A postdoctoral position of 3 years, funded by the Laboratory of Excellence Integrative Biology of Emerging Infectious Diseases (LabEx IBEID: http://www.pasteur.fr/labex/ibeid), is available in the "Biologie moléculaire et immunologie parasitaires et fongiques" research unit directed by Nadia Haddad at the National Veterinary School of Alfort.

Identification of tick molecules that contribute to tick-borne pathogens transmission

Ticks, second only to mosquitoes, are the most important vectors of viral, bacterial and parasitic pathogens that affect humans and animals worldwide. Conventional control of tick-borne diseases is unsatisfactory, and new control strategies that are compatible with values of sustainable development and capable of addressing pathogen diversity and even anticipating pathogen emergence must be sought. One attractive solution is the development of vaccine strategies that target conserved components of ticks that play key roles in vector infestation or vector capacity. The primary rate-limiting step in this endeavour is identification of tick components that assure such functions and that represent protective antigenic targets. Indeed, and despite their importance, molecular interactions between ticks and the pathogens they transmit remain a “black box”.

The immediate goal of the project is to discover tick proteins that are implicated in pathogen transmission and to elucidate their function. The vaccine potential of these proteins will then be evaluated in different models. For this purpose, we have identified Ixodes ricinus proteins (by high throughput sequencing) that are highly expressed in tick salivary glands, and notably during bacterial infection. The transcriptome of the salivary gland of I. ricinus will be datamined to assign functional roles to tick proteins, and the implication of selected candidates in bacteria transmission will be evaluated by RNAi. The function of the most interesting genes will then be studied. Recombinant proteins corresponding to highly-expressed secreted proteins of functional interest will be produced, and their capacity to elicit an immune response tested in mice. Finally, the capacity of promising candidates to afford protection against ticks and TBP will be assessed in several challenge models of infection (mice, sheep, bovine). Ultimately, this project should provide 1) a better knowledge of molecular mechanisms underlying pathogen transmission by I. ricinus, the most important vector in Europe 2) immediate leads for better control of TBD and 3) knowledge to instruct development of next generation vaccines against TBD.

Candidate requirements: The successful candidate will have well-developed skills in bioinformatics and notably as regards prediction of protein function. Skills in molecular biology and murine immunology are also sought, but, if lacking, may be acquired in the host laboratory.

To apply: Applicants should send their CV, a motivation letter and 3 references to Sarah Bonnet (sbonnet@vet-alfort.fr) USC INRA Bartonella-tiques, UMR BIPAR ENVA-ANSES-UPEC, 23 Avenue du Général de Gaulle, 94706 Maisons-Alfort cedex, France.