Figure 6. Fluoro-substituted STn vaccines induce efficient antitumor immunotherapy, T cell-mediated immunity and antibody immune response in the absence of adjuvant.
(A) 1-KLH, 2-KLH, 3-KLH and 4-KLH in the absence of adjuvant were immunized five times at biweekly intervals and animals were challenged via the tail vein 7 days after the 4th immunization with 1.5 × 105 CT-26 cells. Two weeks after tumor challenge, animals were euthanized, lungs were weighted and assessed for tumor load. Results are presented as median values for groups. (B) ELISPOT IFN-γ-releasing lymphocyte assay. ELISPOT assays of the number of IFN-γ-releasing splenocytes among 2.5 × 105 splenocytes derived from each mouse. Results are presented as median values for groups of 6 mice. (C–D) IgG subtypes after immunized with 1-KLH, 2-KLH, 3-KLH and 4-KLH without adjuvant by ELISA with a 1:1000 dilution of pooled sera. (E–F) ELISA anti-STn antibody titers after 5th immunization. Results are presented as median values for groups of 6 mice (E) or as the mean of individual ± standard deviation (SD) (F). The results in (A-B, E-F) are representative of three independent experiments. *p < 0.05, **p < 0.01 and ***p < 0.001. The results in (C–D) represent the mean ± SEM of at least two experiments.