bluuebunny/crossref_metadata_2025_split huggingface dataset:
GENETIC CONTROL OF IMMUNE RESPONSES IN VITRO
Authors: Kapp Judith A. , Pierce Carl W. , Benacerraf Baruj 
Published: June 2004

Although nonresponder, H-2s and H-2q, mice fail to develop GAT-specific PFC responses to GAT, they do develop GAT-specific PFC responses when stimulated by GAT complexed to an immunogenic carrier such as methylated bovine serum albumin. The studies described in this paper show that injection of nonresponder mice with GAT specifically decreases their ability to develop anti-GAT PFC responses to a subsequent challenge with GAT-MBSA. Addition of GAT to cultures of spleen cells from nonresponder mice also prevents development of the GAT-specific PFC responses stimulated by GAT-MBSA. Thus, interaction of nonresponder spleen cells with GAT leads to the induction of unresponsiveness in vivo and in vitro.
Various parameters of the tolerance induction have been investigated and described. A comparison of the effects of GAT on B cells indicates that nonresponder B cells are more readily rendered unresponsive by soluble GAT than are responder B cells. The significance of these data for our understanding of Ir gene regulation of the immune response is discussed.
RESTRICTION OF GENE EXPRESSION IN B LYMPHOCYTES AND THEIR PROGENY
Authors: Jones Patricia P. , Craig Susan W. , Cebra John J. , Herzenberg Leonard A. 
Published: June 2004

To determine whether or not B lymphocytes are committed to the synthesis of a single immunoglobulin heavy chain isotype during their differentiation into plasma cells, rabbit lymph node and Peyer's patch cells were separated into populations with and without membrane IgM, using a fluorescence-activated cell sorter (FACS). The potential of the µ-bearing (µ+) and non-µ-bearing (µ-) cells to give rise to plasma cells both in vivo after transfer into irradiated recipients and in vitro in the presence of pokeweed mitogen was assessed by immunofluorescence techniques, and the relative proportions of the cytoplasmic Ig-stained cells (CSC) synthesizing each class of heavy chains were determined.
Most of the CSC arising in vitro from µ-bearing lymph node and Peyer's patch cells contained IgM; all IgM CSC appeared to be derived from µ+ cells. Peyer's patch lymphocytes, however, did not generate IgM CSC after cell transfer and thus may be functionally different from lymph node µ+ cells. It was found also that nearly all of the many IgA CSC generated by Peyer's patch lymphocytes either in culture or after transfer were derived from µ- cells. Further fractionation of these µ- cells with the FACS after they had been membrane stained with anti-b locus allotype reagents revealed that the precursors of IgA CSC belong to a minor population of cells which do have b locus light chain determinants on their membranes, although they do not have detectable µ-chains. These cells are not found in lymph nodes.
Although the majority of Peyer's patch and lymph node cells were found to be precommitted to the synthesis of a single heavy chain isotype, a small proportion of cells may not be similarly restricted. Some of the CSC with membrane IgM were found to contain cytoplasmic IgA or IgG. In addition, µ+ populations did give rise to low numbers of IgA and IgG CSC. The implications of these results, obtained under experimental conditions, on the normal differentiation of B lymphocytes in situ are discussed.
STUDIES OF THE HUMAN LYMPHOCYTE RECEPTOR FOR HEAT-AGGREGATED OR ANTIGEN-COMPLEXED IMMUNOGLOBULIN
Authors: Dickler Howard B. 
Published: June 2004

The lymphocyte receptor for complexed immunoglobulin was shown not to bind heat-aggregated human serum albumin, bovine serum albumin, transferrin, F(ab')2, reduced and alkylated Ig, and mildly oxidized Ig, which indicated that the receptor is specific for a site dependent on disulfide bond(s) on the Fc portion of complexed Ig. Inhibition experiments provided evidence that the same receptor binds both heat-aggregated Ig and antigen-antibody complexes.
Lymphocytes treated with pronase were no longer able to bind Ig complexes, which suggested that the receptor is a protein or glycoprotein. Additional evidence was obtained that lymphocyte surface Ig and the receptor for complexed Ig are distinct since the former could be capped without affecting the distribution of the latter, and surface Ig was not detectable after trypsinization of lymphocytes, whereas the binding of Ig complexes was unaffected by such treatment. Incubation of lymphocytes which had bound Ig complexes in tissue culture medium at 37°C revealed that the complexes remained on the surface membrane for several hours, and that only a minority of lymphocytes binding complexes showed cap formation.
Lymphocytes which had heat-aggregated IgG specifically bound to their receptors for complexed Ig were markedly inhibited in their ability to mediate antibody-dependent cytotoxicity, thus providing strong evidence for the necessity of the receptor in this immune activity. Titration of this inhibition with varying amounts of complexes revealed distinct plateaus in the dose-response curve. This suggested that there may be more than one kind of receptor and/or different populations of lymphocytes which bear the receptor.
SPONTANEOUS RELEASE OF T-CELL RECEPTORS FOR ALLOANTIGENS
Authors: Ramseier Hansruedy 
Published: June 2004

