Immunology Flashcards
(140 cards)
1
Q
What are the phagocytes of the myeloid cells?
A
netrophils and macrophages/monocytes
2
Q
What do neutrophils granules contain?
A
lysozyme, collagenase and elastase
3
Q
Neutrophils arise from a hematoppoietic precursor cell stimulated with what cytokine?
A
G-CSF
4
Q
What are teh two main APCs that are myeloids?
A
monocytes/macrophages and dendritic cells
5
Q
What are mast cells?
A
Bone-marrow derived cells within mucosal and dermal tissue that are a rich source of histamine and heparin
6
Q
What are basophils?
A
bone-marrow derieved, common hematopoietic precursor with mast cell. highly acidic granophils, not much known about function
7
Q
What are the role of eosinophils
A
large granules died by acidic dyes, granules contain heparin, cytokines, heparina dn hydrolytic enzymes produced in response to parasitic infection
8
Q
What are the two main types of dendritic cells?
A
Conventional dentridtic cells and plasmacytoid
9
Q
What is the role of conventional dendritic cells?
A
Primary effector cell linking innate and adaptive immune arms, activating naive t cells
10
Q
What is the role of plasmacytoid dendritic cells?
A
Plays an important role in antiviral immune rsponse and produce the anti-viral cytokines IFNalpha and IFNBeta
11
Q
What are follicular denddritic cells?
A
Characterized by numerous membranous projections and are localized within specilaized collecteions of activated b cells within lymph nodes etc.,
12
Q
What are the roles of follicles for?
A
Cell rich zones, for activating b cells, with germinal center of the folicle being the locaiton for majority of it
13
Q
How are natural killer cells distinct from t and b cells?
A
Mediate effector functions without first recognizing antigen, (natural killer t cells are a rare and little understood cell with characterisitcs of t and nk cells)
14
Q
What surface protein is on all t cell subclasses?
A
CD3
15
Q
What surface proteins are typical of almost all b cells?
A
CD19 and CD20
16
Q
What are the surface rpoteins indicative of NK cells?
A
CD16 and FcRgamma
17
Q
What cells are indicated by CD34 surface protein and c-kit surface marker proteins?
A
Pluripotent self-renewing cells within bonemarrow, heatopoietic
18
Q
What are the two portions of the spleen?
A
red pulp and white pulp
19
Q
What is MALT?
A
Muscosal associated lympoid tissue, a collection of myeloid nad lympoid cells that specifically traffic into anatomical close proximity to epithelial surfacee
20
Q
What is intraepithelial lymphocytes?
A
tend to be gammadelta TCR T cells that specifically recognize and respond to lipid antigens
21
Q
What are langerhans cells?
A
Specialized immature dendritic cell resident to the most interior layer of squamous epithelium, fucntion as sentinel
22
Q
What is the major histocompatibilty complex?
A
Series of genes and its products involved in determining compatibility of self and foreing bodies
23
Q
MHC I samples waht?
A
MHC I samples the cytoplasm/proteosome of the cell
24
Q
What is MHC 2 sample?
A
THings phagocytosed and lysed in the lysozome
25
What does IFN-gamma do in relation to peptide generation?
Protective cytokine, associated with viral infection, induces expression of 3 replacement beta proteasome subunits called LMPs
26
What is TAP?
Transporter assocated with antigen processing, transports peptides into ER to bind MHC1
6-15 AA peptides ending with L,I,V,M
27
What size peptide to class 1 MHC molecules bind?
Only 8-10 amino acids with an LIVM anchor resideu
28
What is tapasin?
Thought to tether newly synthesized class I MHC moleucles to TAP to keep them in close proximity
29
What type of cells do MHC I display their peptides to?
Cytotoxic CD8 T cells
30
What type of cells do MHC II display their peptides to?
Helper CD4 T cells
31
WHat protein prevents protein loading of MHCII in the ER lumen?
Invariant Chain
32
What is CLIP?
THe portion of the invariant chain left within hte MHC II binding groove once the rest of it has been removed
33
What protein removes CLIP from binding groove?
HLA-DM
34
What is cross presetation?
Where specialized antigen presenting cells are able to present antigens that were phagocytosed on both MHC II as well as MHC I
35
What is CD1?
