UNLABELLEDTo investigate the effect of immune response mediated by the T cells stimulated with the specific antigen (oxidized low-density lipoprotein, oxLDL) on plaque stability in coronary heart disease.

METHODSThis study involved 20 patients with acute myocardial infarction (AMI), 34 with unstable angina pectoris (UAP), 27 with stable angina pectoris (SAP) and 22 healthy control subjects. With MTS/PMS colorimetric assay, the T cells from all the subjects were tested for proliferative response to stimulation by 5 microg/ml oxLDL and 5 microg/ml low-density lipoprotein (LDL). Interferon-gamma (IFN-gamma) concentration in the proliferative response of the T cells was measured with enzyme-linked immunosorbent assay (ELISA).

RESULTSThe proliferative response of the T cells elicited by 5 microg/ml oxLDL stimulation was significantly higher in the AMI and UAP groups than in the SAP and control groups (P<0.05). Similarly, IFN-gamma concentration in the proliferative response of the T cells to 5 microg/ml oxLDL stimulation was significantly higher in the former two groups (P<0.05). In the AMI and UAP groups, 5 microgLDL stimulation (P<0.001).

CONCLUSIONThe immune response mediated by the T cells to specific antigen stimulation, especially the immune response mediated by T helper type 1 (Th1) cells secreting IFN-gamma, may play an important role in the plaque instability and the occurrence of acute coronary syndrome.

Aged ; Coronary Disease ; immunology ; Female ; Humans ; Interferon-gamma ; secretion ; Lipoproteins, LDL ; immunology ; Male ; Middle Aged ; T-Lymphocytes ; immunology ; metabolism ; T-Lymphocytes, Helper-Inducer ; immunology ; metabolism

Oxidized low density lipoprotein (LDL) seems to take a part in atherogenesis through direct interactions with macrophages, endothelial cells, and smooth muscle cells, and is thought to participate in renal glomerular injury. For the purpose of illustrating the role of oxidized LDL in the human diseases, monoclonal antibodies were developed and characterized, recognizing oxidized LDL-specific epitopes that do not exist on native LDL. LDL was oxidized by the incubation with CuSO4, and used as immunogen. Splenocytes from the immunized mouse and mouse myeloma cells were fused to produce hybridomas, which were screened for the secretion of oxidized LDL-specific antibodies. Immunoblot analysis and binding affinity assay showed that these monoclonal antibodies recognize malondialdehyde-conjugated peptide epitopes.
Antibodies, Monoclonal ; Antibody Affinity ; Antibody Specificity ; Enzyme-Linked Immunosorbent Assay ; Epitopes ; Human ; Lipoproteins, LDL/immunology* ; Malondialdehyde/immunology ; Malondialdehyde/analysis ; Peptide Fragments/immunology ; Thiobarbituric Acid Reactive Substances/analysis

The role of autoantibody against oxidized low-density lipoprotein (LDL) in the pathogenesis of atherosclerosis is still unknown. The purpose of this study was to determine whether autoantibodies against malondialdehyde (MDA)-modified LDL are associated with coronary artery disease (CAD) and clinical presentations of CAD in non-diabetic patients without acute myocardial infarction (AMI). We determined the serum levels of autoantibody against MDA-modified LDL by ELISA in 71 patients with angiographically significant CAD (> or = 50% diameter stenosis in at least 1 vessel) and 80 controls without angiographically significant CAD. Among the total 151 subjects, 30 subjects did not have any clinical ischemic event, 90 subjects had stable angina symptoms, and 31 subjects had unstable angina symptoms. The autoantibody titer, expressed mean optical density units, was significantly higher in patients with CAD than in controls (0.177+/- 0.014 versus 0.127+/- 0.011, respectively; p=0.006) and higher in unstable angina group than in stable angina group (0.240+/- 0.025 versus 0.145+/- 0.007, respectively; p < 0.001). By logistic regression analysis, the high autoantibody titer was associated significantly with CAD (P=0.008), independent of age, gender, body mass index, triglyceride concentration, and the ratio of total cholesterol-high density lipoprotein (HDL) cholesterol. In multiple regression analysis, presence of CAD, smoking history and low HDL-cholesterol level were independent factors associated with a increased anti-oxLDL Ab titer. The autoantibody titer was significantly lower in nonsmoker than smoker (p=0.019) and higher in low HDL- cholesterol (< or = 35 mg/dl) group than in high HDL-cholesterol group (p=0.012). Elevated autoantibody titer was associated with CAD and the unstable clinical presentation of CAD. Our results suggest that immune response to oxidized LDL may play a role in the pathogenesis of atherosclerosis and plaque instability.
Aged ; Angina, Unstable/*blood/*immunology ; Antibody Formation ; Autoantibodies/*analysis ; Coronary Disease/immunology ; Female ; Human ; Lipoproteins, LDL/*drug effects/*immunology ; Male ; Malondialdehyde/*pharmacology ; Middle Age

