bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antibody-Dependent Cell-Mediated Cytotoxicity by Human Lymphocytes
Authors: Fuson E. W. , Whitten H. D. , Ayers R. D. , Lamon E. W. 
Published: January 2023

Abstract
A study has been made of the ability of IgM and IgG to initiate ADCC by normal human peripheral blood lymphocytes (PBL) in a 51Cr release assay with sheep erythrocytes as target cells. The immunochemical purity of the IgM and IgG preparations was confirmed by ion-exchange and affinity chromatography. Passage of the IgM over DEAE-cellulose removed its C-dependent hemolytic as well as ADCC activity, whereas no activity was removed from IgM by passage over a Sepharose 4B-Protein A column. The opposite was observed with IgG; DEAE-cellulose removed no activity and the protein A column effectively depleted IgG activity in both C-dependent hemolysis and ADCC. The IgM-induced ADCC was compared to IgG-induced ADCC on the basis of kinetics, dose-response, and effector-target cell ratios required. In addition, it was shown that preincubation of lymphocytes facilitated IgM-induced ADCC but had little effect on IgG-induced ADCC. When preincubated PBL were used as effector cells the following was found: The time requirements for induction of cellular cytotoxicity by IgM and IgG were similar when the antibodies were used at concentrations near their hemolytic end point titers. Dose-response curves of IgM and IgG indicated that lymphocytes were induced to be cytotoxic more efficiently by IgM when the antibody classes were compared on the basis of molecules/target cell required to produce 50% lysis. The effector-target cell ratio producing optimal lysis in the assay was the same for both classes of antibody. In contrast, the cytotoxicity produced by freshly isolated PBL against IgM-sensitized target cells was significantly lower than against IgG-sensitized target cells in all comparisons.
Primary Structural Analysis of Human C4
Authors: Andrews David W. , Capra J. Donald 
Published: January 2023

Abstract
C4 has been isolated from human plasma by a three-step procedure and its component chains have been separated. Partial amino acid sequence analysis of these chains reveals considerable polymorphic variability. Chains isolated from individual donors have been examined to define this polymorphism at the primary structural level. The structure of the γ-chain has been more intensively investigated using fragmentation with CNBr, and the resulting peptides have been partially sequenced. The longer CNBr fragments of the γ-chain have been further fragmented with trypsin after citraconylation. Sequence data concerning these peptides will be presented and discussed.
In Vivo and in Vitro Inhibition of Complement by Chlorazol Fast Pink
Authors: Bauman N. , Brockman J. A. 
Published: January 2023

Abstract
Chlorazol Fast Pink (CFP) is a sulfonic acid azo dye, first described as an in vitro complement inhibitor in 1952 (Lambert & Richley, B. J. Exp. Path. 33, 327, 1952). We have examined CFP in vivo and in vitro and found that it inhibits complement dependent lesions in laboratory rodents, and that these effects are correlated with depression of serum complement. In some cases, CFP has been compared with pentosan polysulfate (PPS), another anionic complement inhibitor.
CFP and PPS, injected intraperitoneally, block Forssman shock and Forssman cutaneous vasculitis in guinea pigs and the reverse passive Arthus reaction in guinea pigs and rats. Inhibition of these reactions is accompanied by an inhibition of serum complement, demonstrable by an assay of “undiluted” serum. In this assay, serum is laid over EA embedded in an agarose matrix in a capillary tube, and the zone of lysis measured with an optical micrometer.
Identification of Properdin, B, D, and C3 As Biosynthetic Products of Guinea Pig Peritoneal Macrophages and Influence of Culture Conditions on Their Secretion
Authors: Brade Volker , Fries Wolfgang , Bentley Carolyn 
Published: January 2023

Abstract
Monolayers of adherent cells (a.c.) were prepared from peritoneal cells obtained from guinea pigs injected three days previously with starch gel. In serum-free medium, a.c. were cultured for approximately 40 hr under the following conditions: 1) On a plastic surface in MEM. 2) On a plastic surface in MEM plus 0.2% lactalbuminhydrolysate (LH). 3) On a plastic surface coated with glutaraldehyde-linked BSA (BSA-surface) in MEM. 4) On a BSA-surface in MEM plus LH. The culture conditions were found to be slightly improved by LH and the BSA-surface alone, or in combination, as judged by lactatdehygrogenase and lysosomal enzyme determinations, trypan blue exclusion tests, and cell number. When culture supernatants (c.s.) from monolayers cultured these four different conditions were tested in the same order for functional activity of C3 and D, the respective values were found to be 5.7 × 107 site forming units (SFU) C3 and 70 U D; 4.5 × 107 SFU C3 and 27 U D; 1.1 × 107 SFU C3 and 2 U D; 0.3 × 107 SFU C3 and 6.5 U D.
Granulocyte (GR) Aggregometry: A New Assay for the Detection of C5a and Complement (C) Activation
Authors: Craddock Philip R. , Lammi Carol J. , Bowers Timothy K. 
Published: January 2023

