immunology Flashcards

1
Q

is the immune system big - explain

A

enormous
scattered throughout the body
connected by blood and lymph
not localized, very diffuse

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2
Q

describe the immune systems role in protection

A

protects whole body at all times
must reach all parts of body at the same time

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3
Q

what does immune system protect against

A

pathogens - bacteria, viruses, parasites
altered body cells - cancer

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4
Q

what happen when immune system turns on us

A

autoimmune disorders - own immune system sees you as foreign
foreign tissues: transplant or graft - immunosuppressant stops rejection

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5
Q

name the 2 prongs of immune system

A

non specific/innate immunity
specific/adaptive immunity
born with both

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6
Q

describe briefly innate/nonspecific immunity

A

first line of defence
does not need to recognize pathogen - nonspecific
same response each time it sees a pathogen

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7
Q

describe briefly specific/adaptive immunity

A

requires recognition of the pathogen
faster response when it sees the same pathogen again

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8
Q

describe the 3 mains way things are discovered in science

A

accidents of nature - like a stroke - reveals that stroke effects speech
leaps of faith - make observation and test
serendipity - happy accidents

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9
Q

name and describe something that was discovered by serendipity

A

Penicillin
fungus on plates
no other bacteria can grow there - discovered first antibiotic

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10
Q

name and describe something that was discovered by accidents of nature

A

SCID
lack of formation of immune system
david vetter
missing a specific cytokine important for different immune cells
injected with bone marrow from sister - but she had mononucleosis (epstein barr virus) and david died

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11
Q

describe aids (discovery)

A

80s in young men
HIV kills T helper cells
which are important in adaptive immune response

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12
Q

name and describe something that was discovered by leap of faith

A

smallpox vaccination
1796 - edward jenner
saw milkmaids had pox on hands but dont get small pox
they contracted cow pox
took puss of pox and injected into son and he did well
this caught on and people were doing this - saves lives

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13
Q

describe smallpox

A

dreadful infectious disease- killed over 300 million people and lasted for 3000 years and killed 30% of those who had it

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14
Q

is small pox still an issue

A

no
last man who had it in world = 1977 ali maow maalin - survived with treatment
2 other cases = accidental lab exposure - 1978 - one died
Eradicated in 1980

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15
Q

why is immunization called vaccination

A

Because smallpox virus = vaccinia virus - vaccine comes from cow pox

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16
Q

what are the 3 main components of immune system

A

lymphoid organs
immune cells - leukocytes
Secretions of immune cells - cytokines

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17
Q

describe types of lymphoid organs

A

primary lymphoid organs - sites where stem cells divide and immune cells develop
secondary lymphoid organs - sites where most immune responses occur

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18
Q

name types of sites of primary lymphoid organs

A

bone marrow (yolk sac and fetal liver in embryo)
thymus

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19
Q

describe bone marrow (primary lymphoid organs)

A

fetal liver in embryo - site of hematopoiesis
blood cells produced here - B cells and immature T cells
site where B cells mature

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20
Q

describe thymus (primary lymphoid organs)

A

located above heart
contains T cells, scattered dendritic cells, epithelial cells and macrophages
site where T cells mature
atrophies after maturity (small in old people)

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21
Q

name the 3 secondary lymphoid organs

A

lymph nodes - main site
spleen
lymphoid nodules

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22
Q

describe lymph nodes (secondary lymphoid organs)

A

scattered in body ~ 600 of them
biggest ` 1cm in size
filter microbes - filters and traps
macrophages in nodes phagocytize microbes that enter lymph
site where immune reponse occurs - carry back and fight in lymph nodes

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23
Q

describe spleen (secondary lymphoid organs)

A

largest lymphoid organ
removes microbes and old erythrocytes

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24
Q

describe lymphoid nodules (secondary lymphoid organs)

A

tonsils & adenoids at back of throat - help protect respiratory tract
peyers patches (in gut) and MALT (mucosal associated lymphoid tissues - at every place that contacts external environment)
appendix - part of SI

