Inhibiting NF-κB signaling reduces CXCR4 expression and abrogates T-cell migration. Splenocytes from C57BL/6 mice were treated with DMSO or Bay11 (1 μM) and cocultured for 12 days with BMDCs from F1 hybrids. CXCR4 expression was assessed by flow cytometry on (A) CD4⁺ and (B) CD8⁺ T cells; n = 3. On day 8 postculture, nonadherent cells were harvested from cocultures (as above) and their chemotactic response to SDF-1α was analyzed. Cells were added to Transwell inserts; 0 or 100 ng/ml SDF-1α was added to wells. Cultures were incubated for 3 hours, at which time migrated cells were harvested from wells and CD4⁺ and CD8⁺ T cells were enumerated by flow cytometry. The chemotactic index (number of cells migrated into 100 ng/ml SDF-1α wells/number of cells migrated into 0 ng/ml SDF-1α wells) was calculated for DMSO- or Bay11-treated (C) CD4⁺ and (D) CD8⁺ T cells; n = 3. Data are the mean ± SEM, and were analyzed using two-way ANOVA plus Bonferroni post-test (A-B) or two-tailed unpaired Student t test (C-D). *P < .05; **P < .01; ***P < .001.