摘要:

AbstractThe aggregation factor (AF) from sponges mediates a heterophilic interaction of homologous cells. Applying electron microscopical means, we succeeded only very rarely in identifying the 90 S AF particle in tissue sections fromGeodia cydonium.By means of a fluorescent antibody technique, we have now localized the cell binding domain of the AF in situ. Previous studies in this laboratory have led to the identification of the 47‐kDa cell binding protein of the AF, using the monoclonal antibody (mab) 5D2‐D11 [Gramzow M, Bachmann M, Zahn RK, Uhlenbruck G, Dorn A, Müller WEG, J Cell Biol, 102:1344–1349, 1986]. This mab and mab 7D5, directed against a 92‐kDa protein in the AF complex, were chosen for the fluorescent studies. By using mab 5D2‐D11, the plasma membranes of cells from different regions in the sponge could be brightly stained. However, mab 7D5 reacted only very weakly with the sponge surfaces. By applying the immuno‐blotting technique it was furthermore demonstrated that the cell binding protein is present both in the associated form with AF complex and in a free state. Moreover, it was established that the 47‐kDa binding protein is not present in (1) homologous glycoconjugates, (2) lectin, or (3) collagen; these components are known to be involved in cell‐ma

ISSN:0730-2312    

DOI:10.1002/jcb.240310402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractThe colony‐stimulating factor, CSF‐1, selectively stimulates the survival, proliferation, and differentiation of mononuclear phagocytes. The solubilization, assay, and characteristics of the CSF‐1 receptor from the J774.2 murine macrophage cell line are described. The recovery of cell‐surface receptor in the postnuclear supernatant membrane fraction of hypotonically disrupted cells was 76%. Recovery of the ligand binding activity of the receptor after solubilization of this fraction with 1% Triton X‐100 was ∼ 150%. The binding of125I‐CSF‐1 to intact cells and membrane preparations was consistent with the existence of a single class of high‐affinity receptor sites. In contrast, the equilibrium binding of125I‐CSF‐1 to the solubilized postnuclear fraction indicated the existence of two distinct classes of binding site (apparent Kds 0.15 nM and 10 nM). A rapid assay was developed for the high‐affinity sites, which were shown to be associated with the CSF‐1 receptor. The function of the low‐affinity sites, which have not been demonstrated on intact cells or cell membranes and which are 13 times more abundant than the high‐affinity sites, is unknown. The solubilized high‐affinity receptor‐CSF‐1 complex was stable on storage at 0°C and −70°C but dissociated at 37°C. Dissociation also occurred at 0°C in buffers of low pH

ISSN:0730-2312    

DOI:10.1002/jcb.240310403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractBiochemical evidence is presented for the autophagic destruction of liver mitochondria in the influenza B virus model of Reye's syndrome in mice. Separation of lysosomes and autophagic vacuoles from mitochondria was accomplished by prior treatment of the mice with Triton WR‐1339, resulting in uptake of detergent by these organelles (tritosomes), reducing their densities. The organelles were banded in a discontinuous sucrose gradient. Total protein in the heavy tritosomal fraction increased from 1–2% in controls to 7–8% in virus‐treated animals. Ornithine carbamoyl transferase (OCTase), a mitochondrial marker, increased from 2–3% (controls) to 11–15% (virus‐treated), and glucose‐6‐phosphatase, a marker for endoplasmic reticulum, increased from 1–2% (controls) to 8–10% (virus‐treated). β‐Galactosidase, a soluble enzyme in the lysosome, and OCTase also increase in the cell extract fraction following virus treatment, indicating that there was turnover o

ISSN:0730-2312    

DOI:10.1002/jcb.240310404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractRabbits were immunized with a synthetic heptapeptide of the sequence Arg‐Asn‐Arg‐Ser‐Ser‐Arg‐Ser corresponding to the carboxy‐terminal region of the SV40 viral proteins VP2 and VP3. The raised antibodies recognize the viral proteins in enzyme‐linked immunosorbent (ELISA) and Western blot assay. Specificity of the antibodies were confirmed by competition experiments. The antibodies recognize VP2 and VP3 in infected cells by immunofluorescence and in subcellular fractions by ELISA. No interaction with virio

