Zachary + Notes Flashcards
(249 cards)
1
Q
Fibronectin
A
Surface protein, plays a role in cell-to-cell and cell-to ECM interactions
2
Q
Ligand
A
extracellular signal
3
Q
What do the rER/golgi complex and smooth ER synthesize
A
rER and golgi complex synthesize proteins and glycorproteins
smooth ER synthesis of lipids, steroids, and carbohydrates
4
Q
Function and examples of second messengers
A
Ca, cAMP, cGMP, inositol triphosphate, diacyclglycerol, arachidonic acid and NO
initiate an intracellular signal transduction cascade that stimulates or alters a metabolic pathway. Translates “first messages” from the plasma membrane into specific actions within the cell and its organelles to maintain homeostasis or defend against infection/injury
5
Q
Uncoiled chromatin is called?
A
Euchromatin
Dispersed throughout the nucleus and actively involved in production of messenger RNA (mRNA)
6
Q
Tightly coiled chromatin is called?
A
Heterochromatin
Clumped around the inner nuclear membrane and is inactive
7
Q
What is the site of transcription?
A
Nuelcolus
also processes rRNA
consists of ribosomal DNA, RNA, and ribosomal proteins including RNA polymerases imported from teh cytosol
8
Q
Function or rER?
A
Protein synthesis
Translation of mRNA with assembly of amino acids into peptides begins on ribosomes that are free in teh cytosol
**cells that produce abundant protein and thus have abundant rER tend to have more basophilic cytoplasm because of the ample nucleic acid (RNA) in the ribosome
9
Q
Ribosomes function
A
Facilitate the synthesis of proteins in cells (translation)
Function is to translate information encoded in mRNA into polypeptide chains of amino acids that make up proteins
10
Q
sER function
A
NOT protein synsthesis
Involved in synthesis of lipids, steroids, and carbohydrates as well as the metabolism of exogenous substances such as drugs or toxins
cells w/ abundant sER have pale eosinophilic finely vacuolated cytoplasm
11
Q
Lysosomes contain _______
Peroxisomes are specialized for _________
A
Acid hydrolases that can digest most chemical compoounds
B-oxidation of fatty acids and degradation by catalse of of the H2O2 produced
12
Q
Size/elements of cytoskeleton and function of each
A
- Actin microfilaments (6-7 nm). –> facilitate cell motility (ameboid movement [ chemotaxis ], cilia, pseudopodia)
- Intermediate filaments (10 nm) –> facilitate physical strength and shape of cells and tissues
- Microtubules (25 nm). –> move organelles and vesicles within the cytosol of a cell and chromosomes via mitotic spindles during cell division
13
Q
What connects each type of cell-to-cell junction?
A
Tight junctions - protein complex
Gap junctions - connexon
Adherens junction - vinculin and cadherin
Desmosome junction - attachemtn plaque and desmogleins
Hemidesmosome junction - desmopenetrin
14
Q
What mutation is linked to CKCKs an dBrussels griffons (brachycephalic dz)
A
Missense mutation in bone morphogenetic protein 3 (BMP3)
15
Q
MOA of hypoxia and effects at cellular level?
A
Cellular oxygen depleted –> oxidative phosphorylation stops –> cell moves to anaerobic metabolism (e.g. glycolysis) or dies
As ATP production declines –> drop stimulates hexokinases, phosphofructokinase 1 (PFK1)
…PFK1 catalyzes phosphorylation of fructose 6-phosphate to fructose 1,6 biphosphate
End products of glycolysis = heat, ATP, pyruvate
16
Q
MOA of cell swelling w/ hypoxia/ischemia?
A
Deficiency of ATP causes failure of Na/K-ATPase pumps w/ influx of Na, Ca, and water into the cytosol and loss of K and Mg from the cytosol
Switch to anaerobic metabolism w/ production of ATP (and pyruvate) through gycolysis
- Glycolysis depletes cellular glycogen, leads to an accumulation of lactate w/ decreased intracellular pH, and produces heat which may cause cell injury
17
Q
Describe assembly of MAC
A
Enzymatic cleavage of C5b from C5
C6 binds to C5b
C7 binds to C5bC6 –> lipophilic
alpha, beta, gamma subunits of C8 bind –> MAC penetrates nearby cell membrane lipid layer
Binding and oligomerization of C9 then complets formation of the MAC –> lytic pore
CD59 protects leukocytes, epithelial cells, enothelial cells by blocking penetration of C5b-8 precursors and blocks incorportation of C9 into the MAC and protects host cells against cell membrane injury
18
Q
Caspases in apoptosis
A
Caspases are cysteine proteases that cleave peptides after aspartate residues
Initiator caspases (caspase-8) activated by death-inducing signaling complex of the extrinsic pathway
Caspase 9 activated w/ apoptosome in teh intrinsic pathway
Caspase 2 activated by p53 following DNA damage
Initiator caspases activated effector caspase 3, 6, and 7 that execute apoptosis
19
Q
Players in extrinsic (death receptor-initiated) vs intrinsic (mitochondrial pathway)
A
Extrinsic: TRADD, FADD, RIPK1, Caspase 8 –> caspase 3, 7; Bak (Bcl-2) Bax (Bcl-2)
Intrinsic: MOMP, BH3only proteins (proapoptotic proteins), Caspase 9, Apaf-1, AIF (apoptosis-inducing factor)
Execution phase - initator caspases (2,8,9 or 10) cleave the downstream effector (executioner) mainly 3,6,7
20
Q
Cell cycle check points and Cyclin D?
