bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced C8 beta messenger RNA expression in families with hereditary C8 beta deficiency.
Authors: Warnick P R , Densen P 
Published: December 2022

Abstract
Individuals with functional C8 beta deficiency are at increased risk for systemic neisserial infections. Studies by others have shown that the structural gene for this protein appears intact in deficient individuals. We studied affected individuals from 10 unrelated families to determine the basis for their defect. Using chain-specific antisera, C8 beta was undetectable on immunoblots of their sera. The polymerase chain reaction was used to probe cDNA synthesized from RNA isolated from human liver cells, HepG2 cells, peripheral blood monocytes, and fibroblasts to identify a readily available cell source expressing C8 beta message. Cells from each of these sources expressed C8 beta message. The identity of the amplified product was confirmed and this approach was used to probe cDNA synthesized from RNA harvested from monocytes or fibroblasts obtained from two unrelated families with C8 beta deficiency. C8 beta mRNA was readily detectable in C8 beta sufficient and heterozygous family members but required Southern blotting and hybridization to the 32P-labeled C8 beta probe for detection in the homozygous deficient probands. These results suggest that C8 beta-deficient individuals produce less C8 beta-specific mRNA than do normals and that the underlying basis for this deficiency is an abnormality in intracellular events that precede secretion.
Induction of tolerance to syngeneic IgE in neonatal mice.
Authors: Haba S , Nisonoff A 
Published: December 2022

Abstract
We have previously shown that adult A/J mice are tolerant to syngeneic IgE at the level of T cells, but not B cells. T cells of mice are responsive until the age of 2 to 3 wk, which correlates with the time of appearance of serum IgE. Tolerance can be induced earlier by neonatal administration of IgE in saline. We report here that purified nonimmune adult B cells, but not T cells, can transfer the state of tolerance to neonatal mice. As few as 2 x 10(6) B cells are effective. If IgE-bearing or IgE-secreting cells prove to be responsible, the amount of cell-bound IgE that can induce tolerance must be very small. The results also indicate that suppressor T cells do not have a major role in maintenance of self-tolerance to IgE.
Expression of CR2 (the C3dg/EBV receptor, CD21) on normal human peripheral blood T lymphocytes.
Authors: Fischer E , Delibrias C , Kazatchkine M D 
Published: December 2022

Abstract
The expression of CR2 (the C3dg/EBV receptor, CD21) on normal human T lymphocytes was investigated using purified peripheral blood T cells and indirect immunofluorescence with biotinylated anti-CR2 mAb and streptavidin-phycoerythrin. Thirty to 40% of normal peripheral blood T lymphocytes expressed CR2 Ag. The cells expressed three nonoverlapping epitopes of CR2. The specificity of the staining for CR2 epitopes was demonstrated by the ability of unlabeled anti-CR2 mAb but not of anti-CR1 mAb of the same isotype to compete for the binding of biotinylated anti-CR2 mAb to T cells. The intensity of staining of T lymphocytes with anti-CR2 mAb was approximately 10-fold lower than that of peripheral blood B cells. CR2 was immunoprecipitated from purified T lymphocytes as a single protein of apparent Mr 145,000. The presence of CR2 on normal human T lymphocytes suggests that the receptor may modulate the function of T cells in the immune response and the susceptibility of the cells to infection by lymphocytotropic viruses.
Mapping the epitopes of neutralizing anti-human IL-3 monoclonal antibodies. Implications for structure-activity relationship.
Authors: Lokker N A , Strittmatter U , Steiner C , Fagg B , Graff P , Kocher H P , Zenke G 
Published: December 2022

Abstract
The epitopes of neutralizing mAb were mapped in order to identify a receptor binding site on human IL-3 (huIL-3). To initiate this structure and activity analysis, four neutralizing mAb were selected on the basis of preventing rhuIL-3 stimulated proliferation of peripheral blood cells from a patient with chronic myelogenous leukemia (CML). In order to identify continuous epitopes, the neutralizing mAb were assayed in a solid-phase ELISA for their reactivity with either denatured rhuIL-3 or with the peptides generated by digestion of rhuIL-3 by using two different proteinases. Two of the neutralizing mAb recognized single fragments from both digestions. Amino acid (aa) sequence determination showed that these peptides overlap, defining a region of 22 aa (aa 29 to 50 of the mature rhuIL-3 protein). In a competition ELISA, the two continuous epitopes were shown to be linked to one another and to the two discontinuous epitopes, suggesting that all four neutralizing mAb bind to a discrete region of the IL-3 molecule, which might be involved in binding to the IL-3R.
Absence of preferential homologous H/L chain association in hybrid hybridomas.
Authors: De Lau W B , Heije K , Neefjes J J , Oosterwegel M , Rozemuller E , Bast B J 
Published: December 2022

