bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional and phenotypic properties of subpopulations of murine thymocytes.I. The bulk of peanut agglutinin‐positive Lyt‐1,2,3 thymocytes lacks precursors of cytotoxic T lymphocytes responsive to interleukin 2 (T cell growth factor)
Authors: Kisielow Pawel , Von Bochmer Harald , Haas Werner
Published: February 2007

Thymocytes were separated according to their surface phenotype and tested for cytotoxic T lymphocyte (CTL) precursor function by stimulation with allogeneic or hapten‐coupled cells, with or without addition of T cell growth factor (interleukin 2). The data show that only a minor subpopulation of thymocytes agglutinated by peanut agglutinin, expressing relatively high amounts of H‐2K antigen, contained CTL precursors. The remaining population, approximately 80%, could not be induced to generate CTL, even in the presence of interleukin 2.
Human T cell lines with antigen specificity and helper activity
Authors: Lanzavecchia Antonio , Ferrarini Manlio , Celada Franco
Published: February 2007

Human T blasts, obtained by stimulation of peripheral blood mononuclear cells (PBM) with tetanus toxoid, diphtheria toxoid or Candida albicans, were expanded in long‐term culture using alternate periods of antigen restimulation and growth in media containing interleukin 2. The cells gave a proliferative response only to the antigen originally used for stimulation. Such a response was strictly dependent upon the presence of autologous but not of allogeneic mitomycin C‐treated mononuclear cells. When added to autologous PBM depleted of E‐rosetting cells together with the specific antigen, the T blasts induced a polyclonal proliferation and differentiation of B cells. Allogeneic B cells were activated by antigen‐stimulated T blasts only in the presence of irradiated mononuclear cells autologous to the responding T blasts.

The above responses seemed not to be regulated solely by the release of soluble factors; apparently cell to cell interactions had to take place to obtain an efficient B cell activation.
Experimental autoimmune uveitis in the athymic nude rat
Authors: Salinas‐Carmona Mario Cesar , Nussenblatt Robert B. , Gery Igal
Published: February 2007

A single injection of the retinal soluble antigen (S‐Ag, 30 pg) to the Lewis or the heterozygous (rnu/+) rats induces a severe bilateral uveitis, characterized initially by infiltration of the retina with inflammatory cells. The athymic nude rat (homozygous rnu/rnu), which lacks the thymus gland and T cell‐mediated functions, does not develop ocular inflammatory disease, clinically or histologically, after repeated challenges with S‐Ag. Circulating anti‐S‐Ag antibodies were found in S‐Ag‐immunized Lewis rats and in the heterozygous, but not the athymic nude rats. Good proliferative responses to concanavalin A, S‐Ag and purified protein derivitive of tuberculin (PPD) were found in lymphocyte cultures prepared from the draining lymph nodes of immunized heterozygous rats, but not when lymphocytes from the athymic nude rats were used. Uveitis could be induced in the athymic nude rat when lymphocytes from S‐Ag‐immunized heterozygous rats were transferred to them. By stimulating the donor lymphocytes in vitro with S‐Ag before transfer, the number of recipients that developed uveitis was increased. On the other hand, it was impossible to transfer disease with hyperimmune serum alone. The possible role of T lymphocytes in the induction of experimental autoimmune uveitis with S‐Ag is discussed.
Messenger RNA from allotype‐defined rabbits directing the cell‐free synthesis of immunoglobulin heavy and light chains
Authors: Pavirani Andrea , Mage Rose , Fitzmaurice Leona
Published: February 2007

