bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radioimmunoassay for the Third Component of Human Complement
Authors: Lorenz P. E. , Tack B. F. , Schechter A. N. 
Published: January 2023

Abstract
The third component of human complement (C3) was purified to homogeneity by the method of Tack and Prahl (Biochem. 15: 4513, 1976). Sheep and rabbits were made hyperimmune with C3, as well as with activation fragments C3b, C3c, and C3d, as determined by standard double-diffusion assays. Radiolabeling of C3 and each of the fragments was performed by reductive alkylation with tritiated sodium borohydride (10 Ci/mmol) and formaldehyde. This method, which effects the methylation of free amino groups, allowed labeling to specific activities of ∼ 4 × 105 cpm/µg, with minimal change in function as determined by the hemolytic activity assay for C3. Competitive binding studies were conducted by incubation of the labeled and native C3 proteins with a 1/10,000 dilution of the sheep antiserum; free protein was separated from bound with a burro anti-sheep IgG antiserum. This radioimmunoassay indicated an affinity constant of about 5 × 109 liters/mole and with 100-µl samples could be used quantitatively in the range from 2 to 80 ng of C3.
The Role of Sialic Acid in the Functional Activity and Catabolism of C1̄-INH
Authors: Man Doreen P. , Minta Joe O. 
Published: January 2023

Abstract
Human C1̄-INH is a 4S neuraminoglycoprotein in normal serum that complexes stoichiometrically with and thereby inhibits the enzymatic activities of C1̄s, C1̄r, kallikrein, plasmin, activated Hageman factor, anaphylatoxin inactivator. Inherited deficiency of C1̄-INH activity has been associated with the clinical syndrome of hereditary angioneurotic edema. In this study, the effect of the enzymatic removal of sialic acid from C1̄-INH on its functional activity and metabolic behavior was evaluated. C1̄-INH was isolated from normal human plasma by column chromatography and preparative polyacrylamide gel electrophoresis. The highly purified protein was shown by SDS polyacrylamide gel electrophoresis to be comprised of a single polypeptide chain, m.w. 90,000. Incubation of C1̄-INH, at pH 7.4 with Vibrio cholerae neuraminidase at a ratio of 10:1 (wt/unit) for 60 min at 37°C resulted in the release of about 12% of the total sialic acid content. This treatment did not result in any gross alteration of the structure of C1̄-INH as assessed by its antigenicity, m.w. and C1̄s inhibitory activity.
Characterization of the Complement Lesion: The Formation of Trans-Membrane Channels and Their Mechanism of Assembly
Authors: Michaels David W. , Abramovitz Aaron S. , Hammer Carl H. , Mayer Manfred M. 
Published: January 2023

Abstract
Planar lipid bilayer membranes (BLM) have been used to study three features of the C5b-9 membrane attack sequence, namely: 1) whether the C5b-9 complex is assembled outside or within the membrane, 2) whether membrane thickness plays a role in the action of the cytolytic sequence, and 3) whether the terminal components increase membrane permeability in discrete steps, i.e., quanta, which would suggest trans-membrane channels.
In the first study involving “CIS/TRANS” experiments, we examined the process of C5b-9 assembly with respect to “sidedness”. The results show that the cytolytic sequence is divided into two reaction pairs, C5b, 6 plus C7 and C5b-8 plus C9. The reaction between the partners of each pair requires their presence on the same side of the membrane. However, the coupling between the pairs, i.e., between the C5b, 6, 7 complex and C8, can occur from opposite sides of the membrane, indicating that it occurs within the lipid interior of the bilayer.
Studies on the Lytic Sensitivity of Paroxysmal Nocturnal Hemoglobinuria (PNH) Erythrocytes (E)
Authors: Packman C. H. , Rosenfeld S. I. , Jenkins D. E. , Leddy J. P. 
Published: January 2023

