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PubMed1990

Characterization of the mouse thrombospondin gene and evaluation of the role of the first intron in human gene expression.

We have isolated the mouse thrombospondin (TS) gene and determined the DNA sequence of the first nine exons and eight introns. Comparison with the human cDNA sequence reveals a high degree of conservation in coding sequences. Exon 3 of the mouse gene, which encodes the heparin-binding domain of TS, has a higher degree of nucleotide substitution than the other exons, but the distribution of charged and hydrophobic amino acids found in the human protein is generally conserved. DNA and protein sequences in exons 6-9, which encode a procollagen homology and motifs very similar to those found in at least two malarial parasite proteins, are highly conserved. The first two of the three malarial homologies in TS, which are also found in properdin and in components C6-9 of the lytic complement complex, are each encoded by a separate exon (8 and 9) in the mouse gene. Since the sequence data did not reveal substantial similarity in sequence between intron I in the human and mouse genes, we have reexamined the role of the first intron in the transcriptional regulation of the human TS gene. In accord with published studies (Laherty, C.D., Gierman, T.M., and Dixit, V.M. (1989) J. Biol. Chem. 264, 11222-11227), we find that deletion of some intronic segments from TS-chloramphenicol acetyltransferase (CAT) constructs reduces CAT activity in NIH 3T3 cells. However, deletion of the same sequences from TS-bovine growth hormone constructs does not affect the expression of bovine growth hormone in these cells. We conclude that differences in the activity of TS-CAT constructs reflect post-transcriptional differences that are peculiar to the resulting chimeric transcripts and that there is currently no evidence for a transcriptional enhancer in the first intron of the human TS gene.

Amino Acid Sequence↗

PubMed1989

Human IgA1 initiates complement-mediated killing of Neisseria meningitidis.

We studied the effect of human IgA1, the predominant IgA subclass in serum, on C-mediated killing of Neisseria meningitidis. We purified monomeric IgA1 from normal human serum and tetravalent meningococcal polysaccharide vaccinate serum by using the following successive chromatographic steps: jacalin lectin affinity, Superose 12 FPLC gel filtration, Mono Q FPLC anion exchange, and anti-IgG affinity. SDS-PAGE, ELISA, and Western immunoblot analyses of the IgA1 detected no trace of contaminating IgG or IgM. IgA1 initiated partial or complete lysis (62 to 100%) of nine group C strains by using either normal, hypogammaglobulinemic, factor B-depleted, or properdin-deficient human serum as a C source, but IgA1 was unable to effect killing in serum chelated with 10 mM MgCl2 and 10 mM EGTA. Lytic activity was dependent on the group C strain and the source of the IgA1; neither IgA1 preparation was bactericidal for all nine strains. Removal of the Fc portion of IgA1 with pepsin completely abolished bactericidal activity. We purified and radiolabeled C component C3, and found that IgA1 did not increase C3 deposition. With the use of a group C polysaccharide ELISA, we found that the vaccinate IgA1 had a high titer of group C polysaccharide antibody, whereas the IgA1 purified from normal human serum had no detectable group C polysaccharide specificity. Absorption of the vaccinate IgA1 with alum-bound group C polysaccharide did not affect the killing of a sensitive strain, but it did potentiate the killing of a previously resistant strain. Western immunoblots of whole cell lysates, outer membrane complex, and purified lipooligosaccharide showed that the bactericidal IgA1 was specific for several outer membrane proteins. Four of the proteins recognized by both IgA1 preparations had apparent Mr of 29, 42, 66, and 74 kDa. We conclude that IgA1, when bound to specific outer membrane proteins, can initiate lysis of group C meningococci via the classical C pathway, and that initiation of lysis is an Fc-dependent event which occurs without an increase in C3 deposition.

Adult↗

PubMed1989

Modulation of monocyte complement synthesis by lymphocytes and lymphocyte-conditioned media.

