Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0920652 (skin irritant)
 188 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The murine local lymph node assay (LLNA) is a method for the prospective identification of chemical contact allergens. The current validated protocol assesses lymphocyte proliferation induced in the draining lymph node as a function of in situ incorporation of radiolabeled thymidine. We have explored the potential utility of an alternative nonradioisotopic marker of cell division, the cytoplasmic dye carboxyfluoresein succinimidyl ester (CFSE). Using this method, the cell phenotype and the number of divisions each cell has undergone can be tracked using flow cytometry. BALB/c strain mice were exposed topically to various concentrations of the contact allergens 2,4-dinitrochlorobenzene (DNCB), oxazolone (ox) or hexyl cinnamic aldehyde (HCA), or to the nonsensitizing skin irritant methyl salicylate (MS). Five days later, lymph node cells (LNC) were labeled with CFSE, cultured for 96 h, then incubated with fluorescent labeled anti-CD4 (T helper) and -CD8 (T cytotoxic) cell antibodies, and proliferating CD4+ and CD8+ cells analyzed by flow cytometry. In LNC populations derived from vehicle-treated animals, less than 1% of either cell population had undergone one cell division or more. Topical exposure to MS (2.5 to 20%) did not increase the frequencies of proliferating cells. Exposure to all three allergens, however, resulted in a marked increase in the percentages of both CD4+ and CD8+ cells undergoing division, with up to 5% and 3% of these cells, respectively, proliferating in response to DNCB and oxazolone, and with lower levels of proliferation stimulated by HCA. These preliminary data suggest that this method may be applied to provide the basis of a nonradioisotopic end point for the LLNA, particularly for the identification of potent contact allergens.
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PMID:Assessment of cumulative allergen-activated lymph node cell proliferation using flow cytometry. 1270 Apr 20

ABSTRACT Chromium is a common human contact allergen, but it is not known whether chromates cause contact hypersensitivity by immunological mechanisms similar to those induced by strong haptens. To understand the immunological events of contact hypersensitivity to chromates, we investigated whether and how chromate sensitization alters lymphocyte subsets in draining lymph nodes (DLNs), blood, and spleens in mice. BALB/c mice were sensitized by painting their ears with 0.5% potassium dichromate or vehicle alone on 3 consecutive days. Flow cytometric analysis of lymphocyte surface antigens showed that the chromate exposure significantly increased the percentage of B cells and decreased the percentages of T cells in the DLNs. This was accompanied by a relative increase in T cells and a relative decrease in B cells in peripheral blood. In contrast to the chromate, sodium dodecyl sulfate (a skin irritant) did not affect B cells or T cells in the three compartments. Moreover, sensitization to the chromate led to dose-dependent decreases in the percentages of CD4(+) T cells and CD8(+) T cells in the DLNs. However, CD4(+) and CD8(+) memory T cells were significantly increased in the blood and DLNs of the chromate-sensitized mice. Additionally, the percentage of B cells in the DLNs but not blood was dose-dependently increased in the chromate-sensitized mice. Histologically, B-cell areas were dramatically enlarged in the DLNs of the chromate-sensitized mice. Thus, this report provides basic information to further elucidate the role of individual lymphocyte subsets in contact hypersensitivity to chromates.
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PMID:Contact sensitizer potassium dichromate alters lymphocyte populations in draining lymph nodes and blood in mice. 2002 Aug 74