The lab's research aims to optimise the anti-cancer properties of the oncolytic parvovirus Minute Virus of Mice (MVM). Recent data from the lab demonstrate the ability of MVM to infect glioblastoma stem cells (Gil-Ranedo et al., Cell Reports 2021), or the use of sialic acid as a receptor in glioblastoma cells (Tania-Calvo et al., Frontiers Microbiology, 2024). In a logical progression from these contributions, the project proposed here addresses key steps of MVM entry into the cell, from contacts with the sialic receptor on the cell surface, to trafficking of the incoming particle through the endosome, and its subsequent invasion of the nucleus to initiate infection. To analyse the molecular mechanisms involved, the following objectives are proposed:

Objective 1 . Analysis of the endocytic pathway followed by the virus in human glioblastoma cells (1st-2nd year). We will analyse the interaction with the sialic receptor and the subsequent endosomal trafficking of the viral particle by comparing wild-type MVM with selected mouse mutants that have alterations in capsid residues that interact with sialic acid. Analyses will be carried out with all three viruses in human transformed cells including glioblastoma:

• Task a. Effect of pH on capsid binding to the receptor.
• Task b. Effect of endosomal pH on infectious entry.
• Task c. Endosomal proteolytic processing of the capsid.

Objective 2 . Entry of MVM parvovirus into the nucleus of human cancer cells (2nd-3rd year). The incoming viral particle has to pass through the nuclear pore complex (NPC). To We will study:

• Task a. Localisation of the incoming capsid in relation to the nuclear envelope.
• Task b. Configuration of the capsid and the NPC during the entry process.
• Task c. Comparison of entry into the nucleus in different cell types.

Objective 3 . Effect of cell cycle and cell transformation on viral entry into the nucleus (3rd-4th year). Cell physiology determines the efficacy of Parvovirus infection at many levels. This study will focus on:

• Task a. Efficacy of nuclear translocation of the capsid in relation to cell proliferation.
• Task b. Transport of the virus to the nucleus as a function of the cell cycle. The proposed objectives are feasible as they are in line with the technical and scientific expertise of the group and the resources and equipment available at the research