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Chronic obstructive pulmonary disease (COPD) is a condition characterized by chronic airway inflammation and obstruction, primarily caused by tobacco smoking. Although the involvement of immune cells in COPD pathogenesis is well established, the contribution of innate lymphoid cells (ILCs) remains poorly understood. ILCs are a type of innate immune cells that participate in tissue remodeling processes, but their specific role in COPD has not been fully elucidated. During COPD, the breakdown of pulmonary elastin generates elastin peptides that elicit biological activities on immune cells. This study aimed to investigate the presence of ILC in patients with COPD and examine the impact of elastin peptides on their functionality. Our findings revealed an elevated proportion of ILC2 in the peripheral blood of patients with COPD, and a general activation of ILC as indicated by an increase in their cytokine secretion capacity. Notably, our study demonstrated that serum from patients with COPD promotes ILC2 phenotype, likely due to the elevated concentration of IL-5, a cytokine known to favor ILC2 activation. Furthermore, we uncovered that this increase in IL-5 secretion is partially attributed to its secretion by macrophages upon stimulation by elastin peptides, suggesting an indirect role of elastin peptides on ILC in COPD. These findings shed light on the involvement of ILC in COPD and provide insights into the potential interplay between elastin breakdown, immune cells, and disease progression. Further understanding of the mechanisms underlying ILC activation and their interaction with elastin peptides could contribute to the development of novel therapeutic strategies for COPD management. NEW & NOTEWORTHY Elastin-derived peptides, generated following alveolar degradation during emphysema in patients with COPD, are able to influence the response of type 2 innate lymphoid cells. We show that the orientation of innate lymphoid cells in patients with COPD is shifted toward a type 2 profile and that elastin peptides are indirectly participating in that shift through their influence of macrophages, which in turn impact innate lymphoid cells.

Purpose: Age-related macular degeneration (AMD), the leading cause of blindness in western populations, is associated with an overactive complement system, and an increase in circulating antibodies against certain epitopes, including elastin. As loss of the elastin layer of Bruch's membrane (BrM) has been reported in aging and AMD, we previously showed that immunization with elastin peptide oxidatively modified by cigarette smoke (ox-elastin), exacerbated ocular pathology in the smoke-induced ocular pathology (SIOP) model. Here we asked whether ox-elastin peptide-based immunotherapy (PIT) ameliorates damage., Methods: C57BL/6J mice were injected with ox-elastin peptide at two doses via weekly subcutaneous administration, while exposed to cigarette smoke for 6 months. FcγR -/- and uninjected C57BL/6J mice served as controls. Retinal morphology was assessed by electron microscopy, and complement activation, antibody deposition and mechanisms of immunological tolerance were assessed by Western blotting and ELISA., Results: Elimination of Fcγ receptors, preventing antigen/antibody-dependent cytotoxicity, protected against SIOP. Mice receiving PIT with low dose ox-elastin (LD-PIT) exhibited reduced humoral immunity, reduced complement activation and IgG/IgM deposition in the RPE/choroid, and largely a preserved BrM. While there is no direct evidence of ox-elastin pathogenicity, LD-PIT reduced IFNγ and increased IL-4 within RPE/choroid. High dose PIT was not protective., Conclusions: These data further support ox-elastin role in ocular damage in part via elastin-specific antibodies, and support the corollary that PIT with ox-elastin attenuates ocular pathology. Overall, damage is associated with complement activation, antibody-dependent cell-mediated cytotoxicity, and altered cytokine signature., (Copyright © 2021. Published by Elsevier Ltd.)

Primary Sjögren's syndrome is an autoimmune disease that is predominantly seen in women. The disease is characterized by exocrine gland dysfunction in combination with serious systemic manifestations. At present, the causes of pSS are poorly understood. Pulmonary and renal inflammation are observed in pSS mice, reminiscent of a subset of pSS patients. A growing body of evidence indicates that inflammation mediated by Damage-Associated Molecular Patterns (DAMPs) contributes to autoimmunity, although this is not well-studied in pSS. Degraded extracellular matrix (ECM) constituents can serve as DAMPs by binding pattern-recognition receptors and activating Myd88-dependent signaling cascades, thereby exacerbating and perpetuating inflammatory cascades. The ECM components biglycan (Bgn) and decorin (Dcn) mediate sterile inflammation and both are implicated in autoimmunity. The objective of this study was to determine whether these ECM components and anti-ECM antibodies are altered in a pSS mouse model, and whether this is dependent on Myd88 activation in immune cells. Circulating levels of Bgn and Dcn were similar among pSS mice and controls and tissue expression studies revealed pSS mice had robust expression of both Bgn and Dcn in the salivary tissue, saliva, lung and kidney. Sera from pSS mice displayed increased levels of autoantibodies directed against ECM components when compared to healthy controls. Further studies using sera derived from conditional knockout pSS mice demonstrated that generation of these autoantibodies relies, at least in part, on Myd88 expression in the hematopoietic compartment. Thus, this study demonstrates that ECM degradation may represent a novel source of chronic B cell activation in the context of pSS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Kiripolsky, Kasperek, Zhu, Li, Wang, Yu and Kramer.)

Abdominal aortic aneurysm (AAA) disease causes dilation of the aorta, leading to aortic rupture and death if not treated early. It is the 14th leading cause of death in the U.S. and 10th leading cause of death in men over age 55, affecting thousands of patients. Despite the prevalence of AAA, no safe and efficient pharmacotherapies exist for patients. The deterioration of the elastic lamina in the aneurysmal wall is a consistent feature of AAAs, making it an ideal target for delivering drugs to the AAA site. In this research, we conjugated nanoparticles with an elastin antibody that only targets degraded elastin while sparing healthy elastin. After induction of aneurysm by 4-week infusion of angiotensin II (Ang II), two biweekly intravenous injections of pentagalloyl glucose (PGG)-loaded nanoparticles conjugated with elastin antibody delivered the drug to the aneurysm site. We show that targeted delivery of PGG could reverse the aortic dilation, ameliorate the inflammation, restore the elastic lamina, and improve the mechanical properties of the aorta at the AAA site. Therefore, simple iv therapy of PGG loaded nanoparticles can be an effective treatment option for early to middle stage aneurysms to reverse disease progression and return the aorta to normal homeostasis.

Background and Aims: Proteins containing advanced glycation end products are highly immunogenic and anti-advanced glycation end products antibodies (anti-AGEs antibodies) are found in the sera of diabetics., Materials and Methods: Enzyme-linked immunosorbent assay (ELISA) was used for measuring levels of anti-advanced glycation end products antibodies in sera of 93 patients with type 2 diabetes mellitus and arterial hypertension (mean age 61.4±11.3 years, diabetes duration 9.88±3.12 years; hypertension duration 9.28±4.98). These values were compared to serum anti-AGEs antibodies in 42 age and sex matched controls. Diabetics were divided in two groups according to presence or absence of microangiopathy, group 1 (n=67) and group 2 (n=26), respectively., Results: Serum levels of anti-AGEs antibodies in patients with type 2 diabetes mellitus and arterial hypertension were statistically significantly higher than those in the control group (1.39±0.39 vs. 1.05±0.32), (p<0.05). Group 1 showed significantly higher levels of anti-AGEs antibodies than those of healthy controls (1.53±0.14 vs. 1.05±0.32), (p<0.01). Anti-AGEs antibodies levels were higher in patients with microvascular complications than these in patients without complications. Anti-AGEs antibodies correlate with diastolic blood pressure (r=0.26, p=0.05) and body mass index (r=0.37, p=0.03). We found significantly higher percentage of positive patients for anti-AGEs antibodies (mean+2SD) in group 1 than in group 2., Conclusion: Determining the levels of serum anti-AGEs antibodies can help physicians make early diagnosis and prognosis of the severity of late diabetic complications in hypertensive patients., (This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Background: Porcine circovirus type 2 (PCV2) is an economically important pathogen affecting swine industry worldwide. The production of current PCV2 vaccines is time-consuming and expensive. Elastin-like polypeptides (ELP) undergo temperature-dependent inverse phase transition and ELPylated proteins can be purified simply by inverse transition cycling (ITC)., Methods: The Cap protein of PCV2b, together with the virus neutralizing (VN) epitopes of PCV2a, PCV2d and PCV2e, was expressed in E. coli as an ELPylated protein, and purified by ITC in the presence of mild detergents. For the control purpose, the Cap protein was also expressed as a His-tagged protein and purified by nickel affinity chromatography. The formation of ELPylated VLP (ELP-VLP) and His-tagged VLP (VLP) was revealed by transmission electron microscopy. Mice were immunized two times with the two forms of VLP and the antigen-specific IgG antibody, VN antibody, cytokine responses and immunoprotection against PCV2 challenge were compared., Results: ELPylated Cap protein was expressed as a soluble protein and purified to 94.3% purity by ITC in the presence of 1% Triton X-100 and 0.5 M urea. His-tagged Cap fusion protein was expressed as insoluble inclusion bodies and purified to 90% purity under denatured conditions. The two purified fusion proteins assembled into VLP with similar morphology. Compared to immunization with VLP, immunization with ELP-VLP induced significantly (p < 0.01) stronger VN antibody response and slightly (p < 0.05) stronger Cap-specific IgG antibody response, cytokine production and immunoprotection against PCV2 challenge., Conclusion: A novel ELPylation platform for easy preparation of PCV2 VLP was established and the prepared ELP-VLP was more immunogenic than VLP. The ELPylation technology could be used for other VLP preparation and the prepared ELP-VLP could be developed as a novel PCV2 subunit vaccine.