Abstract
Products of C-activation (particularly C5a) induce chemotaxis, phagocytosis, and lysosomal exocytosis by GR, and thus profoundly influence the role of GR in inflammation. We have recently reported that C5a will induce GR aggregation in vitro. This aggregation is specifically dependent on C5a in that aggregating activity can be generated in normal but not C5-deficient plasma by incubation with zymosan (ZYM); the aggregating activity in normal ZYM-treated plasma is limited to a single peak of 17,000 daltons, is heat stable (56° × 30 min), and is inhibited by incubation with anti-C5 but not anti-C3 antisera. The amplitude of the aggregator response is proportional to log2 [C5a]. GR aggregation might therefore be used as an assay for C5a and thus for C activation. The aggregation response of GR to C5a is amplified tenfold by the addition of cytochalasin B (CB).
Complement Expression on Lymphoid Cells
Authors: Ferrone S. F. , Pellegrino M. A. , Gorski J. P. , Cooper N. R. 
Published: January 2023

Abstract
Earlier studies showed that peripheral human lymphoid cells (PBL) and cultured lymphoblastoid cells (CL) express, but do not secrete, C4. Membrane expression of C4 is detectable by immunochemical, radiochemical and immunofluorescence techniques. CL absorbed C4 α- and β-chain antibodies, as assayed by radioimmunoassay, thus CL express C4 α- and β-chain determinants. CL also produce other C components since several rabbit antisera to human CL of B and T cell origin contain antibodies to human C1q, C1r, C3, C4, C5, C6, C7, C8 and P.
Our earlier studies showed that some, but not all, antisera to human C4 inhibited the mixed lymphocyte reaction (MLR) between allogeneic human PBL, suggesting a role for C4 in immune recognition phenomena. Because of variable MLR inhibition with different antisera by us and by other workers, we have further investigated the effect of anti-C4 on the MLR.
Purification of the Third Component of Rabbit Complement
Authors: Giclas Patricia C. , Henson Peter M. 
Published: January 2023

Abstract
Rabbit C3 has been isolated from normal rabbit plasma by a method based on that developed for human C3 by Tack and Prahl (Biochem. 15:4513, 1976). Fractionation of the rabbit plasma with polyethylene glycol was followed by DEAE-sepharose chromatography, gel filtration and final separation on hydroxyl apatite. The C3 obtained by this technique is hemolytically active and represents 7–15% of the plasma C3.
Rabbit C3 migrates as a single band on SDS gels with an estimated molecular weight of 186,000, and can be separated on SDS gels into α and β chains of 132,000 and 70,000, respectively, under reducing conditions.
Preliminary studies of the biologic activities of the rabbit C3 preparations indicate that it binds to rabbit peripheral blood neutrophils. The C3 remaining in the supernatant after incubation with the neutrophils is no longer hemolytically active, and SDS gels of this material show that it has been cleaved into two major fragments. Studies are in progress to determine the nature of the interaction between rabbit C3 and the neutrophils.
The Effect of Danazol in Acquired C1̄ Inhibitor Deficiency: Changes in C1̄ Inhibitor and Complement Levels
Authors: Hauptmann G. , Mayer S. , Lang J. M. , Oberling F. , Mayer G. 
Published: January 2023

Abstract
Several cases of acquired C1̄ inhibitor (C1̄ INH) deficiencies and angioedema have been reported in association with lymphoproliferative diseases. An acquired C1̄ INH deficiency can be distinguished from the hereditary angioedema by the adsence of C1̄ INH deficiency in other family members, by the profound reduction of the C1 level in addition to the reduction of C4 and C2 levels, and by the presence, in most cases, of serum immunoglobulin abnormalities and of a high C1 depleting activity in the serum of a patient suffering from a lymphoproliferative disease. In addition to the three cases previously described (Blut 32: 195, 1976) we have now observed a fourth case of acquired C1̄ INH deficiency and we have studied the effect of the treatment with Danazol on the C1̄ INH and complement levels.
A 57-year-old man presented with a lymphoproliferative disease, IgM dysglobulinemia and the characteristic complement profile of an acquired C1̄ INH deficiency.
Deviated Lysis: Formation of a Properdin Stabilized C3/C5 Convertase As the Active Principle Underlying the Phenomenon
Authors: Kolb W. P. , Podack E. R. , Müller-Eberhard H. J. 
Published: January 2023

