bluuebunny/crossref_metadata_2025_split huggingface dataset:
The augmentation of tumor‐specific immunity by virus help. II. Enhanced induction of cytotoxic T lymphocyte and antibody responses to tumor antigens by vaccinia virus‐reactive helper T cells
Authors: Shimizu Yoshio , Fujiwara Hiromi , Ueda Shigeharu , Wakamiya Nobutaka , Kato Shiro , Hamaoka Toshiyuki 
Published: February 2007

AbstractThe present study investigates the role of vaccinia virus‐reactive helper T cells in causing enhanced induction of syngeneic tumor immunity. Vaccinia virus‐reactive helper T cell activity capable of inducing the augmented generation of cytotoxic T lymphocyte (CTL) or antibody responses was generated in C3H/HeN mice by inoculating i.p. live virus. Immunization of these mice with vaccinia virus‐infected syngeneic X5563 plasmacytoma or MH134 hapatoma cells led to augmented induction of immune resistance against the challenge with corresponding viable tumor cells when compared with the incidence of resistance observed in control mice not primed to vaccinia virus. In vitro cytotoxicity tests utilizing spleen cells and serum from mice which resulted in the augmented tumor resistance by virus help have revealed that spleen cells from C3H/HeN mice immune to the X5563 plasmacytoma exhibited appreciable anti‐X5563 CTL activity, whereas serum from these mice failed to display any antibody response. In contrast, MH134‐immune mice exhibited potent anti‐MH134 antibody, but not CTL responses. Such an anti‐tumor CTL or antibody response augmented by vaccinia virus‐reactive helper T cells was found to be tumor specific. These results are discussed in the context of (a) the functional diversity of tumor antigens, and (b) mechanisms of virus help that are involved in various forms of augmented induction of syngeneic tumor immunity.
Antibody‐mediated allotype suppression in adult mice: The role of antigen, effector isotype and regulatory T cells
Authors: Curling Elisabeth M. A. , Dresser David W. 
Published: February 2007

AbstractIt has been reported (Contemp. Top. Immunobiol. 1974. 3: 41) that allotype‐specific T suppressor cells can be induced after monoclonal anti‐allotype treatment of neonatal (BALB/c × SJL) F1 (Igha/b) mice. Here we show that (BALB/c × CB20)F1 adult‐derived spleen cells (SC) are, by contrast, potently suppressed by monoclonal allotype‐specific reagents, (when transferred into irradiated BALB/c recipients) in the absence of primary T suppressor cell induction. Such suppression is only induced in activated B cells [exposed to lipopolysaccharide or sheep red blood cells (SRBC)], and is probably dependent on the isotype of the anti‐allotype sera administered. For example, two independently produced IgG1 monoclonal reagents raised against the Igh‐1b allotype were poorly suppressive or nonsuppressive, whereas an IgG3 and an IgG2a monoclonal antibody induced a 90% suppression of the target allotype in transferred adult SC. It was found that suppression was not due to a depletion of antigen‐specific T cell help since: (a) the addition of SRBC‐educated T cells did not break suppression and (b) suppressed SC were as good a source of T cell help as normal SC, in the response of virgin or memory B cell (Thy‐1‐depleted) responses to SRBC in vivo.Suppression was maintained in suppressed cells which had been rechallenged with SRBC after transfer into a second irradiated recipient, but was not induced in normal SC when these were admixed with an equal number from this suppressed SC population.These findings point to a possible mechanism for the regulation of B cell expression, through the formation of an antibody‐Ig receptor complex at the surface of the B lymphocyte. After complexing the target cell is either deleted or inactivated. The response to SRBC was reduced or ablated for at least 70 days after treatment with a single dose of anti‐allotype serum.
Culture of thymic epithelial cells from mice and agerelated studies on the growing cells
Authors: Small Myra , Barr‐Nea Liliane , Aronson Moshe 
Published: February 2007

AbstractCulture of epithelial cells from the thymus of mice was achieved in a medium modified to favor epithelial growth while inhibiting proliferation of fibroblasts. Epithelial cells were identified by the presence of desmosomes in electron microscopic preparations and by antibody to intermediate filaments containing keratin. Morphologically, the cells thus positively identified displayed two main patterns: carpets of large flat cells resembling paving stones which are confluent along the length of their membranes, and networks of cells interconnected by long cytoplasmic processes. These two types of cells were dominant in cultures derived from mice of all ages tested (newborn to nine months) but the relative proportion of each type appeared to change with the age of the donor mice and also with the concentrations of cortisone in the culture medium. Autoradiography revealed that the cultured cells were dividing, and that (in the presence of cortisone) the rate of DNA synthesis was decreased in a portion of the epithelial cells derived from mice in which thymic involution was already underway.
Inulin‐induced activation of factor B in whole serum: Description of structural modifications in the Ba fragment
Authors: Davrinche Christian , Charlionet Roland , Rivat Claude , Helal Ahmed Nourredhine , Lefranc Gérard 
Published: February 2007

