bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lymphocyte adhesion mediated by lymphocyte function-associated antigen-1. I. Long term augmentation by transient increases in intracellular cAMP.
Authors: Haverstick D M , Gray L S 
Published: January 2023

Abstract
Lymphocyte adhesion to target cells is mediated, in part, by the interaction of lymphocyte function-associated Ag-1 (LFA-1) with intercellular adhesion molecule-1 (ICAM-1). Cells of the B cell line, JY, express both coreceptors and have been used as a model for intercellular adhesion mediated by these molecules. Elevation of the intracellular cAMP concentration ([cAMP]i), by any of several reagents, for periods as brief as 30 min, led to enhanced intercellular adhesion in a concentration dependent manner 5 to 8 h later. Two protein kinase A inhibitors, KT5720 and H-89, but not the protein kinase C inhibitor calphostin C, blocked the effects of elevated [cAMP]i. These data suggest a role for protein kinase A in this response. The adhesion augmented by increased [cAMP]i was due to LFA-1/ICAM-1 interactions between cells because it was blocked by either anti-LFA-1 or anti-ICAM-1 mAb. Elevated [cAMP]i induced cell surface patching of LFA-1, but not ICAM-1, and this redistribution preceded intercellular adhesion. Finally, redistribution of LFA-1 was not mediated by the cytoskeleton. These results suggest a model in which transient activation of protein kinase A results in increased local concentration of LFA-1 at the cell surface and in augmented long term adhesion mediated by this integrin.
Evidence for extrathymic development of TNK cells. NK1+ CD3+ cells responsible for acute marrow graft rejection are present in thymus-deficient mice.
Authors: Kikly K , Dennert G 
Published: January 2023

Abstract
The predominant mechanism responsible for acute specific rejection of allogeneic and parental bone marrow by irradiated mice is due to a cell (TNK) that expresses the NK cell surface markers NK1 and ASGM1 as well as TCR. Here we analyze the question as to whether TNK cells require a functional thymus for their development. Using adoptive cell transfer assays, evidence is presented that, as is the case in normal mice, NK1+ CD3+ effector cells are responsible for rejection in thymus-deficient nude mice and that the specificity of rejection is indistinguishable from that of normal mice. To reveal the presence of TNK cells in the spleen of nude mice, double staining for NK1 and CD3 followed by FACS analysis was done. It is shown that NK1+ CD3+ cells are present in the spleens of nude but not euthymic mice, suggesting that the lack of a functional thymus stimulates either Ag expression or the number of TNK cells. In support of this finding, the treatment of irradiated marrow reconstituted mice with cyclosporin A leads to the appearance of TNK cells in the spleen. The relative efficiency of spleen cells from nude and cyclosporin A-treated mice to transfer resistance in adoptive cell transfers was assessed and found to be higher than that of normal spleen, consistent with the higher frequency of these cells in thymus-defective mice. The fate of NK1+ CD3+ cells subsequent to stimulation with an allogeneic marrow graft indicates that these cells proliferate in nude mice without gaining cytolytic activity. In euthymic mice, however, NK1+ CD3+ cells appear transiently but disappear in favor of CD4+ and CD8+ cells that proliferate in response to an allogeneic marrow graft. The CD8+ cells express cytolytic activity with specificity similar to that of the acute rejection mechanism, consistent with the suggestion that TNK cells differentiate into CD8+ killer cells. The reason why TNK cells in nude mice fail to differentiate into CD8+ CTL is explained by the lack of Th cells.
Demonstration of a CD3+ lymphocyte subset in the epidermis of athymic nude mice. Evidence for T cell receptor diversity.
Authors: Payer E , Strohal R , Kutil R , Elbe A , Stingl G 
Published: January 2023

