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PubMed1983

Murine lupus nephritis. Effects of glucocorticoid on circulating and tissue-bound immunoreactants.

We investigated the effects of methylprednisolone on immunoreactants of plasma and kidney to determine factors that might be relevant to the arrest of murine lupus nephritis. At the onset of nephritis, at about 5 months of age, the mice were divided in two groups and received either methylprednisolone or saline injections for 12 weeks. Before and after therapy (or saline injections), we determined the concentrations of plasma IgG, complement (C3), anti-DNA antibodies, Clq-reactive materials, creatinine, and urea nitrogen; in the kidneys, we assessed the relative distribution of IgG, IgM, and C3 in glomeruli, and we determined the concentration of IgG and anti-DNA activity of the eluted proteins. Our results indicated that methylprednisolone administered at the onset of nephritis preserved glomerular structure and function by decreasing the amount of tissue-bound immunoreactants and by inducing a preferential localization of immunoreactants in mesangia. Of the immunoreactants studied in plasma, a decreased concentration of IgG, but not the concentrations of anti-DNA antibodies, C3, and Clq-reactive materials, was associated with the arrest of nephritis. The anti-DNA activity in the renal eluates was very low and comparable in treated and untreated mice. Immune complex systems other than, or in addition to, DNA-anti-DNA likely play a role in the pathogenesis of murine lupus nephritis.

Animals↗

PubMed1988

A comparative immunoelectron microscopic study of typical and atypical cases of pemphigoid.

Using an immunoelectron microscopic technique we have compared the ultrastructural localization of IgG and complement (C3) in the basement membrane zone of three typical cases of bullous pemphigoid and three atypical variant cases (nodular, polymorphic and localized pemphigoid, respectively). There was no significant difference in the in vivo ultrastructural localization of these immunoreactants between the typical and the atypical cases of pemphigoid. In all cases IgG and C3 were detected between the basilar surface of the basal keratinocytes and the basal lamina. Moreover, the in vitro binding sites of circulating anti-basement membrane zone antibodies were identical in the case of nodular pemphigoid and a typical pemphigoid as control. We also observed that immunoreactants were not deposited beneath melanocytes.

Aged↗

PubMed2005

[Study of huchang qingfei pellets on immune function in rats infected with Mycoplasma pneumoniae].

OBJECTIVE: To study the effects and mechanism of Huchang Qingfei pellets on immune function in rats infected with mycoplasma pneumoniae. METHOD: A rat model of mycoplasmal pneumonia (MP) was developed in repeated intranasal infectious routes and then the humoral and cellular immunocompetences were detected by radioimmunoassay, immune-turbidimetry and flow cytometry. RESULT: The levels of serum IgG,IgM and IL-2, IL-6 were enhinced obviously, the complement C3 and TNF-alpha were decreased and the ratio of CD4+ /CD8+ was improved significantly in the Huchang groups as compared with MP model group. CONCLUSION: Huchang Qingfei pellets can reinforce immune function via preventing both cellular and humoral immunity from depression in the rats with MP.

Animals↗

PubMed1987

Biosynthesis and secretion of the third component of complement by human endothelial cells in vitro.

The third component of complement (C3) is synthesized and released by cultured human capillary endothelial cells. After the incubation of cells in a methionine-free medium containing 35S-methionine for 48 hr, culture supernatants were immunoprecipitated with anti-human C3 serum. SDS solubilization and 2-ME reduction of the immunoprecipitates, followed by separation with SDS-polyacrylamide gel electrophoresis and autoradiography, revealed two major bands comparable to those of the alpha and beta chains of human C3. The content of C3 in the culture medium harvested at different time-intervals was determined by ELISA. The C3 secretion rate was about 250 ng/10(6) cells/5 days in the primary culture medium and 75 ng/10(6) cells/5 days after seven passages. The capillary endothelial cells described here have factor VIIIRAg specific for endothelial cells, and exhibit ring formation resembling capillary lumina, but they lack Weibel-Palade bodies.

