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PubMed1985

Immune complexes and complement abnormalities in patients with cystic fibrosis. Increased mortality associated with circulating immune complexes and decreased function of the alternative complement pathway.

Serum samples from 139 patients with cystic fibrosis (CF) were tested for complement abnormalities and circulating immune complexes (CIC). We found no consistent changes in whole complement activity. However, we found CIC in 29% of these patients and decreased activity of the alternative complement pathway (ACP) in 36%. During 5 yr of observation, mortality was much higher in patients whose sera contained CIC (p less than 0.001) or decreased ACP activity (p less than 0.01). Of patients with both abnormalities, 31% died; however, no deaths occurred in patients with normal ACP activity and negative tests for CIC (p less than 0.001). During a subsequent 2.5-yr period, 55% of patients greater than or equal to 21 yr old with both findings died. In contrast, no deaths occurred in older patients lacking this combination (p = 0.0062). Circulating immune complexes but not decreased ACP activity were an independent risk factor for death. Our findings support the hypothesis that humoral immune mechanisms may contribute to morbidity and mortality in CF.

Adolescent↗

PubMed2004

Comparison of CpG s-ODNs, chromatin immune complexes, and dsDNA fragment immune complexes in the TLR9-dependent activation of rheumatoid factor B cells.

Synthetic single-stranded oligodeoxynucleotides (15-30 bp) containing CpG motifs and phosphorothioate backbones (CpG s-ODN), immune complexes consisting of anti-nucleosome mAbs and mammalian chromatin (chromatin IC), and immune complexes consisting of anti-hapten mAbs and haptenated-double stranded DNA fragments ( approximately 600 bp) can all effectively stimulate transgenic B cells expressing a rheumatoid factor receptor by a TLR9-dependent process. However, differential sensitivity to both s-ODN and small molecule inhibitors suggests that stimulatory CpG sODN and chromatin IC may either access TLR9 via different routes or depend on discrete activation parameters. These data have important implications regarding the therapeutic application of TLR9 inhibitors to the treatment of systemic autoimmune diseases.

Animals↗

PubMed1989

Antibodies to chicken progesterone receptor peptide 523-536 recognize a site exposed in receptor-deoxyribonucleic acid complexes but not in receptor-heat shock protein-90 complexes.

We have prepared monospecific polyclonal rabbit antibodies to the peptide sequence 523-536 of the chicken progesterone receptor. This region, located between the DNA-binding and hormone-binding domains, is predicted by hydropathic analyses to be on the surface of the protein. The synthetic peptide was coupled to keyhole limpet hemocyanin and injected into rabbits. Three rabbits produced antibodies; all three are specific for progesterone receptors, recognize both native and denatured receptor, and do not interfere with either hormone binding or receptor recognition of its DNA response element in gel retardation assays. However, the antibodies do not interact with cytosolic 8S receptor complexes which contain the heat shock protein hsp90, suggesting that this site is occluded in the 8S complex. In contrast, the antibodies recognize a type of receptor dimer which forms on the DNA response element. Thus, these antibodies are a unique tool for studying receptor protein-protein interactions.

Amino Acid Sequence↗

PubMed1988

Human peripheral blood and pleural fluid eosinophils can be induced by immune complexes to release IgG immune complexes and aggregated IgE.

The ability of IgG and IgE immune complexes and of phorbol myristate acetate (PMA), a soluble membrane activator, to stimulate hydrogen peroxide (H2O2) release and to induce oxygen radical-mediated cytotoxic activity by human peripheral blood (PBL) eosinophils and by PBL neutrophils was evaluated in normal volunteers and patients with hypereosinophilic malignant pleural effusions due to lung cancer. PMA stimulated a significant respiratory burst. Similar results were obtained with IgG IC stimulation, although the levels of H2O2 were lower. Agg IgE induced H2O2 release only by PBL and PE eosinophils and not by neutrophils. PMA stimulation resulted in detectable cytotoxic activity. IgG IC generated both PBL and PE eosinophil and PBL neutrophil cytotoxicity. Agg IgE induced significant cellular cytotoxicity in both PBL and PE eosinophils. This study suggests that eosinophil oxidative metabolic burst and cytotoxic activity stimulated by IgG and IgE immune complexes could represent a possible mechanism of parenchymal injury in eosinophilic disorders.

