bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microtubule Assembly and Function in Normal and Glutathione Synthetase-Deficient Polymorphonuclear Leukocytes
Authors: Oliver Janet M. , Spielberg Stephen P. , Pearson Christine B. , Schulman Joseph D. 
Published: December 2022

Abstract
Depression of glutathione (GSH) by specific and non-specific oxidants has been shown before to cause microtubule disassembly and to prevent Concanavalin A (Con A)-induced assembly in human polymorphonuclear leukocytes. These data indicate either that a critical level of GSH is required for assembly or that products of GSH oxidation such as glutathione disulfide (GSSG) cause disassembly. Neutrophils from a patient with GSH synthetase deficiency contain only 20% normal GSH (far below the depressed level associated with microtubule inhibition in normal cells) with no corresponding elevation of GSSG. These cells provide a test system to analyze the biochemical pathway connecting GSH to microtubule integrity. Con A induces a rapid and equal increase in centriole-associated microtubules in both normal and GSH-deficient cells. Thus, levels of GSH above 20% of normal are not essential to promote microtubule assembly. On the other hand, our data emphasize an important role for normal (high) GSH in protecting tubulin against direct attack by oxidants such as H2O2: in normal neutrophils phagocytosis induces microtubule assembly despite concomitant production of H2O2; in GSH-deficient cells microtubule assembly is prevented. Tertiary butylhydroperoxide (BHP) is confirmed to be a highly specific GSH oxidant, inhibiting Con A-induced microtubule assembly in normal but not GSH-deficient cells. In both cases the GSH:GSSG ratio is lowered from approximately 100:1 to below 10:1. However, the absolute level of GSSG achieved after BHP in GSH-deficient cells is only one-fifth that obtained in normals. It is suggested that a critical level of GSSG must be attained to inhibit microtubule assembly and/or cause microtubule disassembly after the specific oxidation of GSH.
Inhibition of Tumor Growth Mediated by Lymphocytes Sensitized in Vitro to a Syngeneic Murine Teratocarcinoma 402AX
Authors: Bartlett Perry F. , Fenderson Bruce A. , Edidin Michael 
Published: December 2022

Abstract
TerC, a cell line derived from a strain 129 teratocarcinoma 402AX, was used to sensitize syngeneic 129 (H-2bc) splenic lymphocytes in vitro. The effector cells generated inhibited in vitro growth of TerC as measured by an 125I-IUDR post-labeling technique. It was also shown, with a modified Winn assay, that the sensitized cells were effective in preventing TerC growth in vivo. The effector lymphocyte was nonadherent to nylon wool, was sensitive to anti-Thy-1·2 + C, and was phenotypically Ly 1-2+. The anti-TerC effector T lymphocytes were not functional in a 51Cr-release assay. However, this failure to lyse appears not to be due to some intrinsic membrane resistance since both BCG and ConA-activated killers were able to lyse TerC. The TerC-sensitized lymphocytes displayed no H-2 restriction and were able to growth inhibit in vitro a wide range of tumorigenic cell lines, e.g., P815 (H-2d), EL-4 (H-2b),Sal (H-2a), and BALB/c (H-2d) 3T12. Mouse blastocyst cell lines were also inhibited. BALB/c 3T3 and mouse fibroblast cell strains were not growth inhibited. Thus, it appears that oncofetal antigens expressed on TerC are capable of initiating a cell-mediated response and that these antigenic specificities are shared by many transformed cell lines.
Suppressor Cell Activity in Tumor-Bearing Mice
Authors: Farrar William L. , Elgert Klaus D. 
Published: December 2022

