bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biochemical and functional characterization of proteoglycans isolated from basophils of patients with chronic myelogenous leukemia.
Authors: Metcalfe D D , Bland C E , Wasserman S I 
Published: December 2022

Abstract
Human basophils were obtained from three donors with myelogenous leukemia. Proteoglycans were labeled by using [35S]sulfate as precursor and were extracted in 1 M NaCl with protease inhibitors to preserve their native structure. [35S]proteoglycans filtered on Sepharose 4B with an average m.w. similar to that of a rat heparin proteoglycan that has an estimated m.w. of 750,000. The [35S]glycosaminoglycan side chains filtered with an average m.w. slightly smaller than a 60,000-m.w. glycosaminoglycan marker. The [35S]glycosaminoglycans were resistant to heparinase and susceptible to degradation by chondroitin AC lyase and chondroitin ABC lyase. The intact [35S]glycosaminoglycans chromatographed on DEAE Sepharose as a single peak eluting just before an internal heparin marker. These findings indicate that the [35S]glycosaminoglycans were made up only of chondroitin sulfates. No heparin was identified. The chondroitin sulfate disaccharides that resulted from the action of chondroitin ABC lyase on the basophil glycosaminoglycans consisted of 92% delta Di-4S, 6% delta Di-6S, and 2% disulfated disaccharides. The [35S]chondroitin sulfate proteoglycans were susceptible to cleavage with proteases and could be shown to be released intact from basophils during degranulation initiated by the calcium ionophore A23187. The basophil proteoglycans and glycosaminoglycans were capable of binding histamine in water, but not in phosphate-buffered saline, and had no anticoagulant activity.
Increasing extracellular potassium causes calcium-dependent shape change and facilitates concanavalin A capping in human neutrophils.
Authors: Roberts R L , Mounessa N L , Gallin J I 
Published: December 2022

Abstract
Stimulation of human polymorphonuclear leukocytes (PMN) by chemoattractants is associated with changes in membrane potential, and it has been speculated that these changes are important in PMN function. In the present study, human PMN isolated on Percoll gradients were exposed to extracellular K+ concentrations, which have been shown to depolarize PMN. Incubation of PMN at 37 degrees C for 15 min in 125 mM K+ increased the number that capped fluoresceinated concanavalin A (Con A) to 78% +/- 5.1 with 6.9% +/- 0.8 forming Con A caps in 5 mM K+ (p less than 0.001). In the absence of lectins, high K+ induced polarization of PMN shape with pseudopod and uropod formation (2.4% +/- 0.1 polarized in 5 mM K+ vs 83.4% +/- 1.0 polarized in 125 mM K+ p less than 0.001). Control studies, in which Na+ was decreased by substituting choline chloride or sucrose, indicated that the K+ effects were specific and not due to lowering of Na+. Increasing K+ also stimulated preferential secretion of the specific (secondary) granule constituents, caused significant mobilization of receptors for the peptide N-formyl-methionyl-leucyl-phenylalanine (fmet-leu-phe), and increased the number of PMN migrating in chemotactic assays. Unlike the capping of Con A and shape change, however, the increase in fmet-leu-phe binding, degranulation, and locomotion was not specific for raising extracellular K+ and occurred when choline chloride was substituted for sodium chloride, suggesting that these effects may be due to the lowering of Na+ or the changing of the Na+ to K+ ratio. In related studies designed to examine the mechanism of these K+-induced effects, shape change and Con A cap formation were inhibited by the absence of extracellular calcium or the presence of the calcium channel blockers, methoxyverapamil (100 microM), manganese (2 mM), or cobalt (2 mM), suggesting that the K+-induced changes depend on an influx of calcium. Thus, the increase of extracellular K+ induces calcium-dependent membrane changes in PMN similar to those seen when PMN are stimulated by a chemoattractant.
Auranofin affects early events in human polymorphonuclear neutrophil activation by receptor-mediated stimuli.
Authors: Hafström I , Seligmann B E , Friedman M M , Gallin J I 
Published: December 2022

