CoVID-19 can develop into Post-COVID syndrome of potentially high morbidity, with procoagulation and reactivation of dormant viral infections being hypothesized pathophysiological mechanisms. We report on a patient suffering from fatigue, post exertional malaise, pain and neurological symptoms as a consequence of the second CoVID infection. Using live confocal microscopy on native whole blood samples we detected microaggregates of thrombocytes, leukocytes and plasma proteins in peripheral blood. In addition, there was specific cellular immunological reactivity to EBV. Upon anticoagulatory and virustatic pharmacological therapy we observed dissolution of microaggregates and significant stable clinical remission. We suggest to consider circulating microaggregates as a morphological indicator of chronic post-COVID syndrome.

The lymphatic system is responsible for fluid drainage from almost every organ in the body. It sustains tissue homeostasis and is also a central part of the immune system. With the discovery of cell-specific markers and transgenic mouse models, it has become possible to gain some insight into the developmental and functional roles of lymphatic endothelial cells (LECs). Only recently, a more direct regulatory role has been assigned to LECs in their functions in immunity responses and chronic diseases. Here, we discuss the changes occurring in aged lymphatic system and the role of lymphatic capillaries in some age-related diseases and experimental animal models.(c) 2020 The Author(s) Published by S. Karger AG, Basel

Atherosclerosis, the principal cause of heart attack, stroke, and gangrene of the extremities, remains a major contributor to morbidity and mortality in the Western world. Since heat shock protein (hsp) 65 is the major antigenic component of Mycobacterium tuberculosis, we then immunized rabbits with this component alone and found it to be capable of inducing atherosclerosis in the same manner as Freund's complete adjuvant. Therefore, serum antibodies against hsp 65 cross react with the human 60-kDa homologue present in high levels in atherosclerotic lesions mainly associated with macrophages and endothelial cells, supporting our concept of a humorally mediated immune reaction against hsp 60 in atherogenesis. Hsp expression in arterial endothelium can be induced or augmented by various types of stress, such as hypercholesterolemia, heat treatment, exposure to oxygen radicals or a cytokines, ischemia, and hemodynamic overload, surgical stress, and infections.

Age-dependent diseases are exponentially increasing due to the improvement of socio-economical perspective and the rapid increase of life expectancy in Western countries. Cardiovascular diseases (CVDs) represent the biggest cause of deaths worldwide. Among them, atherosclerosis is the most important representative leading to the known severe sequelae, i.e., myocardial infarction, stroke, and peripheral arterial occlusion. Evidence for an (auto)antigen-driven process at these sites of inflammation became available only recently. During the last decades, efforts have been done to identify exogenous and/or autologous antigens that may induce local cardiovascular immune reactions. Among them, the main candidates for such antigens are oxidized low-density lipoprotein (ox-LDL) and heat shock proteins (HSPs). Risk factors for CVDs (i.e., cigarette smoking, hypertension, diabetes, elevated lipid levels, and chronic infections) induce HSP60 and adhesion molecule expression in vascular endothelial cells (ECs), initiating the first inflammatory events. This chapter summarizes the involvment of innate and adpative immunity in atherosclerosis focusing on HSP60. Moreover, a scenario on the potential development of HSP60-based vaccines against atherosclerosis is also shown.

Atherosclerosis is a multifactorial inflammatory disease of the arteries that manifests itself with calcified plaque formation within endothelial cells and the smooth muscle cell layer of vessels. T cells that recognize endogenous Hsp60 on endothelial cells initiate the disease. Here, we first describe the initial experiments that led to the discovery of Hsp60 as an autoantigenic driver of atherosclerosis. Then, we address numerous epidemiological and experimental studies performed by our lab and others that have firmly established Hsp60 as an autoantigen. In addition, we describe the pathogenic mechanisms mediated by Hsp60 and list known inducers of ectopic Hsp60 expression. Finally, we discuss the potential of Hsp60-based vaccination against atherosclerosis.

