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Evaluation of the autoimmune response in leprosy.

Immunological responses to a panel of antigens were evaluated in 27 patients with lepromatous and 20 patients with tuberculoid leprosy and compared with 24 pulmonary tuberculosis patients, 25 systemic lupus erythematosus patients and 41 healthy blood donors. Some autoantibody specificities were extensively studied for the first time in mycobacterial infections. Striking immunoserological abnormalities were found in patients with lepromatous leprosy, particularly in those presenting with relapse. Inhibition assays were performed, providing a tool for further analysis of the binding range of specific anti-N.D.O. BSA antibodies and strengthening the suggestion of molecular mimicry reactions between cytoskeletal proteins, host stress proteins and Mycobacterium leprae antigens or stress proteins. A significant serological overlap between lepromatous leprosy and autoimmune diseases is indicated.

Autoantibodies↗

Autoimmune response to anti-apoptotic protein survivin and its association with antibodies to p53 and c-myc in cancer detection.

Survivin, an inhibitor of apoptotic protein, is over-expressed in many cancers but not in normal differentiated adult tissues. Recently, antibodies to survivin have been demonstrated in patients with lung and colorectal cancer. Whether antibodies to survivin can be used as a marker for the diagnosis of cancer, and how antibody to survivin is related to antibodies against tumor suppressor protein p53 and oncoprotein c-myc remains to be evaluated. In the present study, the full-length recombinant proteins survivin, p53 and c-myc, were expressed and used as antigens in enzyme-linked immunosorbent assay (ELISA) and Western blot for the detection of antibodies to these three proteins. Sera from 1137 patients with 11 different types of cancer were analyzed. Antibodies to survivin were detected in 8.4% (96/1137), with a significant difference from the control groups consisting of normal individuals and autoimmune disease patients (p<0.05). Of 1137 cancer sera, 546 were also tested for the presence of antibodies to p53 and c-myc. Frequencies of antibodies to p53 and c-myc were 11.5 and 12.3%, respectively. Although antibodies to either one of three antigens do not reach levels of sensitivity, which could become routinely useful in diagnosis, it appears that there are different patterns of antibody frequency in individual cancer type. The results also indicated that when the presence of antibody to any one of these three antigens was considered, the cumulative frequency was increased to 27.3% (149/546) for the total group of cancer patients. It became apparent from our data that the combination of antibodies might acquire higher sensitivity.

Antibodies, Neoplasm↗

Immunization of rats with polypeptide chains from torpedo acetylcholine receptor causes an autoimmune response to receptors in rat muscle.

Four polypeptide chains were purified from acetylcholine receptor of Torpedo californica electric organ. Their apparent molecular weights were 64,000, 57,000, 49,500, and 38,000. Rats immunized with any of the four chains produced antibodies that crossreacted with rat muscle receptors in vivo. Specificities of anti-chain sera were evaluated in vitro by reaction with native receptor solubilized from electric organs and muscles of several species and by inhibition of this reaction with the purified polypeptide chains. The chains are immunologically distinct from one another. Antigenic determinants comparable to each chain of torpedo receptor are found in receptor from both rat and human muscle. At least part of each of these determinants is exposed on the extracellular surface of the muscle membrane. The most immunogenic determinants on native receptor are lost on denaturation to polypeptide chains. Its component peptides are much less immunogenic than native receptor, and induce antibodies of different specificity. Anti-receptor antibodies of many specificities can cause experimental autoimmune myasthenia gravis.

Acetylcholine↗

Antigen-induced inhibition of autoimmune response to rat male accessory glands: distinct role of I-A and I-E-positive peritoneal cells.

