Aptamers Recognizing Glycosylated Hemagglutinin Expressed on the Surface of Vaccinia Virus-Infected Cells

Abstract

Traditional methods for detection and identification of pathogenic viruses or bacteria tend to be slow and cumbersome. We have developed aptamer probes with the capacity to rapidly detect the presence of viral infection with specificity and sensitivity. Vaccinia virus (VV) was chosen as the model because it is closely related to variola virus that causes smallpox. A method known as cell-SELEX (Systematic Evolution of Ligands by Exponential Enrichment) was used to generate very selective and highly specific aptamers designed to recognize proteins expressed on the surface of VV-infected cells. Characterization of the aptamers showed that the virus-encoded hemagglutinin, a protein expressed on the surface of infected cells, is the preferential binding target. These studies show the feasibility of generating aptamers against a given specific infectious agent and will enable further development of aptamers as diagnostic and/or therapeutic tools against a broad range of infectious agents.

Isolation of ssDNA aptamers that inhibit rabies virus

“…This agreed with the fact that host cell-surface changes do not occur immediately upon RABV infection [13]. Once the infection has progressed to the acute phase, the infected cell surface has been modified by viral proteins.…”

Aptamers against pathogenic microorganisms

“…These aptamers were able to bind not only SELEX target cells but also other cell lines infected by the same virus, and demonstrated no affinity to non-infected cells. The same group of authors obtained DNA aptamers against vaccinia virus-infected HeLa cells and discovered their molecular target, which turned out to be hemagglutinin (Parekh et al, 2010). DNA aptamers selected against vaccinia viral particles were able to inhibit the infection in vitro (Nitsche et al, 2007).…”

Cell-SELEX: Aptamer Selection Against Whole Cells

“…Aptamers have been reported to be generated against various target cells, such as cells highly expressing specific protein of interest [25], a certain type of cancer cells [9], cancer stem cells [17], adipocyte cells [26] virus-infected cells [19,21], and bacteria [27,28]. Most of these aptamers are selected by using live cells, except in one case using fixed cells [8], which may due to that the target molecules on live cells are present in their native state.…”