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25
where do immune cells travel
blood and lymphatic vessels
26
what are immune cells
Leukocytes white blood cells
27
why are they called B cells
remove bursa of chicken = no more b cells
28
describe the 2 lineages of wbcs
lymphoid or myeloid
29
what does lymphoid committed stem cell give rise to
lymphocytes = T cells (cytotoxic T cells CD8+, helper T cells CD4 +, regulatory T cells CD4+) B cells NK cells
30
what does myeloid committed stem cell give rise to - form immune system
neutrophil monocyte --> macrophage and dendritic cells eosinophil basophil
31
why are granulocytes important
release different components like histamines - increase blood flow and allergic response cytokines effectors
32
which cells are granulocytes
esoinophils basophils mast cells
33
describe eosinophils
destroys parasites
34
describe basophils
release a variety of chemicals, histamine, prostaglandins
35
describe mast cells
release chemicals histamines
36
describe neutrophils
phagocytes first important one at site of infection
37
describe monocytes
become macrophages and dendritic cells (phagocytes)
38
when is immune system activated
when breach in barrier - at level of skin allows pathogens to get into tissue starts with nonspecific branch - things like inflammation
39
describe the nonspecific/innate immunity branch
ability of body to defend against microbes and other foreign substances without recognition of pathogen first line of defence - physical barriers second line of defence - cellular factors and humoral factors
40
define first line of defence and name the 3 components
barriers to skin and creating an unpleasant environment for microorganisms Additional physical and mechanical barriers Chemical and microbiological barriers
41
describe skin (first line of defence)
water resistant prevents entry of foreign substances
42
describe additional physical and mechanical barriers (first line of defence)
tight junctions in epithelia - like in gut mucus hair and cilia - lungs so move out stuff and wont be infected
43
describe chemical and microbiological barriers (first line of defence)
secretions - sebum, lysozyme, gastric juice normal flora - microbiological components - help fight bacteria and infection
44
describe second line of defence - innate immunity
no memory - humoral factors inflammation and fever Antimicrobial substances - acute phase reactants (happen quick)= c reactive protein (produced by liver in response to inflammation), complement, cytokines interferons mobilize wbcs to site of infection to help fight off
45
what is inflammation
non specific response to tissue damage
46
what are 4 distinct signs and symptoms of inflammation
redness heat pain swelling
47
what are 3 stages of inflammation
vasodilation emigration of phagocytes tissue repair
48
describe vasodilation (inflammation)
Widening of blood vessels allow more blood to flow to site increased permeability of capillaries allows substances to go to damaged site stretch of capillary and endothelial cells allows more fluid to move into tissues
49
what are humoral substances
Discourage microbial growth or spread of pathogen
50
name the 3 humoral substances
interferons complement iron binding proteins
51
describe interferons (humoral substances)
antiviral proteins
52
what does type 1 interferon prevent
viral replication
53
describe how type 1 interferon prevents viral replication
usually - viruses come in and use DNA to replicate then cells die and virus particles go on to infect other cells cell detects virus and secretes interferons these have receptors and when activated causes cell to produce antiviral proteins - these prevent virsu from using cell to replicate
54
describe complement (humoral substances)
large family of plasma proteins with multiple functions 30 different proteins participate in the immune cascades
55
describe pathway of innate immunity for complement
pathogen surfaces --> complement activation (C3b) --> opsonization of pathogens = bind to surface of bacteria and prepare for eating
56
describe function of complement C3b as an opsonin
C3b receptor C3b sticks to bacteria and makes it easier for phagocytes to recognize foreign cell and ingest bacteria
57
describe iron binding proteins (humoral substances)
transferrin very important for bacterial infection non specific response will sequester iron and want to keep it away from infection - makes it harder for bacteria to divide since it wont have enough iron
58
what does bacteria in blood lead to
sepsis so bacteria must travel in immune system
59
what does opsonization mean
prepare for eating
60
describe how a monocyte becomes a macrophage or dendritic cell