Background: Atherosclerosis is the leading cause of death worldwide. The disease development is by and large driven by old age and lifestyle factors, such as diet, physical activity, and smoking. In the present study, we have investigated the effect of exercise and diet on the development of atherosclerosis in young and aged mice. Objective: This study aimed at comparing multiple age-dependent factors that may influence atherosclerosis in a transgenic mouse model. Methods: Young (14 weeks) and aged (49–52 weeks) C57BL/6 wild-type (WT) and atherosclerosis-prone ApoE–/– mice were subjected to physical endurance exercise on a treadmill, with or without a high-fat diet. Five weeks later, the frequencies of regulatory T cells (TREGs) in lymph nodes were assessed by flow cytometry, plasmatic cytokines (interleukin [IL]-1β, IL-6, IL-10, IL-17, interferon-γ, tumor necrosis factor-α, and transforming growth factor [TGF]-β1) levels were determined by Luminex assay. Lipids (cholesterol and triglycerides) and anti-heat shock protein 60 (HSP60) autoantibodies were measured by ELISA. Aortic lesion sizes were assessed by en face imaging. Microarray analysis and qPCR of skeletal muscle gene expression were also performed. Results: Exercise leads to a reduction of aortic lesions in young ApoE–/– and aged WT mice independent of diet. In most groups, this reduction was followed by an increased proportion of TREGs and TGF-β1 levels. Moreover, gene expression analysis showed that exercise seems to affect the AMPK signaling pathway. In particular, PGC-1α1 mRNA was induced in aged WT mice, whereas it was reduced in young ApoE–/– mice. In addition, GSEA analysis showed a marked reduction in the insulin signaling pathway in aged ApoE–/– mice. Conclusion: Practicing endurance exercise seems to be enough for reducing early aortic lesion formation, independent of diet. However, this was only true in mice with smaller aortic lesions, since mice with large, advanced, complicated atherosclerotic plaques did not show any reduction in lesion size with exercise training.

Background: Atherosclerosis is a chronic inflammatory disease of the artery wall where both innate and adaptive immunity play important roles. Modulation of the immune response against the stress protein antigen, heat shock protein (HSP) 60, by administration of mycobacterial HSP65 (mbHSP65) orally and/or nasally shows promising therapeutic results in young animals in the sense of less severe experimental atherosclerosis; however, the case of aged animals with already established atherosclerosis has so far never been investigated. Objective: To investigate if mbHSP65 immunization would further accelerate atherosclerotic progression in aged ApoE-/- mice (18 months old) with already long-established atherosclerosis and if these mice could be orally tolerized against mbHSP65. Methods: Aged wild-type (WT) and ApoE-/- mice (65 weeks) were immunized and/or orally treated with mbHSP65 and then either kept on normal chow or changed to high-cholesterol diet (HCD). Atherosclerosis was assessed by en face analysis and the number of CD4+CD25+FoxP3+ T regulatory cells (Tregs) was assessed by flow cytometry in lymph node and spleen cells. Total cholesterol and triglyceride levels were determined. Soluble mammalian HSP60 and anti-mouse HSP60 (mHSP60) and anti-mbHSP65 antibodies were detected by enzyme-linked immunosorbent assay. Results: As expected, aged WT mice had only minor lesions in the aorta, which did not change under HCD for 14 weeks. Aged ApoE-/- mice already had large complicated plaques, which increased in size under HCD. mbHSP65 immunization led to a significant aggravation of atherosclerosis in both WT and ApoE-/- mice irrespective of the nature of their diet. This increase was accompanied by increased titers of both anti-mHSP60 and anti-mbHSP65 antibodies in the circulation. The increased plaque formation could be significantly diminished with oral mbHSP65 tolerization. An increased number of Tregs and lower or unchanged levels of cholesterol and triglycerides were associated with the reduced size of aortal lesions. Conclusion: Oral tolerization against mbHSP65 could be used both to prevent and to treat chronic atherosclerosis in aged individuals.

