UCI News

Study: Immune protein actually aids enemy bacteria

In a new study, UC Irvine microbiologist Manuela Raffatellu has found that our immune response can sometimes make us vulnerable to the very bacteria it's supposed to protect us from.

February 6, 2014

UC Irvine microbiologist Manuela Raffatellu has found that our immune response can sometimes make us vulnerable to the very bacteria it’s supposed to protect us from. A study published today in the journal Immunity reveals that the immune protein interleukin-22 enhances the growth of dangerous bacteria–such as salmonella, which causes food poisoning–and curbs the proliferation of healthy bacteria commonly found in the gut. “Surprisingly, we found that interleukin-22 not only fell short in protecting the host against the spread of salmonella but was actually beneficial to these harmful bacteria,” said Raffatellu, an assistant professor of microbiology & molecular genetics. “Our findings have important implications for the development of treatment strategies against pathogens that can resist interleukin-22-induced responses.” While IL-22 does not protect against all pathogens, the protein still plays a crucial role in controlling the spread of some harmful microbes. “Blocking interleukin-22 during infection would be too detrimental to the host, so a more promising therapeutic strategy would be to specifically target the alternative pathways used by salmonella and, potentially, other pathogens to evade interleukin-22’s defenses,” Raffatellu said.