Generalized arterial calcification of infancy (GACI) and pseudoxanthoma elasticum (PXE) are characterized by pathologic calcifications in the media of large- and medium sized arteries. GACI is associated with biallelic mutations in ENPP1 in the majority of cases, whereas mutations in ABCC6 are known to cause PXE. Different treatment approaches including bisphosphonates and orally administered pyrophosphate (PP i ) were investigated in recent years, but reversion of calcification could not be achieved. With this study, we pursued the idea of a combination of controlled drug delivery through nanoparticles and active targeting via antibody conjugation to develop a treatment for GACI and PXE. To establish a suitable drug delivery system, the chelating drug diethylenetriamine pentaacetic acid (DTPA) was conjugated to nanoparticles composed of human serum albumin (HSA) as biodegradable and non-toxic particle matrix. To accomplish an active targeting of the elastic fibers exposed through calcification of the affected areas, the nanoparticle surface was functionalized with an anti-elastin antibody. Cytotoxicity and cell interaction studies revealed favorable preconditions for the intended i.v. application. The chelating ability was evaluated in vitro and ex vivo on aortic ring culture isolated from two mouse models of GACI and PXE. The positive results led to the conclusion that the produced nanoparticles might be a promising therapy in the treatment of GACI and PXE., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Aim: Abdominal aortic aneurysms (AAA) is a life-threatening weakening and expansion of the abdominal aorta due to inflammatory cell infiltration and gradual degeneration of extracellular matrix (ECM). There are no pharmacological therapies to treat AAA. We tested the hypothesis that nanoparticle (NP) therapy that targets degraded elastin and delivers anti-inflammatory, anti-oxidative, and ECM stabilizing agent, pentagalloyl glucose (PGG) will reverse advance stage aneurysm in an elastase-induced mouse model of AAA., Method and Results: Porcine pancreatic elastase (PPE) was applied periadventitially to the infrarenal aorta in mice and AAA was allowed to develop for 14 days. Nanoparticles loaded with PGG (EL-PGG-NPs) were then delivered via IV route at 14-day and 21-day (10 mg/kg of body weight). A control group of mice received no therapy. The targeting of NPs to the AAA site was confirmed with fluorescent dye marked NPs and gold NPs. Animals were sacrificed at 28-d. We found that targeted PGG therapy reversed the AAA by decreasing matrix metalloproteinases MMP-9 and MMP-2, and the infiltration of macrophages in the medial layer. The increase in diameter of the aorta was reversed to healthy controls. Moreover, PGG treatment restored degraded elastic lamina and increased the circumferential strain of aneurysmal aorta to the healthy levels., Conclusion: Our results support that site-specific delivery of PGG with targeted nanoparticles can be used to treat already developed AAA. Such therapy can reverse inflammatory markers and restore arterial homeostasis., Competing Interests: NRV is a significant shareholder in Elastrin therapeutics Inc. who have licensed elastin targeting nanoparticle patent from Clemson University.

Purpose: Age-related macular degeneration (AMD) is the leading cause of blindness in Western populations. While an overactive complement system has been linked to pathogenesis, mechanisms contributing to its activation are largely unknown. In aged and AMD eyes, loss of the elastin layer (EL) of Bruch's membrane (BrM) has been reported. Elastin antibodies are elevated in patients with AMD, the pathogenic significance of which is unclear. Here we assess the role of elastin antibodies using a mouse model of smoke-induced ocular pathology (SIOP), which similarly demonstrates EL loss., Methods: C57BL/6J mice were immunized with elastin or elastin peptide oxidatively modified by cigarette smoke (ox-elastin). Mice were then exposed to cigarette smoke or air for 6 months. Visual function was assessed by optokinetic response, retinal morphology by spectral-domain optical coherence tomography and electron microscopy, and complement activation and antibody deposition by Western blot., Results: Ox-elastin IgG and IgM antibodies were elevated in ox-elastin immunized mice following 6 months of smoke, whereas elastin immunization had a smaller effect. Ox-elastin immunization exacerbated smoke-induced vision loss, with thicker BrM and more damaged retinal pigment epithelium (RPE) mitochondria compared with mice immunized with elastin or nonimmunized controls. These changes were correlated with increased levels of IgM, IgG2, IgG3, and complement activation products in RPE/choroid., Conclusions: These data demonstrate that SIOP mice generate elastin-specific antibodies and that immunization with ox-elastin exacerbates ocular pathology. Elastin antibodies represented complement fixing isotypes that, together with the increased presence of complement activation seen in immunized mice, suggest that elastin antibodies exert pathogenic effects through mediating complement activation.

The identification and use of antibodies dominate the biologic, clinical diagnostic, and therapeutic landscapes. In particular, antibodies have become essential tools in a variety of protein analytical experiments and to study the disposition of biologic therapeutics. One emerging class of peptide biologics is known as the elastin-like polypeptides (ELPs), which are repetitive protein polymers inspired by human tropoelastin. A major limitation in the clinical translation of ELP biologics has been a lack of a monoclonal antibody (mAb) to characterize their identity during expression. To facilitate these studies, we successfully generated a new mAb that is specific toward ELPs and ELP fusion proteins. A purified antibody was evaluated in an ELISA, western blotting, and immunofluorescence assay. The optimal anti-ELP mAb proved to be highly reactive and specific toward ELPs. Moreover, they were able to detect ELPs with a variety of aliphatic guest residues. ELPs phase-separate in response to heating; furthermore, when incubated at a great excess of ELPs, the anti-ELP mAb partially blocks phase separation. These findings are direct evidence that novel murine mAbs can be raised against purified ELPs. This new reagent will enable purification, experimental detection, and characterization of these biopolymers.

Loss of immune tolerance to self-antigens can promote chronic inflammation and disrupt the normal function of multiple organs, including the lungs. Degradation of elastin, a highly insoluble protein and a significant component of the lung structural matrix, generates proinflammatory molecules. Elastin fragments (EFs) have been detected in the serum of smokers with emphysema, and elastin-specific T cells have also been detected in the peripheral blood of smokers with emphysema. However, an animal model that could recapitulate T cell-specific autoimmune responses by initiating and sustaining inflammation in the lungs is lacking. In this study, we report an animal model of autoimmune emphysema mediated by the loss of tolerance to elastin. Mice immunized with a combination of human EFs plus rat EFs but not mouse EFs showed increased infiltration of innate and adaptive immune cells to the lungs and developed emphysema. We cloned and expanded mouse elastin-specific CD4 + T cells from the lung and spleen of immunized mice. Finally, we identified TCR sequences from the autoreactive T cell clones, suggesting possible pathogenic TCRs that can cause loss of immune tolerance against elastin. This new autoimmune model of emphysema provides a useful tool to examine the immunological factors that promote loss of immune tolerance to self., (Copyright © 2019 by The American Association of Immunologists, Inc.)

