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J L Kadish

Publications and source records attributed to J L Kadish.

16 recordsLinked to original sources
PubMed1995

Biochemical properties of the ligand-binding 20-kDa subunit of the beta-glucan receptors on human mononuclear phagocytes.

beta-Glucan receptors are present on mammalian leukocytes and initiate phagocytosis of particulate yeast beta-glucans, such as zymosan particles. Human monocytes and U937 cells express two membrane proteins of 180 and 160 kDa, each of which binds particulate yeast glucan through a 20-kDa polypeptide constituent. In this report, the structural composition of the two beta-glucan receptors and the biochemical properties of their polypeptide constituents were examined. The 180-kDa receptor was composed of three disulfide-linked polypeptides of 95, 60, and 20 kDa, whereas the 160-kDa receptor was a multimer of two polypeptides of 27 and 20 kDa. Unlike other receptor constituents, the 20-kDa polypeptide was nonglycosylated and focused at two distinct isoelectric points. Immunoblots of the focused polypeptides showed the two 20-kDa variants and the 95-kDa subunit to be constitutively tyrosine-phosphorylated, a feature not previously reported for receptors on human mononuclear phagocytes. Dephosphorylation of the receptor proteins resulted in the loss of antigenic phosphotyrosine without affecting the antigenicity of either 20-kDa variant for the anti-idiotypic antibody to beta-glucan receptors. Separate analysis of the 160-kDa receptor showed it contained both variants of the 20-kDa polypeptide. Thus, the 20-kDa subunit constituent of the two beta-glucan receptors is a functionally and chemically unique polypeptide with apparent microheterogeneity in its primary structure.

Amino Acids↗
PubMed1990

Production and isolation of rabbit anti-idiotypic antibodies directed against the human monocyte receptor for yeast beta-glucans.

beta-Glucan receptors are present on mammalian phagocytic cells and provide an important physiologic mechanism for opsonin-independent clearance of yeasts and fungi. To prepare an immunologic probe to human monocyte beta-glucan receptors, an approach was taken that focused on the ligand specificity of the receptors as expressed by an anti-Id. The algal beta-glucan laminarin was chemically coupled to protein carriers to prepare an immunogenic beta-glucan. Three mouse IgG2a mAb were raised against laminarin, and one, mAb OEA10, exhibited specificity for the soluble unit ligand yeast heptaglucoside and the ligands present on zymosan and glucan particles that are recognized by monocyte beta-glucan receptors. These findings prompted usage of mAb OEA10 as immunogen for the preparation of an anti-Id. The resulting rabbit antiserum was subjected to sequential immunoaffinity chromatography to purify anti-idiotypic antibodies. The final product contained only IgG by SDS-PAGE and was shown to be specific by its selectively blocking binding of 125I-mAb OEA10 to laminarin. Pretreatment of adherent monocytes with 0.4 micrograms/ml of the anti-Id reduced the numbers of monocytes ingesting zymosan and glucan particles by 64 and 43%, respectively, whereas ingestion of IgG-coated SRBC was unaffected by as much as 16 micrograms/ml of the anti-Id. Incubation of adherent monocytes with increasing amounts of 125I-anti-Id in the absence and presence of 40-fold molar excess unlabeled anti-Id revealed dose-dependent specific binding, which approached plateau levels with 1 microgram/ml of labeled anti-Id. Thus, the anti-Id binds to monocytes and displays functional characteristics of soluble beta-glucan ligands, indicating that some of the anti-idiotypic antibodies recognize epitopes within monocyte beta-glucan receptors.

Animals↗
PubMed1986

Phagocytosis of unopsonized zymosan particles by trypsin-sensitive and beta-glucan-inhibitable receptors on bone marrow-derived murine macrophages.