In vitro synthesis studies were performed utilizing poly A(+)‐RNA and lymphocytes from the spleens of rabbits hyperimmunized with Micrococcus luteus or Streptococcus pneumoniae (type III). Poly A(+)‐RNA isolated after 4 M guanidinium thiocyanate extraction and oligo(dT)‐selection appeared to be undegraded on CH3HgOH‐agarose gel electrophoresis and demonstrated biological activity when translated in a rabbit reticulocyte cell‐free system. The electrophoretic patterns of the specifically immunoprecipitated cell‐free products were compared with those of Nonidet‐P40 extracts (lysates) and secretions (supernatants) from rabbit spleen lymphocyte cultures and serum proteins. Kappa light chains with specific b allotypes, as well as immunoglobulin heavy chains, were identified. The efficient translation of mRNA of defined allotypes was a necessary prerequisite for production of characterized cDNA clones and identification of genomic sequences for rabbit immunoglobulin heavy and light chains.
IgM‐ and IgD‐bearing peripheral blood lymphocytes differentiate to IgM but not IgG or IgA immunoglobulin‐secreting cells
Authors: Saiki Osamu , Ralph Peter
Published: February 2007

Human peripheral blood mononuclear cells were depleted of surface IgM+ or IgD+ cells and assayed for mitogen‐induced differentiation to immunoglobulin‐secreting cells (ISC) of IgM, IgG and IgA classes. Stimulatory agents included T cell‐dependent poke weed mitogen, B cell mitogen Staphylococcus aureus bacteria strain Cowan I, and a combination of the two which gives uniform, high levels of ISC from all normal donors. Depletion of either IgM‐ or IgD‐bearing B lymphocytes resulted in loss of cells bearing the other Ig class and blocked most of the mitogenic reactivity to anti‐IgM and anti‐IgD. Proliferative responses to Cowan I in these depleted populations were about 20% that of unfractionated mononuclear cells. Depletion of T cells increased the mitogenic response to Cowan I and to the two antibody preparations, showing that they are T‐independent mitogens. Depletion of IgD+ cells caused partial loss of mitogen‐induced IgM ISC (22%‐60% of unseparated controls) but no loss of IgG or IgA ISC. Depletion of IgM‐bearing cells caused complete loss of IgM ISC, but no loss of IgG or IgA ISC. We previously demonstrated that anti‐IgM antibody blocked mitogen induction of Ig secretion of these three classes in spleen cells, but only IgM secretion in blood mononuclear cells. Together, the results suggest that the majority of cells in normal blood responding to mitogens to mature to IgG or IgA production belong to IgM−, IgD− B cell subsets, in contrast to precursors of secreting cells for these isotypes in the spleen. Thus, these blood precursors appear to be more mature than the corresponding spleen cells.
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

Monoclonal 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

The 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

The 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

Epstein‐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

The 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

The 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

On 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

A 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

The 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

Requirements 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

The 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

T 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

A 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

To 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

Alloantigen‐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

The 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.
Production of high titers of interferon‐gamma by prestimulated murine spleen cells
Authors: Marcucci Fabrizio , Klein Beate , Kirchner Holger , Zawatzky Rainer
Published: February 2007

Concanavalin A (Con A)‐induced interferon‐gamma (IFN‐γ) production by murine spleen cells prestimulated with Con A for different periods of time has been studied. Highest titers of antiviral activity were obtained by restimulation of cells that had been prestimulated with Con A for 3 days. These cells produced up to 30 times more IFN than freshly isolated spleen cells stimulated under the same conditions. In an effort to explain this rise in the capacity to produce IFN‐γ, the possibility that it was due to the inactivation of a suppressor cell was excluded. The addition of freshly isolated spleen cells at different concentrations to prestimulated cells did not affect subsequent Con A‐induced IFN‐γ production. Separation of freshly isolated or prestimulated spleen cells by velocity sedimentation at unit gravity showed that in the latter case most of the IFN‐γ was produced by a population of large‐sized cells not present in the former population. It was concluded from these experiments that prestimulation of spleen cells with Con A gives rise to a population of large‐sized cells that produce, upon restimulation with the same mitogen, much higher titers of IFN‐γ than those obtained upon primary stimulation of small resting lymphocytes.
A monoclonal anti‐idiotypic antibody against anti‐receptor antibodies from myasthenic sera
Authors: Lefvert Ann‐Kari , James Richard W. , Alliod Christine , Fulpius Bernard W.
Published: February 2007