Abstract
Deviated lysis (d.l.), as described by Rother et al. (Z. Immun.-Forsch. Bd. 148:172, 1974), is the ability of activated complement, either on the surface of the activating particle or in the fluid phase, to lyse nonsensitized target cells in the presence of EDTA. We wish to report experiments conducted to characterize the active principle responsible for this activity. D.1. activity was generated by incubating NHS with inulin for 10 to 20 min at 37°C. The reaction was terminated by the addition of EDTA (10 mM final concentration) and centrifugation to separate pellet-associated and fluid phase activities, which were assayed for their ability to lyse chicken erythrocytes (ChE) in GVB-10 mM EDTA (GVBE).
Characterization of the sucrose-stabilized fluid phase d.l. activity revealed a major peak possessing a m.w. of 250–350,000 daltons and an S-rate of 14 to 16 S as determined by chromatography with Bio-Gel A-0.5 M and sucrose density gradient ultracentrifugation. D.1. activity present in column and gradient fractions was completely inhibited by monospecific antisera to properdin, factor B or C3 but not by anti-C4.
A Quantitative Comparison of the Biologic Activity of Membrane-Bound C3 and C4 In Vitro
Authors: Kurlander R. J. , Rosse W. F. 
Published: January 2023

Abstract
Human red cells (E) were specifically and singly coated with either C4, C3b, or C3d by using human serum as the source of complement, and the amount of each component fixed was measured quantitatively by antiglobulin consumption tests. The immune adherence (IA) of E-C4, E-C3b and E-C3d to peripheral blood monocytes and polymorphonuclear leukocytes (PMN) was dependent upon the amount of the component on the red cell surface. The amount of adherence per molecule of component fixed was slightly greater with E-C4 than with E-C3b and much less than either with E-C3d. However, E-C3d adherence was more stable to washing or mechanical disruption than E-C3b adherence; E-C4 adherence was less stable than either. Unlike E-C3b when incubated with heated serum, resulting in E-C3d with continued IA activity, E-C4 incubated with serum completely lost IA activity.
51Cr-labeled E-C4, E-C3b and E-C3d were not lysed during incubation with monocytes even though they readily adhere to monocytes.
C6–C7: A Further “Complement Supergene”
Authors: Lachmann P. J. , Hobart M. J. 
Published: January 2023

Abstract
The genetic polymorphism of C6 is well established. The two common alleles have frequencies of 0.6 and 0.35 which makes C6 a very useful genetic marker. Genetic polymorphism of C7 has now also been demonstrated. Three alleles have been found, of which only the commonest occurs at a frequency above 0.05. Family studies have so far shown no cross-overs between C6 and C7 in 21 informative meioses, indicating close linkage between the loci.
There is no significant evidence for linkage between the C6, C7 locus and any other marker tested. These include C3, HLA, Gm, and many red cell antigenic and enzyme markers. From rather limited family data, close linkage to C1̄-inhibitor and C3b inactivator deficiencies can also be excluded. Further evidence for C6,C7 association is provided by an individual with a remarkable genetic complement deficiency affecting both C6 and C7. The propositus, who is in good general health, has low, but detectable, levels of both C6 (c1%) and C7 (c3%); other components being within the normal limits.
The Role of C1q in the Internal Activation of the First Component of Complement (C1): Studies in Serum of a Selective C1q-Deficient Patient
Authors: Loos Michael , Thesen Rolf , Berkel A. Izzet 
Published: January 2023

Abstract
The serum of a 10-year-old boy was found to be totally deficient in hemolytic C1 activity. The lack of C1 activity was due to a selective deficiency of C1q whereas the titres of the other components including C1r and C1s were found within the normal range. We looked for C1q functionally as well as immunochemically. There was no decrease of serum immunoglobulins IgG, IgM, or IgA. Addition of highly purified human C1q to the serum restored the whole complement activity as well as the C1 activity. In ultracentrifugation studies the sedimentation rates of the restored C1 molecules were found mostly in the 18.6S region when the experiment was performed with 0.06 µ VBS containing gradients; however, C1 activity was found only in the 12.6S region when a gradient with 0.15 µ VBS was used. The dose-response curve of the restored C1 molecule showed the same nonlinear shape as that of C1 in normal human serum.
Responses of Human Platelets to Immunologic Stimuli: Independent Roles for Complement (C), Fibrinogen and IgG in Zymosan Activation
Authors: Martin S. E. , Breckenridge R. T. , Rosenfeld S. I. , Leddy J. P. 
Published: January 2023

