bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinct short‐lived and long‐lived antibody‐producing cell populations
Authors: Ho Faith , Lortan Jennifer E. , MaClennan Ian C. M. , Khan Mahmood 
Published: February 2007

AbstractThis report analyzes the life span of Ig‐containing cells (IgCC) in different sites of antibody production. The experimental approach was based upon the observations that most IgCC are derived from proliferating precursors while IgCC themselves are mainly nondividing end cells. Rats were given a continuous infusion of [3H] thymidine via an osmotic pump inserted in the peritoneal cavity. At intervals of 1,3, 5 or 10 days after starting infusions, tissues were taken and analyzed by a combination of immunohistology and autoradiography to identify the proportions of IgCC which had gone through S phase of the cell cycle during the period of infusion. After 3 days infusion the median and (range) percent‐labeled IgCC in the medullary cords of mesenteric and cervical lymph nodes and the red pulp of the spleen were, respectively, 88 (81–90), 75 (66–77) and 88 (82–93). Conversely that for IgCC in bone marrow was only 13 (11–17) and that in the lamina propria of the jejunum 47 (33–68). The rate of increase in labeling of bone marrow IgCC with length of infusion was approximately linear. Extrapolation of this slope suggests that bone marrow IgCC have a life span in excess of 3 weeks. The slopes of increase in IgCC labeled with time for lymph nodes and spleen were clearly biphasic suggesting that while most IgCC in these tissues have a life span of less than 3 days, there is also a minor population of long‐lived IgCC. The lamina propria appears to have approximately equal proportions of long and short‐lived IgCC. The life span of IgCC, with the exception of IgMCC, appears to be a feature of the site of antibody production rather than the Ig class produced. Almost all IgM‐containing cells were found to be short lived.
Functional heterogeneity of nonresting B cells in human blood
Authors: Richard Yolande , Leprince Corinne , Treton Dominique , Galanaud Pierre 
Published: February 2007

AbstractAmong human peripheral blood B cells we localized the precursors of two interleukin‐dependent B cell activation processes: the specific response to a particulate antigen, trinitrophenylated polyacrylamide beads (TNP‐PAA) and the polyclonally induced response to pokeweed mitogen. In both cases the precursors belong to the OKB7+, sIgD−, mouse red blood cell− subpopulation. However, they differ when cell density, reflecting the stage of activation reached by B cells in peripheral blood, is considered. Only B cells of intermediate density respond to TNP‐PAA, whereas the optimal response to pokeweed mitogen is obtained with the cells displaying the lower density. The lack of response of the more dense (resting) B cells to TNP‐PAA suggests that the T dependency of this antigen is not based on linked recognition, and fits with our demonstration that this particulate antigen can trigger B cells in the presence of T cell factor. More importantly, our results show that nonresting B cells are functionally heterogeneous according to their degree of preactivation: the responsiveness to specific signals provided by a nonmitogenic hapten‐carrier conjugate would be acquired before that to polyclonal activators.
Human complement factor H: isolation of cDNA clones and partial cDNA sequence of the 38‐kDa tryptic fragment containing the binding site for C3b
Authors: Schulz Thomas F. , Schwäble Wilhelm , Stanley Keith K. , Weiß Elisabeth , Dierich Manfred P. 
Published: February 2007

AbstractWe isolated cDNA clones coding for the functionally important tryptic N‐terminal 38‐kDa fragment of human complement control protein factor H using polyclonal and monoclonal antibodies to screen a human liver cDNA library cloned in a bacterial expression vector, PEX‐1. By testing the reactivity of antibodies specific for the recombinant proteins produced by individual clones with proteolytic fragments of serum H the exact position of these cDNA clones within H was mapped. One clone, H‐19, coding for the 38‐kDa fragment of H was sequenced and found to code for 289 amino acids derived from the 38‐kDa N‐terminal fragment as well as for the first 108 amino acids belonging to the complementary 142‐kDa tryptic fragment. The derived protein sequence could be arranged in 6 highly homologous repeats of about 60 amino acids each, the homology between the repeats being determined by the characteristic position of cysteine, proline, glycine, tyrosine and tryptophane residues. The region coding for the epitope recognized by one of our monoclonal antibodies was localized by subcloning restriction fragments of H‐19 into the expression plasmid and testing for the expression of this epitope.
Induction of chronic idiotype suppression by ligands binding to the variable (not the constant) region of the idiotypic target
Authors: Saito Takashi , Tokuhisa Takeshi , Rajewsky Klaus 
Published: February 2007

