Cell culture

About: Cell culture is a research topic. Over the lifetime, 133361 publications have been published within this topic receiving 5364150 citations. The topic is also known as: cell culture techniques.

F4/80, a monoclonal antibody directed specifically against the mouse macrophage

Abstract: A hybridoma clone which secretes a macrophage (MΦ)-specific monoclonal antibody, F4/80, was produced by fusing spleen cells from a rat hyperimmunized with cultured thioglycollate-induced mouse peritoneal MΦ with a mouse myeloma, NS1. Binding of antibody to primary cells and cell lines was detected by radioimmune indirect binding assay, autoradiography or fluorescence-activated cell sorter analysis. F4/80 binds to mouse MΦ from the peritoneal cavity or other sources, blood monocytes, MΦ derived from bone marrow precursors in culture and MΦ-like cell lines, but not to other cells, including polymorphonuclear leukocytes, lymphocytes or fibroblasts. F4/80 does not bind to MΦ via Fc receptors, is not cytotoxic and is of the rat IgG2b subclass. Since F4/80 binds to all MΦ defined by adherence, morphology and immune phagocytosis, it provides a new marker to define the MΦ in the mouse. Large differences in expression of antigen F4/80 were found, depending on intraperitoneal stimulation, time in culture and stage of maturation. Immunoprecipitation experiments demonstrated that the antigen F4/80 is part of a component of Mr 160000 which is synthesized by the MΦ and, at least in part, exposed on the cell surface.

Terminal differentiation of human promyelocytic leukemia cells induced by dimethyl sulfoxide and other polar compounds.

Abstract: A human leukemic cell line (designated HL-60) has recently been established from the peripheral blood leukocytes of a patient with acute promyelocytic leukemia. This cell line displays distinct morphological and histochemical commitment towards myeloid differentiation. The cultured cells are predominantly promyelocytes, but the addition of dimethyl sulfoxide to the culture induces them to differentiate into myelocytes, metamyelocytes, and banded and segmented neutrophils. All 150 clones developed from the HL-60 culture show similar morphological differentiation in the presence of dimethyl sulfoxide. Unlike the morphologically immature promyelocytes, the dimethyl sulfoxide-induced mature cells exhibit functional maturity as exemplified by phagocytic activity. A number of other compounds previously shown to induce erythroid differentiation of mouse erythroleukemia (Friend) cells can induce analogous maturation of the myeloid HL-60 cells. The marked similarity in behavior of HL-60 cells and Friend cells in the presence of these inducing agents suggests that similar molecular mechanisms are involved in the induction of differentiation of these human myeloid and murine erythroid leukemic cells.

Purification, Characterization, and in vitro Differentiation of Cytotrophoblasts from Human Term Placentae*

Abstract: Highly purified functional cytotrophoblasts have been prepared from human term placentae by adding a Percoll gradient centrifugation step to a standard trypsin-DNase dispersion method. The isolated mononuclear trophoblasts averaged 10 microns in diameter, with occasional cells measuring up to 20-30 microns. Viability was greater than 90%. Transmission electron microscopy revealed that the cells had fine structural features typical of trophoblasts. In contrast to syncytial trophoblasts of intact term placentae, these cells did not stain for hCG, human placental lactogen, pregnancy-specific beta 1-glycoprotein or low mol wt cytokeratins by immunoperoxidase methods. Endothelial cells, fibroblasts, or macrophages did not contaminate the purified cytotrophoblasts, as evidenced by the lack of immunoperoxidase staining with antibodies against vimentin or alpha 1-antichymotrypsin. The cells produced progesterone (1 ng/10(6) cells . 4 h), and progesterone synthesis was stimulated up to 8-fold in the presence of 25-hydroxycholesterol (20 micrograms/ml). They also produced estrogens (1360 pg/10(6) cells . 4 h) when supplied with androstenedione (1 ng/ml) as a precursor. When placed in culture, the cytotrophoblasts consistently formed aggregates, which subsequently transformed into syncytia within 24-48 h after plating. Time lapse cinematography revealed that this process occurred by cell fusion. The presumptive syncytial groups were proven to be true syncytia by microinjection of fluorescently labeled alpha-actinin, which diffused completely throughout the syncytial cytoplasm within 30 min. Immunoperoxidase staining of cultured trophoblasts between 3.5 and 72 h after plating revealed a progressive increase in cytoplasmic pregnancy-specific beta 1-glycoprotein, hCG, and human placental lactogen concomitant with increasing numbers of aggregates and syncytia. At all time points examined, occasional single cells positive for these markers were identified. RIA of the spent culture media for hCG revealed a significant increase in secreted hCG, paralleling the increase in hCG-positive cells and syncytia identified by immunoperoxidase methods. We conclude that human cytotrophoblasts differentiate in culture and fuse to form functional syncytiotrophoblasts.

Identification of Genes Periodically Expressed in the Human Cell Cycle and Their Expression in Tumors

Abstract: The genome-wide program of gene expression during the cell division cycle in a human cancer cell line (HeLa) was characterized using cDNA microarrays. Transcripts of >850 genes showed periodic variation during the cell cycle. Hierarchical clustering of the expression patterns revealed coexpressed groups of previously well-characterized genes involved in essential cell cycle processes such as DNA replication, chromosome segregation, and cell adhesion along with genes of uncharacterized function. Most of the genes whose expression had previously been reported to correlate with the proliferative state of tumors were found herein also to be periodically expressed during the HeLa cell cycle. However, some of the genes periodically expressed in the HeLa cell cycle do not have a consistent correlation with tumor proliferation. Cell cycle-regulated transcripts of genes involved in fundamental processes such as DNA replication and chromosome segregation seem to be more highly expressed in proliferative tumors simply because they contain more cycling cells. The data in this report provide a comprehensive catalog of cell cycle regulated genes that can serve as a starting point for functional discovery. The full dataset is available at http://genome-www.stanford.edu/Human-CellCycle/HeLa/.

A cell-killing monoclonal antibody (anti-Fas) to a cell surface antigen co-downregulated with the receptor of tumor necrosis factor

Abstract: We have prepared an mAb specific for a human cell surface component (termed anti-Fas mAb). Anti-Fas shows cell-killing activity that is indistinguishable from the cytolytic activity of TNF. Fas antigen was characterized by western blotting, indicating that Fas antigen is a cell surface protein with a molecular weight of 200,000, which is different from the molecular weight of TNF-R. Fas antigen, however, is co-downregulated with the TNF-R when cells sensitive to the cytolytic activity of TNF are incubated with either TNF or anti-Fas. In contrast, Fas antigen on cells insensitive to TNF is not co-downregulated with the TNF-R. We suggest that the cell-killing activity of TNF is mediated by Fas antigen associated with the TNF-R.