bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monoclonal antibodies to mouse complement receptor type 1 (CR1). Their use in a distribution study showing that mouse erythrocytes and platelets are CR1-negative.
Authors: Kinoshita T , Takeda J , Hong K , Kozono H , Sakai H , Inoue K 
Published: December 2022

Abstract
mAb to murine C receptor type 1 (CR1) were produced and three of them were characterized. One antibody, designated as 8C12, immunoprecipitated a protein of 190,000 Mr from a detergent extract of surface-labeled spleen cells and stained spleen B but not T lymphocytes in fluorescent flow cytometry. It inhibited both CR1-mediated rosette formation and the cofactor activity of CR1 for factor I-mediated cleavage of C3b, suggesting that it recognizes the ligand-binding site of CR1. The two other antibodies, designated as 7G6 and 7E9, recognized different epitopes from that recognized by 8C12, and they cross-reacted with a protein of 150,000 Mr that is present in a spleen extract. The distribution of CR1 in murine hemopoietic cells was studied by binding experiments with radiolabeled 8C12 and fluorescent flow cytometry. When CR1 was not detected by 8C12 alone, the two other antibodies were used in combination with 8C12 to confirm the negative results. Almost all B lymphocytes from the spleen, lymph nodes, and peripheral blood were CR1 positive. Most of the Thy-1-positive lymphocytes from these tissues were CR1 negative. Thymus lymphocytes were also CR1 negative. Peritoneal macrophages and chemotactic factor stimulated but not unstimulated peripheral blood granulocytes were CR1 positive. In contrast to human E, mouse E were CR1 negative. This pattern of distribution was consistent with previous results obtained by rosette assays. Although mouse platelets cause immune adherence hemagglutination with C3b-bearing SRBC, they are CR1 negative. Three other lines of evidence also indicated that platelets are CR1 negative. First, no band of CR1 was demonstrated by immunoprecipitation with 8C12 of an extract of surface-labeled platelets. Second, 8C12, which inhibited rosette formation by lymphocytes, alone or in combination with 7G6 and 7E9, did not inhibit immune adherence between platelets and C3b-bearing SRBC. Third, polyclonal rabbit IgG prepared from anti-mouse CR1 antiserum did not inhibit immune adherence by platelets. These results strongly suggest that the C3b-binding factor(s) on mouse platelets is different from CR1 and that processing of C3b-bearing immune complexes in mouse blood may be mediated by a new and as yet unidentified C3b-binding factor(s).
Recombinant human IFN-gamma, but not IFN-alpha or IFN-beta, enhances MHC- and non-MHC-encoded glycoproteins by a protein synthesis-dependent mechanism.
Authors: Giacomini P , Tecce R , Gambari R , Sacchi A , Fisher P B , Natali P G 
Published: December 2022

Abstract
Despite quantitative as well as qualitative differences, all three types of IFN (IFN-alpha, IFN-beta, and IFN-gamma) modulate the synthesis as well as the expression of class I and class II histocompatibility Ag and a melanoma-associated Ag located in the plasma membrane as well as the cytoplasm of human melanoma cells. By employing inhibitors of RNA and protein synthesis it was demonstrated that IFN-alpha and -beta increase the expression of histocompatibility products and this tumor-associated Ag by a process not requiring new protein synthesis. In contrast, IFN-gamma does require de novo protein synthesis for its modulatory activity. Thus, it appears that IFN might trigger various adaptive functions in different cell lineages by inducing at least two separate sets of responses specific for either IFN-alpha and -beta or IFN-gamma. Because the induction requirements for (2'-5')-oligoadenylate synthetase as well as for the development of a cellular antiviral state by different IFN also display a similar protein synthesis dependence pattern, the present results suggest that a similar set of cellular mediators may be involved in the modulation of antigenic expression by IFN-gamma in human melanoma cells.
Coculture of mouse IL-3-dependent mast cells with 3T3 fibroblasts stimulates synthesis of globopentaosylceramide (Forssman glycolipid) by fibroblasts and surface expression on both populations.
Authors: Katz H R , Dayton E T , Levi-Schaffer F , Benson A C , Austen K F , Stevens R L 
Published: December 2022

