bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunochemical Properties of Murine Ss Protein
Authors: Goldman Margaret B. , Goldman John N. 
Published: January 2023

Abstract
Circulating levels of the Ss protein of mouse serum, an antigenic homologue of human C4, are controlled by alleles within the S region of the H-2 complex. We have shown that the Ss protein can exist in at least two forms, distinguishable by electrophoresis, ion exchange chromatography and gel filtration. An electrophoretically slow form with an apparent molecular weight of approximately 160,000 by gel filtration is found in EDTA plasma and an electrophoretically faster form with an apparent molecular weight of approximately 130,000 by gel filtration is found in incubated serum. Ss protein antigen can be separated from C4 functional hemolytic activity by either ion exchange chromatography or gel filtration done under certain conditions. Because of this the functional relationship of the Ss protein and C4 were examined further. EAC142 obtained by incubating EA in mouse serum had readily demonstrable C4 function and could be agglutinated with anti-Ss antibody. These cells lost their C4 hemolytic function but not Ss agglutinability upon incubation in EDTA.
Studies on Bovine Complement
Authors: Linscott William D. , Triglia Richard P. 
Published: January 2023

Abstract
Fetal bovine serum is in widespread use for in vitro antibody-synthesizing systems, but very little attention has been paid to the complement (C) activity of this serum, at least partly because methods have not been developed for measuring some bovine C components, particularly C3. We report here some studies on bovine C1, and a simple assay for bovine C3 and its use to measure the C3 content of a number of commercial and other fetal bovine serum preparations, which were “good” or “bad” with respect to their ability to support (in vitro antibody synthesis. The C1, C3b-inactivator and conglutinin contents of these preparations will also be reported.
C1 was precipitated twice from normal bovine serum at 0.03 M NaCl and 0.005 M phosphate concentration, pH 7.5 (O. Barta, R. A. Nelson, C. Y. Kuo, Immunol. Commun. 5:75, 1976). It had a C1H50 titer of 210,000 [vs 33,000 for Cordis guinea pig (GP) C1] in a standard assay with EAC4gp, yielding a Z plot slope of 1.00.
In Vitro Synthesis of the First Component of Complement (C1) by Human and Guinea Pig Peritoneal Macrophages
Authors: Loos Michael , Müller Wolfgang , Storz Rosemarie 
Published: January 2023

Abstract
The C1-subcomponent C1q was described to be synthesized by isolated macrophages as shown by detection of radiolabeled C1q precipitin lines developed with an anti-C1q antiserum (Stecher, V. J., and Thorbecke, G. J., J. Immunol. 99, 643 (1967). The proof of the additional synthesis of the two other C1-subcomponents C1r and C1s by macrophages failed so far. Evidence is presented that whole C1 activity (i.e., C1q, C1r, and C1s) was detectable in the supernatants of serum-free short-term cultured human as well as guinea pig peritoneal macrophages. Petri dishes covered with glutaraldehyde cross-linked BSA were used for culturing the monolayers in M199 for 72 to 96 hours at 37°C. The function of C1 was tested hemolyticly by binding to EA or to EAC4 (C1q function) and, after washing the cells, by the following generation of C3 convertase activity from C4 and C2 (C1s function). No C1 activity was found in cultures containing more than 0.1% of heat-inactivated fetal calf or autologous serum.
The Capacity of Lymphoblastoid Cells to Activate the Alternative Complement Pathway Is Correlated with their Transformation by Epstein-Barr Virus
Authors: Mc-Connell I. , Lachmann P. J. , Lint T. , Klein G. 
Published: January 2023

Abstract
Cultured human lymphoblastoid cells derived from patients with Burkitt's lymphoma or infectious mononucleosis have been shown to activate the alternative complement pathway by an antibody-independent mechanism. Lymphocytes from normal or leukemic patients do not have this activity.
All lymphoblastoid cells and most lymphoma lines derived from patients with Burkitt's lymphoma carry Epstein-Barr virus DNA in their genome. Recently, EBV-negative Burkitt lymphoma lines have been established and these can be converted to EBV-positive sublines by superinfection in vitro with EBV. The existence of these lines allows us to test the hypothesis that transformation of cells with EBV confers on them the property of activating the alternative pathway.
Two EBV-negative lines and eight EBV converted sublines were tested for their ability to activate the alternative pathway in hypogammaglobulinaemic and normal human serum. Activation was assayed by demonstrating bound C3 on the membrane by immunofluorescence; by measuring C3 conversion in the serum by the Laurell technique; and consumption of total alternative pathway activity in serum by using a hemolytic assay.
Modulation of the Immune Response by Pretreatment of Antigen with Complement
Authors: Opferkuch W. , Horn W. , Falkenberg F. , Lennartz K. J. 
Published: January 2023

