bluuebunny/crossref_metadata_2025_split huggingface dataset:
IgA-Fc Receptors on Mouse Lymphoid Cells
Authors: Strober Warren , Hague Norma E. , Lum Lawrence G. , Henkart Pierre A. 
Published: December 2022

Abstract
Receptors specific for IgA were sought on mouse lymphoid cells by using a rosetting technique in which cells are exposed to modified ox red blood cells (ORBC) coated with IgA myeloma proteins having specificity for the modified ORBC. It was found that 4 to 6% of unseparated spleen lymphoid cells (pre-incubated at 37°C overnight) formed rosettes with MOPC 315-coated TNP-ORBC, with QUPC 52-coated dextran-ORBC, and with SAPC 10-coated arabinogalactan ORBC, whereas modified ORBC alone or modified ORBC mixed with irrelevant myelomas did not form appreciable numbers of rosettes; the cells forming rosettes were not neutrophils as shown by appropriate staining techniques. Thirteen to 22% of spleen cells also formed rosettes with IgG-coated ORBC (either IgG rabbit anti-TNP-coated TNP-ORBC or rabbit IgG anti-ORBC-coated ORBC); however, by using similar techniques, no cells forming rosettes with IgM-coated ORBC could be found. The specificity of the IgA-binding sites thus demonstrated was shown in inhibition studies: IgA antigen-antibody complexes formed near equivalence or, indeed, purified IgA were found to inhibit rosette formation with IgA-coated ORBC, whereas IgG complexes or purified IgG were found to cause no such inhibition. These inhibition studies were buttressed by depletion studies in which removal of cells binding IgG-coated ORBC with rosetting procedures was shown to have little or no effect on the percentage of cells binding IgA-coated ORBC in the residual cell population. The cells capable of binding IgA-coated ORBC are at least in part T cells in that the binding of IgA-coated ORBC is a property of nylon-column passed cells containing &lt;3% sIg positive cells; in addition, 2 to 3% of thymocytes bind IgA-coated ORBC. Finally, the IgA binding sites appear to be Fc-specific in that F(ab′)2 fragments of IgA do not block IgA-rosette formation. In summary, we have identified an IgA-Fc-specific binding site on mouse lymphoid cells, including mouse T cells.
Target-Effector Interaction in the Natural Killer (NK) Cell System
Authors: Roder John C. , Kiessling Rolf , Biberfeld Peter , Andersson Birger 
Published: December 2022

Abstract
We have previously shown that a subpopulation of nylon wool nonadherent, lymphoid cells in normal mice binds selectively to tumor cell targets that are sensitive to killing by natural killer (NK) cells. In the present report these target-binding cells (TBC) were enriched or depleted by velocity sedimentation and the isolation of single target-effector conjugates indicated that the majority of TBC killed their targets. Furthermore, the frequency of TBC correlated well (r = 0.86) with lysis in a population during kinetics experiments. TBC resembled small, resting lymphocytes with membrane specializations in the area of target cell contact as indicated by electron microscopy and cytochemical techniques. Target cell binding occurred before lysis in kinetics studies and regenerated in parallel with the lytic potential of a trypsinized population devoid of surface Ig or θ-bearing cells. Cell contact was prevented in the presence of EDTA whereas metabolic inhibitors or inhibitors of serine proteases suppressed lysis with no effect on the frequency of TBC. Conversely, an interferon-inducing agent elevated NK-mediated cytolysis with no effect on the level of TBC. These results suggest that i) the majority of TBC that we detect represents the NK cell and ii) lysis and binding are independently controlled events. A tentative model of NK-mediated lysis is proposed.
Rat Mast Cell-Eosinophil Interaction in Antibody-Dependent Eosinophil Cytotoxicity to Schistosoma Mansoni Schistosomula
Authors: Capron Monique , Rousseaux Jean , Mazingue Christine , Bazin Hervé , Carpon André 
Published: December 2022

