bluuebunny/crossref_metadata_2025_split huggingface dataset:
The roles of host and donor cells in the rejection of skin allografts by T cell‐deprived rats injected with syngeneic T cells
Authors: Dallman Margaret J. , Mason Donald W. , Webb Michael 
Published: February 2007

AbstractMonoclonal antibodies that define rat T helper cells and cytotoxic T cell precursors were used to deplete thoracic duct lymphocytes of one or other of these subsets and the residual cells injected into syngeneic T cell‐deprived rats bearing skin allografts. The subsequent fate of the grafts was compared with that of grafts on rats injected with unfractionated donor cells. Removal of cytotoxic T cell precursors from the donor inoculum did not affect the ability of the injected cells to mediate destruction of the grafts whereas removal of T helper cells led to prolonged graft survival. Using monoclonal antibodies to label cryostat sections, the phenotypes of the cells infiltrating rejecting grafts and healthy grafts were also established. Seven days after grafting syngeneic or allogeneic skin on T cell‐deprived rats, all grafts were heavily infiltrated with Ia+ macrophages, but by 4 weeks this infiltrate had subsided and the grafts, whether syngeneic or allogeneic, were in perfect condition. At this time animals bearing grafts were injected with thoracic duct lymphocytes depleted of cytotoxic T cell precursors. Within 6 days of these cell transfers the allogeneic grafts, but not the syngeneic ones, were infiltrated with large numbers of mononuclear cells. Many of these cells were T cells, as judged by their expression of a pan T cell antigen, defined by the monoclonal antibody MRC OX‐19, and many were Ia' macrophages. In addition there was a very heavy infiltrate of cells labeled by the MRC OX‐8 monoclonal antibody which detects both rat cytotoxic T cells and natural killer cells.T cell‐deprived rats contained elevated numbers of nonspecific cytotoxic cells. Evidence was obtained that these cells were MRC OX‐8+. The possible role of these cells and of Ia+ macrophages in allograft rejection is discussed. As part of these studies the phenotypes of the cytotoxic T cell precursor and the cytotoxic effector cell were determined. It was shown that both cell types were indistinguishable, in terms of their reactivities with monoclonal anti‐rat T cell antibodies, from rat suppressor T cells.
Frequency analysis of cytolytic T cell precursors (CTL‐P) generated in vivo during lethal rabies infection of mice. I. Distinction of CTL‐P with different interleukin 2 sensitivity
Authors: Reddehase Matthias Johannes , Cox James Hilton , Koszinowski Ulrich Helmut 
Published: February 2007

AbstractThe aim of this study was to determine the number and state of activity of cytolytic T lymphocytes (CTL) and their precursors (CTL‐P) present in vivo during the early stages of viral infection. The local response to lethal infection with rabies virus was used as a model system that is not accessible to analysis by secondary activation in vitro. The local response to alloantigen served as a control. Experimental protocols were established that allow frequency estimates of in vivo antigen‐triggered CTL‐P. Data allow a distinction between CTL‐P activated in vivo by alloantigen and viral antigen with respect to their different capacity to utilize T cell growth factors (inter‐leukins). In vivo alloantigen‐primed CTL‐P generate, in vitro, an active effector progeny in the presence of interleukins of xenogeneic origin, whereas the majority of virus‐specific CTL‐P, in spite of considerable expansion in vivo, fail to generate CTL in vitro unless antigen is added.
Expression of a distinct B cell clonotype profile after recovery from antigen‐induced unresponsiveness
Authors: Etlinger Howard M. , Heusser Christoph H. 
Published: February 2007

AbstractThe purpose of these experiments was to determine whether the B cell clonotype profile expressed in mice which have recovered from antigen‐induced unresponsive‐ness is similar to that of nontolerized mice. Unresponsiveness to phosphorylcholine (PC) was initiated by injection of neonatal mice with PC‐coupled human gamma globulin, resulting in the inability to respond to challenge with PC‐lipopolysaccharide at 1.5 months of age. By 3 months of age, pretreated mice were 50% responsive while by 5 and 7.5 months of age, full responsiveness was observed. At each time point two differences distinguished the anti‐PC antibody from nonpretreated mice. First, whereas nonpretreated mice displayed T15 dominance, pretreated mice did not. Second, the average avidity of T15‐negative antibody produced in pretreated mice was greater than that in nonpretreated mice and similar to that of T15‐positive antibody. Possible mechanisms for this “permanent” alteration of the antibody profile are discussed.
Immature B cells in fetal development and immunodeficiency: Studies of IgM, IgG, IgA and IgD production in vitro using epstein‐Barr virus activation
Authors: Pereira Scott , Webster David , Platts‐Mills Thomas 
Published: February 2007

