The CC ligand chemokine family members CCL17/CCL22 predict the survival and response to immune checkpoint blockade therapy of patients with head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is considered an immunosuppressive malignancy. Cross-talk between cancer cells and immune cells is modulated in part by CC ligand (CCL) chemokines, having a major effect on tumor progression. However, the predictive value and function of CCL family members in HNSCC have not been elucidated. Here, the predictive value of CCL members in cancer prognosis and Immune checkpoint blockade therapy response was investigated. CCL17 and CCL22 were screened as the key CCL chemokines in HNSCC through co-expression analysis. Further, the correlation between CCL17/CCL22 expression and cancer immune infiltration were evaluated based on TIMER and were validated by a set of scRNA-seq data. Moreover, the expression level of CCL17/CCL22 we evaluated to predict the response to Immune checkpoint blockade therapy in a panel of cancer types by using the TIDE database. Results indicated that CCL17/CCL22 had a high co-expression correlation and had a marginally statistical significance with the overall survival in HNSCC patients (P value = 0.057 and 0.055, respectively). Our findings showed high expression of CCL17/CCL22 was positively correlated with CD4 T cell infiltration levels in HNSCCs and activate mTORC1 signaling pathway in CD4 T cells. Further analysis from TIDE showed the high expression of CCL17/CCL22 might predict favorable responses to immune checkpoint blockade therapy in HNSCC patients. These findings provide an insight into the predictive roles of CCL17/CCL22 in HNSCC.