In vitro cultivation of murine spleen cells resulted in a spontaneous release of receptors for alloantigens. This was revealed by the capacity of cell-free culture supernates to recognize alloantigens as measured in the PAR assay. Qualitatively, recognition responses obtained with these supernates reproduced faithfully those found with the corresponding cells.
Large amounts of receptors were released by untreated spleen cells and by spleen cells treated with a rabbit antimouse immunoglobulin serum and complement, smaller amounts were released by bone marrow cells, and native thymus cells released none. Spleen cells from nude mice and spleen cells from normal mice treated with anti-θ serum and complement showed no release of receptors. It was concluded that receptors active in the PAR test were of T-cell origin.
Release of T-cell receptors was found to be discontinuous and proceeded in waves. The amount of released receptors depended on the number of cells cultivated. Release occurred at 37°C but not at 4°C. Interaction with antigen, however, was temperature-independent. In contrast to T-cell receptors, a release of H-2 antigens could not be detected with the culture conditions employed.
GENERATION OF CYTOTOXIC T LYMPHOCYTES IN VITRO
Authors: Cerottini Jean-Charles , Engers Howard D. , MacDonald H. Robson , Brunner K. Theodor 
Published: June 2004

Mouse cytotoxic T lymphocytes (CTL) were generated in mixed leukocyte cultures (MLC) using spleen cells as responding cells and irradiated allogeneic spleen cells as stimulating cells. Cytotoxicity was assessed by a quantitative 51Cr assay system and the relative frequency of CTL in individual cell populations was estimated from dose-response curves. Inclusion of 2-mercaptoethanol in the MLC medium resulted in a 20–40-fold increase in the relative number of CTL generated at the peak of the response. Under these culture conditions, cell-mediated cytotoxic activity was detectable in MLC populations as early as 48 h after the onset of the cultures.
When spleen cells from mice immunized with allogeneic tumor cells 2–4 mo previously were cultured with irradiated spleen cells of the same alloantigenic specificity (MLC-Imm), it was found that the cell-mediated cytotoxic response was detectable earlier and reached higher levels than that observed in a primary MLC. At the peak of the response, MLC-Imm populations were observed to lyse up to 50% of the target cells within 3 h at a lymphocyte: target cell ratio of 0.3:1. Immunological and physical characterization of the effector cells generated in MLC-Imm indicated that they were medium to large-sized T lymphocytes. Altogether, these studies suggested the existence of an anamnestic cell-mediated cytotoxic response in MLC-Imm.
GENETIC ASPECTS OF CANINE MIXED LEUKOCYTE CULTURES
Authors: van den Tweel J. G. , Vriesendorp H. M. , Termijtelen A. , Westbroek D. L. , Bach M. L. , van Rood J. J. 
Published: June 2004

Recent data stress the importance of matching donor and recipient of an organ graft for both the serologically defined (SD) and lymphocyte-defined (LD) determinants. To allow experimental evaluation of the effect of these SD and LD structures in a noninbred experimental animal, mixed leukocyte culture tests were performed between SD identical and nonidentical dogs to clarify the LD system in these animals.
The results of these experiments can be summarized as follows: (a) In the dog there is a LD locus distinct from the known SD loci, which in all probability is localized outside the first (SD-1) series locus on the chromosome. (b) The crossing-over frequency between the SD and LD loci on the chromosome is low. (c) Studies in SD identical unrelated dogs and random unrelated dogs show an apparent high linkage disequilibrium between SD and LD loci. (d) The LD system in dogs is polymorphic.
ANTIGENIC MODULATION IN VITRO
Authors: Stackpole Christopher W. , Jacobson Janet B. , Lardis Michael P. 
Published: June 2004

