bluuebunny/crossref_metadata_2025_split huggingface dataset:
DNP-Lys-Ficoll: A T-Independent Antigen Which Elicits Both IgM and IgG Anti-DNP Antibody-Secreting Cells
Authors: Sharon Raphael , McMaster Philip R. B. , Kask Anne M. , Owens James D. , Paul William E. 
Published: December 2022

Abstract
The 2,4-dinitrophenyl-lysyl derivative of Ficoll (DNP-Lys-Ficoll) was prepared and examined for immunogenicity. This antigen elicited large numbers of DNP-specific plaque-forming cells (PFC) of the IgM and IgG2 class in the spleens of C57BL/6 mice. Similar responses were observed in congenitally athymic (nu/nu) mice and in their littermates indicating that DNP-Lys-Ficoll is a T-independent antigen. The responses of nu/nu mice included a large number of IgG2 DNP-specific PFC, indicating that IgG responses can be initiated in the absence of mature thymus-dependent (T) lymphocytes. Cell transfer studies confirmed the T independence of the response and indicated that priming with DNP-Lys-Ficoll induces only a very meager degree of memory. Because they can be obtained in large quantities and in relatively pure form, DNP-Lys-Ficoll and other hapten conjugates of Ficoll should prove most valuable in the delineation of the mode of activation of precursors of antibody-secreting cells by T-independent antigens.
Release of Mitogenic Factor by Mouse Lymph Node Cells Stimulated with PHA in Vitro. Inhibition of This Phenomenon by the Addition of Thymocytes
Authors: Jacobsson Hans , Blomgren Henric 
Published: December 2022

Abstract
Thymidine uptakes of mouse lymph node cells and thymocytes in response to phytomitogen lectins were investigated in vitro. It was observed that mixtures of lymph node cells and thymocytes yielded higher 3H-TdR incorporations than expected when exposed to concanavalin A (Con A) or pokeweed mitogen (PWM), but lower incorporations than anticipated with phytohemagglutinin (PHA) as a stimulant. The observed enhancement of the response could be explained by factors which are stimulatory for thymocytes released by the lymph node cells. However, such mitogenic factors (MF) were released not only by Con A and PWM exposed cells but also by PHA expose lymph node cells. Further experiments showed that the admixture of thymocytes inhibited the release of MF by lymph node cells exposed to PHA but not to Con A or PWM. Since medullary thymocytes did not exhibit any inhibitory activity, it is likely that cortical thymocytes are responsible for this effect. The mechanism by which thymocytes inhibit MF production of lymph node cells exposed to PHA is not clear. MF was efficiently produced by lymph node cells cultured with PHA in “thymocyte-conditioned” medium and the MF activity was only marginally decreased by absorption with thymocytes.
The results are discussed in the light of recent findings showing that thymocytes may both enhance and depress the immune response of other lymphocytes.
The Role of T Cells in IgG Production; Thymus-Dependent Antigens Induce B Cell Memory in the Absence of T Cells
Authors: Schrader John W. 
Published: December 2022

Abstract
B cell memory was shown to develop in congenitally athymic (nu/nu) mice after injection with small amounts of thymus-dependent antigens, in particular heterologous serum proteins, such as fowl γ-globulin (FGG) or DNP-bovine-serum albumin (DNP-BSA). Large doses of protein (10 mg) tended to produce a specific B cell unresponsiveness, although there was still some evidence of B cell priming. The antigen did not have to be in a multivalent form to interact with B cell so as to induce immunologic memory or tolerance.
In contrast to the induction of B cell memory, the production of IgG antibody in this system was found to be strongly T cell dependent. Thymus-independent antigens like LPS or POL with pronounced adjuvant effects on IgG production in normal or surgically thymectomized mice, could not replace T cells in allowing an IgG response against thymus-dependent antigens in congenitally athymic mice. However, the action of T cells once activated is likely to be non-antigen-specific, since it was shown that supernatants of antigen-activated-syngeneic T cells stimulated IgG production in cultures of primed B cell populations non-antigen-specifically.
Binding of Poly (Glu60Ala30Tyr10) by Thymic Lymphocytes from Genetic Responder and Non-Responder Mice: Effect of Antihistocompatibility Serum
Authors: James Kennedy L. , Dorf Martin E. , Unanue Emil R. , Benacerraf Baruj 
Published: December 2022

