bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification and characterization of a novel membrane activation antigen with wide cellular distribution
Authors: Schulz Thomas F. , Mitterer Manfred , Vogetseder Werner , Böck Güinther , Myones Barry L. , Dierich Manfred P. 
Published: March 2007

Abstract A monoclonal antibody, 7F7, raised against the Raji B lymphoblastoid cell line reacted with about 35% of peripheral blood B cells, germinal center B cells, follicular dendritic cells and some vascular endothelial cells. Although not found on resting T cells this antigen was strongly expressed on CD4+ and CD8+ T cells activated with phytohemagglutinin, pokeweed mitogen and anti‐T3, and its expression on B cells was enhanced after stimulation with pokeweed mitogen. It is strongly expressed 24 h after stimulation with phytohemagglutinin and its expression is reduced but not eliminated by cyclosporin A treatment. The molecule defined by antibody 7F7 is found on some, but not all, B cell lines, on an HTLV‐I‐transformed T cell line and on the promyelocytic cell line U937. Immunoprecipitation from externally and metabolically labeled Raji cells revealed a single‐chain molecule of 85 kDa.
Physiology of IgD IX. Effect of IgD on immunoglobulin production in young and old mice
Authors: Swenson Christina D. , Vollenhoven Ronald F. Van , Xue Bin , Siskind Gregory W. , Thorbecke G. Jeanette , Coico Richard F. 
Published: March 2007

AbstractWeekly i.p. injections of IgD from birth in (SJL × BALB/c)F1 mice were found to accelerate the development of IgG‐ and IgA‐secreting cells and to increase the numbers of Ig‐secreting cells of all isotypes in 17–28‐day‐old mice, but not in 7–10‐day‐old mice. Similarly, repeated weekly injections of IgD in normal adult BALB/c mice increased the numbers of reverse plaque‐forming cells/spleen for all isotypes studied, including IgM, IgG1, IgG2, and IgA, but not for IgD itself. No such effect was observed in IgD‐treated aged (20 months old) BALB/c mice. The absence of an effect of IgD on Ig secretion appeared to correlate with a lack of induction of receptors for IgD on T cells of the host, both in 7–10‐day‐old and in aged mice. In 7–10‐day‐old mice this lack of induction appeared due to their very low numbers of L3T4+ T cells. A comparison was made between the effect of a single injection of IgD or lipopolysaccharide (LPS) on numbers of Ig‐secreting cells in the spleen determined 1–7 days after injection. Both agents caused increases, but the increase in IgM‐producing cells was much greater after LPS (day 4), while IgD caused a relatively greater increase in IgG2 and IgA (days 4–7). Increases in IgGl and IgG3‐producing cells induced by LPS and IgD were of similar magnitude (days 6–7). IgD production, however, was not increased. The number of cells producing antibody of anti‐trinitrophenyl (TNP) specificity was enhanced by LPS (day 4), but not by a single injection of IgD, although more than one injection of IgD caused a significant increase in anti‐TNP‐producing cells above background.LPS, but not IgD, caused B cell proliferation in vitro in the presence or absence of γ ‐irradiated Tδ cells. However, in vivo, IgD injections caused a significant increase in the percentage of lymphoid follicles with germinal centers in lymph nodes from 17–21‐day‐old and normal adult mice, but not in 7–10‐day‐old or aged mice. Such an effect was also absent in 24–28‐day‐old mice, where germinal center development, even in untreated mice, was very high.
Regulatory activity of the human CD8+ cell subset: a comparison of CD8+ cells from the intestinal lamina propria and blood
Authors: Lee Alfred , Sugerman Harvey , Elson Charles O. 
Published: March 2007