Adult↗

PubMed2005

Backbone dynamics of a symmetric calmodulin dimer in complex with the calmodulin-binding domain of the basic-helix-loop-helix transcription factor SEF2-1/E2-2: a highly dynamic complex.

Calmodulin (CaM) interacts specifically as a dimer with some dimeric basic-Helix-Loop-Helix (bHLH) transcription factors via a novel high affinity binding mode. Here we report a study of the backbone dynamics by (15)N-spin relaxation on the CaM dimer in complex with a dimeric peptide that mimics the CaM binding region of the bHLH transcription factor SEF2-1. The relaxation data were measured at multiple magnetic fields, and analyzed in a model-free manner using in-house written software designed to detect nanosecond internal motion. Besides picosecond motions, all residues also experience internal motion with an effective correlation time of approximately 2.5 ns with squared order parameter (S(2)) of approximately 0.75. Hydrodynamic calculations suggest that this can be attributed to motions of the N- and C-terminal domains of the CaM dimer in the complex. Moreover, residues with significant exchange broadening are found. They are clustered in the CaM:SEF2-1mp binding interface, the CaM:CaM dimer interface, and in the flexible helix connecting the CaM N- and C-terminal domains, and have similar exchange times (approximately 50 micros), suggesting a cooperative mechanism probably caused by protein:protein interactions. The dynamic features presented here support the conclusion that the conformationally heterogeneous bHLH mimicking peptide trapped inside the CaM dimer exchanges between different binding sites on both nanosecond and microsecond timescales. Nature has thus found a way to specifically recognize a relatively ill-fitting target. This novel mode of target-specific binding, which neither belongs to lock-and-key nor induced-fit binding, is characterized by dimerization and continuous exchange between multiple flexible binding alternatives.

Binding Sites↗

PubMed1985

Circulating immune complex-like materials which bind to heat inactivated C1q interfere with the C1q solid phase assay for immune complexes.

C1q solid phase assay (C1q SP) was devised based on the fact that immune complexes (IC) and aggregated human globulin (AHG) bind to C1q. Neither IC nor AHG was found to bind to heat inactivated C1q. On the other hand, circulating immune complex (CIC)-like materials in patients' sera were able to bind to heat inactivated C1q, indicating that these CIC-like materials are not true CIC. Gel filtration analysis showed that molecular size of such CIC-like materials was almost the same as monomeric IgG, while true CIC were in heavy fractions. True CIC did not bind to heat inactivated C1q but bind only to native C1q. The CIC-like activity is not due to rheumatoid factors. About 2/3 of CIC positive sera by C1q-SP are not really CIC positive but are due to interference by the CIC-like materials.

Animals↗

PubMed1991

C3 activation products, C3 containing immune complexes, the terminal complement complex and native C9 in patients with rheumatoid arthritis.

Complement activation products, C9 and C3-containing circulating immune complexes (CIC), were evaluated in plasma and synovial fluid (SF) from patients with rheumatoid arthritis (RA) and osteoarthritis. C3 activation products and the fluid phase terminal complement complex were considerably elevated in SF from RA patients reaching levels five- to eighttimes that in plasma, consistant with a local activation of the whole cascade in the joints. The results emphazise the importance of detecting C3 activation by neoepitope expression instead of single fragment determinations. The concentration of native C9 was lower in synovial fluid compared with plasma, consistant with the excessive local complement activation. Increased CIC levels which correlated with the degree of complement activation were also found in the SF from the RA patients.

Adult↗

PubMed1991

Serological evidence for major histocompatibility complex (B complex) antigens in broilers selected for humoral immune response.

Genetic selection for early humoral immune responsiveness against two simultaneous antigens, namely, heat-killed Escherichia coli and Newcastle disease virus vaccine (NDV), was performed in a heterogenic population of broiler chickens. The humoral immune response was measured prior to 24 days of age, depending on the vaccine. Chicks were divided into two populations according to their antibody response: a population of high responders to both antigens and a population of low responders. After four generations of selection, a significant difference was observed in the immune response of the two populations, and therefore, an attempt was made to identify possible differences in the segregation of major histocompatibility complex genes. Using alloantisera prepared in B-congenic White Leghorn, the high responders exhibited a high percentage of chickens having erythrocytes agglutinated with B5 antisera, and the low responders exhibited a high percentage of chicks with erythrocytes agglutinated with B15 and B19 antisera. The B13 antisera agglutinated cells of similar proportions of chickens in the two populations. A random commercial broiler flock was screened with the antisera, and correlation was high between B haplotype and antibody level to E. coli following vaccination. The present work indicated the possibility of a direct association between the genetic characteristics represented in the B complex and humoral antibody response in a broiler population.