Murine bone marrow cells, plated at 4 X 10(4) cells/well and cultured in 50% fibroblast CM, yielded pure populations of large, individual, adherent cells that were phagocytic and morphologically indistinguishable from macrophages. Adherent macrophages appeared in small numbers with 24 h of culture, increased to maximal cell numbers within 10 days of culture, and remained at these cell densities for at least 11 weeks in culture. The capacities of adherent macrophages to ingest unopsonized zymosan particles and EsIgG, at inputs of 1.25 X 10(7) targets, were expressed by 7 and 40% of the cells derived from 24-hour cultures, respectively, were increased at nearly identical rates to comparable maximal levels within 10-14 days of culture and were exhibited by essentially all adherent cells derived from 2-11-week cultures. The percentage of adherent macrophages from twelve 3-6-week cultures ingesting greater than or equal to 1, greater than or equal to 6 and greater than or equal to 10 zymosan particles was 89 +/- 5, 47 +/- 11 and 14 +/- 9% (mean +/- SD, n = 12), respectively, and the percentage ingesting greater than or equal to 1, greater than or equal 6 and greater than or equal to 10 EsIgG was 86 +/- 5, 49 +/- 10 and 14 +/- 8%, respectively. Incubation of adherent macrophages with mannan-free ss-glucan particles at inputs of 5 X 10(5)-5 X 10(7)/ml initiated a phagocytic response comparable to that obtained with the same doses of zymosan particles which contained mannan and beta-glucan. Preincubation of adherent macrophages with 100 micrograms/ml of a fully soluble beta-glucan, laminarin, and solubilized barley beta-glucan reduced subsequent macrophage phagocytosis of greater than or equal to 6 zymosan particles by 53 and 40%, respectively. In contrast, yeast alpha-mannan was less than 1% as active, and 10 mg/ml reduced the number of adherent macrophages ingesting greater than or equal to 1 zymosan particles by 64%. At concentrations as high as 2 mg/ml, laminarin and barley beta-glucan had no effect on Fc receptor-mediated ingestion of EsIgG, and mannan at 20 mg/ml also failed to inhibit EsIgG ingestion. Pretreatment of adherent macrophages with 20 micrograms/ml of trypsin reduced the number of cells ingesting greater than or equal to 1 zymosan particles from 89 to 10% and those ingesting greater than or equal to 6 zymosan from 43 to 0%, whereas pretreatment with as much as 100 micrograms/ml of trypsin failed to decrease macrophage ingestion of EsIgG.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1985

Identification with monoclonal antibodies of different regions of human plasma fibronectin, including that which interacts with human monocyte fibronectin receptors.

The determinant specificities of five monoclonal anti-fibronectin antibodies, designated BC7, CE9, BD4, AB3 and CPG1, were defined and mapped within intact human plasma fibronectin by immunoblot analyses with defined fragments of fibronectin. The latter were derived by tryptic, chymotryptic or cathepsin D digestion of the intact molecule and fractionated by DE-cellulose chromatography and gelatin and/or heparin affinity chromatography. Monoclonal BC7 recognizes intrachain disulphide-formed determinants within the 27,000 MW N-terminal domain; monoclonal CE9 recognizes determinants within an 18,000 MW fragment immediately adjacent to the carboxyl end of the gelatin-binding domain; monoclonal BD4 recognizes determinants within the cell-adhesive domain and within 150,000 of the N-terminus; monoclonal AB3 recognizes intrachain disulphide-formed determinants within 35,000 of the COOH-terminus of the intact molecule and detectable only on the alpha-chain polypeptide subunit; and monoclonal CPG1 recognizes determinants present on both chains of the intact molecule and immediately adjacent to the interchain disulphide bonds at the COOH-terminus. None of the epitopes recognized by these monoclonal antibodies is present at alternative regions of the intact molecule. Fab fragments of each of these monoclonal antibodies were incubated with gelatin-coated sheep erythrocytes which had been reacted with a fixed amount of intact plasma fibronectin. When these target particles were incubated with monolayers of human monocytes and the resultant rosettes were quantitated, the Fab fragments of BD4 markedly inhibited the proportion of monocytes binding these fibronectin-bearing targets, whereas none of the other Fab fragments had an inhibitory effect. Thus, monocyte fibronectin receptors which mediate adherence of fibronectin bridges to a target via gelatin recognize regions within the cell-adhesive domains of intact fibronectin but not regions at the amino or carboxy terminals.

Antibodies, Monoclonal↗
PubMed1985

Characterization of the opsonic and monocyte adherence functions of the specific fibronectin fragment that enhances phagocytosis of particulate activators.