Abstract
The binding of 125I-labeled GAT by murine thymocytes was studied by autoradiography. GAT binding was highly temperature dependent. Significantly more thymocytes bound GAT at 37°C than at 4°C. GAT bound at 37°C was usually distributed in a “cap” over one pole of the cell. Preincubation of thymocytes with specific anti-H-2 serum markedly inhibited the subsequent binding of GAT. The frequency of antigen-binding thymocytes was not significantly affected by preincubation of thymocytes with anti-Thy-1 serum or a number of anti-immunoglobulin in sera.
The immune response to GAT is controlled by an H-2 linked immune response gene(s). Mice of strains that are H-2p, H-2q or H-2s (non-responders) fail to develop effective T cell helper function necessary for a humoral immune response to GAT under most conditions. However, both responder and non-responder strains had similar numbers of thymocytes capable of binding GAT in vitro, indicating that T cells from non-responder strains of mice do possess a recognition mechanism for GAT.
Binding Parameters of the Interaction Between Rat IgE and Rat Mast Cell Receptors
Authors: Conrad Daniel H. , Bazin Hervé , Sehon Alec H. , Froese Arnold 
Published: December 2022

Abstract
Rat monoclonal IgE was purified by a combination of gel filtration and isoelectric focusing. The binding parameters of the IgE-target cell interaction were studied. The target cells used were normal rat peritoneal mast cells (RMC) and neoplastic rat basophilic leukocytes (RBL). Binding assays were performed by adding different amounts of IgE to a constant cell number. A Scatchard analysis of the data indicated that both cell types have a similar affinity for rat IgE; the equilibrium constant was in the order of 109 M-1. However, RBL have a higher number of receptor sites per cell—approximately 6 × 105 versus 3 × 105 for normal RMC. Since RMC have more than double the surface area of RBL, the data indicate a much higher receptor density on RBL.
Immunosuppression Induced in Vitro by Mastocytoma Tumor Cells and Cell-Free Extracts
Authors: Kamo Isao , Patel Chandu , Kateley John , Friedman Herman 
Published: December 2022

Abstract
Suppressed anti-sheep RBC responses occurred when spleen cells from mastocytoma-bearing mice were incubated in vitro and immunized with red blood cells. Marked immunosuppression also occurred when mastocytoma cells were added to spleen cell cultures from normal mice immunized in vitro with the sheep RBC. Suppressed immune responses also occurred when the mastocytoma cells were separated from the normal cells by 0.4-µ nucleopore membranes, but not by dialysis membranes in double chambered culture vessels. Cell-free homogenates prepared from mastocytoma cells, as well as ascitic fluid from tumor-bearing mice, also impaired the responsiveness of normal splenocytes to the SRBC. The suppressive activity of the cell-free homogenates was abolished by heating at 56°C for 30 min. The immunosuppressive activity, however, was retained in supernatant ultracentrifugates of the cell-free homogenate after 100,000 × G for 90 min. Immuno-suppression was most evident when mastocytoma extracts were added to cultures of normal splenocytes at the time of in vitro immunization and culture initiation. Suppression was not reversed by washing of the cultured cells and addition of fresh medium. Immunosuppression also occurred when mastocytoma extracts were incubated with spleen cells from allogeneic tumor resistant C57BL/6 mice. Additional physicochemical analyses should provide information as to the nature and specificty of the inhibitory factor(s) and its role as an immunoregulatory substance important in the host-tumor relationship.
Hepatitis B Core Antigen
Authors: Moritsugu Yasuo , Gold Jon W. M. , Wagner JoAnn , Dodd Roger Y. , Purcell Robert H. 
Published: December 2022

Abstract
Radioactive cores were prepared from concentrated Dane particles by DNA polymerase reaction followed by CsCl density gradient centrifugation. Two radioactive peaks were obtained: one peak with an average density of 1.36 g/cm3 in CsCl contained cores that possessed full serologic reactivity; the other peak, with a density of 1.28 to 1.32 g/cm3, contained cores associated with globulin. A double antibody immunoprecipitation test was developed, using the radioactive heavy cores as a source of antigen. The test was at least 300 times as sensitive as complement fixation for detecting antibody to core.
Thymus-Dependent Sensitizing Processes Involved in the Induction of CNS Disease in Mice by Parainfluenza Type 1 Virus
Authors: Iwasaki Y. , Aden D. , Koprowski H. 
Published: December 2022