The present report describes the structural and functional characteristics of the population of peritoneal cells (PC) from rats injected intraperitoneally (i.p.) 2 h or 24 h previously with a suppressor dose of a purified fraction (FI) of rat male accessory glands (RAG: FI-PC2h and FI-PC24h, respectively). Both populations of PC showed the presence of the autoantigens of RAG on their membrane. The study of cell surface marker showed increase of OX17 (I-E) in FI-PC2h and OX6 (I-A) in FI-PC24h. I.p. injection of FI-PC2h 10 and 3 days prior to immunization with chemically modified (diazotized arsanilic and sulfanilic acid) RAG (MRAG) in complete Freund's adjuvant induced suppression of the delayed-type hypersensitivity (DTH) response to MRAG, whereas the i.p. injection of FI-PC24h induced potentiation of DTH response to MRAG when compared with controls (animals injected 10 and 3 days prior to immunization with PC from rats injected i.p. with an unrelated antigen). The treatment of FI-PC2h with OX17 and FI-PC24h with OX6 prior to the transfer blocked the suppression and potentiation described above. These findings show that the i.p. injection of an FI of RAG at a suppressor dose induces PC with immunologically opposite characteristics, depending on the time of obtention.

Animals↗

Pulmonary inflammation induced by a recombinant Brugia malayi gamma-glutamyl transpeptidase homolog: involvement of humoral autoimmune responses.

BACKGROUND: A major allergen from the lymphatic filarial parasite Brugia malayi implicated in the pathogenesis of tropical pulmonary eosinophilia (TPE) has recently been cloned and identified as the homolog of the membrane-bound mammalian enzyme gamma-glutamyl transpeptidase (gamma-GT). Patients with acute TPE show autoreactive antibodies against endogenous gamma-GT from the pulmonary epithelium. MATERIALS AND METHODS: Recombinant B. malayi gamma-GT, alone or adsorbed to aluminium hydroxide (AL), was used in a BALB/c mouse model to analyze its antigenic/allergenic potential, its potential to induce pulmonary inflammation, and its capacity to induce autoreacting antibodies. RESULTS: Mice immunized with B. malayi gamma-GT showed significant levels of gamma-GT-specific IgG1, IgG2a, IgG3, IgA, IgE antibodies, and mild blood eosinophilia, even in the absence of adjuvant. Intranasal challenge with B. malayi gamma-GT induced peribronchial and perivascular inflammation characterized by a mixed infiltrate of lymphocytes, neutrophils, eosinophils, and macrophages. Both IL-4 and IFN-gamma were detected in the peripheral blood and in the bronchoalveolar lavage fluid of immunized and intranasally challenged mice. Histological analysis of murine lungs using affinity-purified antibodies from mice immunized with the parasite's gamma-GT revealed the presence of autoimmune antibodies against pulmonary epithelium. Western blot analysis identified the 55 kDa heavy chain subunit of the murine gamma-GT as the target of autoreactive/crossreacting antibodies. CONCLUSION: Our data from the in vivo mouse model demonstrate the potent allergenicity/antigenicity of B. malayi gamma-GT, and its capacity to induce pulmonary inflammation upon intranasal challenge. This leads to breakdown of tolerance against endogenous murine gamma-GT. Thus, humoral autoimmunity against the airways epithelium may contribute to the pathogenesis of TPE.

Animals↗

Induction of in vitro autoimmune responses by mononuclear blood cells in Hashimoto's thyroiditis.

T cell proliferative responses were generated in vitro in lymphocytes from Hashimoto's thyroiditis (HT) patients using antigen presenting cells (APC) separated by fibronectin adherence and culture in serum free medium (SFM). HT cells were found to respond to the heterologous antigen, keyhole limpet haemocyanin (KLH), as well as to the homologous antigens thyroglobulin (Tg), myelin basic protein (MBP), myoglobin (Mb), and sarcolemma (Sl). Positive responses were dependent upon gamma-interferon, interleukin 1, and interleukin 2. The ratio of HT T helper/inducer cells to T suppressor/cytotoxic cells was elevated at the inception of culture, and further increased during the 9 day culture period. Our data show a generalized defect in self-tolerance by HT T cells which may have been revealed by preincubation of antigen with restricted numbers of APC and subsequent culture in SFM.

Adolescent↗

Anti-Ro/SSA associated recurrent annular erythema: autoimmune response to recombinant 60- and 52-kDa Ro/SSA proteins.