The functional opsonic and monocyte adherence domains within the 180,000 m.w. opsonic fibronectin fragment (180K-opFnf) that selectively augments human monocyte phagocytosis of particulate activators of the alternative complement pathway were analyzed with Fab fragments of monoclonal anti-fibronectin antibodies BC7, CE9, BD4, AB3, and CPG1, and with fragments of intact human plasma fibronectin derived by cathepsin cleavage and isolated by affinity chromatography. Monoclonals AB3 and CPG1, which recognize epitopes within 40,000 daltons of the carboxy terminus of intact fibronectin, and the cathepsin D-derived, disulfide-linked fragments that contain these epitopes each inhibited the opsonic function of 180K-opFnf. Monoclonals AB3 and CPG1 inhibited monocyte ingestion of rabbit erythrocytes (Er) by 60 and 50%, respectively, when 180K-opFnf was pretreated with 20 micrograms of these monoclonals, but neither monoclonal affected the enhanced monocyte ingestion of Er pretreated with the fibronectin fragment. The pretreatment of Er with 5 micrograms and 40 micrograms of the disulfide-linked, cathepsin D derivatives isolated from high and low affinity heparin fractions, respectively, inhibited the proportion of ingesting monocytes by 60%, but these types of fragments had little effect when concurrently incubated with the opsonic fragment and Er. Monoclonals CE9 and BD4, which recognize epitopes located adjacent to or within the cell-adhesive domain of intact fibronectin, respectively, inhibited the monocyte adherence function of 180K-opFnf, as evidence by their comparable inhibitory effects when present before or after Er were opsonized with 180K-opFnf. When 20 micrograms of monoclonals CE9 and BD4 were each introduced before and after Er were opsonized with 180K-opFnf, monocyte ingestion was inhibited by 60 and 65% and by 51 and 60%, respectively. At 42 micrograms, cathepsin D-derived, non-gelatin-binding, low affinity heparin fragments that contained both BD4 and CE9 determinants or only the BD4 determinant inhibited monocyte ingestion by 53 and 74%, respectively, when concurrently incubated with 180K-opFnf and target Er, but were without effect when used to pretreat Er before the addition of 180K-opFnf. Thus, the inhibitory effects produced by monoclonals AB3 and CPG1 and by cathepsin D-derived, disulfide-linked fragments containing their corresponding epitopes demonstrated that the opsonic domain within 180K-opFnf is immunologically similar to regions within the carboxy terminus of intact plasma fibronectin.(ABSTRACT TRUNCATED AT 400 WORDS)

Adjuvants, Immunologic↗
PubMed1983

Tissue factor activity of normal and neoplastic cells: quantitation and species specificity.

The expression of tissue factor activity was evaluated in homogenates and in intact whole cells from a variety of human and nonhuman cell lines of normal and neoplastic origin. A high degree of species specificity in the interaction of tissue factor with other coagulation factors was observed in guinea pig, rat, mouse, and hamster cells. Tissue factor was present in significant amounts in homogenates of both the normal and neoplastic cells tested in all four species examined. No correlation was observed between the amount of tissue factor detected in cell homogenates and the derivation of the cell line from normal versus neoplastic tissue. Intact cells also expressed tissue factor activity, but lower levels were found in most cell lines examined. The significance of these data is discussed with regard to fibrin deposition around tumors in vivo.

Animals↗
PubMed1981

Augmentation of human monocyte opsonin-independent phagocytosis by fragments of human plasma fibronectin.

Human plasma fibronectin isolated by gelatin-affinity chromatography increases in a dose-dependent fashion the number of human monocytes that ingest particulate activators of the human alternative complement pathway in a fully synthetic medium. The fibronectin effect is selective for these particulate activators, does not extend to particles whose ingestion is dependent upon opsonization with IgG, and is not observed with pretreatment of the monocytes. Affinity chromatography with monoclonal antibody to plasma fibronectin of 440,000 daltons reveals that only 12-53% of the protein in a phagocytically active gelatin-affinity-purified fibronectin preparations is bound to the antibody. The protein eluted after affinity chromatography with monoclonal antibody of active preparations, which represented 10-43% of the protein applied, exhibits a 2- to 10-fold increment of activity per microgram of protein above the starting gelatin-affinity-purified material. Thus, the activity that augments the percent of human monocytes ingesting particulate activators of the alternative pathway is antigenically defined as plasma fibronectin. Preparations containing only intact 440,000-dalton fibronectin are also bound to and eluted from the monoclonal antibody, but they fail to augment phagocytosis. When inactive 440,000-dalton plasma fibronectin is subjected to limited trypsin cleavage, phagocytosis-enhancing activity develops that is bound to and elutes from the affinity column prepared with monoclonal antibody, thereby indicating that the enhancing activity of plasma fibronectin resides in cleavage fragments.

Clone Cells↗
PubMed1979

Fibrin and atherogenesis--a hypothesis.

It has recently been found that endothelial cells exhibit an unusual change in cellular behavior in response to contact with fibrin. The possible implications of this finding with regard to the mechanism of atherogenesis are discussed. It is proposed that mural fibrin in vivo may produce a disorganized endothelium which can act as a nidus for further fibrin deposition and platelet aggregation. In the presence of inadequate fibrinolysis, a prolonged endothelial lesion could occur which may eventually result in atheromatous plaque formation. This view of atherogenesis requires reduced fibrinolytic activity as a prerequisite for plaque formation, a requirement which is in agreement with currently known data associating atherogenic risk factors with inhibited fibrinolysis.

