bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation of Alternative Pathway C3 Convertases Formed in the Presence of C3 Nephritic Factor (C3NeF)
Authors: Daha M. R. , Fearon D. T. , Austen K. F. 
Published: January 2023

Abstract
Interaction of C3b or EAC43, an erythrocyte intermediate bearing C3b, with B and D̄ results in formation of a labile fluid phase or cell-bound alternative pathway C3-convertase, . C3NeF, purified free of antigenic and functional activated properdin, stabilizes the labile convertase site on EAC43B and thus its capacity to stabilize and permit isolation of fluid phase C3B was examined.
Reaction mixtures containing 3.40 µg 131I-C3 (C3*) or 1.86 µg 125I-B (B*) alone, C3* and B*, C3*, B* and 5 ng D̄, and C3*, B*, D̄ and 0.1 units C3NeF in 100 µ1 DGVB++ were incubated for 30 min at 30°C, assessed for residual C3* and B* hemolytic activities, and 75 µl subjected to sucrose density ultracentrifugation (UCF). Interaction of C3* and B* did not diminish their hemolytic activities or alter UCF-characteristics. The presence of D̄ resulted in 76% depletion of B* and C3* hemolytic activities, but no convertase activity was recognized in the UCF fractions and B* and C3* sedimented at 5.9 S and 8.2 S, respectively.
The Allotyping of Complement Components in Whole Serum by Iso-Electric Focusing in Gel followed by Specific Haemolytic Assay
Authors: Hobart M. J. , Lachmann P. J. 
Published: January 2023

Abstract
Specific in gel hemolytic assays previously described by this laboratory have been used to detect complement components after the separation of the proteins of whole serum by isoelectric focusing. Characteristic band patterns for C4, C2, C5, C6, C7, and factors B and D have so far been seen after isoelectric focusing in thin polyacrylamide gel slabs.
The genetic polymorphism in Factor B is easily demonstrated by this method and a hitherto undescribed allele has been found.
A common polymorphism with a uniform distribution in different populations has been found for C6. Not less than four “rare” C6 alleles have been found in addition to the two common ones. Furthermore, in conjunction with Dr. C. A. Alper, a family has been shown to carry a “silent” C6 allele. It has not so far been possible to establish linkage between the C6 gene and other gentic markers. These include HL-A, red cell groups, C3 polymorphism, and C1̄-inhibitor deficiency.
Isolation and Characterization of Guinea Pig Properdin Using an EAC4h3g Intermediate
Authors: Nicholson A. , Austen K. F. 
Published: January 2023

Abstract
The properdin assay consisted of incubating 0.1 ml of an EAC4h3g (1 × 108) suspension in DGVB++ containing limited factor B and excess D̄, plus 0.1 ml of serum fractions for 5 min at 30C. Then 0.3 ml of guinea pig serum diluted 1:4 in 0.04 M EDTA buffer was added and the mixtures were incubated for 60 min at 37°C. One unit of properdin was defined as the reciprocal of the dilution of properdin which gave a Z of 1.0 above the background lysis caused by limited B and excess D̄ alone. The EAC4h3g intermediate was made by modifying the procedure described by Fearon et al. for making EAC4h3h (J. Exp. Med. 138:1305, 1975). Factors B and D̄ were purified from guinea pig serum by modifications of previously published methods (Brade et al., J. Immunol. 109:1174, 1972 and 112:1845, 1974). The factor B preparation contained 1495 units/O.D.280; the factor D̄ preparation contained 10,450 units/O.D.280.
Studies on the Mechanism of Immune Cytolysis
Authors: Okada H. 
Published: January 2023

Abstract
Sheep erythrocytes (E) and mouse mammary tumor cells (MM102) were sensitized with F(ab′)2 antibodies which had been prepared by pepsin digestion after passage through a Sepharose column coupled with anti-Fc to remove intact IgG. Those cells were lyzed at the incubation with rabbit serum (RaS) or guinea pig serum (GPS). Since E-F(ab′)2 did not fix C1 (E-F(ab′)2 was incubated with purified C1, and the fixed C1 to the cells was examined with C1 transfer to EAC4) and did not react with 125I-anti-Fc, the possibility was excluded that intact IgG antibodies had been remaining in the F(ab′)2 fraction. However no hemolysis of E-F(ab′)2 was observed at the incubation with C4-deficient GPS. To examine the effect of natural antibody, E, E-IgG (slightly sensitized) as well as E-F(ab′)2 were treated with EDTA-serum and the cells were incubated with 1/40 GPS after washing with GVB++. By the treatment with EDTA-serum, the hemolysis of E-F(ab′)2 was remarkably enhanced.
Inefficient Utilization of the Fifth Component of Guinea Pig Complement in Cobra Venom Factor-Induced Complement Lysis; Efficient Utilization of Human C5
Authors: Vogt W. , Lynen R. , Schmidt G. , Dieminger L. 
Published: January 2023

