Toxicological Sciences 68, 420-428 (2002)
Copyright © 2002 by the Society of Toxicology
IMMUNOTOXICOLOGY |
Use of a B Cell Marker (B220) to Discriminate between Allergens and Irritants in the Local Lymph Node Assay
* The Procter & Gamble Company, Miami Valley Laboratories, P.O. Box 538707, Cincinnati, Ohio 4523–8707; and
Syngenta Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire SK10 4TJ, United Kingdom
It has been shown that exposure of mice to contact allergens induces B cell activation in the draining lymph nodes (DLN), as seen by an increase in the percentage of B220+ or IgG/IgM+ cells. We have now examined whether the measurement of the percentage of B220+ cells could be used as an alternative or supplementary endpoint for the local lymph node assay (LLNA) to differentiate between allergenic responses and those few irritants that induce low-level proliferation in the DLN. Mice were treated on the ears, daily for 3 consecutive days, with various allergens (1-chloro-2,4-dinitrobenzene, 
-hexylcinnamaldehyde, trinitrochlorobenzene, isoeugenol, and eugenol) or irritants (benzalkonium chloride, methyl salicylate, salicylic acid, and sodium lauryl sulfate). The DLN were excised 72 h following the final topical treatment, and the cells were prepared for B220 analysis using flow cytometry. The percentage of B220+ cells in lymph nodes derived from test and vehicle-treated animals was determined for 5 allergens and 4 irritants tested in multiple experiments (n = 3 to 17). As expected, the percentage of B220+ B cells was increased with each of the allergens tested, whereas irritant treatment did not cause similar increases. Moreover, the method was reproducible. For example, the strong allergen, 1-chloro-2,4-dinitrobenzene and the weak allergen, -hexylcinnamaldehyde were identified as allergens in 17 of 17 and in 12 of 13 experiments, respectively. The percentage of B220 values for each chemical treatment (41 observations for allergens; 28 observations for irritants) versus the percentage of B220 values for the concurrent vehicle controls were plotted, and a classification tree model was developed that defined a B220 test:vehicle ratio cutoff of 1.25 for discriminating between allergens (>1.25) and irritants (<1.25). Using this B220 test:vehicle ratio of 1.25 in 93% of the 69 independent observations made, the allergens and irritants tested were identified correctly. Finally, to evaluate the performance of this model in a second independent laboratory, 3 allergens and 2 irritants were tested. Each of the allergens and irritants were classified correctly using the B220 test:vehicle ratio cutoff of 1.25. These data demonstrate that analysis of B220 expression in DLN may be useful in differentiating between allergen and irritant responses induced in chemically treated mice.
Key Words: allergens; irritants; local lymph node assay, B cells; flow cytometry.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  L. Lv, G.-Y. Yan, Y.-L. Zhao, X.-J. He, X. Jiang, Y.-Q. Zhuo, Y.-L. Wang, L. Wang, and X.-B. Cen Investigation of the Dermal Sensitizing Potential of Traditional Medical Extracts in Local Lymph Node Assays Experimental Biology and Medicine, March 1, 2009; 234(3): 306 - 313. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. R. Boverhof, B. B. Gollapudi, J. A. Hotchkiss, M. Osterloh-Quiroz, and M. R. Woolhiser Evaluation of a toxicogenomic approach to the local lymph node assay (LLNA) Toxicol. Sci., February 1, 2009; 107(2): 427 - 439. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Nierkens, L. Nieuwenhuijsen, M. Thomas, and R. Pieters Evaluation of the Use of Reporter Antigens in an Auricular Lymph Node Assay to Assess the Immunosensitizing Potential of Drugs Toxicol. Sci., May 1, 2004; 79(1): 90 - 97. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. E. Humphreys, R. J. Dearman, and I. Kimber Assessment of Cumulative Allergen-Activated Lymph Node Cell Proliferation Using Flow Cytometry Toxicol. Sci., May 1, 2003; 73(1): 80 - 89. [Abstract] [Full Text] [PDF]
|
|