Self-Adjuvanting Peptide Vaccines Against Cervical Cancer
Human papillomaviruses are members of the Papovaridae
family of non-enveloped deoxyribonucleic acid viruses.
They infect the skin or mucosa of vertebrate hosts.
The DNA genome encodes six non-structural proteins,
and two structural capsid proteins.
Proteins E1, E2, and E4 participate in viral gene replication,
transcription and genome amplification, respectively,
whereas proteins E5, E6, and E7 are identified as HPV oncoproteins,
which initiate HPV infection and the evasion of host immune responses.
HPVs infect cervical epithelial cells and use the growth and
differentiation of these cells to carry out their own life cycle.
When the HPV genome is transformed from an extra chromosomal
state to an integrated phase within the host’s chromosome,
the disease progresses from precancerous lesions to high-grade lesions.
Once the immune system fails to clear persistent HPV
infections, there is a high chance that cervical cancer will develop.
There are currently two prophylactic HPV vaccines: Gardasil and Cervarix,
that have been developed and commercialized to the global market.
They utilize recombinant L1 virus-like particles
to induce virus-neutralizing antibodies directed towards
conformational epitopes of the L1 capsid protein.
Both vaccines are able to protect against the most common HPV type,
HPV-16, which is responsible for up to 59% of all cervical cancer cases.
For this reason, a therapeutic HPV vaccine would be
highly advantageous for treatment of the HPV-infected population.
Peptide-based approaches for developing therapeutic
vaccines against HPV-associated cancers showed promising results
in several early clinical trials.
Vaccin Res Open J. 2019; 4(1): 21-29. doi: 10.17140/VROJ-4-114