Changes in the Immune Cell Repertoire for the Treatment of Malignant Melanoma

Immune checkpoint inhibitors (ICIs) have been used for the treatment of various types of cancers, including malignant melanoma. Mechanistic exploration of tumor immune responses is essential to improve the therapeutic efficacy of ICIs. Since tumor immune responses are based on antigen-specific immune responses, investigators have focused on T cell receptors (TCRs) and have analyzed changes in the TCR repertoire. The proliferation of T cell clones against tumor antigens is detected in patients who respond to treatment with ICIs. The proliferation of these T cell clones is observed within tumors as well as in the peripheral blood. Clonal proliferation has been detected not only in CD8-positive T cells but also in CD4-positive T cells, resident memory T cells, and B cells. Moreover, changes in the repertoire at an early stage of treatment seem to be useful for predicting the therapeutic efficacy of ICIs. Further analyses of the repertoire of immune cells are desirable to improve and predict the therapeutic efficacy of ICIs.

Automated summary

Immune checkpoint inhibitors (ICIs) are used for the treatment of various cancers, and understanding the mechanism of tumor immune responses can improve their efficacy. Investigating T cell receptors (TCRs) and changes in the TCR repertoire has revealed increased proliferation of T cell clones in patients responding to ICIs. This proliferation is observed in tumors as well as in the peripheral blood, suggesting that analyzing immune cell repertoire can help predict and enhance the therapeutic efficacy of ICIs.