Identification and validation of novel aptamers against fungal cells

Abstract

We encounter thousands of species of fungi each day, only a few of these are pathogenic to humans and even fewer are life threatening. However, current fungal infection treatments come with a wide variety of issues. With some exhibiting high nephrotoxicity due to targeting issues, and others a lack of efficiency.
Aptamers are short oligonucleotides, which exhibit affinity and specificity for a target molecule. These aptamers are determined through the process of SELEX. This is where target molecules, or in this case whole cells, are incubated with a pool of random aptamers. Non-binding aptamers are removed and binding aptamers are eluted and amplified by PCR. This enriches the pool with binding aptamers. This process continues as a cycle with each round of selection removing non-binding aptamers, and further amplifying the numbers of binding aptamers. Once rounds of selection are completed then the aptamers can be tested individually for their binding properties. Aptamers have already been found to be useful in industrial settings, with some aptamers even beginning to show in clinical settings.
This study took whole cell A. fumigatus and C. albicans, in order to select aptamers that were specific to these cells without limiting the targets by incubating with individual target molecules. This study found isolated 11 aptamers with binding potential; these were then tested further to determine the binding capabilities, and their specificity. These aptamers were then isolated, sequenced and characterised to compare against each other and to attempt to determine key binding regions of the aptamers.