Viruses cannot exist without their hosts.
“Systems Virology” is a scientific field to understand “viruses” from multiple aspects in the combination of experimental virology and a variety of sciences such as bioinformatics, molecular evolution, phylogenetic, paleobiology, and mathematics. We consider the virus-host interaction and the events triggered by virus infections as:
- A “mutualism” and “conflict”
- An evolutionary viewpoint
- Interactions “in micro (molecular mechanism)” and “in macro (transmission/epidemic)”
, and aim to address these virological issues through multiple scientific approaches.
Followings are our projects:
1. Evolutionary episode of viruses and hosts.
We address the scenario of “the evolutionary arms race (also known as evolutionary cat-and-mouse game)” between viruses and hosts.
For instance, we address the evolutionary episode of retroviruses (e.g., HIV, the causative agent of AIDS) and their host mammals (e.g., human).
Question: How did viruses emerge and interact with the hosts?“Evolution” is a stem of life science and one of the most difficult scientific fields to demonstrate. Through systems virological approaches, we reveal the evolutionary “mutualism” and “conflict” between viruses and hosts, which had happened, happening, and will happen in the history of the earth.
2. Impact of endogenous viruses
Approximately 8% of the human genome is occupied by the elements derived from viruses, which are called “endogenous retrovirus”. This is evidence that the organisms including mammals and humans have suffered from the attacks of a variety of viruses and have taken some of them into their genomes during evolution.
Question: What are the roles of “endogenous viruses” in the hosts?Through the approaches by bioinformatics and cell biology, we reveal the evolutionary “mutualism” of viruses and hosts.
3. Virus infections at “multi-omics” viewpoint
HIV, measles virus, herpes virus, and flu... All of these are viruses, but the outcomes caused by their infections are different.
Question: Why is the pathogenicity of each virus different?To deeply understand virus infection and its pathogenicity, we use animal models and perform multi-omics analyses. Through the multi-omics analyses (e.g., transcriptome, genome, and epigenome), we investigate the “conflict” of viruses and hosts.
4. Spatio-temporal dynamics of virus infections
When viruses are infected with the hosts, viruses replicate in the infected cells. During this process, certain viruses exhibit pathogenicity, whereas the host immunity responses against them. Certain virus infections can be controlled by the immune responses and be recovered, however, some viruses cannot be controlled by the hosts and lead to death.
Question: What are the determinant(s) responsible for the “destiny” of virus infection?“Systems Virology” aims to quantitatively understand the spatio-temporal dynamics of virus infections. For instance, will a virus-infected cell continue producing progenies, be latent, or die? We address the destiny of virus-infected cells in vivo (i.e., the “conflict” of viruses and hosts at single-cell level).
5. Understanding of the viruses living with humans
You may imagine that viruses are pathogenic and the causative agents of diseases. However, most viruses are NOT pathogenic. Rather, “the hygiene hypothesis” suggests that the immunity of the host without asymptomatic virus infections can be vulnerable.
Question: Where and what kinds of viruses exist in the human body?Through “big data” analysis, we aim to describe the “mutualism” and “conflict” of virus infections in humans and reveal the virus infections that can associate with human health and diseases.