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F Colotta

Publications and source records attributed to F Colotta.

At least 73 records · Page 4Linked to original sources
PubMed1991

Chemotactic cytokine gene expression and production induced in human monocytes by membrane proteoglycans from Klebsiella pneumoniae.

The present study was designed to investigate the effect of membrane proteoglycans (MPG) from Klebsiella pneumoniae on production of the chemotactic cytokine, IL-8, and monocyte chemotactic protein (MCP) by human peripheral blood monocytes. Exposure of human peripheral blood monocytes to MPG in vitro induced high levels of mRNA transcripts for IL-8 and MCP, as assessed by Northern blot analysis. Cytokine gene expression was associated with the production of chemotactic activity in the supernatants. The levels of IL-8 and MCP expression induced by MPG were comparable with those elicited by LPS. Induction of chemotactic cytokines in mononuclear phagocytes may play a role in the immunomodulatory activity of MPG.

Chemokine CCL2↗
PubMed1991

Nonsense mutations affect C1 inhibitor messenger RNA levels in patients with type I hereditary angioneurotic edema.

Members of two unrelated families with type I hereditary angioneurotic edema (HANE) were found to have elevated levels of C1 inhibitor (C1INH) mRNA. DNA sequence analysis of PCR-amplified monocyte C1INH mRNA revealed normal and mutant transcripts, as expected in this disorder that occurs in heterozygous individuals. Single base mutations near the 3' end of the coding sequence were identified in affected members of each family. One mutation consisted of insertion of an adenosine at position 1304 which created a premature termination codon (TAA), whereas the second consisted of deletion of the thymidine at position 1298 which created a premature termination codon (TGA) 23 nucleotides downstream. These mutations are approximately 250 nucleotides upstream of the natural termination codon. Nuclear run-off experiments in one kindred revealed no difference in transcription rates of the C1INH gene between the patients and normals. C1INH mRNA half-life experiments were not technically feasible because of the prolonged half-life of the normal transcript. Dideoxynucleotide primer extension experiments allowed the differentiation of the normal and mutant transcripts. These studies showed that the mutant transcript was not decreased relative to the normal, and this therefore was at least partially responsible for the C1INH mRNA elevation. This elevation may be due to the decreased catabolism of the mutant transcript.

Angioedema↗
PubMed1990

Thrombin induces c-fos expression in cultured human endothelial cells by a Ca2(+)-dependent mechanism.

The proto-oncogene c-fos has been implicated in the modulation of various cell functions. We have found that thrombin, a pleiotropic activator of endothelial cells, induced c-fos mRNA in human umbilical vein endothelial cells (HEC). This effect was dose-related (0.05 to 1.0 U/mL) and transient (maximal after 1 hour and negligible within 4 hours). Since thrombin activates phosphoinositide (PI) turnover through a pertussis toxin (PT)-sensitive guanosine triphosphate-binding regulatory protein(s) (G-protein) with subsequent stimulation of protein kinase C (PKC) and Ca2+ movements, we investigated whether these intracellular pathways are also responsible for c-fos induction. PT inhibited thrombin's effect on c-fos expression, but had no effect on c-fos expression by phorbol myristate acetate (PMA). Down regulation of PKC by prolonged exposure to PMA had no effect on thrombin and ionomycin stimulation of c-fos, but inhibited PMA activation of this gene. Quenching of the Ca1(2+) increase in response to quin2 loading in the absence of external Ca2+ suppressed thrombin activity on c-fos transcription. Under the same conditions PMA activity was not inhibited or only partially inhibited. Interleukin-1 beta (IL-1 beta) and basic fibroblast growth factor (bFGF) stimulation of c-fos mRNA level were not inhibited by quin2; on the contrary, ionomycin effect was blocked by this agent. These results indicate that thrombin-induced c-fos expression in HEC does not require a fully active PKC but is dependent on normal intracellular Ca2+ availability.

Calcium↗
PubMed1990

Heat shock induces the transcriptional activation of c-fos protooncogene.