Abstract
Spleen cells from fibrosarcoma-bearing mice elaborated a factor of 30 to 50,000 daltons in m.w. that was capable of inhibiting DNA synthesis and DNA polymerase activities of mitogen-stimulated lymphocytes plus unrelated cell types. The cells responsible for producing these factors were characterized as anti-Thy 1 serum- and hydrocortisone-sensitive mildly nylon wool adherent spleen cells (suggesting a suppressor T cell). Both DNA polymerases alpha (α) and beta (β) were significantly inhibited by prepared supernatants from cultures of tumor-bearing host (TBH) spleen cells. DNA polymerase polymerase (IDP). Basal levels of TBH lymphocyte DNA synthesis and polymerase α activity were always higher than their normal counterparts; however, upon mitogen stimulation this was reversed. Normal animal spleen cell DNA polymerase α activity exhibited a direct correlation with mitogen-induced DNA synthesis. In the presence of mitogen, normal spleen cells demonstrated a significant increase in DNA synthesis with a corresponding increase in DNA polymerase α activity, whereas TBH spleen cells upon mitogen stimulation resulted in a concomitant decrease in DNA synthesis and polymerase activity. Inhibition kinetics revealed that IDP was not a competitive inhibitor of DNA polymerase α and did not bind directly to the DNA template in the absence of polymerase. The kinetics imply the production of an enzyme-substrate-inhibitor complex which cannot undergo further reaction to yield a normal product. The data suggest that substances elaborated by tumor-induced suppressor cells operate at a molecular site of DNA polymerases resulting in inhibited cellular proliferation.
X-Linked Genetic Control of Hapten-Polysaccharide-Mediated Specific Immune Unresponsiveness in CBA/N Mice
Authors: Merchant Bruce , Snippe Harm , Lizzio Elaine F. , Inman John K. 
Published: December 2022

Abstract
CBA/N mice carry an X-linked recessive B cell defect which prevents them from making antibody responses to thymic independent antigens such as arsonate-, sulfonate-, or DNP-conjugated Ficolls. They do, however, make good plaque-forming cell (PFC) responses to the same haptens coupled to hemocyanin; thus, they do not selectively lack Ig receptors reactive with these haptens. When CBA/N mice are injected with DNP-Ficoll 1 or 2 hr before immunization with DNP-hemocyanin, their otherwise normal PFC response to this thymic dependent antigen is virtually abolished. As little as 10 ng of DNP-Ficoll can profoundly suppress the fourth day, direct PFC response to 50 µg of DNP-hemocyanin. Hence, the B cell defect that causes failure of CBA/N mice to respond to DNP-Ficoll is not associated with a failure to recognize this haptenated thymic independent antigen. The CBA/N susceptibility to haptenated Ficoll blockade is hapten specific. A similar type of hapten-specific blockade can be mediated by DNP-conjugated pneumococcal polysaccharide. This susceptibility to hapten-specific polysaccharide-mediated blockade occurs in the male but not the female hybrid offspring of defective CBA/N female mice. Hence, it is transmitted via the X chromosome and is recessive or has reduced penetrance in females. Our findings indicate that this X-linked vulnerability to hapten-specific, polysaccharide-mediated blockade probably represents a separate functional aspect of the basic X-linked recessive CBA/N defect which heretofore was recognized mainly as an inability to respond to most thymic independent antigens.
Impairment of Cell-Mediated Immunity in Mutation Diabetic Mice (db/db)
Authors: Mandel Mark A. , Mahmoud Adel A. F. 
Published: December 2022

Abstract
Mutation diabetes in the mouse occurs in the C57BL/Ks strain. All homozygous animals (db/db) develop obesity, elevated blood sugar levels and increased or normal blood insulin concentration. The defects in cellular immunity in db/db mice and their littermate controls were examined both in vivo and in vitro. Significant suppression of delayed footpad swelling and first and second set skin allograft rejection time were observed. In addition, DNA synthesis in spleen cells after nonspecific mitogen stimulation was markedly inhibited. Diabetic animals with a mean blood sugar of 512 ± 101 mg/100 ml did not respond to exogenous insulin therapy by lowering their blood sugar levels or reversing the defect in DNA synthesis. Adding insulin to spleen cell culture in vitro had no demonstrable effect on their response to mitogens. Thus, mutation diabetic mice with their known defect in the peripheral utilization of insulin have markedly suppressed cell-mediated immune mechanisms.
The Subclass Specificity for the Binding of Murine Myeloma Proteins to Macrophage and Lymphocyte Cell Lines and to Normal Spleen Cells
Authors: Segal David M. , Titus Julie A. 
Published: December 2022

