Immunology Chapters 1-6 (Exam 2) Flashcards
1
Q
What is the main function of the immune system?
A
distinguish self from nonself
2
Q
Which immune system branch is specific and has memory?
A
acquired/adaptive immunity
3
Q
Which immune system branch is non-specific and has no memory?
A
innate immunity
4
Q
What are the anatomical barriers?
A
Anatomical barriers can be mechanical, chemical, and biological
mechanical factors
-skin (desquamation)
-mucus membranes (flushing action of tears, saliva, mucus, urine, mucociliary elevator, peristalsis)
chemical factors
-skin (antimicrobial fatty acids of sweat)
-lysozyme and phospholipase A of tears and saliva
-antimicrobial effects of defensins from respiratory and GI tract
-opsonin of surfactants from lungs
-bile
biological factors
-normal flora on skin competing with pathogens for nutrients and attachment sites
5
Q
What are the 5 basic humoral components?
A
1) complement
2) coagulation system
3) lactoferrin and transferrin
4) lysozyme
5) cytokines
6
Q
What are complement proteins? What do they do?
Think basic level
A
-group of blood proteins that function with Abs to recognize and eliminate pathogens
-helps Abs and phagocytic cells to clear pathogens
7
Q
What are the 3 functions of the coagulation system in humoral immunity?
A
1) increases vascular permeability
2) recruits phagocytic cells
3) platelets secrete B-lysins
8
Q
What competes with bacteria for iron?
A
lactoferrin and transferrin
9
Q
Lysozyme breaks down….
A
bacterial cell walls
10
Q
What are cytokines?
A
-cell signaling proteins like interleukins (ILs), interferons (IFNs), and lymphokines
-ex: macrophages secrete IL1
11
Q
Which cells are involved in the innate immune system?
A
-neutrophils
-monocytes/macrophages
-NK cells
-eosinophils
-basophils
12
Q
define racial immunity
A
natural immunity shared by most of the members of a genetically related population, ex Native Americans vs European races
13
Q
define species immunity
A
natural immunity shared by all members of a species
ex: resistance of birds to brucellosis
14
Q
define individual immunity
A
natural immunity not shared by most other members of the race and species, it is rare
15
Q
Adaptive immunity reacts with a _________ pathogen
A
specific
16
Q
Cell mediated and humoral/Ab immunity is a part of which immune system branch?
A
adaptive/acquired immunity
17
Q
What are the 4 hallmarks of adaptive immune response?
A
1) self vs non-self discrimination (typically responds to only foreign molecules)
2) memory (each pathogen is remembered by a signature Ab)
3) specificity (distinguishes minor differences in molecular structure to determine non-self antigens)
4) diversity (can produce a highly diverse set of recognition molecules)
18
Q
What are the primary central lymphoid organs? What happens at these sites?
A
-BM
-thymus
-fetal liver
-its like a boot camp, prepping for stress
-this is where lymphocytes are developed
-stem cells are differentiated and become functional mature lymphocytes
19
Q
What is the primary lymphoid organ for fetuses?
A
fetal liver
20
Q
What are the primary lymphoid organs for everyone besides fetuses?
A
BM and thymus
21
Q
What are the secondary peripheral lymphoid organs/tissues?
A
-spleen
-lymph nodes
-tonsils
-peyer’s patches
-appendix
-various mucosa associated lymphoid tissues (MALT)
MALTs are aggregates of non-encapsulated lymphoid tissue found in lamina propria and submucosal areas of GI tract, respiratory, and genitourinary tracts (BALT, GALT, SALT)
22
Q
Mature lymphocytes migrate from primary lymphoid organs to secondary lymphoid organs. Which lymph cells can be found in secondary peripheral lymphoid tissues?
A
B and T cells
23
Q
What are the 3 blood cells?
A
-erythrocytes (RBCs)
-platelets (thrombocytes)
-leukocytes (WBCs)
24
Q
RBCs are involved in…..
A
oxygen transfer
25
Platelets are involved in....
blood clotting and inflammation
26
Leukocytes are derived from where?
polymorphonuclear (PMN) granulocytes (multiple shaped nucleus, multi-lobed nucleus, granules in cytoplasm)
27
What are the 3 types of WBCs?