Antigens↗

PubMed1984

Immunoreactants in murine lupus nephritis: effects of azathioprine.

We studied the effects of azathioprine on immunoreactants of plasma and kidney to determine factors that might be relevant to the arrest of nephritis in NZB/W mice. Before and after a course of azathioprine (or saline injections) for 12 weeks, we determined the plasma concentrations of IgG, complement (C3), antiDNA antibodies, and C1q-reactive materials; in the kidneys, we studied deposits of IgG, IgM, and C3 in glomeruli, and we determined the concentration of IgG and antiDNA activity of the eluted proteins. Azathioprine administered at the onset of nephritis preserved glomerular structure and function; the amount of tissue-bound immunoreactants was decreased overall, and immunoreactants were preferentially localized in mesangial areas. A decreased plasma concentration of IgG, but not the concentrations of antiDNA antibodies, C3 and C1q-reactive materials, was associated with the arrest of nephritis. The antiDNA activity in renal eluates was very low and was comparable in treated and untreated mice. Immune complex systems other than, or in addition to, DNA-antiDNA likely play a role in the pathogenesis of murine lupus nephritis.

Animals↗

PubMed2001

Schistosoma japonicum cathepsin D aspartic protease cleaves human IgG and other serum components.

Recombinant cathepsin D aspartic protease of Schistosoma japonicum cleaved human IgG in vitro in a time and dose-dependent manner. Optimal cleavage was seen at pH 3.6-4.5; modest cleavage remained at pH 5.0, and no cleavage was detected above pH 5.0. Amino terminal sequencing of the major cleavage fragments of human IgG identified a Fab fragment from the VH1 domain, and 2 cleavage sites in the CH2 domain below the hinge region. The P1 and P1' residues at the 2 CH2 cleavage sites were Phe254-Leu255 and Leu325-Thr326, indicating a preference by the schistosome protease for bulky hydrophobic residues flanking the scissile bond. No cleavage of the immunoglobulin light chain was detected. In addition, the recombinant schistosome protease indiscriminately degraded the human serum proteins complement C3 and serum albumin into numerous small fragments. These results demonstrate specific cleavage of human IgG by the recombinant schistosome aspartic protease, and highlight the broad range digestive specificity of the enzyme which may play a role in the degradation of host serum proteins ingested as part of the schistosome bloodmeal.

Amino Acid Sequence↗

PubMed2005

Available carbon source influences the resistance of Neisseria meningitidis against complement.

Neisseria meningitidis is an important cause of septicaemia and meningitis. To cause disease, the bacterium must acquire essential nutrients for replication in the systemic circulation, while avoiding exclusion by host innate immunity. Here we show that the utilization of carbon sources by N. meningitidis determines its ability to withstand complement-mediated lysis, through the intimate relationship between metabolism and virulence in the bacterium. The gene encoding the lactate permease, lctP, was identified and disrupted. The lctP mutant had a reduced growth rate in cerebrospinal fluid compared with the wild type, and was attenuated during bloodstream infection through loss of resistance against complement-mediated killing. The link between lactate and complement was demonstrated by the restoration of virulence of the lctP mutant in complement (C3(-/-))-deficient animals. The underlying mechanism for attenuation is mediated through the sialic acid biosynthesis pathway, which is directly connected to central carbon metabolism. The findings highlight the intimate relationship between bacterial physiology and resistance to innate immune killing in the meningococcus.

Animals↗

PubMed1986

Circulating immune complexes, insulin antibodies, and deposits of immunoglobulins in the skin in diabetes.

