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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1992-12-18
pubmed:abstractText
The mechanism by which a horse conceptus-derived immunosuppressive factor (HCS) of M(r) > 100,000 inhibits lymphocyte proliferation was investigated. The factor was obtained from the culture supernatants of 20-day-old horse conceptuses; activity, identified by reduced uptake of [3H]thymidine by mitogen-stimulated lymphocytes, was greatest (P < 0.01) in cultures stimulated by mitogen from pokeweed. HCS also suppressed cell proliferation stimulated by phytohaemagglutinin (P < 0.01), but had no effect on lipopolysaccharide-stimulated cells (P > 0.05). Data from a fluorescence-activated cell sorter indicated that supplementation with HCS reduced the number of T cells in phytohaemagglutinin-stimulated cultures and suppressed proliferation of T and B cells in pokeweed-mitogen-stimulated cultures compared with controls. Cell proliferation was greater (P < 0.01) in cultures supplemented with HCS 24 h after stimulation than in those treated at the start of stimulation, and was even greater (P < 0.01) when cells were treated 48 h after stimulation. The removal of HCS from treated lymphocyte cultures resulted in complete recovery of cell responsiveness, and stimulated proliferation of treated cells did not differ (P > 0.05) from that of control cells. The addition of stimulated equine lymphocyte supernatant to cultures supplemented with HCS did not significantly increase (P > 0.05) cell proliferation in response to pokeweed mitogen. Addition of recombinant human interleukin 2 (rIL-2) to HCS-treated cultures did not alter the suppressive activity of HCS, although cell proliferation was greater in cultures supplemented with rIL-2 than in controls (P < 0.01). HCS inhibition of IL-2 receptor (IL-2R) function was investigated using an IL-2-dependent murine cytolytic T lymphocyte cell line; the fraction of HCS of M(r) > 100,000 had no effect (P > 0.05) on proliferation of IL-2-dependent murine cytolytic T lymphocyte cells induced by rIL-2. Together, these data suggest that HCS suppresses proliferation of T lymphocytes during the early stages of cell activation by inhibiting IL-2R interaction and that this suppression interferes with interactions between T cells and B cells, thereby also indirectly inhibiting proliferation of B cells. The potent immunosuppressive capacity of HCS may be one factor responsible for inhibiting cell-mediated fetal allograft rejection during pregnancy.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-4251
pubmed:author
pubmed:issnType
Print
pubmed:volume
96
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
309-22
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Involvement of interleukin 2 receptors in conceptus-derived suppression of T and B cell proliferation in horses.
pubmed:affiliation
Department of Animal Science, LSU Agricultural Center, Baton Rouge.
pubmed:publicationType
Journal Article, Comparative Study