Recurrent annular erythema associated with anti-Ro/SSA antibody response has recently been recognized as a distinct clinical entity. Serum samples from 15 anti-Ro/SSA positive patients with recurrent annular erythema were tested by enzyme-linked immunosorbent assay (ELISA) for reactivity with full-length recombinant human 60-kDa and 52-kDa Ro/SSA proteins. All the 15 sera were positive for anti-60-kDa Ro/SSA, and 11 sera (73.3%) contained anti-52-kDa Ro/SSA. These results suggest the importance of 60-kDa polypeptide component of the Ro/SSA particle as a potential target in anti-Ro/SSA associated annular erythema.

Adolescent↗

An Epstein Barr virus-related cross reactive autoimmune response in multiple sclerosis in Norway.

In studies of patients in Norway with multiple sclerosis (MS), we have found cross reactive autoantibodies related to the Epstein Barr virus nuclear antigen-1 (EBNA-1). The MS patients had elevated IgG antibody to EBNA-1, as measured by reactivity with a synthetic glycine/alanine peptide, P62, which represents the glycine/alanine repeat in EBNA-1. The mean titer of anti-P62 in patients with acute relapse at the time of assay was significantly higher than in the remaining patients. Patients with remitting/relapsing MS also had elevated autoantibody to a lymphocyte protein, p542, cross reactive with EBNA-1 through a glycine/serine epitope. High titered anti-EBNA-1 antibodies from some MS, as well as from some SLE sera, were shown to cross react with 80-82 kDa and 60 kDa proteins in neuroglial cells.

Amino Acid Sequence↗

Apoptotic splenocytes drive the autoimmune response to poly(ADP-ribose) polymerase 1 in a murine model of lupus.

Although defects in apoptosis have been linked to both human and murine lupus, the exact mechanisms remain unknown. Moreover, it is not clear whether such defects are primary or secondary events in disease pathogenesis. To address these issues, we used an induced model of murine lupus, the parent-into-F(1) model of chronic graft-versus-host disease (cGVHD) in which a lupus-like phenotype highly similar to human systemic lupus erythematosus is reliably induced in normal F(1) mice. We addressed the role of nuclear Ags modified by caspases during apoptosis as potential targets of the autoantibody response and our results identify poly(ADP-ribose) polymerase 1 (PARP-1) as a frequently targeted autoantigen. Additional proteins cleaved during apoptosis were also targeted by the immune response. Importantly, female mice exhibited significantly greater numbers of apoptotic cells in germinal centers and higher serum anti-PARP-1 Ab levels compared with male cGVHD mice. Serum anti-PARP-1 levels in male cGVHD mice could be elevated to levels comparable to those of female cGVHD mice by the injection of apoptotic syngeneic F(1) splenocytes early in the disease course. These results provide a mechanism by which lupus autoantibodies target apoptotic molecules. Specifically, T cell-driven polyclonal B cell activation characteristic of systemic lupus erythematosus is sufficient to saturate otherwise normal apoptotic clearance mechanisms, permitting apoptotic material to accumulate, serve as autoantigens, and drive autoantibody production.

Animals↗

Comparison of rheumatoid factors of rheumatoid arthritis patients, of individuals with mycobacterial infections and of normal controls: evidence for maturation in the absence of an autoimmune response.

