Brainscape's Knowledge GenomeTM

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


See full index

Immunology 430 > Chapter 1: Basics Concepts in Immunology > Flashcards

Chapter 1: Basics Concepts in Immunology Flashcards

1
Q

What are the three strategies against microbial threat?

A

Avoidance:
- Anatomical barriers
- Behaviors to avoid diseased animals (ex. hygiene)

Tolerance:
- Protecting tissues against toxins
- Repairing damages

Resistance:
- Activating innate and adaptive immunity
- Stimulating inflammation

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

What are the four phases of the immune response?

A
  • Anatomical barriers
    • Skin mucosa, epithelium, intestine
  • Complement/ antimicrobial proteins
    • C3, defensins, RegIIIγ
  • Innate immune cells
    • Macrophages, granulocytes, NK, epithelial cells
  • Adaptive immunity
    • B cells, antibodies, T cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Compare the timing of the innate immune response and adaptive immune response .

A

Innate:
- First line of defense
- Try to prevent spread
- Fast response

Adaptive:
- Recognizes and eliminates pathogens quickly
- May take days and be too late if innate cannot reduce spread effectively

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

Outline the steps and purpose of the compliment system.

A
  • Pathogen must overcome physical barriers
  • Complements are a set of plasma proteins
  • Can attach to pathogen so it can be more easily be identified by macrophage
  • Can form pores in pathogen promoting inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is the immune system activated?

A
  • Activation via inflammatory inducers which indicate presence of pathogens or damaged tissue
  • Sensor cells detect inducers using innate recognition receptors
  • Mediators then amplify immune response
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What type of cells comprise most of the innate immune response?

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

What are sensor cells? What are pattern recognition receptors?

A
  • Sensor cells initially screen for self and non self via recognition receptors
  • Pattern recognition receptors (PRRs) are innate receptors that recognize pathogen-associated molecular patters (PAMPs)
    • PAMPs are not present in all microorganisms, conserved in evolution, identified on cell wall
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are TLR and NOD receptors?

A
  • They’re PRRs
  • Toll-like receptors (TLR)
  • Nucleotide-binding and oligomerization domain (NOD) - like receptors

Other types of receptors: Mannose, glycan, scavenger

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

How do sensor cells induce an inflammatory response? What is a chemokine?

A
  • Via production of mediators such as chemokines and cytokines
  • A specialized subgroup of secreted proteins that act as a chemoattractant. Neutrophils and monocytes are attracted by their chemokine receptors
  • Accumulation of fluid and while blood cells causes redness, swelling, heat, and pain known as inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Outline the steps involved in inflammation.

A
  • Macrophage encounters microorganism = cytokine/chemokine release
  • Response to chemokines is increase permeability and dilation of blood vessels (vasodilation) results in inflammation
  • Chemokines from macrophages attract neutrophils + WBC to infection
    • As epithelial adhesive properties alter, pain is caused
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a lymphocyte? Why are they important in an immune response?

A
  • A type of WBC usually B,T, or NK cell
  • They’re important due to high variability in antigen receptors on surface
  • Antigens can always be recognized due to unique antigen receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What happens when a Naïve B-cell encounters an antigen?

A
  • BCR on the naïve B cell encounter an antigen, receptor binds
  • B cell to proliferate and differentiate into a plasma cell as a response
  • Effector form (plasma cell) will secrete antibodies (Ig)
  • Antigen then becomes the target of the B cell’s progeny
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What happens when a TCR on a T cell binds to an antigen?

A
  • T cell encounters antigen, receptor binds
  • T cell proliferates and differentiates into an effector T lymphocyte
    • Helper T cells (CD4+)(coreceptor 4) Activates immune B cells
    • Cytotoxic T-cells (CD8+)(coreceptor 8) releases cytotoxins to induce apoptosis and membrane proliferation to kill infected cells
    • Regulatory T cells control immune reaction to avoid autoimmunity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is an MHC? What is its purpose?

A
  • Major histocompatibility complex
  • Two classes
    • Class I - antigen recognized by cytotoxic T cell (expressed in all nucleated cells)
    • Class II - antigen recognized by T-helper cells (expressed in antigen presenting cells (dendritic, macro, B cells)
  • The purpose of MHC is to bind the epitope peptide and present it to the T cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How are lymphocytes able to have so many unique receptors?

A
  • Antigen receptor genes are assembled by somatic gene rearrangements of incomplete gene segments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is clonal expansion?

A
  • When an antigen binds and activates a B cell, proliferation will create many identical progeny which develop into effector (plasma) cells which release identical antibodies
  • Gene rearrangement is irreversible so progeny will have antibodies identical to surface receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do helper T cells do to help B-cells?

A
  • When a B-cell is activate, the antigen is bound to MHCII which presents the antigen to a helper T cell
  • Helper T cell then activates releasing cytokines which help in the proliferation (replication)of the B-cells and differentiation (creating plasma cells)
  • Helper T cells also aid in formation of B-memory cells
18
Q

Outline the steps in Clonal Selection Theory.

A
  • Each lymphocyte is unique with its own specificity
  • Interaction of B-cell with antigen results in activation
  • Differentiated effector cell will produce antibodies identical to parent B cell
  • Lymphocytes that were self antigens are removed thus absent from mature lymphocyte inventory
19
Q

What happens to self reactive lymphocytes?