Abstract
It is known that inactivation of C3 leads to a decreased immune response both in vivo and in vitro, and it has been concluded that C3b is involved in the generation of an immune response to T-dependent antigens (reviewed by Pepys, Transplant. Rev. 32, 93 (1976)). Thus it appeared of interest to investigate whether complement components other than C3 influence the magnitude of an immune response.
Sheep erythrocytes were pretreated with IgM anti-Forssman antibody and subsequently reacted with either purified complement components or whole guinea pig serum. 2 × 108 SRBC (or ghosts, respectively, in the case of lysed SRBC) were injected, either i.v. or i.p. into naive NMRI or (B6D2)F1 mice. The immune response was assayed by either titrating antibody concentrations in serum or by the Jerne Plaque technique.
Injection of E, EA(IgM), EAC1-7 caused similar immune responses. On the other hand, injection of EA(IgM) lysed by complement (E*) led to a 10-fold decrease of the immune response.
Implications Concerning the Complement System in a Patient with Hereditary Angioneurotic Edema and Glomerulonephritis
Authors: Spitzer R. E. , Stitzel A. E. 
Published: January 2023

Abstract
An 11-year-old white female with focal glomerulonephritis was found to have a complete absence of functional C1 esterase inhibitor. Serum levels of C1 esterase inhibitor measured by immunochemical analysis, however, were only slightly reduced. Prolonged depression of serum C2 and C4, evidence of circulating and active C1 esterase, and normal levels of serum C3 and alternative pathway proteins were also present. Several family members had similar immunochemical findings. Neither the patient nor her family had clinical signs of hereditary angioneurotic edema (HANE) despite the continued C consumption which has persisted for at least 24 months. These findings suggest that mechanisms other than the generation of a vasoactive peptide from C2 might be responsible for the clinical features of HANE.
Further, evidence from immunofluorescence studies of the deposition of IgG and C3 on the kidney of this patient suggests the participation of an immune complex and terminal C activity in the genesis of the glomerulonephritis.
Regulation of C3 and C3b Activity by Lymphocytes: A New Control Mechanism
Authors: Spitzer R. E. , Stitzel A. E. , Urmson J. R. , Rittenhouse K. , Bock G. H. 
Published: January 2023

Abstract
Sera from patients with acute lymphoblastic leukemia or active transplant rejection contain high concentrations of a material which regulates C3 and C3b activity. Preliminary isolation of this material reveals that it is able to interfere with both C3 and C3b activity. Lysis of EAC4̄2 by purified C3–C9 or C3 consumption by is inhibited if this material is present when C3 is added. There is no effect if this material is removed before the addition of C3 implying an interaction with native C3 or a C3-like structure which competes with the active enzymatic sites. If, however, this material is added to or cells and then removed, addition of C3bINA or C3bINA and β1H has no effect on the subsequent lysis by C5–C9 () or factors B, D, and C3–C9 (EAC43b). These latter results imply a direct irreversible effect of this substance on bound C3b.
In Vitro Activation of Complement by Isolated Human Heart Subcellular Membranes
Authors: Giclas Patricia C. , Pinckard R. Neal , Olson Merle S. 
Published: January 2023

Abstract
Activation of human complement (C) occurred in vitro when mitochondrial membranes isolated from normal human heart tissue were incubated with normal human serum. This activation, as measured by C3 depletion, was not completely inhibited by blocking classical pathway activity in serum treated with EGTA, in C2-deficient serum, or in C1-depleted serum, nor in serum heated at 50°C for 30 min to block the alternative pathway, but it could be prevented by blocking the classical and the alternative pathway simultaneously with EDTA, or by treating heated serum (50°C, 30 min) with EGTA. Factor B was converted in normal serum as well as in EGTA-treated serum, but not in EDTA-treated serum. Mitochondrial membranes had no direct enzymatic or other activity that could inactivate functionally or highly purified C4 or C3, but the membranes could bind and activate C1 either in serum or in functionally pure C1 preparations. C4 also bound to the mitochondrial membranes only in the presence of C1. These data suggest that the activation of C by heart subcellular membranes involved both the classical and the alternative pathways, that the mitochondrial membrane preparations were capable of forming stable complexes with C1 and C4, but not C3, and that the mitochondrial membrane preparations did not contain enzymes or have inherent properties that could directly cause C3 conversion.
Human Alternative Complement Pathway: Membrane-Associated Sialic Acid Regulates the Competition between B and β1H for Cell-Bound C3b
Authors: Kazatchkine Michel D. , Fearon Douglas T. , Austen K. Frank 
Published: January 2023

Abstract
The relative affinity of B and β1H for particle-bound C3b is influenced by the relative abundance of cell surface sialic acid moieties and determines whether or not the particle has the capacity to activate the human alternative complement pathway. The effect of membrane sialic acid on the binding of B and β1H to particle bound C3b was determined with radiolabeled proteins and a technique for separating bound from free ligand by centrifugation of the particles through an oil/aqueous interphase. The affinity constants at equilibrium and the effective number of C3b binding sites for B and β1H on the particles were determined by Scatchard analysis of the binding data. The sheep erythrocyte (Es) served as a nonactivating particle, whereas the activating particles included Es from which 80% of the membrane sialic acid residues had been removed by sialidase or 80 to 85% had been converted to heptulosonic acid by NaIO4 and NaBH4 treatment and zymosan particles that lack sialic acid. The affinity constants at equilibrium for C3b on EsC3b were 1 × 107 M-1 for β1H and 2.1 × 106 M-1 for B, in the presence of 5 mM Mg++, indicating an approximately 5-fold greater affinity of β1H for the binding sites that were present in approximately equal numbers for the two ligands as determined by Scatchard analysis. The affinity of B at equilibrium for C3b bound to sialic acid-deficient sheep erythrocytes and to zymosan was the same as that for C3b on Es, and the calculated number of effective binding sites for B agreed with the number of sites estimated by the prior uptake of radiolabeled C3b. In contrast, the number of C3b binding sites with an affinity for β1H of approximately 107 M-1 on sialic acid-deficient EsC3b or ZyC3b was only ⅕ to ⅙ the number interacting with B. The presence of additional binding sites for β1H with an affinity so low that they were not revealed by the Scatchard analysis because of the dominant effect of the high affinity sites was determined in competitive binding studies between B and β1H for C3b on sialic acid-deficient surfaces. The affinity constant of β1H for these sialic acid independent C3b sites is approximately 7 × 105 M-1, a Kβ1H at least 10-fold less than that of the sialic acid-dependent high affinity C3b sites. The relative inefficiency of β1H in competing with 125I-B for uptake by C3b on the sialic acid-deficient erythrocytes correlated with the decreased capacity of β1H to decay-dissociate C3b,Bb from such particles. Thus a deficiency of sialic acid diminishes the number of high affinity C3b sites for β1H and creates an activating particle on which binding of B by C3b is favored relative to β1H and decay-dissociation of C3b,Bb by β1H is impaired.
XenCSA: Cell Surface Antigens Related to the Major Glycoproteins (gp70) of Xenotropic Murine Leukemia Viruses
Authors: Morse Herbert C. , Chused Thomas M. , Boehm-Truitt Marilyn , Mathieson Bonnie J. , Sharrow Susan O. , Hartley Janet W. 
Published: January 2023

Abstract
Antisera from rabbits immunized with rabbit corneal (SIRC) cells infected with xenotropic murine leukemia viruses (MuLV) were tested for their reactivity with MuLV and the surface of cells exogenously or endogenously infected with MuLV. The sera demonstrated class specificity for gp 70 determinants of intact xenotropic MuLV. Only molecules with characteristics of gp70 were precipitated out of radiolabeled antigens from the surface of cell lines exogenously infected with MuLV or from lymphocytes of normal mice. Cross-reactivity between virion envelope and cell surface antigens was demonstrated by absorption testing. The set of crossreactive antigens present on the envelopes of xenotropic MuLV and murine lymphocytes was termed XenCSA for xenotropic MuLV envelope-related cell surface antigen.
XenCSA expression on thymocytes and spleen cells from 63 strains of inbred mice was assessed by immunofluorescence using flow microfluorometry. Lymphocytes from both tissues of all strains expressed XenCSA but to a highly variable extent. Based on mean fluorescence values, thymocytes and spleen cells from each strain were classified as being high or low for XenCSA. There was a high association for expression of XenCSA and GIX on thymocytes but no correlation with Fv-1, T1a, H-2, Pca-1, or GCSA. The level of XenCSA expressed on the cell surface was also independent of the amount of infectious xenotropic MuLV produced by those cells.
Use of total lymphoid irradiation (TLI) in studies of the T cell-dependence of autoantibody production in rheumatoid arthritis.
Authors: Tanay A , Strober S , Logue G L , Schiffman G 
Published: January 2023