AbstractThis study was done to better define the immunoregulatory mechanisms in the human intestinal lamina propria (LP). Peripheral blood (PB) and LP cells were obtained from patients having intestinal resections. CD4+ and CD8+ cell subsets were isolated using hybridoma antibodies in a panning technique. Graded numbers of LP and PB CD8+ cells were added to cultures of autologous fresh B cells plus CD4+ cells plus pokeweed mitogen. After 10 days incubation in vitro, the supernatants were collected, and IgM and IgA synthesis was measured by isotype‐specific sandwich ELSA. Both PB and LP CD8+ cells suppressed IgM and IgA synthesis by indicator cultures consisting of 5 × lo4 B cells plus 5 × 104 CD4+ cells to a comparable extent. However, when these same CD8+ cells were added to indicator cultures of 5 × 104 B cells plus 105 CD4+ cells, PB CD8+cells still suppressed, but LP CD8+cells enhanced IgM and IgA synthesis. LP but not PB CD8+cells also augmented IgM and IgA synthesis in cultures with suboptimal immunoglobulin synthesis. Despite these results, LP CD8+cells were not able to provide help for B cell immunoglobulin synthesis when these two cell types were cultured together with pokeweed mitogen. The mechanism of immunoglobulin augmentation by LP CD8+ cells appeared to involve antagonism of a CD4+rather than CD8+suppressor cells. We conclude that functional heterogeneity is more evident within the LP CD8+ subset, with both suppressor and contra‐suppressor activities demonstrable, with the latter representing a major activity in LP but not in PB CD8+cells.
The function of human intercellular adhesion molecule‐1 (ICAM‐1) in the generation of an immune response
Authors: Dougherty Graeme J. , Murdoch Sarah , Hogg Nancy 
Published: March 2007

AbstractMonoclonal antibody RR1/1 directed against the putative LFA‐1 ligand molecule intracellular adhesion molecule‐1 (ICAM‐1) was found to inhibit the T cell prolifera‐tive response to the antigen PPD. Interestingly, the percentage of unstimulated monocytes which expressed ICAM‐1 on their surface appeared to vary greatly from person to person although the majority of monocytes did express high levels of ICAM‐1 within their cytoplasm and surface expression could be rapidly induced on most cells by adherence to fibronectin. Resting T cells showed no evidence of surface or cytoplasmic ICAM‐1 although expression was induced both within the cell and on the membrane as a result of activation with phytohemagglutinin or a combination of OKT3 and phorbol 12, 13‐dibutyrate. The significance of these findings with respect to the function of monocyte and T cell in the generation of an immune response is disussed.
Genetic regulation of multispecific antibody responsiveness: improvement of “high” and “low” characters
Authors: Mouton Denise , Siqueira Maria , Sant'Anna Osvaldo A. , Bouthiuier Yolande , Ibanez Olga , Ferreira Vera C. A. , Mevel Jean‐Claude , Reis Moema H. , Piatti Rosa Maria , Stiffel Claude , Biozzi Guido 
Published: March 2007

AbstractThe five selections carried out in the mouse for high or low antibody responsiveness to various multideterminant immunogens were successful. In all cases the large interline difference was shown to result from the additive effects of several independently segregating loci (polygenic regulation). However, important peculiarities were demonstrated in these original selections concerning either the cellular mechanisms operating or the effect of the selected genes on antibody responses to antigens unrelated with those used for the selection (multi‐specific effect). In an attempt to improve and generalize the effect of selection, the 5 high and the 5 low lines were inter‐crossed to obtain populations with a balanced proportion of the 5 genomes. These two populations were then submitted to selective breedings in which the phenotypic character was the weighted responses to pluri‐antigen immunization. The data obtained in 16 consecutive generations of two selective breedings (general‐primary, GP and general‐secondary, GS, responses) carried out from these populations are reported. The genetic parameters of the response to GP and GS selections are compared with those obtained in the original selections. The final result of both GP and GS selections demonstrate a marked improvement of the high and low antibody production traits, both quantitatively (interline divergence) and qualitatively (multi‐specific effect). The success of GP and GS selections agrees with the concept that distinct groups of genes are preferentially affected by selection according to the nature of the selection antigen and the immunization procedure.
Enhancement in Igha mouse strains of the “natural” suppressive activity of normal T splenocytes against the expression of Igh‐1b allotype. I. Molecular aspects of the chronic suppression obtained
Authors: Benaocb Philippe , Burdenave Guy 
Published: March 2007