ISSN:0730-2312    

DOI:10.1002/jcb.240310405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractThe histogenesis of Ewing sarcoma, the second most frequent bone tumor in humans, remains controversial. Four Ewing cell lines were analyzed by immunological methods. A panel of antibodies directed to T, B, and myelomonocytic markers gave negative results. Surface antigens recognized on Ewing cells were found to be related to the neuroectoderm lineage. Ganglioside GD2, a marker of neuroectodermal tissues and tumors, was present on all lines. These were also stained by the mouse monoclonal antibody HNK‐1, which detects a carbohydrate epitope present on several glycoconjugates of the nervous system, including two glycoproteins, the myelin‐associated glycoprotein and the neural cell‐adhesion molecule (N‐CAM), and an acidic glycolipid of the peripheral nervous system. The P61 monoclonal antibody, which reacts with a peptide moiety of N‐CAM, and a rabbit antiserum, raised to purified mouse N‐CAM and not recognizing the HNK‐1‐defined epitope, were also reactive. By contrast, all antibodies specific for hematopoietic cell surface antigens were totally negative. Besides these antigenic features, Ewing sarcoma cells are characterized by a specific t(11:22)(q24;q12) translocation also observed in neuroepithelioma, a neuroectodermal tumor, suggesting a possible evolutionary related origin. The recent finding that the human N‐CAM gene is located at the vicinity of the breakpoint on chromosome 11 indicates that it might be involved in genetic rearrangements occurri

ISSN:0730-2312    

DOI:10.1002/jcb.240310406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

Abstractc‐myconcogene is the most extensively studied member of themycgene family. which now consists of three characterized members, namely the c‐myc, N‐myc, and L‐mycgenes. Deregulation owing to amplification and/or rearrangements of the c‐mycgene have been described in a variety of human malignancies. Several neuroblastomas have amplifications of the N‐mycgenes. The c‐myc, N‐myc, or L‐myconcogenes are also found amplified in different cell lines from small cell carcinomas of the lung. In this study, we have examined the c‐myc, N‐myc, and c‐erbBoncogenes in 34 clinical and autopsy tumor specimens representing various histopathological types of human lung cancer, including nine small cell lung cancers. A 30‐fold amplification of the N‐mycgene was found in a tumor histopathologically and histochemically verified as a typical adenocarcinoma. No amplifications of the c‐mycor c‐erbBoncogenes were seen in any of the tumors. In the DNA of one small cell carcinoma, an extra c‐mycand N‐myccross‐hybridizing restriction fragment was observed, possibly owing to an amplification of

ISSN:0730-2312    

DOI:10.1002/jcb.240310407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

摘要:

AbstractA metastatic variant cell subline of the Abelson virus‐transformed murine large lymphoma/lymphosarcoma RAW 117 has been selected in vivo ten times for liver colonization. Highly metastatic subline RAW117‐H10 forms greater than 200 times as many gross surface liver tumor nodules as the parental line RAW117‐P. Analysis of cellular proteins and glycoproteins indicates reduced expression of murine Moloney leukemia virus‐associated p15, p30, and gp70, and increased expression of a sialoglycoprotein, gp150, in the highly metastatic H10 cells. Northern analyses of oncogene expression suggested that mRNA of various oncogenes was expressed equally or not expressed in the RAW117 cells of differing metastatic potential. Differential gene expression was examined using a cDNA library of 17,600 clones established from poly A+mRNA isolated from H10 cells. The cDNA library was screened by the colony hybridization technique using probes made from both RAW117‐P and ‐H10 cells. Approximately 99.5% of these cDNA clones were expressed identically in P and H10 cells. Of the few differentially expressed cDNA clones (approx. 150/17,600), one‐half of these were identified as Moloney leukemia virus sequences in a separate probing with a radiolabeled Moloney leukemia virus probe. The remainder of the differentially expressed mRNA detected by colony hybridization of the cDNA library were expressed at higher levels (approx. 1/6) or lower levels (approx. 1/3) in the highly metasta

ISSN:0730-2312    

DOI:10.1002/jcb.240310408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY

ISSN:0730-2312    

DOI:10.1002/jcb.240310401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1986

数据来源: WILEY