Culture supernatants from mitogen- and antigen-stimulated human peripheral blood lymphocytes (PBL), stimulated synthesis of the second complement component (C2) by human monocytes, but not as effectively as the stimulated PBL themselves, which adhered to the monocytes and caused marked spreading. In contrast to PBL, lymphocytes isolated from the synovial membranes (SML) of patients with rheumatoid arthritis and their culture supernatants were able to stimulate C2 synthesis without exposure to mitogens or antigens. Depletion of B and T populations showed that T cells were responsible for stimulation of C2 synthesis. Further studies of synthesis rates of C2, C3 factor B (B), C1 inhibitor, and properdin (P) were undertaken, and it was found that lymphocytes and their supernatants increased synthesis of C2, B and C1 inhibitor, and reduced synthesis of C3 and P. This profile of activity was identical to that produced by the addition of recombinant gamma-interferon (rIFN-gamma) to the cultures. Furthermore the addition of a monoclonal antibody to rIFN-gamma to cultures abrogated the effects of rIFN-gamma, and almost completely reversed the effects of lymphocytes and their supernatants. Thus it appears that gamma-interferon is the lymphocyte product which is responsible for the modulation of monocyte complement synthesis. The results of studies with synovial membrane lymphocytes raise the possibility that this process occurs in vivo. Monocyte C2 had a higher specific functional activity (SpFA) than serum C2 isolated from serum or C2 produced by HepG2 cells. Monocyte C2 formed a C3 convertase which had a longer half-life than that found with both serum C2 or HepG2 C2. Thus monocyte C2 behaves like oxidized C2. Monocytes exposed to rIFN-gamma, lymphocytes or lymphocyte-conditioned medium (LCM) produced C2 which had an even higher SpFA. Although antibody to IFN-gamma prevented any increase in C2 synthesis in monocyte cultures containing lymphocytes or LCM, C2 SpFA was still increased. Thus a second lymphocyte product is responsible for this 'oxidation' effect. This production of 'oxidized' C2 by monocytes and further 'oxidation' by the action of either lymphocytes or gamma-interferon might play a significant role in the perpetuation of complement activation at sites of inflammation.

Cells, Cultured↗

PubMed1989

Electrophoretic and isoelectric focusing studies in Brazilian Indians: data on four systems.

Three-hundred ninety-nine individuals living in seven populations of two Brazilian Indian tribes (Macushi and Içana River Indians) were tested for the phosphoglucomutase 1 (PGM1), properdin factor B (BF), haptoglobin (HP), and alpha-1-antitrypsin (PI) systems. We observed significant internal heterogeneity in the two tribes for the PGM1 alleles and in the Macushi for the HP markers. Frequencies in three of the four systems (the exception being BF) also show clear differences in the Macushi and Içana River Indians. Compared with other ethnic groups, South American Indians generally present high frequencies of PGM1*1B, BF*S, HP*1S, and PI*M3. On the other hand, PGM1*1A, PI*M1, and PI*M2 are reduced, and HP*1F is absent or rare. This is the first report about HP subtypes among American Indians.

Brazil↗

PubMed1989

[Disordered immunologic reactivity in patients with chronic calculous cholecystitis].

In patients with chronic calculous cholecystitis, the number of T-lymphocytes decreased, the number of B-lymphocytes and their ability to transform into the blasts in response to stimulation of the specific bacterial antigen increased, the synthesis of immunoglobulins intensified, a titre of the antibodies specific to microflora of the biliary mucosa grew, the levels of complement, lysozyme and properdin decreased, the bacterial activity of blood serum was suppressed. It is necessary to correct these disorders in the process of preoperative preparation of the patients.

Adult↗

PubMed1989

Rapidly progressive glomerulonephritis undetected by routine school urinalysis: a case report.

A twelve year old girl with rapidly progressive glomerulonephritis (RPGN) is reported. First symptoms of renal failure developed in August 1987 just five months after a routine school urinalysis which detected no abnormalities. The patient developed end stage renal failure within 2 months of onset. Continuous ambulatory peritoneal dialysis (CAPD) was introduced to manage the renal failure, and open renal biopsy was performed simultaneously in order to elucidate the underlying renal disease in this patient. Microscopic examination of the biopsy specimen demonstrated marked formation of crescents in about 90% of the glomeruli, and some of the glomeruli were already sclerotic. Granular depositions of IgG(trace), IgA(1+), IgM(3+), properdine(3+), Clq(3+) and C3(3+) were observed by immunofluorescence staining. A definite diagnosis of rapidly progressive glomerulonephritis was made as the cause of renal failure in this patient. It was suggested that open renal biopsy is useful in diagnosing the underlying kidney disease of end stage renal failure in cases where the clinical course is relatively short.

Child↗

PubMed1989

Immunohistochemical demonstration of complement components in formalin-fixed and paraffin-embedded renal tissues.