AbstractSeveral approaches have been used in our attempts to increase the “natural” ability of normal T splenocytes (Tn) from BALB/c or BC8 mice (both Igha ) to induce, in F1 hybrids, a suppression of Igh‐lb expression (IgG2a of b haplotype). These heterozygous F1 were produced by mating these Igha mice and their Ighb‐congenic partners (CB20 and C57BL/6, respectively). The most powerful approaches were to sensitize the Igha mice by either autologous splenocytes coated with Igh‐lb or B splenocytes from Ighb‐congenic mice. In F1 having paternally inherited the b haplotype the sensitized T splenocytes (Tn) prepared from such mice are able to induce, like Tn when injected at birth, a chronic suppression of Igh‐lb expression. However, the suppression was established with a much higher efficiency: already at 6 weeks of age in 100% of the F1 treated with 1 × 107 Ts vs. a final rate of 70% progressively reached only at 42 weeks of age in the F1 treated with 4 × 107 Ts. In F1 having maternally inherited Ighb the differences were even more pronounced than with 4 × 107 Tn i.e. the suppression induction was almost totally ineffective, whereas with 2 × 107−4 × 107 Ts a rate of 100% treated F1 subjected to suppression was reached at 19 weeks of age. As the productions of IgM, IgD and IgA of the b haplotype were not affected by the suppression, the Ts are believed to act on the Igh‐lb′ cells. Attempts were also made to induce allotypic suppression of other b allotypes by the use, as sensitizing cells, of myeloma cells carrying Igh‐6b (IgM of b haplotype). We failed in revealing any sign of a T cell reactivity against Igh‐6b similar to the reactivity against Igh‐lb. The use of Igh‐6b+ myeloma cells grown in an Igh′ or in an Igha background allowed us to assume that the cells responsible for the sensitization are, in the Ighb B lymphocyte population, either the Igh‐lb+ lymphocytes or the lymphocytes having passively adsorbed this allotype, or both.
Mycobacteria‐reactive Lyt‐2+ T cell lines
Authors: Libero Gennaro De , Flesch Inge , Kaufmann Stefan H. E. 
Published: March 2007

AbstractThe biological activities of mycobacteria‐reactive Lyt‐2+ T cells were characterized in vitro. T cells from mice immunized with killed Mycobacterium tuberculosis or viable M. bovis were restimulated in vitro and cloned under limiting dilution conditions. Several L3T4−Lyt‐2+ T cell lines, some of them KJ16+, were established. These T cell lines were capable of lysing mycobacteria‐primed macrophages in an antigen‐specific way. The cytolytic activity of some T cell lines was found to be class I restricted, whereas others showed antigen‐specific killing in the absence of apparent H‐2 restriction. Several T cell lines produced interferon‐γ after appropriate stimulation. Furthermore, these T cell lines could induce tuberculostatic macrophage capacities by apparently two different mechanisms, namely by secretion of lymphokines (most probably interferon‐γ) and by direct cell qontact. We conclude that CD8 T cells with antigen‐specific cytolytic potential are generated during tuberculosis and that these T cells are involved in the immune response to tubercle bacilli.
Human immune response to allergens of house dust mite, Dermatophagoides pteronyssinus. IV. Occurrence of natural autologous anti‐idiotypic antibodies
Authors: Saint‐Remy Jean‐Marie R. , Lebecque Serge J. , Lebrun Philippe M. , Jacqnemin Marc G. 
Published: March 2007

AbstractIgG isolated from the plasma of seven individuals hypersensitive to the common house dust mite Dermatophagoides pteronyssinus (DPT) was exhaustively adsorbed onto insolubilized DPT. The unbound fraction was found by radioimmunoassay to contain antibodies recognizing the variable region of both anti‐DPT IgG and IgE antibodies. This recognition was idiotype (Id)‐specific as it persisted after passage over insolubilized polyclonal IgG of unrelated specificity.Most of these anti‐Id IgG carried the internal image of the initial antigen in that they competitively inhibited the binding of anti‐DPT antibodies to DPT. Immunoadsorption of anti‐Id IgG onto insolubilized anti‐DPT IgG antibodies from the same individual completely eliminated their reaction with anti‐DPT IgG but not with anti‐DPT IgE, suggesting that idiotopes included in the antigen‐binding site of specific IgG and IgE antibodies were not identical. Anti‐Id IgG recognizing idiotopes located outside the antigen‐binding site (bystander idiotopes) were also completely removed by passage over insolubilized anti‐DPT IgG; in this case the reaction of the anti‐Id IgG with both anti‐DPT IgG and anti‐DPT IgE was inhibited, indicating that, for a given individual, bystander idiotopes were shared between anti‐DPT antibodies pertaining to these two isotypes.
Inhibition of the proliferative response of human B lymphocytes to B cell growth factor by transforming growth factor‐beta
Authors: Petit‐Koskas Elisabeth , Génot Elisabeth , Lawrence David , Kolb Jean‐Pierre 
Published: March 2007