Background Thoracic aortic aneurysm ( TAA ) and dissection ( TAD ) are characterized by progressive disorganization of the aortic wall matrix, including elastin, a highly immunogenic molecule. Whether acquired autoimmune responses can be detected in TAA / TAD patients who are smokers is unknown. The objectives of this study were to determine whether TAA / TAD smokers have increased T-cell responses to human elastin fragments, and to determine whether autoimmune responses in TAA / TAD smokers are dependent on chronic obstructive pulmonary disease. Methods and Results In a cross-sectional study (N=86), we examined peripheral blood CD 4 + T cell responses to elastin fragments in never-, former-, or current-smokers with or without TAA / TAD . CD 4 + T cells were co-cultured with irradiated autologous peripheral blood CD 1a + / CD 14 + antigen presenting cells pulsed with or without elastin fragments to measure cytokine production. Baseline plasma concentration of anti-elastin antibodies and elastin-degrading enzymes (eg, matrix metalloproteinase-9, and -12, and neutrophil elastase) were measured in the same cohort. elastin fragment-specific CD 4 + T cell expression of interferon-γ, and anti-elastin antibodies were dependent on history of smoking in TAA / TAD patients but were independent of chronic obstructive pulmonary disease. Matrix metalloproteinase-9, and -12, and neutrophil elastase plasma concentrations were also significantly elevated in ever-smokers with TAA / TAD . Conclusions Cigarette smoke is associated with loss of self-tolerance and induction of elastin-specific autoreactive T- and B-cell responses in patients with TAA / TAD . Development of peripheral blood biomarkers to track immunity to self-antigens could be used to identify and potentially prognosticate susceptibility to TAA / TAD in smokers.

Background: The pathogenesis driving the formation of abdominal aortic aneurysms continues to be poorly understood. Therefore, we systemically define the cytokine and circulating immune cell environment observed in human abdominal aortic aneurysm compared with risk-factor matched controls., Methods: From 2015 to 2017, a total of 274 patients donated blood to the Indiana University Center for Aortic Disease. Absolute concentrations of circulating cytokines were determined, using enzyme-linked immunosorbent assays while the expression of circulating immune cell phenotypes were assayed via flow cytometric analysis., Results: Human abdominal aortic aneurysm is characterized by a significant depletion of the antigen-specific, CD4 + Tr1 regulatory lymphocyte that corresponds to an upregulation of the antigen-specific, inflammatory Th17 cell. We found no differences in the incidence of Treg, B10, and myeloid-derived suppressor regulatory cells. Similarly, no disparities were noted in the following inflammatory cytokines: IL-1β, C-reactive protein, tumor necrosis factor α, interferon γ, and IL-23. However, significant upregulation of the inflammatory cytokines osteopontin, IL-6, and IL-17 were noted. Additionally, no changes were observed in the regulatory cytokines IL-2, IL-4, IL-13, TNF-stimulated gene 6 protein, and prostaglandin E2, but we did observe a significant decrease in the essential regulatory cytokine IL-10., Conclusion: In this investigation, we systematically characterize the abdominal aortic aneurysm-immune environment and present preliminary evidence that faulty immune regulation may also contribute to aneurysm formation and growth., (Copyright © 2018 Elsevier Inc. All rights reserved.)

CD4 + Th1-CXCR3 signalling pathway may play a key role in chronic obstructive pulmonary disease (COPD). The aim of this study was to explore Th1/Th2 cytokines ratio differences in patients in different stages of COPD and to confirm the hypothesis that elastin exposure might serve as an antigen to initiate the stimulation of CD4 + Th1-CXCR3 immune inflammation pathway. Patients of COPD in different stages and normal individuals were enrolled. Ten millilitres of peripheral blood was drawn from patients. The concentration of CXCR3, IFN-γ, IL-2, IL-4 and IL-13 in plasma was detected by ELISA. The Naïve CD4 + T cells were isolated from the peripheral blood mononuclear cells, which were stimulated by elastin and collagen before determining the level of IFN-γ secretion by ELISPOT. Compared with control group, the concentration of CXCR3 in the acute exacerbation COPD (AECOPD) group was higher (P < .05). The concentration of IFN-γ and IL-2 in AECOPD group was lower than that in remission (P < .05). The concentration of IFN-γ in the AECOPD and remission was higher than that in controls (P < .05), while IL-2 was opposite (P < .01). The concentration of IL-4 and IL-13 in AECOPD group was higher than that in the controls (P < .05). The CD4 + Th1 cells stimulated by the elastin as antigen secreted more IFN-γ than that by collagen (P < .01). CXCR3 was highly expressed in patients with COPD. There were different Th1/Th2 cytokines in different stages of COPD. The CD4+Th1-specific conversion and activation may be an initiator of COPD immune inflammatory response., (© 2018 The Foundation for the Scandinavian Journal of Immunology.)

Novel thermo-sensitive elastin-like recombinamers (ELRs) containing bioactive molecules were created for use as a biomimetic biomaterial for tissue regeneration. For effective use for in vivo applications, it is essential to ensure that they do not induce adverse inflammatory, immune, or allergic responses that inhibit tissue repair. Therefore, we sought to establish a pre-clinical approach to evaluate biocompatibility in experimental mice using ELRs as a prototype biomaterial. First, we measured in vitro proliferation and cytokine production from BALB/c and C57BL/6 mouse splenocytes incubated with ELRs. Second, we used a rapid, high throughput in vivo approach in which inflammatory cells and cytokines were measured following an intraperitoneal implantation. Lastly, a subchronic in vivo approach was used in which ELRs or positive controls were subcutaneously implanted and the implantation sites were assessed for inflammation and gene expression. We found that ELRs induced mild inflammation and minimal fibrosis compared to the intense response to Vitoss. Additionally, implantation increased antigen-specific antibody titers for both groups and gene expression profiling of the implantation sites revealed the upregulation of inflammation, fibrosis, and wound healing-related genes in ELR and positive control-implanted mice compared to sham controls. These data demonstrate that ELRs appear safe for use in tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 924-934, 2018., (© 2017 Wiley Periodicals, Inc.)

The most abundant proteins in the arteries are those of extracellular matrix, ie. collagen and elastin. Due to their long half-lifes these proteins have an increased chance to undergo glycation. The aim of this study was to determine relationship between the content of the main extracellular matrix proteins and the advanced glycation end products (AGEs) in arteries. In this study 103 fragments of aorta were analyzed by ELISA and immunobloting for the content of collagens type I, III and IV and elastin and the content of advanced glycation end-products (AGE). A negative correlation between the content of collagens type III and IV and AGE (r = -0,258, p = 0,0122, and a weak negative correlation between collagen type III and age of the sample donor (r = 0,218, p = 0,0262) were demonstrated. This result comes as a surprise and it contradicts an intuitive assumption that with more glycation substrate, i.e. matrix proteins, more AGE products are expected. We have concluded that the results of the ELISA tests must have been influenced by the glycation. As a consequence, either modified protein molecules were not being recognized by the antibodies, or the glycation, and formation of crosslinks have blocked access of the antibodies to the antigen. It will conceal the effect of the linear dependence between the result (absorbance/densitometry) from the quantity of protein to which the antibody is directed.

Cytotoxic T lymphocyte (CTL)-mediated immune responses are the primary defense mechanism against cancer and infection. CTL epitope peptides have been used as vaccines to boost CTL responses; however, the efficacy of these peptides is suboptimal. Under current vaccine formulation and delivery strategies, these vaccines are delivered into and processed inside antigen-presenting cells such as dendritic cells (DCs). However, the intracellular process is not efficient, which at least partially contributes to the suboptimal efficacy of the vaccines. Thus, we hypothesized that directly loading epitopes onto MHC class I complexes (MHC-Is) on the DC surface would significantly improve the efficacy of the epitopes because the direct loading bypasses inefficient intra-DC vaccine processing. To test the hypothesis, we designed an immune-tolerant elastin-like polypeptide (iTEP)-delivered CTL vaccine containing a metalloproteinase-9 (MMP-9)-sensitive peptide and an CTL epitope peptide. We found that the epitope was released from this MMP-sensitive vaccine through cleavage by DC-secreted MMP-9 outside of the DCs. The released epitopes were directly loaded onto MHC-Is on the DC surface. Ultimately, the MMP-sensitive vaccine strikingly increased epitope presentation by DCs by 7-fold and enhanced the epitope-specific CD8+ T-cell response by as high as 9.6-fold compared to the vaccine that was uncleavable by MMP. In summary, this novel direct-loading strategy drastically boosted vaccine efficacy. This study offered a new avenue to enhance CTL vaccines.