The most common complication of silicone breast implants is capsular contracture (massive scar formation around the implant). We postulate that capsular contracture is always a sequel to inflammatory processes, with both innate and adaptive immune mechanisms participating. In general, fibroblasts and macrophages have been used as cell types to evaluate in vitro the biocompatibility of breast implant surfaces. Moreover, also T cells have been found at the implant site at the initial stage of fibrous capsule formation. However, only few studies have addressed the influence of surfaces with different textures on T-cell responses. The aim of the present study was to investigate the immune response of human peripheral blood mononuclear cells (PBMC) to commercially available silicone breast implants in vitro. PBMC from healthy female blood donors were cultured on each silicone surface for 4 days. Proliferation and phenotype of cultured cells were assessed by flow cytometry. Cytokine levels were determined by multiplex and real-time assay. We found that silicone surfaces do not induce T-cell proliferation, nor do they extensively alter the proportion of T cell subsets (CD4, CD8, naïve, effector memory). Interestingly, cytokine profiling identified matrix specific differences, especially for IL-6 and TNF-α on certain surface topographies that could lead to increased fibrosis.

an extensive collaborative study, Liu et al. [3] correlated perceived age by assessors looking at digital facial images of 2,693 elderly Dutch Europeans from the Rotterdam Study with the results of genome-wide association studies of these individuals. The strongest genetic associations with perceived age were found for multiple single nucleotide polymorphisms in the melanocortin 1 receptor ( MC1R ) gene. Individuals homozygous for a given MC1R risk haplotype on average looked up to 2 years older than noncarriers and this effect was independent of chronological age, sex, skin color, and sun damage (wrinkles, pigmented spots). Thus, MC1R seems to play a role in youthful looks that is independent of its known function in melanin synthesis. On a sideline, it is of interest to remember that the MC1R gene harbors a considerable amount of Neandertal sequences [4] , i.e., genetic information that may be related to cellular stress resistance. The evolutionary importance of face recognition is also supported by the fact that primates possess several special “face recognition spots” in their temporal brain lobes, as lucidly described for noninitiated readers by the Nobel laureate Eric Kandel [5] . Humans have three such “face spots,” monkeys at least five. Of note: we cannot discriminate faces – even from close acquaintances – if presented upside down. Perhaps the higher number of “face spots” in monkeys is due to the fact that they spend their life climbing on trees where recognizing faces from all perspectives is necessary. While these cortical areas allow for recognition of faces in general, a recent paper reported on the discovery of two additional areas that are destined to memory and thus recognition of known faces [6] . For the annual Editorials of Gerontology , I have made it a custom to first address an issue that may be of general interest for gerontological research. This time, I will briefly put forward some thoughts on the determination of an individual’s biological age. The much faster pace of cultural as compared to biological evolution results in a significantly longer life expectancy of humankind and this process is still ongoing. However, it also becomes increasingly difficult to judge the biological age of elderly persons in relation to their known chronological age. So, depending on his/her genetic background and the exposure to certain environmental conditions, a 50-year-old can biologically correspond to a 70-year-old, while an octogenarian can intellectually and physically perform like a 50-year-old. While chronological age perfectly matches biological age in infants and young adults, this distinction becomes more uncertain with progressing age. So far, attempts to define laboratory or other markers for the biological age of a given person have met with limited success. Thus, for the selection of healthy human cohorts for immunogerontological research, the SENIEUR protocol was established several decades ago [1, 2] . This protocol is based on three groups of selection criteria, i.e., life history, laboratory values, and drug intake. Although the SENIEUR protocol proved to be helpful, it did not allow for the determination of the real biological age of a given presumably healthy study subject. In recent years, a new approach to define a person’s biological age has afforded more satisfactory results: face analysis. In a nutshell, these studies show that face expression reflects our biological age surprisingly accurately. In Published online: November 23, 2017