A
Cells enter G1 in response to growth factors that also cause accumulation of cyclins whose roles are to modulate the progress of G1
Cyclin D activation of CDK4/6 results in phosphorylation of retinoblastoma (RB) protein –> release the transcription factor E2F and enables the cell to pass through the so called restriction point in G1
2nd check point at G2M –> if DNA is incorrectly replicated in the S phase or if the mitotic spindle is not properly formed in the M phase –> growth arrest
21
Q
Describe the various types of endocytosis
A
Caveolae-mediated: caveolae are noncoated plasma membrane invaginations (caveolin)
- fluid, membrane proteins and some receptor bound molecules (e.g. folate)
Pinocytosis and receptor-mediated: clathrin-coated pit that invaginates –> pinches off, and fuses with endosome macromolecules
- pinocytosis = clathrin coated pit*
- most surface receptor-ligand pairs
22
Q
Compare/contrast size of cytoskeleton elements
A
Actin microfilaments = 5-9 nm
Intermediate filaments = 10 nm
Microtubules = 25 nm
23
Q
Compare/contrast function of cytoskeleton elements
A
Actin microfilaments - formed from globular protein actin (G-actin) - most abundant cytosolic protein in cells. G-actin –> form F-actin.
Intermediate filaments - lamin A, B, and C; vimentin, desmin, neurofilaments, glial fibrillary acidic protein, cytokeratins. Impart tensile strength and allow cells to bear mechanical stress.
Microtubules - alpha and beta tubulin; constantly enlongating/shrinking hollow tube w/ defined polarity. FXN = mitosis –> chromatid separation during mitosis
24
Q
MOA of Wnt/Frizzled
A
Wnt protein ligands, regulate intracellular levels of beta-catein
Wnt binds to Frizzled –> recruitment of Disheveled –> leads to disruption of degradation-targeting complex –> allowing beta-catenin to translate to the nucleus
beta-catenin then migrates to the nucleus and acts as a transcription factor
25
Function of MYC and JUN>
transcription factors that regulate expression of genes needed for growth
26
p53 function
regulates expression of genes that lead to growth arrest
27
Where does antithrombin III act
Factor X and IIa
28
Which cyclin-dependent kinases regulate each part of the cell cycle?
D-CDK4, D-CDK6, and E-CDK2 regulate G1-S transition by phosphorylating the Rb protein
Cyclin A-CDK2 and A-CDK1 are active in S phase
Cyclin B-CDK1 essential for G2-M transition
**INK4 inhibitors (p16, p15, p18, p19) act on cyclin D-CDK4 and D-CDK6 (G1-S transition)** all other inhibitors can inhibit ALL CDKs
29
What is the function of catalase (w/ ROS)
Catalase is located in peroxisomes and decomposes H2O2
30
Function of SOD w/ ROS
converts superoxide to hydrogen peroxide
Manganese - SOD (mitochondria)
Copper - zinc - SOD: (cytosol)
31
Glutathione peroxidase function in ROS
protects against injury by catalyzing free radical breakdown
32
Mechanisms of cellular sensecence
Telomere attrition - progressive shortening of telomeres results in cell cycle arrest
Activation of tumor suppressor genes - CDKN2A locus seems to be involved in controlling replicative senescence, encodes p16 (INK4a)
33
Adhesion molecules involved in migration through the endothelium?
PECAM (CD31)
JAM A, B, C
CD99
34
Endogenous chemoattractants for neutrophils?
IL-8
C5a
LTB4
35
Macrophages contain?
```
acid hydrolases
collagenase
elastase
phospholipase
plasminogen activator
```
36
Eosinophils contain
major basic protein = cytotoxic to parasites
37
Alpha1 antitrypsin
major inhibitor of neutrophil elastase
38
Alpha 2 macroglobulin
plasmin inhibitor
39
Describe teh 3 functions of the complement system
1. Inflammation - C3a, C5a and lesser extent C4a (anaphylatoxins) = cleavage products stimulate histamine release, increasing vascular permeability and causing vasodilation.
C5a = chemoattractant for neutrophils, monocytes, eosinophils, and basophils
C5a activates lipoxygenase pathway of AA metabolism
2. Opsonization and phagocytosis
C3b acts as opsonins adn promote phagocytosis by neutrophils and macrophages
3. Cell lysis - deposition of the MAC on cells makes these cells permeable to water and ions and results in death (lysis) of the cells
40
Which complement component acts as an opsonin?
C3b
41
Inhibitors of complement?
C1 inhibitor (C1 INH) - block activation of C1, the first protein of the classical pathway
Decay accelerating factor (DAF) and CD59
- DAF prevents formation of C3 convertases
- CD59 inhibits formation of membrane attack complex
42
What in hibits formation of MAC?
CD59
43
Function of C3a and C5a
Function of C5a
Function of C3b
C3a and C5a = anaphylatoxins
C5a = chemotactic fragments
C3b = opsonins
44
TFPI, protein C and thrombomodulin are pro or anti-coagulant
Anticoagulant
45
What coats intracytoplasmic vesicles?
Protein caveloin
46
Prostacyclin
Vasodilator
Formed by endothelial cells from arachidonic acid by a processes catalyzed by prostacyclin synthase.
Prevents adhesion of platelets to the endothelium and avoids blood clot formation
47
Factors secreted by endothelial cells that result in smooth muscle contraction and relaxation
Relaxation - NO (vasodilation)
Contraction - endothelin-1 (vasoconstriction)
48
Opsonization
mannose-binding lectin and C-reactive protein
49
Which parts of the complement system activate the innate immune system and which opsonize?
Alternative and lectin pathways = innate
Mannose-binding lectin and C-reactive protein = opsonization
50
what is the inflammasome
Protein complex that recognizes products of dead cells and some microbes and induces the secretion of biologically active interleukin 1
Inflammasome consists of a sensor protein ( a leucine-rich protein called NLRP3), an adapter and the enzyme caspase-1
51
What does the NLRP3 inflammasome need for activation?