Treatment of murine 3T3 fibroblasts with mild elevated temperature (43 degrees C for 45 minutes) followed by recovery at 37 degrees C induced high levels of c-fos mRNA. The maximal c-fos induction was found after recovery at 37 degrees C for 15 minutes. Sodium arsenite induced both hsp 70 and c-fos transcripts. Induction of hsp 70 and c-fos by heat shock did not require intact protein synthesis. c-fos mRNA induced by heat shock was more stable (T1/2 greater than 90 minutes) than that induced by phorbol esters (t1/2 approximately 30 minutes). Northern blot analysis in the presence of actinomycin D and nuclear run off experiments demonstrated that heat shock augmented the transcription rate of c-fos protooncogene. Human growth hormone under the control of a murine genomic c-fos fragment spanning 770 bp 5' from the start of transcription is induced in transfected cells in response to heat shock. These data indicate that heat shock induces c-fos protooncogene acting at both transcriptional and post-transcriptional (i.e. via stabilization of transcripts) levels.

Animals↗
PubMed1990

Monocyte chemotactic and activating factor gene expression induced in endothelial cells by IL-1 and tumor necrosis factor.

Inflammation, thrombosis, and immunity involve close interactions between leukocytes and vascular endothelium. Endothelial cells represent both targets and producers of lymphokines. Our study was designed to define the capacity of human endothelial cells (HEC) to produce a novel, recently purified, and molecularly cloned monocyte chemotactic and activating factor. This factor has been identified in the culture supernatants of tumor cell lines (tumor-derived chemotactic factor (TDCF)) as well as activated monocytes and fibroblasts (monocyte chemotactic and activating protein, MCAF, or monocyte chemoattractant protein-1, MCP-1). IL-1 induced high levels of production of chemotactic activity for monocytes in culture supernatants of HEC. IL-1-treated HEC expressed high levels of MCAF/MCP-1/TDCF mRNA transcripts, as assessed by Northern blot analysis. TNF and LPS, unlike IL-6, also induced MCAF/MCP-1/TDCF gene expression. Nuclear run off experiments revealed that IL-1-activated transcription of the MCAF/MCP-1/TDCF gene. The production of MCAF/MCP-1/TDCF may represent one of the mechanisms whereby endothelial cells, exposed to inflammatory signals, participate in the regulation of leukocyte extravasation. Production of this cytokine by vascular cells may in particular be relevant under conditions of selective extravasation and activation of mononuclear phagocytes.

Biological Factors↗
PubMed1990

c-fos and c-myc expression in human endothelial cells as a function of different culture conditions.

Cultured human umbilical vein endothelial cells (HEC) could be induced to express c-fos and c-myc mRNA by either serum or ECGS (endothelial cell growth supplement). Neither agonist separately could support HEC proliferation but the combination did. Expression of c-fos and c-myc mRNA in the presence of both serum and ECGS was similar to that observed after each of the two stimuli was introduced separately. c-fos and c-myc expression in cultured HEC, even if related, is not necessarily accompanied by stimulation of cell growth.

Blood↗
PubMed1990

Interleukin-6 gene expression and production induced in human monocytes by membrane proteoglycans from Klebsiella pneumoniae.

The present study was designed to investigate the effect of membrane proteoglycans (MPG) from Klebsiella pneumoniae on IL-6 production by human peripheral blood monocytes. Exposure in vitro to MPG induced release of IL-6 activity from human monocytes, as assessed by the 7TD1 hybridoma assay. MPG-induced hybridoma growth factor activity was blocked by anti-IL-6 antibodies. MPG induced expression in human monocytes of IL-6 mRNA transcripts as assessed by Northern blot analysis. Induction of IL-6 in mononuclear phagocytes may play a role in the immunomodulatory activity of MPG.

Bacterial Outer Membrane Proteins↗
PubMed1990

Interleukin-2 receptor expression in human mast cells and basophils.

Surgical human thymus, upper respiratory tract, lung and small and large bowel specimens were analyzed for the presence of interleukin 2 receptor (IL2-R)-positive cells. Histochemical (toluidine) and immunologic (anti-IL2-R monoclonal antibody) staining procedures revealed a distinct anti-IL2-R positivity in most of metachromatically staining cells. These positive cells were observed not only in tissues showing strong inflammatory reaction and mast cell hyperplasia, as in Crohn's disease, but also in those not histologically affected by pathologic conditions. This finding suggested that human mast cells, like T blast cells, express the p55 chain of IL2-R on their surface. To see whether IL2-R was being actively synthesized, a cell preparation rich in peripheral blood basophils (PBB), which are cells closely related to mast cells, was obtained. Ultrastructural analysis of PBB after indirect immunogold procedure revealed that the vast majority expressed the IL2-R. Moreover, the presence of intracellular reaction products in the cytoplasm of most membrane-positive PBB was indicative of active antigen synthesis. Furthermore, Northern blot analysis evidenced specific IL2-R mRNA in PBB, while its expression was augmented several times when PBB were cultured in the presence of stimulated T cell supernatant.

