Selection of oligonucleotides specific to chicken peripheral blood mononuclear cells in whole blood ex vivo system
Synthetic CpG oligodeoxinucleotides (ODNs) have the capacity to improve innate and acquired immune responses to various pathogens and enhance vaccination efficacy. We investigated the effectiveness of 'ex vivo' selection of oligonucleotides with possible immune features using the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) method. ODNs called aptamers, which displayed binding to peripheral blood mononuclear cells (PBMC), were selected in whole chicken blood, and then tested for accumulation in target cell via real-time PCR. Selected aptamers showed a 2.26 fold increase in cell binding versus the initial control library. Immuno-stimulatory properties of the selected aptamers were tested by monitoring IL-1 and IL-6 relative gene expression in whole blood. When compared to negative control, selected aptamers up-regulated IL-1 and IL-6 expression by 2.12 fold and 1.37 fold, respectively. Thus, our results demonstrate that SELEX is an effective method to select aptamers specific to chicken PBMC with possible immune stimulatory features.