bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of the Classical and Alternate Complement Pathways in Host Defenses Against Cryptococcus Neoformans Infection
Authors: Diamond Richard D. , May Joseph E. , Kane Michael A. , Frank Michael M. , Bennett John E. 
Published: December 2022

Abstract
The relationship between complement and the heat labile factors known to be necessary for phagocytosis of Cryptococcus neoformans by human leukocytes has been examined. C. neoformans or purified cryptococcal polysaccharide consumed 36.2 to 76.3% of late complement components (C3-9) in guinea pig serum. Phagocytic studies with C2-deficient human serum and C4-deficient guinea pig serum permitted evaluation of the roles of the classical (C142) and alternate complement pathways in the phagocytosis of these organisms.
The number of cryptococci ingested per neutrophil (phagocytic index) at 30 min in sera with only alternate pathway function was 40 to 60% of that found in sera with both classical and alternate complement pathways intact. When purified C2 or C4 was added back to the corresponding deficient sera, phagocytic indices increased to ranges obtained by using corresponding normal sera with both complement pathways active. By 2 hr, phagocytic indices for deficient sera equaled phagocytic indices for normal sera. Early classical complement components were therefore required for optimum phagocytic kinetics. The fact that late components of complement were required for phagocytosis was established by the fact that chelation of Ca++ and Mg++ with EDTA inhibited the reaction, as did heating at 56°C and use of serum depleted of the late components of complement by cobra venom factor. None of the sera used in these studies had detectable anti-cryptococcal antibody by an indirect fluorescent antibody technique, but absorption of human sera at 0°C with cryptococci lowered phagocytic indices to about 10% of normal. The loss of activity after absorption was demonstrated to be due to loss of specific antibody which was required to activate the C142 pathway as well as to loss of properdin which was required to activate the alternate pathway. The classical complement pathway appeared to be functioning primarily to activate the alternate pathway, which in turn was responsible for opsonization. Serum depleted of properdin or of the heat labile properdin factor B was markedly deficient in opsonic activity. In the former case addition of properdin restored optimal kinetics. Thus, function of the classical pathway in normal serum did not adequately mediate opsonization.
Unlike serum, spinal fluid did not opsonize cryptococci. With fluorescent anti-human β1C, little or no complement was detectable on the surface of cryptococci obtained from the spinal fluid of four patients with cryptococcal meningitis, but was found on cryptococci after incubation in fresh sera from these patients. However, cerebrospinal fluid from two of three patients with active disease could restore opsonic activity of fresh serum absorbed with cryptococci.
In vitro Studies of Cell-Mediated Immunity in an Acute Viral Infection
Authors: McFarland Henry F. 
Published: December 2022

Abstract
The effect of Sindbis virus-sensitized lymphocytes on acutely infected mouse embryo fibroblasts has been studied in vitro. Sindbis virus-immune lymphocytes are capable of lysing the infected target cells bearing surface viral antigen before viral-induced lysis occurs. The cytotoxicity was virus-specific since lymphocytes sensitized to yellow fever virus were unable to kill the Sindbis virus-infected target cells. The effector cell in this in vitro assay has been shown to be a T cell, and the cytotoxic reaction can be blocked by Sindbis virus-immune serum.
In distribution to lysis of infected cells by T cells, viral clearance is dependent on a population of noncytotoxic, adherent cells, probably macrophages. Further, macrophage function in this assay was virus-specific, since adherent cells from animals immunized to a second virus were unable to reduce significantly virus content. Consequently, the full expression of recovery mechanisms in this model of an acute viral infection most likely depends on a balance between lymphocyte-mediated lysis of infected cells and viral clearance by macrophages and antibody.
The Serum Factor Stimulating Colony Formation In Vitro by Murine Plasmacytoma Cells: Response to Antigens and Mineral Oil
Authors: Metcalf Donald 
Published: December 2022

