Immunology Chapter 10 – Preventing infection at mucosal surfaces
The mucosal immune system
Mucosal tissues (400 m2): tissues that are covered with mucus:
Gastrointestinal tract
o Small intestine: small layer of mucus. Has villi + crypt and Payer’s
patches
o Large intestine: several layers of mucus – due to the fact that there are
more bacteria here. Has only crypt and no Payer’s patches
Respiratory tract
Urogenital tract
Mucus:
Network of huge glycoproteins with repetitive
polypeptide chains
Highly glycosylated and therby negatively charged
Binds water, antimicrobial peptides and IgA
Secreted by Globlet cells
Function of mucosal tissues:
Gas exchange
Uptake of food components
Excretion of waste
Reproduction
Sensory function
--> Therefore, the mucosal tissues are covered with a thin layer of epithelium
Most pathogens enter body via mucosal tissues due to:
Large area
Thin layer of epithelium
Functions of mucosal immune system – 75% of all lymphocytes are in mucosal
immune system:
Activation of immune responses against pathogens
Avoiding of immune responses to harmless antigens – pollen you inhale or
pinda’s you eat --> induction of tolerance
Unwanted mucosal immune reactions:
Allergies: lot of mucus
Coeliac disease: allergic for gluten
Inflammation of intestines
o Crohn’s disease
o Ulcerative colitis
Anatomical features
1. Intimate interactions between mucosal epithelia and
lymphoid tissues
2. Specific tissues in mucosal immune system
Waldeyer’s ring: ring of lymphoid tissues that
consist:
o Tonsils: epithelium --> B cell follicles + crypt
The mucosal immune system
Mucosal tissues (400 m2): tissues that are covered with mucus:
Gastrointestinal tract
o Small intestine: small layer of mucus. Has villi + crypt and Payer’s
patches
o Large intestine: several layers of mucus – due to the fact that there are
more bacteria here. Has only crypt and no Payer’s patches
Respiratory tract
Urogenital tract
Mucus:
Network of huge glycoproteins with repetitive
polypeptide chains
Highly glycosylated and therby negatively charged
Binds water, antimicrobial peptides and IgA
Secreted by Globlet cells
Function of mucosal tissues:
Gas exchange
Uptake of food components
Excretion of waste
Reproduction
Sensory function
--> Therefore, the mucosal tissues are covered with a thin layer of epithelium
Most pathogens enter body via mucosal tissues due to:
Large area
Thin layer of epithelium
Functions of mucosal immune system – 75% of all lymphocytes are in mucosal
immune system:
Activation of immune responses against pathogens
Avoiding of immune responses to harmless antigens – pollen you inhale or
pinda’s you eat --> induction of tolerance
Unwanted mucosal immune reactions:
Allergies: lot of mucus
Coeliac disease: allergic for gluten
Inflammation of intestines
o Crohn’s disease
o Ulcerative colitis
Anatomical features
1. Intimate interactions between mucosal epithelia and
lymphoid tissues
2. Specific tissues in mucosal immune system
Waldeyer’s ring: ring of lymphoid tissues that
consist:
o Tonsils: epithelium --> B cell follicles + crypt