Abstract
The involvement of IgG2a antibodies and mast cells in antibody-dependent eosinophil cytotoxicity suggested a possible interaction between mast cells and eosinophils for in vitro killing of Schistosoma mansoni schistosomula. Cell purification procedures showed that a minimum ratio of mast cells was required to obtain eosinophil cytotoxicity. The incubation of mast cells with heat-aggregated IgG2a immunoglobulins before addition to a mast cell-depleted eosinophil population induced a significant degree of inhibition of cytotoxicity. Similarly, the heat-aggregated IgG2a Fc fragment had a strong inhibitory effect whereas incubation of mast cells with Fab fragment failed to inhibit the cytotoxic effect. The Fc portion of IgG2a immunoglobulins therefore seemed to be involved in binding to the mast cell surface. Furthermore, it was demonstrated that soluble mediators released after mast cell activation either by compound 48/80, or by IgE, or IgG2a-dependent reaction had the same effect as intact mast cells. These observations suggest that the eosinophil-dependent cytotoxicity mechanism requires a signal provided by soluble mast cell mediators in addition to antibody.
C3-Mediated Cytoadherence
Authors: Landen Beate , Strunkheide Klaus , Dierich Manfred P. 
Published: December 2022

Abstract
Particles carrying C3 in a random distribution (Etan-C3) bound to C3 receptor (Raji+) cells independent of temperature and irrespective of whether the Raji cells were fixed with glutardialdehyde. In contrast, the reactivity of EAC43b, having grouped C3b in clusters, was dependent on temperature. The interaction with Raji cells was inhibited if the latter were treated with a fixative. The reaction of both Etan-C3 and EAC43b was a function of the concentration of C3 and C3b, respectively. The conclusion is drawn that for the interaction between C3/C3b-carrying particles and C receptor cells the receptors and the ligands have to be grouped in a similar typographic distribution, irrespective if this arrangement is provided already from the beginning or if it is obtained only by lateral movement of one or both reaction partners.
Human Macromolecular Insoluble Cold Globulin (MICG)
Authors: Hauptman Stephen P. , Kansu Emin , Sobczak Gloria , Serno Maryann 
Published: December 2022

Abstract
Thymus cell-derived macromolecular insoluble cold globulin (T-MICG) is a 225,000-dalton protein, selectively synthesized in human T cells. Null cell-derived macromolecular insoluble cold globulin (N-MICG) is a 185,000-dalton protein, synthesized in null cells, and antigenically distinct from T-MICG. Evidence to support these conclusions was provided by using isolated cell preparations that were radiolabeled, lysed in desoxycholate, and precipitated with monospecific antiserum to each component. These studies demonstrated that antiserum to T-MICG precipitated a 225,000 dalton protein from PBL and T cells, but not from B or null cells. Antiserum to N-MICG reacted with a 185,000 dalton protein present in PBL and null cells, but not with lysates from either T or B cells.
The plasma membrane distribution of these proteins was shown by absorption of antiserum to T + N-MICG with either isolated T or null cells. Antibody-induced cytotoxicity and immunofluorescence confirmed the cell surface location of T and N-MICG.
Divergent biologic effects of these antisera were also noted. Antiserum to T-MICG inhibited T cell rosette formation and the one-way mixed lymphocyte reaction, although anti-N-MICG antiserum had no such effect. The potential importance of these proteins is discussed.
Human Leukocyte Inhibitory Factor (LIF): Two Distinct Molecular Species
Authors: Brown Alan P. , Rocklin Ross E. 
Published: December 2022

Abstract
Human leukocyte inhibitory factor or LIF was generated in vitro by stimulating blood lymphocytes with concanavalin A (Con A). The control and Con A active supernatants were partially purified by gel filtration on Sephadex G-100. The fraction containing LIF (68,000 daltons) activity was then subjected to isoelectric focusing (pH 3 to 10 ampholines) in a sucrose gradient. Two LIF activities were reproducibly recovered by this procedure. One molecular form was found to have an isoelectric point of approximately pH 5.0 and the other approximately pH 8.5. Both molecular species were rechromatographed on Sephadex G-75 and found to have the same apparent m.w. (68 to 75,000). Furthermore, the biologic activity of both factors was destroyed after treatment with diisopropylphosphofluoridate, suggesting that they may be esterases.
Immunosuppressive Activity of Canine Pulmonary Surface Active Material
Authors: Ansfield Michael J. , Kaltreider H. Benfer , Benson Bradley J. , Caldwell Joseph L. 
Published: December 2022

