The mucus covering our mucosal surfaces is an intimate part of the innate immune system and the first line of defense against microbial challenges. This is especially prominent in the lower parts of the intestine where we have to protect ourselves at the same time as we live in a symbiotic relation without trigger an overt immune response. We have shown that colon has a double-layered mucus layer built around the MUC2 mucin. The inner of these act as a barrier and does not allow bacteria to penetrate. With an absence of MUC2 or defects in the mucus, bacteria reach the epithelial cells, penetrate into the crypts, and into the epithelial cells. In experimental colitis models this inner mucus layer is penetrable to bacteria and in patients with active colitis. This renewal is to continue studies on how the mucus layers are formed and built by the use of biochemical methods, especially mass spectrometry, and the use of various types of gene knock-out animals that are colonized with bacteria or germ-free. Patient studies on biopsies will follow changes in penetrability processes over the cyclic changes observed ulcerative colitis. The role of different mucus proteins on mucus properties will be studied and manipulated by recombinant mucus proteins and pharmacological agents. The three aims that will be studied are:
Aim 1 : To obtain a deeper functional and molecular understanding of the small intestinal mucus and its main component the MUC2 mucin in relation to mucus detachment, bacterial selection, and goblet cell uptake of antigens via transglutamination.
Aim 2. To obtain a functional and cell biological understanding of the many different types of goblet cells in the intestine and their different secretory machinery.
Aim 3. To obtain a functional understanding of how the mucus and its main components protect the mucosal surfaces of colon and inhibits ulcerative colitis. Expected results are novel ways to improve the protection of colon and by novel principles of the intestinal mucosal immunology that could have importance for understanding the disease ulcerative colitis.

Public Health Relevance

The large intestine harbors an enormous amount of bacteria that are in the normal situation still does not cause us any problem. Our discovery of an inner mucus layer in colon that were shown to separate the bacteria from us has provided a new understanding and suggested that defects in this mucus can be part of the initiation mechanism for the disease ulcerative colitis. This is a relatively common disease, increasing in the Western world, that cause severe personal suffering as well as high costs for the health care system.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project--Cooperative Agreements (U01)
Project #
5U01AI095473-08
Application #
9965713
Study Section
Special Emphasis Panel (ZAI1)
Program Officer
Rothermel, Annette L
Project Start
2011-07-22
Project End
2021-06-30
Budget Start
2020-07-01
Budget End
2021-06-30
Support Year
8
Fiscal Year
2020
Total Cost
Indirect Cost
Name
Goteborg University
Department
Type
DUNS #
350582359
City
Gothenburg
State
Country
Sweden
Zip Code
SE-4053
Ermund, Anna; Trillo-Muyo, Sergio; Hansson, Gunnar C (2018) Assembly, Release, and Transport of Airway Mucins in Pigs and Humans. Ann Am Thorac Soc 15:S159-S163
Nyström, Elisabeth E L; Birchenough, George M H; van der Post, Sjoerd et al. (2018) Calcium-activated Chloride Channel Regulator 1 (CLCA1) Controls Mucus Expansion in Colon by Proteolytic Activity. EBioMedicine 33:134-143
Schroeder, Bjoern O; Birchenough, George M H; Ståhlman, Marcus et al. (2018) Bifidobacteria or Fiber Protects against Diet-Induced Microbiota-Mediated Colonic Mucus Deterioration. Cell Host Microbe 23:27-40.e7
Schneider, Hannah; Pelaseyed, Thaher; Svensson, Frida et al. (2018) Study of mucin turnover in the small intestine by in vivo labeling. Sci Rep 8:5760
Svensson, Frida; Lang, Tiange; Johansson, Malin E V et al. (2018) The central exons of the human MUC2 and MUC6 mucins are highly repetitive and variable in sequence between individuals. Sci Rep 8:17503
Birchenough, George; Schroeder, Bjoern O; Bäckhed, Fredrik et al. (2018) Dietary destabilisation of the balance between the microbiota and the colonic mucus barrier. Gut Microbes :1-5
Fernández-Blanco, Joan Antoni; Fakih, Dalia; Arike, Liisa et al. (2018) Attached stratified mucus separates bacteria from the epithelial cells in COPD lungs. JCI Insight 3:
Ermund, Anna; Meiss, Lauren N; Dolan, Brendan et al. (2018) The mucus bundles responsible for airway cleaning are retained in cystic fibrosis and by cholinergic stimulation. Eur Respir J 52:
Trillo-Muyo, Sergio; Nilsson, Harriet E; Recktenwald, Christian V et al. (2018) Granule-stored MUC5B mucins are packed by the non-covalent formation of N-terminal head-to-head tetramers. J Biol Chem 293:5746-5754
Ermund, Anna; Meiss, Lauren N; Rodriguez-Pineiro, Ana M et al. (2017) The normal trachea is cleaned by MUC5B mucin bundles from the submucosal glands coated with the MUC5AC mucin. Biochem Biophys Res Commun 492:331-337

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