Abstract
Mouse IL-3-dependent bone marrow culture-derived mast cells (BMMC) and mouse 3T3 fibroblasts, cultured separately or together, were examined for their cell surface expression and biosynthesis of globopentaosylceramide, a marker of the mouse serosal mast cell. As assessed by flow cytometric analysis, BMMC cultured for up to 7 wk in 50% WEHI 3-conditioned medium containing IL-3 did not bind the B1.1 anti-globopentaosylceramide mAb (six experiments). A total of 10 +/- 4% (mean +/- SD, three experiments) of 3T3 fibroblasts that had reached confluence in medium without IL-3 bound B1.1 antibody and, after an additional approximately 28 days of culture in that medium or in 50% WEHI 3-conditioned medium, 12 +/- 3% (mean +/- SD, five experiments) and 16 +/- 7% (mean +/- SD, three experiments) of the cells, respectively, bound the antibody. After coculture of BMMC and confluent 3T3 fibroblasts for 28 days in 50% WEHI 3-conditioned medium, followed by dispersal and purification of the cells, 92 +/- 18% of the mast cells and 92 +/- 16% (mean +/- SD, seven experiments) of the fibroblasts were B1.1+. Whereas the increase in the expression of the epitope bound by B1.1 antibody on fibroblasts was noted by day 14 of coculture, expression of the epitope on mast cells did not occur until day 21 (three experiments). Biosynthesis of globopentaosylceramide was assessed by intrinsic radiolabeling of each cell population and identification of the extracted neutral glycosphingolipids by TLC and autoradiography. Synthesis of globopentaosylceramide was not detected in extracts of 9 x 10(6) BMMC, 1 x 10(6) confluent 3T3 fibroblasts cultured alone for 28 days, or 9 x 10(6) mast cells purified from 28-day cocultures but was readily detected in extracts of 3 x 10(5) fibroblasts purified from the same cocultures. These findings indicate that BMMC stimulate an increase in the synthesis and expression of globopentaosylceramide on 3T3 fibroblasts and suggest that the subsequent appearance of this neutral glycosphingolipid on the surface of the mast cells is due to its secretion by fibroblasts and adsorption to the mast cell surface. Thus, the interactions between mast cells and fibroblasts during coculture alter the biochemical and Ag phenotypes of both populations.
The biosynthesis and assembly of T cell receptor alpha- and beta-chains with the CD3 complex.
Authors: Koning F , Lew A M , Maloy W L , Valas R , Coligan J E 
Published: December 2022

Abstract
The biosynthesis, processing, and assembly of the TCR alpha- and beta-chains with each other and with the CD3 complex were investigated on both cell surface positive (TCR+CD3-) and negative (TCR-CD3-) cell lines. The results indicate that 1) in cell surface TCR-CD3- cell lines (MOLT 3, CCRF-CEM), TCR-beta, but not alpha-chains are present intracellularly. TCR-beta-CD3 complexes are readily found in these cell lines, but no evidence for final processing or cell surface expression of such incomplete TCR-CD3 complexes is observed. 2) In the cell surface TCR+CD3+ cell line HPB-ALL, both alpha- and beta-chains are present intracellularly. Whereas non-glycosylated forms of TCR-beta chain can be detected, only more mature forms of TCR alpha-chains are detected indicating that the alpha-chains are more rapidly glycosylated than the beta-chains. 3) The large majority of the intracellular alpha- and beta-chains is not disulfide linked and a small fraction of these is associated with CD3. 4) Only small amounts of the total intracellular TCR chains are found as CD3-associated disulfide-linked alpha beta-heterodimers. 5) Final processing of TCR chains for cell surface expression takes place after formation of these TCR-alpha beta-CD3 complexes. Thus, both the TCR alpha- and beta-chains are over-produced and only relatively small amounts of these chains form CD3-associated heterodimers that are processed for cell surface expression. Analogous results were obtained with a non-leukemic CTL clone. Based on these observations, a model for the biosynthesis and assembly of the TCR-CD3 complex is presented.
Increased plasma membrane permeability to Ca2+ in anti-Ig-stimulated B lymphocytes is dependent on activation of phosphoinositide hydrolysis.
Authors: Ransom J T , Chen M , Sandoval V M , Pasternak J A , Digiusto D , Cambier J C 
Published: December 2022

