Immune immunotherapy has improved, with immune checkpoint inhibitors (ICIs) being the most effective. Antitumor responses mediated by ICIs generally depend on T cells capable of recognizing different types of cells.
Recently, potent ICIs, such as nivolumab and pembrolizumab, have been applied to an increasing number of cancers, offering therapeutic advantages. Although ICIs are not responsive to ICIs, a significant proportion of patients do not respond to ICIs.
ICI-mediated antitumor responses rely on the expression of PD-L1 in T cells capable of recognizing cancer cells. Immune cells such as CD8+ T cells are associated with increased cancer incidence and increased immunotherapy efficacy.
They can also lead to T cell deficiency, which can lead to resistance to immunotherapy. The success of chimeric antigen receptor (CAR) T cell infusions for cancer and lymphoma patients demonstrates the importance of T cells in combating tumors. Considering potential factors in cancer immunotherapy, CD8+ T cells play a key role in determining therapeutic response to ICIs. According to the distribution of cytotoxic immune cells in the modern microscopic tumor (TME), they fall into one of three main categories: immunologically inflamed, immunologically controlled, and dynamic. Also called "hot tumors," immunologically inflamed tumors are characterized by advanced T cell progression. Based on interferon-γ (IFN-γ) markers, PD-L1 expression, and tumor mutational burden (TMB), the inflamed tumor is more susceptible to ACE inhibitors, which can be prescribed to control the immune system and make tumors "hot tumors." If not immune-controlled, CD8+ T cells are present only at the margins of invasion, leading to a different phenotype.