OBJECTIVETo investigate the relation of the levels of C-reactive protein (CRP) and antibodies against oxidized low-density lipoprotein (anti-oxLDL) to with acute coronary syndrome (ACS).

METHODSThe levels of CRP, anti-oxLDL and anti-LDL were measured and compared in 96 subjects including 26 with acute myocardial infarction (AMI), 29 with unstable angina pectoris (UAP), 20 with stable angina pectoris (SAP) and 21 control subjects to evaluate the relationship between CRP and anti-oxLDL.

RESULTSBoth CRP and anti-oxLDL levels in patients with ACS, including AMI and UAP, were significantly higher than those in SAP patients and the control subjects (P<0.05), but the level of anti-LDL showed no significant difference between the groups (P>0.05). There was significant positive correlation between the levels of CRP and anti-oxLDL (P<0.001).

CONCLUSIONThe specific immune response to oxLDL may play an important role in the instability of plaque and the occurrence of ACS, and anti-oxLDL level may serve as an important specific marker for the instability of plaque.

Aged ; Antibodies ; blood ; immunology ; Biomarkers ; blood ; metabolism ; C-Reactive Protein ; metabolism ; Case-Control Studies ; Coronary Disease ; blood ; complications ; metabolism ; pathology ; Female ; Humans ; Lipoproteins, LDL ; immunology ; Male ; Middle Aged

OBJECTIVETo examine the effect of ginsenoside Rb1 (GRb1) on the immune maturation of monocyte-derived dendritic cells (DCs) induced by oxidized low-density lipoprotein (OX-LDL).

METHODSHuman monocytes purified by CD14+ immuno-magnetic beads were differentiated and induced into immature DCs, which were randomly divided into 6 groups, Group A treated with PBS, Group B treated with OX-LDL, Group C and D treated respectively with GRb1 and ciglitazone, Group E and F were pretreated with the two testing drugs respectively followed by OX-LDL. The immuno-phenotypic expression (CD40, CD1a, and HLA-DR) and endocytosis function of DCs were examined using flow cytometry, the concentration of interleukin-12 (IL-12) and tumor necrosis factor alpha (TNF-alpha) in the culture supernatants were measured with ELISA.

RESULTSCompared with Group B, Group E showed significantly lowered immuno-phenotypic expression of DCs in terms of CD40 (67.4 +/- 1.62 vs. 145.69 +/- 14.86), CD1a (79.64 +/- 3.04 vs. 159.89 +/- 6.09), and HLA-DR (46.43 +/- 2.85 vs. 99.33 +/- 17.11), as well as higher endocytosis level (88.13% +/- 1.06% vs. 25.90% +/- 5.77%, all P < 0.01). Meantime, the serum levels of IL-12 (88.65 +/- 5.59 ng/L vs. 716.69 +/- 36.35 ng/L) and TNF-alpha (133.27 +/- 11.98 ng/L vs. 968.10 +/- 36.42 ng/L) obviously decreased (P < 0.01). The surface molecular expression of DCs and the secretion of inflammatory factors in Group F also obviously decreased, showing insignificant difference from Group E (P > 0.05).

CONCLUSIONGRb1 could obviously inhibit the OX-LDL-induced maturation of DCs, showing similar effects to ciglitazone.