Abstract
Bispecific mAb contain two Ag-combining sites each composed of a different combination of H and L chains. The resulting ability to react with and cross-link two different Ag makes these molecules a novel tool for application in biology and medicine. Intact bispecific mAb can be made only by biologic means, e.g., by fusion of two established hybridomas. Appropriate assembly of bispecific mAb by these hybrid cells depends on H = L chain behavior: strong preferential homologous H-L pairing would benefit the yield of bispecific antibodies. We have analyzed the Ig species produced by eight hybrid hybridomas (quadromas). Quadroma-produced IgG was fractionated and characterized for H and L chain content. The Ag reactivities were verified by using ELISA and immunofluorescence. Preferential homologous pairing was seen only with a minority of H-L chain pairs; L chains associated on average in a random fashion with H chains. This indicates that in the B cells from which the parental hybridomas were obtained, no strong selection had occurred on H-L recombination. Our results extend recent biochemical competitive H-L reassociation experiments, where on average an at random association of L chains with H chains was found; evidently this random association occurs in our biologic system as well. For the biologic production of bispecific antibodies this means that only in a small number of cases the "ideal" producer will be met. From the viewpoint of generation of antibody diversity, our results favor a large freedom for combinatorial binding of H and L chains during B cell ontogeny.
Differential requirements for cellular cytoskeleton in human macrophage complement receptor- and Fc receptor-mediated phagocytosis.
Authors: Newman S L , Mikus L K , Tucci M A 
Published: December 2022

Abstract
We investigated the requirement for cellular cytoskeleton in CR- and FcR-mediated phagocytosis by human monocyte-derived macrophages (M phi). Inhibition of actin microfilament (MF) assembly and stability by cytochalasins B and D completely inhibited M phi phagocytosis of sheep E coated with C3b (EC3b), iC3b (EC3bi), and IgG (EIgG) via CR1, CR3, and FcR, respectively. Ligand-binding to either CR or FcR was not effected by cytochalasins. Nocodazole (NOC), which prevents microtubule (MT) polymerization, and taxol, which causes random polymerization of MT inhibited M phi phagocytosis of EC3b(i) but not EIgG. However, the combination of taxol (5 x 10(-4) M) and NOC (2 x 10(-6) M) augmented M phi CR-mediated phagocytosis. In addition, agents known to increase intracellular cGMP augmented phagocytosis of EC3b(i). Conversely, agents that increase intracellular cAMP inhibited CR-mediated phagocytosis. These agents had no effect on FcR-mediated phagocytosis, and did not effect ligand-binding to CR or FcR. PMA markedly enhanced CR- but not FcR-mediated phagocytosis, and augmentation of CR-mediated phagocytosis by PMA was inhibited by both CD and NOC. In contrast, the synthetic diacylglycerol, 1-oleoyl-2-acetoyl-sn-3-glycerol augmented, and inhibitors of protein kinase C inhibited M phi phagocytosis via CR and FcR. These data indicate that for adherently cultured human M phi: 1) binding of ligand-coated E to CR or FcR does not require an intact cytoskeleton; 2) intact actin microfilament are required for phagocytosis via CR and FcR; 3) phagocytosis via CR1 and CR3 but not FcR is dependent on MT assembly; 4) PMA most likely augments CR-mediated phagocytosis through promotion of MT assembly; and 5) PKC activity is involved in the phagocytic signal generated by both CR and FcR.
Connective tissue mast cells in contact with fibroblasts express IL-3 mRNA. Analysis of single cells by polymerase chain reaction.
Authors: Razin E , Leslie K B , Schrader J W 
Published: December 2022