We analyzed the rheumatoid factors (RF) produced by Epstein-Barr virus-transformed monoclonal B cells established from four patients with rheumatoid arthritis (RA), three individuals with a history of Mycobacterium tuberculosis (TB) and four normal controls (NI). Fifty-eight RF were analyzed for specific activity (international units-RF/microgram) for the Fc part of IgG and their interaction with tetanus toxoid (TT) and DNA (polyspecificity). Furthermore, we sequenced the V-D-J heavy chain region of 16 (9TB-/7RA-) RF. Significant differences were observed between the NI-RF and the TB- and RA-RF. While the RF repertoire of normal individuals comprised of low-avidity RF of which the majority (15/17) were polyspecific, more than half of the TB- and RA-RF were monoreactive. Furthermore, the monospecific TB- and RA-RF were of significantly higher avidity than the NI-RF (RA > TB > > NI). With respect to polyspecificity specificity, the RF in the three groups were comparable: the interaction with DNA, TT as well as with Fc was inhibited either by an increase of the ionic strength to 0.3-0.5 M NaCl or by addition of the polyanion dextran sulfate, indicating that the antibodies interacted with similar anionic epitopes shared by the three antigens. Analysis of the V-D-J heavy chain regions showed significant differences between the respective RF. The salt-sensitive binding was highly correlated with the presence of arginine in the complementarity-determining region 3 (CDR3). Furthermore, whereas the polyspecific RF consisted predominantly of germ-line encoded antibodies, the genes of the monospecific RA/TB-RF were somatically mutated (RA > TB). It is therefore likely that maturation of RF can be initiated by chronic infections and that monospecific, somatically mutated RF are not a unique characteristic of autoimmune diseases.

Adolescent↗

Distinctive patterns of autoimmune response induced by different types of mineral oil.

Although mineral oils are generally considered nontoxic and have a long history of use in humans, the mineral oil Bayol F (incomplete Freund's adjuvant, IFA) and certain mineral oil components (squalene and n-hexadecane) induce lupus-related anti-nRNP/Sm or -Su autoantibodies in nonautoimmune mice. In the present study, we investigated whether medicinal mineral oils can induce other types of autoantibodies and whether structural features of hydrocarbons influence autoantibody specificity. Female 3-month-old BALB/c (16-45/group) mice each received an i.p. injection of pristane (C19), squalene (C30), IFA, three medicinal mineral oils (MO-F, MO-HT, MO-S), or PBS. Sera were tested for autoantibodies and immunoglobulin levels. Hydrocarbons were analyzed by gas chromatography/mass spectrometry. IFA contained mainly C15-C25 hydrocarbons, whereas MO-HT and MO-S contained C20-C40, and MO-F contained C15-C40. Pristane and n-hexadecane were found in IFA (0.17% and 0.10% w/v, respectively) and MOs (0.0026-0.027%). At 3 months, pristane and IFA induced mainly IgG2a, squalene IgG1, and MOs IgG3 and IgM in sera. Anti-cytoplasmic antibodies were common in mice treated with MO-F, as well as those treated with pristane, squalene, and IFA. Anti-ssDNA and -chromatin antibodies were higher in MO-F and MO-S than in untreated/PBS, squalene-, or IFA-treated mice, suggesting that there is variability in the induction of anti-nRNP/Sm versus -chromatin/DNA antibodies. The preferential induction of anti-chromatin/ssDNA antibodies without anti-nRNP/Sm/Su by MO-S and MO-F is consistent with the idea that different types of autoantibodies are regulated differently. Induction of autoantibodies by mineral oils considered nontoxic also may have pathogenetic implications in human autoimmune diseases.

Alkanes↗

Epitope mapping of the cloned human autoantigen, histidyl-tRNA synthetase. Analysis of the myositis-associated anti-Jo-1 autoimmune response.

Autoantibodies that bind aminoacyl-tRNA synthetases are strongly associated with the human inflammatory myopathies polymyositis and dermatomyositis, but their molecular origins and relationship to pathogenesis are not known. To address these issues, we wished to identify the autoantigenic epitopes which react with these autoantibodies and to this end, we previously isolated a full length cDNA clone encoding the target Ag recognized most frequently by myositis sera, histidyl-tRNA synthetase (HRS). In the present study, we have analyzed the HRS autoepitopes by two amino acid insertion linker mutagenesis of HRS proteins expressed in Cos 1 cells. A series of mutant HRS cDNA were constructed and the expressed proteins were tested for enzyme activity and for immune reactivity with a panel of sera with anti-Jo-1 antibodies. Immunoblotting and immunoprecipitation analyses revealed that anti-Jo-1 antibodies recognize multiple conformation-dependent and independent epitopes on HRS and that the autoepitopes vary among different myositis patients.

