Recent Advances and Next Breakthrough in Immunotherapy for Cancer Treatment

Abstract

With the huge therapeutic potential, cancer immunotherapy is expected to become the mainstream of cancer treatment. In the current field of cancer immunotherapy, there are mainly five types. Immune checkpoint blockade therapy is one of the most promising directions. Adoptive cell therapy is an important component of cancer immunotherapy. The therapy with the cancer vaccine is promising cancer immunotherapy capable of cancer prevention. Cytokine therapy is one of the pillars of cancer immunotherapy. Oncolytic immunotherapy is a promising novel component of cancer immunotherapy, which with significantly lower incidence of serious adverse reactions. The recent positive results of many clinical trials with cancer immunotherapy may herald good clinical prospects. But there are still many challenges in the broad implementation of immunotherapy. Such as the immunotherapy cannot act on all tumors, and it has serious adverse effects including but not limited to nonspecific and autoimmunity inflammation. Here, we center on recent progress made within the last 5 years in cancer immunotherapy. And we discuss the theoretical background, as well as the opportunities and challenges of cancer immunotherapy.

Figure 1

Components and brief mechanisms of cancer immunotherapy.

Figure 2

The brief antitumor mechanism of CTLA-4 and PD-1/PD-L1 blocking antibodies. (a) In the tumor microenvironment, the T cell surface is highly inhibited by inhibitory immunoregulatory receptors, such as CTLA-4 and PD-1/PD-L1, which prevents the immune activation of T cells and the killing of tumors. (b) The use of PD-1/PD-L1 or CTLA-4 blocking antibodies can eliminate the immunosuppressive effects of PD-1/PD-L1 or CTLA-4, thereby activating the immune response of T cells to kill tumors.

Figure 3

The mechanism of adoptive cell therapy. ACT with TILs separates TIL cells from tissues near the tumor, and large-scale expand in vitro, then reintroduce into the patient. ACT with TCR or CAR separates T cells of patient peripheral blood and is genetically modified to express TCR or CAR, then it can specifically recognize and attack tumor cells when reinfused into the patient. Before the adoptive transfer to the patients, they are treated with a lymphodepletion adjustment regimen.