Inflammatory and immune aspects of atherosclerosis.
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Animals↗
Biomedical subjects
J George
Publications and source records attributed to J George.
Oral tolerance to low dose beta 2-glycoprotein I: immunomodulation of experimental antiphospholipid syndrome.
Oral tolerance was induced in BALB/c mice by feeding low dose beta2-glycoprotein I (beta2GPI). The beta2GPI-fed mice did not develop serologic and clinical markers of experimental antiphospholipid syndrome (APS) upon immunization with the autoantigen. The treated group was characterized by low titers of serum anti-beta2GPI and anticardiolipin Abs in the serum, lack of fetal resorptions, low incidence of thrombocytopenia, and normal aPTT (activated partial thromboplastin time) values. Beta2GPI given orally before priming with beta2GPI resulted in complete prevention of experimental APS development; beta2GPI given at an early stage of the disease reduced clinical manifestations. However, administration of beta2GPI 70 days postimmunization had a less significant effect on disease expression. Tolerized mice exhibited a diminished T lymphocyte proliferation response to beta2GPI in comparison with beta2GPI-immunized mice fed with OVA. When nontolerant beta2GPI-primed T lymphocytes were mixed with T lymphocytes derived from tolerized mice, a significant inhibition of proliferation upon exposure to beta2GPI was observed. The induction of suppression was beta2GPI specific and driven, as well as TGF-beta mediated. The beta2GPI-specific response of T lymphocytes from the beta2GPI-fed mice was reversed by anti-TGF-beta Abs. The tolerance was adoptively transferred by CD8+ T cells from the tolerized mice into naive mice. Those CD8+ cells were MHC class I restricted, found to secrete TGF-beta, and had no cytolytic activity. Oral administration of beta2GPI suppressed priming of CTLs in the recipient mice. In sum, beta2GPI-induced oral tolerance has an immunomodulatory effect in experimental APS, demonstrating the importance of beta2GPI in the pathogenesis of the disease.
Administration, Oral↗
Induction of early atherosclerosis in LDL-receptor-deficient mice immunized with beta2-glycoprotein I.
BACKGROUND: Immunization with beta2-glycoprotein I (beta2GPI), the probable target of autoimmune anticardiolipin antibodies, results in experimental antiphospholipid syndrome in different mouse strains. The present study was undertaken to evaluate the effect of beta2GPI immunization on the progression of atherosclerosis. METHODS AND RESULTS: In the first experiment, 3 groups of LDL receptor-deficient (LDL-RD) mice (n=15 per group) were immunized with either beta2GPI or ovalbumin or were not immunized and were fed a chow diet for 12 weeks. In a second experiment, 3 groups of LDL-RD mice (n=10 per group) were immunized similarly and fed an atherogenic diet for 6 weeks. All beta2GPI-immunized mice developed high titers of anti-beta2GPI antibodies as well as a specific lymph node proliferation to beta2GPI. The average cholesterol levels did not differ between the mice fed similar diets, regardless of the immunization protocol. Atherosclerosis was enhanced in the beta2GPI-immunized mice (mean aortic lesion, 26 000+/-5700 microm2) in comparison with their ovalbumin-immunized (mean, 3000+/-1099 microm2; P<0.01) and nonimmunized (mean, 2250+/-700 microm2; P<0.01) littermates. The average lesion size in the beta2GPI-immunized mice fed an atherogenic diet (mean, 98 000+/-8305 microm2) was larger than the ovalbumin-immunized mice (mean, 81 250+/-12 933 microm2; P=NS) or the nonimmunized controls (mean, 75 625+/-7281 microm2; P=NS). The atherosclerotic plaques in the beta2GPI-immunized mice appeared to be more mature, and denser infiltration of CD4 lymphocytes was present in the subendothelium of the aortic sinuses from this group of mice. CONCLUSIONS: The results of the present study provide the first direct evidence for the proatherogenic effect of ss2GPI immunization and establish a new model for immune-mediated atherosclerosis.
Animals↗
Required buried alpha-helical structure in the bilirubin UDP-glucuronosyltransferase, UGT1A1, contains a nonreplaceable phenylalanine.
