bluuebunny/crossref_metadata_2025_split huggingface dataset:
A single amino acid mutation in CDR3 of the 3-14-9 L chain abolished expression of the IDA 10-defined idiotope and antigen binding.
Authors: Hall B L , Zaghouani H , Daian C , Bona C A 
Published: December 2022

Abstract
The ABPC 48 myeloma protein and the 3-14-9 mAb derive their V region genes from the same VH and V kappa gene families. They also share a cross-reactive idiotope defined by the anti-Id mAb IDA 10. Whereas ABPC 48 is specific for bacterial levan, 3-14-9 showed a significant Ag-binding activity to aminophenyl-beta-N-acetylglucosaminide (AZO). In order to define the molecular basis of idiotope expression and Ag-binding activity, we have cloned the genes encoding the 3-14-9 H and L chain V region genes, generated antibodies that carry mutations within the L chain genes, by site-directed mutagenesis, and investigated the effects of those mutations with respect to IDA 10 idiotope expression and binding to AZO. Our findings show that, whereas expression of the IDA 10-defined idiotope requires association of both the H and L chains, a single change (glycine to phenylalanine) at position 91 in the third complementarity-determining region of the L chain abolished both idiotope expression and Ag-binding activity. In addition, a L chain change of alanine to threonine at position 25 allowed idiotope expression to some extent but significantly reduced binding activity to AZO. These data suggest that a single amino acid change can play a crucial role in the functional activity and structural integrity of antibodies.
Characterization of germ-line genes of the VGAM3.8 VH gene family from BALB/c mice.
Authors: Sims M J , Krawinkel U , Taussig M J 
Published: December 2022

Abstract
Five germ-line genes of the VGAM3.8 VH family in BALB/c mice have been isolated from genomic libraries and sequenced. The genes are functional and three are expressed in antibodies of different specificities. Overall nucleotide sequence homologies within the family are greater than 90%, whereas homologies with other VH families are less than 70%. Southern blot hybridization and sequencing indicate a minimum family size of six genes. Differences in the coding regions are mostly confined to CDR, where there is a high replacement/silent substitution ratio, indicative of positive selection for diversification associated with Ag binding. VHVGAM3.8 sequences are highly conserved, and polymorphism in the coding regions appears to be very limited. Evidence is presented that the family has evolved, and been homogenized, by recombinatorial events.
Oncostatin M induces tyrosine phosphorylation in endothelial cells and activation of p62yes tyrosine kinase.
Authors: Schieven G L , Kallestad J C , Brown T J , Ledbetter J A , Linsley P S 
Published: December 2022

Abstract
Oncostatin M is a polypeptide cytokine produced by activated and transformed T lymphocytes that has diverse biologic effects, including growth inhibition of tumor cells and induction of IL-6 expression in cultured human endothelial cells (HEC). HEC are highly responsive to oncostatin M and express high levels of oncostatin M receptors relative to other cell types. Oncostatin M has previously been found to bind a specific receptor of 150 to 160 kDa. We have found through the use of anti-phosphotyrosine immunoblotting that oncostatin M induces tyrosine phosphorylation in HEC. Anti-phosphotyrosine antibodies specifically immunoprecipitated labeled oncostatin M cross-linked to its receptor, demonstrating that the oncostatin M receptor is either directly phosphorylated on tyrosine after ligand binding or is tightly associated with a phosphotyrosyl protein in these cells. The tyrosine kinase inhibitor herbimycin A blocked the induction of IL-6 by oncostatin M in HEC. In addition, immune complex kinase assays showed that oncostatin M markedly increased the activity of the p62yes tyrosine kinase with a small increase in p59fyn but no increase in p56lyn tyrosine kinase activity in HEC. We conclude that oncostatin M utilizes a tyrosine phosphorylation signal transduction pathway in HEC involving the activation of the p62yes tyrosine kinase, and that this tyrosine phosphorylation pathway leads to the induction of IL-6 expression.
Multiple hemopoietic growth factors stimulate activation of mitogen-activated protein kinase family members.
Authors: Welham M J , Duronio V , Sanghera J S , Pelech S L , Schrader J W 
Published: December 2022