Animals↗

PubMed2006

Immune complex-loaded dendritic cells are superior to soluble immune complexes as antitumor vaccine.

Dendritic cells (DCs) play an important role in the induction of T cell responses. Fc gammaRs, expressed on DCs, facilitate the uptake of complexed Ag, resulting in efficient MHC class I and MHC class II Ag presentation and DC maturation. In the present study, we show that prophylactic immunization with DCs loaded with Ag-IgG immune complexes (ICs) leads to efficient induction of tumor protection in mice. Therapeutic vaccinations strongly delay tumor growth or even prevent tumors from growing out. By depleting CD4+ and CD8+ cell populations before tumor challenge, we identify CD8+ cells as the main effector cells involved in tumor eradication. Importantly, we show that DCs that are preloaded in vitro with ICs are at least 1000-fold more potent than ICs injected directly into mice or DCs loaded with the same amount of noncomplexed protein. The contribution of individual Fc gammaRs to Ag presentation, T cell response induction, and induction of tumor protection was assessed. We show that Fc gammaRI and Fc gammaRIII are capable of enhancing MHC class I-restricted Ag presentation to CD8+ T cells in vitro and that these activating Fc gammaRs on DCs are required for efficient priming of Ag-specific CD8+ cells in vivo and induction of tumor protection. These findings show that targeting ICs via the activating Fc gammaRs to DCs in vitro is superior to direct IC vaccination to induce protective tumor immunity in vivo.

Animals↗

PubMed1991

[Study of detailed conditions in DNA probe test by use of Gen-Probe Rapid Diagnostic System for identification of Mycobacterium avium complex and Mycobacterium tuberculosis complex].

In order to improve feasibility of technical procedures in Gen Probe Rapid Diagnostic System (Gen Probe Inc., San Diego, CA, U.S.A.) for identification of Mycobacterium avium complex (MAC) and M. tuberculosis complex (MTC), we studied several test conditions in the DNA probe testing, such as stability of test bacterial suspension, optimal duration of bacterial cultivation, the number of organisms in test bacterial suspension required for accurate determination, and so on. With respect to concentration of organisms (MAC and MTC) in test bacterial suspension (0.1ml), we found that 5-fold dilution as well as 5-fold condensation of the standard bacterial suspension (McFarland No.1) gave substantially the same result as in the case where bacterial suspension at the standard concentration was used. This indicates that the test bacterial suspensions (0.1ml) containing either 1.5 X 10(7)-5 X 10(8) of MAC or 3 X 10(5)-8 X 10(6) of MTC are available for the DNA probe testing. Test bacterial suspension at McFarland No.1 prepared from fresh cultures (3-4 week-old) could be stored either at -80, -20 or 4 degrees C at least for 17 weeks without significant loss of reactivity to M. avium, M. intracellulare and MTC DNA probes. In this case, stability of DNA probe-reactivity was preserved in the following order: MTC, M. avium and M. intracellulare. Concerning the age of bacterial cultures, at least 16-week-old cultures of MAC and MTC after initial appearance of cell growth on 1% Ogawa's egg media were sufficiently reactive to either MAC or MTC DNA probe. In this case, MTC showed most stable reactivity during the course of long-term cultivation.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA Probes↗

PubMedDate not supplied

Humoral immunity and composition of immune complexes in patients with rheumatoid arthritis, with special reference to IgE-containing immune complexes.