Abstract
Interaction of cobra venom factor with properdin Factors B and D̄ leads to generation of a C3- and C5-cleaving enzyme complex consisting of CVF and the larger fragment (Bb) of Factor B (Vogt et al., Hoppe-Seyler's Z. Physiol. Chem. 355:171, 1974). On incubation with EDTA-serum (C-EDTA) and red cells the CVFB̄ complex activates the terminal complement sequence and induces hemolysis (Pickering et al., Proc. Natl. Acad. Sci. 62:521, 1969). Hunsicker et al. (J. Immunol. 110:128, 1973) found that this indirect lysis involving activation of C5 in the fluid phase and subsequent cell fixation of C, C8 and C9, is inefficient when guinea pig C-EDTA is used but becomes marked when a trace of human serum is added. The enhancing activity provisionally called “Factor E” by Hunsicker et al., has been purified from human serum and identified as the fifth component of human complement, by immunoelectrophoresis, reaction with anti-C5 antiserum and functional tests.
The Role of the Capsular Polysaccharide in the Activation of the Alternative Pathway by the Pneumococcus
Authors: Winkelstein J. A. , Bocchini J. A. , Schiffman G. 
Published: January 2023

Abstract
The alternative pathway plays a significant role in the non-immune host's defense against the pneumococcus. The following studies concern the role of the capsular polysaccharide in the activation of the alternative pathway by the pneumococcus.
Some pneumococcal capsular polysaccharides, but not all, are able to activate the alternative pathway. Soluble purified capsular polysaccharide types 1, 4, and 25 activate C3 in C4-deficient guinea pig serum (C4D GPS), where types 2, 3, 14, and 19 do not. Since capsular polysaccharides exist in their native form attached to the pneumococcal surface, selected capsular polysaccharides were also tested when coupled by CrCl3 to a particulate carrier, sheep erythrocytes. When attached to sheep erythrocytes, capsular polysaccharide types 2 and 3 failed to consume C3 in C4D GPS, paralleling the results obtained when they were in solution. In contrast, type 25 capsular polysaccharide coupled to erythrocytes not only consumed C3 in C4D GPS, as it had when in solution, but also initiated alternative pathway lysis of the erythrocytes.
Pre-B Cells: Bone Marrow Persistence in Anti-µ-Suppressed Mice, Conversion to B Lymphocytes, and Recovery after Destruction by Cyclophosphamide
Authors: Burrows Peter D. , Kearney John F. , Lawton Alexander R. , Cooper Max D. 
Published: January 2023

Abstract
Chronic treatment of mice from birth with anti-µ antibodies aborts development of B lymphocytes and plasma cells. In these studies we show that bone marrow from anti-µ-treated mice contains a population of cells with cytoplasmic IgM, but which lack detectable cell-surface IgM. These cells are analogous to pre-B cells, defined in ontogenetic studies as the immediate precursors of B lymphocytes. Pre-B cells from bone marrow of anti-µ treated mice retain their functional integrity, as evidenced by their ability to give rise to sIgM+, LPS-responsive lymphocytes in culture. We also show that cyclophosphamide treatment destroys pre-B cells and that recovery of pre-B cells in bone marrow precedes the regeneration of sIgM+ B lymphocytes. Generation of B lymphocytes in adult mice apparently occurs exclusively in the bone marrow because induction of extramedullary hemopoiesis in spleen was not accompanied by the appearance of pre-B cells in that organ.
Inhibition of Cytolytic T Lymphocyte Activity with Subcellular Alloantigen Preparations and with Unlabeled Allogeneic Target Cells
Authors: Linna T. Juhani , Engers Howard D. , Cerottini Jean-Charles , Brunner K. Theodor 
Published: January 2023