Abstract
The effects of canine surface active material (SAM), a lipoprotein unique to the lung, on the proliferative response of lymphocytes to immune stimulation were investigated. Peripheral blood lymphocytes were cultured in the presence of either endobronchial lavage fluid or purified SAM extracted from such lavage fluids. Cultures were stimulated with mitogens (Con-A, or PWM) or allogeneic cells (MLC), and the proliferative responses were measured by the uptake of tritiated thymidine.
Culture of lymphocytes in autologous endobronchial lavage fluid resulted in a suppressed response to all three stimuli: MLC (33% control response), PWM (54% control), Con-A (75% control). Culture of lymphocytes with purified SAM produced a dose-dependent inhibition of the responses to these stimuli (MLC &gt; PWM &gt; Con-A). Fifty percent inhibition of lymphocyte responses to MLC, PWM, or Con-A was produced by 4.2, 7.5, or 12.5 µg protein/ml of purified SAM, respectively. Supraoptimal doses of mitogens failed to alter the observed inhibitory activities. SAM was not cytotoxic for lymphocytes in these experiments. SAM was most inhibitory when added to lymphocytes at the time of mitogen stimulation; progressively less inhibition was produced by SAM added at increasing intervals of time after stimulation. Lymphocytes preincubated with SAM for 24 or 48 hr, washed, and then cultured in fresh medium displayed persistently suppressed responses.
These results demonstrate that canine SAM is a potent suppressor of lymphocyte proliferation in vitro. In vivo, SAM is found only in the lung and, during fetal development, is secreted by the lung into amniotic fluid. The presence of SAM in these locations may have important implications for our understanding of pulmonary and maternal-fetal immunology.
Susceptibility of Friend Virus Antigen-Modulated Erythroleukemic Cells to Lysis by T Lymphocytes from Mice with Dormant Friend Virus Infections
Authors: Genovesi Eugene V. , Marx Preston A. , Wheelock E. Frederick 
Published: December 2022

Abstract
Spleen cells from DBA/2 mice with dormant Friend leukemia virus (FLV) infections or from mice immunized with x-irradiated FLC-745 erythroleukemic cells are not cytolytic for FLC-745 cells when tested directly, but acquire cytolytic activity in vitro by cultivation with x-irradiated FLC-745 cells. Spleen cells cultured from normal mice do not acquire such cytolytic activity. Cytolytic activity resides in the T lymphocyte population. Alloantiserum, but not antisera against FLV-virion polypeptides, inhibited the lysis of FLC-745 cells by cytolytic T lymphocytes. To understand further the role of cellular and humoral immune anti-FLV responses in mice with dormant FLV-infections, in vitro experiments were conducted that mimicked the in vivo FLV-specific immune environment of these mice. We found that FLV-immune serum from mice with dormant FLV-infections modulated FLV-antigen expression on the surfaces of FLC-745 cells without affecting their susceptibility to lysis by cytolytic T lymphocytes. These results suggest that cytolytic T lymphocytes restrain the outgrowth of FLV-antigen-modulated erythroleukemic cells in mice with dormant FLV infections and that the targets for cell-mediated lysis may be H-2d-associated antigens.
A Reexamination of Humoral Tolerance in Chickens Congenitally Infected with an Avian Leukosis Virus
Authors: Qualtiere Louis F. , Meyers Paul 
Published: December 2022

Abstract
In a reexamination of congenital infection of chickens with ALV, one of the classical models of immunologic tolerance, we were unable to demonstrate that there was any evidence suggesting humoral immune reactivity to the infecting virus. In ALV-F42 congenitally infected birds that have a persistent viremia and no neutralizing antibody detectable by conventional means, we could find no evidence of host IgG deposits in the kidneys, nor any suggestion of renal pathology or damage. In addition, attempts to precipitate any putative circulating infections virus-antibody complexes by treatment with a highly specific anti-globulin were negative nor were there titer differences in the viremic plasmas of bursectomized birds compared to nonbursectomized birds, indicating that the chickens were not making either a masked neutralizing or a nonneutralizing antibody response to the infecting virus. The evidence presented indicates that congenital infection of chickens with ALV does, at least at the humoral level, result in a state of immunologic tolerance to the infecting agent.
Genetic Control of the Immune Response to Staphylococcal Nuclease
Authors: Pisetsky David S. , Riordan Stephen E. , Sachs David H. 
Published: December 2022

