Nanorobotic Study Lends Insight Into Autoimmune Pathology

Published in PLoS One, “our research represents a unique intersection between the fields of biology and engineering that has allowed entirely new investigational strategies to be applied to the study of clinical disease,” says senior author Animesh A. Sinha, MD, PhD, Rita and Ralph Behling Professor and Chair of dermatology.

Although the study focused on the autoimmune skin disorder Pemphigus vulgaris (PV), the techniques employed could help researchers develop and screen treatments for a wide range of autoimmune diseases, estimated to affect 5-10 percent of the U.S. population.

Using PV, a rare blistering disease, as a model, the researchers revealed new details of how autoantibodies destroy healthy cells in skin.

“We haven’t understood why some antibodies generated by the condition cause blisters while others do not,” says Sinha.

By studying in intense detail the connections between skin cells, Sinha and his colleagues found that pathogenic antibodies change structural and functional properties of skin cells in distinct ways.

“Our data suggest a new model for the action of autoantibodies involving two steps or ‘hits’ in the development of lesions,” says Sinha.

“The first results in the initial separation of cells, but only the pathogenic antibodies drive further intracellular changes that lead to the breaking of the cell junction and blistering.”

The research has the potential to help clinicians identify who may be at risk for developing PV by distinguishing between disease-causing and nonpathogenic autoimmune antibodies.

PV leads to often painful blistering of the skin and mucous membranes. Generally treated with immunosuppressive agents such as corticosteroids, the condition is life-threatening if untreated.

The researchers applied atomic force microscopy (AFM) — a technique originally developed to study nonbiological materials — to visualize “the point at which a cell is going to implode because it’s under autoimmune attack,” says Sinha.

The technology allowed researchers to obtain extremely high-resolution, three-dimensional images of cell junctions in the process of rupturing.

“These micron-sized spots on cell membranes are very complex molecular structures, yet their small size has made them resistant to detailed investigation,” notes Sinha.

AFM utilizes a probe-like tip that, when tapped against a cell, sends information about the cell’s mechanical properties, such as thickness, elasticity, viscosity and electrical potential.

The technique has far-reaching applications for studying clinical disease.

“It could help scientists pinpoint several key changes in cell behavior, including the differentiation of stem cells or the development of metastases in cancer,” says Sinha.

The research team also employed existing and novel nanorobotic techniques.

This included performing “a kind of nanodissection,” says Sinha, “where we physically detached cells from each other at certain points to test what that did to their mechanical and biological functions.”

Data from these experiments were then combined with information about functional changes in cell behavior to develop a nanomechanical profile for specific cellular states.

Such phenotyping has broad application and should allow researchers to develop predictive models of cellular behavior for any kind of cell, Sinha envisions.

“Ultimately, in the case of autoimmunity, we should be able to use these techniques as a high-throughput assay to screen hundreds or thousands of compounds that might block the effects of autoantibodies,” Sinha notes.

“The technology also could be used to identify novel agents with therapeutic potential in given individuals,” he adds.

“Such strategies aim to advance us toward a new era of personalized medicine.”

Kristina Seiffert-Sinha, MD, research assistant professor of dermatology, is a first co-author on the paper, “Nanorobotic Investigation Identifies Novel Visual, Structural and Functional Correlates of Autoimmune Pathology in a Blistering Skin Disease Model.”

The study also involved engineering and medical scientists at Michigan State University, the City University of Hong Kong and the University of Pennsylvania.

It was funded by UB, UB’s Behling Dermatology Fund, the National Science Foundation and the National Institutes of Health.