A
  • Normally eliminated or functionally inactivated
  • Eventually self reactive antigens produced are eliminated before maturation (clonal deletion)
  • Immature lymphocytes that receive too much or little signal removed by apoptosis
  • Induction of anergy (inactivation of immature B-cells)
20
Q

Where do lymphocytes mature? What are primary lymphoid organs? What are secondary lymphoid organs?

A
  • Mature in bone marrow or thymus (T cells)
  • Circulate in blood and lymph system
  • Where lymphocytes develop from non functional precursors (bone marrow and thymus)
  • Where mature naive lymphocytes are maintained and adaptive immune responses are carried out
  • Lymph nodes, spleen, mucosal lymphoid tissue of gut, and other mucosa
21
Q

Outline the steps involved in adaptive immune responses leading up to antigen presentation.

A
  • PRR on dendritic cells bind to PAMPs on pathogen leading to engulfment
  • Bacteria is engulfed by macrophage encased in vacuole
  • Lysosomes fuse and digest bacteria
  • Antigen from digested bacteria are presented by MHCII on the surface of the macrophage
22
Q

How do dendritic cells activate naive T cells?

A
  • Immature dendritic cell in peripheral tissue migrates via lymphatic vessels to lymph node where naive T cells are found and activated
  • Surface proteins (co-stimulatory molecules) are expressed on dendritic cells and stimulate proliferation and differentiation
  • Dendritic cell or other APC (antigen presenting cell) will display peptide fragment to naive T cell to activate
  • Other APC can be macrophages and B cells but dendritic cells are main presenters
23
Q

Why are dendritic cells important?

A
  • They bridge innate and adaptive immunity
24
Q

How can infections be detected by lymphocytes in peripheral tissue or other areas?

A
  • Lymphocytes circulate and hen encountering a pathogen release chemokines to attract more WBC
  • Free antigens circulating may also end up in lymph nodes and be picked up by APC (antigen presenting cells)
  • Once lymphocyte differentiates into effector cell it will leave lymphoid organ and enter blood to reach infection
25
Q

What are lymphoid organs?

A
  • Aggregates of lymphocytes that trap antigens and APC from sites of infection to present antigens to lymphocytes which causes an adaptive response
  • Spleen, lymph nodes, and mucosal-associated lymphoid tissue
26
Q

What is the structure and function of a lymph node?

A
  • Follicles made up of B-cells
  • Paracortical area made of T cells (also where APC are)
  • Medullary cords made of macrophages and plasma cells
  • Activate B and T cells move close so T cells can carry out helper function
  • B cells proliferate and differentiate creating germinal centers expanding the lymph node
27
Q

What is the function of the spleen?

A
  • Not connected to lymphatic system and relies on circulation
  • Filters and detects antigens and pathogens in blood
  • Filters old RBC and stores platelets
  • Lymphoid tissue in white pulp, platelets in red pulp
28
Q

Describe the structure of white pulp.

A
  • Periarteriol lymphoid sheath made of T cells
  • Follicles made of B cells (also form germinal center)
  • Marginal zone made of Unique B cells, macrophages, dendritic cells
29
Q

Describe the structure of Peyer’s patches in GALT.

A
  • Follicle-B-cells
  • T-cell dependent areas
  • Subepithelial dome - T,B, dendritic cells
  • Microfold (M) cells are specialized cells that collect and transport pathogens from lumen to the dome
  • Tonsils, adenoids, appendix, Peyer’s patches in small intestine
30
Q

What happens to lymphocytes after an infection is overcome?

A
  • Effector cells die and antibody levels decline
  • Long lived plasma cells can remain for years to lifetime
  • A significant number of progeny B and T cells will remain as clonal cells which can be reactived
31
Q

Compare the primary vs secondary response to a pathogen.

A

Primary:
- Naive B cell
- 4-7 days, peak at 7-10
- Lower antigen affinity

Secondary:
- Memory B cell
- 1-3 days, peak 3-5 days
- Higher antigen affinity

32
Q

Why are vaccines so important?

A
  • Vaccines mimic primary response for disease in which adaptive immune system may respond too late
  • Most effective way to control infectious diseases
33
Q

What is the significance of effector mechanisms in innate and adaptive immunity?

A
  • For each of the four major lymphocytes there is a corresponding type of T cell with generally similar functional characteristics
34
Q
A
35
Q

What are the three effector mechanisms of immunity?

A
  • Neutralization
    • Antibodies bind to bacterial toxins/viruses and are then ingested by macrophages
  • Opsonization
    • Bacteria is coated with antibodies to facilitate phagocytosis
  • Complement
    • antibodies attach to bacteria which result in bacteria being lysed and digested
36
Q

What is the function of MHC I?

A
  • CD8 (cytotoxic) T-cells recognize MHC I
  • Infected cells display antigen in the MHC I complex
  • CD8 cells recognize the MHC I molecule and kill the infected cell
37
Q

What is the function of MHC II?

A
  • CD4 (helper) T-cells recognize MHC II
  • Activates macrophage causing lysosomes to fuse to vesicle then kill bacteria
38
Q

What do TH2 cells produce

A

Interleukin-4,5,13
- Recruit eosinophils activates Mast and Basophils

39
Q

What does TH 17 do?

A

Produces Interleukin-17
- Recruit neutrophils
- Works against Bacteria and Fungi

40
Q

What does TFH do?

A

Regulates antibody production

41
Q
A

Immunology 430 (19 decks)

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