Abstract
Colony formation in agar-medium by three transplanted mouse plasmacytomas (MOPC-460; MOPC-315; HPC-127) was stimulated by addition of serum from mice injected with endotoxin or a variety of bacterial antigens. This effect was potentiated by the addition of mercaptoethanol. The active serum factor was heat-labile but resisted ether treatment and was non-dialysable. Serum plasmacytoma-stimulating activity was localized electrophoretically as a single peak of β mobility and was separable from the colony-stimulating factor stimulating granulocytic and macrophage colony growth. Injection of mineral oil to BALB/c mice increased the capacity of serum or peritoneal cells to stimulate plasmacytoma colony formation in vitro.
Regulation of T Lymphocyte Function by Immunoregulatory Alphaglobulin (IRA)
Authors: Menzoian James O. , Glasgow Arthur H. , Nimberg Richard D. , Cooperband Sidney R. , Schmid Karl , Saporoschetz Inna , Mannick John A. 
Published: December 2022

Abstract
Immunoregulatory alphaglobulin, IRA, has been shown to suppress T cell-dependent immune responses. The present studies were to determine the effect of IRA on B cell-mediated immune responses. IRA-protein, and a more purified species, IRA peptide were shown to inhibit the T cell-mediated responses of spontaneous rosette formation between human peripheral lymphocytes and sheep red blood cells (SRBC) and the plaque-forming cell response in mice injected with SRBC. The same IRA preparations were ineffective in suppressing rosette formation between human peripheral lymphocytes and EAC-SRBC and the plaque-forming cell response to Escherichia coli lipopolysaccharide, both of which are B cell-mediated, T cell-independent immune responses. Therefore, we believe that IRA is effective in nonspecific suppression of only immune responses dependent on T cell function.
Interaction of Isoantibody and Cytotoxic Lymphocytes with Allogeneic Tumor Cells
Authors: Faanes Ronald B. , Choi Yong Sung 
Published: December 2022

Abstract
Specific isoantibody against DBA/2J mastocytoma cells was purified from immune serum by immunoadsorption without losing its inhibiting activity of lymphocyte-mediated cytotoxicity (LMC). The molecular nature of the isoantibody was studied with 125I-labeled antibody (125I-IS). The Ig nature was verified by specific serology with rabbit anti-mouse Ig, acrylamide gel analysis, and specific binding to mastocytoma cells.
The fate of 125I-IS on the surface of activity metabolizing mastocytoma cells was studied. Almost all 125I-IS are bound to mastocytoma cells, inhibiting T cell-mediated cytotoxicity. At the time of the onset of the “escape” from IS inhibition of LMC, 20 to 30% of bound 125I-IS was released and the surface antigens were regenerated. This phenomenon is also temperature dependent, requiring active metabolism of the target cells.
Isolation of an Enzyme from Streptococcus Sanguis Which Specifically Cleaves IgA
Authors: Plaut Andrew G. , Genco Robert J. , Tomasi Thomas B. 
Published: December 2022

Abstract
IgA protease, a metal-dependent endopeptidase elaborated by bacteria normally found in the human oral cavity and intestinal tract, can be isolated in good yield from culture filtrates of Streptococcus sanguis. The enzyme has pronounced specificity for secretory and serum IgA, which it cleaves to form Fcα and Fabα fragments.
Inactivation of Slow Reacting Substance of Anaphylaxis (SRS-A) by Arylsulfatases
Authors: Orange Robert P. , Murphy Robert C. , Austen K. Frank 
Published: December 2022

Abstract
Two different arylsulfatase preparations inactivated slow reacting substance of anaphylaxis (SRS-A) in a dose-related fashion. The loss of SRS-A activity could not be attributed to β-glucuronidase activity in the arylsulfatase preparations or to nonspecific adsorption to proteins. The arylsulfatase and SRS-A inactivating activities shared similar pH requirements, kinetics, and elution properties on Sephadex G-200 gel filtration. With spark source mass spectrometry, analysis of highly purified preparations of SRS-A revealed an abundance of 32S and 40Ca in the active samples as compared to controls. These findings indicate that SRS-A may contain a sulfate ester group.
Activation of the Alternate Pathway of Human Complement by Rabbit Cells
Authors: Platts-Mills Thomas A. E. , Ishizaka Kimishige 
Published: December 2022

