[Progresses on Antitumor Immune Mechanisms of Protozoon].

A variety of protozoons (Amoeba, Trypanosoma cruzi, Eimeria, Plasmodium falciparum and Toxoplasma gondii, etc.) can activate and regulate the human immune system, change tumor-induced immunosuppression, and enhance the anti-tumor immune response. This paper reviews the effects of protozoon on cellular and humoral immunity, the tumor microenvironment in tumor-bearing organisms, and reveals the antitumor immune mechanisms of protozoon.