Abstract
The existence of CD3/TCR-bearing lymphocytes in athymic and thymectomized chimeric mice implies that T cell maturation can occur in the absence of a thymus. Considering the possibility that the epidermis may be one of the organs providing T cell educating stimuli, we attempted to characterize the Thy-1+ epidermal lymphocyte population of athymic mice. Immunohistologic studies of epidermal sheets revealed (1) that Thy-1+ epidermal cells of C57BL/6 nu/nu mice are CD5-, CD4-, and predominantly CD8-, and (2) that a minor subset of these cells displays anti-CD3 epsilon reactivity. Although these CD3+ epidermal cells could hardly be detected at 6 wk of age, they comprised approximately 2% of all Thy-1+ epidermal cells in 12-mo-old athymic mice. Most of these CD3+ cells expressed TCR-gamma/delta, but TCR-alpha/beta+ cells were also present. TCR-gamma/delta+ epidermal T cells of athymic mice preferentially expressed TCR V gamma 2, V gamma 4, and V gamma 5 specificities rather than TCR V gamma 3 as found on DETC of euthymic mice. Using mitogenic stimuli, we have succeeded in establishing cell lines and clones from BALB/c nu/nu and C57BL/6 nu/nu epidermis. Their marker profile corresponds to that seen on resident CD3+ epidermal cells, as well as on a very small subset of CD3+ splenic and lymph node lymphocytes of athymic mice. The ontogenetic relationship, if any, between the epidermal and lymphoid CD3+, CD5-, CD4-, CD8- cells, has yet to be clarified. Cell lines/clones representative of resident CD3+ epidermal cells of nu/nu mice should provide a useful tool in the elucidation of homing patterns and functional properties of extrathymically matured T cells.
Developmentally regulated expression of the beta 4 integrin on immature mouse thymocytes.
Authors: Wadsworth S , Halvorson M J , Coligan J E 
Published: January 2023

Abstract
Integrins are a superfamily of alpha beta heterodimers, most of which serve as cell surface receptors for extracellular matrix proteins. In this report, we demonstrate that the recently described alpha 6 beta 4 integrin, previously thought to be limited to epithelial cells and Schwann cells, is expressed on immature mouse thymocytes. The presence of alpha 6 beta 4 is controlled by regulation of beta 4 expression, because alpha 6 was expressed by virtually all cells examined, paired with the beta 1 integrin chain to form VLA-6. During fetal ontogeny, beta 4 was highly expressed by 35% of day-13 thymocytes, 75% of day-14 to -15 thymocytes, then rapidly declined to low levels by birth. In neonates and adults, beta 4 expression was highest on CD4- CD8- CD3- and TCR(+)-gamma delta subsets. Correlation of IL-2R, CD44 and beta 4 on CD4- CD8- thymocytes revealed maximal levels on the intermediate CD44- IL-2R+ subset. Most CD4- CD8+ TCR- thymocytes and a significant fraction of CD4+ CD8+ thymocytes were beta 4lo, whereas the most mature J11d- single positive thymocytes were beta-4. Overall, down-regulation of beta 4 was associated with up-regulation of CD4, CD8, and CD3 in the thymus. alpha 6 beta 4 was undetectable on fetal liver or bone marrow cells, lymphocytes from lymph node, spleen, or blood, and mitogen-activated splenic T cells cultured up to 10 wk with IL-2. The data suggest that alpha 6 beta 4 is up-regulated after pro-T cells enter the thymus and may have a thymus-specific function for T cells. The developmentally regulated pattern of expression and the prominence of alpha 6 beta 4 on day-13 to -16 fetal and adult CD4- CD8- CD3- thymocytes further suggest this unusual integrin may play a role in early T cell development, including stages before acquisition of the TCR.
Cloning and expression of recombinant Aspergillus fumigatus allergen I/a (rAsp f I/a) with IgE binding and type I skin test activity.
Authors: Moser M , Crameri R , Menz G , Schneider T , Dudler T , Virchow C , Gmachl M , Blaser K , Suter M 
Published: January 2023

