bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Suppressive Effect of Immunization on the Proliferative Responses of Rat T Cells in Vitro
Authors: Bash Jerry A. , Singer Andrew M. , Waksman Byron H. 
Published: December 2022

Abstract
Rats given large i.v. doses of ovalbumin or sheep erythrocytes manifest suppressed spleen cell responses (3H-thymidine incorporation) to PHA within hours. Removal of glass wool-adherent cells totally restores responsiveness to that of normal nonadherent spleen cell cultures. Carrageenan, selectively toxic for macrophages, partially restores responses of antigen-suppressed spleen cells in culture, suggesting a supportive role for macrophages in the suppression phenomenon. Treatment of donors with low doses of cyclophosphamide (20 to 50 mg/kg) at the time of antigen injection abrogates the ability of their spleen cells to suppress the responses of normal cells to PHA. The low dose of cyclophosphamide required indicates a target other than the B cell or macrophage and suggests the possibility that cyclophosphamide eliminates the suppressor T cell component of the macrophage-T cell complex.
Antigen-Specific and Nonspecific Mediators of T Cell/B Cell Cooperation
Authors: Harwell Lee , Kappler John W. , Marrack Philippa 
Published: December 2022

Abstract
T cell-containing lymphoid populations produce a nonantigen-specific mediator(s) (NSM) which can replace T cell helper function in vitro in the response of B cells to sheep red blood cells (SRBC), but not to the hapten-protein conjugate, trinitrophenyl-keyhole limpet hemocyanin, (TNP-KLH). NSM produced under three conditions: 1) stimulation of KLH-primed cells with KLH; 2) allogeneic stimulation of normal spleen cells; and 3) stimulation of normal spleen cells with Con A (but not PHA) are indistinguishable on the basis of their biologic activity and m.w., estimated as 30 to 40,000 daltons by G-200 chromatography. Production of NSM is dependent on the presence of T cells. The action of NSM on B cells responding to SRBC in the presence of 2-mercaptoethanol is unaffected by severe macrophage depletion. Extensive absorption of NSM with SRBC failed to remove its activity, confirming its nonantigen-specific nature.
Cell-Mediated Immunity to Friend Virus-Induced Leukemia
Authors: Ting Chou-Chik , Bonnard Guy D. 
Published: December 2022

Abstract
Primary and secondary cell-mediated cytotoxic responses to FBL-3 cells, a syngeneic Friend virus-induced leukemia in C57BL/6 mice, could be generated by in vitro techniques as tested by the 125IUdR release assay. The specificity of the cytotoxic reactions appeared to be directed against the Friend type-specific antigen and the FMR (Friend, Moloney, Rauscher) antigen which were also the major antigens for transplantation immunity to FBL-3. In comparison to the primary cytotoxic response, the secondary cytotoxic response was accelerated (detected at an earlier time after sensitization), enhanced (gave much higher levels of cytotoxicity), was also longer lasting, and could be induced by a wide dose range of tumor cells. The secondary response could only be induced with lymphocytes obtained from regressors that were resistant to FBL-3 challenge; lymphocytes from mice with progressive tumor growth had no detectable secondary response. It was found that both induction phase and the effector phase of cytotoxic responses were T cell dependent. The characteristics of these reactions were thus very similar to those obtained with in vivo immunization or challenge, providing a good correlation with in vivo tumor immunity.
Regulatory Serum Lipoproteins: Regulation of Lymphocyte Stimulation by a Species of Low Density Lipoprotein
Authors: Curtiss Linda K. , Edgington Thomas S. 
Published: December 2022

