Tuning IL-2 signaling by ADP-ribosylation of CD25
Abstract
Control of immunologic tolerance and homeostasis rely on Foxp3 1 CD4 1 CD25 1 regulatory T cells (Tregs) that constitutively express the high affinity receptor for Interleukin-2, CD25. Tregs proliferate in response to injections of IL-2/anti-IL-2 antibody complexes or low doses of IL-2. However, little is known about endogenous mechanisms that regulate the sensitivity of CD25 to signaling by IL-2. Here we demonstrate that CD25 is ADP-ribosylated at Arg35 in the IL-2 binding site by ecto-ADP-ribosyltransferase ARTC2.2, a toxin-related GPI-anchored ecto-enzyme. ADP-ribosylation inhibits binding of IL-2 by CD25, IL-2-induced phosphorylation of STAT5, and IL-2-dependent cell proliferation. Our study elucidates an as-yet-unrecognized mechanism to tune IL-2 signaling. This newly found mechanism might thwart Tregs at sites of inflammation and thereby permit a more potent response of activated effector T cells.
Domains
Life Sciences [q-bio] Immunology Life Sciences [q-bio] Biochemistry, Molecular Biology Life Sciences [q-bio] Biotechnology Life Sciences [q-bio] Immunology Vaccinology Life Sciences [q-bio] Immunology Immunotherapy Life Sciences [q-bio] Immunology Adaptive immunology Life Sciences [q-bio] Bioengineering
Origin : Publisher files allowed on an open archive
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