Abstract
Aspergillus fumigatus secretes an 18-kDa nonglycosylated IgE-binding protein. This protein was previously shown to be a ribotoxin, like alpha-sarcin and mitogillin. A 686-bp long A. fumigatus cDNA encoding an 18-kDa ribotoxin was cloned and expressed in Escherichia coli as a fusion protein with six adjacent histidines (rAsp f I/a). rAsp f I/a was purified to homogeneity by Ni(2+)-chelate affinity chromatography and refolded. The recombinant protein was enzymatically active resulting in the cleavage of 28S rRNA within a universally conserved region. rAsp f I/a was cytotoxic for EBV immortalized or PHA stimulated human PBMC. Furthermore, rAsp f I/a was recognized by murine mAb made against an 18-kDa ribotoxin. IgE of individuals allergic to A. fumigatus bound to rAsp f I/a as shown by ELISA, dot blots, and Western blots. rAsp f I/a elicited positive immediate type I skin reactions in individuals allergic to A. fumigatus but not in healthy control individuals. The results show that rAsp f I/a has similar functional characteristics when compared to the native 18-kDa ribotoxin. rAsp f I/a expressed in E. coli can therefore be used as a standardized Ag/allergen for serologic and clinical diagnosis of A. fumigatus-associated diseases.
Diversity in MHC class II ovalbumin T cell epitopes generated by distinct proteases.
Authors: Vidard L , Rock K L , Benacerraf B 
Published: January 2023

Abstract
It is generally accepted that a limited number of T cell epitopes are generated by APC from an immunogenic protein. To ascertain the number of determinants on OVA recognized in the context of the H-2s haplotype, we generated 19 T-T hybridomas against OVA and H-2s and we synthesized 46 overlapping peptides spanning the entire protein. Eighteen T-T hybrids were stimulated by eight different peptides. The peptide recognized by one T cell hybrid was not identified. The effect of four protease inhibitors on the processing and presentation of OVA by the LS.102.9 B cell hybridoma seemed to implicate several groups of proteases in the processing of this Ag. Alkylation of cysteine residues with iodoacetic acid showed in a few cases a dramatic decrease in the capacity of OVA to stimulate T-T hybrids recognizing cysteine-free peptides. In contrast, two T-T hybrids recognizing cysteine containing peptides were not affected by the alkylation, suggesting that alkylation inhibited the processing of OVA without affecting peptide interaction with class II MHC molecules. These data demonstrate that the repertoire of peptides generated by APC from OVA is not limited to one or few immunodominant peptides, and results from the activity of several endopeptidases and/or exopeptidases. In addition, the structure of the Ag (native or denatured) was shown to affect the efficiency with which different epitopes are generated.
Sequential analysis of T cells in the liver during murine listerial infection.
Authors: Hiromatsu K , Matsuzaki G , Tauchi Y , Yoshikai Y , Nomoto K 
Published: January 2023

Abstract
Phenotypes and functions of T cells in the liver were studied after an i.p. inoculation with viable Listeria monocytogenes in mice. T cells in the liver of untreated C3H/HeN mice (C3H; H-2k, Mls-2a) contain Thy-1.2+TCR-alpha beta + cells as a majority and Thy-1.2+TCR-gamma delta + cells and Thy-1.2-TCR-gamma delta + cells as minorities. The liver of untreated C3H mice did not contain T cells expressing V beta 3 and V beta 11, which are potentially autoreactive against self-superantigens of Mls-2a and Dvbl, respectively. On days 3 to 6 after infection, Thy-1.2-CD4lowTCR-alpha beta + T cells or Thy-1.2-TCR-gamma delta + T cells increased significantly in number and proportion in the liver whereas T cells with these phenotypes were hardly detected in the spleen, lymph nodes, peripheral blood, and peritoneal cavity during the course of the infection. The Thy-1.2-CD4lowTCR-alpha beta T cells contained V beta 3 or V beta 11-bearing cells in high frequencies. The potentially autoreactive V beta 3- or V beta 11-bearing T cells disappeared from the liver on day 7 after infection. Furthermore, the V beta 3+ and V beta 11+ cells but not V beta 8+ cells disappeared after culture for 24 h at 37 degrees C. In vitro stimulation of liver T cells using anti-V beta 11 mAb showed no proliferative response. These results suggest that the potentially autoreactive clones with Thy-1.2-CD4low phenotypes, which increased in number after listerial infection, may be anergized after interaction with self-Ag and may be programmed to die. These potentially autoreactive clones induced in the liver of Listeria-infected mice may not be functionally relevant to the host defense against Listeria.
Digestion of Histoplasma capsulatum yeasts by human macrophages.
Authors: Newman S L , Gootee L , Morris R , Bullock W E 
Published: January 2023

Abstract
The strategies used by Histoplasma capsulatum yeasts to survive and multiply within human macrophages (M phi) are unknown. To better understand these strategies we studied the intracellular fate of viable vs heat-killed (HK) yeasts in human monocyte-derived M phi. Initial studies demonstrated that phagolysosome fusion was present in M phi ingesting either viable or HK yeasts. Viable yeasts multiplied within M phi phagolysosomes, whereas M phi completely digested intracellular FITC-labeled HK yeasts within 24 h after ingestion. This observation was confirmed by electron microscopy. M phi that had ingested colloidal gold-labeled HK yeasts contained gold particles but no visible yeasts at 24 h. Digestion of HK yeasts was evident as early as 4 h after phagocytosis, and was complete by 24 h. M phi digestion of HK yeasts was blocked completely when M phi were cultured for 24 h in the presence of chloroquine. In M phi simultaneously ingesting both viable and HK yeasts, viable yeasts multiplied, but HK yeasts were digested within the same cell. M phi that had ingested viable yeasts digested them completely when M phi were cultured for 24 h in the presence of cycloheximide or amphotericin B. Coculture of infected M phi with nystatin or ketoconazole resulted in inhibition of growth, but the yeasts were not digested. These data indicate that: 1), HK Hc yeasts are easily digested by preformed M phi lysosomal hydrolases; 2), viable Hc yeasts survive and multiply within M phi phagolysosomes, but the yeasts do not secrete a factor(s) that affects the ability of other phagolysosomes within the same M phi to digest killed yeasts; and 3), inhibition of yeast protein synthesis or cell wall biosynthesis is sufficient to render viable yeasts susceptible to digestion by human M phi.
The human recombinant c-kit receptor ligand, rhSCF, induces mediator release from human cutaneous mast cells and enhances IgE-dependent mediator release from both skin mast cells and peripheral blood basophils.
Authors: Columbo M , Horowitz E M , Botana L M , MacGlashan D W , Bochner B S , Gillis S , Zsebo K M , Galli S J , Lichtenstein L M 
Published: January 2023