A monoclonal anti‐idiotypic antibody has been developed against anti‐acetylcholine receptor antibodies purified from the serum of one myasthenic patient. The idiotype is present on a subpopulation of antibodies directed against the toxin‐binding region of the receptor. The monoclonal antibody cross‐reacts with antibodies from other myasthenic sera, suggesting shared idiotypic specificities.
Induction of interferon in murine bone marrow‐derived macrophage cultures by 10‐carboxymethyl‐9‐acridanone
Authors: Storch Elke , Kirchner Holger
Published: February 2007

10‐Carboxymethyl‐9‐acridanone (CMA) induced high titers of interferon (IFN) in murine leukocyte cultures. Thymocytes, lymph node, spleen and peritoneal exudate cells responded to CMA with IFN production. Pure macrophages derived from the bone marrow were the most efficient producers of CMA‐induced IFN. The yields of IFN‐α β in the macrophage supernatants depended on the concentration of the inducer and titers up to 3000 IU/ml were measured after exposure to the optimal dose (500 μg/ml). CMA was found to be the first low molecular weight compound that induced in vitro titers of IFN nearly as high as obtained after exposure to Newcastle disease virus, which is one of the most potent interferon inducers.
Study of the idiotypy of lipopolysaccharide‐specific polyclonal and monoclonal antibodies
Authors: Hiernaux Jacques R. , Schroer Kenneth R. , Baker Phillip J. , Rudbach Jon A. , Bona Constantin
Published: February 2007

The monoclonal antibodies produced by a variety of hybridomas making antibody specific for E. coli 0113 lipopolysaccharide (LPS) were purified by affinity chromatography and their fine specificity studied. All reacted specifically with the polysaccharide moiety of LPS from E. coli 0113 and from Neisseria lactamica; two reacted with LPS from Pseudomonas aeruginosa and one reacted with LPS from Klebsiella pneumoniae. Polyclonal and monoclonal syngeneic and semi‐syngeneic anti‐idiotypic antisera were produced to study the idiotypy of LPS‐specific monoclonal antibodies which express a complex cross‐reactive idiotype (IdX) as well as individual idiotypes. E. coli 0113 LPS‐specific antibodies produced by B ALB/c mice express this IdX and the kinetics for its expression was examined using mice either primed or hyperim‐munized with LPS; idiotypic maturation was observed, but we were unable to detect an auto‐anti‐idiotypic antibody response. This IdX was expressed on E. coli 0113 LPS‐specific antibodies from all strains of mice examined, indicating that its expression is not restricted by genes linked to the IgCH locus.
Nature of the antigenic complex recognized by T lymphocytes. IX. Direct immunochemical demonstration of nominal antigen on the macrophage cell surface
Authors: Malek Thomas R. , Shevach Ethan M.
Published: February 2007

As an initial approach to macrophage (Mϕ) antigen handling, guinea pig Mϕ pulsed with the radiolabeled terpolymer L‐glutamic acid, L‐lysine, L‐tyrosine (GLT) were modified with the cell surface‐specific probe 2,4,6‐trinitrobenzenesulfonic acid either immediately after pulsing (fresh) or 24 h after pulsing (aged); nonidet P‐40 extracts were prepared from these cells and analysis of these extracts with anti‐trinitrophenyl antisera was performed in a quantitative radioimmunoassay. Such experiments indicated that fresh GLT‐pulsed Mϕ contained a pool of intracellular GLT as well as a distinct pool of cell surface GLT. In contrast, aged GLT‐pulsed Mϕ lacked intracellular GLT but expressed GLT on the cell surface. In addition, a pool of cell surface GLT was also detected on Ia−Mϕ and on Mϕ from guinea pigs which were nonres‐ponders to GLT. Thus, this study provides a direct demonstration of the presence of exogenous antigen on the Mϕ cell surface. However, the cell surface expression of GLT does not appear to be an exclusive property expressed by functional Ia+ antigen‐presenting Mϕ.
The effects of cyclosporin A on the chicken immune system
Authors: Nowak Jerzy S. , Kai Osamu , Peck Richard , Franklin Richard M.
Published: February 2007