The modulation or loss of thymus-leukemia (TL) antigenicity from the surfaces of mouse RADA1 leukemia cells and normal thymocytes during incubation with TL antibody in vitro at 37°C was investigated by cytotoxicity, immunofluorescence, and immunoelectron microscopy. The fate of bivalent and monovalent antibody during modulation was visualized by fluorescence microscopy. Considerable antibody remained bound to the cell surface after modulation, bivalent antibody being displaced topographically into "patches" and "caps" while monovalent antibody was only slightly aggregated on the cell surface. Some antibody was internalized, presumably by pinocytosis, and was sequestered into the Golgi region of the cell. Capping usually occurred over the pole of the cell opposite from the Golgi region, which may explain the lack of extensive pinocytosis of modulating bivalent antibody. Since modulation with monovalent antibody occurs without patch or cap formation, gross topographical redistribution of TL antigen-antibody complexes is not required for modulation, although more subtle displacement of these complexes may be involved.
Modulation was demonstrable by cytotoxicity with guinea pig C' but not with absorbed rabbit C', indicating that modulated TL antigens remain bound to the cell surface. A heat-labile factor in TL antiserum and in mouse serum in general is responsible for "blocking" the cytolytic interaction of guinea pig C' with modulated TL antigen-antibody complexes.
ONTOGENY OF B-LYMPHOCYTE FUNCTION
Authors: Goidl Edmond A. , Siskind Gregory W. 
Published: June 2004

The ontogeny of the ability of B lymphocytes to produce an antihapten response which is heterogeneous with respect to affinity for the antigenic determinant was studied in a cell transfer system. The heterogeneity of affinity of the immune response of lethally irradiated mice reconstituted with syngeneic, adult thymus cells and fetal or neonatal tissues as a source of B lymphocytes was studied. It was found that B cells from 17 day fetal liver or neonatal liver are highly restricted with respect to heterogeneity of affinity as compared with adult spleen or bone marrow. The B-cell population achieves an adult character with respect to heterogeneity of affinity by 2 wk of age. The peripheral lymphoid tissues (spleen) appear to mature in this respect more rapidly than do central lymphoid tissues (bone marrow). Spleens from 10-day old donors behave in an adult, heterogeneous manner while bone marrow from the same donors exhibit a marked restriction in heterogeneity of affinity. Germfree mice produce an immune response which is indistinguishable from conventionally reared adult animals with respect to heterogeneity of affinity.
The earlier appearance of the ability to transfer a heterogeneous immune response in spleen as compared with bone marrow suggests that the increasing heterogeneity of the B-lymphocyte population which occurs between birth and 2 wk of age is the result of a differentiation event and not of a somatic mutation or recombination event.
INHERITANCE OF ANTIBODY SPECIFICITY
Authors: Imanishi Thereza , Mäkelä O. 
Published: June 2004

Our data suggest that fine specificity of antihapten antibodies is a useful Mendelian marker of variable (V) genes. We found that some mouse strains (e.g., C57/BL6) consistently produced heteroclitic anti-(4-hydroxy-3-nitrophenyl)acetyl (NP) antibodies (relative affinity for related (4-hydroxy-5-iodo-3-nitrophenyl)acetyl and (4-hydroxy-3.5-dinitrophenyl)acetyl was always &gt;2) while other strains (e.g., CBA) produced "conventional" anti-NP antibodies (relative affinities were consistently &lt;1).
48 (CBA x C57BL/6)F1 mice were studied and most of them had heteroclitic anti-NP antibodies. They were backcrossed to the recessive CBA parent, and 87 backcross animals were similarly tested. Those heterozygous for the C57BL/6 heavy (H)-chain allotype were similar to the C57BL/6 and the F1 mice while mice homozygous for the CBA allotype were indistinguishable from the CBA. Such monogenic inheritance was observed only in the primary response.
Predominance of allotype-linked genes in the control of the fine specificity characteristics was confirmed by immunizing selected homozygous mouse strains. These mice contained various mixtures of genes from C57BL, BALB/c, and other strains. Specificity of their anti-NP was exclusively determined by genes linked to the H-chain allotype, no influence could be attributed to other genes including the H-2-linked genes.
Scanning electron microscopy of tobacco mosaic virus-labeled lymphocyte surface antigens
Authors: Hammerling U , Polliack A , Lampen N , Sabety M , De Harven E 
Published: June 2004