Abstract
Stimulation of hemopoietic cells with IL-3, IL-4, IL-5, granulocyte-macrophage-CSF and Steel factor-(SLF) induced tyrosine phosphorylation of a number of protein substrates. Two of these proteins, designated p42 and p44, were tyrosine phosphorylated rapidly in response to treatment with IL-3, IL-5, granulocyte-macrophage-CSF and SLF, but not IL-4. We demonstrate that these common substrates are members of the mitogen-activated protein kinase (MAP kinase) family of protein serine/threonine kinases. Ion-exchange chromatography yielded a peak of MAP kinase activity eluting at 0.3 to 0.32 M NaCl. Immunoblotting of column fractions with antiphosphotyrosine antibodies showed coelution of the peak of MAP kinase enzyme activity with the p42 and p44 tyrosine phosphorylated species, and with two proteins of 42 and 44 kDa which were immunoreactive with anti-MAP kinase antibodies. Moreover, a characteristic shift in mobility of the p42 and p44 species was observed after factor treatment. Time-course analyses and subsequent ion-exchange chromatography demonstrated SLF activation of MAP kinase activity was maximal after 2 min of factor treatment and decreased to basal levels after 30 min stimulation. By contrast, activation of MAP kinase after IL-5 treatment was not as rapid. Maximal activity was observed 15 min after stimulation and remained elevated for up to 60 min after IL-5 addition. Investigation of the role of protein kinase C in the mechanism of activation by these growth factors demonstrated that specific inhibition of protein kinase C led to a reduction, but not ablation, of the SLF and IL-3 induced stimulation of MAP kinase activity. The use of synthetic peptide substrates confirmed SLF and IL-5 activate isoforms of MAP kinases. These results demonstrate that members of the MAP kinase family are involved in common signal transduction events elicited by IL-3, IL-5, granulocyte-macrophage-CSF and Steel factor, but not those involving IL-4.
Impaired calcium mobilization in CD4+ and CD8+ T cells in a retrovirus-induced immunodeficiency syndrome, murine AIDS.
Authors: Makino M , Sei Y , Arora P K , Morse H C , Hartley J W 
Published: December 2022

Abstract
After infection with LP-BM5 murine leukemia viruses, susceptible strains of mice develop a severe and progressive immunodeficiency disease, termed murine AIDS (MAIDS), features of which include markedly impaired T cell response to mitogens or specific Ag stimulation and decreased production of IL-2. Since an elevation of intracellular calcium concentration resulting from binding of Ag to the TCR is associated with IL-2 production, T cells from mice either uninfected or infected with LP-BM5 murine leukemia viruses were examined by a calcium mobilization assay. Both CD4+ and CD8+ T cells from infected mice manifested impaired calcium mobilization responses upon in vitro stimulation with anti-CD3 mAb or Con A. The abnormalities appeared early after virus inoculation and showed no difference in time course between subsets of T cells. Frequencies of prestimulation calcium-positive cells among both CD4+ and CD8+ cells in mice with MAIDS were significantly higher than those for uninfected mice. These abnormalities were associated with presence of the MAIDS-inducing defective virus genome, but were not induced by infection of mice genetically resistant to development of MAIDS or with nonpathogenic helper murine leukemia virus, a virus component that induces high spontaneous proliferation of T cells, even in MAIDS-resistant mice.
Phospholipase activation during monocyte adherence and spreading.
Authors: Lefkowith J B , Lennartz M R , Rogers M , Morrison A R , Brown E J 
Published: December 2022

Abstract
Phospholipase activation is an important element in cellular signal transduction. In our study we investigated the role and regulation of phospholipase activation during human monocyte adherence and spreading. In human monocytes, phospholipase inhibition (with bromophenacyl bromide (BPB) or manoalide) impaired cell adherence and spreading. In contrast, neither cyclooxygenase/lipoxygenase inhibition nor platelet activating factor receptor blockade affected these responses. The impaired adherence and spreading induced by phospholipase inhibition with BPB could be partially reversed by the addition of nM levels of arachidonate (20:4(n - 6)). Dihomogammalinolenic acid (20:3(n - 6)) could substitute for arachidonate, but other polyunsaturated fatty acids were ineffective in this regard. The phospholipase inhibitor, BPB was selective in its effects on cellular phospholipase activities. BPB inhibited adherence/spreading-related and PMA-stimulated phospholipase activities, but not Ca2+ ionophore-stimulated phospholipase activity. To further probe for the role of Ca2+ in monocyte adherence and spreading, monocytes were loaded with MAPTAM (bis-(2-amino-5-methylphenoxy)-ethane-N,N,N',N', tetraacetic acid tetraacetoxymethyl ester), an EGTA analog. In contrast to phospholipase inhibition, intracellular Ca2+ chelation with MAPTAM did not affect monocyte adherence but did inhibit monocyte spreading. MAPTAM partially inhibited adherence/spreading-stimulated phospholipase activity, but did not inhibit PMA-stimulated phospholipase activity. These data suggest that human monocyte adherence and spreading may sequentially activate Ca(2+)-independent and then Ca(2+)-dependent phospholipases to release arachidonate. The activation of phospholipase and the release of arachidonate appear to be integral parts of the adhesion process.
Protein tyrosine phosphorylation induced via the IgG receptors Fc gamma Ri and Fc gamma RII in the human monocytic cell line THP-1.
Authors: Scholl P R , Ahern D , Geha R S 
Published: December 2022

