The UCSF team has already developed a regulatory T cell-based therapy that can prevent and even reverse the course of autoimmune diabetes in mouse models, and this study begins to analyze how such protection occurs in vivo, she explained.
"By understanding the interplay between pathogenic cells and protective cells, we hope to be able to refine the therapy to enhance its efficacy."
The microscopy technique is a vital new tool, Tang said. "The function of the immune system involves multiple cell types interacting dynamically in three dimensions, which is very difficult to analyze in vivo -- and nearly impossible to authentically reproduce in vitro."
The team of immunologists and diabetes researchers used the new microscope to show that when Treg cells are absent, the potentially destructive autoreactive T cells, known as T helper cells, swarm around the dendritic cells where they are primed to attack the body's own tissue -- the cause of type 1 diabetes, arthritis and other autoimmune diseases.
The scientists showed that Treg cells prevent this destructive response after they and the T helper cells independently interact with dendritic cells. The mechanism of this protective effect remains a major immunology puzzle. The new study suggests that regulation may occur through direct or indirect modification of the critical antigen-presenting dendritic cells ?the scavenger cells of the immune system that pick up and display self proteins that trigger the auto-aggressive T cell response, said Jeffrey Bluestone, PhD, distinguished professor of metabolism and endocrinology at UCSF and senior author on the paper. Bluestone directs the UCSF Diabetes Center.
The research provides a "blueprint" of what immune regulation looks like, says study co-author Max Krummel, PhD, UCSF assistant professor of pathology whose lab adapted the new two-photon microscopy technique for visualizing cell-cell i
Source:University of California - San Francisco