bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of α-Fetoprotein and Other Serum Factors Derived from Hepatoma-Bearing Rats on the Mixed Lymphocyte Response
Authors: Parmely Michael J. , Thompson John S. 
Published: December 2022

Abstract
Serum α-globulin fractions isolated by physiocochemical techniques from normal adult Buffalo rats suppressed lymphocyte proliferation in vitro. The factors responsible for mixed lymphocyte culture suppression appeared to be strain specific since they were not demonstrable in the same fractions from normal LBN rat serum. Similar fractionation of the serum from Buffalo rats bearing the Morris Hepatoma 7777 obtained from two different sources also yielded suppressive protein fractions that differed both chemically and functionally.
Both variants of this hepatoma produced high serum concentrations of α-fetoprotein (AFP), providing an opportunity to study the possible immunoregulatory role of their fetal-associated globulins. Fractions rich in AFP that lacked other serum α-globulins were obtained by gel filtration chromatography and were devoid of any in vitro immunosuppressive activity. When AFP that was further purified by immunoabsorption was added to mixed lymphocyte cultures, no effect was observed at doses below 400 µg/ml. The MLC response was augmented with higher doses, similar to albumin purified by the same methods.
Reduction of the in Vitro Cytotoxic Lymphocyte Response Produced by in Vivo Exposure to Semiallogeneic Cells: Recruitment or Active Suppression?
Authors: Miller Richard G. , Phillips Robert A. 
Published: December 2022

Abstract
Twenty-four hours after intravenous injection of (C57BL/6 × DBA/2) F1 hybrid lymphoid cells into C57BL/6 mice, the in vitro cytotoxic lymphocyte (CL) response of the C57BL/6 spleen and LN cells against DBA/2 alloantigens can be greatly reduced. The reduction is specific for the foreign alloantigens injected; is reduced by irradiating the cells before injection; develops significantly within 10 min of injection, thereafter increasing with a time constant of about 2 hr; varies with the number and origin of cells injected; can be induced by several subpopulations of injected cells within one tissue; varies with the host organ tested (e.g., injection of 104 semiallogeneic LN cells can reduce hose LN response more than 100-fold and have no effect on host spleen); and (for the LN response) is largely reversed by treatment with anti-H-2 antibody plus complement specific for the injected cells. The reduction appears to be induced by grafted cells entering host lymphoid organs rather than, e.g., host cells being specifically recruited to go elsewhere.
When cocultured with normal cells, lymphoid cells from mice injected as above do not reduce the in vitro CL response of the normal cells but do if left in vivo for 7 days before testing. If left 1 day in vivo, followed by 4 days culture in vitro with the same alloantigen, they strongly reduce the normal cell response. The reduction is increased by both the in vivo and in vitro exposure. The grafted cells, once in the host lymphoid tissue, appear to activate a host suppressor mechanism which develops in vitro and reduces the CL response.
Two Types of Antibody Dependent Cell-Mediated Cytotoxicity, Arming and Sensitization
Authors: Imir T. , Saksela Eero , Mäkelä O. 
Published: December 2022

Abstract
Haptenated chicken erythrocytes, anti-hapten antibodies and normal spleen cells were used for a study of parameters of antibody-dependent cell-mediated cytotoxicity (ADCC). Anti-hapten antibody was introduced to the reaction either bound to the target cells (sensitization) or to the effector cells (arming). Our data suggest that the same effector cells and the same antibodies were responsible for both types of reactions. More antibody was required for arming (ca. 1 ng/ml) than for sensitization (ca. 10 pg/ml).
Antibodies of several mammalian species could cooperate in ADCC with human, rat, or guinea pig spleen effector cells, but fowl antibodies were inefficient in the arming of mammalian effector cells.
Rat and human spleen cells were powerful effector cells whereas guinea pig, rabbit, and mouse spleens yielded weakly cytotoxic suspensions. Rabbit antibodies, on the other hand, were efficient, but rat antibodies were less efficient in ADCC. Mouse and guinea pig antibodies appear to take an intermediate position.
Our data suggest that ADCC effector cells of the spleen contain phagocytic and nonphagocytic cells, and the non-phagocytic effector cells still constitute a heterogeneous population.
Isolation of a Human Lymphocyte Mitogen from Wheat Germ with N-Acetyl-D-Glucosamine Specificity
Authors: Brown John M. , Leon Myron A. , Lightbody James J. 
Published: December 2022

