scholarly journals Rapid cell surface appearance of endocytic membrane proteins in Chinese hamster ovary cells.

1981 ◽  
Vol 1 (3) ◽  
pp. 261-268 ◽  
Author(s):  
B Storrie ◽  
T D Dreesen ◽  
K M Maurey
Keyword(s):  
Membrane Proteins ◽  
Cell Surface ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Gel Electrophoresis ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Surface Appearance ◽  
Ovary Cells ◽  
One Dimensional

Lactoperoxidase was used to selectively radiolabel endocytic membrane. CHO cells were incubated with enzyme at 37 degrees C for 10 min to permit lactoperoxidase internalization. Radioiodination was done at 4 degrees C. About 90% of the radioiodinated products pelleted at 100,000 X g. From 12 to 15 different electrophoretic species were detected by one-dimensional gel electrophoresis. When cells labeled by internalized lactoperoxidase were warmed to 37 degrees C, the incorporated radioactivity was lost in a biphasic manner with an overall t1/2 of approximately 20 h. Upon warming cells to 37 degrees C, the labeled species became sensitive to pronase or trypsin digestion. The increase in protease sensitivity was progressive over a 10- to 20-min period. Maximally 45% of the initially intracellular radiolabel could be released. A digest of exterior-radioiodinated cells released 50% of the incorporated radioiodine. These observations strongly suggest a rapid shuttling of approximately 90% of the radioiodinated membrane species initially present within the cell to the cell surface.

Rapid cell surface appearance of endocytic membrane proteins in Chinese hamster ovary cells

1981 ◽  
Vol 1 (3) ◽  
pp. 261-268
Author(s):  
B Storrie ◽  
T D Dreesen ◽  
K M Maurey
Keyword(s):  
Membrane Proteins ◽  
Cell Surface ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Gel Electrophoresis ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Surface Appearance ◽  
Ovary Cells ◽  
One Dimensional

Lactoperoxidase was used to selectively radiolabel endocytic membrane. CHO cells were incubated with enzyme at 37 degrees C for 10 min to permit lactoperoxidase internalization. Radioiodination was done at 4 degrees C. About 90% of the radioiodinated products pelleted at 100,000 X g. From 12 to 15 different electrophoretic species were detected by one-dimensional gel electrophoresis. When cells labeled by internalized lactoperoxidase were warmed to 37 degrees C, the incorporated radioactivity was lost in a biphasic manner with an overall t1/2 of approximately 20 h. Upon warming cells to 37 degrees C, the labeled species became sensitive to pronase or trypsin digestion. The increase in protease sensitivity was progressive over a 10- to 20-min period. Maximally 45% of the initially intracellular radiolabel could be released. A digest of exterior-radioiodinated cells released 50% of the incorporated radioiodine. These observations strongly suggest a rapid shuttling of approximately 90% of the radioiodinated membrane species initially present within the cell to the cell surface.

Review of the current methods of Chinese Hamster Ovary (CHO) cells cultivation for production of therapeutic protein

2020 ◽  
Vol 17 ◽  
Author(s):  
Shazid Md. Sharker ◽  
Md. Atiqur Rahman
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Mass Production ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Therapeutic Protein ◽  
Specific Productivity ◽  
Ovary Cells ◽  
Further Development ◽  
Interesting Area

Most of clinical approved protein-based drugs or under in clinical trial have a profound impact in the treatment of critical diseases. The mammalian eukaryotic cells culture approaches, particularly the CHO (Chinese Hamster Ovary) cells are mainly used in the biopharmaceutical industry for the mass-production of therapeutic protein. Recent advances in CHO cell bioprocessing to yield recombinant proteins and monoclonal antibodies have enabled the expression of quality protein. The developments of cell lines are possible to upgrade specific productivity. As a result, it holds an interesting area for academic as well as industrial researchers around the world. This review will concentrate on the recent progress of the mammalian CHO cells culture technology and the future scope of further development for the mass-production of protein therapeutics.

scholarly journals Cloning and characterization of small circular DNA from Chinese hamster ovary cells.

