T‐cell immunoglobulin mucin 3 blockade drives an antitumor immune response in head and neck cancer

T‐cell immunoglobulin mucin 3 ( TIM 3) contributes to immune suppression during progression of many cancers, but the precise role of TIM 3 in head and neck squamous cell carcinoma ( HNSCC ) is not clearly understood. In this study, we report that TIM 3 expression was significantly up‐regulated in patients with HNSCC and associated with lymph node metastasis. Additionally, TIM 3 expression was increased in patients with recurrent HNSCC and patients with preradiotherapy or prechemotherapy. We also characterized CD 8 + T cells and CD 11b + CD 33 + myeloid‐derived suppressor cells ( MDSC s) in human HNSCC , and found that their expression was positively correlated with TIM 3 expression. To determine the underlying mechanism of TIM 3 in immune response during HNSCC progression, we utilized the Tgfbr1/Pten 2c KO HNSCC mouse model with TIM 3 overexpression. Treatment with anti‐ TIM 3 monoclonal antibody effectively suppressed tumor growth through restoring effector T‐cell function by targeting CD 4 + TIM 3 + cells and CD 8 + TIM 3 + cells and decreasing MDSC s. Our findings demonstrate TIM 3 expression in patients with HNSCC and suggest anti‐ TIM 3 immunotherapy as a novel therapeutic approach for effective treatment of HNSCC .