Abstract
The genetic linkage relationship of two antinuclease idiotypes produced by the BALB/c strain was investigated in the backcross (BALB/c × CB.20) × CB.20. These two idiotypes were detected by Lewis rat anti-idiotypic antisera prepared against affinity-purified A/J and SJL antinuclease antibodies, termed the A/J and SJL idiotypes, respectively. Both idiotypes were found to be linked to the IgCHa immunoglobulin heavy chain allotype locus. There was, however, a high frequency of recombination observed between both markers and the IgCHa locus, with eight of 83 backcross animals recombinant for the A/J idiotype and five of 83 recombinant for the SJL idiotype. All such recombinant animals were IgCHb/b homozygotes that had gained one or both idiotypes. These results are consistent with a genetic map of VH region genes in the BALB/c strain in which genes determining the SJL idiotype are closer to the IgCHa allotype locus than are genes determining the A/J idiotype. This high frequency of recombination may indicate that the chromosome segment containing VH region genes is very large or that it has structural features that promote recombination.
Cell Types Required for H-2-Restricted Cytotoxic Responses Generated by Trinitrobenzene Sulfonate-Modified Syngeneic Cells or Trinitrophenyl-Conjugated Proteins
Authors: Pettinelli Carla B. , Schmitt-Verhulst Anne-Marie , Shearer Gene M. 
Published: December 2022

Abstract
Murine spleen cells were fractionated over nylon wool or Sephadex G-10 columns, and the cell types involved in the generation of trinitrophenyl (TNP)-specific, H-2 restricted (TNP-self) cytotoxic effector cells were studied from cultures stimulated with trinitrobenzene sulfonate (TNBS)-modified syngeneic cells, TNP-conjugated soluble proteins such as bovine γ-globulin (TNP-BGG), or bovine serum albumin (TNP-BSA). Unfractionated or nylon nonadherent responding cells generated such effectors, irrespective of whether the cultures were stimulated with TNBS-modified cells or TNP-conjugated proteins. TNP-modified T lymphocytes, B lymphocytes, and phagocyte-enriched spleen cells were all capable of stimulating TNP-self effectors. TNP-self as well as allogeneic cytotoxic responses were dependent on the presence of a radioresistant non-T cell that was removed by Sephadex G-10 fractionation and was replaced by irradiated, Thy 1.2-negative, glass adherent spleen cells, enriched in phagocytic cells. Results obtained by using glass adherent cells that were allogeneic or semi-syngeneic to the responding cells indicated that H-2 homology was not required for efficient glass adherent cell function, and that the H-2 restriction of TNP-self effectors is not determined by these glass adherent cells.
Failure of NZB Spleen to Respond to Prethymic Bone Marrow Suppressor Cells
Authors: Dauphinée Michael J. , Talal Norman 
Published: December 2022

Abstract
Mouse bone marrow contains θ-negative lymphocytes that can suppress an in vitro plaque response by spleen cells primed in vivo with burro red blood cells (BRBC). These bone marrow cells are radiosensitive and can be induced with thymosin fraction 5 or α1 thymic peptides to express the θ antigen. Enrichment for these suppressor pre-T lymphocytes can be achieved by a one-step density centrifugation, macrophage depletion, or a combination of both procedures.
NZB mice, which spontaneously develop an autoimmune disorder, have a suppressor abnormality revealed by this assay system. Upon analysis, they have normal BM pre-T suppressor cells but their spleen cells are refractory to the BM suppressor signal. NZB BM suppressor cells inhibit the response by DBA/2 spleen cells, but DBA/2 BM suppressor cells do not inhibit NZB spleen. This resistance to suppression is a property of the B cell fraction recovered from NZB spleen.
Study on the Turnover of the Receptor for the Third Component of Complement on Human Lymphoid Cells
Authors: Rosso di San Secondo V. E. M. , Meroni P. L. , Fortis C. , Tedesco F. 
Published: December 2022

Abstract
The in vitro turnover of the receptor for the third component of complement (C3) was studied in normal peripheral blood lymphocytes (PBL) and in lymphoblastoid cells from established cell cultures of both “normal” and “malignant” origin. The turnover was evaluated by studying i) the disappearance rate of the C3-receptor in cells in which the protein synthesis was blocked by cycloheximide and puromycin, ii) the reexpression rate of the C3-receptor after treatment of the cells with either rabbit antiserum against B lymphocytes or mouse C activated through the alternative pathway by inulin. The results show that the C3-receptor of all the lymphoid cells has roughly a half-life of about 3 to 4 hr. However, the cultured lymphoblastoid cells were less sensitive than normal PBL to inhibition by cycloheximide and showed a faster reexpression rate of the C3-receptor. A spontaneous release of the receptor was found to occur, since a receptor-like activity was detected in the spent culture medium of long-term cultured lymphoid cells.
Immunoregulatory Circuits among T Cell Sets: Effect of Mode of Immunization on Determining Which Lyl T Cell Sets Will be Activated
Authors: Eardley D. D. , Kemp J. , Shen F. W. , Cantor H. , Gershon R. K. 
Published: December 2022