Background: Abdominal aortic aneurysm (AAA) is a prevalent disease affecting around 5% of the population aged more than 65 years. The exact etiology and physiopathology of AAA still raises questions, and elective surgery is currently the only treatment option for this often progressive disease. In this study, we hypothesized and tested a pathophysiological model that depicts AAA as an inflammation-triggered autoimmune disease with remnant vessel wall peptide fragments as the antigen., Methods: A pilot study with male AAA patients (n = 14) and male controls (n = 8) was conducted. In both study groups, peripheral blood monocytes and plasma were separated from whole blood by centrifugation. An ELISpot test was performed on cultured white blood cells for the presence of elastin-specific T-lymphocytes. An Enzyme-linked immuno sorbent assay (ELISA) was performed on plasma for the presence of elastin-specific IgG molecules., Results: ELISpot interferon-gamma secretion in AAA (7.7 ± 9.5%) and control (4.6 ± 3.5%) and ELISA anti-elastin IgG titer in AAA (77.5 ± 17.8%) and control (78.2 ± 31.5%) were not significantly different (P = 0.94 and P = 0.55, respectively). Both results are expressed as a percentage relative to the respective positive and negative control., Conclusions: The results of our pilot study did not indicate a clear and invariable autoimmune process directed against remnant elastin peptide fragments. Further research into the model mechanics and a possible antigen is still necessary. In the mean time, the model as presented here already offers a pathophysiological framework to further research into the possible remnant epitope-driven AAA etiology., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Cytotoxic T lymphocyte (CTL) epitope peptide-based vaccines are widely used in cancer and infectious disease therapy. We previously generated an immune-tolerant elastin-like polypeptides (iTEPs)-based carrier to deliver a peptide CTL vaccine and enhance the efficiency of the vaccine. To further optimize the vaccine carrier, we intended to potentiate its function by designing an iTEP-based carrier that was able to deliver adjuvant and a vaccine epitope as one molecule. Thus, we fused a 9-mer H 100 , a peptide derived from the high-mobility group box 1 protein (HMGB1) that could induce activation of dendritic cells (DCs), with an iTEP polymer to generate a new iTEP polymer named H 100 -iTEP. The H 100 -iTEP still kept the feature of reversible phase transition of iTEPs and should be able to be used as a polymer carrier to deliver peptide vaccines. The expression levels of CD80/CD86 on DCs were assessed using flow cytometry. The iTEP fusion-stimulated IL-6 secretion by DCs was measured with ELISA. Activation of antigen-specific CD8 + T cells induced by iTEP fusions was examined through a B3Z hybridoma cell activation assay. In vivo CTL activation promoted by iTEP fusions was detected by an IFN-γ-based ELISPOT assay. The iTEP fused with H 100 could induce maturation of DCs in vitro as evidenced by increased CD80 and CD86 expression. The iTEP fusion also promoted activation of DCs by increasing secretion of a proinflammatory cytokine IL-6. The N-terminus or C-terminus fusion of H 100 to iTEP had a similar effect and a reduced form of cysteine in iTEP fusions was required for DC stimulation. iTEP fusions potentiated a co-administrated CTL vaccine by increasing an antigen-specific CTL response in vitro and in vivo. When the H 100 -iTEP was fused to a CTL epitope to generate a one-molecule vaccine, this self-adjuvanted vaccine elicited a stronger antigen-specific CTL response than a vaccine adjuvanted by Incomplete Freund's Adjuvant. Thus, we have successfully generated a functional, one-molecule iTEP-based self-adjuvanted vaccine.

Degeneration of elastin plays a vital role in the pathology and progression of abdominal aortic aneurysm (AAA). Our previous study showed that pentagalloyl glucose (PGG), a core derivative of tannic acid, hinders the development of AAAs in a clinically relevant animal model when applied locally. In this study, we tested whether targeted nanoparticles (NPs) can deliver PGG to the site of an aneurysm and prevent aneurysmal growth by protecting elastin. PGG-loaded albumin NPs with a surface-conjugated elastin-specific antibody were prepared. Aneurysms were induced by calcium chloride-mediated injury to the abdominal aorta in rats. NPs were injected into the tail vein after 10 days of CaCl 2 injury. Rats were euthanized after 38 days. PGG delivery led to reduction in macrophage recruitment, matrix metalloproteinase (MMP) activity, elastin degradation, calcification, and development of aortic aneurysm. Such NP delivery offers the potential for the development of effective and safe therapies for AAA.

Abdominal aortic aneurysm is a dynamic vascular disease characterized by inflammatory cell invasion and extracellular matrix degradation. Damage to elastin in the extracellular matrix results in release of elastin-derived peptides (EDPs), which are chemotactic for inflammatory cells such as monocytes. Their effect on macrophage polarization is less well known. Proinflammatory M1 macrophages initially are recruited to sites of injury, but, if their effects are prolonged, they can lead to chronic inflammation that prevents normal tissue repair. Conversely, anti-inflammatory M2 macrophages reduce inflammation and aid in wound healing. Thus, a proper M1/M2 ratio is vital for tissue homeostasis. Abdominal aortic aneurysm tissue reveals a high M1/M2 ratio in which proinflammatory cells and their associated markers dominate. In the current study, in vitro treatment of bone marrow-derived macrophages with EDPs induced M1 macrophage polarization. By using C57BL/6 mice, Ab-mediated neutralization of EDPs reduced aortic dilation, matrix metalloproteinase activity, and proinflammatory cytokine expression at early and late time points after aneurysm induction. Furthermore, direct manipulation of the M1/M2 balance altered aortic dilation. Injection of M2-polarized macrophages reduced aortic dilation after aneurysm induction. EDPs promoted a proinflammatory environment in aortic tissue by inducing M1 polarization, and neutralization of EDPs attenuated aortic dilation. The M1/M2 imbalance is vital to aneurysm formation., (Copyright © 2016 by The American Association of Immunologists, Inc.)

Rationale: Matrix metalloproteinases (MMPs)-mediated extracellular matrix destruction is the major cause of development and progression of abdominal aortic aneurysms. Systemic treatments of MMP inhibitors have shown effectiveness in animal models, but it did not translate to clinical success either because of low doses used or systemic side effects of MMP inhibitors. We propose a targeted nanoparticle (NP)-based delivery of MMP inhibitor at low doses to the abdominal aortic aneurysms site. Such therapy will be an attractive option for preventing expansion of aneurysms in patients without systemic side effects., Objective: Our previous study showed that poly(d,l-lactide) NPs conjugated with an antielastin antibody could be targeted to the site of an aneurysm in a rat model of abdominal aortic aneurysms. In the study reported here, we tested whether such targeted NPs could deliver the MMP inhibitor batimastat (BB-94) to the site of an aneurysm and prevent aneurysmal growth., Methods and Results: Poly(d,l-lactide) NPs were loaded with BB-94 and conjugated with an elastin antibody. Intravenous injections of elastin antibody-conjugated BB-94-loaded NPs targeted the site of aneurysms and delivered BB-94 in a calcium chloride injury-induced abdominal aortic aneurysms in rats. Such targeted delivery inhibited MMP activity, elastin degradation, calcification, and aneurysmal development in the aorta (269% expansion in control versus 40% elastin antibody-conjugated BB-94-loaded NPs) at a low dose of BB-94. The systemic administration of BB-94 alone at the same dose was ineffective in producing MMP inhibition., Conclusions: Targeted delivery of MMP inhibitors using NPs may be an attractive strategy to inhibit aneurysmal progression., (© 2015 American Heart Association, Inc.)