moves out into tissues = macrophage or dendritic cells (called dendritic because fingerlike projections look like drendrites on neuronal cells)
61
what else does second line of defence include
cellular factors - Natural killer (NK) cells (lymphocytes) and phagocytes (neutrophils)
62
describe NK cells
class of lymphocytes - similar to cytotoxic t cells target virus infected cells and cancer cells attack and kill targets directly after binding tom them not antigen specific - does not to recognize
63
describe how NK cells work
cells do not express MHC class 1 release chemicals that lead to death of infected or abnormal body cells releases perforin - forms pores in cells and then granzymes go in to cell and destroy it
64
describe relationship between MHC class 1 and NK cells
MHC 1 proteins expressed on all normal nucleated body cells recognized by NK cells and they will not kill it altered or absent MHC1 proteins do not stimulate a negative signal NK cell is activated and releases agents that kill the cell
65
what do phagocytes do
non specifically engulf microbial invaders
66
name 3 types of phagocytes
fixed tissue macrophages - already in tissues neutrophils - will be recruited to site of injury monocytes - macrophages and dendritic cells
67
name 4 steps of phagocytosis and intracellular destruction of a microbe
adherence ingestion digestion killing
68
describe phagocytosis and intracellular destruction of a microbe
recognition from endosome & brings in bacteria in membrane bound compartment (endocytosis and phagosome formation) --> combines with lysosome (low pH destroys bacteria) --> forms phagolysosome --> release of end products into or out of cells --> debris and signals
69
how do phagocytes recognize microbes
Detects unique conserved structures that are essential to microbial physiology (molecular signature of infection) bacteria has cell wall proteins that mammals do not have called PAMPS (pathogen associated molecular patterns)
70
what are PAMPS
cell wall components that can be recognized - body doesnt express lipopolysaccharide (LPS) of gram negative bacteria peptidoglycan (PGN) of gram positive bacteria
71
what are PAMPS recognized by
immune system receptors = pattern recognition receptors (PRR), including toll like receptors on the surface of the macrophage
72
what are toll like receptors
Family of highly conserved transmembrane receptors essential for microbial recognition via PAMPs nonspecific event
73
name the 2 domains for TLRs (toll like receptors)
extracellular domain for recognition of pathogens intracellular signalling domain
74
name things recognized by toll like receptors
lipoproteins Peptidoglycans dsDNA flagellin lipopolysaccharides
75
what starts process of inflammation
Signalling starting with toll like receptors
76
describe the starting process of inflammation
fixed tissue macrophages in tissues have TLRs on surface and they recognize bacteria (PAMPS) and sends signal cytokines start inflammation process - neutrophils come first signalling event starts inflammation
77
describe emigration of phagocytes (steps of inflammation) - informally
phagocytes go to capillary spaces neutrophils move out and leave capillary to site of infection and pick up bacteria
78
name 3 processes of emigration of phagocytes (steps of inflammation)
chemotaxis margination diapedesis
79
describe chemotaxis (emigration of phagocytes)
chemically stimulated movement of phagocytes chemokines/chemoattractants - attract phagocytes (neutrophils)
80
describe margination (emigration of phagocytes)
sticking to endothelial cell neutrophils will adhere and stick
81
describe diapedesis (emigration of phagocytes)
phagocytes move across capillary wall finger like projections between pores of endothelial cells and moves into tissue
82
describe specific role of neutrophils in inflammation
neutrophils die in process of killing bacteria NETs- neutrophil extracellular traps are made of processed chromatin and bound to granular and selected cytoplasmic proteins which come from lysed neutrophils leads to production of pus - mixture of dead bacteria and neutrophils
83
describe APCs (antigen presenting cells) - informally
more macrophages and dendritic cells - move to site of injury take to lymph node and activate immune system phagocytize some bacteria and bring back to lymph node and spleen to activate immune response
84
what are antigens aka
immunogen - material that induces an immune response allergen - if inducing an allergic response ligand - for activating system
85
what does antigen stand for
ANTIbody GENerator antibodies bind to antigen
86
what can antigens be
whole cell or part of a cell non microbial = pollen, egg whites, incompatible blood cells, transplanted tissues
87
what is epitope
part of antigen recognized by immune cell and part that binds to antibody