Abstract
Lyl T cells are able to induce B cells to make antibody and also to induce a resting Ly123 T cell set to exert potent feedback suppression. Which of these two pathways Lyl T cells take can be influenced by the mode of immunization. In particular, in vitro immunized Lyl T cells are more likely to induce suppression than are Lyl T cells immunized in vivo even when both populations deliver the same amount of help to purified B cells. The feedback suppression induced by the Lyl T cells immunized in vitro can be distinguished from suppression mediated by Ly2+ T cells; in the former case suppression is preceded by a precocious antibody response, whereas suppression mediated by Ly2+ T cells is apparent throughout the entire period of observation.
Naturally Occurring Circulating Immune Complexes: Normal Human Serum Contains Idiotype-Anti-Idiotype Complexes Dissociable by Certain IgG Antiglobulins
Authors: Morgan Alton C. , Rossen Roger D. , Twomey Jeremiah J. 
Published: December 2022

Abstract
Sera from 19 of 23 healthy subjects contained a 24 to 26S complex (NTC). When passed over heat-aggregated IgG (HAGG) Sepharose, the NTC complex dissociated into a 7S IgG that was cytotoxic for malignant melanoma cells, and into an IgG antiglobulin (NTC antiglobulin) that only reacted with autologous cytotoxin. Prior incubation with soluble extracts of melanoma cells, but not with extracts of colon cancer or sarcoma, blocked recombination of isolated cytotoxin with NTC antiglobulin. Thus, NTC antiglobulin had attributes of an anti-idiotype. Cohn Fr II contained NTC complexes from many donors. A second IgG antiglobulin (ACF) was found in sera from patients with advanced cancer or rheumatoid arthritis. When added to normal donor sera, ACF caused NTC antiglobulin and 7S cytotoxin to dissociate. ACF combined with Fab′ of the allogeneic NTC cytotoxin to create a new complex that facilitated complement-dependent cytolysis of malignant melanoma cells. Sera with ACF activity also contained NTC. However, the cytotoxin in these sera was not detectable until the endogenous ACF and NTC antiglobulin had been removed by adsorption to HAGG Sepharose.
In ACF-containing sera, ACF fixed to NTC antiglobulin but would not react with the cytotoxin. In contrast, ACF reacted with the cytotoxin but not NTC antiglobulin in allogeneic sera. Thus, some natural antibodies circulate with their antigen-combining sites blocked by endogenous antiglobulins. Other antiglobulins, such as ACF, can facilitate detection of these blocked antibodies if they react with the components of the complex in a way that facilitates their dissociation.
Limiting Dilution Analysis of Alloantigen-Reactive T Lymphocytes
Authors: Ryser Jean-Etienne , MacDonald H. Robson 
Published: December 2022

Abstract
A sensitive mixed leukocyte microculture (micro MLC) system has been developed in which both proliferative and cytolytic responses can be detected from small numbers of responding alloantigen-reactive T lymphocytes. Cytolysis and proliferation in micro MLC were assessed by conventional 51Cr release and 3H-thymidine uptake assays, respectively. Optimal sensitivity of the system was dependent on several parameters, the most important of which was the presence of supernatant fluid derived from secondary MLC (2° MLC SN). Under optimal conditions, formal limiting dilution analysis could be achieved since excellent discrimination between positive and negative microcultures was obtained for both the cytolytic and proliferative assays. The system was therefore used to obtain simultaneously minimal estimates of the frequency of cytolytic T lymphocyte precursors (CTL-P) and of the precursors of proliferating T lymphocytes (PTL-P). The results of a series of experiments involving C57BL/6 spleen cells responding against DBA/2 alloantigens indicated that the minimal frequency of CTL-P was approximately 2-fold lower than the frequency of PTL-P in the same responding cell population (average of 1:570 and 1:290, respectively). Since analysis of individual micro MLC further demonstrated that essentially all CTL-P were contained within the PTL-P population, the simplest interpretation of these findings would be that approximately 50% of alloantigen-reactive T cells in this strain combination have the capacity to give rise to specific CTL. Some applications of this model system are briefly discussed.