Highly prevalent colorectal cancer-infiltrating LAP⁺ Foxp3⁻ T cells exhibit more potent immunosuppressive activity than Foxp3⁺ regulatory T cells.
Mucosal Immunol 2014;
7:428-39. [PMID:
24064667 PMCID:
PMC3931584 DOI:
10.1038/mi.2013.62]
[Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 06/13/2013] [Accepted: 07/09/2013] [Indexed: 02/04/2023]
Abstract
Although elevated CD4⁺Foxp3⁺ regulatory T cell (Treg) frequencies within tumors are well documented, the functional and phenotypic characteristics of CD4⁺Foxp3⁺ and CD4⁺Foxp3⁻ T cell subsets from matched blood, healthy colon, and colorectal cancer require in-depth investigation. Flow cytometry revealed that the majority of intratumoral CD4⁺Foxp3⁺ T cells (Tregs) were Helios⁺ and expressed higher levels of cytotoxic T-lymphocyte antigen 4 (CTLA-4) and CD39 than Tregs from colon and blood. Moreover, ∼30% of intratumoral CD4⁺Foxp3⁻ T cells expressed markers associated with regulatory functions, including latency-associated peptide (LAP), lymphocyte activation gene-3 (LAG-3), and CD25. This unique population of cells produced interleukin-10 (IL-10) and transforming growth factor-β (TGF-β), and was ∼50-fold more suppressive than Foxp3⁺ Tregs. Thus, intratumoral Tregs are diverse, posing multiple obstacles to immunotherapeutic intervention in colorectal malignancies.
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