Abstract
We have investigated the role of protein tyrosine phosphorylation in transmembrane signaling via the IgG receptors Fc gamma RI and Fc gamma RII in the human monocytic cell line THP-1. Fc gamma RI and Fc gamma RII were selectively engaged using the anti-Fc gamma RI mAb 197 (IgG2a) and the anti-Fc gamma RII mAb IV.3 (IgG2b). Addition to cells of mAb 197, but not addition of IgG2a mAb of irrelevant specificity, resulted in the rapid induction of cytoplasmic protein tyrosine phosphorylation as assessed by antiphosphotyrosine immunoblotting. A similar pattern of tyrosine phosphorylation was induced by mAb IV.3, but not by control IgG2b mAb. The induction of tyrosine phosphorylation by anti-Fc gamma R mAb was not dependent on antibody Fc region-FcR interactions, because tyrosine phosphorylation was also induced by cross-linked anti-Fc gamma RI F(ab')2 fragments and by cross-linked anti-Fc gamma RII Fab fragments. To investigate the relationship of Fc gamma R-induced tyrosine phosphorylation and activation of phospholipase C, which is known to follow Fc gamma R engagement, we assessed the effect of the tyrosine kinase inhibitor herbimycin A on Fc gamma R-induced Ca2+ flux. Herbimycin A strongly inhibited cellular Ca2+ flux induced by mAb 197, but did not inhibit Ca2+ flux induced by aluminum fluoride, suggesting that tyrosine phosphorylation may be important in regulating Fc gamma R-mediated activation of phospholipase C. Consistent with this, mAb 197 induced rapid phosphorylation of the gamma-1 isoform of phospholipase C. Finally, herbimycin A strongly inhibited the induction of TNF-alpha mRNA accumulation by Fc gamma R cross-linking. These results suggest that protein tyrosine phosphorylation may play an important role in the activation of phospholipase C and in the induction of monokine gene expression that follows engagement of Fc gamma R in human monocytes.
Decay-accelerating factor functions as a signal transducing molecule for human monocytes.
Authors: Shibuya K , Abe T , Fujita T 
Published: December 2022

Abstract
Decay-accelerating factor (DAF) is a glycosylphosphatidylinositol-anchored membrane protein that protects cells from damage by autologous complement activation. Of the four mAb against DAF prepared in our laboratory, 1C6 completely blocked DAF function, whereas 5B2 partially blocked it. Using these mAb, we investigated whether human monocytes were activated via DAF molecules. When monocytes were incubated with 1C6 alone, glucose was consumed in significant amounts and phagocytosis of latex beads was enhanced, indicating that the monocytes had been activated. However, 1C6 did not enhance the production of monokines, TNF-alpha, and IL-1 alpha and -beta. The F(ab')2 fragment of 1C6 also activated monocytes, whereas 5B2 and the Fab fragment of 1C6 could not. To further examine monocyte activation, these cells were treated with phosphatidylinositol-specific phospholipase C. Increased glucose consumption and enhanced phagocytic activity by 1C6 were considerably reduced in monocytes treated with phosphatidylinositol-specific phospholipase C. In addition, we found that 1C6 stimulated the generation of inositol trisphosphate. These results demonstrate that the signal transmitted via the DAF molecule is capable of stimulating monocytes.
Effects of CD4 synthetic peptides on HIV type I envelope glycoprotein function.
Authors: Repke H , Gabuzda D , Palù G , Emmrich F , Sodroski J 
Published: December 2022

