Host Defense

Question 1

Humoral Immunity

Answer 1

main protective response extra cellular bacteria
IgG opsonizes and toxin specific antibodies neutralize
IgM and IgG activate classical complement to lyse

Question 2

Septic Shock

Answer 2

Gram negative and Gram positive bacteria give off

TNF and IL-1

Question 3

Superantigens

Bacterial toxins

Answer 3

• bind to class II MHC proteins on APCs

- bind to Va or Vb chain on T cells which leads to T cell activation

Question 4

Rheumatic fever

Answer 4

cross reactive antibodies induced by streptococcal M protein

Question 5

Poststreptococcal glomerulonephritis

Answer 5

infection with streptococci, antibodies that form immune complexes with bacterial antigens

Question 6

Natural Killer Cells in intracellular bacteria

Answer 6

Innate immunity

activated by macrophage produced IL-12, then produces INF gamma to activate more macrophages

Question 7

DTH like type IV reaction intracellular bacteria

Answer 7

TH1 cells become activated and release INF gamma which activates macrophages

Question 8

Type I a and b interferon innate immunity viruses

Answer 8

upregulate expression of Class I MHC

activates NK cells

Question 9

Sequence of Immune Response in viruses

Answer 9

From early to late:
Type I IFN
NK Cells
CTLs
Antibodies

Question 10

neutrophils in fungal infections

Answer 10

main mediators of innate immunity

Question 11

TH1 mediated immunity, adaptive immunity

In fungal infections

Answer 11

Crytococcus neoformans eliminated by CTLs

Intracellular fungus HIstoplasma capsulatum, granuloma

Question 12

Protozoa in macrophages of parasites

Answer 12

CD4 T lymphocytes–> IFN gamma –> activates macrophages

Question 13

Plasmodium in adaptive immunity of parasite infestations

Answer 13

TH1 mediated CTLs

Question 14

Helminth infestations

Answer 14

IgE and eosinophils during ADCC, Th2 immunity

Outer layer of helminths activate alternative complement

Resistant to neutrophils and macrophages because they are thick

Question 15

Innate immunity

Answer 15

Phagocytosis

Alternative complement pathway

Question 16

Adaptive immunity

Answer 16

Humoral immunity main protective response
IgM and IgG
Classical complement

Question 17

Polysaccharide capsules

Answer 17

Inhibit alternative complement

Resist phagocytosis

Question 18

Mycobacterium

Answer 18

Inhibits fusion of phagocytes and lysosomes

May scavenge reactive oxygen intermediates to prevent bacterial kill

Question 19

Cytoplathic effect

Answer 19

When viruses lyse host cells

Question 20

Viruses- adaptive immunity, HUMORAL

Answer 20

Humoral immunity important if antibodies are present

Question 21

Viruses- adaptive immunity, CTLs

Answer 21

CTLs during established virus infections
Presented on class I MHC 
CTLs=Most effective form of immunity against viruses