AbstractIt was previously shown that in C57BL/6 mice chronic suppression of an idiotypically defined subset of λ1 chain‐bearing anti‐(4‐hydroxy‐3‐nitrophenyl)acetyl (NP) antibodies is achieved by neonatal administration of allogeneic monoclonal anti‐idiotope antibodies reactive with this subset, or by NP coupled to mouse immunoglobulin. The present data show that isologous monoclonal anti‐idiotope antibodies have the same effect. In contrast, antibodies against constant region determinants of λ1, μ or δ immunoglobulin chains failed to induce chronic suppression of the same antibody subset. Furthermore, the effect of the anti‐idiotope antibodies was neutralized by idiotypic antibodies of the IgG1 class, injected before or together with the anti‐idiotype. These results suggest that the mere complexing of idiotypic molecules on the B cell surface or in the circulation is insufficient for the induction of chronic idiotype suppression. In the present system, induction appears to require the binding of a ligand to idiotype‐bearing receptor V regions, expressed on the surface of B (or T ?) cells.
T lymphocyte control of autoreactivity: analysis with human T cell clones and limiting dilution culture
Authors: Deusch Kai , Moebius Ulrich , Zum Büschenfelde Karl‐Hermann Meyer , Meuer Stefan C. 
Published: February 2007

AbstractTo investigate cellular mechanisms controlling activated autoreactive T lymphocytes, a limiting dilution system was established employing cloned autoreactive major his‐tocompatibility complex class II specific lymphocytes (a2/7) as stimulator cells for autologous peripheral blood mononuclear cells. At low responder/stimulator ratios, cytotoxic effector cells were generated capable of lysing clone a2/7. Importantly, within the population of cells mediating autocytotoxic effector function, differential specificities were found to exist. The generation of such autocytotoxic T lymphocytes appears to be inhibited by an additional population of cells circulating at lower frequency suggesting that autoreactivity is controlled at distinct levels by discrete functional cellular subsets.
Interleukin 1 inhibitory activity secreted by a human myelomonocytic cell line (M20)
Authors: Barak Vivian , Treves Avraham J. , Yanai Peter , Halperin Miriam , Wasserman Dror , Biran Shoshana , Braun Sergei 
Published: February 2007

AbstractCulture supernatants from a myelomonocytic cell line (M20) were found to inhibit interleukin 1 (IL 1) activity in vitro. The factor, isolated from these supernatants, inhibited augmentation of phytohemagglutinin response of mouse thymus cells induced by IL 1 derived from several established cell lines. Various IL 1‐dependent activities such as lymphocyte and fibroblast proliferation in vitro were also inhibited by the factor. The factor did not inhibit IL 2‐induced or other proliferative responses not related to IL 1. Preliminary biochemical characterization of the factor indicated that the activity resides in a protein with a molecular mass of 52 kDa.
Temporal regulation of influenza hemagglutinin expression in vaccinia virus recombinants and effects on the immune response
Authors: Coupar Barbara E. H. , Andrew Marion E. , Both Gerald W. , Boyle David B. 
Published: February 2007

AbstractRegulation of the expression of influenza A/PR/8/34 hemagglutinin (HA) by the vaccinia virus promoters PF (early), P7.5 (early and late) and PL11 (late) has been demonstrated using HA‐vaccinia recombinant viruses W‐PR8‐HA3, W‐PR8‐HA6 and W‐PR8‐HA, respectively. Levels of HA on the surface of W‐PR8‐HA3 (PF)‐infected cells were lower than with either W‐PR8‐HA6 (P7.5) or W‐PR8‐HA8 (PL11). Expression of HA under the control of the late promoter PL11 was inhibited in the absence of DNA replication. All three recombinant viruses stimulated a specific antibody response in mice which was dependent on the presence of infectious virus. Recognition of HA by cytotoxic T lymphocytes (CTL) was assessed by the ability of the viruses to stimulate naive precursors in vivo, to restimulate primed CTL in vitro and by target cell recognition. HA expressed under the control of either of the promoters with early function (PF or P7.5) was recognized by CTL when W‐PR8‐HA3 or VV‐PR8‐HA6 were used to prime or restimulate splenocytes or to infect target cells. On the other hand, HA expressed by W‐PR8‐HA8 (PL11) failed to prime for a CTL response in naive CBA/H mice, was ineffective at restimulation of primed splenocytes and failed to produce target cells for recognition by specific CTL. However, in BALB/c mice W‐PR8‐HA8 did prime for a specific CTL response. These studies show that HA synthesized early in infection was recognized by both B and T cells while HA expressed after DNA replication was not generally recognized by T cells. The implications of the observations with the late promoter with respect to the use of late promoters in potential vaccinia virus‐based vaccines are considered.
Human T cell clones can induce in vitro IgE synthesis in normal B cells regardless of alloantigen recognition or specificity for peculiar antigens
Authors: Del Prete Gianfranco , Maggi Enrico , Macchia Donatella , Tiri Antonio , Parronchi Paola , Ricci Mario , Romagnani Sergio 
Published: February 2007