Abstract
Low density lipoproteins (LDL) containing apolipoprotein B were separated from 15 fresh normal human serum pools by three independent isolation methods including sequential ultracentrifugal flotation, affinity chromatography, and polyanion precipitation. A discrete subpopulation of LDL (LDL-In) was isolated which possessed comparable inhibitory activity for PHA, PWM, and allogenic cell stimulated human lymphocytes in vitro at concentrations of 1 to 10 µg protein/1 × 105 lymphocytes/0.25 ml culture. LDL-In was characterized by a mean buoyant density of 1.055 g/ml in KBr, a m.w. of 2 to 3 × 106 daltons and a composition of 20 to 25% protein and 75 to 80% lipid with β electrophoretic mobility. The biologic activity of LDL-In was non-cytotoxic, independent of mitogen concentration, and dependent upon the concentration of serum in the culture assay.
The effect was temporally dependent requiring approximately 24 hr for induction of a stable suppressed state. Suppression was reversible with shorter periods of exposure to LDL-In. LDL-In did not inhibit lymphocytes at periods greater than 19 hr after stimulation, suggesting that LDL-In may influence metabolic events associated with the inductive phase of lymphocyte activation by lectins and allogeneic cells. LDL-In was clearly distinguishable from T lymphocyte E rosette inhibitory factor since it did not influence E rosette function of lymphocytes. The physicochemical and biologic properties of LDL-In clearly distinguish this regulatory lipoprotein from previously described immunoregulatory factors.
Effect of Murine Cytomegalovirus on the in Vitro Responses of T and B Cells to Mitogens
Authors: Selgrade Maryjane K. , Ahmed Aftab , Sell Kenneth W. , Gershwin M. Eric , Steinberg Alfred D. 
Published: December 2022

Abstract
Both in vitro and in vivo murine cytomegalovirus (MCMV) infection depressed the responses of lymphocytes to both B and T cell mitogens. The possibilities that macrophages or nonspecific T cell inhibition of B cells might account for the depressed responses were eliminated. In vitro data suggested that B cell responses are more susceptible to this depression than T cell responses. The possibility that the depression of T cell responses is not a direct effect of viral infection of lymphocytes is discussed.
To investigate further the interaction between B and T lymphocytes and MCMV, mice with B and T cell deficiences were studied. A comparison of the susceptibility of athymic Nu/Nu mice and T cell competent Nu/+ littermates to MCMV showed that the LD50 for Nu/Nu mice is 10-fold lower than that for Nu/+ mice, but Nu/+ mice given an LD50 of virus died much sooner after infection than Nu/Nu mice given an LD50. Pathogenic mechanisms responsible for death may be different in these two groups of mice. Similarly the MCMV LD50 for B cell-deficient mice (treated with goat anti-mouse IgM serum) was 10-fold lower than the LD50 for mice treated with normal goat serum, but given an LD50 of virus, the latter died sooner after infection than the former. In contrast, there was little difference between the LD50 or time of death after MCMV infection of CBA × DBA F1 male mice (which are deficient in their response to thymic independent antigens) and their normal littermates, the CBA × DBA F1 female mice.
Studies on the Terminal Stages of Antibody-Complement Mediated Killing of a Tumor Cell
Authors: Boyle Michael D. P. , Ohanian Sarkis H. , Borsos Tibor 
Published: December 2022

Abstract
A comparison of the events leading from T* to dead cells and E* to E ghost and hemoglobin was made. Transformation of T* to dead cells was inhibitable by EDTA, NaF, histamine, DMSO, cytochalasin B and 3′5′ cAMP. Transformation of E* to E ghost and hemoglobin was only inhibited by EDTA.
Effect of Six Weekly Transfusions on Canine Marrow Grafts: Tests for Sensitization and Abrogation of Sensitization by Procarbazine and Antithymocyte Serum
Authors: Weiden Paul L. , Storb Rainer , Slichter Sherrill , Warren Reed P. , Sale George E. 
Published: December 2022