Abstract
Mast cell-fibroblast interactions have been extensively investigated in the last few years. Fibroblasts support the in vitro survival but not proliferation of mouse connective-tissue type mast cells. However, the factor(s) that allow their survival on fibroblast monolayers has not been identified. We have investigated the presence of mRNA for IL-3 and granulocyte-macrophage-CSF in single mouse mast cells, before and after co-culture with 3T3 fibroblasts, using the polymerase chain reaction technique. The system was calibrated first by using in vitro generated population of mouse bone-marrow derived mast cells (BMMC). Significant differences in the amplification of IL-3 cDNA were observed in each of the BMMC cells examined, whereas the amplification of cDNA for the alpha-subunit of the Fc epsilon RI were similar. Inasmuch as murine cultured IL-3-dependent mast cells differentiate into connective tissue-like mast cells when co-cultured with 3T3 fibroblasts without any exogenous supply of growth factors, it was of interest to determine whether these connective tissue-like mast cells produce IL-3 message. Separation of the differentiated BMMC from the fibroblast monolayer, by either trypsinization or by single cell manipulation revealed the synthesis of a detectable amount of IL-3 mRNA in these mast cells. Whether this IL-3 mRNA was induced by fibroblasts was further investigated using connective tissue mast cells freshly purified from the mouse peritoneal cavity. Only about 20% of these connective tissue mast cells produced detectable amount of granulocyte-macrophage-CSF mRNA whereas in less than 10% of the cells IL-3 mRNA was detected. However, when these connective tissue mast cells were co-cultured with 3T3 fibroblasts for 18 hours and then separated, IL-3 mRNA were detected in most of the cells whereas no such mRNA was detected in tissue mast cells incubated for 18 h with medium derived from 3T3 fibroblasts. Therefore we conclude that fibroblasts induce the accumulation of IL-3 mRNA in connective tissue mast cells. The production of IL-3 may play a role in the survival of this type of mast cells on the fibroblast monolayer.
The fate of CD4-8- T cell receptor-alpha beta+ thymocytes.
Authors: Levitsky H I , Golumbek P T , Pardoll D M 
Published: December 2022

Abstract
CD4-8- TCR-alpha beta+ thymocytes represent a distinct population whose fate and function have remained a mystery. We show here that this thymocyte subset bears NK1, a surface Ag previously thought to be expressed exclusively by TCR- NK cells. Analysis of peripheral lymphocytes for the coexpression of TCR-alpha beta and NK1 revealed a subset with similar characteristics to the NK1+ thymocytes: a large fraction that are CD4-8- and a skewed TCR repertoire in which V beta 8 is overrepresented. Thymus transplant experiments into congenically marked athymic (nude) mice revealed that the NK1+TCR alpha beta+ subset was exclusively thymus derived and represented a distinct subset from the thymus-independent NK1+TCR- population. Finally, the NK1+TCR alpha beta+ population preferentially localizes to the bone marrow. These results demonstrate that this T cell subset is exported to the periphery after developing in the thymus. Their unique surface Ag expression and tissue localization suggest an immune function distinct from classical T cells.
IL-2 secretion and T cell clonal anergy are induced by distinct biochemical pathways.
Authors: Norton S D , Hovinen D E , Jenkins M K 
Published: December 2022

Abstract
In Th1 clones, TCR occupancy together with a costimulatory signal from APC results in IL-2 production. TCR occupancy alone results in unresponsiveness (anergy) to antigenic stimulation, a phenomenon that may be important for self-tolerance in vivo. Inasmuch as inositol phosphate production occurs during the induction of anergy other biochemical signals must be necessary for IL-2 production. Here we assess the role of tyrosine-specific protein kinases using the specific inhibitor, genistein. IL-2 secretion and responsiveness were very dependent on tyrosine-specific protein kinase activation and could be completely blocked under conditions where inositol phosphate generation occurred normally. Although anergy induction could also be blocked by inhibition of tyrosine-specific protein kinase activation this probably occurred indirectly via inhibition of inositol phospholipid hydrolysis. The differential susceptibility of IL-2 secretion and anergy induction to inhibition by genistein indicates that positive and negative outcomes of TCR occupancy may be mediated by distinct biochemical pathways.
Alloreactive lymphocytes from T cell receptor (beta-chain) transgenic mice do not mediate a graft-versus-host reaction.
Authors: Rimm I J , Ghayur T , Gasser D L , Rosenkrantz K , Burakoff S J , Seidman J G , Ferrara J L 
Published: December 2022

Abstract
The injection of mature T cells into a tolerant or immunocompromised allogeneic host animal produces a graft versus host response (GVHR) that can result in splenomegaly, immunosuppression and death of the host animal. We demonstrate here that lymphocytes from T cell receptor beta-chain (TCR-beta) transgenic mice, in which the expression of the transgene inhibits endogenous beta- and gamma-gene rearrangements and thus causes abnormal T cell development, are unable to mediate a GVHR. The GVHR was measured after the injection of lymphocytes from transgenic mice into normal F1 mice and also after transplantation of bone marrow and lymphocytes from transgenic mice into lethally irradiated F1 recipients. In both systems, cells from transgenic mice failed to produce a significant GVHR. Cells from the transgenic mice were able to recognize the foreign histocompatibility Ag of the host in vitro and in vivo although the transgenic mice rejected skin grafts more slowly than controls. Thus, lymphocytes from transgenic mice were unable to produce a GVHR despite the presence of alloreactive T cells. These results suggest that lymphocytes from TCR-beta transgenic mice fail to mediate a GVHR either because lymphocytes with a single transgenic TCR-beta chain have a limited ability to recognize allogeneic cells in vivo or because the transgenic mice lack lymphocyte subsets that are important for the mediation of a GVHR.
Analysis of the binding of C-reactive protein to chromatin subunits.
Authors: Du Clos T W , Marnell L , Zlock L R , Burlingame R W 
Published: December 2022

Abstract
C-reactive protein (CRP) is an acute phase serum protein in man. The functional activities of CRP, like Ig, include complement activation and enhancement of phagocytosis. CRP binding to several substrates, including phosphocholine, individual denatured histones, and chromatin, has been demonstrated. We previously demonstrated that CRP binding to chromatin is dependent on the presence of histone H1, despite the fact that CRP binds to purified individual histones H2A and H2B, as well as to H1. In this report we examined the binding of CRP to native sub-nucleosomal chromatin fragments. CRP binding to the H2A-H2B dimer and (H3-H4)2 tetramer was demonstrated and these reactions were inhibited by phosphocholine. However, no binding to the subnucleosome complexes (H2A-H2B)-DNA and (H3-H4)2-DNA was seen. Similarly, CRP binding to H1 was eliminated when H1 was reconstituted with DNA. The reconstitution of H1-depleted chromatin with H1 restored CRP binding. CRP binding to nucleosome core particles, as previously demonstrated by others, was confirmed. Therefore, the interaction of CRP with individual core histones does not appear to be responsible for the binding of CRP to native chromatin. However, binding to core particles could be mediated by differentially exposed determinants on H2A and H2B.
Two major serum components antigenically related to complement factor H are different glycosylation forms of a single protein with no factor H-like complement regulatory functions.
Authors: Timmann C , Leippe M , Horstmann R D 
Published: December 2022

Abstract
Factor H is a 150-kDa serum glycoprotein with key regulatory functions in the alternative pathway of complement activation. Two glycoproteins with a molecular mass of approximately 42 and 37 kDa that react with an antiserum against factor H were purified from human plasma. The two glycoproteins have identical N-terminal amino acid sequences but differ in glycosylation. Sequence comparisons indicated that they both correspond to a 1.4-kb mRNA recently cloned from human liver cDNA. The serum concentration of the two glycoproteins together was estimated to be approximately 40 mg/liter. They were found not to exert factor H-like regulatory functions in the alternative pathway. Thus, the 42-kDa glycoprotein described here appears to be distinct from the previously characterized factor H-related protein of similar size, suggesting that human serum contains two factor-H related molecules which both have a molecular mass of 41 to 43 kDa but which differ largely in structure.
Neutrophil responses to lipopolysaccharide. Effect of adherence on triggering and priming of the respiratory burst.
Authors: Aida Y , Pabst M J 
Published: December 2022

