bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frequency of human B cells that differentiate in response to anti-CD3-activated T cells.
Authors: Amoroso K , Lipsky P E 
Published: January 2023

Abstract
Activation of T cells by mAb to the CD3 molecular complex induces the differentiation of many more Ig-secreting cells (ISC) from resting human B cells in bulk cultures than do other modes of polyclonal B cell activation. In the current experiments, a limiting dilution assay was used to demonstrate that this increase in ISC generation reflects an increased frequency of responding B cells. Highly purified B cells were cultured at densities of between 1000 cells and 0.5 cell per microwell with fresh, mitomycin C-treated T cells (T mito) or T cell clones stimulated by immobilized mAb to CD3. After 5 days in culture, the number of wells containing ISC was determined, and the frequency of responding B cells was calculated. The proportion of B cells responding to anti-CD3-stimulated T cells was very large (10.7 +/- 2.8%) and greatly surpassed that induced by other polyclonal activators. B cells cultured with anti-CD3-stimulated T cell clones responded better than did those cultured with T mito. The addition of exogenous IL-2 or IL-6 to cultures supported by activated T mito enhanced the frequency of responding B cells, whereas IL-4 did not increase the generation of ISC and inhibited the augmentation of B cell responses induced by IL-2. Supplementation of cultures with mitomycin C-treated B cells as accessory cells had less of an effect. The addition of both accessory cells and IL-2 markedly increased B cell responsiveness, with precursor frequencies of 60 to 80% noted. In some experiments, cultures were carried out for 7 to 14 days and supernatants were analyzed for IgM, IgG, and IgA secretion. B cells activated by anti-CD3-stimulated T cells produced all three Ig isotypes. When the classes of Ig produced by single B cells were examined, it was observed that the stimulation of individual B cell precursors led to the production of multiple Ig isotypes, suggesting that isotype switching occurs in these cultures. These results demonstrate that under optimum culture conditions, T cells stimulated with immobilized anti-CD3 can activate the majority of human peripheral blood B cells to produce Ig and induce isotype switching by many.
Cholera toxin acts synergistically with IL-4 to promote IgG1 switch differentiation.
Authors: Lycke N , Severinson E , Strober W 
Published: January 2023

Abstract
Previously, we reported that cholera toxin (CT) causes LPS-stimulated membrane (m)IgM+ B cells to undergo increased switch differentiation to IgG- and IgA-producing B cells. In this study we determined whether this effect is specific for one or several of the IgG subclasses and whether B cells exposed to CT respond differently to IL-4, a lymphokine with switching capabilities. In initial studies we found that in LPS-stimulated, mIgM+ B cell cultures, CT eightfold enhanced the formation of IgG1-producing B cells, whereas it only weakly enhanced, one- to twofold, the formation of IgG3-producing B cells. In addition, CT synergistically enhanced the induction of IgG1-producing B cells by IL-4, even at plateau concentrations of IL-4. In contrast, IgM and IgG3 responses were suppressed in the CT plus IL-4-containing cultures as compared to those containing only LPS or LPS and CT. Furthermore, CT plus IL-4 had no enhancing effect on the formation of cells producing IgA; on the contrary, the presence of IL-4 led to a reversal of the stimulatory effect of CT on the IgA response. In further studies, we found that CT affected B cell differentiation at the gene level, before final gene recombination has occurred. Thus, CT together with LPS induced faint but detectable germline gamma 1 RNA transcripts not seen with cells cultured in LPS alone. However, more strikingly, CT enhanced by several-fold expression of germline gamma 1 RNA transcripts in LPS-stimulated B cell cultures containing optimal IgG1-inducing concentrations of IL-4. In addition, despite its weakly positive effect on IgG3 production. CT inhibited expression of germline gamma 3 RNA transcripts in cultures containing LPS and caused a further decrease in such transcripts in cultures containing LPS and IL-4. Finally, we found that CT enhanced the in vivo IgG1 but not the IgG3 or IgM anti-DNP serum antibody response of mice immunized with DNP-LPS. Taken together, these studies suggest that CT more strongly promotes B cell differentiation to IgG1 than to any other IgG subclass in LPS-stimulated cultures. CT acts alone or in synergy with IL-4, early in B cell differentiation to promote IgG1 expression in LPS-stimulated B cell cultures, probably by inducing early steps in the switch to this isotype such as the production of germline gamma 1 RNA transcripts.
Bacterial killing and inhibition of inner membrane activity by C5b-9 complexes as a function of the sequential addition of C9 to C5b-8 sites.
Authors: MacKay S L , Dankert J R 
Published: January 2023