Abstract
We have previously shown that blood transfusions can immunize a dog and lead to rejection of a subsequent marrow graft despite lethal total body irradiation (TBI). Sensitization to histocompatibility antigens induced by two prior transfusions of whole blood could be overcome by a regimen of procarbazine and anti-thymocyte serum (ATS) preceding TBI. The current study investigated a) whether this regimen could abrogate sensitization induced by six weekly transfusions given from days -50 to -15 preceding a marrow graft, and b) whether platelet survival studies and two in vitro tests of immunity could predict marrow graft rejection.
All donor-recipient pairs were histoincompatible, unrelated, and of different breed. Twenty-two recipients received platelet concentrate transfusions and eight received whole blood transfusions. Recipients were given 1200 R TBI and a graft of marrow and peripheral blood leukocytes from the transfusion donor on day 0. Three of 15 recipients (20%) given procarbazine, 12.5 mg/kg i.v. on days -8, -6, and -4, and ATS, 0.6 ml/kg subcutaneously on days -7, -5 and -3, rejected their grafts, whereas 11 of 15 dogs (73%) not given procarbazine and ATS rejected their grafts (p &lt; 0.01).
Serum lymphocytotoxic antibodies, peripheral leukocyte migration inhibition, and in vivo donor platelet reccvery and survival were studied in those recipients receiving six weekly transfusions and in 18 other recipients receiving a single donor transfusion 3 months before marrow grafting. No significant correlation was found among these in vitro and in vivo tests of sensitization. Sensitization to marrow grafts was not reliably detected by the presence of cytotoxic antibodies or leukocyte migration inhibition. Platelet survival, however, was positively correlated with the results of marrow grafting in 12 of 15 (80%) evaluable recipients (p ∼ 0.15).
This study confirms, with a different immunization schedule, that procarbazine and ATS can abrogate sensitization to histocompatibility antigens induced by multiple prior transfusions in histoincompatible, unrelated canine donor-recipient pairs and thus permit successful engraftment of donor marrow.
Inhibition of Antigen-Induced B Lymphocyte Activation in Vitro by Cytochalasin B
Authors: Roberts Robert L. , La Via Mariano F. 
Published: December 2022

Abstract
Cytochalasin B (CB), a fungal metabolite which disrupts microfilaments. and will inhibit capping and other events requiring membrane movement, suppressed the production of antibody-forming cells (AFC) in both mouse whole spleen cultures immunized with sheep erythrocytes (SRBC) and in mouse B lymphocyte cultures immunized with the thymic independent antigen DNP-Ficoll (DF). CB at a concentration of 1 µg/ml inhibited the AFC response by more than 90% in spleen cell cultures immunized with SRBC. This inhibition was completely reversible by removal of CB up to 24 hr after the start of culture. Spleen cells cultured in the presence of CB for the first 48 to 72 hr had a decreased AFC response similar to that of cultures in which SRBC had been withheld for the same period of time. Incubating whole spleen cell or B lymphocyte cultures immunized with DF for as short as 6 hr decreased the AFC response more than 60%. Antibody secretion, cell viability, and antigenicity of the SRBC and DF were not affected by CB.
The results of these experiments favor the concept that movement of surface receptors is necessary in activating lymphocytes to differentiate into AFC. The differential response to CB observed in SRBC and DF stimulated cultures makes the technique employed a useful tool to study membrane events occurring between antigen interaction with surface receptor and the initiation of differentiative events.
Diversity among Rabbit Antibody Light Chain Amino Terminal Sequences
Authors: Cannon L. Edward , Margolies Michael N. , Strosberg A. Donny , Chen Francis W. , Newell John , Haber Edgar 
Published: December 2022

Abstract
The amino terminal (positions 0 to 20) amino acid sequences of 22 rabbit antibody light chains are reported and compared with 44 amino terminal sequences previously described in the literature. Rabbit κ light chains demonstrate three different amino terminal chain lengths and considerable variability at the amino terminal end. In relating amino terminal sequence to b locus allotype, allotype-specific residues (amino acid residues unique to all light chains having a given allotype) were not identified, although certain residue alternatives were unique to some of the b5 and b9 light chains.
There was no correlation of antibody specificity with amino terminal sequence. In the most striking example, identical amino terminal sequences were associated with two different carbohydrate specificities (type VIII pneumococcal polysaccharide and streptococcal group A carbohydrate) and an aminophenyltrimethylammonium specificity. An obligatory association of amino terminal sequence with complete variable region framework sequences was not observed. Thus, it is not always possible to predict the framework homology among a given pair of light chains by examination of their amino terminal sequences.
The limited diversity seen among the variable regions of murine myelomas that have the same antigen-binding properties is not found in the light chains of specifically elicited rabbit antibodies.
Humoral Immunity in Experimental Syphilis
Authors: Bishop Nancy H. , Miller James N. 
Published: December 2022