AbstractEpstein‐Barr virus has been used as a B cell mitogen to explore the parallels between the B cells found in patients with hypogammaglobulinemia and the immature B cells in fetal tissues. Peripheral blood lymphocytes from 29 cases of late onset hypogammaglobulinemia (common variable immunodeficiency) and from 10 cases of X‐linked hypogammaglobulinemia were depleted of T lymphocytes and stimulated with virus in vitro. Immunoglobulin production was measured over a 4‐week culture period using inhibition radioimmunoassays for IgM, IgG, IgA and IgD. The results were compared with those seen with fetal liver cells, cord blood lymphocytes and adult lymphocytes. Virus‐stimulated cells from fetal sources produced small amounts of IgG and IgA relative to IgM, the ratio of IgM to IgG in the second week being in all cases greater than 10. Similar patterns were seen in 25/29 cases of late onset hypogammaglobulinemia, and in the eight cases of X‐linked hypogammaglobulinemia that responded in vitro. In contrast, the ratio of IgM to IgG was always less than 8 in cultures of normal adult peripheral blood or bone marrow lymphocytes, and also in cultures from four cases of hypogammaglobulinemia known independently to have abnormal circulating suppressor cells. Eight cases of selective IgA deficiency showed reduced IgA production; six of these showed a normal ratio of IgM to IgG production. Thus, the B lymphocytes which circulate in many patients with hypogammaglobulinemia are functionally immature.
Restoration of antibody responsiveness in early thymectomized Xenopus by implantation of major histocompatibility complex‐mismatched larval thymus
Authors: Pasquier Louis Du , Horton John D. 
Published: February 2007

AbstractThe restorative potential of isogeneic and fully allogeneic thymic implants to restore in vivo antibody responsiveness to a thymus‐dependent antigen has been examined in thymectomized clawed toads. Isogeneic clones (Xenopus laevis/gilli and X. laevis/muelleri hybrids) of known major histocompatibility complex (MHC) haplotypes were thymectomized at 5‐7 days, implanted with MHC‐identical or ‐mismatched (normal or irradiated) thymuses from 5‐week‐old larvae and 4 months later injected with dinitrophenylated keyhole limpet hemocyanin. IgM antibody responsiveness (measured by phage inactivation) was restored in terms of its quantity, affinity and specificity in those thymectomized animals given two haplotype‐different thymuses. Isoelectric focusing data revealed that low molecular weight antibody production was also restored with isogeneic and allogeneic thymus and that the antibody spectrotypes were of the host type. The finding that in vivo T‐B collaboration in thymectomized animals develops normally following thymus implantation, even when the thymus genotype is disparate from the host, is discussed both in the light of previous experiments revealing MHC restriction of Xenopus T helper cells in vitro and in terms of the role of the thymus in promoting adaptive differentiation of this lymphocyte subset.
Antigen specificity and frequency of autologous and allogeneic helper T cells in the in vitro production of antibody against influenza virus by human blood lymphocytes
Authors: Smith Caroline M. , Callard Robin E. 
Published: February 2007

AbstractThe frequency of antigen‐specific helper T cells in human peripheral blood mononuclear cells was determined by limiting dilution analysis of specific in vitro antibody responses to influenza virus A/X‐31 (A‐H3N2). Limiting numbers of irradiated E rosette‐forming (E+) (T) cells were added to a constant number of syngeneic non‐rosette‐forming (E−) (“B”) cells and their ability to support production of antibody to influenza virus determined. The frequency of T helper cells was then calculated by a Poisson distribution analysis and found to range between 0.78 × 10−5 and 2.86 × 10−5. Specific antibody production can be obtained in this system from allogeneic combination of E− and E+ cells provided that the added E+ cells are irradiated to abrogate alloactivated T suppressor effects. Limiting dilution analysis applied to determine the frequency of helper T cells under these conditions showed that in most, but not all, cases the frequency of T helper cells was higher in allogeneic combinations. This result could be interpreted as showing an increase in the number of activated specific T helper cells, due perhaps to a positive allogeneic effect. On the other hand, it could also be explained by the alloactivation of an entirely different subset of nonspecific helper cells, or by the production of a nonspecific allogeneic helper factor. The specificity of T cell help in allogeneic combinations was therefore examined by adding limiting numbers of E− cells to a fixed number of E− cells and simultaneously challenging with two non‐cross‐reacting influenza viruses A/X‐31 and B/HK. Under these conditions, individual cultures produced antibody to A/X‐31, B/HK or both. The frequency of cultures producing antibody to both viruses was as predicted for the chance occurrence of specific helper T cells for both antigens being present in the same culture. The fact that a significant number of individual cultures made antibody to only one antigen in both autologous and allogeneic combinations showed that T cell help was antigen‐specific in both situations. Thus, for human in vitro antibody responses, antigen‐specific T cell help can be obtained across a major histocompatibility (complex) barrier.
Effect of deoxyguanosine on lymphopoiesis in the developing thymus rudiment in vitro: Application in the production of chimeric thymus rudiments
Authors: Jenkinson Eric J. , Franchi Leslie L. , Kingston Rosetta , Owen John J. T. 
Published: February 2007