Abstract
A lectin, isolated from wheat germ by affinity chromatography on chitin, was mitogenic for purified human peripheral blood lymphocytes. Peak incorporation of 3H-thymidine was observed after incubation of lymphocyte cultures with wheat germ mitogen for 7 to 10 days. When lymphocytes were separated into two fractions based on their ability to form rosettes with unsensitized sheep erythrocytes, the mitogen induced a negligible proliferative response in either fraction. Mixing experiments demonstrated a strong response in the T lymphocyte fraction which required the collaboration, but not proliferation, of cells present in the nonrosetting fraction. Stimulation was specifically abolished by addition of N-acetyl-D-glucosamine at initiation of culture.
Cytomegalovirus Specific IgM and IgG Response in Humans Studied by Radioimmunoassay
Authors: Knez Violeta , Stewart John A. , Ziegler Donald W. 
Published: December 2022

Abstract
An indirect solid phase micro-radioimmunoassay (RIA) was adapted for the measurement of anti-cytomegalovirus class-specific immunoglobulin M (IgM) and immunoglobulin G (IgG). Cytomegalovirus (CMV) antigen (Ag) was added to the wells of microtiter plates and desiccated onto the bottom surface of the wells. Serial dilutions of human CMV antisera were added and allowed to react with the Ag. The amount of viral antibody (Ab) was determined by measuring the specific binding of 125I-labeled goat antihuman IgG (125I-AHIgG) and/or IgM (125I-AHIgM). The multiple factors which influence the test were determined.
Serial samples of sera from CMV-positive patients showed progressive increases in Ab titers on the basis of specific binding of 125I-AHIgG. The titers of IgM class anti-CMV Ab were also determined with the same sera, and enhancement of the titers was demonstrated when the incubation periods of the first Ag-Ab reaction were extended from 1 to 3 hr.
The competition between the different Ig classes of Ab for CMV Ag and the involvement of rheumatoid factor (RF) were investigated. The anti-CMV IgG that may compete with the IgM determination was removed by adsorption of sera with Staphylococcus aureus (Cowan 1). The RF that would cause false anti-CMV IgM results was adsorbed with glutaraldehyde-insolubilized IgG. Our results indicate that this RIA is a practical, specific, and reproducible technique for detection of specific IgG and IgM Ab to CMV.
Trypsin-Induced Increase in Intracellular Cyclic AMP of Lymphocytes
Authors: Shneyour Amir , Patt Yehuda , Trainin Nathan 
Published: December 2022

Abstract
Trypsin increases intracellular levels of cyclic AMP (cAMP) in lymphocytes. The trypsin-induced increase in cAMP is blocked by specific trypsin inhibitors and by high concentrations of different proteins. Several proteolytic enzymes from various sources, including other pancreatic proteases, do not cause an increase in cAMP under the same experimental conditions. Immobilized trypsin induces the same increase in cAMP as does free trypsin. The trypsin-induced rise in cAMP is not due to inhibition of cAMP phosphodiesterase, but consistent activation of adenylate cyclase by trypsin could not be demonstrated. The extent of the trypsin-induced increase in intracellular cAMP correlates with the type of the lymphocyte and with the state of maturity attained by the cells. Transformed lymphocytes and nonlymphoid cells do not react at all.
Kinetic Analysis of Target Cell Destruction by Effector T Cells
Authors: Thorn Richard M. , Henney Christopher S. 
Published: December 2022

Abstract
Murine cytotoxic T cell activity was evaluated in analogy with the methods used to characterize enzymes. Concordant with this analogy, the relationship between “steady-state” lytic rates and target cell (“substrate”) number was described by a hyperbola, the asymptote of which was the maximum rate of lysis (“V”) and was directly proportional to the number of killer cells. The number of target cells required to reach a rate of one-half V (“K”) was independent of the number of effector cells, but was found to vary with the total cell concentration in the cultures.
The kinetic analogy was extended to analyze this variability by studying the inhibition of cytolysis caused by normal syngeneic lymphocytes. A value for K in the absence of non-killer cells (“Kh”) was evaluated. This term, which was independent of effector cell frequency, was a measure of lytic efficiency and, as such, was used to compare various effector cell populations.
The Kh value for a number of lymphoid cell populations from identically immunized C57BL/6 mice was found to vary considerably, thereby providing direct evidence that effector populations have different lytic efficiencies. Because of this variability, the widely used practice of comparing killer cell populations solely on the basis of their relative lytic activity may often be invalid.
Concurrently Circulating Hepatitis B Surface Antigen and Heterotypic Anti-HBs Antibody
Authors: Le Bouvier George L. , Capper Roy A. , Williams Alan E. , Pelletier Marie , Katz Alfred J. 
Published: December 2022