Abstract
We have employed zymosan (Z), 1 particle/15 platelets, as an in vitro probe for the study of the effects of immunologic reactions on human platelets. Studies by others had shown a) that human platelets respond with aggregation and release reactions when exposed to Z previously treated with normal plasma; b) that an intact alternative C pathway as well as fibrinogen are required; and c) that the critical plasma reactants are Z bound. Using genetically C-deficient human plasmas, we have previously reported requirements for C5, C6, and C7 but not C8 in the formation of the active Z-complex.
Utilizing agammaglobulinemic (agamma) plasma and washed human platelets, we have demonstrated a requirement for IgG in this reaction. Agamma plasma did not support Z-induced platelet activation, whereas Z previously incubated in normal plasma activated agamma platelets. This agamma plasma defect was corrected by purified normal IgG, but not by F(ab′)2 or Fc fragments.
Multiple Forms of Properdin
Authors: Medicus R. G. , Müller-Eberhard H. J. 
Published: January 2023

Abstract
Properdin exists in at least three functionally different forms. The form which is isolated by the most rapid (two-step) procedure from fresh serum we designate native properdin (nP). Purified nP is characterized by its inability to bind to solid phase C3b, to stabilize the labile C3/C5 convertase, to form a soluble C3 convertase in serum, and by its capacity to reconstitute P-depleted serum with respect to C3 consumption by zymosan or inulin. The second form of P, designated pre-P, is characterized by its ability to bind reversibly to solid phase C3b, to stabilize the labile C3/C5 convertase formed with multiple C3b molecules, and to reconstitute P-depleted serum in a manner analogous to nP. The third form is active P, referred to as P̄. It is characterized by its ability to bind irreversibly to solid phase C3b, to stablize the labile C3/C5 convertase as well as the single C3b C3 convertase and to assemble the soluble C3 convertase when added to serum independent of zymosan or inulin.
Mechanism of Action of β1H Globulin on C3b
Authors: Ruddy Shaun , Carlo Jaime , Conrad Daniel 
Published: January 2023

Abstract
The activity of the “C3b Inactivator Accelerator,” described at the Sixth Complement Workshop, has since been found to reside in β1H globulin, a 150,000 m.w. glycoprotein (K. Whaley and S. Ruddy, Science 193:1011–1013, 1976; and J. Exp. Med. 144:1147–1163, 1976). This protein accelerates the rate of inactivation of the hemolytic activity of the C3b by C3b Inactivator and also increases the rate of proteolysis of C3b by C3b Inactivator. In addition, β1H has direct effects on C3b, preventing its participation in either the classical or alternative pathway C5 convertases, and increasing the rate of decay of factor B from the alternative pathway convertase, .
Some of these apparent diverse effects of β1H may be explained by its binding to C3b. This is evidenced by 1) agglutination of cellular intermediates exposed to β1H by monospecific antibody to β1H, 2) immunofluorescent staining of such intermediates with fluorescein-labeled anti-β1H, 3) depletion of β1H activity from the fluid phase of reactions containing C3b.
Complement Activation in Human Serum by Urate Crystals, Evidence for a Role for IgG
Authors: Russell I. J. , Papaloannou C. , McDuffie F. C. 
Published: January 2023

Abstract
Previous studies of complement activation in serum by urate crystals have not supported a role for immunoglobulins (Naff and Byers, J. Lab. Clin. Med. 81:797, 1973). The recent demonstration by Kozin and McCarty (J. Lab. Clin. Med. 89:1314, 1977) of adsorption of IgG to urate crystals prompted us to reexamine this question. Addition of urate crystals (10 mg per ml.) to hypogamma-globulinemic serum reduced hemolytic activity only slightly but caused virtually complete depletion from normal serum. Addition of 7S IgG (10 mg per ml) but not IgA (10 mg/ml) nor IgM (10 mg/ml) restored the ability of such serum to demonstrate depletion of C activity by urate crystals. Urate crystals were able to inactivate C3 in normal human serum but not in C2 deficient human serum nor in C4 deficient guinea pig serum. This effect is mediated primarily through the classical pathway.
Translation of Precursors of C4 and Albumin by Isolated Guinea Pig m-RNA
Authors: Sakiyama Yukio , Hall Robert E. , Colten Harvey R. 
Published: January 2023