AbstractA total number of 119 (98 CD 4+ and 21 CD 8+) T cell clones were established from tonsil and peripheral blood of three nonallergic individuals and examined for their ability to induce in vitro IgE synthesis in normal B cells.Following preactivation for 24 h with phytohemagglutinin, 34 clones (33 CD4+ and 1 CD 8+) induced normal B cells to synthesize remarkable amounts of IgE in vitro. In contrast, equal numbers of T blasts of phytohemagglutinin‐induced T cell lines obtained from unfractionated T lymphocyte suspensions of the same donors did not show such an effect. The in vitro IgE synthesis evoked by T cell clones was detectable between day 6 and 9 and peaked on day 12. Most clones maintained their ability to stimulate in vitro IgE synthesis in repeated assays over a 3‐month period. The induction of IgE synthesis by cloned T cells did not reflect alloantigen recognition on target B cells, since T cell clones induced IgE synthesis in B cells from all randomly selected donors tested, including autologous B cells.Preincubation for 24 h with optimal stimulatory concentrations of anti‐CD 3 (OKT 3) monoclonal antibody or its addition through the entire culture period also enabled T cell clones to stimulate de novo IgE synthesis in vitro in normal B cells. Virtually all the T cell clones active on IgE synthesis induced the in vitro production of remarkable amounts of IgM and IgG as well.These data indicate that several human T cell clones can induce normal B cells to synthesize immunoglobulin of different classes, including IgE, regardless of alloantigen recognition on target B cells or specificity for peculiar antigens. The activity of these clones was apparently mediated by triggering of the monomorphic molecular complex CD 3, immediately before or during the incubation of T cell clones with the target B cells.
A human T cell‐specific cDNA clone (YT16) encodes a protein with extensive homology to a family of protein‐tyrosine kinases
Authors: Koga Yasuhiro , Caccia Nicolette , Toyonaga Barry , Spolski Rosanne , Yanagi Yusuke , Yoshikai Yasunobu , Mak Tak W. 
Published: February 2007

AbstractWe report here the isolation of a human T cell‐specific cDNA clone (YT16) that encodes a protein with extensive homology to a family of transformation and proliferation‐related protein‐tyrosine kinases (PTK). The message size of YT16 is 2.2 kb and it encodes a protein of 507 amino acids with a mol. mass of 57136 Daltons. The deduced protein sequence has an overall homology of about 50% to the viral oncogene products of src and yes. Around the PTK catalytic domain, the homologies increase to 70–80% between the deduced protein sequence of YT16 and those of the PTK viral oncogenes. Of special interest is the extensive homology between the deduced protein sequence of YT16 and that of a recently reported murine B and T lymphocyte‐specific PTK, lskT. It is possible that YT16 either encodes the human homologue of this murine gene, or a protein with similar function(s) in T cells.
HgCl2 induces nonspecific immunosuppression in Lewis rats
Authors: Pelletier Lucette , Pasquier Régine , Rossert Jérome , Druet Philippe 
Published: February 2007

AbstractBrown‐Norway (BN) rats injected with HgCl2 have been previously shown to develop a variety of autoimmune abnormalities. The susceptibility of BN rats is genetically controlled, and Lewis rats bearing a different RT1 haplotype are resistant. It will be shown in the present study that the number of MRC OX‐8+ (suppressor/cytotoxic) cells increases in the spleen and lymph nodes of Lewis rats injected with HgCl2. The responsiveness to T cell mitogens and to alloantigens is concomitantly inhibited. Spleen cells from Lewis rats injected with HgCl2 fail to induce a local graft‐vs.‐host reaction. Data presented show that MRC OX‐8+ cells are involved in the immunosuppression in Lewis rats treated with HgCl2. Furthermore, lymph node cells and MRC OX‐8+ cells from these rats are able to inhibit the normal mixed lymphocyte reaction indicating that suppression is active. Thus, HgCl2 is able to trigger immune dysregulation leading either to autoimmunity or to immunosuppression depending upon the genetic background of the rat strain tested.
Homozygosity in the major histocompatibility complex region influences natural killer cell activity in man
Authors: Dubey Devendra P. , Yunis Ivan , Leslie Crystal A. , Mehta Cyrus , Yunis Edmond J. 
Published: February 2007

