Ex vivo cytokine responses following intranasal peptide, before and after skin grafting. HY^AbDby peptide and peptide plus LPS intranasally treated mice at day 5. Three mice from each group of mice, given 3 × 100 μg HY^AbDby with (A,C) or without (B,D) 3 μg LPS were killed and cervical lymph nodes taken for ELISPOT analysis. Panels A and B show the IFN-γ response in the presence of irradiated female splenocytes alone or pulsed with HY^DbUty or HY^AbDby peptide; panels C and D show the IL-2 response. PBS- and HY^AbDby peptide–pretreated mice 8 and 21 days after skin grafting. Two groups of B6 females (8 mice/group) pretreated with 3 × 100 μg HY^AbDby peptide or PBS intranasally were given grafts with syngeneic male skin 10 days later. Recipients were killed 8 (5 mice per group) and 21 (3 mice per group) days later, and cell suspensions from graft-draining lymph nodes, from PBS-treated (E,G,I,K) and peptide-treated mice (F,H,J,L), were tested by ELISPOT assay for IFN-γ (E,F,I,J) and IL-2 (G,H,K,L) production in response to irradiated female splenocytes alone or pulsed with HY^DbUty or HY^AbDby peptide. Results are expressed as spots/2 × 105 cells. Each symbol represents an individual mouse.