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J W Pollard

Publications and source records attributed to J W Pollard.

At least 73 records · Page 4Linked to original sources
PubMed1993

Mouse placental macrophages have a decreased ability to present antigen.

Large numbers of macrophages can be found in an animal's uteroplacental unit. This high concentration of macrophages suggests they must play an important role during placental development. To gain a better understanding of the functional capacity of placental macrophages, we have obtained a highly enriched placental macrophage culture and have derived several cell lines from this population. Both placental macrophages and cell lines show colony-stimulating factor 1-dependent growth, express Fc receptors, and can perform Fc-receptor-mediated phagocytosis. In addition, they express macrophage markers Mac-1, F4/80, and CD14. Although placental macrophages express major histocompatibility complex class II molecules constitutively, they display a decreased ability to present protein antigens to T cells. Since primary fetal liver macrophages of the same gestational stage also show a decreased ability to present antigens, this phenomenon may reflect a developmental stage of macrophages.

Animals↗
PubMed1993

Delayed hematopoietic development in osteopetrotic (op/op) mice.

Changes in structure, cellularity, hematopoietic progenitor cell and macrophage content, and osteoclast activity were investigated in the hematopoietic organs of the colony-stimulating factor 1(CSF-1)-less osteopetrotic (op/op) mouse. The data indicated that op/op mice undergo an age-related hematopoietic recovery and resolution of osteopetrosis, suggesting that the hematopoietic system has the capacity to use alternative mechanisms to compensate for the absence of an important multifunctional growth factor, CSF-1. In young animals, op/op femurs were heavily infiltrated with bone, and marrow cellularity was significantly reduced. After 6 wk of age, there was an increase in the marrow space available for hematopoiesis. The femoral cavity of op/op mice progressively enlarged, and by 22 wk of age its appearance and marrow cellularity was comparable to that of controls. The percentage of op/op mononuclear phagocytes, defined by F4/80 antigen expression, progressively increased to normal levels by 35 wk of age. There was no difference in the incidence of both primitive and mononuclear phagocyte-committed, CSF-1-responsive progenitor cells in op/op marrow, but their femoral content was significantly reduced in young mice. During the period of reduced hematopoiesis in the marrow of young op/op mice, splenic hematopoietic activity was elevated. This mutant mouse represents a system for the study of the CSF-1-independent regulatory mechanisms involved in hematopoietic regulation.

Animals↗
PubMed1993

Normal distribution of tumor necrosis factor-alpha messenger ribonucleic acid and protein in the uteri, placentas, and embryos of osteopetrotic (op/op) mice lacking colony-stimulating factor-1.

In order to map mouse tumor necrosis factor-alpha (TNF) gene expression in detail and to determine whether transcription or translation of the TNF gene is regulated by uterine colony stimulating factor-1 (CSF-1), preimplantation embryos, oviducts, uteri, and uteroplacental units were studied in various strains of mice. These included homozygous osteopetrotic (op/op) female mice, which completely lack CSF-1, and heterozygous (+/op) females, which have normal levels of CSF-1. TNF mRNA was identified in all samples except preimplantation embryos by use of Northern blot hybridization or reverse transcriptase polymerase chain reaction. In situ hybridization and immunocytochemical experiments showed that the TNF gene was expressed in mouse oviduct and uterine epithelial cells, decidual cells, macrophage-like cells, placental trophoblast, and embryos. Despite an absence of CSF-1, TNF gene expression in the uteri, placentas, and embryos of op/op mothers did not differ in any major respect from expression in +/op or other strains of mice. The results of this study therefore indicate that the TNF gene is transcribed and translated in an ordered sequence through mouse gestation, and that maternal CSF-1 is not essential to expression of this cytokine gene. Collectively, these findings are consistent with a major role for TNF in mouse reproduction and development and with a potential compensatory function for this potent polypeptide factor in CSF-1 deficiency.

Animals↗
PubMed1992

Caeruloplasmin biosynthesis by the human uterus.

The blue copper protein caeruloplasmin is synthesized mainly by hepatocytes. An alternative transcript for caeruloplasmin produced in certain extrahepatic tissues, CP-1, contains an additional 12 nucleotides encoding 4 amino acids not present in the hepatic transcript, CP-2 [Yang, Friedrichs, Cupples, Bonifacio, S Sanford, Horton & Bowman (1990) J. Biol. Chem. 265, 10780-10785]. We have demonstrated transcription of caeruloplasmin mRNA by a well-differentiated human uterine epithelial adenocarcinoma cell line, Ishikawa, and by human uterine endometrium and purified endometrial glands. Identical CP-2 nucleotide sequences were obtained for partial caeruloplasmin transcripts from human liver and Ishikawa cells, indicating that CP-2 transcripts are produced by uterine epithelial lining cells. The synthesis of caeruloplasmin protein was demonstrated for Ishikawa cells and another uterine adenocarcinoma cell line, ECC1. Peptide-mapping analysis indicated that caeruloplasmin secreted by Ishikawa cells was structurally identical with the protein synthesized by the human hepatoblastoma cell line HepG2. The secretion of a 135,000-M(r) caeruloplasmin by Ishikawa and ECC1 cells, comparable with that of the human hepatoblastoma cell line, HepG2, indicated similar processing of uterine and hepatic caeruloplasmin. Incorporation of 67Cu into caeruloplasmin was demonstrated for Ishikawa and ECC1 cells, suggesting that the human uterus produces a bioactive form of caeruloplasmin and possesses the necessary metal transporters and intracellular machinery for copper incorporation into this protein.