Cell Differentiation ; drug effects ; Cells, Cultured ; Dendritic Cells ; cytology ; drug effects ; immunology ; Flow Cytometry ; Ginsenosides ; pharmacology ; Humans ; Lipoproteins, LDL ; Monocytes ; cytology ; drug effects ; immunology

OBJECTIVE: To detect the levels of index related to inflammation such as soluble CD40 ligand (sCD40L), neutrophil collagenase-8 (MMP-8), and pregnancy associated plasma protein-A (PAPP-A) , lipid peroxidation and autoimmune indexes such as oxidized low density lipoprotein (ox-LDL) and its antibody (ox-LDL Ab) in patients with coronary heart disease, and to investigate its relationship with acute coronary syndrome (ACS). METHODS: Contents of sCD40L, MMP-8, PAPP-A, ox-LDL and ox-LDL Ab in the peripheral blood were measured by enzyme-linked immunosorbent assay from 109 patients with coronary heart disease including 36 acute myocardial infarction (AMI), 38 unstable angina pectoris (UAP), and 35 stable angina pectoris (SAP) and 36 controls without coronary heart disease. RESULTS: The levels of each index in the peripheral blood of ACS patients (including AMI and UAP) were higher than those of SAP patients and controls (P < 0.05), and the difference of each index between UAP group and AMI group in ACS patients had no statistical significance (P > 0.05). The levels of each index of SAP patients, except PAPP-A, were all higher than those of controls (P <0.05). All the indexes were helpful in diagnosis of ACS. The area under the ROC curve of each index is between 0.7 and 0.9. CONCLUSION The increase of sCD40L, MMP-8, PAPP-A, ox-LDL and ox-LDL Ab levels in peripheral blood may be related to the pathogenesis of ACS, and can be used as potential markers of unstable atherosclerosis plaque.
Aged ; Angina, Unstable ; blood ; immunology ; Autoantibodies ; blood ; Biomarkers ; blood ; CD40 Ligand ; blood ; Coronary Artery Disease ; blood ; immunology ; Female ; Humans ; Lipoproteins, LDL ; blood ; immunology ; Male ; Matrix Metalloproteinase 8 ; blood ; Middle Aged ; Myocardial Infarction ; blood ; immunology ; Pregnancy-Associated Plasma Protein-A ; metabolism

Atherosclerosis is an inflammatory disease as well as a lipid disorder. Atherosclerotic plaque formed in vessel walls may cause ischemia, and the rupture of vulnerable plaque may result in fatal events, like myocardial infarction or stroke. Because morphological imaging has limitations in diagnosing vulnerable plaque, molecular imaging has been developed, in particular, the use of nuclear imaging probes. Molecular imaging targets various aspects of vulnerable plaque, such as inflammatory cell accumulation, endothelial activation, proteolysis, neoangiogenesis, hypoxia, apoptosis, and calcification. Many preclinical and clinical studies have been conducted with various imaging probes and some of them have exhibited promising results. Despite some limitations in imaging technology, molecular imaging is expected to be used both in the research and clinical fields as imaging instruments become more advanced.
Atherosclerosis/*diagnosis/pathology/radiography ; Endothelial Cells/metabolism ; Humans ; Inflammation/pathology ; Lipoproteins, LDL/metabolism ; Macrophages/immunology/metabolism ; Plaque, Atherosclerotic ; Positron-Emission Tomography ; Tomography, Emission-Computed, Single-Photon

Atherosclerosis ; etiology ; prevention & control ; Cytokines ; secretion ; Dendritic Cells ; drug effects ; immunology ; Endocytosis ; Fenofibrate ; pharmacology ; Humans ; Immunophenotyping ; Lipoproteins, LDL ; toxicity ; Monocytes ; cytology ; PPAR alpha ; agonists ; physiology

