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M Y Stoeckle

Publications and source records attributed to M Y Stoeckle.

31 records · Page 2Linked to original sources
PubMed1993

Transformation-associated cytokine 9E3/CEF4 is chemotactic for chicken peripheral blood mononuclear cells.

9E3/CEF4, which is released from transformed chicken embryo fibroblasts (CEF), is a member of the platelet factor 4 family of inflammatory proteins and may be the avian homolog of interleukin-8. Since the function of 9E3/CEF4 is unknown, we examined the effect of the protein on mitogenicity and chemotaxis, as well as its expression, in fibroblasts and peripheral blood cells. 9E3/CEF4 mRNA was expressed in chicken peripheral blood monocytes, and its expression was stimulated by incubation of the monocytes with lipopolysaccharide or phorbol myristic acetate. Boyden double-membrane analysis of chemotaxis showed that 9E3/CEF4 was chemotactic for chicken peripheral blood mononuclear cells, as well as for heterophils. Untransformed CEF and CEF transformed with Rous sarcoma virus also migrated to 9E3/CEF4 protein, as measured by Boyden single-membrane analysis. 9E3/CEF4 was slightly mitogenic for CEF, causing a doubling of [3H]thymidine uptake when added to serum-starved CEF.9E3/CEF4 was found associated not only with the cell and in the culture medium of Rous sarcoma virus-transformed CEF but also with the extracellular matrix. The in vivo role of 9E3/CEF4 may be involved with chemotaxis and metastasis, rather than with direct stimulation of mitogenicity.

Animals↗
PubMed1992

Infectious diseases.

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Acquired Immunodeficiency Syndrome↗
PubMed1992

Acquired resistance and granuloma formation in experimental visceral leishmaniasis. Differential T cell and lymphokine roles in initial versus established immunity.

In naive BALB/c mice, acquisition of resistance to Leishmania donovani and formation of antileishmanial tissue granulomas are linked expressions that require both L3T4+ and Lyt 2+ cells as well as both IL-2 and IFN-gamma. To determine the mechanisms of established resistance to L. donovani, rechallenged immune BALB/c mice were treated with T cell- and lymphokine-depleting mAb or cyclosporin A. In the liver, resistance to rechallenge was inhibited by treatment with anti-Lyt 2 but not anti-L3T4 mAb. Resistance was also impaired by anti-IL-2 treatment but not by anti-IFN-gamma mAb. The hepatic granulomatous response to rechallenge, however, was not impaired by either anti-Lyt 2 or anti-IL-2 mAb nor by anti-L3T4 or anti-IFN-gamma treatment. In contrast, cyclosporin A suppressed granuloma formation but not antileishmanial activity. These results indicate a particularly important antileishmanial host defense role for Lyt 2+ cells and IL-2 in sensitized animals, and when compared to prior observations in L. donovani-infected naive mice, suggest that 1) discrete T cell- and lymphokine-dependent mechanisms are involved in initial acquisition of resistance vs established immunity, 2) more than one mechanism can mediate the development of tissue granulomas, and 3) granuloma formation by itself may not be required nor necessarily sufficient to confer antimicrobial activity.

Animals↗
PubMed1992

Removal of a 3' non-coding sequence is an initial step in degradation of gro alpha mRNA and is regulated by interleukin-1.

I have previously shown that IL-1 regulates the stability of gro alpha mRNA in fibroblasts and that decay is associated with appearance of a smaller species of gro RNA that lacks poly(A). In this study, the relationship between the two species of gro RNA, which migrate at 1.3 and 0.9 kilobases, was characterized. Following withdrawal of IL-1 or addition of IL-1 receptor antagonist, 1.3 kilobase gro alpha mRNA was rapidly degraded and this was associated with increased expression of the 0.9 kilobase RNA. This increase occurred in the presence of actinomycin D, indicating that the 0.9 kilobase gro RNA was a product of a pre-existing transcript. In cells treated with 1 pg/ml IL-1, both species were induced but the 0.9 kilobase RNA appeared later, consistent with a precursor-product relationship. In cells treated with higher doses of IL-1, the 0.9 kilobase RNA was not expressed. Using an RNAase protection assay, the 0.9 kilobase poly(A)-minus gro RNA was found to be derived from gro alpha mRNA by removal of a 130-nucleotide sequence from the 3' non-coding region. This is one of few examples of formation of an mRNA decay intermediate in vivo; it indicates that degradation of the body of gro alpha mRNA is initiated by site-specific nuclease attack. Characterization of the mechanism of gro alpha mRNA degradation is a first step towards identification of the ribonuclease that controls gro alpha mRNA stability.

Base Sequence↗
PubMed1991

Post-transcriptional regulation of gro alpha, beta, gamma, and IL-8 mRNAs by IL-1 beta.