Abstract
Parainfluenza type 1 virus injected intracerebrally into adult mice induced a mononuclear cell infiltration in the subarchnoidal and perivascular spaces, exudation of inflammatory cells into parenchymal tissue and preferential chronic degeneration of white matter (1, 2). No correlation was found between the severity of the central nervous system (CNS)2 lesions and the levels of circulating hemagglutination inhibition antibody (2). Inactivation of the virus by ultraviolet light (UV) did not affect the ability of the virus to produce the CNS lesions in these mice (3).
As part of an inquiry into the mechanisms involved in the production of CNS lesions, the present study reports the response of athymic nude mice and sensitization through prior CNS exposure to virus antigen in immunocompetent mice.
Materials and Methods. Inocula. The 6/94 strain of parainfluenza type 1 virus, originally isolated from cell cultures of brain tissue from two multiple sclerosis patients (4), was propagated in embryonated hen's eggs.
Endotoxin-Stimulated Spleen Cells: Characterization of the Responding Cells
Authors: Gormus Bobby J. , Shands Joseph W. 
Published: December 2022

Abstract
The percentage of endotoxin-stimulated lymphoblasts possessing C3 receptors (CR) decreases during a 72-hr period of in vitro cultivation. In studies reported here we attempted to determine whether the drop in the percentage of CR+ blast cells resulted from receptor loss by transformed cells or whether it resulted from the proliferation of additional blast cell types which lacked the CR.
Using methods which permitted simultaneous detection of cytoplasmic IgM, the presence of the CR, and 3H-thymidine uptake we found that: a) LPS stimulation resulted in a progressive increase in the number of IgM+ blasts, b) these constituted approximately 30% of the total cell population at 72 hr after LPS stimulation, c) of the IgM+ blasts 72 to 84% were CR+ and 16 to 28% were CR- at 72 hr, d) from 48 to 72 hr there was no decrease in the percentage of IgM+ blasts possessing the CR, and e) an additional blast cell type was observed which incorporated 3H-thymidine but which was IgM- and lacked the CR. These cells constituted from 11 to 27% of total 3H-thymidine+ cells at 72 hr after LPS stimulation. We conclude that the decrease in the percentage of CR+ blasts in LPS-stimulated spleen cell cultures is not due to receptor loss from IgM+ blasts cells but apparently is partly due to the stimulation and proliferation of other cell type(s) which lack(s) the CR. This cell(s), although its functional identity is unknown, does not appear to be of thymic origin. The heterogeneity of the markers on LPS-stimulated blast cells suggests that a heterogeneous population of cells responds to LPS.
Radiosensitivity of T and B Lymphocytes
Authors: Anderson Robert E. , Warner Noel L. 
Published: December 2022

Abstract
Radiation injury in defined populations of B cells was investigated utilizing an allotype congenic transfer system. The amount of donor immunoglobulin present in the recipient's serum was found to be directly proportional to the number of viable cells injected, and on this basis approximate D37 values for the inoculated B cells were determined in several experiments and found to fall in the 70 to 145 rad range depending upon the specific experimental conditions. Since the sensitivity of T cells to radiation-induced interphase death can be modified by prior exposure to select mitogens and antigens, an attempt was made to demonstrate a similar phenomenon with respect to B cells. The results indicate that the radiosensitivity of B cells can be slightly influenced by prior incubation with mitogens and only equivocally changed by activation with antigen.
Non-T Cell Killing of Mammary Tumor Cells by Spleen Cells: Secretion of Antibody and Recruitment of Cells
Authors: Blair Phyllis B. , Lane Mary-Ann 
Published: December 2022

Abstract
Both T cell-mediated killing and non-T cell-mediated killing of target MTV-induced mammary tumor cells can be detected in microcytotoxicity assay tests of spleen cells from mice immunologically responsive to either the histocompatibility antigens or the virus-associated antigens of the target cells. The non-T cell-mediated cytotoxicity is antibody-dependent; otherwise inactive cells (null cells) can be recruited to activity by target cell-specific factors obtained from the supernatant of short-term cultures of sensitized B cells or provided by the introduction of a small number of sensitized B cells to the wells of the assay plate.
Antibody-Dependent Cell-Mediated Cytotoxicity in Humans
Authors: Trinchieri Giorgio , Bauman Peter , de Marchi Mario , Tökés Zoltán 
Published: December 2022

Abstract
Mononuclear cells from human peripheral blood are able to destroy alloantibody-coated target cells of a human lymphoblastoid line. The effector cell is a nonadherent, non-phagocytic, medium sized lymphoid cell. This cell is not detectable in early human fetuses. Its activity is destroyed by x-ray treatment in vitro but is not inhibited by anti-immunoglobulin sera. Its efficiency in antibody-dependent cell-mediated cytotoxicity is rapidly lost in culture and this loss is prevented by stimulation with allogeneic cells.
Mitogenic Effect of Bacterial Peptidoglycans Possessing Adjuvant Activity
Authors: Damais C. , Bona C. , Chedid L. , Fleck J. , Nauciel C. , Martin J. P. 
Published: December 2022

