Activation and exhaustion marker expression on immune cells from patients with solid tumors 9367

Abstract Description Activation and exhaustion marker expression have become critical for evaluating the efficacy of immune checkpoint inhibitors in cancer therapy. Exhaustion biomarkers, such as Programmed Death-Ligand 1 (PD-L1) and Lymphocyte-Activation Gene 3 (LAG-3), were analyzed in solid tumors alongside co-expression of T-cell activation markers, such as CD86 and Ki67, to gain insights into the immune cell status. Flow cytometry was used to characterize LAG-3 and PD-L1 expression on cytotoxic and memory T cells from patients with various solid tumors, including melanoma, non-small cell lung cancer (NSCLC), and breast cancer, using cryopreserved peripheral blood mononuclear cell (PBMC) samples. The expression of exhaustion markers, LAG-3 and PD-L1, was variable across patients with solid tumors, with elevated levels observed on CD8+ T cells. This suggests an up-regulation in response to persistent tumor antigenic stimulation. The co-expression of exhaustion markers on CD8+ T cells may indicate a role in T-cell dysfunction and immune evasion. These findings highlight the complexity of exhaustion marker expression in immune cells and their influence on immune responses in patients with solid tumors. By integrating LAG-3 and PD-L1 profiling with other markers of immune activation and exhaustion, this study underscores the potential of these markers as predictive biomarkers for immunotherapy response and provides insights into mechanisms of immune evasion in solid tumor cancers. Topic Categories Immune Mechanisms of Human Disease (HUM)