AbstractOn the basis of reports that deoxyguanosine is selectively toxic for adult T lymphocytes, the usefulness of this compound in the production of lymphocyte‐depleted embryonic thymus rudiments in an in vitro organ culture system was investigated. The results showed that a period of exposure to deoxyguanosine causes depletion of the lymphoid cells while the stromal elements continue to survive, with many of the cells showing an epithelial morphology and expression of I region products of the major histocompatibility complex (MHC). When associated with either fetal liver or another thymus fragment as a source of T cell precursors in transfilter experiments, these “empty” thymuses become recolonized, enabling the production of chimeric thymus with stromal and lymphoid cells of different haplotypes. In combination with functional assays, this system offers an entirely in vitro approach to questions relating to the repertoire potential of T cell precursors from different sources and the role of the thymus in tolerance and MHC restriction.
Low susceptibility to the induction of experimental autoimmune encephalomyelitis in a substrain of the otherwise susceptible Lewis rat
Authors: Källén Bengt , Lögdberg Lennart 
Published: February 2007

AbstractA substrain of the Lewis rat, Lew/Mol, differing from ordinary Lewis rats in that it is hardly susceptible to the induction of experimental autoimmune encephalomyelitis (EAE) is described. The Lew/Mol rats did not mount a host‐vs. ‐graft response towards cells from an EAE‐susceptible substrain of Lewis rats (Lew/Mai) and vice versa. This argues against the possibility that the origin of Lew/Mol rats involves accidental cross‐breeding with other rat strains. Thus the EAE‐resistance in Lew/Mol rats is interpreted as being due to a mutation(s) in a gene(s) regulating the susceptibility to EAE. Specific pathogen‐free Lew/Mol rats were more resistant to EAE induction than Lew/Mol rats bred under conventional conditions, emphasizing the importance of environmental factors. Neither cyclophosphamide treatment nor increased age resulted in marked susceptibility in the Lew/Mol rats, although aging apparently had some effect, as a few animals did show neurological signs. Approximately half of (Lew/Mol × Lew/Mai) F1 hybrids developed EAE with neurological signs. In this respect, Lew/Mol rats differ from another recently described EAE‐resistant substrain of the Lewis rat (LeR).
Two‐dimensional gel analysis of the polypeptides precipitated by a polymorphic HLA‐DR1,2,w6 monoclonal antibody: Evidence for a third locus
Authors: de Kretser Theonne A. , Crumpton Michael J. , Bodmer Julia G. , Bodmer Walter F. 
Published: February 2007

AbstractThe SDR1 monoclonal antibody reacts only with cells which express the HLA‐DR1, 2,w6 or w8 allogeneic specificities. Two‐dimensional nonequilibrium pH gradient/ sodium dodecyl sulfate polyacrylamide gel electrophoretic analyses of SDR1 im‐munoprecipitates from [35S]methionine biosynthetically labeled cells revealed the typical pattern of la antigens, namely two polypeptides of about 34kDa and 29kDa (designated ϵ and β−3) as well as the “basic invariant spot” of about 31 kDa. The ϵ and β‐3 polypeptides were only weakly represented in similar analyses of immunoprecipitates performed using a monomorphic HLA‐DR monoclonal antibody, TDR31.1. The ϵ and β−3 polypeptides of B lymphoblastoid cell lines homozygous for HLA‐DR2 and w6 were structurally polymorphic as judged by two‐dimensional gel analyses. This polymorphism was independent of the HLA‐DR specificity. It is concluded that the SDR1 antibody recognizes a polymorphic set of la antigens that are coded by a locus other than HLA‐DR. These antigens probably also express the MT1 (DC1, LB12) alloantigenic specificity and are most likely the human equivalent of the murine I‐A subregion antigens.
Major histocompatibility complex‐restricted cellular interactions determining B cell activation
Authors: Julius Michael H. , Chiller Jacques M. , Sidman Charles L. 
Published: February 2007

