A Dual-Type L2 11-88 Peptide from HPV Types 16/18 Formulated in Montanide ISA 720 Induced Strong and Balanced Th1/Th2 Immune Responses, Associated with High Titers of Broad Spectrum Cross-Reactive Antibodies in Vaccinated Mice

Figure 5

Neutralizing antibody responses in mice vaccinated with the dual-type L2 11-88 × 1 peptide formulated in different adjuvants. Mice (5/group) were immunized (s.c.) three times at two-week interval with 25 μg of L2 11-88 × 1 formulated in alum (50 μg), CFA (at 1 : 1 ratio), Montanide ISA 720 (adjuvant/antigen ratio of 2 : 1), Montanide 50V2 (at 1 : 1 ratio), and MF59 (at 1 : 1 ratio). Mice administered with PBS were regarded as negative control. Two weeks after the last vaccination, blood samples were collected and twofold serially diluted sera (starting dilution at 1 : 50) were tested for in vitro neutralization of either HPV 16 (a) or HPV 18 (b) pseudovirions. The neutralizing antibody titers were expressed as the reciprocal dilution at which 50% of the pseudovirions were neutralized compared to positive control wells. End point titers were plotted and means reflected as horizontal lines. A neutralizing titer of <1 : 50 was considered as not detectable (ND). and . ns: not significant.

(a)

(b)