Immune Response (lecture) Flashcards
What two cell types are primarily responsible for neutralizing cytoplasmic infections (one is innate, the other is adaptive)?
Innate imm. NK cells
Adaptive imm. CTL
What cell is primarily responsible for directly neutralizing vesicular infections?
Macrophages (activated by T-cells and NK cells)
What antibody is primarily responsible for clearing epithelial infections?
IgA
What are the two primary innate immunity responses to viral infections?
Inhibition of infection by Type 1 IFN
Direct killing of infected cells by NK cells
What are the three effects of IFN 1 (IFN-a and IFN-B)?
Intracellular sequestration of things a virus needs to survive
Increased NK cell ligands (on infected cell)
Activate NK cells
What is responsible for initiating IFN 1 production?
Pathogen Associated Molecular Patterns (PAMP) of viruses
A lack of what MHC on an infected cell induces death from an NK cell?
MHC I
What are the two mechanisms by which NK cells kill other cells?
Perforin production –> cell leakage
Granzymes –> induced apoptosis
What adaptive immunity cell type is primarily responsible for killing of virus infected cells? What is the other action of the adaptive immune system?
CTLs (specialized CD8) directly kill infected cells
Antibodies block viral binding and entry
What are the three actions by CTLs that lead to fighting a virus infected cell?
Perforin production
Granzyme release into infected cell
FasL induces apoptosis
Which Ig types are primarily responsible for blocking virus binding and entry?
IgG and IgA
What cell type is responsible for Ig type switching?
CD4 helpers
Approximately how long does it take for the adaptive immune system to spin up?
1 week
Mycobacterium, Listeria and Leishmania are all examples of what type of infective agents?
Intracellular
What two cytokines are key in the NK cell - macrophage feedback loop?
IL-12 (from macrophages) and IFN-gamma (from NK cells)
What IFN is responsible for macrophage activation?
IFN-gamma
What adaptive immunity cell type is the first to respond to intracellular pathogens?
CD 4
What cytokine signals CD4 T cells to differentiate into TH1 cells?
IL-12
What adaptive immunity cell is the source of IFN-gamma in response to an intracellular pathogen?
TH1
What complement pathway is independent of the adaptive immune system?
Classical (activated by antibodies)
What is “the most important” complement protein?
C3
What C3 protein is responsible for inflammation?
C3a
What C3 protein is responsible for MAC formation?
C3b
What cell types are the heavy lifters of adaptive immunity to extracellular pathogens?
B cells (antibodies) CD4 T-helpers
What are the two effects of antibodies in the adaptive immune system in response to extracellular pathogens?
opsonization and complement activation
What are the three adaptive immune system cell types responsible for fighting parasite infections?
TH2
Eosinophils
B-cells (IgE)
What cytokine is responsible for signaling Ig switching to IgE?
IL-4
What cytokine activates eosinophils?
IL-5
IgE binding to Mast cells results in _______.
degranulation - histamine degranulation is key to anaphylaxis
How do IL-4 and IL-10 influence macrophage activity?
They both result in suppression of macrophages
What is the primary IFN and cell type of innate immunity involved in virus defense?
IFN-1
NK cells
What are the 3 adaptive immune system cells involved in virus defenses?
CD8
CD4
B cell
What are the two main innate immune system defenses against intracellular pathogens?
Phagocytosis
NK cells
Which adaptive immune system cells are mainly responsible for intracellular pathogen defense (2)?
CD4 (TH1)
CD8
What are the two innate immunity system defenses against extracellular pathogens?
Complement
Phagocytosis
What are the adaptive immune system defenses against extracellular pathogens?
B cells
Ig
CD4