Abstract
Murine myeloma proteins of the four IgG subclasses and of the IgA and IgM classes have been examined for their ability to inhibit the binding of affinity cross-linked trimeric rabbit IgG to various types of murine cells. In addition, proteins of the IgG1, IgG2a, and IgG2b subclasses have been cross-linked with dimethyl suberimidate and the purified oligomers have been tested for direct binding. With a macrophage line (P388D1), a lymphocyte line (AKTB-1), and normal spleen cells, proteins of the IgG1, IgG2a, and IgG2b subclasses all compete for binding at the same site. Differences in binding affinities between proteins of the IgG1, IgG2a, and IgG2b subclasses are small and are not greater than differences in affinities when proteins within a subclass are compared. Proteins of the IgG3 subclass and the IgM and IgA classes do not significantly inhibit IgG binding at the highest concentrations tested.
P388D1 cells are also able to bind iodinated monomeric IgG2a proteins with higher affinity than expected from inhibition studies. This binding is inhibitable by proteins of the IgG1, 2a, and 2b subclasses, and is trypsin sensitive. These results could be explained by the existence of a second type of receptor, or by assuming that the iodination procedure increases the affinity of IgG2a proteins for P388D1 cells.
Studies on Cytotoxicity Generated in Human Mixed Lymphocyte Cultures
Authors: Seeley Janet K. , Golub Sidney H. 
Published: December 2022

Abstract
Human mixed lymphocyte cultures (MLC) have been observed to generate cytotoxicity not only against allospecific targets but also against autochthonous control target cells. This work investigates the types of target cells susceptible to the MLC-activated effectors and also analyzes the time course of the generation of these activities. Normal human peripheral blood lymphocytes (PBL) were sensitized to normal allogeneic mitomycin C-treated PBL in MLC and subsequently were tested for cytotoxicity against various targets in a 51Cr-release cell-mediated lympholysis (CML) assay. Two types of cytotoxic activities were clearly distinguishable by the types of target cells susceptible to the effectors: a) The allocytotoxicity was directed at the relevant allogeneic Con A blasts (alloblasts), but not to the autochthonous control Con A blast (autoblast) targets. b) In contrast, the “anomalous” cytotoxicity, which was originally defined as alloactivated cytotoxicity against the autochthonous lymphoblastoid cell line (auto-LCL) target, was shown to have a broad range of cytotoxic activity against all cultured cell line targets tested. The allocytotoxicity was further distinguished from the “anomalous” reactivity by studies on the time of development in culture of these activities. The peak anomalous activity always occurred 1 or 2 days earlier and declined more rapidly than the peak allocytotoxicity. Experiments to find common antigenic determinants between the sensitizing cells and targets susceptible to anomalous cytotoxicity revealed no obvious antigenic relationships.
Activation of Human B Lymphocytes
Authors: Dimitriu Alexandra , Fauci Anthony S. 
Published: December 2022

Abstract
Human monocytes, after in vitro activation by mixed lymphocyte culture (MLC) superantants produce a monokine (MK) that enhances the plaque-forming cell (PFC) response of pokeweed mitogen (PWM)-stimulated human B lymphocytes. Technical conditions and kinetics of MK production were established. Irradiation of monocytes (5000 rads) does not abolish MK production but heat-killed cells are unable to release the factor. Highly T cell-deplated monocyte populations still produced the PFC-enhancing factor. The same MK has an inconsistent enhancing effect on the PFC responses of lipopolysaccharide (LPS) and nocardia water-soluble mitogen (NWSM)-stimulated B cells. Other macrophage activators such as LPS, phytohemagglutinin (PHA), and latex particles failed to induce consistently the liberation of the PFC-enhancing MK. The target cell for the MK activity on PWM-stimulated B cells appears to be the B lymphocyte itself. These studies demonstrate that soluble monocyte products can have substantial modulatory effects on human B cell function.
Hapten-Specific Tolerance Induced by Hapten Conjugates of d-Glutamic Acid, d-Lysine (D-GL) or Isologous γ-Globulin: Evidence for Central B Cell Tolerance in the Presence of Carrier-Primed Helper T Cells
Authors: Katz David H. , Borel Yves 
Published: December 2022

Abstract
A comparison has been made of the well known hapten-specific tolerance systems induced, respectively, by hapten-D-GL or hapten-isologous γ-globulin conjugates. The principal question addressed in this study concerned the comparative maintenance of B cell tolerance, induced by one or the other method, after adoptive transfer into carrier-primed, irradiated recipient animals and, in addition, what role, if any, might be played by T lymphocytes in the tolerant donor cell population in maintaining such tolerance. The results clearly show that insofar as the hapten-specific B cell is concerned, no obvious difference exists in the capacity to maintain tolerance adoptive transfer between the hapten-D-GL and hapten-isologous γ-globulin systems; such cells remained tolerant even in the presence of excess helper T cell activity. Moreover, under the conditions employed, depletion of T lymphocytes from the tolerant donor cell population did not affect the maintenance of hapten-specific B cell tolerance after adoptive transfer to irradiated recipients.
In Situ Lymphoid Cells of Mouse Mammary Tumors
Authors: Blazar Beverly A. , Heppner Gloria H. 
Published: December 2022