Abstract
The assembly of the C5b-9 complex on the outer membrane of C-sensitive cells of Escherichia coli results in a rapid inhibition of inner membrane function and ultimately a loss of cell viability. Cells bearing C5b-8 sites suffer no deleterious effects; however, the addition of C9 results in a rapid inhibition of inner membrane function and cell death. An attempt was made to examine the relationship between the toxic effects of the C5b-9 complex and the number of C9 molecules per C5b-8 site. Cells bearing C5b-8 sites were exposed to excess C9 at 0 degrees C and washed three times at 4 degrees C. The number of C9 molecules bound to each cell was equivalent to the number of C5b-8 sites present on each cell, and no additional C9 molecules could be bound when the cells were maintained at 4 degrees C. These cells were then incubated at 37 degrees C for 3 min and returned to 0 degrees C, a technique which exposed additional C9-binding sites equivalent to the number of C9 molecules previously bound to the cells. This technique was repeated and demonstrated that the sequential build-up of a C5b-9 site with two C9 molecules per C5b-8 site was capable of inhibiting both inner membrane function (respiration and amino acid transport) and cell viability. Three C9 molecules per complex had effects that approached the inhibitory effects of complexes formed in the presence of excess C9.
Protein D of Haemophilus influenzae. A novel bacterial surface protein with affinity for human IgD.
Authors: Ruan M R , Akkoyunlu M , Grubb A , Forsgren A 
Published: January 2023

Abstract
Protein D, a novel surface protein of the bacterial species Haemophilus influenzae with affinity for human IgD, was isolated after solubilization with sonication and Sarcosyl-extraction by a single SDS-PAGE step. From 1 ml of packed bacteria was prepared 0.25 mg of purified protein D. The apparent m.w. of protein D was estimated to 42,000 by SDS-PAGE and gel chromatography. Edman degradation cycles of protein D produced no amino acid phenylthiohydantoin derivatives and the amino-terminal end of the single protein D polypeptide chain is thus probably blocked. Protein D differs from all previously described outer membrane proteins (protein 1 to 6) of H. influenzae. Thus, protein D did not react with antibodies against protein 1 or protein 2 and the latter proteins did not bind IgD. Protein D was found to exhibit unique Ig-binding properties. Thus, in dot blots protein D bound four different human IgD myeloma proteins but not IgG, IgM, IgA, IgE, or some additional proteins. On the IgD molecule, constant parts of the H chains both in the Fab and Fc fragments appear responsible for the interaction with protein D. This novel Ig-binding reagent promises to be of theoretical and practical interest in immunologic and microbiologic research.
Analysis of beta 2-microglobulin gene expression in the developing mouse embryo and placenta.
Authors: Jaffe L , Jeannotte L , Bikoff E K , Robertson E J 
Published: January 2023

Abstract
The major transplantation (MHC) Ag in the mouse are cell-surface glycoproteins composed of a 40- to 45-kDa H chain and a 12-kDa L chain, beta 2-microglobulin (beta 2 m). Regulation of MHC gene expression during early development is thought to play a critical role in maternal tolerance of the fetal allograft. We have used in situ hybridization techniques to characterize the temporal and spatial pattern of expression of the beta 2 m gene in the developing mouse embryo. beta 2 m mRNA is first detected in the extra-embryonic derivatives of the early primitive streak stage embryo where it is specifically restricted to the tissues of the ectoplacental cone and chorion. Expression of the beta 2 m gene continues in these tissues during formation of the definitive placenta. beta 2 m transcripts were also detected in the tissues of the visceral yolk sac starting at 10.5 days. Comparable levels of expression were observed in both the visceral yolk sac endoderm and the extra-embryonic mesoderm. These results clearly indicate that the onset of beta 2 m gene expression is not restricted to early hemopoietic cells. In the embryo-proper, significant levels of beta 2 m mRNA were not detected until day 9.5. At this stage, we observed a strong signal over the liver rudiment. The remaining somatic tissues expressed low levels of transcripts. Similar results were obtained at later stages of development, i.e., the fetal liver was consistently the most strongly positive organ. Overall these in situ hybridization studies define the pattern of beta 2 m gene transcription and thus potential sites of surface expression of class I proteins in specific cell lineages in the early postimplantation stage embryo.
Sustained engraftment of mice transplanted with IL-1-primed blood-derived stem cells.
Authors: Fibbe W E , Hamilton M S , Laterveer L L , Kibbelaar R E , Falkenburg J H , Visser J W , Willemze R 
Published: January 2023