The study of surface antigen by immunoelectron microscopy has been hampered by the fact that thin sections of cells provide only a view of the cell perimeter in an essentially two- dimensional fashion. Although the reconstruction of the entire cell from serial sections has been accomplished (1), it remains too exacting a technique and will find only exceptional application. Carbon-platinum replicas (2) allow the inspection of larger surface areas and therefore are better suited for studying the distribution of antigens (3). But since only relatively smooth surfaces will yield stable replicas, cells with large numbers of microvilli are not amenable to this technique.
Despire its limited resolution, scanning electron microscopy (SEM) seems to be the method of choice because it can provide a view of almost half of the surface of a cell close to its natural configuration, particularly after critical point or freeze drying (4, 5). Immunological-labeling methods have not yet been routinely applied to SEM although both latex spheres (6) and hemocyanin (7) have been used with some success. The optimal visual marker should possess the following properties: be of a distinctive shape, chemically stable, and have per se a low binding affinity for cell surfaces. Tobacco mosaic virus (TMV), a marker with which we are familiar in transmission electron microscopy (8), seems to meet these demands; it has rod-like shape and defined dimensions (15 x 300 nm) and in addition it can easily be distinguished from surface microvilli. As the hybrid antibody technique (9) is also applicable to TMV, we have attempted to combine such immunological labeling with SEM. We present evidence that surface antigens can indeed be visualized by SEM, using the TMV marker in conjunction with the hybrid antibody technique.
Dissociation between mitogenicity and immunogenicity of TNP- lipopolysaccharide, a T-independent antigen
Authors: Jacobs DM , Morrison DC 
Published: June 2004

Two models have been proposed to explain triggering of B cells by so-called T-independent antigen. Feldmann and Basten (1) proposed that the interaction of multiple repeating determinants on polymeric antigens with specific Ig receptors on the B-cell surface is sufficient to provide the signals for division of these cells and differentiation to antibody-forming cells. In contrast, coutinho et al. (2, and see review, 3) have claimed that there is only one signal, a mitogenic signal, receptors acting merely as passive focusing devices to localize the antigen on specific cells where it delivers a mitogenic signal resulting in differentiation to an antibody-producing cell. This model rests primarily on the demonstration that at high concentration all T-independent antigens they have tested are mitogenic for B cells (4-6). Compatible with this hypothesis are the observations that hydrolysis of lipopolysaccharide (LPS) to remove the ester- linked fatty acids of the mitogenic lipid A component abrogates its mitogenic (7,8) activity as well as its ability, when substituted with the TNP hapten, to induce a T-independent anti- TNP response (9). However, alkali treatment of LPS, although not changing its antigenic component (8), may also modify the molecule physically or chemically which could account for loss of immunogenic properties (10). We therefore investigated other reagents which interact with LPS in a more chemically defined manner in an effort to clarify the relationship between the mitogenic and immunogenic properties of this molecule.
Polymyxin B (PB) is one of a family of cyclic peptide antibiotics which are bactericidal for most gram-negative bacteria. It prevents the lethal endotoxic activity of LPS (11, 12) and changes the physical structure of LPS (13). We report here that low doses of PB added to cultures of mouse spleen cells inhibit the mitogenic activity of TNP-LPS, a T- independent antigen, and native LPS, but do not suppress the immune response to TNP-LPS. PB interacts with TNP-LPS and LPS causing a physical change in the molecule. In addition, polymyxin-treated LPS is no longer mitogenic. These results suggest a dissociation between the mitogenic and immunogenic properties of TNP-LPS.
New mutant and congenic mouse stocks expressing the murine leukemia virus-associated thymocyte surface antigen G(IX)
Authors: Stockert E , Boyse EA , Obata Y , Ikeda H , Sarkar NH , Hoffman HA 
Published: June 2004

