TCF1 regulates the stem-like properties of CD8
+ T cell subpopulations, which enables the persistence and differentiation into effector T cells. Conversely, TOX supports the epigenetic and transcriptional programs of exhausted T cells
11. Multiplex immunofluorescence staining of CK, CD8, TCF1, and TOX (
Figure 1M) enabled quantification of total CD8
+ T cells, TCF1
+CD8
+ T cells, and TOX
+CD8
+ T cells. Elevated intratumoral COX-2 expression was inversely correlated with the infiltration of TCF1
+CD8
+ T cells (
Figure 1N,
Table S1). A stratified analysis was performed to assess the impact of COX-2 expression on the prognosis associated with TCF1
+CD8
+ T cell infiltration. Patients in the cohort with low COX-2 expression exhibiting high levels of TCF1
+CD8
+ T cell infiltration had significantly improved OS (
Figure 1O). Conversely, the degree of TCF1
+CD8
+ T cell infiltration within the cohort characterized by high COX-2 expression did not show a significant correlation with OS, suggesting that COX-2 expression may influence the prognostic role of TCF1
+CD8
+ T cells in this patient population (
Figure 1O). These results indicated that COX-2 expression may have an immunosuppressive role in NSCLC, limiting the infiltration of stem-like T cells and compromising treatment efficacy.