Amino Acyl-tRNA Synthetases↗

Acute autoimmune response in a case of pyromellitic acid dianhydride-induced hemorrhagic alveolitis.

A 17-year-old man was occupationally exposed to pyromellitic acid dianhydride dust during the production of epoxy resin in a chemical factory. He was clinically diagnosed as having acute hemorrhagic alveolitis associated with anemia. The serologic analysis revealed a high concentration of IgG antibodies against pyromellitic acid dianhydride-treated human serum albumin (PMDA-HSA). Immunoblotting with PMDA-treated human serum as antigen and the patient's serum as the first antibody showed that additional PMDA-modified serum proteins other than HSA were recognized by the patient's IgG antibodies in the higher mol. mass range (> 67 kDa). No specific IgG could be detected against other anhydride conjugates (maleic acid, MA; phthalic acid, PA) with the exception of a reaction with the trimellitic acid anhydride-conjugated HSA (TMA-HSA). No specific IgE antibodies could be detected against any of the above mentioned antigens, but immunoblotting of the patient's serum indicated IgG4-type autoantibodies against in vitro PMDA-treated Ig molecules of normal serum proteins.

Acute Disease↗

[Humoral autoimmune responses to neurospecific proteins in rats with experimental allergic encephalomyelitis and immunomodulation with allogeneic nervous tissue].

Possible immunocorrective effect of the embryonic nervous tissue (NT) and using the model of an experimental allergic encephalomyelitis (EAE) in treating patients with demyelinizing diseases is a prospective field of research. EAE was induced by immunization of rats with the mixture of the spinal cord and BCV at paw pillows. Immunocorrective effect of the allogenic NT was studied in the animals with EAE following the intraperitoneal injection of a newborn rat's NT, namely: enriched fractions of glial and neuronal cell populations. Both intact and EAE animals, treated with culture medium, were used as controls. The clinical signs appeared on 12-th day after EAE inducing. The severe clinical course of EAE was accompanied with statistically significant higher titers of the autoantibodies to MBP as compared with the mild clinical course. The results obtained evidence for the possible immunocorrective effect of enriched fractions of the newborn rat's nervous cells on EAE, and for immunosuppressive effect of the neuronal fraction of NT on the immunopathological processes in EAE.

Animals↗

Autoimmune response in women with endometriosis.

PROBLEM: The aim of this study was to investigate the humoral immune response to the female reproductive tissues associated with endometriosis (grades I-III) (n = 52), compared with a group of healthy fertile women (n = 6). METHOD OF STUDY: An ELISA with cultured endometrial cell lines in monolayer was used to determine the presence of anti-endometrial antibodies (AEA). For anti-zona pellucida antibodies (AZPA) assessment a conventional ELISA was employed. The presence of antibodies to human sperm (ASA) was performed by the tray agglutination test (TAT). RESULTS: Endometriosis grade III was associated with AEA in serum in the 45.4% of patients. The presence of AEA in serum is correlated to endometriosis severity. The 8.7% of women with endometriosis showed ASA, and the 10.9% of them were positive for AZPA. Antibodies specific for endometrial cells do not show reaction to any gamete antigen (sperm or oocyte), suggesting that they are not cross reactive. CONCLUSIONS: Severity of endometriosis is correlated with high titers of AEA.

Adult↗

Maternal-fetal interactions on the regulation of the autoimmune response.

