Lecture 5: Innate Immunity Flashcards
What immunity uses identical toll-like receptors?
Innate immunity
What immunity uses distinct antibody molecules?
Adaptive immunity
PAMPs and DAMPs are found in what immunity?
Innate immunity
What immunity may recognize nonmicrobial antigens?
Adaptive immunity
What immunity is encoded in the germline with limited diversity?
a. Innate immunity
What immunity is encoded by genes produced by somatic recombination of gene segments?
a. Adaptive immunity
Are the cells of the innate system clonal or nonclonal? Adaptive immunity?
a. Nonclonal = innate
b. Clonal = adaptive
This is the accumulation of leukocytes. Phagocytic cells, plasma proteins, and fluid derived from the blood at an extravascular tissue site of infection or injury
Acute inflammation (innate)
What are the 2 principle types of reactions of the innate immune system?
a. Stimulate Acute inflammation
b. Anti-viral defenses
These are type 1 interferons
a. Interferon a/b
Anti-viral defenses in the innate system are mediated by
a. NK cells
b. Interferon a/b
NK cells mediate what?
a. The killing of virus-infected cells
These are secreted by virus-infected cells, bind to receptors on surrounding cells, and induce an anti-viral state in those cells
Interferons a/b
Can both the innate and adaptive immune systems share some of the same effector mechanisms?
Yes
Can both the innate and adaptive immune systems recognize nonmicrobial substances?
a. Yes
Does the innate or adaptive immune system have memory?
Adaptive
What are some examples of toll-like receptors?
a. Lipopolysaccharide b. Peptidoglycan
c. Lipopeptides
d. Flagellin
What are possible responses to the activation of toll-like receptors?
a. Acute inflammation
b. Activate adaptive immunity
c. Antiviral state
d. Macrophage/neutrophil activity
NOd-like receptors (NLRs) recruit what complexes?
Inflammasomes that promote inflammation
These are a family of cytosolic proteins that recognize PAMPs and DAMPs and recruit inflammasomes
a. NOD-like receptors
These are cytosolic sensors of viral RNA that respond to viral nucleic acids by inducing the production of the antiviral type 1 interferon
RIG-like receptors
What are the components of the innate immune response?
a. Epithelial barrier
b. Phagocytes (neutrophils/macrophages)
c. Dendritic cells
d. Mast cells
e. Lymphoid cells
f. Complement system
g. NK cells
What types of phagocytes are in the innate immune system?
a. Neutrophils
b. monocytes/macrophages
These are circulating phagocytic cells in the innate immune system
Neutrophils
This is the most abundant leukocyte blood and the 1st cell type to respond to most infections
Neutrophils
Blood monocytes differentiate into ______ after entering tissues
Tissue macrophages
These secrete cytokines that induce inflammation and ingest and destroy microbes in the innate
immune system
Macrophages
Describe how long neutrophils and macrophages survive in tissues
a. Neutrophils = short few hours
b. Macrophages = long time
These are also referred to as “sentinel cells”
Dendritic cells
These secrete cytokines and present antigenic peptides to T cells
Dendritic cells
These are present in the skin and mucosal epithelium
Mast cells
Mast cells contain what? And cause what?
a. Vasoactive amines
b. Vasodilation and capillary permeability
These are lymphocyte-like cells
Innate lymphoid cells
These produce cytokines but lack T cell antigen receptors (TCRs)
Innate lymphoid cells
This system induces inflammation, opsonizes microbes enhancing their phagocytosis and causes osmotic lysis of microbes
Complement system
What are the pathways that activate the complement system?
a. Alternative pathway
b. Classical pathway
c. Lectin pathway
What initiates the alternative pathway?
Microbe
What initiates the classical pathway?
Antibody
What initiates the lectin pathway?
Mannose-binding lectin
C3a =
Inflammation
C3b =
Opsonization and phagocytosis
C5a =
Inflammation
C6-9 =
Lysis of microbe
These kill virus-infected cells
NK cells
These secrete interferon y (gamma) which activates macrophages
NK cells
Do NK cells directly bind to pathogens and kill them?
No
When the inhibitory receptor is not engaged, what does NK cell do?
Activated, kills the infected cell
NK cell’s inhibitory receptors engage what?
Self-antigens presented on an interacting cell X
These are secreted by virus-infected cells and induce an anti-viral state in surrounding cells
IFN a/b
When the inhibitory receptor is engaged, what does NK cell do?
Not activated
How many signals are required for lymphocyte activation in the innate immune system?
2 signals