Signal 1 - TLR signaling and NF-kB mediated upregulation of NLRP3 and pro-forms IL-1beta and IL-18
Signal 2 - sensing of aforementioned stimuli resulting in aggregation of NLRP3 proteins and co-localization with ASC (apoptosis-associated speck-like protein) containing a carboxy-terminal caspase activation and recruitment domain
**activated caspase-1 cleaves pro-forms IL-1beta and IL-18 and induces pore formation via the inflammasome protein gasdermin D --> pyroptosis
52
Describe the signaling pathway for TLR4
LPS binds to CD14 part of TLR4. --> AP-1 and NFkB --> transcription
53
Cell surface markers of NK cells?
CD16
CD56
**do not express TCR or Ig**
54
Do ILCs lack TCRs?
Yes
55
What are MHCs called in humans?
HLA (human leukocyte antigens)
56
Compare/contrast MHC I vs MHC II
MHC I molecules - expressed on ALL nucleated cells and platelets
- alpha heavy chain (a1, a2, a3; a3= binding site for CD8+ T cells)
MHC II - expressed on cells that present ingested antigens and respond to T-cell help (macrophages, B lymphocytes, dendritic cells)
- B2 domain is bonding site for CD4+ T lymphocytes
57
What are the costimulators of antigen presenting cells?
B7 proteins (CD80 and CD86) expressed on APCs are recognized by CD28 receptor on naive T cells
58
Function of IL-4
Acts on B cells to stimulate class switching to IgE
Promotes development of additional Th2 cells
59
Function of IL-5
Eosinophilc development and activation
60
Function of IL-13
Enhances IgE production
Acts on epithelial cells to stimulate mucus secretion
61
How are mast cells activated?
Cross-linking of high affinity IgE Fc receptors
C5a and C3a (anaphylatoxins) bind to receptors on mast cells
62
Which part of complement results in opsonization
C3b
63
If antigen is presented to T cells w/o adequate levels of costimulators ______ the cells become _____
CD28
anergic
64
What is the function of CTLA-4 and PD-1
Cytotoxic T lymphocyte sassociated antigen and programmed death (PD-1) immune checkpoints are negative regulators of T cell immune function
Function in peripheral tolerance
CTLA4 is a CD28 homolog w/ higher binding affinity for B7
PD-1 is a member of the B7/CD28 family of costimulatory receptors
**think of them as the second signal for T cell activation as they downregulate T-cell activation to maintain peripheral tolerance and can be exploited by tumors to induce an immunosuppressive state that allows tumors to grow and develop instead of being eliminated by the immune system**
CTLA4 and PDL1 inhibitors are used in certain cancers to limit growth
65
Function of Gasdermin D
Executioner of pyroptosis
Was thought to be a substrate of caspase-1 but has been identified in caspase-1 and caspase-11 mediated activation of pyroptosis
66
Function of PI3K/Akt pathway
Normally promotes cellular survival
67
List proinflammatory eicoanoids
Prostaglandins
Thromboxanes
Leukotrienes
**are part of the "eocosanoid storm"
68
Lists cytokines mainly involved in the "cytokine storm"
IL-6
IL-1beta
TNF-alpha
69
What are the types of monocytes?
Classical : CD14++ and CD16-
- anti-inflammatory due to having highest production of IL-10
Nonclassical: CD14+ and CD16++
- express genes associated w/ cytoskeletal rearrangement, allowing for partolling behavior along the endothelium to survey tissues, very little secretory activity (only triggered by viruses or nucleic acids)
Intemrediate: CD14++ and CD16+
- greatest inflammatory potential and are the greatest producers of ROS, highest expression of MHC-complex II, strong capability of inducing CD4+ T cell proliferation. Some studies say they are robust producers of IL-10
70
What in nucleated mammalian cells resists MAC lytic killing?
CD46
CD55
CD59
71
w/ complement what cleaves C5?
C3b cleaves C5 to yield C5a and C5b
72
What are the three regions that composes MAC?
Asymmetric region - C5b, C6, C7, C8
Hinge region - C7, C8, two C9
C9 oligomer
73
MOA of MAC activation of the inflammasome?
MAC signaling activates NLRP3 inflammasome
--> activation of caspase-1
processes the proproteins into active IL-1beta and IL-18
74
Where is vWF synthesized?
Endothelial cells and megakaryocytes
75
What regulates transcription of the vWF gene in endothelial cells?
Endothelial-specific cis-acting promoter regions in GATA, Ets, H1, and NFAT5
**NO evidence that transcription of the vWF gene is regulated by inflammatory cytokines and the JAK-STAT signaling pathway**
76
Where is ADAMTS13 synthesized?
Liver
some evidence to say skeletal muscle, heart, and placenta
77
Anticoagulatant factors of the endothelium?
