immunology 5

Question 1

Toll Like Receptors (TLR) that recognize bacteria

Answer 1

1, 2, 4, 5, 6, 9

Question 2

toll like receptors (TLR) that recognize viruses

Answer 2

3, 7, 8, 9

Question 3

common features of adaptive immune response to pathogens

Answer 3

intracellular pathogens-Th1-mediated activation of cytotoxin T cells; cell mediated immunity
extracellular pathogen-Th2-mediated activation of humoral immunity

Question 4

immune response to viruses

Answer 4

innate-type I interferons signals through JAK/STAT pathways to exert antiviral functions
humoral mediated by antibodies-block viral entry, stimulate phagocytosis, activate complement for lysis of virus infected cells and mediated ADCC to kill virus infected cells
cell-mediated-cytoxic T cells kill virus infected cells anf T helper cells activate macrophages

Question 5

immune response to bacteria

Answer 5

innate-recognition by PRR and cytokine release, complement activation, inflammation and phagocytosis
adaptive to extracellular-humoral-neutralization (IgA and IgG), opsonization (IgM better than IgG) complement activation, phagocytosis and ADCC less important
adaptive to intracellular-cell-mediated-Th1 cells activate macrophages and enable killing and destruction by cytotoxic T cells and NK cells

Question 6

evasion of immune response

Answer 6

Viruses
RNA virus-antigenic variation
DNA virus-besides antigenic variation, express immunoregulatory genes that block interferon signaling
bacteria
evasion of innate-interfere with TLR signaling, resistance to antibacterial peptides, block phagocytosis, if intracellular bacteria interfere with phagosome maturation and or escape phagosome
evasion of adaptive-antigenic variation and secrete proteases to destroy antibodies or cytokines

Question 7

parasites

Answer 7

organisms that live in/on host and gets nutrients from the host or at the expense of the host
protozoa-single celled intracellular or extracellular
helminths-multicellular and extracellular
arthropods-multicellular and extracellular

Question 8

immune response to protozoa

Answer 8

innate mechanism similar to bacteria and virus
mutual adaptation and species-specific infection is important
stimulate both cell mediated and humoral response
humoral-antibodies opsonize parasites in blood and tissue
cell mediated is important for intracellular protozoa

Question 9

extracellular protozoa

Answer 9

similar response to bacteria
Th22 responses are important-macrophages produce IL-22
recruitment of neutrophils-oxidative damage to pathogens

Question 10

intracellular protozoa

Answer 10

intracellular location protects organisms from immune detection
some actively penetrate cells
Th1 responses are important
recruitment of cytotoxic T cells

Question 11

immune evasion-protozoa

Answer 11

parasite-induced immunosuppression
reduced antigenicity of encysted protozoan
antigenic variation
infection more common in immunosuppressed host

Question 12

adverse consequences

Answer 12

immune response to protozoa may result in hypersensitivity
type 1: trichomoniasis infection that causes local irritation of genital tract
type II: parasite antigens bind to host erythrocytes
type III: immune complex formation in visceral leishmaniasis

Question 13

immune response to helminths

Answer 13

mostly Th2 adaptive response
effectiveness of response depends on
genetic susceptibility
host age, gender and overall health
site of infection
parasite burden
helminth species
larvae and adults trigger Th2 response-attacked by eosinophils and basophils
adults worms are expelled from mucosal surface IgE binding
similar clinical signs to type I hypersensitivity-eosinophilia, edema, asthma and urticaria
thick cuticle or tegument
Th2 effector cells are important in destroying migration larvae-eosinophils and macrophages release Th2 cytokines-cuticle damage
innate immune cells and Th2 cells secrete IL-4, 5 and 13
eosinophils have FC receptors and bind to opsonized worms
IgE dependent eosinophil mediated response important for larval response

Question 14

immune evasion-helminths

Answer 14

migrating larvae are very good at immune evasion
innate immunity-neutrophil inhibitors, surface antioxidants and inference with complement
adaptive immunity-reduced antigenicity over time, antigenic variation and interference with antigen processing

Question 15

imunosuppresion

Answer 15

common feature of parasitized animals
parasites produce immunosuppressive molecules
redirection of T cell response-produce Il-10 which is immunosuppressive

Question 16

immune response to arthropods

Answer 16

fleas, ticks, mosquitos, mites lice
inject saliva-digestive enzymes and immunomodulatory substances
three types of response-Th1 response, Th2, and cutaneous hypersensitivity

Question 17

immune response to fungi

Answer 17

innate-PRR recognize fungal PAMPS, neutrophil recruitment-moderately effective, small spores may be ingested by macrophages
adaptive response-Th1 most important, activated macrophages and neutrophils

Question 18

using immune system components to diagnose infection

Answer 18

enzyme linked immunoso