Abstract
Guinea pig RNA was isolated from liver homogenates by phenol-chloroform-ethanol extraction and applied to a Sigmacell type 50 column in Tris (40 mM) buffer containing KCl (1.0 M) and MgCl2 (0.4 mM). Messenger RNA was eluted from the column, precipitated in ethanol and NaCl (1.0 M) washed in the same solution and redissolved in distilled water. The m-RNA was then added to a mixture containing rabbit reticulocyte polysomes (in some experiments pretreated with a micrococcal nuclease) an energy source, rat t-RNA, hemin, 3H-labeled leucine, 19 unlabeled amino acids and optimal concentrations of K+ and Mg++. Total protein synthesis by micrococcal nuclease-treated reticulocyte lysate was increased nearly four-fold (3700 cpm to 13,260 cpm) in the presence of m-RNA. Under these conditions, single-chain precursors of guinea pig albumin (m.w. &gt; 68,000) and of C4 (m.w. ≥ 205,000) were synthesized, each accounting for less than 0.5% of the newly synthesized total protein.
Modulation of the C3 Receptor by HLA Antibodies and C1, 4, 2, and 3 Components of Complement
Authors: Sargent A. U. 
Published: January 2023

Abstract
Recent studies have suggested linkage of genes regulating synthesis of C2 and genes of the MHC complex with M.S. and certain autoimmune diseases. As Ig-secreting plasma cells are related ontogenically to a subpopulation of B lymphocytes which selectively express the C3 receptor, these findings suggest linkage of C2, CRL cells and membrane products of MHC genes, with pathogenic mechanisms mediating diseases of humoral immunity. The following studies were initiated to determine whether a functional relationship could be demonstrated between antibodies to membrane products of MHC genes, the activation unit of the classical complement pathway and C3 receptors. Monospecific HLA-A2 antibody and functionally pure human C1, C4, and C2 were used to initiate the assembly of C3 convertase on membranes of enriched populations of human B lymphocytes. The sensitized lymphocytes were then incubated with EAC1-3 cellular intermediates and formation of C3 rosettes was determined. Formation of C3 rosettes with the sensitized lymphocytes was reduced by over 50% from values obtained with unsensitized controls.
Presence of a C4-Binding Protein (C4-bp) in Human Serum
Authors: Scharfstein Julio , Ferreira Arturo , Gigli Irma , Nussenzweig Victor 
Published: January 2023

Abstract
As published elsewhere (Ferreira et al., J. Exp. Med., in press) mouse serum contains a 10S β-globulin which specifically binds to fluid phase activated Ss (C4) protein. This new protein was named Ss-bp or C4-bp. A search was made in human serum for the presence of a protein with similar properties. Human serum was incubated at 37°C with washed immune precipitates and centrifuged. Activated C4 was isolated from the supernatant by precipitation with a monospecific antiserum to C4, and injected into rabbits. The resulting antiserum was tested against whole human serum by crossed-immunoelectrophoresis. It reacted only against C4 and an additional serum component with properties very similar to those of mouse C4-bp.
Human C4-bp is a heat stable β-globulin which is found in the exclusion volume after filtration of serum or EDTA-plasma through a Sephadex G-200 column. It has a sedimentation coefficient of 13S as determined by sucrose gradient ultracentrifugation of serum from a patient with hereditary angioedema (HAE) with low levels of C4.
Release of 86Rb+ and 14C-Phosphatidyl Choline Markers from Liposomes, and of Hemoglobin from Erythrocytes, by Activated Complement: Effect of Length and Unsaturation of Acyl Chains and of Cholesterol/Phospholipid Ratio
Authors: Shin Moon L. , Paznekas William A. , Abramovitz Aaron S. , Mayer Manfred M. 
Published: January 2023

Abstract
The cytolytic action of complement (C) is believed to be due to the formation of trans-membrane channels by insertion of peptides from C5b-9 into the lipid bilayer. We have previously reported that phospholipid (PL) is released from the liposomal bilayer by activated C, along with channel formation. Since channel formation and PL removal involve lipid-protein interactions, the chemical properties of the lipids in the membrane would be expected to influence these processes. In the present work, we have studied the C-mediated release of 86Rb+ from the aqueous compartment and 14C-phosphatidyl choline (PC) from the lipid bilayer of liposomes containing different amounts of cholesterol, and liposomes made from PL differing with respect to acyl chain length and unsaturation. Effect of acyl chain length. Liposomes prepared from C(14:0)2, C(16:0)2 and C(18:0)2 lecithins, with a cholesterol/PL ratio of 0.75, were treated with antibody (Ab) and C.