A conserved hydrophobic region in the bilirubin-type UDP-glucuronosyltransferase isozyme was first uncovered as a consequence of a deleterious mutation in the UGT1A1 (HUG-Br1) isozyme of a Crigler-Najjar (CN) Type I patient. According to analysis by the RAOARGOS computer program, this hydrophobic region in UGT1A1 is located between residues 159-177 and defines a buried helix centered over position 169-172 with a positive factor of 1.22. Further analysis showed that the planar phenol-type UGT1A6 (HLUG P1) isoform, unlike the steroid-type UGT2B7 (UDPGTh2) isozyme, has a similar conserved hydrophobic region and that the positive factor for its buried helix is 1.14 compared to the threshold of 1.13 for such a structure. The analysis detected the typical membrane-insertion-signal sequence and a membrane-anchoring domain in each isoform. The different amino acid sequence patterns between positions 168-172 for the three types of isoforms and the deleterious mutations in this microregion (MRA) of UGT1A1 in CN-I patients are evidence of a critical and descriminating role for MRA. With the recombinant UGT1A1 enzyme and its mutants, P167G, F170del, F170L, F170I, F170V, F170A, F170Y, F170E, F171L, F171I, F171V, F171A, F171Y, or L175Q, expressed in COS-1 cells, bilirubin glucuronidating activity at both pH 6.4 and 7.6 demonstrated that Phe-170 is not replaceable, whereas Phe-171 can be replaced by Leu without any loss of activity. The less hydrophobic buried helix in the phenolic-type UGT1A6 has a Tyr/Leu at position 170/171; this isoform glucuronidated bilirubin at 1/10 the level of that by UGT1A1 with a Km (bilirubin) of 25 microM compared to that for UGT1A1 of 5. 0 microM.
Amino Acid Sequence↗
How reminders given to patients and physicians affected pap smear use in a health maintenance organization: results of a randomized controlled trial.
BACKGROUND: Despite its effectiveness as a method of controlling cervical carcinoma, the use of Pap smear testing remains incomplete, and its promotion in the primary care setting provides an important opportunity for intervention. METHODS: The authors conducted a randomized controlled trial that involved three sites of a health maintenance organization (HMO) serving an urban minority population. Their aim was to evaluate the impact of reminders given to patients and physicians on site visitation by patients and Pap smear use. Eligible women (n=5801) were randomly assigned to 1 of 4 intervention combinations (in which reminders were given to either the patient or the physician, to both, or to neither). If they were ineligible for patient reminder intervention, patients were randomized only to physician reminder intervention (the presence or absence of it). The letter of reminder mailed to the patient invited women due for Pap smears to visit the HMO site, and the reminder for physicians was a medical record notice that a Pap smear was due. Logistic and survival analyses were used to investigate the correlation of intervention status with visitation, interval of time to a visit, and Pap smear use. RESULTS: In the primary intent-to-treat analysis, there was no significant effect of either patient or physician reminder interventions on rates of visitation or Pap smear completion. The secondary efficacy analyses demonstrated no overall effect of either patient or physician reminders, but effects among subgroups of women at individual HMO sites were noted. At Site 3, there was an apparent increase in time to the next visit among the subgroup of women with a chronic illness (16 weeks with intervention vs. 9 weeks without). With the physician reminder, the odds that a Pap smear would be given during the study year were increased among women without a previous Pap smear at Site 1 (adjusted odds ratio=1.39) and those with a chronic illness at Site 2 (adjusted odds ratio=3.38). CONCLUSIONS: Reminders given to patients and physicians had a limited impact on visitation by patients to the HMO sites or Pap smear completion. Although some subgroups of women may benefit, the authors also observed a possibly unfavorable impact among other subgroups. These results emphasize the importance of identifying more effective interventions, targeting them to women most likely to benefit, and not overlooking the possibility that preventive intervention will have an unanticipated adverse effect.
Adolescent↗
Target recognition of beta2-glycoprotein I (beta2GPI)-dependent anticardiolipin antibodies: evidence for involvement of the fourth domain of beta2GPI in antibody binding.
