Abstract

MICA protein is expressed many types of human cancers as result of cellular stress. MICA expressing cancers cells are recognized by the receptor NKG2D present on the Natural Killer cells. This binding activates the elimination of the target cells by cytotoxic lymphocytes. However, MICA in gastric cancer is released in soluble from, which can lead to NKG2D downregulation and tumor scape, thus being a promising therapeutic target (Figure 1). We demonstrated the high binding affinity between these proteins using ELISA, and a ratio 4:1 of NKG2D:MICA concentration, we obtained a good signal for detect union (Figure 3). Also, we found that pre incubated MICA with scFV-αMICA (developed from phage display library), increased the binding of MICA to NKG2D in ELISA (Figure 4 and 5). With this assay, we can develop a methodology which can detect the behavior of MICA from the MICA-NKG2D complex upon scFV-α-MICA binding.