bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cross-linking of B cell receptor-related MB-1 molecule induces protein tyrosine phosphorylation in early B lineage cells.
Authors: Matsuo T , Nomura J , Kuwahara K , Igarashi H , Inui S , Hamaguchi M , Kimoto M , Sakaguchi N 
Published: December 2022

Abstract
Cross-linking of surface B cell Ag receptor (BCR) induces tyrosine phosphorylation of BCR-associated components through a receptor-mediated signal transmission pathway. B cell-specific mb-1 and B29 genes encode the alpha/beta components of the BCR-associated complex in mature sIgM+ B cells. Here, we studied the involvement of the mb-1 gene product, MB-1, in the BCR-related structure of immature B cells. Affinity-purified anti-MB-1 antibody coprecipitated mu chain/20-kDa/15-kDa proteins together with monomer MB-1 and Ig-alpha/Ig-beta heterodimer components from digitonin lysates of the pre-B cell line 18.81. The monomer MB-1 and Ig-alpha in the pre-B cell line were shown to migrate with identical patterns in nonequilibrium pH gradient gel electrophoresis/SDS-PAGE. Western blot analysis showed that MB-1 protein is coprecipitated with mu chain from the pre-B cell line. We studied the tyrosine phosphorylation response of bone marrow B lineage cells as well as spleen B cells after cross-linking of BCR-related components with anti-mu, anti-kappa, and anti-MB-1 antibodies. We identified the activation of tyrosine kinase by direct cross-linking of MB-1 expressed on the surface of early B lineage cells. Anti-mu antibody stimulation induced the activation of tyrosine kinase in early (5- to 10-min) and late (30- to 120-min) responses in bone marrow early B lineage cells. Anti-MB-1 mAb (11-18-5) induced the late response exclusively but anti-kappa antibody induced only the early response. These results clearly indicate that MB-1 acts in the BCR-mediated signal transmission in early B lineage cells. To explore the molecular mechanism of protein tyrosine phosphorylation in bone marrow B lineage cells, we studied associated components of the BCR complex by using an in vitro kinase reaction and observed the phosphorylation of a 60-kDa protein in pre-B cell lines. The 60-kDa phosphoprotein coprecipitated with MB-1 and the BCR-related complex is very similar to the Src-type Fyn tyrosine kinase or a Fyn-related protein.
Ig repertoire expression of BALB/c primary and secondary B cell precursors specific for phosphorylcholine.
Authors: Wu P , Ward R E 
Published: December 2022

Abstract
To better understand the regulation of Ig repertoire expression and the generation of memory B cells, we have used the splenic focus assay to analyze primary and in vitro generated secondary phosphorylcholine (PC)-specific BALB/c B cell precursors. A quantitative analysis of the kinetics of appearance of these precursors over the time of the culture period was performed. The precursors were analyzed for TEPC15 Id expression, H chain isotype, relative affinity, and epitope specificity (PC vs p-nitrophenyl PC). In addition, we tested the hypothesis that primary and secondary precursors could be distinguished on the basis of the expression of the cell-surface Ag defined by the mAb JIId. We found that secondary in vitro PC-hemocyanin stimulation resulted in an increase in the anti-PC precursor frequency, relative to primary stimulation, of 37%. This increase was caused almost entirely by the secondary stimulation of non-TEPC15 expressing precursors. Relative to the primary precursors, the secondary precursors also: 1) expressed a lower percentage of IgM and a higher percentage of IgG, 2) had a higher relative affinity, and 3) expressed a lower level of JIId-defined Ag. Very little difference was observed in the epitope specificity of the primary vs secondary precursor repertoire. Based on an analysis of the kinetics of the response, together with JIId cell sorting and transfer experiments, our results support a model whereby a portion of the secondary anti-PC response is derived from secondary precursors arising from primary precursors, and the other portion is derived from distinct secondary precursors expressing a relatively low amount of the JIId Ag.
Differential expression of IgE and IgG4 specific antibody responses in asymptomatic and chronic human filariasis.
Authors: Kurniawan A , Yazdanbakhsh M , van Ree R , Aalberse R , Selkirk M E , Partono F , Maizels R M 
Published: December 2022