Abstract
In the early days of testing for hepatitis B surface antigen (HB8Ag)2 and the homologous antibody (anti-HB8), there were reports of antigen and antibody co-existing in the same serum specimen (1, 2). Their subspecificities were not determined; but their homotypic character was evidently inferred, and in keeping with this idea were certain results obtained by complement fixation (3), and electronmicroscopic observations of circulating complexes apparently made up of HB8Ag-positive Australia particles and antibody molecules (4). Some recent studies have adduced further evidence for the existence of such complexes (5), whereas others have failed to substantiate the concurrent presence of HB8Ag and homologous anti-HB8, at least in the blood of asymptomatic carriers of the antigen (6).
With the definition of distinct antigenic phenotypes of HB8Ag, there arose the theoretical possibility that Australia particles of one phenotype might co-circulate with free anti-HB8 antibody directed against antigenic configurations characteristic of a different phenotype.
Studies on the Mechanism of Lymphocyte-Mediated Cytolysis
Authors: Rubens Robert P. , Henney Christopher S. 
Published: December 2022

Abstract
Alloimmune spleen cells (C57BL/6 anti P815), but not normal spleen cells, lyse syngeneic (EL4) target cells in the presence of Con A. Con A dependent cytotoxicity was mediated by T cells and required the continued presence of lectin. Cytolysis in the presence of a succinylated derivative was equivalent to that seen with the parent Con A molecule.
In contrast to previous reports of Con A dependent cytolysis, however, we conclude that lysis is not primarily caused by directly cytotoxic T cells. The reasons for this conclusion are: Removal of directly cytotoxic cells by adsorption on P815 monolayers did not alter the Con A dependent cytolysis of EL4 cells;Populations in which no direct T killers were demonstrable (e.g., spleen cells harvested 5 days after alloimmunization) lysed both P815 and EL4 cells in the presence of Con A; andCon A dependent cytolysis, but not direct cytotoxicity, could be induced by culturing normal C57BL/6 spleen cells for 4 days with a sonicated extract of P815 cells.
We hypothesize that the cell “activated” to lyse targets in the presence of Con A is a T cell which has differentiated lytic potential following alloantigenic stimulation, but has either insufficient density or affinity of antigen receptors to serve as a directly cytotoxic cell. The role of Con A is viewed as 2-fold: i) to “bridge” killer and target cell, and ii) to “activate” the effector.
Development of Mast Cells in Vitro
Authors: Ishizaka Teruko , Adachi Toshihiro , Chang Tong-Hsuan , Ishizaka Kimishige 
Published: December 2022

Abstract
Mast cells were obtained by long term culture of rat thymus cells on rat embryonic fibroblast monolayers. Pure mast cell preparations obtained by culture were incubated with 125I-labeled rat E myeloma protein to study receptors for IgE on their surface. When the cells were obtained after 35 to 45 days culture, the average number of receptors per mast cell was 100,000 to 400,000. An equilibrium constant of the binding reaction between their receptor and rat IgE was in the order of 108 M-1. The histamine content of the cultured mast cells was 0.2 to 5 µg/106 cells. The measurement of histamine content in mast cells recovered after different periods of culture suggested that the histamine content increased with maturation. Even after 45 to 50 days culture, the histamine content of cultured mast cells was significantly lower than that in rat peritoneal mast cells. The cultured mast cells were passively sensitized in vitro with rat IgE antibody against Nippostrongylus brasiliensis. The sensitized cells released histamine upon incubation with the antigen. It was also found that cultured mast cells released histamine upon exposure to compound 48/80. These results indicated that cultured mast cells have physiologic functions similar to those of normal rat mast cells, but they have not reached full maturation.
Delineation and Quantitation of Human Peripheral Blood Lymphocyte Subpopulations by Electrophoretic Mobility and Role of Surface Charge in Cell to Cell Interaction
Authors: Hanjan S. N. S. , Talwar G. P. , Kidwai Zeba , Nath Indira 
Published: December 2022

