Exam 1: Innate Immunity Flashcards
What are the 3 barriers of innate immunity?
- Physical barriers
- Humoral Barriers ( comp. system)
- Cellular barriers (NK cells, Phagocytic cells)
What are the 3 defense factors of Physical barriers
- Mechanical
- Chemical
- Microbiological
What is the most important humoral factor of the innate immunity?
Complement system
Activation of the coagulative system causes what?
blood coagulation at site of damage preventing entry of bacteria
What is beta-lysine?
substance produced by platelets that has a bactericidal effect against g+ bacteria during the coagulation process
Why is lactoferin produced during coagulation?
sequesters iron and bacteria cannot grow without Fe
Enzyme released during coagulation that digests the bacterial cell wall?
Lysozyme
Released during Coagulation adn inhibits the replication of viruses.
Interferons
Responsible for the inc. in temp. during inflammation and induces acute phase proteins which are bactericidal.
Interleukin 1
What are the cellular barriers of the innate response?
- NEutrophils
- Macrophages
- NK and LAK cells
- Eosionophils
What are the two vital cells of the phagocytic system?
- Neutrophils
2. Macrophages
The most numerous innate immune cell
Neutrophils
What is expressed on the surface of neutrophils
CD66
What two types of granules are found in neutrophils?
- Azurophilic granules
2. Secondary granules
What 4 substances are found in the Azurophilic granules of neutrophils?
- Defensins
- Proteolytic enzymes
- Lysozyme
- Myeloperoxidase
What 3 substances are found in the secondary granules of neutrophils?
- Lysozyme
- Lactoferin
- NADPH Oxidase
What is the importance of NADPH oxidase found in the secondary granules of neutrophils
for the production of toxic radicals
What is expressed on the surface of macrophages?
- CD14
- CD11b
- F4/80
T/F. Macrophages do not posses granules, but instead have lysosomes.
T
What do macrophages react to?
Danger signals(SOS)
What are the 4 danger signals macrophages respond to?
- N-Formyl-methionine
- Peptides
- Complement
- Cytokines
Wht are the 4 receptors found on a phagocytes?
- Fc receptors
- Complement receptors
- Scavenger receptors
- TLR
What is the role of the Fc receptor in phagocytes?
to bind to the fc region of the antibody and enhance metabolic activity of the phagocyte
What do complement receptors on phagocytes bind to?
C3b bind to bacterium and then binds to phagocyte
What do scavenger receptors on phagocytes bind to?
polyamines found on bacterial surfaces
What do TLRs recognize?
PAMPs
The active process of capturing and ingesting foreign objects/microorganisms by phagocytes.
Phagocytosis
What are the 4 functions of phagocytosis
- Destroy microorganisms
- remove damaged cells
- production of cytokines for inflammatory rxn
- process and present antigens
What are the two killing pathways of neutrophils, monocytes, and macrophages?
- Oxidative pathway
2. Non- oxidative pathway
Which pathway of intracellular killing is dependent on ROS and RNS
Oxidative pathway
Which pathway of intracellular killing is dependent on lysosomal toxic substances?
Non-Oxidative pathway
What are the 4 mechanisms of the non-oxidative intracellular killing pathway?
- Cationic proteins
- Lysozyme
- Lactoferrin
- Proteolytic and hydrolytic enzymes
Natural or innate immune system receptors that recognize molecular patterns produced by microorganism
PRR
Repetitive motifs of molecules such as lipopolysaccharide, peptidoglycan, etc. expressed on microbial pathogens and not found on host tissues
PAMP
Endogenous molecules released from damaged cells
DAMPs
Major PRRs located on host cell membranes or withing the host cells that signal the presence of invaders in innate immune response
TLRs
What is the endpoint of signalling by TLRs?
production of proinflammatory cytokines
What are NOD like receptors (NLR)
found inside cell
detect pathogens in cytoplasm
What are the two types of NOD like receptors
- NOD 1
2. NOD 2
What does NOD1 recognize
bacterial peptidoglycans
What does NOD2 recognize?
muramyl dipeptides
WHich receptors are expressed in the cytoplasm and detect viral RNA?
RIG like receptors
Receptors that bind to carbohydrates and are involved in fungal recognition
C type lectin receptors (CLRs)
Found in the large granules of neutrophils, these receptors detect microbial peptidoglycan and induce production of defensisn
PGRPs
Where are PGRPs found in pigs?
on the skin, bone marrow, and intestines
Changes in serum protein during infection
Acute phase response
Which of the following types of immunity are animals born with and is functional at birth?
a. adaptive immunity
b. acquired immunity
c. specific immunity
d. innate immunity
d. innate immunity
Which of the following statements is not true?
a. innate immunity is directed specifically to the infectious agent
b. innate immunity is not affected by prior exposure to the agent
c. innate immunity is not acquired, it is inherited
d. innate immunity operates constantly to prevent the establishment of any infection
a. innate immunity is directed specifically to the infectious agent
Will the innate immune system respond with the same level of response each time it is presented with a certain bacteria?
a. the initial response is weak
b. the second response is weaker than the first
c. the level of response will be the same b/c innate responses are not specific
d. only the initial response is the strongest
c. the level of response will be the same
T/F. Often in the innate immune system, one or multiple cells can recognize the same microorganism
T
T/F. The innate immune response is more specific than the adaptive immune response.
F
What receptors do neutrophils and macrophaes use to recognize microbial patterns?
a. TLR
b. Mucosal Receptors
c. Adrenoceptors
d. Cytokine receptors
a. TLR
Which of the following statements reguarding innate immune mechanisms is true?
a. innate immunity is activated by recognition of pathogen associated molecular patterns (PAMPs)
b. Innate immunity is effected only against bacteria
c. all of the cells in the innate immune system are phagocytic
d. Activation of innate immunity leads to the development of an memory component that is more effective upon second encounter with the same pathogen
a. innate immunity is activated by recognition of PAMPs
An enzyme found in tears and saliva that degrades the peptidoglycan of the cell wall of bacteria
a. amylase
b. lysozyme
c. keratinase
d. streptokinase
b. lysozyme
Protein found in neutrophils and macrophages and other body secretions that binds iron, thus making it unavailable for microbial growth is called:
a. lysozyme
b. peroxidase
c. lactoferin
d. complement protein
c. lactoferin
