Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

M & D > Ch 18: Adaptive Specific Host Defenses > Flashcards

Ch 18: Adaptive Specific Host Defenses Flashcards

1
Q

Adaptive immunity displays specificity and memory

A

Specificity:
=> means the adaptive immune system can recognize slight differences between pathogens (more accurately between antigens)

Memory:
=> menas that the adaptive immune system changes over time, responds to the second challenge by the same pathogen more quickly but in different, better ways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Primary response

A

the response which follows the first exposure to a pathogen of antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

secondary response

A

the response whihc follows further exposures to the same (specific) pathogen or antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

adaptive immunity depends on lymphocytes

A

B and T cells

lyphocytes can rearrange their DNA after exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

B lymphocytes

A

mature in the bone marrow (the bursa in birds) and secrete antibodies (Ab)

most antibodies circulate in the blood, B cells and Ab are called humoral defence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

T lymphocytes

A

mature in thymus

secrete cytokines and interleukines (Th cells) or kill virus infected cells (CTLs)

cellular defence or immunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Antigens (Ag)

A

An Ag is a unique biological structure found only on one type of pathogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Viral Ag

A

all viruses have capsids, only influenza viruses have haemagglutinin proteins in the capsid, only influenze strain A H3N3 has the type H3 haemagglutinin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Protein Ag

A

proteins are the best Ag followed by carbs, nucleic acids, and lipids (most immunogenic)

protein Ag stimulate both humoral and cellular function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Carbohydrate Ag

A

stimulate only humoral immunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Lipid and Nucleic acid Ag

A

are only antigenic if attacherd to a protein or other moleucle called a hapten

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

epitope

A

the smallest part of an antigen recognized by an AB or a T cell receptor

large Ag have many epitopes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Antibodies

A

glycoproteins produced and secreated by B cells

all antibodies are at least bivalent

5 classes// isotypes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

IgM

A

the first Ab produced

is a pentamer of IgG like structyures so has 10 heavy and 10 light chains

is the Ab of teh primary respose

food at afflutination but does not bind Ag very strongly

activates complement

some B cells become memory cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

IgG

A

cirvulatory Ab, second type produced

bivalent, can bind two identical antigens

consistant domains interact with receptors on macrophage and neutrophils to cause opsinization and complement activation

oGG is the Ab of the secondary response

higher affinity than IgM

opsinizes, activates complement, agglutinates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

IgA

A

Ab agaisnt multicellular pathogens, also involved with allergies

secreted onto mucosal surfaces and binds pathogens there

dimer of bivalent Ab, so it has 4 heavy and 4 light chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

IgD

A

B cell surface Ab, B cell receptor

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Antibody strucutre IgG

A

4 polypeptides, 2 heavy and 2 light chains

each chain is made up of variable and consistant domains

the variable domain from one light chain and a variable domain from one heavy chain combine to form the antigen binding site

constant domains interact with receptors on macrophage and neutrophils to cause opsinization and complement activaiton

light chains have 1 variable domain and 1 constant domain

Heavy chains have 1 variable and 3 constant domains

19
Q

B cells and antibodies

A

Ab are only produced by B cells

As B cells amture, they undergorandom genetic rearrangement in the genes for Ab
=> in the varaiable region, generates a unique specificity for each Ab

each B cell produces a unique Ab

20
Q

B cell activation

A

IgD as the B cell receptor

when the B cell is activated by binding Ag to the IgD then IgM Ab are produced and secreted

B cells require T cells to activate

21
Q

Neutralization

A

Binding of antibodies to toxins// viruses to prevent them from attaching to receptors

IgG and IgM

binding of antibodies to bacterial cells to prevent them from attaching to epithelial and other cells

binding of antibodies to viruses to prevbent them from attaching to receptors

22
Q

Opsinization

A

binding of antibodies to bacteria then macrophage can bind to the Fc or constant region of that antibody - increases phagocytosis

23
Q

Agglutinization

A

Cross-linking of viruses and bacteria through at least bivalent antibodies to form clumps or aggregates

these clumps can be filtered out of the blood and lymph by the spleen and kidneys

24
Q

Complement activaiton

A

the classic pathway of complement activation starts with antibodies binding to bacteria

MAC attack to punch holes through membranes

three ways for complement activation

25
Q

Antibody dependent cell mediated cytotoxicity

A

works against large pathogens but also your own cells

antibodies bind to pathogen

NK cells and macrophages bind to the Fc or constant region of the antibodies and are stimulated to release granzymes to kill the pathogen