Some aspects of the effects of cyclosporin A (CsA) on the chicken immune system are described. High serum levels of CsA could be maintained by i.m. administration of the drug in a neutral oil (Miglyol 812) every three days. After a transient decrease in peripheral blood T lymphocytes, the blood picture remained normal over a dosage period of three weeks. Mitogenic stimulation of the peripheral blood lymphocytes was strongly depressed, however.

Whereas there was a trend to decreased primary immune response of T‐dependent (sheep red blood cells, human γ‐globulins) and T‐independent (B. abortus) antigens, high variation in individual response made this trend statistically insignificant, except for the response to B. abortus at a CsA dose of 50 mg/kg. There was also a trend to decreased secondary IgM response to T‐dependent antigens and increased IgM response to the T‐independent antigens. The clearest alteration in secondary humoral response was the block of IgG (+ IgA) response to both categories of antigens. There was only a slight decrease in body weight after 3 weeks of CsA administration, a decrease in the absolute weights of thymus and spleen (but not bursa) at 50 mg/kg and a decrease in relative weight only in the case of the thymus. Despite these changes, the histology of the thymus, particularly the cortex, was normal. The major histological changes were in the spleen where there was a depletion of the periarteriolar lymphytic sheath, a marked increase in granulated cells, a decrease in germinal centers, and the appearance of large numbers of Mott cells. This type of cell was occasionally found in bone marrow and very rarely in liver and the mucosal connective tissue of the bursa, tissues which were otherwise normal. The Mott cell may arise as a result of the changes in T cell subsets leading to an uncontrolled production of nonsecreted immunoglobulins.
Physiology of IgD. II. Lack of humoral immune responsiveness in lymph nodes of mice treated with anti‐IgD from birth
Authors: Baine Yaela , Chen Yung‐Wu , Jacobson Ethel B. , Pernis Ben , Siskind Gregory W. , Thorbecke G. Jeanette
Published: February 2007

Previous studies have shown that anti‐IgD‐suppressed mice give normal primary and secondary splenic plaque‐forming cell responses following i.v. challenge, although mice suppressed by the injection of anti‐IgD from birth lack IgD‐bearing cells in all lymphoid tissue examined. The present studies show that, in contrast, secondary immune responses in regional lymph nodes of such mice, even after i.v. priming with trinitrophenylated B. abortus, respond to a challenge injection in the footpad up to only < 10% of control levels. When compared with respect to B cell numbers transferred, primed spleen cells from control and anti‐IgD‐suppressed mice are about equally effective in producing adoptive secondary plaque‐forming cell responses in the spleens of recipient mice. Lymph nodes in recipients of anti‐IgD‐suppressed primed spleen cells show much lower responses than do lymph nodes in recipients of control primed cells, both upon immediate and delayed challenge with antigen in the footpads. It is concluded that the immunodeficiency caused by suppression with anti‐IgD is much more marked in peripheral lymph nodes than in the spleen. The possible relationship of these results to the migratory properties of IgD+ as compared to IgD− B cells is discussed.
The frequency of mutant‐specific killer precursors in related and unrelated mouse strains
Authors: von Boehmer Harald , Bennink Jack , Langhorne Jean
Published: February 2007

The frequency of mutant‐specific cytotoxic T lymphocyte precursors (CTL‐P) has been analyzed in several mouse strains. While H‐2 antigens of responder strains have a limited influence on the frequency of major H antigen‐specific CTL‐P, the frequency of mutant‐specific CTL‐P can be equally as high in unrelated and related strains. In general, the frequency does not reflect the closeness of kinship between stimulator and responder.
Immunogenic variants obtained by mutagenesis of mouse mastocytoma P815. V. H‐2 associativity of variant‐specific antigens
Authors: van Snick Jacques , Maryanski Janet , Van Pel Aline , Parmiani Giorgio , Bonn Thierry
Published: February 2007

