patients. Subsequently, verification of anti-AMFR antibody selectivity was conducted using high-density peptide and protein arrays, and Western blotting. CONCLUSIONS AND CLINICAL RELEVANCE:: Further validation in additional study sets will be needed to determine the clinical value of the observed decrease in AMFR plasma levels in osteoporosis patients, but AMFR may aid our understanding of disease mechanisms and could support existing tools for diagnosis and monitoring of patient mobility within osteoporosis

Antibodies in children with malaria to PfEMP1, RIFIN and SURFIN expressed at the Plasmodium falciparum parasitized red blood cell surface

Abstract Naturally acquired antibodies to proteins expressed on the Plasmodium falciparum parasitized red blood cell (pRBC) surface steer the course of a malaria infection by reducing sequestration and stimulating phagocytosis of pRBC. Here we have studied a selection of proteins representing three different parasite gene families employing a well-characterized parasite with a severe malaria phenotype (FCR3S1.2). The presence of naturally acquired antibodies, impact on rosetting rate, surface reactivity and opsonization for phagocytosis in relation to different blood groups of the ABO system were assessed in a set of sera from children with mild or complicated malaria from an endemic area. We show that the naturally acquired immune responses, developed during malaria natural infection, have limited access to the pRBCs inside a blood group A rosette. The data also indicate that SURFIN4.2 may have a function at the pRBC surface, particularly during rosette formation, this role however needs to be further validated. Our results also indicate epitopes differentially recognized by rosette-disrupting antibodies on a peptide array. Antibodies towards parasite-derived proteins such as PfEMP1, RIFIN and SURFIN in combination with host factors, essentially the ABO blood group of a malaria patient, are suggested to determine the outcome of a malaria infection

Affinity proteomics discovers decreased levels of AMFR in plasma from Osteoporosis patients

PURPOSE:: Affinity proteomic approaches by antibody bead arrays enable multiplexed analysis of proteins in body fluids. In the presented study, we investigated blood plasma within osteoporosis to discovery differential protein profiles and to propose novel biomarkers candidates for subsequent studies. EXPERIMENTAL DESIGN:: Starting with 4608 antibodies and plasma samples from 22 women for an untargeted screening, a set of 72 proteins were suggested for further analysis. Complementing these with targets from literature and other studies, a targeted bead array of was built to profile for 92 proteins in plasma samples of 180 women from two independent population-based studies. RESULTS:: Differential profiles between osteoporosis patients and matched controls were discovered for 12 proteins in at least one of the two study sets. Among these targets, the levels of Autocrine Motility Factor Receptor (AMFR) were concordantly lower in plasma of female osteoporosis patients. Subsequently, verification of anti-AMFR antibody selectivity was conducted using high-density peptide and protein arrays, and Western blotting. CONCLUSIONS AND CLINICAL RELEVANCE:: Further validation in additional study sets will be needed to determine the clinical value of the observed decrease in AMFR plasma levels in osteoporosis patients, but AMFR may aid our understanding of disease mechanisms and could support existing tools for diagnosis and monitoring of patient mobility within osteoporosis

SURGE complex of Plasmodium falciparum in the rhoptry-neck (SURFIN4.2-RON4-GLURP) contributes to merozoite invasion

10.1371/journal.pone.0201669PLoS ONE138e0201669POLN

Serum Autoantibody Profiling of Patients with Paraneoplastic and Non-Paraneoplastic Autoimmune Retinopathy

Purpose: Although multiple serum antiretinal autoantibodies (ARAs) have been reported in patients with paraneoplastic and non-paraneoplastic autoimmune retinopathy ((n)pAIR), not all retinal antigens involved in (n)pAIR are specified. This study aims to serologically identify patients with presumed (n)pAIR through determination of both known and unknown ARAs by autoantibody profiling. Methods: An antigen suspension bead array using 188 different antigens representing 97 ocular proteins was performed to detect ARAs in serum samples of patients with presumed (n)pAIR (n = 24), uveitis (n = 151) and cataract (n = 21). Logistic regressions were used to estimate the associations between ocular antigens and diagnosis. Validation of interphotoreceptor matrix proteoglycan 2 (IMPG2) and recoverin antigens was performed by immunohistochemistry and immunoblot, respectively. Results: Samples of patients with presumed (n)pAIR exhibited a broad spectrum of ARAs. We identified retinal antigens that have already been described previously (e.g. recoverin), but also identified novel ARA targets. Most ARAs were not specific for (n)pAIR since their presence was also observed in patients with cataract or uveitis. High titers of autoantibodies directed against photoreceptor-specific nuclear receptor and retinol-binding protein 3 were more common in patients with presumed (n)pAIR compared to uveitis (p = 0.015 and p = 0.018, respectively). The presence of all other ARAs did not significantly differ between groups. In patients with presumed (n)pAIR, anti-recoverin autoantibodies were the most prevalent ARAs. Validation of bead array results by immunohistochemistry (anti-IMPG2) and immunoblot (anti-recoverin) showed concordant results in (n)pAIR patients. Conclusions: Patients with (n)pAIR are characterized by the presence of a broad spectrum of ARAs. The diagnosis of (n)pAIR cannot be based on the mere presence of serum ARAs, as these are also commonly present in uveitis as well as in age-related cataract patients