RESUMEN
BACKGROUND: DNA-directed RNA interfering (RNAi) mediators that follow the classic Watson-Crick base pairing to bind to their molecular targets and exert their silencing capacities have been identified to be relatively insensitive to single nucleotide polymorphisms (SNPs). The experimental evaluation of a few putative genomic SNPs in a quasi-species population is the only approach scientists have been employing so far for the experimental validation of the efficacy of oligonucleotide drugs on a given population. These studies are inherently constrained by the number of SNPs that can be experimentally supported in the context of an identified molecular target. MATERIALS AND METHODS: To address this sampling limitation, we have developed a method to report the relative sensitivity of all known and unknown polymorphisms to a prospective therapeutic drug. The power of ultra-deep next generation sequencing (NGS) allows us to test drug effect in vitro on all possible SNPs of a molecular target, in a patient-free manner. We are presenting the technical details to our approach that is empowering unbiased pharmacodynamic studies at the population level for sequence-specific oligonucleotide drugs and genome editing tools.
Asunto(s)
Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Oligonucleótidos/uso terapéutico , Polimorfismo de Nucleótido Simple , Evaluación Preclínica de Medicamentos , Edición Génica , Genómica , Humanos , Interferencia de ARNRESUMEN
The therapeutic application of siRNA (short interfering RNA) shows promise as an alternative approach to small-molecule inhibitors for the treatment of human disease. However, the major obstacle to its use has been the difficulty in delivering these large anionic molecules in vivo. A potential approach to solving this problem is the chemical conjugation of siRNA to the cationic CPPs (cell-penetrating peptides), Tat-(48-60) (transactivator of transcription) and penetratin, which have been shown previously to mediate protein and peptide delivery in a host of animal models. In this transaction, we review recent studies on the utility of siRNA for the investigation of protein function in the airways/lung. We show that, despite previous studies showing the utility of cationic CPPs in vitro, conjugation of siRNA to Tat-(48-60) and penetratin failed to increase residual siRNA-mediated knockdown of p38 MAPK (mitogen-activated protein kinase) (MAPK14) mRNA in mouse lung in vivo. Significantly, we will also discuss potential non-specific actions and the induction of immunological responses by CPPs and their conjugates and how this might limit their application for siRNA-mediated delivery in vivo.
Asunto(s)
Sistemas de Liberación de Medicamentos , Pulmón/metabolismo , Péptidos , Señales de Clasificación de Proteína/fisiología , Transporte de Proteínas/fisiología , ARN Interferente Pequeño/administración & dosificación , Animales , HumanosRESUMEN
Modern peptide and protein subunit vaccines suffer from poor immunogenicity and require the use of adjuvants. However, none of the currently licensed adjuvants can elicit cell-mediated immunity or are suitable for mucosal immunization. In this study we explored the immunological effect of nasal co-administration of adjuvants with distinct functions: cholera toxin subunit B, a potent mucosal adjuvant that induces strong humoral responses, muramy di-peptide (MDP), an adjuvant known to elicit cell mediated immunity but rarely used nasally, and chitosan, an adjuvant that achieves specific physiological effects on mucosal membranes that improve antigen uptake. Groups of five female BALB/c mice received on days 1 and 56 nasal instillations of the recombinant Helicobacter pylori antigen urease admixed to single or multiple adjuvant combinations. Serum IgG kinetics were followed over 24 weeks. At the conclusion of the experiment, local antibody responses were determined and antigen-specific recall responses in splenocyte cultures were assayed for proliferation and cytokine production. The combination of adjuvants was shown to further contribute to the increased antigenicity of recombinant H. pylori urease. The data presented here outline and support facilitation of increased immunomodulation by an adjuvant previously defined as an effective mucosal adjuvant (chitosan) for another adjuvant (MDP) that is not normally effective via this route.