Abstract
Auranofin, a new oral antirheumatic gold compound, in concentrations achieved therapeutically, inhibits neutrophil phagocytosis, chemotaxis, chemiluminescence, reduction of cytochrome c, and release of lysosomal enzymes. To further characterize the mechanism by which auranofin affects neutrophils, we studied the effects of auranofin on unstimulated properties and functions of neutrophils as well as on rapidly stimulated functions. When examined by electron microscopy, 4 micrograms/ml of auranofin significantly decreased the number of visualized centriole-associated microtubules in resting cells. Furthermore, auranofin inhibited neutrophil spreading on glass and caused a decrease in negative surface charge (electrophoretic mobility). In addition, auranofin inhibited several fmet-leu-phe-stimulated responses such as shape change, increases in centriole-associated microtubules, decreases in surface charge, and elicited membrane potential changes (di-O-C5(3) dye response). Auranofin (1 micrograms/ml) inhibited fmet-leu-phe-stimulated superoxide and hydrogen peroxide production by 80% (p less than 0.05), and also increased the affinity of receptors for fmet-leu-phe (from Ka 0.035 to Ka 0.48, p less than 0.001). Auranofin also affected neutrophil responses to phorbol myristic acetate (PMA). The total amount of PMA-stimulated superoxide production was suppressed by as little as 0.4 micrograms/ml of auranofin, but the lag time for activation was shortened by low concentrations of auranofin (0.5 to 1 microgram/ml). Four micrograms per milliliter of auranofin suppressed the decrease in surface charge induced by PMA. However, auranofin did not influence superoxide production elicited by the ionophore A23187. The results indicate that auranofin affects the earliest detected responses in neutrophil activation by certain receptor-mediated stimuli.
Deoxyadenosine (AdR) inhibition of newly activated lymphocytes: blockade at the G0-G1 interface.
Authors: Redelman D , Bluestein H G , Cohen A H , Depper J M , Wormsley S 
Published: December 2022

Abstract
The mechanism responsible for the lymphocytotoxicity associated with congenital adenosine deaminase (ADA) deficiency has been ascribed to an accumulation of dATP. Elevated levels of dATP can then lead to inhibition of DNA synthesis by inhibiting ribonucleotide reductase and causing a depletion of the other deoxynucleotide triphosphates (dNTP). This hypothesis was derived principally from studies with murine and human lymphoblastoid cell lines (LCL) and apparently confirmed in a limited number of investigations with lectin-stimulated lymphocytes. Our biochemical studies of lectin-stimulated mouse and human lymphocytes were not consistent with the dATP model and suggested that AdR exerted effects on lymphocyte activation that preceded the initiation of DNA synthesis. In the current studies, we focused on the effects of AdR on the early events in T lymphocyte activation, because we found they were the most sensitive to AdR toxicity. AdR blocked neither the production of T cell growth factor (TCGF) by lectin-stimulated lymphocytes nor the expression of TCGF receptors as detected by the anti-Tac monoclonal antibody that recognizes the human TCGF receptor. AdR did, however, block the early TCGF-dependent events leading to the entry into the cell cycle. By using the metachromatic fluorescence stain acridine orange, we found that AdR blocked the increased synthesis of RNA that characterizes the entry into the G1 phase of the cell cycle from the G0, resting state. Because these early effects were caused by the lowest doses of AdR, and because they preceded the synthesis of DNA by 15 to 20 hr, it suggested that these effects may be principally responsible for the in vivo toxicity associated with ADA deficiency. Furthermore, none of the other proposed biochemical mechanisms, e.g., inhibition of methylation, diminution of ATP levels, or incorporation of AdR into polyadenylated RNA, appeared adequate to explain AdR toxicity during T lymphocyte activation.
Characterization of monoclonal antibody 155.8 and partial characterization of its proteoglycan antigen on human melanoma cells.
Authors: Harper J R , Bumol T F , Reisfeld R A 
Published: December 2022

Abstract
Immunization of mice with a plasma membrane-enriched fraction from human malignant melanoma cells and subsequent generation of hybridomas resulted in the isolation of an IgG1 monoclonal antibody, 155.8, that recognizes chondroitin sulfate proteoglycans. By cell binding analysis, 155.8 was shown to react with seven of eight cultured melanoma cell lines, but not with a variety of lymphoblastoid cell lines or cultured tumor cells derived from other solid tumor types. Indirect immunoprecipitation of the 155.8 antigen from intrinsically labeled melanoma cells revealed a glycoprotein of Mr = 250,000 and a sulfated molecule of Mr greater than 400,000. The antigen was identified as a chondroitin sulfate type A/C proteoglycan synthesized by melanoma cells on the basis of its sensitivity to chondroitinase ABC digestion and the identification of sulfated glycosaminoglycans released from the antigen immunoprecipitated by 155.8. The determinants recognized by antibodies 155.8 and 9.2.27, another anti-chondroitin sulfate proteoglycan, immunoprecipitate only a proteoglycan from high density cesium chloride gradient fractions, (1.487 g/liter); however, they immunoprecipitate a free glycoprotein of Mr = 250,000 from low density fractions (1.317 g/liter). This demonstrated that the 155.8 and 9.2.27 determinants, both of which reside on the glycoprotein of Mr = 250,000, are also present in the proteoglycan, suggesting that this glycoprotein is the proteoglycan core protein. Monoclonal antibody 155.8 reacts with a determinant on the core protein distinct from that recognized by 9.2.27. Proteoglycans bearing 155.8 determinants are distributed on the surface of cultured melanoma cells in a punctated fashion that apparently resolves to short, filamentous structures at high magnification. Immunohistochemical analysis demonstrated that 155.8-defined proteoglycans are found in freshly biopsied melanoma tissue, suggesting that these antigens are also synthesized in vivo by melanoma cells.
Potentiating effect of muramyl dipeptide and its lipophilic analog encapsulated in liposomes on tumor cell killing by human monocytes.
Authors: Sone S , Mutsuura S , Ogawara M , Tsubura E 
Published: December 2022

Abstract
Human monocytes harvested from healthy donors and separated by discontinuous gradient centrifugation and adherence were highly cytotoxic to allogeneic melanoma cells, but did not affect nontumorigenic cells, as measured by lysis of the cells. After 4 days incubation of these monocytes in medium, they showed little, if any, cytolytic activity. Hydrophilic muramyl dipeptide (MDP) or lipophilic muramyl tripeptide (MTP-PE) was encapsulated within multilamellar (MLV) liposomes composed of phosphatidylserine-phosphatidylcholine. The cultured monocytes were rendered tumoricidal by interaction for 24 hr with MDP or liposomes containing soluble MDP or lipophilic MTP-PE. Moreover, freshly isolated monocytes treated for 24 hr with liposomes containing MDP or MTP-PE remained tumoricidal during culture for up to 5 days. About 1,600-times lower concentration of MDP entrapped in liposomes than of free MDP in the medium was effective for rendering monocytes tumoricidal. Similarly, about 80-times lower concentration of MTP-PE in liposomes than of free MDP was effective for the activation of monocytes. It is concluded that MLV liposomes containing MDP or MTP-PE are far more efficient in potentiating the tumoricidal activity of human monocytes than unencapsulated, free MDP.
Induction of NKCF-like activity in mixed lymphocyte-tumor cell culture: direct involvement of mycoplasma infection of tumor cells.
Authors: Wayner E A , Brooks C G 
Published: December 2022

Abstract
Co-culture of CBA/J spleen cells and certain lines of YAC-1 stimulators resulted in the appearance of NKCF-like activity in 24- to 48-hr supernatants. Numerous other in vitro cell lines were effective stimulators of this splenic cytotoxic factor (SCF). The cells participating in SCF production were absent from normal thymocytes and were present in BALB/c nu/nu spleen, were nonadherent, asialo GM1+, and bore low levels of Thy-1.2. SCF could mediate lysis of certain NK-sensitive tumor targets in an 18-hr 51Cr-release assay. However, the induction of SCF was not correlated with the ability of a particular cell line to be lysed by NK cells, but showed an absolute correlation with the presence of mycoplasma contamination in cultured tumor cell lines. Mycoplasma negative cell lines, including an uninfected but NK-sensitive subline of YAC-1, were unable to induce SCF. Decontamination of mycoplasma-infected lines with antibiotics or by passage through syngeneic mice abrogated the ability of infected tumor cells to stimulate SCF. The ability to induce SCF could be restored by reinfection with mycoplasma. Tumor cell-free supernatants from contaminated cultures were mitogenic for CBA spleen cells and could themselves induce SCF activity in spleen cell supernatants. SCF production and the agent responsible could be removed by passing such supernatants through 0.1-micron filters. The organism apparently responsible for SCF induction from CBA spleen cells was typed and found to be Mycoplasma orale, a nonfermentative, arginine-dependent, common tissue culture contaminant. About 50 to 60% of SCF activity could be removed by 0.1-micron filters, suggesting that SCF is composed of two components: mycoplasma organisms themselves and a soluble cytotoxic factor produced in response to mycoplasma.
T cell-accessory cell interactions that initiate allospecific cytotoxic T lymphocyte responses: existence of both Ia-restricted and Ia-unrestricted cellular interaction pathways.
Authors: Singer A , Kruisbeek A M , Andrysiak P M 
Published: December 2022

Abstract
The specificity of the T-accessory cell interactions that initiate primary allospecific cytotoxic T lymphocyte (CTL) responses were found to be surprisingly diverse and of three distinct major histocompatibility complex (MHC) specificities, involving responder T cell recognition of: a) self-Ia accessory cell determinants, b) allo-Ia accessory cell determinants, or c) allo-K/D accessory cell determinants. Any one of these T-accessory cell interactions was sufficient to initiate allospecific CTL responses. It was observed that when accessory cells did not express foreign class I MHC determinants, primary allospecific CTL responses were invariably initiated by Ia-restricted T-accessory cell interactions. In contrast, it was observed that when accessory cells did express foreign class I MHC determinants, primary allospecific CTL responses could be initiated by Ia-independent T-accessory cell interactions that were specific for allogeneic, but not self, K/D determinants and that did not involve recognition of polymorphic Ia determinants. The MHC specificities of the T-accessory cell interactions that initiate primary allospecific and primary trinitrophenyl (TNP)-self CTL responses were also compared. It was observed that primary allospecific and primary TNP-self CTL responses could be initiated by self-Ia-restricted T-accessory cell interactions, and that in both responses the Ia determinants that the responding T cells recognized as self-specificities on the accessory cell surface were those that their precursors had encountered on radiation-resistant thymic elements in their differentiation environment. In contrast to the initiation of primary TNP-self CTL responses that required the activation by accessory cells of Ia-restricted T helper (TH) cells, allospecific CTL responses could also be initiated by class I-restricted T cells specific for accessory cell K/D determinants. Interestingly, such class I-restricted T cells present in primary responder cell populations were triggered only by recognition of allogeneic, but not self, K/D accessory cell determinants, even when the accessory cells were modified with TNP. Thus, the present study demonstrates that primary allospecific CTL responses, but not TNP-self CTL responses, are initiated by Ia-restricted or Ia-independent cellular interaction pathways. These results raise the possibility that unprimed class I-restricted TH cells that mediate the Ia-independent cellular interaction pathway may predominantly express an allospecific, but not a self + X-specific, receptor repertoire. Possible mechanisms by which these distinct T-accessory cell interactions initiate primary allospecific CTL responses are discuss
Modulation of F1 cytotoxic potentials by GvHR: role and mode of action of non-MHC genes that determine the hybrid resistance to GvHR-associated suppression of F1 cytotoxic potential.
Authors: Ishikawa H , Kubota E , Saito K 
Published: December 2022

Abstract
The resistance of unirradiated F1 mice against graft-vs-host reaction (GvHR) induced by lymphocytes from certain parental strains is apparently a violation of the basic law in classical transplantation immunity. To explore genetic mechanisms of this peculiar phenomenon, GvHR-associated immunosuppression was examined on various kinds of F1 mice undergoing GvHR induced by parental lymphocytes. In F1 mice raised by crossing DBA/2 mice with various H-2-congeneic B10-series strains, parental lymphocytes having non-H-2 genetic background of DBA (DBA/2 and DBA/1) invariably could not induce GvHR-associated immunosuppression, irrespective of the H-2 haplotype incompatibility involved, whereas lymphocytes of the partner parental strain induced the immunosuppression. The number of the relevant loci in the DBA non-H-2 was assessed to be three recessive loci by examination of the capability to induce the GvHR-associated immunosuppression on lymphocytes from individual (B 10.D2 X DBA/2)F1 X DBA/2 backcross mice. On the other hand, in F1 mice raised by crossing C3H/He or AKR/J mice with various H-2-congeneic B10-series strains, parental lymphocytes of H-2k haplotype, irrespective of their non-H-2 haplotype, invariably could not induce the GvHR-associated immunosuppression. Furthermore, it was revealed that non-H-2 genes of parental C3H or AKR incorporated in the F1 mice determine the resistance of the F1 mice against the H-2k-induced GvHR. The results of examination of the resistance on individual (B10 X [B10.BR X C3H/He]F1) and (B10 X [B10.BR X AKR/J]F1) mice suggested that three non-H-2 loci of C3H/He or two non-2 loci of AKR/J incorporated in F1 hybrids could determine the resistance of the respective F1 mice.
The immunocompetence of murine stromal cell-associated thymocytes.
Authors: Fink P J , Weissman I L , Kaplan H S , Kyewski B A 
Published: December 2022