Abstract
Two purified peptidoglycans extracted from E. coli or B. megaterium strongly stimulated the spleen lymphocytes of rabbits and of normal or nude mice. Both preparations can substitute for Mycobacteria in Freund's complete adjuvant. The peptidoglycan extracted from M. lysodeikticus by a similar procedure which lacks adjuvant activity, did not induce blast transformation. However, the monomere of the E. coli peptidoglycan was devoid of mitogenicity although it has also a marked adjuvant activity.
Resistance to Herpes Simplex Type 2 Virus Induced by an Immunopotentiator (Pyran) in Immunosuppressed Mice
Authors: Morahan Page S. , McCord Ronald S. 
Published: December 2022

Summary
BALB/c female mice depleted of T lymphocytes by adult thymectomy, lethal irradiation, and bone marrow reconstitution (TXB mice) are approximately 10 times more susceptible than normal mice to i.v. or intravaginal infection with herpes simplex virus type 2. Treatment with the immunopotentiator pyran is effective in protecting both normal or TXB mice against lethal infection with the herpes virus. The results suggest a possible role for immunopotentiator-activated macrophages in the increased resistance afforded mice by treatment with pyran.
Induction of Mouse Type-C RNA Virus by Lipopolysaccharide
Authors: Greenberger Joel S. , Phillips S. Michael , Stephenson John R. , Aaronson Stuart A. 
Published: December 2022

Summary
BALB/c mouse cells contain genetic information for xenotropic and mouse cell-tropic endogenous type-C RNA viruses. Halogenated pyrimidines induce both viruses from BALB/c embryo fibroblasts and spleen cells in tissue culture. Lipopolysaccharide, and to a lesser extent concanavalin-A, are shown to activate specifically xenotropic virus release by BALB/c spleen cells.
Human Lymphocyte Subpopulation: Early and Late Rosettes
Authors: Yu David Tak Yan 
Published: December 2022

Abstract
In the process of forming SRBC rosettes of human lymphocytes, two types were distinguished, the early and late rosettes. The former appeared immediately whereas the latter required further incubation at 4°C. In this study, the two types of cells were separated by gradient centrifugation and studied separately. It was found that the proportion of caps in the late rosettes was much greater than in the early ones. Treatment of the former by trypsin, AET, and neuraminidase decreased this proportion so that it resembled the late one. It was postulated that some of the differences in the early and late RFC lie in the differences in the content of membrane sulphydryl and sialic acid groups and distribution of SRBC receptors.
Secondary Cell-Mediated Cytotoxic Response to Syngeneic Mouse Tumor Challenge
Authors: Holden Howard T. , Kirchner Holger , Herberman Ronald B. 
Published: December 2022

Abstract
When C57BL/6 mice previously immunized with murine sarcoma virus (MSV) were challenged with a Rauscher virus-induced lymphoma, RBL-5, a secondary cell-mediated cytotoxic response could be detected by the 51Cr release cytotoxicity assay. The level and distribution of the secondary cytotoxic response was affected by the route of challenge. Animals injected i.p. demonstrated a high level of cytotoxicity in the peritoneal exudate cells 3 days after challenge and subsequently cytotoxicity was detected in most lymphoid organs, although at lower levels. However, when the animals were challenged intramuscularly in the leg, the response was not detected as rapidly and furthermore cytotoxic lymphocytes were found only in the draining lymph node and not in other lymphoid organs. Treatment of the effector cells with anti-ϑ and complement showed the secondary response to be predominately dependent on T cells. In addition, the cytotoxicity was specific in that cells lacking cross-reacting antigens were not killed by these attacker cells from mice undergoing a secondary response.
Hyperacute Rejection and Enhancement of Mouse Skin Grafts by Antibodies with a Distinct Specificity
Authors: Jansen Jan L. J. , Koene Robert A. P. , v. Kamp Gerard J. , Hagemann Jacq. F. H. M. , Wijdeveld Paul G. A. B. 
Published: December 2022