Abstract
A modified procedure is proposed for determination of electrophoretic mobility (EPM) of lymphocytes which enables readings on 200 cells from a sample size of 5 × 106 lymphocytes. In normal human peripheral blood, B lymphocytes (bearing surface immunoglobulin and receptor for activated C3) were found to carry the lowest charge (0.94 ± 0.05 µ/sec/V/cm). Their number on the EPM basis was 16.9 ± 4.2%. Two subpopulations of T lymphocytes, one carrying high charge (TH) with a mean EPM of 1.26 ± 0.04 µ/sec/V/cm and the other carrying lower charge (TL) with a mean EPM of 1.11 ± 0.03 µ/sec/V/cm were discernible. The former subpopulation of T cells formed spontaneous rosettes with SRBC in 10 min and the latter represented the remaining T lymphocytes which formed rosettes with 24 hr of incubation with SRBC.
The number of early rosette-forming cells increased from 69 to 89% when T cells were incubated with neuraminidase-treated SRBC. These observations suggest that complementary electrostatic charge on T cells and SRBC are among the forces facilitating formation of rosettes between these cells.
Lack of Interaction of Circulating T Cells with Phytohemagglutinin in Bacillary Positive Untreated Lepromatous Leprosy Patients—Identification of Subpopulation of Lymphocytes by Shifts in Electrophoretic Mobility
Authors: Talwar G. P. , Hanjan S. N. S. , Mehra V. L. , Kidwai Zeba 
Published: December 2022

Abstract
Incubation of human peripheral blood lymphocytes from normal healthy subjects with phytohemagglutinin (PHA), causes the reduction of the surface charge of a subpopulation of T cells by 1363 ± 242 e.s.u./cm2. The affected subpopulation was predominantly the high charge-bearing cells identifiable with early (10 min) rosette-forming cells with sheep erythrocytes. Purified lymphocytes obtained from untreated bacillary-positive, lepromatous leprosy patients contained high charge-bearing T lymphocyte subpopulation. However, incubation with PHA did not result in the shift of electrophoretic mobility of these cells, suggesting the absence of interacting sites for the mitogen on the surface of these cells. The absence of mitogen-interacting sites is not an inherent trait of leprosy patients; the surface charge of lymphocytes from Dapsone-treated bacillary-negative subjects was reduced upon incubation with PHA. A close correlation was found between the number of cells whose charge alters on incubation with PHA and the transformation index obtained with this mitogen.
Immunologic Properties of Bacterial Lipopolysaccharide (LPS)
Authors: Skidmore Barry J. , Chiller Jacques M. , Weigle William O. 
Published: December 2022

Abstract
Lymphoid cells obtained from the C3H/HeJ mouse strain respond abnormally to LPS in vitro, as shown by the fact that they are unable to make a mitogenic response to some LPS preparations and make only a low mitogenic response to other LPS preparations. In contrast, cells from a closely related C3H substrain, the C3H/St, are highly responsive to both types of LPS preparations. Experiments were carried out to determine the cellular basis of these genetically determined LPS response differences. This question was approached by studying the mitogenic response to LPS in cultures containing mixtures of various combinations of B cells, T cells, and macrophages from C3H/HeJ and C3H/St mice. Experiments utilizing an LPS preparation to which the C3H/HeJ is totally unresponsive (negative LPS) revealed, first, that either spleen cells, or partially purified T cells and/or macrophages obtained from C3H/St, could not restore the ability of C3H/HeJ spleen cells to respond to LPS, indicating that the C3H/HeJ is not deficient in an LPS-specific helper cell population which may be required for mitogenesis. Secondly, the addition of either spleen cells or partially purified T cells or macrophages from the C3H/HeJ to spleen cells from the C3H/St did not inhibit the mitogenic response to LPS, suggesting that the presence of suppressor cell activity is also not involved. Experiments analogous to those described, except utilizing another LPS preparation to which the C3H/HeJ is partially responsive (positive LPS), also failed to demonstrate reconstitutive or suppressive effects when C3H/HeJ and C3H/St spleen cells were admixed.
The results obtained indicate that the defect in the C3H/HeJ mouse strain that limits its responsiveness to positive LPS and which renders it totally unresponsive to negative LPS appears to be an intrinsic defect in the capacity of B cells to react to the mitogenic stimulus of LPS.
Effect of Selective Complement Deficiency on the Rate of Neutralization of Enveloped Viruses by Human Sera
Authors: Leddy John P. , Simons Ruth L. , Douglas R. Gordon 
Published: December 2022

