Dr. Andre Ouellette, professor of pathology , and his team found that cells called Paneth cells emit small antibiotic proteins called defensins that kill bacteria within minutes of sensing that the bacteria are there. Although these researchers have linked Paneth cells to antibiotic activity in the intestine previously, the cells exact role had never been pinpointed. The intestine is constantly exposed to infectious agents, including bacteria, fungi, single-celled organisms and viruses, Ouellette said. But we ve never had a clear understanding of how our innate immune system protects us from infections in the intestine. The innate immune system is hard-wired to kill infectious agents immediately on contact, without having to produce specific antibodies.
Paneth cells help protect the intestine by responding to infections rapidly and effectively.
Disruptions in how Paneth cells work could hold secrets to how certain gastrointestinal orders are caused. Paneth cells are like sentinels that protect this cell renewal process from bacterial infestation by forming a chemical barrier of immunity. The UCI team and their colleagues found that when they added bacteria to the crypts, the Paneth cells reacted by secreting the antibiotic defensins, which were effective at killing bacteria. The researchers found that Paneth cells did not react to infections by fungi or one-celled animals called protozoa. Only bacteria elicited a response from the Paneth cells in these experiments, even though the defensins emitted by Paneth cells previously have been shown to be effective against fungi and protozoa.