Sixty-five insulin-dependent diabetes mellitus (IDDM) patients at the Steno-Memorial Hospital entered the present study. Of these, 43.1 percent had one or more late diabetic complication, 19.3 percent had circulating immune complexes (CIC)--there was a tendency for CIC to be related to late diabetic complications (P = 0.1) - and 16.9 percent had elevated total S-IgG. Elevated S-IgG values were related neither to CIC, to complications, nor to IgG deposits in the skin. Three patients had elevated total S-IgM, IgD and, IgE, respectively. No patients had elevated total S-IgA. Insulin antibodies were present in 41.9 percent. They were related to neither CIC nor clinical complications. No patients had rheumatoid factors (RF) or granulocyte-specific antinuclear antibodies (ANA). 12.3 percent had a low titre of organ non-specific ANA. No relationship could be established between ANA and complications or CIC. As regards skin deposits IgG was present at the dermo-epidermal junction zone (DEJ) and/or in the dermal vessels in 75.4 percent of the patients; IgA was present in 35.4 percent; and IgM in 32.3 percent. IgD and IgE were absent in all patients. Fibrinogen deposits were found in 80 percent and complement C3 in 32.3 percent. No correlation was found between skin deposits and CIC, on one hand, or clinical complications, on the other. From the present work, we conclude that humorally mediated immunological processes are active in IDDM. However, the exact role of this activity still remains to be defined.

Adolescent↗

PubMed1982

Immunohistological study of human lungs by immunoperoxidase technique.

An unlabelled antibody peroxidase-antiperoxidase method for the detection of IgG, IgM, complement (C3 and Clq), fibrinogen and albumin was applied to routinely processed paraffin sections of lung from 27 cases. The results in 11 cases were compared with those obtained by immunofluorescence using frozen sections. Tissue was obtained from surgical specimens of cases with interstitial pneumonia comprising 10 of the usual type (UIP) and three of the desquamative type (DIP). Tissue was also obtained from the specimens of cases with sarcoidosis (two cases) and granulomatous inflammation of unknown cause (one case). There were 11 control cases, nine with primary carcinoma of the lung and two with metastatic tumours of the lung. Immunoglobulins of various types and complement were seen in diseased lung tissue. Although most of these deposits were probably due to a non-immunological mechanism there was evidence of the possible implication of immune complexes in three cases of UIP and in the interstitial pneumonia present in the two cases of sarcoidosis. The immunoperoxidase technique is a more sensitive method than immunofluorescence and has the additional advantage of the easy identification of the precise sites of the various deposits.

Adult↗

PubMed1983

An ACTH-induced renal glomerular lesion in the mouse: immunofluorescence microscopy.

Mice were injected with adrenocorticotropic hormone (ACTH) and the glomerular lesion that was induced was studied by light and immunofluorescence microscopy. By light microscopy, kidneys from ACTH-treated mice showed typical ACTH-induced glomerular lesions. Immunofluorescence of kidneys from ACTH-treated mice revealed intense staining for IgG and IgM in the extraglomerular mesangium (EGM), in Bowman's space, and in the ascending thick limb of Henle near the macula densa. Staining for immunoglobulins was unchanged after treatment with acid buffer. Immunoreactivity for complement (C3) was confined largely to the EGM and Bowman's space. Staining for albumin was almost exclusively in Bowman's space or the peripheral glomerular tuft in discrete aggregates. The above patterns of IgG, IgM, C3 and albumin were seen in control mice, although much less frequently. The results show that in mice, treatment with ACTH results in the increased accumulation of plasma proteins in the juxtaglomerular apparatus (JGA). This effect may reflect a role for the JGA in the normal clearing of plasma proteins from the glomerulus and/or directly from the blood.

Adrenocorticotropic Hormone↗

PubMed1996

[The immunologic influence of clinical implantation of the machinable bioactive glass ceramics (MBGC)].

The levels of the immunoglobulins (IgG, IgA, IgM), complements (C3, C4) and circulating immune complex (CIC) of the patients were measured before and after implantation of the machinable bioactive glass ceramics in maxillofacial surgery. No significant changes were detected. The results indicate that the patients' immunologic function and status were not affected by the material and machinable bioactive glass ceramics is good bloodcompatibility.

Adolescent↗

PubMed2005

Effects of eccentric exercise-induced muscle injury on blood levels of platelet activating factor (PAF) and other inflammatory markers.

