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- Ahlgren, Sara, et al.
(författare)
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Targeting of HER2-Expressing Tumors Using 111In-ABY-025, a Second-Generation Affibody Molecule with a Fundamentally Reengineered Scaffold
- 2010
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667 .- 2159-662X. ; 51:7, s. 1131-1138
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Tidskriftsartikel (refereegranskat)abstract
- Overexpression of HER2 in breast carcinomas predicts response to trastuzumab therapy. Affibody molecules based on a non-immunoglobulin scaffold have demon-strated high potential for in vivo molecular imaging of HER2-expressing tumors. Re-engineering of the molecular scaffold has led to a second generation of optimized Affibody molecules, having a surface distinctly different from the parental protein domain from staphylococcal protein A. The new tracer showed further increased melting point, stability and overall hydrophilicity compared to the parental molecule, and was shown to be more amenable for chemical peptide synthesis. The goal of this study was to assess potential effects of this extensive re-engineering on HER2 targeting, using ABY-025, a DOTA conjugated variant of the novel tracer. Methods: 111In-ABY-025 was compared with previously evaluated parent HER2-binding Affibody tracers in vitro and in vivo. The in vivo behavior was further evaluated in mice bearing SKOV-3 xenografts, in rats and in cynomolgus macaques. Results: 111In-ABY-025 bound specifically to HER2 in vitro and in vivo. Direct comparison with the previous generation of HER2-binding tracers showed that ABY-025 retained excellent targeting properties. Rapid blood clearance was shown in mice, rats and macaques. A highly specific tumor uptake of 16.7 ± 2.5 %IA/g was seen at 4 h after injection. The tumor-to-blood ratio was 6.3 at 0.5 h, 88 at 4 h, and increased up to 3 days after injection. Gamma camera imaging of tumors was already possible 0.5 h after injection. Furthermore, repeated i.v. administration of ABY-025 did not induce antibody formation in rats. Conclusions: The biodistribution of 111In-ABY-025 was in remarkably good agreement with the parent tracers, despite profound re-engineering of the non-binding surface. The molecule displayed rapid blood clearance in all species investigated and excellent targeting capacity in tumor bearing mice, leading to high tumor-to-organ-ratios and high contrast imaging shortly after injection.
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| 3. |
- Brink, Mikael, et al.
(författare)
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Anti-citrullinated protein antibody specificities and pulmonary fibrosis in relation to genetic loci in early rheumatoid arthritis
- 2022
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Ingår i: Rheumatology. - : Oxford University Press. - 1462-0324 .- 1462-0332. ; 61:12, s. 4985-4990
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Pulmonary manifestations in RA are common comorbidities, but the underlying mechanisms are largely unknown. The added value of a multiplex of ACPA and genetic risk markers was evaluated for the development of pulmonary fibrosis (PF) in an inception cohort. Methods A total of 1184 patients with early RA were consecutively included and followed prospectively from the index date until death or 31 December 2016. The presence of 21 ACPA fine specificities was analysed using a custom-made microarray chip (Thermo Fisher Scientific, Uppsala, Sweden). Three SNPs, previously found related to PF were evaluated, rs2609255 (FAM13A), rs111521887 (TOLLIP) and rs35705950 (MUC5B). ACPA and genetic data were available for 841 RA patients, of whom 50 developed radiologically defined PF. Results In unadjusted analyses, 11 ACPA specificities were associated with PF development. In multiple variable analyses, six ACPA specificities were associated with increased risk of PF: vimentin (Vim)60-75, fibrinogen (Fib)beta 62-78 (72), Fib alpha 621-635, Bla26, collagen (C)II359-369 and F4-CIT-R (P < 0.01 to P < 0.05). The number of ACPA specificities was also related to PF development (P < 0.05 crude and adjusted models). In multiple variable models respectively adjusted for each of the SNPs, the number of ACPA specificities (P < 0.05 in all models), anti-Vim60-75 (P < 0.05, in all models), anti-Fib beta 62-78 (72) (P < 0.001 to P < 0.05), anti-CII359-369 (P < 0.05 in all models) and anti-F4-CIT-R AQ4 (P < 0.01 to P < 0.05), anti-Fib alpha 621-635 (P < 0.05 in one) and anti-Bla26 (P < 0.05 in two) were significantly associated with PF development. Conclusion The development of PF in an inception cohort of RA patients was associated with both presence of certain ACPA and the number of ACPA specificities and risk genes.
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| 5. |
- Brink, Mikael, et al.