Abstract
Pure 7S IgG2 was prepared from B6AF1 anti-B10.D2 ascites fluid by affinity chromatography. This preparation was extensively absorbed with B10.D2 red blood cells to remove the antibodies directed against the serologically defined antigens of the major histocompatibility complex. After absorption the serum had retained in vitro cytotoxic activity against 45% of B10.D2 spleen cells. The absorbed and unabsorbed 7S IgG2 antibodies were tested for their capacity to induce enhancement and, in the presence of rabbit complement, hyperacute rejection of B10.D2 skin grafts in B6AF1 recipient mice. The enhancing capacity of 7S IgG2 was completely unimpaired after absorption. However, the absorbed preparation was unable to induce hyperacute rejection of the grafts even if very high doses were administered. The results show that hyperacute rejection of skin grafts in this model is mediated by antibodies directed against the serologically defined antigens (i.e., H-2K antigens) of the H-2 complex. They further support the hypothesis that immunologic enhancement is mediated by antibodies directed against Ir-region-associated antigens.
Induction of Mouse Homocytotropic Antibodies to Timothy Pollen Antigens
Authors: Fairchild Sally S. , Malley Arthur 
Published: December 2022

Abstract
The IgG1 and IgE homocytotropic antibody responses of LAF1 and C3H mice to timothy pollen antigens are defined. Both mouse strains responded to low doses of crude timothy pollen extract (WST) or a major antigen of timothy pollen coupled to a purified fraction of Ascaris suum (Antigen B-Ascaris). Titers in LAF1 mice were greater than those in C3H mice. Regardless of the immunogen, antigen B was the major determinant recognized by the homocytotropic antibodies; PCA titers with WST or antigen B for challenge were equivalent and PCA activity could be inhibited by antigen D, a dialyzable fraction of timothy pollen possessing the antigen B determinant in monovalent form. The possible usefulness of antigen D for in vivo and in vitro studies of specific immune suppression of cellular activity is discussed.
Class Differences in the Antibody Response of HLC and LLC Mice to Sheep Red Blood Cells
Authors: Silver Donald M. , Chai Chen K. 
Published: December 2022

Abstract
The immune response to sheep red blood cells (SRBC) has been studied in two mouse lines selectively bred for a difference in leukocyte levels. Low leukocyte count (LLC) mice responded to multiple injections of 4 × 107 SRBC with a predominant IgM response whereas high leukocyte count (HLC) mice produced IgG almost exclusively, even after a single injection of SRBC. F1 mice responded like the LLC parent and backcross data implied genetic control at multiple loci. No correlation was found between the class of antibody produced in response to SRBC and the leukocyte count in backcross mice. Large numbers of plaque-forming cells (PFC) were detected in the spleens of HLC mice relative to the number detected in LLC spleens after primary and secondary immunizations with SRBC.
Antigenic Selection of IgG Precursor Subpopulations
Authors: Elliott L. H. , Roszman T. L. 
Published: December 2022

Abstract
The temporal increase in the antigen-binding characteristic of the IgG antibody synthesized after primary immunization is thought to result from antigen preferentially selecting those precursors of the antibody-forming cells with higher affinity receptors. We have investigated this regulatory role of antigen on the selection and expression of IgG precursor subpopulations in rabbit lymph node populations undergoing the secondary anti-bovine serum albumin (BSA) response in vitro. The data indicate that although immunologic memory increased between 1 and 4 months after immunization there was not an increase in antigen sensitivity. We also determined the avidity of the IgG antibody secreted by PFC elicited in the cell cultures. Although the avidity of antibody secreted by PFC elicited with low concentrations of antigen was 2-fold greater than when high concentrations of antigen were employed, analyses of the avidity subpopulations of IgG PFC revealed that memory potential was not restricted to high affinity-primed cells. Moreover, populations of PFC that gave differing avidity values were similar in terms of their plaque diameters and IgG secretion rates.
X Chromosome-Linked Defect of CBA/HN Mice in Production of Tumor-Reactive Naturally Occurring IgM Antibodies
Authors: Martin Sue Ellen , Martin W. John 
Published: December 2022

Abstract
Tumor-reactive naturally occurring antibodies (NOA) could be readily detected in sera of many mouse strains including congenitally athymic (nude) and germ free (gf) mice. Mice of the CBA/HN strain, however, were found to possess low or undetectable levels of NOA against a wide range of tumor cell lines. Genetic studies indicated that the defect in production of tumor-reactive NOA in CBA/HN mice was largely determined by the absence of an X chromosome-linked gene and is probably similar to the known X chromosome defect of this mouse strain in their antibody response to thymus-independent antigens. In spite of the low level of tumor-reactive NOA, CBA/HN mice do not have a high incidence of spontaneous tumors. These findings suggest that if tumor reactive NOA are involved in immune surveillance against malignancy they are unlikely to act directly in a quantitative manner in the detection and elimination of autochthonous tumors.