Brainscape's Knowledge GenomeTM

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


See full index

Microimm 2500 > (I) Lecture 5: Intro to Adaptive Immunity > Flashcards

(I) Lecture 5: Intro to Adaptive Immunity Flashcards

1
Q

Main Cells of Adaptive Immunity

A

From lymphoid progenitors

B cells: antibodies
- important against EXTRACELLULAR pathogens

T cells: helper T cells (Th cells, CD4+ T cells) and cytotoxic T cells (CTL; CD8+ T cells)
- important against INTRACELLULAR pathogens

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

Primary response

A

FIRST exposure to pathogen

Kicks in later

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

Secondary response

A

subsequent exposure to the SAME pathogen
- memory B & T cells respond
- later and faster due to immunological MEMORY

adaptive b/c immune response is more efficient w/ re-exposure to an identical pathogen (memory)

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

Primary Immune Response

A
  1. Establishment of infection
  2. Inductive phase (turns on adaptive immune cells)
  3. Effector phase (adaptive cells perform)
  4. Memory phase

most adaptive cells die but a few remain as memory cells

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

Naive B and T cells

A

never encountered a pathogen before

differentiate into effector cells

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

Effector cells

A

B cells = plasma cells

T cells = helper T cells and cytotoxic T cells

they die once pathogen is destroyed

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

Memory cells

A

remain after infection is resolved

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

Immunological memory

A

initial exposure either due to vaccination or natural exposure
- naive B & T cells respond and become effectors
- primary immune response: memory B & T cells form

secondary exposure
- memory B & T cells respond
- more effector cells form
- faster and stronger response

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

Basis of Vaccination

A

Basis of vaccination is immunological memory to bypass primary response

Lots of antibodies against pathogens years after vaccination

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

Primary Lymphoid Tissue

A

where lymphocytes are developed

  • Thymus (T cells)
  • Bone marrow (B and T cells start here)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Secondary Lymphoid Tissue

A

where naive lymphocytes are further differentiated

  • lymph nodes
  • spleen (filters blood)
  • mucosa-associated lymphatic tissue (MALT)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Lymph

A

Interstitial tissue fluid that enters the lymphatic vessels to be transported back into the blood

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

Lymphatic system

A

network of tissues, vessels and organs that work in close proximity with the circulatory system

lymphatic capillaries run parallel to blood caplillaries

when lymph leaves tissues it carries wast products from tissues like dead cells, CO2 and pathogens

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

Lymph nodes

A

filters lymph that passes through

perfect spot for immune cells to “look for” pathogens

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

Vaccine injections

A

Typically intramuscular, on the arm
- good blood flow
- optimizes immune response
- vaccine components travel to closest lymph node (usually in armpits)

  • other routes of admin: subcutaneous (infants), orally, nasally
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Lymphoid tissue

A

B cells develop in bone marrow

T cells start to develop in bone marrow and finish developing in the THYMUS

17
Q

T-Cell Development

A

Th Cell (CD4+) = double positive precursor loses CD8

CTL (CD8+) = double positive precursor loses CD4

18
Q

Spleen

A

Not actually in lymphatic system (does NOT filter lymph)

Filters BLOOD

Shows similar B/T cell organization where they meet BLOOD-BORNE PATHOGENS

19
Q

MALT

A

Mucosa-associated lymphoid tissue

  • site where B and T cells meet pathogens in mucosal areas
  • found in oral-pharyngeal cavity and gastrointestinal, respiratory, urogenital tracts
  • MALT is located in tonsils, lungs, colon, appendix, etc
  • Microfold cells (M cells) help transport antigens into the tissue
20
Q

B-cell and T-cell receptors

A

Naive B and T cells migrate to secondary lymphoid tissues to find pathogens

B/T cells express SURFACE receptors that recognize and bind to a pathogen/antigen

both have a variable region, constant region, transmembrane region and cytoplasmic tail

21
Q

Antigen

A

any macromolecule that the variable region of a BCR/TCR can bind to

can be microbes or our own cells
- ex. blood type is determined based on antigens on blood cells (A, B, Rh)

a microbe expresses many copies of its own unique antigens

22
Q

Blood type with all 3 antigens

A

Type AB+

  • has type A and B antigens and Rh factor
23
Q

Blood type with no antigens

A

Type O

24
Q

Epitope

A

a motif that is recognized by immune cells
- a given antigen may contain several motifs

Variable region of a BCR/TCR binds to one unique epitope based on STRUCTURAL FIT

25
Q

Antigens vs PAMPs

A

A PAMP is expressed by a WIDE VARIETY of pathogens and is recognized by PRRs (innate)

An antigen is a molecular structure that is generally UNIQUE to a specific pathogen and is recognized by a specific antigen receptor (BCR/TCR adaptive response)
- ex. H1N1 influenza

26
Q

Antigen Recognition

A

Shape and size of the antigen determines specificity of antigen binding site of receptor

Antibodies can recognize linear (exposed) or conformational derterminants in folded proteins

27
Q

B- cell receptor and antibody

A

Can be membrane-bound form (BCR) or secreted form (antibody)

Membrane-bound form contains a spacer, hydrophobic segment and cytosolic segment

The transmembrane domain and cytosolic segments are lost from membrane-bound to antibody form

Both antibody and membrane-bound form
- have the same antigen specificity
- can bind pathogen directly

28
Q

T-cell receptor

A

has a double chain (alpha and beta)

NOT secreted

need antigen to be PRESENTED to them in a MHC molecule (CANNOT bind directly)

29
Q

BCR and TCR regions

A

BCRs and TCRs have two variable regions

BCR has a heavy-chain variable region and the light-chain variable region

TCR has an alpha and beta region

30
Q

Variable regions

A

encoded in gene segments of only PART of the receptor domain

segments are rearranged through somatic DNA recombination (gene rearrangement) to form a UNIQUE variable region coding sequence

31
Q

Diversity of B/T cell receptors

A

more unique TCRs than BCRs

B and T cells make surface receptors UNIQUE to each individual, which are NOT passed on to offspring

Both B and T cells express many exact copies of a receptor with a unique antigen binding site

Each B/T cell expresses a BCR/TCR with a variable region specific for one unique peptide

32
Q

Clonal expansion

A

When a specific antigen is encountered, that cell proliferates to create an army of cells with the same specificity

33
Q

Clonal Selection

A

Different clones of B/T cells go through a deletion process to weed out self-recognizing receptors

Remaining cells enter circulation to secondary lymphoid tissues where they can interact w/ antigens/pathogens

Can then undergo clonal expansion if a specific antigen is encountered

34
Q

What properties do T cell receptors and antibodies have in common?

A

They both contain a variable region and a constant region

35
Q

B cell receptor

A

has 2 heavy chains and 2 light chains

Microimm 2500 (29 decks)

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