Published: 5.3.2026
Text: Visa Ruokolainen
Editing: Viestintätoimisto Jokiranta Oy
Images: Aapo Tervonen (author photo), Shutterstock

When talking about viruses, the coronavirus pandemic and the SARS-CoV-2 virus that caused it are probably the first to come to our mind. Many will also recall the virus vector-based vaccines developed to tackle the pandemic. They are a good example of how we have learnt to modify viruses into useful tools on the basis of enhanced scientific knowledge and the development of molecular biological methods.

The continuous accrual of scientific knowledge facilitates the design of new, increasingly accurate nanosized tools with the potential to improve human health. Such modern nanosized tools include, for example, oncolytic viruses. Oncolytic refers to the ability to destroy cancer cells. Oncolytic viruses are specifically targeted to kill cancer cells that form cancerous tumours.

The development of viral tools requires basic research

When viruses are being modified into drugs, it is essential to guarantee their safety in use. This is a major challenge in the development of oncolytic viruses. In order to ensure the safety of virus-based drugs, they must be precisely targeted and effective.

The oncolytic ability of viruses can be influenced by, for example, the following methods:

• Viruses are modified to effectively target the desired cells, such as different types of cancer cells.
• Viruses are modified to replicate in cancer cells as efficiently as possible. If the virus replication in the cells is inefficient, the amount of the oncolytic virus required for therapeutic use is so high that it may result in hazardous adverse effects in the body.
• Viruses are modified to produce extra protein, which will make the cancerous tumour highly sensitive to the body’s own immune defence.
• Viruses are modified to spread more efficiently into the surrounding cancer cells.

Success in modifying viruses in the ways described above demands a great deal of detailed knowledge, and thus, the product development of oncolytic viral drugs calls for basic research as well.

New technologies help to remove bottlenecks

The most common oncolytic virus is Herpes Simplex Virus 1 (HSV-1), which has already been used for the treatment of, for example, skin cancer. My own research focuses on the efficient replication of HSV-1 and it relates to the aforementioned possibility for modifying an oncolytic virus to make it even more effective.

The replication of HSV-1 occurs within the host cell nucleus, which is a part of the cell surrounded by a membrane and containing our DNA (genome). The tight interaction of the DNA and the virus that is being replicated creates a bottleneck in an infection by affecting the viral release from the nucleus. The factors contributing to the ability of the virus to exit the nucleus are not yet well known.

In my research, I employ fluorescence lifetime imaging microscopy (FLIM), which shows the movements of the DNA and the virus in the nucleus and provides more information than traditional fluorescence microscopy. It allows us to extremely accurately measure different variables, such as, molecular density or ion concentrations. By means of a new assessment method, we can observe with a high temporal and spatial resolution the impact of new types of factors on the movement of the virus surrounded by the DNA in the nucleus – in the changing conditions of living host cells.

Towards a healthier future

The aim of my research is to study the impacts of those molecular factors that are vital for normal cell function and their changes in a viral infection at the level of individual cells. According to my findings, the virus replication site is bordered by an area of high molecular density that is surrounded by a zone of high calcium concentration. These factors may restrict the viral release from the nucleus and, thereby, affect the infectivity of the virus. Further analyses may expose dynamic interactions between the DNA and virus in certain environments and, thus, help us to identify the mechanism that allows the virus to find its way out of the nucleus. Using this knowledge, it might be possible to develop an oncolytic virus with a more efficient replication capacity.

It can be stated that, from a human perspective, viruses can be both good and bad. According to scientists involved in the study of viruses that transfer from animals to humans, a new pandemic is just a question of time. By studying viruses and understanding their biology we can, however, prepare ourselves for what is coming. The accrual of scientific knowledge will also be of benefit in terms of other global health challenges, such as in the fight against the growing number of cancer cases.

 

 

Visa Ruokolainen, PhD, Virologist, is currently working as a Senior Lecturer in the Department of Biological and Environmental Science at the University of Jyväskylä.  He is engaged in the study of cell-virus interactions in living cells, using fluorescence microscopy in a Biosafety Level 2 laboratory.