Immunology-Innate Immunity

Question 1

What are some non-specific (innate) protective mechanisms?

Answer 1

Physical barriers: skin, ciliated mucous membranes

Humoral factors: lysozyme, complement, interferons Species-specific regulating factors: nutritional requirements, pH, temperature

Cellular mechs: phagocytosis

Question 2

How is specific immunity acquired?

Answer 2

contact with the infectious agent (antigen)

Question 3

Interferons

Answer 3

small polypeptides, mainly produced by virus-infected cells, render uninfected cells resistant to infection (due to production of enzymes that digest nucleic acids)

Question 4

What cells are involved in innate protection?

Answer 4

Blood granulocytes (neutrophils, eosinophils, basophils), blood monocytes, mast cells, macrophages

Question 5

What do cells such as neutrophils and macrophages contain that help them target ‘dangerous’ molecules?

Answer 5

Pattern Recognition Receptors (PRR)

Question 6

Cytokines

Answer 6

secreted polypeptides produced by activated cells that signal other cells

Question 7

Macrophages

Answer 7

tissue-specific populations

engagement of PRR triggers phagocytosis acute inflammation, induction of adaptive immune response

secrete cytokines immature macrophages= blood monocytes

Question 8

Neutrophils

Answer 8

acute inflammation

attracted by complement activation, cytokine production, and changes to vascular endothelium

principal phagocytes of blood

secrete defensins and bactenecins that disrupt bacterial membrane

accumulation of neutrophils= pus housed in abscess

Question 9

Eosinophils

Answer 9

<5% of leukocytes in normal blood

increases in parasite-infected animals

not phagocytic

target surface of parasites by means of antibody or complement

prominent in allergic reactions

Question 10

Basophils/Mast cells

Answer 10

principally localized at epithelial surfaces

induce acute inflammation

respond to parasite infection production of cytokines to induce acute inflammatory response

armed by specific antibody of IgE class

subsequent contact with antigen causes degranulation and release of enzymes and vasoactive contration

Question 11

Answer 11

basophil

Question 12

Answer 12

eosinophil

Question 13

Answer 13

macrophage

Question 14

Answer 14

mast cells

Question 15

Answer 15

neutrophil

Question 16

Pattern Recognition Receptors (PRR)

Answer 16

expressed on most cell types

different ones expressed by different cells

trigger phagocytosis and expression of cytokines