Thymoglobulin (ATG) is a polyclonal rabbit antibody against human thymocytes used as a T cell-depleting agent in organ transplantation. Its polyclonal character suggests that its effect may go far beyond just T cell depletion. The aim of this study was to further elucidate possible mechanisms underlying the suppressive activity of ATG. For in vitro studies, human peripheral blood mononuclear cells (PBMC) were incubated with ATG or control Ig for various time points. Foxp3+ regulatory cells (Tregs) and monocytes were phenotypically analyzed by flow cytometry and functionally tested by in vitro suppression assays. Cytokine levels were determined by quantitative RT- PCR, Multiplex or ELISA techniques. In vitro, the frequencies of Foxp3+ Tregs increased when human PBMC were stimulated with ATG as compared with stimulation by rabbit Ig or without stimulation. ATG-treated cells suppressed proliferation of autologous PBMC stimulated with anti-CD3 and anti-CD28 monoclonal antibodies and this suppression could be reversed by exogenous IL-2. The Foxp3+ expression dropped down on day 10, which suggests that it is transient. Monocytes and natural killer cells stimulated with ATG down-modulated CD16. Monocytes suppressed the proliferation of autologous PBMC. However, there were not statistically significant differences in IL-10, TNF-α and TGF-β1 secretion by monocytes stimulated with ATG or control rabbit Ig. These findings suggest that ATG has immunomodulatory effects that go beyond T cell depletion and induction of Foxp3+ Tregs. The induction of immunosuppressive monocytes might have a protective role in delaying transplant rejection.

Thymoglobulin (ATG) is a polyclonal rabbit antibody against human thymocytes used as a T cell-depleting agent to prevent or treat allotransplant rejection. The aim of the present study was to investigate the effect of low dose ATG treatment exclusively on T cells using a humanized BALB/c human CD3Ɛ transgenic mouse model expressing both human and murine T cell receptors (TCR). Mice received a single intravenous (i.v.) injection of ATG. Blood and peripheral lymphoid organs were obtained after different time points. We found a significant T cell depletion in this mouse model. In addition, regulatory T cells (Tregs) proved to be less sensitive to depletion than the rest of T cells and the Treg:non-Treg ratio was therefore increased. Finally, we also investigated the effect of ATG in a heterotopic allogenic murine model of heart transplantation. Survival and transplant function were significantly prolonged in ATG-treated mice. In conclusion, we showed (a) an immunosuppressive effect of ATG in this humanized mouse model which is exclusively mediated by reactivity against human CD3Ɛ; (b) provided evidence for a relative resistance of Tregs against this regimen; and

Atherosclerosis is the leading cause of death in the world. We have previously shown that expression of heat shock protein 60 (HSP60) on the surface of endothelial cells is the main cause of initiating the disease as it acts as a T cell auto-antigen and can be triggered by classical atherosclerosis risk factors, such as infection (e.g. Chlamydia pneumoniae), chemical stress (smoking, oxygen radicals, drugs), physical insult (heat, shear blood flow) and inflammation (inflammatory cytokines, lipopolysaccharide, oxidized low density lipoprotein, advanced glycation end products). In the present study, we show that increasing levels of sodium chloride can also induce an increase in intracellular and surface expression of HSP60 protein in human umbilical vein endothelial cells. In addition, we found that elevated sodium induces apoptosis.