IgE-containing circulating immune complexes (IgE-CIC) were determined with a 2.5% PEG-precipitation assay in 98 patients with classical or definite rheumatoid arthritis (RA). Of the 45 IgE-CIC positive sera, only 4 had elevated total serum IgE. IgE-CIC positive patients had more active disease than patients without IgE-CIC, as determined by their more swollen joints and higher Ritchie indices (p less than 0.04 and 0.02, respectively). Apart from IgE, other immunoglobulin isotypes, rheumatoid factor (RF) of the IgG-, IgA- and IgM-classes, C3 and antinuclear antibodies could be demonstrated in the IgE-containing PEG-precipitates. IgE-RF could not be demonstrated in serum or in IgE-CIC. Anti-IgE of the IgM-class (IgMaIgE) were frequently found (28/45 patients) in the IgE-positive PEG-precipitates. All 14 patients positive for IgGaIgE in the IgE-CIC were also positive for IgMaIgE in the CIC. As in the serum, there was a good correlation in the CIC between the level of IgGaIgE and the level of IgMaIgE (r = 0.64). The correlation between the respective levels of IgGaIgE and IgMaIgE in serum and in CIC was high (r = 0.93 and 0.79, respectively). On the other hand, only 1 patient was positive for IgAaIgE in the IgE-CIC. We conclude that IgE and aIgE of the IgM- and IgG-classes are frequently present in the immune complex form in RA and that they are correlated with the clinical activity of arthritis.

Adult↗

PubMed1989

[Complement-mediated solubilization of immune complexes in immune complex nephritis].

In order to examine the ability of complement to solubilize the immune complexes (IC) in vivo, we made acute or chronic serum sickness nephritis in 10 rabbits or 12 rats with injection of BSA as antigen (Ag). Animals were divided into two groups. The 500 mu or 50 mu/week of cobra venom factor (CVF) for rabbits or rats was administered intraperitoneally in one group of animals to reduce the serum complement levels and complement-mediated solubilization of immune complex. On the other hand, the 2 ml or 0.2 ml/week of turpentine oil (TO) was injected intramuscularly in another group of animals to elevate the serum complement levels. The renal biopsy was performed with weekly intervals in each animals, and the specimens were stained for antigen (BSA), antibody (IgG) and C3 by immunofluorescence techniques. The result in this experiments showed the significant difference between TO-, and CVF-treated animals in the degree of disappearance of IC in the kidney lesions. The undetectable amount of IC (especially BSA) was remained in the renal tissue of TO-treated animals. This fact indicated that complement might act to solubilize the IC deposited in the tissue in vivo also.

Animals↗

PubMed1989

Circulating immune complexes and rheumatoid arthritis: the induction of immune complex formation between rheumatoid factor and IgG by polyethylene glycol.

Circulating immune complexes (CIC) as detected by the C1q binding assay (C1qBA) in sera from patients with rheumatoid arthritis (RA) were not demonstrable in these sera with the indirect granulocyte phagocytosis test (IGPT). This discrepancy could be explained by the finding that polyethylene glycol (PEG), used in the C1qBA, enhanced the binding of rheumatoid factor IgM (RFIgM) and IgG resulting in immune complex (IC) formation. The addition of PEG to RA sera and subsequent testing of these sera in the IGPT revealed increased uptake of IC by these cells, dependent on the PEG dose. Addition of purified RFIgM to a normal human serum generated a positive IGPT in a dose dependent way. We conclude that in RA sera PEG induces IC between RFIgM and IgG. Therefore, assays devised to measure CIC in RA sera which are based on PEG (like the C1qBA) overestimate the amounts of IC present in the circulation in vivo.

Antigen-Antibody Complex↗

PubMed1988

From the archaic matrix of the oedipus complex to the fully developed oedipus complex. Theoretical perspective in relation to clinical experience and technique.

The opposition between the "archaic matrix of the oedipus complex" and the fully developed oedipus complex leads the author to compare two distinct types of patients: those who do not conform to the neurotic model (patients who probably witnessed and were the victims of disintegration of the family and the effacement of the father's image) and the neurotic patient for whom Freud's discovery was intended. The consequences of differences of organization specific to each type of patient are numerous. This study restricts itself to examining the different mode of interpretation in each case, although the choice of this does not depend solely upon the analyst, since interpretation is the product of the encounter between patient and analyst.

Adult↗

PubMed1987

Streptococcal protein G-gold complex: comparison with staphylococcal protein A-gold complex for spot blotting and immunolabeling.