88
what bridges gap between innate and adaptive immunity
dendritic cells - via antigen presentation by phagocytes happens at lymph nodes dendritic cell brings it back lymph node (region where other immune cells are)
89
describe specific/adaptive immunity
mediated by antibodies or cells humoral antibody mediated immunity and cell mediated immunity
90
what is MHC
major histocompatibility complex (MHC)
91
name the 2 classes of MHC
MHC-1 (HLA-A, HLA-B, HLA-C) MHC-2 (HLA-DP,HLA-DQ, HLA-DR) only twins can have the MHCs on their cells Signature of self - no one else would have the same - very hard for transplants
92
where is MHC-1 found
on all nucleated cells
93
where is MHC-2 found
on all APCs (macrophages, dendritic cells, B cells)
94
when do T cell receptors recognize antigens
only when they are associated with MHC-2 proteins (on surface) part of antigen presentation process
95
what do APCs present
present exogenous antigens with MHC-II on surface of phagocyte
96
describe steps of APC
ingest antigen digestion into peptide fragments synthesize and package MHC-II molecules bind peptide fragments to MHC-II insert antigen-MHC-II complexes on plasma membrane
97
name and describe the 2 antigen characteristics of adaptive immunity (acquired, specific)
reactivity = antibody binds specifically to antigen that provoked it immunogenicity - can provoke an immune response by producing antibody to that antigen
98
which cells are APCs
MHC-II + antigen interdigitating dendritic cell/ professional APC (carry antigen to regional lymph node and start process) macrophage B lymphocyte (cell)
99
define specific/adaptive immunity
ability of body to defend against specific microbes and foreign substances involves memory for previously encountered antigens
100
which cells involved with adaptive/specific immunity
B and T cells must recognize specific foreign material to be attacked
101
what is an antigen
any molecule that can trigger an adaptive immune response against itself of the cell bearing it
102
name 3 stages of typical adaptive immune response
recognition of an antigen by lymphocytes lymphocyte activation attack launched by the activated lymphocytes and their secretions (cytotoxic t cells - kill directly or plasma cells - secrete antibodies)
103
describe humoral cells - specific/adaptive immunity
B cells transform into plasma cells and produce and secrete antibodies use antibodies and complement to kill
104
describe cell mediated cells - specific/adaptive immunity
cytotoxic t cells kill infected cells attack infected body cells, cancer cells, foreign cells
105
describe origins of B cells and T cells
lymphoid stem cell --> immature T and B cells T cells = go to thymus to mature B cells - go to secondary lymphoid organs, needs activation by antigen cells from T cells (cytotoxic cells) kill cells - must recognize antigen first also have memory cells B and T cells must recognize antigen T helper cell needed to fully activate T and B cells
106
describe process though lymph node
mature cells move into lymph bode APC must find B and T cell to start process - it finds them APC recognizes antigens antigen recognized by specific receptors expressed in T cells to have recognition coreception required (B7-CD28 along with MHC-II + peptide -TCR)
107
what is checkpoint inhibition
all biological processes need shut off controls immune response involves displacement of CD28 from B7 by CTLA4 or PD-1
108
describe checkpoint inhibition
T cell is binding to APC it will express MHC1 on surface - matches APC but eventually it will present new receptor (CTLA4 or PD-1 (similar)) and this is signal to turn off - no more t cells killing in some cases = produce antibodies that are specific for CTLA4 or PD1 = will bind and prevent from being inactivated so T cells can keep killing - used in cancer therapy to kill cancerous cells
109
describe a situation on an APC
MHC-1 on APC activates T helper cells B cell will only be activated if it recognizes antigen and either directly or via cytokines will be activated by helper T cell
110
describe humoral antibody mediated immunity (specific/adaptive immunity)
involves B cells (lymphocytes) transform into plasma cells synthesize and secrete antibodies memory B cells - to respond faster recognize pathogen
111
describe cell mediated immunity (specific/adaptive immunity)
involves cytotoxic T cells - similar to NK cells kills infected body cells, cancer cells, foreign cells
112
what do macrophages do (to T helper cells)
at level of their endosome they can put together their own MHC class 2 molecule again with part of peptide (fragment of antigen) and carry it to regional lymph node encounters T helper cells that have appropriate receptor on their surface
113
what does APC-MHCII-ANTIGEN complex do when it moves to regional lymph node
activates T helper, cytotoxic T cells and B cells --> all these cells produce memory cells B cells also need to be activated by interaction of with antigen but needs cytokines form T helper cells to fully activate (to produce plasma cells that secrete antibodies)
114
name the 3 steps of activate T helper cells
1 - specific recognition (MHC2 +peptide-T cell receptor) 2 - co reception (CD28-B7) cytokine release from APC (stimulates T helper cell)
115
what type of cells are T helper cells and what does that mean
CD4+ cells there is also some recognition event between APC and T helper cell with respect to CD4
116
do B cells have to directly interact with APC
no
117
can B cells act as APCS - explain
yes they can they can process and present antigen to T helper cell can take in some of pathogen and break out and present on surface via MHC class 2 and with help of CD$ molecule will activate T helper cell
118
describe serum protein electrophoresis during infection and during normal
normal - super high peak in albumin, lower alpha 1, higher alpha 2, higher beta, low gamma globulin infection - super high peak in albumin, lower alpha 1, higher alpha 2, higher beta, high peak gamma globulins (antibodies)
119
describe plasma cells - EM and other factors
cytoplasm completely filled with membranous structures = ER (endoplasmic reticulum) need this bc cells are essentially protein factors only job = produce antibodies ~thousands/min short life span ~ one week
120
define antibodies
part of a group of proteins called globulins immunoglobulins (Ig)
121
what do antibodies contain
two identical heavy chains two identical light chains
122
what are regions of antibodies
variable region - variable heavy and light chain constant region - handle at bottom
123
describe variable region of antibodies
antigen binding site FAB region antigen binding fragment hypervariable region
124
describe constant region of antibodies
same in all antibodies of a class Fc region crystallizable fragment
125
what is purpose of hypervariable region of variable region of antibodies
hyper variable regions must be different to recognize different antigens and give antibody specificity
126
what is antibody class determined by
constant region, Fc protein makeup
127
name the 5 classes of antibodies
IgG IgA IgM IgD IgE
128
describe structure of antibodies
Y shaped globular
129
describe IgGs
most numerous cross the placenta (pass from mom to fetus) small size 2 binding sites = divalent peak in electrophoresis
130
describe IgAs
found in MALT (mucosal associated tissues - anything in contact with outside world like lungs) and breast milk (passed from mom to nursing child) 4 binding sites = tetravalent harder to move through body dimer
131
describe IgMs
first formed complement activation (opens complement cascade) decavalent pentamer harder to move through body
132
describe IgDs
prenatal
133
describe IgEs
allergy
134
what is antibody mediated immunity carried out by
B cells
135
describe how antibody mediated immunity is carried out
B cells become activated in spleen, lymphoid nodule or lymph node, (secondary lymphoid organ) in presence of microbe undergo clonal selection (have right receptor and clone of B cell will be selected to produce more of them) to produce = plasma cells and memory cells
136
what do memory cells allow
faster response if antigen is seen again
137
name the 2 types of antibody immunity
actively or passively acquired
138
describe actively acquired antibody immunity
the persons own immune system responds to microbe long lasting protection - memory cells involved natural or artificial
139
describe passively acquired antibody immunity
person receives antibodies from another person or animal temporary protection - no memory cells involved natural or artificial
140
describe types of actively acquired antibody immunity
natural = develops when person is exposed to an antigen by chance (ex=flu) artificial = develops when person is purposefully exposed to antigen (ex=flu vaccine)
141
describe types of passively acquired antibody immunity
natural = IgG from mother to fetus across placenta & IgA in breast milk artificial = receive serum containing antibodies from person or animal that has been vaccinated (ex=ebola/covid)
142
define active immunity
resistance due to bodys contact with microorganism, their toxins or other antigenic components (from infection or vaccine)
143
what type of thing is active immunity
vaccine = may consist of small quantities of living or dead pathogens, small quantities of toxins or harmless antigenic molecules derived from microorganism or its toxin does not cause disease but response (parts of immune response)