AbstractThe effects of transforming growth factor‐beta (TGF‐β) on the proliferative response of human B cells to the low molecular weight B cell growth factor (BCGF) have been investigated in this study. It was found that TGF‐β”, at picomolar concentrations, strongly inhibited the BCGF‐induced proliferation of anti‐μ. chain or Staphylococcus aureus Cowan I‐activated human B cells and also of a BCGF‐dependent cell line derived from a human lymphocytic nodular lymphoma. This inhibitory effect was detected in normal and serum‐free culture conditions. The suppression was greatly reduced when TGF‐β was added to the culture one day after BCGF and could be reverted by removing TGF‐β from the culture medium. Since TGF‐β has been detected in supernatants from activated T cells, this factor may represent an important regulatory molecule in the feedback control of B cell activation.
Correlated expression of surface antigens in human thymocytes. Evidence of class IHLA modulation in thymic maturation
Authors: Gambon Francisco , Kreisler Miguel , Díaz‐Espada Fernando 
Published: March 2007

AbstractThe correlated expression of several surface antigens (CD 1, class I HLA, CD 3) was examined in human unfractionated thymocytes or selected subsets by using single or double‐color flow cytometry. Prethymocyte subpopulations expressed high levels of HLA. A high proportion of cortical cells expressed low levels of either HLA or CD 3 antigens. Most of these HLA+ cortical cells corresponded to the more immature cells and did not express HLA‐B loci products. CD 1 a and CD 3 antigens were expressed in a high percentage of cells and the levels of expression of each antigen in individual cells were inversely correlated. These data and the contour of double‐color histograms are suggestive of the existence of a single pathway of thymocyte differentiation in which class I HLA expression is switched off around the time of the initiation of CD 3 (and Ti?) expression. We suggest that the anti‐major histocompatibility complex (MHC) specificity of the unselected Ti receptor may be incompatible with the expression of MHC products on the cell membrane. At this stage, CD1 antigens, whose expression is inversely correlated with that of HLA, may fulfill the role of MHC antigens. The latter can be re‐expressed later on, once the anti MHC specificities of the Ti receptors have been selected against. Studies on in vitro modulation of HLA molecules by interferon‐a did not reveal any correlation to the expression of CD 1 or CD 3 antigens.
Murine CD2 gene expression during fetal thymus ontogeny
Authors: Owen Michael J. , Jenklnson Eric J. , Brown Marion H. , Sewell William A. , Krissansen Geoffrey W. , Crumpton Michael J. , Owen John J. T. 
Published: March 2007

AbstractThe expression of the murine CD 2 gene and the interleukin 2 receptor IL2R has been investigated during fetal thymus ontogeny. CD2 mRNA was undetectable at embryonic day 14 but was readily detectable at day 15 of gestation. Surface IL2R expression was maximal at day 14 and was clearly detectable at day 13. These results indicate that IL2R expression precedes that of CD2 by at least 2 days.
Reactivity of Ly‐2+ T cells against 2,4,6‐trinitrophenyl (TNP)‐modified syngeneic stimulator cells: specificity, frequency of interleukin 2‐producing Ly‐2+ helper T cells and clonal segregation from Ly‐2+ cytotoxic T lymphocytes
Authors: Schmitt Joachim , Wagner Hermann , Heeg Klaus 
Published: March 2007

AbstractThe in vitro reactivity of purified murine Ly‐2+ and L3T4+ T cells towards 2,4,6‐trinitrophenyl (TNP)‐modified syngeneic stimulator cells was analyzed. Both T cell subpopulations autonomously proliferated and produced interleukin 2. In either the Ly‐2+ or L3T4+ T cell subset the frequencies of TNP‐specific interleukin 2 (IL 2)‐producing T lymphocyte precursors (IL 2 TL‐p) were equally high (f = 1/400–1/1000). Clonally developing IL 2 TL of either T cell subset showed an exquisite antigen (TNP) specificity as shown by the split culture approach. TNP‐specific Ly‐2+ IL‐2 TL used class I MHC (H‐2K ) gene products as major histocompatibility complex (MHC) restriction elements, while L3T4+ IL 2 TL proved to be class I1 MHC (H‐21‐Ak I‐Ek) restricted. Clonal segregation analyses revealed that the majority of clonally developing TNP‐reactive Ly‐2+ TL segregated into either IL 2 TL‐p or cytotoxic T lymphocyte presursors, i.e. both functions appear to be mutually exclusive. Less than 10% of the responding Ly‐2+ T cells seemed to be bifunctional. These findings provide compelling evidence for the L3T4+ T cell‐independent, autonomous reactivity of Ly‐2+ T cells in MHC‐restricted antigen‐specific responses and suggest T‐T cell interactions within the functional heterogenous Ly‐2+ T cell population.
Stimulation and proliferation of CD4+ peripheral blood T lymphocytes induced by an anti‐CD4 monoclonal antibody
Authors: Carrel Stefan , Moretta Alessandro , Pantaleo Giuseppe , Tambussi Giuseppe , Isler Patrick , Perussia Bice , Cerottini Jean‐Charles 
Published: March 2007

