Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-2-18
pubmed:abstractText
Tumor cells may influence the host's immune reactivity by the production of immunosuppressive factors (ISFs). In this study, the effects of ISFs derived from nine polyclonal colorectal carcinoma (CRC) cell lines on PHA-induced lymphocyte proliferation and cytokine secretion was investigated. We found that most of the culture supernatants (8/9) from CRC cell lines contained ISFs, which inhibited T cell proliferation to a variable degree in a dose-dependent manner. Comparison of T cell proliferation in the presence or absence of monocytes showed that monocytes can modulate the effects of tumor-derived ISFs on lymphocyte function. In addition, exposure of activated PBMC to the tumor cell supernatants resulted in an altered secretion of cytokines by these cells, i.e. the secretion of IFN-gamma was generally reduced while the secretion of IL-1beta, IL-2 and TNF-alpha was little affected. We further investigated the supernatants' inhibitory effects on PBMC in respect to the production of prostaglandin E(2) (PGE(2)). It was found that PGE(2) was secreted by all tumor cell cultures. Therefore this substance is probably involved in the immunosuppression in vivo. However, the secreted PGE(2) was shown not to be solely responsible for the observed suppression of lymphocyte proliferation in vitro. Our results suggest that the secretion of ISF is a common property of CRCs as demonstrated with newly established CRC cell cultures, and therefore this may also be an important immune escape mechanism of colonic carcinomas in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1010-4283
pubmed:author
pubmed:copyrightInfo
Copyright 2000 S. Karger AG, Basel
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:articleTitle
Comparison of the effects of immunosuppressive factors from newly established colon carcinoma cell cultures on human lymphocyte proliferation and cytokine secretion.
pubmed:affiliation
Institute of Immunobiology, University of Freiburg, Germany.
pubmed:publicationType
Journal Article, Comparative Study