Summary Chapter 10

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