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HKU-PRP News

09 Jan 2019

Congratulations to Fionn Ma!

Another graduation at HKU-Pasteur! Supervised by Roberto Bruzzone, Fionn Ma got her MPhil with her thesis titled “Investigation on the Functional Roles of Interaction between Human Karyopherin Isoforms and Nucleoprotein of Influenza B Virus“.

She will now work as a Research Assistant in Sophie Valkenburg’s team to continue her journey in HKU-Pasteur Research Pole.

Summary of her thesis:

Influenza B viruses are capable of causing disease with severity similar to that of influenza A. Nonetheless, unlike influenza A viruses that naturally exits in waterfowls, influenza B does not have an established animal reservoir and is largely restricted to humans. Factors determining the host specificity of influenza B virus have not been well studied. To establish interspecies transmission, a virus must be able to propagate efficiently in host cells of both species. The nuclear translocation of viral proteins of the ribonucleoprotein complex (vRNP) is a crucial step during virus replication, which relies on a group of cellular protein called karyopherin subunit α (KPNAs). These KPNA isoforms recognize nuclear localization sequences (NLS) on vRNP components and other cargo proteins and facilitate their transportation across nuclear pore complexes (NPC).

In this study, we showed that the nucleoprotein (NP) of influenza B virus interacted with human KPNA 1, 2, 3, 4, and 6. KPNA silenced human cells were employed to determine the roles of each KPNA on viral polymerase activity, transcription efficiency and virus replication. We showed that absence of KPNA2 decreased the polymerase activity of influenza B for 60%. However, KPNA2 silencing did not affect viral transcription and replication in our infection model. From our transcriptomic analysis, distinctive cellular responses were triggered between the cells infected by influenza A and B viruses suggesting that the two viruses may adapt to different strategies upon infection.

Given that studies on influenza B viruses are relatively limited compared to those on influenza A, our study gained a better understanding on the interplay between the host factors and NP of influenza B virus.

We wish you all the best Fionn!