Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1999-8-3
pubmed:abstractText
It is now well documented that apoptosis represents the prevalent mode of death in lymphoid cultures and occurs spontaneously in late-exponential phase of batch cultures following nutrient exhaustion. In an attempt to enhance the cell survival of these cell lines, we have initially engineered nonproducing NS/0 myeloma cells with a vector expressing the adenoviral E1B-19K protein. NS/0 cells transfected with E1B-19K were found to be more resistant to apoptosis occurring in the late phase of batch culture and under stressful conditions such as cultivation in glutamine-free medium or following heat shock. In this study, we have characterised a number of NS/0 subclones constitutively expressing different levels of E1B-19K, as well as several subclones in which the expression of E1B-19K was regulated by a tetracycline-controllable gene switch. We have found that a threshold E1B-19K level was required in order to achieve protection against apoptosis. The extent of resistance against cell death induced by nutrient deprivation in glutamine-free medium and in the late phase of batch cultures correlated with the level of E1B-19K expression up to an optimal level where further increases in E1B-19K levels did not result in significant additional protection. To assess the effects of E1B-19K on antibody productivity, an apoptosis-resistant NS/0 clone was then transfected with a chimeric antibody construct. Despite their improved viability, the antibody productivity of E1B-19K clones in batch culture was not significantly improved. Moreover, while the use of E1B-19K considerably delayed cell death, cells eventually died by apoptosis. Surprisingly, E1B-19K had no beneficial effect on the efficiency of fusion of NS/0 myelomas and splenocytes for the generation of hybridoma cells. Furthermore, the resulting hybridomas, although expressing E1B-19K at levels comparable to the myeloma parent, were no longer resistant to apoptosis. This indicates that the ability of E1B-19K to prevent apoptosis is not only dose-dependent but also seems to be cell-type dependent.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-3592
pubmed:author
pubmed:copyrightInfo
Copyright 1999 John Wiley & Sons, Inc.
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
516-28
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Dose-dependent reduction of apoptosis in nutrient-limited cultures of NS/0 myeloma cells transfected with the E1B-19K adenoviral gene.
pubmed:affiliation
Groupe d'Ingénierie des Cellules Animales, Institut de Recherche en Biotechnologie, Conseil National de Recherches du Canada, 6100 Avenue Royalmount, Montréal, PQ, Canada, H4P 2R2.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't