Alla Piirsoo, associate professor of molecular virology

Research:

Human papillomaviruses (HPV) are small circular DNA genome viruses that infect the skin and mucous epithelium. To date, more than 200 different types of HPV have been identified. Most HPV infections are asymptomatic and harmless to the body. However, some HPV virus types are tumorigenic, and their infection accounts for approximately five percent of all human cancers. HPV infection is the most significant risk factor for cervical, anogenital, and certain types of head and neck cancers. Although various vaccines are available against HPV infections, they are not effective against ongoing infections and are developed only against a small number of different virus types. Therefore, medical issues arising from HPV infections remain highly relevant in society for the foreseeable future.

HPV infection and viral genome replication occur in very few cell types and involve a large number of host cell factors. We study the mechanisms of HPV genome replication with the ultimate goal of identifying novel therapeutic targets and methods to suppress the efficiency of viral infection.

Specifically, we focus on:

Investigating post-translational modifications of HPV replication proteins E1 and E2. These proteins are the only viral proteins required for HPV genome replication, and their activity is regulated by host cell proteins. We have identified several protein kinases, including CK2 and PKA, which phosphorylate these proteins. Additionally, we have shown that depending on the HPV type, the phenotype dependent on E1 and E2 phosphorylation can be completely opposite. We also investigate the mechanistic differences in the regulation of the activities of E1 and E2 proteins of HPV types infecting skin and mucous epithelium.

Screening small-molecule chemical libraries to find new drug candidates to suppress HPV genome replication in infected cells.

Studying the effects of some host cell transcription factors (mainly from the GLI and POU-HD families) and DNA repair signaling pathways on HPV replication regulation in context.

Team:

Undergraduate student:

Nika Mikhailava

Master's student:

Ruslan Ibragimov

Ph.D. student:

Elina Lototskaja

Laboratory assistant:

Sofiya Babok

Regina Pipitš