By in vitro mutagenesis of mastocytoma P815, it is possible to obtain tumor cell variants that are rejected by syngeneic mice (tum−). Most of these variants carry new individual antigens and stimulate a specific cytolytic T cell (CTL) response in mixed leukocyte tumor cell culture (MLTC). The H‐2 associativity of this response was examined for six different variants by measuring the inhibition of cell‐mediated cytolysis by antibodies directed against products of the K or the D end of the H−2d complex. The lysis was either not inhibited (variants P91 and PI 16) or inhibited selectively by anti‐Kd (variants P21, P32 and P198) or anti‐Dd antibodies (variant P35). All these tum− variants expressed Kd and Dd antigens as measured by absorption of H‐2 alloantisera.

Long‐term CTL clones can be obtained that are specific for individual turn antigens. The pattern of H‐2 associativity obtained with MLTC‐derived CTL against four tum− variants was verified with CTL clones directed against the specific antigens of these variants. Concordant results were observed in all cases. In addition to CTL clones specific for tum− antigens, it is possible to isolate clones against a P815 tumor‐associated antigen found on all P815 tum− variants. For these clones no clear associativity with either Kd or Dd products was found.
Cross‐reactivity of the NPa and NPb idiotypic responses of BALB/c and C57BL/6 mice to (4‐hydroxy‐3‐nitrophenyl)acetyl (NP)
Authors: White‐Scharf Mary E. , Imanishi‐Kari Thereza
Published: February 2007

A comparative antigenic analysis was carried out to determine whether cross‐reactivity exists between the major idiotypic responses to (4‐hydroxy‐3‐nitrophenyl)acetyl (NP) in BALB/c and C57BL/6 mice. Extensive cross‐reactivity exists between the NPa (BALB/c) and NPb (C57BL/6) allotype‐linked idiotypic responses to NP. The cross‐reactive determinants of the NPb idiotype are confined to one particular group of NPb‐positive monoclonal antibodies. The extent of cross‐reactivity between this group of C57BL/6 antibodies and idiotype‐positive monoclonal antibodies of BALB/c is so great that they cannot be readily distinguished as NPb‐ or NPa‐positive antibodies with polyclonal anti‐idiotypic reagents. That this cross‐reactivity is not unique to monoclonal antibodies was confirmed by the demonstration of these cross‐reactive determinants in the immune sera of individual BALB/c and C57BL/6 mice. Additionally, evidence was obtained from these experiments and from earlier ones from this laboratory which suggests that the BALB/c idiotypic response to NP‐protein conjugate is more homogeneous than the C57BL/6 idiotypic responses.
Content of a cross‐reactive idiotype in nonimmune A/J sera
Authors: Barrett Mary C. , Nisonoff Alfred
Published: February 2007

The anti‐p‐azophenylarsonate antibodies of A/J mice express a major intrastrain cross‐reactive idiotype (CRIA). Using a sensitive radioimmunoassay we were unable to detect significant quantities of molecules bearing CRIA in nonimmune A/J sera. The upper limit is 140 ng/ml. Possible reasons for variability of such data in the published literature are discussed.
Selective inhibition of antigen‐induced “step one” in cytotoxic T lymphocytes by anti‐Lyt‐2 antibodies
Authors: Gullberg Martin , Larsson Eva‐Lotta
Published: February 2007

Stimulation of mixed lymphocyte cultures with ultraviolet (UV)‐irradiated stimulator cells leads to selective activation of Lyt−2+ cytotoxic T lymphocyte precursurs (CTL‐P) to acquire interleukin 2 (IL2) reactivity: (a) no proliferative response, nor IL2 production was observed in these cultures; (b) upon addition of preformed Unconditioned media (IL2‐CM), a vigorous proliferative response was observed; (c) the IL2‐dependent proliferation was reduced by approximately 90% after depletion of Lyt−2+ responder cells; and (d) specific CTL were generated upon the initial triggering by UV‐irradiated stimulators and IL2 expansion. This system therefore provides suitable conditions for studying the role of Lyt‐2 antigens in initial, antigen‐specific induction of CTL‐P, as well as at their effector phase.