Antithrombin
TFPI
Protein C
78
MOA of intravascular coagulation in septic conditions
1. Downregulation of endothelial thrombomodulin
2. Decline of plasma anticoagulant proteins (TFIP, AT)
3. Activated endothelial cells and leukocytes --> produce Tissue Factor
4. NETs provide a scaffold for intravascular coagulation by activating the intrinsic pathway, facilitating FXa-mediated thrombin generation and inactivating TFPI
5. Upregulation of fibrinolysis inhibitors (PAI-1 and TAFI)
**recombinant thrombomodulin and antithrombin gamma are potential therapeutic agents that may restore anticoagulant potential w/in the septic microcirculation**
79
Platelet binding - site for vwf and collagen
vwf - G1b - V - IX
collagen - GPVI
80
What is the binding of platelets that sets off NETosis
Platelet CD40L binds to its receptor CD40 on neutrophils --> results in beta2 integrin activation, promoting initiation of the oxidative burst, which can be a key driver of NET formation
81
Mechanism of ITP
Autoantibodies targeting platelet surface glycoproteins --> clearance by mononuclear phagocytic system (antibody-mediated destruction)
T cells play a central role in platelet destruction in ITP
- proinflammatory Th1, Th17, Th22 predominates
```
Immune regulators (e.g. T and B regulatory cells) are dysfuntional in ITP
- reduction in Treg
```
82
Gene involved in congenital macrothrombocytopenia
B1 tubulin gene mutation
83
Platelet receptors for fibrinogen, von willebrand, CD42d
GPIIb/IIIa - CD41/CD61, fibrinogen receptor
GP1b/IX - CD42c/CD42a, vWF
GPV. - CD42d
84
Low vs high shear stress platelet adhesion/receptors
Low shear stress - GPIIb - IIIa and fibrinogen
High shear stress - GPIb - IX - V and collagen
85
Platelet agonists responsible for shape change
```
ADP
Collagen
EPI
Thrombin
Thromboxane
PAF
```
86
Alpha vs dense granule contents (platelets also have lysosome granuels)
Alpha - Firinogen, Fibronectin, Factor V, FVIII, PDGF, Thrombospondin, vWF, P-select, TGF-Beta
Dense - think proaggregatng = iCa, ADP/ATP, GDP/GTP, serotonin, histamine, epinephrine
87
Main agonists for platelet aggregation?
```
ADP
TXA2
Thrombin
- binds GPIIb-IIIa receptor w/ ADP and TxA2
- converts fibrinogen to fibrin
```
88
What does ADAMTS13 do
Cleaves ultralarge multimers of vWF (ultralarge is what is initially released from endothelial cells and ADAMTS13 comes in and breaks up the multimer)
89
Receptor of Bernard-Soulier Syndrome
Inherited deficiency of GP1b-V-IX
90
Receptor of Glanzmann thbombasthenia
GPiiB-IIIa
91
Receptor for vWF deficiency
GpIV
92
Function of defensins/cathelicidins
Produced by neutrophils, macrophages, barrier epithelial
Amphipathic - microbicidal
WBC recruitmentment/activation
Bind/neutralize LPS
Stimulate wound healing
93
TLR3 use MYD88?
No, it does not use MYD88 adapter protein and uses TRIF
94
WHich TLR uses both adapter proteins MYD88 and TRIF
TLR4
95
Adapter protein of NOD-like receptors
CARD (caspase)
signals with end result NfKb to get transcription
96
What are the two NODs?
NOD1 - recognize proteoglycans of Gram negative
NOD2 - gram - and positive
**also recognize DAMPs**
97
Function of the 4 different type of macrophages
1. Red pump MO - phagocytose senescent RBC (iron processing)
2. Marginal zone - capture blood borne antigens
3. Metallophilic macrophages - produce type I interferons
4. Tingible body macrophage s- CD68, phagocytosis of apoptotic lyphocytes (autoimmune dz if these don't work well)
98
What are follicular dendritic cells
```
In germinal centers
DO NOT EXPRESS MHC CLass II (most APCs have MHC class II)
```
Express FcR and CR
Store and present Ag-Ab and Ag-C3b complexes to B cells
**Primary function = help with b cell memory**
99
Plasmacytoid DCs express?
DO NOT express CD11c or CD14
Express TLR7 (ssRNA), TLR9 (unmethylate CpG)
Produce large amounts of type I IFNs
100
What are the first and second signals w/ CD4 and CD8?
```
Signal 1 (CD4) = MHC Class II
Signal 2 (CD4) = CD28. (B7-1 CD80; B7-2 CD86)
```
```
Signal 1 (CD8) = MHC Class I
Signal 2 (CD8) = CD40L (CD40 on APCs)
```
**lack of signal --> apoptosis or anergy**
101
Types of Tregs?
Thymus derived (tTregs) - self-reactive and prevent autoimmune disease
Peripherally-induced (pTregs) - induced from CD4 T cells in response to specific cytokines, Ags, stimuli
**Neurophilin I marker**
102
FOX3P?
Important transcripitional marker of Tregs
103
B cell signals
Signal 1 - Ig-apha (CD79a) and Ig-beta (CD79b)
Signal 2 - CD21
**CD21 is also a complement receptor - so will also bind C3b and C3d**
**also binds CD40**
104
CTLA4 and PD-1
Induced on activated T cells, has a higher affinity for B7 so can cause competitive inhibition
PD-1 binds B7-H1 - also inhibits
**both used as cancer immunotherapy targets**
105
What is an example of a soluble PRR
Pentraxin
106
Which enzyme starts the arachidonic acid cascade?
Phospholipase A2
107
Which cytokine drives the differentiation of Th2 cells?
IL-4
108
Which types of immune hypersensitivites are antibody mediated?
Types 1, 2, and 3
Type 1 - immediate, IgE
Type 2 - ag-ab mediated, IgM, IgG
Type 3 - immune complex, IgG, IgM
109
What does IL-4 do to T cells
Produces Th2 cells
110
Receptor of autoimmune thrombocytopenic purpura
GpIIb : IIIa
111
Mechanism of positive selection for T cells
Clonal expaions of T cells that recognize MHC in thymus
112
Mechanism of negative selection/clonal deletion
Clonal deletion of T cells w/ TCRs that recognize self-Ag presented by APCs
Expression of self-Ag on medullary thymic epithelial cells stimulated by AIRE
Eliminated by Fas-FasL mediated apoptosis
Some self-reactive CD4+ T cells maintained as Tregs
113
Checkpoints w/ T cells??