Although there are many articles describing the detection of complement components in formalin-fixed and paraffin-embedded renal tissues, it is still difficult to obtain reproducible results. The authors determined the optimal conditions for detecting complement components in routine paraffin sections by the avidin-biotin-peroxidase complex method and concluded that proteolytic digestion of the deparaffinized sections was crucial to detect complement and to preserve tissue structures. The optimal proteolytic digestion was a 15-minute incubation at 37 degrees C in trypsin solution, 0.5 mg/ml, pH 7.6. Under these conditions, all of the complement components so far studied (C1q, C1s, C4, C3c, C3b, C5, C6, C9, and properdin) were detected without significant destruction of tissue structures in 52 renal biopsy specimens from patients with various forms of glomerulonephritis. Immunohistochemistry using the avidin-biotin-peroxidase complex method was equivalent to indirect immunofluorescence and superior to direct immunofluorescence in utility and was useful in the diagnosis of glomerular diseases.

Complement System Proteins↗

PubMed1989

[Resistance to infection. Physiology and pathology of the immune system].

The contribution of observations in congenital deficiency disorders to our understanding of normal mechanisms can hardly be overestimated, as may in particular be seen in the complex field of mechanisms aiming at maintaining the individual integrity. After a brief summary of the natural lines of defense we demonstrate a few cases with typical deficiencies, i.e. of the integuments (ciliary dyskinesia syndrome), of the phagocytes (chronic granulomatous disease = CGD), of specific immune reactions (antibody deficiency syndrome, severe combined immunodeficiency = SCID and syndromes with associated immunodeficiencies), and finally of the complement properdin system. Classification of these Primary Immunodeficiency Syndromes (= PIDS) with exceptional research potential as proposed by an expert panel of the WHO turned out to be quite useful also for the understanding of by far more frequent secondary disorders, in particular of the recently observed acquired immunodeficiency syndrome = AIDS due to an infection with the human immunodeficiency virus (= HIV). For pediatricians in industrialized countries, however, children with frequently recurring, but trivial infections are of considerable practical importance. A clear diagnostic concept is the necessary base for the proposed treatment, counselling and help for the inflicted parents.

Antibody Formation↗

PubMed1989

[Scleroderma and HLA antigens].

A possible HLA disease association was investigated in 40 patients (38 female, 2 male) with progressive systemic scleroderma (PSS), and 42 patients (32 female, 10 male) with morphea. HLA ABCDR/DQ, glyoxalase and properdin factor B (GLO and BF) phenotypes of patients were compared with 193 healthy controls. Four PSS family studies were performed. The following relative risk (rR) values were determined in PSS: A1 (1.38), A2 (1.39), B8 (1.67), B15 (3.22) and in morphea: A3 (1.43), B7 (1.39), B40 (1.81), BW60 (2.49), DR2 (2.38) and DRW8 (2.55), indicating a relatively weak, HLA-linked genetic predisposition for the manifestation of these dermatological disorders. The HLA "risk" antigens for the two clinically different subtypes of the disease are also different: raised A1/B8 frequencies such as those in our PSS group are related to high (or pathologic) immune response (autoimmune disorders). In contrast, A3 B7 DR2 elevations such as those recorded in our morphea group correlate with low immune response. Following exposition to certain suspected environmental factors (quartz, chemical solvents, drugs, viral fragments), the HLA phenotype may thus predipose some individuals--predominantly women--to different clinical patterns of the disease. HLA typing may thus be useful in clinical differential diagnosis (recent subtyping protocols) and possibly also for determination of the prognosis, i.e. HLA-B8 seems to be related to an acute, inflammatory course of PSS, and HLA-B7/DR2, to rather mild morphea patterns.

Adult↗

PubMed1989

Antistasin, an inhibitor of coagulation and metastasis, binds to sulfatide (Gal(3-SO4) beta 1-1Cer) and has a sequence homology with other proteins that bind sulfated glycoconjugates.