1984 ◽  
Vol 4 (1) ◽  
pp. 173-180 ◽  
Author(s):  
S W Stanfield ◽  
D R Helinski
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Single Copy ◽  
Chromosomal Dna ◽  
Cho Cell ◽  
Ovary Cells ◽  
Chromosomal Sequences

Small polydisperse circular (spc) DNA was isolated and cloned, using BglII from Chinese hamster ovary (CHO) cells. The properties of 47 clones containing at least 43 different BglII fragments are reported. The majority of the clones probably contain entire sequences from individual spcDNA molecules. Most of the clones were homologous to sequences in CHO cell chromosomal DNA, and many were also homologous to mouse LMTK- cell chromosomal sequences. The majority of homologous CHO cell chromosomal sequences were repetitive, although a few may be single copy. Only a small fraction of cloned spcDNA molecules were present in every cell; most occurred less frequently than once in 15 cells. Localization studies indicated that at least a portion of spcDNA is associated with the nucleus in CHO cells.

scholarly journals Continued initiation of DNA synthesis in arginine-deprived Chinese hamster ovary cells.

1977 ◽  
Vol 73 (1) ◽  
pp. 200-205 ◽  
Author(s):  
A S Weissfeld ◽  
H Rouse
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Cell Multiplication ◽  
Ovary Cells ◽  
Cell Cycle Phases

When exponentially growing CHO cells were deprived of arginine (Arg), cell multiplication ceased after 12 h, but initiation of DNA synthesis continued: after 48 h of starvation with continuous [3H]thymidine exposure, 85% of the population had incorporated label, as detected autoradiographically. Consideration of the distribution of exponential cells in the various cell cycle phases leads to a calculation that most cells in G1 at the time that Arg was removed, as well as those in S, engaged in some DNA synthesis during starvation. In contrast, isoleucine (Ile)-starved cells did not initiate DNA synthesis, as has been reported by others. Experiments with cells synchronized by mitotic selection confirmed this difference in Arg- and Ile- deprived behavior, but also showed that cells which underwent the mitosis leads to G1 transition during Arg starvation remained arrested in G1 (G0?). The results suggest that Arg-deprived cells continue to maintain some proliferative function(s) while Ile-deprived cells do not.

scholarly journals The pericentriolar material in Chinese hamster ovary cells nucleates microtubule formation

1977 ◽  
Vol 73 (3) ◽  
pp. 601-615 ◽  
Author(s):  
RR Gould ◽  
GG Borisy
Keyword(s):  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Carbon Coated ◽  
Pericentriolar Material ◽  
And Function

The structure and function of the centrosomes from Chinese hamster ovary (CHO) cells were investigated by electron microscopy of negatively stained wholemount preparations of cell lysates. Cells were trypsinized from culture dishes, lysed with Triton X-100, sedimented onto ionized, carbon-coated grids, and negatively stained with phosphotungstate. The centrosomes from both interphase and dividing cells consisted of pairs of centrioles, a fibrous pericentriolar material, and a group of virus-like particles which were characteristic of the CHO cells and which served as markers for the pericentriolar material. Interphase centrosomes anchored up to two dozen microtubules when cells were lysed under conditions which preserved native microtubules. When Colcemid-blocked mitotic cells, initially devoid of microtubules, were allowed to recover for 10 min, microtubules formed at the pericentriolar material, but not at the centrioles. When lysates of Colcemid-blocked cells were incubated in vitro with micotubule protein purified from porcine brain tissue, up to 250 microtubules assembled at the centrosomes, similar to the number of microtubules that would normally form at the centrosome during cell division. A few microtubules could also be assembled in vitro onto the ends of isolated centrioles from which the pericentriolar material had been removed, forming characteristic axoneme- like bundles. In addition, microtubules; were assembled onto fragments of densely staining, fibrous material which was tentatively identified as periocentriolar material by its association of CHO can initiate and anchor microtubules both in vivo and in vitro.

scholarly journals Selection of mutant Chinese hamster ovary cells altered glycoproteins by means of tritiated fucose suicide.

1981 ◽  
Vol 1 (10) ◽  
pp. 902-909 ◽  
Author(s):  
C B Hirschberg ◽  
R M Baker ◽  
M Perez ◽  
L A Spencer ◽  
D Watson
Keyword(s):  
Chinese Hamster Ovary ◽  
Gel Electrophoresis ◽  
Trichloroacetic Acid ◽  
Chinese Hamster Ovary Cells ◽  
Sodium Dodecyl ◽  
Chinese Hamster ◽  
Wild Type ◽  
Ovary Cells ◽  
Replica Plating ◽  
Selection Of