AbstractThe investigation of inulin‐induced conversion of human factor B in serum by isoelectrofocusing revealed physiological modifications in the primary structure of the Ba fragment. Evidence has been obtained that a nascent Ba, generated by the hydrolytic action of the D component on B in serum, was a short‐lived product and that a fast release of carboxy‐terminal arginine and lysine residues occurred involving a serum carboxypeptidase B enzyme.
Irreversible inactivation of activated cytotoxic T lymphocyte precursor cells by “anti‐self” suppressor cells present in murine bone marrow T cell colonies
Authors: Muraoka Shizuko , Ehman David L. , Miller Richard G. 
Published: February 2007

AbstractWhen added to a mixed lymphocyte culture, cells in T cell colonies grown from bone marrow (BM) suppressed the development of cytotoxic activity against H‐2 antigens shared by the colony cells and the stimulator cells, apparently by inactivating cytotoxic T lymphocyte precursor cells (CTLP). From the point of view of the added suppressor cells, the suppression was against self‐reactive cells. The suppressor cells were resistant to γ irradiation (1500 rds) but sensitive to UV irradiation. Inactivated CTLP separated from the suppressor cells by cell sorting could not be reactivated on being recultured with fresh stimulator cells, suggesting the suppression is irreversible. There was a critical time window, extending roughly from 20 to 40 h after culture initiation, during which the suppressor cell had to be present if CTLP were to be inactivated. During the first 20 h and after 40 h of exposure to stimulator cells, CTLP were resistant to the suppressor cell. Direct experimental evidence is presented against the possibility that the suppressor cells derived from BM colonies act by augmenting the production of Lyt‐2+ suppressor cells from the responder population which then produce the suppression, or that the suppressor cells interfere with an early interaction between CTLP and stimulator cells. We conclude that the suppressor cells in T cell colonies grown from BM act directly on activated CTLP and permanently inactivate them.
The role of B cell differentiation factors and specific T cell help in the pathogenesis of primary hypogammaglobulinemia
Authors: Brenner Malcolm K. , North Margaret E. , Chadda Hakikat R. , Newton Christine A. , Malkovsky Mirek , Webster A. David B. , Farrant John 
Published: February 2007

AbstractWe have examined the function of T and B cells from patients with late onset primary acquired hypogammaglobulinemia (PHG). T cells from these patients give effective help to normal B cells for antigen‐dependent antibody synthesis. PHG mononuclear cells also synthesize normal quantities of B cell differentiation factors, which enhance IgG, IgM and antigen‐dependent antibody synthesis by normal lymphocytes. While patient T cells appear to behave appropriately, the responsiveness of patient B cells is abnormal. Although they respond to differentiation factors with increased synthesis of IgM, overall levels are 10–50‐fold lower than normal B cells, and they produce little or no IgG. This pattern of response is not altered if normal T cells are the source of help. The poor response of the B cell appears to represent immaturity rather than an inherent defect, as IgG‐secreting clones can be obtained after Epstein‐Barr virus transformation of lymphocytes from certain patients, and some of these clones respond to differentiation factors with increased IgG production. The lack of any functional defect in the T population, and the apparent immaturity rather than abnormality of the B cells, may implicate accessory cells in the pathogenesis of the disease.
The effects of idiotype on the ability of IgG1 antiphosphorylcholine antibodies to protect mice from fatal infection with Streptococcus pneumoniae
Authors: Briles David E. , Forman Colynn , Hudak Susan , Claflin J. Latham 
Published: February 2007

AbstractAnti‐phosphorylcholine (PC) antibodies of the mouse are found in three different idiotype families: T15, M603 and M511. These subgroups exhibit different specificities for PC analogs and utilize light chains of different VL subgroups. In this study we have found that IgG1 antibodies of the T15 idiotype are much more protective against pneumococcal infection than IgG1 antibodies of the M511 or M603 idiotypes. This finding provides additional evidence that the T15 VH and VL genes may have evolved to protect mice from infection with PC‐bearing pathogens.
The D segment defines the T15 idiotype: the immunoresponse of A/J mice to Pneumococcus pneumoniae
Authors: Berek Claudia 
Published: February 2007