Antistasin, a 15-kDa salivary protein from the Mexican leech Haementeria officinalis, inhibits both blood coagulation and the metastasis of tumors (Tuszynski, G. P., Gasic, T. B., and Gasic, G. J. (1987) J. Biol. Chem. 262, 9718-9723). Antistasin binds to heparin-agarose, suggesting the protein interacts with sulfated glycoconjugates. The specificity of the interaction between antistasin and heparin was tested by measuring the binding of antistasin to various lipids and by comparing the ability of several charged glycoconjugates to inhibit binding. Of the lipids tested, antistasin binds with high affinity only to sulfatide (Gal(3-SO4)beta 1-1Cer) and does not bind to comparable levels of phospholipids, neutral glycosphingolipids, gangliosides, or cholesterol-3-SO4. The binding of antistasin to sulfatide is inhibited by dextran sulfate, fucoidan, and heparin, with I50 values of 1.5, 9.2, and 16 micrograms/ml, respectively. Comparable levels of chondroitin sulfates A, B, C, keratan sulfate, or hyaluronic acid do not inhibit binding. Comparisons of the amino acid sequences of antistasin and other sulfatide or heparin-binding proteins revealed a region of homology, based around the sequence Cys-Ser-Val-Thr-Cys-Gly-X-Gly-X-X-X-Arg-X-Arg, which may be a sulfated glycoconjugate binding domain. In addition, homologies were found with the alternate complement pathway protein properdin and coat proteins from malaria circumsporozoites and Herpes simplex I.

Amino Acid Sequence↗

PubMedDate not supplied

[The effect of Opisthorchis invasion on the clinical course and outcome of abdominal typhoid. Indicators of non-specific resistance and phagocytosis in patients with abdominal typhoid combined with chronic opisthorchiasis].

A number of non-specific resistance indices (complement, properdin, lysozyme, bactericidal activity of blood serum, phagocytosis indices) in Opisthorchis-invaded abdominal typhoid patients as well as in acute and chronic carriers of Salmonella typhi was inferior to those of uninvaded patients (with the exception of bactericidal index). Complete recovery from opisthorchiasis stimulated the cessation of S. typhi elimination and increase in the level of some non-specific resistance factors.

Chronic Disease↗

PubMed1989

Complement activation in human lymphoid germinal centres.

The presence of complement activation products has been studied in morphologically normal human lymphatic tissue from tonsil, spleen and lymph node. Newly established monoclonal antibodies (mAbs) with reactivity against the C4 cleavage fragments C4a, C4b, C4c and C4d were applied on cyrostat sections in the indirect immunoperoxidase staining technique. Irrespective of organ type, C4d activation product could be detected in germinal centres of all secondary lymphoid follicles. To substantiate this finding, the complete sequence of complement activation products was investigated by a series of mono- and polyclonal antibodies to the complement proteins C1, C2, C3, factor B, C5, C9 to C5b-9 neoantigens and to the regulatory complement proteins C4 binding protein (C4bp), factor I, factor H and properdin. Similar to C4d, all secondary follicles exhibited a strong staining reaction for C3d antigens restricted to germinal centres. At the same site, albeit with distinctly weaker intensity, components of the membrane attack complex (MAC) C5b-9 were found. The simultaneous deposition of C1, C4b and C4bp in certain germinal centres indicates that complement activation is induced via the classical pathway. Concomitant deposition of IgM suggests IgM-antigen complexes that have been trapped on follicular dendritic cells (FDC) during normal immune response as the most likely candidates for activators of the classical pathway. Our data demonstrate that human lymphoid germinal centres as important sites of immune regulation closely interrelate with the complete cascade of complement-activation products, including the membrane attack complex (MAC).

Antigen-Antibody Complex↗

PubMed1985

A DNA restriction fragment length polymorphism in the complement region of the human MHC shows an absolute correlation with polymorphism of complement factor B(Bf) defined by isoelectric focusing.

The gene coding for properdin factor Bf is located in the human major histocompatibility complex and is closely linked to the genes coding for the complement components C2 and C4. Recently, by Southern blotting techniques, a restriction fragment length polymorphism was identified using the endonuclease Taq I, which subdivides haplotypes carrying the F allele of factor Bf. The F allotype has also been subdivided at the protein level by isoelectric focusing into two subtypes Fa and Fb. We have investigated the DNA of 41 healthy unrelated individuals with known BfF subtypes using the 2.3 kb factor Bf cDNA probe to determine if there is any correlation between the Taq I polymorphism and F subtype. We have found that in 23 individuals who carried the Fb subtype a 6.6 kb Taq I fragment was present. The remaining 18 individuals carried the Fa subtype and showed only the 4.5 kb Taq I fragment on Southern blotting (P = 10(-12). This striking correlation (r = 1) between the Fb protein and DNA polymorphism is surprising especially as the 4.5 kb and 6.6 kb Taq I fragments overlap the Bf and C2 genes and the polymorphic Taq I site is located within the C2 gene.

Alleles↗

PubMed1979

Mapping of the structural gene for the second component of complement with respect to the human major histocompatibility complex.

