bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the interaction of human eosinophils and neutrophils with opsonized particles.
Authors: Yazdanbakhsh M , Eckmann C M , Roos D 
Published: December 2022

Abstract
The interaction of human eosinophils with opsonized particles was compared with that of human neutrophils. When eosinophils are stimulated with serum-opsonized zymosan particles, the lag time in H2O2 production is twice as long as found with neutrophils. Moreover, the concentration of these IgG + C3-coated particles required for optimal stimulation is about four times as high for eosinophils as for neutrophils. Under these conditions, the two cell types generate similar amounts of H2O2. However, eosinophils produce twice as much H2O2 as do neutrophils when stimulated with the soluble agent phorbol myristate acetate. Thus, although the oxidase capacity of eosinophils is larger than that of neutrophils, opsonized zymosan is a weak trigger for this activity in eosinophils. This phenomenon may be due to differences between the two cell types in the plasma membrane receptors or in the receptor oxidase transducing signal. The following are indications for the first possibility. i) IgG interacts poorly with the Fc gamma receptors on the eosinophil surface compared with those on neutrophils. This was shown by the inability of IgG-coated zymosan or IgG-coated latex to trigger any substantial H2O2 production by eosinophils unless brought into close contact with these cells by centrifugation. In contrast, neutrophils are stimulated by these particles both in suspension and in a pellet. The dissimilarity of the Fc gamma receptors on eosinophils and neutrophils was also shown with respect to antigenicity, determined by the monoclonal antibodies 3G8 and CLB-FcR-1. ii) Eosinophils contain about half as many receptors for C3b and C3bi on their surface as do neutrophils, also detected with monoclonal antibodies. The interaction of IgG subclasses with functional Fc gamma receptors on eosinophils and neutrophils showed that eosinophils release twice as much H2O2 as do neutrophils upon interaction with IgG1-, IgG2-, or IgG3-coated Sepharose beads, but this difference becomes fivefold with IgG4-coated Sepharose. This might be of relevance to the situation of chronic antigenic stimulation, e.g., in chronic schistosomiasis, in which eosinophil numbers and IgG4 antibody levels are elevated.
Immunostimulation by cytomegalovirus (CMV): helper T cell-dependent activation of immunoglobulin production in vitro by lymphocytes from CMV-immune donors.
Authors: Yachie A , Tosato G , Straus S E , Blaese R M 
Published: December 2022

Abstract
Cytomegalovirus (CMV) is the cause of a number of different diseases ranging from self-limited benign infections in healthy adults to life threatening illnesses among immunocompromised hosts and newborns. Suppression of cell-mediated immunity is often found in cases of acute CMV infection, and in addition, the virus may also be a potent stimulant of lymphoid cells in vivo. We studied cellular proliferation and immunoglobulin (Ig) production induced by CMV to determine its effect on human lymphocytes in vitro. The CMV that was added to cultures of lymphocytes from CMV-seronegative donors failed to induce either significant cellular proliferation or Ig production. By contrast, CMV-stimulated cultures from CMV-seropositive donors induced both prominent cellular proliferation and Ig production. B cell differentiation into Ig-secreting cells required the presence of T cells, and this T cell help was sensitive to irradiation with 2000 rad and to treatment with cyclosporin A. When T cells were depleted of OKT4+ cells with monoclonal antibody and complement, the co-cultured B cells failed to produce Ig, whereas the depletion of OKT8+ cells had no effect on the Ig-secreting cell response. Inactivation of CMV before culture did not result in a reduction of either cellular proliferation or Ig production. Thus, infection of target cells is not required for in vitro lymphocyte activation by CMV. These results demonstrate that CMV is a potent activator of B cells inducing Ig production in vitro, and that this process requires the presence of virus-specific memory T cells.
A heat-modifiable outer membrane protein carries an antigen specific for the species Yersinia enterocolitica and Yersinia pseudotuberculosis.
Authors: Ogasawara M , Kobayashi S , Arai S , Laheji K , Hill J L , Kono D H , Yu D T 
Published: December 2022

