WI-38-tế bào

WI-38

From Wikipedia, the free encyclopedia

WI-38 is a diploid human cell culture line composed of fibroblasts derived from lung tissue of an aborted white (caucasian) female fetus.^[1] The cell line, isolated by Leonard Hayflick and Paul Moorhead in the 1960s,^[2] has been used extensively in scientific research, with applications ranging from developing important theories in molecular biology to the production of many types of vaccines. .^[3] ".^[4]

Contents

  [hide] 

• 1History
• 2Applications
• 3References
• 4External links

History[edit]

The WI-38 cell line stemmed from earlier work with growing cell cultures done by Hayflick and Moorhead. Observations of similar cell lines led to the discovery that cells would gradually experience signs of senescence as they divided, first slowing and then stopping division altogether.^[2][5] This finding would later be known as the Hayflick limit, which indicated that normal human cells could only undergo a limited number of divisions, and later contributed to the discovery of the biological roles of telomeres.^[6] However, during this period of research, the team also discovered that if cells were properly stored in a freezer, cells would remain viable and could provide enormous numbers of cells for research purposes. Based on this, Hayflick was given another line of fetal stem cells to try to preserve and duplicate using this method.^[4] This cell line became WI-38.

Applications[edit]

WI-38 was invaluable to early researchers, especially those studying virology and immunology, since it was a readily-available cell line of normal human tissue, unlike the HeLa line, which were cancerous cells. Researchers in labs across the globe have since used WI-38 in their discoveries, most notably in the development of vaccines. Over a billion^[4] vaccine doses worldwide can be traced to work done on WI-38, covering conditions including measles and rubella.^[7]

WI-38 cells are used to produce several vaccines including Adenovirus, MMR and Varicella zoster. Infected WI-38 cells secrete the virus, and can be cultured in large volumes suitable for commercial production.

Huh7-tế bào gan

From Wikipedia, the free encyclopedia

Huh7 is a type of human liver cell that may be grown in the laboratory for research purposes. According to the web site huh7.com, it is "a well differentiated hepatocyte-derived carcinoma cell line, originally taken from a liver tumor in a 57-year-old Japanese male in 1982."^[1] It is used extensively in hepatitis C and dengue virus research.^[2][3]

Huh7 cells have been instrumental in hepatitis C research. Until 2005, it was not possible to culture hepatitis C in the laboratory. The introduction of the Huh7 cell line permitted screening of drug candidates against laboratory-cultured hepatitis C virus and permitted the development of new drugs against hepatitis C.^[4][2][5]

U937 (tế bào)

U937 cell-tế bào

From Wikipedia, the free encyclopedia

U937 cells are a model cell line used in biomedical research.^[1] They were isolated from the histiocytic lymphoma of a 37-year-old male patient ^[2] and are used to study the behaviour and differentiation of monocytes. U937 cells mature and differentiate in response to a number of soluble stimuli, adopting the morphology and characteristics of mature macrophages.

U937 cells are of the myeloid lineage and so secrete a large number of cytokines and chemokines either constitutively (e.g. IL-1 and GM-CSF) or in response to soluble stimuli. TNFα and recombinant GM-CSF independently promote IL-10 production in U937 cells.^[3]

The HLA alleles present in U937 cells are HLA-A*03:01, A*31:01, B*18:01, B*51:01, Cw*01:02 and Cw*07:02.^[4]

Raji (tế bào lymphoma từ máu người)

Raji cell - tế bào lymphoma từ máu người

From Wikipedia, the free encyclopedia

Raji cell culture.

Raji cell line is the first continuous human cell line from hematopoietic origin.^[1] The cell lines produce an unusual strain of Epstein-Barr virus which will both transform cord blood lymphocytes and induce early antigens in Raji cells. Translocations between chromosomes 8 and 22 have occurred in all three lines, but the cells synthesize immunoglobulin M with light chains of the kappa type, in contrast to the usual concordance between a translocation involving chromosome 22 and lambda chain synthesis. Both kappa genes and one lambda gene are rearranged. These findings indicate either that translocation may occur as a separate event from immunoglobulin gene rearrangement or that the proposed hierarchical sequence of immunoglobulin gene rearrangements is not always adhered to. The data also imply that in cells containing a translocation between the long arm of chromosome 8 and a chromosome bearing an immunoglobulin gene, alteration of cellular myc expression may occur regardless of the immunoglobulin gene that is expressed.^[2] Raji cell is widely used as a transfection host and also to understand the hematopoietic and other cell malignancies. It also used for detection of immune complex because it possesses and expresses several receptors for certain complement components, as well as Fc receptors for immunoglobulin G.^[3]