Abstract
IL-1 is considered the primary mediator of the acute phase response. One of the characteristic manifestations of this response is early neutrophilia that is probably caused by release of mature neutrophils from the bone marrow into the peripheral blood. In the present study, we assessed whether IL-1 had a similar releasing effect on the number of circulating progenitor cells and stem cells. Female BALB/c mice were injected i.p. with increasing (0.1-1.0 micrograms/mouse) concentrations of rhu-IL-1 alpha. IL-1 injection resulted in a marked dose-dependent increase in the number of polymorphonuclear neutrophils, granulocyte-macrophage colony-forming units (CFU-GM), and cells forming spleen colonies (CFU-S day 8 and day 12). The maximal increase was found at 4 to 8 h after injection of 1 micrograms IL-1 per mouse, yielding a mean fivefold elevation in neutrophil count, and a mean 30-fold and 10-fold increase in the number of circulating CFU-GM and CFU-S, respectively. In a subsequent series of experiments, lethally irradiated (8.5 Gy) female recipient animals were transplanted with 5 x 10(5) blood mononuclear cells derived from male IL-1-treated animals. Long-term survival was obtained in 68% of mice transplanted with peripheral blood cells derived from donor animals at 6 h after a single injection of 1 micrograms IL-1. The mean number of circulating CFU-GM in these donor animals was 557/ml blood. At 6 mo after transplantation, greater than 95% of the bone marrow cells were of male origin, as determined using in situ hybridization with a Y-chromosome specific probe. In contrast, long-term survival was reached in less than 10% of mice transplanted with an equal number of blood cells derived from saline-treated controls or donor animals treated with a dose of 0.1 micrograms IL-1. These results indicate that a single injection of IL-1 induces a shift of hematopoietic progenitor cells and marrow repopulating cells into peripheral blood and that these cells can be used to rescue and permanently repopulate the bone marrow of lethally irradiated recipients.
Tetraparental mice reveal complex cellular interactions of the mutant, autoimmunity-inducing lpr gene.
Authors: Katagiri T , Azuma S , Toyoda Y , Mori S , Kano K , Cohen P L , Eisenberg R A 
Published: January 2023

Abstract
Lpr is a murine recessive autosomal mutant gene that, in conjunction with the background genes of different inbred mouse strains, produces varied syndromes of lymphadenopathy and autoantibody production. We have investigated the cellular basis of the lpr determined phenomena by constructing allophenic (tetraparental) chimeras of MRL/Mp-lpr/lpr combined with C57BL/6 and MRL/+ combined with C57BL/6-lpr/lpr. The appearance of lymphadenopathy, lpr atypical T cells, and autoantibodies was found to depend on the relative amounts +/+ and lpr tissue. The failure of these three abnormalities to correlate in certain animals suggested different pathways of lpr gene action. Furthermore, in the lpr predominant animals, both the lymphadenopathy and autoantibodies were essentially entirely contributed by the lpr donor. The expression of the lpr gene within the same cells expressing the MRL or B6 background determined the pathologic and serologic manifestations characteristic of the disease of that lpr strain, despite the presence of +/+ cells of the other background in the same individual. The lpr syndrome thus depends on the intracellular interaction of the lpr and background genes, and on positive signalling between different lpr cell populations.
The mechanism of internalization of platelet-activating factor in activated human neutrophils. Enhanced transbilayer movement across the plasma membrane.
Authors: Bratton D L , Dreyer E , Kailey J M , Fadok V A , Clay K L , Henson P M 
Published: January 2023

