K. Hariharan et al., TUMOR-REGRESSION IN MICE FOLLOWING VACCINATION WITH HUMAN-PAPILLOMAVIRUS E7 RECOMBINANT PROTEIN IN PROVAX(TM), International journal of oncology, 12(6), 1998, pp. 1229-1235
Induction of CD8(+) cytotoxic T lymphocytes (CTLs) specific for human
papillomavirus (HPV) antigens provides an attractive strategy for immu
notherapy of HPV-related cancers in humans. In this study, we investig
ated the potential of utilizing soluble E7 protein of HPV 16 in an adj
uvant formulation, PROVAX(TM) as a vaccine against a progressively gro
wing E7 transfected K1735-X21 (H-2(k)) metastatic melanoma cells (HOPE
2) in a mouse model. Vaccination of HOPE2 tumor bearing mice (C3H) wit
h E7 protein in PROVAX resulted in significant inhibition of tumor gro
wth, compared to mice vaccinated with E7 in Alum or saline. In vivo de
pletion of CD8(+) or CD4(+) cells indicated that CD8(+) cells are the
major effector cells in mediating the anti-tumor activity in this mode
l. Furthermore, E7-specific CTL activity in vitro was detected in tumo
r bearing mice vaccinated with E7-PROVAX. Our studies suggest that rec
ombinant HPV antigens in combination with PROVAX could serve as an eff
ective subunit vaccine to stimulate tumor specific CD8(+) T cell media
ted immunity against HPV-related cancers.