Base Sequence↗
PubMed1992

A study of granulated metrial gland cell differentiation in pregnant, macrophage-deficient, osteopetrotic (op/op) mice.

A population of uterine natural killer (NK) cells, commonly called granulated metrial gland (GMG) cells, differentiates in the mouse uterus during normal pregnancy. Little is known regarding the process of differentiation of GMG cells or of other NK cell subsets. It has been suggested that macrophage precursors, under the combined influences of the cytokine growth factors colony stimulating factor-1 (CSF-1) and interleukin-2, become NK-cell like in morphology, pattern of target cell lysis and surface antigen phenotype. Mice expressing the mutation osteopetrosis (op/op) are unable to produce the cytokine CSF-1. To determine whether CSF-1 is required for the successful differentiation of uterine NK cells, implantation sites in pregnant, op/op mice were studied histologically. GMG cell differentiation appeared to progress normally in op/op mice studied between days 7 and 14 of gestation. Thus, the growth factor CSF-1 is not required for differentiation of the uterine NK cell subset known as GMG cells and probably GMG cells do not differentiate from macrophage precursor cells which are deficient in op/op mice.

Animals↗
PubMed1992

Isolation and characterization of four CSF-1-dependent placental macrophage cell lines.

By selection and cloning in the presence of colony-stimulating factor 1 (CSF-1), we have obtained from separate explants of individual 12- or 13-day mouse placentas four clonal cell lines dependent on CSF-1 for survival and growth in culture. All four cell lines show characteristics consistent with their derivation from placental macrophages. We describe the effects of CSF-1 on growth, morphology, and CSF-1 receptor phosphorylation. One cell line, JPL2A, which shows relatively complete growth arrest in the absence of CSF-1, was characterized in detail with respect to the effects of CSF-1 on DNA synthesis and protein turnover and its response to the duration of CSF-1 stimulation. In contrast to previous studies, our results suggest that extended stimulation leads to continuous recruitment of cells competent to reenter the cell cycle. These findings are discussed in terms of growth factor effects on the cell cycle and the usefulness of these cell lines for further study of growth factor signal transduction in macrophages.

Animals↗
PubMed1992

A comparison of two autoradiographic methods for detecting radiolabeled nucleic acids in embryos.

Two methods for preparing embryos for autoradiographic study of newly synthesized nucleic acids are described and compared. The first method consists of rapidly fixing radiolabeled embryos with acetic acid:methanol, spreading them on glass slides and exposing them for 8 days with a photographic emulsion. The second method consists of fixing, embedding in resin, and sectioning the embryos before their exposure with the emulsion for 3 weeks. Both techniques have many applications in studies of early embryonic activity, but the spread technique is very sensitive, simpler, and faster.

Animals↗
PubMed1992

Expression of CSF-1/c-fms and SF/c-kit mRNA during preimplantation mouse development.

c-fms and c-kit are structurally related tyrosine kinase receptors for colony-stimulating factor-1 (CSF-1) and for steel factor (SF), respectively. The level of c-fms mRNA, like c-kit mRNA, increases during the maturation of oocytes and is an abundant maternal message found in the unfertilized oocyte. Following fertilization, the level of both c-fms and c-kit oocyte mRNAs decreases rapidly until they are no longer detected by the early 2-cell stage. By the late 2-cell stage, both mRNAs are reexpressed, albeit at low levels. This low level of mRNA expression continues throughout preimplantation development. CSF-1 and SF transcripts are not detected in early preimplantation embryos, but are detected in cumulus cells, oviduct, and uterus, suggesting a paracrine action of these growth factors during the preimplantation period. The patterns of CSF-1/c-fms mRNA and SF/c-kit mRNA expression are consistent with the hypothesis that these two ligand/receptor systems may act in a compensatory or synergistic manner during preimplantation development.

Animals↗
PubMed1992

Colony stimulating factor-1 stimulates Ishikawa cell proliferation and lipocortin II synthesis.