144
describe general principle of active immunity
exposure to antigenic substance results in active immune response that induces formation of memory cells required for rapid, effective response to future infections by that particular organism (more robust)
145
define passive immunity
direct transfer of antibodies from one person to another
146
describe 2 examples of passive immunity
fetus receives maternal IgG antibodies that cross placenta breast fed children receive IgA antibodies in moms milk (intestinal mucosa is permeable to IgA antibodies during early life - short, will get diluted out or used in system)
147
what is important for infant during first months of life and why
passive immunity - sources of protection antibody synthesizing capacity is relatively poor
148
name the 6 antibody functions
Neutralizing Antigen Agglutination of Antigens Precipitation of Antigens Activating Complement Opsonization Antibody-Dependent Cellular Cytotoxicity
149
describe neutralizing antigen (antibody functions)
antibody binds to toxin released by antigen and prevents from infecting us - so toxin will not reach target
150
what do mRNA vaccines do
allows your body to produce antigens
151
describe agglutination of antigens (antibody functions)
glues them together prevent from travelling and easier to phagocytize
152
describe precipitation of antigens (antibody functions)
bring our of body fluid and hold them together makes easier for phagocytosis keeps antigen from preforming function
153
describe activating complement (antibody functions)
starts out with fist complement protein (inactive) and leads to membrane attack complement bacteria find matching antigen = activates C1 complement (first complement protein now active - activates C1)
154
describe opsonization (antibody functions)
antibody binds microbe and opsonizes it makes it more visible to phagocytes
155
describe antibody dependent cellular cytotoxicity (antibody functions)
via cytotoxic T cells antigen response
156
what are complements
serum proteins
157
describe activating complement (antibody functions) - pathway
classical pathway - antigen antibody complexes --> complement activation --> opsonization of pathogens and killing of pathogens by membrane attack complex
158
describe activation of classical complement pathway by antibody binding to bacterial antigen
set off cascade and activate other complement member in family complement proteins serve as pores in cell and leads to death
159
describe opsonization (antibody functions) in more detail
phagocytes have receptors specifically to FC branch of antibody Recognition of antibody of certain class aids in phagocytosis
160
describe graph of rate of antibody production following initial exposure to antigen (~ 4 stages)
1 month scale slow in beginning = do not have many of the lymphocytes with appropriate receptor on surface then expand clones and increase rate and number of production of antibodies peaks = have antibodies present for variable amounts of time - depends on specific antigen end = antibodies broken down and fade away - higher concentration than initial but not much higher since infection is over
161
describe graph of rate of antibody production following subsequent exposure to same antigen
expanded clones and now have memory cells so very rapid and much higher response that is longer lasting
162
what are the 3 main adaptive immunity components
lymphocytes must gain immunocompetence - develop antigen receptors B cells - produce antibodies T cells - cytotoxic T cells (CD8+) and helper T cells (CD4+)
163
why do we get sick
not fast enough or enough antibodies at first exposure
164
name the 3 types of T cells
cytotoxic T cells= CD8+ helper T cells =CD4+ regulatory T cells = CD4+
165
describe how lymphocytes develop antigen receptors
variable region on receptor has a variety of genes that encode for it = V,D, & J (joining) each individual cell choses a V D and J segment with help of RAGs then choose one segment from constant region
166
describe RAGs
recognize splice sites at beginning of different segments and put them together to produce one possible outcome recombination activating genes
167
what are TdT
Terminal deoxynucleotidyl transferase can add single or multiple nucleotides at end of segments that have been joined creates frameshift - so will have different output for that allows infinite production of antigen receptors
168
what type of antibodies are produced during response (graph) and why
IgM produced first = best to activate complement system but too big to move well so switch to IgGs IgGs = memory cells and expanded clones also others like IgAs
169
describe process of making an antigen receptor
