SPATIAL AND CHEMICAL SURFACE GUIDANCE OF THE CELL IMMUNE FUNCTION

Studying of how different signaling pathways spatially integrate in cells requires selective manipulation and control of different transmembrane ligand-receptor pairs at the same time. In this work, we explored a novel for precisely arranging two arbitrarily chosen ligands in a micron-scale 2D pattern. The approach is based on lithographic patterning of Au and TiO₂ films, following by their selective functionalization with thiolated Ni-NTA and biotinyated phosphonic acid, respectively, and their further biofunctionalization by Ni-NTA/Histidine and Neutravidin/biotin conjugations. We demonstrated the selectivity of chemical and biological functionalizations by XPS and immunofluorescence imaging, respectively.

We applied our approach to produce the first of their type bi-functional surfaces with controllably positioned ligands for activating receptors of natural killer (NK) immune cells, and used these NK cells as a model system to demonstrate the potency of our surface in guiding site-selective cell attachment and activation. We demonstrated that upon applying the suitable ligand or ligand-combination, our surfaces guided the appropriate single- or bi-functional attachment and activation. These encouraging results demonstrate the effectiveness of our system as an experimental platform aimed at the comprehensive understanding of the immunological synapse. Furthermore, the great simplicity, modularity and specificity of our approach makes it applicable for myriad of combinations of other biomolecules, turning it to the “swiss knife” of bio-interfaces, with endless potential applications.