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PERSISTENT SUPPRESSION OF CONTACT HYPERSENSITIVITY, AND ALTERED T-CELL PARAMETERS IN F344 RATS EXPOSED PERINATALLY TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)
Citation:
Walker, D. B., W C. Williams, C B. Copeland, AND R J. Smialowicz. PERSISTENT SUPPRESSION OF CONTACT HYPERSENSITIVITY, AND ALTERED T-CELL PARAMETERS IN F344 RATS EXPOSED PERINATALLY TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD). TOXICOLOGY. Elsevier Ireland Limited, Limerick, Ireland, 197:57-66, (2004).
Description:
Abstract
The outcome of perinatal low-level TCDD exposure on the T cell-mediated contact hypersensitivity response (CHS) in adult F344 rats was investigated. Suppression of the 2,4- dinitrofluorobenzene (DNFB)-specific contact hypersensitivity reponse occurred in mature offspring of dams dosed by gavage with 1 or 3 g TCDD/kg on gestation day 14. To determine if this effect was correlated with altered distribution or activation of major T cell subtypes, cells of the auricular lymph node draining the hapten-treated skin were evaluated by flow cytometry for expressed phenotype, including activation markers, 24 hours after challenge. Six-month-old female offspring with significantly decreased CHS and born to dams given 3 g TCDD/kg, had significantly greater proportion of CD4+ T cells expressing a naive phenotype marker, CD45RChi, in their draining nodes. The greater relative frequency of this CD4+ subset in peripheral lymphoid tissues associated with a reduced CHS in these rats may be attributed to a reduction in the proportion of CD4+ T cells maintaining or recruited into an activated state. The CHS proved to be a valuable bioassay for investigating long-term immunotoxic effects of perinatal TCDD exposure in rats.