Abstract
We studied neutrophil responses to LPS using three methodologic refinements: Teflon bags or serum-coated glass tubes that did not directly trigger neutrophils, LPS-free cytochrome c to measure O2- release, and heat-inactivated serum to inhibit inactivation of LPS by neutrophils. Neutrophils incubated in uncoated glass or plastic tubes adhered to the glass and released O2-, but were not primed for enhanced release of O2- in response to triggering by FMLP. Triggering by the glass or plastic surface did not occur if the neutrophils were stirred to prevent adherence. Adherence to glass or plastic and O2- release were not affected by a mAb (IB4) directed against the beta-chain of the leukocyte adhesion family of surface glycoproteins (CD11/CD18). Neutrophils incubated in glass or plastic did not show enhanced expression of alkaline phosphatase on their surface. When neutrophils were incubated in serum-coated glass tubes or in Teflon bags, there was no O2- release. However, adherence, expression of alkaline phosphatase, and release of O2- were triggered by adding 1 ng/ml LPS plus 1% serum, but not by either LPS or serum alone. In the presence of LPS and serum, O2- release was much higher when the cells were unstirred (adherent) rather than stirred. However, both unstirred and stirred cells expressed a similar elevated level of alkaline phosphatase. LPS-triggered O2- release and adherence were inhibited by antibody IB4. In contrast, priming by LPS for enhanced FMLP-triggered O2- release was greater in stirred cells than in unstirred cells. The antibody enhanced priming of unstirred neutrophils. These results suggested that uncoated glass or plastic triggered O2- release without involvement of leukocyte adhesion glycoproteins. However, neutrophils incubated with LPS and serum expressed alkaline phosphatase and IB4-inhibitable adherence glycoproteins that allowed neutrophils to interact with serum-coated glass or Teflon to trigger O2- release. Priming by LPS for enhanced response to FMLP was suppressed in adherent neutrophils, and this suppression was partly released by IB4. Thus, triggering and priming were reciprocally regulated by neutrophil glycoproteins interacting with surfaces.
Tumor necrosis factor-alpha priming of phospholipase A2 activation in human neutrophils. An alternative mechanism of priming.
Authors: Bauldry S A , McCall C E , Cousart S L , Bass D A 
Published: December 2022

Abstract
The cytokine, TNF-alpha, interacts with human neutrophils (PMN) via specific membrane receptors and primes leukotriene B4 (LTB4) production in PMN for subsequent stimulation by calcium ionophores. We have further examined the effects of TNF-alpha on arachidonic acid (AA) release, LTB4 production, and platelet-activating factor (PAF) formation in PMN by prelabeling cells with either [3H]AA or [3H]lyso-PAF, priming with human rTNF-alpha, and then stimulating with the chemotactic peptide, FMLP. TNF-alpha, alone, had little effect; minimal AA release, LTB4 or PAF production occurred after PMN were incubated with 0 to 1000 U/ml TNF-alpha. However, when PMN were first preincubated with 100 U/ml TNF-alpha for 30 min and subsequently challenged with 1 microM FMLP, both [3H] AA release and LTB4 production were elevated two- to threefold over control values. Measurement of AA mass by gas chromatography and LTB4 production by RIA confirmed the radiolabeled results. TNF-alpha priming also increased PAF formation after FMLP stimulation. These results demonstrate that TNF-alpha priming before stimulation with a physiologic agonist can enhance activation of phospholipase A2 (PLA2) resulting in increased AA release and can facilitate the activities of 5-lipoxygenase (LTB4 production) and acetyltransferase (PAF formation). Reports in the literature have hypothesized that the priming mechanism involves either production of PLA2 metabolites, increased diglyceride (DG) levels, or enhanced cytosolic calcium levels induced by the priming agent. We investigated these possibilities in TNF-alpha priming of PMN and report that TNF-alpha had no direct effect on PLA2 activation or metabolite formation. Treatment of PMN with TNF-alpha did not induce DG formation and, in the absence of cytochalasin B, no increased DG production (measured by both radiolabel techniques and mass determinations) occurred after TNF-alpha priming followed by FMLP stimulation. TNF-alpha also had no effect on basal cytosolic calcium and did not enhance intracellular calcium levels after FMLP stimulation. These results suggest that an alternative, as yet undefined, mechanism is active in TNF-alpha priming of human PMN.