If co-stimulatory signal CD28 binding CD80/86 on APCs is absent then T cells become unresponsive
Blockade of 2nd signals called "checkpoints"
- CTLA-4 binds B7 molecules w/ higher affinity and inhibits
- PD-1 binds ligants on wide varierty of cells-
114
Markers to find Tregs?
FOXP3
CD25 (IL-2R)
115
Factor H
part of inhibitory pathway
cofactor for Factor I
w/ deficiency get unreglated elaboration of C3b --> activation of alternative pathway
116
Chediak Higashi syndrome
Inherited mutation in Lyst gene
affects anything w/ granules
117
What stimulates movement of fluids and proteins through endothelial cells?
VEGF
118
How does IL-1, TNF and hypoxia result in endothelial cell gaps
Cytoskeletal reorganization of microtubules and microfilament proteins
119
Mediators for leukocyte adhesion
L-selectin and VLA-4. (LEUKOCYTE)
| s-Le^X AND VCAM-1. (ENDOTHELIAL)
120
Mediators for leukocyte rolling
L-selectin
E-selectin ligand-1 (ELS-1)
PSGL-1
121
What activates leukocyte integrins?
IL-8 and inflammatory cytokines (TNF, IL-1)
122
What results in stable adhesion in leukocyte adhesion?
L-selectin is cleaved by ADAM17 and leukocytes express integrins
B1/B2 integrins bind tightly to iCAM1/2 ligands on endothelial cells --> stable adhesion
123
What is associated w/ locomotion w/ neuts?
Mac-1 and iCAM-1 interactions
**cytoskeletal re-organization --> leukocytes spread out and "crawl" toward endothelial cell borders**
124
Factors involved in transendothelial migration
PECAM-1 (CD31)
CD99
JAMs
125
Leukocyte migration through ECM (chemotaxis) mediated by
mediate across areas of the BM w/ less type IV collagen and laminin 10 (path of least resistance)
Leukocytes express VLA-3 (binds ECM fibronectin)
Tail anchored by LFA-1 (binds iCAM-1 on endothelial cell or pericyte)
126
What is a critical mediator of proinflammatory monocyte adhesion
High mannose N-glycosylation of iCAM-1
127
List vasoconstrictors and vasodilators
out of..endothelial, angiotensin II, NO, prostacyclin
Vasoconstriction - endothelian, angiotensin II
Vasodilation - NO, prostacyclin (PGI2)
128
Granules in neutrohils?
Specific - lactoferrin, lysozyme, ALP, type IV collagnase, LADs, plasminogen activation, Phospholipase A2
Azurophilic - MPO. lysozyme, cationic proteins, acid hydrolases, elastase, nonspecific collagenase, BPI, defensins, cathespin G, phospholipase A2
129
Monocyte subtypes
Classical - CD14++, CD16-
-phagocytosis, microbial kiling and wound healing, produce high levels of IL-10
Non-classical: CD14+ / CD16++
- damage/infection
Intermediate: CD14++ / CD16+
- pro-inflammatory, express MHC-II --> CD4 T cell proliferation, produce ROS
- robust producers of IL-10
130
What is the most frequently mutated oncogenic pathway
Receptor tyrosine kinase
..downstream from TK is signal transucer RAS
...downstream of RAS is MAPK and PI3K/AKT pathway
131
List growth factor receptors
Tyrosine kinases (most important in cancer)
ERBB1 - encodes epidermal growth factor receptor (EGFR), point mutation in ertain cancers (lung adenocarcinomas)
ERBB2 - encode HER2, amplified in breast cancer
RAS
PI3K
MYC
D clcylins
132
What applies the breaks to RAS activation?
GAP
133
What applies the breaks to PI3K?
PTEN - inhibits growth
134
Function of CDK4 and D cyclins
Form a complex that phosphorylates RB, allowing the cell to progress through the G1 restriction point
135
CIP/KIP family (p21, p27 (CDKN1A-D)
Block the cell cycle by binding to cyclin-CDK complexes
p21 is induced by the tumor suppressor p53
p27 responds to growth suppresors such as TGF-beta
136
INK4/ARF famly (CDKN2A-C)
p16/INK4a binds to cyclin D-CDK4 and promotes the inhibitory effects of RB
p14/ARF increases p53 levels by inhibiting MDM2 activity
137
RB
Tumor suppressive "pocket" protein that binds E2F transcription factors in its hypophosphorylated state, preventing G1/S transition - also interacts w/ severe transcriptionf actors that regulate differentiation
138
p53
tumor suppressor
causes cell cycle arrest and apoptosis - acts mainly through p21 to cause cell cycle arrest
Causes apoptosis by inducing the transcription of pro-apoptotic genes such as BAX
Levels of p53 are negatively regulated by MDM2 through a feedback loop
p53 is required for the G1/S checkpoint and is a main component of the G2/M checkpoint
139
What is a protooncogene
normal cellular genes whose products promote cell proliferation
140
Oncogenes
mutated or overexpressed versions of proto-oncognees that function autonomously, having lost dependence on normal growth promoting signals
141
Examples of mutations in growth factor receptors
- EGF
- HER2
- JAK2
- ABL/BCR
- RAS point mutation
- PI3K/BRAF
Activation of the EGF receptor tyrosine kinase by point mutations (lung cancer)
Activation of HER2 receptor tyrosien kinase by gene amplification (breast cancer)
Activation of JAK2 tyrosien kinase by point mutatios (myeloproliferative disorders)
Activation of the ABL nonreceptor tyrosien kinase by chromosomal translocation and creation of a BCR-ABL fusion gene (CML, ALL)
Activation of RAS by point mutations (many cancers)
Activaiton of PI3K and BRAF serine / threonine kinases by point mutations (many cancers)
142
Mutated growth factor in lung cancer?
