Linked Life Data

3876369

Source:http://linkedlifedata.com/resource/pubmed/id/3876369

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1985-11-21
pubmed:abstractText
The role of accessory cells (AC) in the initiation of mitogen-induced T cell proliferation was examined by comparing the effect of intact macrophages (M phi) with that of 4-beta-phorbol 12-myristate 13-acetate (PMA). In high-density cultures, purified guinea pig T cells failed to proliferate in response to stimulation with phytohemagglutinin (PHA), concanavalin A (Con A), or PMA alone. The addition of M phi to PHA or Con A but not PMA-stimulated cultures restored T cell proliferation. The addition of PMA to high-density T cell cultures stimulated with PHA or Con A also permitted [3H]thymidine incorporation, but was less effective than intact M phi in this regard. This action of PMA was dependent on the small number of AC contaminating the T cell cultures as evidenced by the finding that PMA could not support mitogen responsiveness of T cells that had been depleted of Ia-bearing cells by planning, even when these cells were cultured at high density. When PMA was added to T cell cultures supported by optimal numbers of M phi, catalase-reversible suppression of responses was noted. Even in cultures containing catalase, PMA failed to enhance responsiveness above that supported by optimal numbers of M phi. A low-density culture system was used to examine in greater detail the possibility that PMA could completely substitute for M phi in promoting T cells activation. In low-density cultures, mitogen-induced T cell proliferation required intact M phi. PMA could not support responses even in cultures supplemented with interleukin 1-containing M phi supernatants or purified interleukin 2 alone or in combination. Similar results were found in high-density cultures of T cells depleted of Ia-bearing cells. These results support a model of T cell activation in which AC play at least two distinct roles. The initiation of the response requires a signal conveyed by an intact M phi, which cannot be provided by either a M phi supernatant factor or PMA. The response can be amplified by additional M phi or M phi supernatant factors. PMA can substitute for M phi in this regard and can provide the signal necessary for amplification of T cell proliferation supported by small numbers of intact AC.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:volume
135
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2946-52
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Signals involved in T cell activation. I. Phorbol esters enhance responsiveness but cannot replace intact accessory cells in the induction of mitogen-stimulated T cell proliferation.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.