Animals↗
PubMed1990

IL-1 transcriptionally activates the neutrophil chemotactic factor/IL-8 gene in endothelial cells.

Leucocytes and vascular cells interact closely in inflammation and immunity and cytokines are important mediators of this interaction. The present study was designed to define the capacity of human endothelial cells (HEC) to produce a monocyte-derived neutrophil chemotactic factor (provisionally termed IL-8). IL-8 is a polypeptide chemotactic for neutrophils originally identified in the culture supernatant of lipopolysaccharide (LPS)-stimulated monocytes. IL-1 induced high levels of production of neutrophil chemotactic activity in culture supernatants of HEC. Optimal stimulation of activity was observed when HEC were cultured with 10-100 ng/ml IL-1 beta for 16 hr. Anti-IL-8 antibody blocked the chemotactic activity for neutrophils of IL-1-activated HEC supernatants. IL-1-treated HEC expressed high levels of IL-8 mRNA transcripts, as assessed by Northern blot analysis. Tumour necrosis factor (TNF) and LPS, unlike the inflammatory monokine IL-6, also induced IL-8 expression. Nuclear run-off experiments revealed that IL-1 activated transcription of the IL-8 gene. The production of IL-8 may represent a mechanism whereby endothelial cells, exposed to inflammatory signals, participate in the regulation of neutrophil extravasation.

Cells, Cultured↗
PubMed1989

Increased expression of urokinase mRNA in bovine aortic endothelial cells treated with propranolol.

Propranolol, a beta-adrenergic blocker agent widely used in a number of cardiovascular disorders, increases plasminogen activator (PA) activity in confluent bovine aortic endothelial cells (BAEC). This effect is time and dose dependent (10-100 microM). Hybridization studies with specific cDNA showed that propranolol was able to induce an increase in urokinase mRNA expression in a dose and time dependent manner. The propranolol effect seems to be specific for urokinase mRNA, because it does not affect a-actin mRNA expression. Cycloheximide, similarly to propranolol, also increases urokinase mRNA, indicating that the gene expression may be regulated by some rapidly turning over protein. When compounds were used in combination, a superinduction phenomenon was observed.

Animals↗
PubMed1989

Interleukin-1 and tumor necrosis factor production in acute non-lymphoid leukemia.

We have investigated interleukin-1 (IL-1) and tumor necrosis factor (TNF) release in 20 patients with acute non-lymphoid leukemia (ANLL) after culture with bacterial lipopolysaccharide (LPS) or in the absence of deliberate stimulation. IL-1 and TNF were identified by appropriate bioassays inhibitable by specific antibodies. The capacity to produce IL-1 was expressed by most ANLL cases investigated irrespective of the FAB (French, American, British) subtype. However, the M4 and M5 cases tended to be better producers of IL-1 than M1-M3 cases. In contrast, TNF release was only restricted to M5 leukemias (3 out of 4 cases examined). Cytokine production may therefore provide additional criteria for a functional classification of ANLL. A considerable proportion of ANLL cases (7/18 bone marrow samples and 12/20 blood samples) released appreciable quantities of IL-1 in culture in the absence of deliberate stimulation. "Spontaneous" TNF production was also detected in 1 out of 3 M5 cases. Cells were cultured under LPS-negative conditions and polymixin B did not affect spontaneous cytokine release. Moreover, Northern blot analysis showed that freshly isolated, non-cultured ANLL cells expressed IL-1 beta transcripts. Inasmuch as IL-1 is responsible for hemopoietin-1 activity and IL-1 induces colony stimulating factor production in various cell types, the observation of IL-1 production in ANLL suggests that this mediator may be involved in regulatory amplifying circuits of leukemic cell proliferation.

Biomarkers, Tumor↗
PubMed1989

Expression of c-jun protooncogene in human myelomonocytic cells.