Abstract
Studies of the specificity of target cell lysis by cytolytic T lymphocytes (CTL) are usually based on assays measuring the competitive inhibition of radioactively labeled target cell lysis with intact unlabeled cells carrying antigens of the same or different specificities. So far, attempts to inhibit lysis with subcellular antigen preparations have met with little success. In order to obtain more favorable conditions for competitive inhibition of target cell lysis with subcellular antigens, we have introduced two modifications of the techniques of CTL induction and lysis, including a) generation of CTL by stimulating spleen cells from alloimmune mice with particulate alloantigen preparations in vitro, and b) restriction of effector to target cell interaction (in the presence or absence of particulate antigen) to 15 min, thus restricting lysis to those target cells initially bound to CTL. With these modifications of the standard 51Cr-release assay, specific inhibition by unlabeled target cells was readily and consistently demonstrable. Subcellualr particulate antigen preparations were also able to inhibit specifically CTL activity, but the inhibition was usually less marked than with intact target cells, and not every antigen preparation had the capacity to inhibit in an immunologically specific way.
Tumor Cell Cytostasis by Macrophages and Antibody in Vitro
Authors: Pasternack Gary R. , Johnson Robert J. , Shin Hyun S. 
Published: January 2023

Abstract
Tumor cells in a cytostatic state caused by macrophages and antibody were isolated. Such suppressed cells excluded vital dye, incorporated uridine and leucine, and metabolized glucose. They did not, however, incorporate thymidine, nor did they resume cell division in culture. During prolonged culture, these cells eventually died. In this system, cytostasis was an all-or-nothing phenomenon at the level of the individual cell. Once in the cytostatic state tumor cells did not resume proliferation.
Pharmacologic Control of the Hormonally Modulated Immune Response
Authors: Pierpaoli Walter , Maestroni Georges J. M. 
Published: January 2023

Abstract
A recently developed pharmacologic means for suppressing acquired immunity by drugs acting on neuroendocrine regulation has been applied to transplantation immune reactions. A number of drugs have been tested singly and in combination for their capacity to suppress the immune response of mice grafted with allogeneic skin. Another model involved newborn F1 hybrid recipients inoculated with spleen cells from donors of parental strains that had been made specifically “unresponsive” by drug and alloantigen treatment. These procedures led to the identification of a combination of four drugs that induced a remarkable delay in allograft rejection and a prolonged unresponsiveness to alloantigens. This combination of drugs also abrogated the graft-vs-host-runting syndrome in newborn hybrid recipients.
Specific Suppression of Anti-Hapten Reaginic Antibody Titers with Hapten-Coated Liposomes
Authors: Schwenk Robert , Lee Weng Y. , Sehon Alec H. 
Published: January 2023

Abstract
Reaginic antibodies of DNP and ovalbumin (OA) were induced in B6D2F1 mice by a single i.p. injection of 1 µg of DNP3-OA suspended with 1 mg of Al(OH)3 in 0.5 ml of saline. The anti-DNP reaginic antibody titers were markedly depressed by treatment of mice with DNP-coated liposomes. This treatment, however, did not affect the level of antibody formation to OA.
Alteration of the Fatty Acid Composition of Membrane Phospholipids in Mouse Lymphoid Cells
Authors: Mandel Gail , Shimizu Stanley , Gill Ronald , Clark William 
Published: January 2023

Abstract
A simple method is described for introducing exogenous fatty acids into the membrane phospholipids of the murine leukemia cell EL-4, and into the membrane phospholipids of resting mouse lymphocytes. The method involves culturing of the cells with free or methylated fatty acids at concentrations up to 50 µg/ml. The presence of serum in the culture medium does not interfere with fatty acid uptake, but does increase the growth rate and viability of the cells. Membrane lipid composition returns to normal after the cells are grown in medium without exogenous fatty acid. Fractionation of the cell membranes confirmed that exogenous fatty acids were incorporated into the phospholipids of the plasma membrane.
Functional Properties of EL-4 Tumor Cells with Lipid-Altered Membranes
Authors: Mandel Gail , Clark William 
Published: January 2023

Abstract
The effect of fatty acid substitution of membrane phosphatides on a number of surface-mediated phenomena in EL-4 cells was examined. Tumor cells were grown in the presence of fatty acids that could be expected, on the basis of their physical properties, either to stiffen or fluidize the plasma membrane. Substitution of EL-4 cell membrane phosphatides with as much as 74% nonade-canoic acid (19:0) had no effect on either conjugation with effector cells or subsequent cytolysis by the effector cells. Substitution with linolenic acid (18:3) or elaidic acid (18:1trans) likewise affected neither conjugation nor cytolysis. Substitition with these fatty acids also had no effect on the susceptibility of EL-4 cells to cytolysis by antibody plus complement. On the other hand, the rate of patching of H-2 surface antigens was very sensitive to substitution by both 19:0 and 18:3. Although not conclusive, these results suggest that alterations of the fluid state of the membrane that affect lateral movements of surface proteins may not affect cytolytic processes.
The Requirement for the Fc Portion of Antibody in Antigen-Antibody Complex-Mediated Suppression
Authors: Morgan Edward L. , Tempelis Constantine H. 
Published: January 2023