Abstract
Evidence for a humoral mechanism in immunity to experimental syphilis was provided by the demonstration of immune rabbit serum factor(s) capable of inactivating virulent Treponema pallidum, Nichols strain, in an in vitro-in vivo neutralization test. After intratesticular infection, rabbits were bled periodically and their resistance to reinfection was determined by challenge with T. pallidum. The results of challenge showed that resistance to reinfection begins to develop by 11 days after infection, becomes complete by 3 months, and persists for at least 2 years. In the neutralization test, a mixture of treponemal suspension and serum from the infected animals was incubated anaerobically at 34°C and the virulence of the treponemes was determined by intradermal inoculation into normal rabbits. Complete inactivation of treponemes by immune serum required heat-stable and heat-labile (56°C, 30 min) serum components and 16 hr of incubation, and was accelerated by pre-incubation of the treponemes for 4 hr with nonimmune serum but not by 100 µg/ml of added lysozyme. Serum-neutralizing activity, first demonstrable 1 month postinfection, was quantitated by a neutralizing endpoint (NEP). A relatively close quantitative correlation was shown between the development of resistance to symptomatic reinfection and the appearance and persistence of both TPI antibody and neutralizing serum factor(s). The nature of the serum factor(s), the mechanism of treponemal inactivation, and the application of the test in assessing the immune status are discussed.
Studies on Glycopeptide Released by Trypsin from Sheep Erythrocytes
Authors: Kitao Takeshi , Takeshita Masazumi , Hattori Kenichi 
Published: December 2022

Abstract
Pretreatment of sheep erythrocytes with trypsin abolishes their specific binding and rosette formation with human T lymphocytes. A glycopeptide containing sialic acid is released from the intact sheep erythrocytes by incubation with trypsin and purified. This glycopeptide contains activity that can be bound to T lymphocytes and produces inhibition of rosette formation. This component with a m.w. of about 10,000 contains galactose, acetylglucosamine, acetylgalactosamine, sialic acid, and serine. These results suggest that the glycopeptide released by trypsin treatment may contain the site of the T cell receptor of sheep erythrocytes.
Isolation and Partial Characterization of AgF-1:A Rat Lymphocyte Membrane Antigen
Authors: Williams Phillip B. C. , DeWitt Charles W. 
Published: December 2022

Abstract
A genetically defined, serologically identified antigen of the rat lymphocyte membrane (AgF-1) has been isolated. Viable spleen and lymph node cells, prepared by Ficoll-Hypaque density centrifugation from Fischer rats, were radioiodinated with soluble lactoperoxidase. Extracts obtained with Nonidet P-40 were shown to contain numerous radiolabeled proteins including cell-surface globulin. AgF-1 was isolated from these extracts by precipitation with a highly specific alloantibody in conjunction with xenospecific anti-globulin antibody and polyethylene glycol (PEG). The use of PEG greatly increased the efficiency of the double antibody technique.
The putative antigenic peak was eluted from sodium dodecyl sulfate polyacrylamide gels (SDS-PAGE) and specific antigenic activity was recovered. Removal of the SDS from these eluates was achieved by equilibration with urea and passage over an anion exchange resin. Renaturation, as evidenced by specific inhibition of complement-mediated cytotoxicity, occurred upon the removal of urea by dialysis. The m.w. of the purified antigen was estimated to be 35 to 40,000 daltons by SDS-PAGE and was unaffected by reduction with 2-mercaptoethanol. Amino acid composition was roughly similar to those reported for the major histocompatibility antigens of the rat and other species.
Antibody to Murine Leukemia Virus: Genetic Control Linked to the H-2 Locus in PL Mice
Authors: Nowinski Robert C. , Doyle Theresa 
Published: December 2022

Abstract
Mice of a wide variety of inbred strains naturally produce antibody against endogenous ecotropic leukemia viruses (MuLV) (1, 2). This immune response appears to be strain specific, however, since mice of high leukemic strains and mice of some low leukemic strains do not produce appreciable amounts of antibody against MuLV. The failure of mice of high leukemic strains to produce antibody against MuLV is not the result of immunologic tolerance induced by persistent viral replication, since F1 hybrids of mice of high and low leukemia strains produce high titers of antiviral antibody (3, 4). Recently, we have described that the immune nonresponsiveness of AKR mice is genetically controlled by an immune response (Ir) gene in the IXth linkage group (3). We describe here a similar observation with mice of the high leukemic PL strain, thus suggesting that a genetically controlled immune nonresponsiveness to MuLV may be a general characteristic of mice of high leukemic strains.
When Is a Mouse “Old”?
Authors: Walford Roy L. 
Published: December 2022

