RN Immunologic System and Infectious Diseases EAQ-
Verified Solution
contraction/homeostasis - ANSWER: Body's immune system goes back to___and
some of the lymphocytes that are no longer being stimulated by antigen are not
needed and begin to die by apoptosis (programmed cell death)
regulatory T cell - ANSWER: Antigen-specific CD4 T-cell that functions to suppress or
limit immune responses
Suppress CD4 and CD8 T cell effector functions
Identified by expression of CD3, CD4, CD25, FOXP3
When activated, produce IL-10, TGF-B (anti-inflammatory cytokines)
lymphocyte tissue distribution - ANSWER: Lymph nodes > spleen > bone marrow =
intestines > lungs > skin > blood = liver
germinal center - ANSWER: Center region of lymphatic nodule of a lymph node
where lymphocytes mature
Contain rapidly dividing B cells
chemokines - ANSWER: Type of cytokine
Attract leukocytes to site of inflammation
innate immunity - ANSWER: Immediate, always present in body
Specificity for structures shared by classes of microbes or damaged cells
Limited diversity of receptors
Nonclonal-identical receptors on all cells of same lineage
Memory cells respond in same way every time
Stimulated by pathogen-associated molecular patterns (PAMPs)
adaptive immunity - ANSWER: Delayed speed of response
Highly defined specificity
Two types of receptors but with high diversity
Clonal-clones of lymphocytes with distinct specificities express different receptors
Memory cells remember and respond quicker and stronger
pattern recognition receptors (PRRs) - ANSWER: Recognize highly conserved,
repetitive structures
Recognize essential microbial products --> micros cannot mutate to evade innate
immunity
Located in distinct cellular compartments (cytosol, extracellular, endosome)
toll-like receptors - ANSWER: Present at cell surface and in endosomal
compartments, avoid attaching host structures
Each binds a different class of microbial structures
Specific for different components of microbes
,Cell surface - microbial proteins, lipids, polysacchrides
Endosome - nucleic acids of digested microbes
ex. NFkB, IRFs
C type lectin receptors (CLRs) - ANSWER: Class of PRRs
In plasma membrane
Recognize carbohydrates, some specific viruses
retinoic acid inducible gene (RIG) I like receptor (RLRs) - ANSWER: Class of PRRs
In cytoplasm
Recognize viral RNA
Induces type I interferon production
DNA sensors - ANSWER: Class of PRRs
In cytoplasm
Recognize viral DNA
Induces type I interferon production
ex. AIM2, DHX9
NOD like receptors - ANSWER: Class of PRRs
In cytoplasm
Sense DAMPs and PAMPs
NOD1/2 - recognize bacterial peptidoglycans
NLRPs - recognize multiple structures, enhances production of IL-1B (inflammatory
cytokine
- gain of function mutation --> autoinflammatory syndromes
inflammasome - ANSWER: NLRP3 + adaptor + capase 1
Recognize substance --> oligomerizes with adaptor protein + inactive capase 1 -->
active capase 1 --> cleave pro-IL-1B --> active IL-1B --> acute inflammation
intraepithelial T lymphocytes - ANSWER: T cells but express antigen receptors of
limited diversity
Recognize microbial lipids and shared structures
Express gamma, delta receptors/chains
Patrol epithelial layers
neutrophils - ANSWER: Most abundant blood leukocytes (PMNs)
First responders to site of infection
Rapid turnover/short lifespan
Develop from bone marrow stem cells
Recruited by granulocyte colony stimulating factor (G-CSF)
Up to 20 k/ul during infection
Low numbers - more susceptible to infections
monocytes - ANSWER: Less abundant in blood (.5-1 k/ul)
Ingest microbes in blood and tissue
, Differentiate into macrophages in tissues
Survive for long periods of time
macrophages - ANSWER: 1. resident - been in tissues since development, plays roll in
homeostasis
- liver, brain, lungs
2. monocyte derived
Produce cytokines that induce and regulate inflammation
Ingest and destroy microbes
Clear dead tissues and initiate tissue repair
respiratory burst - ANSWER: Activation of NADPH oxidase complex reacts with O2 to
create/rapidly release ROS to kill microbes
Plays role in creation and neutralization of ROS
dendritic cell - ANSWER: Produce cytokines to initiate inflammation and activate T
cell lymphocytes
Triggered by PAMPs, DAMPs
Found in tissues, epithelium lymphoid organs
Bridge between innate and adaptive immunity
mast cells - ANSWER: Bone-marrow derived cells found in skin and mucosal
epithelium
Activated by PAMPs, DAMPs
Contain amines that cause vasodilation and increased capillary permeability
Proteolytic enzymes that can kill bacteria or inactive microbial toxins
Lipid mediates (prostaglandins) and cytokines (TNF) --> inflammation
Bind to IgE antibody to produce allergic reactions
innate lymphoid cells - ANSWER: Do not express T cell antigen receptors
Perform similar functions - secrete cytokines, can directly kill cells
Differentiate in response to environmental cues
natural killers cells (NKs) - ANSWER: Part of innate immune system
Kill cells when exposed to nonspecific activation signal on target cell or absent MHC I
molecule
Also kills by ADCC (Fc binds to CD16/FcyIII)
Activity enhanced by IL-2, IL-12, IFN-a, IFN-B
Contain abundant cytoplasmic granules --> induce apoptosis in target cells via
perforin and granzymes
Activation controlled by balance of activating (NKG2D, CD16) and inhibitory (KIRs)
receptors
complement system - ANSWER: System of hepatically synthesized plasma proteins
that play a role in innate immunity and inflammation
May proteins are enzymes that produce reactive proteins
