Eca. Paul et al., CONDITIONALLY IMMORTALIZED INTESTINAL EPITHELIAL-CELLS - NOVEL-APPROACH FOR STUDY OF DIFFERENTIATED ENTEROCYTES, The American journal of physiology, 265(1), 1993, pp. 30000266-30000278
Clonal cell lines have been established from primary fetal rat intesti
nal epithelial cells by stable transfection with plasmids containing e
ither the simian virus 40 (SV40) large T-antigen gene under the contro
l of the heavy metal inducible metallothionein promoter (pMTWt) or the
thermolabile SV40 T-antigen gene under the control of the SV40 early
promoter (pZipSVtsa58). pMTWt-transfected cells produced sufficient T-
antigen to allow them to proliferate both when the metallothionein pro
moter was induced and uninduced. No differences were observed in the p
attern of intestinal epithelial markers expressed when the cells were
cultured in the presence or absence of inducing agent (zinc). In contr
ast, fetal rat intestinal epithelial cells transfected with pZipSVtsa5
8 were immortalized conditionally; cells proliferated at 32-degrees-C
but ceased to proliferate between 48 and 72 h of culture at 39-degrees
-C. Four of these cell lines were characterized in detail; they showed
microvilli and tight junctions as well as dome formation and expresse
d functional and biochemical markers of intestinal epithelial cells, i
ncluding keratins 8, 19, and 21, aminopeptidase N, and dipeptidyl pept
idase IV. One cell line, 2/4/Al, expressed in addition a low level of
lactase and sucrase-isomaltase. The amount and/or activity of some of
these markers changed during the switch from the proliferative to the
nonproliferative state (switch from culture at 32 to 39-degrees-C), re
sulting in a more differentiated phenotype and mimicking similar chang
es taking place during intestinal epithelial cell differentiation in v
ivo.