Abstract
The role of the Fc portion of antibody in immune complex-induced suppression was studied in vivo and in vitro. BSA pheasant anti-BSA complexes, formed in antigen excess (Ag1Ab1), were found to suppress both responses to BSA and SRBC. When complexes were formed with F(ab′)2 fragments of pheasant anti-BSA, no suppression was observed, indicating that the Fc piece was indeed essential for the induction of Ag-Ab complexmediated suppression.
Studies on the Terminal Stages of Immune Hemolysis
Authors: Boyle Michael D. P. , Langone John J. , Borsos Tibor 
Published: January 2023

Abstract
The intermediate product EAC1-8 released cytoplasmic components as a result of at least two sequential reactions after its interaction with C9. Binding of C9 to EAC1-8 occurred in a few minutes even at 0°C. Trypsinization of EAC1-9 prepared and held at low temperature resulted in nullification of the potential hemolysis of these cells. A brief incubation at 30 or 37°C resulted in the formation of an intermediate whose hemolytic potential could not be nullified by trypsin. The failure of trypsin to nullify hemolysis was attributed to the insertion of C9 into the cell membrane. Studies on the effect of EDTA or low temperature suggested that the reported temperature-dependent step in E* formation described by Frank et al. was the insertion of C9. The results of the studies with 86Rb-labeled EAC1-8 indicated that a transmembrane channel was not formed until after the C9 had been inserted and a further reaction or reactions had occurred.
Genetic Control of the T Lymphocyte Proliferative Response to Staphylococcal Nuclease: Evidence for Multiple MHC-Linked Ir Gene Control
Authors: Schwartz Ronald H. , Berzofsky Jay A. , Horton Clare L. , Schechter Alan N. , Sachs David H. 
Published: January 2023

Abstract
Genetic control of the T lymphocyte proliferative response to staphylococcal nuclease was investigated with the sensitive peritoneal exudate, T lymphocyte enriched cells (PETLES) assay. All mouse strains examined responded to nuclease when immunized with large doses (0.6 nmole) of the antigen in complete Freund's adjuvant. Nevertheless, control of responsiveness by major histocompatibility (MHC)-linked immune response (Ir) genes was discerned when the nuclease responses were normalized to the PPD response of the same strain and compared among strains possessing the same non-H-2 background. In addition, lowering the immunization dose enhanced the difference between low and high responder strains. Genetic mapping studies carried out under these limiting conditions confirmed the earlier findings of an Ir-Nase gene mapping to the I-B subregion of the H-2 complex on the basis of low responsiveness by the B10.A(4R) and B10.A(5R) recombinant strains. However, immunization of these recombinant strains with 0.6 nmole of nuclease demonstrated a difference in their responsiveness, suggesting that the genetic control might be more complex. This suggestion was confirmed by cross-stimulation studies of nuclease-primed PETLES with fragments of nuclease. The pattern of the proliferative responses was found to be controlled by MHC-linked genes mapping in the I (and possibly the K and D) region, and appeared to be unique for each haplotype. In the case of the 4R and 5R recombinants the patterns appeared different from either that for the high responder B10.A or that for the low responder B10 parental strains. These results suggest that several Ir genes are involved in the T cell proliferative response to nuclease. Furthermore, the fact that fragments of nuclease, which possess little of the tertiary structure of the native molecule, could stimulate a proliferative response in PETLES immunized to whole nuclease suggests that T cells, in contrast to most antibodies, recognize antigenic determinants that possess a similar conformation in both the native molecule and the fragments.
Absence of Correlation of Ig-1 Allotype and IgE Antibody Suppression in SJL Mice
Authors: Itaya Takaki , Okumura Ko , Watanabe Naohiro , Ovary Zoltan 
Published: January 2023

Abstract
In previous studies it has been found that in the SJL strain of mice, normal thymus-derived cells have a suppressor effect on anti-hapten IgE production. It has also been demonstrated with (SJL × BALB/c)F1 mice and backcrosses to the SJL parent that the suppressive function is inherited by a single autosomal Menedelian gene, not linked to the H-2 gene complex (1).
Chronic allotype suppression can be obtained in (SJL × BALB/c)F1 progenies if the BALB/c female before mating is immunized with Ig-lb (paternal, i.e., SJL) allotype (2, 3). In the suppressed (SJL × BALB/c)F1 mice IgG2a immunoglobulin subclass can be detected, but only of the Ig-la allotype and not of the Ig-lb allotype. It is well known that the IgG2a immunoglobulin subclass carries the Ig-la and Ig-lb allotypes.
It was of interest, therefore, to examine if in the sera of the backcross mice (SJL × BALB/c)F1 × SJL a correlation could be found between the nonpersistence of anti-hapten IgE production and the Ig-Ib allotype.
Association of C8 Deficiency with Sickle-Thalassemia Hemoglobinopathy
Authors: Agnello Vincent , Pariser Kenneth M. , Babott Doreen 
Published: January 2023

