Fig. 3.
Induction of peptide specific IFN-γproducing cells by intranasal immunization with the mixture of E744–62 (Q19D) and E643–57 (Q15L) peptides from HPV-16 using the mutant cholera toxin (CT-2*) as adjuvant. Cells isolated from spleen, CLN and MLN of C57BL/6 mice immunized by the intranasal route with mixture of Q19D and Q15L peptides were stimulated in vitro using medium, cognate peptides or a non-specific negative control peptide individually (2μg/ml) in a 96 well plate ELISPOT. After 48h the plates were washed and developed and the number IFN-γproducing spot forming cells were enumerated in each well and the number of spot forming cells calculated per 1 ×106 cells is plotted. Average values and errors bars were calculated from 2 separate experiments consisting of 3 mice in each. Responses were considered positive when they were above 50 SFC/well and at least double the number obtained in cells cultured with medium alone (this cut-off value shown as horizontal line in the two panels). The p values were calculated comparing with the medium alone control and values ≤ 0.05 (*) are considered significant.