1) neutrophils
2) eosinophils
3) basophils
28
95% of polymorphonuclear (PMNs) are which WBC?
neutrophils
29
Which WBC is most active with bacterial antigens?
neutrophils
30
Which WBC contains defensins, lysozyme, and lactoferrin?
neutrophils
31
2-5% of WBCs are....
eosinophils
32
Which WBC degranulates upon stimulation, and contains cytotoxic proteins within the granules to defend against parasitic helminth (flatworms and roundworms- the ones that migrate through the body)?
eosinophils
33
Which WBC is involved in the development of allergies and asthma?
eosinophils
34
Which WBC is the least numerous one (less than 1% of WBCs)?
basophils
35
Which WBC degranulates upon stimulation and performs phagocytosis through the release of histamine and serotonin to induce inflammation?
basophils
36
Which WBC is similar to mast cells in tissues that are involved in allergic reactions?
basophils
37
Which WBC is responsible for inflammatory reactions during immune response like the formation of acute and chronic allergic diseases including anaphylaxis, asthma, atopic dermatitis, and hay fever?
basophils
38
Which WBC releases heparin to prevent blood clotting?
basophils
39
What do anti-histamines do?
airway constriction and blood vessel dilation (BP decreases)
note: epi would have opposite effects
40
Which cells are derived from mononuclear agranulocytes (one lobed nucleus, no granules in the cytoplasm)?
monocytes and macrophages
41
What is the difference between monocytes and macrophages?
monocytes stay in peripheral blood for approx. 3 days and then move to the CT to become macrophages
42
What are the 3 functions of monocytes and macrophages?
1) phagocytosis (engulf antigens)
2) antigen presentation (adaptive immune system)
3) cytotoxic production (cell signaling with interleukins (ILs))
43
What is another name for the mononuclear phagocyte system (MPS)?
reticuloendothelial system (RES)
44
What is the mononuclear phagocyte system (MPS)/reticuloendothelial system (RES)?
-a part of the immune system that consists of phagocytic cells
-located in reticular CT
-the cells are primarily monocytes and macrophages and accumulate in lymph nodes and the spleen
-brucellosis is a bacterial infection that affects the RES
45
Lymphocytes include large granular lymphocytes (ex: NK cells) and the small lymphocytes (ex: T cells and B cells). Lymphocytes usually have different _____ molecules expressed on the cell surfaces, serving as surface receptors that identify cell type and being recognized by antibodies
CD
note: CD stands for clusters of differentiation, there are 250+ CD markers, each coating the surface of various cells
46
What cells are the "license to kill" cells?
NK cells
47
What CD marker do NK cells have?
CD16
48
Which cells play a role in innate immunity by destroying virus infected cells and tumor cells by secreting perforin and granzyme which kills virus infected cells and tumor cells?
NK cells
49
Which lymphocyte cells do not require recognition of MHC proteins?
NK cells
50
Which cell besides NK cells secretes perfornin and granzyme?
cytotoxic T cells
51
20% of WBCs include....
T cells and B cells
52
What are the principle cells of the adaptive immune system?
T cells and B cells
53
Which cells retain memory of a previous infection so that they can mount a faster and stronger response upon reinfection?
T cells and B cells
54
B lymphocytes are B cells that have a BCR. What are the CD markers here?
CD19 and CD20
55
Which cells are primarily responsible for humoral immunity (releasing Abs)?
B lymphocytes
56
B cells are created in the BM and mature in the BM. This process is called?
antigen-independent
57
In the presence of antigen (antigen-dependent) in the secondary lymphoid tissues, B cells become metabolically active and differentiate into _________ cells and _________ cells.
plasma, memory
58
Which cells secrete large quantities of antibodies?
plasma cells
59
T lymphocytes are T cells that have TCR. What are the CD markers here?
CD2 and CD3
60
Do we have more B cells or T cells in the body?
T cells
61
Which cells are chiefly responsible for cell-mediated immunity?
T lymphocytes
62
T cells are created in the BM and mature in the thymus. T cells, after they see an antigen, it will become highly activated and will secrete specific proteins, such as __________________ and __________________, depending on their subtype/function
cytokines (interleukins), cytotoxic granules
63
HelperT cells are also known as helper T lymphocytes. What CD marker do they have?
CD4
64
What do TH1 cells do?
-help CD8 cells become activated cytotoxic T cells
-stimulates activities of cytotoxic T cells
65
What do TH2 cells do?
produce/secrete IL4/IL5/IL6 to help B cells develop into antibody-producing plasma cells (helps humoral immunity)
66
Cytotoxic T lymphocytes are also called CTLs. What CD marker do they have?