Abstract
The hemolysis of sheep red blood cells (SRBC) occurs via the classical complement pathway and is blocked by ethylene glycol bis-amino tetraacetate (EGTA). By contrast, fresh normal human serum in EGTA buffer was found to cause &gt;90% hemolysis of unsensitized rabbit red blood cells (RaRBC) at a final dilution of 1:15. Absorbing human serum with RaRBC at 0°C will remove only 45% of this hemolytic activity and the same activity is present in human hypogammaglobulinemic serum. When rabbit lymphocytes were incubated with human serum in EGTA buffer, complement fixation occurred on their surface which was demonstrated with radiolabeled antibodies to human C3 or as “blocking” of the complement receptor. With purified complement components it was shown that the EGTA buffer completely blocked C1 but not C4, C2, or the late complement components. These findings show that a rabbit cell surface component can activate the alternate pathway of complement in human serum and suggest that this activation does not involve antibody.
Further Studies on the Inhibition of Allergic Encephalomyelitis by l-Asparaginase
Authors: Khan Amanullah , Levine Seymour 
Published: December 2022

Abstract
l-Asparaginase inhibited the hyperacute form of EAE in rats. The inhibition was inversely proportional to the intensity of the eliciting immunization. Passive transfer experiments proved that at least part of the inhibition was related to effects on the fully immunized lymphoid cells and its interaction with the neural target. The inhibition was caused by specific enzyme activity and not by endotoxin contamination or nonspecific stress.
Comparison of Irradiated and Mitomycin-Treated Mouse Spleen Cells As Stimulating Cells in Mixed Lymphocyte Cultures and in vitro Sensitization
Authors: Hodes Richard J. , Terry William D. 
Published: December 2022

Abstract
Mitomycin-treated and irradiated mouse spleen cells were compared as stimulating cells in allogeneic mixed lymphocyte culture (MLC) and as sensitizing cells in in vitro allogeneic sensitization. C57BL/6 and BALB/C spleen cells were irradiated at doses up to 5000 rads or treated with mitomycin C to inhibit DNA synthesis. Irradiated cells, as well as mitomycin-treated cells, were efficient both in stimulating MLC and in sensitizing in vitro.
Properties of Antisera to Ganglioside GM1 and Asialo GM1
Authors: Naiki Masaharu , Marcus Donald M. , Ledeen Robert 
Published: December 2022

Abstract
The object of this study is to prepare antisera to purified glycosphingolipids for immunocytochemical studies. Rabbits were immunized with ganglioside GM1 complexed either to methylated BSA or to a glycoprotein isolated from human erythrocytes, and to asialo GM1 complexed to the erythrocyte glycoprotein. IgG and IgM antibody fractions were separated by chromatography on Sephadex G-200 and their properties were determined by complement fixation. IgG antibodies to asialo GM1 were highly specific and exhibited little cross-reactivity with GM1 or other glycolipids, but IgM antibodies cross-reacted extensively with gangliosides GM1 and GD1b. Complement fixation of IgG anti-asialo GM1 with asialo GM1 was completely inhibited by about 15 nmoles of ganglio-N-tetraose, the carbohydrate moiety of this glycolipid.
Both IgG and IgM antibodies to GM1 cross-reacted extensively with asialo GM1 and GD1b, but specific IgG antibodies to GM1 were revealed by absorption with asialo GM1. The specific and cross-reacting IgG antibodies to GM1 were inhibited by the pentaose moiety of this glycoplipid, but these antibodies were much harder to inhibit than IgG anti-asialo GM1. These results demonstrate that it is possible to prepare specific antisera to purified glycolipids with a single administration of antigen, in contrast to previous studies in which repeated injections of ganglioside mixtures were employed.
Immunity to Experimental Cholera
Authors: Pierce Nathaniel F. , Reynolds Herbert Y. 
Published: December 2022

Abstract
The protective role of serum IgG antitoxin was studied in dogs transfused either with whole plasma or purified serum IgG from hyperimmunized dogs. Washings of jejunal Thiry-Vella loops after plasma transfusion yielded IgG antitoxin. Furthermore, dogs transfused with antitoxic plasma were protected against intrajejunal challenge with cholera toxin and this protection could not be diminished by extensive washing of the jejunum prior to toxin challenge. Finally, intact dogs transfused with antitoxic serum IgG were highly protected against orogastric challenge with viable Vibrio cholerae. These results indicate that serum IgG can play a protective role at the surface of the gut mucosa or within its lumen. They also suggest that serum-derived antibody may exert its effect while intimately associated with the mucosa, a position in which it may be protected from rapid destruction by proteolytic enzymes.
The Modulating Effect of Cholera Enterotoxin on the Immune Response
Authors: Chisari Francis V. , Northrup Robert S. , Chen Lincoln C. 
Published: December 2022