Contents

  [hide] 

• 1Background
• 2Description
  • 2.1Raji Cell Line Human
• 3Raji Cell Binding Test
  • 3.1Raji Cell Assay for Immune Complexes
  • 3.2Raji cell Radio-immune Assay for Detecting Immune Complexes in Human Sera
• 4References
• 5External links

Background[edit]

Based on the morphological characteristic, this cell is categorized as lymphoblast-like.^[4] This suspension cell is derived from B-lymphocyte of an 11-year-old Nigerian Burkitt's lymphoma male patient in 1963. R.J.V. Pulvertaft is the first person who established this cell line.^[4] The culture medium used to grow this cell line is RPMI supplemented with serum. Some characteristics of Raji cell is lack of differentiation thus shows the formation of large aggregations consist of hundreds individual cells. The cells are relatively large in diameter (5-8 μm), have irregular indented nuclei, and almost extensive cytoplasm with free ribosomes which tend to clump.^[5] Raji cell grows as single, non-motile, free-floating (non-adhesion) individuals or doublets to glass. Some cells look elongated like pear-shaped with larger, multinucleate, round cells.^[5]

Raji cell is widely used as a transfection host and also to understand the hematopoietic and other cell malignancies. It also use for detection of immune complex because it possesses and expresses and lots of receptors for certain complement components, as well as Fc receptors for immunoglobulin G.^[3]

Description[edit]

A cell of a cultured line of lymphoblastoid cells derived from a Burkitt lymphoma; it possesses numerous receptors for a certain complement components and is thus suitable for use in detection of immune complexes. It expresses certain complement receptors as well as Fc receptors for immunoglobulin G.^[6]

Raji Cell Line Human[edit]

-Biological source --> Lymph from human

-Description --> Human Black, Burkitt's lymphoma

-Growth Mode --> Suspension

-Karotype --> 2n=46, diploid

-Morphology --> Lymphoblastoid

-Research Areas --> Kits/ Lysates/ Other -> Lysates -> Whole Cell Lysates -> Human^[7]

-Shipped In --> Dry ice

-Storage Temperature --> -196 degrees C.^[8] Raji cell slide can be stored for up to 6 months at 4 °C under desiccate conditions.

Raji Cell Binding Test[edit]

A test for the detection of soluble immunoglobulin (Ig)G-antigen complexes. Raji cells are a line EBV-transformed lymphocytes with surface Fc receptors. Complexes are detected by their ability to compete with a radiolabelled aggregated IgG for binding to cells.^{[citation needed]}

Raji Cell Assay for Immune Complexes[edit]

Using a standard Raji assay employing 125I-IgG goat anti-human Fc gamma, the digestion of Raji cells with pronase reduced by 95% their ability to bind complement-fixed aggregated human gamma globulin and complement-fixed tetanus toxoid-antitetanus toxin complexes. However, binding at 37 degrees C of IgG from the sera of 16 patients with systemic lupus erythematosus (SLE) to pronase-digested Raji cells was reduced much less consistently and extensively (9-100% reduction; mean reduction of 51%). In more detailed studies of two SLE sera, sucrose density gradient centrifugation showed that greater than 50% of the IgG binding to undigested Raji cells sedimented in the 7S region. Pepsin digestion of immunoglobulin fractions from four SLE sera caused a reduction in SLE IgG binding to undigested Raji cells when detected with 125I anti-Fc gamma, but an increase when binding was detected with 125I-anti-Fab, suggesting that substantial SLE IgG can bind through F(ab')2 regions. Binding of IgG from SLE sera was not directed at neoantigenic sites induced by pronase digestion because binding activity was adsorbed with undigested cells as readily as with digested cells. Moreover, sera from 10 SLE patients that had negative Raji assays contained no IgG that bound to pronase-digested Raji cells. Meaning that, much of the IgG bound at 37 degrees C to Raji cells from the sera of many patients with SLE does not represent immune complexes but is probably antibody directed toward sites on the Raji cell.^[9]

Raji cell Radio-immune Assay for Detecting Immune Complexes in Human Sera[edit]