A prototypic "immediate early" gene, c-fos, has been extensively investigated in relation to the differentiation and activation of myelomonocytic cells. The c-fos gene product is associated in transcriptional complexes with the c-jun product. These protooncogenes are part of the regulatory network of gene expression. The present study was designed to investigate expression of the c-jun protooncogene in human circulating myelomonocytic cells. We found that c-jun is constitutively expressed in normal monocytes and granulocytes, whereas low levels of transcripts are found in lymphocytes. Acute myelogenous leukemia (AML) samples of French-American-British Cooperative Group (FAB) subtypes 1 through 4 express appreciable levels of this protooncogene. Normal phytohemagglutinin (PHA)-activated lymphocytes express high levels of c-jun. Expression in normal myelomonocytic cells is detectable even after 18 hours of culture. The c-jun transcripts in myelomonocytic cells have a half-life of approximately 20 minutes and are superinduced by cycloheximide, which affects both the degradation rate of mRNA and the transcriptional activity of the c-jun gene. Functional activation of monocytes and granulocytes with phorbol esters, lipopolysaccharide, and tumor necrosis factor (TNF) increase c-jun expression. This induction is rapid, transient, and does not require intervening protein synthesis. Runoff experiments showed that in freshly isolated untreated monocytes, the c-jun gene is constitutively transcribed, and that induction by lipopolysaccharide is at least in part at the transcriptional level. Moreover, lipopolysaccharide (LPS) treatment reduced the degradation rate of c-jun transcripts, prolonging the half-life to approximately two hours. Expression of c-jun in resting and activated monocytes and granulocytes suggests that this protooncogene may play a role in the differentiation and activation of cells belonging to the myelomonocytic lineage.

Cells, Cultured↗
PubMed1988

c-fos proto-oncogene expression in human NK/LGL cells: expression is not constitutive and is associated with functional activation.

Unlike mature myeloid and monocytic cells and cell lines committed to terminal myelomonocytic differentiation, highly purified preparations of human natural killer cells/large granular lymphocytes (NK/LGL) did not spontaneously express the c-fos proto-oncogene. Transient expression of c-fos in NK/LGL was associated with functional activation with IL-2, IFN-gamma, LPS and PMA, which increased their cytotoxic activity, lymphokine secretion and in vitro chemotaxis. These results, together with the finding that T-cell receptor genes are in germ-line configuration in the vast majority of peripheral blood NK/LGL, are compatible with the hypothesis that these cells represent a separate hematopoietic lineage.

Cholera Toxin↗
PubMed1988

Interleukin-1 induces c-fos protooncogene expression in cultured human endothelial cells.

In the present study we have evaluated the expression of c-fos protooncogene in normal human endothelial cells (HEC) by Northern blot analysis. HEC do not show neither constitutive nor cycloheximide-induced expression of c-fos protooncogene. When HEC were treated with cytokines known to modulate a number of specialized functions of these cells, we observed that, unlike interferon-gamma, interleukin-1 (IL-1) and tumor necrosis factor (TNF) were able to induce appreciable levels of c-fos in HEC. Both IL-1 alpha and IL-1 beta induced c-fos transcripts in HEC. Maximal levels of c-fos mRNA induced by IL-1 were found after 1 hour of treatment, with undetectable levels at 4 and 7 hours. c-fos induction in HEC by IL-1 and TNF may play a role in the acquisition of functional properties induced in HEC by these cytokines.

Cells, Cultured↗
PubMed1988

Role of GM-CSF in phagocyte recruitment and regulation of c-fos protooncogene expression.

Recombinant GM-CSF induced migration across polycarbonate filters of monocytes and polymorphonuclear leukocytes. Checkerboard analysis revealed that induction of phagocyte migration involved actual chemotaxis. Hence GM-CSF, released by activated endothelium and leukocytes, may play a role in phagocyte recruitment to amplify resistance against noxious agents. Activation of leukocytes by GM-CSF was associated with early, transient augmentation of the expression of the c-fos protooncogene. c-fos expression may be associated with functional reprogramming of phagocytes by this cytokine.

Chemotaxis, Leukocyte↗
PubMed1987

Cytotoxic effector function of B lymphoblasts.

EBV-transformed B lymphoblastoid cell lines and clones were cytotoxic in vitro against Actinomycin D-pretreated WEHI 164 sarcoma cells, a system in which mononuclear phagocytes were previously identified as effectors. Similarly, unlike resting B cells, normal B lymphoblasts stimulated for 72 hr with Staphylococcus aureus Cowan I and purified according to the expression of the B cell surface marker B1, demonstrated appreciable cytolytic activity. B lymphoblastoid cells and derived supernatants were cytotoxic for Actinomycin D-pretreated WEHI 164 cells, and killing was inhibited by an anti-lymphotoxin but not an anti-tumor necrosis factor antiserum. Thus, B lymphoblasts have cytotoxic potential, mediated by lymphotoxin or a lymphotoxin-like soluble product.

B-Lymphocytes↗