Abstract
Cholera enterotoxin (CE) is a potent adjuvant when administered simultaneously with sheep red blood cells (SRBC) and an immunosuppressant when given 12 hr before or after the antigen. Antigen clearance is not modified, but splenic adenyl cyclase activity is significantly enhanced reaching peak levels within 12 hr. Theophylline enhances the modest adjuvant effect of 0.01 µg of CE and inhibits the pronounced adjuvant effect of 0.05 µg. The relationship between adenyl cyclase stimulation and modulation of the immune response is discussed.
Anti-Histone KSAchicken Antibody from Guinea Pig
Authors: Mura Casilda , Huang P. C. , Levy David A. 
Published: December 2022

Abstract
Avian erythrocyte-specific histone KSA was purified from chicken red blood cells by selective extraction and by chromatography on amberlite CG-50 columns. This histone was used in the production of antibody in guinea pigs. By immunoprecipitation and microcomplement-fixation tests, the antibody was shown to be specific for histone KSA; reaction was not seen with histones KAP, ARE, GRK, LAK, and KAS. The observation supports the notion that histone KSA has an independent origin from the other histones.
Antibody Affinity
Authors: Gopalakrishnan P. V. , Karush Fred 
Published: December 2022

Abstract
Rabbit antibody of restricted heterogeneity induced by a lactoside determinant has been specifically purified and further fractionated into functionally homogeneous populations. These preparations have been used to evaluate the association constants for binding to the bacteriophage φX174 to which had been coupled multiple lactoside groups. The constants were obtained from equilibrium neutralization experiments and compared to the association constants for the binding of a monovalent lactosyl-containing ligand. The central finding is that the constant for the binding of the antibody to bacteriophage is greater by a factor of 104 than that for the monovalent ligand. As previously suggested in another system, this effect is attributed to bivalent interaction and serves to establish the generality of the enhancement phenomenon. The use of functionally homogeneous antibody precluded the possibility that selection of high-affinity antibody was responsible for enhancement. The issue of the number of critical sites available for neutralization on the conjugated bacteriophage was clarified by comparison of the observed reactivation kinetics with the behavior predicted from a model system. It was inferred that the number of such sites did not exceed two and could be one. Thus the process of neutralization and reactivation can be adequately described by an analysis based on single-site kinetics.
Cytotoxic Activity of Lymphocytes
Authors: Walker Sharyn M. , Lucas Zoltan J. 
Published: December 2022

Abstract
Antibody to human lymphotoxin was elicited in rabbits immunized with partially purified supernatants of human spleen cells stimulated by phytohemagglutinin; Anti-LT activity, assayed by neutralizing soluble LT toxicity to indicator mouse L cells, is confined to the immunoglobulin fraction of the serum; it cannot be removed by adsorption to L cells, human fibroblasts or lymphocytes, or to human serum. Anti-LT activity is removed by immunoadsorption to Sepharose conjugated with goat antisera to rabbit 7S immunoglobulin; partial recovery of anti-LT activity is effected by elution with high molarity acid buffer. The amounts of antisera necessary to effect neutralization are linearly proportional to LT concentration. Anti-human LT neutralizes the toxicity of supernatants of human lymphocytes activated by other, non-PHA mitogens (antigens to which the lymphocyte donors are sensitive) and allogeneic lymphocytes in mixed leucocyte culture. However, anti-human LT is specific for human LT as it will not neutralize guinea pig or rat LT.
Induction of Lymphocyte-Mediated Cytotoxicity against Allogeneic Tumor Cells by Concanavalin a in Vivo
Authors: Anaclerio Allessandro , Waterfield J. Douglas , Möller Göran 
Published: December 2022