Purpose: Elastin is a major arterial structural protein, and elastin-derived peptides are related to arterial change. We previously reported on a novel assay developed using aortic elastin peptides; however, its clinical implications remain unclear. In this study, we assessed whether anti-elastin antibody titers reflect the risk of coronary artery disease (CAD) or its characteristics., Materials and Methods: We included 174 CAD patients and 171 age- and sex-matched controls. Anti-elastin antibody titers were quantified by enzyme-linked immunosorbent assay. Parameters of arterial stiffness, including the augmentation index (AI) and heart-to-femoral pulse wave velocity (hfPWV), were measured non-invasively. The clinical and angiographic characteristics of CAD patients were also evaluated. Associations between anti-elastin levels and vascular characteristics were examined by linear regression analysis., Results: The median blood level of anti-elastin was significantly lower in the CAD group than in the controls [197 arbitrary unit (a.u.) vs. 63 a.u., p<0.001]. Levels of anti-elastin were significantly lower in men and in subjects with hypertension, diabetes mellitus, hyperlipidemia, or high hfPWV. Nevertheless, anti-elastin levels were not dependent on atherothrombotic events or the angiographic severity of CAD. In a multivariate analysis, male sex (β=-0.38, p<0.001), diabetes mellitus (β=-0.62, p<0.001), hyperlipidemia (β=-0.29, p<0.001), and AI (β=-0.006, p=0.02) were ultimately identified as determinants of anti-elastin levels., Conclusion: Lower levels of anti-elastin are related to CAD. The association between antibody titers and CAD is linked to arterial stiffness rather than the advancement of atherosclerosis.

Purpose: One of the major hurdles facing nanomedicines is the antibody production against nanoparticles that subsequently results in their opsonization and clearance by macrophages. The objective of this research was to examine and identify the sequence of a low-immunogenic peptide based on recombinant elastin-like polypeptides (ELPs) that does not evoke IgG response and can potentially be used for masking the surfaces of the nanoparticles., Methods: Biopolymers composed of a DNA condensing domain in fusion with anionic, neutral and cationic elastin-like peptides were genetically engineered. The biopolymers were used to complex with plasmid DNA and form ELP-coated nanoparticles. Then, the potential immunogenicity of nanoparticles in terms of IgM/IgG response after repeated injections was evaluated in Balb/c immunocompetent mice., Results: The results revealed the sequence of a non-immunogenic ELP construct that in comparison to control group did not elicit any significant IgG response, whereas the vector/DNA complexes that were coated with polyethylene glycol (PEG) did elicit significant IgG response under the same conditions., Conclusions: The identification of the sequence of an ELP-based peptide that does not induce IgG response opens the door to more focused in-depth immunotoxicological studies which could ultimately lead to the production of safer and more effective drug/gene delivery systems such as liposomes, micelles, polymeric nanoparticles, viruses and antibodies.

Neutrophil (PMNL) influx precedes lung macrophage (LM) influx into the lung following exposure of newborn pups to 60% O2. We hypothesized that PMNL were responsible for the signals leading to LM influx. This was confirmed when inhibition of PMNL influx with a CXC chemokine receptor-2 antagonist, SB-265610, also prevented the 60% O2-dependent LM influx, LM-derived nitrotyrosine formation, and pruning of small arterioles. Exposure to 60% O2 was associated with increased lung contents of neutrophil elastase and α-elastin, a marker of denatured elastin, and a decrease in elastin fiber density. This led us to speculate that neutrophil elastase-induced elastin fragments were the chemokines that led to a LM influx into the 60% O2-exposed lung. Inhibition of neutrophil elastase with sivelestat or elafin attenuated the LM influx. Sivelestat also attenuated the 60% O2-induced decrease in elastin fiber density. Daily injections of pups with an antibody to α-elastin prevented the 60% O2-dependent LM influx, impaired alveologenesis, and impaired small vessel formation. This suggests that neutrophil elastase inhibitors may protect against neonatal lung injury not only by preventing structural elastin degradation, but also by blocking elastin fragment-induced LM influx, thus preventing tissue injury from LM-derived peroxynitrite formation., (Copyright © 2015 the American Physiological Society.)

Diagnosis of chronic progressive lymphoedema (CPL) in draught horses, including the Belgian Draught Horse, is mainly based on clinical evaluation of typical lower limb lesions. A deficient perilymphatic elastic support, caused by a pathological elastin degradation in skin and subcutis, has been suggested as a contributing factor for CPL. Elastin degradation products induce the generation of anti-elastin Ab (AEAb), detectable in horse serum by ELISA. For a clinically healthy group of draught horses, a significantly lower average AEAb-level than 3 clinically affected groups (mild, moderate and severe symptoms) was demonstrated previously. To improve CPL-diagnosis, we evaluated the AEAb-ELISA as an in vitro diagnostic aid in individual horses. Test reproducibility was assessed, performing assays independently in 2 laboratories on a total of 345 horses. Possible factors associated with AEAb-levels (age, gender, pregnancy, test lab and date of blood collection) were analyzed using a mixed statistical model. Results were reproducible in both laboratories. AEAb-levels in moderately and severely affected horses were significantly higher than in healthy horses. Nevertheless, this was only demonstrated in barren mares, and, there was a very large overlap between the clinical groups. Consequently, even when a high AEAb cut-off was handled to obtain a reasonable specificity of 90%, a very low sensitivity (21%) of AEAb for CPL-diagnosis was obtained. Results on the present sample demonstrate that the described ELISA procedure is of no use as a diagnostic test for CPL in individual horses., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A disintegrin and a metalloproteinase domain (ADAM) 9 is known to be expressed by monocytes and macrophages. In this study, we report that ADAM9 is also a product of human and murine polymorphonuclear neutrophils (PMNs). ADAM9 is not synthesized de novo by circulating PMNs. Rather, ADAM9 protein is stored in the gelatinase and specific granules and the secretory vesicles of human PMNs. Unstimulated PMNs express minimal quantities of surface ADAM9, but activation of PMNs with degranulating agonists rapidly (within 15 min) increases PMN surface ADAM9 levels. Human PMNs produce small quantities of soluble forms of ADAM9. Surprisingly, ADAM9 degrades several extracellular matrix (ECM) proteins, including fibronectin, entactin, laminin, and insoluble elastin, as potently as matrix metalloproteinase-9. However, ADAM9 does not degrade types I, III, or IV collagen or denatured collagens in vitro. To determine whether Adam9 regulates PMN recruitment or ECM protein turnover during inflammatory responses, we compared wild-type and Adam9(-/-) mice in bacterial LPS- and bleomycin-mediated acute lung injury (ALI). Adam9 lung levels increase 10-fold during LPS-mediated ALI in wild-type mice (due to increases in leukocyte-derived Adam9), but Adam9 does not regulate lung PMN (or macrophage) counts during ALI. Adam9 increases mortality, promotes lung injury, reduces lung compliance, and increases degradation of lung elastin during LPS- and/or bleomycin-mediated ALI. Adam9 does not regulate collagen accumulation in the bleomycin-treated lung. Thus, ADAM9 is expressed in an inducible fashion on PMN surfaces where it degrades some ECM proteins, and it promotes alveolar-capillary barrier injury during ALI in mice., (Copyright © 2014 by The American Association of Immunologists, Inc.)