Abstract
Recent studies suggest that cellular internalization of platelet-activating factor (PAF), a potent ether phospholipid mediator of inflammation, is modulated by, as yet undefined cellular mechanisms. Using an albumin extraction method, the internalization of PAF and several PAF analogues was studied in the resting and stimulated human neutrophil. Our data demonstrate that internalization of these analogues is largely dependent on the state of cellular activation and that the process is not specific for certain unique structural features of the PAF molecule including the 1-position ether linkage, 2-position acetyl substitution, or choline polar head group. Furthermore, the internalization process was shown not to be dependent on the PAF receptor, metabolism of the molecule, or the process of endocytosis. Data are presented to suggest that the route of internalization of PAF is enhanced transbilayer movement (flipping) across the plasma membrane occurring as a result of changes in membrane physical properties accompanying cellular activation. It is proposed that in addition to enhanced internalization of PAF, modulation of PAF biosynthesis and net release from the stimulated neutrophil may be consequences of enhanced transbilayer movement of PAF across the activated plasma membrane.
A protective monoclonal antibody specifically recognizes and alters the catalytic activity of schistosome triose-phosphate isomerase.
Authors: Harn D A , Gu W , Oligino L D , Mitsuyama M , Gebremichael A , Richter D 
Published: January 2023

Abstract
mAb M.1 was previously shown to recognize a 28-kDa Ag in all stages of the human helminth parasite, Schistosoma mansoni, and to bind to the surface membranes of newly transformed schistosomula in a transient manner. Here we demonstrate that M.1 passively transfers partial resistance (41-49%) to cercarial challenge in naive mice. Thus, the 28-kDa Ag recognized by M.1 is a putative vaccine candidate. After immunoaffinity purification, tryptic digests of the 28-kDa Ag were prepared and individual peptides were sequenced. Amino terminus sequences of tryptic peptides of the 28-kDa Ag had high (79-87%) sequence homology with the mammalian glycolytic/gluconeogenic enzyme triosephosphate isomerase (TPI). Purified, native 28-kDa Ag from adult parasites was shown to function enzymatically in an analogous manner to yeast and mammalian TPI in the reverse reaction. Addition of M.1 antibody to the enzyme reaction altered the catalytic activity of schistosome TPI. To determine the immunologic cross-reactivity of this vaccine candidate with mammalian TPI, Western blot analysis was performed and demonstrated that M.1 was immunologically specific for the schistosome enzyme.
A lectin-binding, protease-resistant mycobacterial ligand specifically activates V gamma 9+ human gamma delta T cells.
Authors: Pfeffer K , Schoel B , Plesnila N , Lipford G B , Kromer S , Deusch K , Wagner H 
Published: January 2023

Abstract
Bacterial (exogeneous) superantigens have been defined as bifunctional proteinaceous molecules. They bind to class II MHC molecules of presenting cells and engage with particular TCR-V beta gene elements, thereby activating alpha beta T cells in a V beta-oriented fashion. In previous studies we have elucidated that gamma delta T cells exhibit a propensity to vigorously respond toward mycobacterial Ag. Intrigued by this finding we now analyzed whether mycobacteria express a superantigen for a subset of human gamma delta T cells definable by the selective use of TCR-V gene elements. Here we describe that a protease-resistant, low m.w. (1 to 3 kDa) component of mycobacteria selectively activates gamma delta T cells expressing TCR-V gamma 9 gene segments. Contained in mycobacterial lysates it stimulates TCR-V gamma 9-positive gamma delta T cells at a frequency of 1/6. Stimulation is critically dependent on the presence of class II MHC-positive presenting cells, the important structure being HLA-DR molecules. The fine specificity of the V gamma 9 seeking mycobacterial ligand differs from the gamma delta T cell-stimulating structures expressed by Daudi cells. In addition, the mycobacterial, V gamma 9-seeking ligand is bound selectively to lectins such as UEAI, SBA, and DBA. We conclude that mycobacteria contain a component that acts as a superantigen for human gamma delta T cells and we believe it is this property that explains the vigorous participation of gamma delta T cells in mycobacterial infections.
Human mb-1 gene: complete cDNA sequence and its expression in B cells bearing membrane Ig of various isotypes.
Authors: Yu L M , Chang T W 
Published: January 2023