Beta2-glycoprotein I (beta2GPI) is an absolute requirement for the binding of autoimmune anticardiolipin Abs (aCL) to cardiolipin (CL). We evaluated the target recognition of human beta2GPI by IgG derived from two patients with primary and two with secondary antiphospholipid syndrome. The total IgG serum fractions and beta2GPI affinity-purified IgGs were assessed by using various domain-deleted mutants (DM) of human beta2GPI (DMs: I-III, I-IV, II-V, III-V, IV-V, and V) and mouse mAbs against individual beta2GPI domains. The four IgGs bound slightly to CL in the absence of beta2GPI and showed increased binding in the beta2GPI presence. Following affinity purification of the IgGs on a beta2GPI column, reactivity toward CL was absent. DMs containing domain V inhibited the binding of biotinylated beta2GPI to CL. The addition to CL-coated plates of DM V, but not the other DMs, reduced the binding of all four IgGs. The anti-beta2GPI IgGs bound only to complete beta2GPI and DM I-IV coated on the plates. The binding to plate-adsorbed beta2GPI could be inhibited by complete beta2GPI and DM I-IV, the latter being a more efficient inhibitor. Further, the human anti-beta2GPI IgGs could compete with the binding to beta2GPI of Cof-21 mouse mAb (directed at domain IV), but not with the two other mouse mAbs. The results suggest that some "autoimmune:" beta2GPI-dependent anticardiolipin Abs recognize a beta2GPI target that is distinct from the CL-binding site in domain V. The target site for some antiphospholipid syndrome IgGs appear to reside in domain IV of beta2GPI.
Animals↗
Differential effects of anti-beta2-glycoprotein I antibodies on endothelial cells and on the manifestations of experimental antiphospholipid syndrome.
BACKGROUND: The antiphospholipid syndrome (APS) entails a prothrombotic state associated with the presence of anticardiolipin antibodies (aCL). aCL were shown to promote endothelial cell and platelet activation and to induce an APS-like syndrome in mice when administered intravenously. Recent data suggest that aCL target the plasma cofactor beta2-glycoprotein I (beta2GPI) rather than negatively charged phospholipids. However, it has not been determined whether different epitope-specific anti-beta2GPI antibodies obtained from one patient possess pathogenic properties. METHODS AND RESULTS: Three beta2GPI-binding IgM monoclonal antibodies (mAbs) (ILA-1, ILA-3, and ILA-4) were cloned from a patient with APS. The three antibodies were shown to bind beta2GPI immobilized on irradiated plates, yet only ILA-1 bound beta2GPI coated onto nonirradiated plates. Furthermore, when using the anti-beta2GPI enzyme-linked immunosorbent assay, ILA-1 was the only mAb inhibited by fluid phase beta2GPI. ILA-1 and ILA-3, but not ILA-4, induced adherence of U937 cells to endothelial cells in vitro (reflecting activation of endothelial cells). mAbs ILA-1 and ILA-3 as opposed to ILA-4 induced significant expression of adhesion molecules when preincubated with human umbilical vein endothelial cells. Passive administration of ILA-1 and ILA-3 to pregnant BALB/c mice induced clinical findings consistent with APS (increased fetal resorptions, reduced platelet counts, and prolonged activated partial thromboplastin time), whereas both ILA-4 and the control human IgM did not produce similar effects. CONCLUSIONS: The results of the study demonstrate the differential effects of various populations of anti-beta2GPI antibodies on endothelial cell activation and on experimental APS.
Adult↗
Ciprofloxacin immunomodulation of experimental antiphospholipid syndrome associated with elevation of interleukin-3 and granulocyte-macrophage colony-stimulating factor expression.
OBJECTIVE: To evaluate the immunomodulatory potential of ciprofloxacin in mice with experimental antiphospholipid syndrome (APS). METHODS: Ciprofloxacin or ceftazidime (control antibiotic) was given to mice with experimentally induced APS. The titers of autoantibodies, levels of cytokines, and number of cytokine-producing cells were determined by enzyme-linked immunosorbent assay. Myeloid progenitor cells were determined by granulocyte-macrophage colony-forming unit, and interleukin-3 (IL-3) messenger RNA (mRNA) was tested by Northern analysis. RESULTS: A decrease in the incidence of pregnancy loss and an improvement in the clinical manifestations of APS were noted in the mice treated with ciprofloxacin, compared with the mice given ceftazidime. The effect of ciprofloxacin was found to be associated with increased serum levels of IL-3 and with increased IL-3 mRNA transcription in the splenocytes. Expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) was documented by elevated titers in the sera and elevated numbers of colony-forming cells in the bone marrow. CONCLUSION: Ciprofloxacin prevents the manifestations of experimental APS. This effect may be associated with increased IL-3 levels and GM-CSF expression.