Abstract
PNH E have an unexplained membrane defect making them highly susceptible to complement (C) lysis. Studies by others have found: 1) equal binding of antibody (Ab), C1 and C4, and similar C2 Tmax and decay, on PNH and normal human E; 2) markedly increased C3 binding by PNH E relative to Ab or C4 binding; 3) supranormal lysis per unit of C3 bound; 4) comparable numbers of 10nm electron microscopic (EM) ring lesions on lysed PNH and normal E membranes; and 5) in the presence of fluid phase and C5–C9, increased lysis of and C5 binding to PNH E, but equal lysis of PNH and normal E for a given quantity of C5 bound.
Our studies sought to further define the lytic behavior of PNH E. The PNH patients studied included cases with predominant populations of highly C-sensitive E (“type III”), or with intermediately sensitive E (“type II”), or with mixtures of E types.
Molecular Interactions of the Control Proteins C3b Inactivator and β1H with Various Complement Intermediates
Authors: Pangburn M. K. , Schreiber R. D. , Müller-Eberhard H. J. 
Published: January 2023

Abstract
Radioiodinated β1H was demonstrated to bind to sheep EAC4b, EAC4,2,3b and EC3b, but not to E, EA, EAC4,2 or to C3bINA and β1H treated EC3b. This binding was dependent upon the C3b concentration on the surface of the cells and could be inhibited by unlabeled β1H, free C3b or high concentrations of Factor B. The presence of activated properdin on EC3b cells did not affect β1H binding. Binding of radioiodinated C3bINA was demonstrated by stabilizing the enzyme substrate complex EC3b, βIH, C3bINA at 0°C. Binding of 125I-C3bINA to EC3b in the presence of β1H was 30-fold greater than in the absence of this cofactor. C3bINA binding was approximately stoichiometric with respect to bound β1H and this interaction had an apparent binding constant at 0°C of 108 M-1.
Fearon and Austen (J. Exp. Med. 146: 22, 1977) have reported that C3b on rabbit erythrocytes is protected from C3bINA and β1H action.
Enzymatic Inactivation of Complement by Mouse Saliva
Authors: Weill J. C. , Girard J. F. , Leca G. , Ayed K. 
Published: January 2023

Abstract
While searching for lymphocyte surface antigens in mouse saliva, we have observed that this secretion prevented the cmediated lysis of lymphocytes in a microlymphocytoxicity test (Terasaki plate). Mouse saliva has a preferential action on the C3 and C5 molecule which are degraded within 1 min in whole human serum, and then acts later on C2 and C4. Mouse saliva has no action on C1 and late components C6 to C9. With purified components the kinetic action of mouse saliva is slowed down. The action of saliva is inhibited by PMSF, TCLK, and aprotinine which indicates the role of a tryptic-like enzyme. When mouse saliva is injected i.v. into rats, the hemolytic capacity of their C is completely abolished in the first 24 hr and then recovers to its normal level on the 3rd day after injection. This inhibition of the C reaction is also obtained with rat and rabbit saliva but never with any of the human saliva tested.
Identity of Murine C4 and the MHC-Associated S Region Antigens
Authors: Wilde Charles E. , Capra J. Donald 
Published: January 2023

Abstract
As part of ongoing studies on the alloantigens of the murine major histocompatibility complex, the structures of the Ss and Slp antigens are being elucidated. These serum proteins exhibit m.w. of 200,000 daltons on SDS-polyacrylamide gels. Following reduction and alkylation, three subunits of 93,000, 78,000, and 35,000 daltons are generated. These subunits (molecular structures) are similar in size to the subunits of the human C4 C component as determined in our laboratory and by others. Furthermore, serologic cross-reactivity has been demonstrated between the murine S region antigens and human C4, with various antisera. The S region antigens are extremely labile, and are degraded by an activity in murine serum in a pattern similar to that generated by the action of C4b inactivator on human C4. Initial functional studies indicate that the ability to reconstitute the lytic capability of C4-deficient guinea pig serum co-purifies with the Ss antigenic activity.
The in Vitro Suppression of Spontaneous Erythrocyte Autoimmune Responses with Lymphocytes Activated with Concanavalin A
Authors: Ramshaw Ian A. , Woodsworth Mary , Eidinger David 
Published: January 2023

