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Biomedical subjects

M B Prystowsky

Publications and source records attributed to M B Prystowsky.

101 records · Page 6Linked to original sources
PubMed1983

Biologic properties of homogeneous interleukin 3. I. Demonstration of WEHI-3 growth factor activity, mast cell growth factor activity, p cell-stimulating factor activity, colony-stimulating factor activity, and histamine-producing cell-stimulating factor activity.

Interleukin 3 (IL 3) was initially defined as a factor in conditioned media from concanavalin A-stimulated lymphocytes (Con A CM) that induces the enzyme 20-alpha-hydroxysteroid dehydrogenase (20 alpha SDH) in cultures of nu/nu splenic lymphocytes. To determine the spectrum of additional "biologic" activities, IL 3 was purified to homogeneity and its properties were assessed. The protein preparation was judged to be homogeneous IL 3 by the following criteria: 1) elution of a peak of IL 3 with a constant specific activity in the last step of purification, 2) presence of a single protein by SDS-PAGE analysis, 3) receptor-binding activity against IL 3-dependent cell lines, 4) a specific activity of congruent to 0.2 ng/ml required for 50% of maximal biologic activity, and 5) the presence of a single amino terminal sequence. With the use of this preparation of IL 3, the dose-response curves for 20 alpha SDH induction were identical or similar to the dose-response curves for the activities of 1) WEHI-3 growth factor, 2) mast cell growth factor, 3) P cell-stimulating factor, and 4) histamine-producing cell-stimulating factor. In addition, homogeneous IL 3 had colony-stimulating factor activity, although only approximately 2% of the total CSF activity found in Con A CM was associated with IL 3. The major peak of CSF activity could be resolved from IL 3 by DEAE column chromatography and lacked many of the biologic activities associated with IL 3.

Animals↗
PubMed1983

Partial purification and characterization of a colony-stimulating factor secreted by a T lymphocyte clone.

The mouse T lymphocyte clone L2 secretes a minimum of 10 lymphokine activities affecting at least 5 different target cells. Large amounts of colony-stimulating factor (CSF) (8.6 X 10(6) U/ml) can be obtained by stimulating L2 cells with concanavalin A. The major CSF activity secreted by L2 cells has been enriched to a specific activity of approximately 2-4 X 10(8) colonies/mg of protein using hydrophobic-interaction, gel-permeation, ion-exchange, and lectin-affinity chromatography. This preparation of CSF contains no detectable interleukin 2, interleukin 3, or interferon. The major L2-cell CSF induces granulocyte/macrophage colonies from bone marrow cells. This GM CSF has an apparent Mr of 22,000 as determined by gel-permeation chromatography. Treatment of L2-cell CSF with proteolytic enzymes abrogates biologic activity.

Animals↗
PubMed1982

Alloreactive cloned T cell lines. VI. Multiple lymphokine activities secreted by helper and cytolytic cloned T lymphocytes.

Culture supernatants generated by alloantigenic or lectin stimulation of a cloned helper T lymphocyte, designated L2, contain interleukin 2 (IL 2), granulocyte/macrophage colony-stimulating factor (CSF), B cell stimulating factor (BCSF), macrophage (Ia+)-recruiting factor (MIRF), (Ia+)-inducing activity, gamma-interferon, Fc receptor-enhancing activity, macrophage migration inhibitory factor (MIF), macrophage activation factor (MAF), interleukin 3 (IL 3), and a factor responsible for prolonging the synthesis and secretion of the fourth and second components of complement by guinea pig peritoneal macrophages. Erythropoietin was not detected. A spontaneously arising variant of L2, designated L2V, produces much lower quantities of macrophage-stimulating activities, IL 2, and interferon. However, when compared to L2, L2V produces much higher levels of BCSF, equivalent amounts of IL 3, and slightly smaller amounts of CSF. Unlike L2V, a cytolytic clone, designated L3, secretes lymphokines that primarily affect macrophage function. The time course of lymphokine production by L2 cells indicates that for the six lymphokine activities studied there are three different times at which maximal or near maximal levels are reached, as follows: 1) IL 2, 12 to 24 hr; 2) IL 3 and CSF, 24 to 48 hr; and 3) (Ia+)-inducing activity, MAF, and interferon, 48 hr or later. Only IL 2 activity disappears during the 8-day culture cycle. The time course data and the differential production of activities by the three types of lymphocyte clones suggest that at least four terminal effector lymphokine molecules account for the ten biologic activities tested.

Animals↗
PubMed1981

Solid-phase peptide synthesis under continuous-flow conditions.