CD8
67
What do cytotoxic T cells do?
kill virus infected cells and tumor cells (target cells) with perforin and granzyme
68
What do regulatory T cells do (also known as Tregs or suppressor cells)?
dampen the activity of B and T lymphocytes and inhibit the immune response (prevents body from reacting against self, like autoimmunity)
"united nations"
69
T cell receptors (TCR) molecules provides the ____________ for an individual T cell to recognize a particular antigen. The function of TCR is to recognize the antigen. This recognition is "MHC restricted" because the TCR also requires interactions with MHC
specificity
note: TCR provides the SPECIFICITY for an individual T cell to recognize its particular Ag, however, this recognition is "MHC restricted" bc the TCR also requires interactions with MHC
70
What are the co-receptors (think T cells)? What do they do?
CD4 and CD8
-they help the T cell bind to the target cell by "grabbing" onto the MHC molecule
71
define antigenicity
ability to specifically bind to an antibody or cell-mediated receptor
Antigen = antibody generation
72
T/F: every immunogen is an antigen but not every Ag is an immunogen
TRUE
73
define immunogen
any Ag with the ability to induce a humoral and/or cell-mediated immune response
74
What are haptens?
-incomplete antigens (small molecules like sugars or chemicals) that are antigenic but not immunogenic (usually bc too small to induce Ab synthesis)
-need a large carrier, which is a larger protein molecule to attach with hapten (this is called a hapten-carrier conjugate)
-the hapten may become one of the antigenic determinants (epitope) toward which Ab synthesis is directed
75
What are epitopes?
-antigenic determinants
-a section of an Ag molecule that stimulates Ab formations and to which the Ab binds
-only certain parts of a molecule are actually antigenic
76
One of the factors influencing the immunogenicity is the contribution of the immunogen. What 5 things make something immunogenic?
select all that apply question
1) foreignness
-immune system normally discriminates between self and non-self such that only foreign molecules are immunogenic
2) size
-usually the larger the molecule then the more immunogenic it is
-small molecules usually don't generate immune response
3) chemical composition
-usually the more complex the substance is chemically then the more immunogenic it will be
4) physical form
-particulate antigens are more immunogenic than soluble
-denatured antigens are more immunogenic than native form
5) degradability (Ag processing by APCs)
-antigens that can easily be phagocytosed are generally more immunogenic
-for most antigens, the development of an immune response requires that the antigen be phagocytosed, processed, and presented to helper T cells by an APC
77
One of the factors influencing the immunogenicity is the chemical nature of immunogens. What are the 4 molecules?
1) proteins
-the vast majority of immunogens are proteins
-these can be pure proteins, glycoproteins, or lipoproteins
-proteins are the best immunogen
2) polysaccharides
-pure polysaccharides and lipopolysaccharides are good immunogens
3) nucleic acids
-usually poorly immunogenic
-may become more immunogenic when single-stranded or when complexed with proteins
4) lipids
-lipids are usually NON-immunogenic, but they can be haptens
-lipids are the worst Ag
78
The vast majority of immunogens are....
proteins
79
What is the best immunogen?
proteins
80
What is the worst immunogen?
lipids
81
One of the factors influencing the immunogenicity is endogenous Ag vs. exogenous Ag. What is the difference here?
test q
difference is where the Ag came from
-endogenous antigens have been generated within previously normal cells as a result of abnormal cell metabolism like tumor cells or viral infections and binds to MHC 1 and has been processed within the cytoplasm
-exogenous Ag originates from the outside- fragments of extracellular bacterial cells that are engulfed and processed by an APC and bind to MHC II and has been internalized by phagocytosis or endocytosis and processed within the endocytic pathway
82
One of the factors influencing the immunogenicity is the method of administration of immunization. What are the 3 routes?
1) dose
2) route (subcutaneous and intramuscular routes are best compared to IV or intragastric routes (these routes can alter the nature of the response)
3) adjuvant (substances that can enhance the immune response to an immunogen (ex: vaccine) while having few if any direct effects when given by themselves, although adjuvants can cause fever and inflammation)
83
One of the factors influencing the immunogenicity is the contribution of the biological system. What 2 big things play in here?
genetics and age!