26
Q

Two MHC classes

A

MHC I is found on all nucleated cells

MHC II is found only on macrophage, DC and B cells (aka APCs)

MHC protiens are found attached to the cell membrane but mostly outside the cell

All MHC protiens bind antigens and present them to receptors on other cells

27
Q

MHC I proteins present antigens derived form inside the cell

A

these antigens are normally derived from host protiens so are “self” antigens

NK and CTL cells recognize these as “self” and do not attack those cells

When a cells is infected with a virus, or an intracellular bacteria “non-self” antigens are presented

NK and CTL cells recognize these as “non-self” and attack those cells and kill them (NK cells recognize the absence of MHC I)

28
Q

MHC II protiens present antigens derived outside the cell

A

macrophage and DC phagocytoize antigens form outside the cell

antigens are broken up in phagolysosomes

parts of the antigens attack to MHC II and are displayed on the outside of antigen presenting cells

these interact with T cells to activate them

29
Q

T cells

A

T cells produce a unique receptor TcR whihc is found on the surface of each T cell

also produced by random rearrangement of TcR genes

30
Q

T cells are activated by binding Ag to the TcR

A

the antigen must be presented ot the T cell by another cell

Activation is achieved by binding of the TcR to the antigen attached tot he MHC molecule

macrophage and DC cells present using MHC II

all other cells present Ag using MHC I

31
Q

Differentiation of T cells

A

T cells differentiate into T helper cells and CTLs

Th cells differentiate into Th1 and Th2 and Th17 cells

Th1 activate CTLs
Th2 activate B cells

CTLs when activated recognize virus and bacteria infected cells through MHC I and attack and kill them

32
Q

which portion of the antibody does the NK cell bind to

A

Fc

antibody bind to cell, NK cell recognizes, and kills the antibody bound cell

33
Q

Active immunity

A

creating your own immunity or activation of your own immune system because you actually got the infection

34
Q

passive immunity

A

cells and antibodies that were created in somebody elses active immune response are transferred to you, you dont actually get the infection

convalescence plasma when no other better option is avalible

35
Q

Herd immunity

A

not actually immunity, that is, not an individual immune response

in a population there are susceptible and non susceptible people

pathogens have to spread from host to host

if there are enough people in a population then the pathogen cannot find or spread to a new host// susceptible person

36
Q

live attenuated vaccinces

A

a pathogen is weakened by a spontaneous process or by human intervention

live attenuated duck egg, serial passages to attapt to a non-human host to reduce virulence

cons, are recombination with wild types and attenuated vaccine can become virulent again

this pathogen is injected into people

in connot cause the disease but can replicate in the host

usually provides strong cell and humoral immunity often for life

37
Q

inactivated vaccines

A

the pathogen is killed or made incapable of reproduction before being used in avaccine

phenols and propanol-lactones to inactivate viruses

not as strong an immune reaction and usually only humoral immunity is activated

38
Q

subunit vaccines

A

contain only a single protein or several proteins from the pathogen

not as strong an immune reaction adn usually only humoral

ex= flu vaccines used today, H and N proteins only

39
Q

toxoid vaccines

A

tetnus and diptheria vaccines

some bacterial infections are due solely to the production of a toxin

toxins are produced and inactivated and used in the vaccine via heat denaturation or gluteraldehyde

40
Q

conjugate vaccines

A

polysaccharides are not immunogenic but are virulence factors (ie capsules)

bacterial polysaccharides are chemically bound// conjugated to protiens and used in a vaccinne

protein causes the production of Ab against the polysaccharide

41
Q

DNA vaccines

A

the gene for an antigenic protien from the pathogen is inserted into a DNA plasmid moleucle

this plasmid is transfected into host cells

plasmid directs the transcription and translation of the pathogen protein

presentation of non-self protein on MHC I leads to immune system inactivaiton

42
Q

mRNA vaccines

A

the gene for an antigenic protein from the pathogen is inserted into a DNA plasmid molecule

this plasmid is transfected into E. coli cells which are grown and lysed to obtain a lot of plasmid DNA

the plasmid DNA is used with enzymes 9RNA pol) to produce mRNA for the pathogen protein

43
Q

how do we get the mRNA vaccine into you

A

the mRNA is packaged into lipid nanoparticles

these nanoparticles are injected into a person and the mRNA enters into the cytoplasm of the cell

cell translates the mRNA into protein which is presented as non=self protein on MHC I and leads to immune system inactivation

M & D (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions