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Biomedical subjects

A Kulczycki

Publications and source records attributed to A Kulczycki.

At least 37 records · Page 2Linked to original sources
PubMed1985

Bovine IgG and human immune responses: Con A-induced mitogenesis of human mononuclear cells is suppressed by bovine IgG.

Cow's milk contains 0.6-0.9 mg/ml of IgG. Under certain circumstances humans might potentially absorb significant amounts of bovine IgG and/or large fragments of bovine IgG from their diets. Normal human peripheral blood mononuclear cells were cultured with bovine milk IgG and various mitogens to begin to investigate whether bovine IgG might influence human immunologic responses. Elsewhere we have shown that bovine milk IgG at concentrations of 300 micrograms/ml completely suppressed synthesis of IgG, IgA, and IgM (96-98% suppression) in pokeweed (PWM)-stimulated cultures. Suppression was dose dependent from 40 to 300 micrograms/ml. Milk-derived bovine IgG heated at 63 degrees C during 30 min was more potent in suppression than unheated IgG. IgG from goat's milk also suppressed Ig synthesis. Bovine serum IgG and other xenogeneic serum immunoglobulins, even when heat-aggregated, had little effect on Ig synthesis. Preincubation of MNCs with bovine milk IgG and PWM for 1 day followed by washing and incubation with PWM for 14 days resulted in suppression of antibody secretion. In this study, Con A-stimulated cultures were pulsed after 3 or 4 days with 3H-thymidine for 4 h, and mitogenic responses were measured. Bovine IgG at concentrations as low as 300 micrograms/ml significantly suppressed the mitogenic response of human mononuclear cells. These studies suggest that ingested milk immunoglobulins may have the potential to modulate immune responses in humans.

Animals↗
PubMed1984

Human neutrophils and eosinophils have structurally distinct Fc gamma receptors.

Human Fc gamma receptors were isolated from surface radioiodinated granulocytes and eosinophils by using repetitive affinity chromatography on human IgG-Sepharose columns. Analysis by SDS-polyacrylamide gel electrophoresis demonstrated that cell preparations containing eosinophils possessed a 43,000 Mr Fc gamma-binding macromolecule. Nylon wool-filtered cells from patients with eosinophilia and cell cultures derived from normal donors provided highly purified eosinophil preparations that expressed only the 43,000 Mr Fc gamma receptor. Granulocyte populations yielded the 52,000 to 68,000 Mr Fc gamma receptor characteristic of neutrophils as well as the Fc gamma-binding macromolecules apparently derived from eosinophils. The 43,000 Mr Fc gamma receptor of the eosinophil and the 31,000 and 34,000 Mr fragments that appear to be derived from it were able to rebind selectively to human IgG1-Sepharose, Fc gamma 1-Sepharose, IgG3-Sepharose, and Fc gamma 3-Sepharose. In contrast, the 52,000 to 68,000 Mr Fc gamma receptor from neutrophils could rebind only to IgG1-Sepharose and Fc gamma 1-Sepharose. The results demonstrate that the Fc gamma receptor of human eosinophils is distinct in structure from the neutrophil Fc gamma receptor and that these Fc gamma receptors, at least in their solubilized states, differ in specificity for human IgG3.

Chromatography, Affinity↗
PubMed1983

Selective phosphorylation of the IgE receptor in antigen-stimulated rat mast cells.

Purified rat serosal mast cells were sensitized with mouse immunoglobulin E (IgE) anti-2,4-dinitrophenyl antibody, partially depleted of phosphate, labeled with [32P]orthophosphate, and stimulated with dinitrophenylated bovine serum albumin or control protein. After 15-120 seconds at 37 degrees C, the cells were extracted with nonionic detergent. IgE receptors were purified by repetitive affinity chromatography and were analyzed by NaDodSO4/polyacrylamide gel electrophoresis and radioautography. Antigenic stimulation of intact rat mast cells produced a rapid and marked increase in the phosphorylation of the surface-exposed alpha component of the IgE receptor. However, phosphorylation of the 33,000 Mr beta component of the IgE receptor was not altered significantly by antigen stimulation. This suggests that the selective increase in phosphorylation of the IgE receptor alpha component may be part of the physiologic mediator secretion process triggered by antigen.

Animals↗
PubMed1983

Human monocytes, B lymphocytes, and non-B lymphocytes each have structurally unique Fc gamma receptors.

Human Fc gamma-binding macromolecules were isolated from subpopulations of mononuclear cells by repetitive affinity chromatography. Mononuclear cells, nylon wool-filtered cells, plastic-nonadherent cells, and plastic-adherent cells from normal donors were radiolabeled by using 125I and lactoperoxidase. Washed cells were solubilized in 1% NP-40 buffer containing proteinase inhibitors at 0 degrees C. Fc gamma receptors were purified on human IgG-Sepharose columns by use of the repetitive affinity chromatography procedure. Analysis by SDS-polyacrylamide gel electrophoresis demonstrated only a 52,000 to 58,000 Mr Fc gamma receptor from nonadherent cell populations. Both rosetting and nonrosetting subpopulations of non-B lymphocytes expressed the 52,000 to 58,000 Mr receptor. The predominant Fc gamma receptor isolated from plastic-adherent cells was a 60,000 to 68,000 Mr macromolecule. Cell preparations enriched in B lymphocytes yielded prominent 43,000 Mr Fc gamma receptors. Thus human monocytes, B lymphocytes, and non-B lymphocytes each appear to have structurally distinct and unique Fc gamma receptors.

Chemical Phenomena↗
PubMed1982

Ligand binding specificity of a rabbit alveolar macrophage receptor for C3b.

We have recently reported the isolation from rabbit alveolar macrophages of a receptor which retained its ligand-binding activity for the third component of complement (C3) and for its major proteolytic derived activation fragment (C3b). The isolated receptor demonstrated a greater ability to bind C3b than an equimolar amount of C3. C3b differs from C3 in at least two ways: it is a proteolytic cleavage product of C3 and it lacks the internal thiolester bond of C3. We have analyzed the binding ability to isolated receptor to various C3 and C3b analogs and we demonstrate that the specificity of the C3b-C3b receptor interaction depends upon the lysis of the C3 thiolester bond and accompanying conformational change rather than upon proteolytic cleavage of the C3 molecule. Minimal, if any, binding of C3 with an intact thiolester bond to the isolated receptor was demonstrable.

Animals↗
PubMed1982

Comparison of the receptors for IgE of various rat basophilic leukaemia cell lines. I. Receptors isolated by IgE-sepharose and IgE and anti-IgE.

REceptors for IgE of rat basophilic leukaemia (RBL) cells, maintained in different laboratories were isolated by means of IgE-Sepharose or IgE and anti-IgE, and characterized by SDS-polyacrylamide gel electrophoresis. All cell lines were found to be associated with a receptor molecule (R) which could be isolated either with IgE-Sepharose or IgE and anti-IgE and a second receptor (H) which could only be isolated with the aid of IgE-Sepharose. The relative amounts of these two molecules, as isolated from surface iodinated cells, varied from the RBL cell line to the other and their apparent molecular weights were not identical on all cell lines. Since comparisons were made on the same gel using receptors isolated from cells labelled with different isotopes of iodine, differences in molecular weight must be considered as being intrinsic and not due to methodological variations. These results provide an explanation why differences were observed among receptors for IgE as characterized in various laboratories. In spite of the fact that the various RBL cell lines originated from the same chemically-induced tumour they have, over the years, undergone changes which are reflected in the receptors for IgE.

Animals↗
PubMed1981

The cell surface receptor for immunoglobulin E. Effect of tunicamycin on molecular properties of receptor from rat basophilic leukemia cells.