Mutant Chinese hamster ovary cells altered in glycoproteins have been isolated by selecting for ability to survive exposure to [6-3H]fucose. Mutagenized wild-type cells were permitted to incorporate [3H]fucose to approximately 1 cpm of trichloroacetic acid-insoluble radioactivity per cell and then frozen for several days to accumulate radiation damage. The overall viability of the population was reduced by 5- to 50-fold. Four consecutive selection cycles were carried out. The surviving cells were screened by replica plating-fluorography for clones showing decreased incorporation of fucose into trichloroacetic acid-insoluble macromolecules. Considerable enrichment for cells deficient in fucose uptake or incorporation into proteins (or both) was found in populations surviving the later selection cycles. Two mutant clones isolated after the fourth selection cycle had the same doubling time as the wild type, but contained only 30 to 40% as much fucose bound to proteins as the wild type. Sialic acid contents of the mutants and the wild type were similar. The mutants differed quantitatively and qualitatively from the wild type and from each other with respect to total glycoprotein profiles as visualized by sodium dodecyl sulfate gel electrophoresis. Differences were also found in resistances to cytotoxicity of lectins such as concanavalin A and wheat germ agglutinin.

scholarly journals Evidence for intracellular partitioning of serine and glycine metabolism in Chinese hamster ovary cells

1996 ◽  
Vol 313 (3) ◽  
pp. 991-996 ◽  
Author(s):  
Michael R. NARKEWICZ ◽  
S. David SAULS ◽  
Susan S. TJOA ◽  
Cecilia TENG ◽  
Paul V. FENNESSEY
Keyword(s):  
Cell Lines ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Mitochondrial Protein ◽  
Chinese Hamster ◽  
Serine Hydroxymethyltransferase ◽  
Cho Cell ◽  
Ovary Cells ◽  
Glycine Metabolism

Serine hydroxymethyltransferase (SHMT) is the primary enzyme in the interconversion of serine and glycine. The roles of mitochondrial and cytosolic SHMT in the interconversion of serine and glycine were determined in two Chinese hamster ovary (CHO) cell lines that both contain cytosolic SHMT but either have (CHOm+) or lack (CHOm-) mitochondrial SHMT. Mitochondrial SHMT activity was significantly reduced in CHOm- (0.24±0.11 nmol/min per mg of mitochondrial protein) compared with CHOm+ (3.21±0.66 nmol/min per mg of mitochondrial protein; P = 0.02) cells, whereas cytosolic SHMT activity was similar in CHOm- and CHOm+ cells (1.09±0.31 and 1.53±0.12 nmol/min per mg of cytosolic protein respectively; P = 0.57). In CHOm+ and CHOm- cells, the relative flux of glycine to serine measured with either [1-13C]- or [2-13C]-glycine was similar (CHOm-: 538±82 nmol/24 per mg of DNA; CHOm+: 616±88 nmol/24 h per mg of DNA; P = 0.42). In contrast, the relative flux of serine to glycine measured with [1-13C]serine was low in CHOm- cells (80±28 nmol/24 h per mg of DNA) compared with CHOm+ cells (3080±320 nmol/24 h per mg of DNA; P = 0.0001). The rate of glycine production determined by UA-2[1-13C]glycine dilution was lower in CHOm- (1200±200 nmol/24 h per mg of DNA) than CHOm+ (10200±1800 nmol/24 h per mg of DNA; P = 0.03) cells, whereas glycine utilization was similar in the two cell lines. Serine production was similar in the two cell lines but serine utilization was lower in CHOm- (3800±1200 μmol/24 h per mg of DNA) than CHOm+ (6600±1000 nmol/24 h per mg of DNA; P = 0.0002) cells. Increasing the serine concentration in the medium resulted in an increase in glycine production in CHOm+ but not in CHOm- cells. Intracellular studies with [1-13C]serine confirm the findings of decreased glycine production from serine. In CHO cells there is partitioning of intracellular serine and glycine metabolism. Our data support the hypothesis that mitochondrial SHMT is the primary pathway for serine into glycine interconversion.

Characteristics of nonpathogenic strains of Listeria monocytogenes

1991 ◽  
Vol 37 (8) ◽  
pp. 647-650 ◽  
Author(s):  
J. M. Farber ◽  
J. I. Speirs ◽  
R. Pontefract ◽  
D. E. Conner
Keyword(s):  
Listeria Monocytogenes ◽  
Key Words ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
The Other ◽  
Ovary Cells

Five strains of nonpathogenic Listeria monocytogenes were characterized for (i) hemolysin production, (ii) cytolysis of Chinese hamster ovary (CHO) cells, and (iii) ability to attach and enter intestine 407 cells. Four of the five strains produced variable hemolysis and were weakly cytolytic for Chinese hamster ovary cells, whereas the other isolate was consistently hemolytic and strongly cytolytic for CHO cells. None of the strains was able to penetrate intestine 407 cells. In addition, two of the five strains were found to be nonmotile. Key words: Listeria monocytogenes, nonpathogenic, attachment, motility, hemolysis.

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