Abstract
The gene product of the steel locus of the mouse represents a growth factor for murine mast cells and a ligand for the c-kit proto-oncogene receptor, a member of the tyrosine kinase receptor class of oncogenes (for review, see O. N. Witte. 1990. Cell 63:5). We have studied the effect of the human recombinant c-kit receptor ligand stem cell factor (rhSCF) on the release of inflammatory mediators from human skin mast cells and peripheral blood basophils and compared its activity to that of rhIL-3, rhSCF (1 ng/ml to 1 microgram/ml) activated the release of histamine and PGD2 from mast cells isolated from human skin. Analysis by digital video microscopy indicated that purified human skin mast cells (84 +/- 5% pure) responded to rhSCF (0.1 to 1 microgram/ml) challenge with a rapid, sustained rise in intracellular Ca2+ levels that was accompanied by secretion of histamine. A brief preincubation (10 min) of mast cells with rhSCF (0.1 pg/ml to 1 ng/ml) significantly enhanced (100 +/- 35%) the release of histamine induced by anti-IgE (3 micrograms/ml), but was much less effective on IgE-mediated release of PGD2. In contrast, a short term incubation with rhSCF did not potentiate the secretion of histamine activated by substance P (5 microM). A 24-h incubation of mast cells with rhSCF did not affect the release of mediators induced by anti-IgE (3 micrograms/ml), probably due to receptor desensitization, rhSCF (1 ng/ml to 3 micrograms/ml) neither caused release of histamine or leukotriene C4 (LTC4) release from leukocytes of 14 donors, nor induced a rise in intracellular Ca2+ levels in purified (greater than 70%) basophils. Brief preincubation (10 min) of leukocytes with rhSCF (1 ng/ml to 3 micrograms/ml) caused an enhancement (69 +/- 11%) of anti-IgE-induced release of histamine that was significant at concentrations as low as 3 ng/ml (p less than 0.05), whereas it appeared less effective in potentiating IgE-mediated LTC4 release. In contrast, a prolonged incubation (24 h) with rhSCF (0.1 pg/ml to 100 ng/ml) did not enhance the release of histamine or LTC4 induced by anti-IgE (0.1 microgram/ml), whereas rhIL-3 (3 ng/ml) significantly potentiated the release of both mediators.(ABSTRACT TRUNCATED AT 400 WORDS)
Calcium rather than protein kinase C is the major factor to activate phospholipase D in FMLP-stimulated rabbit peritoneal neutrophils. Possible involvement of calmodulin/myosin L chain kinase pathway.
Authors: Kanaho Y , Nishida A , Nozawa Y 
Published: January 2023

Abstract
In the present study, we first investigated which of the factors, protein kinase C (PKC) or Ca2+, plays an important role in activation of phospholipase D (PLD) of rabbit peritoneal neutrophils stimulated by the chemoattractant FMLP. PLD activity was assessed by measuring [3H]phosphatidylethanol ([3H]PEt), the unambiguous marker of PLD, generated by [3H]lyso platelet-activating factor-prelabeled neutrophils in the presence of ethanol. PKC inhibitors, staurosporine and 1-(5-isoquinolinesulfonyl-2-methylpiperazine dihydrochloride, augmented the plateau level of [3H]PEt produced in FMLP-stimulated cells, although they had no effect on the initial rate of the formation. Furthermore, it was found that the FMLP-stimulated [3H]PEt formation was inhibited by pretreatment of cells with PMA, a PKC activator, and exposure of cells to staurosporine before PMA pretreatment moderately blocked the PMA inhibition. Ca2+ ionophore ionomycin, as well as FMLP, stimulated [3H]PEt formation, accompanied by a decrease in [3H]phosphatidylcholine, in a time- and concentration-dependent manner. Both FMLP and ionomycin absolutely required extracellular Ca2+ to increase [3H]PEt formation. These results imply that elevated intercellular Ca2+ by FMLP stimulation is the major factor for PLD activation and that PKC rather negatively regulates the enzyme activity. Interestingly, a calmodulin inhibitor, N-(6-aminohexyl)-5-chloro-1- naphthalenesulfonamide, and a myosin L chain kinase inhibitor, 1-(5-iodonaphthalene-1-sulfonyl)-1H-h exahydro-1,4-diazepine hydrochloride, both inhibited the ionomycin- and FMLP-stimulated [3H]PEt formation in a concentration-dependent manner. Results obtained in this study suggest that, in FMLP-stimulated rabbit peritoneal neutrophils, increased intracellular Ca2+ activates PLD through calmodulin/myosin L chain kinase pathway and, thereafter, the enzyme activation is turned off by simultaneously activated PKC.
Two major groups of neutralizing anti-gp120 antibodies exist in HIV-infected individuals. Evidence for epitope diversity around the CD4 attachment site.
Authors: Chamat S , Nara P , Berquist L , Whalley A , Morrow W J , Köhler H , Kang C Y 
Published: January 2023