Expression of the cytokine gene gro, also known as melanoma growth stimulatory activity, is induced by inflammatory stimuli, including IL-1. To determine whether gro expression is regulated at a post-transcriptional level, the effect of IL-1 on gro mRNA stability was examined. Treatment of fibroblasts with IL-1 beta caused a dose-dependent induction of gro mRNA. When IL-1 was withdrawn, gro mRNA decayed rapidly with a half life of 1 hour. This decay occurred whether or not actinomycin D was added to block new transcription. In contrast, when IL-1 was present in the medium, the level of gro mRNA was stable over 8 hours following addition of actinomycin D. In addition, the stability of a related mRNA, IL-8, was found to be regulated by IL-1. To examine whether Northern results reflected expression of gro alpha, or of the closely related genes, gro beta and gro gamma, RNA samples were analyzed by PCR. All three genes were found to be induced by IL-1 and all mRNAs were stabilized in the presence of IL-1. Northern analysis revealed a minor species of gro mRNA which lacked poly(A). The pattern of expression of this RNA suggested that it was a decay intermediate of one or more of the gro mRNAs. The findings indicate that mRNA stabilization is an important component of IL-1 induced gene expression.

Base Sequence↗
PubMed1991

Extrapulmonary Pneumocystis carinii infections in the acquired immunodeficiency syndrome.

Pneumocystis carinii is a frequent cause of interstitial pneumonitis in patients with cell-mediated immunodeficiencies. Extrapulmonary P carinii infection is a rare manifestation of disease caused by this organism. Nevertheless, reports of extrapulmonary P carinii infection are increasing in the setting of the acquired immunodeficiency syndrome (AIDS). We report two cases of extrapulmonary P carinii infection in patients with AIDS and review the literature on this subject. We identified 37 such cases: in 19 cases, P carinii pneumonia was present concurrently; in 18 cases, involvement was exclusively extrapulmonary. A minority of patients were receiving aerosolized pentamidine isethionate therapy. Most patients had a history of P carinii pneumonia, and other AIDS-related illnesses, such as cytomegalovirus infection, mycobacterial disease, candidiasis, Kaposi's sarcoma, and cryptococcosis were common. Concurrent cytomegalovirus infection indicated a poor prognosis, while otic pneumocytosis was associated with a favorable outcome. Pathologic evidence suggested that extrapulmonary pneumocystosis occurred by hematogenous and lymphatic dissemination from the lungs in most cases. In other cases, extrapulmonary pneumocystosis appeared to be due either to reactivation of latent infection in extrapulmonary sites or to primary infection of these sites. Further studies are needed to determine the true frequency of extrapulmonary involvement in P carinii infections and to define risk factors for acquisition of extrapulmonary pneumocytosis.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Serum and v-src increase the level of a CCAAT-binding factor required for transcription from a retroviral long terminal repeat.

Transcription from the long terminal repeat (LTR) of Rous sarcoma virus (RSV) in rat 3Y1 fibroblasts was dependent on the presence of serum. Within 1 hr after addition of serum to a serum-deprived culture, there was a fivefold increase in the level of transcripts initiated at the LTR. This stimulation did not require synthesis of new proteins. The induction of transcription by serum was mostly dependent on two CCAAT boxes in the LTR. Within 1 hr after addition of serum, there was also an increase in the level of a nuclear protein that bound to the two CCAAT boxes, even in the presence of cycloheximide. This serum-induced CCAAT factor also bound CCAAT sequences from other promoters, for example, those of human heat shock protein 70, human c-Ha-ras, and human histone 1, but not to the adenovirus origin of replication or the SV40 enhancer core sequence, suggesting that it was related to CP1 or CP2. Expression from the RSV LTR was not dependent on serum in v-src-transformed cells. Using temperature-sensitive v-src, it was shown that the tyrosine kinase activity of the oncogene increased the amount of CCAAT factor that was present in the nucleus. These findings demonstrate that a basal transcription factor, the CCAAT-binding factor, could be a second messenger for transducing a primary signal from serum to the cellular transcriptional apparatus. This also suggests a pathway by which a tyrosine kinase oncogene could influence the transcription of several genes in the nucleus.

Animals↗
PubMed1990

Two burgeoning families of platelet factor 4-related proteins: mediators of the inflammatory response.

The inflammatory response involves the recruitment and activation of various types of cells from the systemic circulation and from local tissues. One important component of the inflammatory response is the activation of platelets at sites of tissue injury and inflammation. In particular, activated platelets release large amounts of two proteins, platelet factor 4 (PF4) and beta-thromboglobulin (beta TG), which mediate several inflammatory processes. Recently, many novel proteins that are structurally related to PF4 and beta TG have been identified. The PF4-related proteins are secreted by white blood cells, endothelial cells, and fibroblasts in response to various inflammatory and mitogenic stimuli. Like PF4, these proteins appear to be inflammatory response mediators; several of them are potent chemoattractants, activating agents, or mitogens for specific cell types that are involved in the inflammatory response. The study of PF4-related proteins provides new insight into the mechanisms of the immune response, and may result in the development of new therapeutic agents.

Amino Acid Sequence↗
PubMed1989

Processing of 9E3 mRNA and regulation of its stability in normal and Rous sarcoma virus-transformed cells.

