Chemokine receptor induction on CD4⁺ T cells following their activation in MLNs and PLNs. (A-B) CFSE-labeled OT-II cells were injected into C57BL/6J.Ly5.1 mice and their expression of chemokine receptors in MLNs and PLNs was determined by flow cytometry, in the absence of or 2 days after intraperitoneal administration of OVA plus LPS. (A) Representative chemokine receptor staining (lines represent level at which < 2% cells stained with isotype-matched control antibody) and (B) mean (±SEM) chemokine receptor-positive cells among 7-AAD^– Ly5.2⁺ OT-II cells. Results are from 3 to 5 experiments, using pooled cells from 3 mice/experiment. *P < .03, paired 2-tailed Student t test, for differences between priming in MLNs and PLNs.