Abstract
The biochemical basis of Ca2+ mobilization after anti-Ig binding to B cell Ag-R has been further characterized by flow cytometric analysis of indo-1-loaded B cells. The ability to distinguish intracellular Ca2+ release from extracellular Ca2+ influx by using an extracellular calcium depletion-repletion approach has allowed us to study the relationship between the mobilization of Ca2+ from these sources. Studies involving manipulation of the Ca2+ gradient across the plasma membrane indicate that a significant portion of the Ca2+ mobilization response is preserved even when the normal inwardly directed Ca2+ gradient is reversed. In the presence of an extracellular calcium concentration ([Ca2+]o) of 10 microM, the response to anti-Ig is not blocked by the organic Ca2+ channel blockers. This response is not reduced by further depletion of [Ca2+]o by EGTA Ca2+-binding buffers. Thus, the Ca2+ response that occurs when [Ca2+]o less than or equal to 10 microM represents intracellular calcium release. Analysis of B cells stimulated with anti-Ig in low Ca2+ medium ([Ca2+]o = less than 10 microM) followed by repletion of [Ca2+]o to 1 to 5 mM reveals that a significant increase in permeability of the plasma membrane to Ca2+ develops in the stimulated cells. The resultant Ca2+ influx is nimodipine (20 microM) sensitive. Both intracellular Ca2+ release and Ca2+ influx are reduced in parallel as the concentration of anti-Ig stimulus is decreased, suggesting that Ca2+ influx may be coupled to the release of intracellular stores. Neomycin blocks anti-Ig-stimulated formation of inositol trisphosphate, which mediates release of Ca2+ from the endoplasmic reticulum. It also blocks the anti-Ig-induced release of intracellular Ca2+ stores as well as Ca2+ influx, indicating that both responses may be dependent upon phosphatidylinositol 4,5-bisphosphate hydrolysis.
Idiotype stimulation of T lymphocytes from Trypanosoma cruzi-infected patients.
Authors: Gazzinelli R T , Morato M J , Nunes R M , Cançado J R , Brener Z , Gazzinelli G 
Published: December 2022

Abstract
Anti-Trypanosoma cruzi epimastigote antibodies (anti-epi) from pooled and individual sera from patients with chronic Chagas' disease were purified on immunoaffinity columns of epimastigotes antigens (epi) coupled to activated Sepharose 4B. SDS-PAGE analysis of purified anti-epi preparations showed only the presence of human IgG H and L chains. These antibodies preparations showed similar Western blotting profiles as the sera pools from which they originated. The main polypeptides recognized by anti-epi had apparent molecular masses 31, 46, 51, 75 and 85 kDa. No difference in these patterns were detected between anti-epi from pooled sera of cardiac (anti-epiC) and indeterminate (anti-epiI) clinical forms. Anti-epi preparations (20 to 60 micrograms/ml) of pooled and individual sera stimulated proliferation of homologous and autologous PBMN or T-lymphocyte-enriched population. The stimulatory ability was dependent upon the PBMN-anti-epi combinations. There is no direct correlation between the level of PBMN response to epi and anti-epi stimuli. Comparison of the stimulatory activities of anti-epiC vs anti-epiI on PBMN of either cardiac or indeterminate group of patients indicate that anti-epiC is significantly more active than anti-epiI (p less than 0.025). These data demonstrate the presence of auto-anti-idiotypic-T cells in chagasic patients and lead to the possibility that idiotype/anti-idiotype interactions may play a role in determining the pathogenesis of chagasic cardiopathy.
Failure or success in the restoration of virus-specific cytotoxic T lymphocyte response defects by dendritic cells.
Authors: Kast W M , Boog C J , Roep B O , Voordouw A C , Melief C J 
Published: December 2022

Abstract
C57BL/6 (B6, H-2b) mice are CTL responders to both Sendai virus and Moloney leukemia virus. In the former response the H-2Kb class I MHC molecule is used as CTL restriction element, in the latter response the H-2Db molecule. B6 dendritic cells (DC) are superior in the presentation of Sendai virus Ag to CTL in comparison with B6 normal spleen cells. Con A blasts have even less capacity to present viral Ag than NSC, and LPS blasts show an intermediate capacity to present viral Ag. H-2Kb mutant bm1 mice do not generate a CTL response to Sendai virus, but respond to Moloney leukemia virus, as demonstrated by undetectable CTL precursors to Sendai virus and a normal CTL precursor frequency to Moloney virus. Compared to B6 mice, other H-2Kb mutant mice show decreased Sendai virus-specific CTL precursor frequencies in a hierarchy reflecting the response in bulk culture. The Sendai virus-specific CTL response defect of bm1 mice was not restored by highly potent Sendai virus-infected DC as APC for in vivo priming and/or in vitro restimulation. In mirror image to H-2Kb mutant bm1 mice, H-2Db mutant bm14 mice do not generate a CTL response to Moloney virus, but respond normally to Sendai virus. This specific CTL response defect was restored by syngeneic Moloney virus-infected DC for in vitro restimulation. This response was Kb restricted indicating that the Dbm14 molecule remained largely defective and that a dormant Kb repertoire was aroused after optimal Ag presentation by DC. In conclusion, DC very effectively present viral Ag to CTL. However, their capacity to restore MHC class I determined specific CTL response defects probably requires at least some ability of a particular MHC class I/virus combination to associate and thus form an immunogenic complex.
The role of L3T4+ and Lyt-2+ T cells in the IgE response and immunity to Nippostrongylus brasiliensis.
Authors: Katona I M , Urban J F , Finkelman F D 
Published: December 2022

Abstract
The role of L3T4+ and Lyt-2+ T cells in protective immunity to Nippostrongylus brasiliensis (Nb) was studied in BALB/c mice that were depleted of either the L3T4+ or Lyt-2+ T cell population by injection with rat mAb specific for the appropriate determinant. Host responses to Nb infection including spontaneous elimination of adult worms, development of intestinal mucosal mast cell hyperplasia and the generation of a polyclonal IgE response were all completely blocked by 0.5 mg anti-L3T4 antibody administered simultaneously with Nb inoculation. However, administration of 0.5 mg of anti-Lyt-2 antibody at the same time and 7 days after inoculation with Nb had no effect on any of these responses. Injection of anti-L3T4 antibody as late as 9 days after Nb inoculation interfered with spontaneous cure of Nb infection and anti-L3T4 antibody injection 11 days after Nb inoculation inhibited serum IgE levels measured on day 13 by 50%. In addition, administration of anti-L3T4 antibody at the time of the peak serum IgE response, 13 days after Nb inoculation, accelerated the decline in serum IgE levels. Injection of previously Nb-infected mice with anti-L3T4 antibody at the time of a second Nb inoculation prevented the development of a secondary IgE response but did not affect immunity to Nb infection based on finding no adult worms in the intestines of these mice. These data indicate that 1) L3T4+ T cells are required for spontaneous cure of Nb infection, development of intestinal mucosal mast cell hyperplasia, and the generation and persistence of an IgE response during primary infection with Nb and 2) L3T4+ T cells are required for a considerable time after inoculation for optimal development of these responses. However, L3T4+ T cells are not required for all protective responses in immune mice. In contrast, our data indicate that considerable depletion of the Lyt-2+ T cell population has no significant effect on either worm expulsion or the generation of serum IgE responses.
Characteristics and epitope mapping of a cloned human autoantigen La.
Authors: Sturgess A D , Peterson M G , McNeilage L J , Whittingham S , Coppel R L 
Published: December 2022

Abstract
The La (SS-B) polypeptide is a ribonucleoprotein against which high titer antinuclear antibodies (ANA) react in the human autoimmune disease primary Sjögren's syndrome. To identify the autoepitopes with which the ANA anti-La (anti-SS-B) reacts, we isolated a 1.4-kb cDNA clone for La from a lambda gt10 library made from a human Burkitt's cell line. This clone contained an open reading frame of 1065 bp, encoding a 40.1-kDa polypeptide that corresponded to the carboxyl-terminal end of the La protein. The predicted polypeptide sequence of the recombinant protein was highly charged and unrelated to any previously published sequence. We also compared this clone to a previously published cDNA sequence for La and demonstrated significant differences, particularly that the open reading frame in our cDNA continued for 926 additional bases 3' to a putative termination codon in the previously reported sequence. The recombinant La protein was expressed in Escherichia coli and tested for reactivity with 200 sera containing ANA of various specificities. Only the sera containing anti-La antibodies reacted with the cloned La. By expressing subclones of the La cDNA as fusion proteins with beta-galactosidase, we have localized at least one epitope for the binding of anti-La antibodies to the carboxyl-terminal 103 amino acids of the La protein. No anti-La binding could be demonstrated to the region of the La protein that had previously been predicted to contain an autoepitope for the binding of anti-La (SS-B) antibodies. Studies of cloned autoepitopes could provide important clues to the role ANA play in disease and lead to targeted intervention in the treatment of primary Sjögren's syndrome.
Sites of switch recombination in IgG2b- and IgG2a-producing hybridomas.
Authors: Katzenberg D R , Birshtein B K 
Published: December 2022