AbstractThe effect of homozygosity at HLA loci on natural killer (NK) cell activity has been examined. Lymphocytes obtained from heterozygous and homozygous individuals were incubated with 51Cr‐labeled, NK‐sensitive K562 cells at different effector/target ratios, and lytic activity was determined. Homozygous cells, obtained from individuals who are known HLA homozygotes (homozygous typing cells) and from selected families, had low NK activity compared to those heterozygous donors. This low cytotoxic activity had no correlation with sex, but did correlate with homozygosity at the HLA‐A, B and/or DR loci. A significantly lower number of cells, which bind to anti‐Leu 7 antibody, was found in homozygous donors. However, this reduced number of Leu 7+ cells could only partially account for the decrease in NK activity. These studies suggest that in some individuals homozygosity at HLA may be linked to genes that control NK activity.
β‐Cyclodextrin as a substitute for fetal calf serum in the primary antibody response in vitro
Authors: Ohmori Hitoshi , Yamamoto Itaru 
Published: February 2007

AbstractFetal calf serum (FCS) must be present at 10% in the culture medium for optimally eliciting the primary antibody response to sheep erythrocytes (SRBC) in murine lymphocytes. The response was no longer observed when FCS was reduced to less than 1%. However, we found that the addition of 250–500 μg/ml β‐cyclodextrin (β‐CD) to RPMI 1640 medium containing 1% FCS restored the immune response to a level comparable to that observed in 10% FCS‐containing medium. β‐CD did not further augment the response in the presence of 10% FCS. The order of effectiveness of various cyclodextrin compounds tested was as follows: β‐CD (100) > α‐CD(30) > γ‐CD(10) > heptakis (2,6‐O‐dimethyl)β‐CD (< 1). The in vitro antibody response varied drastically depending on the lot of FCS added to the culture medium. The important observation was that even a deficient lot of FCS could elicit the antibody response as efficiently as a good lot if it was added to the culture medium at 1% in combination with β‐CD, β‐CD was also effective in inducing the primary antibody responses to both SRBC and dinitrophenylated Ficoll in serum‐free RPMI 1640 medium containing bovine serum albumin, insulin and transferrin. In serum‐free conditions, the responses were 40–50% of those in serum‐containing medium. β‐CD did not increase the number of antibody‐forming cells nonspecifically, nor did it show a significant mitogenic activity and cytotoxicity. These data suggest that β‐CD is a useful material as a serum substitute in inducing primary antibody response in vitro.
Molecular analysis of the murine lupus‐associated anti‐self response: involvement of a large number of heavy and light chain variable region genes
Authors: Kofler Reinhard , Noonan Daniel J. , Strohal Robert , Balderas Robert S. , Moller Niels P. H. , Dixon Frank J. , Theofilopoulos Argyrios N. 
Published: February 2007

AbstractThe mRNA encoding heavy and light chains of a hybridoma‐derived monoclonal IgM,x anti‐immunoglobulin (rheumatoid factor) and an IgG3,x anti‐histone autoantibody from systemic lupus erythematosus and arthritis‐prone MRL/Mp‐lpr/lpr mice have been molecularily cloned, and the nucleotide sequences corresponding to their variable regions have been determined. To investigate whether autoantibodies with specificities frequently observed in lupus disease might share common structural components, the sequences obtained in this study have been compared with those of a monoclonal MRL/Mp‐lpr/lpr IgM,x anti‐DNA autoantibody previously analyzed in our laboratory (J. Exp. Med. 1985. 161: 805). The 3 immunoglobulins employed different heavy chain variable region (VH) genes belonging to the large J558 VH gene family, x light chain variable region (Vx) genes from 3 different Vx groups, and different diversity and joining segments. Our findings suggest that murine lupus‐associated autoantibodies of different specificities do not have genetic components in common to signal their self‐reactive nature and are encoded by a large number of immunoglobulin gene elements.
Induction of suppression following autologous mixed lymphocyte reaction; role of a novel 2H4 antigen
Authors: Takeuchi Tsutomu , Rudd Christopher E. , Schlossman Stuart F. , Morimoto Chikao 
Published: February 2007

