Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1996-6-4
pubmed:abstractText
Exposure to radon and its progeny induces significant damage to the cells of the respiratory tract and causes lung cancer. Whether a similar exposure to radon would alter the functions of the immune system has not been previously investigated. In the current study, we investigated the effect of exposure of C57BL/6 mice to 1000 or 2500 working-level months (WLM) of radon and its progeny by inhalation, on the number and function of T lymphocytes in lymphoid organs. The control mice received uranium ore dust carrier aerosol by inhalation. Exposure to radon induced marked decrease in the total cellularity of most lymphoid organs such as thymus, peripheral lymph nodes (PLN), and lung-associated lymph nodes (LALN), when compared to the controls. The percentage of T cells increased, while that of non-T cells decreased, in all peripheral lymphoid organs at both the doses of radon. In the thymus, particularly at 2500 WLM of radon exposure, there was a marked decrease in CD4+CD8+ T cells and an increase in the immature CD4-CD8- T cells. Such alterations in both the numbers and percentages of lymphocytes and macrophages in radon-exposed mice may have resulted from the cell killing by the alpha particles as the immune cells were migrating through the lungs, or it may have been caused by altered migration of cells, inasmuch as expression of CD44, a molecule involved in migration and homing of immune cells, was significantly altered on cells found in different lymphoid organs. In the LALN, where one would predict the largest number of damaged cells to be present, there was a significant decrease in the T-cell responsiveness to mitogens while the B-cell response was not affected. Such alterations may have resulted from the direct effect of alpha-particle exposure on the migrating lymphocytes, altered percentage of lymphocytes as seen in secondary lymphoid organs, or altered expression of adhesion molecules involved in cell activation such as CD44 and CD3. Interestingly, radon exposure caused and increase in the T- and B-cell responsiveness to mitogens in the spleen and PLN. Since there is little evidence of direct radiation dose from radon in lymphoid organs, our studies demonstrating immunological alterations suggest an indirect effect of radon exposure that may have significant repercussions on the development of hypersensitivity and increased susceptibility to infections and cancer in the lung.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0098-4108
pubmed:author
pubmed:issnType
Print
pubmed:day
19
pubmed:volume
47
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
535-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8614022-Administration, Inhalation, pubmed-meshheading:8614022-Aerosols, pubmed-meshheading:8614022-Alpha Particles, pubmed-meshheading:8614022-Animals, pubmed-meshheading:8614022-Antigens, CD44, pubmed-meshheading:8614022-B-Lymphocytes, pubmed-meshheading:8614022-CD4-CD8 Ratio, pubmed-meshheading:8614022-Dose-Response Relationship, Drug, pubmed-meshheading:8614022-Dust, pubmed-meshheading:8614022-Female, pubmed-meshheading:8614022-Flow Cytometry, pubmed-meshheading:8614022-Lung, pubmed-meshheading:8614022-Lymph Nodes, pubmed-meshheading:8614022-Lymphocyte Activation, pubmed-meshheading:8614022-Lymphocyte Count, pubmed-meshheading:8614022-Macrophages, pubmed-meshheading:8614022-Mice, pubmed-meshheading:8614022-Mice, Inbred C57BL, pubmed-meshheading:8614022-Radon, pubmed-meshheading:8614022-Spleen, pubmed-meshheading:8614022-T-Lymphocytes, pubmed-meshheading:8614022-Thymus Gland, pubmed-meshheading:8614022-Uranium
pubmed:year
1996
pubmed:articleTitle
Effect of radon on the immune system: alterations in the cellularity and functions of T cells in lymphoid organs of mouse.
pubmed:affiliation
Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg 24061, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S.