Abstract
When normal mouse spleen cells are cultured in vitro, large numbers of cells develop that produce antibody toward antigens found on bromelain-treated mouse erythrocytes (BrMRBC). The in vitro culture also generates T cells that mediate DTH toward these antigens. We have suggested that under in vivo conditions, suppressor T cells maintain these immune responses at a low level but that this suppression wanes when the cells are cultured in vitro. The present study examines the effect of concanavalin A (Con A) on the in vitro development of humoral and cell-mediated immunity to BrMRBC. Mitogenic concentrations of Con A prevented the development of both the PFC and TDTH responses toward BrMRBC. The Con A-induced suppression was due to the induction of suppressor T cells; thus the addition of Con A-activated cells to fresh spleen cell cultures prevented the development of both the PFC and TDTH response against BrMRBC.
Allogeneic Placenta is a Paternal Strain Antigen Immunoabsorbent
Authors: Wegmann Thomas G. , Singh Bhagirath , Carlson George A. 
Published: January 2023

Abstract
A partially purified 125I-labeled antibody directed against the murine major histocompatibility complex and injected i.v. into pregnant females is selectively absorbed by the placenta when the fetus bears the appropriate target antigen. The placenta specifically absorbs the antibody at both 13 days and 17 days of gestation, and the differential uptake is found as early as 2 hr after injection and as late as 12 hr. It is also seen in 13-day placentas that have had the fetus removed surgically, indicating that fetal circulation is not essential for the absorption to take place. Specificity controls eliminate the possibility that the differential uptake is due to Fc receptor binding or undefined effects of hybrid vigor. This increase in binding is not seen in the livers, spleens, kidneys, or lungs of the pregnant females. There is a slight decrease in radioactivity in the serum. These results indicate that the placenta is a paternal antigen-bearing immunoabsorbent that could serve as a barrier between the maternal immune response and the semi-allogeneic fetus.
Spontaneous Cytotoxicity
Authors: Muchmore A. V. , Decker J. M. , Blaese R. M. 
Published: January 2023

Abstract
We have shown that human mononuclear cells become spontaneously cytotoxic to a variety of erythrocyte targets after 7 days of in vitro culture. This phenomenon of spontaneous cytotoxicity occurs in low concentration of either autologous serum or FCS and is independent of any known stimulant. It does not require exogenous antibody, mitogen, or antigen. Once expressed, the cytotoxic cell has little, if any, specificity. Monocytes appear to be responsible for this observed in vitro cytotoxicity. We now present evidence that the development of spontaneous monocyte-mediated cytotoxicity in vitro is completely reversed by the addition of optimally mitogenic doses of PWM. PWM appears to reverse monocyte-mediated killing by stimulating a potent cell-mediated suppressor. This suppressor cell is radiosensitive and its action is blocked by inhibitors of protein synthesis. In contrast to other mitogen-driven suppressor models, PWM will inhibit spontaneous monocyte-mediated cytotoxicity even when added as late as 6 hr before the end of a 7-day culture.
Histamine Release Due to Bivalent Penicilloyl Haptens: The Relation of Activation and Desensitization of Basophils to Dynamic Aspects of Ligand Binding to Cell Surface Antibody
Authors: Dembo M. , Goldstein B. , Sobotka A. K. , Lichtenstein L. M. 
Published: January 2023