Abstract
The effect of total lymphoid irradiation (TLI) on T cell-dependent and -independent humoral immune responses was studied in patients with intractable rheumatoid arthritis (RA). The serum levels of several autoantibodies and of antibodies to diphtheria (DT) and tetanus (TT) toxoids and to pneumococcal polysaccharide (PPS; 12 antigenic types) were studied before and after TLI. In addition, the patients were given a booster injection of DT and TT and a single injection of pneumococcal vaccine after radiotherapy. Antibody levels to DT and TT decreased about twofold after TLI and did not rise significantly (p greater than 0.05) after a booster injection. However, there was no reduction in antibody levels to PPS after TLI, and a significant rise in titers was observed after a single vaccination (p less than 0.01). The serum levels of rheumatoid factor (RF), anti-nuclear antibody (ANA), and granulocyte associated IgG rose slightly after TLI. Thus, the autoantibodies and antibodies to polysaccharides appear to be relatively independent of helper T cell function, which is markedly reduced after TLI. On the other hand, antibodies to protein antigens such as DT and TT appear to be more closely dependent upon T helper function in man, as has been reported in rodents. The findings suggest that T cell-independent autoantibody responses alone do not maintain the joint disease activity in RA, because improvement in joint disease after TLI has been reported.
Sex-associated differences in the regulation of immune responses controlled by the MHC of the mouse.
Authors: Weinstein Y , Ran S , Segal S 
Published: January 2023

Abstract
The immunologic potential of T lymphocytes and antigen-presenting cells (APC) from male and female mice were compared. Lymphocytes from female mice or from male mice that cannot produce and respond to testosterone (Tfm/y) were more reactive than male lymphocytes to alloantigens in MLR. Spleen cells from Tfm/y mice equipped with estrogen implants showed a higher responsiveness than control Tfm/y to alloantigens. The removal of suppressive adherent cells or the addition of T cell growth factor (TCGF) enhanced the proliferative activity of the cells in the MLR. The responsiveness of female cells to alloantigens, however, remained superior to that observed in male cells. Similarly, in the presence of TCGF, thymocytes from female mice react more effectively than male cells in MLR. In addition, Con A-stimulated spleen cells from female mice produce more interleukin 2 (IL 2) than do spleen cells from males or female mice treated with testosterone. Lymphocytes from immunized mice were tested for their ability to respond to soluble antigens (KLH and OVA) in vitro. Again, female immunocompetent cells respond more vigorously than male cells or cells originating in female mice with testosterone implants. APC from female spleen were more efficient than male APC in initiating a secondary response in primed lymphocytes from either males or female mice. Moreover, castration of male mice enhanced, and treatment of female mice with androgen reduced, the efficiency of antigen presentation. In conclusion, these data suggest that female cells are superior to male cells in immunologic functions that are known to be associated with reactions to and recognition of histocompatibility antigens, i.e., antigen presentation and MLR. Furthermore, our present data indicate that the differential reactivity of immunocytes between male and female mice depends on the hormonal balance of the animal.
Antigens from trichinella spiralis that induce a protective response in the mouse.
Authors: Silberstein D S , Despommier D D 
Published: January 2023