Abstract
A method of separating lymphoid cells from solid mouse mammary tumors was developed and evaluated. In this method the tumors are digested with 0.01% collagenase, 0.01% DNAase, and 0.025% trypsin in Dulbecco's PBS into suspensions of cells with a viability of 90%. The suspensions are fractionated on a continuous gradient of Ficoll in tissue culture medium. In model experiments this gradient was found to separate, cleanly, admixed cells of an established mammary tumor cell line and dissociated thymus glands. Recovery rates were 50% for the tumor cells and 80% for the thymocytes. The preparation of the cell suspensions and the gradient separation procedure are not harmful to the cells as indicated by trypan blue exclusion and the ability to grow in cell culture.
In Situ Lymphoid Cells of Mouse Mammary Tumors
Authors: Blazar Beverly A. , Miller Fred R. , Heppner Gloria H. 
Published: December 2022

Abstract
Lymphoid cells were isolated by isokinetic gradient centrifugation from mouse mammary tumors and evaluated for their ability to affect tumor cell survival with the microcytotoxicity assay. In all experiments stimulation of the growth or survival of tumor cells was seen. This stimulation was not seen with separated lymphoid cells treated with anti-lymphocyte serum and complement. The lymphoid cells separated from tumors were more stimulatory than were lymph node cells; even when lymph node cells of the tumor bearer were cytotoxic to the tumor cells, the separated tumor-associated lymphoid cells were markedly stimulatory. The gradient procedure had no effect on the activity of sensitized lymph node cells, but it did separate cytotoxicity and stimulation into different fractions.
Immunosuppressive Activity of Antibody Directed Against Endogenous C-Type Virus Interferes with Early Events of the Immune Response
Authors: Schumann Gebhard , Moroni Christoph 
Published: December 2022

Abstract
We have analyzed the effects of an antiserum prepared against BALB/c endogenous xenotropic C-type virus on the humoral immune response of mice. Both in vivo and in vitro, this serum suppresses the response to sheep red blood cells, an effect that can be absorbed out by purified BALB/c xenotropic C-type virus or Friend leukemia virus, but not by Rous sarcoma virus. The serum produces its maximum effect when administered together with or before the antigen, but not 24 hr later. This suggests that it acts on an early event of the immune response. Evidence is presented to show that the critical viral antigen is expressed before the spleen cells are experimentally stimulated by antigen. The same immunosuppressive effect was observed in a variety of mouse strains, including the high-leukemia incidence AKR strain and virusfree 129/J mice, indicating that it is independent of the expression of endogenous virus. The finding that a viral antigen is involved in the transition from a resting to a dividing lymphocyte is discussed with respect to viral involvement in leukemia.
Effects of Costimulator on Immune Responses in Vitro
Authors: Shaw Jennifer , Monticone Vicky , Mills Gordon , Paetkau Verner 
Published: December 2022

Abstract
We recently described a factor, costimulator, that is required for the concavalin A-induced proliferation of CBA mouse thymocytes in vitro (see Reference 1). Using the costimulator dependence of mouse thymocytes as an assay, we have now determined that spleen cells from congenitally athymic (nude) BALB/c mice do not produce costimulator in response to Con A, and spleen cells depleted of Thy 1-positive cells do not respond to it in the presence of Con A. Thus, costimulator both requires thymus-derived (Thy 1+) lymphocytes for its production and has an effect on this type of cell. (However, the costimulator-producing and responsive cells may be different.) Purified costimulator preparations are a source of the required second component for the stimulation of adult, CBA/J thymic lymphocytes by PHA, normally a poor mitogen for these cells. They also enhance the level of DNA synthesis in a mixed leukocyte reaction, and the specific generation of cytotoxic lymphocytes to allogeneic tumor cells in vitro. Costimulator is not H-2 restricted in its effects, and it is produced in mixed leukocyte reactions. Finally, it has been possible to grow normal, primary thymic lymphocytes in culture for about 20 days by adding partially purified costimulator to the cultures.
Complement-Induced Modifications in Membrane Fluidity: Studies with Resealed and Glutaraldehyde-Treated Erythrocyte Membrane Ghosts
Authors: Giavedoni Elda B. , Mason Ronald P. , Dalmasso Agustin P. 
Published: December 2022

