GP (Gorben) Pijlman GP (Gorben) Pijlman


PhD theses Arbovirus group

2019 Zika virus transmitted by mosquitoes via junk RNA

Mosquito-transmitted flaviviruses such as Zika virus (ZIKV) are responsible for over 400 million human infections each year. Unfortunately, the molecular mechanisms that facilitate flavivirus transmission by mosquitoes remain unclear. Here, we demonstrate that noncoding subgenomic flavivirus RNA (sfRNA), that is produced by all flaviviruses, plays a critical role in ZIKV transmission by Aedes aegypti mosquitoes. ZIKV requires sfRNA to overcome the mosquito midgut barrier and efficiently accumulate in the mosquito saliva. We reveal that the mosquito protein ME31B has antiviral activity and specifically binds to sfRNA. These results establish sfRNA as a determinant of ZIKV transmission by mosquitoes and provide mechanistic insights into the functions of this noncoding RNA.

Arbovirus group June 2013 - thesis defense Stefan Metz

Amaya Serrano - Jelke Fros - Mia Hikke - Stefan Metz - Gorben Pijlman - Corinne Geertsema

Arbovirus group May 2012

Gorben Pijlman - Sarah Nadif - Wouter v/d Braak - Corinne Geertsema - Jöelle Jansen - Just Vlak - Mia Hikke - Jelke Fros - Stefan Metz - Ruud Peters - Jeroen Bok - Christel de Krom 

Arbovirus group (extended version) November 2019

Top: Monique van Oers - Marieke Pleiter - Lotte Azink - Sandra Abbo - Marleen Henkens - Jelke Fros - Marie Thölke - Just Vlak - Gorben Pijlman - Hera Saouadogo - Linda Van Oosten - Kirsten Bronsvoort - Gwen Nowee - Bright Amoah - Jeroen Kortekaas

Bottom: Erick Bermundez - Ties Baljet - Tessy Hick - Chikungunya - Haidong Wang - Jerome Comes

Pamplona road trip 2015 - thesis defense Amaya Serrano

Amaya Serrano - Giel Göertz - Jelke Fros - Mia Hikke - Gorben Pijlman

Arbovirus group July 2015

Gregory Gorree - Herman Breukink -  Giel Göertz - Mia Hikke - Gorben Pijlman - Corinne Geertsema - Stef v/d Krieken - Laura Vet

Professor Arbovirology & Medical Biotechnology

Gorben Pijlman obtained his MSc in Biotechnology and Bioprocess Engineering at Wageningen University, the Netherlands in 1999. Next, he carried out PhD research in the baculovirus research group of prof. Dr. Just M. Vlak, where he worked on the molecular mechanisms underlying the ‘baculovirus defective interference’ phenomenon. This research resulted in further improvements of the powerful baculovirus expression system. In 2003, he joined the Flavivirus research group of prof. Alex Khromykh at the University of Queensland in Brisbane, Australia, for postdoctoral research on West Nile virus replication and the role of the enigmatic subgenomic flavivirus RNA (sfRNA) in viral pathogenesis and antiviral RNAi. Later on, he became involved in the Australian biotech start-up RepliKUN to develop and improve flavivirus replicon vectors for vaccines and cancer gene therapy applications. In 2007, he returned to Wageningen to take up a permanent position as Assistant Professor Arboviruses.

The current research programme is an interesting mix of fundamental virology focused at arbovirus-host interactions and applied studies on arbovirus vaccine development. In the period 2009-2013, the group developed a successful virus-like particle (VLP) vaccine that protects against chikungunya virus infection. Since early 2013 the arbovirus group conducts arbovirus transmission studies using live mosquitoes (Culex and Aedes spp.) and class pathogenic arboviruses (Chikungunya, West Nile, Usutu and, since 2016, Zika virus), in a purposely-built biosafety level 3 (BSL3) laboratory at Wageningen campus. At present, the group works on a COVID-19 vaccine by expressing SARS-CoV-2 spikes in insect cells (H2020 Prevent-nCoV consortium).

2016 Research: Viral Non-Coding RNA Determines Flavivirus Transmission by Mosquitoes

"a small RNA for a virus, a giant leap for transmission"

Understanding the flavivirus transmission cycle is important to identify novel targets to interfere with disease and to aid development of virus control strategies. Flaviviruses produce an abundant, non-coding viral RNA called sfRNA in both arthropod and mammalian cells. To evaluate the role of sfRNA in flavivirus transmission, we infected mosquitoes with the flavivirus West Nile and an sfRNA-deficient mutant West Nile virus. We demonstrate that sfRNA determines the infection and transmission rates of West Nile virus in Culex pipiens mosquitoes. Comparison of infection via the blood meal versus intrathoracic injection, which bypasses the midgut, revealed that sfRNA is important to overcome the mosquito midgut barrier. We also show that sfRNA is processed by the antiviral RNA interference machinery in mosquitoes. This is the first report to describe a pivotal biological function of sfRNA in arthropods. The results explain why sfRNA production is evolutionary conserved.

