The soluble cytoplasmic tail of CD45 (ct-CD45) in human plasma contributes to keep T cells in a quiescent state.

ABSTRACT: The cytoplasmic tail of CD45 (ct-CD45) is proteolytically cleaved and released upon activation of human phagocytes. It acts on T cells as an inhibitory, cytokine-like factor in vitro. Here, we show that ct-CD45 is abundant in human peripheral blood plasma from healthy adults compared with plasma derived from umbilical cord blood and plasma from patients with rheumatoid arthritis or systemic lupus erythematosus. Plasma depleted of ct-CD45 enhanced T-cell proliferation, while addition of exogenous ct-CD45 protein inhibited proliferation and reduced cytokine production of human T lymphocytes in response to TCR signaling. Inhibition of T-cell proliferation by ct-CD45 was overcome by costimulation via CD28. T-cell activation in the presence of ct-CD45 was associated with an upregulation of the

SUBMITTER: Puck A 

PROVIDER: S-EPMC5244668 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature