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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1985-3-20
pubmed:abstractText
Cellular events during the development of thymic lymphomas in young B10.BR mice given leukemogenic split-dose irradiation were studied by examining the differentiation of functional T lymphocyte precursors in the regenerating thymus. It was found that leukemogenic radiation treatment resulted in a sustained depression of the level of thymic cytotoxic T lymphocyte precursors (CTLp) and of mixed lymphocyte reactivity of thymus cells when assessed between 1 and 4 mo after irradiation, in spite of the fact that the total number of thymocytes was restored to the normal level within 2 mo and continued to increase thereafter. In vitro mixing studies of normal thymocytes with thymus cells from split-dose irradiated mice provided no evidence for active suppression as a mechanism for this depressed activity. The ability of bone marrow cells from split-dose irradiated mice to regenerate the thymus and to differentiate into functional CTLp was examined by use of supralethally irradiated Thy-1 congenic recipients. Reconstitution of supralethally irradiated B10.BR Thy-1.2 mice with normal bone marrow from B10.BR Thy-1.1 mice resulted in the complete repopulation of host-thymus with donor-derived cells when assessed at 4 wk after reconstitution. Lymphocytes from the regenerating thymus of these animals were shown to contain high levels of CTLp which were donor-derived. On the other hand, when the recipient mice were reconstituted with bone marrow cells from donor mice which had been split-dose irradiated 1 mo earlier, regeneration of the recipient thymus was severely depressed when assessed at 4 wk to 3 mo after reconstitution. Although variable but small numbers of donor-derived Thy-1+ cells were detected, CTL activity for alloantigen could not be induced in these donor-derived cells. The results suggest that T cell precursors derived from split-dose irradiated donor mice were unable to undergo active proliferation and differentiation into functional CTLp. The significance of these findings on radiation-induced thymic leukemogenesis is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:volume
134
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2026-31
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
Cellular events during radiation-induced thymic leukemogenesis in mice: abnormal T cell differentiation in the thymus and defect of thymocyte precursors in the bone marrow after split-dose irradiation.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't