2015 Culex pipiens is a highly competent vector for Usutu virus transmission in the Netherlands

"Usutu virus may be a prelude to West Nile virus transmission in northwestern Europe"

Originating from Africa, Usutu virus (USUV) first emerged in Europe in 2001. This mosquito-borne flavivirus caused high mortality rates in its bird reservoirs, which strongly resembled the introduction of West Nile virus (WNV) in 1999 in the United States. Mosquitoes infected with USUV incidentally transmit the virus to other vertebrates, including humans, which can result in neuroinvasive disease. USUV and WNV co-circulate in parts of southern Europe, but the distribution of USUV extends into central and northwestern Europe. In the field, both viruses have been detected in the northern house mosquito Culex pipiens, of which the potential for USUV transmission is unknown. To understand the transmission dynamics and assess the potential spread of USUV, we determined the vector competence of C. pipiens for USUV and compared it with the well characterized WNV. We show for the first time that northwestern European mosquitoes are highly effective vectors for USUV, with infection rates of 11% at 18 °C and 53% at 23 °C, which are comparable with values obtained for WNV. Interestingly, at a high temperature of 28 °C, mosquitoes became more effectively infected with USUV (90%) than with WNV (58%), which could be attributed to barriers in the mosquito midgut. Small RNA deep sequencing of infected mosquitoes showed for both viruses a strong bias for 21-nucleotide small interfering (si)RNAs, which map across the entire viral genome both on the sense and antisense strand. No evidence for viral PIWI-associated RNA (piRNA) was found, suggesting that the siRNA pathway is the major small RNA pathway that targets USUV and WNV infection in C. pipiens mosquitoes.

Arbovirus battle front

Corinne Geertsema - Just Vlak - Gorben Pijlman - Mia Hikke - Jelke Fros - Stefan Metz

Arbo's at IMAV 2019 Glasgow

Julian Bakker - Haidong Wang - Tessy Hick - Jody Hobson-Peters - Gorben Pijlman - Jelke Fros - Sandra Abbo

Arbovirus group June 2016

Corinne Geertsema - Giel Göertz - Niek Savelkoul - Jurre Steens - Jelle Sterk - Gorben Pijlman

Mark Corten - Sandra Abbo - Robin v/d Braak

Sabbatical Prof. Roy Hall and Dr. Sonja Hall-Mendelin, summer 2018

Arbovirus & Fros groups 2023

top: Gorben Pijlman - Lisa Nijhof - Monique van Oers - Juul Steeghs - Frederic Josee - Sophie van der Vlugt - Linda de Jong - Corinne Geertsema - Marleen Henkens - Linda van Oosten - Davita Bosveld - Tristan Gommeren - Jelke Fros - Dennis Kenbeek

bottom: Lisa van Sluijs - Joyce van Bree - Tessy Hick - Cathelijne Lamboo - Kristel Doets - Jerome Comes - Bob Liet - Luca Schmidt

BSL3 team 2018

Jelke Fros - Gorben Pijlman - Julian Bakker - Giel Goertz

Corinne Geertsema - Sandra Abbo - Marleen Henkens - Haidong Wang

Chantal Vogels - Tessa Visser - Tim Mohlmann - Sander Koenraadt

2017 Research: Zika and chikungunya virus in a single mosquito bite

Zika virus and chikungunya virus are highly pathogenic arthropod-borne viruses that are currently a serious health burden in the Americas, and elsewhere in the world. Zika and chikungunya co-circulate in the same geographical regions and are mainly transmitted by Aedes aegypti mosquitoes. There is a growing number of case reports of Zika and chikungunya co-infections in humans, but it is uncertain whether co-infection occurs via single or multiple mosquito bites. We have now discovered that Yellow fever mosquitoes can carry both the Zika virus and the chikungunya virus in their saliva, which implies that people can be infected with both viruses in a single bite.