Verified Solution
contraction/homeostasis - ANSWER: Body's immune system goes back to___and
some of the lymphocytes that are no longer being stimulated by antigen are not
needed and begin to die by apoptosis (programmed cell death)
regulatory T cell - ANSWER: Antigen-specific CD4 T-cell that functions to suppress or
limit immune responses
Suppress CD4 and CD8 T cell effector functions
Identified by expression of CD3, CD4, CD25, FOXP3
When activated, produce IL-10, TGF-B (anti-inflammatory cytokines)
lymphocyte tissue distribution - ANSWER: Lymph nodes > spleen > bone marrow =
intestines > lungs > skin > blood = liver
germinal center - ANSWER: Center region of lymphatic nodule of a lymph node
where lymphocytes mature
Contain rapidly dividing B cells
chemokines - ANSWER: Type of cytokine
Attract leukocytes to site of inflammation
innate immunity - ANSWER: Immediate, always present in body
Specificity for structures shared by classes of microbes or damaged cells
Limited diversity of receptors
Nonclonal-identical receptors on all cells of same lineage
Memory cells respond in same way every time
Stimulated by pathogen-associated molecular patterns (PAMPs)
adaptive immunity - ANSWER: Delayed speed of response
Highly defined specificity
Two types of receptors but with high diversity
Clonal-clones of lymphocytes with distinct specificities express different receptors
Memory cells remember and respond quicker and stronger
pattern recognition receptors (PRRs) - ANSWER: Recognize highly conserved,
repetitive structures
Recognize essential microbial products --> micros cannot mutate to evade innate
immunity
Located in distinct cellular compartments (cytosol, extracellular, endosome)
toll-like receptors - ANSWER: Present at cell surface and in endosomal
compartments, avoid attaching host structures
Each binds a different class of microbial structures
Specific for different components of microbes
,Cell surface - microbial proteins, lipids, polysacchrides
Endosome - nucleic acids of digested microbes
ex. NFkB, IRFs
C type lectin receptors (CLRs) - ANSWER: Class of PRRs
In plasma membrane
Recognize carbohydrates, some specific viruses
retinoic acid inducible gene (RIG) I like receptor (RLRs) - ANSWER: Class of PRRs
In cytoplasm
Recognize viral RNA
Induces type I interferon production
DNA sensors - ANSWER: Class of PRRs
In cytoplasm
Recognize viral DNA
Induces type I interferon production
ex. AIM2, DHX9
NOD like receptors - ANSWER: Class of PRRs
In cytoplasm
Sense DAMPs and PAMPs
NOD1/2 - recognize bacterial peptidoglycans
NLRPs - recognize multiple structures, enhances production of IL-1B (inflammatory
cytokine
- gain of function mutation --> autoinflammatory syndromes
inflammasome - ANSWER: NLRP3 + adaptor + capase 1
Recognize substance --> oligomerizes with adaptor protein + inactive capase 1 -->
active capase 1 --> cleave pro-IL-1B --> active IL-1B --> acute inflammation
intraepithelial T lymphocytes - ANSWER: T cells but express antigen receptors of
limited diversity
Recognize microbial lipids and shared structures
Express gamma, delta receptors/chains
Patrol epithelial layers
neutrophils - ANSWER: Most abundant blood leukocytes (PMNs)
First responders to site of infection
Rapid turnover/short lifespan
Develop from bone marrow stem cells
Recruited by granulocyte colony stimulating factor (G-CSF)
Up to 20 k/ul during infection
Low numbers - more susceptible to infections
monocytes - ANSWER: Less abundant in blood (.5-1 k/ul)
Ingest microbes in blood and tissue
, Differentiate into macrophages in tissues
Survive for long periods of time
macrophages - ANSWER: 1. resident - been in tissues since development, plays roll in
homeostasis
- liver, brain, lungs
2. monocyte derived
Produce cytokines that induce and regulate inflammation
Ingest and destroy microbes
Clear dead tissues and initiate tissue repair
respiratory burst - ANSWER: Activation of NADPH oxidase complex reacts with O2 to
create/rapidly release ROS to kill microbes
Plays role in creation and neutralization of ROS
dendritic cell - ANSWER: Produce cytokines to initiate inflammation and activate T
cell lymphocytes
Triggered by PAMPs, DAMPs
Found in tissues, epithelium lymphoid organs
Bridge between innate and adaptive immunity
mast cells - ANSWER: Bone-marrow derived cells found in skin and mucosal
epithelium
Activated by PAMPs, DAMPs
Contain amines that cause vasodilation and increased capillary permeability
Proteolytic enzymes that can kill bacteria or inactive microbial toxins
Lipid mediates (prostaglandins) and cytokines (TNF) --> inflammation
Bind to IgE antibody to produce allergic reactions
innate lymphoid cells - ANSWER: Do not express T cell antigen receptors
Perform similar functions - secrete cytokines, can directly kill cells
Differentiate in response to environmental cues
natural killers cells (NKs) - ANSWER: Part of innate immune system
Kill cells when exposed to nonspecific activation signal on target cell or absent MHC I
molecule
Also kills by ADCC (Fc binds to CD16/FcyIII)
Activity enhanced by IL-2, IL-12, IFN-a, IFN-B
Contain abundant cytoplasmic granules --> induce apoptosis in target cells via
perforin and granzymes
Activation controlled by balance of activating (NKG2D, CD16) and inhibitory (KIRs)
receptors
complement system - ANSWER: System of hepatically synthesized plasma proteins
that play a role in innate immunity and inflammation
May proteins are enzymes that produce reactive proteins