Abstract
Benzylated derivatives of a peptide (CD4(81-92)) representing the CDR3-like region of CD4 were previously found to inhibit gp120 binding, HIV-1 infectivity, and syncytium formation. These results have been interpreted to indicate a role for the corresponding CD4 region in these processes. The peptide (TbYICbEbVEDQKAcEE) is the prototype of a series of similar CD4(81-92) derivatives. We report that this peptide noncompetitively inhibits binding to CD4 of both gp120 and a mAb (MAX.16H5), both of which recognize the CDR2-like region of CD4. The binding of an antibody (Leu 3a) that is directed against a different area of the D1 domain of CD4 was also inhibited. The peptide derivative inhibited both HIV-1- and HTLV-1-mediated syncytium formation in the same concentration range. Nonbenzylated cyclic and linear peptides representing the CDR3-like region of CD4 (CD4(84-101)) had only minor effects on gp120 binding which were not sequence specific. The results of this study suggest that the effects of benzylated CD4(81-92) derivatives on HIV-1 binding or fusion should not be used to reach conclusions about the function of the corresponding CD4 region.
Origin and fate of IgE-bearing lymphocytes. II. Gut-associated lymphoid tissue as sites of first appearance of IgE-bearing B lymphocytes and hapten-specific IgE antibody-forming cells in mice immunized with benzylpenicilloyl-keyhole limpet hemocyanin by various routes: relation to asialo GM1 ganglioside+ cells and IgE/CD23 immune complexes.
Authors: Auci D L , Chice S M , Heusser C , Athanassiades T J , Durkin H G 
Published: December 2022

Abstract
The organs in which B cells bearing membrane-bound IgE (sIgE+) and benzylpenicilloyl (BPO)-specific IgE antibody-forming cells (AFC) first appeared were determined in BALB/c mice given BPO-keyhole limpet hemocyanin (10 micrograms) in aluminum hydroxide by various routes (i.p, gavage, s.c., i.v., or i.m.). In mice immunized by the i.p. route, the numbers and location of sIgE+ B cells and asialo GM1 ganglioside (AsGm1+) cells, the location of IgE/CD23 immune complexes, and the numbers of BPO-specific IgE AFC in lymphoid organs were determined. With all routes of immunization, no sIgE+ B cells or BPO-specific IgE AFC were ever detected in any organ before day 8. On day 8, with the s.c., i.v., or i.m. routes, sIgE+ B cells and IgE AFC appeared exclusively in Peyer's patches (PP); with the i.p. or gavage routes, sIgE+ B cells simultaneously appeared in both PP and mesenteric lymph nodes, whereas IgE AFC appeared only in PP. In mice immunized by the i.p. route, IgE/CD23 immune complexes and strikingly increased numbers of AsGm1+ cells transiently appeared only in PP after the appearance and preceding the "disappearance" of the sIgE+ B cells and IgE AFC. The data suggest that specific IgE responses originate in gut-associated lymphoid tissue and appear later in spleen. The data also associate the appearance of IgE/CD23 immune complexes and AsGm1+ cells with the "disappearance" of sIgE+ B cells and IgE AFC from PP.
Microfilament assembly modulates phospholipase C-mediated signal transduction by the TCR/CD3 in murine T helper lymphocytes.
Authors: DeBell K E , Conti A , Alava M A , Hoffman T , Bonvini E 
Published: December 2022

Abstract
Cytoskeletal involvement in the response to TCR/CD3 ligation and in signal transduction was investigated in a murine Th cell type 2 clone. Cells coated with the hamster anti-CD3 mAb, 145-2C11 (2C11 mAb), and exposed to goat anti-hamster demonstrated an increase in polymerized actin as well as an increase in inositol phospholipid hydrolysis mediated by activation of phospholipase C. Pretreatment with cytochalasins (Cyt) (D or B), drugs that interact with cellular actin, prevented actin polymerization, and augmented the initial rate and total amount of inositol phosphates produced. Drugs modifying microtubule function were ineffective. The intracellular Ca2+ rise attributed to InsP3 and InsP4 generated in response to CD3 perturbation was augmented by CytD. CytD treatment did not affect inositol phosphate generation resulting from the stimulation of guanine nucleotide-binding proteins with aluminium tetrafluoride, indicating that the action of CytD was specific for receptor-mediated inositol phospholipids. CytD decreased the rate of anti-CD3-induced receptor internalization. These data suggest that the assembly of microfilaments plays a role in CD3 internalization and that a CytD-sensitive mechanism uncouples the TCR/CD3 complex from phospholipase C-mediated signaling.
Phenotypic and functional characterization of c-kit expression during intrathymic T cell development.
Authors: Godfrey D I , Zlotnik A , Suda T 
Published: December 2022

