Time Course Gene Expression Microarray Analysis of a Mouse B-cell Line (CH12.LX) Activated with Lipopolysaccharide and Treated with 2,3,7,8-Tetrachlorodibenzo-p-dioxin

The objective of the study was to characterize gene expression cascade involved in the suppression of B-cell activation and differentiation by 2,3,7,8-tetrachlorodibenzo-p-dixoxin (TCDD). The underlying hypothesis was that multiple nodes in the B-cell differentiation network are directly or indirectly regulated by TCDD through its receptor, the AHR. The mouse B-cell line (CH12.LX) was plated at 1X10^5 cells/ml at time 0 and activated with lipopolysaccharide (LPS, Salmonella typhosa). The cells were then treated with either dimethyl sulfoxide (DMSO, 0.01%) or 10 nM 2,3,7,8-tetrachlorodibenzo-p-dixoxin (TCDD). The cells were harvested at 0, 8, 12, 24, 36, and 48 hrs post-treatment. At the 0 hr time point, cells were untreated. A total of 4 experimental replicates per time point per treatment group were included with the cells for each replicate treated and harvested on separate days. Single color Affymetrix Mouse 430 2.0 arrays were used.