B7-H1/CD80 interaction is required for the induction and maintenance of peripheral T-cell tolerance

JJ Park, R Omiya, Y Matsumura… - Blood, The Journal …, 2010 - ashpublications.org
JJ Park, R Omiya, Y Matsumura, Y Sakoda, A Kuramasu, MM Augustine, S Yao, F Tsushima…
Blood, The Journal of the American Society of Hematology, 2010ashpublications.org
T-cell tolerance is the central program that prevents harmful immune responses against self-
antigens, in which inhibitory PD-1 signal given by B7-H1 interaction plays an important role.
Recent studies demonstrated that B7-H1 binds CD80 besides PD-1, and B7-H1/CD80
interaction also delivers inhibitory signals in T cells. However, a role of B7-H1/CD80 signals
in regulation of T-cell tolerance has yet to be explored. We report here that attenuation of B7-
H1/CD80 signals by treatment with anti–B7-H1 monoclonal antibody, which specifically …
Abstract
T-cell tolerance is the central program that prevents harmful immune responses against self-antigens, in which inhibitory PD-1 signal given by B7-H1 interaction plays an important role. Recent studies demonstrated that B7-H1 binds CD80 besides PD-1, and B7-H1/CD80 interaction also delivers inhibitory signals in T cells. However, a role of B7-H1/CD80 signals in regulation of T-cell tolerance has yet to be explored. We report here that attenuation of B7-H1/CD80 signals by treatment with anti–B7-H1 monoclonal antibody, which specifically blocks B7-H1/CD80 but not B7-H1/PD-1, enhanced T-cell expansion and prevented T-cell anergy induction. In addition, B7-H1/CD80 blockade restored Ag responsiveness in the previously anergized T cells. Experiments using B7-H1 or CD80-deficient T cells indicated that an inhibitory signal through CD80, but not B7-H1, on T cells is responsible in part for these effects. Consistently, CD80 expression was detected on anergic T cells and further up-regulated when they were re-exposed to the antigen (Ag). Finally, blockade of B7-H1/CD80 interaction prevented oral tolerance induction and restored T-cell responsiveness to Ag previously tolerized by oral administration. Taken together, our findings demonstrate that the B7-H1/CD80 pathway is a crucial regulator in the induction and maintenance of T-cell tolerance.
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