EGF receptor tyrosine kinase by point mutation
143
Mutated growth factor in breast cancer
HER2 receptor tyrosine kinase by gene amplification
144
MUtation of growth factor receptros in myeloproliferative disorders
JAK2 tyrosine kinase by point mutations
145
Mutation of growth factor receptor in CML and ALL
Activation of the ABL nonreceptor tyrosien kinase by chromosomal translocation and creation of BCR-ABL fusion gene
146
Many cancers cause a common mutation in a single growth factor receptor
Activation of RAS by point mutations
Activation of PI3K and BRAF serine/threonine kinases by point mutations
147
What is the key regulator of the G1/S cell cycle
RB
148
List the common growth factors and growth inhibitors
Growth Factors - EGF, PDGF
Growth Inhibitors - TGF-beta, p53
149
Describe MOA of RB
RB, when hypophosphorylated exerts antiproliferative effects by binding and inhibiting E2F transcription factors that regulate genes required for cells to pass through the G1-S phase cell cycle
w/ growth factor signaling --> RB hyperphosphorylated and inactivated --> promoting cell cycle progression
150
Relationship of CDK4 with RB
CDK4 along with CDK6 and E-CDK2 hyperphosphorylate RB --> results in release of E2F. -->activates transcription of S-[hase genes
**CDKinase inhibitors inhibit phorphorylation of RB - cell cycle will not continue/cell arrest when RB is hypophophorylated** so CDKinase inhibitors INHIBIT cell growth
151
MDM2 effects on p53
inhibition
152
How does p53 break away from the inhibition of MDM2
Protein kinases - ATM and ATR will stimulate phosphorylation of a number of proteins, including p53 and MDM2 --> disrupting the binding and degradation of p53 by MDM2 --> allowing p53 to accumulate
153
Are MAPK and PI3K/AKT pro growth or anti-growth pathways?
Pro-growth
154
How does p53 result in disrupting neoplastic growth/transformation?
Rapid onset cell cycle arrest
Senescence
Programmed cell death (pro-apoptotic genes BAX and PUMA)
155
Effect of the E6 protein of HPV on p53?
Inactivation
156
What is p21
CDK inhibitor
157
APC is the gatekeeper of _______ neoplasia
Colonic
158
What is beta-catenin
A prooncogene
159
Relationship of beta-catenin, APC, and WNT
In absence of WNT signaling, APC causes degradation of beta-catenin --> prevents growth
WNT signaling blocks formation of the destruction complex, stabilizing beta-catenin/TCF complex promotes growth of colonic epithelial cells by increasing transcription of MYC, cyclin D, and other genes
Mutation of APC --> elevated levels of beta catenin --> cell growth
**APC = tumor suppressor gene**
**Beta-catenin proto-oncogene, promotes cell growth**
WNT needed to degraded APC to get cell growth
w/o no WNT no growth
160
What downregulates E-cadherin?
SNAIL and TWIST
when SNAIL downregulates E-cadherin --> get epithelial to mesenchymal transition
161
Down regulation of _____ leads to epithelial-to-mesenchymal transition
E-cadherin
**down regulation occurs by transcriptional receptor SNAIL**
162
WT1 function
Transcriptional activator of genes involved in renal and gonadal differentiation
Regulates mesenchymal-to-epithelial transition that occurs in kidney development
Mutations cause Wilms' tumor
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VHL function
Links ubiquitin chains to specific protein substrates --> promoting degradation by the proteasome
HIF1alpha is a critical substrate for VHL
w/ oxygen--> HIF1a hydroxylated and binds to VHL -> ubiquitation and degradation
w/o oxygen -> no hydroxylation and VEGF and PDGF are promoted
Loss of function of VHL --> increase levels of angiogenic factors --> favor cell growth
164
Anoikis
loss of adhesion to BM
165
Which gene is overexpressed with B-cell lymphoma
BCL2
166
Functions of p53, RAS, MYC, and MAPK signaling w/ angiogenesis
p53 upregulates angiogensis inhibitor thrombospondin-1
RAS, MYC, and MAPK upregulate VEGF expression to stimulate angiogenesis
167
MMP9 function
gelatinase that cleaves type IV collegen (BM)
**also stimulates release of VEGF from ECM-sequestered pools**
168
SNAIL and TWIST result in
decreased e-cadherin
169
What are positively charged AA and negatively charged AA?
Positive - Arg, His, Lys
Negative - Asp, Glu
170
Briefly describe point mutations (silent, nonsense, missense)
Silent - change at the RNA/DNA level but does not affect the protein
Nonsense - results in a STOP mutation
Missense
- Conservative = retain most of protein function (ex TCC and AGG both code for Arg)
- Non-conservative = protein function not retained (ex TGC and ACG do not code for the same AA)
171
Which AA is most affected by mutations?
Cytosine
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DNA major mechanisms of repair
Single strand break = base excision repair (PARP1, XRCCl)
Double strand break = homologous recombination or non-homologous end joining
- ATM/ATR; BRCA1 Rad51, Ku proteins, CHK1/2
Mismatch = MMR, MLH1 or MSH2
173
Examples of G-protein coupled receptors
Chemokines (e.g. LTB4, CXCL8, eotaxin, C5a)
174
Notch (receptor) refers to the actual physical receptor - name an activating ligand and inhibiting ligand
Activating ligand (DLL4)
Inhibiting ligand (jagged)
175
What is unique about phospholipase C
Introduces calcium
176
Cytokines/lymphos function through the _____ pathway and chemokines function through the _____ pathway
JAK/STAT
GPCR
177
TGF beta function
Immunosuppressive (inhibitor) - dampens the immune response
Promotes fibrosis/wound healing
Role in epithelial to mesenchymal transition
178
Which SMADs are activating and which are inhibitory?