Abstract
We study the time-dependent aspects of activation and desensitization of passively sensitized human basophils by a bivalent penicilloyl hapten, [BPO]2, in the presence or absence of a monovalent penicilloyl hapten, [BPO]1. Data presented in this and the preceding paper are found to be consistent with a simple kinetic model of the binding and cross-linking reaction between [BPO]1, [BPO]2, and cell surface IgE. It is shown that the rapid perturbation of cross-linked IgE by simple dilution or washing of cells or by addition of excess [BPO]1 causes re-equilibration of the rate of histamine release within a matter of seconds. This demonstrates that no stable antigenindependent “activated” state of basophils exists and that cross-linked antibody is necessary throughout the entire time course of histamine release.
In addition, we show that desensitization requires the continuing presence of cross-linked antibody on the cell surface and that the rate of desensitization is a monotone increasing function of the number of cross-linked IgE molecules per cell. The rate of desensitization also appears to be a saturable function of the number of cross-linked IgE antibodies.
In light of the kinetic model these data indicate that the binding and cross-linking reaction between [BPO]1, [BPO]2, and cell surface IgE approaches thermal equilibrium with a time constant on the order of 10 sec or less. This in turn implies that cyclic aggregates of [BPO]2 and IgE are unstable. Finally, since release and desensitization occur on a time scale of 100 sec or more, dynamic, as opposed to equilibrium, properties of the cross-linking reaction are unlikely to have any influence on [BPO]2-induced histamine release.
Langerhans Cells Trap Tick Salivary Gland Antigens in Tick-Resistant Guinea Pigs
Authors: Allen John R. , Khalil Hanaa M. , Wikel Stephen K. 
Published: January 2023

Abstract
In the infested skin of tick-resistant guinea pigs, indirect immunofluorescence techniques have revealed that antigens from the ticks' salivary glands are associated with discrete dendritic cells in the epidermis. Evidence is presented to support the suggestion that these antigen-retaining cells are Langerhans cells.
Suppression and Enhancement of the Rabbit Primary in Vitro Antibody Response with Anti-Allotype Antibody: Concurrent Effects on Thymidine Incorporation, Blastogenesis, and Cell Surface Ig
Authors: Roux Kenneth H. , Metzger Dennis W. , Dray Sheldon 
Published: January 2023

Abstract
We have adapted an in vitro culture system to study the dose-dependent effects of purified anti-light chain allotype (b4 or b5) antibody on the primary Ab response of rabbit spleen cells to sheep erythrocytes. At high doses, anti-b4 or anti-b5 Ab suppressed the anti-SRBC response and the expression of cell surface immunoglobulins while stimulating blastogenesis and thymidine incorporation. At low doses, anti-allotype Ab markedly enhanced the immune response and, to a lesser extent, thymidine incorporation and blastogenesis. The mitogenic effect of anti-allotype Ab was observed in the absence of antigen only at the higher doses. When tested on heterozygous b4b5 SpC, the high and low doses of Ab selectively modulated the immune response with respect to cells bearing the target allotype. In vivo induced allotype suppression could not be reversed by culturing SpC with high or low doses of purified anti-allotype Ab directed against the expressed allotype. Our data support the concept that anti-Ig Ab reacts directly with B cell surface Ig to trigger a mitogenic response. This trigger, however, is not sufficient to induce differentiation to anti-SRBC secreting cells in the absence of the antigen.
F1 Hybrid Anti-Parental H-2k Cell-Mediated Lympholysis
Authors: Warner John F. , Cudkowicz Gustavo 
Published: January 2023