Abstract
Three pedigrees with hereditary C8 deficiency have thus far been reported. All three propositi have been black. Two additional cases of selective C8 deficiency are reported here, a black female with complete deficiency of C8 and a black male with approximately 50% of the C8 normal mean. Both have sickle-thalassemia hemoglobinopathy (S-T) with virtually identical percentages of A2, F and S hemoglobin. The female has two offspring that carry only the sickle trait and have normal C8 levels. Family studies have not been possible in the second case. Four additional patients with sickle-thalassemia hemoglobinopathy have been thus far studied. All have normal C8 levels, but their hemoglobin patterns while diagnostic for S-T disease differ significantly from the first two cases studied. The C8 levels in several cases of sickle cell, sickle trait, thalassemia, and thalassemia trait disease, thus far studied have been normal.
Lack of C5 Convertase-Generating Activity in Naja haje Cobra Factor
Authors: Bauman N. 
Published: January 2023

Abstract
Commercial cobra factor is prepared from the venom of either Naja naja, the Indian cobra, or Naja haje, the Egyptian cobra, and is not marked as to source. Cobra factor from Naja haje (CVFh), although able to generate C3-cleaving activity, does not support passive lysis. Cobra venom from Naja naja (CVFn), upon incubation with normal human serum, depletes C3 through C9, and causes conversion of C3 and B as observed in immunoelectrophoresis. CVFh also causes conversion of C3 and B and depletes C3; but C5 through C9 are spared. CVFh and CVFn were found to be equally resistant to C3bINAhu.
When CVFn was incubated with normal human or guinea pig serum, an activity was generated which was detectable as a zone of hemolysis in agarose plates containing guinea pig erythrocytes and EDTA, when placed near a well containing human or rat, but not guinea pig, CEDTA.
Regulation of Macrophage Motility by Components of the Complement System
Authors: Bianco C. , Götze O. , Cohn Z. A. 
Published: January 2023

Abstract
Inhibition of macrophage migration is a well established assay for delayed hypersensitivity. The inhibitory factor (MIF) is a lymphokine which also plays a role in macrophage activation. In this report we show that complement derived peptides can regulate the motility of macrophages in a MIF type assay. Cleavage products of factor B inhibit migration, while cleavage products of C5 increase macrophage migration.
Mouse peritoneal cells obtained 5 days after i.p. injection of mineral oil were washed and centrifuged into capillary tubes. The capillaries were sectioned at the medium-cell interface and placed into chambers containing 450 µl of 10% heat-inactivated fetal bovine serum (56°C, 1 hr) in RPMI 1640 medium. After addition of the complement derived peptides, the chambers were incubated for 18 hr at 37°C and the areas of migration determined. More than 90% of the cells remained viable at the end of the assay.
Affinity Labeling of C1s̄ with an Extended Reagent
Authors: Bing David H. , Laura Richard , Cory Michael 
Published: January 2023

Abstract
The reagent m-[o-(2-chloro-5-sulfonylfluorphenylureido) phenoxybutoxybenzamidine [mCP(PBA)-F] is an extended affinity labeling reagent in which the reactive sulfonylfluoride is 17.1 Å from a cationic benzamidine function that competitively inhibits C1s̄ esterase and protease activity. Purified human C1s̄ with high specific esterolytic activity was selectively and irreversibly inactivated with mCP(PBA)-F. At 16.6 µM mCP(PBA)-F and 22.1 µM C1s̄, the time course of inactivation followed pseudo first order kinetics (kL = 2.45 × 10-3 sec-1, 23°C). The initial rate of inactivation of C1s̄ at several mCP(PBA)-F concentrations followed a rectangular hyperbolic function preducted for affinity labeling kinetics (KL = 87.3 µM, k2 = 3.02 × 10-3 sec-1). The hydrolyzed affinity labeling reagent lacking the reactive sulfonylfluoride group [mCP(PBA)-OH] was a strong competitive inhibitor (KI = 6.82 µM vs 0.63 mM for benzamidine alone) implicating active site binding.