Abstract
Thymocyte subpopulations that associate in vivo with distinct nonlymphoid cells of the thymus have been isolated, and their immunocompetence was analyzed. Previous studies have indicated that greater than 95% of such cells bear a surface antigen phenotype representative of immature thymocytes, and are among the earliest thymic compartments repopulated by bone marrow-derived cells after lethal and sub-lethal irradiation. Stromal cell-associated thymocytes may be activated in vivo because they proliferate well in vitro with no additional stimulus, and show little increase in proliferation with the addition of T cell mitogens or allogeneic spleen cells. Stromal cell-associated T cells contain cytotoxic T lymphocyte (CTL) precursors that are indistinguishable from mature peripheral T cells by the parameters of self tolerance, alloreactivity, H-2 restriction, and stringency of self H-2 preference. CTL precursor frequencies and the cytotoxic activity of cells further separated on the basis of high levels of Thy-1 expression argue against the possibility that stromal cell-associated CTL activity is due solely to contaminating mature lymphocytes. Our data suggest that stromal cell-associated thymocytes represent an intermediate subpopulation of thymocytes that is functionally mature and that expresses an immature surface phenotype. Furthermore, the imposition of self tolerance and MHC restriction specificity appears to be tightly associated with the acquisition of immunocompetence in these thymocyte subpopulations.
Conversion of a tolerogenic to an immunogenic signal by P388AD.2 cells, a lymphoid dendritic cell-like tumor line.
Authors: Phipps R P , Pillai P S , Scott D W 
Published: December 2022

Abstract
The lymphoid dendritic cell-like tumor P388AD.2 is capable of converting a tolerogenic signal into an immunogenic one. In the present study, adherent P388AD.2 cells were pulsed with the tolerogen, fluoresceinated (FL) sheep gamma-globulin (SGG), washed, and incubated with normal spleen cells. After 24 hr, the spleen cells were harvested and challenged in secondary cultures with immunogenic doses of FL-thymic independent (TI) antigens. The plaque-forming cell response on day 3 of secondary culture was increased as much as 400% compared with control spleen cultures exposed to untreated P388AD.2 cells. The increased response was specific for the FL-hapten and occurred only when P388AD.2 cells were pulsed with FL-Ig or FL-F(ab')2 fragments, but not with FL-synthetic tolerogens or other FL-antigens. Furthermore, the augmentation required histocompatible T cells in the primary cultures. Additional experiments showed that if cultures were devoid of Lyt-1+ cells but not Lyt-2+ cells, no augmentation occurred. A variety of other macrophage-like tumor cells, some with known antigen presenting properties, were tested for the ability to present tolerogen in an immunogenic fashion. Only an I-A+ J774 clone was able to present tolerogen in an immunogenic fashion. However, we failed to find a correlation between the presence of surface Ia antigen and tolerogen-presenting ability. The results suggest that certain types of cells may play a role in immune regulation by abrogating the tolerogenicity of Ig tolerogens via their presentation in an immunogenic mode.
IgG-protein A complexes modulate thymidine incorporation into DNA of antibody and complement-stimulated cells.
Authors: Shearer W T , Green C G , Patel P , Langone J J 
Published: December 2022

Abstract
Incubation of protein A (PA) and molar excess of whole rabbit immune IgG in solution favored the formation of high m.w. complexes with the molecular formula of [(IgG)2(PA)]2, which enhanced the incorporation of [3H]thymidine ([3H]dThd) into DNA of L cells, especially in the presence of rabbit or human complement (C). In contrast, complexes with the molecular formula (IgG)(PA), formed by incubation of IgG with molar excess of PA, failed to enhance, or inhibited, the incorporation of [3H]dThd into cells treated with immune IgG alone or with C present, respectively. Concanavalin A (Con A), which is known to bind to critical exposed oligosaccharide structures present in the Fc region of IgG in the [(IgG)2(PA)]2 complexes, reversed the enhancement of [3H]dThd incorporation, and alpha-methyl mannoside, but not D-galactose, inhibited the Con A reversal. The [(IgG)2(PA)]2 complexes efficiently activated the C cascade, caused significantly higher levels of aggregation of cells, and increased the binding of immune IgG to the cells when compared to the (IgG)(PA) complexes. Both types of complexes, isolated by sucrose density ultracentrifugation, were precipitable in a radioimmunoassay with chicken anti-PA antibodies and were capable of binding to intact L cells.