Abstract
The capacity of human sera genetically deficient in selective complement (C) components to enhance neutralization of enveloped viruses was examined by kinetic plaque reduction assays. Vaccinia virus, a DNA virus, and vesicular stomatitis virus (VSV), an RNA virus, were studied. Exogenous rabbit or human antibody to vaccinia virus, and guinea pig or human antibody to VSV were provided in limiting, C-dependent concentrations. IgG antibodies predominated in most of the antisera employed.
C5-deficient and C6-deficient human sera consistently supported normal rates of neutralization of either virus; this effect was heat-labile. C4-deficient human serum did not exceed heat-inactivated serum in any neutralization assay. C1r-deficient serum displayed slight heat-labile neutralizing capacity against vaccinia but none against VSV. C2- and C3-deficient sera consistently exhibited measurable but clearly subnormal rates of neutralization. Two fresh agammaglobulinemic sera failed to inactivate either virus in the absence of added antibody.
These results confirm and extend earlier evidence, based on neutralization of herpes simplex and Newcastle disease viruses in the presence of early (IgM) antibody and functionally pure guinea pig C components or C-deficient animal sera, that the late-acting components C5–C9 are not required for C-dependent neutralization. Data on four enveloped viruses now agree that this function is mediated by C1–C3, although C1 plus C4 appear to have some neutralizing capacity. This requirement for C1–C3 is overcome, however, in the presence of higher antibody concentrations, suggesting that the contribution of the C system to viral neutralization in vivo may be chiefly in the early phase of infection when antibody is limited.
Cell-Mediated Cytotoxicity Against Measles Virus in SSPE
Authors: Kreth Hans W. , ter Meulen Volker 
Published: December 2022

Abstract
In patients with subacute sclerosing panencephalitis (SSPE) virus persistency has been explained by a blocking factor of specific cell-mediated immunity in SSPE serum and cerebrospinal fluid (CSF). In the present study the effect of SSPE serum and CSF on cell-mediated cytotoxicity against 51Cr-labeled allogenic measles virus-infected target cells was tested.
Pretreatment of SSPE peripheral lymphoid cells by serum or CSF neither blocked nor increased measles-specific cytotoxicity when cells were subsequently tested in FCS containing tissue culture medium. However, killing activity was always enhanced after pretreatment of target cells or direct addition of serum or CSF to the cytotoxic assay. Enhancement was also observed with non-SSPE-derived measles antibodies. The effect was dependent on measles antibody concentrations. These results suggest that antibody-dependent killing by K cells is intact in patients with SSPE. It is possible that virus-infected brain cells are protected from an immune attack in vivo by antibody-induced antigenic modulation.
Generation of Human Plaque-Forming Cells in Culture: Tissue Distribution, Antigenic and Cellular Requirements
Authors: Dosch Hans-Michael , Gelfand Erwin W. 
Published: December 2022

Abstract
A system for the induction of specific, hemolytic plaque-forming cells from normal human lymphocytes in vitro (HcPFC) has been established and cells from various normal lymphoid tissues have been investigated. Normal values for anti-SRBC HcPFC responses in cultures of 107 Ficoll-Hypaque separated lymphocytes range from 2000 (bone marrow) to 7000 (spleen) and 15,000 (tonsillar and peripheral blood lymphocytes). HcPFC responses to ovalbumin were lower by a factor of 2 to 4. Anti-SRBC as well as anti-ovalbumin responses required the cooperation of T lymphocytes and IgM-bearing B lymphocytes and the magnitude of the response was antigen dose dependent. Addition of adherent cells as well as of 2-mercaptoethanol enhanced the response. On the basis of the data obtained in experiments examining the role of B and T lymphocytes, a tentative model of cellular interaction has been postulated, suggesting a major role for antigen concentration in the modulation of the response via reactive T lymphocytes.