We studied the expression of 9E3 mRNA, which is known to be induced in chicken embryo fibroblasts by p60v-src activity and by serum. In addition to full-length 9E3 mRNA, we identified several smaller RNAs that hybridized with 9E3 cDNA. One of these RNAs hybridized with a 5' 9E3 cDNA probe but not with a 3' cDNA probe. The other hybridized with a 3' cDNA probe but lacked 5' sequences, including the entire 9E3 coding region. Only the latter RNA was polyadenylylated, as determined by RNase H digestion in the presence of oligo(dT). The level of the small RNAs increased after treatment with cycloheximide and actinomycin D, indicating that the small RNAs were produced by processing of preexisting transcripts. The derivation of the small RNAs from 9E3 mRNA rather than from a related gene was confirmed by S1 nuclease analysis. The 3' terminus of the 5' RNA and the 5' terminus of the 3' RNA mapped to the same position, which suggested that the small RNAs were formed by endonucleolytic cleavage of 9E3 mRNA at a specific site in the 3' noncoding region. We also found that the stability of 9E3 mRNA was increased after serum stimulation and was greater in Rous sarcoma virus-transformed than in uninfected cells. The relative amount of the small RNAs as compared with the full-length transcript was greatest under conditions in which the full-length transcript was least stable. These data suggest that site-specific endonucleolytic cleavage regulates the stability of 9E3 mRNA.

Animals↗
PubMed1988

78-kilodalton glucose-regulated protein is induced in Rous sarcoma virus-transformed cells independently of glucose deprivation.

To identify mRNAs with altered expression in Rous sarcoma virus (RSV)-transformed cells, we screened a chicken embryo fibroblast (CEF) cDNA library by differential hybridization. One clone, designated R1H, showed markedly elevated mRNA expression in RSV-transformed cells. Nucleotide sequence analysis indicated that R1H mRNA encodes 78-kilodalton glucose-regulated protein (GRP78). Chicken GRP78 was found to be very highly conserved in comparison with rat GRP78 (96% identity between chicken and rat amino acid sequences). In contrast to previous observations, we found that GRP78 was induced in RSV-transformed cells in the absence of glucose deprivation. When cells were grown in glucose-supplemented medium, the level of GRP78 mRNA was approximately fivefold higher in RSV-transformed CEF than in transformation-defective virus-infected or uninfected CEF. Similar changes in GRP78 protein content were also found. Using a temperature-sensitive mutant of RSV and supplemental glucose, we found a gradual increase in the level of GRP78 mRNA beginning at 4 h after shiftdown to permissive temperature. Uridine supplementation did not block the induction seen in CEF infected with a temperature-sensitive mutant. These results indicate that GRP78 is induced by p60v-src in the absence of glucose deprivation.

Animals↗
PubMed1987

Transformation by Rous sarcoma virus induces a novel gene with homology to a mitogenic platelet protein.

A cDNA clone, designated 9E3, was isolated from a chick embryo fibroblast (CEF) cDNA library. 9E3 mRNA was 20-fold higher in CEF following transformation by Rous sarcoma virus because of increased transcription rate. In CEF infected with temperature-sensitive mutants, increased 9E3 mRNA was found within 2 hr of a shift to permissive temperature. Nucleotide sequence and in vitro translation results indicate that 9E3 mRNA encodes an 11 kd polypeptide that is homologous to human connective tissue activating peptide III (CTAP-III), a mitogenic platelet alpha-granule protein, and to beta-thromboglobulin and platelet factor 4. The reported biological activities of CTAP-III suggest that elevated expression of 9E3 may play a role in producing some of the phenotypic features of RSV-transformed cells.

Amino Acid Sequence↗
PubMed1987

Segment-specific and common nucleotide sequences in the noncoding regions of influenza B virus genome RNAs.

The nucleotide sequences of the 3' noncoding regions of all eight segments of influenza B virus RNA and the sequences of the 5' noncoding regions of segments 4-8 were determined in virus strains isolated over a period of 40 years. Nearly complete conservation of the noncoding sequences was found. Nine nucleotides at the 3' termini and 11 nucleotides at the 5' termini were common to all segments examined. In the region immediately adjacent to the common 3' terminal region, the nucleotides were specific for each segment and these segment-specific sequences were conserved in all strains examined. In each of the five segments in which both termini were examined, the segment-specific 3' sequences exhibited perfect inverted complementarity to a segment-specific sequence adjacent to the common 5' terminus. In addition, in the 3' noncoding region of RNA segments 1-3, which encode proteins involved in RNA synthesis, a single nucleotide substitution at position 10 was found that distinguishes these segments from segments 4-8. Comparison of these data with published reports has revealed that some of the features found in the noncoding regions of influenza B virus are also present in influenza A and C virus RNAs. In the RNAs of all three virus types, there is a segment-specific sequence of nucleotides near the 3' terminus that shows inverted complementarity to a sequence near the 5' terminus. This segment-specific sequence may play a role in the transcription of individual segments or in sorting of segments during virion assembly.

Animals↗