84
What are the other names for antibody?
gamma globulins or immunoglobulins
85
define antibody
proteins produced by plasma cells as a response of stimulation by antigen
86
What is the structure of Abs?
Y configuration
87
What is the function of the Fab region in an antibody?
test q
-antigen binding
-the variation/sequence differences in AAs allows a wide range of specific activity and recognizes many different kinds of antigens
88
What is the function of the Fc region in an antibody?
-constant region
-this is where complement activation occurs
-this region attracts inflammatory cells
-in charge of opsonization (phagocytosis by macrophages with assistance of Ab and complement)
-macrophages have receptor for Fc region and complement, so this also enhances opsonization
89
How many Ab classes are there?
test q
5
90
Which Ab is the most abundant?
test q
IgG
91
Which Ab is the smallest (monomer)?
test q
IgG
92
Which Ab is transplacental and confers immunity to fetus and neonate within first few weeks of birth?
test q
IgG
this is the smallest Ab, so it can easily cross placenta barrier
also this natural passive immunity
93
Which Ab helps opsonization?
test q
IgG
94
How many Ag binding sites does IgA have?
4
94
Which Ab is an opsonin?
test q
IgG
95
Which Abs help in neutralization? Rank them from best to least best
test q
1) IgM (best/highest neutralization function)
2) IgA
3) IgG
96
What are the 2 types of IgA?
test q
1) serum type (circulatory in blood, monomer form)
2) secretory type (slgA, dimer (2 monomers), seen in tears, mouth, breast milk/colostrum, and secretory mucosomembrane surfaces such as GI tract and urinary tract)
97
Where is secretory IgA found?
test q
-tears, mouth, breast milk/colostrum
-secretory mucosomembrane surfaces such as GI tract and urinary tract
98
Rank the Abs from highest to lowest conc.
test q
1) IgG (highest conc.)
2) IgA
3) IgM
4) IgD
E) IgE (lowest conc.)
99
Which Ab is the largest (pentamer)?
test q
IgM (has 10 Ag binding sites)
100
Which Ab is the first to be made by the fetus with B cells and follows antigen stimulus?
test q
IgM
101
Which Ab has similar function to IgG but with higher valency/strength?
test q
IgM
102
Which Ab is found on the surface of B cells with the BCR?
test q
IgD
103
Which Ab does not bind complement?
test q
IgD
104
Which Ab binds to basophils and mast cells and is associated with allergies and parasitic infections?
test q
IgE
105
What are agglutinins?
Ab that combines with particulate Ag and causes agglutination (clumping) (ex: blood typing)
106
What are precipitins?
Ab that combines with soluble Ag (toxins, viruses or any soluble antigenic protein) to form a precipitation complex
107
What are the 2 opsonins we learned in class?
1 is an Ab= IgG
and 1 is a complement protein= C3b
108
What are lysins?
-Ab that will lyse particulate Ag
-usually needs the presence of complement (a normal serum protein) to complete this reaction
109
What is antitoxin?
soluble Ab that neutralizes toxins (ex: tetanus toxin, diphtheria toxin, botulism toxin)
110
define affinity
strength of the reaction between a *single* antigenic determinant and a single Ab
111
define avidity
*overall* strength of binding between an Ag with many determinants and multivalent Abs (multiple binding sites)
112
define specificity
ability of an individual antibody combining site to react with only one antigenic determinant and the ability of a population of antibody molecules to react with only one antigen
113
define cross reactivity
ability of an individual Ab combining site to react with more than one antigenic determinant and the ability of a population of Ab molecules to react with more than one Ag
114
Abs are formed or acquired through....
-natural infection and recovery
-vaccination (killed or attenuated)
-transplacental (only IgG)
-breast milk feeding for secretory IgA
-receiving Abs from another person (ex: tetanus antitoxin)
115
All blood and immune cells originate from ___________________ in the bone marrow
pluripotent stem cells
116
T lymphocytes originate in the bone marrow, take a trip through blood to the thymus to undergo ___________________ development and maturation before moving to secondary lymphoid tissues (spleen, lymph nodes, appendix, etc.)
antigen independent
117
Which cells are chiefly responsible for cell mediated immunity?
cytotoxic T cells (appear early in the immune response and release granules to attack virus infected cells, tumor cells, transplants, fungi, TB, leprosy, etc)
117
Which cell stimulates cytotoxic T cells/ CD8 and helps with cell mediated immunity?