Proliferation of the Ishikawa human endometrial adenocarcinoma cell line is under the concerted control of oestrogen and progesterone. Here we demonstrate that Ishikawa cells express colony stimulating factor-1 (CSF-1), CSF-1 receptor mRNA and are growth stimulated by CSF-1 treatment. An early event associated with CSF-1 treatment is the induction of lipocortin II synthesis, a protein whose expression is also under oestrogen and progesterone control. However, neither CSF-1 or CSF-1 receptor mRNA appear to be modulated by oestrogen or progesterone.

Adenocarcinoma↗
PubMed1992

Differential mRNA expression of the phosphoprotein p19/SCG10 gene family in mouse preimplantation embryos, uterus, and placenta.

The p19/SCG10 gene family encodes two structurally related cellular proteins that are implicated in signal transduction during differentiation of mammalian cells. Previous evidence suggests that both genes are expressed in a stage-specific manner but that expression of p19 is widespread, whereas that of SCG10 is restricted to developing neurons. To determine at which developmental stage these two genes are first expressed, we have probed for mRNA transcripts in preimplantation embryos and the utero-placental unit of the mouse. As determined by polymerase chain reaction (PCR) to amplify reverse-transcribed RNA, expression of both genes was detected in preimplantation embryos, although the temporal pattern was distinct. p19 mRNA appeared transiently in 2-cell embryos, was undetectable in morulae and early blastocysts and reappeared in expanded blastocysts. In contrast, embryonic expression of SCG10 mRNA commenced in morulae and was maintained through to the blastocyst stage. Interestingly, only SCG10 expression could be detected in blastocysts derived from cultures of 2-cell embryos. During the post-implantation period, SCG10 transcripts were only detected in the uterus and placenta by reverse transcriptase-PCR, whereas p19 mRNA could be detected by Northern blotting and showed stage-specific expression in both tissues. The data confirm that, at later developmental stages, expression of p19 is widespread while that of SCG10 is more restricted. The expression of both genes in preimplantation embryos suggests distinct but possibly overlapping roles for p19 and SCG10 in early mammalian development.

Animals↗
PubMed1992

Expression of the colony-stimulating factor-1 receptor (c-fms proto-oncogene product) in the human uterus and placenta.

This study describes the expression pattern in the human uteroplacental unit of c-fms, the proto-oncogene that encodes the receptor for colony-stimulating factor-1. Quantitative mRNA analysis showed that c-fms mRNA expression in placental tissues was lowest in first trimester samples and highest at the end of pregnancy. Expression of c-fms mRNA was also high in first trimester endometrium and term chorion. Although c-fms mRNA was approximately 3.7 kb in size on northern blots of all placental, endometrial, and chorion preparations, trophoblast-specific transcription of c-fms exon 1 was confirmed by primer-directed amplification of reverse-transcribed total RNA. Immunohistochemistry using both polyclonal and monoclonal anti-c-fms protein antibodies showed that c-fms protein was expressed over the entire trophoblastic area during the first trimester but became progressively restricted to the villous syncytiotrophoblast as pregnancy advanced. Of particular interest was the high level of c-fms protein expression in the intermediate trophoblasts of the villous sprouts during first trimester. The synthesis of c-fms protein was also detected in glandular epithelial cells and decidual cells of first trimester endometrium and in the extra-villous trophoblastic layer of the chorion.

Base Sequence↗
PubMed1992

Expression of colony-stimulating factor-1 in the human uterus and placenta.

Previous studies in the mouse have strongly implicated colony-stimulating factor-1 (CSF-1) in the regulation of placental development. In this study of human pregnancy, we detected CSF-1 in serum, endometrium, placenta, chorion, amnion, and amniotic fluid, with significant increases in serum and endometrial samples from the first trimester compared to levels in nonpregnant controls. CSF-1 mRNA was demonstrated in all of these tissues, except amnion, with a significant increase within the first trimester endometrial samples over nonpregnant control values. In addition to the major 4.0-kilobase mRNA, other species of CSF-1 mRNA were detected, which were shown to be due to alternative splicing within exon 6 and the alternative use of exon 9 or 10. In the endometrium, CSF-1 was localized to glandular epithelial and endothelial cells. In first trimester placenta, CSF-1 was in the cytotrophoblasts lining the villous core and in the cytotrophoblastic shell. During the second trimester, CSF-1 was localized to villous mesenchymal cells. By the third trimester, CSF-1 was only detected in cells lining the villous vessels. The detection of CSF-1 during gestation strongly supports a role for CSF-1 in the regulation of placental function in humans by autocrine and/or paracrine mechanisms.

Amnion↗
PubMed1992

Modulation of thermal killing of bovine lymphocytes and preimplantation mouse embryos by alanine and taurine.

