Immunity (IAS44, 56, 58, 59, 60-62)

Question 1

Immunity - know that they are broadly defined into SPECIFIC and NON SPECIFIC defence mechanisms

The basic recognition mechanism of non-specific defence?

Answer 1

Pattern recognition receptors (ie recognizing common structural components of bacteria and viruses that are made up of carbohydrates, lipids, proteins and nucleic acids)

eg toll-like receptors

Question 2

Know the anatomical barriers of defense (non-specific):

Skin, mucosa

Secretions by skin: inhibit microbial growth

Question: What are defensins? (hint: why are they included as a component of anatomical defense barriers - ie where are they secreted)

Answer 2

Defensins: Antimicrobial peptides expressed by leukocytes and epithelial cells destroy invading pathogens

Question 3

Know chemical mechanisms of non-specific defense:

Lysozymes in tears & saliva
Pepsin (secreted by gastric glands → break down bacteria cell wall)

Question 4

Know microbiological aspects of non-specific defence:

Mainly normal flora (Skin - resident and transient) and microbiota

What is the function??

Answer 4

Colonization resistance - prevents potentially pathogenic organisms from colonizing and invading

Know that they are associated with various metabolic ans immunological functions

Know that an altered microbiota can cause diseases