Abstract
The aim of this study was to dissect neutralizing anti-gp120 antibody populations in seropositive asymptomatic individuals. Murine anti-Id mAb were raised against polyclonal affinity-purified human anti-gp120 antibodies. These anti-Id mAb were used to fractionate anti-gp120 antibodies from a pool of HIV-positive sera into idiotypically distinct anti-gp120 antibody (Id+Ab) preparations. Immunochemical and neutralization studies indicated that all Id+Ab that neutralized HIV-1 in vitro interacted with either the V3 loop or the CD4 attachment site of gp120. The V3-specific Id+Ab neutralized HIV-1 in a strain-restricted manner. Id+Ab specific for the CD4 attachment site exhibited different spectra of neutralizing activities against multiple strains of HIV-1. This finding indicates that multiple, antigenically diverse epitopes reside around the CD4 attachment site of gp120. Significantly, depletion of the Id+Ab from affinity-purified total anti-gp120 antibodies abrogated most of the neutralizing activities of these antibodies, suggesting that neutralizing anti-gp120 antibodies consist of two major specificities, either to the V3 region or to the CD4 attachment site. The understanding of specificities and neutralizing activities of different anti-gp120 antibodies in seropositive healthy individuals will be helpful for designing effective vaccines and immunotherapeutic strategies for AIDS.
Soluble forms of CD40 inhibit biologic responses of human B cells.
Authors: Fanslow W C , Anderson D M , Grabstein K H , Clark E A , Cosman D , Armitage R J 
Published: January 2023

Abstract
We have expressed the CD40 surface Ag as both a soluble 28-kDa molecule and a 57-kDa Fc fusion protein containing the human IgG1 Fc region. Soluble CD40 and the Fc fusion protein inhibited the proliferative response of anti-IgM-activated human B cells to the CD40 mAb G28-5. Similarly, G28-5- and IL-4-induced IgE secretion from PBMC depleted of T cells was effectively blocked by both forms of soluble CD40. Although the soluble constructs of CD40 had only a minimal inhibitory effect on IL-4-mediated proliferation of anti-IgM-activated B cells, IL-4-induced soluble CD23 shedding from both PBMC and T cells depleted of PBMC, and IgE secretion from PBMC, were significantly reduced in a concentration-dependent manner when soluble CD40 was present in the culture. The data presented demonstrate that both soluble forms of the CD40 molecule are biologically active, and suggest that the ligand for CD40 is inducible in IL-4-stimulated cultures and that it mediates both shedding of sCD23 and IgE secretion.
Human myoblasts as antigen-presenting cells.
Authors: Goebels N , Michaelis D , Wekerle H , Hohlfeld R 
Published: January 2023

Abstract
Human myoblasts, cultured from muscle and purified to greater than 95%, were investigated for their capacity to act as facultative APC. The myoblasts reacted with antidesmin mAb and had the capacity to fuse into multinucleated myotubes in appropriate medium. The expression of HLA class I, HLA-DR, HLA-DP, HLA-DQ, intercellular adhesion molecule-1 (ICAM-1/CD54), lymphocyte function-associated (LFA) molecules LFA-1 (CD11a/CD18), LFA-2 (CD2), and LFA-3 (CD58) was investigated by FACS analysis before and after induction for various times with human rIFN-gamma, TNF-alpha, or both. Without cytokine induction, myoblasts expressed only HLA-class I and LFA-3. IFN-gamma alone or in combination with TNF-alpha induced the expression of HLA-DR and ICAM-1 reaching a plateau after 48 h, followed by HLA-DP and even later HLA-DQ. TNF-alpha alone induced only ICAM-1. The functional capacity of myoblasts to present Ag to CD4+ T cells was investigated using autologous T cell lines specific for tuberculin, tetanus toxoid, and human myelin basic protein. Noninduced myoblasts or myoblasts treated with TNF-alpha alone could not present any of these Ag to the T cells. However, myoblasts treated with IFN-gamma induced Ag-specific proliferation. In the presence of relevant Ag, myoblasts were killed by the T cells as observed by microscopy and measured by 51Cr release. Ag-specific T cell proliferation and myoblast killing was inhibited in the presence of anti-DR mAb. These results suggest that human myoblasts may act as facultative APC during local immune reactions in muscle.