The MannCWhitney U test was used to examine statistical significance. Other immune biomarkers to predict response of nivolumab treatment We then hypothesized that this pre-existing CD8+ TILs in responder tissues might have higher cytolytic activity, which could be restored by nivolumab treatment. of TILs in post-treatment tissues in the responders. Results Response-based classification of melanoma patients treated with nivolumab We obtained pre- and post-treatment tumor tissues from 13 metastatic melanoma patients who were treated with nivolumab. According to the RECIST criteria,19 2 cases were judged as partial response (PR), 6 cases as stable disease (SD), and 5 cases as progressive disease (PD) (Table?1). The autoimmune-like adverse events were observed in 3 cases; grade 1 hypothyroiditis in 1 PR case, grade 2 psoriasiform dermatitis in 1 PR case, and grade 4 myasthenia gravis with systemic myocarditis and myositis in 1 SD case (Table?1). To examine effect of immunological parameters on clinical end result, we defined responders (n = 5) as patients who achieved PR or those who revealed SD with progression-free survival (PFS) of greater than a median period (233?d) of this cohort, and non-responders (n = 8) as patients who revealed PD or those who revealed SD with PFS of less than the median (Table?1). Table 1. Patient demographic data. and mRNA levels in the pre-treatment tumor tissues and found that expression levels of both and were significantly higher in pre-treatment tumors of responders (n = 5) than those of non-responders (n = 8) (= 0.03 for PD-L1 and = 0.04 for PD-L2) (Fig.?1A and B); a strong correlation between the expression levels of these two molecules was also observed (Fig.?S1A). Because responders experienced higher expression levels of and in tumors than non-responders (Fig.?S1B), we assumed that this responders had a higher quantity of pre-existing intratumoral CD8+ T cells where the PD-1-PD-L1/2-dependent inhibitory mechanism was likely to be dominant. Open in a separate window Physique 1. Comparison of expression levels of multiple immune-related genes in pre-treatment tumors between responders and non-responders. (ACD) Expression levels of (A), (B), (C), and (D) genes in surgically resected pre-treatment tumors in responders and non-responders are shown. The and are offered. (F) Predictive scores for individual patients were calculated based on expression levels of which were significantly higher in the tumors of responders compared with those of non-responders. Horizontal lines represent the means. The MannCWhitney U test was used to examine statistical significance. Other immune biomarkers to predict response of nivolumab Tezosentan treatment We then hypothesized that this pre-existing CD8+ TILs in responder tissues might have higher cytolytic activity, which could be restored by nivolumab treatment. As expected, mRNA level of granzyme A (= 0.01) (Fig.?1C). The expression level of was significantly correlated with those of (= 0.001) and (= 0.002) (Fig.?S1C). In addition, it is well known that HLA class I molecules must be expressed in tumor cells to be recognized by CTLs. Hence, we examined mRNA level of = 0.006) (Fig.?1D). We further examined expression levels of additional immune-related genes including as well as ratios of in the pre-treatment tumors. Although there were no statistically significant differences in expression levels of and between the two groups (Fig.?S2), the Tezosentan and ratios were significantly higher in tumors in responders than those in non-responders (= 0.04 and 0.02, respectively), and the ratio showed higher tendency in responders, compared with non-responders (p = 0.12) (Fig.?1E). Based on statistical significance of each gene, we selected three possible predictive markers, = 0.0016) (Fig.?1F). Nivolumab-driven immunological changes in the tumor microenvironment It is likely that blocking the PD-1 immune checkpoint can reinvigorate the pre-existing CTLs and enhance antitumor immune Rabbit polyclonal to Complement C4 beta chain responses. We therefore examined immunological changes between pre- and post-treatment melanoma tissues and found that nivolumab treatment increased the number of CD8 T cells as indicated by the increase of mRNA in tumor tissues in most of the cases (Fig.?2A). Particularly, in the malignancy tissue of patient M11, who was a non-responder but manifested severe autoimmune adverse events21 displayed the most significant degree (4.1-folds) of increase (Fig.?2A, and perforin 1 (expression between the responder and non-responder groups were not statistically significant (Fig.?2B), we observed significant changes of expression levels between the two groups (= 0.009) (Fig.?2C). These data implying the enhancement of cytotoxic T cell activity might also be supported by the Th1-dominant cellular immunity in tumor tissues. We thereby investigated fold switch of expression ratio of between Tezosentan before and after the nivolumab treatment, which was likely to represent intratumoral Th1/Th2 balance. The expression ratio of was significantly increased in responders than non-responders (= 0.03) (Fig.?2D), suggesting.