Abstract
The outer membranes of gram-negative bacteria are considered to be of importance in host-bacteria interaction, in protective immunity, and occasionally in subclassification within a species. In this study, the outer membranes of several strains of Yersinia enterocolitica and Y. pseudotuberculosis were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). It was found that the appearance of the major proteins depended on the temperature at which they were solubilized in SDS. A protein was identified with the use of two-dimensional gels and preparative SDS-PAGE, which was equivalent to the "heat-modifiable protein" (protein II) of other Enterobacteriaceae species. A monoclonal antibody, 4G1, was generated against an isolated preparation of this Y. enterocolitica protein. This antibody was tested with whole cell bacterial antigens of 46 individual bacterial strains. The reactive strains included only Y. enterocolitica and Y. pseudotuberculosis. In addition, the reactivity of the 4G1 monoclonal antibody preparation could be absorbed only with Y. enterocolitica and Y. pseudotuberculosis, and not with other strains of bacteria. The reactivity of this 4G1 monoclonal antibody was also tested by the Western Blot technique. Six individual strains were tested: a Y. enterocolitica serotype 0:3, a Y. enterocolitica serotype 0:9, an Escherichia coli, a Salmonella typhimurium, a Shigella flexneri, and a Klebsiella pneumoniae. The 4G1 antibody reacted with only the proteins of the two Y. enterocolitica strains. In conclusion, the equivalent of the heat-modifiable protein was present in Y. enterocolitica and Y. pseudotuberculosis. Moreover, this protein also carried a species-specific antigenic determinant.
Polymorphic class II sequences linked to the rat major histocompatibility complex (RT1) homologous to human DR and DQ sequences.
Authors: Palmer M J , Buck D A , Frelinger J A , Wettstein P J 
Published: December 2022

Abstract
Until recently, the analysis of Class II genes linked to the rat major histocompatibility complex, RT1, has been confined to serologic and electrophoretic analysis of their gene products. To obtain a more definitive estimate of the number and relative polymorphism of RT1 Class II sequences, we performed Southern blot analysis of rat genomic DNA employing human cDNA probes specific for Class II heavy and light chain genes. Southern blots of EcoRI and BamHI digests of genomic DNA from ten inbred strains, expressing eight RT1 haplotypes, were hybridized with the human DQ beta or DR beta cDNA that are homologous to Class II light chain sequences. Four to eight bands were observed to hybridize with the light chain cDNA: band sizes ranged from 2.5 to 28 kb. Restriction fragment patterns were polymorphic; the only identical patterns observed were those associated with RT1 haplotypes with identical RT1.B regions. The number and size of bands hybridizing with DQ beta and DR beta suggested a minimum of four light chain sequences in each haplotype. Southern blots of BamHI and EcoRI digests of genomic DNA from the same strains were hybridized with a DR alpha cDNA that is homologous to Class II heavy chain sequences. All RT1 haplotypes expressed either a 10.0-kb or 13.0-kb band when digested with BamHI, and either a 17-kb or 3.7-kb band when digested with EcoRI. Considerably less polymorphism was detected with the DR alpha probe; this observation is consistent with previously reported limited protein polymorphism of the rat equivalent of the I-E alpha subunit. The size and number of bands hybridizing with the DR alpha probe suggests a minimum of two heavy chain sequences. These observations suggest that the RT1 complex includes more Class II sequences than have been observed in serologic and electrophoretic analyses of Class II gene products. Furthermore, the level of polymorphism of RT1 Class II sequences appears to be comparable with mouse and human Class II sequences.
Presence of an antigen-specific T cell subset that forms IgE-suppressive factor and IgG-suppressive factor on antigenic stimulation.
Authors: Jardieu P , Uede T , Ishizaka K 
Published: December 2022