Objective: The aim of this study was to identify atherogenic and atheroprotective peptides of bacterial HSP60 [ taking mycobacterial HSP65 (mbHSP65) as a potent paradigmatic representative] that could be used as candidates for an orally applied tolerizing vaccine against atherosclerosis.Methods: ApoE(-/)-mice were immunized with mbHSP65 protein or peptides, given mbHSP65 orally and then kept either on chow or high cholesterol diet. Atherosclerosis was assessed by en face and immunohistological analysis. Anti-HSP autoantibodies were detected by ELISA. The number and in vitro suppressive function of splenic and lymph node regulatory T cells (Tregs) were analyzed by flow cytometry. Specific T cell reactivity against mbHSP65 protein or peptides was assessed by proliferation assay.Results: Decreased lesion size was accompanied by (a) increased splenic Treg numbers; (b) increased interleukin (IL)-10 mRNA levels in the aorta; (c) increased levels of anti-mbHSP65 and anti-mouse HSP60 antibodies pointing to pro-eukaryotic HSP60 humoral crossreaction, not curtailed by oral tolerization; (d) most importantly, we identified and functionally characterized novel atherogenic and atheroprotective mbHSP65 epitopes.Conclusion: Atheroprotective mbHSP65 peptides may be considered as potential candidates for the development of a tolerizing vaccine to prevent and treat atherosclerosis, while keeping protective immunity to non-atherogenic domains of mbHSP65 intact. (C) 2015 Elsevier Ireland Ltd. All rights reserved.

Objectives: Atherosclerosis is a multifactorial autoimmune disease, which has been shown by our laboratory to be initiated by heat shock protein 60 (HSP60)-reactive T cells. In order to add the last piece to the puzzle, we have here developed a new method for studying the migration potential of PBMCs, stimulated with HSP60 and other known atherogenic antigens, into autologous healthy and diseased human arterial specimens.

Background: Dupuytren's disease is characterised by fibrotic nodule and cord formation in the palmar aponeurosis. The pathophysiology of the disease is still unknown, although cell stress and subsequent activation of immune mechanisms seems to be crucial. Materials and methods: Surgically obtained tissue and blood samples of 100 Dupuytren patients were processed by immunohistochemistry, flow cytometry, as well as immunoscope analysis. Macroscopically normal aponeurotic tissue served as control. Results: Locally, microvascular alterations and massive infiltration by mononuclear cells (CD3+, CD4>CD8, CD45RO>CD45RA, S100 protein, CD56, CD68, scarce CD19 and mast cells) forming perivascular clusters were found in DD tissue. Cytokine profiling of fibromatosis tissue-derived T-cells showed a Th1/TH17-weighted immune response. Immunoscope analysis revealed a restricted T-cell receptor alpha/beta repertoire pointing to an (auto) antigen-driven process. Conclusion: The striking accumulation of immune cells, expression of leukocyte adhesion molecules, as well as pro-inflammatory and profibrotic cytokines near markedly narrowed vessels supports the theory that the abnormal proliferation of fibroblasts and production of extracellular matrix proteins in DD seems to be related to immune-mediated microvascular damage. The restricted T-cell receptor repertoire of intra-lesional T-cells points to an antigen-driven process. T-cells seem to play an important role in the development of Dupuytren's disease.

Atherosclerosis is a chronic, multifactorial disease that starts in youth, manifests clinically later in life, and can lead to myocardial infarction, stroke, claudication, and death. Although inflammatory processes have long been known to be involved in atherogenesis, interest in this subject has grown in the past 30-40 years. Animal experiments and human analyses of early atherosclerotic lesions have shown that the first pathogenic event in atherogenesis is the intimal infiltration of T cells at arterial branching points. These T cells recognize heat shock protein (HSP)60, which is expressed together with adhesion molecules by endothelial cells in response to classic risk factors for atherosclerosis. Although these HSP60-reactive T cells initiate atherosclerosis, antibodies to HSP60 accelerate and perpetuate the disease. All healthy humans develop cellular and humoral immunity against microbial HSP60 by infection or vaccination. Given that prokaryotic (bacterial) and eukaryotic (for instance, human) HSP60 display substantial sequence homology, atherosclerosis might be the price we pay for this protective immunity, if risk factors stress the vascular endothelial cells beyond physiological conditions.