It is shown herein that monoclonal anti‐Lyt‐2 antibodies inhibit antigen‐specific acquisition of IL2 reactivity by CTL‐P, which results in 85% reduction of the proliferative response mediated by IL2‐CM. CTL‐P which have been induced by antigen to IL 2 reactivity, prior to addition of anti‐Lyt‐2 antibodies, however, are not affected in their IL2‐dependent proliferation. Furthermore, both the specific and lectindependent cytolytic activity of effector CTL generated by UV‐irradiated stimulators and IL2‐CM is blocked by addition of anti‐Lyt‐2 antibodies in the cytotoxicity assay. The implications of these findings for the role of Lyt‐2 antigen in antigen recognition by T cells are discussed.
Cytotoxic T cell recognition of Epstein‐Barr virus‐infected B cells. III. Establishment of HLA‐restricted cytotoxic T cell lines using interleukin 2
Authors: Wallace Lesley E. , Rowe Martin , Gaston J. S. Hill , Rickinson Alan B. , Epstein M. Anthony
Published: February 2007

Epstein‐Barr virus (EBV)‐specific cytotoxic T cell precursors, present in the circulation of previously infected (seropositive) individuals, have been reactivated in vitro by challenging with autologous EBV‐transformed cells, and the reactivated populations subsequently expanded as interleukin 2 (IL2)‐dependent cell lines. These lines were dominated by T cells possessing the cytotoxic/suppressor cell surface phenotype and, when tested for effector function in chromium‐release assays, demonstrated potent EBV‐specific, HLA‐A and ‐B antigen‐restricted cytotoxicity even when derived from seropositive donors whose initial cytotoxic response to in vitro reactivation was relatively weak. With all the lines tested from 10 seropositive donors, strong killing of autologous EBV‐transformed cells was observed in the absence of any significant lysis of autologous mitogen‐stimulated lymphoblasts or of a panel of EBV genome‐negative cell lines sensitive to natural killing. Furthermore, the availability of IL2‐expanded effectors cell populations allowed their being tested upon a wide panel of allogeneic EBV‐transformed targets such that the dominant HLA‐restricted reactivities within these populations could be identified. Monoclonal antibody blocking experiments confirmed that lysis of the autologous EBV‐transformed cell line by IL2‐expanded effectors could be specifically inhibited (a) by pretreatment of the target cells with antibodies binding to the HLA/β2‐microglobulin complex, and (b) by pretreatment of the effector cells with the cytotoxic/suppressor T cell‐specific antibody Leu 2a.
The immune response against anti‐idiotope antibodies. I. Induction of idiotope‐bearing antibodies and analysis of the idiotope repertoire
Authors: Takemori Toshitada , Tesch Hans , Reth Michael , Rajewsky Klaus
Published: February 2007

In the present analysis we dissect the idiotype repertoire, independently of haptenbinding specificity, by immunizing different strains of mice with cross‐linked monoclonal anti‐idiotopet antibodies against antibody B1‐8. B1‐8 is a monoclonal antibody with specificity for the hapten (4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) and carries a germ line gene‐encoded variable region. The results demonstrate that the expression of B1‐8 idiotopes and their association with eachother and with NP‐binding specificity are strain‐specific. Certain idiotopes are expressed on antibodies differing in antigen‐binding specificity, whereas one of the idiotopes appears strictly associated with NP‐binding antibodies. The genetic analysis provides strong evidence that the strain specificity of the idiotope repertoire is a result of V region polymorphism in the mouse.