Abstract
B6D2F1 mice were given three i.v. injections of ovalbumin (OA), and antigen-specific T cell clones were established from their spleen cells. One of the FcR+ T cell clones formed IgE-binding factors on incubation with OA-pulsed syngeneic macrophages. Neither soluble antigen nor macrophages alone induced factor formation. T cell hybridomas were constructed by fusion of the antigen-specific T cell clone with BW 5147 cells. Among 11 T cell hybridomas established, six clones produced IgE-binding factors on incubation with OA-pulsed BDF1 macrophages. Mouse IgE also induced the same hybridoma to form IgE-binding factors. The majority of IgE-binding factors formed by two T hybridomas and by those produced by the parent T cell clone had affinity for peanut agglutinin but for neither lentil lectin nor Con A. These hybridomas and the original T cell clone spontaneously released glycosylation-inhibiting factor, which inhibits the assembly of N-linked oligosaccharide(s) on IgE-binding factors. On antigenic stimulation, the T cell hybridomas produced both IgE-binding factors and IgG-binding factors. The IgE-binding factors consisted of three species with m.w. of 60,000, 30,000, and 15,000. Both the 60K and 15K IgE-binding factors selectively suppressed the IgE response of DNP-OA-primed rat mesenteric lymph node cells, whereas IgG-binding factors selectively suppressed the IgG response. The results indicate that antigen-primed FcR+ T cells produced IgE-suppressive factors and IgG-suppressive factors on antigenic stimulation. However, the T cell hybridomas were not committed to suppressive activity. When the hybridomas were stimulated by antigen in the presence of glycosylation-enhancing factor (GEF), the 60K, 30K, and 15K IgE-binding factors formed by the cells selectively potentiated the IgE response. IgG-binding factors formed by the cells in the presence of GEF failed to suppress the IgG response. It appears that antigen-specific FcR+ T cells regulate the antibody response through the formation of Ig-binding factors, but that the function of the cells could be switched from suppression to enhancement, depending on the environment of the cells.
B cell immune repertoire diversifies in a predictable temporal order in vitro.
Authors: Teale J M 
Published: December 2022

Abstract
The appearance of functional, antigen-specific B cells was studied in an in vitro fetal organ culture system in the absence of environmental influences associated with circulation and cell migration. In this way the B cell diversification process could be analyzed when genetic influences were dominating. By using this system in combination with the splenic focus assay, the frequency of developing B cells responsive to a number of hapten probes was measured. The results indicate that B cell diversification in vitro, in the apparent absence of many environmental influences, results in the appearance of antigen-responsive B cells in a predictable, temporal order. The results suggest that the acquisition of the expressed repertoire to a large extent is genetically controlled.
Mitogen-like monoclonal anti-actin antibodies.
Authors: Rosenblatt H M , Parikh N , McClure J E , Meza I , Hwo S Y , Bryan J , Shearer W T 
Published: December 2022

Abstract
Monoclonal antibodies (IgM kappa) have been produced to actin isolated electrophoretically from L cell extracts. These monoclonal anti-actin antibodies bind to intact L cells and modulate DNA synthesis and cell proliferation, much like affinity-purified polyclonal rabbit antibody to the same Mr 42,000 actin. In addition, monoclonal antibodies specific for actin from Entamoeba histolytica also bound to and modulated the growth of L cells. A monoclonal antibody directed against a neuroblastoma surface antigen did not produce stimulation of L cells, and the binding activity of anti-actin monoclonal antibody to L cells was removed by absorption with actin covalently coupled to Sepharose. These observations demonstrate the specificity of interaction between the anti-actin monoclonal antibodies and the surface of intact L cells. We conclude that a surface actin-like molecule on the L cell, when bound by specific monoclonal antibody, initiates a stimulatory signal which results in enhanced cellular metabolism.
GVHR elicited by products of class I or class II loci of the MHC: analysis of the response of mouse T lymphocytes to products of class I and class II loci of the MHC in correlation with GVHR-induced mortality, medullary aplasia, and enteropathy.
Authors: Piguet P F 
Published: December 2022