Event Abstract Back to Event Oral anti-CD3 antibody treatment ameliorates mHSP65-induced atherosclerosis Cecilia Grundtman1, Maja A. Buszko1*, Hermann Dietrich2 and Georg Wick1 1 Innsbruck Medical University, Division of Experimental Pathophysiology & Immunology, Austria 2 Innsbruck Medical University, Central Laboratory Animal Facility, Austria Aim-Accumulating evidence suggests that activated T-cells are the first invaders of the arterial intima in early human atherosclerosis lesions. Early atherosclerosis can also be reduced in animal models after T-cell depletion and after oral anti-CD3 antibody feeding. However, no study has shown the effect of oral anti-CD3 antibody treatment after immunizations with potentially atherogenic antigens. Methods-Mice received 4 immunizations with mycobacterial heat shock protein 65 (mHSP65) (50μg/dose). Non-immunized mice served as controls. To test if we could reduce atherosclerosis in ApoE-/- mice we gave 8 oral feedings with anti-CD3 antibody or with the control IgG (5μg/feeding). The oral feedings were given both to non-immunized and mHSP65-immunized mice. Concomitantly with the first immunization, mice were either kept on normal chow diet (CD) or given high-cholesterol diet (HCD). All animals were sacrificed at week 22 and the aorta was surgically removed for Oil-Red staining to determine total plaque size. Blood was collected for determination of autoantibodies against eukaryotic (human) HSP60 (hHSP60) and prokaryotic mHSP65. Spleen and lymph nodes were collected for CD4+CD25+Foxp3+ T regulatory cell (Treg) determination. Results-Oral administration of anti-CD3 antibody significantly reduced atherosclerotic lesion formation both in non-immunized and in mHSP65-immunized mice compared with controls. We observed an increase in Tregs in anti-CD3 antibody treated mice. mHSP65-immunized mice showed increased autoantibody titers to hHSP60/mHSP65. These titers were unchanged after oral treatment. Conclusion-Our findings indicate that oral anti-CD3 antibody treatment has an atheroprotective effects both, in non-immunized and mHSP65-immunized mice. This effect might go via the induction of Tregs. Keywords: Atherosclerosis, monoclonal antibodies, oral tolerance, regulatory T cells, mouse models Conference: 15th International Congress of Immunology (ICI), Milan, Italy, 22 Aug - 27 Aug, 2013. Presentation Type: Abstract Topic: Immune-mediated disease pathogenesis Citation: Grundtman C, Buszko MA, Dietrich H and Wick G (2013). Oral anti-CD3 antibody treatment ameliorates mHSP65-induced atherosclerosis. Front. Immunol. Conference Abstract: 15th International Congress of Immunology (ICI). doi: 10.3389/conf.fimmu.2013.02.00936 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 28 Jun 2013; Published Online: 22 Aug 2013. * Correspondence: Miss. Maja A Buszko, Innsbruck Medical University, Division of Experimental Pathophysiology & Immunology, Innsbruck, Austria, Maja.Buszko@i-med.ac.at Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Cecilia Grundtman Maja A Buszko Hermann Dietrich Georg Wick Google Cecilia Grundtman Maja A Buszko Hermann Dietrich Georg Wick Google Scholar Cecilia Grundtman Maja A Buszko Hermann Dietrich Georg Wick PubMed Cecilia Grundtman Maja A Buszko Hermann Dietrich Georg Wick Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Fibrosis is the production of excessive amounts of connective tissue, i.e., scar formation, in the course of reactive and reparative processes. Fibrosis develops as a consequence of various underlying diseases and presents a major diagnostically and therapeutically unsolved problem. In this review, we postulate that fibrosis is always a sequela of inflammatory processes and that the many different causes of fibrosis all channel into the same final stereotypical pathways. During the inflammatory phase, both innate and adaptive immune mechanisms are operative. This concept is exemplified by fibrotic diseases that develop as a consequence of tissue damage, primary inflammatory diseases, fibrotic alterations induced by foreign body implants, "spontaneous" fibrosis, and tumor-associated fibrotic changes.