Cai G, Karni A, Oliveira EML, Weiner HL, Hafler DA, Freeman GJ. PD-1 ligands, negative regulators for activation of naïve, memory, and recently activated human CD4+ T cells.
Cell Immunol 2004;
230:89-98. [PMID:
15598424 DOI:
10.1016/j.cellimm.2004.09.004]
[Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2004] [Accepted: 09/14/2004] [Indexed: 02/06/2023]
Abstract
We examined the role of the PD-1 pathway on the activation of naive, memory, and recently activated human CD4+ T cells to test whether they responded differently. PD-1 ligand blockade modestly enhanced the percentage of responding T cells and production of IFN-gamma in a primary response to myelin basic protein (MBP) in normal donors. PD-1 ligand blockade strongly enhanced proliferation and cytokine production by memory or recently activated T cells (tetanus toxoid and MBP). Blockade of PD-L1 alone had more effect than PD-L2, consistent with its higher expression on ex vivo dendritic cells; furthermore, anti-PD-L1 plus anti-PD-L2 resulted in the greatest enhancement. Moreover, PD-L1-Ig inhibited anti-CD3 induced activation of naive, memory, and recently activated CD4+ T cells. Together, our data demonstrated PD-1 functioned as a negative regulatory pathway on naive T cells during a primary response, and more potently, on memory or recently activated T cells during a secondary response.
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