Abstract
The transmembrane protein, IgM-alpha, a product of mb-1 gene, has been shown to be specifically associated with membrane-bound IgM on the plasma membrane of B lymphocytes. Recent studies have suggested that IgM-alpha may play a role in transducing signals from the Ag receptors during the activation of B cells. A large amount of information has been obtained in the mouse system regarding IgM-alpha and other components of the newly conceived B cell Ag receptor complex. Here we report the cloning and the nucleotide sequencing of cDNA clones of human mb-1, covering the entire length of the mRNA. At the amino acid sequence level, human and murine mb-1 share a high homology in their transmembrane and intracytoplasmic segments, suggesting an important biologic function for these regions of mb-1. A major difference, mainly in the 3' untranslated part, exists between our cDNA sequence and the published partial human mb-1 cDNA sequence. It has also been observed that human mb-1 is expressed not only by B cell lines expressing membrane-bound Ig of mu and delta isotypes but also those expressing membrane-bound Ig of alpha and gamma isotypes.
Shared human melanoma antigens. Recognition by tumor-infiltrating lymphocytes in HLA-A2.1-transfected melanomas.
Authors: Kawakami Y , Zakut R , Topalian S L , Stötter H , Rosenberg S A 
Published: January 2023

Abstract
Three predominantly CD8+ CTL lines, TIL 501, TIL 620, and TIL 660, were generated from three HLA-A2+ melanoma patients by culturing tumor-infiltrating lymphocytes in 1000 U/ml IL-2. These tumor-infiltrating lymphocytes lysed 12 of 18 HLA-A2+ autologous and allogeneic melanomas, but none of 20 HLA-A2-negative melanomas. They also did not lyse the MHC class I negative lymphoma-leukemia cell lines, Daudi, K562, or HLA-A2+ non-melanoma cell lines including PHA or Con A-induced lymphoblast, fibroblast, EBV-transformed B cell, Burkitt's B cell lymphoma, and colon cancer cell lines. Autologous and allogeneic melanoma lysis was inhibited by anti-CD3, by anti-MHC class I, and by anti-HLA-A2 mAb, indicating recognition of shared tumor Ag among melanoma cell lines in a TCR-dependent, HLA-A2-restricted manner. Six HLA-A2-negative melanoma cell lines obtained from five HLA-A2-negative patients were co-transfected with the HLA-A2.1 gene and pSV2neo. All 17 cloned transfectants expressing cell surface HLA-A2 molecules, but none of 12 transfectants lacking HLA-A2 expression, were lysed by these three HLA-A2-restricted, melanoma-specific CTL. Lysis of the HLA-A2+ transfectants was inhibited by anti-CD3, by anti-MHC class I, and by anti-HLA-A2 mAb, indicating recognition of shared tumor Ag on transfectants in a TCR-dependent, HLA-A2-restricted manner. These results identify the HLA-A2.1 molecule as an Ag-presenting molecule for melanoma Ag. They also suggest that common melanoma Ag are expressed among melanoma patients regardless of HLA type. These findings have implications for the development of melanoma vaccines that would induce antitumor T cell responses.
Activation of murine epidermal TCR-gamma delta+ T cells by keratinocytes treated with contact sensitizers.
Authors: Huber H , Descossy P , van Brandwijk R , Knop J 
Published: January 2023

Abstract
The vast majority of TCR gamma delta+, CD4-, CD8- T cells resident in the adult mouse epidermis expresses tissue-specific V-region genes (V gamma 3/V delta 1) in the absence of junctional diversity. The role this unique T cell population plays in the immune surveillance of the skin is not clear. It has been shown that dendritic epidermal T cells (DETC) were activated by stressed keratinocytes and that stimulated DETC produced, for example, a keratinocyte-specific growth factor. To investigate whether DETC are involved in the induction of a contact allergy, we examined the influence of contact sensitizers and nonsensitizing contact irritants on the DETC response toward epidermal symbionts. We show that 9 of 15 cloned DETC are specifically activated, apparently in a non-MHC-restricted way, to proliferate in the presence of keratinocytes or unseparated epidermal cells, which were treated with a sensitizing agent either in vivo or in vitro. All seven tested contact sensitizing substances activated all of the reactive DETC, while keratinocytes/epidermal cells treated with nonsensitizing irritants were as nonstimulatory as vehicle controls. We demonstrate that direct cell to cell contact of DETC and stimulatory keratinocytes/epidermal cells was required and that the TCR was involved in the induction of DETC proliferation. This specific reactivity of DETC toward keratinocytes or epidermal cells pretreated with a contact sensitizer may be indicative of participation of epidermal T cells in the induction of a contact sensitivity and points to a possible role of DETC in the skin immune system.