Adjuvants, Immunologic↗
Functional properties of antiendothelial cell antibodies.
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Animals↗
Partial lipodystrophy, mesangiocapillary glomerulonephritis, and complement dysregulation. An autoimmune phenomenon.
Partial lypodistrophy (PLD) is a rare disease in which, there is loss of fat usually from the upper part of the body. The disease is frequently associated with mesangiocapillary (membranoproliferative) glomerulonephritis Type II (MCGN II). In the early 1970s, it was noticed that MCGN II and/or PLD was sometimes associated with dysfunction of the complement system as reported in several case descriptions and studies. Subsequently, an IgG autoantibody was detected-C3 nephritic factor (C3NeF). The target of this autoantibody is the alternative pathway C3 convertase-C3bBb. There are sporadic case reports that linked PLD, MCGNII, and C3NeF with autoimmune diseases. This association may be more than a coincidence. The complement deficiency may lead to perturbation of the immune system, which may trigger some of the autoimmune diseases. This article will be focused on the association among PLD, MCGN II and C3NeF.
Autoimmune Diseases↗
A technique to obtain correct rotational alignment during closed locked intramedullary nailing of the femur.
Closed intramedullary nailing is a successful method of treating adult femoral shaft fractures. In comminuted or segmental fractures, this operation is associated with an incidence of rotational malalignment and malunion. After locked nailing, this can only be corrected by further operation. A simple method of judging and obtaining rotational alignment in such cases intra-operatively is described. A comparison of two groups of patients with such fractures, one using this technique and the other using conventional methods of judging alignment, revealed statistically significant improvement in rotational alignment (p = 0.016).
Adolescent↗
Hyperimmunization of apo-E-deficient mice with homologous malondialdehyde low-density lipoprotein suppresses early atherogenesis.
The role of the immune system in modulating atherosclerosis has recently been the subject of intensive research. Several previous authors have put forward a paradigm of the autoimmune process occurring in the vicinity of the plaque. Two recent studies have shown that immunization of rabbits with homologous modified low-density lipoprotein (LDL) led to suppression of atherosclerosis. In the current study we evaluated the effects of homologous malondialdehyde (MDA)-LDL immunizations on atherogenesis in apo-E-deficient mice. Two groups of female chow-diet-fed, apo-E-deficient mice (n = 10) were either immunized with homologous MDA-LDL or with phosphate buffer saline (PBS) at 2-week intervals. The mice were sacrificed 12 weeks following the primary immunization. The MDA-LDL-immunized mice were shown to develop high titers of anti-MDA-LDL antibodies. Atherosclerosis, determined by the lesion size at the aortic sinus, was significantly suppressed in the MDA-LDL-immunized mice as compared with their littermates immunized with PBS (mean area +/- S.D.; 74000 +/- 17300 microm2 versus 158000 +/- 12800 microm2; P < 0.01). No differences were found between the groups with respect to the cellular composition of the atherosclerotic plaques. The results of this study show that immunization with MDA-LDL has a protective effect in apo-E-deficient mice, and further suggests that this mouse model is suitable for studies of immunomodulation.
Animals↗
Targeted gene knockout mediated by triple helix forming oligonucleotides.
Triple helix forming oligonucleotides (TFOs) recognize and bind sequences in duplex DNA and have received considerable attention because of their potential for targeting specific genomic sites. TFOs can deliver DNA reactive reagents to specific sequences in purified chromosomal DNA (ref. 4) and nuclei. However, chromosome targeting in viable cells has not been demonstrated, and in vitro experiments indicate that chromatin structure is incompatible with triplex formation. We have prepared modified TFOs, linked to the DNA-crosslinking reagent psoralen, directed at a site in the Hprt gene. We show that stable Hprt-deficient clones can be recovered following introduction of the TFOs into viable cells and photoactivation of the psoralen. Analysis of 282 clones indicated that 85% contained mutations in the triplex target region. We observed mainly deletions and some insertions. These data indicate that appropriately constructed TFOs can find chromosomal targets, and suggest that the chromatin structure in the target region is more dynamic than predicted by the in vitro experiments.