Abstract
A series of monoclonal antibodies was generated for the purpose of studying antigens of the infective L1 larva of Trichinella spiralis. Primary immunization of donor BALB/c mice was by oral infection with L1 larvae. Secondary immunization and screening procedures for hybridoma clones employed a pool of affinity-purified antigens recognized by pooled serum from infected rabbits. Three monoclonal antibodies, chosen for their high reactivity in screening assays and their unique specificities, were raised in quantity, purified, and attached to Sepharose 4B for affinity chromatography. The antigens selected by each affinity column were of different m.w. (37K, 48K, and 50/55K) and possessed different abilities to induce protection. The 48K antigen induced a high level of protection at biologically relevant doses (1.0 and 0.1 micrograms protein/mouse). The 50/55K antigen induced a lower level of protection than the 48K antigen, but was still effective at similar doses. The 37K antigen elicited protection only at a dose of 50 micrograms protein/mouse, and was not as effective as the unpurified antigen at any dose. Earlier studies indicated that many antigens involved in the immune response are secreted. Therefore, worm secretions and two subcellular fractions of homogenized worms (S2 = cytosol, S3 = soluble portion of the large particle fraction) were analyzed for content of the three purified antigens by a double antibody sandwich enzyme-linked assay. The 48K and 50/55K antigens represent significant components of the secretions (12% and 5%, respectively) but relatively minor components of the S2 and S3 fractions. The 37K antigen represents a major component of the S2 fraction, but is essentially absent from S3 and secretions. Immunocytolocalization studies employing immunoperoxidase methods on infected muscle tissue show that the 48K antigen is located in the beta-stichocytes, the lining of the gut, and the surface of the cuticle. The 50/55K antigen was detected in the alpha-stichocytes and was occasionally observed in the gut or on the cuticle. The 37K antigen was detected only in the pseudocoelom. The results from the quantitative ELISA and immunocytolocalization show that the two antigens that induce a protective response are secreted proteins. These data constitute the first account of antigens purified from a nematode that induce a strong protective response. One of these (48K) confers a level of protection comparable to that elicited by exposure of an entire infection.
Accessory cell requirement for activation antigen expression and cell cycle progression by human T lymphocytes.
Authors: Williams J M , Ransil B J , Shapiro H M , Strom T B 
Published: January 2023

Abstract
Stringent accessory cell (AC) depletion by a three-step procedure--plastic adherence, nylon wool adherence, followed by simultaneous treatment with two anti-AC monoclonal antibodies + complement--has allowed the demonstration of several AC-dependent stages in the T cell activation pathway. Simultaneous analysis of DNA content and cell surface immunofluorescence (correlation of activation antigen expression with cell cycle position) or DNA and RNA content (cell cycle position) of cultured cells was accomplished by dual parameter flow cytometry. AC-depleted, PHA-stimulated human peripheral blood T lymphocytes (PBTL) failed to exhibit "early" indicators of activation, including increased RNA content, expression of three activation-associated cell surface proteins (IL 2 receptor, transferrin receptor, and 4F2 protein), and the production of IL 2. The AC-depleted PBTL that failed to express these "early" markers of activation also failed to progress into the "late" phase of activation, DNA synthesis. All indicators of PHA responsiveness were fully replenished upon addition of AC but were only reconstituted to intermediate levels by addition of excess quantities of either highly purified IL 1 or crude AC-conditioned medium with lymphocyte-activating factor activity. These data suggest that the AC membrane plays a key and as yet undefined role in the stimulation of T cells by PHA.
Hapten-modified basophils: a model of human immediate hypersensitivity that can be elicited by IgG antibody.
Authors: Akiyama K , Pruzansky J J , Patterson R 
Published: January 2023

Abstract
Trimellitic anhydride (TMA) was incubated with human leukocytes to produce leukocytes with trimellityl (TM) haptenic determinants. The basophils in these TM leukocytes released histamine when challenged with human serum containing IgG but no IgE antibodies against TM determinants. Controls of TMA-treated cells exposed to normal human sera or untreated cells exposed to anti-TM sera released no histamine. The most relevant site of TMA modification of the basophil was receptor-bound IgE. This was demonstrated by the marked reduction in histamine release if IgE was removed from the leukocytes before TMA treatment and challenge and also by activation of release from untreated cells by passive sensitization with TM-IgE before challenge. Affinity-purified IgG from an anti-TM serum released much more histamine from TMA-treated cells than did the IgG-poor effluent at similar protein concentrations. These observations suggest a new model of hypersensitivity resulting from human exposure to chemicals capable of combining with autologous proteins. In some individuals this could result in both an immune response to the new determinants without the production of significant quantities of IgE antibodies and hapten modification of receptor-bound IgE on mast cells and basophils. After sufficient antibody was produced, reexposure to the chemical with hapten modification of mast cells or basophils or both could result in mediator release and clinical symptoms. This mechanism may be relevant to immediate-type chemical hypersensitivity reactions in which IgE antibody has not been demonstrated.