Final answer:
HPV expresses viral proteins to neutralize the host cell's defenses, particularly the p53 protein, to promote viral replication and increase the risk of cervical cancer.
Step-by-step explanation:
The reason why it is advantageous for HPV to express viral proteins, specifically E6, in the keratinocytes is because it allows the virus to bypass the cell's natural defense mechanisms against DNA damage. In normal cells, the p53 protein plays a critical role in detecting DNA damage and can induce cell cycle arrest or apoptosis to prevent the propagation of mutations. However, when high-risk HPV enters a cell, its E6 protein binds to p53, leading to the neutralization of this tumor suppressor protein. As a result, the cell cycle checkpoints are compromised, the cell is kept in a state conducive to fast growth, and apoptosis is impaired, allowing the cell to replicate despite having DNA damage. This process facilitates the viral replication and persistence within the host, increasing the risk of cervical cancer. HPV's strategy of expressing proteins like E6 is a remarkable evolutionary advantage, as it promotes the survival and proliferation of the virus within the host organism by preventing the normal cellular response to genomic errors.