Baculovirus recombinants marques à l’aide d’un système de marquage de l’ADN fluorescent et ses applications

La présente invention a trait au domaine des systèmes rapporteurs. Plus particulièrement, la présente invention concerne un baculovirus modifié exprimant un système rapporteur permettant son identification directe par fluorescence. L'invention concerne également la quantification d'une population de baculovirus marqués, ainsi que l'utilisation de ces baculovirus en tant que biomarqueurs, seuls ou combinés à un système de ciblage spécifique. L'invention trouve son application notamment pour l'identification et la quantification directe de populations cellulaires, pour la sélection directe de baculovirus recombinants lors de la production et la quantification directe de baculovirus recombinants ainsi que de leur stabilité au sein d'un stock viral. Les baculovirus marqués selon l'invention peuvent également être utilisés comme mimétiques d'autres pathogènes, notamment de classe II et III, pour l'évaluation de protocoles de désinfection

Host range extension of Cydia pomonella granulovirus: adaptation to Oriental Fruit Moth, Grapholita molesta

Among various Cydia pomonella granulovirus (CpGV) isolates, the Mexican isolate (CpGV-M) has demonstrated a significant ability to reduce damage induced by the oriental fruit moth, Grapholita molesta (Busck) (=Cydia molesta) in peach crops. To obtain a more efficient virus for G. molesta control, an experimental virus population was constructed by mixing various CpGV isolates. This mixture was then selected for replication in a G. molesta laboratory colony. After 12 successive passages on this alternative host, the insecticidal efficacy of the virus population had improved. The concentration of virus occlusion bodies required to kill 90 % of neonate larvae was 450-fold lower than that of the original isolate mixture, and 120-fold lower than that of the CpGV-M isolate alone. Following adaptation to this alternative host, the efficacy against its natural host, the codling moth, C. pomonella, was conserved. This mixed isolate population can be produced on C. pomonella without loss of efficacy, which is useful from a commercial production perspective. This adapted virus isolate mixture is likely to prove more effective than individual component isolates at controlling G. molesta

Cydia pomonella granulovirus Genotypes Overcome Virus Resistance in the Codling Moth and Improve Virus Efficiency by Selection against Resistant Hosts▿

Cydia pomonella granulovirus (CpGV) has been used for 15 years as a bioinsecticide in codling moth (Cydia pomonella) control. In 2004, some insect populations with low susceptibility to the virus were detected for the first time in southeast France. RGV, a laboratory colony of codling moths resistant to the CpGV-M isolate used in the field, was established with collection of resistant insects in the field followed by an introgression of the resistant trait into a susceptible colony (Sv). The resistance level (based on the 50% lethal concentrations [LC50s]) of the RGV colony to the CpGV-M isolate, the active ingredient in all commercial virus formulations in Europe, appeared to be over 60,000-fold compared to the Sv colony. The efficiency of CpGV isolates from various other regions was tested on RGV. Among them, two isolates (I12 and NPP-R1) presented an increased pathogenicity on RGV. I12 had already been identified as effective against a resistant C. pomonella colony in Germany and was observed to partially overcome the resistance in the RGV colony. The recently identified isolate NPP-R1 showed an even higher pathogenicity on RGV than other isolates, with an LC50 of 166 occlusion bodies (OBs)/μl, compared to 1.36 × 106 OBs/μl for CpGV-M. Genetic characterization showed that NPP-R1 is a mixture of at least two genotypes, one of which is similar to CpGV-M. The 2016-r4 isolate obtained from four successive passages of NPP-R1 in RGV larvae had a sharply reduced proportion of the CpGV-M-like genotype and an increased pathogenicity against insects from the RGV colony