Arbovirus group October 2017

Meliawati Poniman - Gwen Nowee - Giel Göertz - Gorben Pijlman - Corinne Geertsema - Sandra Abbo - Jelke Fros

Rik Stuart - Anwar Hiralal - Marleen Henkens - Erich Breukink - Mitchell Neijenhuizen

Arbovirus group November 2018

Top: Corinne Geertsema – Tessy Hick – Nika Zibrat – Giel Göertz – Iris Swart – Chris van Toor – Just Vlak – Ahmad Ibrahim – Gorben Pijlman – Jelke Fros

Bottom: Marleen Henkens – Sandra Abbo – Haidong Wang – Imke Visser – Christina Emmanouilidou – Joyce van Bree

2018 Chikungunya virus outsmarts innate immunity

Chikungunya virus is an emerging pathogen associated with large outbreaks on the African, Asian, European, and both American continents. In most patients, infection results in high fever, rash, and incapacitating (chronic) arthralgia. CHIKV effectively inhibits the first line of defense, the innate immune response. As a result, stimulation of the innate immune response with interferons (IFNs) is ineffective as a treatment for CHIKV disease. The IFN response requires an intact downstream signaling cascade called the JAK/STAT signaling pathway, which is effectively inhibited by CHIKV nonstructural protein 2 (nsP2) via an unknown mechanism. The research described here specifies where in the JAK/STAT signaling cascade the IFN response is inhibited and which protein domain of nsP2 is responsible for IFN inhibition. The results illuminate new aspects of antiviral defense and CHIKV counterdefense strategies and will direct the search for novel antiviral compounds.


We currently work on a COVID-19 vaccine within the Prevent-nCoV

The Prevent-nCoV consortium has selected a lead candidate, ABNCoV2, that is currently being tested in the COUGH-1 clinical phase I/II study ( This study has shown high-level and broad in vitro efficacy with low reactogenicity ( Meanwhile, we continue to work on additional vaccine candidates to help alleviate the burden of COVID-19 and prepare for future variants.

Sabbatical Dr. Jody Hobson-Peters (University of Queensland, Brisbane, Australia), autumn 2019

Sandra Abbo - Jody Hobson-Peters - Gorben Pijlman - Jerome Comes - Tessy Hick

2020 Asian bush mosquito can transmit Zika and Usutu viruses

The Asian bush mosquito Aedes japonicus is invading Europe and was first discovered in Lelystad, the Netherlands in 2013, where it has established a permanent population. Here, we investigate the risk of transmission of ZIKV and USUV by the Asian bush mosquito Aedes japonicus. We found that field-collected Ae. japonicus mosquitoes can experimentally transmit ZIKV and USUV. Of the orally infected mosquitoes, 3% (ZIKV) and 13% (USUV) showed virus-positive saliva after 14 days at 28°C. We also found that ZIKV and USUV activated the antiviral RNA interference immune response of Ae. japonicus. Moreover, a strong barrier in the mosquito midgut restricted virus dissemination, since 96% (ZIKV) and 88% (USUV) of the mosquitoes injected with ZIKV or USUV showed virus-positive saliva. Additionally, we discovered a narnavirus in Ae. japonicus. Given that Ae. japonicus can transmit ZIKV and USUV, we should consider this mosquito as a potential vector for arboviral diseases in Europe.


Arbovirus group 2022

Top: Monique van Oers - Thijmen Zegers - Luzhao Li - Corinne Geertsema - Christiaan Helmes - Sara Ripamonti - Wessel Willemsen - Abbas Freydoonian - Carmen van de Waterbeemd - Taja Zotler - Jelke Fros - Joyce van Bree - Gwen Nowee - Jerome Comes

Bottom: Linda van Oosten - Qiuhong Miao - Tessy Hick - Marleen Henkens - Gorben Pijlman - Sandra Abbo


Research 2022. Our S1-VLP vaccine is on par with BioNTech/Pfizer in protecting against disease. Read the Journal of Virology article via this

We previously described a two-component nanoparticle vaccine, S1-VLP, based on the SARS-CoV-2 spike S1 domain. We have now undertaken a vaccination and challenge study in K18-hACE2 transgenic mice, which provide a robust and lethal model of SARS-CoV-2 infection. Mice vaccinated with the S1-VLP vaccine or the BioNTech/Pfizer mRNA vaccine BNT162b2 were fully protected from signs of disease and weight loss. These data show that our previously described two-component nanoparticle vaccine S1-VLP provides protective immunity in mice against SARS-CoV-2 infection and disease without a requirement for additional adjuvants. The S1-VLP vaccine induced neutralizing antibody responses that were comparable with those induced by BNT162b2. This VLP display platform is readily amendable to any (or even multiple) SARS-CoV-2 variants of concern.



Research 2021. Our prototype covid-19 vaccine S1-VLP is ready and actually works. Read the mBio article via this link.

Vaccination is essential to reduce disease severity and limit the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Protein-based vaccines are useful to vaccinate the world population and to boost immunity against emerging variants. Their safety profiles, production costs, and vaccine storage temperatures are advantageous compared to mRNA and adenovirus vector vaccines. Here, we use the versatile and scalable baculovirus expression vector system to generate a two-component nanoparticle vaccine to induce potent neutralizing antibody responses against SARS-CoV-2 variants. These nanoparticle vaccines can be quickly adapted as boosters by simply updating the antigen component.