Vaccines represent a strategic successful tool to prevent or contain diseases with high morbidity as well as mortality. However, despite the extensive and wide use, we still have a limited knowledge on mechanisms underlying the effective elicitation of protective immune responses by vaccines, which represents the final outcome of a effective cooperation between the innate and adaptive arms of the immunity. Immunity is made of a multifaceted set of integrated responses involving a dynamic interaction of thousands of molecules, whose list is constantly updated to fill the several empty spaces of this puzzle. The recent development of new technologies and computational tools allows to perform a comprehensive and quantitative analysis of the interactions between all of the components of immunity over time.
The global transcriptional profile of PBMCs stimulated with HIV candidate vaccine (Virus-Like Particles, VLPs) has been evaluated in HIV-infected patients with low/high viral load compared to healthy volunteers. Baseline activation of chemokine production was observed in PBMC from HIV infected patients and innate immune stimulation with HIV-VLPs was not blunted. The immune profile among HIV-infected patients was found to be qualitatively similar but quantitatively extremely variable. This diversity was independent of viral load and it might be dependent on individual immunogenetic traits or concurrent immunological status.
This ex-vivo screening strategy represent an efficient tool for guiding modifications/optimizations of vaccination strategies and understanding failures in individuals enrolled in clinical trials.
The potential of systems biology in general in providing relevant and novel insights in the mechanisms of action of vaccines in order to improve their design and effectiveness, will be discussed.