Abstract
Sir: In recent years the discipline of gerontology—at one time a domain occupied almost entirely by physiologists approaching retirement—has achieved sufficient maturity that investigators experienced primarily in other areas have begun to pursue investigations in the realm of “aging” research. By “aging” I refer to late-life changes, although in another context the term might equally apply to any temporal alterations in function regardless of where they fall in the animals' lifespan (i.e., to a special case of developmental biology).
There are two reasons for an awakened interest in gerontology on the part of immunologists: 1) analogous to the neonatal period, the period of advanced age tends to emphasize or dissect certain features of the immune response (suppressor cell activity, for example), and may present opportunities for fundamental studies in immunology itself; 2) the immune functional changes which occur during aging may contribute substantially to the pathogenesis of those diseases which show a peak incidence in late life, including cancer, vascular disease, maturity-onset diabetes, and others (1).
Generation of Specific Helper Cells and Suppressor Cells in Vitro for the IgE and IgG Antibody Responses
Authors: Ishizaka Kimishige , Adachi Toshihiro 
Published: December 2022

Abstract
Normal splenic lymphocytes from BDF1 mice were cultured on ovalbumin (OA)-bearing syngeneic peritoneal adherent cells for 5 days and their subsequent helper function was tested by an adoptive transfer technique. Lymphocytes harvested from the culture were mixed with DNP-KLH-primed spleen cells and transferred into irradiated syngeneic mice followed by challenge with DNP-OA. The results showed that the cultured lymphocytes has helper function for both IgE and IgG anti-DNP antibody responses. Depletion of mast cells and T cells in the peritoneal adherent cell preparations did not affect the generation of helper cells in the culture. The helper function of the cultured lymphocytes was abolished by the treatment with anti-ϑ antiserum and complement and was specific for ovalbumin. The OA-specific helper T cells were generated in vitro by the culture of a T cell-rich fraction of normal spleen on T cell-depleted OA-bearing peritoneal cells. If the normal splenic lymphocytes or T cell-rich fraction were cultured with 10 µg/ml of OA in the absence of macrophages, cultured lymphocytes lacked helper function. The transfer of splenic lymphocytes or splenic T cells cultured with soluble OA to normal non-irradiated mice, however, suppressed both IgG and IgE antibody responses of the recipients to subsequent immunization with D-NP-OA. The suppressor cells were sensitive to anti-ϑ antiserum and complement and their activity was specific for OA. The cultured cells transferred into normal mice did not suppress anti-hapten antibody response to DNP-KLH. Normal lymphocytes cultured on OA-bearing macrophages and had helper function in adoptive transfer experiments failed to suppress antibody response of nonirradiated recipients to DNP-OA. The results indicate that OA-bearing macrophages primed T cells and generated helper T cells, whereas the culture of normal lymphocytes with soluble OA in the absence of macrophages generated suppressor T cells.
The Ultrastructure of C1t, a Subcomponent of the First Component of Complement: An E.M. and Ultracentrifuge Study
Authors: Pinteric L. , Assimeh S. N. , Kells D. I. C. , Painter R. H. 
Published: December 2022

Abstract
C1t is a 9.5 S α1 glycoprotein that has been shown to be a fourth subcomponent of the first component of complement. The m.w. of C1t was found to be 233,000 by sedimentation equilibrium in the ultracentrifuge. A subunit m.w. of 23,000 was obtained by sedimentation equilibrium in 5.95 M guanidinium chloride. No change in either m.w. was produced by prior reduction and alkylation. In the electron microscope characteristic pentagonal figures of 85 Å diameter were observed together with rod-like figures which appear to be stacked assemblies of the pentagonal figures. These observations lead us to propose that C1t is a noncovalent, decameric protein with the subunits disposed at the vertices of two regular pentagons joined at one of their faces. A possible relationship between C1t and the P-component of amyloid is discussed.