each choose V D J use TdT to change receptor so its unique to specific B cell M constant region to create IgM BUT can switch this constant region to a gamma segement to produce IgG
170
can plasma cells produce different classes of antibodies and why
one one variable region that will determine specificity but plasma cells can produce different classes (by switching constant region)
171
will the body create self antigens
usually - under normal circumstances = no
172
what is one way to recognize self
Major histocompatibility complex (MHC) unique to each person, except in identical twins, important in tissue/organ transplant rejection
173
what is immune tolerance and explain
develops during fetal and early postnatal life due to clonal detection or clonal inactivation of cells that match body antigens - basically get rid of any lymphocytes that have receptors that recognize own body
174
describe development of T cell tolerance in utero in the thymus - 3 concepts
T cells must recognize MHCII molecules - any T cells that cannot will be negatively selected (destroyed) T cells should not recognize self proteins, cells expressing own MHCI - will be negatively selected 95% of T cells produced will be destroyed bc they are self reactive
175
how are T cells negatively selected (destroyed)
die by apoptosis
176
do cytotoxic T cells need recognition of antigen
yes
177
why do B and T cells response more rapidly if seeing same antigen
amplification due to production of memory cells
178
name the 2 types of antigens
exogenous endogenous
179
describe endogenous antigens
produced by body cell cytotoxic T cells must recognize it
180
describe exogenous antigens
foreign material comes from outside body
181
name type of endogenous antigens and explain process
infected body cells (virally infected) = synthesis of MHCI molecules binding of peptide fragments to MHCI molecules packing of antigen-MHCI complexes insertion of antigen-MHCI complexes into plasma membrane
182
name the type of exogenous antigens and explain process
antigen presenting cells = synthesis of MHCII molecules binding of peptide fragments to MHCII molecules packing of antigen-MHCII complexes insertion of antigen-MHCII complexes in plasma membrane
183
describe process of cell mediated killing of virus infected cells
dendritic cell intermediary = T cell receptor T cell receptor releases cytokines = critical for activation of B cells and cytotoxic T cells cytotoxic T cells must also recognize antigen leads to killing of infected body cell by cytotoxic T cell (release of perforin and granzymes)
184
what do infected body cells present antigens use to present antigens to cytotoxic T cells
MHCI signal that own body cells are infected or altered
185
describe how cytotoxic T cells kill virus infected cells
need cytokine from T help to lead to production and cell division then the many cells can kill using perforin and granzymes
186
name the 5 factors that alter resistance to infection
protein calorie malnutrition preexisting disease stress and state of mind sleep deprivation modest exercise and physical conditioning
187
describe protein calorie malnutrition (factors that alter resistance to infection)
greatest contributor to decreased resistance to infection worldwide need appropriate materials to mount effective immune response
188
describe preexisting disease (factors that alter resistance to infection)
like if already fighting infection infectious or non-infectious- can predispose body to infection
189
describe stress and state of mind (factors that alter resistance to infection)
can enhance or reduce resistance to infection and cancer
190
describe sleep deprivation (factors that alter resistance to infection)
associated with decreased immune function
191
describe modest exercise and physical conditioning (factors that alter resistance to infection)
net beneficial effects on immune system and host resistance
192
why do immunodeficiency diseases happen
results from weak, underactive or impaired immune system like missing proteins or cells in immune system
193
describe SCID
severe combined immunodeficiency disease immunodeficiency disease a group of related diseases that arise from an absence of both B and T cells and some cases NK cells (could be caused by lack of cytokine needed for development of these cells)
194
describe AIDS
acquired immunodeficiency syndrome immunodeficiency disease infects and kills helper T cells (which are central in inactivation of B cells and cytotoxic T cells) resulting in impaired immune responses to infectious organisms
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name 5 harmful immune responses
tissue/graft rejection transfusion reactions allergy - hypersensitivity autoimmune disease excessive inflammatory responses