Not encoded in MHC, presents lipid antigents to NK-Tcells, also travels with invariant chain
36
What is the Major Histocompatibility complex?
the genetic locus responsible for tissue rejection, the genes are codominant
37
How many MHC genes are there in the human genome?
6 MHC genes, 3 of each class
38
Where is the MHC complex located?
on chromosome 6
39
WHat chance is there that MHC matchs at all 10 products between siblings?
1 in 4
40
What is the structure of class 1 MHC?
The alpha chain is the heavy chain, spans the membrane, Beta 2 is a light chain and doesnt span and then alpha 1 and 2 contain the polymorphic residue that bind the peptide
41
What gene is related to ankylosing spondilitis?
93% of patients with ankylosing spondilitis have HLA-B27, increases risk by 100 fold
42
What are the three parts of teh T cell receptor?
Variable, Joining, and diversity
43
Are TCR high or low affinity binding? BCR ?
TCR are low, and BCR are high
44
What type of chains are T cell antigen receptors composed of?
alpha and beta chains, sometimes gamma/delta
45
What cytokine causes lymphocytes to proliferate?
IL-7 produced by bone marrow stromal cells provides mitogenic signal for devolping lymphocytes to proliferate
46
What are alphabeta T cells?
The most abundant type of T cell, MHC restricted
47
What are the gammadelta T cells?
Common only in gut mucosa, and are not MHC restricted
48
The variable TCRbeta chain is composed of what?
Three segments, V, D and J as well as the constant region
49
The TCRalpha chain is composed of what?
Only V and J segments and the addition of the constant region
50
What needs to be expressed by T cells to get past the first checkpoint?
The beta chain, with a surrogate light chain on the surface
51
What needs to be expressed by the T cell to get past the second checkpoint?
Both the alpha and beta chain need to be expressed on teh surface
52
Each variable region of TCRBeta and alpha have what?
3 regions of hypervariability known as CDR1, 2 and 3, which are amino acid differnces
53
How is antigenic diversity created junctionally in TCR cells?
Removal of nucleotides, addition of nucleotides by TdT and strand repair during recombination process
54
What is TdT enzyme?
adds nucleotides to junction, to create antigenic diveristy
55
What is LFA1?
T cell integrin, that allows binding of naive T cell to an APC, that is presenting an antigen the T cell recognizes
56
Gammadelta TCR recognize waht?
lipids instead of peptides
57
Ciriculating naive T cell require what two signals to become active?
MHC antigen peptide complex and CD 28 interaction with co-stim molcule on APC
58
CD28 interacts with what?
B7-1/B7-2 on the APC, CD28 is on the t cell
59
CTLA4 is waht?
A co-stimulator receptor ona t cell that also interacts with B7, late in response, ITIM inhibits it
60
ICAM1 is what on t cells?
AN adhesion molecules
61
When macrophages ingest an antigen what occurs?
Secretion of IL12
Increase levels of MHC
upregulate costim molecule B7
62
IL-2 does what?
produced by an activated t cell, and causes T cell proliferation. Daughter cells are clones of the t cell
63
What costimulatory molecule on t cell, binds to an amplilfication signal to maintain an immune response inside the APC?
CD40L on tcell binds CD40 on APC, used by helper t cells to activate macrophages and B lymphocytes
64
How are CD4+ t cells idffreentaited into Th1 helper t cells
BY IFNgamma, IL12
65
Th1 helper t cells are involved in what type of immune response
phagocyte mediated killing of intracellular bactera, stimulate antibody production to bind APC Fc receptors, activate complement production, stimulates costim molecules. produce IFNgamma
66
What cytokines drive T cells to a Th2 cell?
IL4
67
What is the role of Th2 helper t cells
isotype switching, involved in parasite dfense, and allergy, produce IL4,, IL5 and IL10
68
What cytokines and chemokines are involved in driving T cells to Th17 cells?
TGFbeta IL6 IL23
69
What are Th17 cells involved in?
neutrophil inflmmation, combatting extracellular bacteria and fungi, produce IL17
70
What chemokines are involved in the activationo f endothelial cells, at the site of infection?
TNF and IL1
71
What is the role fo L-selectin?
Involved in trafficking of t cells back to lymphoid tissue
72
E-and P-selectin are involved in what?
trafficking to site of infection
73
Integrins LFA1 and VLA4 are involved in what?
enhances tighter adhesion of t cells to endothelium at site of ifection
74
VLA4 on Effector t cells adheeres to what protei on endothelial cells?