Abstract
A population of 164 adult individuals resident in an area endemic for Brugia malayi lymphatic filariasis has been studied for humoral immune responses to filarial parasites. Antibody levels to Ag extracted from adult worms were determined for each of the IgG subclasses, for IgM and for IgE. The dominant isotype of antifilarial antibody was IgG4, which represented 88% of total IgG in asymptomatic microfilaremics, most of whom possessed 100 to 1000 micrograms/ml of specific antibody of this subclass (geometric mean 762 micrograms/ml). Patients with chronic disease (elephantiasis), who were generally amicrofilaremic, had substantially higher levels of IgG1, IgG2, and IgG3, but a 3.4-fold lower geometric mean level of specific IgG4 (222 micrograms/ml) than asymptomatics with or without microfilaremia. In contrast, specific IgE antibody levels in cases of elephantiasis were on average 4.5 times higher than those found in the asymptomatic carrier state. The majority of microfilaremics were therefore typified by extremely high specific IgG4 concentrations and relatively low IgE reactivities, whereas clinical cases tended to show the reverse relationship. The possible roles of these isotypes and the implications of changing IgG4/IgE balances in disease are discussed.
Ity influences the production of IFN-gamma by murine splenocytes stimulated in vitro with Salmonella typhimurium.
Authors: Ramarathinam L , Niesel D W , Klimpel G R 
Published: December 2022

Abstract
The Ity-Lsh-Bcg genetic locus in the mouse has been documented to confer innate resistance to at least three intracellular pathogens: Salmonella typhimurium, Leishmania donovani, and Mycobacterium. Expression of the resistance gene(s) results in a slower net growth of these pathogens in the reticuloendothelial system early postinfection. Although it is clear that the resident macrophages in resistant mice are functionally superior with regard to antimicrobial activity, the exact mechanism(s) underlying the control exerted by this gene is not understood. Using S. typhimurium infection as a model, we have examined the influence of this resistance gene(s) on the production of IFN-gamma, a cytokine known to play an important role in host-defense against several intracellular pathogens. We compared IFN-gamma production by splenocytes from resistant (Ity(r)) and sensitive (Ity(s)) inbred mouse strains after stimulation in vitro with S. typhimurium. Spleen cells from Ity(r) mouse strains produced significantly higher levels of IFN-gamma when compared to spleen cells obtained from Ity(s) mouse strains. Enhanced IFN-gamma production was not a generalized response to bacteria. Listeria monocytogenes induced comparable levels of IFN-gamma production from both Ity(r) (CBA/J) and Ity(s) (C57BL/6) mice. Splenocytes from Ity congenic mouse strains displayed similar differences in the level of IFN-gamma produced after S. typhimurium stimulation, with spleen cells from the Ity(r) strain producing significantly higher levels of IFN-gamma when compared to spleen cells from the Ity(s) strain. A requirement for adherent cells and/or adherent cell-derived factors has been documented for IFN-gamma production by S. typhimurium-stimulated splenocytes. Interestingly, supernatant from adherent cells obtained from Ity(r) mouse strains was found to induce the production of significantly higher levels of IFN-gamma when compared to adherent cell supernatant from Ity(s) strains. Nylon wool nonadherent cells from Ity(s) mouse strains produced high levels of IFN-gamma when exposed to supernatants obtained from adherent cells of Ity(r) mouse strains. In contrast, nylon wool nonadherent cells from Ity(r) mouse strains produced reduced levels of IFN-gamma when exposed to supernatant obtained from adherent cells of Ity(s) mouse strains. Thus, modulation of IFN-gamma production appears to be a function of the Ity(r) gene(s). This study documents for the first time that the Ity locus may play a role in controlling resistance to Salmonella infection by regulating IFN-gamma production by NK cells.
Salmonella typhimurium induces IFN-gamma production in murine splenocytes. Role of natural killer cells and macrophages.
Authors: Ramarathinam L , Niesel D W , Klimpel G R 
Published: December 2022

Abstract
IFN-gamma is a cytokine known to play an important role in host defense against Salmonella typhimurium. The lymphoid cells required for in vitro production of IFN-gamma after S. typhimurium stimulation of mouse spleen cells was investigated. Spleen cells depleted of cells bearing NK1.1, asialo GM1, Thy 1.2, or CD5 resulted in a significant reduction in IFN-gamma production after stimulation with S. typhimurium. In contrast, Con A-induced IFN-gamma production was only slightly reduced after depletion of NK1.1- or asialo GM1-bearing cells. Spleen cells from SCID mice produced elevated levels of IFN-gamma after stimulation with S. typhimurium. IFN-gamma production by SCID spleen cells was dependent upon asialo GM1+ T cells, suggesting that NK cells were the cells producing IFN-gamma in response to S. typhimurium. Splenic adherent cells were required for optimal IFN-gamma production. However, direct contact between the adherent and nylon wool nonadherent (NWNA) cell populations was not essential. IFN-gamma production was observed when the adherent and NWNA cell populations were physically separated or when supernatant from S. typhimurium-stimulated adherent cells was added to NWNA cells. Optimal IFN-gamma production was dependent on the presence of TNF-alpha, inasmuch as addition of antibody to TNF-alpha to spleen cell or NWNA cell cultures significantly reduced IFN-gamma production. However, addition of rTNF-alpha did not induce IFN-gamma production by NWNA cells. These findings document the existence of a T-independent mechanism for early IFN-gamma production in response to S. typhimurium, and show that TNF-alpha is necessary but not sufficient for the production of IFN-gamma.
Toxoplasma gondii induces a T-independent IFN-gamma response in natural killer cells that requires both adherent accessory cells and tumor necrosis factor-alpha.
Authors: Sher A , Oswald I P , Hieny S , Gazzinelli R T 
Published: December 2022

Abstract
Spleen cells from scid mice produce high levels of IFN-gamma when exposed to either live tachyzoites of Toxoplasma gondii or a soluble parasite extract. Small numbers of parasites are sufficient to stimulate this response, which is also induced by cell-free supernatants of cultured tachyzoites. The parasite molecules responsible for triggering IFN-gamma production are heat-labile but resistant to freezing and thawing. Depletion of NK cells or adherent cells from the splenocyte population abolishes the response. Moreover, cultured bone marrow-derived NK cells are stimulated by Toxoplasma to produce IFN-gamma, but only when supplemented with adherent peritoneal washout or thioglycollate-induced exudate cells. Supernatants of macrophages preincubated with T. gondii extract also induce IFN-gamma synthesis by cultured NK cells. Addition of neutralizing mAb against TNF-alpha abolishes the IFN-gamma response of scid spleen cells exposed to the parasite or of NK cells incubated with supernatants of adherent cells stimulated with T. gondii extract. Moreover, splenic adherent cells produce low levels of TNF-alpha in response to the parasite. Nevertheless, TNF-alpha alone is not sufficient to trigger IFN-gamma production from purified NK cell populations. These findings provide the first example of the stimulation of T-independent IFN-gamma production by a protozoan. The ability of T. gondii to trigger this pathway may underlie its induction of strong IFN-gamma-dependent nonspecific and specific cell-mediated immunity.
Increased expression of CD11b and functional changes in eosinophils after migration across endothelial cell monolayers.
Authors: Walker C , Rihs S , Braun R K , Betz S , Bruijnzeel P L 
Published: December 2022

Abstract
Eosinophils from sputum, nasal polyps, and bronchoalveolar lavages of asthmatics demonstrated a considerably increased CD11b expression, compared with blood eosinophils. Furthermore, the tissue eosinophils expressed ICAM-1 (CD54) and HLA-DR, whereas peripheral blood eosinophils did not. In vitro migration of peripheral blood eosinophils across IL-1-activated human umbilical vein endothelial cell monolayers caused a considerable up-regulation of CD11b and CD35 expression, no induction of ICAM-1 or HLA-DR, and a small but significant decrease in CD11a, CD29, and CD32 expression. These changes were only partially inducible with supernatants from nonactivated or IL-1-activated endothelial cells, platelet-activating factor, or a variety of recombinant cytokines. Thus, cell-cell interactions mediated by receptor-ligand binding or endothelial cell membrane-bound mediators, rather than soluble factors, are responsible for the altered eosinophil surface marker expression. Indeed, preparations of membrane fragments from IL-1-stimulated endothelial cells were able to induce up-regulation of CD11b, which was not inhibitable with the platelet-activating factor antagonist WEB 2086 or antibodies against ELAM-1, VCAM-1, or ICAM-1. Investigation of the functional significance of the increased CD11b expression on eosinophils revealed only minimal changes in the adherence or transmigration capacity. Nevertheless, increased CD11b expression was related to an increased capacity to generate superoxide after stimulation with opsonized zymosan. Thus, cell-cell interactions between eosinophils and endothelial cells induce a considerable up-regulation of CD11b and CD35 on eosinophils and an increased capacity to generate an oxidative burst.
Functional and molecular characterization of tumor-infiltrating lymphocytes transduced with tumor necrosis factor-alpha cDNA for the gene therapy of cancer in humans.
Authors: Hwu P , Yannelli J , Kriegler M , Anderson W F , Perez C , Chiang Y , Schwarz S , Cowherd R , Delgado C , Mulé J 
Published: December 2022

Abstract
TNF is effective in causing the regression of selected murine tumors when administered at high concentrations. Therapeutic levels in humans cannot be obtained systemically, however, because of dose-limiting toxicity. The development of immunotherapy with IL-2 and tumor-infiltrating lymphocytes (TIL), which can accumulate at tumor sites in some patients, and of efficient retroviral techniques for gene transfer into eukaryotic cells has allowed new therapeutic approaches using TNF. We have retrovirally transduced human TIL with the gene for TNF in an attempt to deliver high concentrations of TNF to the tumor site without dose-limiting systemic toxicity. Successful gene insertion was confirmed by Southern hybridization in 16 of 16 transduced and selected TIL cultures from 15 different patients, with an estimated 28 to 93% transduced cells within each culture. Transduced selected TIL cultures produced greater amounts of TNF, compared with nontransduced controls, in 11 of 16 cultures evaluated. However, overall production of TNF was &gt; 30-fold lower, compared with a transduced and highly selected tumor cell line control (MEL-TNF). In addition, steady state levels of vector-derived transcript in nine of 10 transduced selected TIL cultures were &lt; 14% of the amount seen in the MEL-TNF control line. In an attempt to increase TNF production, TIL were transduced with a mutated form of TNF containing the IFN-gamma signal peptide in place of the transmembranous region, to enhance secretion into the endoplasmic reticulum. By using this vector, TNF production increased by an average of fivefold. These studies demonstrate that TIL can be genetically modified to express and secrete a protein for use in targeted cancer therapy but that partial expression blockades exist that prevent maximal cytokine production by introduced genes in TIL.
Selective and nonselective stages in homing of T lymphocytes to the central nervous system during experimental allergic encephalomyelitis.
Authors: Karin N , Szafer F , Mitchell D , Gold D P , Steinman L 
Published: December 2022

Abstract
The diversity of Ag-specific receptors on T cells homing to an inflammatory infiltrate in the central nervous system has been analyzed. Experimental autoimmune encephalomyelitis, a T cell-mediated inflammatory disease of the central nervous system, was induced in Lewis rats with a CD4+, CD8- T cell line specific for peptide 68-86 of myelin basic protein. Within the line a wide array of TCR V beta genes was transcribed including the V beta 8, V beta 10, V beta 15, V beta 16, and V beta 19 families. Accumulation of T cells at the site of inflammation was determined by using RNA-polymerase chain reaction amplification of rearranged TCR V beta transcripts derived from brain. By 8 to 10 h after i.p. infusion of the pathogenic T cell line, TCR V beta transcripts, including mainly V beta families that were predominantly rearranged by the line, could be identified in brains. Restricted TCR V gene transcripts with predominance of the V beta 8 family were identified in brain 48 h after injection, before onset of disease. Paralysis was apparent by 4 to 5 days after injection. At this time diverse V beta gene transcripts were detected in brain, reaching a maximum by day 9, when paralyzed rats have recovered. By day 14 a second stage of limited heterogeneity in the T cell infiltrate could be identified with predominant expression of V beta 8, V beta 9, V beta 10, and V beta 19. Interestingly, three out of these four V beta families were predominantly expressed within the encephalitogenic line. Thus, T cell migration to brain in experimental autoimmune encephalomyelitis is characterized by a rapid penetration of T cells followed by a selective trapping of T cells before the clinical manifestations of disease. When clinical disease was present the T cell infiltrate was diverse, whereas in the post-acute phase of disease the T cells in the central nervous system had limited heterogeneity with selective accumulation of T cells transcribing the same V regions that were detected in the line that incited disease.
Functional effect of IL-7-enhanced CD19 expression on human B cell precursors.
Authors: Wolf M L , Weng W K , Stieglbauer K T , Shah N , LeBien T W 
Published: December 2022

Abstract
We have previously demonstrated that IL-7 can sustain the growth of normal human B cell precursors (BCP) for several weeks on bone marrow-derived stromal cells. Flow cytometric analysis of BCP recovered from IL-7 supplemented cultures revealed two- to threefold higher levels of cell surface CD19, compared with BCP maintained without IL-7. Short term culture of BCP showed that IL-7 enhancement of CD19 was dose-dependent, with increases detected by day 1 and plateauing by days 3 to 4. IL-7 increased cell-surface CD19 on small lymphoid cells, and to a greater degree on lymphoblasts, whereas cell-surface CD10 was unchanged. The CD34+/CD19+ pro-B cell population showed a greater increase in cell-surface CD19 compared with pre-B and immature B cells. IL-1, IL-3, IL-4, IL-6, and stem-cell factor had no effect on CD19. The potential functional significance of IL-7-enhanced cell-surface CD19 was examined using a F(ab')2 fragment of anti-CD19. This reagent had no effect on [3H]TdR incorporation in BCP cultured in the absence or presence of IL-7 for 5 days, but homotypic adhesion of BCP was induced at a concentration as low as 1.0 ng/ml F(ab')2 anti-CD19. IL-7 enhanced the F(ab')2 anti-CD19 induced homotypic adhesion of BCP in a dose-dependent manner. Blocking antibody studies indicated that members of the beta 1 or beta 2 integrin families did not mediate anti-CD19-induced homotypic adhesion, even though the adhesion was completely ablated by 10 mM EDTA. The pre-B and immature leukemic B cell lines NALM-6 and 1E8 expressed comparable levels of cell-surface CD19, and exhibited comparable increases after IL-7 stimulation. However, their homotypic adhesion responses to anti-CD19 were different. NALM-6 cells exhibited a strong homotypic adhesion response to anti-CD19 that was EDTA-resistant, and beta 1/beta 2 integrin independent. 1E8 cells only responded to anti-CD19 after IL-7 stimulation; this response was EDTA-sensitive and beta 1/beta 2 integrin independent. These collective results indicate that IL-7 not only acts as a growth factor for human BCP, but also regulates signal transduction through cell-surface CD19.
Structure of the human C2 gene.
Authors: Ishii Y , Zhu Z B , Macon K J , Volanakis J E 
Published: December 2022

Abstract
A human genomic cosmid clone, S22A, was used to characterize the structure of the human C2 gene. Eighteen exons spanning 18 kb of DNA were mapped by nucleotide sequencing of exon-containing subclones and by Southern blotting. Introns vary in length between 83 bp and 4.4 kb and all intron/exon boundaries follow the AG/GT consensus rule for splicing. Exon 1 encodes 270 bp of the 5'-untranslated region of the C2 cDNA C2HL5-3 and 15 amino acids of the leader peptide. The three short consensus repeats of C2b are encoded by the single exons 2, 3, and 4, respectively. The von Willebrand factor type A-like domain of C2a is encoded by exons 6-10 and the serine protease domain by exons 11-18. Exons 5 and 15 appear to be unique to the C2 and factor B genes.
Monoclonal antibody that distinguishes between a phosphorylated, beta 2-microglobulin-associated, and a free, nonphosphorylated, chain of MHC class I.
Authors: Thor G , Sepulveda H , Chada S , Dutton R W 
Published: December 2022

Abstract
We have shown that a mAb, 7.2.14, recognizes a conserved sequence in exon 7 of a number of murine MHC class I molecules. 7.2.14 binding is abolished when the molecule is phosphorylated, presumably at a serine residue in exon 7, whereas treatment of material in cell lysates with alkaline phosphatase increases the intensity of the binding. A genomic construct containing Dd was transfected into human fibroblasts and a clonal cell line expressing high levels of surface MHC was selected. Cell lysates were prepared from surface-iodinated cells and analyzed by using a panel of antibodies. An apparent size heterogeneity was detected in the MHC class I gene product precipitated by different anti-class I MHC antibodies, suggesting that more than one conformational species of Dd was present. This was further investigated regarding the molecules precipitated by antibodies 34-2-12, M1/42, and 7.2.14. After preclearing of surface-iodinated cell lysates by using one antibody, challenge with the others still precipitated a Dd molecule, confirming that there were three independent conformations of the Dd gene product. A similar complexity could be observed in the lysates of surface-labeled spleen cells from C57BL/6 mice. A major polypeptide at approximately 48 to 50 kDa, representing the MHC H chain, was seen, and one or two as yet unidentified but strongly associated polypeptides at 41 kDa and 56 kDa were also visible. Sequential clearing of surface-iodinated material with one antibody followed by precipitation with the other confirmed that the 7.2.14-reactive material was distinct from that which reacted with M1/42. We propose that the 7.2.14-reactive 50-kDa band is the nonphosphorylated form of class I MHC, which exists in a conformation different from that of the conventional 48-kDa, phosphorylated, beta 2-microglobulin-associated entity.