Abstract
We have studied the expression and function of c-kit on subsets of mouse thymocytes. c-kit was primarily expressed on subpopulations of CD4-CD8-CD3- triple negative (TN) cells. The strongest c-kit expression was associated with subsets that represent the least mature TN cells, including CD44+CD25- TN, and a subpopulation of CD25+ TN. These cells were also Thy-1lo, H-2Khi TSA-1hi, HSAlo, B220-, Mac-1-, and Gr-1-. Additionally, the recently described pre-TN thymocyte population (CD4loCD3-CD8-) was also c-kit+. CD25+ TN thymocytes proliferated in the presence of IL-7 and stem cell factor (the ligand for c-kit), and this proliferation was completely inhibited in the presence of anti-c-kit. Furthermore, the addition of anti-c-kit to 2-deoxyguanosine-treated fetal thymic lobes undergoing reconstitution with fetal liver-derived precursor cells inhibited their T cell differentiation potential. These observations indicate an important role for c-kit/stem cell factor interactions during early thymocyte development.
Regulation of LFA-1 avidity in human B cells. Requirements for dephosphorylation events for high avidity ICAM-1 binding.
Authors: Hedman H , Lundgren E 
Published: December 2022

Abstract
Regulation of the avidity of LFA-1 (CD11a/CD18, alpha L beta 2) for its ligand ICAM-1 (CD54) was studied in human B cells by evaluating the effects of a phorbol ester, anti-IgM antibodies, staurosporine, and okadaic acid. We monitored changes in LFA-1 avidity by quantifying binding of cells to an immobilized rICAM-1 fusion protein. In this assay, the protein kinase C-activating phorbol ester PDB and anti-IgM antibodies, as well as the protein kinase inhibitor, staurosporine, were able to induce LFA-1-dependent binding to ICAM-1. This demonstrates that the high avidity state of LFA-1 can be induced by a protein kinase C-dependent and by a protein kinase C-independent pathway. Furthermore, treatment of the cells with the protein phosphatase inhibitor, okadaic acid, inhibited binding to ICAM-1. Treatment with staurosporine before addition of okadaic acid not only induced enhanced binding of cells to ICAM-1, but also dramatically reduced the ability of okadaic acid to inhibit binding. These results suggest a critical role for a protein phosphatase in inducing the high avidity state of LFA-1 as well as a role for a protein kinase in inducing the low avidity state of LFA-1.
Activation requirements of newborn thymic gamma delta T cells.
Authors: Lynch F , Shevach E M 
Published: December 2022

Abstract
We have analyzed the requirements for the induction of proliferative responses by thymic CD4-CD8- gamma delta T cells. Enriched populations of CD4-CD8- thymocytes from newborn mice, purified by negative selection with anti-CD4, anti-CD8, and anti-TCR alpha beta mAbs were found to contain approximately 20% gamma delta T cells that were p55IL-2R-. When these cells were cultured with a panel of lymphokines (IL-1, -2, -4, and -7), a small response was observed to some of the cytokines tested individually; however, combinations of certain lymphokines (IL-1 + 2, IL-1 + 7, and IL-2 + 7) were found to induce significant proliferation and the selective outgrowth (75-90%) of gamma delta T cells. These cells were IL-2R+, remained CD4-, yet expressed variable levels of CD8. A limited analysis with specific anti-V gamma and V delta mAb suggested that there had not been a selective expansion of preexisting V gamma 2, V gamma 3, or V delta 4 populations in response to the stimulatory lymphokine combinations. Thymic CD4-CD8- gamma delta T cells were unresponsive to stimulation with immobilized anti-pan gamma delta mAb alone. However, in the presence of immobilized anti-pan gamma delta mAb and IL-1, IL-2, or IL-7, but not IL-4, a vigorous proliferative response was observed. Phenotypic analysis showed that 80 to 95% of the proliferating cells were polyclonally expanded gamma delta T cells, expressed the p55IL-2R, and the majority remained CD4-CD8-. Blocking studies with anti-IL-2R mAb showed that stimulation with anti-pan gamma delta + IL-1, but not anti-pan gamma delta + IL-7 was dependent on endogenously produced IL-2. Collectively, these studies suggest that the activation requirements of newborn thymic gamma delta T cells differ markedly from alpha beta T cells in that gamma delta T cells 1) respond to combinations of cytokines in the absence of TCR cross-linking, 2) can respond to TCR cross-linking in the presence of exogenous cytokines, 3) but are unable to activate endogenous cytokine production solely in the presence of TCR cross-linking.