Protein G, a cell wall protein isolated from human group G streptococci strain G148, binds in a similar manner as protein A from Staphylococcus aureus to the Fc portion of IgG molecules. Indeed, protein G has been proposed as a superior Fc binding protein due to its broader species reactivity. Thus, we have prepared a complex of protein G with particles of colloidal gold and determined its applicability for spot-blot analysis and postembedding immunolabeling by comparing it with protein A-gold complex. By spot-blot analysis no difference in binding of protein G-gold or protein A-gold to IgG molecules from a whole spectrum of animal species was observed. Moreover, using rabbit, sheep, or goat anti-rat albumin antibodies to detect nitrocellulose-immobilized rat albumin or antigenic sites in paraffin and Lowicryl K4M thin sections from rat liver, no difference was found with protein G-gold or protein A-gold. Similarly, no difference in binding to protein G-gold or protein A-gold was observed with a battery of monoclonal antibodies. However, in contrast to expectations, protein A-gold reacted well with both sheep and goat IgG molecules; indeed, for the light and electron microscopic localization of albumin with sheep or goat antibodies it was as efficient as protein G-gold. These results demonstrate, therefore, that both protein G-gold and protein A-gold are useful second step reagents for immunolabeling and that protein G-gold was not a superior probe in the systems tested.

Albumins↗

PubMed1985

Phagocytosis by mouse peritoneal macrophages plated on monoclonal antibody-coated immune complex-substrates: effects of complexes of different IgG subclasses on Fc receptor functions.

Macrophages plated on immune complex-coated substrates of different mouse IgG subclasses were examined for their capacities to phagocytose sheep red blood cells (SRBC) coated with monoclonal antibodies (MAb) of various IgG subclasses. IgG2a-and IgG2b-coated substrates abrogated macrophage phagocytosis of particles coated with any of the four mouse IgG subclasses. These results were confirmed by the use of two MAb of each of the IgG2a and IgG2b subclasses, with one of the MAb specific for dinitrophenyl groups and the others for SRBC. IgG3-coated substrates reduced the macrophage uptake of IgG2a-but not IgG2b-coated particles. Rabbit IgG-coated substrates ablated the uptake of SRBC coated with all mouse IgG subclasses. Resident and thioglycollate-elicited macrophages showed similar phagocytosis reduction when plated on these immune complexes. The phagocytosis of complement-coated particles was not affected by these IgG-coated substrates. Macrophages plated on both IgG2a-and IgG2b-coated substrates showed reduced immunofluorescence staining by an anti-IgG2b Fc receptor (FcR) Ab, 2.4G2 and reduced E(IgG2a) and E(IgG2b) binding. The results show that substrates coated with various IgG subclasses can abrogate phagocytosis mediated by FcR that do not have binding specificity for the substrate-immobilized Fc ligand, and suggest that the three classes of mouse FcR co-modulate.

Animals↗

PubMed1983

[The major OLA histocompatibility complex in sheep. Study of 6 new factors and definition of a 3rd locus of the complex: OLA-C].

6 new OLA factors of the Sheep histocompatibility complex are described. 3 of them, C 14, C 15, C 17 are the products of 3 alleles at a third locus of the complex: OLA-C, closely linked to OLA-A and B. Two factors A 13 and B 12 are the products of 2 alleles at OLA-A and B loci. The last factor (16) is the product of an OLA gene, the locus of which is not yet defined. 28 haplotypes are described. Genes at the 3 OLA loci are in linkage disequilibrium.

Alleles↗

PubMed1982

C1q-latex assay for immune complexes. Complexes that react with both C1q and monoclonal rheumatoid factor in lupus erythematosus and lung cancer.

A solid phase radioassay for measurement of ICs in biological fluids is described in which ICs present in test sample bind to C1q immobilized on latex particles and bound complexes are quantitated by reaction with radioiodinated mRF. The radioassay can reproducibly measure 10 ng of aggregated human IgG in serum and differentiate soluble complexes from IC-like materials that precipitate with centrifugation or low temperature or stick to test tube walls. Reagents used in the assay, including C1q-L, can be stored for extended periods of time before use. One hundred four of 171 sera from patients with SLE and 8 of 50 sera from patients with LC, assayed by this method, contained elevated levels of ICs relative to controls . IC levels determined by this method correlated with IC data generated by 125I-C1q-PEG precipitation. Raji cell radioimmune assay, and solid-phase conglutinin assay, in some cases but not other.

Antigen-Antibody Complex↗