VCAM1
75
What signals are involved in trafficking to lmphatic tissue?
CCR7(chemokine receptor) and L-selectin
76
What signals are involved int rafficking to peripheral tissues for effector t cells?
CXCR10 and E or P selectin
77
What cytokines does CD4 Th2 effector cells produce?
IL4, IL10, IL 5 ad IL13, inducing eosinophil inflammation and causing humoral responses
78
What cytokines does Th17 cells produce?
IL17 and IL22, leading to recruitment of PMN and monocytes
79
What do CD8 cells use to kill target cells?
Perforins-- to form a pore in target cell
granzymes--serine proteases which activate apopotsis
Fas ligand which induces apoptosis by Fas Receptor
80
What is an epitope?
Part of a native protein, lipid, or lipoprotein antigeen that is recognized by B lymphocyte antigen receptors.
81
Antigen is presented to membrane bound what for antigen recognition on a b cell?
Antigen is presented to membrne bound IgM on Naive b cells
82
Naive B cell requires 2 signals for activation?
BCR binds antigen
| CR2/CD21(complement receptor) activated by C3d complement protein or TLR activated microbial PAMP
83
Two or more BCRs must be cross linked by what to become activated?
Antigen
84
What is ITAM?
immunoreceptor tyrosine-based activation motif
85
What are the two types of stintigens with stmulation to make an effector b cell and what is the differnce?
T independent and T dependent
independent localize to spleen, bone marrow, peritoneal cavity and mucosal tissue typically lipid or antigens with repetivtive structure
Dependent requires a T cell and is typically a protein antigen
86
What is the ligand needed for T cell mediated activation of B cells?
CD40 and CD40L
87
What is the role of each different isotype of Ig?
IgM--Complement activation
IgG-- Fc receptor depndent phagocyte response; complement activation; neonatal immunity
IgE--Immunity against helminths; Mast Cell degranulation(immediate hypersensitivity)
IgA--Mucosal immunity
88
What cytokine causes the production of the IgG subclass?
IFN-gamma
89
What cytokine causes the production of IgE?
IL4
90
What cytokine causes the production of IgA?
TGFBeta or BAFF
91
What causes the production of IgM
T independent activation
92
Folicular helper T cells do what?
Provide survival signal to maturing B cells
93
What is the source of TNFalpha?
```
Comes from macrophages, downstream of pathogen encounter and NFkappaB. Endothelial cells activation
neutrophils activation
hypothalamus fever
liver synthesis of acute phase
muscle fat metabolism
cells apoptosis
```
94
What is the source of IL1?
Macrophages, endothelial cells, epithelial cells
95
What is the prinicpal target of IL1?
ENdothelailal cell activation
hypothalamus fever
liver synthesis of acute phase proteins
96
What is the principal target of IL6?
Liver synthesis of acute phase proteins
| b cells: proliferation of antibody-producing cells
97
What are involved in neutrophil influx?
G-CSF+GM-CSF(proliferation in bone marrow and egress of PMNs), IL-8(chemotatic) and Chemokine(leukocytes and PMNs;
downstream of pathogen encounter and NFkappaB actiavtion
98
What are the four stages of PMN extravasation?
Rolling, integrin actiavtion by chemokines, stable adhesion, and migration through endothelium
99
What does APC expression of CTLA-4 serve to do negatively regulate what response?
Competes B7 to stop signal through CD28. CD28 is an inflammatory cell
100
IL2 and IL2R, do what?
Provide cell-contact independent, pro-proliferative; are targets of several important medications
101
IL12 promotes what?
Th expression of IFNgamma (TH1 pathway)
102
TGFBeta drives Thelper cells to wha?
Treg by supressing TH1 and Th2
103
What is teh default pathway, when there are no APC cytokines?
TH2 is the default
104
IL10 promotes what sort fo T celledevelopment?
Treg development
105
IL4 and IL5 cause what sort of drive?
```
TH2 helper cells
IL-4 class swithces to IgG, IgE; supresses Th1
IL-5 causs class switch to IgA; promote eosinophilia
```
106
Overabundance of Th17 is associated with what?
autoimmunity
107
TH17 is made by what combination fo cytokines?
IL-6 IL23 and TGFBeta acting as a group
108
What ligands are involved in B cell activation?