SMAD 6/7 = inhibitory....ALL others activating
179
What is the main inhibitory protein for SMAD?
SMURF
180
What are SMADs
Transcription factors for TGF-beta
181
Main three tumor suppressor genes?
Rb
p53
P16/Ink4a/ARF (CDKN2A)
182
What is the function of CDK4/6?
To inhibit retrinoblastoma and are represesed by p16
183
Which part of the cell cycle/checkpoint do Rb and p16 function?
G1S checkpoint
184
p21, 27 and 57 function at what CDK?
p16, p15, p18, and p19 function at which CDK areas?
CDK2, CDK1
CDK4 for p16, p15, p18, and p19
185
Which CDKs regulate the G1-S checkpoint
D-CDK4, D-CDK6, and E-CDK2 by phosphorylating the Rb protein
186
Which CDKs regulate in S phase?
A-CDK2
| A-CDK1
187
Which CDKs function in the G2 to M transition?
B-CDK1
188
What can block CDK activity?
CDK inhibitors = INK4 inhibitors (p16, p15, p18, p19) and p21, p27, p57
189
Active RB is??
Hypophorphoyrolate - because it is working to inhibit transcription
190
Inactive RB is?
Hyperphorphorylated - inactivated so cannot suppress any more and transcription occcurs
191
Mechanism of epithelial to mesenchymal transition
Gradual loss of E-cadherin
Upregulation of Snail 1/2 (slug), ZEB 1/2, Twist 1 (TFs)
Increased DNA methylation - shuts off "epithelial genes"
192
What is the rate limiting step for formation of glutathione
Cystine (system xC) - regulatory in ferroptosis
193
what stimulates transocytosis?
Vegf
194
MARGINATION CAPTURING AND TETHERING MEDIATED BY?
LEUKOCYTE - L-SELECTIN AND VLA-4, ESL-1, PSGL-1
ENDOTHELIAL CELL - s-Le^x and VCAM, E-selectin and P-selectin
**s-Le^x binds to l-selectin typically in post-capillary venules*
195
P-selectin is from?
Preformed in Weibel-Palade bodies and platelet alpha granules
196
What cleaves L-selectin
ADAM17 --> once cleaved then leukocytes express integrins activated to a high affinity state in the previous step
197
Migration through the ECM mmediated by?
Leukocytes migrate w/ areas with less type IV collagen and laminin 10
Leukocytes express VL-3 at leading edge of the leukocyte --> binds to fibronectin
Tail anchored by LFA-1 on iCAM on endothelial cell or pericyte (modified smooth muscle cells)
198
How do NETs directly kill pathogens
adhered microbes are killed by antimicrobital proteins such as histones and cathepsin
199
What in hibits terminal complement activation
CD59
200
Immature langerhans cells bind
CCR6 to CCL20 (in skin)
201
Function of FGF7
keratinocyte growth factor
202
FGF10 fxn
epithelial cell differentiation
203
TGF beta functions
Profibrosis
- (promotes mesencymal proliferation, inhibits epithelial and endothelial)
- stimultes production of collagen, fibronectin, proteoglycans
- decreases MMPs and increases TIMPs
Anti-inflammatory
- induces Treg differentiation
- TGF-beta, IL-6 and IL-1 or (TGFbeta and IL-21) induce Th17 differentiaotn (classical macrophages activation)
Bind serine-threonine kinase receptors (TBR1, II and III)
Induce phosphorylation og SMADs
204
What does TGF bind to?
Not GPCreceptors - bind serine-threonine kinase receptors
SMADs are phosphorylated when TGF binds to receptor --> and normally SMAD7 is inhibitiing Co-SMAD --> SMAD7 would inhibit (antifibrosis and proinflammatory)
205
Angiotranscriptoion growth factors
HIF-1 alpha
EGR-1
206
What regulates VEGF
Notch signaling
207
Thrombospondin fxn
Promotes plateelt aggregation
Inhibits heparin
Antigngiogenic
Actiates TGF-beta
208
List roles of thrombin
Monocyte activation
Neutrophil adhesion
Cleaves fibrinogen to fibrin and activates many clotting factors
Through PARs - it activates endothelial cells to express adhesion molecules and fibrinolytic vasoactive and cytokine mediators
Platelet aggregation --> activation of TxA2 --> fibrin
209
PARs are expressed on which cell types?
Endothelium
Monocytes
Dendritic cells
T cells
210
Thrombin and PAR
Thrombin activates PAR receptors --> ex on platelets causes downstream pathways to become activated and perform further effector functions --> platelet aggregation
211
List the 3 main anticoagunts
Protein C and S
TFPI (tissue factor pathway inhibitor)
Antithrombin
212
Function of antithrombin
Inhibits thrombin
Inhibits FIXa, FXa, FXIa, FXIIa. (9, 10, 11, 12)
**basically inhibits the intrinsic pathway**
so lack of antithrombin --> hypercoaguable
213
What does TFPI inactivate?
FVIIa and TF complex (extrinsic pathway)
Inactivate FXa
214
What promotes Warburg metabolism?
RAS, MYC, induce contribute to Warburg
PTEN, NFI, p52 oppose Warburg
215
Main mechanism of inactivation of hydroxyl radicals?
conversion to H20 by glutathione peroxidase
216
Which of the following does NOT inhibit platelet activation/aggregation
1. Thrombin
2. Prostacyclin
3. Thrombomodulin
4. Endothelial protein c receptor
Thrombin
217
What stimulates mitogenesis of smoth muscle and fibroblasts?
