Differences in local immune cell landscape between Q fever and atherosclerotic abdominal aortic aneurysms identified by multiplex immunohistochemistry (original) (raw)
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Chronic Inflammation, Immune Response, and Infection in Abdominal Aortic Aneurysms
European Journal of Vascular and Endovascular Surgery, 2006
Abdominal aortic aneurysms (AAA) are associated with atherosclerosis, transmural degenerative processes, neovascularization, decrease in content of vascular smooth muscle cells, and a chronic infiltration, mainly located in the outer aortic wall. The chronic infiltration consists mainly of macrophages, lymphocytes, and plasma cells. The dominant cells are Th2 restricted CD3C lymphocytes expressing interleukine 4, 5, 8, and 10, and tumor necrosis factor-a for regulation of the local immune response. They also produce interferon-g and CD40 ligand to stimulate surrounding cells to produce matrix metalloproteases and cysteine proteases for aortic matrix remodeling. The lymphocyte activation may be mediated by microorganisms as well as autoantigens generated from vascular structural proteins, perhaps through molecular mimicry. As in autoimmune diseases, the risk of AAA is increased by certain genotypes concerning human leucocyte antigen class II. These types are also associated with increased aneurysmal inflammation indicating a genetic susceptibility to aortic inflammation. Chlamydia pneumoniae is often detected in AAA but the validity of the methods can be questioned, and two small antibiotic trials have been disappointing. However, serum antibodies against C. pneumoniae have been associated with AAA growth and cross-react with AAA wall proteins. Thus, immune responses mediated by microorganisms and autoantigens may play a pivotal role in AAA pathogenesis.
Disease Markers, 2009
Objectives: Inflammation is critical in abdominal aortic aneurysm (AAA) but there is no current consensus on which inflammation related cytokines are important. The aim of this review was to systemically assess previous studies investigating the relative expression of inflammation associated cytokines within human AAA samples. Methods: The MEDLINE database was searched for studies which simultaneously examined an array of different inflammation associated cytokines in aortic samples in order to identify those associated with AAA. Focused searches were then conducted for further studies assessing relative concentrations of these cytokines in aortic samples in relation to AAA. Appropriate studies were assessed by two reviewers independently. Results: Eighteen studies were included. A number of different cytokines have been consistently found to be upregulated within AAA by comparison to aortic samples removed from patients without cardiovascular disease, however findings relative to samples of aortic athero-thrombosis were less consistent. TNFA and INFG appear to be the most consistently associated with AAA in studies using both normal and atherosclerotic controls. Cautious interpretation of these data is recommended due to a number of methodological problems. Conclusions: This systematic review suggests that TNFA and INFG are the most consistently upregulated cytokines in large AAAs. Further studies utilizing larger populations, new proteomic techniques and better patient matching are required.
Cytokine Pattern in Aneurysmal and Occlusive Disease of the Aorta
Journal of Surgical Research, 2001
Background. Prominent inflammatory infiltrates of macrophages and T-lymphocytes are found in both aortic occlusive disease (AOD) and abdominal aortic aneurysms (AAA). These cells secrete different cytokines that might affect matrix turnover through modulation of matrix metalloproteinase expression. A different cytokine pattern might account for the evolution of AOD vs AAA.
Flow Cytometry Analysis of Immune Cells Within Murine Aortas
Journal of Visualized Experiments, 2011
Atherosclerosis is a chronic inflammatory process of medium and large size vessels that is characterized by the formation of plaques consisting of foam cells, immune cells, vascular endothelial and smooth muscle cells, platelets, extracellular matrix, and a lipid-rich core with extensive necrosis and fibrosis of surrounding tissues. 1 The innate and adaptive arms of the immune response are involved in the initiation, development and persistence of atherosclerosis. 2, 3 There is a significant body of evidence that different subsets of the immune cells, such as macrophages, dendritic cells, T and B lymphocytes, are present within the aortas of healthy and atherosclerosis-prone mice 4. Additionally, immune cells are found in the surrounding aortic adventitia which suggests an important role of this tissue in atherogenesis. 2 For some time, the quantitative detection of different types of immune cells, their activation status, and the cellular composition within the aortic wall was limited by RT-PCR and immunohistochemical methods for the study of atherosclerosis. Few attempts were made to perform flow cytometry using human aortas, and a number of problems, such as a high autofluorescence, have been reported 5,6. Human atherosclerotic plaques were digested with collagenase 1, and free cells were collected and stained for CD14+/CD11c+ to highlight macrophage-derived foam cells. In this study, a "mock" channel was used to avoid false-positive staining. 6 Necrotic materials accumulating during the digestion process give rise in a large amount of debris that generates a high autofluorescence in aortic samples. To resolve this problem, a panel of negative and positive controls has been proposed, but only double staining could be applied in these samples. We have developed a new flow cytometry-based method 7 to analyze the immune cell composition and characterize the activation, proliferation, differentiation of immune cells in healthy and atherosclerosis-prone aorta. This method allows the investigation of the immune cell composition of the aortic wall and opens possibilities to use a broad spectrum of immunological methods for investigations of immune aspects of this disease.
Infection and Immunity, 2000
As this obligate intracellular bacterium inhabits monocytes and macrophages, we wondered if pathogenesis of Q fever endocarditis is related to defective intracellular killing of C. burnetii by monocytes. Monocytes from healthy controls eliminated virulent C. burnetii within 3 days. In contrast, monocytes from patients with ongoing Q fever endocarditis were unable to eliminate bacteria even after 6 days. In patients who were cured of endocarditis, the monocyte infection was close to that of control monocytes. This killing deficiency was not the consequence of generalized functional impairment, since patient monocytes eliminated avirulent C. burnetii as did control cells. The addition of supernatants of C. burnetii-stimulated monocytes from patients with ongoing endocarditis to control monocytes enabled them to support C. burnetii survival, suggesting that some soluble factor is responsible for bacterial survival. This factor was related to tumor necrosis factor (TNF): expression of TNF mRNA and TNF release were increased in response to C. burnetii in patients with ongoing endocarditis compared to cured patients and healthy controls. In addition, neutralizing anti-TNF antibodies decreased C. burnetii internalization, an early step of bacterial killing, in monocytes from patients with ongoing endocarditis but did not affect delayed steps of intracellular killing. We suggest that Q fever-associated activation of monocytes allows the survival of C. burnetii by modulating early phases of microbial killing.