Adult female rats were immunized with 5 mg or 25 mg of modified rat male accessory glands (MRAG) incorporated to complete Freund's adjuvant (CFA) before, during, and after pregnancy. The mothers and litters were exchanged between the experimental and normal groups. The offspring were brought up to 20 days of age and immunized with 5 mg of MRAG-CFA and 5 mg of human serum albumin (HSA)-CFA. Anti-MRAG antibodies were detected in the offspring brought up by the immunized mothers and the titers were similar to those of the foster mothers whereas in the offspring of the experimental group fostered by normal mothers antibodies to MRAG were not detected. The DTH performed in the offspring 13 days after the immunization was significantly diminished in male and female offspring from the 5 mg and 25 mg experimental group fostered by normal mothers (P less than 0.0005 for all groups). Similar results were found when the offspring from normal mothers were suckled by mothers immunized with MRAG-CFA. To assess whether MRAG or HSA administered to female rats reached the offspring via the placenta or the milk, female rats were immunized with 3 mg of 125I-MRAG-CFA or with 3 mg of 125I-HSA-CFA. When radioactivity was measured in neonates (n = 11) that were suckled by the 125I-MRAG-CFA immunized mothers, the specific activity was 116 in stomach (0.4 micrograms of MRAG) and 940 in the total organs (3.8 micrograms of MRAG).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Autoimmune response to advanced glycosylation end-products of human LDL.

Advanced glycosylation end-products (AGEs) are believed to play a significant role in the development of vascular complications in diabetic patients. One such product, AGE-LDL, has been shown to be immunogenic. In this report, we describe the isolation and characterization of human AGE-LDL antibodies from the sera of seven patients with Type 1 diabetes by affinity chromatography using an immobilized AGE-LDL preparation that contained primarily the AGE N epsilon (carboxymethyl)lysine (CML, 14.6 mmol/mol lysine), and smaller amounts of N epsilon (carboxyethyl)lysine (CEL, 2.7 mmol/mol lysine). The isolated antibodies were predominantly IgG of subclasses 1 and 3, and considered proinflammatory because of their ability to promote Fc gamma R-mediated phagocytosis and to activate complement. We determined dissociation constants (Kd) for the purified antibodies. The average Kd values (4.76 +/- 2.52 x 10(-9) mol/l) indicated that AGE-LDL antibodies are of higher avidity than oxidized LDL antibodies measured previously (Kd = 1.53 +/- 07 x 10(-8) ml/l), but of lower avidity than rabbit polyclonal LDL antibodies (Kd = 9.34 x 10(-11)). Analysis of the apolipoprotein B-rich lipoproteins isolated with polyethylene glycol-precipitated antigen-antibody complexes from the same patients showed the presence of both CML and CEL, thus confirming that these two modifications are recognized by human autoantibodies. A comparative study of the reactivity of purified AGE-LDL antibodies with CML-LDL and CML-serum albumin showed no cross-reactivity.

Autoantibodies↗

Sequence similarity and structural homologies are involved in the autoimmune response elicited by mouse hepatitis virus A59.

The features of autoantibodies (autoAb) to liver fumarylacetoacetate hydrolase (FAH) elicited in mice infected with mouse hepatitis virus (MHV) were studied by ELISA and western-blot competition assays. All sera tested contained Ab to cryptic FAH epitopes according with results from western-blot tests, whereas ELISA data indicated that some of these same sera did recognize native epitopes of the autoantigen (autoAg). Such differences were detected in individual sera from various mouse strains, and were ascribed to the fact that proteins insolubilized on solid supports expose a variety of conformational and cryptic antigenic determinants. On the other hand, whereas results from both experimental protocols showed that anti-MHV Ab did not cross-react with the soluble autoAg, the opposite situation did not show analogous results. Thus, binding of autoAb to insolubilized FAH could be inhibited by MHV depending on the mouse serum or the experimental protocol used. Additionally, a set of synthetic homologous peptides from mouse FAH and various viral proteins was employed to analyze the Ab repertoire of MHV-infected mice. Results indicated that two homologous peptides were recognized by most Ab: the N-terminal sequences (1-10) from FAH and the nucleocapside, both sharing 50% of identity, and sequence 2317-2326 of the RNA polymerase, a peptide showing 30% of identity with FAH 11-20. Results indicated that MHV-infection triggers at least three distinct Ab populations: anti-MHV, anti-FAH and cross-reacting Ab. This cross-reaction implies either sequential or conformational epitopes from both the viral proteins and the autoAg and may differ between individuals.

Animals↗