It has been reported that exercise with eccentric contractions can induce damage and inflammation in human muscle tissue, the severity of which depends on the duration and the intensity of exercise. Platelet activating factor (PAF) is a potent inflammatory mediator implicated in a series of pathophysiological conditions. We sought to investigate the relationship between PAF and eccentric exercise induced muscle damage. Thirteen healthy, recreationally active male subjects (27.5+/-3.78 year) performed 36 maximum voluntary eccentric contractions on a motorized muscle dynamometer using the elbow flexor muscles of the non-dominant arm. Venous blood samples were collected immediately before and after exercise at 2, 24, 48, 72 and 96 h. PAF was isolated, purified and determined by a platelet aggregation assay. Serum levels of creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive protein (CRP) and complement C3 (C3), plasma level of fibrinogen and whole blood level of leukocytes (and their subsets) were determined. Established indicators of muscle damage as maximum isometric torque (MIT), range of motion (ROM), relaxed arm angle (RANG), flexed arm angle (FANG), arm circumference (CIRC) and muscle soreness were also measured at the same time points. PAF, leukocytes, CK and LDH were elevated after exercise, while other biochemical parameters such as CRP, C3 and fibrinogen were unchanged. We also observed an inverse association between PAF and MIT and ROM, as well as a positive association with other markers of muscle injury, i.e. CK, LDH, FANG and CIRC (all P's<0.05). Our findings may imply a role for PAF in the mechanism of eccentric exercise induced muscle damage.

Adult↗

PubMed2003

Five month persistence of Helicobacter pylori infection in guinea pigs.

Seven Dunkin-Hartley guinea pigs were infected with the Sydney strain of H. pylori (SS1). Gastric histopathology was evaluated and serum antibody response to H. pylori cell-surface proteins was analysed by enzyme immunoassay (EIA) and immunoblot. Tissue and faecal samples from five control animals were analysed for the presence of naturally occurring Helicobacter spp. infection by culture and Helicobacter genus-specific PCR. The H. pylori infection persisted for 5 months, in most animals accompanied by a histologically severe antral gastritis, exhibiting focal degeneration and necrosis of gastric crypt epithelium. Increased numbers of mitotic figures were observed in the gastric epithelium, indicating a regenerative process. Infected animals displayed specific antibodies towards H. pylori cell-surface proteins in immunoblot, whereas EIA was of dubious value creating false-positive results. Serum complement C3 and cholesterol levels appeared to be elevated in infected animals. Helicobacter spp. infection was not detected in the control animals. The persistent infection, accompanied by severe gastritis and a prominent serum antibody response, and the apparent absence of a natural Helicobacter spp. infection makes the guinea pig model useful in H. pylori research.

Animals↗

PubMed1999

Escherichia coli msbB gene as a virulence factor and a therapeutic target.

A mutation in the msbB gene of Escherichia coli results in the synthesis of E. coli lipopolysaccharide (LPS) that lacks the myristic acid moiety of lipid A. Although such mutant E. coli cells and their purified LPS have a greatly reduced ability to stimulate human immune cells, a minor reduction in the mouse inflammatory response is observed. When the msbB mutation is transferred into a clinical isolate of E. coli, there is a significant loss in virulence, as assessed by lethality in BALB/c mice. When a cloned msbB gene is provided to functionally complement the msbB mutant, virulence returns, providing direct evidence that the msbB gene product is an important virulence factor in a murine model of E. coli pathogenicity. In the genetic background of the clinical E. coli isolate, the msbB mutation also results in filamentation of the cells at 37 degrees C but not at 30 degrees C, a reduction in the level of the K1 capsule, an increase in the level of complement C3 deposition, and an increase in both opsonic and nonopsonic phagocytosis of the msbB mutant, phenotypes that can help to explain the loss in virulence. The demonstration that the inhibition of msbB gene function reduces the virulence of E. coli in a mouse infection model warrants further investigation of the msbB gene product as a novel target for antibiotic therapy.

