Document 1026
 DOCN  M9541026
 TI    Proliferation inhibition and CD4/CD8 thymocyte subset skewing by in vivo
       exposure of C57BL/6 mice to Ah receptor-binding
       3,3',4,4'-tetrachlorobiphenyl.
 DT    9504
 AU    Esser C; Lai Z; Gleichmann E; Medical Institute of Environmental
       Hygiene, Dusseldorf, Germany.
 SO    Exp Clin Immunogenet. 1994;11(2-3):75-85. Unique Identifier : AIDSLINE
       MED/95127259
 AB    3,3',4,4'-Tetrachlorobiphenyl (TCB) and other Ah receptor-binding
       xenobiotics lead to thymus atrophy and immunosuppression, the former
       possibly causing the latter. In order to better understand the
       TCB-induced events in the murine thymus, we analyzed the effects of TCB
       on the proliferation capacity and maturation kinetics of different
       thymocyte subsets in 2-week-old C57BL/6 mice (i.e. of the Ahb-1
       'dioxin-sensitive' genotype). Mice were injected with a single dose of
       TCB, and the development of thymocytes was followed up for 10 days using
       flow cytometric surface marker analysis combined with measurement of DNA
       content by 7-amino-actinomycin D staining. Already 2 days after exposure
       to TCB, fewer of the more immature thymocytes (CD4-CD8-, CD4-CD8+ alpha
       beta TCR-) were proliferating than in thymi from control animals.
       Eventually this led to a severe decrease in thymus cellularity.
       Moreover, a shift towards the CD4-CD8+ mature subpopulation was
       observed. The effects were reversible, and proliferation and CD4/CD8
       subset distribution returned to normal levels within the observation
       period. The results are in good agreement with the data obtained
       previously in vitro with fetal thymus organ cultures.
 DE    Animal  Cell Differentiation/DRUG EFFECTS  CD4-Positive
       T-Lymphocytes/*DRUG EFFECTS  CD8-Positive T-Lymphocytes/*DRUG EFFECTS
       Flow Cytometry  Lymphocyte Transformation/DRUG EFFECTS  Mice  Mice,
       Inbred C57BL  Polychlorinated Biphenyls/*PHARMACOLOGY  Receptors, Aryl
       Hydrocarbon/METABOLISM  Support, Non-U.S. Gov't  T-Lymphocyte
       Subsets/DRUG EFFECTS  Thymus Gland/CYTOLOGY/*DRUG EFFECTS  JOURNAL
       ARTICLE

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