Background and Objective: A correlation between the levels of antibodies to alpha-elastin (alpha-AEAb) and tropoelastin (tropo-AEAb) and the corresponding peptide concentration is found in human serum in health and disease. Serum elastin peptide and anti-elastin antibodies (AEAb) levels are age-related and vary with the stages of atherosclerotic vascular damage. This study aims to determine if elastin metabolism (assessed by the ratio of tropo-AEAb to alpha-AEAb) differs in patients with symptomatic carotid stenosis versus subjects with asymptomatic stenosis., Patients and Methods: Alpha-AEAb and tropo-AEAb were measured by ELISA in blood sera of 65 patients with ultrasound verified high-grade symptomatic carotid stenosis (resulting in stroke 1-7 days before measurement) compared to 51 patients with asymptomatic stenosis., Results: Serum anti-alpha-elastin IgG levels are extremely increased in symptomatic versus asymptomatic carotid stenosis. The ratio of tropo-AEAb (reflecting elastin synthesis) to alpha-AEAb (a function of elastin degradation) was 3.7 in symptomatic stenosis versus 14.2 in asymptomatic stenosis (p<0.001)., Conclusions: There is a significant difference in elastin metabolism in patients with symptomatic carotid stenosis versus asymptomatic stenosis. The ratio of tropo-AEAb to alpha-AEAb as an index of elastin synthesis/degradation proves useful in investigation of atherosclerotic lesions and may represent a new immunologic marker for carotid plaque destabilization., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Novel tissue-engineering approaches for cardiovascular matrices based on xenogeneic extracellular matrix protein (ECMp) constituents require a detailed evaluation of their interaction with essential immune cell subsets playing a role in innate or adaptive immunity. Therefore, in this study, the effects of xenogeneic (porcine, bovine) collagen type I and elastin as the two main components of the heart valve ECM were analyzed in comparison to their human equivalents. First, their potential to induce maturation and cytokine secretion of human dendritic cells (DC) was tested by flow cytometry. Second, the influence on proliferation and cytokine release of purified human B and T cells was measured. We could demonstrate that xenogeneic collagen type I and elastin are not able to trigger the maturation of DC as verified by the lack of CD83 induction accompanied by a low tumor necrosis factor-α release. Moreover, both ECMp showed no effect on the proliferation and the interleukin-6 release of either unstimulated or prestimulated B cells. Additionally, anti-CD3-induced purified T cell proliferation and secretion of cytokines was not affected. All in vitro data verify the low immunogenicity of porcine and bovine collagen type I and elastin and favor their suitability for tissue-engineered scaffolds.

This study investigates both the physicochemical properties and immunogenicity of a genetically engineered elastin-like block corecombinamer (ELbcR) containing a major membrane protein sequence from Mycobacterium tuberculosis. The recombinant production of this ELbcR allows the production of large quantities of safe, antigenic particle-based constructs that directly and reversibly self-assemble into highly biocompatible, multivalent, monodisperse, and stable nanovesicles with a diameter of 55 nm from the same gene product using a highly efficient and cost-effective inverse transition cycling (ITC) procedure. The compositional complexity of these vesicles is retained after secondary processes such as endotoxin removal, sterilization, and lyophilization. An initial pro-chemotactic cytokine response (IL-1β) followed by a pro-Th2/IL-5 response was observed in mice plasma following subcutaneous administration of the antigen-loaded nanovesicles in mice. This biphasic model of cytokine production was coupled with humoral isotype switching from IgM- to IgG-specific antibodies against the antigen, which was only observed in the presence of both the antigen and the polymer in the same construct and in the absence of additional adjuvants.

Rationale: Antielastin autoimmunity has been hypothesised to drive disease progression in chronic obstructive pulmonary disease (COPD). The proposed mechanism is currently disputed by conflicting data. The authors aimed to explore antibody responses against elastin in a large and extensively characterised COPD population and to assess elastin-specific peripheral T-cell reactivity in a representative subgroup., Methods: Antielastin antibodies were analysed with indirect ELISA on the plasma of 320 patients with COPD (Global Initiative for Chronic Obstructive Lung Disease 1-4) and 143 smoking controls. In a second group of 40 patients with COPD and smoking controls, T-cell responses against extracellular matrix (elastin, collagen I and collagen V) were determined with enzyme-linked immunosorbent spot (EliSpot) (interferon γ (IFNγ) and interleukin-2) on peripheral blood mononuclear cells and compared with the responses of 11 never-smoking controls., Results: Antielastin antibody titres were not elevated in patients with COPD compared with smoking controls and even decreased significantly with increasing severity of COPD (p<0.001). Lower antielastin antibody titres were also found in a subgroup of patients with CT-proven emphysema. Elastin-specific INFγ-mediated T helper 1 responses could not be revealed in smoking subjects with and without COPD. Collagen I-mediated T-cell responses were also absent, which contrasted with a significant increased anticollagen V response in the smoking controls and patients with COPD compared with the never smokers (p=0.008). Collagen V-mediated T-cell responses could not discriminate between patients with COPD and smoking controls., Conclusion: A systemic immune response against elastin could not be identified in patients with COPD. By contrast, collagen V-mediated autoimmunity was increased in the subgroup of smokers and may potentially contribute to the pathogenesis of COPD.

Background: Elastin is an essential component of selected connective tissues that provides a unique physiological elasticity. Elastin may be considered a signature protein of lungs where matrix metalloprotease (MMP) -9-and -12, may be considered the signature proteases of the macrophages, which in part are responsible for tissue damage during disease progression. Thus, we hypothesized that a MMP-9/-12 generated fragment of elastin may be a relevant biochemical maker for lung diseases., Methods: Elastin fragments were identified by mass-spectrometry and one sequence, generated by MMP-9 and -12 (ELN-441), was selected for monoclonal antibody generation and used in the development of an ELISA. Soluble and insoluble elastin from lung was cleaved in vitro and the time-dependent release of fragments was assessed in the ELN-441 assay. The release of ELN-441 in human serum from patients with chronic obstructive pulmonary disease (COPD) (n = 10) and idiopathic pulmonary fibrosis (IPF) (n = 29) were compared to healthy matched controls (n = 11)., Results: The sequence ELN-441 was exclusively generated by MMP-9 and -12 and was time-dependently released from soluble lung elastin. ELN-441 levels were 287% higher in patients diagnosed with COPD (p < 0.001) and 124% higher in IPF patients (p < 0.0001) compared with controls. ELN-441 had better diagnostic value in COPD patients (AUC 97%, p = 0.001) than in IPF patients (AUC 90%, p = 0.0001). The odds ratios for differentiating controls from COPD or IPF were 24 [2.06-280] for COPD and 50 [2.64-934] for IPF., Conclusions: MMP-9 and -12 time-dependently released the ELN-441 epitope from elastin. This fragment was elevated in serum from patients with the lung diseases IPF and COPD, however these data needs to be validated in larger clinical settings.

The elastin metabolism in systemic sclerosis (SSc) has been known to be abnormal. The authors investigated relationship between the clinical manifestations of systemic sclerosis (SSc) and serum levels of soluble elastin-derived peptide (S-EDP) and anti-elastin antibodies. Serum samples were obtained from 79 patients with SSc and 79 age- and sex-matched healthy controls. Concentrations of serum S-EDP and anti-elastin antibodies were measured by ELISA. The serum concentrations of S-EDP in SSc patients were significantly higher than in healthy controls (median, 144.44 ng/mL vs 79.59 ng/mL, P < 0.001). Serum EDP concentrations were found to be correlated with disease duration in SSc (P = 0.002) and particularly in diffuse cutaneous SSc (P = 0.005). Levels of anti-elastin antibodies were found to be more elevated in SSc patients than in healthy controls (median, 0.222 U vs 0.191 U, P = 0.049), more increased in diffuse cutaneous SSc than limited cutaneous SSc (median, 0.368 U vs 0.204 U, P = 0.031). In addition, levels of anti-elastin antibodies were also found to be negatively associated with presence of anti-centromere antibody (P = 0.023). The S-EDP levels were not found to be correlated with levels of anti-elastin antibodies. The increased S-EDP and anti-elastin antibody levels and association with clinical and laboratory characteristics may reflect the abnormal metabolism in SSc.