AbstractIn the immune response of BALB/c mice (Igha) to Pneumococcus the majority of antibodies express the idiotype of the myeloma protein TEPC15 (T15). In contrast mice of the A/J strain (Ighe) do not express this idiotype. Using (BALB/c × A/J)F1, F2 or backcross mice it could be shown that in allotype heterozygous animals (Igha/e) Pneumococcus pneumoniae preferentially stimulates B cells expressing a heavy chain (H) encoded by genes in the BALB/c H chain gene complex. Phosphorylcholine (PC)‐specific hybridoma lines were established from BALB/c and A/J spleen cells and idiotypically analyzed using monoclonal antibodies (mAb) specific for the T15 idiotopes 32/65, 10/13, 16/13 or 21A5. Whereas the majority of the BALB/c PC‐binding mAb express these idiotopes, only some of the A/J mAb are positive for one or the other of the idiotopes formed by the variable (V) regions of the H and the light chain of the myeloma protein T15. However, 80% of the A/J PC‐binding hybridoma proteins were bound by the anti‐idiotopic mAb 21A5. This mAb is specific for a determinant partially formed by the Cα and partially by the V regions of the myeloma protein T15. The mRNA of one of these T15− A/J PC‐binding hybridoma lines was sequenced. VH and Vx were identical with sequences found for BALB/c T15‐like antibodies. The sequence of the D segment was structurally very different. The importance of the D segment in the dominant expression of the T15 idiotype is discussed.
Direct evaluation of antigen binding to human T lymphocyte clones: involvement of major histocompatibility complex products in antigen binding
Authors: Zanders Edward D. , Feldmann Marc , Green Nicola , Lamb Jonathan R. 
Published: February 2007

AbstractCloned human helper T lymphocytes reactive with a defined peptide (p20; residues 306‐329) of the HA‐1 molecule of influenza virus hemagglutinin were analyzed for their capacity to specifically bind peptide antigen. Three different methods of analyzing antigen binding to T cell receptors were compared. One method involved the binding of radiolabeled T cells to antigen‐pulsed populations of sheep erythrocyte rosette‐negative (E−) cells (B cells and monocytes). The binding was antigen specific, in that only E− cells pulsed with the appropriate antigen bound the treated T cells, and was inhibitable by free peptide. Furthermore, antigen binding was major histocompatibility complex‐restricted in that only E− cells histocompatible at the HLA‐D region locus bound the T cells, and monoclonal antibody of the relevant specificity was able to inhibit the binding. Secondly, it was demonstrated that tritiated T cells could bind to insolubilized antigen (p20) in the absence of E− cells. The binding was inhibited by anti‐class II antibody suggesting that the interaction of antigen with the T cells involves recognition of T cell major histocompatibility complex class II determinants. Finally, radiolabeled peptides were also used to detect binding to the appropriate clones in the absence of presenting cells. This binding was specific, inhibitable by the appropriate unlabeled peptide and temperature dependent. These studies demonstrate that the process of antigen binding to receptors is analyzable and should in turn facilitate the analysis of the mechanism of T cell activation.
Analysis of immunological tolerance to major histocompatibility complex antigens. I. High frequencies of tolerogen‐specific cytotoxic T lymphocyte precursors in mice neonatally tolerized to class I major histocompatibility complex antigens
Authors: Heeg Klaus , Wagner Hermann 
Published: February 2007

AbstractInjection of (CBA × A)F1 cells into neonatal CBA mice rendered them tolerant to skin grafts of (CBA × A)Fi origin. Limiting dilution analysis revealed a very low frequency of tolerogen‐inducible cytotoxic T lymphocyte precursors (CTL‐P) in spleens of tolerant mice. Two in vitro procedures allowed, however, the induction of tolerogen‐specific CTL‐P of high frequencies in tolerant mice: (a) the “by‐pass” activation of spleen cells from tolerant mice by concanavalin A under short‐term bulk culture conditions followed by culture of limiting numbers of activated responder cells, and (b) absorption of spleen cells from tolerant mice on monolayers of tolero‐gen‐activated T cells from normal syngeneic mice. Furthermore, spleen ceils from tolerant mice, recently challenged with a tolerogen ‐ bearing skin graft, specifically suppressed the activation of tolerogen ‐ reactive splenic CTL‐P from normal CBA mice under limiting dilution conditions. These data confirm the presence of tolerogen‐specific CTL‐P of high frequency in tolerant mice and suggest their functional inactivation through a suppressive mechanism.
The murine thymic nurse cell: An isolated thymic microenvironment
Authors: Andrews Paul , Boyd Richard L. 
Published: February 2007