Abstract
We investigated the effect of antibody and complement (C) on the fluidity of the lipid bilayer of resealed membrane ghosts by means of electron spin resonance spectroscopy. In contrast to intact red cells, resealed membrane ghosts do not rupture after treatment with C and thus C-induced changes in membrane properties can be directly ascribed to the action of C. Membranes treated with antibody alone (MA) had no modifications in the fluidity parameters. Treatment of MA with normocomplementemic rabbit serum, but not with C6-deficient rabbit serum, produced a significant increase in T‖' and a decrease in Δl and Δh, which are indicative of a more rigid structure. These modifications were absent from MA treated with the first eight C components (MAC1–8) but became apparent upon addition of C9 to the MAC1–8. Cross-linkage of the membrane proteins with glutaraldehyde increased the rigidity of the lipid bilayer. Membranes pretreated with 0.025% glutaraldehyde still responded to C with an additional increment in rigidity. However, the spin label became insensitive to C when the membranes were pretreated with 0.25% glutaraldehyde. Treatment with glutaraldehyde did not impair the development of C lesions as evaluated by the release of entrapped marker molecules. Therefore, the C-induced changes in membrane fluidity, when observed, are only the concomitant of the C lesion and not an essential component of their mechanism of production.
The Complex of C5b and C6: Isolation, Characterization, and Identification of a Modified form of C5b Consisting of Three Polypeptide Chains
Authors: Yamamoto Ken-Ichi , Gewurz Henry 
Published: December 2022

Abstract
A new method for isolation of the complex of C5b and C6 (C5b-6) which yielded milligram quantities of C5b-6 of high purity was devised. C5 and C6 first were separated from C7 by column chromatography on DEAE-cellulose. C5b-6 then was generated from the C7-free reagent by incubation with serum-treated zymosan, and purified by DEAE-cellulose and Bio-Gel A 1.5 m column chromatography. Upon analysis by sucrose density gradient ultracentrifugation and gel filtration, two forms of the C5b-6 complex were recognized. The first maintained its complexed state (10.4S) during ultracentrifugation, and formed aggregates (&gt;16S) upon reaction with C7. The second and predominant form dissociated into C5b (7.6S) and C6 (5.7S) during ultracentrifugation and did not form aggregates with C7. Both forms retained their elution characteristics on gel filtration over a 1-month period at 4°C. SDS-polyacrylamide gel electrophoretic analysis also revealed two different forms of the C5b-6 complex. C5b-6 capable of aggregating with C7 was a complex of unmodified C5b and C6. The predominant form was, however, a complex of modified C5b (designated C5b′) and C6. In the absence of a reducing agent, both forms of C5b had an apparent m.w. of 180,000 daltons. Upon reduction, C5b yielded two polypeptide chains designated α′ (103,000 daltons) and β (75,000 daltons), whereas C5b′ dissociated into three polypeptide chains, i.e., two fragments of the α′ chain designated α′1 (75,000 daltons) and α′2 (27,500 daltons), and the β chain (75,000 daltons). The possible significance of this proteolytic modification of C5b in relation to the hemolytic efficiency of lysis mediated by C5b-6 is discussed.
T Cell Growth Factor: Parameters of Production and a Quantitative Microassay for Activity
Authors: Gillis Steven , Ferm Mary M. , Ou Winny , Smith Kendall A. 
Published: December 2022

Abstract
Several soluble factors have recently been associated with the proliferation and differentiation of thymus-derived lymphocytes. One of these factors present in medium conditioned by T cell mitogen-stimulated lymphocytes has the ability to promote the long-term culture of normal and antigen-specific cytotoxic T cells. We report a method to test for this proliferative stimulus in the form of a sensitive microassay based upon the tritiated thymidine incorporation of continuous murine tumorspecific cytotoxic T cell lines (CTLL). The microassay requires microliter quantities of sample fluid and is amenable to quantitative analysis. This highly reproducible, quantitative assay for T cell growth factor (TCGF) has allowed investigation as to the kinetics of TCGF generation and has revealed that T lymphocytes are required for its production. Further investigation has supported the notion that this nonspecies-specific factor is actively removed from tissue culture medium by the proliferation of either T cell mitogen-activated lymphocytes or CTLL.