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.

Clonal cell lines from the rat central nervous system

Abstract: Five neuronal and a large collection of putative glial cell lines from the rat central nervous system have been established in clonal cell culture and partially characterised. These cells shed new light on the distribution of neurotransmitter synthesis and brain-specific antigens among nerve and glia.

CD147-spike protein is a novel route for SARS-CoV-2 infection to host cells.

Abstract: In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2, no specific and effective drugs for treating this disease have been reported until today. Angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2, mediates the virus infection by binding to spike protein. Although ACE2 is expressed in the lung, kidney, and intestine, its expressing levels are rather low, especially in the lung. Considering the great infectivity of COVID-19, we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection. Here, we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein. The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody, Meplazumab, inhibits SARS-CoV-2 amplification. Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells, which can be neutralized by CD147 extracellular fragment. Viral loads are detectable in the lungs of human CD147 (hCD147) mice infected with SARS-CoV-2, but not in those of virus-infected wild type mice. Interestingly, virions are observed in lymphocytes of lung tissue from a COVID-19 patient. Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dose-dependent manner, which is specifically inhibited by Meplazumab. Furthermore, CD147 mediates virus entering host cells by endocytosis. Together, our study reveals a novel virus entry route, CD147-spike protein, which provides an important target for developing specific and effective drug against COVID-19.

Human CD14 mediates recognition and phagocytosis of apoptotic cells

Abstract: Cells undergoing programmed cell death (apoptosis) are cleared rapidly in vivo by phagocytes without inducing inflammation1. Here we show that the glycosylphosphatidylinositol-linked plasma-membrane glycoprotein CD14 (refs 2, 3) on the surface of human macrophages is important for the recognition and clearance of apoptotic cells. CD14 can also act as a receptor that binds bacterial lipopolysaccharide (LPS), triggering inflammatory responses4. Overstimulation of CD14 by LPS can cause the often fatal toxic-shock syndrome5,6. Here we show that apoptotic cells interact with CD14, triggering phagocytosis of the apoptotic cells. This interaction depends on a region of CD14 that is identical to, or at least closely associated with, a region known to bind LPS. However, apoptotic cells, unlike LPS, do not provoke the release of pro-inflammatory cytokines from macrophages. These results indicate that clearance of apoptotic cells is mediated by a receptor whose interactions with ‘non-self’ components (LPS) and ‘self’ components (apoptotic cells) produce distinct macrophage responses.

Soluble CD14 participates in the response of cells to lipopolysaccharide.

Abstract: CD14 is a 55-kD protein found both as a glycosylphosphatidyl inositol-linked protein on the surface of mononuclear phagocytes and as a soluble protein in the blood. CD14 on the cell membrane (mCD14) has been shown to serve as a receptor for complexes of lipopolysaccharide (LPS) with LPS binding protein, but a function for soluble CD14 (sCD14) has not been described. Here we show that sCD14 enables responses to LPS by cells that do not express CD14. We have examined induction of endothelial-leukocyte adhesion molecule 1 expression by human umbilical vein endothelial cells, interleukin 6 secretion by U373 astrocytoma cells, and cytotoxicity of bovine endothelial cells. None of these cell types express mCD14, yet all respond to LPS in a serum-dependent fashion, and all responses are completely blocked by anti-CD14 antibodies. Immunodepletion of sCD14 from serum prevents responses to LPS, and the responses are restored by addition of sCD14. These studies suggest that a surface anchor is not needed for the function of CD14 and further imply that sCD14 must bind to additional proteins on the cell surface to associate with the cell and transduce a signal. They also indicate that sCD14 may have an important role in potentiating responses to LPS in cells lacking mCD14.

Differentiation of human bone marrow osteogenic stromal cells in vitro: induction of the osteoblast phenotype by dexamethasone

Abstract: Human bone marrow stromal cells were examined for their osteogenic potential in an in vitro cell culture system Dexamethasone (Dex) treatment induced morphological transformation of these cells from an elongated to a more cuboidal shape, increased their alkaline phosphatase activity and cAMP responses to PTH and prostaglandin E2, and was essential for mineralization of the extracellular matrix Dex-induced differentiation of human bone marrow stromal cells was apparent after 2-3 days of treatment and reached a maximum at 7-14 days, as judged by alkaline phosphatase activity, although induction of osteocalcin by 1,25-dihydroxyvitamin D3 was attenuated by Dex Withdrawal of Dex resulted in an enhancement of the 1,25-dihydroxyvitamin D3-induced secretion of osteocalcin, whereas alkaline phosphatase activity and the cAMP response to PTH remained at prewithdrawal levels The steady state mRNA level of osteonectin was not affected by Dex Our results, which demonstrate that Dex conditions the differentiation of human bone marrow osteogenic stromal cells into osteoblast-like cells, support the hypothesis of a permissive effect of glucocorticoids in ensuring an adequate supply of mature osteoblast populations Furthermore, the established human bone marrow stromal cell culture provides a good model of an in vitro system to study the regulation of differentiation of human bone osteoprogenitor cells