New discovery shows parasite manipulates body’s natural defense system

The parasite exploits the binding of host SOD3 to T cells, resulting in impaired T cells’ ability to defend against pathogenic infection. The Sun Wukong represents cytotoxic T cells, the golden cloth rope represents host SOD3, the monster represents parasites, and the golden hoop represents IFN-γ and other immune effective factors. Parasites hijack host T cells through elevated SOD3 expression, resulting in impaired early immune response to parasitic infection.
New research reveals how a protein called superoxide dismutase 3 plays a surprising role in weakening the body’s defenses during parasitic infections. A team of scientists led by Dr. Chen Qijun from Shenyang Agricultural University in China made the findings and published them in the journal Nature Communications.
Researchers explored how the immune system, which protects the body from harmful invaders, responds to parasitic infections, focusing on the role of superoxide dismutase 3. destructive molecules produced), manipulated by the parasite to avoid destruction. Studies have found higher levels of this protein in malaria patients and mice infected with certain parasites. Notably, mice that did not produce superoxide dismutase 3 lived longer and had fewer parasites in their blood than normal mice. This suggests that the protein may help the parasite survive by interfering with the body’s natural defenses.
Scientists discovered that superoxide dismutase 3 is released by a type of white blood cell called neutrophils, which are immune cells that respond early to infection. The protein attaches to another type of immune cell called T cells, which are critical for coordinating the body’s attack on infection, and prevents them from producing important molecules that signal the body to fight infection. One of the molecules is interleukin-2, a protein that helps activate the immune response, while the other is interferon-gamma, which is essential for clearing parasites from the body. “Our findings reveal active fronts in the arms race between the parasite and the host’s immune system,” explains Dr. Chen, highlighting the battle between the body’s defenses and the parasite’s survival strategies.
Scientists have also shown that mice lacking superoxide dismutase 3 produce more interferon gamma early in infection, which enhances their resistance to Plasmodium (the parasite that causes malaria) and Toxoplasma gondii (a parasite that causes malaria) and Toxoplasma gondii (a parasite that causes malaria). The ability of parasites such as parasites to cause severe complications in humans). Conversely, animals with higher protein levels were more susceptible to these infections. The researchers explain that while superoxide dismutase 3 normally helps protect the body from harmful molecules, it weakens the immune response and makes it easier for parasites to multiply.
Therapies targeting superoxide dismutase 3 could provide new ways to treat parasitic infections. For example, blocking the protein’s activity might boost the body’s defenses and make it harder for parasites to survive. “Superoxide dismutase 3 can serve as a potential target for developing interventions to reduce the severity of diseases caused by protozoan parasites,” said Dr. Chen. However, they also note that more research is needed to fully understand how this protein works and to develop effective treatments.
The findings highlight the surprising ways in which parasites exploit the body’s immune system, raising new possibilities for research into treatments that could better prepare the body to fight these infections.
Journal reference
Li Qiang, Lu Kai, Jiang Na, etc. “SOD3 suppresses early cellular immune responses to parasitic infection.” Nature Communications, 2024.
About the author
Dr. Chen Qijunis a renowned parasitologist who has been studying protozoan parasites and related diseases for more than 30 years. In 1981, he received higher education at Changchun Veterinary University and received a doctorate. Obtained PhD degree in 1994. His research career began immediately thereafter as associate professor at KI and senior research scientist at the Swedish Institute for Infectious Disease Control. He mainly studies the pathogenicity of parasites Plasmodium falciparum The aim is to understand the molecular background of severe malaria pathogenesis. Since then, he has been actively working at the forefront of malaria research, making outstanding discoveries in parasite biology and host-parasite interactions, and has an extensive record and widely recognized publications. In 2006, he was appointed as the chief parasitologist of Jilin University and the Chinese Academy of Medical Sciences, and continued to conduct research on protozoan parasites such as Plasmodium, Toxoplasma gondii, and Trypanosoma brucei. From 2018 to 2024, he served as the president of Shenyang Agricultural University. Currently, he is the chief scientist of the National Key Research and Development Project, a basic research consortium on protozoan parasites spanning 2016 to 2025. made a huge contribution. He has published more than 160 papers and invited reviewers, with a high citation record.