A Parasite/Bacteria Coinfection that Provides Protection to the Human Host

It has been known for decades that parasitic infections have a dramatic effect on the human immune system. For instance, some evidence suggests that certain allergic reactions are due, in part, to IgE molecules responding to antigens that are similar to proteins found on various parasitic worms, causing the immune system to overreact. What has been less well understood is the immune response to coinfections of parasites and pathogenic bacteria like Helicobacter pylori. Now, a new study from investigators at the Technical University of Munich (TUM) has completed the first study of the effects of simultaneous infection with blood flukes (schistosomes) and H. pylori—a common occurrence in some parts of the world. Findings from the new study were published recently in Cell Reports through an article titled “Concomitant Infection of S. mansoni and H. pylori Promotes Promiscuity of Antigen-Experienced Cells and Primes the Liver for a Lower Fibrotic Response.” Around 240 million people worldwide are afflicted with schistosomiasis, an illness caused by flatworms of the genus schistosoma, commonly known as blood flukes. These parasites generally enter the human body with water from lakes, ponds, or rivers. Worms, larvae, and eggs are transported to various organs in the body through the bloodstream. The species Schistosoma mansoni is especially damaging to the liver, where it causes cirrhosis.