Selenium (Se) is an exogenous antioxidant that performs its role via expression of selenoproteins. Pathological changes of the structure of the vessel wall, elastin turnover and collagen production may lead to increased stiffness of the vessels with decreased blood flow to the peripheries. The level of anti-elastin antibodies (AEABs) may give information for elastin metabolism. The aim of the study is to investigate the influence of Se intake on the vessel wall changes and production of AEABs in spontaneously hypertensive rats (SHR). Twenty-four male, 32-week-old SHR were used, divided into three groups, G1, G2 and G3. Before blood and morphological testing, G1 received a low-Se diet for eight weeks, G2 received a diet with adequate Se content and G3 received a diet with Se supplementation. The Se nutritional status was assessed by determination of glutathione peroxidase-1 (GPx-1) activity in whole blood, using the 'Ransel' kit. The rats from group G3 showed higher GPx-1 activity and lower level of AEABs than the other groups (P = 0.021), and the aortic wall histology showed slight degenerative changes compared with other rats. A low-Se diet caused severe changes to the aortic wall's ultrastructure, whereas Se supplementation slowed the changes down. The morphometry revealed a thicker abdominal aortic wall in rats of G1 compared with the other groups, and reduced thickness of the wall of the left coronary artery in G3 compared with the other groups (P < 0.05). Our results have shown that low Se intake leads to severe changes in the vessel walls in SHR, whereas selenium supplementation slows down the elastin degradation and degenerative changes of the vessel walls.

Background: After deep excision of burn eschar down to the muscle fascia patients have a non-reversible loss of the skin and underlying subcutaneous tissue. These patients would benefit from the development of a sufficient epidermal, dermal, and hypodermal tissue-engineered replacement provided by new technologies of tissue engineering. The aim of the present study was to determine whether keratinocytes and preadipocytes grow simultaneously on a bovine-derived collagen-elastin matrix under in vitro conditions in order to obtain a multi-layer skin substitute., Methods: Human keratinocytes as well as human preadipocytes were seeded onto a collagen-elastin matrix (Matriderm®). Human preadipocytes were isolated from human subcutaneous adipose tissue and seeded onto the scaffold directly after isolation. Keratinocytes were isolated from fresh human split-thickness skin harvests and seeded onto the surface of the scaffold after 4 days of proliferation. Twenty one days after seeding all scaffolds were histologically evaluated, using hematoxylin eosin, immunohistochemical staining with collagen IV as well as immunofluorescence labeling with anti-Ki67 antibody and DAPI (4',6-diamidino-2-phenylindole)., Results: Simultaneous growth of keratinocytes and preadipocytes could be observed on the collagen-elastin matrix. Keratinocytes adhered well to the surface of the matrix and formed a confluent epidermis-like layer. Preadipocytes adhered well and also penetrated into the deeper layers of the matrix., Conclusion: In this study, a collagen-elastin matrix served as a suitable scaffold for simultaneous culturing of preadipocytes and keratinocytes. Preadipocytes showed good penetration into deeper layers of the scaffold, whereas keratinocytes attached only to the uppermost surface of the matrix. This approach towards a multi-layered skin substitute might be a useful asset for future reconstructive surgery., (Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.)

Liberation of elastin peptides from damaged lung may be a mechanism of autoimmune lung disease. Citrullination, and anti-citrullinated protein antibody formation occurs in smokers, but the role of smoking in autoantibody generation relevant to pulmonary disease is unclear. Anti-elastin, anti-cyclic citrullinated peptide (anti-CCP) and anti-mutated citrullinated vimentin (anti-MCV) antibodies were measured in 257 subjects with α₁-antitrypsin deficiency (AATD), 113 subjects with usual chronic obstructive pulmonary disease (COPD) and 22 healthy nonsmokers. Levels were compared between groups, against phenotypic features and against smoke exposure. Anti-elastin antibodies were higher in controls relative to AATD (p = 0.008) and usual COPD (p < 0.00001), and in AATD relative to usual COPD (p < 0.00001). Anti-elastin levels showed a threshold at 10 pack-yrs, being higher in those who had smoked less (p = 0.004). No relationships between antibody levels and clinical phenotype were seen after adjustment for smoke exposure. Anti-CCP antibodies were higher in usual COPD than AATD (p = 0.002) but the relationship to smoke exposure was less clear. Smoke exposure is the main determinant of anti-elastin antibody levels, which fall after 10 pack-yrs. Local antibody complexes may be a better measure of elastin directed autoimmunity than circulating levels.

Background: Smoking is the major etiologic factor in COPD, yet the exact underlying pathogenetic mechanisms have not been elucidated. Since a few years, there is mounting evidence that a specific immune response, partly present as an autoimmune response, contributes to the pathogenesis of COPD. Increased levels of anti-Hep-2 epithelial cell and anti-elastin autoantibodies as well as antibodies against airway epithelial and endothelial cells have been observed in COPD patients. Whether the presence of these autoantibodies contributes to the pathogenesis of COPD is unclear., Methods: To test whether induction of autoantibodies against lung matrix proteins can augment the smoke-induced inflammatory response, we immunized mice with a mixture of the lung extracellular matrix (ECM) proteins elastin, collagen, and decorin and exposed them to cigarette smoke for 3 or 6 months. To evaluate whether the immunization was successful, the presence of specific antibodies was assessed in serum, and presence of specific antibody producing cells in spleen and lung homogenates. In addition, the presence of inflammatory cells and cytokines was assessed in lung tissue and emphysema development was evaluated by measuring the mean linear intercept., Results: We demonstrated that both ECM immunization and smoke exposure induced a humoral immune response against ECM proteins and that ECM immunization itself resulted in increased macrophage numbers in the lung. The specific immune response against ECM proteins did not augment the smoke-induced inflammatory response in our model., Conclusions: By demonstrating that smoke exposure itself can result in a specific immune response and that presence of this specific immune response is accompanied by an influx of macrophages, we provide support for the involvement of a specific immune response in the smoke-induced inflammatory response as can be seen in patients with COPD.

Rationale: In patients with chronic inflammatory lung disease, pulmonary proteases can generate neoantigens from elastin and collagen with the potential to fuel autoreactive immune responses. Antielastin peptide antibodies have been implicated in the pathogenesis of tobacco-smoke-induced emphysema. Collagen-derived peptides may also play a role., Objectives: To determine whether autoantibodies directed against elastin- and collagen-derived peptides are present in plasma from three groups of patients with chronic inflammatory lung disease compared with a nonsmoking healthy control group and to identify whether autoimmune responses to these peptides may be an important component of the disease process in these patients., Methods: A total of 124 patients or healthy control subjects were recruited for the study (Z-A1AT deficiency, n = 20; cystic fibrosis, n = 40; chronic obstructive pulmonary disease, n = 31; healthy control, n = 33). C-reactive protein, IL-32, and antinuclear antibodies were quantified. Antielastin and anti-N-acetylated-proline-glycine-proline autoantibodies were measured by reverse ELISA., Measurements and Main Results: All patients were deemed stable and noninfective on the basis of the absence of clinical or radiographic evidence of recent infection. There were no significant differences in the levels of autoantibodies or IL-32 in the patients groups compared with the healthy control subjects., Conclusions: Antielastin or anti-N-acetylated proline-glycine-proline autoantibodies are not evident in chronic inflammatory lung disease.

Background: Antibodies recognizing the elastin precursor tropoelastin (ATEAb) or degradation products alpha-elastin (AEAb) are found in the serum of healthy human subjects, as a part of a homeostatic mechanism which assembles new or clears altered elastin structures. Serum ATEAb (reflecting elastin synthesis) and AEAb (reflecting elastin destruction) appear to correlate with the production and breakdown of the elastic tissue, respectively., Objective: The aim of this study was to investigate plasma levels of AEAb and ATEAb in senescence-accelerated prone (SAMP8) and senescence-accelerated resistant (SAMR1) mice, compared with imprinting control region (ICR) mice in order to evaluate their age-related changes., Methods: The levels of AEAb and ATEAb were measured by home-made ELISA in plasma of SAMP8, SAMR1, and ICR mice, grouped according to their age (3 and 9 months) and sex. The specificity of AEAb and ATEAb activity in mouse plasma, and elastin-derived peptides (EDP) in sera of ICR mice at 3 and 9 months of age were tested by competitive ELISA., Results: The specificity of AEAb and ATEAb in mouse plasma was confirmed by the competitive investigations. The levels of AEAb in the plasma of SAMR1 and SAMP8 were increased compared to the levels measured in ICR on the matched ages (p < 0.001). Age-related increase of the levels of AEAb and ATEAb was established in the 3 strains (p < 0.001). Significantly higher levels of AEAb were established in female 9-month-old mice compared to males in all strains. The ATEAb:AEAb ratio was significantly lower in the SAM compared to the ICR strain. Positive correlation was established between the levels of serum AEAb and EDP in mouse sera of ICR mice., Conclusion: Variations with age in the plasma levels of AEAb and ATEAb were established in SAM compared with ICR, and in SAMP8 compared with SAMR1. Our findings suggest that increased anti-elastin IgG autoantibodies could be used as a marker of aging in SAM and possibly contribute to the processes of aging. The absence of a difference between SAMP8 and SAMR1 regarding the ATEAb:AEAb ratio raises the question if SAMR1 are an appropriate control of SAMP8 in terms of the senescence of the elastic tissues., (2009 S. Karger AG, Basel.)