Families have been HLA typed, and allotypes of the second component of complement and properdin factor B determined. The lod score for the C2 structural gene and HLA-B from the study of 11 families and 55 informative meioses was 14.39 at maximum likelihood estimate of the recombination fraction of .02. This is related to other estimates of the distance between these two genes. The relative kinetic activities of the C2 allotypes were studied and no differences were demonstrated. No crossovers between Bf and C2 were observed.

Adult↗

PubMed1977

[Anticomplementary activity of a polyanion: polyanion: pentosan-poly-sulfoester. I. "In vitro" study and "in vivo" trial in human glomerulonephritis (author's transl)].

The drug, pentosan-poly-sulfoester (PPS), has an anticomplementary activity (ACA) on human serum both in vitro and in vivo, as judged by a reduction in total hemolytic complement activity (CH 50). In vitro, this ACA is very potent, immediate and temperature independent. In vivo this ACA obtained with a IV dose of 100 mg per 8 hours eg 300 mg/24 h, increases with the duration of treatment (mean time:30 days), suggesting a cumulative effect. Eleven patients with glomerulonephritis (GN) received such a treatment (8 with acute post-streptococcal GN and 3 with mesangio-proliferative GN). In patients with already marked hypocomplementemia, the ACA is difficult to establish, while in patients with normal complement activity or moderate hypocomplementemia, the decrease of CH 50 level in serum is obvious. There was no significant change inthe serum level of C3, C4, properdin factor B as measured by radial immunodiffusion technique. The clinical course of these GN was apparently not affected by this treatment. Neverthless, the in vivo ACA of PPS is firmly established and we can speculate that this functional depletion in complement may prevent or decrease the liberation of humoral mediators of inflammation.

Complement C3↗

PubMed1988

The significant of complement and immunoglobulin determination in healthy pregnant women and patients with EPH gestoses.

Complements C3 and C4, IgG, IgM, IgA and properdin factor B (PFB) were determined in maternal blood sera, sera from the umbilical cord and amniotic fluid in the group consisting of 30 healthy pregnant women and 30 patients with EPH gestoses. PFB and IgG were measured in urine, as well. Significant decrease of C3 complement in maternal sera and PFB in urine was found in the group with EPH gestoses, while a slight C4 complement enhancement was recorded in both maternal sera and the blood sera from the umbilical cord. PFB was conspicuously increased in maternal blood sera. IgG level was higher in the blood sera from the umbilical cord in comparison with that found in maternal sera in both groups examined. IgG, IgM and IgA levels were decreased in the group of patients with EPH gestoses in all fluids examined, while IgA level was significantly increased in the sera prepared from the blood from the umbilical cord.

Amniotic Fluid↗

PubMed1988

HLA, C4, Bf, Gm and autoantibodies in rheumatoid arthritis.

Sera from 48 subjects with rheumatoid arthritis (RA), more than 80% of which were seropositive, were examined for the presence of antibodies to intact nuclei (ANA) by immunofluorescence, extractable nuclear antigens (ENA), double-stranded DNA by immunoassay and immunoglobulins, i.e. rheumatoid factors (RF) by haemagglutination. The genetic markers of HLA, the fourth complement component (C4) and properdin factor (Bf), which are all coded for within the major histocompatibility complex and Gm immunoglobulin allotypic markers were all analysed in relation to various parameters of these autoantibodies. The only significant association to emerge was between low ENA antibody affinities and the Bf Fs phenotype (p less than 0.02). Although weak associations between individual autoantibody parameters and the other immunogenetic markers were detected, there were no significant HLA, C4 or Gm association with either ANA subsets or RF, a finding which agrees with, and also extends previous HLA studies of predominantly seropositive RA cohorts.

Adolescent↗

PubMed1988

Factor B subtypes in Japanese patients with IgA nephropathy and with idiopathic membranous nephropathy.

The present paper describes a method of subtyping of properdin factor B (BF) using polyacrylamide gel isoelectric focusing followed by immunoblotting, and the distribution of BF subtypes in Japanese patients with IgA nephropathy or idiopathic membranous nephropathy (IMN) along with controls. BF*F allele was splitted into two suballeles, named BF*FA and BF*FB. There were significant differences in the BF suballele frequencies between the IMN patient group and the control group. A significant association of IMN with the BF FA subtype (p less than 0.05) and with the BF FB subtype (p less than 0.001) was also found. BF*FB may be a susceptibility suballele to IMN rather than BF*FA.

Adult↗