Related Experiment Video
Updated: Apr 12, 2026
Multiplexed Immunofluorescence Analysis and Quantification of Intratumoral PD-1+ Tim-3+ CD8+ T Cells
Published on: February 8, 2018
Circulating and tumor-infiltrating Tim-3 in patients with colorectal cancer
Benling Xu1,2, Long Yuan3, Quanli Gao2
1Department of Oncology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, P. R. China.
Abstract:
T-cell exhaustion represents a progressive loss of T-cell function. The inhibitory receptor PD-1 is known to negatively regulate CD8+ T cell responses directed against tumor antigen, but the blockades of PD-1 pathway didn't show the objective responses in patients with colorectal cancer (CRC). Thus, further exploring the molecular mechanism responsible for inducing T-cell dysfunction in CRC patients may reveal effective strategies for immune therapy. This study aims to characterize co-inhibitory receptors on T cells in CRC patients to identify novel targets for immunotherapy. In this study, peripheral blood samples from 20 healthy controls and 54 consented CRC patients, and tumor and matched paraneoplastic tissues from 7 patients with advanced CRC, subjected to multicolor flow cytometric analysis of the expression of PD-1 and Tim-3 receptors on CD8+ T cells. It was found that CRC patients presented with significantly higher levels of circulating Tim-3+PD-1+CD8+ T cells compared to the healthy controls (medians of 3.12% and 1.99%, respectively, p = 0.0403). A similar increase of Tim-3+PD-1+CD8+ T cells was also observed in the tumor tissues compared to paraneoplastic tussues. Tim-3+PD-1+CD8+ T cells in tumor tissues produced even less cytokine than that in paraneoplastic tissues. Functional ex vivo experiments showed that Tim-3+PD-1+CD8+ T cells produced significantly less IFN-γ than Tim-3-PD-1-CD8+ T cells, followed by Tim-3+PD-1-CD8+ T cells, and Tim-3-PD-1+CD8+ T cells, indicating a stronger inhibition of IFN-γ production of Tim-3+CD8+ T cells . It is also found in this study that Tim-3+PD-1+CD8+ T cell increase in circulation was correlated with clinical cancer stage but not histologic grade and serum concentrations of cancer biomarker CEA. Our results indicate that upregulation of the inhibitory receptor Tim-3 may restrict T cell responses in CRC patients, and therefore blockage of Tim-3 and thus restoring T cell responses may be a potential therapeutic approach for CRC patients.
Insights
Colorectal cancer (CRC) patients show increased Tim-3 and PD-1 co-inhibitory receptors on CD8+ T cells, leading to reduced function. Targeting Tim-3 may restore T cell responses and improve CRC immunotherapy.
Area of Science:
- Immunology
- Oncology
- Cellular Biology
Background:
- T-cell exhaustion impairs anti-tumor immunity.
- PD-1 blockade shows limited efficacy in colorectal cancer (CRC).
- Novel targets are needed to overcome T-cell dysfunction in CRC.
Purpose of the Study:
- Characterize co-inhibitory receptors on T cells in CRC patients.
- Identify novel immunotherapy targets for CRC.
- Investigate the role of Tim-3 and PD-1 in T-cell exhaustion in CRC.
Main Methods:
- Multicolor flow cytometry on peripheral blood and tumor tissues from CRC patients and healthy controls.
- Analysis of T-cell exhaustion markers, specifically PD-1 and Tim-3, on CD8+ T cells.
- Ex vivo functional assays measuring cytokine production (IFN-γ).
Main Results:
- CRC patients exhibit significantly higher levels of circulating Tim-3+PD-1+CD8+ T cells compared to healthy controls.
- Elevated Tim-3+PD-1+CD8+ T cells are found in tumor tissues versus paraneoplastic tissues.
- Tim-3+PD-1+CD8+ T cells show reduced IFN-γ production, indicating functional impairment.
- Increased Tim-3+PD-1+CD8+ T cells correlate with clinical cancer stage.
Conclusions:
- Upregulation of the inhibitory receptor Tim-3 restricts T-cell responses in CRC.
- Tim-3+PD-1+CD8+ T cells represent a key exhausted T-cell subset in CRC.
- Blocking Tim-3 may restore T-cell function and represent a potential therapeutic strategy for CRC immunotherapy.
