IL-13/Stat6-mediated sialylation mechanisms of mucins and biological role of sialylated mucins for protection against gastrointestinal nematode infection

2004 Fiscal Year Final Research Report Summary

• Project/Area Number: 15590369
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Parasitology (including Sanitary zoology)
• Research Institution: The Jikei University School of Medicine
• Principal Investigator: ISHIWATA Kenji Jikei University School of Medicine, Lecturer, 医学部, 講師 (00241307)
• Co-Investigator(Kenkyū-buntansha): NAKAMURA Fukumi (UCHIYAMA Fukumi) Miyazaki University School of Medicine, Assistant, 医学部, 助手 (90295204)
• Project Period (FY): 2003 – 2004
• Keywords: Sialic acid / Protection / Mucosalimmunity / IL-13 / Mucins / Gastrointestinal nematode / Mouse / Nippostrongylus brasiliensis

Research Abstract

We previously reported that protection against gastrointestinal nematode, Nippostroagylus brasiliensis, infection in mice was associated with IL-13/Stat6-mediated sialic acid-linked mucin production in goblet cells. The goals of this project are to investigate 1)the mechanism of IL-13/Stat6-mediated sialylation of mucins, and 2)a role of sialylated mucins for protection against N.brasiliensis infection in mice. Since suitable cell lines of mucin producing cells derived from mouse are not available so far, we employed human colon cancer cell line, HT-29. After confirming the mucin production of HT-29 by Periodic Acid Schiff reaction, effects of exogenous IL-13 and IL-4,both bind to IL-4 receptor, on the amount and character of mucins, especially sialylation of mucins, were examined. Base on the characteristics of mucins, activation of signal transduction molecules and expression of enzymes, such as sialyltransferases, were examined in gene and protein levels. Concerning the effects of s ialylated mucins on N.brasiliensis, in vivo and in vitro experiments using sialylated oligosaccharides failed to block the establishment of N.brasiliensis on intestinal villi suggesting that sialic acid affects as being linked to mucins. Further, adult worm implantaion experiments suggested that worm expulsion occurred through not structural but physiological effects of mucus on established adult N.brasiliensis, although the target(s) of the mucus were remained unclear. Related to this, mucus were isolated from small intestine of infected mice to estimate the contents of hexose and sialylated mucins. Although the project has not been done completely, results published by this project will provide significant information about the mechanisms of effector phase of protective response induced by Th2 response against gastrointestinal nematode infection. Additionally, the results will clear the modification mechanisms of mucin production induced by Th2 cytokine, IL-13, which is now the highlight of allergy research.