Search results for "Complement C1"
showing 10 items of 125 documents
Isolation, sequence analysis and characterization of cDNA clones coding for the C chain of mouse C1q. Sequence similarity of complement subcomponent …
1992
A mouse macrophage lambda gt11 cDNA library was screened using a genomic DNA clone coding for the C-chain gene of human C1q. Approximately 600,000 recombinant phage plaques were hybridized with peroxidase-labeled human C-chain probe and detected by enhanced chemiluminescence. Five positive clones were obtained. The size of the full-length cDNA is 1019 bp. The sequence identity of the nucleotide sequence with human C1q C chain is 79%, the identity of the deduced amino acid sequences is 73%. The mouse C1q C chain exhibits the same structural features as the human C chain, e.g. conservation of the cysteine residues. Like the mouse A chain, the mouse C chain has an RGD sequence that may be reco…
The critical concentration of C1-esterase inhibitor (C1-INH) in human serum preventing auto-activation of the first component of complement (C1)
2005
C1-esterase inhibitor (C1-INH) was depleted from normal human serum (NHS) at 4 degrees C by affinity chromatography with a monoclonal anti-C1-INH antibody (mAb 13 E1) coupled to CNBr-activated Sepharose 4B. The C1-INH-depleted serum (C1-INH-depl-HS) had normal levels of C1, C4, and CH 50 and C1-INH concentration was less than 10% of normal (15 microg/ml in C1-INH-depl-HS compared to 230 microg/ml in NHS). C1-auto-activation in C1-INH-depl-HS was followed by measuring C4-consumption in a haemolytic assay and by detection of activated C1s in a C1s-ELISA. After a lag phase of 10-20 min, C1-auto-activation in C1-INH depl-HS occurred and reached its maximum after 40 min at 37 degrees C. In contr…
C1q Production by Bone Marrow Stromal Cells
2007
Autoreactivity to mouse C1q in a murine model of SLE.
1995
A large proportion of systemic lupus erythematosus (SLE) patients develop glomerulonephritis, coincident with the appearance of autoantibodies to C1q, the Fc-recognizing collagen-like subcomponent of the first component of complement, C1. The MRL/lpr/lpr mouse is an established model for SLE, developing both antinuclear and anti-type II collagen autoantibodies, and rheumatoid factors(s), exhibiting reduced complement levels and later on developing glomerulonephritis and often arthritis. We report here an age-dependent decrease in serum C1q levels coincident with the development of IgG2b autoantibodies reactive with mouse C1q in MRL/lpr/lpr mice. Unlike IgG2b, although high levels of IgM, Ig…
A longitudinal study of C1q and anti-C1q autoantibodies in homologous and heterologous pregnancies for predicting pre-eclampsia
2022
C1q, the recognition molecule of the classical pathway of the complement system, plays a central role in pregnancy. Lack of C1q is characterized by poor trophoblast invasion and pregnancy failure. C1q can be the target of an antibody response: anti‐C1q autoantibodies (anti-C1q) are present in several infectious and autoimmune diseases. The presence of these autoantibodies has been detected also in 2-8% of the general population. Recent evidence indicates that women who undergo assisted reproductive technology (ART) have an increased risk of developing pre-eclampsia (PE), particularly oocyte donation (OD) pregnancies. The aim of this study was to characterize the levels of C1q and anti-C1q i…
Biosynthesis of the Collagen-like C1q Molecule and its Receptor Functions for Fc and Polyanionic Molecules on Macrophages
1983
At the beginning of the nineteenth century, knowledge of immunity was limited to a few practical methods based on empirical observations, e.g., the observation by Jenner in 1798 that inoculation with cowpox material induced an immunity to smallpox. The discoveries by Louis Pasteur and Robert Koch that microorganisms caused fermentations and were responsible for a number of infectious diseases, greatly advanced the concepts of susceptibility and immunity in a limited number of diseases. In the late nineteenth century, the complement system was discovered by Fodor(1887), Nuttall(1888), and Buchner (1889a, b) through studying the bactericidal action of blood serum. It was recognized that killi…
The second component of human complement: Detection of two hemolytic forms in plasma by pH Variation
1988
The second component of human complement (C2) in pseudoglobulin prepared from normal plasma eluted as a single peak at high conductivity (30 mS) and pH 4.5 from the cationic exchangers S-Sepharose or Mono S in the Fast Protein Liquid Chromatography (FPLC) System. The C2 was stable at pH 4.5 and 0 degrees C if enzyme inhibitors were used and the pH was raised to 6.0 after elution from the columns. After rechromatography on Mono S in the FPLC System at the median isoelectric point of 5.5 or pH 6.0, the C2 eluted as two distinct hemolytic forms: the first peaked at 16 mS, the second at 30 mS. The two forms of C2 did not correlate with the allotypic variant of C2 in individual, normal human pla…
Studies on the interaction of C1q,a subcomponent of the first component of complement, with porins fromSalmonella minnesotaincorporated into artifici…
1990
AbstractPurified outer membrane proteins (OMP) of Salmonella minnesota, Re-form, were incorporated into liposomes. These induced in macrophages a chemiluminescence signal identical to that of the intact Re-form. This signal was abolished by preincubation of porin-containing liposomes with purified C1q. Incorporation of isolated OMP into black lipid membranes (BLM) resulted in channel-formation which could not be inhibited by isolated C1q. Additionally, incubation of OMP-containing liposomes with BLM resulted in pore-formation within the BLM. This was amplified when lipid A was present within the liposomes. Preincubation of OMP-containing liposomes with purified C1q abolished pore-formation …
Is the Complement Protein C1q a Pro- or Anti-tumorigenic Factor? Bioinformatics Analysis Involving Human Carcinomas
2019
C1q is the first subcomponent of the classical pathway of the complement system and belongs to the C1q/Tumor Necrosis Factor superfamily. C1q can perform a diverse range of immune and non-immune functions in a complement-dependent as well as -independent manner. Being a pattern recognition molecule of the innate immunity, C1q can recognize a number of self, non-self and altered-self ligands and bring about effector mechanisms designed to clear pathogens via opsonisation and inflammatory response. C1q is locally synthesized by macrophages and dendritic cells, and thus, can get involved in a range of biological processes, such as angiogenesis and tissue remodeling, immune modulation, and immu…
Molecular cloning and characterization of the complementary DNA coding for the B-chain of murine Clq
1989
AbstractcDNA clones coding for the B-chain of murine Clq were isolated from a mouse macrophage library. The characterized clones include the total coding region plus a leader sequence. High homology was found with human Clq B-chain in the coding region (81%). Northern blot analysis of total RNA from different tissues of Balb/c mice showed one band of approximately 1.2 kb. The highest signal was found in RNA preparations of thioglycolate-activated peritoneal macrophages. The probe also hybridized with mRNA from spleen, thymus and heart. Extremely weak signals were found in liver, kidney, lung and intestine tissues.