For several reasons the G(IX) antigen (1) has a prominent place in current work on murine leukemia virus (MuLV): In the prototype G(IX+) mouse strain 129, the G(IX) trait is mendelian, and is expressed selectively (though not exclusively) on thymocytes. Thus, expression of this cell surface component is under the control of cellular genes and is subject to the controls governing the differentiation of T lymphocytes (2). Although the 129 mouse produces no demonstrable leukemia virus such as that found in the AKR strain, it was soon realized that G(IX) antigen must in some way be related to MuLV, because productive infection with MuLV is frequently associated with appearance of G(IX) antigen on cells that are genotypically G(IX-), most notably on MuLV-infected rat cells, or cells that belong to other differentiation pathways (1). The basis of this connection between G(IX) and MuLV has recently become clear from the demonstration that G(IX) is one of MuLV envelope. Therefore, our working hypothesis is that the presence of G(IX) is one of the antigens present on gp69/71 (3,4), the major glycoprotein component of the MuLV envelope. Therefore, our working hypothesis is that the presence of G(IX) antigen always denotes the presence of gp69/71 (though not all variants of gp69/71 need necessarily carry G(IX)).
Study of the circumstances under which G(IX) is expressed on the cell surface is thus potentially a powerful approach to understanding how the expression of C-type viral genomes is controlled. Such studies are greatly facilitated by the availability of mutant and congenic strains of inbred mice which differ from the nonmutant or partner strains only with respect to one or another manifestation of the viral genome.
It is for this reason that we record here (Table I) some details of two G(IX) mutant and two G(IX) congenic stocks derived in our colonies at Memorial Sloan-Kettering Cancer Center (MSKCC). In addition, to these four strains, Table I includes data for the three relevant partner strains, and for strain AKR, for comparison. These eight strains all differ from one another with respect to one or more MuLV-related traits.
Pre-emption of human cell-mediated lympholysis by a suppressive mechanism activated in mixed lymphocyte cultures
Authors: Sondel PM , Jacobson MW , Bach FH 
Published: June 2004

The regulation of B-cell and T-cell immune responses has been extensively examined and in the experimental animal appears to involve regulatory or suppressor T cells (1-4). The limitations of in vitro experimentation have made comparable study of nonpathological human suppression quite difficult (5). We report here an in vitro method that generates and quantitates suppressor activity in man after antigen-specific activation in mixed leukocyte culture (MLC).
The one-way MLC induces both a proliferative response (6) and the generation of cytotoxic T lymphocytes (CTLs) (7). Both of these responses are mediated by antigen-specific T-cell subpopulations (8,9) and have been correlated with recognitive and destructive phases of allograft rejection. Recent reports have examined the antigen reactivity of mouse (10,11), rat (12), or human (13,14) lymphocytes obtained after proliferation in MLC. In all cases, after the primary MLC proliferative peak, the recovered lymphocytes rapidly differentiate upon re-exposure to the initial stimulating population, but do so only weakly when exposed to a presumably noncross-reactive third-party stimulating population.
Velocity sedimentation separation studies have shown that the blast cells produced in a primary MLC revert to small lymphocytes that rapidly differentiate into proliferating and/or cytotoxic T lymphocytes upon restimulation with the initial antigen (15). These findings demonstrate that positive selection for the responding population in primary MLC does exist and may account for at least part of the specificity of the secondary response. However, this positive selection does not preclude possible involvement of a suppressor mechanism. In fact we have detected suppressor activity in primary MLC sensitization cultures at a time when the proliferation responsible for positive selection does not preclude possible involvement of a suppressor mechanism. In fact we have detected suppressor activity in primary MLC sensitization cultures at a time when the proliferation responsible for positive selection in not yet significant, suggesting that suppression may be overriding importance in the specificity of MLC-activated secondary responses.
Antipolysaccharide antibodies of restricted heterogeneity secreted by a single lymph node
Authors: Frost H , Braun DG , Poskitt D , Cahill RNP , Trnka Z 
Published: June 2004

Immune responses which give rise to the synthesis of antibodies of restricted heterogeneity can be reproducibly induced in rabbits and mice by streptococcal polysaccharide antigens (1,2). While these reports have demonstrated clonotype restriction in the immune serum of rabbits and mice, they give little information with respect to the clontype restriction in a single reaction site of organized lymphoid tissue, for example a single lymph node. The kinetics of immune responses in lymph nodes in situ have been studied in sheep using a variety of antigens (3-6), and a substantial body of information is available on the changes in cell output, cell type, and the number of antibody-secreting cells which occur within the efferent lymph of antigen-stimulated lymph nodes. However, there is no information with respect to the amount and the heterogeneity of antibody that is secreted by the lymph node or cells within the efferent lymph.
In the present report we have examined the temporal sequence of clonal restriction in the efferent lymph of individual sheep popliteal lymph nodes undergoing an immune response to the streptococcal group A-variant polysaccharide (Av-CHO).