Abstract
A lethal graft-vs-host reaction (GVHR) was elicited by the injection into irradiated (700 rad) mice, reconstituted with T-depleted bone marrow cells (BM), of T lymphocytes incompatible for different loci of the major histocompatibility complex (MHC). The number of T cells needed to kill more than 50% of the recipients by day 40 was about 10(6) for GVHR elicited across the product of the K, D, or E locus, but about 10(5)--10--fold less-when the A locus was involved. The mortality was associated with a medullary aplasia in all strain combinations, but enteropathy was observed only in GVHR elicited by the products of class II, and not class I, loci. Mortality and medullary aplasia were diminished or absent in recipients reconstituted with BM cells from T cell donors instead of cells of the host genotype, which suggests a direct (cytolytic) T-hematopoietic cell interaction. Lymphoproliferation was evident within the host spleen and lymph node 5 days after injection of T lymphocytes incompatible for class II but not class I loci. Spleens from mice suffering from a lethal GVHR were examined by culture in limiting dilution to evaluate the frequency of anti-host T cells and to derive anti-host T cell clones and lines, whose properties were explored. In the GVHR elicited across the A or E region of the MHC, examined between days 7 and 19, a high frequency (10(-2] of anti-host cells was observed. The polyclonal cell lines isolated (16) all displayed MLR responsiveness, antigen-driven IL 2 production, and cytolysis for LPS blasts of the host genotype. However, among 13 clones isolated, two categories were observed: Lyt-2-, which were MLR responders and IL 2 producers (four of 13), and Lyt-2+, which were cytolytic but neither MLR responders nor IL 2 producers (nine of 13). In the GVHR elicited by the K or D region, examined between days 7 and 90, the frequency of anti-host cells was low (10(3) to 10(4], with a tendency to decrease during the progression of the disease. The lines (11) or clones (26) isolated from different mice were all Lyt-2+ and strongly cytolytic but proliferated poorly and produced no IL 2 in MLR. These findings suggest that the Lyt-2+ lymphocytes, recognizing the products of the class I loci, function in vivo without proliferation and without requiring helper T cells. Cell lines specific for class I or class II loci of the MHC produced interferon and colony-stimulating factors.
Molecular associations of class II MHC antigens in mitogen-stimulated B cells.
Authors: Wolfert R L , Goodman M G , Weigle W O 
Published: December 2022

Abstract
Previously, we showed that murine B cell membrane proteins undergo rearrangements in the plasma membrane to form new molecular associations in response to mitogenic stimulation. These complexes were covalently stabilized by photoreactive cross-linking agents and were analyzed by SDS PAGE. We have now identified certain complexes that involve class II MHC products, the Ia antigens. Upon stimulation of B cells with LPS, Ia surface molecules (as identified by radioimmunoprecipitation with polyclonal anti-Ia antiserum) enter into a molecular complex with a 95-kd membrane-associated protein (p95) to form a 200-kd complex that may be stabilized by the cross-linking agent dithiobisphenylazide (DTPA). This molecular association is not observed upon stimulation with mitogenic anti-Ig reagents, nor with the polyclonal B cell activator 8-bromoguanosine. p95 is not a disulfide-linked molecule itself, and by separate immunoprecipitation experiments we have established that it is not a component of surface Ig, transferrin receptor, the B cell Fc receptor, or CR1, the receptor for complement component C3b. Further analysis of the association of Ia antigens with surface proteins, with the use of monoclonal antibodies directed against I-A or I-E, has demonstrated that each subregion gene product forms a unique molecular association. Precipitation of radiolabeled lysates from LPS-activated B cells with anti-I-A reveals the aforementioned association with p95. In contrast, the I-E antigen apparently forms complexes with a multimer of a 15-kd protein to give complexes of 45, 60, 75, and 90 kd. When analyzed by two-dimensional diagonal gels (nonreducing/reducing), only the I-E bands are revealed by autoradiography, indicating that the putative p15 that associates with I-E may not be accessible to surface labeling. The disparate molecular associations for I-A and I-E suggest that the formation of these distinct protein complexes may be functionally related to a different role in the process of cellular activation for each of these Ia subregion gene products.
Molecular events in B cell activation. I. Signals required to stimulate G0 to G1 transition of resting B lymphocytes.
Authors: Monroe J G , Kass M J 
Published: December 2022

Abstract
Anti-immunoglobulin antibodies (anti-Ig) can stimulate a majority of resting B cells via their receptor Ig. Evidence suggests that the signals generated after this ligand-receptor interaction may be transduced via hydrolysis of inositol phospholipids. In other systems, the ability of inositol phospholipid hydrolysis to link receptor-ligand interactions to subsequent activational events has been suggested to relate to the ability of metabolic intermediates of this hydrolytic process to facilitate activation of protein kinase C and mobilization of Ca+2. In this study, we investigated the importance of protein kinase C and Ca+2 mobilization in the signaling mechanism by which anti-Ig drives B cells to undergo G0 to G1 transition. Our results show that pharmacologic inhibition of either protein kinase C activity or channel-mediated Ca+2 influx completely abrogates the increase in RNA synthesis associated with B cell activation after stimulation by anti-Ig. This suggests that pathways leading to both protein kinase C activation and elevation of intracellular Ca+2 are critical for receptor Ig-mediated G0 to G1 transition. Furthermore, studies in which anti-Ig-induced signaling could be bypassed by directly facilitating Ca+2 mobilization and protein kinase C activation using Ca+2 ionophore and phorbol diester show that these events are sufficient to drive the majority of resting B cells into G1 in the absence of additional signaling from accessory cells or extra-cellular factors. However, like anti-Ig-induced stimulation, Ca+2 ionophore and phorbol diester are relatively inefficient in driving B cells that have entered G1 into S phase. We discuss the relevance of these results towards the transduction mechanism linking B cell membrane-associated Ig-generated signals with subsequent activation events.
Characterization of circulating and cutaneous IgA immune complexes in patients with dermatitis herpetiformis.
Authors: Hall R P , Lawley T J 
Published: December 2022

Abstract
Dermatitis herpetiformis (DH) is a chronic, blistering skin disease characterized in part by deposits of IgA at the dermal-epidermal junction. Eighty-five percent of DH patients have granular IgA deposits and have an associated gluten-sensitive enteropathy (GSE). In contrast, 15% of DH patients have a linear pattern of IgA deposits and no associated intestinal abnormality. Although circulating IgA antibodies against skin are not present in these patients, 40% of DH patients do have IgA-containing circulating immune complexes (IgA-CIC). The role and origin of the cutaneous IgA and the IgA-CIC in patients with DH are unknown; however, the association of GSE with the granular IgA deposits suggests that a mucosal immune response may be important in the pathogenesis of DH. We have characterized the IgA subclass composition of the cutaneous IgA deposits in patients with DH, and have isolated and characterized the IgA-CIC from these patients. Twenty-nine of 29 patients with DH and granular IgA deposits were found to have only IgA1 deposits. Ten of 11 patients with linear IgA deposits also had only IgA1 deposits; one of 11 had IgA2 deposits. Isolated IgA-CIC from the sera of eight patients with DH and granular IgA deposits were found to contain both IgA1 (58% +/- 5, mean percent of total IgA +/- SEM) and IgA2 (42% +/- 5), as were IgA-CIC from two patients with ordinary GSE without cutaneous IgA deposits. The IgA subclass composition of the isolated immune complexes was significantly different from the serum IgA1 and IgA2 composition (serum IgA1 = 76% +/- 6; IgA2 = 24% +/- 5, p less than 0.025, Student's t-test), and suggests that the IgA-CIC may arise from gut-associated lymphoid tissue (GALT). Sequential anti-IgA1 absorption of serum which contained IgA-CIC did not remove all the IgA-CIC, suggesting that the complexes circulate as separate IgA1 and IgA2 complexes. The finding of IgA1 alone in the skin of patients with DH suggests that the cutaneous IgA may not arise from GALT, or that IgA1, possibly arising in GALT, is preferentially bound to DH skin. Because IgA-containing CIC which contain both IgA1 and IgA2 were found in the serum of patients with DH and with ordinary GSE, it seems unlikely that IgA-containing CIC are responsible for the cutaneous IgA deposits seen in DH.