Phagocytes play an important role in the defense system of the intestine against various pathogens. If those phagocytes are disturbed, chronic inflammatory bowel diseases can develop. As researchers from Basel have discovered now, amino acid transporters control the development of such macrophages. The results of the study were published in the renowned journal «Communications Biology» raising hope for a possible new treatment approach for inflammatory bowel diseases.

Phagocytes are the most common cells in the intestinal mucosa. They remove dead cell residues and destroy invaded pathogens by initiating an inflammatory reaction that fights the focus of infection. If phagocytes are disturbed, inflammatory bowel diseases can develop, which can cause bloody diarrhea and abdominal pain.

It was previously unclear how such phagocytes develop in the intestinal mucosa. How do macrophages develop? How do chronically inflammatory bowel diseases develop from disturbed phagocytes? How can the development of disrupted macrophages be influenced in a targeted manner? The research group, headed by Prof. Jan Hendrik Niess, Consultant Gastroenterology / Hepatology at Clarunis - University Center for Gastrointestinal and Liver Disesases, is looking for answers to these questions.

One of the research approaches from Basel examines how the local development of phagocytes in the intestinal mucosa can be inhibited. Since macrophages in the intestinal mucosa are in direct contact with the food in the intestine, food components can directly control the development of phagocytes of the intestinal mucosa.

The research group specifically switched off the amino acid transporter CD98 in macrophages and observed that the development of mature macrophages from precursor cells was subsequently inhibited. This led to a reduction in macrophages in the intestinal mucosa and as a consequence reduced the severity of colitis. More detailed investigations showed that switching off the amino acid transporter CD98 programs the cell death of macrophages.

Original article
Philipp Wuggenig, Berna Kaya, Hassan Melhem, C. Korcan Ayata, Swiss IBD Cohort Investigators, Petr Hruz, A. Emre Sayan, Hideki Tsumura, Morihiro Ito, Julien Roux, Jan Hendrik Niess
Loss of the branched-chain amino acid transporter CD98hc alters the development of colonic macrophages in mice
Commun Biol. 2020 Mar 18;3(1):130

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Contact
Prof. Jan Hendrik Niess
Clarunis – Universitäres Bauchzentrum Basel
Gastroenterologie und Hepatologie
Tel.: +41 61 777 74 00, JanHendrik.Niess@clarunis.ch
www.clarunis.ch