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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2007-1-26
pubmed:abstractText
Rac1, one of the Rho family small guanosine triphosphatases, has been shown to work as a "molecular switch" in various signal transduction pathways. To assess the function of Rac1 in the differentiation process of CD4 single-positive (CD4-SP) T cells from CD4CD8 double-positive (DP) cells, we used a DP cell line DPK, which can differentiate into CD4-SP cells upon TCR stimulation in vitro. DPK expressing dominant-negative (dn)Rac1 underwent massive apoptosis upon TCR stimulation and resulted in defective differentiation of CD4-SP cells. Conversely, overexpression of dnRac2 did not affect differentiation. TCR-dependent actin polymerization was inhibited, whereas early ERK activation was unaltered in dnRac1-expressing DPK. We found that TCR-dependent induction of Bcl-2 was suppressed greatly in dnRac1-expressing DPK, and this suppression was independent of actin rearrangement. Furthermore, introduction of exogenous Bcl-2 inhibited TCR-dependent induction of apoptosis and restored CD4-SP generation in dnRac1-expressing DPK without restoring TCR-induced actin polymerization. Collectively, these data indicate that Rac1 is critical in differentiation of CD4-SP from the DP cell line by preventing TCR-induced apoptosis via Bcl-2 up-regulation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0741-5400
pubmed:author
pubmed:issnType
Print
pubmed:volume
81
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
500-8
pubmed:dateRevised
2011-1-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Rac1-mediated Bcl-2 induction is critical in antigen-induced CD4 single-positive differentiation of a CD4+CD8+ immature thymocyte line.
pubmed:affiliation
Department of Microbiology and Immunology, Yamaguchi University School of Medicine, Ube, Japan.
pubmed:publicationType
Journal Article