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describe rejection of tissue grafts or organs - why it happens
MHC-I proteins on graft cells and MHC-II proteins on the macrophages differ from recipients recipients T cells recognize MHC proteins as foreign and cytotoxic T cells with the aid of helper T cells kill cells with foreign MHCs
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how to avoid organ/tissue graft rejection.
radiation to eliminate dividing cells - rapidly dividing lymphocytes drugs that kill actively dividing lymphocytes - decrease recipients T cell population more susceptible to any other infections now
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what is cyclosporine
drug that can help avoid rejection blocks cytokine production from helper T cells eliminates signals for proliferation of helper and cytotoxic T cells
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what is a transfusion reaction
illness causes when rbcs are destroyed during blood transfusion
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why would transfusion reactions happen
rbcs do not have MHC proteins (since no nucleus) but have plasma membrane proteins and carbohydrates that function as antigens ABO system and Rh erythrocyte-membrane antigens
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universal donor of blood
O
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universal recipient of blood
AB
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describe Rh factor
negative or positive has medical important
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describe Rh factor during pregnancy
if mom is + and baby is - mom will attack baby if their bloods mix usually happens during childbirth so drug given to mom to ensure that mom does not attack baby prevents mom blood from targeting blood of fetus in future pregnancies
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describe blood group A (percentage of population, antigen on rbc and antibody in blood)
42% Antigen on rbc = A antibody in blood = anti-B
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describe blood group B (percentage of population, antigen on rbc and antibody in blood)
10% Antigen on rbc = B antibody in blood = anti-A
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describe blood group AB (percentage of population, antigen on rbc and antibody in blood)
3% Antigen on rbc = A & B antibody in blood = neither anti-A OR anti-B
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describe blood group O (percentage of population, antigen on rbc and antibody in blood)
45% Antigen on rbc = NEITHER A or B antibody in blood = BOTH anti-A and anti-B
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what is an allergic reaction
overly reactive to substance that most tolerate well due to exogenous antigens some people react to things that others will not
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name the 2 types of allergic reaction
immediate hypersensitivity delayed hypersensitivity = appears 12-72 hours after allergen exposure
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describe function of mast cells in allergic reactions
mast cells filled with histamine granules in small amounts histamine good since recruits immune cells to site of injury too much = get into blood stream and systemic effect also happens with basophils since also filled with histamine
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what is anaphylaxis
allergic symptoms usually localized to site of antigen entry if large amounts of mast/basophil cells chemicals enter circulation = causes severe hypotension (low bp) and bronchiolar constriction = anaphylaxis = can cause death due to circulatory and respiratory failure
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what is autoimmune disease
inappropriate immune attack triggered by body proteins acting as antigens
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what is immune attack of autoimmune disease consist of
immune attack is mediated by autoantibodies and self reactive T cells direct against body cells that contain these proteins (proteins acting as antigens)
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name 4 types of autoimmune diseases
type 1 diabetes mellitus rheumatoid arthritis multiple sclerosis myasthenia gravis
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describe myasthenia gravis (autoimmune disease)
against a nicotinic acetylcholine receptor that is expresses on muscles make antibodies against muscle receptors and leads to paralysis
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what can dampen immune response
regulatory T cells dampen immune response - possible research area for autoimmune diseases