Cell surface receptors for immunoglobulin E were isolated by repetitive affinity chromatography from rat basophilic leukemia cells biosynthetically labeled with L-[35S]methionine and D-[3H]mannose. Native immunoglobulin E receptor appeared as a very broad band in the 45,000 to 62,000 Mr region in sodium dodecyl sulfate polyacrylamide gels. However, from cells cultured in the presence of tunicamycin, a relatively narrow band with an apparent Mr of 38,000 was isolated. The 38,000 Mr band rebound to immunoglobulin E-Sepharose, was immunoprecipitated with antibodies to immunoglobulin E receptor, shared tryptic peptides with native receptor, and was labeled with L-[35S]methionine but not D-[3H]mannose, and thus appears to be immunoglobulin E receptor lacking N-linked oligosaccharides. It is demonstrated that N-linked oligosaccharides account for much of the apparent heterogeneity of native receptor in sodium dodecyl sulfate polyacrylamide gels and in two-dimensional gel electrophoresis. A receptor-associated protein with apparent Mr = 30,000, prominently labeled with L-[35S]methionine but not with D-[3H]mannose, did not have altered molecular properties when isolated from tunicamycin-cultured cells, and did not share tryptic peptides with receptor.

Animals↗
PubMed1981

Isolation of a biologically active macrophage receptor for the third component of complement.

C3b, the major cleavage fragment of the third component of complement (C3), has been demonstrated to bind to a specific receptor on various mammalian cells. Tissue-bound C3b receptors have also been demonstrated, most conclusively in renal glomeruli. On interaction with C3b, C3b receptors are thought to initiate cellular functions such as phagocytosis and to determine the fate of complement-fixing soluble and particulate immune complexes. We report here the isolation by affinity chromatography of a macrophage glycoprotein with an apparent molecular weight (MW) of approximately 64,000 that has properties expected of the C3b receptor. It is a cell-surface macromolecule (labelled with 125I and lactoperoxidase) which, in its isolated state, retains the ability to bind both C3 and C3b.

Animals↗
PubMed1981

Isolation and partial characterization of Fc gamma-binding proteins of human leukocytes.

We isolated and partially characterized three Fc-binding macromolecules from human leukocytes. Mononuclear cells from normal individuals and from five patients with chronic lymphocytic leukemia and neutrophils from normal donors were surface radiolabeled by using 125I and lactoperoxidase. After detergent solubilization of the cells, Fc gamma-binding macromolecules were purified by repetitive affinity chromatography under a variety of conditions and analyzed by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. Three radiolabeled macromolecules were isolated that retained specific ability to bind to Fc fragments. A 52,000-64,000-mol wt macromolecule was isolated from normal mononuclear and polymorphonuclear cells. A 43,000-mol wt band was characteristic of mononuclear cells, particularly from patients with chronic lymphocytic leukemia. A 33,000-mol wt molecule could be obtained from normal leukocytes under conditions that suggest it might be a proteolytic fragment.

Cell Separation↗
PubMed1981

Characterization of ligand-binding activity of isolated murine Fc gamma receptor.

Fc gamma-binding macromolecules were isolated from 2 murine macrophage-like cell lines by affinity chromatography using various immunoglobulins coupled to Sepharose. P388D1 and J744.2 cells were radiolabeled with 125I using a modified lactoperoxidase method, washed cells were solubilized using NP-40, and the solubilized cell lysates were incubated at 4 degrees C with immunoadsorbents. Fc gamma receptor-like material was obtained from the IgG-Sepharose columns by elution at 4 degrees C with 0.5 N acetic acid containing 1% NP-40 into buffer for neutralization. Purified material thus obtained retained its ligand-binding activity, since approximately 30 to 60% rebound to IgG-Sepharose. Upon analysis by SDS polyacrylamide gel electrophoresis, putative Fc gamma receptor had an apparent m.w. of 50 to 65,000. Neither a comparable SDS-PAGE band nor receptor activity was isolated from a 3rd murine cell line, which lacks the Fc gamma receptor. Putative receptor obtained by elution from IgG2a-Sepharose rebound equally well to IgG2a-, IgG1- and IgG2b-Sepharose, but did not rebind to IgG3-, F(ab')2-, or BSA-Sepharose. Similarly, Fc gamma-binding macromolecules eluted from IgG2b-Sepharose rebound only to IgG2b-, IgG2a- and IgG1-Sepharose rebound only to IgG2b-, IgG2a- and IgG1-Sepharose. The rebinding of either receptor preparation was inhibited in a dose-dependent manner by both monomeric IgG2a and monomeric IgG2b, and myeloma protein from each subclass inhibited to the same extent. Therefore, the mouse Fc gamma receptor in its isolated state does not appear to discriminate between monomeric IgG2a and IgG2b.

Animals↗