AbstractThe thymic nurse cell (TNC) consists of an epithelial cell enclosing lymphoid elements and is found in enzymic digests of the thymus. Although these structures have been implicated in the normal intrathymic development of T lymphocytes, little is known about the in situstructure of this unusual cell complex. In this study, various dyes were introduced into the intact thymus and their differential permeability was used to demonstrate that the TNC exists as a sealed structure in situ.The lymphocytes within the TNC were shown to be isolated from the general thymic environment. Prelimi‐ nary studies on these lymphocytes and the physiology of their active release from individual, micromanipulated TNC in microcultures are reported.
Suppression of polyclonal B cell activation by IgG‐binding factors. Requirement for T cells
Authors: Bich‐Thuy Lě Thi , Revillard Jean‐Pierre 
Published: February 2007

AbstractIgG‐binding factors (IgG‐BF) prepared from cell‐free supernatant of human peripheral blood mononuclear cells interfere with the polyclonal activation of peripheral B cells by decreasing the numbers of IgG‐containing cells and Ig plaque‐ forming cells. Using Nocardia opaca delipidated cell mitogen (NDCM), a T helper cell‐independent polyclonal B cell activator, it was found that the suppressive effect of IgG‐BF was no longer demonstrable after removal of T cells. In pokeweed mitogen‐stimulated cultures, the suppression by IgG‐BF required the presence of radiosensitive T cells. Selective depletion of OKT4+ or OKT8+ subsets in NDCM‐stimulated cultures showed that IgG‐BF required the presence of OKT4+ lymphocytes to induce suppression. It is concluded that the effect of human IgG‐BF was mediated by one or several subsets of T cells.
Early expression in (NZB × DBA/2)F1 hybrids of thymus dysfunction and abnormal antibody production inherited from the NZB parent
Authors: Quere Pascale , Savino Wilson , Dardenne Mireille , Bach Marie‐Anne 
Published: February 2007

AbstractNZB mice, DBA/2 mice and reciprocal F1 hybrids between both strains were studied from birth to two months of age for the secretion of a serum thymic factor, thymulin (formerly named Facteur Thymique Sérique) and for spontaneous and antigen‐induced immune responses: spontaneous splenic anti‐2,4,6‐trinitrophenyl (TNP) plaque‐forming cells (PFC), spontaneous IgM serum levels, immune direct anti‐sheep red blood cells (SRBC) PFC and immune serum antibody production to human gamma globulin (HGG) as well as susceptibility to tolerance induction by deaggregated HGG. An early decline of thymulin serum level was detected from two weeks of age both in NZB mice and F1 hybrids, the latter maintaining a level intermediate between that of both parental strains. Such a fall of circulating thymulin was associated to a decreased number of thymulin‐secreting cells.F1 hybrids and NZB mice exhibited at two and three weeks of age spontaneous anti‐TNP PFC in the spleen, and increased IgM serum levels as compared to DBA/2 mice. When immunized at birth with SRBC or at two weeks of age with HGG, NZB mice and F1 mice similarly exhibited a higher anti‐SRBC antibody response, as measured 5 days later by PFC numbers, and a higher anti‐HGG serum antibody production 2 weeks post‐immunization, than age‐matched DBA/2 mice. F1 hybrids tended to develop with age spontaneous and immune antibody responses lower than NZB mice but still much higher than DBA/2 mice. Conversely, after tolerization at birth with deaggregated HGG NZB mice but not the F1 hybrids produced higher titers of anti‐HGG antibodies upon challenge than similarly tolerized DBA/2 mice. DBA/2 mothered and NZB mothered Fl hybrids did not differ for any parameter tested and no influence of the sex could be detected.
Genetic control of B cell function. III. IgVH‐controlled polymorphism in the frequencies of B cells that recognize xenogeneic red blood cells
Authors: Saizawa Kay M. , Melchers Inga , Eichrnann Klaus 
Published: February 2007