Animals↗
PubMed1979

The effect of fibrin on cultured vascular endothelial cells.

The normal cobblestone monolayer architecture of cultured vascular endothelium becomes rapidly disorganized after contact of the cell layer with a fibrin clot. The cells of a confluent endothelial monolayer separate into individual migratory cells in 4--6 hr after contact with fibrin. The effect is reversible in that removal of the fibrin clot results in resumption of the normal morphology within about 2 hr. No other cell type tested exhibits the same change in organization when exposed to fibrin. A similar morphological change in endothelium does occur after the cell layer is overlaid with a collagen fibril gel but a gel of methylcellulose has no effect. It is proposed that the change in behavior of endothelial cells in response to contact with fibrin may represent a cellular component of fibrinolysis. The implications of this finding for the pathophysiology of disease states involving intravascular fibrin deposition are discussed.

Animals↗
PubMed1978

Hematopoietic thymocyte precursors: IV. Enrichment of the precursors and evidence for heterogeneity.

A method has been developed for the enrichment of the hematopoietic precursors of thymocytes from spleen and bone marrow cells. Up to 40-fold enrichments were obtained resulting in preparations in which as few as 10(5) cells produced prompt repopulation of the thymus of an irradiated mouse. Precursor cells from bone marrow appear to contain the enzyme terminal deoxyribonucleotidyl transferase (Tdt), an agent suggested as a potential somatic mutator. This enzyme (Tdt) was not detectable in any spleen cell preparation examined, including one in which a 40-fold enrichment of thymocyte precursors had been produced. This is the first difference reported between the splenic and bone marrow precursors of thymocytes.

Animals↗
PubMed1977

Hematopoietic thymocyte precursors: II. Properties of the precursors.

The properties of hematopoietic cells which serve as the precursors of cortical thymocytes in irradiated reconstituted mice have been described. These cells have been termed "prothymocytes." They are 10- to 15-mum diameter cells of low buoyant density. They are nonadherent to glass wool and more resistant to the lytic effects of steroids and gamma-irradiation than their progeny. They lack detectable amounts of the surface markers associated with either B or T cells but do bear at least two antigens recognized by antisera to mouse brain.

Animals↗
PubMed1976

Hematopoietic thymocyte precursors. I. Assay and kinetics of the appearance of progeny.

A quantitative assay for the hematopoietic precursor of thymocytes has been developed. Using this assay the kinetics of appearance of the progeny of transfused bone marrow and spleen cells in the thymus of irradiated (760 R) mice has been studied. Precursor cells are seven to eightfold more common in bone marrow than in spleen and are absent from peripheral lymph nodes. They decline in number as the animals age. When hematopoietic cells are injected immediately after lethal irradiation only a small number of cells actually enter the gland. Their progeny are not detectable in the thymus for 8-12 days. The time of their detection depends both upon the size of the residual endogenous thymocyte population and the number of progenitor cells injected. Evidence has been presented that excludes thymic injury as the basis for the delay in the appearance of donor type cells and indicates that neither the production of a "homing" signal in the irradiated animal nor the development of precursor cells are limiting factors in the rate of thymic repopulation. These studies indicate that only an exceedingly small number (less than 100) of prothymocytes are required to repopulate the thymus of an irradiated mouse. This restricted number of progenitors must produce the entire repertory of T-cell immunologic responsiveness seen in the first weeks after repopulation.

Age Factors↗
PubMed1975

Thymic regeneration after lethal irradiation evidence for an intra-thymic radioresistant T cell precursor.

The data presented indicate the existence of a significant pool of radioresistant stem cells which are capable of partially restoring the thymus of heavily irradiated mice. 3-H-TdR incorporation by the thymus of lethally irradiated mice begins 48 to 72 hr after irradiation and increases throughout the next 8 days. By the 9th day after 760 rads, typical corticomedullary architecture has been restored. 890 rads markedly suppressed, but did not totally eliminate this regeneration. Injection of large numbers of syngeneic bone marrow cells immediately after irradiation was without effect on the rate or extent of regeneration. Mice whose bone marrow and spleen were shielded from irradiation showed an identical amount of thymic regeneration as those receiving total body irradiation indicating that the precursor cell pool responsible for the early post irradiation phase of thymic regeneration is most likely an intrathymic population. The cells repopulating the thymus were morphologically indistinguishable from normal thymocytes and were susceptible to cytotoxic antisera against the thymic differentiation antigens Thy-1, TL, LyA2 and LyC2.

Animals↗