Abstract
H-2k-heterozygous F1 hybrid mouse spleen cells cultured with irradiated H-2k-homozygous stimulator cells generated specific anti-parent cytolytic effectors. The parental antigenic determinants recognized by responder cells during induction (afferent arm) and by effector cells during cytolysis (efferent arm) were coded for, or regulated by, the H-2K-Hh-3 region of the MHC, according to recombinant analysis. There were no detectable influences by other linked or unlinked genes on the phenotypic expression of parental antigens; however, the anti-parent responsiveness was modulated by background genes of responder cells. These experiments establish that the K end of H-2 controls determinants of F1 anti-parental H-2k CML, like the D end controls those of F1 anti-parental H-2b CML, thus confirming the basic symmetry of the H-2 complex. The relationship of this primary in vitro cell-mediated response with natural in vivo resistance to parental and allogeneic bone marrow grafts is discussed.
Immune reactivity and immunosuppressive intervention in experimental nephritis. II. Effect of TLI on the course of two models of nephritis in the inbred rat.
Authors: Lowry R P , Forbes R D , Carpenter C B , Gurley K E , Merrill J P 
Published: January 2023

Abstract
Fractionated high-dose (3400 rad) total lymphoid irradiation (TLI) induces a unique and prolonged state of immunologic unresponsiveness. The therapeutic efficacy of TLI in immune glomerular disease was explored in two animal models: the accelerated autologous form of nephrotoxic serum nephritis (AA-NTSN) and autologous immune complex nephritis (AICN). LEW rats with established AA-NTSN, subjected to TLI, manifest decreased levels of circulating antibody to the heterologous (sheep) immunoglobulin G (0.4 +/- 0.2 vs 1.2 +/- 0.3 mg/ml, mean +/- SE respectively, p less than 0.01) early post TLI in association with a reduction in histopathology and albuminuria (6.7 +/- 2.2 vs control 19.6 +/- 5.4 mg/24 hr, mean +/- SE, p less than 0.02). Administration of TLI to rats with established AICN effected significant (p less than 0.001) reduction in albuminuria (162 +/- 30 vs 315 +/- 27), serum creatinine (p less than 0.005), and the incidence of lipemia (p less than 0.01) vs controls. Adoptive transfer studies provided no evidence that the sustained beneficial effect of TLI in AICN was suppressor cell mediated. Thus, the observed therapeutic efficacy of TLI in the treatment of experimental nephritis, shown to be related to a reduction in the level of circulating antibody in AA-NTSN, provides a new model system for study of immunity and immunosuppression in primary glomerular disease.
Phenotypic expression of genetically-controlled natural resistance to Mycobacterium bovis (BCG).
Authors: Stach J L , Gros P , Forget A , Skamene E 
Published: January 2023

Abstract
Mycobacterium bovis (BCG), when maintained in vitro, readily incorporates [3H]uracil, the RNA precursor. The rate of [3H]uracil incorporation into bacilli is sharply reduced when the BCG is phagocytized by murine adherent resident peritoneal macrophages and subsequently released by the lysis of monolayers. Macrophages derived from mouse strains that are innately resistant to BCG infection in vivo (Bcgr) are able to inhibit the [3H]uracil incorporation into the bacilli in a significantly more effective way than macrophages from BCG-susceptible (Bcgs) strains. This difference is best demonstrated with a low rate of infection (BCG: macrophage ratio between 1:1 and 2:1), and is most pronounced at 4 to 5 days after in vitro infection of macrophage monolayers. In vivo interaction of BCG with peritoneal macrophages in situ results in the same pattern of enhanced inhibition of [3H]uracil incorporation by Bcgr macrophages. The use of Bcg-congenic mouse strains has confirmed that the Chromosome 1 Bcg (Ity, Lsh) locus is regulating the antimycobacterial activity of macrophages. We conclude that the resident macrophage is the cell population that expresses the phenotype of genetically determined resistance to BCG infection.
Aggressiveness of SJL/J lymphomas correlates with absence of H-2Ds antigens.
Authors: Rosloniec E F , Kuhn M H , Genyea C A , Reed A H , Jennings J J , Giraldo A A , Beisel K W , Lerman S P 
Published: January 2023