(författare)
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Multiplex Analyses of Antibodies Against Citrullinated Peptides in Individuals Prior to Development of Rheumatoid Arthritis
- 2013
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Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 65:4, s. 899-910
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Tidskriftsartikel (refereegranskat)abstract
- Objective The presence of antibodies against cyclic citrullinated peptides has been demonstrated to precede the onset of symptoms of rheumatoid arthritis (RA) by several years. The aim of this study was to analyze antibodies against 10 citrullinated autoantigen-derived peptides for reactivity before the onset of RA symptoms. Methods A casecontrol study was conducted within the Medical Biobank of Northern Sweden. The study was performed in 409 individuals, 386 of whom donated 717 blood samples before the onset of symptoms of RA (pre-patients). The median period of time predating the onset of RA was 7.4 years. A total of 1,305 population-based control subjects were also studied. Antibodies to 10 citrullinated peptides, fibrinogen 573 (Fib573), Fib591, Fib3652, Fib72, Fib74, -enolase (citrullinated -enolase peptide 1 [CEP-1]), triple-helical type II collagen peptide C1 (citC1III), filaggrin, vimentin 217 (Vim217), and Vim6075, were analyzed using a microarray system. Results The fluorescence intensity of antibodies against Fib3652, Fib74, CEP-1, citC1III, and filaggrin was significantly increased in pre-patients compared with controls (P < 0.001). The levels of the earliest-detectable antibodies (Fib591 and Vim6075) fluctuated over time, with only a slight increase after the onset of disease. The frequency of antibodies against Fib3652, CEP-1, and filaggrin increased gradually, reaching the highest levels before symptom onset. The frequency of a cluster of antibodies, citC1III, Fib573, and Fib74, increased only slightly before the onset of symptoms but increased prominently after disease onset. The odds ratio for the development of RA in individuals expressing both CEP-1 and Fib3652 antibodies (using data from samples obtained <3.35 years predating symptom onset) was 40.4 (95% confidence interval 19.882.3) compared with having either antibody alone. Conclusion Development of an immune response toward citrullinated peptides is initially restricted but expands with time to induce a more specific response, with levels, particularly those of antibodies against CEP-1, Fib3652, and filaggrin, increasing during the predating time period closer to the onset of symptoms.
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| 6. |
- Brink, Mikael, et al.
(författare)
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Rheumatoid factor isotypes in relation to antibodies against citrullinated peptides and carbamylated proteins before the onset of rheumatoid arthritis
- 2016
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Ingår i: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6362. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- Background: The presence of rheumatoid factor (RF), anti-carbamylated protein antibodies (anti-CarP) and antibodies against citrullinated protein and peptides (ACPA) precedes the onset of symptoms of rheumatoid arthritis (RA) by several years. Relationships between the development of these antibodies are not obvious. Methods: Three isotypes [immunoglobulin A (IgA), IgG and IgM) of RF were analysed in 321 pre-symptomatic individuals who provided 598 samples collected a median of 6.2 (interquartile range 7.2) years before the onset of symptoms, and in 492 population control subjects. All samples were donated to the Biobank of Northern Sweden. RF isotypes were analysed using the EliA system (Phadia GmbH, Freiburg, Germany) with 96 % specificity according to receiver operating characteristic curves. Ten ACPA specificities were analysed using the ImmunoCAP ISAC system, and anti-CCP2 and anti-CarP antibodies were evaluated using enzyme-linked immunosorbent assays. Results: The frequencies of RF isotypes in pre-symptomatic individuals were significantly increased compared with control subjects (p < 0.0001). In samples collected >= 15 years before the onset of symptoms, the IgA-RF isotype was significantly more prevalent than the most frequent ACPAs. Combinations of IgM- and IgA-RF isotypes with ACPA specificities [a-enolase (CEP-1/Eno(5-21))], fibrinogen (Fib)beta(36-52), Fiba(580-600), filaggrin (CCP-1/Fil(307-324)) and anti-CCP2 antibodies were associated with a significantly shorter time to onset of symptoms (p < 0.001-0.05). Using conditional inference tree analysis, anti-CCP2 in combination with anti-filaggrin antibodies gave the highest probability, 97.5 %, for disease development. Conclusions: RF isotypes predicted the development of RA, particularly in combination with ACPA, anti-CCP2 or anti-CarP antibodies. The highest probability for disease development was the presence of anti-CCP2 and anti-filaggrin antibodies.
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| 10. |
- Circiumaru, Alexandra, et al.
(författare)
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Anti-Citrullinated Protein Antibody Reactivity towards Neutrophil-Derived Antigens : Clonal Diversity and Inter-Individual Variation
- 2023
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Ingår i: Biomolecules. - : MDPI. - 2218-273X. ; 13:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Why the adaptive immune system turns against citrullinated antigens in rheumatoid arthritis (RA) and whether anti-citrullinated protein antibodies (ACPAs) contribute to pathogenesis are questions that have triggered intense research, but still are not fully answered. Neutrophils may be crucial in this context, both as sources of citrullinated antigens and also as targets of ACPAs. To better understand how ACPAs and neutrophils contribute to RA, we studied the reactivity of a broad spectrum of RA patient-derived ACPA clones to activated or resting neutrophils, and we also compared neutrophil binding using polyclonal ACPAs from different patients.Methods: Neutrophils were activated by Ca2+ ionophore, PMA, nigericin, zymosan or IL-8, and ACPA binding was studied using flow cytometry and confocal microscopy. The roles of PAD2 and PAD4 were studied using PAD-deficient mice or the PAD4 inhibitor BMS-P5.Results: ACPAs broadly targeted NET-like structures, but did not bind to intact cells or influence NETosis. We observed high clonal diversity in ACPA binding to neutrophil-derived antigens. PAD2 was dispensable, but most ACPA clones required PAD4 for neutrophil binding. Using ACPA preparations from different patients, we observed high patient-to-patient variability in targeting neutrophil-derived antigens and similarly in another cellular effect of ACPAs, the stimulation of osteoclast differentiation.Conclusions: Neutrophils can be important sources of citrullinated antigens under conditions that lead to PAD4 activation, NETosis and the extrusion of intracellular material. A substantial clonal diversity in targeting neutrophils and a high variability among individuals in neutrophil binding and osteoclast stimulation suggest that ACPAs may influence RA-related symptoms with high patient-to-patient variability.
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