Bug as a drug: Unveiling anti-cancer properties of Toxoplasma gondii and its therapeutic prospects in cancer immunotherapy

Abstract

In light of the growing global cancer burden, the development of novel therapeutic strategies is urgently needed. Recently, pathogens have been examined for their potential in immunotherapy, with Toxoplasma gondii (T. gondii) emerging as an unexpected yet promising candidate. Given the widespread prevalence of T. gondii, particularly in tropical regions where climatic conditions favor the oocyst transmission, understanding its therapeutic potential may have far-reaching implications for global health. This review explores the potential of T. gondii as a cancer immunotherapy by examining various T. gondii variants characterized in current studies. It highlights the multifaceted mechanisms behind T. gondii's anti-cancer properties, including the induction of Th1 immune responses, immunostimulation of the tumor microenvironment, inhibition of angiogenesis, invasion and metastasis, as well as the induction of cancer cell apoptosis. However, several challenges hinder the application of T. gondii in immunotherapy, such as safety concerns related to viable T. gondii, its limited efficacy against non-solid tumors, and the need for further validation of non-viable T. gondii components. Additionally, the role of humoral immunity and potential synergies with conventional therapies require further investigation. Addressing these challenges could significantly enhance the efficacy and safety of T. gondii-based immunotherapy, offering a novel approach to cancer treatment and potentially improving patient outcomes.