Animals↗
Aliphatic and alicyclic diols induce melanogenesis in cultured cells and guinea pig skin.
We have found that several aliphatic and alicyclic diols induce melanogenesis in cultured S91 mouse melanoma cells and normal human epidermal melanocytes (NHEM). In addition, these compounds induce melanogenesis when applied to guinea pig skin, with transfer of melanin to keratinocytes and formation of "supranuclear caps," as occurs in naturally pigmented skin. The relative order of potency of some of these diols in NHEM is 5-norbornene-2,2-dimethanol > 3,3-dimethyl-1,2-butanediol > cis-1,2-cyclopentanediol > 2,3-dimethyl-2,3-butanediol > 1,2-propanediol. Following treatment with these diols or 3-isobutyl-1-methylxanthine, melanin and tyrosinase activity are increased within S91 cells and NHEM; however, for cultured NHEM, the largest increases of melanin and tyrosinase occur in an extracellular particulate fraction, shown by electron microscopy to consist almost entirely of stage III and IV melanosomes. These results indicate that cultured NHEM treated with diols export melanosomes in a fashion that is commensurate with natural melanogenic processes. In contrast, S91 mouse melanoma cells exhibit aberrant melanosomal trafficking, in accordance with the known defect in myosin-V mediated melanosomal transport. Both S91 cells and NHEM exhibit morphologic changes and growth arrest indicative of differentiation following treatment with diols. The diols described in this report are candidates for use as cosmeceutical tanning agents.
Animals↗
Hantavirus seropositivity in Israeli patients with renal failure.
The hantavirus is known to cause hemorraghic fever with renal syndrome (HFRS), which is widely spread in Europe and Asia. Several reports have shown an association of hantavirus antibody titers and the occurrence of renal dysfunction. From these observations, it appears that the virus is widely distributed, and different strains prevail in various areas. In the present work we studied 81 patients with end-stage renal-failure under hemodialysis (HD) treatment, 55 with mild to moderate renal failure, and 50 healthy subjects for the presence of antibodies to Hantaan and Puumala viruses. We found that 12.3% of the hemodialysis patients and 9% of the mild to moderate renal failure patients had elevated IgG anti-body titers to Puumala virus compared with 2% of the controls. IgM antibodies to Puumala virus was principally elevated in patient with chronic renal failure (CRF) not on hemodialysis (14.5%) compared with the hemodialyzed (1.2%) and controls (0%) subjects. Hantaan virus IgG antibodies were detected in 3.7% of the HD patients, 5.5% of the CRF not on HD, and in none of the controls. IgM Hantaan antibodies were found only in the non-HD renal failure patients. None of the sera were found to contain antibodies to phospholipids or single-stranded DNA. These results emphasize the widespread nature of infection with hantaviruses and imply that elaborate testing for these serologies should be performed, especially in patients with unexplained renal failure.
Female↗
Characterization of murine monoclonal anti-endothelial cell antibodies (AECA) produced by idiotypic manipulation with human AECA.
The IgG fraction of human anti-endothelial cell antibodies (AECA) obtained from a patient with Wegener's granulomatosis was used as immunogen to raise AECA mAb in mice selected among those which developed vasculitis-like lesions after immunization. Three mAb (BGM, 3C8 and 7G2), selected by cyto-ELISA and flow cytometry analyses, featured a specific reactivity with human umbilical vein endothelial cells (HUVEC) and the mouse endothelial cell line H5V; on the contrary, HEp2 cells, the murine melanoma B16 cell line, the extracellular matrix as well as several other antigens tested were not recognized. BGM mAb, an IgG3 precipitating a 70 kDa structure from HUVEC, was able to induce endothelial cells to secrete amounts of IL-6 significantly higher than irrelevant controls or mAb binding different endothelial antigens (i.e. CD31, CD29, ICAM-1 and HLA class I). BGM mAb induced significant levels of antibody-dependent cell cytotoxicity (13 +/- 2.5 versus 0.6 +/- 0.03%). To the best of our knowledge, BGM is the first murine mAb specific for human endothelial cells generated by idiotypic manipulation; secondly, its biological properties further support the notion of a pathogenic role for AECA in autoimmune-mediated diseases.
Animals↗
How much does alcohol contribute to the variability of hepatic fibrosis in chronic hepatitis C?
In order to determine the contribution of alcohol intake to the severity of hepatic fibrosis in patients with chronic hepatitis C, we studied associations between various levels of alcohol intake, other demographic variables and semiquantitative liver histology in 434 cases of chronic hepatitis C. Clinical, demographic and disease-related data were entered into a relational database. Liver histology was scored according to Scheuer. The average daily alcohol intake for the year preceding liver biopsy (recent exposure) and for earlier periods (past exposure) was categorized into five levels of intake. One-third of patients gave a history of alcohol intake that had exceeded 40 g/day for at least 5 years. By univariate analysis, age, but not recent or past alcohol intake or other baseline variables, was associated with portal score (r = 0.14, P = 0.004), fibrosis score (r = 0.46, P < 0.001), total Scheuer score (r = 0.35, P < 0.001). However, by multivariate analysis, age (P < 0.001), past (but not present) alcohol intake (P < 0.001) and birth in Egypt (P = 0.006) were independently associated with fibrosis score. Age, past alcohol and birth place in Egypt contributed 27% to total variance of the hepatic fibrosis score, while age alone accounted for 23%. Age also independently predicted portal activity (P = 0.02) and total Scheuer score (P < 0.001), whereas past alcohol intake correlated with total Scheuer score (P = 0.002) but not with other histological indices. A separate multivariate analysis was performed on a more homogeneous subgroup of 196 patients who acquired hepatitis C by injection drug use. In this subgroup, age (P < 0.05) and past alcohol (P < 0.05) were independently associated with fibrosis score. In both the overall and subgroup analyses, there was a threshold level of past alcohol intake (>80 g/day) beyond which the risk of fibrosis increased significantly. It is concluded that toxic levels of alcohol exposure for at least 5 years accentuate hepatic fibrosis in hepatitis C but the influence of alcohol appears to be minor compared with age and other variables and is exerted only at toxic levels of intake.
Adult↗
Utility of a rapid fecal latex agglutination test detecting the neutrophil protein, lactoferrin, for diagnosing inflammatory causes of chronic diarrhea.
OBJECTIVE: The utility of tests for fecal neutrophils in the setting of chronic diarrhea has not been established. The purpose of this study was to determine the causes of chronic diarrhea associated with fecal neutrophils. METHODS: One fecal specimen from each of 10 normal subjects, 26 patients with known microscopic colitis, 13 with celiac sprue, eight with Crohn's disease, four with ulcerative colitis, and 103 with chronic diarrhea of unknown origin, as well as 10 fecal specimens from a patient with chronic nongranulomatous enterocolitis were analyzed blindly for the presence of a neutrophil granule protein called lactoferrin using a commercial latex agglutination kit. Diagnostic evaluation of the 103 patients with chronic diarrhea was carried out to determine the diagnostic accuracy of this test for chronic inflammatory bowel disease. RESULTS: None of the normal control subjects, three of 39 patients with microscopic colitis or celiac sprue, all 10 specimens from the patient with enterocolitis, and all 12 control patients with ulcerative colitis or Crohn's disease had a positive fecal lactoferrin test. Eleven of 103 patients with chronic diarrhea presenting without a diagnosis had a positive test, and all were diagnosed with an inflammatory condition of the colon (five-, ulcerative colitis; four-, Crohn's disease; one-, ischemic colitis; and one-, microscopic colitis). Only one patient with inflammatory bowel disease had a negative lactoferrin test. The sensitivity, specificity, and positive and negative predictive values of the fecal lactoferrin test for ulcerative or Crohn's colitis were 90%, 98%, 82%, and 99%, respectively. CONCLUSION: The major cause of fecal neutrophils in patients with chronic diarrhea is chronic inflammatory bowel disease of the colon. The latex agglutination test for fecal lactoferrin offers a highly sensitive, specific, and simple means for detection of fecal neutrophils in these patients.
Celiac Disease↗