A system is described for solid-phase synthesis of peptides under continuous-flow conditions with liquid chromatographic equipment, conventional polystyrene supports, and well-defined chemistry. The model tetrapeptide Leu-Ala-Gly-Val was assembled in 99.3% purity in about 4 hr on microporous copoly(styrene-1% divinylbenzene). During coupling, the preformed symmetric anhydrides were conserved by being recycled. Relative yields of the peptide products were determined quantitatively in 20 min by reverse-phase high-pressure liquid chromatography. This rapid assay system was used to examine the influence on product yields of (i) the time and number of couplings per cycle, (ii) microporous versus macroporous polystyrene, and (iii) tert-butoxycarbonyl (Boc) group versus 9-fluorenylmethoxycarbonyl for amine protection. Use of microporous polystyrene and two 30-min couplings of Boc-amino acids per cycle gave the best results. This continuous-flow system provides a rapid and efficient approach to solid-phase peptide synthesis. A 17-residue peptide from chicken ovalbumin was obtained in similar purity and yield from a discontinuous synthesis and from a continuous-flow synthesis.

Amino Acid Sequence↗
PubMed1981

Alloreactive cloned T cell lines. V. Differential kinetics of IL 2, CSF, and BCSF release by a cloned T amplifier cell and its variant.

A noncytolytic, Thy-1+, MIs-responsive cloned T amplifier cell, designated L2, derived from secondary C57BL/6 anti-DBA/2 mixed leukocyte culture was found to produce IL 2 (Interleukin 2), granulocyte/macrophage colony-stimulating factor (CSF), and a polyclonal B cell-stimulating factor (BCSF) after alloantigenic stimulation. IL 2 activity was present transiently, with maximal levels observed 12 to 24 hr after exposure to alloantigen. Only trace amounts were present 96 hr after initiation of culture. CSF and BCSF activities were present at high levels by 24 hr and remained elevated throughout an 8-day culture period. Further evidence that the lymphokine(s) having IL 2 activity is different from those having CSF and BCSF activities was provided by L2V, a variant of L2 that did not produce IL 2. The time course of CSF and BCSF production by L2V after stimulation with alloantigen was similar to that found with L2, although IL 2 activity was not detected at any time. Since the release of lymphokines from both L2 and L2V cells could be induced by Con A in the absence of stimulating alloantigen, it is likely that the biologically active factors were produced by the cloned T cell.

Animals↗
PubMed1978

Detection of H2-b and Thy-1.2 surface antigens on the differentiating murine otocyst using Nomarski optics.

The 12th postcoital day otocyst appears as a hollow cellular ball of pseudostratified columnar epithelium that has entered into its inital stages of differentiation and organogenesis. H-2b antigen was demonstrated on the ectodermally derived epithelial cells of the otocysts and on the mesodermally derived cells of the surrounding mesenchyme. Thy-1.2 antigen was detected in the mesenchymal cells, but not on the epithelial cells of the otocyst. The use of Nomarski optics as a new method for detecting cell surface staining that would otherwise be undetected by bright field optics was demonstrated.

Animals↗
PubMed1975

Intracellular localization of the migration inhibitory factor (MIF) in a long-term human lymphoid cell line.

Subcellular fractions of the human lymphoid cell line PGLC-33H were obtained by N2 cavitation and differential centrifugation. The purity of the fractions was assessed by the use of the following marker enzymes: beta-glucuronidase for the lysosomal-intermediate fraction; a nonspecific esterase for the microsomal fraction; and LDH for the supernatant fraction. These subcellular fractions were studied for MIF activity utilizing human lymphoid cells from established lines as target cells. MIF activity was most consistently found in the microsomal fraction. Also, MIF activity was closely associated with the relative specific activity of exterase. No such correlation with MIF activity could be demonstrated for beta-glucuronidase or LDH.

Cell Fractionation↗
PubMedDate not supplied

Rapamycin blocks IL-2-driven T cell cycle progression while preserving T cell survival.

Effective cellular immune responses require increases in antigen-specific T lymphocytes; IL-2 drives antigen-stimulated T cell proliferation and is largely responsible for the increases observed. We used microarrays containing approximately 9000 mouse cDNAs to study IL-2-induced gene expression. IL-2 induces the expression of genes that regulate cell cycle progression, control cell survival, and increase synthetic and metabolic processes during proliferation. IL-2 also suppresses expression of genes that block cell cycle progression and promote cell death. Rapamycin inhibits IL-2-driven proliferation by downregulating the expression of genes required for key processes required for cell cycle progression. Rapamycin also preserves cell survival by keeping intact the IL-2-induced cell survival programs. These complex multifaceted programs of gene expression permit a dynamic regulation of cellular proliferation and cellular survival.

Animals↗
PubMedDate not supplied

Polypeptide growth factors in the nucleus: a review of function and translocation.

Conventional wisdom declares that polypeptide growth factors act solely by binding to the cell surface and transducing a signal through receptor-mediated kinase cascades; following this, they are endocytosed and degraded. Recent evidence, however, has demonstrated that several growth factors bind to the cell surface and are translocated into the nucleus. Furthermore, these growth factors exert biochemical function within the nucleus. Here we review the growth factors which translocate to the nucleus and/or exert biochemical function within the nucleus, and propose possible translocation mechanisms, including retrograde transport from the cell surface to the nuclear envelope.

Animals↗