Cell
The Aedes albopictus mosquito is known to transmit several arboviruses, and its growing presence in Europe represents a significant threat to public health. We spoke to Dr Mariangela Bonizzoni, Associate Professor of Zoology at the University of Pavia in Italy, about her research into the biological interactions between the mosquito and the viruses it vectors
Getting to the heart of disease transmission The Asian tiger mosquito
Aedes albopictus has spread rapidly across Europe since it emerged in Albania in 1979, putting the population at greater risk of contracting arboviral diseases. Aedes albopictus is known to be responsible for transmitting several arthropod-borne viruses (arboviruses), including dengue fever and chikungunya fever, all of which are nonretroviral RNA viruses, now researchers in the EU funded NIRVS_HOST_INT project aim to shed new light on the topic. “We are looking at the co-evolution between the mosquito vector and the viruses it transmits. We are looking at what factors make a vector a good vector for arboviruses,” outlines Mariangela Bonizzoni, the project’s Principal
investigate the biological interactions between this mosquito and Dengue viruses, in particular looking at how viral sequences are integrated into the host genome. Professor Bonizzoni says this work holds wider importance. “Nonretroviral RNA viruses like Dengue viruses are not supposed to be capable of integrating into the genome of their host, but research shows that in some cases they do. Viral integrations from nonretroviral RNA viruses (NIRVS) have been identified in mosquitoes, and also in other organisms. We don’t know how they do it, and what the consequences are of their integration,” she outlines. Professor Bonizzoni and her colleagues plan to combine data from the lab with data from the field to
We have examples of both vectors adapting to viruses and viruses adapting to a vector. In the case of the recent chikungunya epidemic, which started in the Indian ocean, a mutation appeared in the virus which made it particularly well-adapted for transmission by Ae. albopictus mosquitoes Investigator. Not all mosquitoes are welladapted for transmitting arboviruses, yet both vectors and viruses evolve and adapt, leading to changes in transmission patterns. “We have examples of both vectors adapting to viruses and viruses adapting to a vector. For example, in the case of the recent chikungunya epidemic, which started in the Indian ocean, a mutation appeared in the virus which made it particularly welladapted for transmission by Ae. albopictus,” says Professor Bonizzoni.
NIRVS Aedes albopopictus mosquitoes were not previously the prevalent vector for transmitting the chikungunya virus, but the situation changed because of this specific mutation. Moreover, due to the rapid recent spread of Ae. albopcitus across the world, it is becoming an increasingly important vector for Dengue viruses. Now researchers aim to
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look at whether these integrations have an effect on subsequent infections. “We want to know whether these integrations occur only in the soma or also in the germ-line. If they occur in the germ-line then they could be passed on across generations,” she explains. This has significant implications in terms of long-term exposure to arboviral infections, underlining the wider importance of Professor Bonizzoni’s research. “We hope to identify what factors make some populations of mosquitoes more susceptible or more refractory to arboviral infection. We also aim to identify which species of nonretroviral RNA viruses have the tendency to integrate, and which don’t,” she says. The project’s research will also help scientists learn more about the therapeutic potential of nonretroviral RNA viruses. “It is assumed that nonretroviral RNA viruses cannot integrate with the genome of the hosts. Consequently, based on their transient
Nucleus Host Genome DNA NIRV
NIRV-piRNAs Viral RNA silencing
VIRUS RNA presence in a cell, these type of viruses are being exploited in gene therapy applications, as drugs or vaccine delivery tools,” explains Professor Bonizzoni. “This is based on the assumption that these viruses do not integrate into the genome, but first of all we need to make sure that this is indeed the case. We will look at under which circumstances viral integrations occur, how frequently they occur, and which types of viruses/hosts are involved.” (NIRV-HOST-INT) Population genomics of co-evolution between non-retroviral RNA viruses and their hosts Dr Mariangela Bonizzoni Università degli Studi di Pavia Dipartimento di Biologia e Biotecnologie “Lazzaro Spallanzani” Via Ferrata 9 - 27100 Pavia, Italia T: +39 0382 986324 E: m.bonizzoni@unipv.it Dr Mariangela Bonizzoni is Associate Professor of Zoology at the Department of Biology and Biotechnology of the University of Pavia, Italy. She received her PhD degree in 2004 from the University of Pavia and the Universite’ de Paris XI, with a combined Italian-French program sponsored by the Italian Ministry of Education, Research and University. Dr Bonizzoni’s research focuses on arthropod-borne infectious diseases, with particular emphasis on interactions between the pathogens and their arthropod hosts. She also is interested in the adaptation of vectors to currently available strategies of control. She is author of 41 peer-review publications.
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