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INDUCTION OF T REGULATORY CELLS BY STIMULATION WITH IMMATURE AUTOLOGOUS DENDRITIC CELL ENRICHED POPULATION.
Yide Jin, MD, Laphalle Fuller, PhD, George W. Burke III, MD, Violet Esquenazi, PhD and Joshua Miller, MD. Miami FL, USA, University of Miami, School of Medicine, 33136, Surgery and Miami FL, USA, Miami Veterans Affairs Medical Center, 33136.

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It is now well known that regulatory T cells (Treg) may play a pivotal role in tolerance establishment. In this study, we were able to generate regulatory T cells from peripheral CD3+ pool by multiple stimulation with autologous immature DC enriched population either derived from BMC or peripheral blood. Auto-reactive T cells generated from different individuals were CD4+/CD3+ enriched (>78%) and were abTCR and CD45RA low, CD45RO high. After activation (with self antigen), their expression of CD25 and intracellular CTLA4 levels were elevated. They were auto-reactive, their proliferative response to self-antigen was 3-fold stronger than to allo-antigen, but exhibited no cytotoxicity to the target bearing self-antigens. Tauto expressed IL-4, IL-10 suppressive cytokine messages and showed immune down-regulation on cellular immunity to allo-antigen as well as viral antigen. Cell-to-cell contact, was required for achieving the better Tauto suppression, and the HLA restriction was not always required for the inhibition. This study demonstrated that self-reactive T cells do not always lead to self-damage; they can also be involved in immune regulation. Their immune suppression on cellular immunity to allo-antigen may be beneficial for graft survival.