OBJECTIVE: To observe the effects of immune complexes (IC) prepared from human oxidized density lipoprotein (oxLDL) antibodies and human oxLDL on the foam cell forming and the macrophage activation, and to further uncover the possible mechanisms of immune complexes contributing to the atherosclerosis occurrence. METHODS: The immune complexes of human oxLDL and purified human oxLDL antibodies were added to culture U937 cells by protocols: polyethylene glycol-precipitated insoluble IC (PEG-IC) and IC immobilized by absorption to red blood cells (RBC-IC). With oxLDL as controls and heat-aggregated gamma globulin as an inhibitor of Fc gamma receptor, we measured the cholesterol ester, total cholesterol of the cellular extracts, and quantified the secreted MMP-1 of supernatants from U937 cells. RESULTS: A significant increase of MMP-1 release [(0.769 +/- 0.030) ng/ml vs (0.513 +/- 0.034) ng/ml, P < 0.01] and a higher level of cholesterol ester accumulation [(20.271 +/- 1.668) microg/mg protein vs (17. 226 +/- 1.298 ) microg/mg protein, P < 0.05] in U937 cells incubated with RBC-IC were observed, compared with those incubated with RBC-oxLDL. However, the above quantative difference between the cholesterol ester accumulation induced by oxLDL and insoluble PEG-IC was even more striking, and cholesterol ester accumulation was dosage-dependent. Heat-aggregated gamma globulin (10 mg/ml) as an inhibitor of Fc gamma receptors competitively inhibited cholesterol ester accumulation and decreased PEG-IC stimulating MMP-1 secretion to 71%. CONCLUSION Immune complexe of ox-LDL can transform macrophages into foam cells and activted macrophages. The immunological function of oxLDL is involved in the process of atherosclerosis occurrence.
Antibodies ; pharmacology ; Atherosclerosis ; etiology ; metabolism ; Cholesterol Esters ; metabolism ; Foam Cells ; drug effects ; Humans ; Lipoproteins, LDL ; immunology ; pharmacology ; Macrophage Activation ; drug effects ; Matrix Metalloproteinase 1 ; biosynthesis ; U937 Cells

OBJECTIVETo explore the role of toll-like receptor 4 (TLR4) on oxidized low-density/β₂-glycoprotein I/β₂-glycoprotein I (ox-LDL/β₂GPI/anti-β₂GPI) antibodies complex induced macrophage foam cell formation.

METHODSThe peritoneal macrophages were separated from TLR4 intact C3H/HeN mice and TLR4 defective C3H/HeJ mice. The cells were treated with ox-LDL, ox-LDL/β₂GPI, ox-LDL/anti-β₂GPI, anti-β₂GPI/β₂GPI, ox-LDL/β₂GPI/anti-β₂GPI, lipopolysaccharide (LPS) for 48 h and the foam cells were identified by Oil red O staining for intracellular lipids. The total cellular RNA and the protein lysates were collected. The levels of tissue factor (TF) mRNA in two groups were detected by real-time PCR (RT-PCR), and the expression of phosphorylated nuclear factor-κB (NF-κB) p65 was detected by Western blotting. Monocyte chemotactic protein-1 (MCP-1) secretion from peritoneal macrophages was determined by enzyme linked immunosorbent assay (ELISA) kits.

RESULTSCompared with C3H/HeJ mice, lipid droplets in the cytoplasm of peritoneal macrophages from C3H/HeN mice were significantly increased and phosphorylation-NF-κB expression was significantly upregulated after stimulating by ox-LDL/β₂GPI/anti-β₂GPI complex (P < 0.01). TF mRNA and MCP-1 expression were also upregulated post ox-LDL/β₂GPI/anti-β₂GPI complex stimulation [TF mRNA: 0.041 ± 0.023 vs. 0.005 ± 0.003; MCP-1: (6 200.2 ± 6.4) pg/ml vs. (803.3 ± 5.5) pg/ml, P < 0.01].

CONCLUSIONTLR4 can enhance ox-LDL/β₂GPI/anti-β₂GPI complex induced peritoneal macrophage foam cell formation via upregulating phosphorylation-NF-κB, TF and MCP-1 expression.

Animals ; Antigen-Antibody Complex ; immunology ; Atherosclerosis ; immunology ; metabolism ; Cells, Cultured ; Foam Cells ; immunology ; metabolism ; Lipoproteins, LDL ; immunology ; Macrophages, Peritoneal ; immunology ; metabolism ; Male ; Mice ; Mice, Inbred C3H ; NF-kappa B ; metabolism ; Thromboplastin ; metabolism ; Toll-Like Receptor 4 ; immunology ; metabolism ; beta 2-Glycoprotein I ; immunology