CD40 and CD40L
109
IFNgamma causes class switching to what?
IgG1 and IgG3
110
IL4 causes class switching to what?
IgE
111
TGFBeta causes class switching to what?
IgA
112
FcEpsilonR1 regulates what?
Granulocyte degranulation
113
Histamine does what?
A vasooactive amine stored in granules of mast cells
| Binds to specific receptors
114
Prostaglandin does what?
lipid inflammatory mediators
activae G protein coupled receptors on smooth muscle as a vasodilator
promotes PMN chemotaxis
115
Leukotrienes does what?
Inflammatory mediators that are derivd from arachidonic acid.
Mast cells make leukotriene C4
116
What cytokines cause CD8 T cell cytotoxicity
IFNalpha
| IFNBeta
117
What cytokines are associated with NK cell lysis?
IL15 and IL18, targets NK cells and T cells
118
What is the cause of Amebiasis?
Entamoeba histolytica,
119
Where is Entamoeba histolytica located in the human?
lumenal, intestine leads to invasion of tissues
120
What is the lifecycle of Entameoba histolytica?
Infective-acid resistant cyst ingested, excystation in small intestine, attach to colonic mucosa divide and form cysts that are shed
121
What is the pathology of Entamoeba histolytica?
can be mild or asymptomatic, or dysentery, and occasionally invade through mucosa invade the liver and liver damage
122
How is entamoeba histolytica diagnosed?
travel history
cysts in stool
antigea dn PCR more accurate
123
How is Giardia lamblia transmitted?
Ingestive, fecal/oral
124
What si teh life cycle of Giardia lamblia?
Trophozoites excyst in uper intestine, adhere to lumenal instestine, excretion of cysts, requires only 50-100 cysts for infection
125
What is the pathology of Giardia lamblia?
onset at 2 weeks, non-bloody diarrhea, flatus, acute usually self cure in 1-4 weeks, reinfection possible
126
How is Giardia diagnosed?
ELISA antigen test
127
What are the characterssitics of apicomplexan parasites?
obligate intracellular parasites
apical organelles that utilized for host invasion
comlex lifecycle, sexual cycle in intestinal epithealial cells of definitive hosts
128
What is cryptosporidiosis?
C. hominis, intracellular but extracytoplasmic parasite, high infection rate in developing countries, common secondary infection associated with AIDS outreak 1993 milwaukee due to crappy water filtration
129
What is teh treatment for cryptosporidiosis?
No truly effective treatment
130
What is teh pathology with cryptosporidiosis?
3 or more loose watery bowel movments 24 hrs
shedding of oocysts
similar to giardia but selflimiting in non-immunocompromised
131
Toxoplasmosis is what?
toxoplasma gondii, infects tissue/blood, cats as a definitve host
associated wtih cats feces adn undercooked meats
132
What ist he pathology of Toxoplasmosis?
Initial acute infection often asymptomatic
immunodeficient cannot control infection and can lead to encephalitis
in-utero infection can lead from miscarriage or mental retardation to chorioretinitis
133
How is toxoplasmosis diagnosed?
Serology, indirect immunofluoresence
134
What is Babesiosis?
Babesia microti, located in red blood cells, deer tick definitve host, humans accidental host
135
What is the babesia lifecycle?
Mouse and deertick, exchange blood meal and different gametes and trophocyte, however human accident life cycle
136
HOw is Babesia diagnosed?
Seen inside red blood cells,
137
What is the pathology of Babesia?
Usually nothing, but hemolytic anemia and non-specific flu like sumtoms, some have splenomegaly, hepatomegaly or jaundice
138
What is malaria?
one of 5 plasmodium species, whose definitive host is the mosquito and humans are the intermediate host, greatest risk to children and women prima gravida
139
What is the lifecycle of plasmodium?
mosquito bites human, sporozoites goes to liver, in liver infects hepatocyte and makes meroxoites which then infect red blood cells, producing more merozoites and gametocytes. Gametocytes enter mosquito after it bites again. Where the gametocytes produce sexual reproduction
140
What is the pathology of malaria?
Plasmodium causes fever cycle with bursts of merozoites, anemia from erythrocyte destruction, chills fever, splenomegaly, myalgia, cerebral malaria results from P. flaciparum
latent hepatic form in P. vivax and P. ovale