Abstract
SJL/J lymphomas emerged as H-2Ds-negative variants upon transplantation of their respective H-2Ds-positive spontaneous tumors. Of nine spontaneous SJL/J lymphomas examined, only two contained detectable numbers of H-2Ds-negative tumor cells. Of seven successfully transplanted tumors, however, four emerged as predominantly H-2Ds-negative tumors by their second transplantation. Long term SJL/J lymphoma lines, RCS 5 and SJL/SJL, were also found to be H-2Ds-negative. The expression of H-2Ks and I-As were maintained on all tumor lines examined. H-2Ds-negative tumor cells were consistent stimulators of syngeneic lymphoproliferation, whereas tumors maintaining H-2Ds expression varied in their stimulatory capacity. Transplantation times required to achieve morbidity in syngeneic mice correlated with tumor cell expression of H-2Ds. Tumors maintaining H-2Ds expression were less aggressive and required 57 to 150 days to produce morbidity compared with highly aggressive H-2Ds-negative tumors that required only 7 to 10 days at one-quarter of the cell dose (10(7) cells). Growth curve analysis based on spleen weights (corrected for body weight) indicated that three types of SJL/J lymphomas could be identified based on their expression of H-2Ds and ability to stimulate syngeneic lymphoproliferation: 1) indolent, nonstimulatory H-2Ds-positive tumors; 2) indolent, stimulatory H-2Ds-positive tumors; and 3) highly aggressive, stimulatory H-2Ds-negative tumors.
A mitogenic factor, released by stimulated human mononuclear cells and distinct from interleukin 2 (IL 2), B cell growth factor (BCGF), and interleukin 1 (IL 1).
Authors: Kasakura S , Taguchi M , Watanabe Y , Okubo T , Murachi T , Uchino H , Hanaoka M 
Published: January 2023

Abstract
Two lymphocyte mitogenic factors, interleukin 2 (IL 2) and blastogenic factor (BF), are generated concomitantly in human mixed lymphocyte cultures (MLC). The latter mitogenic factor is directly mitogenic for unstimulated lymphocytes, whereas the former mitogenic factor acts only on previously activated lymphocytes. Both factors had a m.w. range, as determined by gel filtration, of 18,000 to 30,000. Thus, these two factors were inseparable on the basis of m.w. size. However, BF and IL 2 were separable during ion exchange chromatography on the DEAE cellulose and phenyl-Sepharose chromatography. In addition, BF activity in the supernatants of MLC reached a maximum after day 5, whereas IL 2 activity peaked at day 3, thus distinguishing BF from IL 2 kinetically. These results clearly indicate that BF activity is mediated by molecules distinct from IL 2. The biochemical relationship between B cell growth factor (BCGF) and BF was also examined. Because BF was readily separable from BCGF by Con A-Sepharose chromatography, BF is distinguishable from BCGF. No augmentation of PHA-stimulated C3H mouse thymocyte proliferation was associated with the preparation of partially purified BF, demonstrating that BF and IL 1 are distinct molecules. Taken together, these results indicate that BF is clearly distinct from IL 2, BCGF, and IL 1. BF-containing MLC supernatants have direct mitogenic activity on both T and B cells. Both T and B cell blastogenic activities copurified during ammonium sulfate precipitation, gel filtration, DEAE cellulose ion exchange chromatography, and hydrophobic chromatography. Thus, these two activities appear to be biochemically inseparable. Monoclonal anti-Tac, that has been suggested to recognize the receptor for human IL 2, was highly inhibitory to the T cell response to the phenyl-Sepharose preparations of BF (IL 2-free). In contrast, this antibody had minimal or no effect on BF-induced B cell proliferation. However, when MLC supernatants were absorbed with a cloned IL 2-dependent T cell line, only IL 2 activity, but not BF activity, was removed, demonstrating that BF and IL 2 have different binding specificities. The precise mechanism(s) by which anti-Tac inhibits BF-induced proliferation of T cells is unknown at present. Additionally, during the course of these experiments, we observed that Con A-Sepharose chromatography could be used as a simple one-step method of separating BCGF from IL 2.