Addition of alanine and taurine blocked killing of lymphocytes caused by culture at 45 C. The optimal concentration for thermoprotection was achieved at 12.5 mM for L-alanine and 5 mM for taurine. Both D and L forms of alanine provided thermoprotection. The effect of these agents was not simply to increase osmolarity of the culture medium, because NaCl did not provide thermoprotection at comparable concentrations. Alanine and taurine were each tested at concentration of 50 mM for ability to block heat shock-induced killing and developmental retardation of 8- to 16-cell mouse embryos. Both agents enhanced embryo development after exposure to high temperature, though development remained less than that for embryos not exposed to high temperature. In one experiment, for example, 81% of embryos cultured at 38 C advanced in development during culture vs 0% at 42 C, 15% at 42 C with alanine, and 32% at 42 C with taurine. The beneficial effect of alanine at high temperature may have been partly attributable to effects independent of thermoprotection, because development of embryos cultured at 38 C was also improved by alanine.

Alanine↗
PubMed1991

Independently arising macrophage mutants dissociate growth factor-regulated survival and proliferation.

Analysis of a simian virus 40-immortalized colony-stimulating factor 1 (CSF-1) -dependent macrophage cell line (BAC1.2F5) and independently arising autonomous mutants derived from it (aut4A, aut4A.1, aut2A, and aut2A.1) revealed distinct phenotypes. The parental line, BAC1.2F5, is dependent on CSF-1 for survival and growth. Of the mutants derived from BAC1.2F5, aut4A has lost the requirement of CSF-1 for survival; aut4A.1 (derived from aut4A) and aut2A grow in the absence of growth factor but proliferate more rapidly in its presence, and aut2A.1 (derived from aut2A) produces CSF-1 and proliferates as rapidly in the presence as in the absence of exogeneous CSF-1. The separation of the CSF-1 requirement for survival and proliferation observed in aut4A is also observed in a temperature-sensitive (ts) mutant tsgro1. At the nonpermissive temperature, tsgro1 cell proliferation is arrested, but the cells survive provided CSF-1 is present. The four cellular phenotypes observed--immortalization, loss of growth factor requirement for survival, loss of growth factor requirement for proliferation, and loss of growth factor-stimulated proliferation--indicate a divergence of the pathways of growth factor-regulated survival and proliferation and may represent phenotypes occurring at intermediate stages in tumor-cell progression.

Animals↗
PubMed1991

Role of colony stimulating factor-1 (CSF-1) and other lympho-hematopoietic growth factors in mouse pre-implantation development.

Mouse pre-implantation development appears to be under the control of paracrine and autocrine growth factors. The epithelium of the oviduct and the uterus together, with the population of macrophages and lymphocytes present in the reproductive tract from the onset of pregnancy, are thought to be the major sources of paracrine growth factors targeted to the developing embryos. Some of the growth factors are synthesized by both uterine epithelial cells and activated lympho-hematopoietic cells, suggesting a partial overlap of the regulatory signals used by the reproductive and lympho-hematopoietic systems. Such growth factors may be the long sought-after mediators of the synchrony between the pre-implantation embryo and the sex-steroid hormone-induced changes in the uterus.

Animals↗
PubMed1991

A pregnancy defect in the osteopetrotic (op/op) mouse demonstrates the requirement for CSF-1 in female fertility.

Correlative evidence suggests that maternal production of the mononuclear phagocyte growth factor colony stimulating factor-1 (CSF-1) regulates placental development. In order to study the role of CSF-1 in pregnancy the fertility of CSF-1-less osteopetrotic (op/op) mutant mice was investigated. Homozygous mutant crosses (op/op x op/op) were consistently infertile. As expected, op/op males were almost completely fertile when crossed with heterozygous females. Surprisingly, op/op females when mated to heterozygote males were fertile, although at a rate that was 46% of the rate for +/op females x op/op males. These data suggest that CSF-1 is required for pregnancy. However, a maternal CSF-1 source is not absolutely necessary in that pregnancies involving +/op fathers were partially rescued, suggesting that +/op fetuses and/or +/op seminal fluid provides CSF-1 or CSF-1-induced factors which compensate for the absence of maternally produced CSF-1. Despite the complete absence of CSF-1 in the uterus and placenta of op/op mice placental weights were normal, suggesting that proliferation of decidual cells and trophoblasts, both of which express the CSF-1 receptor, may not be solely regulated by CSF-1. Histochemical staining for F4/80 antigen was used to identify macrophages in the uterus and placenta. Uterine macrophages could not be detected in virgin op/op mice although they were abundant in +/op uteri. Interestingly, macrophages could be detected in op/op uteri as uncharacteristically rounded cells in early gestation, however, they were not maintained and no macrophages were apparent beyond Day 14 of pregnancy in op/op mice. Further studies in the osteopetrotic mouse will be useful in delineating those functions required for pregnancy that are regulated by CSF-1.

Animals↗