AbstractRequirements for antigen‐ and major histocompatibility complex (MHC)‐restricted cellular interactions for an in vitro secondary anti‐2,4‐dinitrophenyl (DNP) response, as well as the accompanying polyspecific immune response, are assessed. Induction of the polyspecific B cell response requires only the MHC‐restricted, antigen‐specific activation of helper T cells. Once the latter is accomplished, the polyspecific Ig response is not limited by B cell MHC. In contrast, MHC‐restricted T helper cell activation is not sufficient for the activation of long‐term primed, DNP‐specific B cells. Their activation also depends on antigen presentation in conditions of linked recognition, i.e., hapten covalently linked to carrier, as well as recognition of B cell MHC by helper T cells. Moreover, the results demonstrate that the MHC‐restricted T‐macrophage and T‐B cell interactions are independent and rule out the involvement of MHC‐restricted 3 cell‐MHC, interactions.The differential induction requirements for DNP‐specific and polyspecific B cell responses are considered to reflect different states of B cell activation. When DNP‐primed B cells are derived from animals recently challenged with antigen, their induction requirements are identical to those for polyspecific B cells. The requirements for linked recognition and syngenicity with helper T cells are lost and their amplification is mediated by antigen‐specific, MHC‐restricted helper T cell activation (T cell‐mac‐rophage) alone.Activation requirements limiting the induction of a bystander erythrocyte response mediated by protein‐specific T cells (keyhole limpet hemocyanin) are considered within this context. At low keyhole limpet hemocyanin concentrations, induction requirements for sheep red blood cell‐specific bystander B cells parallel those for polyspecific B cells and recently boosted DNP‐specific B cells. However, at high antigen concentrations, bystander B cells syngeneic to T helper cells are preferentially induced. This latter phenomenon is considered to reflect antigen presentation by B cells.We conclude that the differing requirements for MHC‐restricted T‐macrophage and T‐B cell interactions in different B cell responses depend primarily on the pre‐existing state of B cell activation at the time of challenge.
In vitro studies on the immune regulatory role of complement receptors (C3) present on human B lymphocytes
Authors: Lobo Peter I. , Burge Joseph J. 
Published: February 2007

AbstractThe present studies were aimed at determining whether complement receptors (C3) present on human B lymphocytes had an immunoregulatory role. In these in Vitro studies, human B lymphocyte function was analyzed by quantitating their differentiation into plasmacytoid cells (development of intracytoplasmic immunoglobulin) after polyclonal activation with pokeweed mitogen (PWM), an assay that is known to be T cell‐dependent. Hence, a highly enriched population of B lymphocytes was cultured either alone or in the presence of autologous peripheral blood mononuclear cells (a source of T cells and macrophages). Cultures contained fresh autologous sera and PWM and at day 8, the numbers of plasmacytoid cells was quantitated utilizing cytocentrifuge smears. C3 receptors were activated by incubating B cells with C3‐containing immune complexes (EAC) and as controls, B cells were incubated with the same immune complexes, but lacking C3. The latter complexes failed to rosette with B cells. EAC were formed by sensitizing sheep erythrocytes with rabbit IgM antibody and using either mouse serum complement (EACmo) or isolated human complement components (EAC14b3b).The data from studies performed in 15 normal adults revealed that when EACmo, were interacted with B cells, there was an enhanced (78% ± 37 SD) production of plasmacytoid cells when compared to controls. Interaction of EACmo, with macrophages did not lead to enhanced production of plasma cells. Similar enhancement was observed in all 5 adults with EAC14b3b complexes. B cells depleted of T lymphocytes, when cultured with PWM, formed a few plasmacytoid cells and the number did not increase despite interaction with C3‐containing immune complexes. This indicated that for an augmented response T cells are required. These data suggest that C3 receptors modulate the B lymphocyte function.
Genetic control of sensitivity to moloney leukemia virus in mice. VI. Involvement of virus‐specific T helper cells collaborating with B cells
Authors: Boyer Brititte , Debré Patrice , Seman Michel , Zilberfarb Vladimir , Lévy Jean Paul 
Published: February 2007