Background: Antenatal pulmonary inflammation is associated with reduced risk for respiratory distress syndrome but with an increased risk for bronchopulmonary dysplasia (BPD) with impaired alveogenesis., Objective: We hypothesized that fetal systemic inflammation induced by intravenous (IV) lipopolysaccharide (LPS) would affect lung development in utero., Study Design: Twenty-one fetal sheep were instrumented (107 days gestational age). Control fetuses received saline (N = 12) and 9 in the study group received 100 ng of LPS IV 3 days after surgery. Animals were assessed for lung maturation and structure after 3 (N = 5) and 7 (N = 4) days., Results: Interleukin-6 concentration increased in the bronchoalveolar lavage more than 40-fold 3 days after LPS IV. Processing of pro-surfactant protein (SP)-B to mature SP-B and increased SP-B concentrations were shown 7 days after LPS IV. Deposition of elastin fibers at sites of septation was disturbed within 3 days after LPS IV., Conclusion: Lung maturation and disturbed lung structure occurred after short-term exposure to fetal inflammation and suggests new targeted therapies for BPD.

Problem: The aim of this study was to investigate elastin turnover and autoimmunity in patients with a history of recurrent pregnancy loss (RPL) and during normal pregnancy., Method of Study: Anti-alpha-elastin and anti-tropoelastin IgG and IgM antibodies were measured by a home-made ELISA in serum samples of 60 medically and obstetrically normal pregnant women, classified to three trimester groups, 18 female patients with RPL and 18 healthy non-pregnant women with a history of successful pregnancies. One way analyses of variance and Least Significant Difference method were used for a statistical analysis., Results: Anti-alpha-elastin IgG autoantibodies were significantly decreased in the third trimester pregnant women. IgM anti-alpha-elastin autoantibodies were significantly decreased in all pregnancy groups compared with the controls. Synthesis/degradation ratio of elastin was significantly increased in the third trimester pregnancy group, suggesting decreased elastin degradation during this period of pregnancy. Comparing the RPL patients with the healthy non-pregnant controls showed a significantly increased anti-alpha-elastin IgG antibody and significantly decreased synthesis/degradation ratio in the patient's group, suggesting increased elastin degradation in RPL., Conclusion: Elastin degradation is decreased during normal pregnancy. Increased anti-elastin IgG antibodies may contribute to the pathogenesis of pregnancy losses.

The pathologic role of autoantibodies in many autoimmune diseases is widely accepted. An enzyme immunoassay was used for measurement of antibodies against disease-specific antigens and etiologic agents for cross-reactive antigens associated with them. This antibody assay was applied to a panel of antigens for the detection of different neuroautoimmune diseases that included multiple sclerosis, motor peripheral neuropathies, multifocal motor neuropathy, amyotrophic lateral sclerosis, pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection. We studied women with pregnancies complicated by neural tube defect, neuroborreliosis, autism and patients with possible somatic hypermutation. Antibodies were also measured against antigens and etiologic agents associated with primary biliary cirrhosis and chronic obstructive pulmonary disease. And, finally, antibodies were measured against several tumor antigens or peptides which are expressed in prostatic, breast and colon tissues. This panel of different autoantibodies was applied to 290 patients with neuroautoimmune disorders, cancer, and possible somatic hypermutation. The levels of these antibodies against different tissue-specific antigens and etiologic agents associated with them were significantly elevated in patients versus controls. We hope that this novel 96 antigen-specific ELISA will be used in additional studies that will prove its clinical efficacy, not only for the early diagnosis of many neuroautoimmune, liver and lung autoimmune disorders, but also for prognosis and the implementation of preventive steps for many complex diseases.

An efficient and controlled method for immunodetection, using polystyrene (PS) microbeads conjugated with an elastin-like polypeptide (ELP), was investigated. ELP is a temperature-sensitive polymer that exhibits a hydrophilic-hydrophobic phase transition at the lower critical solution temperature. To introduce amine groups, ELP was modified with lysine for conjugation with PS microbeads functionalized with carboxylic groups. Prostate-specific antigen (PSA), a cancer marker, was detected from a biomolecular mixture using ELP-conjugated PS microbeads and ELP-conjugated antiPSA. External stimuli were used to reversibly separate the PSA-antiPSA complex. The stimuli-responsiveness of the ELP provided a designable generic biosurface for diagnostic detection.

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the US and a major worldwide healthcare problem. The pathophysiologic mechanisms that drive development and progression of this disease are complex and only poorly understood. While tobacco smoking is the primary risk factor, other disease processes also appear to play a role. Components of the innate immune system (eg, macrophages and neutrophils) have long been believed to be important in the development of COPD. More recent evidence also suggests involvement of the adaptive immune system in pathogenesis of this disease. Here we will review the literature supporting the participation of T-cells in the development of COPD, and comment on the potential antigenic stimuli that may account for these responses. We will further explore the prospective contributions of T-cell derived mediators that could contribute to the inflammation, alveolar wall destruction, and small airway fibrosis of advanced COPD. A better understanding of these complex immune processes will lead to new insights that could result in improved preventative and/or treatment strategies.

A polyclonal antibody to elastin-derived hexapeptide repeat, H-(Val-Gly-Val-Ala-Pro-Gly)(3)-NH(2), was prepared in order to investigate the differences between elastin fibres in intimal hyperplasia and media in human atheroscleroic lesions. The hexapeptide repeat and alpha-elastin were recognized by this polyclonal antibody in enzyme-linked immunosorbent assay (ELISA), but other elastin-derived peptides such as tetrapeptide repeat, pentapeptide repeat and nonapeptide were not. In the series of hexapeptide repeats, H-(VGVAPG)(n)-NH(2) where n is 1-7, the polyclonal antibody reacted strongly with oligomers (n = 3-7) and weakly with dimer (n = 2), but not with monomer (n = 1). CD measurements suggested that the beta-turn structure is important for recognition by the polyclonal antibody. In an immunohistochemical study, elastin was stained more strongly in intimal hyperplasia than in media, suggesting that newly synthesized elastin in intimal hyperplasia is morphologically distinct from that in media.

Reasons for Performing Study: Early diagnosis and monitoring progression of chronic diseases in elastin-rich tissues, such as chronic progressive lymphoedema in draught horses and chronic obstructive pulmonary disease (COPD) is still a real challenge in the horse. Use of an enzyme-linked immunosorbent assay (ELISA) to detect anti-elastin antibody (AEAb) levels might be useful to assess the status of such diseases. Baseline levels, representing physiological breakdown of elastin in normal horses, are not available at present., Hypothesis: Levels of AEAb in healthy horses are generally low and follow the same age-related pattern as found in man. Therefore, elevation of AEAb levels in serum can be used to evaluate pathological elastin breakdown in elastin-rich tissues., Methods: Sera of 84 clinically healthy Warmblood horses were evaluated for the presence of AEAbs by means of a modified version of an ELISA technique used in man. The horses were divided in 5 age groups: A) < 4 months; B) 4-23 months; C) 2-3 years; D) 4-10 years; and E) > 11 years., Results: Antibodies to elastin were found in all equine serum samples tested. Their levels were lowest in Group A, low in Groups B and E and highest in animals age 2-10 years., Conclusions: Measuring AEAbs in serum of horses by an ELISA technique proved to be possible and levels were stable during well-defined life stages., Potential Relevance: Changes in AEAb levels are expected to be useful for early diagnosis and for monitoring progression of diseases that affect elastin-rich tissues, such as chronic progressive lymphoedema and COPD.