Acyltransferases↗

PubMed1992

Biological activities of polyethylene-glycol immunoglobulin conjugates. Resistance to enzymatic degradation.

Serum IgG has been covalently bonded to polyethylene glycols of either 2000 or 8000 molecular weight to produce immunoglobulin conjugates with 4.4-27.2% of primary amines bonded to polyethylene glycol. Polyethylene glycol immunoglobulin conjugates retain the ability, comparable to native IgG, to bind to a range of protein and microbial antigens, but have a reduced ability to bind to Fc receptors or to fix complement C3. When 6.8% or more of available primary amines are conjugated, IgG-PEG conjugates are impervious to trypsin, and at 14% or more conjugation, more resistant than native IgG to pepsin and chymotrypsin. We suggest that PEG-Ig conjugates may be useful for the oral treatment of various gastrointestinal diseases in which secretory humoral immunity is insufficient.

Antigens, Protozoan↗

PubMed1993

[Anaphylactoid reaction to vecuronium].

A 4 year-old male (weight 18 kg, height 100 cm) required an emergency operation for the open fracture of his left ankle. He had no history of atopy or allergics. Rapid intubation with vecuronium was planned. To shorten the onset time of vecuronium, the "priming principle" was utilized. Two minutes after the intravenous administration of vecuronium 0.25 mg as a "first dose", bronchospasm and skin rashes appeared. These symptoms resolved following the treatment with aminophylline and steroids. Immunological studies performed two weeks after the operation revealed positive intradermal test to vecuronium, low plasma IgE and elevated complement C3. These results suggest that the reaction was an anaphylactoid reaction caused by physico-chemical histamine release rather than IgE mediated type I allergic reaction. Though vecuronium have a low potential for histamine release, it is important to note that adverse reactions can occur even in patients who have no history of atopy or allergic disorders.

Aminophylline↗

PubMed1989

Cellular and humoral immune responses in Campylobacter pylori-associated chronic gastritis.

Gastric cellular and humoral immune response investigated by immunoperoxidase staining of 53 antral biopsies showed significant differences in Campylobacter pylori-associated gastritis as compared with non-bacterial chronic gastritis and normal controls. IgA, secretory component, and complement C3 coated bacilli were seen in all cases of active chronic gastritis. C3 was always associated with coating by IgA, IgM, or both, which were rarely seen in gastritis without polymorphonuclear neutrophil infiltration. Intraepithelial mononuclear cellular infiltration was seen in 18 of 26 cases of C. pylori-associated chronic gastritis. The intraepithelial mononuclear cells stained positively for T cells and histiocytes.

Antibody Formation↗

PubMedDate not supplied

Antitumor activity and immunological properties of marine algal polysaccharides, especially fucoidan, prepared from Sargassum thunbergii of Phaeophyceae.

Marine algal polysaccharide, GIV-A from Sargassum thunbergii markedly inhibited the growth of Ehrlich ascites carcinoma at the dose of 20 mg/kg per day X10 with no sign of toxicity in mice. GIV-A is suggested to be a hexouronic acid containing L-fucan sulfate, fucoidan by the analyses of physicochemical properties and IR- and NMR-spectra. The results of carbon clearance activity with fucoidan demonstrated that it is acting as a so-called activator of the reticuloendothelial system. Fucoidan enhanced the phagocytosis and chemiluminescence of macrophages. By the immunofluorescent method, binding of the third component of complement (C3) cleavage product to macrophages and the proportion of C3 positive cells were increased. In crossed immunoelectrophoresis, human serum C3 was converted by fucoidan and appeared as the 3rd peak (converted C3). The height of the 3rd peak was directly proportional to the doses of fucoidan. The residual CH50 units of human serum decreased dose-dependently. These results suggest that the antitumor activity of fucoidan is related to the enhancement of immune responses. The present results indicate that fucoidan may open new perspectives in cancer chemotherapy.

Animals↗