Abstract
The in vivo administration of concanavalin A (Con A) induced a dose and time dependent cytotoxic response in spleen cell populations when tested against allogeneic target cells in vitro. Con A doses between 60 µg and 480 µg induced cytotoxicity, which was maximal 24 hr after injection and thereafter disappeared. Cytotoxicity correlated with the time of maximum DNA synthesis and blast transformation in the spleen. The addition of extra Con A to the in vitro test system did not change the kinetics or intensity of cytotoxicity. The results are discussed in terms of the effect of Con A in the activation of cytotoxic lymphocytes and its possible further role in effecting “killer-target” cell binding.
Hapten-Specific IgE Antibody Responses in Mice
Authors: Katz David H. , Hamaoka Toshiyuki , Newburger Peter E. , Benacerraf Baruj 
Published: December 2022

Abstract
The studies presented in this paper were performed to compare the responses of B lymphocytes of the IgG and IgE classes, respectively, to relatively constant conditions of activated T cell participation in antibody production by these cells. Two systems were employed: a) regulation of antibody responses by a potent nonantigen-specific T cell influence provided by the reaction of allogeneic T cells with alloantigens on the surface of antigen-specific B cells (“allogeneic effect”); and b) induction of adoptive secondary cooperative anti-hapten antibody responses by administering hapten and carrier determinants on separate molecules. The data presented here demonstrate that the allogeneic effect, although providing a potent mechanism for stimulating IgG B lymphocytes, either fails to stimulate or suppresses IgE B cells under the same conditions. Furthermore, under circumstances where antibody responses are elicited by administering nonlinked hapten and carrier determinants, the evidence implies that IgE B cells can be stimulated to a greater extent than IgG B cells in conditions of limited T cell participation. Taken collectively, these data support the concept that differences observed in the degree of helper function for one or the other antibody class may reflect differences in sensitivities of IgE vs IgG B cells to the complex enhancing and suppressive regulatory influences of the same T cell populations rather than to the existence of different T cells for different immunoglobulin classes.
Host Responses to Infectious Bovine Rhinotracheitis Virus
Authors: Rouse Barry T. , Babiuk Lorne A. 
Published: December 2022

Abstract
An investigation was made to determine if the nylon wool column technique of Julius et al., (9), could be used to fractionate bovine peripheral blood lymphocytes into T enriched (effluent) and B enriched (adherent) cells. After column filtration, the subpopulations were checked for surface-labeling characteristics with fluorescein-labeled anti-Ig serum (membrane fluorescence), phagocytic activity, response to mitogens, and their reactivity in two in vitro assays that quantitate cell-mediated immunity (CMI) against a bovine herpes virus-infectious bovine rhinotracheitis (IBR) virus. The effluent cells appeared enriched in T cells since few cells showed membrane fluorescence and these cells responded well to the T cell mitogens phytohemagglutinin (PHA) and concanavalin A (Con A). The adherent cells appeared enriched in B cells since many cells showed membrane fluorescence and the cells responded well to lipopolysaccharide (a B cell mitogen) but poorly to PHA and Con A. In the in vitro CMI assays against IBR virus, the effluent cells were far more reactive than the adherent cells implying that these assays are essentially measures of T cell activity.
The implications of the results for the understanding of the mechanism of resistance to herpes virus infections is discussed.
Expression of New Antigens by HL-A Variants of Cultured Lymphoid Cells
Authors: Pious Donald , Soderland Carl 
Published: December 2022

Abstract
Antisera were raised in rabbits to a number of spontaneously occurring and mutagen-induced HL-A2 loss variants of the cultured lymphoid line 8866. The antisera to the variant sublines were absorbed with 8866 and with one or both of the spontaneously occurring variant sublines, and the absorbed antisera were tested to determine whether they retained reactivity for the variant against which the antiserum was raised. A positive result was taken as evidence that the variant expressed a new antigen. By this criterion, neither spontaneously occurring variant appeared to express a new antigen. However, at least two of four mutagen-induced variants appeared to do so. Antiserum against 8866 absorbed with either of the spontaneously occurring HL-A2 loss variants appeared to be a specific HL-A2 reagent, supporting the idea that antigen loss in these variants is limited to the HL-A2 allele.