A sensitivie and simple procedure for the detection and quantitation of soluble complement (C)- fixing immune complexes in sera of patients with various disease states has been developed by utilizing C receptors on Raji cells. These cells lack membrane-bound immunoglobulin but have receptors for IgG Fc, C3b, C3d, and possibly with other C proteins. Uptake experiments showed that both aggregated human gamma globulin (AHG) and 7S IgG bound to receptors for IgG Fc; however, AHG reacted with C bound to cells only via receptors for C and this binding was much more efficient than via IgG Fc receptors. AHG was used as an in vitro model of human immune complexes and its uptake by Raji cells was quantitated by 125I-radiolabeled antihuman IgG. The limit of sensitivity of this test was 6 mug AHG/ml serum. The ability of Raji cells to detect AHG in serum depended on the amount of radioactive antibody used and the size of aggregates. The presence of an excess of C somewhat inhibited binding of AHG containing C to Raji cells. The efficient binding of AHG by receptors for C on Raji cells was used for the detection and quantitation of immune complexes in human sera. Raji cells were incubated with sera to be tested and then reacted with excess radiolabeled antihuman IgG; the amount of radioactivity bound to the washed cells was determined and referred to a standard curve of radioactive antibody uptake by cells previously incubated with increasing amounts of AHG in serum. Thereby immune complexes were detected and quantitated in serum hepatitis, systemic lupus erythematosus, vasculitis, subacute sclerosing panencephalitis, dengue hemorrhagic fever, and malignancies.^[10]

Caco-2 - tế bào biểu mô trực tràng

From Wikipedia, the free encyclopedia

The Caco-2 cell line is a continuous cell of heterogeneous human epithelial colorectal adenocarcinoma cells, developed by the Sloan-Kettering Institute for Cancer Research through research conducted by Dr. Jorgen Fogh.^[1]

Although derived from a colon (large intestine) carcinoma, when cultured under specific conditions the cells become differentiated and polarized such that their phenotype, morphologically and functionally, resembles the enterocytes lining the small intestine.^[2][3] Caco-2 cells express tight junctions, microvilli, and a number of enzymes and transporters that are characteristic of such enterocytes: peptidases, esterases, P-glycoprotein, uptake transporters for amino acids, bile acids, carboxylic acids, etc.

When looking at Caco-2 cell cultures microscopically, it is evident even by visual inspection that the cells are heterogeneous. As a result, over the years the characteristics of the cells used in different laboratories around the world have diverged significantly, which makes it difficult to compare results across labs.^[4]

Caco-2 cells are most commonly used not as individual cells, but as a confluent monolayer on a cell culture insert filter (e.g., Transwell). When cultured in this format, the cells differentiate to form a polarized epithelial cell monolayer that provides a physical and biochemical barrier to the passage of ions and small molecules.^[3][5] The Caco-2 monolayer is widely used across the pharmaceutical industry as an in vitro model of the human small intestinal mucosa to predict the absorption of orally administered drugs. The correlation between the in vitro apparent permeability (P¬app) across Caco-2 monolayers and the in vivo fraction absorbed (fa) is well established.^[6]Transwell diagram

This application of Caco-2 cells was pioneered in the late 1980s by Ismael Hidalgo, working in the laboratory of Ron Borchardt at the University of Kansas, and Tom Raub, who was at the Upjohn Company at the time. Following stints at SmithKline Beecham and Rhone-Poulenc Rorer, Hidalgo went on to co-found a company, Absorption Systems, in 1996, where he remains as Chief Scientist.

The considerable impact of the Caco-2 cell monolayer model can be measured in at least two ways. First, considering that poor pharmacokinetic properties accounted for ~40% of drug failures in development in the early 1990s and only ~10% by 2009, an interval in which Caco-2 monolayers were widely used throughout the pharmaceutical industry to predict absorption, it is not unreasonable to attribute some of that shift to this simple yet powerful model. Second, the 1989 Gastroenterology paper that demonstrated the utility of the model for this application has been cited more than 1000 times since its publication.

The versatility of Caco-2 cells is demonstrated by the fact that, even to this day, they are serving as the basis for the creation of innovative new models that are contributing to our understanding of drug efflux transporters such as P-glycoprotein (ABCB1) and BCRP (ABCG2). RNA interference has been used to silence the expression of individual efflux transporters, either transiently^[7] or long-term.^[8][9]

Contents

  [hide] 

• 1See also
• 2References
• 3Unsorted Sources
• 4External links