AbstractThere is experimental evidence that the CD4 molecule participates in the antigen‐driven activation of T cells expressing this surface glycoprotein. Whether CD4, a member of the immunoglobulin supergene family, acts as a ligand‐binding molecule and/or is directly involved in the activation pathway has yet to be established. In this study, we show that human CD4+ lymphocytes can be activated by exposure to the anti‐CD4 monoclonal antibody (mAb) B66. Normal peripheral blood CD4+ cells were induced to proliferate and to synthesize interleukin 2 (IL2) by the antibody. The specificity of the antibody stimulatory activity was tested by using IL2‐producing clones bearing either CD4 or CD8 on their surface. IL2 production was induced by mAb B66 in CD4+, but not CD8+, clones, whereas both types of clones responded to stimulation by the anti‐CD3 mAb Leu‐4. Despite its unique stimulatory activity, mAb B66 shared with other anti‐CD4 antibodies the ability to inhibit the specific cytolytic activity of CD4+ effector cells. These results clearly indicate that cross‐linking of surface CD4 molecules with appropriate antibodies can fully activate CD4+ lymphocytes. Whether the natural ligand for CD4 can trigger this activation pathway remains to be defined.
T cell recognition of endogenous IgG2a expressed in B lymphoma cells
Authors: Bikoff Elizabeth K. , Yu Hua , Eckhardt Laurel A. 
Published: March 2007

AbstractWe recently characterized a panel of C57BL/6J T cell clones specific for IgG2a of the a allotype in association with I‐Ab. Several of the clones gave surprisingly strong responses in the presence of normal spleen cells from several H‐2b strains, including C3H.SW, A.BY, D1.LP and BALB.B, without the addition of exogenous antigen. Experiments using Igh‐congenic mouse strains demonstrated that this response was directed towards shared allotypic determinants expressed on endogenously synthesized IgG2a molecules in various strains. Here we present evidence that the cell(s) responsible for this stimulation are conventional low density splenic accessory cells. Presentation of endogenously synthesized IgG2a by this population of dendritic cells, macrophages, and/or activated B cells was chloroquine sensitive. Thus, we conclude that this response is probably directed towards secreted IgG2a molecules that are internalized, processed and re‐expressed at the cell surface in association with class II molecules.We also tested the ability of T cell clone B61‐34 to respond in the presence of the B lymphoma cell line M12.C3.A2. A strong response was again observed in the absence of exogenous antigen. Northern gel analysis of M12.C3.A2 messenger RNA provided evidence that these cells synthesize IgG2a in both a secreted and a membrane form. The response directed towards endogenous IgG2a expressed in M12.C3.A2 lymphoma cells is chloroquine resistant and considerably more efficient than that stimulated by IgG2a added as exogenous soluble antigen. These results demonstrate for the first time that B cells have the capacity to present antigenic determinants expressed on endogenously synthesized immunoglobulins to class II‐restricted T cells. The implications of these findings with respect to network models of immune regulation are discussed.
Soluble CD23 is released by B lymphocytes cycling in response to interleukin 4 and anti‐Bp50 (CDw40)
Authors: Cairns Jennifer , Flores‐Romo Leopoldo , Millsum Michelle J. , Guy Graeme R. , Gillis Steven , Ledbetter Jeffrey A. , Gordon John 
Published: March 2007

AbstractAn enzyme‐linked immunoassay was developed to quantitate the production of soluble CD23 from cycling B lymphocytes. This molecule has identity both with B cell‐derived B cell growth factor and with an IgE‐binding factor. B lymphocytes, which had been stimulated for 3 days with phorbol dibutyrate and calcium ionophore, washed and recultured, failed to produce detectable levels of CD23 over the following 3 days. Soluble CD23 was found, however, in the supernatant of cultures where recombinant interleukin 4 had been included. The level of CD23 rose dramatically when anti‐Bp50 had also been added. By contrast, anti‐Bp50, alone or together with low molecular weight T cell‐derived B cell growth factor, failed to promote the release of CD23 in detectable amounts. There was a strong correlation between the appearance of soluble CD23 in culture supernatants and the expression of CD23 on the surface of restimulated cells. The level of CD23 release appeared to relate more to the continued cycling of cells than to their differentiation to immunoglobulin secretion. These findings are discussed with particular emphasis on the role of CD23 as an important multi‐functional lymphokine in B lymphocyte physiology.