[Stimulation of the antiviral innate immune response by pyrimidine biosynthesis inhibitors: a surprise of phenotypic screening]

Trends in Antiviral Strategies

Viral populations are true moving targets regarding the genomic sequences to be targeted in antiviral designs. Experts from different fields have expressed the need of new paradigms for antiviral interventions and viral disease control. This chapter reviews several strategies that aim at counteracting the adaptive capacity of viral quasispecies. The proposed designs are based on combinations of different antiviral drugs and immune modulators, or in the administration of virus-specific mutagenic agents, in an approach termed lethal mutagenesis of viruses. It consists of decreasing viral fitness by an excess of mutations that render viral proteins sub-optimal or non-functional. Viral extinction by lethal mutagenesis involves several sequential, overlapping steps that recapitulate the major concepts of intra-population interactions and genetic information stability discussed in preceding chapters. Despite the magnitude of the challenge, the chapter closes with some optimistic prospects for an effective control of viruses displaying error-prone replication, based on the combined targeting of replication fidelity and the induction of the innate immune response.

Resistance of Hepatitis C Virus to Inhibitors: Complexity and Clinical Implications

Selection of inhibitor-resistant viral mutants is universal for viruses that display quasi-species dynamics, and hepatitis C virus (HCV) is no exception. Here we review recent results on drug resistance in HCV, with emphasis on resistance to the newly-developed, directly-acting antiviral agents, as they are increasingly employed in the clinic. We put the experimental observations in the context of quasi-species dynamics, in particular what the genetic and phenotypic barriers to resistance mean in terms of exploration of sequence space while HCV replicates in the liver of infected patients or in cell culture. Strategies to diminish the probability of viral breakthrough during treatment are briefly outlined.

[Strength and specificity of the CMBA screening platform for bioactive molecules discovery]

Used as powerful chemical probes in Life science fundamental research, the application potential of new bioactive molecular entities includes but extends beyond their development as therapeutic drugs in pharmacology. In this review, we wish to point out the methodology of chemical libraries screening on living cells or purified proteins at the CMBA academic platform of Grenoble Alpes University, and strategies employed to further characterize the selected bioactive molecules by phenotypic profiling on human cells. Multiple application fields are concerned by the screening activity developed at CMBA with bioactive molecules previously selected for their potential as tools for fundamental research purpose, therapeutic candidates to treat cancer or infection, or promising compounds for production of bioenergy.