Platelet-derived growth factor
218
Common variable immunodeficiency is a primary immunodeficiency attributed which of the following
B cell defect
219
Which organelles functions in the metabolism of long-chain fatty acids
peroxisomes
220
Of the following which are non-coding and coding
promoters
enhancers
telomeres
exons
Non-coding: promoters, enchancers, telomeres
Coding: exons
221
Splicing of pre-mRNGA occurs in which location
nucleus
222
What do granzymes cleave
pre-caspases
223
What do NK cells express
CD16
| CD56
224
What do NK cells contain
perforins
| granzyes
225
CDKN2A encodes
p16/INK4a (blocks CDK4-D CDK6-D)
| p14/ARF (activates p52 by inactivating MDM2)
226
Mature dendritic cells express...
CCR7
227
Color of abscess depends on pigment from bacteria (examples for Yellow, Green, Red)
```
Staphlococcus
Streptococcus
Pseudomonas
Corynebacterium
Serratia
```
Yellow - staphylococcus, streptococus, corynebacterium
Green - pseudomonas aeruginosa
Red - serratia marcescens
228
Difference in Th1 vs Th2 granulomas?
Th1 = nodular (tuberculoid) --> mocybacterium bovis/tuberculosis
Th2 = diffuse (lepromatous) --> mycobacterium avium subsp paratuberculosis (Johne's disease)
229
What are equine sarcoids?
Not granulomas
Neoplasm of proliferating fibroblasts caused by bovine papillomavirus (BPV) types 1 and 2 (and 13) and the majoring transforming protein E5
230
IL-1 nad IL-6 stimulate which acute phase proteins?
IL-1 and TNF stimulate SAA
IL-6 stimulates CRP and fibrinogen
231
Fibrinogen and hepcidin role w/ erythrcytes in inflammation?
Fibrinogen induces rouleaux
Hepcidin increases w/ inflammation --> reduces iron availability leading to anemia of chronic disease
232
List the three direct effects of LPS that lead to shock
Activation of Hageman factor --> clotting cascade
Activation of complement cascade
Activation of TLR4 pathway
233
List examples of labile tissues, stable tissues, permanent tissues
Labile (continuously dividing) - hematopoietic cells and surface epitheilal cells
Stable - cells in G0 phase
- liver, kidney, pancreas, endothelial cells, fibroblasts, smooth muscle cells
Permanent tissues - terminally differentiated
- neurons and cardiac myocytes
234
Mechanism of Chediak-Higashi syndrome w/ hemorrhage associated thrombopathia
Defective platelet storage of ADP due to mutation in lysosomal trafficking protein (LYST)
235
What is the dominant histologic feature of an infarct?
ischemic coagulative necrosis (exception is liquefactive necrosis in teh brain)
236
Reperfusion injury mechanism
In ischemic cells, ATP is broken down into hypoxanthine (which is non-reactive in the absence of oxygen)
...w/ addition of oxygen (reperfusion) --> hypoxanthine converted to urates, H2O2, and superoxide
237
Mutations in germ cells vs somatic cells?
Mutations in germ cells --> transmitted to progeny and can give rise to inherited disease
Mutations in somatic cells --> do not cause hereditary disease, but are important in the genesis of cancers
238
All TLRs signal via a common pathway that results in 2 sets of transcription factors...
1. NF-kB (stimulates the synthesis and secretion of cytokines and expression of adhesion molecules --> recruitment of leukocytes and activation)
2. Interferon regulatory factors (IRFs) --> stimulate the production of type 1 interferons, which are antiviral cytokines
239
Where are C-Type lectin receptors?
expressed on plasma membrane of macrphages and dendritic cells
detect fungal glycans and subsequently elicit inflammatory responses
240
RIG-like receptors
located in the cytosol of most cell types
detect viral nucleic acids (particularly viral RNA)
241
What are the four subpopulations of macrophages?
Red pulp macrophages - phagocytose hematogenous pathogens and senescent erythrcoytes
White pulmp macrophages - "tangible body macrophages") remove apoptotic T and B lymphocytes
Marginal zone macrophages - clear pathogens from circulation via high levels of PRRs adn scavenger receptors
Metallophilic macrophages - also present in marginal zone but function is unknown
242
Binding sites of MHC Class I and II
CD8 binding to the alpha3 domain of MHC Class I
CD4 binding to B2 domain on MHC Class II
243
Carcinomas metastasize more commonly via ______
Sarcomas metastazie more commonly via ______
Carcinoma - Lymphatic spread
Sarcoma - Hematogenous spread (more common w/ sarcoma, but carcinomas can also spread this way)
244
Which tumor suppressor gene antagonizes Warburg metabolism?
STK11
245
Anoikis
apoptosis - loss of adhesion to the basement membrne
246
SNAIL and TWIST function
encode transcription factors whose primary function is to promote epithelial to mesenchymal transition (EMT)
247
EMT mechanism
Loss of E-cadherin is a key event in EMT - SNAIL and TWIST are transcriptional suppressors that downregulate its expression
Carcinoma cells downregulate E-cadherin and upregulate vimentin and SMA
**E-cadherin is thus a primary candidate as a metastasis suppressor gene**
248
Inflammation has 5 R's - order them from first to last
**Repair, Recruitment, Removal, Regulation, Recognition**
```
Recognition
Recruitment
Removal
Regulation
Repair
```
249
Caloric restriction increases longevity by reducing the signaling intensity of the ___ pathway and by increasing ___
IGF-1 pathway
increasing sirtuins