AbstractIn this study, we have investigated the cellular and molecular basis for immunoregulatory function of T4+ cells after autologous mixed lymphocyte reaction (AMLR) activation. We demonstrated that the T4+2H4+ subset but not the T4+2H4− subset can proliferate maximally in response to autologous non‐T cells. T4+ cells activated by AMLR exerted suppressor activity on pokeweed mitogen‐driven IgG synthesis of autologous peripheral blood lymphocytes. The suppressor activity by AMLR‐activated T4+ cells required the presence of fresh T8+ cells in the secondary culture, indicating that AMLR‐activated T4+ cells functioned as a suppressor inducer rather than as a suppressor effector population. Following activation of T4+ cells in AMLR, it is the T4+2H4+ subset which induces suppression through the T8 population. Moreover, the treatment of AMLR‐activated T4+2H4+ cells with anti‐2H4 antibody, but not other antibodies, resulted in the abolishment of suppressor inducer function of such cells, suggesting that the 2H4 molecule itself may be involved in the suppressor inducer function. The 2H4 antigen on such cells was shown to be comprised of 220‐kDa and 200‐kDa glycoproteins. These results support the notion that the AMLR may play an important role in generating suppressor inducer signals and in down‐regulating the immune response following self major histocompatibility complex recognition. More importantly, the present studies indicate that the 2H4 antigen on T4 cells serves not only as a phenotypic marker of suppressor inducer cells, but may have a functionally important role itself in inducing suppression.
Supplemental zinc (Zn2+) restores antibody formation in cultures of aged spleen cells II. Effects on mediator production
Authors: Winchurch Richard A. , Togo James , Adler William H. 
Published: February 2007

AbstractIn vitro antibody production to T‐dependent erythrocyte antigens is depressed as a function of age. Supplementation of antibody‐forming cultures with the essential trace element zinc restores the capacity of cells from immunodepressed, aged mice to generate an antibody response. Zn2+ produces maximal enhancement of immune function when it is added to the cultures within the first 24 h. Supernatants obtained from cultures supplemented with zinc from 0–24 h contain soluble, nondialyzable factors which support enhanced antibody production in fresh cultures of cells from aged mice. Interleukin 2 levels in the supernatants from Zn2+‐supplemented cultures were not increased. However, the levels of interleukion 1 were increased approximately 300% over nonsupplemented controls and these increases corresponded with the ability of the supernatants to support antibody formation. Further studies showed that, in addition to enhancing the production of interleukin 1, Zn2+ enhanced the ability of concanavalin A‐activated T cells from aged mice to produce B cell stimulatory factor‐1.
Thymus grafts induce B cell development in nude, X‐linked immune deficient mice
Authors: Karagogeos Domna , Wortis Henry H. 
Published: February 2007

AbstractMice simultaneously expressing the mutations nude and X‐linked immune deficiency (xid) were previously shown to have pro‐B cells and/or early pre‐B cells while lacking Cμ+ and surface Ig+ cells. We now report that thymus grafts restore both T cells and B cells in nude‐xid mice. By the use of Thy‐1 and Igh allogeneic donors it was shown that both the T and B cells were host derived. The B cells had a functional phenotype typical of xid mice. It is concluded that the maturation of xid B cells past the pro‐B or early pre‐B stage is T cell dependent.
Activation of cytotoxic activity in cultures of bone marrow‐derived macrophages by indomethacin
Authors: Voth Rita , Storch Elke , Hüller Karin , Kirchner Holger 
Published: February 2007

AbstractIndomethacin was tested for its ability to augment the cytotoxic capacity of cultured bone marrow‐derived macrophages (MΦ) against P815 and YAC‐1 tumor cells. MΦ were obtained from the bone marrow of C57BL/6 mice precultured for 10–14 days and were virtually 100 percent pure. By addition of indomethacin these cells were activated to kill tumor cells in a 4‐h and 18‐h Cr‐release assay. Since indomethacin is a potent inhibitor of the cyclooxygenase system, MΦ were treated with prostaglandin E2. This treatment partially reversed indomethacin‐induced cytotoxicity. Addition of other cyclooxygenase inhibitors such as acetyl‐salicylic‐acid, diclofenac or carprofen also induced cytotoxicity in bone marrow‐derived MΦ. In all experiments we failed to detect any production of interferon. Addition of anti‐interferon did not alter the cytolytic capacities demonstrating that endogenously induced interferon was not relevant in this mechanism. Our data show that cyclooxygenase inhibitors induce cytolytic activity of murine MΦ not only against a MΦ target but also against YAC‐1 cells usually considered to be targets for natural killer cells.