Sci Adv . . . Xu Wenyue's team reveals new mechanisms for malaria parasite immunity.

Malaria is one of the three most serious infectious diseases in the world. There are nearly 200 million malaria cases and 450000 deaths in the world every year.although the discovery of the antimalarial drug artemisinin has brought good news for the treatment of malaria, with the emergence and spread of artemisinin resistant strains of Plasmodium, the treatment of malaria has brought new challenges.more importantly, artemisinin does not prevent malaria infection.malaria prevention must ultimately rely on effective malaria vaccine. However, there is no safe and efficient malaria vaccine.the main reason is that Plasmodium has a strong immune escape and inhibition strategy. However, the molecular mechanism of immune escape or inhibition of Plasmodium is still unclear.recently, a team of Professor Xu Wenyue from the Army Military Medical University revealed a new immune escape and suppression strategy of Plasmodium.the research achievement is entitled: blood stage malaria sites manifold host in immune responses through the induction of sfgl2, which was published in science advances on February 26, 2020.using the model of Plasmodium falciparum infection, the researchers found that mouse macrophages could recognize the infected erythrocytic Plasmodium through TLR2 on its surface, induce macrophages to secrete MCP-1, recruit and activate NK / NKT cells to produce IFN - γ, thus killing Plasmodium; however, Plasmodium can also induce Treg cells to secrete cellulose like protein 2 (fibrin like) Sfgl2 can act on FC γ IIR receptor on the surface of macrophages, block TLR2 / JNK signaling pathway and MCP-1 secretion by macrophages, thus inhibiting the recruitment of NK / NKT cells and the production of IFN - γ, thus evading the host's immune attack, Plasmodium falciparum finally survives and proliferates.the intrinsic immunity of the host induced by Plasmodium falciparum (P.falciparum) was also found to inhibit the production of MCP-1 by macrophages stimulated by P. falciparum.more importantly, the analysis of serum samples collected from falciparum malaria and vivax malaria patients showed that there was a positive correlation between sfgl2 in serum of malaria patients and the number of protozoa, which confirmed that the research results were consistent with the clinical situation of malaria.in addition, the researchers also found that, unlike sfgl2 in regulating anti-tumor and viral immune responses, sfgl2 secreted by Treg cells after Plasmodium infection plays a role by inhibiting the innate immunity of the host rather than adaptive immunity, thus revealing a novel immunosuppressive mechanism of sfgl2, which can provide an important reference for the Research of sfgl2 in other fields 。the discovery of a new immunosuppressive molecule sfgl2 in the process of malaria infection may not only be used as a molecular marker for the prognosis of malaria patients, but also provide an important target for the immune intervention of malaria and provide an important theoretical basis for the design of effective malaria vaccine. The first author of the paper is Professor Xu Yongwang and Dr. Liu Yongyan.original link: plate maker: Ke