AbstractPrevious work has shown that the primary IgM plaque‐forming cell response of inbred mice to xenogeneic red blood cells (RBC) including sheep, horse and chicken RBC is under the control of two polymorphic genes or sets of genes, one linked to the Igh linkage group and the other of unknown linkage but unlinked to H‐2 and a variety of other known genetic markers. Both genes together control B cell function but do not influence the function of T cells and macrophages. Thus, this system permits the study of two polymorphic loci that control B cell responsiveness. In this study we analyze the role of the Igh region in further detail. In bulk cultures and limiting dilution experiments, we confirm its exclusive influence on B cells also when analyzed separately from the background gene, i.e. in Igh‐congenic strains. Moreover, we find in the majority of experiments 4‐5‐fold differences in sheep RBC‐specific B cell precursor frequencies among lipopolysaccharide‐reactive cells from 3 pairs of Igh‐congenic high and low‐responder strains. Similar frequency differences exist for horse RBC and chicken RBC‐specific B cells but not for B cells with specificity for (4‐hydroxy‐5‐iodo‐3‐nitrophenyl)acetyl (NIP)‐gelatine. These differences are independent of the frequencies of B cells responding to lipopolysaccharide which are shown to be equal between Igh‐congenic pairs of strains. Since the differences in RBC‐specific B cell frequencies closely resemble the differences in bulk culture responses to the corresponding RBC, we conclude that the role of the Igh linkage group in controlling responsiveness to RBC lies in a selective influence on the B cell repertoire concerning precursor cells for RBC specificity. In addition, we find that the VH part of Igh is responsible for the observed frequency differences, suggesting that VH germ‐line genes directly influence the composition of the mature B cell repertoire.
Monoclonal antibodies specific for murine IgM. II. Activation of B lymphocytes by monoclonal antibodies specific for the four constant domains of IgM
Authors: Leptin Maria 
Published: February 2007

AbstractSeventeen monoclonal antibodies specific for IgM and one ϰ light chain‐specific antibody were used to test the effect of immunoglobulin (1g)‐specific antibodies on B cell activation. In soluble form, either alone or together with T cell‐derived growth and maturation factors, none of the antibodies stimulated resting B cells to divide or secrete Ig. The soluble antibodies inhibited lipopolysaccharide‐induced B cell activation. The inhibitory effect of the antibodies was independent of their Fc part. When immobilized, the same antibodies could activate B cells to proliferate and together with T cell‐derived maturation factors to mature to plasma cells. Occupation by immobilized antibody of determinants on any of the four constant region domains and on the light chain of surface Ig can lead to the stimulation of B cells.
Frequency and surface phenotype of human T lymphocytes producing interleukin 2. Analysis by limiting dilution and cell cloning
Authors: Moretta Alessandro 
Published: February 2007

AbstractIn this study we have determined the frequency and distribution of interleukin 2 (IL2)‐producing cells and their precursors (IL2‐P) in the two major subsets of human T cells. The two subsets were identified on the basis of their reactivity (or lack thereof) with anti‐T4 or anti‐T8 monoclonal antibodies. T4+T8− and T4−T8+ cells were first isolated from peripheral blood T cell populations by positive or negative selection using the fluorescence‐activated cell sorter, and then analyzed for total IL2‐P and cytolytic T lymphocyte precursor (CTL‐P) frequencies using a limiting dilution microculture system which allows clonal growth of every T cell. The results indicated that 50‐60% of peripheral blood T cells consisted of IL2‐P. In the T4+T8−subset (which represents 60‐65% of all T cells) about 75% of the cells were IL2‐P, whereas about 15% of T4−T8+ cells exhibited this functional potential. In contrast, about 3% and > 95% of T4+T8− and T4‐T8+ cells, respectively, were CTL‐P. Thus, these data provide direct evidence that there is no absolute correlation between the surface phenotype and the functional potential of human peripheral blood T cells. Moreover, it is evident from this frequency analysis that a significant proportion of T4−T8+ cells have a dual functional potential. IL2‐P and CTL‐P frequencies were also determined in T cell populations which had been activated in allogeneic mixed lymphocyte culture. The IL2‐P frequencies in total T, T4+T8− and T4−T8+ MLC populations were 30, 45 and lo%, respectively. Comparative analysis of IL 2 production and CTL activity at the clonal level confirmed that up to 20% of alloreactive CTL with the T4−T8+ surface phenotype were able to produce IL2 upon specific stimulation. This dual functional capacity was also observed among T4+TS− CTL.