TH1
118
B cells are mainly involved in _________ immunity
humoral (Ab production)
119
The first Ab always secreted is....
test q
IgM
120
The first Ab always secreted is IgM, but then can undergo class switching. What can it switch to?
IgG, IgA, or IgE
121
6 participants are involved to prepare B lymphocyte to be converted to a plasma cell (Ab forming cell for humoral immunity). What are the 6 participants?
test q
3 cells, 3 molecules
-macrophage or another professional APC like DCs or B cells (note: if B cells are the APC then this process will only need 2 cells not 3 in total)
-CD4 lymphocyte/T helper cell
-B lymphocyte/B cell
-exogenous antigen
-MHC class 2
-cytokines IL4, IL5, and IL6
122
6 participants are involved to prepare endogenous antigen for cell mediated immunity. What are the 6 participants?
test q
3 cells, 3 molecules
-any nucleated cell (can be nonprofessional APC or professional APC)
-cytotoxic T lymphocyte
-target cell
-endogenous antigen
-MHC class 1
-perforin and granzyme
123
MHC is a set of molecules displayed on cell surfaces that are responsible for ____________________ and antigen presentation. The MHC molecules control the immune response through recognition of self and non-self
Lymphocyte recognition
124
The MHC is encoded by several genes located on human chromosome ____. MHC genes encode MHC classes ___________
6, 1-3 molecules
125
MHC class 1 molecules are glycoproteins expressed on the surface of ____________________. The major function is presentation of ________________ peptide antigens to CTL cells
Every nucleated cell (non-professional APCs), endogenous
126
Are viruses usually considered endogenous or exogenous?
Endogenous
127
MHC class 2 molecules are glycoproteins that are expressed primarily on ________________________, where they present processed _______________ antigenic peptides to T helper cells
Professional APCs, exogenous
128
Is bacteria usually considered endogenous or exogenous?
Exogenous
129
What are the professional APCs? Where can they be found?
Macrophages, dendritic cells, and B cells
-APCs can be found in skin, lymph nodes, spleen, underneath mucosal epithelium, thymus
130
T/F: B cell can present to TH cell and then the same or a different B cell can make the Abs
true
131
What MHC class do professional APCs have?
Both MHC class 1 and 2
132
What MHC class do non-professional APCs have?
Only class 1
133
What are some examples of non-professional APCs?
Any nucleated cells for example:
-fibroblasts (skin)
-glial cells (brain)
-pancreatic beta cells
-thymic epithelial cells
-thyroid epithelial cells
-vascular endothelial cells
-any of the professional APCs
134
What is antigen processing and presentation? What role do T cells play here?
-processing= antigenic protein must be degraded into peptides (inside APC) in order to be presented for destruction
-T cells must recognize processed Ag
-CTLs recognize the antigen fragment by the way of the TCR
-antigenic presentation= peptide MHC complex is transported to APC cell membrane and is displayed for recognition by T cells
135
Which WBC is best for allergies?
Basophils
136
Which WBC is best for parasites?
Eosinophils
137
Which IL do macrophages produce?
IL1
138
Interactions between ____ molecule (CTL) and MHC class 1 stabilizes and consummate the antigen recognition process allowing CTL to respond to endogenous antigen leading to target cell destruction
CD8
139
MHC class 2 is found on.....
B cells, DCs, and macrophages, aka all are professional APCs
139
The professional APCs present antigen to ___________ cells and they will recognize the antigen through TCR
helper T (CD4)
140
The professional APCs present antigen to helper T (CD4) cells and they will recognize the antigen through TCR. The helper T cells then activate ____________________________ that will lead to destruction of the pathogen
B cells by sending IL4, IL5 and IL6 to produce Abs
(interactions between the CD4 molecule (T helper cells) and class 2 MHC stabilize and consummate the antigen recognition process allowing T helper cells to respond to exogenous antigen leading to B cell activation and production of the antibody)
141
Which cell secretes IL4/IL5/IL6 and helps B cells transform to plasma cell for Ab production and help humoral immunity?
TH2
142
What receptors does a pre T cell have?
none
143
What receptors does a pro T cell have?
both CD4 and CD8
144
a mature B cell is also known as....
naive
145
If a plasma cell doesn't die after Abs are needed/used then what happens?
cancer like multiple myeloma
