About our research

Arthropod-borne viruses are better known by their acronym, arboviruses. This term refers to an exceptionally diverse group of viruses transmitted to humans and other vertebrates by multiple arthropod vectors such as fleas, flies, midges, mosquitoes, and ticks. Even with the diversity of vectors, these viruses share the characteristics of having a complex dual life cycle, involving replication in both vertebrate hosts and arthropod vectors (Figure 1). Arboviruses virtually exist in any known habitat, and thus far, over 500 isolates have been identified within five distinct viral families (Reo-, Rhabdo-, Toga-, Flavi-, and Bunyaviridae). Many arboviruses are important pathogens in livestock and humans, causing severe health problems, often fatal, such as hepatitis, encephalitis, and hemorrhagic fever. Outbreaks are no longer limited to tropical and developing countries. With international trade, travel, and climate change that favors the spread of vectors to new areas, arboviruses are emerging and re-emerging agents of disease that represent a global threat for agricultural productivity and public health. A recent illustration is the rapid spread of the mosquito-borne virus Zika, from Africa to Pacific and to both South and North America. As such, many arboviruses are listed as high-priority pathogens by the World Health Organization and the need to develop research, diagnostic, and therapeutic tools to combat epidemic and pandemic arboviral infections is urgent.

The overall aim of the Lozach group is to obtain a deep knowledge of the biology of viruses transmitted by mosquitoes and ticks, both in their arthropod vectors and in the human host. Our goal is to fully understand the arthropod vector-to-human host transmission with the ultimate objective of identifying novel antiviral strategies. To this end, we employ cellular and molecular techniques in combination with quantitative OMICS technologies, electron microscopy, and high-end fluorescence-based methods to (1) characterize arboviruses in both arthropod vector cells and mammalian host cells and (2) investigate how arboviruses target and enter cells. Our main arbovirus models are the phleboviruses Rift valley fever and Uukuniemi and, the flaviviruses West Nile and Zika. Through this research program, we expect to gain a detailed picture of the molecular and cellular mechanisms subverted by these viruses to infect humans.

 

Our virus picture gallery

  • Uukuniemi viral particles
    Uukuniemi viral particles
  • Uukuniemi virus bound to the cell surface
    Uukuniemi virus bound to the cell surface
  • Uukuniemi virus on filopodia
    Uukuniemi virus on filopodia
    Uukuniemi viral particles are in red
  • Rift Valley fever virus
    Rift Valley fever virus
    Rift Valley fever viral particles are in red
  • Uukuniemi virus on filopodia
    Uukuniemi virus on filopodia
    Uukuniemi viral particles are in red
  • Uukuniemi virus on filopodia
    Uukuniemi virus on filopodia
    Uukuniemi viral particles are in red
  • Uukuniemi virus inside endosomes
    Uukuniemi virus inside endosomes
  • Uukuniemi virus in lysosomes
    Uukuniemi virus in lysosomes
    Uukuniemi virus appears in red and lysosomes in green
  • Rift Valley fever virus protein NSs
    Rift Valley fever virus protein NSs
    NSs (green) forms gigantic nuclear filaments in the nuclei (blue)
  • Uukuniemi virus-mediated cell-cell fusion
    Uukuniemi virus-mediated cell-cell fusion
    The Uukuniemi virus protein N appears in red and the nuclei in blue

 

Our virus movie gallery

 

Our recent contributions to the field

 

Uukuniemi virus as a tick-borne virus model
Mazelier M, Rouxel RN, Zumstein M, Mancini R, Bell-Sakyi L, and Lozach PY
2016, 90:6784-98
Highlighted in Journal of Virology
Manuscript, M segment UUKV strain RVS, M segment UUKV strain HRS

 

Differential Use of the C-Type Lectins L-SIGN and DC-SIGN for Phlebovirus Endocytosis
Léger P, Tetard M, Youness B, Cordes N, Rouxel RN, Flamand M, and Lozach PY
2016, 17:639-56
Manuscript, Movie S1, Movie S2

 

Early bunyavirus-host cell interactions
Albornoz A, Hoffmann A, Lozach PY, and Tischler ND, (Bold indicates multiple corresponding authors)
2016, 8(5)
Manuscript

 

Dynamics of virus-receptor interactions in virus binding, signaling, and endocytosis
Boulant S, Stanifer M, and Lozach PY, (Bold indicates multiple corresponding authors)
2015, 7:2794-815
Manuscript

 

Bunyaviruses: from transmission by arthropods to entry into mammalian-host first-target cells
Léger P and Lozach PY
2015, 10:859-81
Manuscript

 

Genome-wide siRNA screens reveal VAMP3 as a novel host factor required for Uukuniemi virus late penetration
Meier R, Franceschini A, Horvath P, Tetard M, Mancini R, von Mering C, Helenius A, and Lozach PY
2014, 88:8565-78
Highlighted in Future Virology, Journal of Virology, and Medecine Science.
Manuscript, Table S1, Table S2, Table S3, Table S4, Table S5, Table S6, Table S7, Table S8
PhD thesis manuscript of Dr Roger Meier

 

DC-SIGN as receptor for phleboviruses
Lozach PY, Kühbacher A, Meier R, Mancini R, Bitto D, Bouloy M, and Helenius A, (Bold indicates multiple corresponding authors)
2011, 10:75-88
Highlighted in Cell Host & Microbe, Current Opinion in Virology, F1000, Future Virology, and Medecine Science.
Manuscript, Supplementary Information, Movie S1, Movie S2, Movie S3, Movie S4, Movie S5, Movie S6