Abstract
The technique of genomic Southern blot analysis was employed to map the sites of class switch rearrangement in five hybridoma cell lines, four of which produce gamma 2b, whereas the fifth secretes gamma 2a. Two of the class switch recombinations we have mapped represent secondary switches to gamma 2b with a gamma 1 intermediate. We also observe isotype specificity in class switch recombination, with both allele rearranging to the same isotype in the three lines where an unexpressed chromosome is retained. Every 5' break occurred outside of and immediately 5' to the tandem repeats associated with Cmu, a result consistent with earlier studies on myelomas but in contrast to the pattern seen in lymphomas. Seven of the eight 3' switch sites, however, were within tandem repeats. This disparity in the distribution of 5' and 3' break points may reflect a unique role for the mu-associated tandem repeats in the switch process.
Analysis of the anti-Schistosoma mansoni surface antibody response during murine infection and its potential contribution to protective immunity.
Authors: Omer Ali P , Smithers S R , Bickle Q , Phillips S M , Harn D , Simpson A J 
Published: December 2022

Abstract
Absorption of serum from chronically infected mice with homogenized schistosome eggs reduced antibody binding to the schistosomulum surface by 94%, indicating that almost all schistosomulum surface recognition during chronic infection is due to epitopes shared with the egg. Absorption of the serum with egg homogenate from which protein antigens had been removed by boiling and digestion with proteinase K resulted in a similar reduction of antisurface antibody demonstrating that all the shared epitopes that are recognized are carbohydrate in nature. Analysis of the time course of anticarbohydrate antibody production and the levels of antibody in mice infected with a single sex of schistosome indicated that eggs directly stimulated this response. Mouse mAb were identified that bound at very high levels to the schistosomulum surface and that recognized carbohydrate epitopes shared with the egg. Three of these had previously been demonstrated to passively transfer resistance, indicating that these surface carbohydrates are potential targets of protective immunity in the mouse. All the anticarbohydrate mAb also bound to the surface of schistosomula of other schistosome species. Thus, the strong immune response against these epitopes in chronic infection could account for the cross-specific immunity observed. Mice vaccinated with irradiated cercariae lacked high levels of anticarbohydrate antibodies and their recognition of the surface was largely due to antibody to species-specific polypeptide epitopes. With respect to the Mr greater than 200,000 and 38,000 antigens, it was demonstrated that these epitopes were present on the same antigens that bear the carbohydrate moieties recognized by antibodies from chronically infected mice. This specific polypeptide recognition is also reflected in the immunity generated by exposure to irradiated cercariae.
Activation of human T lymphocytes by bryostatin.
Authors: Hess A D , Silanskis M K , Esa A H , Pettit G R , May W S 
Published: December 2022

Abstract
The immunologic effects of bryostatin (Bryo), a PKC activator with antineoplastic activity, were assessed and compared to PMA. Bryo induced IL-2R expression on CD4+ and CD8+ human T lymphocytes with a dose response comparable to PMA. However, Bryo induced only a marginal proliferative response as compared with the vigorous response induced by PMA. Bryo mediated functional receptor expression because the proliferative response was enhanced by addition of rIL-2. Furthermore, the proliferative response was inhibited by the relatively specific Ca+, phospholipid-dependent protein kinase (PKC) inhibitor, H-7, indicating a role of PKC in Bryo-induced activation. Addition of the calcium ionophore, ionomycin, to Bryo-stimulated lymphocytes resulted in the production and secretion of IL-2 with a concomitant proliferative response. This effect of the calcium ionophore could be inhibited by cyclosporine with identical results obtained in PMA-stimulated cultures. A most intriguing finding was that Bryo could effectively antagonize PMA-induced T cell proliferation. Although this mechanism of inhibition is unclear, a discussion with respect to differential effects on potential intracellular PKC isoforms is provided. These studies indicated that Bryo has potent immunopotentiating properties that share some similar effects of the phorbol ester, PMA, but offers the additional property of modulating other phorbol ester effects on proliferation.