AbstractT cell responses to Moloney virus involve cytolytic and helper lymphocytes. In contrast to specific cytolytic T lymphocytes, few studies have been devoted to the characteristics of helper T cells for antibody production. The present experiments describe an assay for Moloney virus‐specific help for B cells using dinitrophenylated virus. This method, using the Moloney virus as a carrier in a hapten‐carrier system, allows to definition of the specific helper function of antibody responses. T helper cells were induced in murine sarcoma virus or inactivated Moloney murine leukemia virus‐primed spleens or lymph nodes. T helper function was due to Thy‐1.2, Lyt‐1+2− cells and was macrophage‐dependent. It was stimulated by whole virus or Moloney gp71 envelope protein but not Moloney p30 internal protein. Cross‐reactive stimuli were obtained with other dinitrophenylated type C viruses. High and low responses were correlated respectively with resistance and susceptibility to Moloney leukemia virus. Cultures of helper T cells with preserved activity have been established and maintained for one month.
Use of monoclonal anti‐idiotypic antibody to P3‐X63Ag8 myeloma protein for analysis and purification of B lymphocyte hybridoma products
Authors: Gheuens Jan , McFarlin Dale E. 
Published: February 2007

AbstractA lymphocyte hybridoma, termed 80 V5B4, that secretes a syngeneic anti‐idiotypic antibody to P3‐×63Ag8 (×63) myeloma protein, is described. A sensitive radioimmunoassay to detect ×63 myeloma protein was developed with this monoclonal anti‐idiotypic antibody which can also be used to remove the ×63 myeloma protein from hybridoma products.
Genetic control of experimental autoimmune encephalomyelitis at the level of cytotoxic lymphocytes in guinea pigs
Authors: Ben‐Nun Avraham , Cohen Irun R. 
Published: February 2007

AbstractTo analyze immunologic mechanisms involved in experimental autoimmune encephalomyelitis (EAE), a system for studying the cytotoxic reaction of guinea pig lymphocytes against syngeneic macrophages pulsed with myelin basic protein (BP) was developed. It was found that both EAE‐susceptible strain 13 and EAE‐resistant strain 2 animals developed cytotoxicity directed against whole BP. However, only strain 13 guinea pigs developed such cells in response to immunization with the encephalitogenic nonapeptide determinant of BP. Strain 2 macrophages appeared able to present the nonapeptide determinant to strain 13 lymphocytes. Anti‐BP cytotoxic lymphocytes were found to be recruited by anti‐BP initiator lymphocytes.
Control of primary IgM antibody responses to H‐2 alloantigens by antigen‐bearing live B lymphocytes
Authors: Nakashima Izumi , Mizoguchi Kenji , Kato Nobuo , Nagase Fumihiko , Isobe Ken‐Ichi , Saito Mitsuru , Suzuki Kenji 
Published: February 2007

AbstractAlloantigen‐bearing (H‐2d+) peripheral red blood cells, but not red cell‐depleted H‐2d+ spleen cells, induce primary IgM anti‐H‐2d plaque‐forming cell responses. In this study it is reported that the primary antibody responses to H‐2d‐ peripheral red blood cells can be markedly suppressed by a subpopulation of H‐2d‐ spleen cells when they are injected simultaneously or a few days before injection of red blood cells. This suppression was antigen (H‐2d)‐specific, did not depend on T cells of either the donor or the recipient, and strictly required live donor cells. An energy‐dependent action of the donor cell cortex and some proliferation of donor cells in the recipient seemed to be involved in the mechanism of suppression. The donor‐suppressor cell type was largely present in the spleen but not in the bone marrow and thymus, and was present in the spleen of athymic nude mice. The suppressor cells displayed the properties of B lymphocytes: they adhered to the nylon wool but not to glass, were of relatively low density (σ < 1.09), and were surface Ig+, Ia+, Fc receptor‐positive but Thy‐1− H‐2d+ suppressor‐donor B lymphocytes might directly signal to antigen‐specific recipient B cells competing with the signal provided by H‐2d+ red blood cells for the B cell activation.
Monoclonal antibody NIM‐R2 shows differential reactivity with virgin and memory B cells
Authors: Marshall‐Clarke Stuart , Chayen Ann , Parkhouse R. M. E. 
Published: February 2007

AbstractThe differential reactivity of virgin and memory B cells with a monoclonal rat antibody (NIM‐R2) has been established by inhibition experiments and cell separations using the fluorescence‐activated cell sorter. B cells which stained strongly with NIM‐R2 gave excellent primary responses in vitro but were unable to transfer substantial memory responses, whereas the weakest staining B cells gave excellent secondary but poor primary responses. NIM‐R2 inhibited all primary responses in vitro which were examined, but failed to affect secondary responses.